From b16c765122f987056e1dc9ef6c214571bb5bd694 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 1 Oct 2018 15:47:53 +0100
Subject: drm/i915: Priority boost for new clients

Taken from an idea used for FQ_CODEL, we give the first request of a
new request flows a small priority boost. These flows are likely to
correspond with short, interactive tasks and so be more latency sensitive
than the longer free running queues. As soon as the client has more than
one request in the queue, further requests are not boosted and it settles
down into ordinary steady state behaviour.  Such small kicks dramatically
help combat the starvation issue, by allowing each client the opportunity
to run even when the system is under heavy throughput load (within the
constraints of the user selected priority).

v2: Mark the preempted request as the start of a new flow, to prevent a
single client being continually gazumped by its peers.

Testcase: igt/benchmarks/rrul
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181001144755.7978-1-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_request.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index a492385b2089..56140ca054e8 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1127,8 +1127,20 @@ void i915_request_add(struct i915_request *request)
 	 */
 	local_bh_disable();
 	rcu_read_lock(); /* RCU serialisation for set-wedged protection */
-	if (engine->schedule)
-		engine->schedule(request, &request->gem_context->sched);
+	if (engine->schedule) {
+		struct i915_sched_attr attr = request->gem_context->sched;
+
+		/*
+		 * Boost priorities to new clients (new request flows).
+		 *
+		 * Allow interactive/synchronous clients to jump ahead of
+		 * the bulk clients. (FQ_CODEL)
+		 */
+		if (!prev || i915_request_completed(prev))
+			attr.priority |= I915_PRIORITY_NEWCLIENT;
+
+		engine->schedule(request, &attr);
+	}
 	rcu_read_unlock();
 	i915_sw_fence_commit(&request->submit);
 	local_bh_enable(); /* Kick the execlists tasklet if just scheduled */
-- 
cgit v1.2.3-59-g8ed1b


From e2f3496e93be3238de2e2e6bfc83b3a83c084ce5 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 1 Oct 2018 15:47:54 +0100
Subject: drm/i915: Pull scheduling under standalone lock

Currently, the backend scheduling code abuses struct_mutex into order to
have a global lock to manipulate a temporary list (without widespread
allocation) and to protect against list modifications. This is an
extraneous coupling to struct_mutex and further can not extend beyond
the local device.

Pull all the code that needs to be under the one true lock into
i915_scheduler.c, and make it so.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181001144755.7978-2-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/Makefile           |   1 +
 drivers/gpu/drm/i915/i915_request.c     |  85 -------
 drivers/gpu/drm/i915/i915_request.h     |   8 -
 drivers/gpu/drm/i915/i915_scheduler.c   | 377 ++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_scheduler.h   |  25 +++
 drivers/gpu/drm/i915/intel_display.c    |   3 +-
 drivers/gpu/drm/i915/intel_lrc.c        | 268 +----------------------
 drivers/gpu/drm/i915/intel_ringbuffer.h |   5 +-
 8 files changed, 411 insertions(+), 361 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/i915_scheduler.c

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 5794f102f9b8..ef1480c14e4e 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -75,6 +75,7 @@ i915-y += i915_cmd_parser.o \
 	  i915_gemfs.o \
 	  i915_query.o \
 	  i915_request.o \
+	  i915_scheduler.o \
 	  i915_timeline.o \
 	  i915_trace_points.o \
 	  i915_vma.o \
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 56140ca054e8..d73ad490a261 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -111,91 +111,6 @@ i915_request_remove_from_client(struct i915_request *request)
 	spin_unlock(&file_priv->mm.lock);
 }
 
-static struct i915_dependency *
-i915_dependency_alloc(struct drm_i915_private *i915)
-{
-	return kmem_cache_alloc(i915->dependencies, GFP_KERNEL);
-}
-
-static void
-i915_dependency_free(struct drm_i915_private *i915,
-		     struct i915_dependency *dep)
-{
-	kmem_cache_free(i915->dependencies, dep);
-}
-
-static void
-__i915_sched_node_add_dependency(struct i915_sched_node *node,
-				 struct i915_sched_node *signal,
-				 struct i915_dependency *dep,
-				 unsigned long flags)
-{
-	INIT_LIST_HEAD(&dep->dfs_link);
-	list_add(&dep->wait_link, &signal->waiters_list);
-	list_add(&dep->signal_link, &node->signalers_list);
-	dep->signaler = signal;
-	dep->flags = flags;
-}
-
-static int
-i915_sched_node_add_dependency(struct drm_i915_private *i915,
-			       struct i915_sched_node *node,
-			       struct i915_sched_node *signal)
-{
-	struct i915_dependency *dep;
-
-	dep = i915_dependency_alloc(i915);
-	if (!dep)
-		return -ENOMEM;
-
-	__i915_sched_node_add_dependency(node, signal, dep,
-					 I915_DEPENDENCY_ALLOC);
-	return 0;
-}
-
-static void
-i915_sched_node_fini(struct drm_i915_private *i915,
-		     struct i915_sched_node *node)
-{
-	struct i915_dependency *dep, *tmp;
-
-	GEM_BUG_ON(!list_empty(&node->link));
-
-	/*
-	 * Everyone we depended upon (the fences we wait to be signaled)
-	 * should retire before us and remove themselves from our list.
-	 * However, retirement is run independently on each timeline and
-	 * so we may be called out-of-order.
-	 */
-	list_for_each_entry_safe(dep, tmp, &node->signalers_list, signal_link) {
-		GEM_BUG_ON(!i915_sched_node_signaled(dep->signaler));
-		GEM_BUG_ON(!list_empty(&dep->dfs_link));
-
-		list_del(&dep->wait_link);
-		if (dep->flags & I915_DEPENDENCY_ALLOC)
-			i915_dependency_free(i915, dep);
-	}
-
-	/* Remove ourselves from everyone who depends upon us */
-	list_for_each_entry_safe(dep, tmp, &node->waiters_list, wait_link) {
-		GEM_BUG_ON(dep->signaler != node);
-		GEM_BUG_ON(!list_empty(&dep->dfs_link));
-
-		list_del(&dep->signal_link);
-		if (dep->flags & I915_DEPENDENCY_ALLOC)
-			i915_dependency_free(i915, dep);
-	}
-}
-
-static void
-i915_sched_node_init(struct i915_sched_node *node)
-{
-	INIT_LIST_HEAD(&node->signalers_list);
-	INIT_LIST_HEAD(&node->waiters_list);
-	INIT_LIST_HEAD(&node->link);
-	node->attr.priority = I915_PRIORITY_INVALID;
-}
-
 static int reset_all_global_seqno(struct drm_i915_private *i915, u32 seqno)
 {
 	struct intel_engine_cs *engine;
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index 7fa94b024968..5f7361e0fca6 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -332,14 +332,6 @@ static inline bool i915_request_completed(const struct i915_request *rq)
 	return __i915_request_completed(rq, seqno);
 }
 
-static inline bool i915_sched_node_signaled(const struct i915_sched_node *node)
-{
-	const struct i915_request *rq =
-		container_of(node, const struct i915_request, sched);
-
-	return i915_request_completed(rq);
-}
-
 void i915_retire_requests(struct drm_i915_private *i915);
 
 /*
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
new file mode 100644
index 000000000000..de9a2ba7c3bc
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_scheduler.c
@@ -0,0 +1,377 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2018 Intel Corporation
+ */
+
+#include <linux/mutex.h>
+
+#include "i915_drv.h"
+#include "i915_request.h"
+#include "i915_scheduler.h"
+
+static DEFINE_SPINLOCK(schedule_lock);
+
+static const struct i915_request *
+node_to_request(const struct i915_sched_node *node)
+{
+	return container_of(node, const struct i915_request, sched);
+}
+
+static inline bool node_signaled(const struct i915_sched_node *node)
+{
+	return i915_request_completed(node_to_request(node));
+}
+
+void i915_sched_node_init(struct i915_sched_node *node)
+{
+	INIT_LIST_HEAD(&node->signalers_list);
+	INIT_LIST_HEAD(&node->waiters_list);
+	INIT_LIST_HEAD(&node->link);
+	node->attr.priority = I915_PRIORITY_INVALID;
+}
+
+static struct i915_dependency *
+i915_dependency_alloc(struct drm_i915_private *i915)
+{
+	return kmem_cache_alloc(i915->dependencies, GFP_KERNEL);
+}
+
+static void
+i915_dependency_free(struct drm_i915_private *i915,
+		     struct i915_dependency *dep)
+{
+	kmem_cache_free(i915->dependencies, dep);
+}
+
+bool __i915_sched_node_add_dependency(struct i915_sched_node *node,
+				      struct i915_sched_node *signal,
+				      struct i915_dependency *dep,
+				      unsigned long flags)
+{
+	bool ret = false;
+
+	spin_lock(&schedule_lock);
+
+	if (!node_signaled(signal)) {
+		INIT_LIST_HEAD(&dep->dfs_link);
+		list_add(&dep->wait_link, &signal->waiters_list);
+		list_add(&dep->signal_link, &node->signalers_list);
+		dep->signaler = signal;
+		dep->flags = flags;
+
+		ret = true;
+	}
+
+	spin_unlock(&schedule_lock);
+
+	return ret;
+}
+
+int i915_sched_node_add_dependency(struct drm_i915_private *i915,
+				   struct i915_sched_node *node,
+				   struct i915_sched_node *signal)
+{
+	struct i915_dependency *dep;
+
+	dep = i915_dependency_alloc(i915);
+	if (!dep)
+		return -ENOMEM;
+
+	if (!__i915_sched_node_add_dependency(node, signal, dep,
+					      I915_DEPENDENCY_ALLOC))
+		i915_dependency_free(i915, dep);
+
+	return 0;
+}
+
+void i915_sched_node_fini(struct drm_i915_private *i915,
+			  struct i915_sched_node *node)
+{
+	struct i915_dependency *dep, *tmp;
+
+	GEM_BUG_ON(!list_empty(&node->link));
+
+	spin_lock(&schedule_lock);
+
+	/*
+	 * Everyone we depended upon (the fences we wait to be signaled)
+	 * should retire before us and remove themselves from our list.
+	 * However, retirement is run independently on each timeline and
+	 * so we may be called out-of-order.
+	 */
+	list_for_each_entry_safe(dep, tmp, &node->signalers_list, signal_link) {
+		GEM_BUG_ON(!node_signaled(dep->signaler));
+		GEM_BUG_ON(!list_empty(&dep->dfs_link));
+
+		list_del(&dep->wait_link);
+		if (dep->flags & I915_DEPENDENCY_ALLOC)
+			i915_dependency_free(i915, dep);
+	}
+
+	/* Remove ourselves from everyone who depends upon us */
+	list_for_each_entry_safe(dep, tmp, &node->waiters_list, wait_link) {
+		GEM_BUG_ON(dep->signaler != node);
+		GEM_BUG_ON(!list_empty(&dep->dfs_link));
+
+		list_del(&dep->signal_link);
+		if (dep->flags & I915_DEPENDENCY_ALLOC)
+			i915_dependency_free(i915, dep);
+	}
+
+	spin_unlock(&schedule_lock);
+}
+
+static inline struct i915_priolist *to_priolist(struct rb_node *rb)
+{
+	return rb_entry(rb, struct i915_priolist, node);
+}
+
+static void assert_priolists(struct intel_engine_execlists * const execlists,
+			     long queue_priority)
+{
+	struct rb_node *rb;
+	long last_prio, i;
+
+	if (!IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
+		return;
+
+	GEM_BUG_ON(rb_first_cached(&execlists->queue) !=
+		   rb_first(&execlists->queue.rb_root));
+
+	last_prio = (queue_priority >> I915_USER_PRIORITY_SHIFT) + 1;
+	for (rb = rb_first_cached(&execlists->queue); rb; rb = rb_next(rb)) {
+		const struct i915_priolist *p = to_priolist(rb);
+
+		GEM_BUG_ON(p->priority >= last_prio);
+		last_prio = p->priority;
+
+		GEM_BUG_ON(!p->used);
+		for (i = 0; i < ARRAY_SIZE(p->requests); i++) {
+			if (list_empty(&p->requests[i]))
+				continue;
+
+			GEM_BUG_ON(!(p->used & BIT(i)));
+		}
+	}
+}
+
+struct list_head *
+i915_sched_lookup_priolist(struct intel_engine_cs *engine, int prio)
+{
+	struct intel_engine_execlists * const execlists = &engine->execlists;
+	struct i915_priolist *p;
+	struct rb_node **parent, *rb;
+	bool first = true;
+	int idx, i;
+
+	lockdep_assert_held(&engine->timeline.lock);
+	assert_priolists(execlists, INT_MAX);
+
+	/* buckets sorted from highest [in slot 0] to lowest priority */
+	idx = I915_PRIORITY_COUNT - (prio & I915_PRIORITY_MASK) - 1;
+	prio >>= I915_USER_PRIORITY_SHIFT;
+	if (unlikely(execlists->no_priolist))
+		prio = I915_PRIORITY_NORMAL;
+
+find_priolist:
+	/* most positive priority is scheduled first, equal priorities fifo */
+	rb = NULL;
+	parent = &execlists->queue.rb_root.rb_node;
+	while (*parent) {
+		rb = *parent;
+		p = to_priolist(rb);
+		if (prio > p->priority) {
+			parent = &rb->rb_left;
+		} else if (prio < p->priority) {
+			parent = &rb->rb_right;
+			first = false;
+		} else {
+			goto out;
+		}
+	}
+
+	if (prio == I915_PRIORITY_NORMAL) {
+		p = &execlists->default_priolist;
+	} else {
+		p = kmem_cache_alloc(engine->i915->priorities, GFP_ATOMIC);
+		/* Convert an allocation failure to a priority bump */
+		if (unlikely(!p)) {
+			prio = I915_PRIORITY_NORMAL; /* recurses just once */
+
+			/* To maintain ordering with all rendering, after an
+			 * allocation failure we have to disable all scheduling.
+			 * Requests will then be executed in fifo, and schedule
+			 * will ensure that dependencies are emitted in fifo.
+			 * There will be still some reordering with existing
+			 * requests, so if userspace lied about their
+			 * dependencies that reordering may be visible.
+			 */
+			execlists->no_priolist = true;
+			goto find_priolist;
+		}
+	}
+
+	p->priority = prio;
+	for (i = 0; i < ARRAY_SIZE(p->requests); i++)
+		INIT_LIST_HEAD(&p->requests[i]);
+	rb_link_node(&p->node, rb, parent);
+	rb_insert_color_cached(&p->node, &execlists->queue, first);
+	p->used = 0;
+
+out:
+	p->used |= BIT(idx);
+	return &p->requests[idx];
+}
+
+static struct intel_engine_cs *
+sched_lock_engine(struct i915_sched_node *node, struct intel_engine_cs *locked)
+{
+	struct intel_engine_cs *engine = node_to_request(node)->engine;
+
+	GEM_BUG_ON(!locked);
+
+	if (engine != locked) {
+		spin_unlock(&locked->timeline.lock);
+		spin_lock(&engine->timeline.lock);
+	}
+
+	return engine;
+}
+
+void i915_schedule(struct i915_request *rq, const struct i915_sched_attr *attr)
+{
+	struct list_head *uninitialized_var(pl);
+	struct intel_engine_cs *engine, *last;
+	struct i915_dependency *dep, *p;
+	struct i915_dependency stack;
+	const int prio = attr->priority;
+	LIST_HEAD(dfs);
+
+	GEM_BUG_ON(prio == I915_PRIORITY_INVALID);
+
+	if (i915_request_completed(rq))
+		return;
+
+	if (prio <= READ_ONCE(rq->sched.attr.priority))
+		return;
+
+	/* Needed in order to use the temporary link inside i915_dependency */
+	spin_lock(&schedule_lock);
+
+	stack.signaler = &rq->sched;
+	list_add(&stack.dfs_link, &dfs);
+
+	/*
+	 * Recursively bump all dependent priorities to match the new request.
+	 *
+	 * A naive approach would be to use recursion:
+	 * static void update_priorities(struct i915_sched_node *node, prio) {
+	 *	list_for_each_entry(dep, &node->signalers_list, signal_link)
+	 *		update_priorities(dep->signal, prio)
+	 *	queue_request(node);
+	 * }
+	 * but that may have unlimited recursion depth and so runs a very
+	 * real risk of overunning the kernel stack. Instead, we build
+	 * a flat list of all dependencies starting with the current request.
+	 * As we walk the list of dependencies, we add all of its dependencies
+	 * to the end of the list (this may include an already visited
+	 * request) and continue to walk onwards onto the new dependencies. The
+	 * end result is a topological list of requests in reverse order, the
+	 * last element in the list is the request we must execute first.
+	 */
+	list_for_each_entry(dep, &dfs, dfs_link) {
+		struct i915_sched_node *node = dep->signaler;
+
+		/*
+		 * Within an engine, there can be no cycle, but we may
+		 * refer to the same dependency chain multiple times
+		 * (redundant dependencies are not eliminated) and across
+		 * engines.
+		 */
+		list_for_each_entry(p, &node->signalers_list, signal_link) {
+			GEM_BUG_ON(p == dep); /* no cycles! */
+
+			if (node_signaled(p->signaler))
+				continue;
+
+			GEM_BUG_ON(p->signaler->attr.priority < node->attr.priority);
+			if (prio > READ_ONCE(p->signaler->attr.priority))
+				list_move_tail(&p->dfs_link, &dfs);
+		}
+	}
+
+	/*
+	 * If we didn't need to bump any existing priorities, and we haven't
+	 * yet submitted this request (i.e. there is no potential race with
+	 * execlists_submit_request()), we can set our own priority and skip
+	 * acquiring the engine locks.
+	 */
+	if (rq->sched.attr.priority == I915_PRIORITY_INVALID) {
+		GEM_BUG_ON(!list_empty(&rq->sched.link));
+		rq->sched.attr = *attr;
+
+		if (stack.dfs_link.next == stack.dfs_link.prev)
+			goto out_unlock;
+
+		__list_del_entry(&stack.dfs_link);
+	}
+
+	last = NULL;
+	engine = rq->engine;
+	spin_lock_irq(&engine->timeline.lock);
+
+	/* Fifo and depth-first replacement ensure our deps execute before us */
+	list_for_each_entry_safe_reverse(dep, p, &dfs, dfs_link) {
+		struct i915_sched_node *node = dep->signaler;
+
+		INIT_LIST_HEAD(&dep->dfs_link);
+
+		engine = sched_lock_engine(node, engine);
+
+		/* Recheck after acquiring the engine->timeline.lock */
+		if (prio <= node->attr.priority || node_signaled(node))
+			continue;
+
+		node->attr.priority = prio;
+		if (!list_empty(&node->link)) {
+			if (last != engine) {
+				pl = i915_sched_lookup_priolist(engine, prio);
+				last = engine;
+			}
+			list_move_tail(&node->link, pl);
+		} else {
+			/*
+			 * If the request is not in the priolist queue because
+			 * it is not yet runnable, then it doesn't contribute
+			 * to our preemption decisions. On the other hand,
+			 * if the request is on the HW, it too is not in the
+			 * queue; but in that case we may still need to reorder
+			 * the inflight requests.
+			 */
+			if (!i915_sw_fence_done(&node_to_request(node)->submit))
+				continue;
+		}
+
+		if (prio <= engine->execlists.queue_priority)
+			continue;
+
+		/*
+		 * If we are already the currently executing context, don't
+		 * bother evaluating if we should preempt ourselves.
+		 */
+		if (node_to_request(node)->global_seqno &&
+		    i915_seqno_passed(port_request(engine->execlists.port)->global_seqno,
+				      node_to_request(node)->global_seqno))
+			continue;
+
+		/* Defer (tasklet) submission until after all of our updates. */
+		engine->execlists.queue_priority = prio;
+		tasklet_hi_schedule(&engine->execlists.tasklet);
+	}
+
+	spin_unlock_irq(&engine->timeline.lock);
+
+out_unlock:
+	spin_unlock(&schedule_lock);
+}
diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h
index 53dc7dbf88b9..68d84a45ad7f 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.h
+++ b/drivers/gpu/drm/i915/i915_scheduler.h
@@ -8,9 +8,14 @@
 #define _I915_SCHEDULER_H_
 
 #include <linux/bitops.h>
+#include <linux/kernel.h>
 
 #include <uapi/drm/i915_drm.h>
 
+struct drm_i915_private;
+struct i915_request;
+struct intel_engine_cs;
+
 enum {
 	I915_PRIORITY_MIN = I915_CONTEXT_MIN_USER_PRIORITY - 1,
 	I915_PRIORITY_NORMAL = I915_CONTEXT_DEFAULT_PRIORITY,
@@ -77,4 +82,24 @@ struct i915_dependency {
 #define I915_DEPENDENCY_ALLOC BIT(0)
 };
 
+void i915_sched_node_init(struct i915_sched_node *node);
+
+bool __i915_sched_node_add_dependency(struct i915_sched_node *node,
+				      struct i915_sched_node *signal,
+				      struct i915_dependency *dep,
+				      unsigned long flags);
+
+int i915_sched_node_add_dependency(struct drm_i915_private *i915,
+				   struct i915_sched_node *node,
+				   struct i915_sched_node *signal);
+
+void i915_sched_node_fini(struct drm_i915_private *i915,
+			  struct i915_sched_node *node);
+
+void i915_schedule(struct i915_request *request,
+		   const struct i915_sched_attr *attr);
+
+struct list_head *
+i915_sched_lookup_priolist(struct intel_engine_cs *engine, int prio);
+
 #endif /* _I915_SCHEDULER_H_ */
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 4c5c2b39e65c..650e01f0c197 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -13188,13 +13188,12 @@ intel_prepare_plane_fb(struct drm_plane *plane,
 
 	ret = intel_plane_pin_fb(to_intel_plane_state(new_state));
 
-	fb_obj_bump_render_priority(obj);
-
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 	i915_gem_object_unpin_pages(obj);
 	if (ret)
 		return ret;
 
+	fb_obj_bump_render_priority(obj);
 	intel_fb_obj_flush(obj, ORIGIN_DIRTYFB);
 
 	if (!new_state->fence) { /* implicit fencing */
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 5f324d6b44d5..28d56387edf5 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -259,102 +259,6 @@ intel_lr_context_descriptor_update(struct i915_gem_context *ctx,
 	ce->lrc_desc = desc;
 }
 
-static void assert_priolists(struct intel_engine_execlists * const execlists,
-			     long queue_priority)
-{
-	struct rb_node *rb;
-	long last_prio, i;
-
-	if (!IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
-		return;
-
-	GEM_BUG_ON(rb_first_cached(&execlists->queue) !=
-		   rb_first(&execlists->queue.rb_root));
-
-	last_prio = (queue_priority >> I915_USER_PRIORITY_SHIFT) + 1;
-	for (rb = rb_first_cached(&execlists->queue); rb; rb = rb_next(rb)) {
-		struct i915_priolist *p = to_priolist(rb);
-
-		GEM_BUG_ON(p->priority >= last_prio);
-		last_prio = p->priority;
-
-		GEM_BUG_ON(!p->used);
-		for (i = 0; i < ARRAY_SIZE(p->requests); i++) {
-			if (list_empty(&p->requests[i]))
-				continue;
-
-			GEM_BUG_ON(!(p->used & BIT(i)));
-		}
-	}
-}
-
-static struct list_head *
-lookup_priolist(struct intel_engine_cs *engine, int prio)
-{
-	struct intel_engine_execlists * const execlists = &engine->execlists;
-	struct i915_priolist *p;
-	struct rb_node **parent, *rb;
-	bool first = true;
-	int idx, i;
-
-	assert_priolists(execlists, INT_MAX);
-
-	/* buckets sorted from highest [in slot 0] to lowest priority */
-	idx = I915_PRIORITY_COUNT - (prio & I915_PRIORITY_MASK) - 1;
-	prio >>= I915_USER_PRIORITY_SHIFT;
-	if (unlikely(execlists->no_priolist))
-		prio = I915_PRIORITY_NORMAL;
-
-find_priolist:
-	/* most positive priority is scheduled first, equal priorities fifo */
-	rb = NULL;
-	parent = &execlists->queue.rb_root.rb_node;
-	while (*parent) {
-		rb = *parent;
-		p = to_priolist(rb);
-		if (prio > p->priority) {
-			parent = &rb->rb_left;
-		} else if (prio < p->priority) {
-			parent = &rb->rb_right;
-			first = false;
-		} else {
-			goto out;
-		}
-	}
-
-	if (prio == I915_PRIORITY_NORMAL) {
-		p = &execlists->default_priolist;
-	} else {
-		p = kmem_cache_alloc(engine->i915->priorities, GFP_ATOMIC);
-		/* Convert an allocation failure to a priority bump */
-		if (unlikely(!p)) {
-			prio = I915_PRIORITY_NORMAL; /* recurses just once */
-
-			/* To maintain ordering with all rendering, after an
-			 * allocation failure we have to disable all scheduling.
-			 * Requests will then be executed in fifo, and schedule
-			 * will ensure that dependencies are emitted in fifo.
-			 * There will be still some reordering with existing
-			 * requests, so if userspace lied about their
-			 * dependencies that reordering may be visible.
-			 */
-			execlists->no_priolist = true;
-			goto find_priolist;
-		}
-	}
-
-	p->priority = prio;
-	for (i = 0; i < ARRAY_SIZE(p->requests); i++)
-		INIT_LIST_HEAD(&p->requests[i]);
-	rb_link_node(&p->node, rb, parent);
-	rb_insert_color_cached(&p->node, &execlists->queue, first);
-	p->used = 0;
-
-out:
-	p->used |= BIT(idx);
-	return &p->requests[idx];
-}
-
 static void unwind_wa_tail(struct i915_request *rq)
 {
 	rq->tail = intel_ring_wrap(rq->ring, rq->wa_tail - WA_TAIL_BYTES);
@@ -381,7 +285,7 @@ static void __unwind_incomplete_requests(struct intel_engine_cs *engine)
 		GEM_BUG_ON(rq_prio(rq) == I915_PRIORITY_INVALID);
 		if (rq_prio(rq) != prio) {
 			prio = rq_prio(rq);
-			pl = lookup_priolist(engine, prio);
+			pl = i915_sched_lookup_priolist(engine, prio);
 		}
 		GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root));
 
@@ -398,7 +302,7 @@ static void __unwind_incomplete_requests(struct intel_engine_cs *engine)
 	if (!(prio & I915_PRIORITY_NEWCLIENT)) {
 		prio |= I915_PRIORITY_NEWCLIENT;
 		list_move_tail(&active->sched.link,
-			       lookup_priolist(engine, prio));
+			       i915_sched_lookup_priolist(engine, prio));
 	}
 }
 
@@ -792,7 +696,6 @@ done:
 	 */
 	execlists->queue_priority =
 		port != execlists->port ? rq_prio(last) : INT_MIN;
-	assert_priolists(execlists, execlists->queue_priority);
 
 	if (submit) {
 		port_assign(port, last);
@@ -1119,12 +1022,7 @@ static void queue_request(struct intel_engine_cs *engine,
 			  struct i915_sched_node *node,
 			  int prio)
 {
-	list_add_tail(&node->link, lookup_priolist(engine, prio));
-}
-
-static void __update_queue(struct intel_engine_cs *engine, int prio)
-{
-	engine->execlists.queue_priority = prio;
+	list_add_tail(&node->link, i915_sched_lookup_priolist(engine, prio));
 }
 
 static void __submit_queue_imm(struct intel_engine_cs *engine)
@@ -1143,7 +1041,7 @@ static void __submit_queue_imm(struct intel_engine_cs *engine)
 static void submit_queue(struct intel_engine_cs *engine, int prio)
 {
 	if (prio > engine->execlists.queue_priority) {
-		__update_queue(engine, prio);
+		engine->execlists.queue_priority = prio;
 		__submit_queue_imm(engine);
 	}
 }
@@ -1166,162 +1064,6 @@ static void execlists_submit_request(struct i915_request *request)
 	spin_unlock_irqrestore(&engine->timeline.lock, flags);
 }
 
-static struct i915_request *sched_to_request(struct i915_sched_node *node)
-{
-	return container_of(node, struct i915_request, sched);
-}
-
-static struct intel_engine_cs *
-sched_lock_engine(struct i915_sched_node *node, struct intel_engine_cs *locked)
-{
-	struct intel_engine_cs *engine = sched_to_request(node)->engine;
-
-	GEM_BUG_ON(!locked);
-
-	if (engine != locked) {
-		spin_unlock(&locked->timeline.lock);
-		spin_lock(&engine->timeline.lock);
-	}
-
-	return engine;
-}
-
-static void execlists_schedule(struct i915_request *request,
-			       const struct i915_sched_attr *attr)
-{
-	struct list_head *uninitialized_var(pl);
-	struct intel_engine_cs *engine, *last;
-	struct i915_dependency *dep, *p;
-	struct i915_dependency stack;
-	const int prio = attr->priority;
-	LIST_HEAD(dfs);
-
-	GEM_BUG_ON(prio == I915_PRIORITY_INVALID);
-
-	if (i915_request_completed(request))
-		return;
-
-	if (prio <= READ_ONCE(request->sched.attr.priority))
-		return;
-
-	/* Need BKL in order to use the temporary link inside i915_dependency */
-	lockdep_assert_held(&request->i915->drm.struct_mutex);
-
-	stack.signaler = &request->sched;
-	list_add(&stack.dfs_link, &dfs);
-
-	/*
-	 * Recursively bump all dependent priorities to match the new request.
-	 *
-	 * A naive approach would be to use recursion:
-	 * static void update_priorities(struct i915_sched_node *node, prio) {
-	 *	list_for_each_entry(dep, &node->signalers_list, signal_link)
-	 *		update_priorities(dep->signal, prio)
-	 *	queue_request(node);
-	 * }
-	 * but that may have unlimited recursion depth and so runs a very
-	 * real risk of overunning the kernel stack. Instead, we build
-	 * a flat list of all dependencies starting with the current request.
-	 * As we walk the list of dependencies, we add all of its dependencies
-	 * to the end of the list (this may include an already visited
-	 * request) and continue to walk onwards onto the new dependencies. The
-	 * end result is a topological list of requests in reverse order, the
-	 * last element in the list is the request we must execute first.
-	 */
-	list_for_each_entry(dep, &dfs, dfs_link) {
-		struct i915_sched_node *node = dep->signaler;
-
-		/*
-		 * Within an engine, there can be no cycle, but we may
-		 * refer to the same dependency chain multiple times
-		 * (redundant dependencies are not eliminated) and across
-		 * engines.
-		 */
-		list_for_each_entry(p, &node->signalers_list, signal_link) {
-			GEM_BUG_ON(p == dep); /* no cycles! */
-
-			if (i915_sched_node_signaled(p->signaler))
-				continue;
-
-			GEM_BUG_ON(p->signaler->attr.priority < node->attr.priority);
-			if (prio > READ_ONCE(p->signaler->attr.priority))
-				list_move_tail(&p->dfs_link, &dfs);
-		}
-	}
-
-	/*
-	 * If we didn't need to bump any existing priorities, and we haven't
-	 * yet submitted this request (i.e. there is no potential race with
-	 * execlists_submit_request()), we can set our own priority and skip
-	 * acquiring the engine locks.
-	 */
-	if (request->sched.attr.priority == I915_PRIORITY_INVALID) {
-		GEM_BUG_ON(!list_empty(&request->sched.link));
-		request->sched.attr = *attr;
-		if (stack.dfs_link.next == stack.dfs_link.prev)
-			return;
-		__list_del_entry(&stack.dfs_link);
-	}
-
-	last = NULL;
-	engine = request->engine;
-	spin_lock_irq(&engine->timeline.lock);
-
-	/* Fifo and depth-first replacement ensure our deps execute before us */
-	list_for_each_entry_safe_reverse(dep, p, &dfs, dfs_link) {
-		struct i915_sched_node *node = dep->signaler;
-
-		INIT_LIST_HEAD(&dep->dfs_link);
-
-		engine = sched_lock_engine(node, engine);
-
-		/* Recheck after acquiring the engine->timeline.lock */
-		if (prio <= node->attr.priority)
-			continue;
-
-		if (i915_sched_node_signaled(node))
-			continue;
-
-		node->attr.priority = prio;
-		if (!list_empty(&node->link)) {
-			if (last != engine) {
-				pl = lookup_priolist(engine, prio);
-				last = engine;
-			}
-			list_move_tail(&node->link, pl);
-		} else {
-			/*
-			 * If the request is not in the priolist queue because
-			 * it is not yet runnable, then it doesn't contribute
-			 * to our preemption decisions. On the other hand,
-			 * if the request is on the HW, it too is not in the
-			 * queue; but in that case we may still need to reorder
-			 * the inflight requests.
-			 */
-			if (!i915_sw_fence_done(&sched_to_request(node)->submit))
-				continue;
-		}
-
-		if (prio <= engine->execlists.queue_priority)
-			continue;
-
-		/*
-		 * If we are already the currently executing context, don't
-		 * bother evaluating if we should preempt ourselves.
-		 */
-		if (sched_to_request(node)->global_seqno &&
-		    i915_seqno_passed(port_request(engine->execlists.port)->global_seqno,
-				      sched_to_request(node)->global_seqno))
-			continue;
-
-		/* Defer (tasklet) submission until after all of our updates. */
-		__update_queue(engine, prio);
-		tasklet_hi_schedule(&engine->execlists.tasklet);
-	}
-
-	spin_unlock_irq(&engine->timeline.lock);
-}
-
 static void execlists_context_destroy(struct intel_context *ce)
 {
 	GEM_BUG_ON(ce->pin_count);
@@ -2359,7 +2101,7 @@ void intel_execlists_set_default_submission(struct intel_engine_cs *engine)
 {
 	engine->submit_request = execlists_submit_request;
 	engine->cancel_requests = execlists_cancel_requests;
-	engine->schedule = execlists_schedule;
+	engine->schedule = i915_schedule;
 	engine->execlists.tasklet.func = execlists_submission_tasklet;
 
 	engine->reset.prepare = execlists_reset_prepare;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 1534de5bb852..f6ec48a75a69 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -498,11 +498,10 @@ struct intel_engine_cs {
 	 */
 	void		(*submit_request)(struct i915_request *rq);
 
-	/* Call when the priority on a request has changed and it and its
+	/*
+	 * Call when the priority on a request has changed and it and its
 	 * dependencies may need rescheduling. Note the request itself may
 	 * not be ready to run!
-	 *
-	 * Called under the struct_mutex.
 	 */
 	void		(*schedule)(struct i915_request *request,
 				    const struct i915_sched_attr *attr);
-- 
cgit v1.2.3-59-g8ed1b


From e9eaf82d97a2b05460ff5ef6a3e07446f7d049fe Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 1 Oct 2018 15:47:55 +0100
Subject: drm/i915: Priority boost for waiting clients

Latency is in the eye of the beholder. In the case where a client stops
and waits for the gpu, give that request chain a small priority boost
(not so that it overtakes higher priority clients, to preserve the
external ordering) so that ideally the wait completes earlier.

v2: Tvrtko recommends to keep the boost-from-user-stall as small as
possible and to allow new client flows to be preferred for interactivity
over stalls.

Testcase: igt/gem_sync/switch-default
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181001144755.7978-3-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_gem.c       |  5 ++++-
 drivers/gpu/drm/i915/i915_request.c   |  2 ++
 drivers/gpu/drm/i915/i915_request.h   |  5 +++--
 drivers/gpu/drm/i915/i915_scheduler.c | 34 ++++++++++++++++++++++++++++------
 drivers/gpu/drm/i915/i915_scheduler.h |  7 +++++--
 5 files changed, 42 insertions(+), 11 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 28e943ee8b5e..7d45e71100bc 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1748,6 +1748,7 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
 	 */
 	err = i915_gem_object_wait(obj,
 				   I915_WAIT_INTERRUPTIBLE |
+				   I915_WAIT_PRIORITY |
 				   (write_domain ? I915_WAIT_ALL : 0),
 				   MAX_SCHEDULE_TIMEOUT,
 				   to_rps_client(file));
@@ -3751,7 +3752,9 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 	start = ktime_get();
 
 	ret = i915_gem_object_wait(obj,
-				   I915_WAIT_INTERRUPTIBLE | I915_WAIT_ALL,
+				   I915_WAIT_INTERRUPTIBLE |
+				   I915_WAIT_PRIORITY |
+				   I915_WAIT_ALL,
 				   to_wait_timeout(args->timeout_ns),
 				   to_rps_client(file));
 
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index d73ad490a261..abd4dacbab8e 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1237,6 +1237,8 @@ long i915_request_wait(struct i915_request *rq,
 		add_wait_queue(errq, &reset);
 
 	intel_wait_init(&wait);
+	if (flags & I915_WAIT_PRIORITY)
+		i915_schedule_bump_priority(rq, I915_PRIORITY_WAIT);
 
 restart:
 	do {
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index 5f7361e0fca6..90e9d170a0cd 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -277,8 +277,9 @@ long i915_request_wait(struct i915_request *rq,
 	__attribute__((nonnull(1)));
 #define I915_WAIT_INTERRUPTIBLE	BIT(0)
 #define I915_WAIT_LOCKED	BIT(1) /* struct_mutex held, handle GPU reset */
-#define I915_WAIT_ALL		BIT(2) /* used by i915_gem_object_wait() */
-#define I915_WAIT_FOR_IDLE_BOOST BIT(3)
+#define I915_WAIT_PRIORITY	BIT(2) /* small priority bump for the request */
+#define I915_WAIT_ALL		BIT(3) /* used by i915_gem_object_wait() */
+#define I915_WAIT_FOR_IDLE_BOOST BIT(4)
 
 static inline bool intel_engine_has_started(struct intel_engine_cs *engine,
 					    u32 seqno);
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
index de9a2ba7c3bc..340faea6c08a 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.c
+++ b/drivers/gpu/drm/i915/i915_scheduler.c
@@ -239,7 +239,8 @@ sched_lock_engine(struct i915_sched_node *node, struct intel_engine_cs *locked)
 	return engine;
 }
 
-void i915_schedule(struct i915_request *rq, const struct i915_sched_attr *attr)
+static void __i915_schedule(struct i915_request *rq,
+			    const struct i915_sched_attr *attr)
 {
 	struct list_head *uninitialized_var(pl);
 	struct intel_engine_cs *engine, *last;
@@ -248,6 +249,8 @@ void i915_schedule(struct i915_request *rq, const struct i915_sched_attr *attr)
 	const int prio = attr->priority;
 	LIST_HEAD(dfs);
 
+	/* Needed in order to use the temporary link inside i915_dependency */
+	lockdep_assert_held(&schedule_lock);
 	GEM_BUG_ON(prio == I915_PRIORITY_INVALID);
 
 	if (i915_request_completed(rq))
@@ -256,9 +259,6 @@ void i915_schedule(struct i915_request *rq, const struct i915_sched_attr *attr)
 	if (prio <= READ_ONCE(rq->sched.attr.priority))
 		return;
 
-	/* Needed in order to use the temporary link inside i915_dependency */
-	spin_lock(&schedule_lock);
-
 	stack.signaler = &rq->sched;
 	list_add(&stack.dfs_link, &dfs);
 
@@ -312,7 +312,7 @@ void i915_schedule(struct i915_request *rq, const struct i915_sched_attr *attr)
 		rq->sched.attr = *attr;
 
 		if (stack.dfs_link.next == stack.dfs_link.prev)
-			goto out_unlock;
+			return;
 
 		__list_del_entry(&stack.dfs_link);
 	}
@@ -371,7 +371,29 @@ void i915_schedule(struct i915_request *rq, const struct i915_sched_attr *attr)
 	}
 
 	spin_unlock_irq(&engine->timeline.lock);
+}
 
-out_unlock:
+void i915_schedule(struct i915_request *rq, const struct i915_sched_attr *attr)
+{
+	spin_lock(&schedule_lock);
+	__i915_schedule(rq, attr);
 	spin_unlock(&schedule_lock);
 }
+
+void i915_schedule_bump_priority(struct i915_request *rq, unsigned int bump)
+{
+	struct i915_sched_attr attr;
+
+	GEM_BUG_ON(bump & ~I915_PRIORITY_MASK);
+
+	if (READ_ONCE(rq->sched.attr.priority) == I915_PRIORITY_INVALID)
+		return;
+
+	spin_lock_bh(&schedule_lock);
+
+	attr = rq->sched.attr;
+	attr.priority |= bump;
+	__i915_schedule(rq, &attr);
+
+	spin_unlock_bh(&schedule_lock);
+}
diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h
index 68d84a45ad7f..dbe9cb7ecd82 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.h
+++ b/drivers/gpu/drm/i915/i915_scheduler.h
@@ -24,13 +24,14 @@ enum {
 	I915_PRIORITY_INVALID = INT_MIN
 };
 
-#define I915_USER_PRIORITY_SHIFT 1
+#define I915_USER_PRIORITY_SHIFT 2
 #define I915_USER_PRIORITY(x) ((x) << I915_USER_PRIORITY_SHIFT)
 
 #define I915_PRIORITY_COUNT BIT(I915_USER_PRIORITY_SHIFT)
 #define I915_PRIORITY_MASK (I915_PRIORITY_COUNT - 1)
 
-#define I915_PRIORITY_NEWCLIENT	((u8)BIT(0))
+#define I915_PRIORITY_WAIT	((u8)BIT(0))
+#define I915_PRIORITY_NEWCLIENT	((u8)BIT(1))
 
 struct i915_sched_attr {
 	/**
@@ -99,6 +100,8 @@ void i915_sched_node_fini(struct drm_i915_private *i915,
 void i915_schedule(struct i915_request *request,
 		   const struct i915_sched_attr *attr);
 
+void i915_schedule_bump_priority(struct i915_request *rq, unsigned int bump);
+
 struct list_head *
 i915_sched_lookup_priolist(struct intel_engine_cs *engine, int prio);
 
-- 
cgit v1.2.3-59-g8ed1b


From 33373258cf021869380140078bb3f9732b7d852d Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 5 Oct 2018 09:03:00 +0100
Subject: drm/i915: Remove the global cache shrink & rcu barrier on allocation
 failure

Earlier, we reasoned that having idled the gpu under mempressure, that
would be a good time to trim our request slabs in order to perform the
next request allocation. We have stopped performing the global operation
on the device (no idling) and wish to make the allocation failure
handling more local, so out with the global barrier that may take a long
time.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181005080300.9908-2-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_request.c | 11 -----------
 1 file changed, 11 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index abd4dacbab8e..28819f8c4da6 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -655,17 +655,6 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 		if (rq)
 			cond_synchronize_rcu(rq->rcustate);
 
-		/*
-		 * We've forced the client to stall and catch up with whatever
-		 * backlog there might have been. As we are assuming that we
-		 * caused the mempressure, now is an opportune time to
-		 * recover as much memory from the request pool as is possible.
-		 * Having already penalized the client to stall, we spend
-		 * a little extra time to re-optimise page allocation.
-		 */
-		kmem_cache_shrink(i915->requests);
-		rcu_barrier(); /* Recover the TYPESAFE_BY_RCU pages */
-
 		rq = kmem_cache_alloc(i915->requests, GFP_KERNEL);
 		if (!rq) {
 			ret = -ENOMEM;
-- 
cgit v1.2.3-59-g8ed1b


From 1e016a8693368c163b18104a28c4edc71858f2d2 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 24 Oct 2018 11:49:39 +0100
Subject: drm/i915: Park signaling thread while wrapping the seqno

A danger encountered when resetting the seqno (using
debugfs/i915_next_seqno) is that as we change the breadcrumb stored in
the HWSP, it may be inspected by the signaler thread leading to
confusion in our sanity checks.

<0> [136.331342] i915/sig-347     3..s1 136336154us : execlists_submission_tasklet: rcs0 awake?=1, active=5
<0> [136.331373] i915/sig-347     3d.s2 136336155us : process_csb: rcs0 cs-irq head=5, tail=0
<0> [136.331402] i915/sig-347     3d.s2 136336155us : process_csb: rcs0 csb[0]: status=0x00000018:0x00000002, active=0x5
<0> [136.331434] i915/sig-347     3d.s2 136336156us : process_csb: rcs0 out[0]: ctx=2.1, global=219 (fence 46:8455) (current 219), prio=0
<0> [136.331466] i915/sig-347     3d.s2 136336156us : process_csb: rcs0 completed ctx=2
<0> [136.332027] gem_exec-1049    0.... 136336246us : reset_all_global_seqno.part.5: rcs0 seqno 219 (current 219) -> -43
<0> [136.332056] gem_exec-1049    0.... 136336251us : reset_all_global_seqno.part.5: bcs0 seqno 183 (current 183) -> -43
<0> [136.332085] gem_exec-1049    0.... 136336255us : reset_all_global_seqno.part.5: vcs0 seqno 191 (current 191) -> -43
<0> [136.332114] gem_exec-1049    0.... 136336259us : reset_all_global_seqno.part.5: vcs1 seqno 180 (current 180) -> -43
<0> [136.332143] gem_exec-1049    0.... 136336262us : reset_all_global_seqno.part.5: vecs0 seqno 212 (current 212) -> -43
<0> [136.332174] i915/sig-347     3.... 136336280us : intel_breadcrumbs_signaler: intel_breadcrumbs_signaler:673 GEM_BUG_ON(!i915_request_completed(rq))

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181024104939.2861-1-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_request.c | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 28819f8c4da6..71107540581d 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -136,6 +136,8 @@ static int reset_all_global_seqno(struct drm_i915_private *i915, u32 seqno)
 			  intel_engine_get_seqno(engine),
 			  seqno);
 
+		kthread_park(engine->breadcrumbs.signaler);
+
 		if (!i915_seqno_passed(seqno, engine->timeline.seqno)) {
 			/* Flush any waiters before we reuse the seqno */
 			intel_engine_disarm_breadcrumbs(engine);
@@ -150,6 +152,8 @@ static int reset_all_global_seqno(struct drm_i915_private *i915, u32 seqno)
 		/* Finally reset hw state */
 		intel_engine_init_global_seqno(engine, seqno);
 		engine->timeline.seqno = seqno;
+
+		kthread_unpark(engine->breadcrumbs.signaler);
 	}
 
 	list_for_each_entry(timeline, &i915->gt.timelines, link)
-- 
cgit v1.2.3-59-g8ed1b


From 39e84937b5b447973f2c7322ce4da35775e1bfbf Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 26 Nov 2018 09:56:10 +0000
Subject: drm/i915: Skip engine serialisation for no-op seqno reset

If the engine's seqno is already at our target seqno (most likely it
hasn't been used since the last reset), we can skip serialising the
engine and leave it as is.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181126095610.20962-1-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_request.c | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 71107540581d..ca95ab2f4cfa 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -136,6 +136,9 @@ static int reset_all_global_seqno(struct drm_i915_private *i915, u32 seqno)
 			  intel_engine_get_seqno(engine),
 			  seqno);
 
+		if (seqno == engine->timeline.seqno)
+			continue;
+
 		kthread_park(engine->breadcrumbs.signaler);
 
 		if (!i915_seqno_passed(seqno, engine->timeline.seqno)) {
-- 
cgit v1.2.3-59-g8ed1b


From 5f5800a765de8414f6fb213c4ad4a1cf529e131d Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 7 Dec 2018 09:02:11 +0000
Subject: drm/i915: Push EMIT_INVALIDATE at request start to backends

Move the common engine->emit_flush(EMIT_INVALIDATE) back to the backends
(where it was once previously) as we seek to specialise it in future
patches.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181207090213.14352-1-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_request.c     | 5 -----
 drivers/gpu/drm/i915/intel_lrc.c        | 9 ++++++---
 drivers/gpu/drm/i915/intel_ringbuffer.c | 6 ++++--
 3 files changed, 10 insertions(+), 10 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index ca95ab2f4cfa..8ab8e8e6a086 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -719,11 +719,6 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	 */
 	rq->head = rq->ring->emit;
 
-	/* Unconditionally invalidate GPU caches and TLBs. */
-	ret = engine->emit_flush(rq, EMIT_INVALIDATE);
-	if (ret)
-		goto err_unwind;
-
 	ret = engine->request_alloc(rq);
 	if (ret)
 		goto err_unwind;
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 3a47a4732fae..a9084a54c0f4 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1276,17 +1276,20 @@ static int execlists_request_alloc(struct i915_request *request)
 
 	GEM_BUG_ON(!request->hw_context->pin_count);
 
-	/* Flush enough space to reduce the likelihood of waiting after
+	/*
+	 * Flush enough space to reduce the likelihood of waiting after
 	 * we start building the request - in which case we will just
 	 * have to repeat work.
 	 */
 	request->reserved_space += EXECLISTS_REQUEST_SIZE;
 
-	ret = intel_ring_wait_for_space(request->ring, request->reserved_space);
+	/* Unconditionally invalidate GPU caches and TLBs. */
+	ret = request->engine->emit_flush(request, EMIT_INVALIDATE);
 	if (ret)
 		return ret;
 
-	/* Note that after this point, we have committed to using
+	/*
+	 * Note that after this point, we have committed to using
 	 * this request as it is being used to both track the
 	 * state of engine initialisation and liveness of the
 	 * golden renderstate above. Think twice before you try
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index c5eb26a7ee79..16084749adf5 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1820,13 +1820,15 @@ static int ring_request_alloc(struct i915_request *request)
 
 	GEM_BUG_ON(!request->hw_context->pin_count);
 
-	/* Flush enough space to reduce the likelihood of waiting after
+	/*
+	 * Flush enough space to reduce the likelihood of waiting after
 	 * we start building the request - in which case we will just
 	 * have to repeat work.
 	 */
 	request->reserved_space += LEGACY_REQUEST_SIZE;
 
-	ret = intel_ring_wait_for_space(request->ring, request->reserved_space);
+	/* Unconditionally invalidate GPU caches and TLBs. */
+	ret = request->engine->emit_flush(request, EMIT_INVALIDATE);
 	if (ret)
 		return ret;
 
-- 
cgit v1.2.3-59-g8ed1b


From dd847a7069747f1963962aee56a5694fbcc40caf Mon Sep 17 00:00:00 2001
From: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Date: Fri, 7 Dec 2018 14:34:28 +0200
Subject: drm/i915: Compile fix for 64b dma-fence seqno
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Many errs of the form:
drivers/gpu/drm/i915/selftests/intel_hangcheck.c: In function ‘__igt_reset_evict_vma’:
./include/linux/kern_levels.h:5:18: error: format ‘%x’ expects argument of type ‘unsigned int’, but argum

Fixes: b312d8ca3a7c ("dma-buf: make fence sequence numbers 64 bit v2")
Cc: Christian König <christian.koenig@amd.com>
Cc: Chunming Zhou <david1.zhou@amd.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20181207123428.16257-1-mika.kuoppala@linux.intel.com
---
 drivers/gpu/drm/i915/i915_gem.c                  |  4 ++--
 drivers/gpu/drm/i915/i915_gem_context.c          |  8 ++++----
 drivers/gpu/drm/i915/i915_request.c              | 12 ++++++------
 drivers/gpu/drm/i915/intel_lrc.c                 |  6 +++---
 drivers/gpu/drm/i915/selftests/intel_hangcheck.c | 14 +++++++-------
 5 files changed, 22 insertions(+), 22 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index c55b1f75c980..b70de1a9e899 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3187,7 +3187,7 @@ i915_gem_reset_request(struct intel_engine_cs *engine,
 	 */
 
 	if (i915_request_completed(request)) {
-		GEM_TRACE("%s pardoned global=%d (fence %llx:%d), current %d\n",
+		GEM_TRACE("%s pardoned global=%d (fence %llx:%lld), current %d\n",
 			  engine->name, request->global_seqno,
 			  request->fence.context, request->fence.seqno,
 			  intel_engine_get_seqno(engine));
@@ -3321,7 +3321,7 @@ static void nop_complete_submit_request(struct i915_request *request)
 {
 	unsigned long flags;
 
-	GEM_TRACE("%s fence %llx:%d -> -EIO\n",
+	GEM_TRACE("%s fence %llx:%lld -> -EIO\n",
 		  request->engine->name,
 		  request->fence.context, request->fence.seqno);
 	dma_fence_set_error(&request->fence, -EIO);
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index b97963db0287..66117a8281ef 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -653,7 +653,7 @@ last_request_on_engine(struct i915_timeline *timeline,
 	rq = i915_gem_active_raw(&timeline->last_request,
 				 &engine->i915->drm.struct_mutex);
 	if (rq && rq->engine == engine) {
-		GEM_TRACE("last request for %s on engine %s: %llx:%d\n",
+		GEM_TRACE("last request for %s on engine %s: %llx:%llu\n",
 			  timeline->name, engine->name,
 			  rq->fence.context, rq->fence.seqno);
 		GEM_BUG_ON(rq->timeline != timeline);
@@ -690,14 +690,14 @@ static bool engine_has_kernel_context_barrier(struct intel_engine_cs *engine)
 		 * switch-to-kernel-context?
 		 */
 		if (!i915_timeline_sync_is_later(barrier, &rq->fence)) {
-			GEM_TRACE("%s needs barrier for %llx:%d\n",
+			GEM_TRACE("%s needs barrier for %llx:%lld\n",
 				  ring->timeline->name,
 				  rq->fence.context,
 				  rq->fence.seqno);
 			return false;
 		}
 
-		GEM_TRACE("%s has barrier after %llx:%d\n",
+		GEM_TRACE("%s has barrier after %llx:%lld\n",
 			  ring->timeline->name,
 			  rq->fence.context,
 			  rq->fence.seqno);
@@ -753,7 +753,7 @@ int i915_gem_switch_to_kernel_context(struct drm_i915_private *i915)
 			if (prev->gem_context == i915->kernel_context)
 				continue;
 
-			GEM_TRACE("add barrier on %s for %llx:%d\n",
+			GEM_TRACE("add barrier on %s for %llx:%lld\n",
 				  engine->name,
 				  prev->fence.context,
 				  prev->fence.seqno);
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 71107540581d..191703986c7b 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -267,7 +267,7 @@ static void free_capture_list(struct i915_request *request)
 static void __retire_engine_request(struct intel_engine_cs *engine,
 				    struct i915_request *rq)
 {
-	GEM_TRACE("%s(%s) fence %llx:%d, global=%d, current %d\n",
+	GEM_TRACE("%s(%s) fence %llx:%lld, global=%d, current %d\n",
 		  __func__, engine->name,
 		  rq->fence.context, rq->fence.seqno,
 		  rq->global_seqno,
@@ -329,7 +329,7 @@ static void i915_request_retire(struct i915_request *request)
 {
 	struct i915_gem_active *active, *next;
 
-	GEM_TRACE("%s fence %llx:%d, global=%d, current %d\n",
+	GEM_TRACE("%s fence %llx:%lld, global=%d, current %d\n",
 		  request->engine->name,
 		  request->fence.context, request->fence.seqno,
 		  request->global_seqno,
@@ -392,7 +392,7 @@ void i915_request_retire_upto(struct i915_request *rq)
 	struct intel_ring *ring = rq->ring;
 	struct i915_request *tmp;
 
-	GEM_TRACE("%s fence %llx:%d, global=%d, current %d\n",
+	GEM_TRACE("%s fence %llx:%lld, global=%d, current %d\n",
 		  rq->engine->name,
 		  rq->fence.context, rq->fence.seqno,
 		  rq->global_seqno,
@@ -433,7 +433,7 @@ void __i915_request_submit(struct i915_request *request)
 	struct intel_engine_cs *engine = request->engine;
 	u32 seqno;
 
-	GEM_TRACE("%s fence %llx:%d -> global=%d, current %d\n",
+	GEM_TRACE("%s fence %llx:%lld -> global=%d, current %d\n",
 		  engine->name,
 		  request->fence.context, request->fence.seqno,
 		  engine->timeline.seqno + 1,
@@ -483,7 +483,7 @@ void __i915_request_unsubmit(struct i915_request *request)
 {
 	struct intel_engine_cs *engine = request->engine;
 
-	GEM_TRACE("%s fence %llx:%d <- global=%d, current %d\n",
+	GEM_TRACE("%s fence %llx:%lld <- global=%d, current %d\n",
 		  engine->name,
 		  request->fence.context, request->fence.seqno,
 		  request->global_seqno,
@@ -958,7 +958,7 @@ void i915_request_add(struct i915_request *request)
 	struct i915_request *prev;
 	u32 *cs;
 
-	GEM_TRACE("%s fence %llx:%d\n",
+	GEM_TRACE("%s fence %llx:%lld\n",
 		  engine->name, request->fence.context, request->fence.seqno);
 
 	lockdep_assert_held(&request->i915->drm.struct_mutex);
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 08fd9b12e4d7..9399db3260ad 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -450,7 +450,7 @@ static void execlists_submit_ports(struct intel_engine_cs *engine)
 			desc = execlists_update_context(rq);
 			GEM_DEBUG_EXEC(port[n].context_id = upper_32_bits(desc));
 
-			GEM_TRACE("%s in[%d]:  ctx=%d.%d, global=%d (fence %llx:%d) (current %d), prio=%d\n",
+			GEM_TRACE("%s in[%d]:  ctx=%d.%d, global=%d (fence %llx:%lld) (current %d), prio=%d\n",
 				  engine->name, n,
 				  port[n].context_id, count,
 				  rq->global_seqno,
@@ -743,7 +743,7 @@ execlists_cancel_port_requests(struct intel_engine_execlists * const execlists)
 	while (num_ports-- && port_isset(port)) {
 		struct i915_request *rq = port_request(port);
 
-		GEM_TRACE("%s:port%u global=%d (fence %llx:%d), (current %d)\n",
+		GEM_TRACE("%s:port%u global=%d (fence %llx:%lld), (current %d)\n",
 			  rq->engine->name,
 			  (unsigned int)(port - execlists->port),
 			  rq->global_seqno,
@@ -952,7 +952,7 @@ static void process_csb(struct intel_engine_cs *engine)
 						EXECLISTS_ACTIVE_USER));
 
 		rq = port_unpack(port, &count);
-		GEM_TRACE("%s out[0]: ctx=%d.%d, global=%d (fence %llx:%d) (current %d), prio=%d\n",
+		GEM_TRACE("%s out[0]: ctx=%d.%d, global=%d (fence %llx:%lld) (current %d), prio=%d\n",
 			  engine->name,
 			  port->context_id, count,
 			  rq ? rq->global_seqno : 0,
diff --git a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
index defe671130ab..33494d922fab 100644
--- a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
+++ b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
@@ -478,7 +478,7 @@ static int __igt_reset_engine(struct drm_i915_private *i915, bool active)
 				if (!wait_until_running(&h, rq)) {
 					struct drm_printer p = drm_info_printer(i915->drm.dev);
 
-					pr_err("%s: Failed to start request %x, at %x\n",
+					pr_err("%s: Failed to start request %llx, at %x\n",
 					       __func__, rq->fence.seqno, hws_seqno(&h, rq));
 					intel_engine_dump(engine, &p,
 							  "%s\n", engine->name);
@@ -579,7 +579,7 @@ static int active_request_put(struct i915_request *rq)
 		return 0;
 
 	if (i915_request_wait(rq, 0, 5 * HZ) < 0) {
-		GEM_TRACE("%s timed out waiting for completion of fence %llx:%d, seqno %d.\n",
+		GEM_TRACE("%s timed out waiting for completion of fence %llx:%lld, seqno %d.\n",
 			  rq->engine->name,
 			  rq->fence.context,
 			  rq->fence.seqno,
@@ -756,7 +756,7 @@ static int __igt_reset_engines(struct drm_i915_private *i915,
 				if (!wait_until_running(&h, rq)) {
 					struct drm_printer p = drm_info_printer(i915->drm.dev);
 
-					pr_err("%s: Failed to start request %x, at %x\n",
+					pr_err("%s: Failed to start request %llx, at %x\n",
 					       __func__, rq->fence.seqno, hws_seqno(&h, rq));
 					intel_engine_dump(engine, &p,
 							  "%s\n", engine->name);
@@ -955,7 +955,7 @@ static int igt_reset_wait(void *arg)
 	if (!wait_until_running(&h, rq)) {
 		struct drm_printer p = drm_info_printer(i915->drm.dev);
 
-		pr_err("%s: Failed to start request %x, at %x\n",
+		pr_err("%s: Failed to start request %llx, at %x\n",
 		       __func__, rq->fence.seqno, hws_seqno(&h, rq));
 		intel_engine_dump(rq->engine, &p, "%s\n", rq->engine->name);
 
@@ -1134,7 +1134,7 @@ static int __igt_reset_evict_vma(struct drm_i915_private *i915,
 	if (!wait_until_running(&h, rq)) {
 		struct drm_printer p = drm_info_printer(i915->drm.dev);
 
-		pr_err("%s: Failed to start request %x, at %x\n",
+		pr_err("%s: Failed to start request %llx, at %x\n",
 		       __func__, rq->fence.seqno, hws_seqno(&h, rq));
 		intel_engine_dump(rq->engine, &p, "%s\n", rq->engine->name);
 
@@ -1329,7 +1329,7 @@ static int igt_reset_queue(void *arg)
 			if (!wait_until_running(&h, prev)) {
 				struct drm_printer p = drm_info_printer(i915->drm.dev);
 
-				pr_err("%s(%s): Failed to start request %x, at %x\n",
+				pr_err("%s(%s): Failed to start request %llx, at %x\n",
 				       __func__, engine->name,
 				       prev->fence.seqno, hws_seqno(&h, prev));
 				intel_engine_dump(engine, &p,
@@ -1440,7 +1440,7 @@ static int igt_handle_error(void *arg)
 	if (!wait_until_running(&h, rq)) {
 		struct drm_printer p = drm_info_printer(i915->drm.dev);
 
-		pr_err("%s: Failed to start request %x, at %x\n",
+		pr_err("%s: Failed to start request %llx, at %x\n",
 		       __func__, rq->fence.seqno, hws_seqno(&h, rq));
 		intel_engine_dump(rq->engine, &p, "%s\n", rq->engine->name);
 
-- 
cgit v1.2.3-59-g8ed1b


From 6faf5916e6beb0dedb0fcbbafbaa152adeaea758 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 28 Dec 2018 14:07:35 +0000
Subject: drm/i915: Remove HW semaphores for gen7 inter-engine synchronisation

The writing is on the wall for the existence of a single execution queue
along each engine, and as a consequence we will not be able to track
dependencies along the HW queue itself, i.e. we will not be able to use
HW semaphores on gen7 as they use a global set of registers (and unlike
gen8+ we can not effectively target memory to keep per-context seqno and
dependencies).

On the positive side, when we implement request reordering for gen7 we
also can not presume a simple execution queue and would also require
removing the current semaphore generation code. So this bring us another
step closer to request reordering for ringbuffer submission!

The negative side is that using interrupts to drive inter-engine
synchronisation is much slower (4us -> 15us to do a nop on each of the 3
engines on ivb). This is much better than it was at the time of introducing
the HW semaphores and equally important userspace weaned itself off
intermixing dependent BLT/RENDER operations (the prime culprit was glyph
rendering in UXA). So while we regress the microbenchmarks, it should not
impact the user.

References: https://bugs.freedesktop.org/show_bug.cgi?id=108888
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181228140736.32606-2-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_debugfs.c     |  19 +---
 drivers/gpu/drm/i915/i915_drv.c         |   2 +-
 drivers/gpu/drm/i915/i915_drv.h         |   3 -
 drivers/gpu/drm/i915/i915_gem.c         |   4 +-
 drivers/gpu/drm/i915/i915_request.c     | 126 ++------------------------
 drivers/gpu/drm/i915/i915_timeline.h    |   8 --
 drivers/gpu/drm/i915/i915_trace.h       |  29 ------
 drivers/gpu/drm/i915/intel_engine_cs.c  |  29 +-----
 drivers/gpu/drm/i915/intel_hangcheck.c  | 155 --------------------------------
 drivers/gpu/drm/i915/intel_ringbuffer.c | 138 ----------------------------
 drivers/gpu/drm/i915/intel_ringbuffer.h |  56 +-----------
 11 files changed, 12 insertions(+), 557 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 2d29ce630c0e..1269d734ade0 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1041,21 +1041,7 @@ static const struct file_operations i915_error_state_fops = {
 static int
 i915_next_seqno_set(void *data, u64 val)
 {
-	struct drm_i915_private *dev_priv = data;
-	struct drm_device *dev = &dev_priv->drm;
-	int ret;
-
-	ret = mutex_lock_interruptible(&dev->struct_mutex);
-	if (ret)
-		return ret;
-
-	intel_runtime_pm_get(dev_priv);
-	ret = i915_gem_set_global_seqno(dev, val);
-	intel_runtime_pm_put(dev_priv);
-
-	mutex_unlock(&dev->struct_mutex);
-
-	return ret;
+	return val ? 0 : -EINVAL;
 }
 
 DEFINE_SIMPLE_ATTRIBUTE(i915_next_seqno_fops,
@@ -4101,9 +4087,6 @@ i915_drop_caches_set(void *data, u64 val)
 						     I915_WAIT_LOCKED,
 						     MAX_SCHEDULE_TIMEOUT);
 
-		if (ret == 0 && val & DROP_RESET_SEQNO)
-			ret = i915_gem_set_global_seqno(&i915->drm, 1);
-
 		if (val & DROP_RETIRE)
 			i915_retire_requests(i915);
 
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index caa055ac9472..dcb935338c63 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -349,7 +349,7 @@ static int i915_getparam_ioctl(struct drm_device *dev, void *data,
 		value = min_t(int, INTEL_PPGTT(dev_priv), I915_GEM_PPGTT_FULL);
 		break;
 	case I915_PARAM_HAS_SEMAPHORES:
-		value = HAS_LEGACY_SEMAPHORES(dev_priv);
+		value = 0;
 		break;
 	case I915_PARAM_HAS_SECURE_BATCHES:
 		value = capable(CAP_SYS_ADMIN);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 936ec09c9490..287f06b9e95a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1948,7 +1948,6 @@ struct drm_i915_private {
 		struct list_head active_rings;
 		struct list_head closed_vma;
 		u32 active_requests;
-		u32 request_serial;
 
 		/**
 		 * Is the GPU currently considered idle, or busy executing
@@ -2396,8 +2395,6 @@ intel_info(const struct drm_i915_private *dev_priv)
 #define HAS_BLT(dev_priv)	HAS_ENGINE(dev_priv, BCS)
 #define HAS_VEBOX(dev_priv)	HAS_ENGINE(dev_priv, VECS)
 
-#define HAS_LEGACY_SEMAPHORES(dev_priv) IS_GEN(dev_priv, 7)
-
 #define HAS_LLC(dev_priv)	((dev_priv)->info.has_llc)
 #define HAS_SNOOP(dev_priv)	((dev_priv)->info.has_snoop)
 #define HAS_EDRAM(dev_priv)	(!!((dev_priv)->edram_cap & EDRAM_ENABLED))
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 39ee67e01bb7..9e65c37daa9c 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3318,7 +3318,7 @@ static void nop_submit_request(struct i915_request *request)
 
 	spin_lock_irqsave(&request->engine->timeline.lock, flags);
 	__i915_request_submit(request);
-	intel_engine_init_global_seqno(request->engine, request->global_seqno);
+	intel_engine_write_global_seqno(request->engine, request->global_seqno);
 	spin_unlock_irqrestore(&request->engine->timeline.lock, flags);
 }
 
@@ -3359,7 +3359,7 @@ void i915_gem_set_wedged(struct drm_i915_private *i915)
 
 	/*
 	 * Make sure no request can slip through without getting completed by
-	 * either this call here to intel_engine_init_global_seqno, or the one
+	 * either this call here to intel_engine_write_global_seqno, or the one
 	 * in nop_submit_request.
 	 */
 	synchronize_rcu();
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 8ab8e8e6a086..2cd1f51963f3 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -111,99 +111,10 @@ i915_request_remove_from_client(struct i915_request *request)
 	spin_unlock(&file_priv->mm.lock);
 }
 
-static int reset_all_global_seqno(struct drm_i915_private *i915, u32 seqno)
+static void reserve_gt(struct drm_i915_private *i915)
 {
-	struct intel_engine_cs *engine;
-	struct i915_timeline *timeline;
-	enum intel_engine_id id;
-	int ret;
-
-	/* Carefully retire all requests without writing to the rings */
-	ret = i915_gem_wait_for_idle(i915,
-				     I915_WAIT_INTERRUPTIBLE |
-				     I915_WAIT_LOCKED,
-				     MAX_SCHEDULE_TIMEOUT);
-	if (ret)
-		return ret;
-
-	GEM_BUG_ON(i915->gt.active_requests);
-
-	/* If the seqno wraps around, we need to clear the breadcrumb rbtree */
-	for_each_engine(engine, i915, id) {
-		GEM_TRACE("%s seqno %d (current %d) -> %d\n",
-			  engine->name,
-			  engine->timeline.seqno,
-			  intel_engine_get_seqno(engine),
-			  seqno);
-
-		if (seqno == engine->timeline.seqno)
-			continue;
-
-		kthread_park(engine->breadcrumbs.signaler);
-
-		if (!i915_seqno_passed(seqno, engine->timeline.seqno)) {
-			/* Flush any waiters before we reuse the seqno */
-			intel_engine_disarm_breadcrumbs(engine);
-			intel_engine_init_hangcheck(engine);
-			GEM_BUG_ON(!list_empty(&engine->breadcrumbs.signals));
-		}
-
-		/* Check we are idle before we fiddle with hw state! */
-		GEM_BUG_ON(!intel_engine_is_idle(engine));
-		GEM_BUG_ON(i915_gem_active_isset(&engine->timeline.last_request));
-
-		/* Finally reset hw state */
-		intel_engine_init_global_seqno(engine, seqno);
-		engine->timeline.seqno = seqno;
-
-		kthread_unpark(engine->breadcrumbs.signaler);
-	}
-
-	list_for_each_entry(timeline, &i915->gt.timelines, link)
-		memset(timeline->global_sync, 0, sizeof(timeline->global_sync));
-
-	i915->gt.request_serial = seqno;
-
-	return 0;
-}
-
-int i915_gem_set_global_seqno(struct drm_device *dev, u32 seqno)
-{
-	struct drm_i915_private *i915 = to_i915(dev);
-
-	lockdep_assert_held(&i915->drm.struct_mutex);
-
-	if (seqno == 0)
-		return -EINVAL;
-
-	/* HWS page needs to be set less than what we will inject to ring */
-	return reset_all_global_seqno(i915, seqno - 1);
-}
-
-static int reserve_gt(struct drm_i915_private *i915)
-{
-	int ret;
-
-	/*
-	 * Reservation is fine until we may need to wrap around
-	 *
-	 * By incrementing the serial for every request, we know that no
-	 * individual engine may exceed that serial (as each is reset to 0
-	 * on any wrap). This protects even the most pessimistic of migrations
-	 * of every request from all engines onto just one.
-	 */
-	while (unlikely(++i915->gt.request_serial == 0)) {
-		ret = reset_all_global_seqno(i915, 0);
-		if (ret) {
-			i915->gt.request_serial--;
-			return ret;
-		}
-	}
-
 	if (!i915->gt.active_requests++)
 		i915_gem_unpark(i915);
-
-	return 0;
 }
 
 static void unreserve_gt(struct drm_i915_private *i915)
@@ -608,9 +519,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	if (IS_ERR(ce))
 		return ERR_CAST(ce);
 
-	ret = reserve_gt(i915);
-	if (ret)
-		goto err_unpin;
+	reserve_gt(i915);
 
 	ret = intel_ring_wait_for_space(ce->ring, MIN_SPACE_FOR_ADD_REQUEST);
 	if (ret)
@@ -743,7 +652,6 @@ err_unwind:
 	kmem_cache_free(i915->requests, rq);
 err_unreserve:
 	unreserve_gt(i915);
-err_unpin:
 	intel_context_unpin(ce);
 	return ERR_PTR(ret);
 }
@@ -771,34 +679,12 @@ i915_request_await_request(struct i915_request *to, struct i915_request *from)
 		ret = i915_sw_fence_await_sw_fence_gfp(&to->submit,
 						       &from->submit,
 						       I915_FENCE_GFP);
-		return ret < 0 ? ret : 0;
-	}
-
-	if (to->engine->semaphore.sync_to) {
-		u32 seqno;
-
-		GEM_BUG_ON(!from->engine->semaphore.signal);
-
-		seqno = i915_request_global_seqno(from);
-		if (!seqno)
-			goto await_dma_fence;
-
-		if (seqno <= to->timeline->global_sync[from->engine->id])
-			return 0;
-
-		trace_i915_gem_ring_sync_to(to, from);
-		ret = to->engine->semaphore.sync_to(to, from);
-		if (ret)
-			return ret;
-
-		to->timeline->global_sync[from->engine->id] = seqno;
-		return 0;
+	} else {
+		ret = i915_sw_fence_await_dma_fence(&to->submit,
+						    &from->fence, 0,
+						    I915_FENCE_GFP);
 	}
 
-await_dma_fence:
-	ret = i915_sw_fence_await_dma_fence(&to->submit,
-					    &from->fence, 0,
-					    I915_FENCE_GFP);
 	return ret < 0 ? ret : 0;
 }
 
diff --git a/drivers/gpu/drm/i915/i915_timeline.h b/drivers/gpu/drm/i915/i915_timeline.h
index ebd71b487220..38c1e15e927a 100644
--- a/drivers/gpu/drm/i915/i915_timeline.h
+++ b/drivers/gpu/drm/i915/i915_timeline.h
@@ -63,14 +63,6 @@ struct i915_timeline {
 	 * redundant and we can discard it without loss of generality.
 	 */
 	struct i915_syncmap *sync;
-	/**
-	 * Separately to the inter-context seqno map above, we track the last
-	 * barrier (e.g. semaphore wait) to the global engine timelines. Note
-	 * that this tracks global_seqno rather than the context.seqno, and
-	 * so it is subject to the limitations of hw wraparound and that we
-	 * may need to revoke global_seqno (on pre-emption).
-	 */
-	u32 global_sync[I915_NUM_ENGINES];
 
 	struct list_head link;
 	const char *name;
diff --git a/drivers/gpu/drm/i915/i915_trace.h b/drivers/gpu/drm/i915/i915_trace.h
index b50c6b829715..5cf378936b05 100644
--- a/drivers/gpu/drm/i915/i915_trace.h
+++ b/drivers/gpu/drm/i915/i915_trace.h
@@ -585,35 +585,6 @@ TRACE_EVENT(i915_gem_evict_vm,
 	    TP_printk("dev=%d, vm=%p", __entry->dev, __entry->vm)
 );
 
-TRACE_EVENT(i915_gem_ring_sync_to,
-	    TP_PROTO(struct i915_request *to, struct i915_request *from),
-	    TP_ARGS(to, from),
-
-	    TP_STRUCT__entry(
-			     __field(u32, dev)
-			     __field(u32, from_class)
-			     __field(u32, from_instance)
-			     __field(u32, to_class)
-			     __field(u32, to_instance)
-			     __field(u32, seqno)
-			     ),
-
-	    TP_fast_assign(
-			   __entry->dev = from->i915->drm.primary->index;
-			   __entry->from_class = from->engine->uabi_class;
-			   __entry->from_instance = from->engine->instance;
-			   __entry->to_class = to->engine->uabi_class;
-			   __entry->to_instance = to->engine->instance;
-			   __entry->seqno = from->global_seqno;
-			   ),
-
-	    TP_printk("dev=%u, sync-from=%u:%u, sync-to=%u:%u, seqno=%u",
-		      __entry->dev,
-		      __entry->from_class, __entry->from_instance,
-		      __entry->to_class, __entry->to_instance,
-		      __entry->seqno)
-);
-
 TRACE_EVENT(i915_request_queue,
 	    TP_PROTO(struct i915_request *rq, u32 flags),
 	    TP_ARGS(rq, flags),
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 561b474cbab1..78fc777c4bf4 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -454,25 +454,8 @@ cleanup:
 	return err;
 }
 
-void intel_engine_init_global_seqno(struct intel_engine_cs *engine, u32 seqno)
+void intel_engine_write_global_seqno(struct intel_engine_cs *engine, u32 seqno)
 {
-	struct drm_i915_private *dev_priv = engine->i915;
-
-	/* Our semaphore implementation is strictly monotonic (i.e. we proceed
-	 * so long as the semaphore value in the register/page is greater
-	 * than the sync value), so whenever we reset the seqno,
-	 * so long as we reset the tracking semaphore value to 0, it will
-	 * always be before the next request's seqno. If we don't reset
-	 * the semaphore value, then when the seqno moves backwards all
-	 * future waits will complete instantly (causing rendering corruption).
-	 */
-	if (IS_GEN_RANGE(dev_priv, 6, 7)) {
-		I915_WRITE(RING_SYNC_0(engine->mmio_base), 0);
-		I915_WRITE(RING_SYNC_1(engine->mmio_base), 0);
-		if (HAS_VEBOX(dev_priv))
-			I915_WRITE(RING_SYNC_2(engine->mmio_base), 0);
-	}
-
 	intel_write_status_page(engine, I915_GEM_HWS_INDEX, seqno);
 	clear_bit(ENGINE_IRQ_BREADCRUMB, &engine->irq_posted);
 
@@ -1300,16 +1283,6 @@ static void intel_engine_print_registers(const struct intel_engine_cs *engine,
 		drm_printf(m, "\tRING_IMR: %08x\n", I915_READ_IMR(engine));
 	}
 
-	if (HAS_LEGACY_SEMAPHORES(dev_priv)) {
-		drm_printf(m, "\tSYNC_0: 0x%08x\n",
-			   I915_READ(RING_SYNC_0(engine->mmio_base)));
-		drm_printf(m, "\tSYNC_1: 0x%08x\n",
-			   I915_READ(RING_SYNC_1(engine->mmio_base)));
-		if (HAS_VEBOX(dev_priv))
-			drm_printf(m, "\tSYNC_2: 0x%08x\n",
-				   I915_READ(RING_SYNC_2(engine->mmio_base)));
-	}
-
 	addr = intel_engine_get_active_head(engine);
 	drm_printf(m, "\tACTHD:  0x%08x_%08x\n",
 		   upper_32_bits(addr), lower_32_bits(addr));
diff --git a/drivers/gpu/drm/i915/intel_hangcheck.c b/drivers/gpu/drm/i915/intel_hangcheck.c
index 495fa145f37f..c3f929f59424 100644
--- a/drivers/gpu/drm/i915/intel_hangcheck.c
+++ b/drivers/gpu/drm/i915/intel_hangcheck.c
@@ -24,144 +24,6 @@
 
 #include "i915_drv.h"
 
-static bool
-ipehr_is_semaphore_wait(struct intel_engine_cs *engine, u32 ipehr)
-{
-	ipehr &= ~MI_SEMAPHORE_SYNC_MASK;
-	return ipehr == (MI_SEMAPHORE_MBOX | MI_SEMAPHORE_COMPARE |
-			 MI_SEMAPHORE_REGISTER);
-}
-
-static struct intel_engine_cs *
-semaphore_wait_to_signaller_ring(struct intel_engine_cs *engine, u32 ipehr,
-				 u64 offset)
-{
-	struct drm_i915_private *dev_priv = engine->i915;
-	u32 sync_bits = ipehr & MI_SEMAPHORE_SYNC_MASK;
-	struct intel_engine_cs *signaller;
-	enum intel_engine_id id;
-
-	for_each_engine(signaller, dev_priv, id) {
-		if (engine == signaller)
-			continue;
-
-		if (sync_bits == signaller->semaphore.mbox.wait[engine->hw_id])
-			return signaller;
-	}
-
-	DRM_DEBUG_DRIVER("No signaller ring found for %s, ipehr 0x%08x\n",
-			 engine->name, ipehr);
-
-	return ERR_PTR(-ENODEV);
-}
-
-static struct intel_engine_cs *
-semaphore_waits_for(struct intel_engine_cs *engine, u32 *seqno)
-{
-	struct drm_i915_private *dev_priv = engine->i915;
-	void __iomem *vaddr;
-	u32 cmd, ipehr, head;
-	u64 offset = 0;
-	int i, backwards;
-
-	/*
-	 * This function does not support execlist mode - any attempt to
-	 * proceed further into this function will result in a kernel panic
-	 * when dereferencing ring->buffer, which is not set up in execlist
-	 * mode.
-	 *
-	 * The correct way of doing it would be to derive the currently
-	 * executing ring buffer from the current context, which is derived
-	 * from the currently running request. Unfortunately, to get the
-	 * current request we would have to grab the struct_mutex before doing
-	 * anything else, which would be ill-advised since some other thread
-	 * might have grabbed it already and managed to hang itself, causing
-	 * the hang checker to deadlock.
-	 *
-	 * Therefore, this function does not support execlist mode in its
-	 * current form. Just return NULL and move on.
-	 */
-	if (engine->buffer == NULL)
-		return NULL;
-
-	ipehr = I915_READ(RING_IPEHR(engine->mmio_base));
-	if (!ipehr_is_semaphore_wait(engine, ipehr))
-		return NULL;
-
-	/*
-	 * HEAD is likely pointing to the dword after the actual command,
-	 * so scan backwards until we find the MBOX. But limit it to just 3
-	 * or 4 dwords depending on the semaphore wait command size.
-	 * Note that we don't care about ACTHD here since that might
-	 * point at at batch, and semaphores are always emitted into the
-	 * ringbuffer itself.
-	 */
-	head = I915_READ_HEAD(engine) & HEAD_ADDR;
-	backwards = (INTEL_GEN(dev_priv) >= 8) ? 5 : 4;
-	vaddr = (void __iomem *)engine->buffer->vaddr;
-
-	for (i = backwards; i; --i) {
-		/*
-		 * Be paranoid and presume the hw has gone off into the wild -
-		 * our ring is smaller than what the hardware (and hence
-		 * HEAD_ADDR) allows. Also handles wrap-around.
-		 */
-		head &= engine->buffer->size - 1;
-
-		/* This here seems to blow up */
-		cmd = ioread32(vaddr + head);
-		if (cmd == ipehr)
-			break;
-
-		head -= 4;
-	}
-
-	if (!i)
-		return NULL;
-
-	*seqno = ioread32(vaddr + head + 4) + 1;
-	return semaphore_wait_to_signaller_ring(engine, ipehr, offset);
-}
-
-static int semaphore_passed(struct intel_engine_cs *engine)
-{
-	struct drm_i915_private *dev_priv = engine->i915;
-	struct intel_engine_cs *signaller;
-	u32 seqno;
-
-	engine->hangcheck.deadlock++;
-
-	signaller = semaphore_waits_for(engine, &seqno);
-	if (signaller == NULL)
-		return -1;
-
-	if (IS_ERR(signaller))
-		return 0;
-
-	/* Prevent pathological recursion due to driver bugs */
-	if (signaller->hangcheck.deadlock >= I915_NUM_ENGINES)
-		return -1;
-
-	if (intel_engine_signaled(signaller, seqno))
-		return 1;
-
-	/* cursory check for an unkickable deadlock */
-	if (I915_READ_CTL(signaller) & RING_WAIT_SEMAPHORE &&
-	    semaphore_passed(signaller) < 0)
-		return -1;
-
-	return 0;
-}
-
-static void semaphore_clear_deadlocks(struct drm_i915_private *dev_priv)
-{
-	struct intel_engine_cs *engine;
-	enum intel_engine_id id;
-
-	for_each_engine(engine, dev_priv, id)
-		engine->hangcheck.deadlock = 0;
-}
-
 static bool instdone_unchanged(u32 current_instdone, u32 *old_instdone)
 {
 	u32 tmp = current_instdone | *old_instdone;
@@ -252,21 +114,6 @@ engine_stuck(struct intel_engine_cs *engine, u64 acthd)
 		return ENGINE_WAIT_KICK;
 	}
 
-	if (IS_GEN_RANGE(dev_priv, 6, 7) && tmp & RING_WAIT_SEMAPHORE) {
-		switch (semaphore_passed(engine)) {
-		default:
-			return ENGINE_DEAD;
-		case 1:
-			i915_handle_error(dev_priv, ALL_ENGINES, 0,
-					  "stuck semaphore on %s",
-					  engine->name);
-			I915_WRITE_CTL(engine, tmp);
-			return ENGINE_WAIT_KICK;
-		case 0:
-			return ENGINE_WAIT;
-		}
-	}
-
 	return ENGINE_DEAD;
 }
 
@@ -433,8 +280,6 @@ static void i915_hangcheck_elapsed(struct work_struct *work)
 	for_each_engine(engine, dev_priv, id) {
 		struct intel_engine_hangcheck hc;
 
-		semaphore_clear_deadlocks(dev_priv);
-
 		hangcheck_load_sample(engine, &hc);
 		hangcheck_accumulate_sample(engine, &hc);
 		hangcheck_store_sample(engine, &hc);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 1102c2e98222..588294a3bbd2 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -556,13 +556,6 @@ static int init_ring_common(struct intel_engine_cs *engine)
 
 	intel_engine_reset_breadcrumbs(engine);
 
-	if (HAS_LEGACY_SEMAPHORES(engine->i915)) {
-		I915_WRITE(RING_SYNC_0(engine->mmio_base), 0);
-		I915_WRITE(RING_SYNC_1(engine->mmio_base), 0);
-		if (HAS_VEBOX(dev_priv))
-			I915_WRITE(RING_SYNC_2(engine->mmio_base), 0);
-	}
-
 	/* Enforce ordering by reading HEAD register back */
 	I915_READ_HEAD(engine);
 
@@ -745,33 +738,6 @@ static int init_render_ring(struct intel_engine_cs *engine)
 	return 0;
 }
 
-static u32 *gen6_signal(struct i915_request *rq, u32 *cs)
-{
-	struct drm_i915_private *dev_priv = rq->i915;
-	struct intel_engine_cs *engine;
-	enum intel_engine_id id;
-	int num_rings = 0;
-
-	for_each_engine(engine, dev_priv, id) {
-		i915_reg_t mbox_reg;
-
-		if (!(BIT(engine->hw_id) & GEN6_SEMAPHORES_MASK))
-			continue;
-
-		mbox_reg = rq->engine->semaphore.mbox.signal[engine->hw_id];
-		if (i915_mmio_reg_valid(mbox_reg)) {
-			*cs++ = MI_LOAD_REGISTER_IMM(1);
-			*cs++ = i915_mmio_reg_offset(mbox_reg);
-			*cs++ = rq->global_seqno;
-			num_rings++;
-		}
-	}
-	if (num_rings & 1)
-		*cs++ = MI_NOOP;
-
-	return cs;
-}
-
 static void cancel_requests(struct intel_engine_cs *engine)
 {
 	struct i915_request *request;
@@ -822,39 +788,6 @@ static void i9xx_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 
 static const int i9xx_emit_breadcrumb_sz = 4;
 
-static void gen6_sema_emit_breadcrumb(struct i915_request *rq, u32 *cs)
-{
-	return i9xx_emit_breadcrumb(rq, rq->engine->semaphore.signal(rq, cs));
-}
-
-static int
-gen6_ring_sync_to(struct i915_request *rq, struct i915_request *signal)
-{
-	u32 dw1 = MI_SEMAPHORE_MBOX |
-		  MI_SEMAPHORE_COMPARE |
-		  MI_SEMAPHORE_REGISTER;
-	u32 wait_mbox = signal->engine->semaphore.mbox.wait[rq->engine->hw_id];
-	u32 *cs;
-
-	WARN_ON(wait_mbox == MI_SEMAPHORE_SYNC_INVALID);
-
-	cs = intel_ring_begin(rq, 4);
-	if (IS_ERR(cs))
-		return PTR_ERR(cs);
-
-	*cs++ = dw1 | wait_mbox;
-	/* Throughout all of the GEM code, seqno passed implies our current
-	 * seqno is >= the last seqno executed. However for hardware the
-	 * comparison is strictly greater than.
-	 */
-	*cs++ = signal->global_seqno - 1;
-	*cs++ = 0;
-	*cs++ = MI_NOOP;
-	intel_ring_advance(rq, cs);
-
-	return 0;
-}
-
 static void
 gen5_seqno_barrier(struct intel_engine_cs *engine)
 {
@@ -2151,66 +2084,6 @@ static int gen6_ring_flush(struct i915_request *rq, u32 mode)
 	return gen6_flush_dw(rq, mode, MI_INVALIDATE_TLB);
 }
 
-static void intel_ring_init_semaphores(struct drm_i915_private *dev_priv,
-				       struct intel_engine_cs *engine)
-{
-	int i;
-
-	if (!HAS_LEGACY_SEMAPHORES(dev_priv))
-		return;
-
-	GEM_BUG_ON(INTEL_GEN(dev_priv) < 6);
-	engine->semaphore.sync_to = gen6_ring_sync_to;
-	engine->semaphore.signal = gen6_signal;
-
-	/*
-	 * The current semaphore is only applied on pre-gen8
-	 * platform.  And there is no VCS2 ring on the pre-gen8
-	 * platform. So the semaphore between RCS and VCS2 is
-	 * initialized as INVALID.
-	 */
-	for (i = 0; i < GEN6_NUM_SEMAPHORES; i++) {
-		static const struct {
-			u32 wait_mbox;
-			i915_reg_t mbox_reg;
-		} sem_data[GEN6_NUM_SEMAPHORES][GEN6_NUM_SEMAPHORES] = {
-			[RCS_HW] = {
-				[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_RV,  .mbox_reg = GEN6_VRSYNC },
-				[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_RB,  .mbox_reg = GEN6_BRSYNC },
-				[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_RVE, .mbox_reg = GEN6_VERSYNC },
-			},
-			[VCS_HW] = {
-				[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VR,  .mbox_reg = GEN6_RVSYNC },
-				[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VB,  .mbox_reg = GEN6_BVSYNC },
-				[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_VVE, .mbox_reg = GEN6_VEVSYNC },
-			},
-			[BCS_HW] = {
-				[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_BR,  .mbox_reg = GEN6_RBSYNC },
-				[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_BV,  .mbox_reg = GEN6_VBSYNC },
-				[VECS_HW] = { .wait_mbox = MI_SEMAPHORE_SYNC_BVE, .mbox_reg = GEN6_VEBSYNC },
-			},
-			[VECS_HW] = {
-				[RCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VER, .mbox_reg = GEN6_RVESYNC },
-				[VCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VEV, .mbox_reg = GEN6_VVESYNC },
-				[BCS_HW] =  { .wait_mbox = MI_SEMAPHORE_SYNC_VEB, .mbox_reg = GEN6_BVESYNC },
-			},
-		};
-		u32 wait_mbox;
-		i915_reg_t mbox_reg;
-
-		if (i == engine->hw_id) {
-			wait_mbox = MI_SEMAPHORE_SYNC_INVALID;
-			mbox_reg = GEN6_NOSYNC;
-		} else {
-			wait_mbox = sem_data[engine->hw_id][i].wait_mbox;
-			mbox_reg = sem_data[engine->hw_id][i].mbox_reg;
-		}
-
-		engine->semaphore.mbox.wait[i] = wait_mbox;
-		engine->semaphore.mbox.signal[i] = mbox_reg;
-	}
-}
-
 static void intel_ring_init_irq(struct drm_i915_private *dev_priv,
 				struct intel_engine_cs *engine)
 {
@@ -2253,7 +2126,6 @@ static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,
 	GEM_BUG_ON(INTEL_GEN(dev_priv) >= 8);
 
 	intel_ring_init_irq(dev_priv, engine);
-	intel_ring_init_semaphores(dev_priv, engine);
 
 	engine->init_hw = init_ring_common;
 	engine->reset.prepare = reset_prepare;
@@ -2265,16 +2137,6 @@ static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,
 
 	engine->emit_breadcrumb = i9xx_emit_breadcrumb;
 	engine->emit_breadcrumb_sz = i9xx_emit_breadcrumb_sz;
-	if (HAS_LEGACY_SEMAPHORES(dev_priv)) {
-		int num_rings;
-
-		engine->emit_breadcrumb = gen6_sema_emit_breadcrumb;
-
-		num_rings = INTEL_INFO(dev_priv)->num_rings - 1;
-		engine->emit_breadcrumb_sz += num_rings * 3;
-		if (num_rings & 1)
-			engine->emit_breadcrumb_sz++;
-	}
 
 	engine->set_default_submission = i9xx_set_default_submission;
 
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 6b41b9ce5f5b..c927bdfb1ed0 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -510,60 +510,6 @@ struct intel_engine_cs {
 	void		(*irq_seqno_barrier)(struct intel_engine_cs *engine);
 	void		(*cleanup)(struct intel_engine_cs *engine);
 
-	/* GEN8 signal/wait table - never trust comments!
-	 *	  signal to	signal to    signal to   signal to      signal to
-	 *	    RCS		   VCS          BCS        VECS		 VCS2
-	 *      --------------------------------------------------------------------
-	 *  RCS | NOP (0x00) | VCS (0x08) | BCS (0x10) | VECS (0x18) | VCS2 (0x20) |
-	 *	|-------------------------------------------------------------------
-	 *  VCS | RCS (0x28) | NOP (0x30) | BCS (0x38) | VECS (0x40) | VCS2 (0x48) |
-	 *	|-------------------------------------------------------------------
-	 *  BCS | RCS (0x50) | VCS (0x58) | NOP (0x60) | VECS (0x68) | VCS2 (0x70) |
-	 *	|-------------------------------------------------------------------
-	 * VECS | RCS (0x78) | VCS (0x80) | BCS (0x88) |  NOP (0x90) | VCS2 (0x98) |
-	 *	|-------------------------------------------------------------------
-	 * VCS2 | RCS (0xa0) | VCS (0xa8) | BCS (0xb0) | VECS (0xb8) | NOP  (0xc0) |
-	 *	|-------------------------------------------------------------------
-	 *
-	 * Generalization:
-	 *  f(x, y) := (x->id * NUM_RINGS * seqno_size) + (seqno_size * y->id)
-	 *  ie. transpose of g(x, y)
-	 *
-	 *	 sync from	sync from    sync from    sync from	sync from
-	 *	    RCS		   VCS          BCS        VECS		 VCS2
-	 *      --------------------------------------------------------------------
-	 *  RCS | NOP (0x00) | VCS (0x28) | BCS (0x50) | VECS (0x78) | VCS2 (0xa0) |
-	 *	|-------------------------------------------------------------------
-	 *  VCS | RCS (0x08) | NOP (0x30) | BCS (0x58) | VECS (0x80) | VCS2 (0xa8) |
-	 *	|-------------------------------------------------------------------
-	 *  BCS | RCS (0x10) | VCS (0x38) | NOP (0x60) | VECS (0x88) | VCS2 (0xb0) |
-	 *	|-------------------------------------------------------------------
-	 * VECS | RCS (0x18) | VCS (0x40) | BCS (0x68) |  NOP (0x90) | VCS2 (0xb8) |
-	 *	|-------------------------------------------------------------------
-	 * VCS2 | RCS (0x20) | VCS (0x48) | BCS (0x70) | VECS (0x98) |  NOP (0xc0) |
-	 *	|-------------------------------------------------------------------
-	 *
-	 * Generalization:
-	 *  g(x, y) := (y->id * NUM_RINGS * seqno_size) + (seqno_size * x->id)
-	 *  ie. transpose of f(x, y)
-	 */
-	struct {
-#define GEN6_SEMAPHORE_LAST	VECS_HW
-#define GEN6_NUM_SEMAPHORES	(GEN6_SEMAPHORE_LAST + 1)
-#define GEN6_SEMAPHORES_MASK	GENMASK(GEN6_SEMAPHORE_LAST, 0)
-		struct {
-			/* our mbox written by others */
-			u32		wait[GEN6_NUM_SEMAPHORES];
-			/* mboxes this ring signals to */
-			i915_reg_t	signal[GEN6_NUM_SEMAPHORES];
-		} mbox;
-
-		/* AKA wait() */
-		int	(*sync_to)(struct i915_request *rq,
-				   struct i915_request *signal);
-		u32	*(*signal)(struct i915_request *rq, u32 *cs);
-	} semaphore;
-
 	struct intel_engine_execlists execlists;
 
 	/* Contexts are pinned whilst they are active on the GPU. The last
@@ -889,7 +835,7 @@ intel_ring_set_tail(struct intel_ring *ring, unsigned int tail)
 	return tail;
 }
 
-void intel_engine_init_global_seqno(struct intel_engine_cs *engine, u32 seqno);
+void intel_engine_write_global_seqno(struct intel_engine_cs *engine, u32 seqno);
 
 void intel_engine_setup_common(struct intel_engine_cs *engine);
 int intel_engine_init_common(struct intel_engine_cs *engine);
-- 
cgit v1.2.3-59-g8ed1b


From ed2922c025c3fd208e0fe7589f587ba37e1a4834 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 28 Dec 2018 17:16:36 +0000
Subject: drm/i915: Remove redundant trailing request flush

Now that we perform the request flushing inline with emitting the
breadcrumb, we can remove the now redundant manual flush. And we can
also remove the infrastructure that remained only for its purpose.

v2: emit_breadcrumb_sz is in dwords, but rq->reserved_space is in bytes

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181228171641.16531-1-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_request.c          | 14 +++++++-------
 drivers/gpu/drm/i915/intel_ringbuffer.c      | 16 ----------------
 drivers/gpu/drm/i915/intel_ringbuffer.h      | 10 ----------
 drivers/gpu/drm/i915/selftests/mock_engine.c |  2 --
 4 files changed, 7 insertions(+), 35 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 2cd1f51963f3..c8603a26606e 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -521,10 +521,6 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 
 	reserve_gt(i915);
 
-	ret = intel_ring_wait_for_space(ce->ring, MIN_SPACE_FOR_ADD_REQUEST);
-	if (ret)
-		goto err_unreserve;
-
 	/* Move our oldest request to the slab-cache (if not in use!) */
 	rq = list_first_entry(&ce->ring->request_list, typeof(*rq), ring_link);
 	if (!list_is_last(&rq->ring_link, &ce->ring->request_list) &&
@@ -616,9 +612,13 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	 * i915_request_add() call can't fail. Note that the reserve may need
 	 * to be redone if the request is not actually submitted straight
 	 * away, e.g. because a GPU scheduler has deferred it.
+	 *
+	 * Note that due to how we add reserved_space to intel_ring_begin()
+	 * we need to double our request to ensure that if we need to wrap
+	 * around inside i915_request_add() there is sufficient space at
+	 * the beginning of the ring as well.
 	 */
-	rq->reserved_space = MIN_SPACE_FOR_ADD_REQUEST;
-	GEM_BUG_ON(rq->reserved_space < engine->emit_breadcrumb_sz);
+	rq->reserved_space = 2 * engine->emit_breadcrumb_sz * sizeof(u32);
 
 	/*
 	 * Record the position of the start of the request so that
@@ -860,8 +860,8 @@ void i915_request_add(struct i915_request *request)
 	 * should already have been reserved in the ring buffer. Let the ring
 	 * know that it is time to use that space up.
 	 */
+	GEM_BUG_ON(request->reserved_space > request->ring->space);
 	request->reserved_space = 0;
-	engine->emit_flush(request, EMIT_FLUSH);
 
 	/*
 	 * Record the position of the start of the breadcrumb so that
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index fc1e29305951..d773f7dd32a9 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1904,22 +1904,6 @@ static noinline int wait_for_space(struct intel_ring *ring, unsigned int bytes)
 	return 0;
 }
 
-int intel_ring_wait_for_space(struct intel_ring *ring, unsigned int bytes)
-{
-	GEM_BUG_ON(bytes > ring->effective_size);
-	if (unlikely(bytes > ring->effective_size - ring->emit))
-		bytes += ring->size - ring->emit;
-
-	if (unlikely(bytes > ring->space)) {
-		int ret = wait_for_space(ring, bytes);
-		if (unlikely(ret))
-			return ret;
-	}
-
-	GEM_BUG_ON(ring->space < bytes);
-	return 0;
-}
-
 u32 *intel_ring_begin(struct i915_request *rq, unsigned int num_dwords)
 {
 	struct intel_ring *ring = rq->ring;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 32606d795af3..99e2cb75d29a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -754,7 +754,6 @@ void intel_legacy_submission_resume(struct drm_i915_private *dev_priv);
 
 int __must_check intel_ring_cacheline_align(struct i915_request *rq);
 
-int intel_ring_wait_for_space(struct intel_ring *ring, unsigned int bytes);
 u32 __must_check *intel_ring_begin(struct i915_request *rq, unsigned int n);
 
 static inline void intel_ring_advance(struct i915_request *rq, u32 *cs)
@@ -895,15 +894,6 @@ static inline bool intel_engine_has_started(struct intel_engine_cs *engine,
 void intel_engine_get_instdone(struct intel_engine_cs *engine,
 			       struct intel_instdone *instdone);
 
-/*
- * Arbitrary size for largest possible 'add request' sequence. The code paths
- * are complex and variable. Empirical measurement shows that the worst case
- * is BDW at 192 bytes (6 + 6 + 36 dwords), then ILK at 136 bytes. However,
- * we need to allocate double the largest single packet within that emission
- * to account for tail wraparound (so 6 + 6 + 72 dwords for BDW).
- */
-#define MIN_SPACE_FOR_ADD_REQUEST 336
-
 static inline u32 intel_hws_seqno_address(struct intel_engine_cs *engine)
 {
 	return engine->status_page.ggtt_offset + I915_GEM_HWS_INDEX_ADDR;
diff --git a/drivers/gpu/drm/i915/selftests/mock_engine.c b/drivers/gpu/drm/i915/selftests/mock_engine.c
index d0c44c18db42..50e1a0b1af7e 100644
--- a/drivers/gpu/drm/i915/selftests/mock_engine.c
+++ b/drivers/gpu/drm/i915/selftests/mock_engine.c
@@ -148,8 +148,6 @@ static struct intel_ring *mock_ring(struct intel_engine_cs *engine)
 	const unsigned long sz = PAGE_SIZE / 2;
 	struct mock_ring *ring;
 
-	BUILD_BUG_ON(MIN_SPACE_FOR_ADD_REQUEST > sz);
-
 	ring = kzalloc(sizeof(*ring) + sz, GFP_KERNEL);
 	if (!ring)
 		return NULL;
-- 
cgit v1.2.3-59-g8ed1b


From 1216e3c3af250ed401577fa6e6561edd7a743fbd Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 28 Dec 2018 17:16:41 +0000
Subject: drm/i915: Drop unused engine->irq_seqno_barrier w/a

Now that we have eliminated the CPU-side irq_seqno_barrier by moving the
delays on the GPU before emitting the MI_USER_INTERRUPT, we can remove
the engine->irq_seqno_barrier infrastructure. Though intentionally
slowing down the GPU is nasty, so is the code we can now remove!

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181228171641.16531-6-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_drv.h          | 84 --------------------------------
 drivers/gpu/drm/i915/i915_gem.c          |  7 ---
 drivers/gpu/drm/i915/i915_irq.c          |  7 ---
 drivers/gpu/drm/i915/i915_request.c      |  8 +--
 drivers/gpu/drm/i915/intel_breadcrumbs.c | 26 ----------
 drivers/gpu/drm/i915/intel_engine_cs.c   |  6 ---
 drivers/gpu/drm/i915/intel_hangcheck.c   | 10 ----
 drivers/gpu/drm/i915/intel_ringbuffer.c  |  4 --
 drivers/gpu/drm/i915/intel_ringbuffer.h  | 10 ----
 9 files changed, 1 insertion(+), 161 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3053b0505dde..13116909fe0d 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3586,90 +3586,6 @@ wait_remaining_ms_from_jiffies(unsigned long timestamp_jiffies, int to_wait_ms)
 	}
 }
 
-static inline bool
-__i915_request_irq_complete(const struct i915_request *rq)
-{
-	struct intel_engine_cs *engine = rq->engine;
-	u32 seqno;
-
-	/* Note that the engine may have wrapped around the seqno, and
-	 * so our request->global_seqno will be ahead of the hardware,
-	 * even though it completed the request before wrapping. We catch
-	 * this by kicking all the waiters before resetting the seqno
-	 * in hardware, and also signal the fence.
-	 */
-	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags))
-		return true;
-
-	/* The request was dequeued before we were awoken. We check after
-	 * inspecting the hw to confirm that this was the same request
-	 * that generated the HWS update. The memory barriers within
-	 * the request execution are sufficient to ensure that a check
-	 * after reading the value from hw matches this request.
-	 */
-	seqno = i915_request_global_seqno(rq);
-	if (!seqno)
-		return false;
-
-	/* Before we do the heavier coherent read of the seqno,
-	 * check the value (hopefully) in the CPU cacheline.
-	 */
-	if (__i915_request_completed(rq, seqno))
-		return true;
-
-	/* Ensure our read of the seqno is coherent so that we
-	 * do not "miss an interrupt" (i.e. if this is the last
-	 * request and the seqno write from the GPU is not visible
-	 * by the time the interrupt fires, we will see that the
-	 * request is incomplete and go back to sleep awaiting
-	 * another interrupt that will never come.)
-	 *
-	 * Strictly, we only need to do this once after an interrupt,
-	 * but it is easier and safer to do it every time the waiter
-	 * is woken.
-	 */
-	if (engine->irq_seqno_barrier &&
-	    test_and_clear_bit(ENGINE_IRQ_BREADCRUMB, &engine->irq_posted)) {
-		struct intel_breadcrumbs *b = &engine->breadcrumbs;
-
-		/* The ordering of irq_posted versus applying the barrier
-		 * is crucial. The clearing of the current irq_posted must
-		 * be visible before we perform the barrier operation,
-		 * such that if a subsequent interrupt arrives, irq_posted
-		 * is reasserted and our task rewoken (which causes us to
-		 * do another __i915_request_irq_complete() immediately
-		 * and reapply the barrier). Conversely, if the clear
-		 * occurs after the barrier, then an interrupt that arrived
-		 * whilst we waited on the barrier would not trigger a
-		 * barrier on the next pass, and the read may not see the
-		 * seqno update.
-		 */
-		engine->irq_seqno_barrier(engine);
-
-		/* If we consume the irq, but we are no longer the bottom-half,
-		 * the real bottom-half may not have serialised their own
-		 * seqno check with the irq-barrier (i.e. may have inspected
-		 * the seqno before we believe it coherent since they see
-		 * irq_posted == false but we are still running).
-		 */
-		spin_lock_irq(&b->irq_lock);
-		if (b->irq_wait && b->irq_wait->tsk != current)
-			/* Note that if the bottom-half is changed as we
-			 * are sending the wake-up, the new bottom-half will
-			 * be woken by whomever made the change. We only have
-			 * to worry about when we steal the irq-posted for
-			 * ourself.
-			 */
-			wake_up_process(b->irq_wait->tsk);
-		spin_unlock_irq(&b->irq_lock);
-
-		if (__i915_request_completed(rq, seqno))
-			return true;
-	}
-
-	return false;
-}
-
 void i915_memcpy_init_early(struct drm_i915_private *dev_priv);
 bool i915_memcpy_from_wc(void *dst, const void *src, unsigned long len);
 
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 9e65c37daa9c..e872d0a179f0 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3230,13 +3230,6 @@ void i915_gem_reset_engine(struct intel_engine_cs *engine,
 			   struct i915_request *request,
 			   bool stalled)
 {
-	/*
-	 * Make sure this write is visible before we re-enable the interrupt
-	 * handlers on another CPU, as tasklet_enable() resolves to just
-	 * a compiler barrier which is insufficient for our purpose here.
-	 */
-	smp_store_mb(engine->irq_posted, 0);
-
 	if (request)
 		request = i915_gem_reset_request(engine, request, stalled);
 
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 0c7fc9890891..fbb094ecf6c9 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1189,13 +1189,6 @@ static void notify_ring(struct intel_engine_cs *engine)
 				rq = i915_request_get(waiter);
 
 			tsk = wait->tsk;
-		} else {
-			if (engine->irq_seqno_barrier &&
-			    i915_seqno_passed(seqno, wait->seqno - 1)) {
-				set_bit(ENGINE_IRQ_BREADCRUMB,
-					&engine->irq_posted);
-				tsk = wait->tsk;
-			}
 		}
 
 		engine->breadcrumbs.irq_count++;
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index c8603a26606e..346418c942a2 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1179,13 +1179,7 @@ restart:
 		set_current_state(state);
 
 wakeup:
-		/*
-		 * Carefully check if the request is complete, giving time
-		 * for the seqno to be visible following the interrupt.
-		 * We also have to check in case we are kicked by the GPU
-		 * reset in order to drop the struct_mutex.
-		 */
-		if (__i915_request_irq_complete(rq))
+		if (i915_request_completed(rq))
 			break;
 
 		/*
diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c
index 447c5256f63a..4ed7105d7ff5 100644
--- a/drivers/gpu/drm/i915/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c
@@ -166,12 +166,6 @@ static void irq_enable(struct intel_engine_cs *engine)
 	 */
 	GEM_BUG_ON(!intel_irqs_enabled(engine->i915));
 
-	/* Enabling the IRQ may miss the generation of the interrupt, but
-	 * we still need to force the barrier before reading the seqno,
-	 * just in case.
-	 */
-	set_bit(ENGINE_IRQ_BREADCRUMB, &engine->irq_posted);
-
 	/* Caller disables interrupts */
 	if (engine->irq_enable) {
 		spin_lock(&engine->i915->irq_lock);
@@ -683,16 +677,6 @@ static int intel_breadcrumbs_signaler(void *arg)
 		}
 
 		if (unlikely(do_schedule)) {
-			/* Before we sleep, check for a missed seqno */
-			if (current->state & TASK_NORMAL &&
-			    !list_empty(&b->signals) &&
-			    engine->irq_seqno_barrier &&
-			    test_and_clear_bit(ENGINE_IRQ_BREADCRUMB,
-					       &engine->irq_posted)) {
-				engine->irq_seqno_barrier(engine);
-				intel_engine_wakeup(engine);
-			}
-
 sleep:
 			if (kthread_should_park())
 				kthread_parkme();
@@ -859,16 +843,6 @@ void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine)
 	else
 		irq_disable(engine);
 
-	/*
-	 * We set the IRQ_BREADCRUMB bit when we enable the irq presuming the
-	 * GPU is active and may have already executed the MI_USER_INTERRUPT
-	 * before the CPU is ready to receive. However, the engine is currently
-	 * idle (we haven't started it yet), there is no possibility for a
-	 * missed interrupt as we enabled the irq and so we can clear the
-	 * immediate wakeup (until a real interrupt arrives for the waiter).
-	 */
-	clear_bit(ENGINE_IRQ_BREADCRUMB, &engine->irq_posted);
-
 	spin_unlock_irqrestore(&b->irq_lock, flags);
 }
 
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 78fc777c4bf4..92ed729db1f2 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -457,7 +457,6 @@ cleanup:
 void intel_engine_write_global_seqno(struct intel_engine_cs *engine, u32 seqno)
 {
 	intel_write_status_page(engine, I915_GEM_HWS_INDEX, seqno);
-	clear_bit(ENGINE_IRQ_BREADCRUMB, &engine->irq_posted);
 
 	/* After manually advancing the seqno, fake the interrupt in case
 	 * there are any waiters for that seqno.
@@ -1536,11 +1535,6 @@ void intel_engine_dump(struct intel_engine_cs *engine,
 	spin_unlock(&b->rb_lock);
 	local_irq_restore(flags);
 
-	drm_printf(m, "IRQ? 0x%lx (breadcrumbs? %s)\n",
-		   engine->irq_posted,
-		   yesno(test_bit(ENGINE_IRQ_BREADCRUMB,
-				  &engine->irq_posted)));
-
 	drm_printf(m, "HWSP:\n");
 	hexdump(m, engine->status_page.page_addr, PAGE_SIZE);
 
diff --git a/drivers/gpu/drm/i915/intel_hangcheck.c b/drivers/gpu/drm/i915/intel_hangcheck.c
index c3f929f59424..51e9efec5116 100644
--- a/drivers/gpu/drm/i915/intel_hangcheck.c
+++ b/drivers/gpu/drm/i915/intel_hangcheck.c
@@ -120,16 +120,6 @@ engine_stuck(struct intel_engine_cs *engine, u64 acthd)
 static void hangcheck_load_sample(struct intel_engine_cs *engine,
 				  struct intel_engine_hangcheck *hc)
 {
-	/* We don't strictly need an irq-barrier here, as we are not
-	 * serving an interrupt request, be paranoid in case the
-	 * barrier has side-effects (such as preventing a broken
-	 * cacheline snoop) and so be sure that we can see the seqno
-	 * advance. If the seqno should stick, due to a stale
-	 * cacheline, we would erroneously declare the GPU hung.
-	 */
-	if (engine->irq_seqno_barrier)
-		engine->irq_seqno_barrier(engine);
-
 	hc->acthd = intel_engine_get_active_head(engine);
 	hc->seqno = intel_engine_get_seqno(engine);
 }
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 13ac01b67ead..f8d3090ed193 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -711,10 +711,6 @@ out:
 static struct i915_request *reset_prepare(struct intel_engine_cs *engine)
 {
 	intel_engine_stop_cs(engine);
-
-	if (engine->irq_seqno_barrier)
-		engine->irq_seqno_barrier(engine);
-
 	return i915_gem_find_active_request(engine);
 }
 
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 99e2cb75d29a..91ef00d34e91 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -365,9 +365,6 @@ struct intel_engine_cs {
 	struct drm_i915_gem_object *default_state;
 	void *pinned_default_state;
 
-	unsigned long irq_posted;
-#define ENGINE_IRQ_BREADCRUMB 0
-
 	/* Rather than have every client wait upon all user interrupts,
 	 * with the herd waking after every interrupt and each doing the
 	 * heavyweight seqno dance, we delegate the task (of being the
@@ -501,13 +498,6 @@ struct intel_engine_cs {
 	 */
 	void		(*cancel_requests)(struct intel_engine_cs *engine);
 
-	/* Some chipsets are not quite as coherent as advertised and need
-	 * an expensive kick to force a true read of the up-to-date seqno.
-	 * However, the up-to-date seqno is not always required and the last
-	 * seen value is good enough. Note that the seqno will always be
-	 * monotonic, even if not coherent.
-	 */
-	void		(*irq_seqno_barrier)(struct intel_engine_cs *engine);
 	void		(*cleanup)(struct intel_engine_cs *engine);
 
 	struct intel_engine_execlists execlists;
-- 
cgit v1.2.3-59-g8ed1b


From d22ba0cb1ffeffa5bf37b7cfab7958706daffee4 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 9 Jan 2019 21:59:32 +0000
Subject: drm/i915: Reduce i915_request_alloc retirement to local context

In the continual quest to reduce the amount of global work required when
submitting requests, replace i915_retire_requests() after allocation
failure to retiring just our ring.

v2: Don't forget the list iteration included an early break, so we would
never throttle on the last request in the ring/timeline.
v3: Use the common ring_retire_requests()

References: 11abf0c5a021 ("drm/i915: Limit the backpressure for i915_request allocation")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190109215932.26454-1-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_request.c | 55 ++++++++++++++++++++++---------------
 1 file changed, 33 insertions(+), 22 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 346418c942a2..f3c3593362ec 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -477,6 +477,38 @@ submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 	return NOTIFY_DONE;
 }
 
+static void ring_retire_requests(struct intel_ring *ring)
+{
+	struct i915_request *rq, *rn;
+
+	list_for_each_entry_safe(rq, rn, &ring->request_list, ring_link) {
+		if (!i915_request_completed(rq))
+			break;
+
+		i915_request_retire(rq);
+	}
+}
+
+static noinline struct i915_request *
+i915_request_alloc_slow(struct intel_context *ce)
+{
+	struct intel_ring *ring = ce->ring;
+	struct i915_request *rq;
+
+	if (list_empty(&ring->request_list))
+		goto out;
+
+	/* Ratelimit ourselves to prevent oom from malicious clients */
+	rq = list_last_entry(&ring->request_list, typeof(*rq), ring_link);
+	cond_synchronize_rcu(rq->rcustate);
+
+	/* Retire our old requests in the hope that we free some */
+	ring_retire_requests(ring);
+
+out:
+	return kmem_cache_alloc(ce->gem_context->i915->requests, GFP_KERNEL);
+}
+
 /**
  * i915_request_alloc - allocate a request structure
  *
@@ -559,15 +591,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	rq = kmem_cache_alloc(i915->requests,
 			      GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
 	if (unlikely(!rq)) {
-		i915_retire_requests(i915);
-
-		/* Ratelimit ourselves to prevent oom from malicious clients */
-		rq = i915_gem_active_raw(&ce->ring->timeline->last_request,
-					 &i915->drm.struct_mutex);
-		if (rq)
-			cond_synchronize_rcu(rq->rcustate);
-
-		rq = kmem_cache_alloc(i915->requests, GFP_KERNEL);
+		rq = i915_request_alloc_slow(ce);
 		if (!rq) {
 			ret = -ENOMEM;
 			goto err_unreserve;
@@ -1218,19 +1242,6 @@ complete:
 	return timeout;
 }
 
-static void ring_retire_requests(struct intel_ring *ring)
-{
-	struct i915_request *request, *next;
-
-	list_for_each_entry_safe(request, next,
-				 &ring->request_list, ring_link) {
-		if (!i915_request_completed(request))
-			break;
-
-		i915_request_retire(request);
-	}
-}
-
 void i915_retire_requests(struct drm_i915_private *i915)
 {
 	struct intel_ring *ring, *tmp;
-- 
cgit v1.2.3-59-g8ed1b


From 9f58892ea9962002399132fd3f40c6a273f8d9e1 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 16 Jan 2019 15:33:04 +0000
Subject: drm/i915: Pull all the reset functionality together into i915_reset.c

Currently the code to reset the GPU and our state is spread widely
across a few files. Pull the logic together into a common file.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190116153304.787-1-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/Makefile                      |    3 +-
 drivers/gpu/drm/i915/i915_debugfs.c                |    2 +
 drivers/gpu/drm/i915/i915_drv.c                    |  206 +--
 drivers/gpu/drm/i915/i915_drv.h                    |   33 +-
 drivers/gpu/drm/i915/i915_gem.c                    |  446 +------
 drivers/gpu/drm/i915/i915_gem_gtt.c                |    1 +
 drivers/gpu/drm/i915/i915_irq.c                    |  238 ----
 drivers/gpu/drm/i915/i915_request.c                |    1 +
 drivers/gpu/drm/i915/i915_reset.c                  | 1389 ++++++++++++++++++++
 drivers/gpu/drm/i915/i915_reset.h                  |   56 +
 drivers/gpu/drm/i915/intel_display.c               |   15 +-
 drivers/gpu/drm/i915/intel_engine_cs.c             |    1 +
 drivers/gpu/drm/i915/intel_guc.h                   |    3 +
 drivers/gpu/drm/i915/intel_hangcheck.c             |    1 +
 drivers/gpu/drm/i915/intel_uc.c                    |    1 +
 drivers/gpu/drm/i915/intel_uncore.c                |  556 --------
 drivers/gpu/drm/i915/selftests/intel_lrc.c         |    2 +
 drivers/gpu/drm/i915/selftests/intel_workarounds.c |    1 +
 18 files changed, 1483 insertions(+), 1472 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/i915_reset.c
 create mode 100644 drivers/gpu/drm/i915/i915_reset.h

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index c34bee16730d..611115ed00db 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -40,9 +40,10 @@ i915-y := i915_drv.o \
 	  i915_mm.o \
 	  i915_params.o \
 	  i915_pci.o \
+	  i915_reset.o \
 	  i915_suspend.o \
-	  i915_syncmap.o \
 	  i915_sw_fence.o \
+	  i915_syncmap.o \
 	  i915_sysfs.o \
 	  intel_csr.o \
 	  intel_device_info.o \
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 24e2d52efa8e..ece72e0e41bc 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -32,6 +32,8 @@
 #include "intel_drv.h"
 #include "intel_guc_submission.h"
 
+#include "i915_reset.h"
+
 static inline struct drm_i915_private *node_to_i915(struct drm_info_node *node)
 {
 	return to_i915(node->minor->dev);
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index dafbbfadd1ad..f462a4d28af4 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -48,6 +48,7 @@
 #include "i915_drv.h"
 #include "i915_trace.h"
 #include "i915_pmu.h"
+#include "i915_reset.h"
 #include "i915_query.h"
 #include "i915_vgpu.h"
 #include "intel_drv.h"
@@ -2205,211 +2206,6 @@ static int i915_resume_switcheroo(struct drm_device *dev)
 	return i915_drm_resume(dev);
 }
 
-/**
- * i915_reset - reset chip after a hang
- * @i915: #drm_i915_private to reset
- * @stalled_mask: mask of the stalled engines with the guilty requests
- * @reason: user error message for why we are resetting
- *
- * Reset the chip.  Useful if a hang is detected. Marks the device as wedged
- * on failure.
- *
- * Caller must hold the struct_mutex.
- *
- * Procedure is fairly simple:
- *   - reset the chip using the reset reg
- *   - re-init context state
- *   - re-init hardware status page
- *   - re-init ring buffer
- *   - re-init interrupt state
- *   - re-init display
- */
-void i915_reset(struct drm_i915_private *i915,
-		unsigned int stalled_mask,
-		const char *reason)
-{
-	struct i915_gpu_error *error = &i915->gpu_error;
-	int ret;
-	int i;
-
-	GEM_TRACE("flags=%lx\n", error->flags);
-
-	might_sleep();
-	lockdep_assert_held(&i915->drm.struct_mutex);
-	assert_rpm_wakelock_held(i915);
-	GEM_BUG_ON(!test_bit(I915_RESET_BACKOFF, &error->flags));
-
-	if (!test_bit(I915_RESET_HANDOFF, &error->flags))
-		return;
-
-	/* Clear any previous failed attempts at recovery. Time to try again. */
-	if (!i915_gem_unset_wedged(i915))
-		goto wakeup;
-
-	if (reason)
-		dev_notice(i915->drm.dev, "Resetting chip for %s\n", reason);
-	error->reset_count++;
-
-	ret = i915_gem_reset_prepare(i915);
-	if (ret) {
-		dev_err(i915->drm.dev, "GPU recovery failed\n");
-		goto taint;
-	}
-
-	if (!intel_has_gpu_reset(i915)) {
-		if (i915_modparams.reset)
-			dev_err(i915->drm.dev, "GPU reset not supported\n");
-		else
-			DRM_DEBUG_DRIVER("GPU reset disabled\n");
-		goto error;
-	}
-
-	for (i = 0; i < 3; i++) {
-		ret = intel_gpu_reset(i915, ALL_ENGINES);
-		if (ret == 0)
-			break;
-
-		msleep(100);
-	}
-	if (ret) {
-		dev_err(i915->drm.dev, "Failed to reset chip\n");
-		goto taint;
-	}
-
-	/* Ok, now get things going again... */
-
-	/*
-	 * Everything depends on having the GTT running, so we need to start
-	 * there.
-	 */
-	ret = i915_ggtt_enable_hw(i915);
-	if (ret) {
-		DRM_ERROR("Failed to re-enable GGTT following reset (%d)\n",
-			  ret);
-		goto error;
-	}
-
-	i915_gem_reset(i915, stalled_mask);
-	intel_overlay_reset(i915);
-
-	/*
-	 * Next we need to restore the context, but we don't use those
-	 * yet either...
-	 *
-	 * Ring buffer needs to be re-initialized in the KMS case, or if X
-	 * was running at the time of the reset (i.e. we weren't VT
-	 * switched away).
-	 */
-	ret = i915_gem_init_hw(i915);
-	if (ret) {
-		DRM_ERROR("Failed to initialise HW following reset (%d)\n",
-			  ret);
-		goto error;
-	}
-
-	i915_queue_hangcheck(i915);
-
-finish:
-	i915_gem_reset_finish(i915);
-wakeup:
-	clear_bit(I915_RESET_HANDOFF, &error->flags);
-	wake_up_bit(&error->flags, I915_RESET_HANDOFF);
-	return;
-
-taint:
-	/*
-	 * History tells us that if we cannot reset the GPU now, we
-	 * never will. This then impacts everything that is run
-	 * subsequently. On failing the reset, we mark the driver
-	 * as wedged, preventing further execution on the GPU.
-	 * We also want to go one step further and add a taint to the
-	 * kernel so that any subsequent faults can be traced back to
-	 * this failure. This is important for CI, where if the
-	 * GPU/driver fails we would like to reboot and restart testing
-	 * rather than continue on into oblivion. For everyone else,
-	 * the system should still plod along, but they have been warned!
-	 */
-	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
-error:
-	i915_gem_set_wedged(i915);
-	i915_retire_requests(i915);
-	goto finish;
-}
-
-static inline int intel_gt_reset_engine(struct drm_i915_private *dev_priv,
-					struct intel_engine_cs *engine)
-{
-	return intel_gpu_reset(dev_priv, intel_engine_flag(engine));
-}
-
-/**
- * i915_reset_engine - reset GPU engine to recover from a hang
- * @engine: engine to reset
- * @msg: reason for GPU reset; or NULL for no dev_notice()
- *
- * Reset a specific GPU engine. Useful if a hang is detected.
- * Returns zero on successful reset or otherwise an error code.
- *
- * Procedure is:
- *  - identifies the request that caused the hang and it is dropped
- *  - reset engine (which will force the engine to idle)
- *  - re-init/configure engine
- */
-int i915_reset_engine(struct intel_engine_cs *engine, const char *msg)
-{
-	struct i915_gpu_error *error = &engine->i915->gpu_error;
-	struct i915_request *active_request;
-	int ret;
-
-	GEM_TRACE("%s flags=%lx\n", engine->name, error->flags);
-	GEM_BUG_ON(!test_bit(I915_RESET_ENGINE + engine->id, &error->flags));
-
-	active_request = i915_gem_reset_prepare_engine(engine);
-	if (IS_ERR_OR_NULL(active_request)) {
-		/* Either the previous reset failed, or we pardon the reset. */
-		ret = PTR_ERR(active_request);
-		goto out;
-	}
-
-	if (msg)
-		dev_notice(engine->i915->drm.dev,
-			   "Resetting %s for %s\n", engine->name, msg);
-	error->reset_engine_count[engine->id]++;
-
-	if (!engine->i915->guc.execbuf_client)
-		ret = intel_gt_reset_engine(engine->i915, engine);
-	else
-		ret = intel_guc_reset_engine(&engine->i915->guc, engine);
-	if (ret) {
-		/* If we fail here, we expect to fallback to a global reset */
-		DRM_DEBUG_DRIVER("%sFailed to reset %s, ret=%d\n",
-				 engine->i915->guc.execbuf_client ? "GuC " : "",
-				 engine->name, ret);
-		goto out;
-	}
-
-	/*
-	 * The request that caused the hang is stuck on elsp, we know the
-	 * active request and can drop it, adjust head to skip the offending
-	 * request to resume executing remaining requests in the queue.
-	 */
-	i915_gem_reset_engine(engine, active_request, true);
-
-	/*
-	 * The engine and its registers (and workarounds in case of render)
-	 * have been reset to their default values. Follow the init_ring
-	 * process to program RING_MODE, HWSP and re-enable submission.
-	 */
-	ret = engine->init_hw(engine);
-	if (ret)
-		goto out;
-
-out:
-	intel_engine_cancel_stop_cs(engine);
-	i915_gem_reset_finish_engine(engine);
-	return ret;
-}
-
 static int i915_pm_prepare(struct device *kdev)
 {
 	struct pci_dev *pdev = to_pci_dev(kdev);
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index da055a86db4d..310d9e1e1620 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2615,19 +2615,7 @@ extern const struct dev_pm_ops i915_pm_ops;
 extern int i915_driver_load(struct pci_dev *pdev,
 			    const struct pci_device_id *ent);
 extern void i915_driver_unload(struct drm_device *dev);
-extern int intel_gpu_reset(struct drm_i915_private *dev_priv, u32 engine_mask);
-extern bool intel_has_gpu_reset(struct drm_i915_private *dev_priv);
-
-extern void i915_reset(struct drm_i915_private *i915,
-		       unsigned int stalled_mask,
-		       const char *reason);
-extern int i915_reset_engine(struct intel_engine_cs *engine,
-			     const char *reason);
-
-extern bool intel_has_reset_engine(struct drm_i915_private *dev_priv);
-extern int intel_reset_guc(struct drm_i915_private *dev_priv);
-extern int intel_guc_reset_engine(struct intel_guc *guc,
-				  struct intel_engine_cs *engine);
+
 extern void intel_engine_init_hangcheck(struct intel_engine_cs *engine);
 extern void intel_hangcheck_init(struct drm_i915_private *dev_priv);
 extern unsigned long i915_chipset_val(struct drm_i915_private *dev_priv);
@@ -2670,20 +2658,11 @@ static inline void i915_queue_hangcheck(struct drm_i915_private *dev_priv)
 			   &dev_priv->gpu_error.hangcheck_work, delay);
 }
 
-__printf(4, 5)
-void i915_handle_error(struct drm_i915_private *dev_priv,
-		       u32 engine_mask,
-		       unsigned long flags,
-		       const char *fmt, ...);
-#define I915_ERROR_CAPTURE BIT(0)
-
 extern void intel_irq_init(struct drm_i915_private *dev_priv);
 extern void intel_irq_fini(struct drm_i915_private *dev_priv);
 int intel_irq_install(struct drm_i915_private *dev_priv);
 void intel_irq_uninstall(struct drm_i915_private *dev_priv);
 
-void i915_clear_error_registers(struct drm_i915_private *dev_priv);
-
 static inline bool intel_gvt_active(struct drm_i915_private *dev_priv)
 {
 	return dev_priv->gvt;
@@ -3048,18 +3027,8 @@ static inline u32 i915_reset_engine_count(struct i915_gpu_error *error,
 	return READ_ONCE(error->reset_engine_count[engine->id]);
 }
 
-struct i915_request *
-i915_gem_reset_prepare_engine(struct intel_engine_cs *engine);
-int i915_gem_reset_prepare(struct drm_i915_private *dev_priv);
-void i915_gem_reset(struct drm_i915_private *dev_priv,
-		    unsigned int stalled_mask);
-void i915_gem_reset_finish_engine(struct intel_engine_cs *engine);
-void i915_gem_reset_finish(struct drm_i915_private *dev_priv);
 void i915_gem_set_wedged(struct drm_i915_private *dev_priv);
 bool i915_gem_unset_wedged(struct drm_i915_private *dev_priv);
-void i915_gem_reset_engine(struct intel_engine_cs *engine,
-			   struct i915_request *request,
-			   bool stalled);
 
 void i915_gem_init_mmio(struct drm_i915_private *i915);
 int __must_check i915_gem_init(struct drm_i915_private *dev_priv);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 5c6089777fde..7185a5b4a5ca 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -27,15 +27,6 @@
 
 #include <drm/drm_vma_manager.h>
 #include <drm/i915_drm.h>
-#include "i915_drv.h"
-#include "i915_gem_clflush.h"
-#include "i915_vgpu.h"
-#include "i915_trace.h"
-#include "intel_drv.h"
-#include "intel_frontbuffer.h"
-#include "intel_mocs.h"
-#include "intel_workarounds.h"
-#include "i915_gemfs.h"
 #include <linux/dma-fence-array.h>
 #include <linux/kthread.h>
 #include <linux/reservation.h>
@@ -46,6 +37,18 @@
 #include <linux/pci.h>
 #include <linux/dma-buf.h>
 
+#include "i915_drv.h"
+#include "i915_gem_clflush.h"
+#include "i915_gemfs.h"
+#include "i915_reset.h"
+#include "i915_trace.h"
+#include "i915_vgpu.h"
+
+#include "intel_drv.h"
+#include "intel_frontbuffer.h"
+#include "intel_mocs.h"
+#include "intel_workarounds.h"
+
 static void i915_gem_flush_free_objects(struct drm_i915_private *i915);
 
 static bool cpu_write_needs_clflush(struct drm_i915_gem_object *obj)
@@ -2873,61 +2876,6 @@ i915_gem_object_pwrite_gtt(struct drm_i915_gem_object *obj,
 	return 0;
 }
 
-static void i915_gem_client_mark_guilty(struct drm_i915_file_private *file_priv,
-					const struct i915_gem_context *ctx)
-{
-	unsigned int score;
-	unsigned long prev_hang;
-
-	if (i915_gem_context_is_banned(ctx))
-		score = I915_CLIENT_SCORE_CONTEXT_BAN;
-	else
-		score = 0;
-
-	prev_hang = xchg(&file_priv->hang_timestamp, jiffies);
-	if (time_before(jiffies, prev_hang + I915_CLIENT_FAST_HANG_JIFFIES))
-		score += I915_CLIENT_SCORE_HANG_FAST;
-
-	if (score) {
-		atomic_add(score, &file_priv->ban_score);
-
-		DRM_DEBUG_DRIVER("client %s: gained %u ban score, now %u\n",
-				 ctx->name, score,
-				 atomic_read(&file_priv->ban_score));
-	}
-}
-
-static void i915_gem_context_mark_guilty(struct i915_gem_context *ctx)
-{
-	unsigned int score;
-	bool banned, bannable;
-
-	atomic_inc(&ctx->guilty_count);
-
-	bannable = i915_gem_context_is_bannable(ctx);
-	score = atomic_add_return(CONTEXT_SCORE_GUILTY, &ctx->ban_score);
-	banned = score >= CONTEXT_SCORE_BAN_THRESHOLD;
-
-	/* Cool contexts don't accumulate client ban score */
-	if (!bannable)
-		return;
-
-	if (banned) {
-		DRM_DEBUG_DRIVER("context %s: guilty %d, score %u, banned\n",
-				 ctx->name, atomic_read(&ctx->guilty_count),
-				 score);
-		i915_gem_context_set_banned(ctx);
-	}
-
-	if (!IS_ERR_OR_NULL(ctx->file_priv))
-		i915_gem_client_mark_guilty(ctx->file_priv, ctx);
-}
-
-static void i915_gem_context_mark_innocent(struct i915_gem_context *ctx)
-{
-	atomic_inc(&ctx->active_count);
-}
-
 struct i915_request *
 i915_gem_find_active_request(struct intel_engine_cs *engine)
 {
@@ -2958,376 +2906,6 @@ i915_gem_find_active_request(struct intel_engine_cs *engine)
 	return active;
 }
 
-/*
- * Ensure irq handler finishes, and not run again.
- * Also return the active request so that we only search for it once.
- */
-struct i915_request *
-i915_gem_reset_prepare_engine(struct intel_engine_cs *engine)
-{
-	struct i915_request *request;
-
-	/*
-	 * During the reset sequence, we must prevent the engine from
-	 * entering RC6. As the context state is undefined until we restart
-	 * the engine, if it does enter RC6 during the reset, the state
-	 * written to the powercontext is undefined and so we may lose
-	 * GPU state upon resume, i.e. fail to restart after a reset.
-	 */
-	intel_uncore_forcewake_get(engine->i915, FORCEWAKE_ALL);
-
-	request = engine->reset.prepare(engine);
-	if (request && request->fence.error == -EIO)
-		request = ERR_PTR(-EIO); /* Previous reset failed! */
-
-	return request;
-}
-
-int i915_gem_reset_prepare(struct drm_i915_private *dev_priv)
-{
-	struct intel_engine_cs *engine;
-	struct i915_request *request;
-	enum intel_engine_id id;
-	int err = 0;
-
-	for_each_engine(engine, dev_priv, id) {
-		request = i915_gem_reset_prepare_engine(engine);
-		if (IS_ERR(request)) {
-			err = PTR_ERR(request);
-			continue;
-		}
-
-		engine->hangcheck.active_request = request;
-	}
-
-	i915_gem_revoke_fences(dev_priv);
-	intel_uc_sanitize(dev_priv);
-
-	return err;
-}
-
-static void engine_skip_context(struct i915_request *request)
-{
-	struct intel_engine_cs *engine = request->engine;
-	struct i915_gem_context *hung_ctx = request->gem_context;
-	struct i915_timeline *timeline = request->timeline;
-	unsigned long flags;
-
-	GEM_BUG_ON(timeline == &engine->timeline);
-
-	spin_lock_irqsave(&engine->timeline.lock, flags);
-	spin_lock(&timeline->lock);
-
-	list_for_each_entry_continue(request, &engine->timeline.requests, link)
-		if (request->gem_context == hung_ctx)
-			i915_request_skip(request, -EIO);
-
-	list_for_each_entry(request, &timeline->requests, link)
-		i915_request_skip(request, -EIO);
-
-	spin_unlock(&timeline->lock);
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
-}
-
-/* Returns the request if it was guilty of the hang */
-static struct i915_request *
-i915_gem_reset_request(struct intel_engine_cs *engine,
-		       struct i915_request *request,
-		       bool stalled)
-{
-	/* The guilty request will get skipped on a hung engine.
-	 *
-	 * Users of client default contexts do not rely on logical
-	 * state preserved between batches so it is safe to execute
-	 * queued requests following the hang. Non default contexts
-	 * rely on preserved state, so skipping a batch loses the
-	 * evolution of the state and it needs to be considered corrupted.
-	 * Executing more queued batches on top of corrupted state is
-	 * risky. But we take the risk by trying to advance through
-	 * the queued requests in order to make the client behaviour
-	 * more predictable around resets, by not throwing away random
-	 * amount of batches it has prepared for execution. Sophisticated
-	 * clients can use gem_reset_stats_ioctl and dma fence status
-	 * (exported via sync_file info ioctl on explicit fences) to observe
-	 * when it loses the context state and should rebuild accordingly.
-	 *
-	 * The context ban, and ultimately the client ban, mechanism are safety
-	 * valves if client submission ends up resulting in nothing more than
-	 * subsequent hangs.
-	 */
-
-	if (i915_request_completed(request)) {
-		GEM_TRACE("%s pardoned global=%d (fence %llx:%d), current %d\n",
-			  engine->name, request->global_seqno,
-			  request->fence.context, request->fence.seqno,
-			  intel_engine_get_seqno(engine));
-		stalled = false;
-	}
-
-	if (stalled) {
-		i915_gem_context_mark_guilty(request->gem_context);
-		i915_request_skip(request, -EIO);
-
-		/* If this context is now banned, skip all pending requests. */
-		if (i915_gem_context_is_banned(request->gem_context))
-			engine_skip_context(request);
-	} else {
-		/*
-		 * Since this is not the hung engine, it may have advanced
-		 * since the hang declaration. Double check by refinding
-		 * the active request at the time of the reset.
-		 */
-		request = i915_gem_find_active_request(engine);
-		if (request) {
-			unsigned long flags;
-
-			i915_gem_context_mark_innocent(request->gem_context);
-			dma_fence_set_error(&request->fence, -EAGAIN);
-
-			/* Rewind the engine to replay the incomplete rq */
-			spin_lock_irqsave(&engine->timeline.lock, flags);
-			request = list_prev_entry(request, link);
-			if (&request->link == &engine->timeline.requests)
-				request = NULL;
-			spin_unlock_irqrestore(&engine->timeline.lock, flags);
-		}
-	}
-
-	return request;
-}
-
-void i915_gem_reset_engine(struct intel_engine_cs *engine,
-			   struct i915_request *request,
-			   bool stalled)
-{
-	if (request)
-		request = i915_gem_reset_request(engine, request, stalled);
-
-	/* Setup the CS to resume from the breadcrumb of the hung request */
-	engine->reset.reset(engine, request);
-}
-
-void i915_gem_reset(struct drm_i915_private *dev_priv,
-		    unsigned int stalled_mask)
-{
-	struct intel_engine_cs *engine;
-	enum intel_engine_id id;
-
-	lockdep_assert_held(&dev_priv->drm.struct_mutex);
-
-	i915_retire_requests(dev_priv);
-
-	for_each_engine(engine, dev_priv, id) {
-		struct intel_context *ce;
-
-		i915_gem_reset_engine(engine,
-				      engine->hangcheck.active_request,
-				      stalled_mask & ENGINE_MASK(id));
-		ce = fetch_and_zero(&engine->last_retired_context);
-		if (ce)
-			intel_context_unpin(ce);
-
-		/*
-		 * Ostensibily, we always want a context loaded for powersaving,
-		 * so if the engine is idle after the reset, send a request
-		 * to load our scratch kernel_context.
-		 *
-		 * More mysteriously, if we leave the engine idle after a reset,
-		 * the next userspace batch may hang, with what appears to be
-		 * an incoherent read by the CS (presumably stale TLB). An
-		 * empty request appears sufficient to paper over the glitch.
-		 */
-		if (intel_engine_is_idle(engine)) {
-			struct i915_request *rq;
-
-			rq = i915_request_alloc(engine,
-						dev_priv->kernel_context);
-			if (!IS_ERR(rq))
-				i915_request_add(rq);
-		}
-	}
-
-	i915_gem_restore_fences(dev_priv);
-}
-
-void i915_gem_reset_finish_engine(struct intel_engine_cs *engine)
-{
-	engine->reset.finish(engine);
-
-	intel_uncore_forcewake_put(engine->i915, FORCEWAKE_ALL);
-}
-
-void i915_gem_reset_finish(struct drm_i915_private *dev_priv)
-{
-	struct intel_engine_cs *engine;
-	enum intel_engine_id id;
-
-	lockdep_assert_held(&dev_priv->drm.struct_mutex);
-
-	for_each_engine(engine, dev_priv, id) {
-		engine->hangcheck.active_request = NULL;
-		i915_gem_reset_finish_engine(engine);
-	}
-}
-
-static void nop_submit_request(struct i915_request *request)
-{
-	unsigned long flags;
-
-	GEM_TRACE("%s fence %llx:%d -> -EIO\n",
-		  request->engine->name,
-		  request->fence.context, request->fence.seqno);
-	dma_fence_set_error(&request->fence, -EIO);
-
-	spin_lock_irqsave(&request->engine->timeline.lock, flags);
-	__i915_request_submit(request);
-	intel_engine_write_global_seqno(request->engine, request->global_seqno);
-	spin_unlock_irqrestore(&request->engine->timeline.lock, flags);
-}
-
-void i915_gem_set_wedged(struct drm_i915_private *i915)
-{
-	struct i915_gpu_error *error = &i915->gpu_error;
-	struct intel_engine_cs *engine;
-	enum intel_engine_id id;
-
-	mutex_lock(&error->wedge_mutex);
-	if (test_bit(I915_WEDGED, &error->flags)) {
-		mutex_unlock(&error->wedge_mutex);
-		return;
-	}
-
-	if (GEM_SHOW_DEBUG() && !intel_engines_are_idle(i915)) {
-		struct drm_printer p = drm_debug_printer(__func__);
-
-		for_each_engine(engine, i915, id)
-			intel_engine_dump(engine, &p, "%s\n", engine->name);
-	}
-
-	GEM_TRACE("start\n");
-
-	/*
-	 * First, stop submission to hw, but do not yet complete requests by
-	 * rolling the global seqno forward (since this would complete requests
-	 * for which we haven't set the fence error to EIO yet).
-	 */
-	for_each_engine(engine, i915, id)
-		i915_gem_reset_prepare_engine(engine);
-
-	/* Even if the GPU reset fails, it should still stop the engines */
-	if (INTEL_GEN(i915) >= 5)
-		intel_gpu_reset(i915, ALL_ENGINES);
-
-	for_each_engine(engine, i915, id) {
-		engine->submit_request = nop_submit_request;
-		engine->schedule = NULL;
-	}
-	i915->caps.scheduler = 0;
-
-	/*
-	 * Make sure no request can slip through without getting completed by
-	 * either this call here to intel_engine_write_global_seqno, or the one
-	 * in nop_submit_request.
-	 */
-	synchronize_rcu();
-
-	/* Mark all executing requests as skipped */
-	for_each_engine(engine, i915, id)
-		engine->cancel_requests(engine);
-
-	for_each_engine(engine, i915, id) {
-		i915_gem_reset_finish_engine(engine);
-		intel_engine_wakeup(engine);
-	}
-
-	smp_mb__before_atomic();
-	set_bit(I915_WEDGED, &error->flags);
-
-	GEM_TRACE("end\n");
-	mutex_unlock(&error->wedge_mutex);
-
-	wake_up_all(&error->reset_queue);
-}
-
-bool i915_gem_unset_wedged(struct drm_i915_private *i915)
-{
-	struct i915_gpu_error *error = &i915->gpu_error;
-	struct i915_timeline *tl;
-	bool ret = false;
-
-	lockdep_assert_held(&i915->drm.struct_mutex);
-
-	if (!test_bit(I915_WEDGED, &error->flags))
-		return true;
-
-	if (!i915->gt.scratch) /* Never full initialised, recovery impossible */
-		return false;
-
-	mutex_lock(&error->wedge_mutex);
-
-	GEM_TRACE("start\n");
-
-	/*
-	 * Before unwedging, make sure that all pending operations
-	 * are flushed and errored out - we may have requests waiting upon
-	 * third party fences. We marked all inflight requests as EIO, and
-	 * every execbuf since returned EIO, for consistency we want all
-	 * the currently pending requests to also be marked as EIO, which
-	 * is done inside our nop_submit_request - and so we must wait.
-	 *
-	 * No more can be submitted until we reset the wedged bit.
-	 */
-	list_for_each_entry(tl, &i915->gt.timelines, link) {
-		struct i915_request *rq;
-
-		rq = i915_gem_active_peek(&tl->last_request,
-					  &i915->drm.struct_mutex);
-		if (!rq)
-			continue;
-
-		/*
-		 * We can't use our normal waiter as we want to
-		 * avoid recursively trying to handle the current
-		 * reset. The basic dma_fence_default_wait() installs
-		 * a callback for dma_fence_signal(), which is
-		 * triggered by our nop handler (indirectly, the
-		 * callback enables the signaler thread which is
-		 * woken by the nop_submit_request() advancing the seqno
-		 * and when the seqno passes the fence, the signaler
-		 * then signals the fence waking us up).
-		 */
-		if (dma_fence_default_wait(&rq->fence, true,
-					   MAX_SCHEDULE_TIMEOUT) < 0)
-			goto unlock;
-	}
-	i915_retire_requests(i915);
-	GEM_BUG_ON(i915->gt.active_requests);
-
-	intel_engines_sanitize(i915, false);
-
-	/*
-	 * Undo nop_submit_request. We prevent all new i915 requests from
-	 * being queued (by disallowing execbuf whilst wedged) so having
-	 * waited for all active requests above, we know the system is idle
-	 * and do not have to worry about a thread being inside
-	 * engine->submit_request() as we swap over. So unlike installing
-	 * the nop_submit_request on reset, we can do this from normal
-	 * context and do not require stop_machine().
-	 */
-	intel_engines_reset_default_submission(i915);
-	i915_gem_contexts_lost(i915);
-
-	GEM_TRACE("end\n");
-
-	smp_mb__before_atomic(); /* complete takeover before enabling execbuf */
-	clear_bit(I915_WEDGED, &i915->gpu_error.flags);
-	ret = true;
-unlock:
-	mutex_unlock(&i915->gpu_error.wedge_mutex);
-
-	return ret;
-}
-
 static void
 i915_gem_retire_work_handler(struct work_struct *work)
 {
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index d24628f184e4..9081e3bc5a59 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -37,6 +37,7 @@
 
 #include "i915_drv.h"
 #include "i915_vgpu.h"
+#include "i915_reset.h"
 #include "i915_trace.h"
 #include "intel_drv.h"
 #include "intel_frontbuffer.h"
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 94187e68d39a..1c6cf024a509 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2930,46 +2930,6 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
-struct wedge_me {
-	struct delayed_work work;
-	struct drm_i915_private *i915;
-	const char *name;
-};
-
-static void wedge_me(struct work_struct *work)
-{
-	struct wedge_me *w = container_of(work, typeof(*w), work.work);
-
-	dev_err(w->i915->drm.dev,
-		"%s timed out, cancelling all in-flight rendering.\n",
-		w->name);
-	i915_gem_set_wedged(w->i915);
-}
-
-static void __init_wedge(struct wedge_me *w,
-			 struct drm_i915_private *i915,
-			 long timeout,
-			 const char *name)
-{
-	w->i915 = i915;
-	w->name = name;
-
-	INIT_DELAYED_WORK_ONSTACK(&w->work, wedge_me);
-	schedule_delayed_work(&w->work, timeout);
-}
-
-static void __fini_wedge(struct wedge_me *w)
-{
-	cancel_delayed_work_sync(&w->work);
-	destroy_delayed_work_on_stack(&w->work);
-	w->i915 = NULL;
-}
-
-#define i915_wedge_on_timeout(W, DEV, TIMEOUT)				\
-	for (__init_wedge((W), (DEV), (TIMEOUT), __func__);		\
-	     (W)->i915;							\
-	     __fini_wedge((W)))
-
 static u32
 gen11_gt_engine_identity(struct drm_i915_private * const i915,
 			 const unsigned int bank, const unsigned int bit)
@@ -3180,204 +3140,6 @@ static irqreturn_t gen11_irq_handler(int irq, void *arg)
 	return IRQ_HANDLED;
 }
 
-static void i915_reset_device(struct drm_i915_private *dev_priv,
-			      u32 engine_mask,
-			      const char *reason)
-{
-	struct i915_gpu_error *error = &dev_priv->gpu_error;
-	struct kobject *kobj = &dev_priv->drm.primary->kdev->kobj;
-	char *error_event[] = { I915_ERROR_UEVENT "=1", NULL };
-	char *reset_event[] = { I915_RESET_UEVENT "=1", NULL };
-	char *reset_done_event[] = { I915_ERROR_UEVENT "=0", NULL };
-	struct wedge_me w;
-
-	kobject_uevent_env(kobj, KOBJ_CHANGE, error_event);
-
-	DRM_DEBUG_DRIVER("resetting chip\n");
-	kobject_uevent_env(kobj, KOBJ_CHANGE, reset_event);
-
-	/* Use a watchdog to ensure that our reset completes */
-	i915_wedge_on_timeout(&w, dev_priv, 5*HZ) {
-		intel_prepare_reset(dev_priv);
-
-		error->reason = reason;
-		error->stalled_mask = engine_mask;
-
-		/* Signal that locked waiters should reset the GPU */
-		smp_mb__before_atomic();
-		set_bit(I915_RESET_HANDOFF, &error->flags);
-		wake_up_all(&error->wait_queue);
-
-		/* Wait for anyone holding the lock to wakeup, without
-		 * blocking indefinitely on struct_mutex.
-		 */
-		do {
-			if (mutex_trylock(&dev_priv->drm.struct_mutex)) {
-				i915_reset(dev_priv, engine_mask, reason);
-				mutex_unlock(&dev_priv->drm.struct_mutex);
-			}
-		} while (wait_on_bit_timeout(&error->flags,
-					     I915_RESET_HANDOFF,
-					     TASK_UNINTERRUPTIBLE,
-					     1));
-
-		error->stalled_mask = 0;
-		error->reason = NULL;
-
-		intel_finish_reset(dev_priv);
-	}
-
-	if (!test_bit(I915_WEDGED, &error->flags))
-		kobject_uevent_env(kobj, KOBJ_CHANGE, reset_done_event);
-}
-
-void i915_clear_error_registers(struct drm_i915_private *dev_priv)
-{
-	u32 eir;
-
-	if (!IS_GEN(dev_priv, 2))
-		I915_WRITE(PGTBL_ER, I915_READ(PGTBL_ER));
-
-	if (INTEL_GEN(dev_priv) < 4)
-		I915_WRITE(IPEIR, I915_READ(IPEIR));
-	else
-		I915_WRITE(IPEIR_I965, I915_READ(IPEIR_I965));
-
-	I915_WRITE(EIR, I915_READ(EIR));
-	eir = I915_READ(EIR);
-	if (eir) {
-		/*
-		 * some errors might have become stuck,
-		 * mask them.
-		 */
-		DRM_DEBUG_DRIVER("EIR stuck: 0x%08x, masking\n", eir);
-		I915_WRITE(EMR, I915_READ(EMR) | eir);
-		I915_WRITE(IIR, I915_MASTER_ERROR_INTERRUPT);
-	}
-
-	if (INTEL_GEN(dev_priv) >= 8) {
-		I915_WRITE(GEN8_RING_FAULT_REG,
-			   I915_READ(GEN8_RING_FAULT_REG) & ~RING_FAULT_VALID);
-		POSTING_READ(GEN8_RING_FAULT_REG);
-	} else if (INTEL_GEN(dev_priv) >= 6) {
-		struct intel_engine_cs *engine;
-		enum intel_engine_id id;
-
-		for_each_engine(engine, dev_priv, id) {
-			I915_WRITE(RING_FAULT_REG(engine),
-				   I915_READ(RING_FAULT_REG(engine)) &
-				   ~RING_FAULT_VALID);
-		}
-		POSTING_READ(RING_FAULT_REG(dev_priv->engine[RCS]));
-	}
-}
-
-/**
- * i915_handle_error - handle a gpu error
- * @dev_priv: i915 device private
- * @engine_mask: mask representing engines that are hung
- * @flags: control flags
- * @fmt: Error message format string
- *
- * Do some basic checking of register state at error time and
- * dump it to the syslog.  Also call i915_capture_error_state() to make
- * sure we get a record and make it available in debugfs.  Fire a uevent
- * so userspace knows something bad happened (should trigger collection
- * of a ring dump etc.).
- */
-void i915_handle_error(struct drm_i915_private *dev_priv,
-		       u32 engine_mask,
-		       unsigned long flags,
-		       const char *fmt, ...)
-{
-	struct intel_engine_cs *engine;
-	intel_wakeref_t wakeref;
-	unsigned int tmp;
-	char error_msg[80];
-	char *msg = NULL;
-
-	if (fmt) {
-		va_list args;
-
-		va_start(args, fmt);
-		vscnprintf(error_msg, sizeof(error_msg), fmt, args);
-		va_end(args);
-
-		msg = error_msg;
-	}
-
-	/*
-	 * In most cases it's guaranteed that we get here with an RPM
-	 * reference held, for example because there is a pending GPU
-	 * request that won't finish until the reset is done. This
-	 * isn't the case at least when we get here by doing a
-	 * simulated reset via debugfs, so get an RPM reference.
-	 */
-	wakeref = intel_runtime_pm_get(dev_priv);
-
-	engine_mask &= INTEL_INFO(dev_priv)->ring_mask;
-
-	if (flags & I915_ERROR_CAPTURE) {
-		i915_capture_error_state(dev_priv, engine_mask, msg);
-		i915_clear_error_registers(dev_priv);
-	}
-
-	/*
-	 * Try engine reset when available. We fall back to full reset if
-	 * single reset fails.
-	 */
-	if (intel_has_reset_engine(dev_priv) &&
-	    !i915_terminally_wedged(&dev_priv->gpu_error)) {
-		for_each_engine_masked(engine, dev_priv, engine_mask, tmp) {
-			BUILD_BUG_ON(I915_RESET_MODESET >= I915_RESET_ENGINE);
-			if (test_and_set_bit(I915_RESET_ENGINE + engine->id,
-					     &dev_priv->gpu_error.flags))
-				continue;
-
-			if (i915_reset_engine(engine, msg) == 0)
-				engine_mask &= ~intel_engine_flag(engine);
-
-			clear_bit(I915_RESET_ENGINE + engine->id,
-				  &dev_priv->gpu_error.flags);
-			wake_up_bit(&dev_priv->gpu_error.flags,
-				    I915_RESET_ENGINE + engine->id);
-		}
-	}
-
-	if (!engine_mask)
-		goto out;
-
-	/* Full reset needs the mutex, stop any other user trying to do so. */
-	if (test_and_set_bit(I915_RESET_BACKOFF, &dev_priv->gpu_error.flags)) {
-		wait_event(dev_priv->gpu_error.reset_queue,
-			   !test_bit(I915_RESET_BACKOFF,
-				     &dev_priv->gpu_error.flags));
-		goto out;
-	}
-
-	/* Prevent any other reset-engine attempt. */
-	for_each_engine(engine, dev_priv, tmp) {
-		while (test_and_set_bit(I915_RESET_ENGINE + engine->id,
-					&dev_priv->gpu_error.flags))
-			wait_on_bit(&dev_priv->gpu_error.flags,
-				    I915_RESET_ENGINE + engine->id,
-				    TASK_UNINTERRUPTIBLE);
-	}
-
-	i915_reset_device(dev_priv, engine_mask, msg);
-
-	for_each_engine(engine, dev_priv, tmp) {
-		clear_bit(I915_RESET_ENGINE + engine->id,
-			  &dev_priv->gpu_error.flags);
-	}
-
-	clear_bit(I915_RESET_BACKOFF, &dev_priv->gpu_error.flags);
-	wake_up_all(&dev_priv->gpu_error.reset_queue);
-
-out:
-	intel_runtime_pm_put(dev_priv, wakeref);
-}
-
 /* Called from drm generic code, passed 'crtc' which
  * we use as a pipe index
  */
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index f3c3593362ec..33eb9df0dd0e 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -29,6 +29,7 @@
 #include <linux/sched/signal.h>
 
 #include "i915_drv.h"
+#include "i915_reset.h"
 
 static const char *i915_fence_get_driver_name(struct dma_fence *fence)
 {
diff --git a/drivers/gpu/drm/i915/i915_reset.c b/drivers/gpu/drm/i915/i915_reset.c
new file mode 100644
index 000000000000..342d9ee42601
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_reset.c
@@ -0,0 +1,1389 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2008-2018 Intel Corporation
+ */
+
+#include <linux/sched/mm.h>
+
+#include "i915_drv.h"
+#include "i915_gpu_error.h"
+#include "i915_reset.h"
+
+#include "intel_guc.h"
+
+static void engine_skip_context(struct i915_request *rq)
+{
+	struct intel_engine_cs *engine = rq->engine;
+	struct i915_gem_context *hung_ctx = rq->gem_context;
+	struct i915_timeline *timeline = rq->timeline;
+	unsigned long flags;
+
+	GEM_BUG_ON(timeline == &engine->timeline);
+
+	spin_lock_irqsave(&engine->timeline.lock, flags);
+	spin_lock(&timeline->lock);
+
+	list_for_each_entry_continue(rq, &engine->timeline.requests, link)
+		if (rq->gem_context == hung_ctx)
+			i915_request_skip(rq, -EIO);
+
+	list_for_each_entry(rq, &timeline->requests, link)
+		i915_request_skip(rq, -EIO);
+
+	spin_unlock(&timeline->lock);
+	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+}
+
+static void client_mark_guilty(struct drm_i915_file_private *file_priv,
+			       const struct i915_gem_context *ctx)
+{
+	unsigned int score;
+	unsigned long prev_hang;
+
+	if (i915_gem_context_is_banned(ctx))
+		score = I915_CLIENT_SCORE_CONTEXT_BAN;
+	else
+		score = 0;
+
+	prev_hang = xchg(&file_priv->hang_timestamp, jiffies);
+	if (time_before(jiffies, prev_hang + I915_CLIENT_FAST_HANG_JIFFIES))
+		score += I915_CLIENT_SCORE_HANG_FAST;
+
+	if (score) {
+		atomic_add(score, &file_priv->ban_score);
+
+		DRM_DEBUG_DRIVER("client %s: gained %u ban score, now %u\n",
+				 ctx->name, score,
+				 atomic_read(&file_priv->ban_score));
+	}
+}
+
+static void context_mark_guilty(struct i915_gem_context *ctx)
+{
+	unsigned int score;
+	bool banned, bannable;
+
+	atomic_inc(&ctx->guilty_count);
+
+	bannable = i915_gem_context_is_bannable(ctx);
+	score = atomic_add_return(CONTEXT_SCORE_GUILTY, &ctx->ban_score);
+	banned = score >= CONTEXT_SCORE_BAN_THRESHOLD;
+
+	/* Cool contexts don't accumulate client ban score */
+	if (!bannable)
+		return;
+
+	if (banned) {
+		DRM_DEBUG_DRIVER("context %s: guilty %d, score %u, banned\n",
+				 ctx->name, atomic_read(&ctx->guilty_count),
+				 score);
+		i915_gem_context_set_banned(ctx);
+	}
+
+	if (!IS_ERR_OR_NULL(ctx->file_priv))
+		client_mark_guilty(ctx->file_priv, ctx);
+}
+
+static void context_mark_innocent(struct i915_gem_context *ctx)
+{
+	atomic_inc(&ctx->active_count);
+}
+
+static void gen3_stop_engine(struct intel_engine_cs *engine)
+{
+	struct drm_i915_private *dev_priv = engine->i915;
+	const u32 base = engine->mmio_base;
+
+	if (intel_engine_stop_cs(engine))
+		DRM_DEBUG_DRIVER("%s: timed out on STOP_RING\n", engine->name);
+
+	I915_WRITE_FW(RING_HEAD(base), I915_READ_FW(RING_TAIL(base)));
+	POSTING_READ_FW(RING_HEAD(base)); /* paranoia */
+
+	I915_WRITE_FW(RING_HEAD(base), 0);
+	I915_WRITE_FW(RING_TAIL(base), 0);
+	POSTING_READ_FW(RING_TAIL(base));
+
+	/* The ring must be empty before it is disabled */
+	I915_WRITE_FW(RING_CTL(base), 0);
+
+	/* Check acts as a post */
+	if (I915_READ_FW(RING_HEAD(base)) != 0)
+		DRM_DEBUG_DRIVER("%s: ring head not parked\n",
+				 engine->name);
+}
+
+static void i915_stop_engines(struct drm_i915_private *i915,
+			      unsigned int engine_mask)
+{
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+
+	if (INTEL_GEN(i915) < 3)
+		return;
+
+	for_each_engine_masked(engine, i915, engine_mask, id)
+		gen3_stop_engine(engine);
+}
+
+static bool i915_in_reset(struct pci_dev *pdev)
+{
+	u8 gdrst;
+
+	pci_read_config_byte(pdev, I915_GDRST, &gdrst);
+	return gdrst & GRDOM_RESET_STATUS;
+}
+
+static int i915_do_reset(struct drm_i915_private *i915,
+			 unsigned int engine_mask,
+			 unsigned int retry)
+{
+	struct pci_dev *pdev = i915->drm.pdev;
+	int err;
+
+	/* Assert reset for at least 20 usec, and wait for acknowledgement. */
+	pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
+	usleep_range(50, 200);
+	err = wait_for(i915_in_reset(pdev), 500);
+
+	/* Clear the reset request. */
+	pci_write_config_byte(pdev, I915_GDRST, 0);
+	usleep_range(50, 200);
+	if (!err)
+		err = wait_for(!i915_in_reset(pdev), 500);
+
+	return err;
+}
+
+static bool g4x_reset_complete(struct pci_dev *pdev)
+{
+	u8 gdrst;
+
+	pci_read_config_byte(pdev, I915_GDRST, &gdrst);
+	return (gdrst & GRDOM_RESET_ENABLE) == 0;
+}
+
+static int g33_do_reset(struct drm_i915_private *i915,
+			unsigned int engine_mask,
+			unsigned int retry)
+{
+	struct pci_dev *pdev = i915->drm.pdev;
+
+	pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
+	return wait_for(g4x_reset_complete(pdev), 500);
+}
+
+static int g4x_do_reset(struct drm_i915_private *dev_priv,
+			unsigned int engine_mask,
+			unsigned int retry)
+{
+	struct pci_dev *pdev = dev_priv->drm.pdev;
+	int ret;
+
+	/* WaVcpClkGateDisableForMediaReset:ctg,elk */
+	I915_WRITE(VDECCLK_GATE_D,
+		   I915_READ(VDECCLK_GATE_D) | VCP_UNIT_CLOCK_GATE_DISABLE);
+	POSTING_READ(VDECCLK_GATE_D);
+
+	pci_write_config_byte(pdev, I915_GDRST,
+			      GRDOM_MEDIA | GRDOM_RESET_ENABLE);
+	ret =  wait_for(g4x_reset_complete(pdev), 500);
+	if (ret) {
+		DRM_DEBUG_DRIVER("Wait for media reset failed\n");
+		goto out;
+	}
+
+	pci_write_config_byte(pdev, I915_GDRST,
+			      GRDOM_RENDER | GRDOM_RESET_ENABLE);
+	ret =  wait_for(g4x_reset_complete(pdev), 500);
+	if (ret) {
+		DRM_DEBUG_DRIVER("Wait for render reset failed\n");
+		goto out;
+	}
+
+out:
+	pci_write_config_byte(pdev, I915_GDRST, 0);
+
+	I915_WRITE(VDECCLK_GATE_D,
+		   I915_READ(VDECCLK_GATE_D) & ~VCP_UNIT_CLOCK_GATE_DISABLE);
+	POSTING_READ(VDECCLK_GATE_D);
+
+	return ret;
+}
+
+static int ironlake_do_reset(struct drm_i915_private *dev_priv,
+			     unsigned int engine_mask,
+			     unsigned int retry)
+{
+	int ret;
+
+	I915_WRITE(ILK_GDSR, ILK_GRDOM_RENDER | ILK_GRDOM_RESET_ENABLE);
+	ret = intel_wait_for_register(dev_priv,
+				      ILK_GDSR, ILK_GRDOM_RESET_ENABLE, 0,
+				      500);
+	if (ret) {
+		DRM_DEBUG_DRIVER("Wait for render reset failed\n");
+		goto out;
+	}
+
+	I915_WRITE(ILK_GDSR, ILK_GRDOM_MEDIA | ILK_GRDOM_RESET_ENABLE);
+	ret = intel_wait_for_register(dev_priv,
+				      ILK_GDSR, ILK_GRDOM_RESET_ENABLE, 0,
+				      500);
+	if (ret) {
+		DRM_DEBUG_DRIVER("Wait for media reset failed\n");
+		goto out;
+	}
+
+out:
+	I915_WRITE(ILK_GDSR, 0);
+	POSTING_READ(ILK_GDSR);
+	return ret;
+}
+
+/* Reset the hardware domains (GENX_GRDOM_*) specified by mask */
+static int gen6_hw_domain_reset(struct drm_i915_private *dev_priv,
+				u32 hw_domain_mask)
+{
+	int err;
+
+	/*
+	 * GEN6_GDRST is not in the gt power well, no need to check
+	 * for fifo space for the write or forcewake the chip for
+	 * the read
+	 */
+	I915_WRITE_FW(GEN6_GDRST, hw_domain_mask);
+
+	/* Wait for the device to ack the reset requests */
+	err = __intel_wait_for_register_fw(dev_priv,
+					   GEN6_GDRST, hw_domain_mask, 0,
+					   500, 0,
+					   NULL);
+	if (err)
+		DRM_DEBUG_DRIVER("Wait for 0x%08x engines reset failed\n",
+				 hw_domain_mask);
+
+	return err;
+}
+
+static int gen6_reset_engines(struct drm_i915_private *i915,
+			      unsigned int engine_mask,
+			      unsigned int retry)
+{
+	struct intel_engine_cs *engine;
+	const u32 hw_engine_mask[I915_NUM_ENGINES] = {
+		[RCS] = GEN6_GRDOM_RENDER,
+		[BCS] = GEN6_GRDOM_BLT,
+		[VCS] = GEN6_GRDOM_MEDIA,
+		[VCS2] = GEN8_GRDOM_MEDIA2,
+		[VECS] = GEN6_GRDOM_VECS,
+	};
+	u32 hw_mask;
+
+	if (engine_mask == ALL_ENGINES) {
+		hw_mask = GEN6_GRDOM_FULL;
+	} else {
+		unsigned int tmp;
+
+		hw_mask = 0;
+		for_each_engine_masked(engine, i915, engine_mask, tmp)
+			hw_mask |= hw_engine_mask[engine->id];
+	}
+
+	return gen6_hw_domain_reset(i915, hw_mask);
+}
+
+static u32 gen11_lock_sfc(struct drm_i915_private *dev_priv,
+			  struct intel_engine_cs *engine)
+{
+	u8 vdbox_sfc_access = RUNTIME_INFO(dev_priv)->vdbox_sfc_access;
+	i915_reg_t sfc_forced_lock, sfc_forced_lock_ack;
+	u32 sfc_forced_lock_bit, sfc_forced_lock_ack_bit;
+	i915_reg_t sfc_usage;
+	u32 sfc_usage_bit;
+	u32 sfc_reset_bit;
+
+	switch (engine->class) {
+	case VIDEO_DECODE_CLASS:
+		if ((BIT(engine->instance) & vdbox_sfc_access) == 0)
+			return 0;
+
+		sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine);
+		sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
+
+		sfc_forced_lock_ack = GEN11_VCS_SFC_LOCK_STATUS(engine);
+		sfc_forced_lock_ack_bit  = GEN11_VCS_SFC_LOCK_ACK_BIT;
+
+		sfc_usage = GEN11_VCS_SFC_LOCK_STATUS(engine);
+		sfc_usage_bit = GEN11_VCS_SFC_USAGE_BIT;
+		sfc_reset_bit = GEN11_VCS_SFC_RESET_BIT(engine->instance);
+		break;
+
+	case VIDEO_ENHANCEMENT_CLASS:
+		sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine);
+		sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
+
+		sfc_forced_lock_ack = GEN11_VECS_SFC_LOCK_ACK(engine);
+		sfc_forced_lock_ack_bit  = GEN11_VECS_SFC_LOCK_ACK_BIT;
+
+		sfc_usage = GEN11_VECS_SFC_USAGE(engine);
+		sfc_usage_bit = GEN11_VECS_SFC_USAGE_BIT;
+		sfc_reset_bit = GEN11_VECS_SFC_RESET_BIT(engine->instance);
+		break;
+
+	default:
+		return 0;
+	}
+
+	/*
+	 * Tell the engine that a software reset is going to happen. The engine
+	 * will then try to force lock the SFC (if currently locked, it will
+	 * remain so until we tell the engine it is safe to unlock; if currently
+	 * unlocked, it will ignore this and all new lock requests). If SFC
+	 * ends up being locked to the engine we want to reset, we have to reset
+	 * it as well (we will unlock it once the reset sequence is completed).
+	 */
+	I915_WRITE_FW(sfc_forced_lock,
+		      I915_READ_FW(sfc_forced_lock) | sfc_forced_lock_bit);
+
+	if (__intel_wait_for_register_fw(dev_priv,
+					 sfc_forced_lock_ack,
+					 sfc_forced_lock_ack_bit,
+					 sfc_forced_lock_ack_bit,
+					 1000, 0, NULL)) {
+		DRM_DEBUG_DRIVER("Wait for SFC forced lock ack failed\n");
+		return 0;
+	}
+
+	if (I915_READ_FW(sfc_usage) & sfc_usage_bit)
+		return sfc_reset_bit;
+
+	return 0;
+}
+
+static void gen11_unlock_sfc(struct drm_i915_private *dev_priv,
+			     struct intel_engine_cs *engine)
+{
+	u8 vdbox_sfc_access = RUNTIME_INFO(dev_priv)->vdbox_sfc_access;
+	i915_reg_t sfc_forced_lock;
+	u32 sfc_forced_lock_bit;
+
+	switch (engine->class) {
+	case VIDEO_DECODE_CLASS:
+		if ((BIT(engine->instance) & vdbox_sfc_access) == 0)
+			return;
+
+		sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine);
+		sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
+		break;
+
+	case VIDEO_ENHANCEMENT_CLASS:
+		sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine);
+		sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
+		break;
+
+	default:
+		return;
+	}
+
+	I915_WRITE_FW(sfc_forced_lock,
+		      I915_READ_FW(sfc_forced_lock) & ~sfc_forced_lock_bit);
+}
+
+static int gen11_reset_engines(struct drm_i915_private *i915,
+			       unsigned int engine_mask,
+			       unsigned int retry)
+{
+	const u32 hw_engine_mask[I915_NUM_ENGINES] = {
+		[RCS] = GEN11_GRDOM_RENDER,
+		[BCS] = GEN11_GRDOM_BLT,
+		[VCS] = GEN11_GRDOM_MEDIA,
+		[VCS2] = GEN11_GRDOM_MEDIA2,
+		[VCS3] = GEN11_GRDOM_MEDIA3,
+		[VCS4] = GEN11_GRDOM_MEDIA4,
+		[VECS] = GEN11_GRDOM_VECS,
+		[VECS2] = GEN11_GRDOM_VECS2,
+	};
+	struct intel_engine_cs *engine;
+	unsigned int tmp;
+	u32 hw_mask;
+	int ret;
+
+	BUILD_BUG_ON(VECS2 + 1 != I915_NUM_ENGINES);
+
+	if (engine_mask == ALL_ENGINES) {
+		hw_mask = GEN11_GRDOM_FULL;
+	} else {
+		hw_mask = 0;
+		for_each_engine_masked(engine, i915, engine_mask, tmp) {
+			hw_mask |= hw_engine_mask[engine->id];
+			hw_mask |= gen11_lock_sfc(i915, engine);
+		}
+	}
+
+	ret = gen6_hw_domain_reset(i915, hw_mask);
+
+	if (engine_mask != ALL_ENGINES)
+		for_each_engine_masked(engine, i915, engine_mask, tmp)
+			gen11_unlock_sfc(i915, engine);
+
+	return ret;
+}
+
+static int gen8_engine_reset_prepare(struct intel_engine_cs *engine)
+{
+	struct drm_i915_private *dev_priv = engine->i915;
+	int ret;
+
+	I915_WRITE_FW(RING_RESET_CTL(engine->mmio_base),
+		      _MASKED_BIT_ENABLE(RESET_CTL_REQUEST_RESET));
+
+	ret = __intel_wait_for_register_fw(dev_priv,
+					   RING_RESET_CTL(engine->mmio_base),
+					   RESET_CTL_READY_TO_RESET,
+					   RESET_CTL_READY_TO_RESET,
+					   700, 0,
+					   NULL);
+	if (ret)
+		DRM_ERROR("%s: reset request timeout\n", engine->name);
+
+	return ret;
+}
+
+static void gen8_engine_reset_cancel(struct intel_engine_cs *engine)
+{
+	struct drm_i915_private *dev_priv = engine->i915;
+
+	I915_WRITE_FW(RING_RESET_CTL(engine->mmio_base),
+		      _MASKED_BIT_DISABLE(RESET_CTL_REQUEST_RESET));
+}
+
+static int gen8_reset_engines(struct drm_i915_private *i915,
+			      unsigned int engine_mask,
+			      unsigned int retry)
+{
+	struct intel_engine_cs *engine;
+	const bool reset_non_ready = retry >= 1;
+	unsigned int tmp;
+	int ret;
+
+	for_each_engine_masked(engine, i915, engine_mask, tmp) {
+		ret = gen8_engine_reset_prepare(engine);
+		if (ret && !reset_non_ready)
+			goto skip_reset;
+
+		/*
+		 * If this is not the first failed attempt to prepare,
+		 * we decide to proceed anyway.
+		 *
+		 * By doing so we risk context corruption and with
+		 * some gens (kbl), possible system hang if reset
+		 * happens during active bb execution.
+		 *
+		 * We rather take context corruption instead of
+		 * failed reset with a wedged driver/gpu. And
+		 * active bb execution case should be covered by
+		 * i915_stop_engines we have before the reset.
+		 */
+	}
+
+	if (INTEL_GEN(i915) >= 11)
+		ret = gen11_reset_engines(i915, engine_mask, retry);
+	else
+		ret = gen6_reset_engines(i915, engine_mask, retry);
+
+skip_reset:
+	for_each_engine_masked(engine, i915, engine_mask, tmp)
+		gen8_engine_reset_cancel(engine);
+
+	return ret;
+}
+
+typedef int (*reset_func)(struct drm_i915_private *,
+			  unsigned int engine_mask,
+			  unsigned int retry);
+
+static reset_func intel_get_gpu_reset(struct drm_i915_private *i915)
+{
+	if (!i915_modparams.reset)
+		return NULL;
+
+	if (INTEL_GEN(i915) >= 8)
+		return gen8_reset_engines;
+	else if (INTEL_GEN(i915) >= 6)
+		return gen6_reset_engines;
+	else if (INTEL_GEN(i915) >= 5)
+		return ironlake_do_reset;
+	else if (IS_G4X(i915))
+		return g4x_do_reset;
+	else if (IS_G33(i915) || IS_PINEVIEW(i915))
+		return g33_do_reset;
+	else if (INTEL_GEN(i915) >= 3)
+		return i915_do_reset;
+	else
+		return NULL;
+}
+
+int intel_gpu_reset(struct drm_i915_private *i915, unsigned int engine_mask)
+{
+	reset_func reset = intel_get_gpu_reset(i915);
+	int retry;
+	int ret;
+
+	/*
+	 * We want to perform per-engine reset from atomic context (e.g.
+	 * softirq), which imposes the constraint that we cannot sleep.
+	 * However, experience suggests that spending a bit of time waiting
+	 * for a reset helps in various cases, so for a full-device reset
+	 * we apply the opposite rule and wait if we want to. As we should
+	 * always follow up a failed per-engine reset with a full device reset,
+	 * being a little faster, stricter and more error prone for the
+	 * atomic case seems an acceptable compromise.
+	 *
+	 * Unfortunately this leads to a bimodal routine, when the goal was
+	 * to have a single reset function that worked for resetting any
+	 * number of engines simultaneously.
+	 */
+	might_sleep_if(engine_mask == ALL_ENGINES);
+
+	/*
+	 * If the power well sleeps during the reset, the reset
+	 * request may be dropped and never completes (causing -EIO).
+	 */
+	intel_uncore_forcewake_get(i915, FORCEWAKE_ALL);
+	for (retry = 0; retry < 3; retry++) {
+		/*
+		 * We stop engines, otherwise we might get failed reset and a
+		 * dead gpu (on elk). Also as modern gpu as kbl can suffer
+		 * from system hang if batchbuffer is progressing when
+		 * the reset is issued, regardless of READY_TO_RESET ack.
+		 * Thus assume it is best to stop engines on all gens
+		 * where we have a gpu reset.
+		 *
+		 * WaKBLVECSSemaphoreWaitPoll:kbl (on ALL_ENGINES)
+		 *
+		 * WaMediaResetMainRingCleanup:ctg,elk (presumably)
+		 *
+		 * FIXME: Wa for more modern gens needs to be validated
+		 */
+		i915_stop_engines(i915, engine_mask);
+
+		ret = -ENODEV;
+		if (reset) {
+			GEM_TRACE("engine_mask=%x\n", engine_mask);
+			ret = reset(i915, engine_mask, retry);
+		}
+		if (ret != -ETIMEDOUT || engine_mask != ALL_ENGINES)
+			break;
+
+		cond_resched();
+	}
+	intel_uncore_forcewake_put(i915, FORCEWAKE_ALL);
+
+	return ret;
+}
+
+bool intel_has_gpu_reset(struct drm_i915_private *i915)
+{
+	return intel_get_gpu_reset(i915);
+}
+
+bool intel_has_reset_engine(struct drm_i915_private *i915)
+{
+	return INTEL_INFO(i915)->has_reset_engine && i915_modparams.reset >= 2;
+}
+
+int intel_reset_guc(struct drm_i915_private *i915)
+{
+	u32 guc_domain =
+		INTEL_GEN(i915) >= 11 ? GEN11_GRDOM_GUC : GEN9_GRDOM_GUC;
+	int ret;
+
+	GEM_BUG_ON(!HAS_GUC(i915));
+
+	intel_uncore_forcewake_get(i915, FORCEWAKE_ALL);
+	ret = gen6_hw_domain_reset(i915, guc_domain);
+	intel_uncore_forcewake_put(i915, FORCEWAKE_ALL);
+
+	return ret;
+}
+
+/*
+ * Ensure irq handler finishes, and not run again.
+ * Also return the active request so that we only search for it once.
+ */
+static struct i915_request *
+reset_prepare_engine(struct intel_engine_cs *engine)
+{
+	struct i915_request *rq;
+
+	/*
+	 * During the reset sequence, we must prevent the engine from
+	 * entering RC6. As the context state is undefined until we restart
+	 * the engine, if it does enter RC6 during the reset, the state
+	 * written to the powercontext is undefined and so we may lose
+	 * GPU state upon resume, i.e. fail to restart after a reset.
+	 */
+	intel_uncore_forcewake_get(engine->i915, FORCEWAKE_ALL);
+
+	rq = engine->reset.prepare(engine);
+	if (rq && rq->fence.error == -EIO)
+		rq = ERR_PTR(-EIO); /* Previous reset failed! */
+
+	return rq;
+}
+
+static int reset_prepare(struct drm_i915_private *i915)
+{
+	struct intel_engine_cs *engine;
+	struct i915_request *rq;
+	enum intel_engine_id id;
+	int err = 0;
+
+	for_each_engine(engine, i915, id) {
+		rq = reset_prepare_engine(engine);
+		if (IS_ERR(rq)) {
+			err = PTR_ERR(rq);
+			continue;
+		}
+
+		engine->hangcheck.active_request = rq;
+	}
+
+	i915_gem_revoke_fences(i915);
+	intel_uc_sanitize(i915);
+
+	return err;
+}
+
+/* Returns the request if it was guilty of the hang */
+static struct i915_request *
+reset_request(struct intel_engine_cs *engine,
+	      struct i915_request *rq,
+	      bool stalled)
+{
+	/*
+	 * The guilty request will get skipped on a hung engine.
+	 *
+	 * Users of client default contexts do not rely on logical
+	 * state preserved between batches so it is safe to execute
+	 * queued requests following the hang. Non default contexts
+	 * rely on preserved state, so skipping a batch loses the
+	 * evolution of the state and it needs to be considered corrupted.
+	 * Executing more queued batches on top of corrupted state is
+	 * risky. But we take the risk by trying to advance through
+	 * the queued requests in order to make the client behaviour
+	 * more predictable around resets, by not throwing away random
+	 * amount of batches it has prepared for execution. Sophisticated
+	 * clients can use gem_reset_stats_ioctl and dma fence status
+	 * (exported via sync_file info ioctl on explicit fences) to observe
+	 * when it loses the context state and should rebuild accordingly.
+	 *
+	 * The context ban, and ultimately the client ban, mechanism are safety
+	 * valves if client submission ends up resulting in nothing more than
+	 * subsequent hangs.
+	 */
+
+	if (i915_request_completed(rq)) {
+		GEM_TRACE("%s pardoned global=%d (fence %llx:%lld), current %d\n",
+			  engine->name, rq->global_seqno,
+			  rq->fence.context, rq->fence.seqno,
+			  intel_engine_get_seqno(engine));
+		stalled = false;
+	}
+
+	if (stalled) {
+		context_mark_guilty(rq->gem_context);
+		i915_request_skip(rq, -EIO);
+
+		/* If this context is now banned, skip all pending requests. */
+		if (i915_gem_context_is_banned(rq->gem_context))
+			engine_skip_context(rq);
+	} else {
+		/*
+		 * Since this is not the hung engine, it may have advanced
+		 * since the hang declaration. Double check by refinding
+		 * the active request at the time of the reset.
+		 */
+		rq = i915_gem_find_active_request(engine);
+		if (rq) {
+			unsigned long flags;
+
+			context_mark_innocent(rq->gem_context);
+			dma_fence_set_error(&rq->fence, -EAGAIN);
+
+			/* Rewind the engine to replay the incomplete rq */
+			spin_lock_irqsave(&engine->timeline.lock, flags);
+			rq = list_prev_entry(rq, link);
+			if (&rq->link == &engine->timeline.requests)
+				rq = NULL;
+			spin_unlock_irqrestore(&engine->timeline.lock, flags);
+		}
+	}
+
+	return rq;
+}
+
+static void reset_engine(struct intel_engine_cs *engine,
+			 struct i915_request *rq,
+			 bool stalled)
+{
+	if (rq)
+		rq = reset_request(engine, rq, stalled);
+
+	/* Setup the CS to resume from the breadcrumb of the hung request */
+	engine->reset.reset(engine, rq);
+}
+
+static void gt_reset(struct drm_i915_private *i915, unsigned int stalled_mask)
+{
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+
+	lockdep_assert_held(&i915->drm.struct_mutex);
+
+	i915_retire_requests(i915);
+
+	for_each_engine(engine, i915, id) {
+		struct intel_context *ce;
+
+		reset_engine(engine,
+			     engine->hangcheck.active_request,
+			     stalled_mask & ENGINE_MASK(id));
+		ce = fetch_and_zero(&engine->last_retired_context);
+		if (ce)
+			intel_context_unpin(ce);
+
+		/*
+		 * Ostensibily, we always want a context loaded for powersaving,
+		 * so if the engine is idle after the reset, send a request
+		 * to load our scratch kernel_context.
+		 *
+		 * More mysteriously, if we leave the engine idle after a reset,
+		 * the next userspace batch may hang, with what appears to be
+		 * an incoherent read by the CS (presumably stale TLB). An
+		 * empty request appears sufficient to paper over the glitch.
+		 */
+		if (intel_engine_is_idle(engine)) {
+			struct i915_request *rq;
+
+			rq = i915_request_alloc(engine, i915->kernel_context);
+			if (!IS_ERR(rq))
+				i915_request_add(rq);
+		}
+	}
+
+	i915_gem_restore_fences(i915);
+}
+
+static void reset_finish_engine(struct intel_engine_cs *engine)
+{
+	engine->reset.finish(engine);
+
+	intel_uncore_forcewake_put(engine->i915, FORCEWAKE_ALL);
+}
+
+static void reset_finish(struct drm_i915_private *i915)
+{
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+
+	lockdep_assert_held(&i915->drm.struct_mutex);
+
+	for_each_engine(engine, i915, id) {
+		engine->hangcheck.active_request = NULL;
+		reset_finish_engine(engine);
+	}
+}
+
+static void nop_submit_request(struct i915_request *request)
+{
+	unsigned long flags;
+
+	GEM_TRACE("%s fence %llx:%lld -> -EIO\n",
+		  request->engine->name,
+		  request->fence.context, request->fence.seqno);
+	dma_fence_set_error(&request->fence, -EIO);
+
+	spin_lock_irqsave(&request->engine->timeline.lock, flags);
+	__i915_request_submit(request);
+	intel_engine_write_global_seqno(request->engine, request->global_seqno);
+	spin_unlock_irqrestore(&request->engine->timeline.lock, flags);
+}
+
+void i915_gem_set_wedged(struct drm_i915_private *i915)
+{
+	struct i915_gpu_error *error = &i915->gpu_error;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+
+	mutex_lock(&error->wedge_mutex);
+	if (test_bit(I915_WEDGED, &error->flags)) {
+		mutex_unlock(&error->wedge_mutex);
+		return;
+	}
+
+	if (GEM_SHOW_DEBUG() && !intel_engines_are_idle(i915)) {
+		struct drm_printer p = drm_debug_printer(__func__);
+
+		for_each_engine(engine, i915, id)
+			intel_engine_dump(engine, &p, "%s\n", engine->name);
+	}
+
+	GEM_TRACE("start\n");
+
+	/*
+	 * First, stop submission to hw, but do not yet complete requests by
+	 * rolling the global seqno forward (since this would complete requests
+	 * for which we haven't set the fence error to EIO yet).
+	 */
+	for_each_engine(engine, i915, id)
+		reset_prepare_engine(engine);
+
+	/* Even if the GPU reset fails, it should still stop the engines */
+	if (INTEL_GEN(i915) >= 5)
+		intel_gpu_reset(i915, ALL_ENGINES);
+
+	for_each_engine(engine, i915, id) {
+		engine->submit_request = nop_submit_request;
+		engine->schedule = NULL;
+	}
+	i915->caps.scheduler = 0;
+
+	/*
+	 * Make sure no request can slip through without getting completed by
+	 * either this call here to intel_engine_write_global_seqno, or the one
+	 * in nop_submit_request.
+	 */
+	synchronize_rcu();
+
+	/* Mark all executing requests as skipped */
+	for_each_engine(engine, i915, id)
+		engine->cancel_requests(engine);
+
+	for_each_engine(engine, i915, id) {
+		reset_finish_engine(engine);
+		intel_engine_wakeup(engine);
+	}
+
+	smp_mb__before_atomic();
+	set_bit(I915_WEDGED, &error->flags);
+
+	GEM_TRACE("end\n");
+	mutex_unlock(&error->wedge_mutex);
+
+	wake_up_all(&error->reset_queue);
+}
+
+bool i915_gem_unset_wedged(struct drm_i915_private *i915)
+{
+	struct i915_gpu_error *error = &i915->gpu_error;
+	struct i915_timeline *tl;
+	bool ret = false;
+
+	lockdep_assert_held(&i915->drm.struct_mutex);
+
+	if (!test_bit(I915_WEDGED, &error->flags))
+		return true;
+
+	if (!i915->gt.scratch) /* Never full initialised, recovery impossible */
+		return false;
+
+	mutex_lock(&error->wedge_mutex);
+
+	GEM_TRACE("start\n");
+
+	/*
+	 * Before unwedging, make sure that all pending operations
+	 * are flushed and errored out - we may have requests waiting upon
+	 * third party fences. We marked all inflight requests as EIO, and
+	 * every execbuf since returned EIO, for consistency we want all
+	 * the currently pending requests to also be marked as EIO, which
+	 * is done inside our nop_submit_request - and so we must wait.
+	 *
+	 * No more can be submitted until we reset the wedged bit.
+	 */
+	list_for_each_entry(tl, &i915->gt.timelines, link) {
+		struct i915_request *rq;
+
+		rq = i915_gem_active_peek(&tl->last_request,
+					  &i915->drm.struct_mutex);
+		if (!rq)
+			continue;
+
+		/*
+		 * We can't use our normal waiter as we want to
+		 * avoid recursively trying to handle the current
+		 * reset. The basic dma_fence_default_wait() installs
+		 * a callback for dma_fence_signal(), which is
+		 * triggered by our nop handler (indirectly, the
+		 * callback enables the signaler thread which is
+		 * woken by the nop_submit_request() advancing the seqno
+		 * and when the seqno passes the fence, the signaler
+		 * then signals the fence waking us up).
+		 */
+		if (dma_fence_default_wait(&rq->fence, true,
+					   MAX_SCHEDULE_TIMEOUT) < 0)
+			goto unlock;
+	}
+	i915_retire_requests(i915);
+	GEM_BUG_ON(i915->gt.active_requests);
+
+	intel_engines_sanitize(i915, false);
+
+	/*
+	 * Undo nop_submit_request. We prevent all new i915 requests from
+	 * being queued (by disallowing execbuf whilst wedged) so having
+	 * waited for all active requests above, we know the system is idle
+	 * and do not have to worry about a thread being inside
+	 * engine->submit_request() as we swap over. So unlike installing
+	 * the nop_submit_request on reset, we can do this from normal
+	 * context and do not require stop_machine().
+	 */
+	intel_engines_reset_default_submission(i915);
+	i915_gem_contexts_lost(i915);
+
+	GEM_TRACE("end\n");
+
+	smp_mb__before_atomic(); /* complete takeover before enabling execbuf */
+	clear_bit(I915_WEDGED, &i915->gpu_error.flags);
+	ret = true;
+unlock:
+	mutex_unlock(&i915->gpu_error.wedge_mutex);
+
+	return ret;
+}
+
+/**
+ * i915_reset - reset chip after a hang
+ * @i915: #drm_i915_private to reset
+ * @stalled_mask: mask of the stalled engines with the guilty requests
+ * @reason: user error message for why we are resetting
+ *
+ * Reset the chip.  Useful if a hang is detected. Marks the device as wedged
+ * on failure.
+ *
+ * Caller must hold the struct_mutex.
+ *
+ * Procedure is fairly simple:
+ *   - reset the chip using the reset reg
+ *   - re-init context state
+ *   - re-init hardware status page
+ *   - re-init ring buffer
+ *   - re-init interrupt state
+ *   - re-init display
+ */
+void i915_reset(struct drm_i915_private *i915,
+		unsigned int stalled_mask,
+		const char *reason)
+{
+	struct i915_gpu_error *error = &i915->gpu_error;
+	int ret;
+	int i;
+
+	GEM_TRACE("flags=%lx\n", error->flags);
+
+	might_sleep();
+	lockdep_assert_held(&i915->drm.struct_mutex);
+	assert_rpm_wakelock_held(i915);
+	GEM_BUG_ON(!test_bit(I915_RESET_BACKOFF, &error->flags));
+
+	if (!test_bit(I915_RESET_HANDOFF, &error->flags))
+		return;
+
+	/* Clear any previous failed attempts at recovery. Time to try again. */
+	if (!i915_gem_unset_wedged(i915))
+		goto wakeup;
+
+	if (reason)
+		dev_notice(i915->drm.dev, "Resetting chip for %s\n", reason);
+	error->reset_count++;
+
+	ret = reset_prepare(i915);
+	if (ret) {
+		dev_err(i915->drm.dev, "GPU recovery failed\n");
+		goto taint;
+	}
+
+	if (!intel_has_gpu_reset(i915)) {
+		if (i915_modparams.reset)
+			dev_err(i915->drm.dev, "GPU reset not supported\n");
+		else
+			DRM_DEBUG_DRIVER("GPU reset disabled\n");
+		goto error;
+	}
+
+	for (i = 0; i < 3; i++) {
+		ret = intel_gpu_reset(i915, ALL_ENGINES);
+		if (ret == 0)
+			break;
+
+		msleep(100);
+	}
+	if (ret) {
+		dev_err(i915->drm.dev, "Failed to reset chip\n");
+		goto taint;
+	}
+
+	/* Ok, now get things going again... */
+
+	/*
+	 * Everything depends on having the GTT running, so we need to start
+	 * there.
+	 */
+	ret = i915_ggtt_enable_hw(i915);
+	if (ret) {
+		DRM_ERROR("Failed to re-enable GGTT following reset (%d)\n",
+			  ret);
+		goto error;
+	}
+
+	gt_reset(i915, stalled_mask);
+	intel_overlay_reset(i915);
+
+	/*
+	 * Next we need to restore the context, but we don't use those
+	 * yet either...
+	 *
+	 * Ring buffer needs to be re-initialized in the KMS case, or if X
+	 * was running at the time of the reset (i.e. we weren't VT
+	 * switched away).
+	 */
+	ret = i915_gem_init_hw(i915);
+	if (ret) {
+		DRM_ERROR("Failed to initialise HW following reset (%d)\n",
+			  ret);
+		goto error;
+	}
+
+	i915_queue_hangcheck(i915);
+
+finish:
+	reset_finish(i915);
+wakeup:
+	clear_bit(I915_RESET_HANDOFF, &error->flags);
+	wake_up_bit(&error->flags, I915_RESET_HANDOFF);
+	return;
+
+taint:
+	/*
+	 * History tells us that if we cannot reset the GPU now, we
+	 * never will. This then impacts everything that is run
+	 * subsequently. On failing the reset, we mark the driver
+	 * as wedged, preventing further execution on the GPU.
+	 * We also want to go one step further and add a taint to the
+	 * kernel so that any subsequent faults can be traced back to
+	 * this failure. This is important for CI, where if the
+	 * GPU/driver fails we would like to reboot and restart testing
+	 * rather than continue on into oblivion. For everyone else,
+	 * the system should still plod along, but they have been warned!
+	 */
+	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
+error:
+	i915_gem_set_wedged(i915);
+	i915_retire_requests(i915);
+	goto finish;
+}
+
+static inline int intel_gt_reset_engine(struct drm_i915_private *i915,
+					struct intel_engine_cs *engine)
+{
+	return intel_gpu_reset(i915, intel_engine_flag(engine));
+}
+
+/**
+ * i915_reset_engine - reset GPU engine to recover from a hang
+ * @engine: engine to reset
+ * @msg: reason for GPU reset; or NULL for no dev_notice()
+ *
+ * Reset a specific GPU engine. Useful if a hang is detected.
+ * Returns zero on successful reset or otherwise an error code.
+ *
+ * Procedure is:
+ *  - identifies the request that caused the hang and it is dropped
+ *  - reset engine (which will force the engine to idle)
+ *  - re-init/configure engine
+ */
+int i915_reset_engine(struct intel_engine_cs *engine, const char *msg)
+{
+	struct i915_gpu_error *error = &engine->i915->gpu_error;
+	struct i915_request *active_request;
+	int ret;
+
+	GEM_TRACE("%s flags=%lx\n", engine->name, error->flags);
+	GEM_BUG_ON(!test_bit(I915_RESET_ENGINE + engine->id, &error->flags));
+
+	active_request = reset_prepare_engine(engine);
+	if (IS_ERR_OR_NULL(active_request)) {
+		/* Either the previous reset failed, or we pardon the reset. */
+		ret = PTR_ERR(active_request);
+		goto out;
+	}
+
+	if (msg)
+		dev_notice(engine->i915->drm.dev,
+			   "Resetting %s for %s\n", engine->name, msg);
+	error->reset_engine_count[engine->id]++;
+
+	if (!engine->i915->guc.execbuf_client)
+		ret = intel_gt_reset_engine(engine->i915, engine);
+	else
+		ret = intel_guc_reset_engine(&engine->i915->guc, engine);
+	if (ret) {
+		/* If we fail here, we expect to fallback to a global reset */
+		DRM_DEBUG_DRIVER("%sFailed to reset %s, ret=%d\n",
+				 engine->i915->guc.execbuf_client ? "GuC " : "",
+				 engine->name, ret);
+		goto out;
+	}
+
+	/*
+	 * The request that caused the hang is stuck on elsp, we know the
+	 * active request and can drop it, adjust head to skip the offending
+	 * request to resume executing remaining requests in the queue.
+	 */
+	reset_engine(engine, active_request, true);
+
+	/*
+	 * The engine and its registers (and workarounds in case of render)
+	 * have been reset to their default values. Follow the init_ring
+	 * process to program RING_MODE, HWSP and re-enable submission.
+	 */
+	ret = engine->init_hw(engine);
+	if (ret)
+		goto out;
+
+out:
+	intel_engine_cancel_stop_cs(engine);
+	reset_finish_engine(engine);
+	return ret;
+}
+
+static void i915_reset_device(struct drm_i915_private *i915,
+			      u32 engine_mask,
+			      const char *reason)
+{
+	struct i915_gpu_error *error = &i915->gpu_error;
+	struct kobject *kobj = &i915->drm.primary->kdev->kobj;
+	char *error_event[] = { I915_ERROR_UEVENT "=1", NULL };
+	char *reset_event[] = { I915_RESET_UEVENT "=1", NULL };
+	char *reset_done_event[] = { I915_ERROR_UEVENT "=0", NULL };
+	struct i915_wedge_me w;
+
+	kobject_uevent_env(kobj, KOBJ_CHANGE, error_event);
+
+	DRM_DEBUG_DRIVER("resetting chip\n");
+	kobject_uevent_env(kobj, KOBJ_CHANGE, reset_event);
+
+	/* Use a watchdog to ensure that our reset completes */
+	i915_wedge_on_timeout(&w, i915, 5 * HZ) {
+		intel_prepare_reset(i915);
+
+		error->reason = reason;
+		error->stalled_mask = engine_mask;
+
+		/* Signal that locked waiters should reset the GPU */
+		smp_mb__before_atomic();
+		set_bit(I915_RESET_HANDOFF, &error->flags);
+		wake_up_all(&error->wait_queue);
+
+		/*
+		 * Wait for anyone holding the lock to wakeup, without
+		 * blocking indefinitely on struct_mutex.
+		 */
+		do {
+			if (mutex_trylock(&i915->drm.struct_mutex)) {
+				i915_reset(i915, engine_mask, reason);
+				mutex_unlock(&i915->drm.struct_mutex);
+			}
+		} while (wait_on_bit_timeout(&error->flags,
+					     I915_RESET_HANDOFF,
+					     TASK_UNINTERRUPTIBLE,
+					     1));
+
+		error->stalled_mask = 0;
+		error->reason = NULL;
+
+		intel_finish_reset(i915);
+	}
+
+	if (!test_bit(I915_WEDGED, &error->flags))
+		kobject_uevent_env(kobj, KOBJ_CHANGE, reset_done_event);
+}
+
+void i915_clear_error_registers(struct drm_i915_private *dev_priv)
+{
+	u32 eir;
+
+	if (!IS_GEN(dev_priv, 2))
+		I915_WRITE(PGTBL_ER, I915_READ(PGTBL_ER));
+
+	if (INTEL_GEN(dev_priv) < 4)
+		I915_WRITE(IPEIR, I915_READ(IPEIR));
+	else
+		I915_WRITE(IPEIR_I965, I915_READ(IPEIR_I965));
+
+	I915_WRITE(EIR, I915_READ(EIR));
+	eir = I915_READ(EIR);
+	if (eir) {
+		/*
+		 * some errors might have become stuck,
+		 * mask them.
+		 */
+		DRM_DEBUG_DRIVER("EIR stuck: 0x%08x, masking\n", eir);
+		I915_WRITE(EMR, I915_READ(EMR) | eir);
+		I915_WRITE(IIR, I915_MASTER_ERROR_INTERRUPT);
+	}
+
+	if (INTEL_GEN(dev_priv) >= 8) {
+		I915_WRITE(GEN8_RING_FAULT_REG,
+			   I915_READ(GEN8_RING_FAULT_REG) & ~RING_FAULT_VALID);
+		POSTING_READ(GEN8_RING_FAULT_REG);
+	} else if (INTEL_GEN(dev_priv) >= 6) {
+		struct intel_engine_cs *engine;
+		enum intel_engine_id id;
+
+		for_each_engine(engine, dev_priv, id) {
+			I915_WRITE(RING_FAULT_REG(engine),
+				   I915_READ(RING_FAULT_REG(engine)) &
+				   ~RING_FAULT_VALID);
+		}
+		POSTING_READ(RING_FAULT_REG(dev_priv->engine[RCS]));
+	}
+}
+
+/**
+ * i915_handle_error - handle a gpu error
+ * @i915: i915 device private
+ * @engine_mask: mask representing engines that are hung
+ * @flags: control flags
+ * @fmt: Error message format string
+ *
+ * Do some basic checking of register state at error time and
+ * dump it to the syslog.  Also call i915_capture_error_state() to make
+ * sure we get a record and make it available in debugfs.  Fire a uevent
+ * so userspace knows something bad happened (should trigger collection
+ * of a ring dump etc.).
+ */
+void i915_handle_error(struct drm_i915_private *i915,
+		       u32 engine_mask,
+		       unsigned long flags,
+		       const char *fmt, ...)
+{
+	struct intel_engine_cs *engine;
+	intel_wakeref_t wakeref;
+	unsigned int tmp;
+	char error_msg[80];
+	char *msg = NULL;
+
+	if (fmt) {
+		va_list args;
+
+		va_start(args, fmt);
+		vscnprintf(error_msg, sizeof(error_msg), fmt, args);
+		va_end(args);
+
+		msg = error_msg;
+	}
+
+	/*
+	 * In most cases it's guaranteed that we get here with an RPM
+	 * reference held, for example because there is a pending GPU
+	 * request that won't finish until the reset is done. This
+	 * isn't the case at least when we get here by doing a
+	 * simulated reset via debugfs, so get an RPM reference.
+	 */
+	wakeref = intel_runtime_pm_get(i915);
+
+	engine_mask &= INTEL_INFO(i915)->ring_mask;
+
+	if (flags & I915_ERROR_CAPTURE) {
+		i915_capture_error_state(i915, engine_mask, msg);
+		i915_clear_error_registers(i915);
+	}
+
+	/*
+	 * Try engine reset when available. We fall back to full reset if
+	 * single reset fails.
+	 */
+	if (intel_has_reset_engine(i915) &&
+	    !i915_terminally_wedged(&i915->gpu_error)) {
+		for_each_engine_masked(engine, i915, engine_mask, tmp) {
+			BUILD_BUG_ON(I915_RESET_MODESET >= I915_RESET_ENGINE);
+			if (test_and_set_bit(I915_RESET_ENGINE + engine->id,
+					     &i915->gpu_error.flags))
+				continue;
+
+			if (i915_reset_engine(engine, msg) == 0)
+				engine_mask &= ~intel_engine_flag(engine);
+
+			clear_bit(I915_RESET_ENGINE + engine->id,
+				  &i915->gpu_error.flags);
+			wake_up_bit(&i915->gpu_error.flags,
+				    I915_RESET_ENGINE + engine->id);
+		}
+	}
+
+	if (!engine_mask)
+		goto out;
+
+	/* Full reset needs the mutex, stop any other user trying to do so. */
+	if (test_and_set_bit(I915_RESET_BACKOFF, &i915->gpu_error.flags)) {
+		wait_event(i915->gpu_error.reset_queue,
+			   !test_bit(I915_RESET_BACKOFF,
+				     &i915->gpu_error.flags));
+		goto out;
+	}
+
+	/* Prevent any other reset-engine attempt. */
+	for_each_engine(engine, i915, tmp) {
+		while (test_and_set_bit(I915_RESET_ENGINE + engine->id,
+					&i915->gpu_error.flags))
+			wait_on_bit(&i915->gpu_error.flags,
+				    I915_RESET_ENGINE + engine->id,
+				    TASK_UNINTERRUPTIBLE);
+	}
+
+	i915_reset_device(i915, engine_mask, msg);
+
+	for_each_engine(engine, i915, tmp) {
+		clear_bit(I915_RESET_ENGINE + engine->id,
+			  &i915->gpu_error.flags);
+	}
+
+	clear_bit(I915_RESET_BACKOFF, &i915->gpu_error.flags);
+	wake_up_all(&i915->gpu_error.reset_queue);
+
+out:
+	intel_runtime_pm_put(i915, wakeref);
+}
+
+static void i915_wedge_me(struct work_struct *work)
+{
+	struct i915_wedge_me *w = container_of(work, typeof(*w), work.work);
+
+	dev_err(w->i915->drm.dev,
+		"%s timed out, cancelling all in-flight rendering.\n",
+		w->name);
+	i915_gem_set_wedged(w->i915);
+}
+
+void __i915_init_wedge(struct i915_wedge_me *w,
+		       struct drm_i915_private *i915,
+		       long timeout,
+		       const char *name)
+{
+	w->i915 = i915;
+	w->name = name;
+
+	INIT_DELAYED_WORK_ONSTACK(&w->work, i915_wedge_me);
+	schedule_delayed_work(&w->work, timeout);
+}
+
+void __i915_fini_wedge(struct i915_wedge_me *w)
+{
+	cancel_delayed_work_sync(&w->work);
+	destroy_delayed_work_on_stack(&w->work);
+	w->i915 = NULL;
+}
diff --git a/drivers/gpu/drm/i915/i915_reset.h b/drivers/gpu/drm/i915/i915_reset.h
new file mode 100644
index 000000000000..b6a519bde67d
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_reset.h
@@ -0,0 +1,56 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2008-2018 Intel Corporation
+ */
+
+#ifndef I915_RESET_H
+#define I915_RESET_H
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+struct drm_i915_private;
+struct intel_engine_cs;
+struct intel_guc;
+
+__printf(4, 5)
+void i915_handle_error(struct drm_i915_private *i915,
+		       u32 engine_mask,
+		       unsigned long flags,
+		       const char *fmt, ...);
+#define I915_ERROR_CAPTURE BIT(0)
+
+void i915_clear_error_registers(struct drm_i915_private *i915);
+
+void i915_reset(struct drm_i915_private *i915,
+		unsigned int stalled_mask,
+		const char *reason);
+int i915_reset_engine(struct intel_engine_cs *engine,
+		      const char *reason);
+
+bool intel_has_gpu_reset(struct drm_i915_private *i915);
+bool intel_has_reset_engine(struct drm_i915_private *i915);
+
+int intel_gpu_reset(struct drm_i915_private *i915, u32 engine_mask);
+
+int intel_reset_guc(struct drm_i915_private *i915);
+
+struct i915_wedge_me {
+	struct delayed_work work;
+	struct drm_i915_private *i915;
+	const char *name;
+};
+
+void __i915_init_wedge(struct i915_wedge_me *w,
+		       struct drm_i915_private *i915,
+		       long timeout,
+		       const char *name);
+void __i915_fini_wedge(struct i915_wedge_me *w);
+
+#define i915_wedge_on_timeout(W, DEV, TIMEOUT)				\
+	for (__i915_init_wedge((W), (DEV), (TIMEOUT), __func__);	\
+	     (W)->i915;							\
+	     __i915_fini_wedge((W)))
+
+#endif /* I915_RESET_H */
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index c6b3b69aaeac..8d6d7ae311f4 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -31,13 +31,7 @@
 #include <linux/slab.h>
 #include <linux/vgaarb.h>
 #include <drm/drm_edid.h>
-#include "intel_drv.h"
-#include "intel_frontbuffer.h"
 #include <drm/i915_drm.h>
-#include "i915_drv.h"
-#include "i915_gem_clflush.h"
-#include "intel_dsi.h"
-#include "i915_trace.h"
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_dp_helper.h>
@@ -48,6 +42,15 @@
 #include <linux/intel-iommu.h>
 #include <linux/reservation.h>
 
+#include "intel_drv.h"
+#include "intel_dsi.h"
+#include "intel_frontbuffer.h"
+
+#include "i915_drv.h"
+#include "i915_gem_clflush.h"
+#include "i915_reset.h"
+#include "i915_trace.h"
+
 /* Primary plane formats for gen <= 3 */
 static const uint32_t i8xx_primary_formats[] = {
 	DRM_FORMAT_C8,
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 200218cb157f..eed0da03ff5e 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -25,6 +25,7 @@
 #include <drm/drm_print.h>
 
 #include "i915_drv.h"
+#include "i915_reset.h"
 #include "intel_ringbuffer.h"
 #include "intel_lrc.h"
 
diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h
index 0f1c4f9ebfd8..744220296653 100644
--- a/drivers/gpu/drm/i915/intel_guc.h
+++ b/drivers/gpu/drm/i915/intel_guc.h
@@ -192,4 +192,7 @@ static inline void intel_guc_disable_msg(struct intel_guc *guc, u32 mask)
 	spin_unlock_irq(&guc->irq_lock);
 }
 
+int intel_guc_reset_engine(struct intel_guc *guc,
+			   struct intel_engine_cs *engine);
+
 #endif
diff --git a/drivers/gpu/drm/i915/intel_hangcheck.c b/drivers/gpu/drm/i915/intel_hangcheck.c
index 51e9efec5116..7dc11fcb13de 100644
--- a/drivers/gpu/drm/i915/intel_hangcheck.c
+++ b/drivers/gpu/drm/i915/intel_hangcheck.c
@@ -23,6 +23,7 @@
  */
 
 #include "i915_drv.h"
+#include "i915_reset.h"
 
 static bool instdone_unchanged(u32 current_instdone, u32 *old_instdone)
 {
diff --git a/drivers/gpu/drm/i915/intel_uc.c b/drivers/gpu/drm/i915/intel_uc.c
index 731b82afe636..e711eb3268bc 100644
--- a/drivers/gpu/drm/i915/intel_uc.c
+++ b/drivers/gpu/drm/i915/intel_uc.c
@@ -26,6 +26,7 @@
 #include "intel_guc_submission.h"
 #include "intel_guc.h"
 #include "i915_drv.h"
+#include "i915_reset.h"
 
 static void guc_free_load_err_log(struct intel_guc *guc);
 
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 681ea532585e..e88f0252d77e 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1715,372 +1715,6 @@ int i915_reg_read_ioctl(struct drm_device *dev,
 	return ret;
 }
 
-static void gen3_stop_engine(struct intel_engine_cs *engine)
-{
-	struct drm_i915_private *dev_priv = engine->i915;
-	const u32 base = engine->mmio_base;
-
-	if (intel_engine_stop_cs(engine))
-		DRM_DEBUG_DRIVER("%s: timed out on STOP_RING\n", engine->name);
-
-	I915_WRITE_FW(RING_HEAD(base), I915_READ_FW(RING_TAIL(base)));
-	POSTING_READ_FW(RING_HEAD(base)); /* paranoia */
-
-	I915_WRITE_FW(RING_HEAD(base), 0);
-	I915_WRITE_FW(RING_TAIL(base), 0);
-	POSTING_READ_FW(RING_TAIL(base));
-
-	/* The ring must be empty before it is disabled */
-	I915_WRITE_FW(RING_CTL(base), 0);
-
-	/* Check acts as a post */
-	if (I915_READ_FW(RING_HEAD(base)) != 0)
-		DRM_DEBUG_DRIVER("%s: ring head not parked\n",
-				 engine->name);
-}
-
-static void i915_stop_engines(struct drm_i915_private *dev_priv,
-			      unsigned int engine_mask)
-{
-	struct intel_engine_cs *engine;
-	enum intel_engine_id id;
-
-	if (INTEL_GEN(dev_priv) < 3)
-		return;
-
-	for_each_engine_masked(engine, dev_priv, engine_mask, id)
-		gen3_stop_engine(engine);
-}
-
-static bool i915_in_reset(struct pci_dev *pdev)
-{
-	u8 gdrst;
-
-	pci_read_config_byte(pdev, I915_GDRST, &gdrst);
-	return gdrst & GRDOM_RESET_STATUS;
-}
-
-static int i915_do_reset(struct drm_i915_private *dev_priv,
-			 unsigned int engine_mask,
-			 unsigned int retry)
-{
-	struct pci_dev *pdev = dev_priv->drm.pdev;
-	int err;
-
-	/* Assert reset for at least 20 usec, and wait for acknowledgement. */
-	pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
-	usleep_range(50, 200);
-	err = wait_for(i915_in_reset(pdev), 500);
-
-	/* Clear the reset request. */
-	pci_write_config_byte(pdev, I915_GDRST, 0);
-	usleep_range(50, 200);
-	if (!err)
-		err = wait_for(!i915_in_reset(pdev), 500);
-
-	return err;
-}
-
-static bool g4x_reset_complete(struct pci_dev *pdev)
-{
-	u8 gdrst;
-
-	pci_read_config_byte(pdev, I915_GDRST, &gdrst);
-	return (gdrst & GRDOM_RESET_ENABLE) == 0;
-}
-
-static int g33_do_reset(struct drm_i915_private *dev_priv,
-			unsigned int engine_mask,
-			unsigned int retry)
-{
-	struct pci_dev *pdev = dev_priv->drm.pdev;
-
-	pci_write_config_byte(pdev, I915_GDRST, GRDOM_RESET_ENABLE);
-	return wait_for(g4x_reset_complete(pdev), 500);
-}
-
-static int g4x_do_reset(struct drm_i915_private *dev_priv,
-			unsigned int engine_mask,
-			unsigned int retry)
-{
-	struct pci_dev *pdev = dev_priv->drm.pdev;
-	int ret;
-
-	/* WaVcpClkGateDisableForMediaReset:ctg,elk */
-	I915_WRITE(VDECCLK_GATE_D,
-		   I915_READ(VDECCLK_GATE_D) | VCP_UNIT_CLOCK_GATE_DISABLE);
-	POSTING_READ(VDECCLK_GATE_D);
-
-	pci_write_config_byte(pdev, I915_GDRST,
-			      GRDOM_MEDIA | GRDOM_RESET_ENABLE);
-	ret =  wait_for(g4x_reset_complete(pdev), 500);
-	if (ret) {
-		DRM_DEBUG_DRIVER("Wait for media reset failed\n");
-		goto out;
-	}
-
-	pci_write_config_byte(pdev, I915_GDRST,
-			      GRDOM_RENDER | GRDOM_RESET_ENABLE);
-	ret =  wait_for(g4x_reset_complete(pdev), 500);
-	if (ret) {
-		DRM_DEBUG_DRIVER("Wait for render reset failed\n");
-		goto out;
-	}
-
-out:
-	pci_write_config_byte(pdev, I915_GDRST, 0);
-
-	I915_WRITE(VDECCLK_GATE_D,
-		   I915_READ(VDECCLK_GATE_D) & ~VCP_UNIT_CLOCK_GATE_DISABLE);
-	POSTING_READ(VDECCLK_GATE_D);
-
-	return ret;
-}
-
-static int ironlake_do_reset(struct drm_i915_private *dev_priv,
-			     unsigned int engine_mask,
-			     unsigned int retry)
-{
-	int ret;
-
-	I915_WRITE(ILK_GDSR, ILK_GRDOM_RENDER | ILK_GRDOM_RESET_ENABLE);
-	ret = intel_wait_for_register(dev_priv,
-				      ILK_GDSR, ILK_GRDOM_RESET_ENABLE, 0,
-				      500);
-	if (ret) {
-		DRM_DEBUG_DRIVER("Wait for render reset failed\n");
-		goto out;
-	}
-
-	I915_WRITE(ILK_GDSR, ILK_GRDOM_MEDIA | ILK_GRDOM_RESET_ENABLE);
-	ret = intel_wait_for_register(dev_priv,
-				      ILK_GDSR, ILK_GRDOM_RESET_ENABLE, 0,
-				      500);
-	if (ret) {
-		DRM_DEBUG_DRIVER("Wait for media reset failed\n");
-		goto out;
-	}
-
-out:
-	I915_WRITE(ILK_GDSR, 0);
-	POSTING_READ(ILK_GDSR);
-	return ret;
-}
-
-/* Reset the hardware domains (GENX_GRDOM_*) specified by mask */
-static int gen6_hw_domain_reset(struct drm_i915_private *dev_priv,
-				u32 hw_domain_mask)
-{
-	int err;
-
-	/* GEN6_GDRST is not in the gt power well, no need to check
-	 * for fifo space for the write or forcewake the chip for
-	 * the read
-	 */
-	__raw_i915_write32(dev_priv, GEN6_GDRST, hw_domain_mask);
-
-	/* Wait for the device to ack the reset requests */
-	err = __intel_wait_for_register_fw(dev_priv,
-					   GEN6_GDRST, hw_domain_mask, 0,
-					   500, 0,
-					   NULL);
-	if (err)
-		DRM_DEBUG_DRIVER("Wait for 0x%08x engines reset failed\n",
-				 hw_domain_mask);
-
-	return err;
-}
-
-/**
- * gen6_reset_engines - reset individual engines
- * @dev_priv: i915 device
- * @engine_mask: mask of intel_ring_flag() engines or ALL_ENGINES for full reset
- * @retry: the count of of previous attempts to reset.
- *
- * This function will reset the individual engines that are set in engine_mask.
- * If you provide ALL_ENGINES as mask, full global domain reset will be issued.
- *
- * Note: It is responsibility of the caller to handle the difference between
- * asking full domain reset versus reset for all available individual engines.
- *
- * Returns 0 on success, nonzero on error.
- */
-static int gen6_reset_engines(struct drm_i915_private *dev_priv,
-			      unsigned int engine_mask,
-			      unsigned int retry)
-{
-	struct intel_engine_cs *engine;
-	const u32 hw_engine_mask[I915_NUM_ENGINES] = {
-		[RCS] = GEN6_GRDOM_RENDER,
-		[BCS] = GEN6_GRDOM_BLT,
-		[VCS] = GEN6_GRDOM_MEDIA,
-		[VCS2] = GEN8_GRDOM_MEDIA2,
-		[VECS] = GEN6_GRDOM_VECS,
-	};
-	u32 hw_mask;
-
-	if (engine_mask == ALL_ENGINES) {
-		hw_mask = GEN6_GRDOM_FULL;
-	} else {
-		unsigned int tmp;
-
-		hw_mask = 0;
-		for_each_engine_masked(engine, dev_priv, engine_mask, tmp)
-			hw_mask |= hw_engine_mask[engine->id];
-	}
-
-	return gen6_hw_domain_reset(dev_priv, hw_mask);
-}
-
-static u32 gen11_lock_sfc(struct drm_i915_private *dev_priv,
-			  struct intel_engine_cs *engine)
-{
-	u8 vdbox_sfc_access = RUNTIME_INFO(dev_priv)->vdbox_sfc_access;
-	i915_reg_t sfc_forced_lock, sfc_forced_lock_ack;
-	u32 sfc_forced_lock_bit, sfc_forced_lock_ack_bit;
-	i915_reg_t sfc_usage;
-	u32 sfc_usage_bit;
-	u32 sfc_reset_bit;
-
-	switch (engine->class) {
-	case VIDEO_DECODE_CLASS:
-		if ((BIT(engine->instance) & vdbox_sfc_access) == 0)
-			return 0;
-
-		sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine);
-		sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
-
-		sfc_forced_lock_ack = GEN11_VCS_SFC_LOCK_STATUS(engine);
-		sfc_forced_lock_ack_bit  = GEN11_VCS_SFC_LOCK_ACK_BIT;
-
-		sfc_usage = GEN11_VCS_SFC_LOCK_STATUS(engine);
-		sfc_usage_bit = GEN11_VCS_SFC_USAGE_BIT;
-		sfc_reset_bit = GEN11_VCS_SFC_RESET_BIT(engine->instance);
-		break;
-
-	case VIDEO_ENHANCEMENT_CLASS:
-		sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine);
-		sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
-
-		sfc_forced_lock_ack = GEN11_VECS_SFC_LOCK_ACK(engine);
-		sfc_forced_lock_ack_bit  = GEN11_VECS_SFC_LOCK_ACK_BIT;
-
-		sfc_usage = GEN11_VECS_SFC_USAGE(engine);
-		sfc_usage_bit = GEN11_VECS_SFC_USAGE_BIT;
-		sfc_reset_bit = GEN11_VECS_SFC_RESET_BIT(engine->instance);
-		break;
-
-	default:
-		return 0;
-	}
-
-	/*
-	 * Tell the engine that a software reset is going to happen. The engine
-	 * will then try to force lock the SFC (if currently locked, it will
-	 * remain so until we tell the engine it is safe to unlock; if currently
-	 * unlocked, it will ignore this and all new lock requests). If SFC
-	 * ends up being locked to the engine we want to reset, we have to reset
-	 * it as well (we will unlock it once the reset sequence is completed).
-	 */
-	I915_WRITE_FW(sfc_forced_lock,
-		      I915_READ_FW(sfc_forced_lock) | sfc_forced_lock_bit);
-
-	if (__intel_wait_for_register_fw(dev_priv,
-					 sfc_forced_lock_ack,
-					 sfc_forced_lock_ack_bit,
-					 sfc_forced_lock_ack_bit,
-					 1000, 0, NULL)) {
-		DRM_DEBUG_DRIVER("Wait for SFC forced lock ack failed\n");
-		return 0;
-	}
-
-	if (I915_READ_FW(sfc_usage) & sfc_usage_bit)
-		return sfc_reset_bit;
-
-	return 0;
-}
-
-static void gen11_unlock_sfc(struct drm_i915_private *dev_priv,
-			     struct intel_engine_cs *engine)
-{
-	u8 vdbox_sfc_access = RUNTIME_INFO(dev_priv)->vdbox_sfc_access;
-	i915_reg_t sfc_forced_lock;
-	u32 sfc_forced_lock_bit;
-
-	switch (engine->class) {
-	case VIDEO_DECODE_CLASS:
-		if ((BIT(engine->instance) & vdbox_sfc_access) == 0)
-			return;
-
-		sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine);
-		sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
-		break;
-
-	case VIDEO_ENHANCEMENT_CLASS:
-		sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine);
-		sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
-		break;
-
-	default:
-		return;
-	}
-
-	I915_WRITE_FW(sfc_forced_lock,
-		      I915_READ_FW(sfc_forced_lock) & ~sfc_forced_lock_bit);
-}
-
-/**
- * gen11_reset_engines - reset individual engines
- * @dev_priv: i915 device
- * @engine_mask: mask of intel_ring_flag() engines or ALL_ENGINES for full reset
- *
- * This function will reset the individual engines that are set in engine_mask.
- * If you provide ALL_ENGINES as mask, full global domain reset will be issued.
- *
- * Note: It is responsibility of the caller to handle the difference between
- * asking full domain reset versus reset for all available individual engines.
- *
- * Returns 0 on success, nonzero on error.
- */
-static int gen11_reset_engines(struct drm_i915_private *dev_priv,
-			       unsigned int engine_mask)
-{
-	const u32 hw_engine_mask[I915_NUM_ENGINES] = {
-		[RCS] = GEN11_GRDOM_RENDER,
-		[BCS] = GEN11_GRDOM_BLT,
-		[VCS] = GEN11_GRDOM_MEDIA,
-		[VCS2] = GEN11_GRDOM_MEDIA2,
-		[VCS3] = GEN11_GRDOM_MEDIA3,
-		[VCS4] = GEN11_GRDOM_MEDIA4,
-		[VECS] = GEN11_GRDOM_VECS,
-		[VECS2] = GEN11_GRDOM_VECS2,
-	};
-	struct intel_engine_cs *engine;
-	unsigned int tmp;
-	u32 hw_mask;
-	int ret;
-
-	BUILD_BUG_ON(VECS2 + 1 != I915_NUM_ENGINES);
-
-	if (engine_mask == ALL_ENGINES) {
-		hw_mask = GEN11_GRDOM_FULL;
-	} else {
-		hw_mask = 0;
-		for_each_engine_masked(engine, dev_priv, engine_mask, tmp) {
-			hw_mask |= hw_engine_mask[engine->id];
-			hw_mask |= gen11_lock_sfc(dev_priv, engine);
-		}
-	}
-
-	ret = gen6_hw_domain_reset(dev_priv, hw_mask);
-
-	if (engine_mask != ALL_ENGINES)
-		for_each_engine_masked(engine, dev_priv, engine_mask, tmp)
-			gen11_unlock_sfc(dev_priv, engine);
-
-	return ret;
-}
-
 /**
  * __intel_wait_for_register_fw - wait until register matches expected state
  * @dev_priv: the i915 device
@@ -2191,196 +1825,6 @@ int __intel_wait_for_register(struct drm_i915_private *dev_priv,
 	return ret;
 }
 
-static int gen8_engine_reset_prepare(struct intel_engine_cs *engine)
-{
-	struct drm_i915_private *dev_priv = engine->i915;
-	int ret;
-
-	I915_WRITE_FW(RING_RESET_CTL(engine->mmio_base),
-		      _MASKED_BIT_ENABLE(RESET_CTL_REQUEST_RESET));
-
-	ret = __intel_wait_for_register_fw(dev_priv,
-					   RING_RESET_CTL(engine->mmio_base),
-					   RESET_CTL_READY_TO_RESET,
-					   RESET_CTL_READY_TO_RESET,
-					   700, 0,
-					   NULL);
-	if (ret)
-		DRM_ERROR("%s: reset request timeout\n", engine->name);
-
-	return ret;
-}
-
-static void gen8_engine_reset_cancel(struct intel_engine_cs *engine)
-{
-	struct drm_i915_private *dev_priv = engine->i915;
-
-	I915_WRITE_FW(RING_RESET_CTL(engine->mmio_base),
-		      _MASKED_BIT_DISABLE(RESET_CTL_REQUEST_RESET));
-}
-
-static int reset_engines(struct drm_i915_private *i915,
-			 unsigned int engine_mask,
-			 unsigned int retry)
-{
-	if (INTEL_GEN(i915) >= 11)
-		return gen11_reset_engines(i915, engine_mask);
-	else
-		return gen6_reset_engines(i915, engine_mask, retry);
-}
-
-static int gen8_reset_engines(struct drm_i915_private *dev_priv,
-			      unsigned int engine_mask,
-			      unsigned int retry)
-{
-	struct intel_engine_cs *engine;
-	const bool reset_non_ready = retry >= 1;
-	unsigned int tmp;
-	int ret;
-
-	for_each_engine_masked(engine, dev_priv, engine_mask, tmp) {
-		ret = gen8_engine_reset_prepare(engine);
-		if (ret && !reset_non_ready)
-			goto skip_reset;
-
-		/*
-		 * If this is not the first failed attempt to prepare,
-		 * we decide to proceed anyway.
-		 *
-		 * By doing so we risk context corruption and with
-		 * some gens (kbl), possible system hang if reset
-		 * happens during active bb execution.
-		 *
-		 * We rather take context corruption instead of
-		 * failed reset with a wedged driver/gpu. And
-		 * active bb execution case should be covered by
-		 * i915_stop_engines we have before the reset.
-		 */
-	}
-
-	ret = reset_engines(dev_priv, engine_mask, retry);
-
-skip_reset:
-	for_each_engine_masked(engine, dev_priv, engine_mask, tmp)
-		gen8_engine_reset_cancel(engine);
-
-	return ret;
-}
-
-typedef int (*reset_func)(struct drm_i915_private *,
-			  unsigned int engine_mask, unsigned int retry);
-
-static reset_func intel_get_gpu_reset(struct drm_i915_private *dev_priv)
-{
-	if (!i915_modparams.reset)
-		return NULL;
-
-	if (INTEL_GEN(dev_priv) >= 8)
-		return gen8_reset_engines;
-	else if (INTEL_GEN(dev_priv) >= 6)
-		return gen6_reset_engines;
-	else if (IS_GEN(dev_priv, 5))
-		return ironlake_do_reset;
-	else if (IS_G4X(dev_priv))
-		return g4x_do_reset;
-	else if (IS_G33(dev_priv) || IS_PINEVIEW(dev_priv))
-		return g33_do_reset;
-	else if (INTEL_GEN(dev_priv) >= 3)
-		return i915_do_reset;
-	else
-		return NULL;
-}
-
-int intel_gpu_reset(struct drm_i915_private *dev_priv,
-		    const unsigned int engine_mask)
-{
-	reset_func reset = intel_get_gpu_reset(dev_priv);
-	unsigned int retry;
-	int ret;
-
-	GEM_BUG_ON(!engine_mask);
-
-	/*
-	 * We want to perform per-engine reset from atomic context (e.g.
-	 * softirq), which imposes the constraint that we cannot sleep.
-	 * However, experience suggests that spending a bit of time waiting
-	 * for a reset helps in various cases, so for a full-device reset
-	 * we apply the opposite rule and wait if we want to. As we should
-	 * always follow up a failed per-engine reset with a full device reset,
-	 * being a little faster, stricter and more error prone for the
-	 * atomic case seems an acceptable compromise.
-	 *
-	 * Unfortunately this leads to a bimodal routine, when the goal was
-	 * to have a single reset function that worked for resetting any
-	 * number of engines simultaneously.
-	 */
-	might_sleep_if(engine_mask == ALL_ENGINES);
-
-	/*
-	 * If the power well sleeps during the reset, the reset
-	 * request may be dropped and never completes (causing -EIO).
-	 */
-	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
-	for (retry = 0; retry < 3; retry++) {
-
-		/*
-		 * We stop engines, otherwise we might get failed reset and a
-		 * dead gpu (on elk). Also as modern gpu as kbl can suffer
-		 * from system hang if batchbuffer is progressing when
-		 * the reset is issued, regardless of READY_TO_RESET ack.
-		 * Thus assume it is best to stop engines on all gens
-		 * where we have a gpu reset.
-		 *
-		 * WaKBLVECSSemaphoreWaitPoll:kbl (on ALL_ENGINES)
-		 *
-		 * WaMediaResetMainRingCleanup:ctg,elk (presumably)
-		 *
-		 * FIXME: Wa for more modern gens needs to be validated
-		 */
-		i915_stop_engines(dev_priv, engine_mask);
-
-		ret = -ENODEV;
-		if (reset) {
-			ret = reset(dev_priv, engine_mask, retry);
-			GEM_TRACE("engine_mask=%x, ret=%d, retry=%d\n",
-				  engine_mask, ret, retry);
-		}
-		if (ret != -ETIMEDOUT || engine_mask != ALL_ENGINES)
-			break;
-
-		cond_resched();
-	}
-	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
-
-	return ret;
-}
-
-bool intel_has_gpu_reset(struct drm_i915_private *dev_priv)
-{
-	return intel_get_gpu_reset(dev_priv) != NULL;
-}
-
-bool intel_has_reset_engine(struct drm_i915_private *dev_priv)
-{
-	return (INTEL_INFO(dev_priv)->has_reset_engine &&
-		i915_modparams.reset >= 2);
-}
-
-int intel_reset_guc(struct drm_i915_private *dev_priv)
-{
-	u32 guc_domain = INTEL_GEN(dev_priv) >= 11 ? GEN11_GRDOM_GUC :
-						     GEN9_GRDOM_GUC;
-	int ret;
-
-	GEM_BUG_ON(!HAS_GUC(dev_priv));
-
-	intel_uncore_forcewake_get(dev_priv, FORCEWAKE_ALL);
-	ret = gen6_hw_domain_reset(dev_priv, guc_domain);
-	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
-
-	return ret;
-}
-
 bool intel_uncore_unclaimed_mmio(struct drm_i915_private *dev_priv)
 {
 	return check_for_unclaimed_mmio(dev_priv);
diff --git a/drivers/gpu/drm/i915/selftests/intel_lrc.c b/drivers/gpu/drm/i915/selftests/intel_lrc.c
index e6073cd4719c..2b2ecd76c2ac 100644
--- a/drivers/gpu/drm/i915/selftests/intel_lrc.c
+++ b/drivers/gpu/drm/i915/selftests/intel_lrc.c
@@ -4,6 +4,8 @@
  * Copyright © 2018 Intel Corporation
  */
 
+#include "../i915_reset.h"
+
 #include "../i915_selftest.h"
 #include "igt_flush_test.h"
 #include "igt_spinner.h"
diff --git a/drivers/gpu/drm/i915/selftests/intel_workarounds.c b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
index 9009d7b8b136..a8cac56be835 100644
--- a/drivers/gpu/drm/i915/selftests/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
@@ -5,6 +5,7 @@
  */
 
 #include "../i915_selftest.h"
+#include "../i915_reset.h"
 
 #include "igt_flush_test.h"
 #include "igt_reset.h"
-- 
cgit v1.2.3-59-g8ed1b


From f1e9c90947979c041130011fbcd070200b5527b5 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Sat, 19 Jan 2019 14:30:24 +0000
Subject: drm/i915: Prevent use of global_seqno=0

We are not allowed to assign rq->global_seqno=0 as it has a special
meaning of "inactive" (not executing on HW).

Fixes: 6faf5916e6be ("drm/i915: Remove HW semaphores for gen7 inter-engine synchronisation")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190119143024.26971-1-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_request.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 33eb9df0dd0e..c7ce27785cda 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -343,6 +343,13 @@ static void move_to_timeline(struct i915_request *request,
 	spin_unlock(&request->timeline->lock);
 }
 
+static u32 next_global_seqno(struct i915_timeline *tl)
+{
+	if (!++tl->seqno)
+		++tl->seqno;
+	return tl->seqno;
+}
+
 void __i915_request_submit(struct i915_request *request)
 {
 	struct intel_engine_cs *engine = request->engine;
@@ -359,7 +366,7 @@ void __i915_request_submit(struct i915_request *request)
 
 	GEM_BUG_ON(request->global_seqno);
 
-	seqno = timeline_get_seqno(&engine->timeline);
+	seqno = next_global_seqno(&engine->timeline);
 	GEM_BUG_ON(!seqno);
 	GEM_BUG_ON(intel_engine_signaled(engine, seqno));
 
-- 
cgit v1.2.3-59-g8ed1b


From 0e21834e18c545bdebed527209a7b6bb8aed9f9b Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 21 Jan 2019 22:21:02 +0000
Subject: drm/i915: Tidy common test_bit probing of i915_request->fence.flags

A repeated pattern is to test the signaled bit of our
request->fence.flags. Make this an inline to shorten a few lines and
remove unnecessary line continuations.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190121222117.23305-20-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_irq.c          | 3 +--
 drivers/gpu/drm/i915/i915_request.c      | 2 +-
 drivers/gpu/drm/i915/i915_request.h      | 5 +++++
 drivers/gpu/drm/i915/intel_breadcrumbs.c | 3 +--
 drivers/gpu/drm/i915/intel_lrc.c         | 2 +-
 drivers/gpu/drm/i915/intel_pm.c          | 2 +-
 drivers/gpu/drm/i915/intel_ringbuffer.c  | 3 +--
 7 files changed, 11 insertions(+), 9 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 1abfc3fa76ad..5fd5080c4ccb 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1182,8 +1182,7 @@ static void notify_ring(struct intel_engine_cs *engine)
 			struct i915_request *waiter = wait->request;
 
 			if (waiter &&
-			    !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
-				      &waiter->fence.flags) &&
+			    !i915_request_signaled(waiter) &&
 			    intel_wait_check_request(wait, waiter))
 				rq = i915_request_get(waiter);
 
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index c7ce27785cda..426194ee978a 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -198,7 +198,7 @@ static void __retire_engine_request(struct intel_engine_cs *engine,
 	spin_unlock(&engine->timeline.lock);
 
 	spin_lock(&rq->lock);
-	if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags))
+	if (!i915_request_signaled(rq))
 		dma_fence_signal_locked(&rq->fence);
 	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &rq->fence.flags))
 		intel_engine_cancel_signaling(rq);
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index d014b0605445..c0f084ca4f29 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -280,6 +280,11 @@ long i915_request_wait(struct i915_request *rq,
 #define I915_WAIT_ALL		BIT(3) /* used by i915_gem_object_wait() */
 #define I915_WAIT_FOR_IDLE_BOOST BIT(4)
 
+static inline bool i915_request_signaled(const struct i915_request *rq)
+{
+	return test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags);
+}
+
 static inline bool intel_engine_has_started(struct intel_engine_cs *engine,
 					    u32 seqno);
 static inline bool intel_engine_has_completed(struct intel_engine_cs *engine,
diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c
index 4fad93fe3678..b58915b8708b 100644
--- a/drivers/gpu/drm/i915/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c
@@ -631,8 +631,7 @@ static int intel_breadcrumbs_signaler(void *arg)
 				rq->signaling.wait.seqno = 0;
 				__list_del_entry(&rq->signaling.link);
 
-				if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
-					      &rq->fence.flags)) {
+				if (!i915_request_signaled(rq)) {
 					list_add_tail(&rq->signaling.link,
 						      &list);
 					i915_request_get(rq);
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index f0fa0f767eb6..382a1262f75a 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -816,7 +816,7 @@ static void execlists_cancel_requests(struct intel_engine_cs *engine)
 	list_for_each_entry(rq, &engine->timeline.requests, link) {
 		GEM_BUG_ON(!rq->global_seqno);
 
-		if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags))
+		if (i915_request_signaled(rq))
 			continue;
 
 		dma_fence_set_error(&rq->fence, -EIO);
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 8b63afa3a221..fdc28a3d2936 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -6662,7 +6662,7 @@ void gen6_rps_boost(struct i915_request *rq,
 	if (!rps->enabled)
 		return;
 
-	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags))
+	if (i915_request_signaled(rq))
 		return;
 
 	/* Serializes with i915_request_retire() */
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 26b7274a2d43..e39e483d8d16 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -836,8 +836,7 @@ static void cancel_requests(struct intel_engine_cs *engine)
 	list_for_each_entry(request, &engine->timeline.requests, link) {
 		GEM_BUG_ON(!request->global_seqno);
 
-		if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
-			     &request->fence.flags))
+		if (i915_request_signaled(request))
 			continue;
 
 		dma_fence_set_error(&request->fence, -EIO);
-- 
cgit v1.2.3-59-g8ed1b


From 9fa4973e91be3e5cb220f7d607c21bf6e82c52d1 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 25 Jan 2019 12:00:04 +0000
Subject: drm/i915: Remove manual breadcumb counting

Now that we know we measure the size of the engine->emit_breadcrumb()
correctly, we can remove the previous manual counting.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190125120005.25191-1-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_request.c     |  4 ++--
 drivers/gpu/drm/i915/intel_engine_cs.c  |  7 +++----
 drivers/gpu/drm/i915/intel_lrc.c        |  4 ----
 drivers/gpu/drm/i915/intel_ringbuffer.c | 28 +++++-----------------------
 drivers/gpu/drm/i915/intel_ringbuffer.h |  2 +-
 5 files changed, 11 insertions(+), 34 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index f941e40fd373..ddc35e9dc0c0 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -650,7 +650,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	 * around inside i915_request_add() there is sufficient space at
 	 * the beginning of the ring as well.
 	 */
-	rq->reserved_space = 2 * engine->emit_breadcrumb_sz * sizeof(u32);
+	rq->reserved_space = 2 * engine->emit_breadcrumb_dw * sizeof(u32);
 
 	/*
 	 * Record the position of the start of the request so that
@@ -901,7 +901,7 @@ void i915_request_add(struct i915_request *request)
 	 * GPU processing the request, we never over-estimate the
 	 * position of the ring's HEAD.
 	 */
-	cs = intel_ring_begin(request, engine->emit_breadcrumb_sz);
+	cs = intel_ring_begin(request, engine->emit_breadcrumb_dw);
 	GEM_BUG_ON(IS_ERR(cs));
 	request->postfix = intel_ring_offset(request, cs);
 
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 8f738a7cd117..ef4c8c50a4ba 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -611,7 +611,7 @@ struct measure_breadcrumb {
 	u32 cs[1024];
 };
 
-static int measure_breadcrumb_sz(struct intel_engine_cs *engine)
+static int measure_breadcrumb_dw(struct intel_engine_cs *engine)
 {
 	struct measure_breadcrumb *frame;
 	unsigned int dw;
@@ -637,7 +637,6 @@ static int measure_breadcrumb_sz(struct intel_engine_cs *engine)
 	frame->rq.timeline = &frame->timeline;
 
 	dw = engine->emit_breadcrumb(&frame->rq, frame->cs) - frame->cs;
-	GEM_BUG_ON(dw != engine->emit_breadcrumb_sz);
 
 	i915_timeline_fini(&frame->timeline);
 	kfree(frame);
@@ -698,11 +697,11 @@ int intel_engine_init_common(struct intel_engine_cs *engine)
 	if (ret)
 		goto err_breadcrumbs;
 
-	ret = measure_breadcrumb_sz(engine);
+	ret = measure_breadcrumb_dw(engine);
 	if (ret < 0)
 		goto err_status_page;
 
-	engine->emit_breadcrumb_sz = ret;
+	engine->emit_breadcrumb_dw = ret;
 
 	return 0;
 
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index d2299425cf2f..5551dd2ec0e6 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -2075,7 +2075,6 @@ static u32 *gen8_emit_breadcrumb(struct i915_request *request, u32 *cs)
 
 	return gen8_emit_wa_tail(request, cs);
 }
-static const int gen8_emit_breadcrumb_sz = 6 + WA_TAIL_DWORDS;
 
 static u32 *gen8_emit_breadcrumb_rcs(struct i915_request *request, u32 *cs)
 {
@@ -2099,7 +2098,6 @@ static u32 *gen8_emit_breadcrumb_rcs(struct i915_request *request, u32 *cs)
 
 	return gen8_emit_wa_tail(request, cs);
 }
-static const int gen8_emit_breadcrumb_rcs_sz = 8 + WA_TAIL_DWORDS;
 
 static int gen8_init_rcs_context(struct i915_request *rq)
 {
@@ -2192,7 +2190,6 @@ logical_ring_default_vfuncs(struct intel_engine_cs *engine)
 
 	engine->emit_flush = gen8_emit_flush;
 	engine->emit_breadcrumb = gen8_emit_breadcrumb;
-	engine->emit_breadcrumb_sz = gen8_emit_breadcrumb_sz;
 
 	engine->set_default_submission = intel_execlists_set_default_submission;
 
@@ -2298,7 +2295,6 @@ int logical_render_ring_init(struct intel_engine_cs *engine)
 	engine->init_context = gen8_init_rcs_context;
 	engine->emit_flush = gen8_emit_flush_render;
 	engine->emit_breadcrumb = gen8_emit_breadcrumb_rcs;
-	engine->emit_breadcrumb_sz = gen8_emit_breadcrumb_rcs_sz;
 
 	ret = logical_ring_init(engine);
 	if (ret)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 107c4934e2fa..09c90475168a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -330,7 +330,6 @@ static u32 *gen6_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 
 	return cs;
 }
-static const int gen6_rcs_emit_breadcrumb_sz = 14;
 
 static int
 gen7_render_ring_cs_stall_wa(struct i915_request *rq)
@@ -432,7 +431,6 @@ static u32 *gen7_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 
 	return cs;
 }
-static const int gen7_rcs_emit_breadcrumb_sz = 6;
 
 static u32 *gen6_xcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 {
@@ -446,7 +444,6 @@ static u32 *gen6_xcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 
 	return cs;
 }
-static const int gen6_xcs_emit_breadcrumb_sz = 4;
 
 #define GEN7_XCS_WA 32
 static u32 *gen7_xcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
@@ -475,7 +472,6 @@ static u32 *gen7_xcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 
 	return cs;
 }
-static const int gen7_xcs_emit_breadcrumb_sz = 8 + GEN7_XCS_WA * 3;
 #undef GEN7_XCS_WA
 
 static void set_hwstam(struct intel_engine_cs *engine, u32 mask)
@@ -885,7 +881,6 @@ static u32 *i9xx_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 
 	return cs;
 }
-static const int i9xx_emit_breadcrumb_sz = 6;
 
 #define GEN5_WA_STORES 8 /* must be at least 1! */
 static u32 *gen5_emit_breadcrumb(struct i915_request *rq, u32 *cs)
@@ -908,7 +903,6 @@ static u32 *gen5_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 
 	return cs;
 }
-static const int gen5_emit_breadcrumb_sz = GEN5_WA_STORES * 3 + 2;
 #undef GEN5_WA_STORES
 
 static void
@@ -2206,11 +2200,8 @@ static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,
 	engine->request_alloc = ring_request_alloc;
 
 	engine->emit_breadcrumb = i9xx_emit_breadcrumb;
-	engine->emit_breadcrumb_sz = i9xx_emit_breadcrumb_sz;
-	if (IS_GEN(dev_priv, 5)) {
+	if (IS_GEN(dev_priv, 5))
 		engine->emit_breadcrumb = gen5_emit_breadcrumb;
-		engine->emit_breadcrumb_sz = gen5_emit_breadcrumb_sz;
-	}
 
 	engine->set_default_submission = i9xx_set_default_submission;
 
@@ -2240,12 +2231,10 @@ int intel_init_render_ring_buffer(struct intel_engine_cs *engine)
 		engine->init_context = intel_rcs_ctx_init;
 		engine->emit_flush = gen7_render_ring_flush;
 		engine->emit_breadcrumb = gen7_rcs_emit_breadcrumb;
-		engine->emit_breadcrumb_sz = gen7_rcs_emit_breadcrumb_sz;
 	} else if (IS_GEN(dev_priv, 6)) {
 		engine->init_context = intel_rcs_ctx_init;
 		engine->emit_flush = gen6_render_ring_flush;
 		engine->emit_breadcrumb = gen6_rcs_emit_breadcrumb;
-		engine->emit_breadcrumb_sz = gen6_rcs_emit_breadcrumb_sz;
 	} else if (IS_GEN(dev_priv, 5)) {
 		engine->emit_flush = gen4_render_ring_flush;
 	} else {
@@ -2281,13 +2270,10 @@ int intel_init_bsd_ring_buffer(struct intel_engine_cs *engine)
 		engine->emit_flush = gen6_bsd_ring_flush;
 		engine->irq_enable_mask = GT_BSD_USER_INTERRUPT;
 
-		if (IS_GEN(dev_priv, 6)) {
+		if (IS_GEN(dev_priv, 6))
 			engine->emit_breadcrumb = gen6_xcs_emit_breadcrumb;
-			engine->emit_breadcrumb_sz = gen6_xcs_emit_breadcrumb_sz;
-		} else {
+		else
 			engine->emit_breadcrumb = gen7_xcs_emit_breadcrumb;
-			engine->emit_breadcrumb_sz = gen7_xcs_emit_breadcrumb_sz;
-		}
 	} else {
 		engine->emit_flush = bsd_ring_flush;
 		if (IS_GEN(dev_priv, 5))
@@ -2310,13 +2296,10 @@ int intel_init_blt_ring_buffer(struct intel_engine_cs *engine)
 	engine->emit_flush = gen6_ring_flush;
 	engine->irq_enable_mask = GT_BLT_USER_INTERRUPT;
 
-	if (IS_GEN(dev_priv, 6)) {
+	if (IS_GEN(dev_priv, 6))
 		engine->emit_breadcrumb = gen6_xcs_emit_breadcrumb;
-		engine->emit_breadcrumb_sz = gen6_xcs_emit_breadcrumb_sz;
-	} else {
+	else
 		engine->emit_breadcrumb = gen7_xcs_emit_breadcrumb;
-		engine->emit_breadcrumb_sz = gen7_xcs_emit_breadcrumb_sz;
-	}
 
 	return intel_init_ring_buffer(engine);
 }
@@ -2335,7 +2318,6 @@ int intel_init_vebox_ring_buffer(struct intel_engine_cs *engine)
 	engine->irq_disable = hsw_vebox_irq_disable;
 
 	engine->emit_breadcrumb = gen7_xcs_emit_breadcrumb;
-	engine->emit_breadcrumb_sz = gen7_xcs_emit_breadcrumb_sz;
 
 	return intel_init_ring_buffer(engine);
 }
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 479bd53d4ac6..0834e91d4ace 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -471,7 +471,7 @@ struct intel_engine_cs {
 #define I915_DISPATCH_SECURE BIT(0)
 #define I915_DISPATCH_PINNED BIT(1)
 	u32		*(*emit_breadcrumb)(struct i915_request *rq, u32 *cs);
-	int		emit_breadcrumb_sz;
+	int		emit_breadcrumb_dw;
 
 	/* Pass the request to the hardware queue (e.g. directly into
 	 * the legacy ringbuffer or to the end of an execlist).
-- 
cgit v1.2.3-59-g8ed1b


From eb8d0f5af4ec2d172baf8b4b9a2199cd916b4e54 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Fri, 25 Jan 2019 13:22:28 +0000
Subject: drm/i915: Remove GPU reset dependence on struct_mutex

Now that the submission backends are controlled via their own spinlocks,
with a wave of a magic wand we can lift the struct_mutex requirement
around GPU reset. That is we allow the submission frontend (userspace)
to keep on submitting while we process the GPU reset as we can suspend
the backend independently.

The major change is around the backoff/handoff strategy for performing
the reset. With no mutex deadlock, we no longer have to coordinate with
any waiter, and just perform the reset immediately.

Testcase: igt/gem_mmap_gtt/hang # regresses
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190125132230.22221-3-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_debugfs.c                |  38 +-
 drivers/gpu/drm/i915/i915_drv.h                    |   5 -
 drivers/gpu/drm/i915/i915_gem.c                    |  18 +-
 drivers/gpu/drm/i915/i915_gem_fence_reg.h          |   1 -
 drivers/gpu/drm/i915/i915_gem_gtt.h                |   1 +
 drivers/gpu/drm/i915/i915_gpu_error.c              | 104 +++---
 drivers/gpu/drm/i915/i915_gpu_error.h              |  28 +-
 drivers/gpu/drm/i915/i915_request.c                |  47 ---
 drivers/gpu/drm/i915/i915_reset.c                  | 392 ++++++++++-----------
 drivers/gpu/drm/i915/i915_reset.h                  |   3 +
 drivers/gpu/drm/i915/intel_engine_cs.c             |   6 +-
 drivers/gpu/drm/i915/intel_guc_submission.c        |   5 +-
 drivers/gpu/drm/i915/intel_hangcheck.c             |  28 +-
 drivers/gpu/drm/i915/intel_lrc.c                   |  91 ++---
 drivers/gpu/drm/i915/intel_overlay.c               |   2 -
 drivers/gpu/drm/i915/intel_ringbuffer.c            |  91 +++--
 drivers/gpu/drm/i915/intel_ringbuffer.h            |  17 +-
 drivers/gpu/drm/i915/selftests/intel_hangcheck.c   |  57 +--
 drivers/gpu/drm/i915/selftests/intel_workarounds.c |   3 -
 drivers/gpu/drm/i915/selftests/mock_gem_device.c   |   4 +-
 20 files changed, 404 insertions(+), 537 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 9a9e1da496dc..76dea0572f3e 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1284,8 +1284,6 @@ static int i915_hangcheck_info(struct seq_file *m, void *unused)
 		seq_puts(m, "Wedged\n");
 	if (test_bit(I915_RESET_BACKOFF, &dev_priv->gpu_error.flags))
 		seq_puts(m, "Reset in progress: struct_mutex backoff\n");
-	if (test_bit(I915_RESET_HANDOFF, &dev_priv->gpu_error.flags))
-		seq_puts(m, "Reset in progress: reset handoff to waiter\n");
 	if (waitqueue_active(&dev_priv->gpu_error.wait_queue))
 		seq_puts(m, "Waiter holding struct mutex\n");
 	if (waitqueue_active(&dev_priv->gpu_error.reset_queue))
@@ -1321,15 +1319,15 @@ static int i915_hangcheck_info(struct seq_file *m, void *unused)
 		struct rb_node *rb;
 
 		seq_printf(m, "%s:\n", engine->name);
-		seq_printf(m, "\tseqno = %x [current %x, last %x]\n",
+		seq_printf(m, "\tseqno = %x [current %x, last %x], %dms ago\n",
 			   engine->hangcheck.seqno, seqno[id],
-			   intel_engine_last_submit(engine));
-		seq_printf(m, "\twaiters? %s, fake irq active? %s, stalled? %s, wedged? %s\n",
+			   intel_engine_last_submit(engine),
+			   jiffies_to_msecs(jiffies -
+					    engine->hangcheck.action_timestamp));
+		seq_printf(m, "\twaiters? %s, fake irq active? %s\n",
 			   yesno(intel_engine_has_waiter(engine)),
 			   yesno(test_bit(engine->id,
-					  &dev_priv->gpu_error.missed_irq_rings)),
-			   yesno(engine->hangcheck.stalled),
-			   yesno(engine->hangcheck.wedged));
+					  &dev_priv->gpu_error.missed_irq_rings)));
 
 		spin_lock_irq(&b->rb_lock);
 		for (rb = rb_first(&b->waiters); rb; rb = rb_next(rb)) {
@@ -1343,11 +1341,6 @@ static int i915_hangcheck_info(struct seq_file *m, void *unused)
 		seq_printf(m, "\tACTHD = 0x%08llx [current 0x%08llx]\n",
 			   (long long)engine->hangcheck.acthd,
 			   (long long)acthd[id]);
-		seq_printf(m, "\taction = %s(%d) %d ms ago\n",
-			   hangcheck_action_to_str(engine->hangcheck.action),
-			   engine->hangcheck.action,
-			   jiffies_to_msecs(jiffies -
-					    engine->hangcheck.action_timestamp));
 
 		if (engine->id == RCS) {
 			seq_puts(m, "\tinstdone read =\n");
@@ -3911,8 +3904,6 @@ static int
 i915_wedged_set(void *data, u64 val)
 {
 	struct drm_i915_private *i915 = data;
-	struct intel_engine_cs *engine;
-	unsigned int tmp;
 
 	/*
 	 * There is no safeguard against this debugfs entry colliding
@@ -3925,18 +3916,8 @@ i915_wedged_set(void *data, u64 val)
 	if (i915_reset_backoff(&i915->gpu_error))
 		return -EAGAIN;
 
-	for_each_engine_masked(engine, i915, val, tmp) {
-		engine->hangcheck.seqno = intel_engine_get_seqno(engine);
-		engine->hangcheck.stalled = true;
-	}
-
 	i915_handle_error(i915, val, I915_ERROR_CAPTURE,
 			  "Manually set wedged engine mask = %llx", val);
-
-	wait_on_bit(&i915->gpu_error.flags,
-		    I915_RESET_HANDOFF,
-		    TASK_UNINTERRUPTIBLE);
-
 	return 0;
 }
 
@@ -4091,13 +4072,8 @@ i915_drop_caches_set(void *data, u64 val)
 		mutex_unlock(&i915->drm.struct_mutex);
 	}
 
-	if (val & DROP_RESET_ACTIVE &&
-	    i915_terminally_wedged(&i915->gpu_error)) {
+	if (val & DROP_RESET_ACTIVE && i915_terminally_wedged(&i915->gpu_error))
 		i915_handle_error(i915, ALL_ENGINES, 0, NULL);
-		wait_on_bit(&i915->gpu_error.flags,
-			    I915_RESET_HANDOFF,
-			    TASK_UNINTERRUPTIBLE);
-	}
 
 	fs_reclaim_acquire(GFP_KERNEL);
 	if (val & DROP_BOUND)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 3c111ad09922..0133d1da3d3c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3001,11 +3001,6 @@ static inline bool i915_reset_backoff(struct i915_gpu_error *error)
 	return unlikely(test_bit(I915_RESET_BACKOFF, &error->flags));
 }
 
-static inline bool i915_reset_handoff(struct i915_gpu_error *error)
-{
-	return unlikely(test_bit(I915_RESET_HANDOFF, &error->flags));
-}
-
 static inline bool i915_terminally_wedged(struct i915_gpu_error *error)
 {
 	return unlikely(test_bit(I915_WEDGED, &error->flags));
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index b359390ba22c..d20b42386c3c 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -657,11 +657,6 @@ i915_gem_object_wait(struct drm_i915_gem_object *obj,
 		     struct intel_rps_client *rps_client)
 {
 	might_sleep();
-#if IS_ENABLED(CONFIG_LOCKDEP)
-	GEM_BUG_ON(debug_locks &&
-		   !!lockdep_is_held(&obj->base.dev->struct_mutex) !=
-		   !!(flags & I915_WAIT_LOCKED));
-#endif
 	GEM_BUG_ON(timeout < 0);
 
 	timeout = i915_gem_object_wait_reservation(obj->resv,
@@ -4493,8 +4488,6 @@ void i915_gem_sanitize(struct drm_i915_private *i915)
 
 	GEM_TRACE("\n");
 
-	mutex_lock(&i915->drm.struct_mutex);
-
 	wakeref = intel_runtime_pm_get(i915);
 	intel_uncore_forcewake_get(i915, FORCEWAKE_ALL);
 
@@ -4520,6 +4513,7 @@ void i915_gem_sanitize(struct drm_i915_private *i915)
 	intel_uncore_forcewake_put(i915, FORCEWAKE_ALL);
 	intel_runtime_pm_put(i915, wakeref);
 
+	mutex_lock(&i915->drm.struct_mutex);
 	i915_gem_contexts_lost(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 }
@@ -4534,6 +4528,8 @@ int i915_gem_suspend(struct drm_i915_private *i915)
 	wakeref = intel_runtime_pm_get(i915);
 	intel_suspend_gt_powersave(i915);
 
+	flush_workqueue(i915->wq);
+
 	mutex_lock(&i915->drm.struct_mutex);
 
 	/*
@@ -4563,11 +4559,9 @@ int i915_gem_suspend(struct drm_i915_private *i915)
 	i915_retire_requests(i915); /* ensure we flush after wedging */
 
 	mutex_unlock(&i915->drm.struct_mutex);
+	i915_reset_flush(i915);
 
-	intel_uc_suspend(i915);
-
-	cancel_delayed_work_sync(&i915->gpu_error.hangcheck_work);
-	cancel_delayed_work_sync(&i915->gt.retire_work);
+	drain_delayed_work(&i915->gt.retire_work);
 
 	/*
 	 * As the idle_work is rearming if it detects a race, play safe and
@@ -4575,6 +4569,8 @@ int i915_gem_suspend(struct drm_i915_private *i915)
 	 */
 	drain_delayed_work(&i915->gt.idle_work);
 
+	intel_uc_suspend(i915);
+
 	/*
 	 * Assert that we successfully flushed all the work and
 	 * reset the GPU back to its idle, low power state.
diff --git a/drivers/gpu/drm/i915/i915_gem_fence_reg.h b/drivers/gpu/drm/i915/i915_gem_fence_reg.h
index 99a31ded4dfd..09dcaf14121b 100644
--- a/drivers/gpu/drm/i915/i915_gem_fence_reg.h
+++ b/drivers/gpu/drm/i915/i915_gem_fence_reg.h
@@ -50,4 +50,3 @@ struct drm_i915_fence_reg {
 };
 
 #endif
-
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 9229b03d629b..a0039ea97cdc 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -39,6 +39,7 @@
 #include <linux/pagevec.h>
 
 #include "i915_request.h"
+#include "i915_reset.h"
 #include "i915_selftest.h"
 #include "i915_timeline.h"
 
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 1f8e80e31b49..4eef0462489c 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -533,10 +533,7 @@ static void error_print_engine(struct drm_i915_error_state_buf *m,
 	err_printf(m, "  waiting: %s\n", yesno(ee->waiting));
 	err_printf(m, "  ring->head: 0x%08x\n", ee->cpu_ring_head);
 	err_printf(m, "  ring->tail: 0x%08x\n", ee->cpu_ring_tail);
-	err_printf(m, "  hangcheck stall: %s\n", yesno(ee->hangcheck_stalled));
-	err_printf(m, "  hangcheck action: %s\n",
-		   hangcheck_action_to_str(ee->hangcheck_action));
-	err_printf(m, "  hangcheck action timestamp: %dms (%lu%s)\n",
+	err_printf(m, "  hangcheck timestamp: %dms (%lu%s)\n",
 		   jiffies_to_msecs(ee->hangcheck_timestamp - epoch),
 		   ee->hangcheck_timestamp,
 		   ee->hangcheck_timestamp == epoch ? "; epoch" : "");
@@ -684,15 +681,15 @@ static void __err_print_to_sgl(struct drm_i915_error_state_buf *m,
 		   jiffies_to_msecs(error->capture - error->epoch));
 
 	for (i = 0; i < ARRAY_SIZE(error->engine); i++) {
-		if (error->engine[i].hangcheck_stalled &&
-		    error->engine[i].context.pid) {
-			err_printf(m, "Active process (on ring %s): %s [%d], score %d%s\n",
-				   engine_name(m->i915, i),
-				   error->engine[i].context.comm,
-				   error->engine[i].context.pid,
-				   error->engine[i].context.ban_score,
-				   bannable(&error->engine[i].context));
-		}
+		if (!error->engine[i].context.pid)
+			continue;
+
+		err_printf(m, "Active process (on ring %s): %s [%d], score %d%s\n",
+			   engine_name(m->i915, i),
+			   error->engine[i].context.comm,
+			   error->engine[i].context.pid,
+			   error->engine[i].context.ban_score,
+			   bannable(&error->engine[i].context));
 	}
 	err_printf(m, "Reset count: %u\n", error->reset_count);
 	err_printf(m, "Suspend count: %u\n", error->suspend_count);
@@ -1144,7 +1141,8 @@ static u32 capture_error_bo(struct drm_i915_error_buffer *err,
 	return i;
 }
 
-/* Generate a semi-unique error code. The code is not meant to have meaning, The
+/*
+ * Generate a semi-unique error code. The code is not meant to have meaning, The
  * code's only purpose is to try to prevent false duplicated bug reports by
  * grossly estimating a GPU error state.
  *
@@ -1153,29 +1151,23 @@ static u32 capture_error_bo(struct drm_i915_error_buffer *err,
  *
  * It's only a small step better than a random number in its current form.
  */
-static u32 i915_error_generate_code(struct drm_i915_private *dev_priv,
-				    struct i915_gpu_state *error,
-				    int *engine_id)
+static u32 i915_error_generate_code(struct i915_gpu_state *error,
+				    unsigned long engine_mask)
 {
-	u32 error_code = 0;
-	int i;
-
-	/* IPEHR would be an ideal way to detect errors, as it's the gross
+	/*
+	 * IPEHR would be an ideal way to detect errors, as it's the gross
 	 * measure of "the command that hung." However, has some very common
 	 * synchronization commands which almost always appear in the case
 	 * strictly a client bug. Use instdone to differentiate those some.
 	 */
-	for (i = 0; i < I915_NUM_ENGINES; i++) {
-		if (error->engine[i].hangcheck_stalled) {
-			if (engine_id)
-				*engine_id = i;
+	if (engine_mask) {
+		struct drm_i915_error_engine *ee =
+			&error->engine[ffs(engine_mask)];
 
-			return error->engine[i].ipehr ^
-			       error->engine[i].instdone.instdone;
-		}
+		return ee->ipehr ^ ee->instdone.instdone;
 	}
 
-	return error_code;
+	return 0;
 }
 
 static void gem_record_fences(struct i915_gpu_state *error)
@@ -1338,9 +1330,8 @@ static void error_record_engine_registers(struct i915_gpu_state *error,
 	}
 
 	ee->idle = intel_engine_is_idle(engine);
-	ee->hangcheck_timestamp = engine->hangcheck.action_timestamp;
-	ee->hangcheck_action = engine->hangcheck.action;
-	ee->hangcheck_stalled = engine->hangcheck.stalled;
+	if (!ee->idle)
+		ee->hangcheck_timestamp = engine->hangcheck.action_timestamp;
 	ee->reset_count = i915_reset_engine_count(&dev_priv->gpu_error,
 						  engine);
 
@@ -1783,31 +1774,35 @@ static void capture_reg_state(struct i915_gpu_state *error)
 	error->pgtbl_er = I915_READ(PGTBL_ER);
 }
 
-static void i915_error_capture_msg(struct drm_i915_private *dev_priv,
-				   struct i915_gpu_state *error,
-				   u32 engine_mask,
-				   const char *error_msg)
+static const char *
+error_msg(struct i915_gpu_state *error, unsigned long engines, const char *msg)
 {
-	u32 ecode;
-	int engine_id = -1, len;
+	int len;
+	int i;
 
-	ecode = i915_error_generate_code(dev_priv, error, &engine_id);
+	for (i = 0; i < ARRAY_SIZE(error->engine); i++)
+		if (!error->engine[i].context.pid)
+			engines &= ~BIT(i);
 
 	len = scnprintf(error->error_msg, sizeof(error->error_msg),
-			"GPU HANG: ecode %d:%d:0x%08x",
-			INTEL_GEN(dev_priv), engine_id, ecode);
-
-	if (engine_id != -1 && error->engine[engine_id].context.pid)
+			"GPU HANG: ecode %d:%lx:0x%08x",
+			INTEL_GEN(error->i915), engines,
+			i915_error_generate_code(error, engines));
+	if (engines) {
+		/* Just show the first executing process, more is confusing */
+		i = ffs(engines);
 		len += scnprintf(error->error_msg + len,
 				 sizeof(error->error_msg) - len,
 				 ", in %s [%d]",
-				 error->engine[engine_id].context.comm,
-				 error->engine[engine_id].context.pid);
+				 error->engine[i].context.comm,
+				 error->engine[i].context.pid);
+	}
+	if (msg)
+		len += scnprintf(error->error_msg + len,
+				 sizeof(error->error_msg) - len,
+				 ", %s", msg);
 
-	scnprintf(error->error_msg + len, sizeof(error->error_msg) - len,
-		  ", reason: %s, action: %s",
-		  error_msg,
-		  engine_mask ? "reset" : "continue");
+	return error->error_msg;
 }
 
 static void capture_gen_state(struct i915_gpu_state *error)
@@ -1847,7 +1842,7 @@ static unsigned long capture_find_epoch(const struct i915_gpu_state *error)
 	for (i = 0; i < ARRAY_SIZE(error->engine); i++) {
 		const struct drm_i915_error_engine *ee = &error->engine[i];
 
-		if (ee->hangcheck_stalled &&
+		if (ee->hangcheck_timestamp &&
 		    time_before(ee->hangcheck_timestamp, epoch))
 			epoch = ee->hangcheck_timestamp;
 	}
@@ -1921,7 +1916,7 @@ i915_capture_gpu_state(struct drm_i915_private *i915)
  * i915_capture_error_state - capture an error record for later analysis
  * @i915: i915 device
  * @engine_mask: the mask of engines triggering the hang
- * @error_msg: a message to insert into the error capture header
+ * @msg: a message to insert into the error capture header
  *
  * Should be called when an error is detected (either a hang or an error
  * interrupt) to capture error state from the time of the error.  Fills
@@ -1929,8 +1924,8 @@ i915_capture_gpu_state(struct drm_i915_private *i915)
  * to pick up.
  */
 void i915_capture_error_state(struct drm_i915_private *i915,
-			      u32 engine_mask,
-			      const char *error_msg)
+			      unsigned long engine_mask,
+			      const char *msg)
 {
 	static bool warned;
 	struct i915_gpu_state *error;
@@ -1946,8 +1941,7 @@ void i915_capture_error_state(struct drm_i915_private *i915,
 	if (IS_ERR(error))
 		return;
 
-	i915_error_capture_msg(i915, error, engine_mask, error_msg);
-	DRM_INFO("%s\n", error->error_msg);
+	dev_info(i915->drm.dev, "%s\n", error_msg(error, engine_mask, msg));
 
 	if (!error->simulated) {
 		spin_lock_irqsave(&i915->gpu_error.lock, flags);
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.h b/drivers/gpu/drm/i915/i915_gpu_error.h
index 604291f7762d..231173786eae 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.h
+++ b/drivers/gpu/drm/i915/i915_gpu_error.h
@@ -85,8 +85,6 @@ struct i915_gpu_state {
 		bool waiting;
 		int num_waiters;
 		unsigned long hangcheck_timestamp;
-		bool hangcheck_stalled;
-		enum intel_engine_hangcheck_action hangcheck_action;
 		struct i915_address_space *vm;
 		int num_requests;
 		u32 reset_count;
@@ -197,6 +195,8 @@ struct i915_gpu_state {
 	struct scatterlist *sgl, *fit;
 };
 
+struct i915_gpu_restart;
+
 struct i915_gpu_error {
 	/* For hangcheck timer */
 #define DRM_I915_HANGCHECK_PERIOD 1500 /* in ms */
@@ -247,15 +247,6 @@ struct i915_gpu_error {
 	 * i915_mutex_lock_interruptible()?). I915_RESET_BACKOFF serves a
 	 * secondary role in preventing two concurrent global reset attempts.
 	 *
-	 * #I915_RESET_HANDOFF - To perform the actual GPU reset, we need the
-	 * struct_mutex. We try to acquire the struct_mutex in the reset worker,
-	 * but it may be held by some long running waiter (that we cannot
-	 * interrupt without causing trouble). Once we are ready to do the GPU
-	 * reset, we set the I915_RESET_HANDOFF bit and wakeup any waiters. If
-	 * they already hold the struct_mutex and want to participate they can
-	 * inspect the bit and do the reset directly, otherwise the worker
-	 * waits for the struct_mutex.
-	 *
 	 * #I915_RESET_ENGINE[num_engines] - Since the driver doesn't need to
 	 * acquire the struct_mutex to reset an engine, we need an explicit
 	 * flag to prevent two concurrent reset attempts in the same engine.
@@ -269,20 +260,13 @@ struct i915_gpu_error {
 	 */
 	unsigned long flags;
 #define I915_RESET_BACKOFF	0
-#define I915_RESET_HANDOFF	1
-#define I915_RESET_MODESET	2
-#define I915_RESET_ENGINE	3
+#define I915_RESET_MODESET	1
+#define I915_RESET_ENGINE	2
 #define I915_WEDGED		(BITS_PER_LONG - 1)
 
 	/** Number of times an engine has been reset */
 	u32 reset_engine_count[I915_NUM_ENGINES];
 
-	/** Set of stalled engines with guilty requests, in the current reset */
-	u32 stalled_mask;
-
-	/** Reason for the current *global* reset */
-	const char *reason;
-
 	struct mutex wedge_mutex; /* serialises wedging/unwedging */
 
 	/**
@@ -299,6 +283,8 @@ struct i915_gpu_error {
 
 	/* For missed irq/seqno simulation. */
 	unsigned long test_irq_rings;
+
+	struct i915_gpu_restart *restart;
 };
 
 struct drm_i915_error_state_buf {
@@ -320,7 +306,7 @@ void i915_error_printf(struct drm_i915_error_state_buf *e, const char *f, ...);
 
 struct i915_gpu_state *i915_capture_gpu_state(struct drm_i915_private *i915);
 void i915_capture_error_state(struct drm_i915_private *dev_priv,
-			      u32 engine_mask,
+			      unsigned long engine_mask,
 			      const char *error_msg);
 
 static inline struct i915_gpu_state *
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index ddc35e9dc0c0..f4241a17e2ad 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1083,18 +1083,6 @@ static bool __i915_spin_request(const struct i915_request *rq,
 	return false;
 }
 
-static bool __i915_wait_request_check_and_reset(struct i915_request *request)
-{
-	struct i915_gpu_error *error = &request->i915->gpu_error;
-
-	if (likely(!i915_reset_handoff(error)))
-		return false;
-
-	__set_current_state(TASK_RUNNING);
-	i915_reset(request->i915, error->stalled_mask, error->reason);
-	return true;
-}
-
 /**
  * i915_request_wait - wait until execution of request has finished
  * @rq: the request to wait upon
@@ -1120,17 +1108,10 @@ long i915_request_wait(struct i915_request *rq,
 {
 	const int state = flags & I915_WAIT_INTERRUPTIBLE ?
 		TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE;
-	wait_queue_head_t *errq = &rq->i915->gpu_error.wait_queue;
-	DEFINE_WAIT_FUNC(reset, default_wake_function);
 	DEFINE_WAIT_FUNC(exec, default_wake_function);
 	struct intel_wait wait;
 
 	might_sleep();
-#if IS_ENABLED(CONFIG_LOCKDEP)
-	GEM_BUG_ON(debug_locks &&
-		   !!lockdep_is_held(&rq->i915->drm.struct_mutex) !=
-		   !!(flags & I915_WAIT_LOCKED));
-#endif
 	GEM_BUG_ON(timeout < 0);
 
 	if (i915_request_completed(rq))
@@ -1140,11 +1121,7 @@ long i915_request_wait(struct i915_request *rq,
 		return -ETIME;
 
 	trace_i915_request_wait_begin(rq, flags);
-
 	add_wait_queue(&rq->execute, &exec);
-	if (flags & I915_WAIT_LOCKED)
-		add_wait_queue(errq, &reset);
-
 	intel_wait_init(&wait);
 	if (flags & I915_WAIT_PRIORITY)
 		i915_schedule_bump_priority(rq, I915_PRIORITY_WAIT);
@@ -1155,10 +1132,6 @@ restart:
 		if (intel_wait_update_request(&wait, rq))
 			break;
 
-		if (flags & I915_WAIT_LOCKED &&
-		    __i915_wait_request_check_and_reset(rq))
-			continue;
-
 		if (signal_pending_state(state, current)) {
 			timeout = -ERESTARTSYS;
 			goto complete;
@@ -1188,9 +1161,6 @@ restart:
 		 */
 		goto wakeup;
 
-	if (flags & I915_WAIT_LOCKED)
-		__i915_wait_request_check_and_reset(rq);
-
 	for (;;) {
 		if (signal_pending_state(state, current)) {
 			timeout = -ERESTARTSYS;
@@ -1214,21 +1184,6 @@ wakeup:
 		if (i915_request_completed(rq))
 			break;
 
-		/*
-		 * If the GPU is hung, and we hold the lock, reset the GPU
-		 * and then check for completion. On a full reset, the engine's
-		 * HW seqno will be advanced passed us and we are complete.
-		 * If we do a partial reset, we have to wait for the GPU to
-		 * resume and update the breadcrumb.
-		 *
-		 * If we don't hold the mutex, we can just wait for the worker
-		 * to come along and update the breadcrumb (either directly
-		 * itself, or indirectly by recovering the GPU).
-		 */
-		if (flags & I915_WAIT_LOCKED &&
-		    __i915_wait_request_check_and_reset(rq))
-			continue;
-
 		/* Only spin if we know the GPU is processing this request */
 		if (__i915_spin_request(rq, wait.seqno, state, 2))
 			break;
@@ -1242,8 +1197,6 @@ wakeup:
 	intel_engine_remove_wait(rq->engine, &wait);
 complete:
 	__set_current_state(TASK_RUNNING);
-	if (flags & I915_WAIT_LOCKED)
-		remove_wait_queue(errq, &reset);
 	remove_wait_queue(&rq->execute, &exec);
 	trace_i915_request_wait_end(rq);
 
diff --git a/drivers/gpu/drm/i915/i915_reset.c b/drivers/gpu/drm/i915/i915_reset.c
index 33408c4e6358..68af017ee548 100644
--- a/drivers/gpu/drm/i915/i915_reset.c
+++ b/drivers/gpu/drm/i915/i915_reset.c
@@ -5,6 +5,7 @@
  */
 
 #include <linux/sched/mm.h>
+#include <linux/stop_machine.h>
 
 #include "i915_drv.h"
 #include "i915_gpu_error.h"
@@ -14,27 +15,31 @@
 
 #define RESET_MAX_RETRIES 3
 
+/* XXX How to handle concurrent GGTT updates using tiling registers? */
+#define RESET_UNDER_STOP_MACHINE 0
+
 static void engine_skip_context(struct i915_request *rq)
 {
 	struct intel_engine_cs *engine = rq->engine;
 	struct i915_gem_context *hung_ctx = rq->gem_context;
 	struct i915_timeline *timeline = rq->timeline;
-	unsigned long flags;
 
+	lockdep_assert_held(&engine->timeline.lock);
 	GEM_BUG_ON(timeline == &engine->timeline);
 
-	spin_lock_irqsave(&engine->timeline.lock, flags);
 	spin_lock(&timeline->lock);
 
-	list_for_each_entry_continue(rq, &engine->timeline.requests, link)
-		if (rq->gem_context == hung_ctx)
-			i915_request_skip(rq, -EIO);
+	if (rq->global_seqno) {
+		list_for_each_entry_continue(rq,
+					     &engine->timeline.requests, link)
+			if (rq->gem_context == hung_ctx)
+				i915_request_skip(rq, -EIO);
+	}
 
 	list_for_each_entry(rq, &timeline->requests, link)
 		i915_request_skip(rq, -EIO);
 
 	spin_unlock(&timeline->lock);
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
 }
 
 static void client_mark_guilty(struct drm_i915_file_private *file_priv,
@@ -61,7 +66,7 @@ static void client_mark_guilty(struct drm_i915_file_private *file_priv,
 	}
 }
 
-static void context_mark_guilty(struct i915_gem_context *ctx)
+static bool context_mark_guilty(struct i915_gem_context *ctx)
 {
 	unsigned int score;
 	bool banned, bannable;
@@ -74,7 +79,7 @@ static void context_mark_guilty(struct i915_gem_context *ctx)
 
 	/* Cool contexts don't accumulate client ban score */
 	if (!bannable)
-		return;
+		return false;
 
 	if (banned) {
 		DRM_DEBUG_DRIVER("context %s: guilty %d, score %u, banned\n",
@@ -85,6 +90,8 @@ static void context_mark_guilty(struct i915_gem_context *ctx)
 
 	if (!IS_ERR_OR_NULL(ctx->file_priv))
 		client_mark_guilty(ctx->file_priv, ctx);
+
+	return banned;
 }
 
 static void context_mark_innocent(struct i915_gem_context *ctx)
@@ -92,6 +99,21 @@ static void context_mark_innocent(struct i915_gem_context *ctx)
 	atomic_inc(&ctx->active_count);
 }
 
+void i915_reset_request(struct i915_request *rq, bool guilty)
+{
+	lockdep_assert_held(&rq->engine->timeline.lock);
+	GEM_BUG_ON(i915_request_completed(rq));
+
+	if (guilty) {
+		i915_request_skip(rq, -EIO);
+		if (context_mark_guilty(rq->gem_context))
+			engine_skip_context(rq);
+	} else {
+		dma_fence_set_error(&rq->fence, -EAGAIN);
+		context_mark_innocent(rq->gem_context);
+	}
+}
+
 static void gen3_stop_engine(struct intel_engine_cs *engine)
 {
 	struct drm_i915_private *dev_priv = engine->i915;
@@ -604,11 +626,8 @@ int intel_reset_guc(struct drm_i915_private *i915)
  * Ensure irq handler finishes, and not run again.
  * Also return the active request so that we only search for it once.
  */
-static struct i915_request *
-reset_prepare_engine(struct intel_engine_cs *engine)
+static void reset_prepare_engine(struct intel_engine_cs *engine)
 {
-	struct i915_request *rq;
-
 	/*
 	 * During the reset sequence, we must prevent the engine from
 	 * entering RC6. As the context state is undefined until we restart
@@ -617,162 +636,85 @@ reset_prepare_engine(struct intel_engine_cs *engine)
 	 * GPU state upon resume, i.e. fail to restart after a reset.
 	 */
 	intel_uncore_forcewake_get(engine->i915, FORCEWAKE_ALL);
-
-	rq = engine->reset.prepare(engine);
-	if (rq && rq->fence.error == -EIO)
-		rq = ERR_PTR(-EIO); /* Previous reset failed! */
-
-	return rq;
+	engine->reset.prepare(engine);
 }
 
-static int reset_prepare(struct drm_i915_private *i915)
+static void reset_prepare(struct drm_i915_private *i915)
 {
 	struct intel_engine_cs *engine;
-	struct i915_request *rq;
 	enum intel_engine_id id;
-	int err = 0;
 
-	for_each_engine(engine, i915, id) {
-		rq = reset_prepare_engine(engine);
-		if (IS_ERR(rq)) {
-			err = PTR_ERR(rq);
-			continue;
-		}
-
-		engine->hangcheck.active_request = rq;
-	}
+	for_each_engine(engine, i915, id)
+		reset_prepare_engine(engine);
 
-	i915_gem_revoke_fences(i915);
 	intel_uc_sanitize(i915);
-
-	return err;
 }
 
-/* Returns the request if it was guilty of the hang */
-static struct i915_request *
-reset_request(struct intel_engine_cs *engine,
-	      struct i915_request *rq,
-	      bool stalled)
+static int gt_reset(struct drm_i915_private *i915, unsigned int stalled_mask)
 {
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int err;
+
 	/*
-	 * The guilty request will get skipped on a hung engine.
-	 *
-	 * Users of client default contexts do not rely on logical
-	 * state preserved between batches so it is safe to execute
-	 * queued requests following the hang. Non default contexts
-	 * rely on preserved state, so skipping a batch loses the
-	 * evolution of the state and it needs to be considered corrupted.
-	 * Executing more queued batches on top of corrupted state is
-	 * risky. But we take the risk by trying to advance through
-	 * the queued requests in order to make the client behaviour
-	 * more predictable around resets, by not throwing away random
-	 * amount of batches it has prepared for execution. Sophisticated
-	 * clients can use gem_reset_stats_ioctl and dma fence status
-	 * (exported via sync_file info ioctl on explicit fences) to observe
-	 * when it loses the context state and should rebuild accordingly.
-	 *
-	 * The context ban, and ultimately the client ban, mechanism are safety
-	 * valves if client submission ends up resulting in nothing more than
-	 * subsequent hangs.
+	 * Everything depends on having the GTT running, so we need to start
+	 * there.
 	 */
+	err = i915_ggtt_enable_hw(i915);
+	if (err)
+		return err;
 
-	if (i915_request_completed(rq)) {
-		GEM_TRACE("%s pardoned global=%d (fence %llx:%lld), current %d\n",
-			  engine->name, rq->global_seqno,
-			  rq->fence.context, rq->fence.seqno,
-			  intel_engine_get_seqno(engine));
-		stalled = false;
-	}
-
-	if (stalled) {
-		context_mark_guilty(rq->gem_context);
-		i915_request_skip(rq, -EIO);
+	for_each_engine(engine, i915, id)
+		intel_engine_reset(engine, stalled_mask & ENGINE_MASK(id));
 
-		/* If this context is now banned, skip all pending requests. */
-		if (i915_gem_context_is_banned(rq->gem_context))
-			engine_skip_context(rq);
-	} else {
-		/*
-		 * Since this is not the hung engine, it may have advanced
-		 * since the hang declaration. Double check by refinding
-		 * the active request at the time of the reset.
-		 */
-		rq = i915_gem_find_active_request(engine);
-		if (rq) {
-			unsigned long flags;
-
-			context_mark_innocent(rq->gem_context);
-			dma_fence_set_error(&rq->fence, -EAGAIN);
-
-			/* Rewind the engine to replay the incomplete rq */
-			spin_lock_irqsave(&engine->timeline.lock, flags);
-			rq = list_prev_entry(rq, link);
-			if (&rq->link == &engine->timeline.requests)
-				rq = NULL;
-			spin_unlock_irqrestore(&engine->timeline.lock, flags);
-		}
-	}
+	i915_gem_restore_fences(i915);
 
-	return rq;
+	return err;
 }
 
-static void reset_engine(struct intel_engine_cs *engine,
-			 struct i915_request *rq,
-			 bool stalled)
+static void reset_finish_engine(struct intel_engine_cs *engine)
 {
-	if (rq)
-		rq = reset_request(engine, rq, stalled);
-
-	/* Setup the CS to resume from the breadcrumb of the hung request */
-	engine->reset.reset(engine, rq);
+	engine->reset.finish(engine);
+	intel_uncore_forcewake_put(engine->i915, FORCEWAKE_ALL);
 }
 
-static void gt_reset(struct drm_i915_private *i915, unsigned int stalled_mask)
+struct i915_gpu_restart {
+	struct work_struct work;
+	struct drm_i915_private *i915;
+};
+
+static void restart_work(struct work_struct *work)
 {
+	struct i915_gpu_restart *arg = container_of(work, typeof(*arg), work);
+	struct drm_i915_private *i915 = arg->i915;
 	struct intel_engine_cs *engine;
 	enum intel_engine_id id;
+	intel_wakeref_t wakeref;
 
-	lockdep_assert_held(&i915->drm.struct_mutex);
-
-	i915_retire_requests(i915);
+	wakeref = intel_runtime_pm_get(i915);
+	mutex_lock(&i915->drm.struct_mutex);
+	WRITE_ONCE(i915->gpu_error.restart, NULL);
 
 	for_each_engine(engine, i915, id) {
-		struct intel_context *ce;
-
-		reset_engine(engine,
-			     engine->hangcheck.active_request,
-			     stalled_mask & ENGINE_MASK(id));
-		ce = fetch_and_zero(&engine->last_retired_context);
-		if (ce)
-			intel_context_unpin(ce);
+		struct i915_request *rq;
 
 		/*
 		 * Ostensibily, we always want a context loaded for powersaving,
 		 * so if the engine is idle after the reset, send a request
 		 * to load our scratch kernel_context.
-		 *
-		 * More mysteriously, if we leave the engine idle after a reset,
-		 * the next userspace batch may hang, with what appears to be
-		 * an incoherent read by the CS (presumably stale TLB). An
-		 * empty request appears sufficient to paper over the glitch.
 		 */
-		if (intel_engine_is_idle(engine)) {
-			struct i915_request *rq;
+		if (!intel_engine_is_idle(engine))
+			continue;
 
-			rq = i915_request_alloc(engine, i915->kernel_context);
-			if (!IS_ERR(rq))
-				i915_request_add(rq);
-		}
+		rq = i915_request_alloc(engine, i915->kernel_context);
+		if (!IS_ERR(rq))
+			i915_request_add(rq);
 	}
 
-	i915_gem_restore_fences(i915);
-}
-
-static void reset_finish_engine(struct intel_engine_cs *engine)
-{
-	engine->reset.finish(engine);
+	mutex_unlock(&i915->drm.struct_mutex);
+	intel_runtime_pm_put(i915, wakeref);
 
-	intel_uncore_forcewake_put(engine->i915, FORCEWAKE_ALL);
+	kfree(arg);
 }
 
 static void reset_finish(struct drm_i915_private *i915)
@@ -780,11 +722,30 @@ static void reset_finish(struct drm_i915_private *i915)
 	struct intel_engine_cs *engine;
 	enum intel_engine_id id;
 
-	lockdep_assert_held(&i915->drm.struct_mutex);
-
-	for_each_engine(engine, i915, id) {
-		engine->hangcheck.active_request = NULL;
+	for_each_engine(engine, i915, id)
 		reset_finish_engine(engine);
+}
+
+static void reset_restart(struct drm_i915_private *i915)
+{
+	struct i915_gpu_restart *arg;
+
+	/*
+	 * Following the reset, ensure that we always reload context for
+	 * powersaving, and to correct engine->last_retired_context. Since
+	 * this requires us to submit a request, queue a worker to do that
+	 * task for us to evade any locking here.
+	 */
+	if (READ_ONCE(i915->gpu_error.restart))
+		return;
+
+	arg = kmalloc(sizeof(*arg), GFP_KERNEL);
+	if (arg) {
+		arg->i915 = i915;
+		INIT_WORK(&arg->work, restart_work);
+
+		WRITE_ONCE(i915->gpu_error.restart, arg);
+		queue_work(i915->wq, &arg->work);
 	}
 }
 
@@ -873,8 +834,6 @@ bool i915_gem_unset_wedged(struct drm_i915_private *i915)
 	struct i915_timeline *tl;
 	bool ret = false;
 
-	lockdep_assert_held(&i915->drm.struct_mutex);
-
 	if (!test_bit(I915_WEDGED, &error->flags))
 		return true;
 
@@ -897,9 +856,9 @@ bool i915_gem_unset_wedged(struct drm_i915_private *i915)
 	 */
 	list_for_each_entry(tl, &i915->gt.timelines, link) {
 		struct i915_request *rq;
+		long timeout;
 
-		rq = i915_gem_active_peek(&tl->last_request,
-					  &i915->drm.struct_mutex);
+		rq = i915_gem_active_get_unlocked(&tl->last_request);
 		if (!rq)
 			continue;
 
@@ -914,12 +873,12 @@ bool i915_gem_unset_wedged(struct drm_i915_private *i915)
 		 * and when the seqno passes the fence, the signaler
 		 * then signals the fence waking us up).
 		 */
-		if (dma_fence_default_wait(&rq->fence, true,
-					   MAX_SCHEDULE_TIMEOUT) < 0)
+		timeout = dma_fence_default_wait(&rq->fence, true,
+						 MAX_SCHEDULE_TIMEOUT);
+		i915_request_put(rq);
+		if (timeout < 0)
 			goto unlock;
 	}
-	i915_retire_requests(i915);
-	GEM_BUG_ON(i915->gt.active_requests);
 
 	intel_engines_sanitize(i915, false);
 
@@ -933,7 +892,6 @@ bool i915_gem_unset_wedged(struct drm_i915_private *i915)
 	 * context and do not require stop_machine().
 	 */
 	intel_engines_reset_default_submission(i915);
-	i915_gem_contexts_lost(i915);
 
 	GEM_TRACE("end\n");
 
@@ -946,6 +904,52 @@ unlock:
 	return ret;
 }
 
+struct __i915_reset {
+	struct drm_i915_private *i915;
+	unsigned int stalled_mask;
+};
+
+static int __i915_reset__BKL(void *data)
+{
+	struct __i915_reset *arg = data;
+	int err;
+
+	err = intel_gpu_reset(arg->i915, ALL_ENGINES);
+	if (err)
+		return err;
+
+	return gt_reset(arg->i915, arg->stalled_mask);
+}
+
+#if RESET_UNDER_STOP_MACHINE
+/*
+ * XXX An alternative to using stop_machine would be to park only the
+ * processes that have a GGTT mmap. By remote parking the threads (SIGSTOP)
+ * we should be able to prevent their memmory accesses via the lost fence
+ * registers over the course of the reset without the potential recursive
+ * of mutexes between the pagefault handler and reset.
+ *
+ * See igt/gem_mmap_gtt/hang
+ */
+#define __do_reset(fn, arg) stop_machine(fn, arg, NULL)
+#else
+#define __do_reset(fn, arg) fn(arg)
+#endif
+
+static int do_reset(struct drm_i915_private *i915, unsigned int stalled_mask)
+{
+	struct __i915_reset arg = { i915, stalled_mask };
+	int err, i;
+
+	err = __do_reset(__i915_reset__BKL, &arg);
+	for (i = 0; err && i < RESET_MAX_RETRIES; i++) {
+		msleep(100);
+		err = __do_reset(__i915_reset__BKL, &arg);
+	}
+
+	return err;
+}
+
 /**
  * i915_reset - reset chip after a hang
  * @i915: #drm_i915_private to reset
@@ -971,31 +975,22 @@ void i915_reset(struct drm_i915_private *i915,
 {
 	struct i915_gpu_error *error = &i915->gpu_error;
 	int ret;
-	int i;
 
 	GEM_TRACE("flags=%lx\n", error->flags);
 
 	might_sleep();
-	lockdep_assert_held(&i915->drm.struct_mutex);
 	assert_rpm_wakelock_held(i915);
 	GEM_BUG_ON(!test_bit(I915_RESET_BACKOFF, &error->flags));
 
-	if (!test_bit(I915_RESET_HANDOFF, &error->flags))
-		return;
-
 	/* Clear any previous failed attempts at recovery. Time to try again. */
 	if (!i915_gem_unset_wedged(i915))
-		goto wakeup;
+		return;
 
 	if (reason)
 		dev_notice(i915->drm.dev, "Resetting chip for %s\n", reason);
 	error->reset_count++;
 
-	ret = reset_prepare(i915);
-	if (ret) {
-		dev_err(i915->drm.dev, "GPU recovery failed\n");
-		goto taint;
-	}
+	reset_prepare(i915);
 
 	if (!intel_has_gpu_reset(i915)) {
 		if (i915_modparams.reset)
@@ -1005,32 +1000,11 @@ void i915_reset(struct drm_i915_private *i915,
 		goto error;
 	}
 
-	for (i = 0; i < RESET_MAX_RETRIES; i++) {
-		ret = intel_gpu_reset(i915, ALL_ENGINES);
-		if (ret == 0)
-			break;
-
-		msleep(100);
-	}
-	if (ret) {
+	if (do_reset(i915, stalled_mask)) {
 		dev_err(i915->drm.dev, "Failed to reset chip\n");
 		goto taint;
 	}
 
-	/* Ok, now get things going again... */
-
-	/*
-	 * Everything depends on having the GTT running, so we need to start
-	 * there.
-	 */
-	ret = i915_ggtt_enable_hw(i915);
-	if (ret) {
-		DRM_ERROR("Failed to re-enable GGTT following reset (%d)\n",
-			  ret);
-		goto error;
-	}
-
-	gt_reset(i915, stalled_mask);
 	intel_overlay_reset(i915);
 
 	/*
@@ -1052,9 +1026,8 @@ void i915_reset(struct drm_i915_private *i915,
 
 finish:
 	reset_finish(i915);
-wakeup:
-	clear_bit(I915_RESET_HANDOFF, &error->flags);
-	wake_up_bit(&error->flags, I915_RESET_HANDOFF);
+	if (!i915_terminally_wedged(error))
+		reset_restart(i915);
 	return;
 
 taint:
@@ -1073,7 +1046,6 @@ taint:
 	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
 error:
 	i915_gem_set_wedged(i915);
-	i915_retire_requests(i915);
 	goto finish;
 }
 
@@ -1099,18 +1071,16 @@ static inline int intel_gt_reset_engine(struct drm_i915_private *i915,
 int i915_reset_engine(struct intel_engine_cs *engine, const char *msg)
 {
 	struct i915_gpu_error *error = &engine->i915->gpu_error;
-	struct i915_request *active_request;
 	int ret;
 
 	GEM_TRACE("%s flags=%lx\n", engine->name, error->flags);
 	GEM_BUG_ON(!test_bit(I915_RESET_ENGINE + engine->id, &error->flags));
 
-	active_request = reset_prepare_engine(engine);
-	if (IS_ERR_OR_NULL(active_request)) {
-		/* Either the previous reset failed, or we pardon the reset. */
-		ret = PTR_ERR(active_request);
-		goto out;
-	}
+	if (i915_seqno_passed(intel_engine_get_seqno(engine),
+			      intel_engine_last_submit(engine)))
+		return 0;
+
+	reset_prepare_engine(engine);
 
 	if (msg)
 		dev_notice(engine->i915->drm.dev,
@@ -1134,7 +1104,7 @@ int i915_reset_engine(struct intel_engine_cs *engine, const char *msg)
 	 * active request and can drop it, adjust head to skip the offending
 	 * request to resume executing remaining requests in the queue.
 	 */
-	reset_engine(engine, active_request, true);
+	intel_engine_reset(engine, true);
 
 	/*
 	 * The engine and its registers (and workarounds in case of render)
@@ -1171,30 +1141,7 @@ static void i915_reset_device(struct drm_i915_private *i915,
 	i915_wedge_on_timeout(&w, i915, 5 * HZ) {
 		intel_prepare_reset(i915);
 
-		error->reason = reason;
-		error->stalled_mask = engine_mask;
-
-		/* Signal that locked waiters should reset the GPU */
-		smp_mb__before_atomic();
-		set_bit(I915_RESET_HANDOFF, &error->flags);
-		wake_up_all(&error->wait_queue);
-
-		/*
-		 * Wait for anyone holding the lock to wakeup, without
-		 * blocking indefinitely on struct_mutex.
-		 */
-		do {
-			if (mutex_trylock(&i915->drm.struct_mutex)) {
-				i915_reset(i915, engine_mask, reason);
-				mutex_unlock(&i915->drm.struct_mutex);
-			}
-		} while (wait_on_bit_timeout(&error->flags,
-					     I915_RESET_HANDOFF,
-					     TASK_UNINTERRUPTIBLE,
-					     1));
-
-		error->stalled_mask = 0;
-		error->reason = NULL;
+		i915_reset(i915, engine_mask, reason);
 
 		intel_finish_reset(i915);
 	}
@@ -1350,6 +1297,25 @@ out:
 	intel_runtime_pm_put(i915, wakeref);
 }
 
+bool i915_reset_flush(struct drm_i915_private *i915)
+{
+	int err;
+
+	cancel_delayed_work_sync(&i915->gpu_error.hangcheck_work);
+
+	flush_workqueue(i915->wq);
+	GEM_BUG_ON(READ_ONCE(i915->gpu_error.restart));
+
+	mutex_lock(&i915->drm.struct_mutex);
+	err = i915_gem_wait_for_idle(i915,
+				     I915_WAIT_LOCKED |
+				     I915_WAIT_FOR_IDLE_BOOST,
+				     MAX_SCHEDULE_TIMEOUT);
+	mutex_unlock(&i915->drm.struct_mutex);
+
+	return !err;
+}
+
 static void i915_wedge_me(struct work_struct *work)
 {
 	struct i915_wedge_me *w = container_of(work, typeof(*w), work.work);
diff --git a/drivers/gpu/drm/i915/i915_reset.h b/drivers/gpu/drm/i915/i915_reset.h
index b6a519bde67d..f2d347f319df 100644
--- a/drivers/gpu/drm/i915/i915_reset.h
+++ b/drivers/gpu/drm/i915/i915_reset.h
@@ -29,6 +29,9 @@ void i915_reset(struct drm_i915_private *i915,
 int i915_reset_engine(struct intel_engine_cs *engine,
 		      const char *reason);
 
+void i915_reset_request(struct i915_request *rq, bool guilty);
+bool i915_reset_flush(struct drm_i915_private *i915);
+
 bool intel_has_gpu_reset(struct drm_i915_private *i915);
 bool intel_has_reset_engine(struct drm_i915_private *i915);
 
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index ef4c8c50a4ba..1a5c163b98d6 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1119,10 +1119,8 @@ void intel_engines_sanitize(struct drm_i915_private *i915, bool force)
 	if (!reset_engines(i915) && !force)
 		return;
 
-	for_each_engine(engine, i915, id) {
-		if (engine->reset.reset)
-			engine->reset.reset(engine, NULL);
-	}
+	for_each_engine(engine, i915, id)
+		intel_engine_reset(engine, false);
 }
 
 /**
diff --git a/drivers/gpu/drm/i915/intel_guc_submission.c b/drivers/gpu/drm/i915/intel_guc_submission.c
index 349ae5844f24..45e2db683fe5 100644
--- a/drivers/gpu/drm/i915/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/intel_guc_submission.c
@@ -834,8 +834,7 @@ static void guc_submission_tasklet(unsigned long data)
 	spin_unlock_irqrestore(&engine->timeline.lock, flags);
 }
 
-static struct i915_request *
-guc_reset_prepare(struct intel_engine_cs *engine)
+static void guc_reset_prepare(struct intel_engine_cs *engine)
 {
 	struct intel_engine_execlists * const execlists = &engine->execlists;
 
@@ -861,8 +860,6 @@ guc_reset_prepare(struct intel_engine_cs *engine)
 	 */
 	if (engine->i915->guc.preempt_wq)
 		flush_workqueue(engine->i915->guc.preempt_wq);
-
-	return i915_gem_find_active_request(engine);
 }
 
 /*
diff --git a/drivers/gpu/drm/i915/intel_hangcheck.c b/drivers/gpu/drm/i915/intel_hangcheck.c
index 741441daae32..5662d6fed523 100644
--- a/drivers/gpu/drm/i915/intel_hangcheck.c
+++ b/drivers/gpu/drm/i915/intel_hangcheck.c
@@ -25,6 +25,17 @@
 #include "i915_drv.h"
 #include "i915_reset.h"
 
+struct hangcheck {
+	u64 acthd;
+	u32 seqno;
+	enum intel_engine_hangcheck_action action;
+	unsigned long action_timestamp;
+	int deadlock;
+	struct intel_instdone instdone;
+	bool wedged:1;
+	bool stalled:1;
+};
+
 static bool instdone_unchanged(u32 current_instdone, u32 *old_instdone)
 {
 	u32 tmp = current_instdone | *old_instdone;
@@ -119,25 +130,22 @@ engine_stuck(struct intel_engine_cs *engine, u64 acthd)
 }
 
 static void hangcheck_load_sample(struct intel_engine_cs *engine,
-				  struct intel_engine_hangcheck *hc)
+				  struct hangcheck *hc)
 {
 	hc->acthd = intel_engine_get_active_head(engine);
 	hc->seqno = intel_engine_get_seqno(engine);
 }
 
 static void hangcheck_store_sample(struct intel_engine_cs *engine,
-				   const struct intel_engine_hangcheck *hc)
+				   const struct hangcheck *hc)
 {
 	engine->hangcheck.acthd = hc->acthd;
 	engine->hangcheck.seqno = hc->seqno;
-	engine->hangcheck.action = hc->action;
-	engine->hangcheck.stalled = hc->stalled;
-	engine->hangcheck.wedged = hc->wedged;
 }
 
 static enum intel_engine_hangcheck_action
 hangcheck_get_action(struct intel_engine_cs *engine,
-		     const struct intel_engine_hangcheck *hc)
+		     const struct hangcheck *hc)
 {
 	if (engine->hangcheck.seqno != hc->seqno)
 		return ENGINE_ACTIVE_SEQNO;
@@ -149,7 +157,7 @@ hangcheck_get_action(struct intel_engine_cs *engine,
 }
 
 static void hangcheck_accumulate_sample(struct intel_engine_cs *engine,
-					struct intel_engine_hangcheck *hc)
+					struct hangcheck *hc)
 {
 	unsigned long timeout = I915_ENGINE_DEAD_TIMEOUT;
 
@@ -265,19 +273,19 @@ static void i915_hangcheck_elapsed(struct work_struct *work)
 	intel_uncore_arm_unclaimed_mmio_detection(dev_priv);
 
 	for_each_engine(engine, dev_priv, id) {
-		struct intel_engine_hangcheck hc;
+		struct hangcheck hc;
 
 		hangcheck_load_sample(engine, &hc);
 		hangcheck_accumulate_sample(engine, &hc);
 		hangcheck_store_sample(engine, &hc);
 
-		if (engine->hangcheck.stalled) {
+		if (hc.stalled) {
 			hung |= intel_engine_flag(engine);
 			if (hc.action != ENGINE_DEAD)
 				stuck |= intel_engine_flag(engine);
 		}
 
-		if (engine->hangcheck.wedged)
+		if (hc.wedged)
 			wedged |= intel_engine_flag(engine);
 	}
 
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 5551dd2ec0e6..185867106c14 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -136,6 +136,7 @@
 #include <drm/i915_drm.h>
 #include "i915_drv.h"
 #include "i915_gem_render_state.h"
+#include "i915_reset.h"
 #include "i915_vgpu.h"
 #include "intel_lrc_reg.h"
 #include "intel_mocs.h"
@@ -264,7 +265,8 @@ static void unwind_wa_tail(struct i915_request *rq)
 	assert_ring_tail_valid(rq->ring, rq->tail);
 }
 
-static void __unwind_incomplete_requests(struct intel_engine_cs *engine)
+static struct i915_request *
+__unwind_incomplete_requests(struct intel_engine_cs *engine)
 {
 	struct i915_request *rq, *rn, *active = NULL;
 	struct list_head *uninitialized_var(pl);
@@ -306,6 +308,8 @@ static void __unwind_incomplete_requests(struct intel_engine_cs *engine)
 		list_move_tail(&active->sched.link,
 			       i915_sched_lookup_priolist(engine, prio));
 	}
+
+	return active;
 }
 
 void
@@ -1732,11 +1736,9 @@ static int gen8_init_common_ring(struct intel_engine_cs *engine)
 	return 0;
 }
 
-static struct i915_request *
-execlists_reset_prepare(struct intel_engine_cs *engine)
+static void execlists_reset_prepare(struct intel_engine_cs *engine)
 {
 	struct intel_engine_execlists * const execlists = &engine->execlists;
-	struct i915_request *request, *active;
 	unsigned long flags;
 
 	GEM_TRACE("%s: depth<-%d\n", engine->name,
@@ -1752,59 +1754,21 @@ execlists_reset_prepare(struct intel_engine_cs *engine)
 	 * prevents the race.
 	 */
 	__tasklet_disable_sync_once(&execlists->tasklet);
+	GEM_BUG_ON(!reset_in_progress(execlists));
 
+	/* And flush any current direct submission. */
 	spin_lock_irqsave(&engine->timeline.lock, flags);
-
-	/*
-	 * We want to flush the pending context switches, having disabled
-	 * the tasklet above, we can assume exclusive access to the execlists.
-	 * For this allows us to catch up with an inflight preemption event,
-	 * and avoid blaming an innocent request if the stall was due to the
-	 * preemption itself.
-	 */
-	process_csb(engine);
-
-	/*
-	 * The last active request can then be no later than the last request
-	 * now in ELSP[0]. So search backwards from there, so that if the GPU
-	 * has advanced beyond the last CSB update, it will be pardoned.
-	 */
-	active = NULL;
-	request = port_request(execlists->port);
-	if (request) {
-		/*
-		 * Prevent the breadcrumb from advancing before we decide
-		 * which request is currently active.
-		 */
-		intel_engine_stop_cs(engine);
-
-		list_for_each_entry_from_reverse(request,
-						 &engine->timeline.requests,
-						 link) {
-			if (__i915_request_completed(request,
-						     request->global_seqno))
-				break;
-
-			active = request;
-		}
-	}
-
+	process_csb(engine); /* drain preemption events */
 	spin_unlock_irqrestore(&engine->timeline.lock, flags);
-
-	return active;
 }
 
-static void execlists_reset(struct intel_engine_cs *engine,
-			    struct i915_request *request)
+static void execlists_reset(struct intel_engine_cs *engine, bool stalled)
 {
 	struct intel_engine_execlists * const execlists = &engine->execlists;
+	struct i915_request *rq;
 	unsigned long flags;
 	u32 *regs;
 
-	GEM_TRACE("%s request global=%d, current=%d\n",
-		  engine->name, request ? request->global_seqno : 0,
-		  intel_engine_get_seqno(engine));
-
 	spin_lock_irqsave(&engine->timeline.lock, flags);
 
 	/*
@@ -1819,12 +1783,18 @@ static void execlists_reset(struct intel_engine_cs *engine,
 	execlists_cancel_port_requests(execlists);
 
 	/* Push back any incomplete requests for replay after the reset. */
-	__unwind_incomplete_requests(engine);
+	rq = __unwind_incomplete_requests(engine);
 
 	/* Following the reset, we need to reload the CSB read/write pointers */
 	reset_csb_pointers(&engine->execlists);
 
-	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+	GEM_TRACE("%s seqno=%d, current=%d, stalled? %s\n",
+		  engine->name,
+		  rq ? rq->global_seqno : 0,
+		  intel_engine_get_seqno(engine),
+		  yesno(stalled));
+	if (!rq)
+		goto out_unlock;
 
 	/*
 	 * If the request was innocent, we leave the request in the ELSP
@@ -1837,8 +1807,9 @@ static void execlists_reset(struct intel_engine_cs *engine,
 	 * and have to at least restore the RING register in the context
 	 * image back to the expected values to skip over the guilty request.
 	 */
-	if (!request || request->fence.error != -EIO)
-		return;
+	i915_reset_request(rq, stalled);
+	if (!stalled)
+		goto out_unlock;
 
 	/*
 	 * We want a simple context + ring to execute the breadcrumb update.
@@ -1848,7 +1819,7 @@ static void execlists_reset(struct intel_engine_cs *engine,
 	 * future request will be after userspace has had the opportunity
 	 * to recreate its own state.
 	 */
-	regs = request->hw_context->lrc_reg_state;
+	regs = rq->hw_context->lrc_reg_state;
 	if (engine->pinned_default_state) {
 		memcpy(regs, /* skip restoring the vanilla PPHWSP */
 		       engine->pinned_default_state + LRC_STATE_PN * PAGE_SIZE,
@@ -1856,17 +1827,14 @@ static void execlists_reset(struct intel_engine_cs *engine,
 	}
 
 	/* Move the RING_HEAD onto the breadcrumb, past the hanging batch */
-	request->ring->head = intel_ring_wrap(request->ring, request->postfix);
+	rq->ring->head = intel_ring_wrap(rq->ring, rq->postfix);
+	intel_ring_update_space(rq->ring);
 
-	execlists_init_reg_state(regs, request->gem_context, engine,
-				 request->ring);
+	execlists_init_reg_state(regs, rq->gem_context, engine, rq->ring);
+	__execlists_update_reg_state(engine, rq->hw_context);
 
-	__execlists_update_reg_state(engine, request->hw_context);
-
-	intel_ring_update_space(request->ring);
-
-	/* Reset WaIdleLiteRestore:bdw,skl as well */
-	unwind_wa_tail(request);
+out_unlock:
+	spin_unlock_irqrestore(&engine->timeline.lock, flags);
 }
 
 static void execlists_reset_finish(struct intel_engine_cs *engine)
@@ -1879,6 +1847,7 @@ static void execlists_reset_finish(struct intel_engine_cs *engine)
 	 * to sleep before we restart and reload a context.
 	 *
 	 */
+	GEM_BUG_ON(!reset_in_progress(execlists));
 	if (!RB_EMPTY_ROOT(&execlists->queue.rb_root))
 		execlists->tasklet.func(execlists->tasklet.data);
 
diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index c81db81e4416..f68c7975006c 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -478,8 +478,6 @@ void intel_overlay_reset(struct drm_i915_private *dev_priv)
 	if (!overlay)
 		return;
 
-	intel_overlay_release_old_vid(overlay);
-
 	overlay->old_xscale = 0;
 	overlay->old_yscale = 0;
 	overlay->crtc = NULL;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 09c90475168a..a9efc8c71254 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -33,6 +33,7 @@
 
 #include "i915_drv.h"
 #include "i915_gem_render_state.h"
+#include "i915_reset.h"
 #include "i915_trace.h"
 #include "intel_drv.h"
 #include "intel_workarounds.h"
@@ -711,52 +712,80 @@ out:
 	return ret;
 }
 
-static struct i915_request *reset_prepare(struct intel_engine_cs *engine)
+static void reset_prepare(struct intel_engine_cs *engine)
 {
 	intel_engine_stop_cs(engine);
-	return i915_gem_find_active_request(engine);
 }
 
-static void skip_request(struct i915_request *rq)
+static void reset_ring(struct intel_engine_cs *engine, bool stalled)
 {
-	void *vaddr = rq->ring->vaddr;
+	struct i915_timeline *tl = &engine->timeline;
+	struct i915_request *pos, *rq;
+	unsigned long flags;
 	u32 head;
 
-	head = rq->infix;
-	if (rq->postfix < head) {
-		memset32(vaddr + head, MI_NOOP,
-			 (rq->ring->size - head) / sizeof(u32));
-		head = 0;
+	rq = NULL;
+	spin_lock_irqsave(&tl->lock, flags);
+	list_for_each_entry(pos, &tl->requests, link) {
+		if (!__i915_request_completed(pos, pos->global_seqno)) {
+			rq = pos;
+			break;
+		}
 	}
-	memset32(vaddr + head, MI_NOOP, (rq->postfix - head) / sizeof(u32));
-}
-
-static void reset_ring(struct intel_engine_cs *engine, struct i915_request *rq)
-{
-	GEM_TRACE("%s request global=%d, current=%d\n",
-		  engine->name, rq ? rq->global_seqno : 0,
-		  intel_engine_get_seqno(engine));
 
+	GEM_TRACE("%s seqno=%d, current=%d, stalled? %s\n",
+		  engine->name,
+		  rq ? rq->global_seqno : 0,
+		  intel_engine_get_seqno(engine),
+		  yesno(stalled));
 	/*
-	 * Try to restore the logical GPU state to match the continuation
-	 * of the request queue. If we skip the context/PD restore, then
-	 * the next request may try to execute assuming that its context
-	 * is valid and loaded on the GPU and so may try to access invalid
-	 * memory, prompting repeated GPU hangs.
+	 * The guilty request will get skipped on a hung engine.
 	 *
-	 * If the request was guilty, we still restore the logical state
-	 * in case the next request requires it (e.g. the aliasing ppgtt),
-	 * but skip over the hung batch.
+	 * Users of client default contexts do not rely on logical
+	 * state preserved between batches so it is safe to execute
+	 * queued requests following the hang. Non default contexts
+	 * rely on preserved state, so skipping a batch loses the
+	 * evolution of the state and it needs to be considered corrupted.
+	 * Executing more queued batches on top of corrupted state is
+	 * risky. But we take the risk by trying to advance through
+	 * the queued requests in order to make the client behaviour
+	 * more predictable around resets, by not throwing away random
+	 * amount of batches it has prepared for execution. Sophisticated
+	 * clients can use gem_reset_stats_ioctl and dma fence status
+	 * (exported via sync_file info ioctl on explicit fences) to observe
+	 * when it loses the context state and should rebuild accordingly.
 	 *
-	 * If the request was innocent, we try to replay the request with
-	 * the restored context.
+	 * The context ban, and ultimately the client ban, mechanism are safety
+	 * valves if client submission ends up resulting in nothing more than
+	 * subsequent hangs.
 	 */
+
 	if (rq) {
-		/* If the rq hung, jump to its breadcrumb and skip the batch */
-		rq->ring->head = intel_ring_wrap(rq->ring, rq->head);
-		if (rq->fence.error == -EIO)
-			skip_request(rq);
+		/*
+		 * Try to restore the logical GPU state to match the
+		 * continuation of the request queue. If we skip the
+		 * context/PD restore, then the next request may try to execute
+		 * assuming that its context is valid and loaded on the GPU and
+		 * so may try to access invalid memory, prompting repeated GPU
+		 * hangs.
+		 *
+		 * If the request was guilty, we still restore the logical
+		 * state in case the next request requires it (e.g. the
+		 * aliasing ppgtt), but skip over the hung batch.
+		 *
+		 * If the request was innocent, we try to replay the request
+		 * with the restored context.
+		 */
+		i915_reset_request(rq, stalled);
+
+		GEM_BUG_ON(rq->ring != engine->buffer);
+		head = rq->head;
+	} else {
+		head = engine->buffer->tail;
 	}
+	engine->buffer->head = intel_ring_wrap(engine->buffer, head);
+
+	spin_unlock_irqrestore(&tl->lock, flags);
 }
 
 static void reset_finish(struct intel_engine_cs *engine)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 5ad46c2fbc0f..f2effd001540 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -120,13 +120,8 @@ struct intel_instdone {
 struct intel_engine_hangcheck {
 	u64 acthd;
 	u32 seqno;
-	enum intel_engine_hangcheck_action action;
 	unsigned long action_timestamp;
-	int deadlock;
 	struct intel_instdone instdone;
-	struct i915_request *active_request;
-	bool stalled:1;
-	bool wedged:1;
 };
 
 struct intel_ring {
@@ -444,9 +439,8 @@ struct intel_engine_cs {
 	int		(*init_hw)(struct intel_engine_cs *engine);
 
 	struct {
-		struct i915_request *(*prepare)(struct intel_engine_cs *engine);
-		void (*reset)(struct intel_engine_cs *engine,
-			      struct i915_request *rq);
+		void (*prepare)(struct intel_engine_cs *engine);
+		void (*reset)(struct intel_engine_cs *engine, bool stalled);
 		void (*finish)(struct intel_engine_cs *engine);
 	} reset;
 
@@ -1018,6 +1012,13 @@ gen8_emit_ggtt_write(u32 *cs, u32 value, u32 gtt_offset)
 	return cs;
 }
 
+static inline void intel_engine_reset(struct intel_engine_cs *engine,
+				      bool stalled)
+{
+	if (engine->reset.reset)
+		engine->reset.reset(engine, stalled);
+}
+
 void intel_engines_sanitize(struct drm_i915_private *i915, bool force);
 
 bool intel_engine_is_idle(struct intel_engine_cs *engine);
diff --git a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
index 12550b55c42f..67431355cd6e 100644
--- a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
+++ b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
@@ -363,9 +363,7 @@ static int igt_global_reset(void *arg)
 	/* Check that we can issue a global GPU reset */
 
 	igt_global_reset_lock(i915);
-	set_bit(I915_RESET_HANDOFF, &i915->gpu_error.flags);
 
-	mutex_lock(&i915->drm.struct_mutex);
 	reset_count = i915_reset_count(&i915->gpu_error);
 
 	i915_reset(i915, ALL_ENGINES, NULL);
@@ -374,9 +372,7 @@ static int igt_global_reset(void *arg)
 		pr_err("No GPU reset recorded!\n");
 		err = -EINVAL;
 	}
-	mutex_unlock(&i915->drm.struct_mutex);
 
-	GEM_BUG_ON(test_bit(I915_RESET_HANDOFF, &i915->gpu_error.flags));
 	igt_global_reset_unlock(i915);
 
 	if (i915_terminally_wedged(&i915->gpu_error))
@@ -399,9 +395,7 @@ static int igt_wedged_reset(void *arg)
 	i915_gem_set_wedged(i915);
 	GEM_BUG_ON(!i915_terminally_wedged(&i915->gpu_error));
 
-	set_bit(I915_RESET_HANDOFF, &i915->gpu_error.flags);
 	i915_reset(i915, ALL_ENGINES, NULL);
-	GEM_BUG_ON(test_bit(I915_RESET_HANDOFF, &i915->gpu_error.flags));
 
 	intel_runtime_pm_put(i915, wakeref);
 	mutex_unlock(&i915->drm.struct_mutex);
@@ -511,7 +505,7 @@ static int __igt_reset_engine(struct drm_i915_private *i915, bool active)
 				break;
 			}
 
-			if (!wait_for_idle(engine)) {
+			if (!i915_reset_flush(i915)) {
 				struct drm_printer p =
 					drm_info_printer(i915->drm.dev);
 
@@ -903,20 +897,13 @@ static int igt_reset_engines(void *arg)
 	return 0;
 }
 
-static u32 fake_hangcheck(struct i915_request *rq, u32 mask)
+static u32 fake_hangcheck(struct drm_i915_private *i915, u32 mask)
 {
-	struct i915_gpu_error *error = &rq->i915->gpu_error;
-	u32 reset_count = i915_reset_count(error);
-
-	error->stalled_mask = mask;
-
-	/* set_bit() must be after we have setup the backchannel (mask) */
-	smp_mb__before_atomic();
-	set_bit(I915_RESET_HANDOFF, &error->flags);
+	u32 count = i915_reset_count(&i915->gpu_error);
 
-	wake_up_all(&error->wait_queue);
+	i915_reset(i915, mask, NULL);
 
-	return reset_count;
+	return count;
 }
 
 static int igt_reset_wait(void *arg)
@@ -962,7 +949,7 @@ static int igt_reset_wait(void *arg)
 		goto out_rq;
 	}
 
-	reset_count = fake_hangcheck(rq, ALL_ENGINES);
+	reset_count = fake_hangcheck(i915, ALL_ENGINES);
 
 	timeout = i915_request_wait(rq, I915_WAIT_LOCKED, 10);
 	if (timeout < 0) {
@@ -972,7 +959,6 @@ static int igt_reset_wait(void *arg)
 		goto out_rq;
 	}
 
-	GEM_BUG_ON(test_bit(I915_RESET_HANDOFF, &i915->gpu_error.flags));
 	if (i915_reset_count(&i915->gpu_error) == reset_count) {
 		pr_err("No GPU reset recorded!\n");
 		err = -EINVAL;
@@ -1162,7 +1148,7 @@ static int __igt_reset_evict_vma(struct drm_i915_private *i915,
 	}
 
 out_reset:
-	fake_hangcheck(rq, intel_engine_flag(rq->engine));
+	fake_hangcheck(rq->i915, intel_engine_flag(rq->engine));
 
 	if (tsk) {
 		struct igt_wedge_me w;
@@ -1341,12 +1327,7 @@ static int igt_reset_queue(void *arg)
 				goto fini;
 			}
 
-			reset_count = fake_hangcheck(prev, ENGINE_MASK(id));
-
-			i915_reset(i915, ENGINE_MASK(id), NULL);
-
-			GEM_BUG_ON(test_bit(I915_RESET_HANDOFF,
-					    &i915->gpu_error.flags));
+			reset_count = fake_hangcheck(i915, ENGINE_MASK(id));
 
 			if (prev->fence.error != -EIO) {
 				pr_err("GPU reset not recorded on hanging request [fence.error=%d]!\n",
@@ -1565,6 +1546,7 @@ static int igt_atomic_reset_engine(struct intel_engine_cs *engine,
 		pr_err("%s(%s): Failed to start request %llx, at %x\n",
 		       __func__, engine->name,
 		       rq->fence.seqno, hws_seqno(&h, rq));
+		i915_gem_set_wedged(i915);
 		err = -EIO;
 	}
 
@@ -1588,7 +1570,6 @@ out:
 static void force_reset(struct drm_i915_private *i915)
 {
 	i915_gem_set_wedged(i915);
-	set_bit(I915_RESET_HANDOFF, &i915->gpu_error.flags);
 	i915_reset(i915, 0, NULL);
 }
 
@@ -1618,6 +1599,26 @@ static int igt_atomic_reset(void *arg)
 	if (i915_terminally_wedged(&i915->gpu_error))
 		goto unlock;
 
+	if (intel_has_gpu_reset(i915)) {
+		const typeof(*phases) *p;
+
+		for (p = phases; p->name; p++) {
+			GEM_TRACE("intel_gpu_reset under %s\n", p->name);
+
+			p->critical_section_begin();
+			err = intel_gpu_reset(i915, ALL_ENGINES);
+			p->critical_section_end();
+
+			if (err) {
+				pr_err("intel_gpu_reset failed under %s\n",
+				       p->name);
+				goto out;
+			}
+		}
+
+		force_reset(i915);
+	}
+
 	if (intel_has_reset_engine(i915)) {
 		struct intel_engine_cs *engine;
 		enum intel_engine_id id;
diff --git a/drivers/gpu/drm/i915/selftests/intel_workarounds.c b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
index a8cac56be835..b15c4f26c593 100644
--- a/drivers/gpu/drm/i915/selftests/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
@@ -214,7 +214,6 @@ out_put:
 
 static int do_device_reset(struct intel_engine_cs *engine)
 {
-	set_bit(I915_RESET_HANDOFF, &engine->i915->gpu_error.flags);
 	i915_reset(engine->i915, ENGINE_MASK(engine->id), "live_workarounds");
 	return 0;
 }
@@ -394,7 +393,6 @@ static int
 live_gpu_reset_gt_engine_workarounds(void *arg)
 {
 	struct drm_i915_private *i915 = arg;
-	struct i915_gpu_error *error = &i915->gpu_error;
 	intel_wakeref_t wakeref;
 	struct wa_lists lists;
 	bool ok;
@@ -413,7 +411,6 @@ live_gpu_reset_gt_engine_workarounds(void *arg)
 	if (!ok)
 		goto out;
 
-	set_bit(I915_RESET_HANDOFF, &error->flags);
 	i915_reset(i915, ALL_ENGINES, "live_workarounds");
 
 	ok = verify_gt_engine_wa(i915, &lists, "after reset");
diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
index 5477ad4a7e7d..8ab5a2688a0c 100644
--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
@@ -58,8 +58,8 @@ static void mock_device_release(struct drm_device *dev)
 	i915_gem_contexts_lost(i915);
 	mutex_unlock(&i915->drm.struct_mutex);
 
-	cancel_delayed_work_sync(&i915->gt.retire_work);
-	cancel_delayed_work_sync(&i915->gt.idle_work);
+	drain_delayed_work(&i915->gt.retire_work);
+	drain_delayed_work(&i915->gt.idle_work);
 	i915_gem_drain_workqueue(i915);
 
 	mutex_lock(&i915->drm.struct_mutex);
-- 
cgit v1.2.3-59-g8ed1b


From 3adac4689f58cb3fb666d92dff0ee73cc97d24d7 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 28 Jan 2019 18:18:07 +0000
Subject: drm/i915: Introduce concept of per-timeline (context) HWSP

Supplement the per-engine HWSP with a per-timeline HWSP. That is a
per-request pointer through which we can check a local seqno,
abstracting away the presumption of a global seqno. In this first step,
we point each request back into the engine's HWSP so everything
continues to work with the global timeline.

v2: s/i915_request_hwsp/hwsp_seqno/ to emphasis that this is the current
HW value and that we are accessing it via i915_request merely as a
convenience.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190128181812.22804-1-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_request.c | 16 ++++++++-----
 drivers/gpu/drm/i915/i915_request.h | 45 +++++++++++++++++++++++++++++++------
 drivers/gpu/drm/i915/intel_lrc.c    |  9 +++++---
 3 files changed, 55 insertions(+), 15 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index f4241a17e2ad..a076fd0b7ba6 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -182,10 +182,11 @@ static void free_capture_list(struct i915_request *request)
 static void __retire_engine_request(struct intel_engine_cs *engine,
 				    struct i915_request *rq)
 {
-	GEM_TRACE("%s(%s) fence %llx:%lld, global=%d, current %d\n",
+	GEM_TRACE("%s(%s) fence %llx:%lld, global=%d, current %d:%d\n",
 		  __func__, engine->name,
 		  rq->fence.context, rq->fence.seqno,
 		  rq->global_seqno,
+		  hwsp_seqno(rq),
 		  intel_engine_get_seqno(engine));
 
 	GEM_BUG_ON(!i915_request_completed(rq));
@@ -244,10 +245,11 @@ static void i915_request_retire(struct i915_request *request)
 {
 	struct i915_gem_active *active, *next;
 
-	GEM_TRACE("%s fence %llx:%lld, global=%d, current %d\n",
+	GEM_TRACE("%s fence %llx:%lld, global=%d, current %d:%d\n",
 		  request->engine->name,
 		  request->fence.context, request->fence.seqno,
 		  request->global_seqno,
+		  hwsp_seqno(request),
 		  intel_engine_get_seqno(request->engine));
 
 	lockdep_assert_held(&request->i915->drm.struct_mutex);
@@ -307,10 +309,11 @@ void i915_request_retire_upto(struct i915_request *rq)
 	struct intel_ring *ring = rq->ring;
 	struct i915_request *tmp;
 
-	GEM_TRACE("%s fence %llx:%lld, global=%d, current %d\n",
+	GEM_TRACE("%s fence %llx:%lld, global=%d, current %d:%d\n",
 		  rq->engine->name,
 		  rq->fence.context, rq->fence.seqno,
 		  rq->global_seqno,
+		  hwsp_seqno(rq),
 		  intel_engine_get_seqno(rq->engine));
 
 	lockdep_assert_held(&rq->i915->drm.struct_mutex);
@@ -355,10 +358,11 @@ void __i915_request_submit(struct i915_request *request)
 	struct intel_engine_cs *engine = request->engine;
 	u32 seqno;
 
-	GEM_TRACE("%s fence %llx:%lld -> global=%d, current %d\n",
+	GEM_TRACE("%s fence %llx:%lld -> global=%d, current %d:%d\n",
 		  engine->name,
 		  request->fence.context, request->fence.seqno,
 		  engine->timeline.seqno + 1,
+		  hwsp_seqno(request),
 		  intel_engine_get_seqno(engine));
 
 	GEM_BUG_ON(!irqs_disabled());
@@ -405,10 +409,11 @@ void __i915_request_unsubmit(struct i915_request *request)
 {
 	struct intel_engine_cs *engine = request->engine;
 
-	GEM_TRACE("%s fence %llx:%lld <- global=%d, current %d\n",
+	GEM_TRACE("%s fence %llx:%lld <- global=%d, current %d:%d\n",
 		  engine->name,
 		  request->fence.context, request->fence.seqno,
 		  request->global_seqno,
+		  hwsp_seqno(request),
 		  intel_engine_get_seqno(engine));
 
 	GEM_BUG_ON(!irqs_disabled());
@@ -616,6 +621,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	rq->ring = ce->ring;
 	rq->timeline = ce->ring->timeline;
 	GEM_BUG_ON(rq->timeline == &engine->timeline);
+	rq->hwsp_seqno = &engine->status_page.addr[I915_GEM_HWS_INDEX];
 
 	spin_lock_init(&rq->lock);
 	dma_fence_init(&rq->fence,
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index c0f084ca4f29..ade010fe6e26 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -130,6 +130,13 @@ struct i915_request {
 	struct i915_sched_node sched;
 	struct i915_dependency dep;
 
+	/*
+	 * A convenience pointer to the current breadcrumb value stored in
+	 * the HW status page (or our timeline's local equivalent). The full
+	 * path would be rq->hw_context->ring->timeline->hwsp_seqno.
+	 */
+	const u32 *hwsp_seqno;
+
 	/**
 	 * GEM sequence number associated with this request on the
 	 * global execution timeline. It is zero when the request is not
@@ -285,11 +292,6 @@ static inline bool i915_request_signaled(const struct i915_request *rq)
 	return test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags);
 }
 
-static inline bool intel_engine_has_started(struct intel_engine_cs *engine,
-					    u32 seqno);
-static inline bool intel_engine_has_completed(struct intel_engine_cs *engine,
-					      u32 seqno);
-
 /**
  * Returns true if seq1 is later than seq2.
  */
@@ -298,6 +300,35 @@ static inline bool i915_seqno_passed(u32 seq1, u32 seq2)
 	return (s32)(seq1 - seq2) >= 0;
 }
 
+static inline u32 __hwsp_seqno(const struct i915_request *rq)
+{
+	return READ_ONCE(*rq->hwsp_seqno);
+}
+
+/**
+ * hwsp_seqno - the current breadcrumb value in the HW status page
+ * @rq: the request, to chase the relevant HW status page
+ *
+ * The emphasis in naming here is that hwsp_seqno() is not a property of the
+ * request, but an indication of the current HW state (associated with this
+ * request). Its value will change as the GPU executes more requests.
+ *
+ * Returns the current breadcrumb value in the associated HW status page (or
+ * the local timeline's equivalent) for this request. The request itself
+ * has the associated breadcrumb value of rq->fence.seqno, when the HW
+ * status page has that breadcrumb or later, this request is complete.
+ */
+static inline u32 hwsp_seqno(const struct i915_request *rq)
+{
+	u32 seqno;
+
+	rcu_read_lock(); /* the HWSP may be freed at runtime */
+	seqno = __hwsp_seqno(rq);
+	rcu_read_unlock();
+
+	return seqno;
+}
+
 /**
  * i915_request_started - check if the request has begun being executed
  * @rq: the request
@@ -315,14 +346,14 @@ static inline bool i915_request_started(const struct i915_request *rq)
 	if (!seqno) /* not yet submitted to HW */
 		return false;
 
-	return intel_engine_has_started(rq->engine, seqno);
+	return i915_seqno_passed(hwsp_seqno(rq), seqno - 1);
 }
 
 static inline bool
 __i915_request_completed(const struct i915_request *rq, u32 seqno)
 {
 	GEM_BUG_ON(!seqno);
-	return intel_engine_has_completed(rq->engine, seqno) &&
+	return i915_seqno_passed(hwsp_seqno(rq), seqno) &&
 		seqno == i915_request_global_seqno(rq);
 }
 
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 2cf99c436658..9ae7f77293a0 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -446,11 +446,12 @@ static void execlists_submit_ports(struct intel_engine_cs *engine)
 			desc = execlists_update_context(rq);
 			GEM_DEBUG_EXEC(port[n].context_id = upper_32_bits(desc));
 
-			GEM_TRACE("%s in[%d]:  ctx=%d.%d, global=%d (fence %llx:%lld) (current %d), prio=%d\n",
+			GEM_TRACE("%s in[%d]:  ctx=%d.%d, global=%d (fence %llx:%lld) (current %d:%d), prio=%d\n",
 				  engine->name, n,
 				  port[n].context_id, count,
 				  rq->global_seqno,
 				  rq->fence.context, rq->fence.seqno,
+				  hwsp_seqno(rq),
 				  intel_engine_get_seqno(engine),
 				  rq_prio(rq));
 		} else {
@@ -742,11 +743,12 @@ execlists_cancel_port_requests(struct intel_engine_execlists * const execlists)
 	while (num_ports-- && port_isset(port)) {
 		struct i915_request *rq = port_request(port);
 
-		GEM_TRACE("%s:port%u global=%d (fence %llx:%lld), (current %d)\n",
+		GEM_TRACE("%s:port%u global=%d (fence %llx:%lld), (current %d:%d)\n",
 			  rq->engine->name,
 			  (unsigned int)(port - execlists->port),
 			  rq->global_seqno,
 			  rq->fence.context, rq->fence.seqno,
+			  hwsp_seqno(rq),
 			  intel_engine_get_seqno(rq->engine));
 
 		GEM_BUG_ON(!execlists->active);
@@ -970,12 +972,13 @@ static void process_csb(struct intel_engine_cs *engine)
 						EXECLISTS_ACTIVE_USER));
 
 		rq = port_unpack(port, &count);
-		GEM_TRACE("%s out[0]: ctx=%d.%d, global=%d (fence %llx:%lld) (current %d), prio=%d\n",
+		GEM_TRACE("%s out[0]: ctx=%d.%d, global=%d (fence %llx:%lld) (current %d:%d), prio=%d\n",
 			  engine->name,
 			  port->context_id, count,
 			  rq ? rq->global_seqno : 0,
 			  rq ? rq->fence.context : 0,
 			  rq ? rq->fence.seqno : 0,
+			  rq ? hwsp_seqno(rq) : 0,
 			  intel_engine_get_seqno(engine),
 			  rq ? rq_prio(rq) : 0);
 
-- 
cgit v1.2.3-59-g8ed1b


From 5013eb8cd601c31e6d7d1b9d3291b24e933b77b2 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 28 Jan 2019 18:18:11 +0000
Subject: drm/i915: Track the context's seqno in its own timeline HWSP

Now that we have allocated ourselves a cacheline to store a breadcrumb,
we can emit a write from the GPU into the timeline's HWSP of the
per-context seqno as we complete each request. This drops the mirroring
of the per-engine HWSP and allows each context to operate independently.
We do not need to unwind the per-context timeline, and so requests are
always consistent with the timeline breadcrumb, greatly simplifying the
completion checks as we no longer need to be concerned about the
global_seqno changing mid check.

One complication though is that we have to be wary that the request may
outlive the HWSP and so avoid touching the potentially danging pointer
after we have retired the fence. We also have to guard our access of the
HWSP with RCU, the release of the obj->mm.pages should already be RCU-safe.

At this point, we are emitting both per-context and global seqno and
still using the single per-engine execution timeline for resolving
interrupts.

v2: s/fake_complete/mark_complete/

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190128181812.22804-5-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_gem.c                |  2 +-
 drivers/gpu/drm/i915/i915_request.c            |  3 +-
 drivers/gpu/drm/i915/i915_request.h            | 30 ++++-----
 drivers/gpu/drm/i915/i915_reset.c              |  1 +
 drivers/gpu/drm/i915/i915_timeline.c           |  4 ++
 drivers/gpu/drm/i915/intel_engine_cs.c         | 15 ++++-
 drivers/gpu/drm/i915/intel_lrc.c               | 31 +++++----
 drivers/gpu/drm/i915/intel_ringbuffer.c        | 87 ++++++++++++++++++++------
 drivers/gpu/drm/i915/selftests/i915_timeline.c |  7 +--
 drivers/gpu/drm/i915/selftests/mock_engine.c   | 19 +++++-
 10 files changed, 139 insertions(+), 60 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 761714448ff3..4e0de22f0166 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2890,7 +2890,7 @@ i915_gem_find_active_request(struct intel_engine_cs *engine)
 	 */
 	spin_lock_irqsave(&engine->timeline.lock, flags);
 	list_for_each_entry(request, &engine->timeline.requests, link) {
-		if (__i915_request_completed(request, request->global_seqno))
+		if (i915_request_completed(request))
 			continue;
 
 		active = request;
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index a076fd0b7ba6..4d58770e6a8c 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -199,6 +199,7 @@ static void __retire_engine_request(struct intel_engine_cs *engine,
 	spin_unlock(&engine->timeline.lock);
 
 	spin_lock(&rq->lock);
+	i915_request_mark_complete(rq);
 	if (!i915_request_signaled(rq))
 		dma_fence_signal_locked(&rq->fence);
 	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &rq->fence.flags))
@@ -621,7 +622,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	rq->ring = ce->ring;
 	rq->timeline = ce->ring->timeline;
 	GEM_BUG_ON(rq->timeline == &engine->timeline);
-	rq->hwsp_seqno = &engine->status_page.addr[I915_GEM_HWS_INDEX];
+	rq->hwsp_seqno = rq->timeline->hwsp_seqno;
 
 	spin_lock_init(&rq->lock);
 	dma_fence_init(&rq->fence,
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index ade010fe6e26..96c586d6ff4d 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -289,6 +289,7 @@ long i915_request_wait(struct i915_request *rq,
 
 static inline bool i915_request_signaled(const struct i915_request *rq)
 {
+	/* The request may live longer than its HWSP, so check flags first! */
 	return test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags);
 }
 
@@ -340,32 +341,23 @@ static inline u32 hwsp_seqno(const struct i915_request *rq)
  */
 static inline bool i915_request_started(const struct i915_request *rq)
 {
-	u32 seqno;
-
-	seqno = i915_request_global_seqno(rq);
-	if (!seqno) /* not yet submitted to HW */
-		return false;
+	if (i915_request_signaled(rq))
+		return true;
 
-	return i915_seqno_passed(hwsp_seqno(rq), seqno - 1);
-}
-
-static inline bool
-__i915_request_completed(const struct i915_request *rq, u32 seqno)
-{
-	GEM_BUG_ON(!seqno);
-	return i915_seqno_passed(hwsp_seqno(rq), seqno) &&
-		seqno == i915_request_global_seqno(rq);
+	return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno - 1);
 }
 
 static inline bool i915_request_completed(const struct i915_request *rq)
 {
-	u32 seqno;
+	if (i915_request_signaled(rq))
+		return true;
 
-	seqno = i915_request_global_seqno(rq);
-	if (!seqno)
-		return false;
+	return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno);
+}
 
-	return __i915_request_completed(rq, seqno);
+static inline void i915_request_mark_complete(struct i915_request *rq)
+{
+	rq->hwsp_seqno = (u32 *)&rq->fence.seqno; /* decouple from HWSP */
 }
 
 void i915_retire_requests(struct drm_i915_private *i915);
diff --git a/drivers/gpu/drm/i915/i915_reset.c b/drivers/gpu/drm/i915/i915_reset.c
index d2dca85a543d..bd82f9b1043f 100644
--- a/drivers/gpu/drm/i915/i915_reset.c
+++ b/drivers/gpu/drm/i915/i915_reset.c
@@ -760,6 +760,7 @@ static void nop_submit_request(struct i915_request *request)
 
 	spin_lock_irqsave(&request->engine->timeline.lock, flags);
 	__i915_request_submit(request);
+	i915_request_mark_complete(request);
 	intel_engine_write_global_seqno(request->engine, request->global_seqno);
 	spin_unlock_irqrestore(&request->engine->timeline.lock, flags);
 }
diff --git a/drivers/gpu/drm/i915/i915_timeline.c b/drivers/gpu/drm/i915/i915_timeline.c
index add8fc33cf6e..e4c11414a824 100644
--- a/drivers/gpu/drm/i915/i915_timeline.c
+++ b/drivers/gpu/drm/i915/i915_timeline.c
@@ -270,6 +270,10 @@ int i915_timeline_pin(struct i915_timeline *tl)
 	if (err)
 		goto unpin;
 
+	tl->hwsp_offset =
+		i915_ggtt_offset(tl->hwsp_ggtt) +
+		offset_in_page(tl->hwsp_offset);
+
 	return 0;
 
 unpin:
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 515e87846afd..ead9c4371fe1 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -660,10 +660,16 @@ static int measure_breadcrumb_dw(struct intel_engine_cs *engine)
 	frame->rq.ring = &frame->ring;
 	frame->rq.timeline = &frame->timeline;
 
+	dw = i915_timeline_pin(&frame->timeline);
+	if (dw < 0)
+		goto out_timeline;
+
 	dw = engine->emit_breadcrumb(&frame->rq, frame->cs) - frame->cs;
 
-	i915_timeline_fini(&frame->timeline);
+	i915_timeline_unpin(&frame->timeline);
 
+out_timeline:
+	i915_timeline_fini(&frame->timeline);
 out_frame:
 	kfree(frame);
 	return dw;
@@ -1426,9 +1432,10 @@ static void intel_engine_print_registers(const struct intel_engine_cs *engine,
 				char hdr[80];
 
 				snprintf(hdr, sizeof(hdr),
-					 "\t\tELSP[%d] count=%d, ring->start=%08x, rq: ",
+					 "\t\tELSP[%d] count=%d, ring:{start:%08x, hwsp:%08x}, rq: ",
 					 idx, count,
-					 i915_ggtt_offset(rq->ring->vma));
+					 i915_ggtt_offset(rq->ring->vma),
+					 rq->timeline->hwsp_offset);
 				print_request(m, rq, hdr);
 			} else {
 				drm_printf(m, "\t\tELSP[%d] idle\n", idx);
@@ -1538,6 +1545,8 @@ void intel_engine_dump(struct intel_engine_cs *engine,
 			   rq->ring->emit);
 		drm_printf(m, "\t\tring->space:  0x%08x\n",
 			   rq->ring->space);
+		drm_printf(m, "\t\tring->hwsp:   0x%08x\n",
+			   rq->timeline->hwsp_offset);
 
 		print_request_ring(m, rq);
 	}
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index e388f37743a2..fdbb3fe8eac9 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -832,10 +832,10 @@ static void execlists_cancel_requests(struct intel_engine_cs *engine)
 	list_for_each_entry(rq, &engine->timeline.requests, link) {
 		GEM_BUG_ON(!rq->global_seqno);
 
-		if (i915_request_signaled(rq))
-			continue;
+		if (!i915_request_signaled(rq))
+			dma_fence_set_error(&rq->fence, -EIO);
 
-		dma_fence_set_error(&rq->fence, -EIO);
+		i915_request_mark_complete(rq);
 	}
 
 	/* Flush the queued requests to the timeline list (for retiring). */
@@ -845,9 +845,9 @@ static void execlists_cancel_requests(struct intel_engine_cs *engine)
 
 		priolist_for_each_request_consume(rq, rn, p, i) {
 			list_del_init(&rq->sched.link);
-
-			dma_fence_set_error(&rq->fence, -EIO);
 			__i915_request_submit(rq);
+			dma_fence_set_error(&rq->fence, -EIO);
+			i915_request_mark_complete(rq);
 		}
 
 		rb_erase_cached(&p->node, &execlists->queue);
@@ -2044,10 +2044,17 @@ static u32 *gen8_emit_breadcrumb(struct i915_request *request, u32 *cs)
 	/* w/a: bit 5 needs to be zero for MI_FLUSH_DW address. */
 	BUILD_BUG_ON(I915_GEM_HWS_INDEX_ADDR & (1 << 5));
 
-	cs = gen8_emit_ggtt_write(cs, request->global_seqno,
+	cs = gen8_emit_ggtt_write(cs,
+				  request->fence.seqno,
+				  request->timeline->hwsp_offset);
+
+	cs = gen8_emit_ggtt_write(cs,
+				  request->global_seqno,
 				  intel_hws_seqno_address(request->engine));
+
 	*cs++ = MI_USER_INTERRUPT;
 	*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
+
 	request->tail = intel_ring_offset(request, cs);
 	assert_ring_tail_valid(request->ring, request->tail);
 
@@ -2056,18 +2063,20 @@ static u32 *gen8_emit_breadcrumb(struct i915_request *request, u32 *cs)
 
 static u32 *gen8_emit_breadcrumb_rcs(struct i915_request *request, u32 *cs)
 {
-	/* We're using qword write, seqno should be aligned to 8 bytes. */
-	BUILD_BUG_ON(I915_GEM_HWS_INDEX & 1);
-
 	cs = gen8_emit_ggtt_write_rcs(cs,
-				      request->global_seqno,
-				      intel_hws_seqno_address(request->engine),
+				      request->fence.seqno,
+				      request->timeline->hwsp_offset,
 				      PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH |
 				      PIPE_CONTROL_DEPTH_CACHE_FLUSH |
 				      PIPE_CONTROL_DC_FLUSH_ENABLE |
 				      PIPE_CONTROL_FLUSH_ENABLE |
 				      PIPE_CONTROL_CS_STALL);
 
+	cs = gen8_emit_ggtt_write_rcs(cs,
+				      request->global_seqno,
+				      intel_hws_seqno_address(request->engine),
+				      PIPE_CONTROL_CS_STALL);
+
 	*cs++ = MI_USER_INTERRUPT;
 	*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
 
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 174795622eb1..ee3719324e2d 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -326,6 +326,11 @@ static u32 *gen6_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 		 PIPE_CONTROL_DC_FLUSH_ENABLE |
 		 PIPE_CONTROL_QW_WRITE |
 		 PIPE_CONTROL_CS_STALL);
+	*cs++ = rq->timeline->hwsp_offset | PIPE_CONTROL_GLOBAL_GTT;
+	*cs++ = rq->fence.seqno;
+
+	*cs++ = GFX_OP_PIPE_CONTROL(4);
+	*cs++ = PIPE_CONTROL_QW_WRITE | PIPE_CONTROL_CS_STALL;
 	*cs++ = intel_hws_seqno_address(rq->engine) | PIPE_CONTROL_GLOBAL_GTT;
 	*cs++ = rq->global_seqno;
 
@@ -427,6 +432,13 @@ static u32 *gen7_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 		 PIPE_CONTROL_QW_WRITE |
 		 PIPE_CONTROL_GLOBAL_GTT_IVB |
 		 PIPE_CONTROL_CS_STALL);
+	*cs++ = rq->timeline->hwsp_offset;
+	*cs++ = rq->fence.seqno;
+
+	*cs++ = GFX_OP_PIPE_CONTROL(4);
+	*cs++ = (PIPE_CONTROL_QW_WRITE |
+		 PIPE_CONTROL_GLOBAL_GTT_IVB |
+		 PIPE_CONTROL_CS_STALL);
 	*cs++ = intel_hws_seqno_address(rq->engine);
 	*cs++ = rq->global_seqno;
 
@@ -441,10 +453,19 @@ static u32 *gen7_rcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 
 static u32 *gen6_xcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 {
-	*cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW;
-	*cs++ = intel_hws_seqno_address(rq->engine) | MI_FLUSH_DW_USE_GTT;
+	GEM_BUG_ON(rq->timeline->hwsp_ggtt != rq->engine->status_page.vma);
+	GEM_BUG_ON(offset_in_page(rq->timeline->hwsp_offset) != I915_GEM_HWS_SEQNO_ADDR);
+
+	*cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
+	*cs++ = I915_GEM_HWS_SEQNO_ADDR | MI_FLUSH_DW_USE_GTT;
+	*cs++ = rq->fence.seqno;
+
+	*cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
+	*cs++ = I915_GEM_HWS_INDEX_ADDR | MI_FLUSH_DW_USE_GTT;
 	*cs++ = rq->global_seqno;
+
 	*cs++ = MI_USER_INTERRUPT;
+	*cs++ = MI_NOOP;
 
 	rq->tail = intel_ring_offset(rq, cs);
 	assert_ring_tail_valid(rq->ring, rq->tail);
@@ -457,14 +478,21 @@ static u32 *gen7_xcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 {
 	int i;
 
-	*cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW;
-	*cs++ = intel_hws_seqno_address(rq->engine) | MI_FLUSH_DW_USE_GTT;
+	GEM_BUG_ON(rq->timeline->hwsp_ggtt != rq->engine->status_page.vma);
+	GEM_BUG_ON(offset_in_page(rq->timeline->hwsp_offset) != I915_GEM_HWS_SEQNO_ADDR);
+
+	*cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
+	*cs++ = I915_GEM_HWS_SEQNO_ADDR | MI_FLUSH_DW_USE_GTT;
+	*cs++ = rq->fence.seqno;
+
+	*cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
+	*cs++ = I915_GEM_HWS_INDEX_ADDR | MI_FLUSH_DW_USE_GTT;
 	*cs++ = rq->global_seqno;
 
 	for (i = 0; i < GEN7_XCS_WA; i++) {
 		*cs++ = MI_STORE_DWORD_INDEX;
-		*cs++ = I915_GEM_HWS_INDEX_ADDR;
-		*cs++ = rq->global_seqno;
+		*cs++ = I915_GEM_HWS_SEQNO_ADDR;
+		*cs++ = rq->fence.seqno;
 	}
 
 	*cs++ = MI_FLUSH_DW;
@@ -472,7 +500,6 @@ static u32 *gen7_xcs_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 	*cs++ = 0;
 
 	*cs++ = MI_USER_INTERRUPT;
-	*cs++ = MI_NOOP;
 
 	rq->tail = intel_ring_offset(rq, cs);
 	assert_ring_tail_valid(rq->ring, rq->tail);
@@ -738,7 +765,7 @@ static void reset_ring(struct intel_engine_cs *engine, bool stalled)
 	rq = NULL;
 	spin_lock_irqsave(&tl->lock, flags);
 	list_for_each_entry(pos, &tl->requests, link) {
-		if (!__i915_request_completed(pos, pos->global_seqno)) {
+		if (!i915_request_completed(pos)) {
 			rq = pos;
 			break;
 		}
@@ -880,10 +907,10 @@ static void cancel_requests(struct intel_engine_cs *engine)
 	list_for_each_entry(request, &engine->timeline.requests, link) {
 		GEM_BUG_ON(!request->global_seqno);
 
-		if (i915_request_signaled(request))
-			continue;
+		if (!i915_request_signaled(request))
+			dma_fence_set_error(&request->fence, -EIO);
 
-		dma_fence_set_error(&request->fence, -EIO);
+		i915_request_mark_complete(request);
 	}
 
 	intel_write_status_page(engine,
@@ -907,14 +934,20 @@ static void i9xx_submit_request(struct i915_request *request)
 
 static u32 *i9xx_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 {
+	GEM_BUG_ON(rq->timeline->hwsp_ggtt != rq->engine->status_page.vma);
+	GEM_BUG_ON(offset_in_page(rq->timeline->hwsp_offset) != I915_GEM_HWS_SEQNO_ADDR);
+
 	*cs++ = MI_FLUSH;
 
+	*cs++ = MI_STORE_DWORD_INDEX;
+	*cs++ = I915_GEM_HWS_SEQNO_ADDR;
+	*cs++ = rq->fence.seqno;
+
 	*cs++ = MI_STORE_DWORD_INDEX;
 	*cs++ = I915_GEM_HWS_INDEX_ADDR;
 	*cs++ = rq->global_seqno;
 
 	*cs++ = MI_USER_INTERRUPT;
-	*cs++ = MI_NOOP;
 
 	rq->tail = intel_ring_offset(rq, cs);
 	assert_ring_tail_valid(rq->ring, rq->tail);
@@ -927,8 +960,15 @@ static u32 *gen5_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 {
 	int i;
 
+	GEM_BUG_ON(rq->timeline->hwsp_ggtt != rq->engine->status_page.vma);
+	GEM_BUG_ON(offset_in_page(rq->timeline->hwsp_offset) != I915_GEM_HWS_SEQNO_ADDR);
+
 	*cs++ = MI_FLUSH;
 
+	*cs++ = MI_STORE_DWORD_INDEX;
+	*cs++ = I915_GEM_HWS_SEQNO_ADDR;
+	*cs++ = rq->fence.seqno;
+
 	BUILD_BUG_ON(GEN5_WA_STORES < 1);
 	for (i = 0; i < GEN5_WA_STORES; i++) {
 		*cs++ = MI_STORE_DWORD_INDEX;
@@ -937,6 +977,7 @@ static u32 *gen5_emit_breadcrumb(struct i915_request *rq, u32 *cs)
 	}
 
 	*cs++ = MI_USER_INTERRUPT;
+	*cs++ = MI_NOOP;
 
 	rq->tail = intel_ring_offset(rq, cs);
 	assert_ring_tail_valid(rq->ring, rq->tail);
@@ -1169,6 +1210,10 @@ int intel_ring_pin(struct intel_ring *ring)
 
 	GEM_BUG_ON(ring->vaddr);
 
+	ret = i915_timeline_pin(ring->timeline);
+	if (ret)
+		return ret;
+
 	flags = PIN_GLOBAL;
 
 	/* Ring wraparound at offset 0 sometimes hangs. No idea why. */
@@ -1185,28 +1230,32 @@ int intel_ring_pin(struct intel_ring *ring)
 		else
 			ret = i915_gem_object_set_to_cpu_domain(vma->obj, true);
 		if (unlikely(ret))
-			return ret;
+			goto unpin_timeline;
 	}
 
 	ret = i915_vma_pin(vma, 0, 0, flags);
 	if (unlikely(ret))
-		return ret;
+		goto unpin_timeline;
 
 	if (i915_vma_is_map_and_fenceable(vma))
 		addr = (void __force *)i915_vma_pin_iomap(vma);
 	else
 		addr = i915_gem_object_pin_map(vma->obj, map);
-	if (IS_ERR(addr))
-		goto err;
+	if (IS_ERR(addr)) {
+		ret = PTR_ERR(addr);
+		goto unpin_ring;
+	}
 
 	vma->obj->pin_global++;
 
 	ring->vaddr = addr;
 	return 0;
 
-err:
+unpin_ring:
 	i915_vma_unpin(vma);
-	return PTR_ERR(addr);
+unpin_timeline:
+	i915_timeline_unpin(ring->timeline);
+	return ret;
 }
 
 void intel_ring_reset(struct intel_ring *ring, u32 tail)
@@ -1235,6 +1284,8 @@ void intel_ring_unpin(struct intel_ring *ring)
 
 	ring->vma->obj->pin_global--;
 	i915_vma_unpin(ring->vma);
+
+	i915_timeline_unpin(ring->timeline);
 }
 
 static struct i915_vma *
diff --git a/drivers/gpu/drm/i915/selftests/i915_timeline.c b/drivers/gpu/drm/i915/selftests/i915_timeline.c
index c34340f074cf..12ea69b1a1e5 100644
--- a/drivers/gpu/drm/i915/selftests/i915_timeline.c
+++ b/drivers/gpu/drm/i915/selftests/i915_timeline.c
@@ -440,11 +440,6 @@ static int emit_ggtt_store_dw(struct i915_request *rq, u32 addr, u32 value)
 	return 0;
 }
 
-static u32 hwsp_address(const struct i915_timeline *tl)
-{
-	return i915_ggtt_offset(tl->hwsp_ggtt) + tl->hwsp_offset;
-}
-
 static struct i915_request *
 tl_write(struct i915_timeline *tl, struct intel_engine_cs *engine, u32 value)
 {
@@ -463,7 +458,7 @@ tl_write(struct i915_timeline *tl, struct intel_engine_cs *engine, u32 value)
 	if (IS_ERR(rq))
 		goto out_unpin;
 
-	err = emit_ggtt_store_dw(rq, hwsp_address(tl), value);
+	err = emit_ggtt_store_dw(rq, tl->hwsp_offset, value);
 	i915_request_add(rq);
 	if (err)
 		rq = ERR_PTR(err);
diff --git a/drivers/gpu/drm/i915/selftests/mock_engine.c b/drivers/gpu/drm/i915/selftests/mock_engine.c
index 919c89fd6ee5..95e890d7f58b 100644
--- a/drivers/gpu/drm/i915/selftests/mock_engine.c
+++ b/drivers/gpu/drm/i915/selftests/mock_engine.c
@@ -30,6 +30,17 @@ struct mock_ring {
 	struct i915_timeline timeline;
 };
 
+static void mock_timeline_pin(struct i915_timeline *tl)
+{
+	tl->pin_count++;
+}
+
+static void mock_timeline_unpin(struct i915_timeline *tl)
+{
+	GEM_BUG_ON(!tl->pin_count);
+	tl->pin_count--;
+}
+
 static struct intel_ring *mock_ring(struct intel_engine_cs *engine)
 {
 	const unsigned long sz = PAGE_SIZE / 2;
@@ -76,6 +87,8 @@ static void advance(struct mock_request *request)
 {
 	list_del_init(&request->link);
 	mock_seqno_advance(request->base.engine, request->base.global_seqno);
+	i915_request_mark_complete(&request->base);
+	GEM_BUG_ON(!i915_request_completed(&request->base));
 }
 
 static void hw_delay_complete(struct timer_list *t)
@@ -108,6 +121,7 @@ static void hw_delay_complete(struct timer_list *t)
 
 static void mock_context_unpin(struct intel_context *ce)
 {
+	mock_timeline_unpin(ce->ring->timeline);
 	i915_gem_context_put(ce->gem_context);
 }
 
@@ -129,6 +143,7 @@ mock_context_pin(struct intel_engine_cs *engine,
 		 struct i915_gem_context *ctx)
 {
 	struct intel_context *ce = to_intel_context(ctx, engine);
+	int err = -ENOMEM;
 
 	if (ce->pin_count++)
 		return ce;
@@ -139,13 +154,15 @@ mock_context_pin(struct intel_engine_cs *engine,
 			goto err;
 	}
 
+	mock_timeline_pin(ce->ring->timeline);
+
 	ce->ops = &mock_context_ops;
 	i915_gem_context_get(ctx);
 	return ce;
 
 err:
 	ce->pin_count = 0;
-	return ERR_PTR(-ENOMEM);
+	return ERR_PTR(err);
 }
 
 static int mock_request_alloc(struct i915_request *request)
-- 
cgit v1.2.3-59-g8ed1b


From 8547444137ec6138ce52fc1938980b737a0d4d9e Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 29 Jan 2019 18:54:50 +0000
Subject: drm/i915: Identify active requests

To allow requests to forgo a common execution timeline, one question we
need to be able to answer is "is this request running?". To track
whether a request has started on HW, we can emit a breadcrumb at the
beginning of the request and check its timeline's HWSP to see if the
breadcrumb has advanced past the start of this request. (This is in
contrast to the global timeline where we need only ask if we are on the
global timeline and if the timeline has advanced past the end of the
previous request.)

There is still confusion from a preempted request, which has already
started but relinquished the HW to a high priority request. For the
common case, this discrepancy should be negligible. However, for
identification of hung requests, knowing which one was running at the
time of the hang will be much more important.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129185452.20989-2-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_gem.c              | 15 +++++++++++
 drivers/gpu/drm/i915/i915_gem_execbuffer.c   | 12 +++++++++
 drivers/gpu/drm/i915/i915_request.c          | 10 +++----
 drivers/gpu/drm/i915/i915_request.h          |  1 +
 drivers/gpu/drm/i915/i915_timeline.c         |  1 +
 drivers/gpu/drm/i915/i915_timeline.h         |  2 ++
 drivers/gpu/drm/i915/intel_engine_cs.c       |  8 +++---
 drivers/gpu/drm/i915/intel_lrc.c             | 39 ++++++++++++++++++++++++----
 drivers/gpu/drm/i915/intel_ringbuffer.c      | 25 +++++++++++-------
 drivers/gpu/drm/i915/intel_ringbuffer.h      |  6 +++--
 drivers/gpu/drm/i915/selftests/mock_engine.c |  2 +-
 11 files changed, 96 insertions(+), 25 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 9c499edb4c13..d92e7ab0005e 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2871,6 +2871,14 @@ i915_gem_object_pwrite_gtt(struct drm_i915_gem_object *obj,
 	return 0;
 }
 
+static bool match_ring(struct i915_request *rq)
+{
+	struct drm_i915_private *dev_priv = rq->i915;
+	u32 ring = I915_READ(RING_START(rq->engine->mmio_base));
+
+	return ring == i915_ggtt_offset(rq->ring->vma);
+}
+
 struct i915_request *
 i915_gem_find_active_request(struct intel_engine_cs *engine)
 {
@@ -2893,6 +2901,13 @@ i915_gem_find_active_request(struct intel_engine_cs *engine)
 		if (i915_request_completed(request))
 			continue;
 
+		if (!i915_request_started(request))
+			break;
+
+		/* More than one preemptible request may match! */
+		if (!match_ring(request))
+			break;
+
 		active = request;
 		break;
 	}
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index f250109e1f66..8eedf7cac493 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1976,6 +1976,18 @@ static int eb_submit(struct i915_execbuffer *eb)
 			return err;
 	}
 
+	/*
+	 * After we completed waiting for other engines (using HW semaphores)
+	 * then we can signal that this request/batch is ready to run. This
+	 * allows us to determine if the batch is still waiting on the GPU
+	 * or actually running by checking the breadcrumb.
+	 */
+	if (eb->engine->emit_init_breadcrumb) {
+		err = eb->engine->emit_init_breadcrumb(eb->request);
+		if (err)
+			return err;
+	}
+
 	err = eb->engine->emit_bb_start(eb->request,
 					eb->batch->node.start +
 					eb->batch_start_offset,
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 4d58770e6a8c..7db15b7b3de8 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -333,7 +333,7 @@ void i915_request_retire_upto(struct i915_request *rq)
 
 static u32 timeline_get_seqno(struct i915_timeline *tl)
 {
-	return ++tl->seqno;
+	return tl->seqno += 1 + tl->has_initial_breadcrumb;
 }
 
 static void move_to_timeline(struct i915_request *request,
@@ -382,8 +382,8 @@ void __i915_request_submit(struct i915_request *request)
 		intel_engine_enable_signaling(request, false);
 	spin_unlock(&request->lock);
 
-	engine->emit_breadcrumb(request,
-				request->ring->vaddr + request->postfix);
+	engine->emit_fini_breadcrumb(request,
+				     request->ring->vaddr + request->postfix);
 
 	/* Transfer from per-context onto the global per-engine timeline */
 	move_to_timeline(request, &engine->timeline);
@@ -657,7 +657,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	 * around inside i915_request_add() there is sufficient space at
 	 * the beginning of the ring as well.
 	 */
-	rq->reserved_space = 2 * engine->emit_breadcrumb_dw * sizeof(u32);
+	rq->reserved_space = 2 * engine->emit_fini_breadcrumb_dw * sizeof(u32);
 
 	/*
 	 * Record the position of the start of the request so that
@@ -908,7 +908,7 @@ void i915_request_add(struct i915_request *request)
 	 * GPU processing the request, we never over-estimate the
 	 * position of the ring's HEAD.
 	 */
-	cs = intel_ring_begin(request, engine->emit_breadcrumb_dw);
+	cs = intel_ring_begin(request, engine->emit_fini_breadcrumb_dw);
 	GEM_BUG_ON(IS_ERR(cs));
 	request->postfix = intel_ring_offset(request, cs);
 
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index 96c586d6ff4d..340d6216791c 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -344,6 +344,7 @@ static inline bool i915_request_started(const struct i915_request *rq)
 	if (i915_request_signaled(rq))
 		return true;
 
+	/* Remember: started but may have since been preempted! */
 	return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno - 1);
 }
 
diff --git a/drivers/gpu/drm/i915/i915_timeline.c b/drivers/gpu/drm/i915/i915_timeline.c
index 79838d89bdb9..5ea3af393ffe 100644
--- a/drivers/gpu/drm/i915/i915_timeline.c
+++ b/drivers/gpu/drm/i915/i915_timeline.c
@@ -135,6 +135,7 @@ int i915_timeline_init(struct drm_i915_private *i915,
 	timeline->i915 = i915;
 	timeline->name = name;
 	timeline->pin_count = 0;
+	timeline->has_initial_breadcrumb = !hwsp;
 
 	timeline->hwsp_offset = I915_GEM_HWS_SEQNO_ADDR;
 	if (!hwsp) {
diff --git a/drivers/gpu/drm/i915/i915_timeline.h b/drivers/gpu/drm/i915/i915_timeline.h
index ab736e2e5707..8caeb66d1cd5 100644
--- a/drivers/gpu/drm/i915/i915_timeline.h
+++ b/drivers/gpu/drm/i915/i915_timeline.h
@@ -48,6 +48,8 @@ struct i915_timeline {
 	struct i915_vma *hwsp_ggtt;
 	u32 hwsp_offset;
 
+	bool has_initial_breadcrumb;
+
 	/**
 	 * List of breadcrumbs associated with GPU requests currently
 	 * outstanding.
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index ead9c4371fe1..8dca76f6315d 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -664,7 +664,7 @@ static int measure_breadcrumb_dw(struct intel_engine_cs *engine)
 	if (dw < 0)
 		goto out_timeline;
 
-	dw = engine->emit_breadcrumb(&frame->rq, frame->cs) - frame->cs;
+	dw = engine->emit_fini_breadcrumb(&frame->rq, frame->cs) - frame->cs;
 
 	i915_timeline_unpin(&frame->timeline);
 
@@ -725,7 +725,7 @@ int intel_engine_init_common(struct intel_engine_cs *engine)
 	if (ret < 0)
 		goto err_breadcrumbs;
 
-	engine->emit_breadcrumb_dw = ret;
+	engine->emit_fini_breadcrumb_dw = ret;
 
 	return 0;
 
@@ -1297,7 +1297,9 @@ static void print_request(struct drm_printer *m,
 	drm_printf(m, "%s%x%s [%llx:%llx]%s @ %dms: %s\n",
 		   prefix,
 		   rq->global_seqno,
-		   i915_request_completed(rq) ? "!" : "",
+		   i915_request_completed(rq) ? "!" :
+		   i915_request_started(rq) ? "*" :
+		   "",
 		   rq->fence.context, rq->fence.seqno,
 		   buf,
 		   jiffies_to_msecs(jiffies - rq->emitted_jiffies),
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index fdbb3fe8eac9..5db16dd8e844 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -624,7 +624,7 @@ static void execlists_dequeue(struct intel_engine_cs *engine)
 		 * WaIdleLiteRestore:bdw,skl
 		 * Apply the wa NOOPs to prevent
 		 * ring:HEAD == rq:TAIL as we resubmit the
-		 * request. See gen8_emit_breadcrumb() for
+		 * request. See gen8_emit_fini_breadcrumb() for
 		 * where we prepare the padding after the
 		 * end of the request.
 		 */
@@ -1283,6 +1283,34 @@ execlists_context_pin(struct intel_engine_cs *engine,
 	return __execlists_context_pin(engine, ctx, ce);
 }
 
+static int gen8_emit_init_breadcrumb(struct i915_request *rq)
+{
+	u32 *cs;
+
+	GEM_BUG_ON(!rq->timeline->has_initial_breadcrumb);
+
+	cs = intel_ring_begin(rq, 6);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	/*
+	 * Check if we have been preempted before we even get started.
+	 *
+	 * After this point i915_request_started() reports true, even if
+	 * we get preempted and so are no longer running.
+	 */
+	*cs++ = MI_ARB_CHECK;
+	*cs++ = MI_NOOP;
+
+	*cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
+	*cs++ = rq->timeline->hwsp_offset;
+	*cs++ = 0;
+	*cs++ = rq->fence.seqno - 1;
+
+	intel_ring_advance(rq, cs);
+	return 0;
+}
+
 static int emit_pdps(struct i915_request *rq)
 {
 	const struct intel_engine_cs * const engine = rq->engine;
@@ -2039,7 +2067,7 @@ static u32 *gen8_emit_wa_tail(struct i915_request *request, u32 *cs)
 	return cs;
 }
 
-static u32 *gen8_emit_breadcrumb(struct i915_request *request, u32 *cs)
+static u32 *gen8_emit_fini_breadcrumb(struct i915_request *request, u32 *cs)
 {
 	/* w/a: bit 5 needs to be zero for MI_FLUSH_DW address. */
 	BUILD_BUG_ON(I915_GEM_HWS_INDEX_ADDR & (1 << 5));
@@ -2061,7 +2089,7 @@ static u32 *gen8_emit_breadcrumb(struct i915_request *request, u32 *cs)
 	return gen8_emit_wa_tail(request, cs);
 }
 
-static u32 *gen8_emit_breadcrumb_rcs(struct i915_request *request, u32 *cs)
+static u32 *gen8_emit_fini_breadcrumb_rcs(struct i915_request *request, u32 *cs)
 {
 	cs = gen8_emit_ggtt_write_rcs(cs,
 				      request->fence.seqno,
@@ -2176,7 +2204,8 @@ logical_ring_default_vfuncs(struct intel_engine_cs *engine)
 	engine->request_alloc = execlists_request_alloc;
 
 	engine->emit_flush = gen8_emit_flush;
-	engine->emit_breadcrumb = gen8_emit_breadcrumb;
+	engine->emit_init_breadcrumb = gen8_emit_init_breadcrumb;
+	engine->emit_fini_breadcrumb = gen8_emit_fini_breadcrumb;
 
 	engine->set_default_submission = intel_execlists_set_default_submission;
 
@@ -2289,7 +2318,7 @@ int logical_render_ring_init(struct intel_engine_cs *engine)
 	/* Override some for render ring. */
 	engine->init_context = gen8_init_rcs_context;
 	engine->emit_flush = gen8_emit_flush_render;
-	engine->emit_breadcrumb = gen8_emit_breadcrumb_rcs;
+	engine->emit_fini_breadcrumb = gen8_emit_fini_breadcrumb_rcs;
 
 	ret = logical_ring_init(engine);
 	if (ret)
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index ee3719324e2d..668ed67336a2 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1607,6 +1607,7 @@ static int intel_init_ring_buffer(struct intel_engine_cs *engine)
 		err = PTR_ERR(timeline);
 		goto err;
 	}
+	GEM_BUG_ON(timeline->has_initial_breadcrumb);
 
 	ring = intel_engine_create_ring(engine, timeline, 32 * PAGE_SIZE);
 	i915_timeline_put(timeline);
@@ -1960,6 +1961,7 @@ static int ring_request_alloc(struct i915_request *request)
 	int ret;
 
 	GEM_BUG_ON(!request->hw_context->pin_count);
+	GEM_BUG_ON(request->timeline->has_initial_breadcrumb);
 
 	/*
 	 * Flush enough space to reduce the likelihood of waiting after
@@ -2296,9 +2298,14 @@ static void intel_ring_default_vfuncs(struct drm_i915_private *dev_priv,
 	engine->context_pin = intel_ring_context_pin;
 	engine->request_alloc = ring_request_alloc;
 
-	engine->emit_breadcrumb = i9xx_emit_breadcrumb;
+	/*
+	 * Using a global execution timeline; the previous final breadcrumb is
+	 * equivalent to our next initial bread so we can elide
+	 * engine->emit_init_breadcrumb().
+	 */
+	engine->emit_fini_breadcrumb = i9xx_emit_breadcrumb;
 	if (IS_GEN(dev_priv, 5))
-		engine->emit_breadcrumb = gen5_emit_breadcrumb;
+		engine->emit_fini_breadcrumb = gen5_emit_breadcrumb;
 
 	engine->set_default_submission = i9xx_set_default_submission;
 
@@ -2327,11 +2334,11 @@ int intel_init_render_ring_buffer(struct intel_engine_cs *engine)
 	if (INTEL_GEN(dev_priv) >= 7) {
 		engine->init_context = intel_rcs_ctx_init;
 		engine->emit_flush = gen7_render_ring_flush;
-		engine->emit_breadcrumb = gen7_rcs_emit_breadcrumb;
+		engine->emit_fini_breadcrumb = gen7_rcs_emit_breadcrumb;
 	} else if (IS_GEN(dev_priv, 6)) {
 		engine->init_context = intel_rcs_ctx_init;
 		engine->emit_flush = gen6_render_ring_flush;
-		engine->emit_breadcrumb = gen6_rcs_emit_breadcrumb;
+		engine->emit_fini_breadcrumb = gen6_rcs_emit_breadcrumb;
 	} else if (IS_GEN(dev_priv, 5)) {
 		engine->emit_flush = gen4_render_ring_flush;
 	} else {
@@ -2368,9 +2375,9 @@ int intel_init_bsd_ring_buffer(struct intel_engine_cs *engine)
 		engine->irq_enable_mask = GT_BSD_USER_INTERRUPT;
 
 		if (IS_GEN(dev_priv, 6))
-			engine->emit_breadcrumb = gen6_xcs_emit_breadcrumb;
+			engine->emit_fini_breadcrumb = gen6_xcs_emit_breadcrumb;
 		else
-			engine->emit_breadcrumb = gen7_xcs_emit_breadcrumb;
+			engine->emit_fini_breadcrumb = gen7_xcs_emit_breadcrumb;
 	} else {
 		engine->emit_flush = bsd_ring_flush;
 		if (IS_GEN(dev_priv, 5))
@@ -2394,9 +2401,9 @@ int intel_init_blt_ring_buffer(struct intel_engine_cs *engine)
 	engine->irq_enable_mask = GT_BLT_USER_INTERRUPT;
 
 	if (IS_GEN(dev_priv, 6))
-		engine->emit_breadcrumb = gen6_xcs_emit_breadcrumb;
+		engine->emit_fini_breadcrumb = gen6_xcs_emit_breadcrumb;
 	else
-		engine->emit_breadcrumb = gen7_xcs_emit_breadcrumb;
+		engine->emit_fini_breadcrumb = gen7_xcs_emit_breadcrumb;
 
 	return intel_init_ring_buffer(engine);
 }
@@ -2414,7 +2421,7 @@ int intel_init_vebox_ring_buffer(struct intel_engine_cs *engine)
 	engine->irq_enable = hsw_vebox_irq_enable;
 	engine->irq_disable = hsw_vebox_irq_disable;
 
-	engine->emit_breadcrumb = gen7_xcs_emit_breadcrumb;
+	engine->emit_fini_breadcrumb = gen7_xcs_emit_breadcrumb;
 
 	return intel_init_ring_buffer(engine);
 }
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 2927b712b973..1f30ffb84936 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -463,8 +463,10 @@ struct intel_engine_cs {
 					 unsigned int dispatch_flags);
 #define I915_DISPATCH_SECURE BIT(0)
 #define I915_DISPATCH_PINNED BIT(1)
-	u32		*(*emit_breadcrumb)(struct i915_request *rq, u32 *cs);
-	int		emit_breadcrumb_dw;
+	int		 (*emit_init_breadcrumb)(struct i915_request *rq);
+	u32		*(*emit_fini_breadcrumb)(struct i915_request *rq,
+						 u32 *cs);
+	unsigned int	emit_fini_breadcrumb_dw;
 
 	/* Pass the request to the hardware queue (e.g. directly into
 	 * the legacy ringbuffer or to the end of an execlist).
diff --git a/drivers/gpu/drm/i915/selftests/mock_engine.c b/drivers/gpu/drm/i915/selftests/mock_engine.c
index 95e890d7f58b..3b226ebc6bc4 100644
--- a/drivers/gpu/drm/i915/selftests/mock_engine.c
+++ b/drivers/gpu/drm/i915/selftests/mock_engine.c
@@ -227,7 +227,7 @@ struct intel_engine_cs *mock_engine(struct drm_i915_private *i915,
 	engine->base.context_pin = mock_context_pin;
 	engine->base.request_alloc = mock_request_alloc;
 	engine->base.emit_flush = mock_emit_flush;
-	engine->base.emit_breadcrumb = mock_emit_breadcrumb;
+	engine->base.emit_fini_breadcrumb = mock_emit_breadcrumb;
 	engine->base.submit_request = mock_submit_request;
 
 	if (i915_timeline_init(i915,
-- 
cgit v1.2.3-59-g8ed1b


From 52c0fdb25c7c919334b97976d05096b441a3eada Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 29 Jan 2019 20:52:29 +0000
Subject: drm/i915: Replace global breadcrumbs with per-context interrupt
 tracking

A few years ago, see commit 688e6c725816 ("drm/i915: Slaughter the
thundering i915_wait_request herd"), the issue of handling multiple
clients waiting in parallel was brought to our attention. The
requirement was that every client should be woken immediately upon its
request being signaled, without incurring any cpu overhead.

To handle certain fragility of our hw meant that we could not do a
simple check inside the irq handler (some generations required almost
unbounded delays before we could be sure of seqno coherency) and so
request completion checking required delegation.

Before commit 688e6c725816, the solution was simple. Every client
waiting on a request would be woken on every interrupt and each would do
a heavyweight check to see if their request was complete. Commit
688e6c725816 introduced an rbtree so that only the earliest waiter on
the global timeline would woken, and would wake the next and so on.
(Along with various complications to handle requests being reordered
along the global timeline, and also a requirement for kthread to provide
a delegate for fence signaling that had no process context.)

The global rbtree depends on knowing the execution timeline (and global
seqno). Without knowing that order, we must instead check all contexts
queued to the HW to see which may have advanced. We trim that list by
only checking queued contexts that are being waited on, but still we
keep a list of all active contexts and their active signalers that we
inspect from inside the irq handler. By moving the waiters onto the fence
signal list, we can combine the client wakeup with the dma_fence
signaling (a dramatic reduction in complexity, but does require the HW
being coherent, the seqno must be visible from the cpu before the
interrupt is raised - we keep a timer backup just in case).

Having previously fixed all the issues with irq-seqno serialisation (by
inserting delays onto the GPU after each request instead of random delays
on the CPU after each interrupt), we can rely on the seqno state to
perfom direct wakeups from the interrupt handler. This allows us to
preserve our single context switch behaviour of the current routine,
with the only downside that we lose the RT priority sorting of wakeups.
In general, direct wakeup latency of multiple clients is about the same
(about 10% better in most cases) with a reduction in total CPU time spent
in the waiter (about 20-50% depending on gen). Average herd behaviour is
improved, but at the cost of not delegating wakeups on task_prio.

v2: Capture fence signaling state for error state and add comments to
warm even the most cold of hearts.
v3: Check if the request is still active before busywaiting
v4: Reduce the amount of pointer misdirection with list_for_each_safe
and using a local i915_request variable inside the loops
v5: Add a missing pluralisation to a purely informative selftest message.

References: 688e6c725816 ("drm/i915: Slaughter the thundering i915_wait_request herd")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190129205230.19056-2-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_debugfs.c                |  28 +-
 drivers/gpu/drm/i915/i915_gem_context.c            |   3 +
 drivers/gpu/drm/i915/i915_gem_context.h            |   2 +
 drivers/gpu/drm/i915/i915_gpu_error.c              |  83 +--
 drivers/gpu/drm/i915/i915_gpu_error.h              |   9 +-
 drivers/gpu/drm/i915/i915_irq.c                    |  82 +--
 drivers/gpu/drm/i915/i915_request.c                | 142 ++--
 drivers/gpu/drm/i915/i915_request.h                |  72 +-
 drivers/gpu/drm/i915/i915_reset.c                  |  16 +-
 drivers/gpu/drm/i915/i915_scheduler.c              |   2 +-
 drivers/gpu/drm/i915/intel_breadcrumbs.c           | 818 ++++++---------------
 drivers/gpu/drm/i915/intel_engine_cs.c             |  35 +-
 drivers/gpu/drm/i915/intel_ringbuffer.c            |   2 +-
 drivers/gpu/drm/i915/intel_ringbuffer.h            |  94 +--
 .../gpu/drm/i915/selftests/i915_mock_selftests.h   |   1 -
 drivers/gpu/drm/i915/selftests/i915_request.c      | 425 +++++++++++
 drivers/gpu/drm/i915/selftests/igt_spinner.c       |   5 -
 drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c | 470 ------------
 drivers/gpu/drm/i915/selftests/intel_hangcheck.c   |   2 +-
 drivers/gpu/drm/i915/selftests/lib_sw_fence.c      |  54 ++
 drivers/gpu/drm/i915/selftests/lib_sw_fence.h      |   3 +
 drivers/gpu/drm/i915/selftests/mock_engine.c       |  17 +-
 drivers/gpu/drm/i915/selftests/mock_engine.h       |   6 -
 23 files changed, 890 insertions(+), 1481 deletions(-)
 delete mode 100644 drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index c9c230499420..29d52304c189 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1315,29 +1315,16 @@ static int i915_hangcheck_info(struct seq_file *m, void *unused)
 	seq_printf(m, "GT active? %s\n", yesno(dev_priv->gt.awake));
 
 	for_each_engine(engine, dev_priv, id) {
-		struct intel_breadcrumbs *b = &engine->breadcrumbs;
-		struct rb_node *rb;
-
 		seq_printf(m, "%s:\n", engine->name);
 		seq_printf(m, "\tseqno = %x [current %x, last %x], %dms ago\n",
 			   engine->hangcheck.seqno, seqno[id],
 			   intel_engine_last_submit(engine),
 			   jiffies_to_msecs(jiffies -
 					    engine->hangcheck.action_timestamp));
-		seq_printf(m, "\twaiters? %s, fake irq active? %s\n",
-			   yesno(intel_engine_has_waiter(engine)),
+		seq_printf(m, "\tfake irq active? %s\n",
 			   yesno(test_bit(engine->id,
 					  &dev_priv->gpu_error.missed_irq_rings)));
 
-		spin_lock_irq(&b->rb_lock);
-		for (rb = rb_first(&b->waiters); rb; rb = rb_next(rb)) {
-			struct intel_wait *w = rb_entry(rb, typeof(*w), node);
-
-			seq_printf(m, "\t%s [%d] waiting for %x\n",
-				   w->tsk->comm, w->tsk->pid, w->seqno);
-		}
-		spin_unlock_irq(&b->rb_lock);
-
 		seq_printf(m, "\tACTHD = 0x%08llx [current 0x%08llx]\n",
 			   (long long)engine->hangcheck.acthd,
 			   (long long)acthd[id]);
@@ -2021,18 +2008,6 @@ static int i915_swizzle_info(struct seq_file *m, void *data)
 	return 0;
 }
 
-static int count_irq_waiters(struct drm_i915_private *i915)
-{
-	struct intel_engine_cs *engine;
-	enum intel_engine_id id;
-	int count = 0;
-
-	for_each_engine(engine, i915, id)
-		count += intel_engine_has_waiter(engine);
-
-	return count;
-}
-
 static const char *rps_power_to_str(unsigned int power)
 {
 	static const char * const strings[] = {
@@ -2072,7 +2047,6 @@ static int i915_rps_boost_info(struct seq_file *m, void *data)
 	seq_printf(m, "RPS enabled? %d\n", rps->enabled);
 	seq_printf(m, "GPU busy? %s [%d requests]\n",
 		   yesno(dev_priv->gt.awake), dev_priv->gt.active_requests);
-	seq_printf(m, "CPU waiting? %d\n", count_irq_waiters(dev_priv));
 	seq_printf(m, "Boosts outstanding? %d\n",
 		   atomic_read(&rps->num_waiters));
 	seq_printf(m, "Interactive? %d\n", READ_ONCE(rps->power.interactive));
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 93e84751370f..6faf1f6faab5 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -327,6 +327,9 @@ intel_context_init(struct intel_context *ce,
 		   struct intel_engine_cs *engine)
 {
 	ce->gem_context = ctx;
+
+	INIT_LIST_HEAD(&ce->signal_link);
+	INIT_LIST_HEAD(&ce->signals);
 }
 
 static struct i915_gem_context *
diff --git a/drivers/gpu/drm/i915/i915_gem_context.h b/drivers/gpu/drm/i915/i915_gem_context.h
index 3769438228f6..6ba40ff6b91f 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/i915_gem_context.h
@@ -164,6 +164,8 @@ struct i915_gem_context {
 	struct intel_context {
 		struct i915_gem_context *gem_context;
 		struct intel_engine_cs *active;
+		struct list_head signal_link;
+		struct list_head signals;
 		struct i915_vma *state;
 		struct intel_ring *ring;
 		u32 *lrc_reg_state;
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 898e06014295..304a7ef7f7fb 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -447,9 +447,14 @@ static void error_print_request(struct drm_i915_error_state_buf *m,
 	if (!erq->seqno)
 		return;
 
-	err_printf(m, "%s pid %d, ban score %d, seqno %8x:%08x, prio %d, emitted %dms, start %08x, head %08x, tail %08x\n",
+	err_printf(m, "%s pid %d, ban score %d, seqno %8x:%08x%s%s, prio %d, emitted %dms, start %08x, head %08x, tail %08x\n",
 		   prefix, erq->pid, erq->ban_score,
-		   erq->context, erq->seqno, erq->sched_attr.priority,
+		   erq->context, erq->seqno,
+		   test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
+			    &erq->flags) ? "!" : "",
+		   test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
+			    &erq->flags) ? "+" : "",
+		   erq->sched_attr.priority,
 		   jiffies_to_msecs(erq->jiffies - epoch),
 		   erq->start, erq->head, erq->tail);
 }
@@ -530,7 +535,6 @@ static void error_print_engine(struct drm_i915_error_state_buf *m,
 	}
 	err_printf(m, "  seqno: 0x%08x\n", ee->seqno);
 	err_printf(m, "  last_seqno: 0x%08x\n", ee->last_seqno);
-	err_printf(m, "  waiting: %s\n", yesno(ee->waiting));
 	err_printf(m, "  ring->head: 0x%08x\n", ee->cpu_ring_head);
 	err_printf(m, "  ring->tail: 0x%08x\n", ee->cpu_ring_tail);
 	err_printf(m, "  hangcheck timestamp: %dms (%lu%s)\n",
@@ -804,21 +808,6 @@ static void __err_print_to_sgl(struct drm_i915_error_state_buf *m,
 						    error->epoch);
 		}
 
-		if (IS_ERR(ee->waiters)) {
-			err_printf(m, "%s --- ? waiters [unable to acquire spinlock]\n",
-				   m->i915->engine[i]->name);
-		} else if (ee->num_waiters) {
-			err_printf(m, "%s --- %d waiters\n",
-				   m->i915->engine[i]->name,
-				   ee->num_waiters);
-			for (j = 0; j < ee->num_waiters; j++) {
-				err_printf(m, " seqno 0x%08x for %s [%d]\n",
-					   ee->waiters[j].seqno,
-					   ee->waiters[j].comm,
-					   ee->waiters[j].pid);
-			}
-		}
-
 		print_error_obj(m, m->i915->engine[i],
 				"ringbuffer", ee->ringbuffer);
 
@@ -1000,8 +989,6 @@ void __i915_gpu_state_free(struct kref *error_ref)
 		i915_error_object_free(ee->wa_ctx);
 
 		kfree(ee->requests);
-		if (!IS_ERR_OR_NULL(ee->waiters))
-			kfree(ee->waiters);
 	}
 
 	for (i = 0; i < ARRAY_SIZE(error->active_bo); i++)
@@ -1205,59 +1192,6 @@ static void gen6_record_semaphore_state(struct intel_engine_cs *engine,
 			I915_READ(RING_SYNC_2(engine->mmio_base));
 }
 
-static void error_record_engine_waiters(struct intel_engine_cs *engine,
-					struct drm_i915_error_engine *ee)
-{
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	struct drm_i915_error_waiter *waiter;
-	struct rb_node *rb;
-	int count;
-
-	ee->num_waiters = 0;
-	ee->waiters = NULL;
-
-	if (RB_EMPTY_ROOT(&b->waiters))
-		return;
-
-	if (!spin_trylock_irq(&b->rb_lock)) {
-		ee->waiters = ERR_PTR(-EDEADLK);
-		return;
-	}
-
-	count = 0;
-	for (rb = rb_first(&b->waiters); rb != NULL; rb = rb_next(rb))
-		count++;
-	spin_unlock_irq(&b->rb_lock);
-
-	waiter = NULL;
-	if (count)
-		waiter = kmalloc_array(count,
-				       sizeof(struct drm_i915_error_waiter),
-				       GFP_ATOMIC);
-	if (!waiter)
-		return;
-
-	if (!spin_trylock_irq(&b->rb_lock)) {
-		kfree(waiter);
-		ee->waiters = ERR_PTR(-EDEADLK);
-		return;
-	}
-
-	ee->waiters = waiter;
-	for (rb = rb_first(&b->waiters); rb; rb = rb_next(rb)) {
-		struct intel_wait *w = rb_entry(rb, typeof(*w), node);
-
-		strcpy(waiter->comm, w->tsk->comm);
-		waiter->pid = w->tsk->pid;
-		waiter->seqno = w->seqno;
-		waiter++;
-
-		if (++ee->num_waiters == count)
-			break;
-	}
-	spin_unlock_irq(&b->rb_lock);
-}
-
 static void error_record_engine_registers(struct i915_gpu_state *error,
 					  struct intel_engine_cs *engine,
 					  struct drm_i915_error_engine *ee)
@@ -1293,7 +1227,6 @@ static void error_record_engine_registers(struct i915_gpu_state *error,
 
 	intel_engine_get_instdone(engine, &ee->instdone);
 
-	ee->waiting = intel_engine_has_waiter(engine);
 	ee->instpm = I915_READ(RING_INSTPM(engine->mmio_base));
 	ee->acthd = intel_engine_get_active_head(engine);
 	ee->seqno = intel_engine_get_seqno(engine);
@@ -1367,6 +1300,7 @@ static void record_request(struct i915_request *request,
 {
 	struct i915_gem_context *ctx = request->gem_context;
 
+	erq->flags = request->fence.flags;
 	erq->context = ctx->hw_id;
 	erq->sched_attr = request->sched.attr;
 	erq->ban_score = atomic_read(&ctx->ban_score);
@@ -1542,7 +1476,6 @@ static void gem_record_rings(struct i915_gpu_state *error)
 		ee->engine_id = i;
 
 		error_record_engine_registers(error, engine, ee);
-		error_record_engine_waiters(engine, ee);
 		error_record_engine_execlists(engine, ee);
 
 		request = i915_gem_find_active_request(engine);
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.h b/drivers/gpu/drm/i915/i915_gpu_error.h
index 231173786eae..74757c424aab 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.h
+++ b/drivers/gpu/drm/i915/i915_gpu_error.h
@@ -82,8 +82,6 @@ struct i915_gpu_state {
 		int engine_id;
 		/* Software tracked state */
 		bool idle;
-		bool waiting;
-		int num_waiters;
 		unsigned long hangcheck_timestamp;
 		struct i915_address_space *vm;
 		int num_requests;
@@ -147,6 +145,7 @@ struct i915_gpu_state {
 		struct drm_i915_error_object *default_state;
 
 		struct drm_i915_error_request {
+			unsigned long flags;
 			long jiffies;
 			pid_t pid;
 			u32 context;
@@ -159,12 +158,6 @@ struct i915_gpu_state {
 		} *requests, execlist[EXECLIST_MAX_PORTS];
 		unsigned int num_ports;
 
-		struct drm_i915_error_waiter {
-			char comm[TASK_COMM_LEN];
-			pid_t pid;
-			u32 seqno;
-		} *waiters;
-
 		struct {
 			u32 gfx_mode;
 			union {
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 0fcdb14c50f4..eab085686a2a 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1169,66 +1169,6 @@ static void ironlake_rps_change_irq_handler(struct drm_i915_private *dev_priv)
 	return;
 }
 
-static void notify_ring(struct intel_engine_cs *engine)
-{
-	const u32 seqno = intel_engine_get_seqno(engine);
-	struct i915_request *rq = NULL;
-	struct task_struct *tsk = NULL;
-	struct intel_wait *wait;
-
-	if (unlikely(!engine->breadcrumbs.irq_armed))
-		return;
-
-	rcu_read_lock();
-
-	spin_lock(&engine->breadcrumbs.irq_lock);
-	wait = engine->breadcrumbs.irq_wait;
-	if (wait) {
-		/*
-		 * We use a callback from the dma-fence to submit
-		 * requests after waiting on our own requests. To
-		 * ensure minimum delay in queuing the next request to
-		 * hardware, signal the fence now rather than wait for
-		 * the signaler to be woken up. We still wake up the
-		 * waiter in order to handle the irq-seqno coherency
-		 * issues (we may receive the interrupt before the
-		 * seqno is written, see __i915_request_irq_complete())
-		 * and to handle coalescing of multiple seqno updates
-		 * and many waiters.
-		 */
-		if (i915_seqno_passed(seqno, wait->seqno)) {
-			struct i915_request *waiter = wait->request;
-
-			if (waiter &&
-			    !i915_request_signaled(waiter) &&
-			    intel_wait_check_request(wait, waiter))
-				rq = i915_request_get(waiter);
-
-			tsk = wait->tsk;
-		}
-
-		engine->breadcrumbs.irq_count++;
-	} else {
-		if (engine->breadcrumbs.irq_armed)
-			__intel_engine_disarm_breadcrumbs(engine);
-	}
-	spin_unlock(&engine->breadcrumbs.irq_lock);
-
-	if (rq) {
-		spin_lock(&rq->lock);
-		dma_fence_signal_locked(&rq->fence);
-		GEM_BUG_ON(!i915_request_completed(rq));
-		spin_unlock(&rq->lock);
-
-		i915_request_put(rq);
-	}
-
-	if (tsk && tsk->state & TASK_NORMAL)
-		wake_up_process(tsk);
-
-	rcu_read_unlock();
-}
-
 static void vlv_c0_read(struct drm_i915_private *dev_priv,
 			struct intel_rps_ei *ei)
 {
@@ -1473,20 +1413,20 @@ static void ilk_gt_irq_handler(struct drm_i915_private *dev_priv,
 			       u32 gt_iir)
 {
 	if (gt_iir & GT_RENDER_USER_INTERRUPT)
-		notify_ring(dev_priv->engine[RCS]);
+		intel_engine_breadcrumbs_irq(dev_priv->engine[RCS]);
 	if (gt_iir & ILK_BSD_USER_INTERRUPT)
-		notify_ring(dev_priv->engine[VCS]);
+		intel_engine_breadcrumbs_irq(dev_priv->engine[VCS]);
 }
 
 static void snb_gt_irq_handler(struct drm_i915_private *dev_priv,
 			       u32 gt_iir)
 {
 	if (gt_iir & GT_RENDER_USER_INTERRUPT)
-		notify_ring(dev_priv->engine[RCS]);
+		intel_engine_breadcrumbs_irq(dev_priv->engine[RCS]);
 	if (gt_iir & GT_BSD_USER_INTERRUPT)
-		notify_ring(dev_priv->engine[VCS]);
+		intel_engine_breadcrumbs_irq(dev_priv->engine[VCS]);
 	if (gt_iir & GT_BLT_USER_INTERRUPT)
-		notify_ring(dev_priv->engine[BCS]);
+		intel_engine_breadcrumbs_irq(dev_priv->engine[BCS]);
 
 	if (gt_iir & (GT_BLT_CS_ERROR_INTERRUPT |
 		      GT_BSD_CS_ERROR_INTERRUPT |
@@ -1506,7 +1446,7 @@ gen8_cs_irq_handler(struct intel_engine_cs *engine, u32 iir)
 		tasklet = true;
 
 	if (iir & GT_RENDER_USER_INTERRUPT) {
-		notify_ring(engine);
+		intel_engine_breadcrumbs_irq(engine);
 		tasklet |= USES_GUC_SUBMISSION(engine->i915);
 	}
 
@@ -1852,7 +1792,7 @@ static void gen6_rps_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir)
 
 	if (HAS_VEBOX(dev_priv)) {
 		if (pm_iir & PM_VEBOX_USER_INTERRUPT)
-			notify_ring(dev_priv->engine[VECS]);
+			intel_engine_breadcrumbs_irq(dev_priv->engine[VECS]);
 
 		if (pm_iir & PM_VEBOX_CS_ERROR_INTERRUPT)
 			DRM_DEBUG("Command parser error, pm_iir 0x%08x\n", pm_iir);
@@ -4276,7 +4216,7 @@ static irqreturn_t i8xx_irq_handler(int irq, void *arg)
 		I915_WRITE16(IIR, iir);
 
 		if (iir & I915_USER_INTERRUPT)
-			notify_ring(dev_priv->engine[RCS]);
+			intel_engine_breadcrumbs_irq(dev_priv->engine[RCS]);
 
 		if (iir & I915_MASTER_ERROR_INTERRUPT)
 			i8xx_error_irq_handler(dev_priv, eir, eir_stuck);
@@ -4384,7 +4324,7 @@ static irqreturn_t i915_irq_handler(int irq, void *arg)
 		I915_WRITE(IIR, iir);
 
 		if (iir & I915_USER_INTERRUPT)
-			notify_ring(dev_priv->engine[RCS]);
+			intel_engine_breadcrumbs_irq(dev_priv->engine[RCS]);
 
 		if (iir & I915_MASTER_ERROR_INTERRUPT)
 			i9xx_error_irq_handler(dev_priv, eir, eir_stuck);
@@ -4529,10 +4469,10 @@ static irqreturn_t i965_irq_handler(int irq, void *arg)
 		I915_WRITE(IIR, iir);
 
 		if (iir & I915_USER_INTERRUPT)
-			notify_ring(dev_priv->engine[RCS]);
+			intel_engine_breadcrumbs_irq(dev_priv->engine[RCS]);
 
 		if (iir & I915_BSD_USER_INTERRUPT)
-			notify_ring(dev_priv->engine[VCS]);
+			intel_engine_breadcrumbs_irq(dev_priv->engine[VCS]);
 
 		if (iir & I915_MASTER_ERROR_INTERRUPT)
 			i9xx_error_irq_handler(dev_priv, eir, eir_stuck);
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 7db15b7b3de8..9ed5baf157a3 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -60,7 +60,7 @@ static bool i915_fence_signaled(struct dma_fence *fence)
 
 static bool i915_fence_enable_signaling(struct dma_fence *fence)
 {
-	return intel_engine_enable_signaling(to_request(fence), true);
+	return i915_request_enable_breadcrumb(to_request(fence));
 }
 
 static signed long i915_fence_wait(struct dma_fence *fence,
@@ -203,7 +203,7 @@ static void __retire_engine_request(struct intel_engine_cs *engine,
 	if (!i915_request_signaled(rq))
 		dma_fence_signal_locked(&rq->fence);
 	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &rq->fence.flags))
-		intel_engine_cancel_signaling(rq);
+		i915_request_cancel_breadcrumb(rq);
 	if (rq->waitboost) {
 		GEM_BUG_ON(!atomic_read(&rq->i915->gt_pm.rps.num_waiters));
 		atomic_dec(&rq->i915->gt_pm.rps.num_waiters);
@@ -377,9 +377,12 @@ void __i915_request_submit(struct i915_request *request)
 
 	/* We may be recursing from the signal callback of another i915 fence */
 	spin_lock_nested(&request->lock, SINGLE_DEPTH_NESTING);
+	GEM_BUG_ON(test_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags));
+	set_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags);
 	request->global_seqno = seqno;
-	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags))
-		intel_engine_enable_signaling(request, false);
+	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags) &&
+	    !i915_request_enable_breadcrumb(request))
+		intel_engine_queue_breadcrumbs(engine);
 	spin_unlock(&request->lock);
 
 	engine->emit_fini_breadcrumb(request,
@@ -389,8 +392,6 @@ void __i915_request_submit(struct i915_request *request)
 	move_to_timeline(request, &engine->timeline);
 
 	trace_i915_request_execute(request);
-
-	wake_up_all(&request->execute);
 }
 
 void i915_request_submit(struct i915_request *request)
@@ -433,7 +434,9 @@ void __i915_request_unsubmit(struct i915_request *request)
 	spin_lock_nested(&request->lock, SINGLE_DEPTH_NESTING);
 	request->global_seqno = 0;
 	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags))
-		intel_engine_cancel_signaling(request);
+		i915_request_cancel_breadcrumb(request);
+	GEM_BUG_ON(!test_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags));
+	clear_bit(I915_FENCE_FLAG_ACTIVE, &request->fence.flags);
 	spin_unlock(&request->lock);
 
 	/* Transfer back from the global per-engine timeline to per-context */
@@ -633,13 +636,11 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 
 	/* We bump the ref for the fence chain */
 	i915_sw_fence_init(&i915_request_get(rq)->submit, submit_notify);
-	init_waitqueue_head(&rq->execute);
 
 	i915_sched_node_init(&rq->sched);
 
 	/* No zalloc, must clear what we need by hand */
 	rq->global_seqno = 0;
-	rq->signaling.wait.seqno = 0;
 	rq->file_priv = NULL;
 	rq->batch = NULL;
 	rq->capture_list = NULL;
@@ -1030,13 +1031,10 @@ static bool busywait_stop(unsigned long timeout, unsigned int cpu)
 	return this_cpu != cpu;
 }
 
-static bool __i915_spin_request(const struct i915_request *rq,
-				u32 seqno, int state, unsigned long timeout_us)
+static bool __i915_spin_request(const struct i915_request * const rq,
+				int state, unsigned long timeout_us)
 {
-	struct intel_engine_cs *engine = rq->engine;
-	unsigned int irq, cpu;
-
-	GEM_BUG_ON(!seqno);
+	unsigned int cpu;
 
 	/*
 	 * Only wait for the request if we know it is likely to complete.
@@ -1044,12 +1042,12 @@ static bool __i915_spin_request(const struct i915_request *rq,
 	 * We don't track the timestamps around requests, nor the average
 	 * request length, so we do not have a good indicator that this
 	 * request will complete within the timeout. What we do know is the
-	 * order in which requests are executed by the engine and so we can
-	 * tell if the request has started. If the request hasn't started yet,
-	 * it is a fair assumption that it will not complete within our
-	 * relatively short timeout.
+	 * order in which requests are executed by the context and so we can
+	 * tell if the request has been started. If the request is not even
+	 * running yet, it is a fair assumption that it will not complete
+	 * within our relatively short timeout.
 	 */
-	if (!intel_engine_has_started(engine, seqno))
+	if (!i915_request_is_running(rq))
 		return false;
 
 	/*
@@ -1063,20 +1061,10 @@ static bool __i915_spin_request(const struct i915_request *rq,
 	 * takes to sleep on a request, on the order of a microsecond.
 	 */
 
-	irq = READ_ONCE(engine->breadcrumbs.irq_count);
 	timeout_us += local_clock_us(&cpu);
 	do {
-		if (intel_engine_has_completed(engine, seqno))
-			return seqno == i915_request_global_seqno(rq);
-
-		/*
-		 * Seqno are meant to be ordered *before* the interrupt. If
-		 * we see an interrupt without a corresponding seqno advance,
-		 * assume we won't see one in the near future but require
-		 * the engine->seqno_barrier() to fixup coherency.
-		 */
-		if (READ_ONCE(engine->breadcrumbs.irq_count) != irq)
-			break;
+		if (i915_request_completed(rq))
+			return true;
 
 		if (signal_pending_state(state, current))
 			break;
@@ -1090,6 +1078,18 @@ static bool __i915_spin_request(const struct i915_request *rq,
 	return false;
 }
 
+struct request_wait {
+	struct dma_fence_cb cb;
+	struct task_struct *tsk;
+};
+
+static void request_wait_wake(struct dma_fence *fence, struct dma_fence_cb *cb)
+{
+	struct request_wait *wait = container_of(cb, typeof(*wait), cb);
+
+	wake_up_process(wait->tsk);
+}
+
 /**
  * i915_request_wait - wait until execution of request has finished
  * @rq: the request to wait upon
@@ -1115,8 +1115,7 @@ long i915_request_wait(struct i915_request *rq,
 {
 	const int state = flags & I915_WAIT_INTERRUPTIBLE ?
 		TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE;
-	DEFINE_WAIT_FUNC(exec, default_wake_function);
-	struct intel_wait wait;
+	struct request_wait wait;
 
 	might_sleep();
 	GEM_BUG_ON(timeout < 0);
@@ -1128,47 +1127,24 @@ long i915_request_wait(struct i915_request *rq,
 		return -ETIME;
 
 	trace_i915_request_wait_begin(rq, flags);
-	add_wait_queue(&rq->execute, &exec);
-	intel_wait_init(&wait);
-	if (flags & I915_WAIT_PRIORITY)
-		i915_schedule_bump_priority(rq, I915_PRIORITY_WAIT);
-
-restart:
-	do {
-		set_current_state(state);
-		if (intel_wait_update_request(&wait, rq))
-			break;
-
-		if (signal_pending_state(state, current)) {
-			timeout = -ERESTARTSYS;
-			goto complete;
-		}
 
-		if (!timeout) {
-			timeout = -ETIME;
-			goto complete;
-		}
+	/* Optimistic short spin before touching IRQs */
+	if (__i915_spin_request(rq, state, 5))
+		goto out;
 
-		timeout = io_schedule_timeout(timeout);
-	} while (1);
+	if (flags & I915_WAIT_PRIORITY)
+		i915_schedule_bump_priority(rq, I915_PRIORITY_WAIT);
 
-	GEM_BUG_ON(!intel_wait_has_seqno(&wait));
-	GEM_BUG_ON(!i915_sw_fence_signaled(&rq->submit));
+	wait.tsk = current;
+	if (dma_fence_add_callback(&rq->fence, &wait.cb, request_wait_wake))
+		goto out;
 
-	/* Optimistic short spin before touching IRQs */
-	if (__i915_spin_request(rq, wait.seqno, state, 5))
-		goto complete;
+	for (;;) {
+		set_current_state(state);
 
-	set_current_state(state);
-	if (intel_engine_add_wait(rq->engine, &wait))
-		/*
-		 * In order to check that we haven't missed the interrupt
-		 * as we enabled it, we need to kick ourselves to do a
-		 * coherent check on the seqno before we sleep.
-		 */
-		goto wakeup;
+		if (i915_request_completed(rq))
+			break;
 
-	for (;;) {
 		if (signal_pending_state(state, current)) {
 			timeout = -ERESTARTSYS;
 			break;
@@ -1180,33 +1156,13 @@ restart:
 		}
 
 		timeout = io_schedule_timeout(timeout);
-
-		if (intel_wait_complete(&wait) &&
-		    intel_wait_check_request(&wait, rq))
-			break;
-
-		set_current_state(state);
-
-wakeup:
-		if (i915_request_completed(rq))
-			break;
-
-		/* Only spin if we know the GPU is processing this request */
-		if (__i915_spin_request(rq, wait.seqno, state, 2))
-			break;
-
-		if (!intel_wait_check_request(&wait, rq)) {
-			intel_engine_remove_wait(rq->engine, &wait);
-			goto restart;
-		}
 	}
-
-	intel_engine_remove_wait(rq->engine, &wait);
-complete:
 	__set_current_state(TASK_RUNNING);
-	remove_wait_queue(&rq->execute, &exec);
-	trace_i915_request_wait_end(rq);
 
+	dma_fence_remove_callback(&rq->fence, &wait.cb);
+
+out:
+	trace_i915_request_wait_end(rq);
 	return timeout;
 }
 
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index 340d6216791c..3cffb96203b9 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -38,23 +38,34 @@ struct drm_i915_gem_object;
 struct i915_request;
 struct i915_timeline;
 
-struct intel_wait {
-	struct rb_node node;
-	struct task_struct *tsk;
-	struct i915_request *request;
-	u32 seqno;
-};
-
-struct intel_signal_node {
-	struct intel_wait wait;
-	struct list_head link;
-};
-
 struct i915_capture_list {
 	struct i915_capture_list *next;
 	struct i915_vma *vma;
 };
 
+enum {
+	/*
+	 * I915_FENCE_FLAG_ACTIVE - this request is currently submitted to HW.
+	 *
+	 * Set by __i915_request_submit() on handing over to HW, and cleared
+	 * by __i915_request_unsubmit() if we preempt this request.
+	 *
+	 * Finally cleared for consistency on retiring the request, when
+	 * we know the HW is no longer running this request.
+	 *
+	 * See i915_request_is_active()
+	 */
+	I915_FENCE_FLAG_ACTIVE = DMA_FENCE_FLAG_USER_BITS,
+
+	/*
+	 * I915_FENCE_FLAG_SIGNAL - this request is currently on signal_list
+	 *
+	 * Internal bookkeeping used by the breadcrumb code to track when
+	 * a request is on the various signal_list.
+	 */
+	I915_FENCE_FLAG_SIGNAL,
+};
+
 /**
  * Request queue structure.
  *
@@ -97,7 +108,7 @@ struct i915_request {
 	struct intel_context *hw_context;
 	struct intel_ring *ring;
 	struct i915_timeline *timeline;
-	struct intel_signal_node signaling;
+	struct list_head signal_link;
 
 	/*
 	 * The rcu epoch of when this request was allocated. Used to judiciously
@@ -116,7 +127,6 @@ struct i915_request {
 	 */
 	struct i915_sw_fence submit;
 	wait_queue_entry_t submitq;
-	wait_queue_head_t execute;
 
 	/*
 	 * A list of everyone we wait upon, and everyone who waits upon us.
@@ -255,7 +265,7 @@ i915_request_put(struct i915_request *rq)
  * that it has passed the global seqno and the global seqno is unchanged
  * after the read, it is indeed complete).
  */
-static u32
+static inline u32
 i915_request_global_seqno(const struct i915_request *request)
 {
 	return READ_ONCE(request->global_seqno);
@@ -277,6 +287,10 @@ void i915_request_skip(struct i915_request *request, int error);
 void __i915_request_unsubmit(struct i915_request *request);
 void i915_request_unsubmit(struct i915_request *request);
 
+/* Note: part of the intel_breadcrumbs family */
+bool i915_request_enable_breadcrumb(struct i915_request *request);
+void i915_request_cancel_breadcrumb(struct i915_request *request);
+
 long i915_request_wait(struct i915_request *rq,
 		       unsigned int flags,
 		       long timeout)
@@ -293,6 +307,11 @@ static inline bool i915_request_signaled(const struct i915_request *rq)
 	return test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags);
 }
 
+static inline bool i915_request_is_active(const struct i915_request *rq)
+{
+	return test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags);
+}
+
 /**
  * Returns true if seq1 is later than seq2.
  */
@@ -330,6 +349,11 @@ static inline u32 hwsp_seqno(const struct i915_request *rq)
 	return seqno;
 }
 
+static inline bool __i915_request_has_started(const struct i915_request *rq)
+{
+	return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno - 1);
+}
+
 /**
  * i915_request_started - check if the request has begun being executed
  * @rq: the request
@@ -345,7 +369,23 @@ static inline bool i915_request_started(const struct i915_request *rq)
 		return true;
 
 	/* Remember: started but may have since been preempted! */
-	return i915_seqno_passed(hwsp_seqno(rq), rq->fence.seqno - 1);
+	return __i915_request_has_started(rq);
+}
+
+/**
+ * i915_request_is_running - check if the request may actually be executing
+ * @rq: the request
+ *
+ * Returns true if the request is currently submitted to hardware, has passed
+ * its start point (i.e. the context is setup and not busywaiting). Note that
+ * it may no longer be running by the time the function returns!
+ */
+static inline bool i915_request_is_running(const struct i915_request *rq)
+{
+	if (!i915_request_is_active(rq))
+		return false;
+
+	return __i915_request_has_started(rq);
 }
 
 static inline bool i915_request_completed(const struct i915_request *rq)
diff --git a/drivers/gpu/drm/i915/i915_reset.c b/drivers/gpu/drm/i915/i915_reset.c
index acf3c777e49d..4462007a681c 100644
--- a/drivers/gpu/drm/i915/i915_reset.c
+++ b/drivers/gpu/drm/i915/i915_reset.c
@@ -29,7 +29,7 @@ static void engine_skip_context(struct i915_request *rq)
 
 	spin_lock(&timeline->lock);
 
-	if (rq->global_seqno) {
+	if (i915_request_is_active(rq)) {
 		list_for_each_entry_continue(rq,
 					     &engine->timeline.requests, link)
 			if (rq->gem_context == hung_ctx)
@@ -751,18 +751,20 @@ static void reset_restart(struct drm_i915_private *i915)
 
 static void nop_submit_request(struct i915_request *request)
 {
+	struct intel_engine_cs *engine = request->engine;
 	unsigned long flags;
 
 	GEM_TRACE("%s fence %llx:%lld -> -EIO\n",
-		  request->engine->name,
-		  request->fence.context, request->fence.seqno);
+		  engine->name, request->fence.context, request->fence.seqno);
 	dma_fence_set_error(&request->fence, -EIO);
 
-	spin_lock_irqsave(&request->engine->timeline.lock, flags);
+	spin_lock_irqsave(&engine->timeline.lock, flags);
 	__i915_request_submit(request);
 	i915_request_mark_complete(request);
-	intel_engine_write_global_seqno(request->engine, request->global_seqno);
-	spin_unlock_irqrestore(&request->engine->timeline.lock, flags);
+	intel_engine_write_global_seqno(engine, request->global_seqno);
+	spin_unlock_irqrestore(&engine->timeline.lock, flags);
+
+	intel_engine_queue_breadcrumbs(engine);
 }
 
 void i915_gem_set_wedged(struct drm_i915_private *i915)
@@ -817,7 +819,7 @@ void i915_gem_set_wedged(struct drm_i915_private *i915)
 
 	for_each_engine(engine, i915, id) {
 		reset_finish_engine(engine);
-		intel_engine_wakeup(engine);
+		intel_engine_signal_breadcrumbs(engine);
 	}
 
 	smp_mb__before_atomic();
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
index 2d172991024f..d01683167c77 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.c
+++ b/drivers/gpu/drm/i915/i915_scheduler.c
@@ -243,7 +243,7 @@ static bool inflight(const struct i915_request *rq,
 {
 	const struct i915_request *active;
 
-	if (!rq->global_seqno)
+	if (!i915_request_is_active(rq))
 		return false;
 
 	active = port_request(engine->execlists.port);
diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c
index b58915b8708b..b0795b0ad227 100644
--- a/drivers/gpu/drm/i915/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c
@@ -29,48 +29,149 @@
 
 #define task_asleep(tsk) ((tsk)->state & TASK_NORMAL && !(tsk)->on_rq)
 
-static unsigned int __intel_breadcrumbs_wakeup(struct intel_breadcrumbs *b)
+static void irq_enable(struct intel_engine_cs *engine)
+{
+	if (!engine->irq_enable)
+		return;
+
+	/* Caller disables interrupts */
+	spin_lock(&engine->i915->irq_lock);
+	engine->irq_enable(engine);
+	spin_unlock(&engine->i915->irq_lock);
+}
+
+static void irq_disable(struct intel_engine_cs *engine)
 {
-	struct intel_wait *wait;
-	unsigned int result = 0;
+	if (!engine->irq_disable)
+		return;
+
+	/* Caller disables interrupts */
+	spin_lock(&engine->i915->irq_lock);
+	engine->irq_disable(engine);
+	spin_unlock(&engine->i915->irq_lock);
+}
 
+static void __intel_breadcrumbs_disarm_irq(struct intel_breadcrumbs *b)
+{
 	lockdep_assert_held(&b->irq_lock);
 
-	wait = b->irq_wait;
-	if (wait) {
+	GEM_BUG_ON(!b->irq_enabled);
+	if (!--b->irq_enabled)
+		irq_disable(container_of(b,
+					 struct intel_engine_cs,
+					 breadcrumbs));
+
+	b->irq_armed = false;
+}
+
+void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine)
+{
+	struct intel_breadcrumbs *b = &engine->breadcrumbs;
+
+	if (!b->irq_armed)
+		return;
+
+	spin_lock_irq(&b->irq_lock);
+	if (b->irq_armed)
+		__intel_breadcrumbs_disarm_irq(b);
+	spin_unlock_irq(&b->irq_lock);
+}
+
+static inline bool __request_completed(const struct i915_request *rq)
+{
+	return i915_seqno_passed(__hwsp_seqno(rq), rq->fence.seqno);
+}
+
+bool intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine)
+{
+	struct intel_breadcrumbs *b = &engine->breadcrumbs;
+	struct intel_context *ce, *cn;
+	struct list_head *pos, *next;
+	LIST_HEAD(signal);
+
+	spin_lock(&b->irq_lock);
+
+	b->irq_fired = true;
+	if (b->irq_armed && list_empty(&b->signalers))
+		__intel_breadcrumbs_disarm_irq(b);
+
+	list_for_each_entry_safe(ce, cn, &b->signalers, signal_link) {
+		GEM_BUG_ON(list_empty(&ce->signals));
+
+		list_for_each_safe(pos, next, &ce->signals) {
+			struct i915_request *rq =
+				list_entry(pos, typeof(*rq), signal_link);
+
+			if (!__request_completed(rq))
+				break;
+
+			GEM_BUG_ON(!test_bit(I915_FENCE_FLAG_SIGNAL,
+					     &rq->fence.flags));
+			clear_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags);
+
+			/*
+			 * We may race with direct invocation of
+			 * dma_fence_signal(), e.g. i915_request_retire(),
+			 * in which case we can skip processing it ourselves.
+			 */
+			if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
+				     &rq->fence.flags))
+				continue;
+
+			/*
+			 * Queue for execution after dropping the signaling
+			 * spinlock as the callback chain may end up adding
+			 * more signalers to the same context or engine.
+			 */
+			i915_request_get(rq);
+			list_add_tail(&rq->signal_link, &signal);
+		}
+
 		/*
-		 * N.B. Since task_asleep() and ttwu are not atomic, the
-		 * waiter may actually go to sleep after the check, causing
-		 * us to suppress a valid wakeup. We prefer to reduce the
-		 * number of false positive missed_breadcrumb() warnings
-		 * at the expense of a few false negatives, as it it easy
-		 * to trigger a false positive under heavy load. Enough
-		 * signal should remain from genuine missed_breadcrumb()
-		 * for us to detect in CI.
+		 * We process the list deletion in bulk, only using a list_add
+		 * (not list_move) above but keeping the status of
+		 * rq->signal_link known with the I915_FENCE_FLAG_SIGNAL bit.
 		 */
-		bool was_asleep = task_asleep(wait->tsk);
+		if (!list_is_first(pos, &ce->signals)) {
+			/* Advance the list to the first incomplete request */
+			__list_del_many(&ce->signals, pos);
+			if (&ce->signals == pos) /* now empty */
+				list_del_init(&ce->signal_link);
+		}
+	}
+
+	spin_unlock(&b->irq_lock);
+
+	list_for_each_safe(pos, next, &signal) {
+		struct i915_request *rq =
+			list_entry(pos, typeof(*rq), signal_link);
 
-		result = ENGINE_WAKEUP_WAITER;
-		if (wake_up_process(wait->tsk) && was_asleep)
-			result |= ENGINE_WAKEUP_ASLEEP;
+		dma_fence_signal(&rq->fence);
+		i915_request_put(rq);
 	}
 
-	return result;
+	return !list_empty(&signal);
 }
 
-unsigned int intel_engine_wakeup(struct intel_engine_cs *engine)
+bool intel_engine_signal_breadcrumbs(struct intel_engine_cs *engine)
 {
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	unsigned long flags;
-	unsigned int result;
+	bool result;
 
-	spin_lock_irqsave(&b->irq_lock, flags);
-	result = __intel_breadcrumbs_wakeup(b);
-	spin_unlock_irqrestore(&b->irq_lock, flags);
+	local_irq_disable();
+	result = intel_engine_breadcrumbs_irq(engine);
+	local_irq_enable();
 
 	return result;
 }
 
+static void signal_irq_work(struct irq_work *work)
+{
+	struct intel_engine_cs *engine =
+		container_of(work, typeof(*engine), breadcrumbs.irq_work);
+
+	intel_engine_breadcrumbs_irq(engine);
+}
+
 static unsigned long wait_timeout(void)
 {
 	return round_jiffies_up(jiffies + DRM_I915_HANGCHECK_JIFFIES);
@@ -94,19 +195,15 @@ static void intel_breadcrumbs_hangcheck(struct timer_list *t)
 	struct intel_engine_cs *engine =
 		from_timer(engine, t, breadcrumbs.hangcheck);
 	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	unsigned int irq_count;
 
 	if (!b->irq_armed)
 		return;
 
-	irq_count = READ_ONCE(b->irq_count);
-	if (b->hangcheck_interrupts != irq_count) {
-		b->hangcheck_interrupts = irq_count;
-		mod_timer(&b->hangcheck, wait_timeout());
-		return;
-	}
+	if (b->irq_fired)
+		goto rearm;
 
-	/* We keep the hangcheck timer alive until we disarm the irq, even
+	/*
+	 * We keep the hangcheck timer alive until we disarm the irq, even
 	 * if there are no waiters at present.
 	 *
 	 * If the waiter was currently running, assume it hasn't had a chance
@@ -118,10 +215,13 @@ static void intel_breadcrumbs_hangcheck(struct timer_list *t)
 	 * but we still have a waiter. Assuming all batches complete within
 	 * DRM_I915_HANGCHECK_JIFFIES [1.5s]!
 	 */
-	if (intel_engine_wakeup(engine) & ENGINE_WAKEUP_ASLEEP) {
+	synchronize_hardirq(engine->i915->drm.irq);
+	if (intel_engine_signal_breadcrumbs(engine)) {
 		missed_breadcrumb(engine);
 		mod_timer(&b->fake_irq, jiffies + 1);
 	} else {
+rearm:
+		b->irq_fired = false;
 		mod_timer(&b->hangcheck, wait_timeout());
 	}
 }
@@ -140,11 +240,7 @@ static void intel_breadcrumbs_fake_irq(struct timer_list *t)
 	 * oldest waiter to do the coherent seqno check.
 	 */
 
-	spin_lock_irq(&b->irq_lock);
-	if (b->irq_armed && !__intel_breadcrumbs_wakeup(b))
-		__intel_engine_disarm_breadcrumbs(engine);
-	spin_unlock_irq(&b->irq_lock);
-	if (!b->irq_armed)
+	if (!intel_engine_signal_breadcrumbs(engine) && !b->irq_armed)
 		return;
 
 	/* If the user has disabled the fake-irq, restore the hangchecking */
@@ -156,43 +252,6 @@ static void intel_breadcrumbs_fake_irq(struct timer_list *t)
 	mod_timer(&b->fake_irq, jiffies + 1);
 }
 
-static void irq_enable(struct intel_engine_cs *engine)
-{
-	if (!engine->irq_enable)
-		return;
-
-	/* Caller disables interrupts */
-	spin_lock(&engine->i915->irq_lock);
-	engine->irq_enable(engine);
-	spin_unlock(&engine->i915->irq_lock);
-}
-
-static void irq_disable(struct intel_engine_cs *engine)
-{
-	if (!engine->irq_disable)
-		return;
-
-	/* Caller disables interrupts */
-	spin_lock(&engine->i915->irq_lock);
-	engine->irq_disable(engine);
-	spin_unlock(&engine->i915->irq_lock);
-}
-
-void __intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine)
-{
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-
-	lockdep_assert_held(&b->irq_lock);
-	GEM_BUG_ON(b->irq_wait);
-	GEM_BUG_ON(!b->irq_armed);
-
-	GEM_BUG_ON(!b->irq_enabled);
-	if (!--b->irq_enabled)
-		irq_disable(engine);
-
-	b->irq_armed = false;
-}
-
 void intel_engine_pin_breadcrumbs_irq(struct intel_engine_cs *engine)
 {
 	struct intel_breadcrumbs *b = &engine->breadcrumbs;
@@ -215,40 +274,6 @@ void intel_engine_unpin_breadcrumbs_irq(struct intel_engine_cs *engine)
 	spin_unlock_irq(&b->irq_lock);
 }
 
-void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine)
-{
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	struct intel_wait *wait, *n;
-
-	if (!b->irq_armed)
-		return;
-
-	/*
-	 * We only disarm the irq when we are idle (all requests completed),
-	 * so if the bottom-half remains asleep, it missed the request
-	 * completion.
-	 */
-	if (intel_engine_wakeup(engine) & ENGINE_WAKEUP_ASLEEP)
-		missed_breadcrumb(engine);
-
-	spin_lock_irq(&b->rb_lock);
-
-	spin_lock(&b->irq_lock);
-	b->irq_wait = NULL;
-	if (b->irq_armed)
-		__intel_engine_disarm_breadcrumbs(engine);
-	spin_unlock(&b->irq_lock);
-
-	rbtree_postorder_for_each_entry_safe(wait, n, &b->waiters, node) {
-		GEM_BUG_ON(!intel_engine_signaled(engine, wait->seqno));
-		RB_CLEAR_NODE(&wait->node);
-		wake_up_process(wait->tsk);
-	}
-	b->waiters = RB_ROOT;
-
-	spin_unlock_irq(&b->rb_lock);
-}
-
 static bool use_fake_irq(const struct intel_breadcrumbs *b)
 {
 	const struct intel_engine_cs *engine =
@@ -264,7 +289,7 @@ static bool use_fake_irq(const struct intel_breadcrumbs *b)
 	 * engine->seqno_barrier(), a timing error that should be transient
 	 * and unlikely to reoccur.
 	 */
-	return READ_ONCE(b->irq_count) == b->hangcheck_interrupts;
+	return !b->irq_fired;
 }
 
 static void enable_fake_irq(struct intel_breadcrumbs *b)
@@ -276,7 +301,7 @@ static void enable_fake_irq(struct intel_breadcrumbs *b)
 		mod_timer(&b->hangcheck, wait_timeout());
 }
 
-static bool __intel_breadcrumbs_enable_irq(struct intel_breadcrumbs *b)
+static bool __intel_breadcrumbs_arm_irq(struct intel_breadcrumbs *b)
 {
 	struct intel_engine_cs *engine =
 		container_of(b, struct intel_engine_cs, breadcrumbs);
@@ -315,536 +340,149 @@ static bool __intel_breadcrumbs_enable_irq(struct intel_breadcrumbs *b)
 	return enabled;
 }
 
-static inline struct intel_wait *to_wait(struct rb_node *node)
+void intel_engine_init_breadcrumbs(struct intel_engine_cs *engine)
 {
-	return rb_entry(node, struct intel_wait, node);
-}
+	struct intel_breadcrumbs *b = &engine->breadcrumbs;
 
-static inline void __intel_breadcrumbs_finish(struct intel_breadcrumbs *b,
-					      struct intel_wait *wait)
-{
-	lockdep_assert_held(&b->rb_lock);
-	GEM_BUG_ON(b->irq_wait == wait);
+	spin_lock_init(&b->irq_lock);
+	INIT_LIST_HEAD(&b->signalers);
 
-	/*
-	 * This request is completed, so remove it from the tree, mark it as
-	 * complete, and *then* wake up the associated task. N.B. when the
-	 * task wakes up, it will find the empty rb_node, discern that it
-	 * has already been removed from the tree and skip the serialisation
-	 * of the b->rb_lock and b->irq_lock. This means that the destruction
-	 * of the intel_wait is not serialised with the interrupt handler
-	 * by the waiter - it must instead be serialised by the caller.
-	 */
-	rb_erase(&wait->node, &b->waiters);
-	RB_CLEAR_NODE(&wait->node);
+	init_irq_work(&b->irq_work, signal_irq_work);
 
-	if (wait->tsk->state != TASK_RUNNING)
-		wake_up_process(wait->tsk); /* implicit smp_wmb() */
+	timer_setup(&b->fake_irq, intel_breadcrumbs_fake_irq, 0);
+	timer_setup(&b->hangcheck, intel_breadcrumbs_hangcheck, 0);
 }
 
-static inline void __intel_breadcrumbs_next(struct intel_engine_cs *engine,
-					    struct rb_node *next)
+static void cancel_fake_irq(struct intel_engine_cs *engine)
 {
 	struct intel_breadcrumbs *b = &engine->breadcrumbs;
 
-	spin_lock(&b->irq_lock);
-	GEM_BUG_ON(!b->irq_armed);
-	GEM_BUG_ON(!b->irq_wait);
-	b->irq_wait = to_wait(next);
-	spin_unlock(&b->irq_lock);
-
-	/* We always wake up the next waiter that takes over as the bottom-half
-	 * as we may delegate not only the irq-seqno barrier to the next waiter
-	 * but also the task of waking up concurrent waiters.
-	 */
-	if (next)
-		wake_up_process(to_wait(next)->tsk);
+	del_timer_sync(&b->fake_irq); /* may queue b->hangcheck */
+	del_timer_sync(&b->hangcheck);
+	clear_bit(engine->id, &engine->i915->gpu_error.missed_irq_rings);
 }
 
-static bool __intel_engine_add_wait(struct intel_engine_cs *engine,
-				    struct intel_wait *wait)
+void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine)
 {
 	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	struct rb_node **p, *parent, *completed;
-	bool first, armed;
-	u32 seqno;
+	unsigned long flags;
 
-	GEM_BUG_ON(!wait->seqno);
+	spin_lock_irqsave(&b->irq_lock, flags);
 
-	/* Insert the request into the retirement ordered list
-	 * of waiters by walking the rbtree. If we are the oldest
-	 * seqno in the tree (the first to be retired), then
-	 * set ourselves as the bottom-half.
-	 *
-	 * As we descend the tree, prune completed branches since we hold the
-	 * spinlock we know that the first_waiter must be delayed and can
-	 * reduce some of the sequential wake up latency if we take action
-	 * ourselves and wake up the completed tasks in parallel. Also, by
-	 * removing stale elements in the tree, we may be able to reduce the
-	 * ping-pong between the old bottom-half and ourselves as first-waiter.
+	/*
+	 * Leave the fake_irq timer enabled (if it is running), but clear the
+	 * bit so that it turns itself off on its next wake up and goes back
+	 * to the long hangcheck interval if still required.
 	 */
-	armed = false;
-	first = true;
-	parent = NULL;
-	completed = NULL;
-	seqno = intel_engine_get_seqno(engine);
-
-	 /* If the request completed before we managed to grab the spinlock,
-	  * return now before adding ourselves to the rbtree. We let the
-	  * current bottom-half handle any pending wakeups and instead
-	  * try and get out of the way quickly.
-	  */
-	if (i915_seqno_passed(seqno, wait->seqno)) {
-		RB_CLEAR_NODE(&wait->node);
-		return first;
-	}
-
-	p = &b->waiters.rb_node;
-	while (*p) {
-		parent = *p;
-		if (wait->seqno == to_wait(parent)->seqno) {
-			/* We have multiple waiters on the same seqno, select
-			 * the highest priority task (that with the smallest
-			 * task->prio) to serve as the bottom-half for this
-			 * group.
-			 */
-			if (wait->tsk->prio > to_wait(parent)->tsk->prio) {
-				p = &parent->rb_right;
-				first = false;
-			} else {
-				p = &parent->rb_left;
-			}
-		} else if (i915_seqno_passed(wait->seqno,
-					     to_wait(parent)->seqno)) {
-			p = &parent->rb_right;
-			if (i915_seqno_passed(seqno, to_wait(parent)->seqno))
-				completed = parent;
-			else
-				first = false;
-		} else {
-			p = &parent->rb_left;
-		}
-	}
-	rb_link_node(&wait->node, parent, p);
-	rb_insert_color(&wait->node, &b->waiters);
-
-	if (first) {
-		spin_lock(&b->irq_lock);
-		b->irq_wait = wait;
-		/* After assigning ourselves as the new bottom-half, we must
-		 * perform a cursory check to prevent a missed interrupt.
-		 * Either we miss the interrupt whilst programming the hardware,
-		 * or if there was a previous waiter (for a later seqno) they
-		 * may be woken instead of us (due to the inherent race
-		 * in the unlocked read of b->irq_seqno_bh in the irq handler)
-		 * and so we miss the wake up.
-		 */
-		armed = __intel_breadcrumbs_enable_irq(b);
-		spin_unlock(&b->irq_lock);
-	}
-
-	if (completed) {
-		/* Advance the bottom-half (b->irq_wait) before we wake up
-		 * the waiters who may scribble over their intel_wait
-		 * just as the interrupt handler is dereferencing it via
-		 * b->irq_wait.
-		 */
-		if (!first) {
-			struct rb_node *next = rb_next(completed);
-			GEM_BUG_ON(next == &wait->node);
-			__intel_breadcrumbs_next(engine, next);
-		}
-
-		do {
-			struct intel_wait *crumb = to_wait(completed);
-			completed = rb_prev(completed);
-			__intel_breadcrumbs_finish(b, crumb);
-		} while (completed);
-	}
-
-	GEM_BUG_ON(!b->irq_wait);
-	GEM_BUG_ON(!b->irq_armed);
-	GEM_BUG_ON(rb_first(&b->waiters) != &b->irq_wait->node);
-
-	return armed;
-}
-
-bool intel_engine_add_wait(struct intel_engine_cs *engine,
-			   struct intel_wait *wait)
-{
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	bool armed;
-
-	spin_lock_irq(&b->rb_lock);
-	armed = __intel_engine_add_wait(engine, wait);
-	spin_unlock_irq(&b->rb_lock);
-	if (armed)
-		return armed;
-
-	/* Make the caller recheck if its request has already started. */
-	return intel_engine_has_started(engine, wait->seqno);
-}
-
-static inline bool chain_wakeup(struct rb_node *rb, int priority)
-{
-	return rb && to_wait(rb)->tsk->prio <= priority;
-}
+	clear_bit(engine->id, &engine->i915->gpu_error.missed_irq_rings);
 
-static inline int wakeup_priority(struct intel_breadcrumbs *b,
-				  struct task_struct *tsk)
-{
-	if (tsk == b->signaler)
-		return INT_MIN;
+	if (b->irq_enabled)
+		irq_enable(engine);
 	else
-		return tsk->prio;
-}
-
-static void __intel_engine_remove_wait(struct intel_engine_cs *engine,
-				       struct intel_wait *wait)
-{
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-
-	lockdep_assert_held(&b->rb_lock);
-
-	if (RB_EMPTY_NODE(&wait->node))
-		goto out;
-
-	if (b->irq_wait == wait) {
-		const int priority = wakeup_priority(b, wait->tsk);
-		struct rb_node *next;
-
-		/* We are the current bottom-half. Find the next candidate,
-		 * the first waiter in the queue on the remaining oldest
-		 * request. As multiple seqnos may complete in the time it
-		 * takes us to wake up and find the next waiter, we have to
-		 * wake up that waiter for it to perform its own coherent
-		 * completion check.
-		 */
-		next = rb_next(&wait->node);
-		if (chain_wakeup(next, priority)) {
-			/* If the next waiter is already complete,
-			 * wake it up and continue onto the next waiter. So
-			 * if have a small herd, they will wake up in parallel
-			 * rather than sequentially, which should reduce
-			 * the overall latency in waking all the completed
-			 * clients.
-			 *
-			 * However, waking up a chain adds extra latency to
-			 * the first_waiter. This is undesirable if that
-			 * waiter is a high priority task.
-			 */
-			u32 seqno = intel_engine_get_seqno(engine);
-
-			while (i915_seqno_passed(seqno, to_wait(next)->seqno)) {
-				struct rb_node *n = rb_next(next);
-
-				__intel_breadcrumbs_finish(b, to_wait(next));
-				next = n;
-				if (!chain_wakeup(next, priority))
-					break;
-			}
-		}
-
-		__intel_breadcrumbs_next(engine, next);
-	} else {
-		GEM_BUG_ON(rb_first(&b->waiters) == &wait->node);
-	}
-
-	GEM_BUG_ON(RB_EMPTY_NODE(&wait->node));
-	rb_erase(&wait->node, &b->waiters);
-	RB_CLEAR_NODE(&wait->node);
+		irq_disable(engine);
 
-out:
-	GEM_BUG_ON(b->irq_wait == wait);
-	GEM_BUG_ON(rb_first(&b->waiters) !=
-		   (b->irq_wait ? &b->irq_wait->node : NULL));
+	spin_unlock_irqrestore(&b->irq_lock, flags);
 }
 
-void intel_engine_remove_wait(struct intel_engine_cs *engine,
-			      struct intel_wait *wait)
+void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine)
 {
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-
-	/* Quick check to see if this waiter was already decoupled from
-	 * the tree by the bottom-half to avoid contention on the spinlock
-	 * by the herd.
-	 */
-	if (RB_EMPTY_NODE(&wait->node)) {
-		GEM_BUG_ON(READ_ONCE(b->irq_wait) == wait);
-		return;
-	}
-
-	spin_lock_irq(&b->rb_lock);
-	__intel_engine_remove_wait(engine, wait);
-	spin_unlock_irq(&b->rb_lock);
+	cancel_fake_irq(engine);
 }
 
-static void signaler_set_rtpriority(void)
+bool i915_request_enable_breadcrumb(struct i915_request *rq)
 {
-	 struct sched_param param = { .sched_priority = 1 };
-
-	 sched_setscheduler_nocheck(current, SCHED_FIFO, &param);
-}
+	struct intel_breadcrumbs *b = &rq->engine->breadcrumbs;
 
-static int intel_breadcrumbs_signaler(void *arg)
-{
-	struct intel_engine_cs *engine = arg;
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	struct i915_request *rq, *n;
+	GEM_BUG_ON(test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags));
 
-	/* Install ourselves with high priority to reduce signalling latency */
-	signaler_set_rtpriority();
+	if (!test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags))
+		return true;
 
-	do {
-		bool do_schedule = true;
-		LIST_HEAD(list);
-		u32 seqno;
+	spin_lock(&b->irq_lock);
+	if (test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags) &&
+	    !__request_completed(rq)) {
+		struct intel_context *ce = rq->hw_context;
+		struct list_head *pos;
 
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (list_empty(&b->signals))
-			goto sleep;
+		__intel_breadcrumbs_arm_irq(b);
 
 		/*
-		 * We are either woken up by the interrupt bottom-half,
-		 * or by a client adding a new signaller. In both cases,
-		 * the GPU seqno may have advanced beyond our oldest signal.
-		 * If it has, propagate the signal, remove the waiter and
-		 * check again with the next oldest signal. Otherwise we
-		 * need to wait for a new interrupt from the GPU or for
-		 * a new client.
+		 * We keep the seqno in retirement order, so we can break
+		 * inside intel_engine_breadcrumbs_irq as soon as we've passed
+		 * the last completed request (or seen a request that hasn't
+		 * event started). We could iterate the timeline->requests list,
+		 * but keeping a separate signalers_list has the advantage of
+		 * hopefully being much smaller than the full list and so
+		 * provides faster iteration and detection when there are no
+		 * more interrupts required for this context.
+		 *
+		 * We typically expect to add new signalers in order, so we
+		 * start looking for our insertion point from the tail of
+		 * the list.
 		 */
-		seqno = intel_engine_get_seqno(engine);
-
-		spin_lock_irq(&b->rb_lock);
-		list_for_each_entry_safe(rq, n, &b->signals, signaling.link) {
-			u32 this = rq->signaling.wait.seqno;
+		list_for_each_prev(pos, &ce->signals) {
+			struct i915_request *it =
+				list_entry(pos, typeof(*it), signal_link);
 
-			GEM_BUG_ON(!rq->signaling.wait.seqno);
-
-			if (!i915_seqno_passed(seqno, this))
+			if (i915_seqno_passed(rq->fence.seqno, it->fence.seqno))
 				break;
-
-			if (likely(this == i915_request_global_seqno(rq))) {
-				__intel_engine_remove_wait(engine,
-							   &rq->signaling.wait);
-
-				rq->signaling.wait.seqno = 0;
-				__list_del_entry(&rq->signaling.link);
-
-				if (!i915_request_signaled(rq)) {
-					list_add_tail(&rq->signaling.link,
-						      &list);
-					i915_request_get(rq);
-				}
-			}
 		}
-		spin_unlock_irq(&b->rb_lock);
-
-		if (!list_empty(&list)) {
-			local_bh_disable();
-			list_for_each_entry_safe(rq, n, &list, signaling.link) {
-				dma_fence_signal(&rq->fence);
-				GEM_BUG_ON(!i915_request_completed(rq));
-				i915_request_put(rq);
-			}
-			local_bh_enable(); /* kick start the tasklets */
-
-			/*
-			 * If the engine is saturated we may be continually
-			 * processing completed requests. This angers the
-			 * NMI watchdog if we never let anything else
-			 * have access to the CPU. Let's pretend to be nice
-			 * and relinquish the CPU if we burn through the
-			 * entire RT timeslice!
-			 */
-			do_schedule = need_resched();
-		}
-
-		if (unlikely(do_schedule)) {
-sleep:
-			if (kthread_should_park())
-				kthread_parkme();
-
-			if (unlikely(kthread_should_stop()))
-				break;
-
-			schedule();
-		}
-	} while (1);
-	__set_current_state(TASK_RUNNING);
-
-	return 0;
-}
+		list_add(&rq->signal_link, pos);
+		if (pos == &ce->signals) /* catch transitions from empty list */
+			list_move_tail(&ce->signal_link, &b->signalers);
 
-static void insert_signal(struct intel_breadcrumbs *b,
-			  struct i915_request *request,
-			  const u32 seqno)
-{
-	struct i915_request *iter;
-
-	lockdep_assert_held(&b->rb_lock);
-
-	/*
-	 * A reasonable assumption is that we are called to add signals
-	 * in sequence, as the requests are submitted for execution and
-	 * assigned a global_seqno. This will be the case for the majority
-	 * of internally generated signals (inter-engine signaling).
-	 *
-	 * Out of order waiters triggering random signaling enabling will
-	 * be more problematic, but hopefully rare enough and the list
-	 * small enough that the O(N) insertion sort is not an issue.
-	 */
-
-	list_for_each_entry_reverse(iter, &b->signals, signaling.link)
-		if (i915_seqno_passed(seqno, iter->signaling.wait.seqno))
-			break;
-
-	list_add(&request->signaling.link, &iter->signaling.link);
-}
-
-bool intel_engine_enable_signaling(struct i915_request *request, bool wakeup)
-{
-	struct intel_engine_cs *engine = request->engine;
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	struct intel_wait *wait = &request->signaling.wait;
-	u32 seqno;
-
-	/*
-	 * Note that we may be called from an interrupt handler on another
-	 * device (e.g. nouveau signaling a fence completion causing us
-	 * to submit a request, and so enable signaling). As such,
-	 * we need to make sure that all other users of b->rb_lock protect
-	 * against interrupts, i.e. use spin_lock_irqsave.
-	 */
-
-	/* locked by dma_fence_enable_sw_signaling() (irqsafe fence->lock) */
-	GEM_BUG_ON(!irqs_disabled());
-	lockdep_assert_held(&request->lock);
-
-	seqno = i915_request_global_seqno(request);
-	if (!seqno) /* will be enabled later upon execution */
-		return true;
-
-	GEM_BUG_ON(wait->seqno);
-	wait->tsk = b->signaler;
-	wait->request = request;
-	wait->seqno = seqno;
-
-	/*
-	 * Add ourselves into the list of waiters, but registering our
-	 * bottom-half as the signaller thread. As per usual, only the oldest
-	 * waiter (not just signaller) is tasked as the bottom-half waking
-	 * up all completed waiters after the user interrupt.
-	 *
-	 * If we are the oldest waiter, enable the irq (after which we
-	 * must double check that the seqno did not complete).
-	 */
-	spin_lock(&b->rb_lock);
-	insert_signal(b, request, seqno);
-	wakeup &= __intel_engine_add_wait(engine, wait);
-	spin_unlock(&b->rb_lock);
-
-	if (wakeup) {
-		wake_up_process(b->signaler);
-		return !intel_wait_complete(wait);
+		set_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags);
 	}
+	spin_unlock(&b->irq_lock);
 
-	return true;
+	return !__request_completed(rq);
 }
 
-void intel_engine_cancel_signaling(struct i915_request *request)
+void i915_request_cancel_breadcrumb(struct i915_request *rq)
 {
-	struct intel_engine_cs *engine = request->engine;
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
+	struct intel_breadcrumbs *b = &rq->engine->breadcrumbs;
 
-	GEM_BUG_ON(!irqs_disabled());
-	lockdep_assert_held(&request->lock);
-
-	if (!READ_ONCE(request->signaling.wait.seqno))
+	if (!test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags))
 		return;
 
-	spin_lock(&b->rb_lock);
-	__intel_engine_remove_wait(engine, &request->signaling.wait);
-	if (fetch_and_zero(&request->signaling.wait.seqno))
-		__list_del_entry(&request->signaling.link);
-	spin_unlock(&b->rb_lock);
-}
-
-int intel_engine_init_breadcrumbs(struct intel_engine_cs *engine)
-{
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	struct task_struct *tsk;
-
-	spin_lock_init(&b->rb_lock);
-	spin_lock_init(&b->irq_lock);
-
-	timer_setup(&b->fake_irq, intel_breadcrumbs_fake_irq, 0);
-	timer_setup(&b->hangcheck, intel_breadcrumbs_hangcheck, 0);
-
-	INIT_LIST_HEAD(&b->signals);
-
-	/* Spawn a thread to provide a common bottom-half for all signals.
-	 * As this is an asynchronous interface we cannot steal the current
-	 * task for handling the bottom-half to the user interrupt, therefore
-	 * we create a thread to do the coherent seqno dance after the
-	 * interrupt and then signal the waitqueue (via the dma-buf/fence).
-	 */
-	tsk = kthread_run(intel_breadcrumbs_signaler, engine,
-			  "i915/signal:%d", engine->id);
-	if (IS_ERR(tsk))
-		return PTR_ERR(tsk);
-
-	b->signaler = tsk;
-
-	return 0;
-}
+	spin_lock(&b->irq_lock);
+	if (test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags)) {
+		struct intel_context *ce = rq->hw_context;
 
-static void cancel_fake_irq(struct intel_engine_cs *engine)
-{
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
+		list_del(&rq->signal_link);
+		if (list_empty(&ce->signals))
+			list_del_init(&ce->signal_link);
 
-	del_timer_sync(&b->fake_irq); /* may queue b->hangcheck */
-	del_timer_sync(&b->hangcheck);
-	clear_bit(engine->id, &engine->i915->gpu_error.missed_irq_rings);
+		clear_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags);
+	}
+	spin_unlock(&b->irq_lock);
 }
 
-void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine)
+void intel_engine_print_breadcrumbs(struct intel_engine_cs *engine,
+				    struct drm_printer *p)
 {
 	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	unsigned long flags;
+	struct intel_context *ce;
+	struct i915_request *rq;
 
-	spin_lock_irqsave(&b->irq_lock, flags);
-
-	/*
-	 * Leave the fake_irq timer enabled (if it is running), but clear the
-	 * bit so that it turns itself off on its next wake up and goes back
-	 * to the long hangcheck interval if still required.
-	 */
-	clear_bit(engine->id, &engine->i915->gpu_error.missed_irq_rings);
-
-	if (b->irq_enabled)
-		irq_enable(engine);
-	else
-		irq_disable(engine);
-
-	spin_unlock_irqrestore(&b->irq_lock, flags);
-}
-
-void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine)
-{
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
+	if (list_empty(&b->signalers))
+		return;
 
-	/* The engines should be idle and all requests accounted for! */
-	WARN_ON(READ_ONCE(b->irq_wait));
-	WARN_ON(!RB_EMPTY_ROOT(&b->waiters));
-	WARN_ON(!list_empty(&b->signals));
+	drm_printf(p, "Signals:\n");
 
-	if (!IS_ERR_OR_NULL(b->signaler))
-		kthread_stop(b->signaler);
+	spin_lock_irq(&b->irq_lock);
+	list_for_each_entry(ce, &b->signalers, signal_link) {
+		list_for_each_entry(rq, &ce->signals, signal_link) {
+			drm_printf(p, "\t[%llx:%llx%s] @ %dms\n",
+				   rq->fence.context, rq->fence.seqno,
+				   i915_request_completed(rq) ? "!" :
+				   i915_request_started(rq) ? "*" :
+				   "",
+				   jiffies_to_msecs(jiffies - rq->emitted_jiffies));
+		}
+	}
+	spin_unlock_irq(&b->irq_lock);
 
-	cancel_fake_irq(engine);
+	if (test_bit(engine->id, &engine->i915->gpu_error.missed_irq_rings))
+		drm_printf(p, "Fake irq active\n");
 }
-
-#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
-#include "selftests/intel_breadcrumbs.c"
-#endif
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 0a610c9691fd..71c01eb13af1 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -458,12 +458,6 @@ cleanup:
 void intel_engine_write_global_seqno(struct intel_engine_cs *engine, u32 seqno)
 {
 	intel_write_status_page(engine, I915_GEM_HWS_INDEX, seqno);
-
-	/* After manually advancing the seqno, fake the interrupt in case
-	 * there are any waiters for that seqno.
-	 */
-	intel_engine_wakeup(engine);
-
 	GEM_BUG_ON(intel_engine_get_seqno(engine) != seqno);
 }
 
@@ -607,6 +601,7 @@ int intel_engine_setup_common(struct intel_engine_cs *engine)
 
 	i915_timeline_set_subclass(&engine->timeline, TIMELINE_ENGINE);
 
+	intel_engine_init_breadcrumbs(engine);
 	intel_engine_init_execlist(engine);
 	intel_engine_init_hangcheck(engine);
 	intel_engine_init_batch_pool(engine);
@@ -717,20 +712,14 @@ int intel_engine_init_common(struct intel_engine_cs *engine)
 		}
 	}
 
-	ret = intel_engine_init_breadcrumbs(engine);
-	if (ret)
-		goto err_unpin_preempt;
-
 	ret = measure_breadcrumb_dw(engine);
 	if (ret < 0)
-		goto err_breadcrumbs;
+		goto err_unpin_preempt;
 
 	engine->emit_fini_breadcrumb_dw = ret;
 
 	return 0;
 
-err_breadcrumbs:
-	intel_engine_fini_breadcrumbs(engine);
 err_unpin_preempt:
 	if (i915->preempt_context)
 		__intel_context_unpin(i915->preempt_context, engine);
@@ -1294,12 +1283,14 @@ static void print_request(struct drm_printer *m,
 
 	x = print_sched_attr(rq->i915, &rq->sched.attr, buf, x, sizeof(buf));
 
-	drm_printf(m, "%s%x%s [%llx:%llx]%s @ %dms: %s\n",
+	drm_printf(m, "%s%x%s%s [%llx:%llx]%s @ %dms: %s\n",
 		   prefix,
 		   rq->global_seqno,
 		   i915_request_completed(rq) ? "!" :
 		   i915_request_started(rq) ? "*" :
 		   "",
+		   test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT,
+			    &rq->fence.flags) ?  "+" : "",
 		   rq->fence.context, rq->fence.seqno,
 		   buf,
 		   jiffies_to_msecs(jiffies - rq->emitted_jiffies),
@@ -1492,12 +1483,9 @@ void intel_engine_dump(struct intel_engine_cs *engine,
 		       struct drm_printer *m,
 		       const char *header, ...)
 {
-	struct intel_breadcrumbs * const b = &engine->breadcrumbs;
 	struct i915_gpu_error * const error = &engine->i915->gpu_error;
 	struct i915_request *rq;
 	intel_wakeref_t wakeref;
-	unsigned long flags;
-	struct rb_node *rb;
 
 	if (header) {
 		va_list ap;
@@ -1565,21 +1553,12 @@ void intel_engine_dump(struct intel_engine_cs *engine,
 
 	intel_execlists_show_requests(engine, m, print_request, 8);
 
-	spin_lock_irqsave(&b->rb_lock, flags);
-	for (rb = rb_first(&b->waiters); rb; rb = rb_next(rb)) {
-		struct intel_wait *w = rb_entry(rb, typeof(*w), node);
-
-		drm_printf(m, "\t%s [%d:%c] waiting for %x\n",
-			   w->tsk->comm, w->tsk->pid,
-			   task_state_to_char(w->tsk),
-			   w->seqno);
-	}
-	spin_unlock_irqrestore(&b->rb_lock, flags);
-
 	drm_printf(m, "HWSP:\n");
 	hexdump(m, engine->status_page.addr, PAGE_SIZE);
 
 	drm_printf(m, "Idle? %s\n", yesno(intel_engine_is_idle(engine)));
+
+	intel_engine_print_breadcrumbs(engine, m);
 }
 
 static u8 user_class_map[] = {
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 668ed67336a2..b889b27f8aeb 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -743,7 +743,7 @@ static int init_ring_common(struct intel_engine_cs *engine)
 	}
 
 	/* Papering over lost _interrupts_ immediately following the restart */
-	intel_engine_wakeup(engine);
+	intel_engine_queue_breadcrumbs(engine);
 out:
 	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);
 
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index 953ccc2617ff..71f8ceb937ff 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -5,6 +5,7 @@
 #include <drm/drm_util.h>
 
 #include <linux/hashtable.h>
+#include <linux/irq_work.h>
 #include <linux/seqlock.h>
 
 #include "i915_gem_batch_pool.h"
@@ -381,22 +382,19 @@ struct intel_engine_cs {
 	 * the overhead of waking that client is much preferred.
 	 */
 	struct intel_breadcrumbs {
-		spinlock_t irq_lock; /* protects irq_*; irqsafe */
-		struct intel_wait *irq_wait; /* oldest waiter by retirement */
+		spinlock_t irq_lock;
+		struct list_head signalers;
 
-		spinlock_t rb_lock; /* protects the rb and wraps irq_lock */
-		struct rb_root waiters; /* sorted by retirement, priority */
-		struct list_head signals; /* sorted by retirement */
-		struct task_struct *signaler; /* used for fence signalling */
+		struct irq_work irq_work; /* for use from inside irq_lock */
 
 		struct timer_list fake_irq; /* used after a missed interrupt */
 		struct timer_list hangcheck; /* detect missed interrupts */
 
 		unsigned int hangcheck_interrupts;
 		unsigned int irq_enabled;
-		unsigned int irq_count;
 
-		bool irq_armed : 1;
+		bool irq_armed;
+		bool irq_fired;
 	} breadcrumbs;
 
 	struct {
@@ -885,83 +883,29 @@ static inline bool intel_engine_has_started(struct intel_engine_cs *engine,
 void intel_engine_get_instdone(struct intel_engine_cs *engine,
 			       struct intel_instdone *instdone);
 
-/* intel_breadcrumbs.c -- user interrupt bottom-half for waiters */
-int intel_engine_init_breadcrumbs(struct intel_engine_cs *engine);
-
-static inline void intel_wait_init(struct intel_wait *wait)
-{
-	wait->tsk = current;
-	wait->request = NULL;
-}
-
-static inline void intel_wait_init_for_seqno(struct intel_wait *wait, u32 seqno)
-{
-	wait->tsk = current;
-	wait->seqno = seqno;
-}
-
-static inline bool intel_wait_has_seqno(const struct intel_wait *wait)
-{
-	return wait->seqno;
-}
-
-static inline bool
-intel_wait_update_seqno(struct intel_wait *wait, u32 seqno)
-{
-	wait->seqno = seqno;
-	return intel_wait_has_seqno(wait);
-}
-
-static inline bool
-intel_wait_update_request(struct intel_wait *wait,
-			  const struct i915_request *rq)
-{
-	return intel_wait_update_seqno(wait, i915_request_global_seqno(rq));
-}
-
-static inline bool
-intel_wait_check_seqno(const struct intel_wait *wait, u32 seqno)
-{
-	return wait->seqno == seqno;
-}
-
-static inline bool
-intel_wait_check_request(const struct intel_wait *wait,
-			 const struct i915_request *rq)
-{
-	return intel_wait_check_seqno(wait, i915_request_global_seqno(rq));
-}
+void intel_engine_init_breadcrumbs(struct intel_engine_cs *engine);
+void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine);
 
-static inline bool intel_wait_complete(const struct intel_wait *wait)
-{
-	return RB_EMPTY_NODE(&wait->node);
-}
+void intel_engine_pin_breadcrumbs_irq(struct intel_engine_cs *engine);
+void intel_engine_unpin_breadcrumbs_irq(struct intel_engine_cs *engine);
 
-bool intel_engine_add_wait(struct intel_engine_cs *engine,
-			   struct intel_wait *wait);
-void intel_engine_remove_wait(struct intel_engine_cs *engine,
-			      struct intel_wait *wait);
-bool intel_engine_enable_signaling(struct i915_request *request, bool wakeup);
-void intel_engine_cancel_signaling(struct i915_request *request);
+bool intel_engine_signal_breadcrumbs(struct intel_engine_cs *engine);
+void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine);
 
-static inline bool intel_engine_has_waiter(const struct intel_engine_cs *engine)
+static inline void
+intel_engine_queue_breadcrumbs(struct intel_engine_cs *engine)
 {
-	return READ_ONCE(engine->breadcrumbs.irq_wait);
+	irq_work_queue(&engine->breadcrumbs.irq_work);
 }
 
-unsigned int intel_engine_wakeup(struct intel_engine_cs *engine);
-#define ENGINE_WAKEUP_WAITER BIT(0)
-#define ENGINE_WAKEUP_ASLEEP BIT(1)
-
-void intel_engine_pin_breadcrumbs_irq(struct intel_engine_cs *engine);
-void intel_engine_unpin_breadcrumbs_irq(struct intel_engine_cs *engine);
-
-void __intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine);
-void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine);
+bool intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine);
 
 void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine);
 void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine);
 
+void intel_engine_print_breadcrumbs(struct intel_engine_cs *engine,
+				    struct drm_printer *p);
+
 static inline u32 *gen8_emit_pipe_control(u32 *batch, u32 flags, u32 offset)
 {
 	memset(batch, 0, 6 * sizeof(u32));
diff --git a/drivers/gpu/drm/i915/selftests/i915_mock_selftests.h b/drivers/gpu/drm/i915/selftests/i915_mock_selftests.h
index 4a83a1c6c406..88e5ab586337 100644
--- a/drivers/gpu/drm/i915/selftests/i915_mock_selftests.h
+++ b/drivers/gpu/drm/i915/selftests/i915_mock_selftests.h
@@ -15,7 +15,6 @@ selftest(scatterlist, scatterlist_mock_selftests)
 selftest(syncmap, i915_syncmap_mock_selftests)
 selftest(uncore, intel_uncore_mock_selftests)
 selftest(engine, intel_engine_cs_mock_selftests)
-selftest(breadcrumbs, intel_breadcrumbs_mock_selftests)
 selftest(timelines, i915_timeline_mock_selftests)
 selftest(requests, i915_request_mock_selftests)
 selftest(objects, i915_gem_object_mock_selftests)
diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
index 4d4b86b5fa11..6733dc5b6b4c 100644
--- a/drivers/gpu/drm/i915/selftests/i915_request.c
+++ b/drivers/gpu/drm/i915/selftests/i915_request.c
@@ -25,9 +25,12 @@
 #include <linux/prime_numbers.h>
 
 #include "../i915_selftest.h"
+#include "i915_random.h"
 #include "igt_live_test.h"
+#include "lib_sw_fence.h"
 
 #include "mock_context.h"
+#include "mock_drm.h"
 #include "mock_gem_device.h"
 
 static int igt_add_request(void *arg)
@@ -247,6 +250,254 @@ err_context_0:
 	return err;
 }
 
+struct smoketest {
+	struct intel_engine_cs *engine;
+	struct i915_gem_context **contexts;
+	atomic_long_t num_waits, num_fences;
+	int ncontexts, max_batch;
+	struct i915_request *(*request_alloc)(struct i915_gem_context *,
+					      struct intel_engine_cs *);
+};
+
+static struct i915_request *
+__mock_request_alloc(struct i915_gem_context *ctx,
+		     struct intel_engine_cs *engine)
+{
+	return mock_request(engine, ctx, 0);
+}
+
+static struct i915_request *
+__live_request_alloc(struct i915_gem_context *ctx,
+		     struct intel_engine_cs *engine)
+{
+	return i915_request_alloc(engine, ctx);
+}
+
+static int __igt_breadcrumbs_smoketest(void *arg)
+{
+	struct smoketest *t = arg;
+	struct mutex * const BKL = &t->engine->i915->drm.struct_mutex;
+	const unsigned int max_batch = min(t->ncontexts, t->max_batch) - 1;
+	const unsigned int total = 4 * t->ncontexts + 1;
+	unsigned int num_waits = 0, num_fences = 0;
+	struct i915_request **requests;
+	I915_RND_STATE(prng);
+	unsigned int *order;
+	int err = 0;
+
+	/*
+	 * A very simple test to catch the most egregious of list handling bugs.
+	 *
+	 * At its heart, we simply create oodles of requests running across
+	 * multiple kthreads and enable signaling on them, for the sole purpose
+	 * of stressing our breadcrumb handling. The only inspection we do is
+	 * that the fences were marked as signaled.
+	 */
+
+	requests = kmalloc_array(total, sizeof(*requests), GFP_KERNEL);
+	if (!requests)
+		return -ENOMEM;
+
+	order = i915_random_order(total, &prng);
+	if (!order) {
+		err = -ENOMEM;
+		goto out_requests;
+	}
+
+	while (!kthread_should_stop()) {
+		struct i915_sw_fence *submit, *wait;
+		unsigned int n, count;
+
+		submit = heap_fence_create(GFP_KERNEL);
+		if (!submit) {
+			err = -ENOMEM;
+			break;
+		}
+
+		wait = heap_fence_create(GFP_KERNEL);
+		if (!wait) {
+			i915_sw_fence_commit(submit);
+			heap_fence_put(submit);
+			err = ENOMEM;
+			break;
+		}
+
+		i915_random_reorder(order, total, &prng);
+		count = 1 + i915_prandom_u32_max_state(max_batch, &prng);
+
+		for (n = 0; n < count; n++) {
+			struct i915_gem_context *ctx =
+				t->contexts[order[n] % t->ncontexts];
+			struct i915_request *rq;
+
+			mutex_lock(BKL);
+
+			rq = t->request_alloc(ctx, t->engine);
+			if (IS_ERR(rq)) {
+				mutex_unlock(BKL);
+				err = PTR_ERR(rq);
+				count = n;
+				break;
+			}
+
+			err = i915_sw_fence_await_sw_fence_gfp(&rq->submit,
+							       submit,
+							       GFP_KERNEL);
+
+			requests[n] = i915_request_get(rq);
+			i915_request_add(rq);
+
+			mutex_unlock(BKL);
+
+			if (err >= 0)
+				err = i915_sw_fence_await_dma_fence(wait,
+								    &rq->fence,
+								    0,
+								    GFP_KERNEL);
+
+			if (err < 0) {
+				i915_request_put(rq);
+				count = n;
+				break;
+			}
+		}
+
+		i915_sw_fence_commit(submit);
+		i915_sw_fence_commit(wait);
+
+		if (!wait_event_timeout(wait->wait,
+					i915_sw_fence_done(wait),
+					HZ / 2)) {
+			struct i915_request *rq = requests[count - 1];
+
+			pr_err("waiting for %d fences (last %llx:%lld) on %s timed out!\n",
+			       count,
+			       rq->fence.context, rq->fence.seqno,
+			       t->engine->name);
+			i915_gem_set_wedged(t->engine->i915);
+			GEM_BUG_ON(!i915_request_completed(rq));
+			i915_sw_fence_wait(wait);
+			err = -EIO;
+		}
+
+		for (n = 0; n < count; n++) {
+			struct i915_request *rq = requests[n];
+
+			if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT,
+				      &rq->fence.flags)) {
+				pr_err("%llu:%llu was not signaled!\n",
+				       rq->fence.context, rq->fence.seqno);
+				err = -EINVAL;
+			}
+
+			i915_request_put(rq);
+		}
+
+		heap_fence_put(wait);
+		heap_fence_put(submit);
+
+		if (err < 0)
+			break;
+
+		num_fences += count;
+		num_waits++;
+
+		cond_resched();
+	}
+
+	atomic_long_add(num_fences, &t->num_fences);
+	atomic_long_add(num_waits, &t->num_waits);
+
+	kfree(order);
+out_requests:
+	kfree(requests);
+	return err;
+}
+
+static int mock_breadcrumbs_smoketest(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct smoketest t = {
+		.engine = i915->engine[RCS],
+		.ncontexts = 1024,
+		.max_batch = 1024,
+		.request_alloc = __mock_request_alloc
+	};
+	unsigned int ncpus = num_online_cpus();
+	struct task_struct **threads;
+	unsigned int n;
+	int ret = 0;
+
+	/*
+	 * Smoketest our breadcrumb/signal handling for requests across multiple
+	 * threads. A very simple test to only catch the most egregious of bugs.
+	 * See __igt_breadcrumbs_smoketest();
+	 */
+
+	threads = kmalloc_array(ncpus, sizeof(*threads), GFP_KERNEL);
+	if (!threads)
+		return -ENOMEM;
+
+	t.contexts =
+		kmalloc_array(t.ncontexts, sizeof(*t.contexts), GFP_KERNEL);
+	if (!t.contexts) {
+		ret = -ENOMEM;
+		goto out_threads;
+	}
+
+	mutex_lock(&t.engine->i915->drm.struct_mutex);
+	for (n = 0; n < t.ncontexts; n++) {
+		t.contexts[n] = mock_context(t.engine->i915, "mock");
+		if (!t.contexts[n]) {
+			ret = -ENOMEM;
+			goto out_contexts;
+		}
+	}
+	mutex_unlock(&t.engine->i915->drm.struct_mutex);
+
+	for (n = 0; n < ncpus; n++) {
+		threads[n] = kthread_run(__igt_breadcrumbs_smoketest,
+					 &t, "igt/%d", n);
+		if (IS_ERR(threads[n])) {
+			ret = PTR_ERR(threads[n]);
+			ncpus = n;
+			break;
+		}
+
+		get_task_struct(threads[n]);
+	}
+
+	msleep(jiffies_to_msecs(i915_selftest.timeout_jiffies));
+
+	for (n = 0; n < ncpus; n++) {
+		int err;
+
+		err = kthread_stop(threads[n]);
+		if (err < 0 && !ret)
+			ret = err;
+
+		put_task_struct(threads[n]);
+	}
+	pr_info("Completed %lu waits for %lu fence across %d cpus\n",
+		atomic_long_read(&t.num_waits),
+		atomic_long_read(&t.num_fences),
+		ncpus);
+
+	mutex_lock(&t.engine->i915->drm.struct_mutex);
+out_contexts:
+	for (n = 0; n < t.ncontexts; n++) {
+		if (!t.contexts[n])
+			break;
+		mock_context_close(t.contexts[n]);
+	}
+	mutex_unlock(&t.engine->i915->drm.struct_mutex);
+	kfree(t.contexts);
+out_threads:
+	kfree(threads);
+
+	return ret;
+}
+
 int i915_request_mock_selftests(void)
 {
 	static const struct i915_subtest tests[] = {
@@ -254,6 +505,7 @@ int i915_request_mock_selftests(void)
 		SUBTEST(igt_wait_request),
 		SUBTEST(igt_fence_wait),
 		SUBTEST(igt_request_rewind),
+		SUBTEST(mock_breadcrumbs_smoketest),
 	};
 	struct drm_i915_private *i915;
 	intel_wakeref_t wakeref;
@@ -812,6 +1064,178 @@ out_unlock:
 	return err;
 }
 
+static int
+max_batches(struct i915_gem_context *ctx, struct intel_engine_cs *engine)
+{
+	struct i915_request *rq;
+	int ret;
+
+	/*
+	 * Before execlists, all contexts share the same ringbuffer. With
+	 * execlists, each context/engine has a separate ringbuffer and
+	 * for the purposes of this test, inexhaustible.
+	 *
+	 * For the global ringbuffer though, we have to be very careful
+	 * that we do not wrap while preventing the execution of requests
+	 * with a unsignaled fence.
+	 */
+	if (HAS_EXECLISTS(ctx->i915))
+		return INT_MAX;
+
+	rq = i915_request_alloc(engine, ctx);
+	if (IS_ERR(rq)) {
+		ret = PTR_ERR(rq);
+	} else {
+		int sz;
+
+		ret = rq->ring->size - rq->reserved_space;
+		i915_request_add(rq);
+
+		sz = rq->ring->emit - rq->head;
+		if (sz < 0)
+			sz += rq->ring->size;
+		ret /= sz;
+		ret /= 2; /* leave half spare, in case of emergency! */
+	}
+
+	return ret;
+}
+
+static int live_breadcrumbs_smoketest(void *arg)
+{
+	struct drm_i915_private *i915 = arg;
+	struct smoketest t[I915_NUM_ENGINES];
+	unsigned int ncpus = num_online_cpus();
+	unsigned long num_waits, num_fences;
+	struct intel_engine_cs *engine;
+	struct task_struct **threads;
+	struct igt_live_test live;
+	enum intel_engine_id id;
+	intel_wakeref_t wakeref;
+	struct drm_file *file;
+	unsigned int n;
+	int ret = 0;
+
+	/*
+	 * Smoketest our breadcrumb/signal handling for requests across multiple
+	 * threads. A very simple test to only catch the most egregious of bugs.
+	 * See __igt_breadcrumbs_smoketest();
+	 *
+	 * On real hardware this time.
+	 */
+
+	wakeref = intel_runtime_pm_get(i915);
+
+	file = mock_file(i915);
+	if (IS_ERR(file)) {
+		ret = PTR_ERR(file);
+		goto out_rpm;
+	}
+
+	threads = kcalloc(ncpus * I915_NUM_ENGINES,
+			  sizeof(*threads),
+			  GFP_KERNEL);
+	if (!threads) {
+		ret = -ENOMEM;
+		goto out_file;
+	}
+
+	memset(&t[0], 0, sizeof(t[0]));
+	t[0].request_alloc = __live_request_alloc;
+	t[0].ncontexts = 64;
+	t[0].contexts = kmalloc_array(t[0].ncontexts,
+				      sizeof(*t[0].contexts),
+				      GFP_KERNEL);
+	if (!t[0].contexts) {
+		ret = -ENOMEM;
+		goto out_threads;
+	}
+
+	mutex_lock(&i915->drm.struct_mutex);
+	for (n = 0; n < t[0].ncontexts; n++) {
+		t[0].contexts[n] = live_context(i915, file);
+		if (!t[0].contexts[n]) {
+			ret = -ENOMEM;
+			goto out_contexts;
+		}
+	}
+
+	ret = igt_live_test_begin(&live, i915, __func__, "");
+	if (ret)
+		goto out_contexts;
+
+	for_each_engine(engine, i915, id) {
+		t[id] = t[0];
+		t[id].engine = engine;
+		t[id].max_batch = max_batches(t[0].contexts[0], engine);
+		if (t[id].max_batch < 0) {
+			ret = t[id].max_batch;
+			mutex_unlock(&i915->drm.struct_mutex);
+			goto out_flush;
+		}
+		/* One ring interleaved between requests from all cpus */
+		t[id].max_batch /= num_online_cpus() + 1;
+		pr_debug("Limiting batches to %d requests on %s\n",
+			 t[id].max_batch, engine->name);
+
+		for (n = 0; n < ncpus; n++) {
+			struct task_struct *tsk;
+
+			tsk = kthread_run(__igt_breadcrumbs_smoketest,
+					  &t[id], "igt/%d.%d", id, n);
+			if (IS_ERR(tsk)) {
+				ret = PTR_ERR(tsk);
+				mutex_unlock(&i915->drm.struct_mutex);
+				goto out_flush;
+			}
+
+			get_task_struct(tsk);
+			threads[id * ncpus + n] = tsk;
+		}
+	}
+	mutex_unlock(&i915->drm.struct_mutex);
+
+	msleep(jiffies_to_msecs(i915_selftest.timeout_jiffies));
+
+out_flush:
+	num_waits = 0;
+	num_fences = 0;
+	for_each_engine(engine, i915, id) {
+		for (n = 0; n < ncpus; n++) {
+			struct task_struct *tsk = threads[id * ncpus + n];
+			int err;
+
+			if (!tsk)
+				continue;
+
+			err = kthread_stop(tsk);
+			if (err < 0 && !ret)
+				ret = err;
+
+			put_task_struct(tsk);
+		}
+
+		num_waits += atomic_long_read(&t[id].num_waits);
+		num_fences += atomic_long_read(&t[id].num_fences);
+	}
+	pr_info("Completed %lu waits for %lu fences across %d engines and %d cpus\n",
+		num_waits, num_fences, RUNTIME_INFO(i915)->num_rings, ncpus);
+
+	mutex_lock(&i915->drm.struct_mutex);
+	ret = igt_live_test_end(&live) ?: ret;
+out_contexts:
+	mutex_unlock(&i915->drm.struct_mutex);
+	kfree(t[0].contexts);
+out_threads:
+	kfree(threads);
+out_file:
+	mock_file_free(i915, file);
+out_rpm:
+	intel_runtime_pm_put(i915, wakeref);
+
+	return ret;
+}
+
 int i915_request_live_selftests(struct drm_i915_private *i915)
 {
 	static const struct i915_subtest tests[] = {
@@ -819,6 +1243,7 @@ int i915_request_live_selftests(struct drm_i915_private *i915)
 		SUBTEST(live_all_engines),
 		SUBTEST(live_sequential_engines),
 		SUBTEST(live_empty_request),
+		SUBTEST(live_breadcrumbs_smoketest),
 	};
 
 	if (i915_terminally_wedged(&i915->gpu_error))
diff --git a/drivers/gpu/drm/i915/selftests/igt_spinner.c b/drivers/gpu/drm/i915/selftests/igt_spinner.c
index 0e70df0230b8..9ebd9225684e 100644
--- a/drivers/gpu/drm/i915/selftests/igt_spinner.c
+++ b/drivers/gpu/drm/i915/selftests/igt_spinner.c
@@ -185,11 +185,6 @@ void igt_spinner_fini(struct igt_spinner *spin)
 
 bool igt_wait_for_spinner(struct igt_spinner *spin, struct i915_request *rq)
 {
-	if (!wait_event_timeout(rq->execute,
-				READ_ONCE(rq->global_seqno),
-				msecs_to_jiffies(10)))
-		return false;
-
 	return !(wait_for_us(i915_seqno_passed(hws_seqno(spin, rq),
 					       rq->fence.seqno),
 			     10) &&
diff --git a/drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c b/drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c
deleted file mode 100644
index f03b407fdbe2..000000000000
--- a/drivers/gpu/drm/i915/selftests/intel_breadcrumbs.c
+++ /dev/null
@@ -1,470 +0,0 @@
-/*
- * Copyright © 2016 Intel Corporation
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice (including the next
- * paragraph) shall be included in all copies or substantial portions of the
- * Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
- * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
- * IN THE SOFTWARE.
- *
- */
-
-#include "../i915_selftest.h"
-#include "i915_random.h"
-
-#include "mock_gem_device.h"
-#include "mock_engine.h"
-
-static int check_rbtree(struct intel_engine_cs *engine,
-			const unsigned long *bitmap,
-			const struct intel_wait *waiters,
-			const int count)
-{
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	struct rb_node *rb;
-	int n;
-
-	if (&b->irq_wait->node != rb_first(&b->waiters)) {
-		pr_err("First waiter does not match first element of wait-tree\n");
-		return -EINVAL;
-	}
-
-	n = find_first_bit(bitmap, count);
-	for (rb = rb_first(&b->waiters); rb; rb = rb_next(rb)) {
-		struct intel_wait *w = container_of(rb, typeof(*w), node);
-		int idx = w - waiters;
-
-		if (!test_bit(idx, bitmap)) {
-			pr_err("waiter[%d, seqno=%d] removed but still in wait-tree\n",
-			       idx, w->seqno);
-			return -EINVAL;
-		}
-
-		if (n != idx) {
-			pr_err("waiter[%d, seqno=%d] does not match expected next element in tree [%d]\n",
-			       idx, w->seqno, n);
-			return -EINVAL;
-		}
-
-		n = find_next_bit(bitmap, count, n + 1);
-	}
-
-	return 0;
-}
-
-static int check_completion(struct intel_engine_cs *engine,
-			    const unsigned long *bitmap,
-			    const struct intel_wait *waiters,
-			    const int count)
-{
-	int n;
-
-	for (n = 0; n < count; n++) {
-		if (intel_wait_complete(&waiters[n]) != !!test_bit(n, bitmap))
-			continue;
-
-		pr_err("waiter[%d, seqno=%d] is %s, but expected %s\n",
-		       n, waiters[n].seqno,
-		       intel_wait_complete(&waiters[n]) ? "complete" : "active",
-		       test_bit(n, bitmap) ? "active" : "complete");
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-static int check_rbtree_empty(struct intel_engine_cs *engine)
-{
-	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-
-	if (b->irq_wait) {
-		pr_err("Empty breadcrumbs still has a waiter\n");
-		return -EINVAL;
-	}
-
-	if (!RB_EMPTY_ROOT(&b->waiters)) {
-		pr_err("Empty breadcrumbs, but wait-tree not empty\n");
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
-static int igt_random_insert_remove(void *arg)
-{
-	const u32 seqno_bias = 0x1000;
-	I915_RND_STATE(prng);
-	struct intel_engine_cs *engine = arg;
-	struct intel_wait *waiters;
-	const int count = 4096;
-	unsigned int *order;
-	unsigned long *bitmap;
-	int err = -ENOMEM;
-	int n;
-
-	mock_engine_reset(engine);
-
-	waiters = kvmalloc_array(count, sizeof(*waiters), GFP_KERNEL);
-	if (!waiters)
-		goto out_engines;
-
-	bitmap = kcalloc(DIV_ROUND_UP(count, BITS_PER_LONG), sizeof(*bitmap),
-			 GFP_KERNEL);
-	if (!bitmap)
-		goto out_waiters;
-
-	order = i915_random_order(count, &prng);
-	if (!order)
-		goto out_bitmap;
-
-	for (n = 0; n < count; n++)
-		intel_wait_init_for_seqno(&waiters[n], seqno_bias + n);
-
-	err = check_rbtree(engine, bitmap, waiters, count);
-	if (err)
-		goto out_order;
-
-	/* Add and remove waiters into the rbtree in random order. At each
-	 * step, we verify that the rbtree is correctly ordered.
-	 */
-	for (n = 0; n < count; n++) {
-		int i = order[n];
-
-		intel_engine_add_wait(engine, &waiters[i]);
-		__set_bit(i, bitmap);
-
-		err = check_rbtree(engine, bitmap, waiters, count);
-		if (err)
-			goto out_order;
-	}
-
-	i915_random_reorder(order, count, &prng);
-	for (n = 0; n < count; n++) {
-		int i = order[n];
-
-		intel_engine_remove_wait(engine, &waiters[i]);
-		__clear_bit(i, bitmap);
-
-		err = check_rbtree(engine, bitmap, waiters, count);
-		if (err)
-			goto out_order;
-	}
-
-	err = check_rbtree_empty(engine);
-out_order:
-	kfree(order);
-out_bitmap:
-	kfree(bitmap);
-out_waiters:
-	kvfree(waiters);
-out_engines:
-	mock_engine_flush(engine);
-	return err;
-}
-
-static int igt_insert_complete(void *arg)
-{
-	const u32 seqno_bias = 0x1000;
-	struct intel_engine_cs *engine = arg;
-	struct intel_wait *waiters;
-	const int count = 4096;
-	unsigned long *bitmap;
-	int err = -ENOMEM;
-	int n, m;
-
-	mock_engine_reset(engine);
-
-	waiters = kvmalloc_array(count, sizeof(*waiters), GFP_KERNEL);
-	if (!waiters)
-		goto out_engines;
-
-	bitmap = kcalloc(DIV_ROUND_UP(count, BITS_PER_LONG), sizeof(*bitmap),
-			 GFP_KERNEL);
-	if (!bitmap)
-		goto out_waiters;
-
-	for (n = 0; n < count; n++) {
-		intel_wait_init_for_seqno(&waiters[n], n + seqno_bias);
-		intel_engine_add_wait(engine, &waiters[n]);
-		__set_bit(n, bitmap);
-	}
-	err = check_rbtree(engine, bitmap, waiters, count);
-	if (err)
-		goto out_bitmap;
-
-	/* On each step, we advance the seqno so that several waiters are then
-	 * complete (we increase the seqno by increasingly larger values to
-	 * retire more and more waiters at once). All retired waiters should
-	 * be woken and removed from the rbtree, and so that we check.
-	 */
-	for (n = 0; n < count; n = m) {
-		int seqno = 2 * n;
-
-		GEM_BUG_ON(find_first_bit(bitmap, count) != n);
-
-		if (intel_wait_complete(&waiters[n])) {
-			pr_err("waiter[%d, seqno=%d] completed too early\n",
-			       n, waiters[n].seqno);
-			err = -EINVAL;
-			goto out_bitmap;
-		}
-
-		/* complete the following waiters */
-		mock_seqno_advance(engine, seqno + seqno_bias);
-		for (m = n; m <= seqno; m++) {
-			if (m == count)
-				break;
-
-			GEM_BUG_ON(!test_bit(m, bitmap));
-			__clear_bit(m, bitmap);
-		}
-
-		intel_engine_remove_wait(engine, &waiters[n]);
-		RB_CLEAR_NODE(&waiters[n].node);
-
-		err = check_rbtree(engine, bitmap, waiters, count);
-		if (err) {
-			pr_err("rbtree corrupt after seqno advance to %d\n",
-			       seqno + seqno_bias);
-			goto out_bitmap;
-		}
-
-		err = check_completion(engine, bitmap, waiters, count);
-		if (err) {
-			pr_err("completions after seqno advance to %d failed\n",
-			       seqno + seqno_bias);
-			goto out_bitmap;
-		}
-	}
-
-	err = check_rbtree_empty(engine);
-out_bitmap:
-	kfree(bitmap);
-out_waiters:
-	kvfree(waiters);
-out_engines:
-	mock_engine_flush(engine);
-	return err;
-}
-
-struct igt_wakeup {
-	struct task_struct *tsk;
-	atomic_t *ready, *set, *done;
-	struct intel_engine_cs *engine;
-	unsigned long flags;
-#define STOP 0
-#define IDLE 1
-	wait_queue_head_t *wq;
-	u32 seqno;
-};
-
-static bool wait_for_ready(struct igt_wakeup *w)
-{
-	DEFINE_WAIT(ready);
-
-	set_bit(IDLE, &w->flags);
-	if (atomic_dec_and_test(w->done))
-		wake_up_var(w->done);
-
-	if (test_bit(STOP, &w->flags))
-		goto out;
-
-	for (;;) {
-		prepare_to_wait(w->wq, &ready, TASK_INTERRUPTIBLE);
-		if (atomic_read(w->ready) == 0)
-			break;
-
-		schedule();
-	}
-	finish_wait(w->wq, &ready);
-
-out:
-	clear_bit(IDLE, &w->flags);
-	if (atomic_dec_and_test(w->set))
-		wake_up_var(w->set);
-
-	return !test_bit(STOP, &w->flags);
-}
-
-static int igt_wakeup_thread(void *arg)
-{
-	struct igt_wakeup *w = arg;
-	struct intel_wait wait;
-
-	while (wait_for_ready(w)) {
-		GEM_BUG_ON(kthread_should_stop());
-
-		intel_wait_init_for_seqno(&wait, w->seqno);
-		intel_engine_add_wait(w->engine, &wait);
-		for (;;) {
-			set_current_state(TASK_UNINTERRUPTIBLE);
-			if (i915_seqno_passed(intel_engine_get_seqno(w->engine),
-					      w->seqno))
-				break;
-
-			if (test_bit(STOP, &w->flags)) /* emergency escape */
-				break;
-
-			schedule();
-		}
-		intel_engine_remove_wait(w->engine, &wait);
-		__set_current_state(TASK_RUNNING);
-	}
-
-	return 0;
-}
-
-static void igt_wake_all_sync(atomic_t *ready,
-			      atomic_t *set,
-			      atomic_t *done,
-			      wait_queue_head_t *wq,
-			      int count)
-{
-	atomic_set(set, count);
-	atomic_set(ready, 0);
-	wake_up_all(wq);
-
-	wait_var_event(set, !atomic_read(set));
-	atomic_set(ready, count);
-	atomic_set(done, count);
-}
-
-static int igt_wakeup(void *arg)
-{
-	I915_RND_STATE(prng);
-	struct intel_engine_cs *engine = arg;
-	struct igt_wakeup *waiters;
-	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
-	const int count = 4096;
-	const u32 max_seqno = count / 4;
-	atomic_t ready, set, done;
-	int err = -ENOMEM;
-	int n, step;
-
-	mock_engine_reset(engine);
-
-	waiters = kvmalloc_array(count, sizeof(*waiters), GFP_KERNEL);
-	if (!waiters)
-		goto out_engines;
-
-	/* Create a large number of threads, each waiting on a random seqno.
-	 * Multiple waiters will be waiting for the same seqno.
-	 */
-	atomic_set(&ready, count);
-	for (n = 0; n < count; n++) {
-		waiters[n].wq = &wq;
-		waiters[n].ready = &ready;
-		waiters[n].set = &set;
-		waiters[n].done = &done;
-		waiters[n].engine = engine;
-		waiters[n].flags = BIT(IDLE);
-
-		waiters[n].tsk = kthread_run(igt_wakeup_thread, &waiters[n],
-					     "i915/igt:%d", n);
-		if (IS_ERR(waiters[n].tsk))
-			goto out_waiters;
-
-		get_task_struct(waiters[n].tsk);
-	}
-
-	for (step = 1; step <= max_seqno; step <<= 1) {
-		u32 seqno;
-
-		/* The waiter threads start paused as we assign them a random
-		 * seqno and reset the engine. Once the engine is reset,
-		 * we signal that the threads may begin their wait upon their
-		 * seqno.
-		 */
-		for (n = 0; n < count; n++) {
-			GEM_BUG_ON(!test_bit(IDLE, &waiters[n].flags));
-			waiters[n].seqno =
-				1 + prandom_u32_state(&prng) % max_seqno;
-		}
-		mock_seqno_advance(engine, 0);
-		igt_wake_all_sync(&ready, &set, &done, &wq, count);
-
-		/* Simulate the GPU doing chunks of work, with one or more
-		 * seqno appearing to finish at the same time. A random number
-		 * of threads will be waiting upon the update and hopefully be
-		 * woken.
-		 */
-		for (seqno = 1; seqno <= max_seqno + step; seqno += step) {
-			usleep_range(50, 500);
-			mock_seqno_advance(engine, seqno);
-		}
-		GEM_BUG_ON(intel_engine_get_seqno(engine) < 1 + max_seqno);
-
-		/* With the seqno now beyond any of the waiting threads, they
-		 * should all be woken, see that they are complete and signal
-		 * that they are ready for the next test. We wait until all
-		 * threads are complete and waiting for us (i.e. not a seqno).
-		 */
-		if (!wait_var_event_timeout(&done,
-					    !atomic_read(&done), 10 * HZ)) {
-			pr_err("Timed out waiting for %d remaining waiters\n",
-			       atomic_read(&done));
-			err = -ETIMEDOUT;
-			break;
-		}
-
-		err = check_rbtree_empty(engine);
-		if (err)
-			break;
-	}
-
-out_waiters:
-	for (n = 0; n < count; n++) {
-		if (IS_ERR(waiters[n].tsk))
-			break;
-
-		set_bit(STOP, &waiters[n].flags);
-	}
-	mock_seqno_advance(engine, INT_MAX); /* wakeup any broken waiters */
-	igt_wake_all_sync(&ready, &set, &done, &wq, n);
-
-	for (n = 0; n < count; n++) {
-		if (IS_ERR(waiters[n].tsk))
-			break;
-
-		kthread_stop(waiters[n].tsk);
-		put_task_struct(waiters[n].tsk);
-	}
-
-	kvfree(waiters);
-out_engines:
-	mock_engine_flush(engine);
-	return err;
-}
-
-int intel_breadcrumbs_mock_selftests(void)
-{
-	static const struct i915_subtest tests[] = {
-		SUBTEST(igt_random_insert_remove),
-		SUBTEST(igt_insert_complete),
-		SUBTEST(igt_wakeup),
-	};
-	struct drm_i915_private *i915;
-	int err;
-
-	i915 = mock_gem_device();
-	if (!i915)
-		return -ENOMEM;
-
-	err = i915_subtests(tests, i915->engine[RCS]);
-	drm_dev_put(&i915->drm);
-
-	return err;
-}
diff --git a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
index 2c38ea5892d9..7b6f3bea9ef8 100644
--- a/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
+++ b/drivers/gpu/drm/i915/selftests/intel_hangcheck.c
@@ -1127,7 +1127,7 @@ static int __igt_reset_evict_vma(struct drm_i915_private *i915,
 
 	wait_for_completion(&arg.completion);
 
-	if (wait_for(waitqueue_active(&rq->execute), 10)) {
+	if (wait_for(!list_empty(&rq->fence.cb_list), 10)) {
 		struct drm_printer p = drm_info_printer(i915->drm.dev);
 
 		pr_err("igt/evict_vma kthread did not wait\n");
diff --git a/drivers/gpu/drm/i915/selftests/lib_sw_fence.c b/drivers/gpu/drm/i915/selftests/lib_sw_fence.c
index b26f07b55d86..2bfa72c1654b 100644
--- a/drivers/gpu/drm/i915/selftests/lib_sw_fence.c
+++ b/drivers/gpu/drm/i915/selftests/lib_sw_fence.c
@@ -76,3 +76,57 @@ void timed_fence_fini(struct timed_fence *tf)
 	destroy_timer_on_stack(&tf->timer);
 	i915_sw_fence_fini(&tf->fence);
 }
+
+struct heap_fence {
+	struct i915_sw_fence fence;
+	union {
+		struct kref ref;
+		struct rcu_head rcu;
+	};
+};
+
+static int __i915_sw_fence_call
+heap_fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
+{
+	struct heap_fence *h = container_of(fence, typeof(*h), fence);
+
+	switch (state) {
+	case FENCE_COMPLETE:
+		break;
+
+	case FENCE_FREE:
+		heap_fence_put(&h->fence);
+	}
+
+	return NOTIFY_DONE;
+}
+
+struct i915_sw_fence *heap_fence_create(gfp_t gfp)
+{
+	struct heap_fence *h;
+
+	h = kmalloc(sizeof(*h), gfp);
+	if (!h)
+		return NULL;
+
+	i915_sw_fence_init(&h->fence, heap_fence_notify);
+	refcount_set(&h->ref.refcount, 2);
+
+	return &h->fence;
+}
+
+static void heap_fence_release(struct kref *ref)
+{
+	struct heap_fence *h = container_of(ref, typeof(*h), ref);
+
+	i915_sw_fence_fini(&h->fence);
+
+	kfree_rcu(h, rcu);
+}
+
+void heap_fence_put(struct i915_sw_fence *fence)
+{
+	struct heap_fence *h = container_of(fence, typeof(*h), fence);
+
+	kref_put(&h->ref, heap_fence_release);
+}
diff --git a/drivers/gpu/drm/i915/selftests/lib_sw_fence.h b/drivers/gpu/drm/i915/selftests/lib_sw_fence.h
index 474aafb92ae1..1f9927e10f3a 100644
--- a/drivers/gpu/drm/i915/selftests/lib_sw_fence.h
+++ b/drivers/gpu/drm/i915/selftests/lib_sw_fence.h
@@ -39,4 +39,7 @@ struct timed_fence {
 void timed_fence_init(struct timed_fence *tf, unsigned long expires);
 void timed_fence_fini(struct timed_fence *tf);
 
+struct i915_sw_fence *heap_fence_create(gfp_t gfp);
+void heap_fence_put(struct i915_sw_fence *fence);
+
 #endif /* _LIB_SW_FENCE_H_ */
diff --git a/drivers/gpu/drm/i915/selftests/mock_engine.c b/drivers/gpu/drm/i915/selftests/mock_engine.c
index 3b226ebc6bc4..08f0cab02e0f 100644
--- a/drivers/gpu/drm/i915/selftests/mock_engine.c
+++ b/drivers/gpu/drm/i915/selftests/mock_engine.c
@@ -86,17 +86,21 @@ static struct mock_request *first_request(struct mock_engine *engine)
 static void advance(struct mock_request *request)
 {
 	list_del_init(&request->link);
-	mock_seqno_advance(request->base.engine, request->base.global_seqno);
+	intel_engine_write_global_seqno(request->base.engine,
+					request->base.global_seqno);
 	i915_request_mark_complete(&request->base);
 	GEM_BUG_ON(!i915_request_completed(&request->base));
+
+	intel_engine_queue_breadcrumbs(request->base.engine);
 }
 
 static void hw_delay_complete(struct timer_list *t)
 {
 	struct mock_engine *engine = from_timer(engine, t, hw_delay);
 	struct mock_request *request;
+	unsigned long flags;
 
-	spin_lock(&engine->hw_lock);
+	spin_lock_irqsave(&engine->hw_lock, flags);
 
 	/* Timer fired, first request is complete */
 	request = first_request(engine);
@@ -116,7 +120,7 @@ static void hw_delay_complete(struct timer_list *t)
 		advance(request);
 	}
 
-	spin_unlock(&engine->hw_lock);
+	spin_unlock_irqrestore(&engine->hw_lock, flags);
 }
 
 static void mock_context_unpin(struct intel_context *ce)
@@ -191,11 +195,12 @@ static void mock_submit_request(struct i915_request *request)
 	struct mock_request *mock = container_of(request, typeof(*mock), base);
 	struct mock_engine *engine =
 		container_of(request->engine, typeof(*engine), base);
+	unsigned long flags;
 
 	i915_request_submit(request);
 	GEM_BUG_ON(!request->global_seqno);
 
-	spin_lock_irq(&engine->hw_lock);
+	spin_lock_irqsave(&engine->hw_lock, flags);
 	list_add_tail(&mock->link, &engine->hw_queue);
 	if (mock->link.prev == &engine->hw_queue) {
 		if (mock->delay)
@@ -203,7 +208,7 @@ static void mock_submit_request(struct i915_request *request)
 		else
 			advance(mock);
 	}
-	spin_unlock_irq(&engine->hw_lock);
+	spin_unlock_irqrestore(&engine->hw_lock, flags);
 }
 
 struct intel_engine_cs *mock_engine(struct drm_i915_private *i915,
@@ -273,7 +278,7 @@ void mock_engine_flush(struct intel_engine_cs *engine)
 
 void mock_engine_reset(struct intel_engine_cs *engine)
 {
-	intel_write_status_page(engine, I915_GEM_HWS_INDEX, 0);
+	intel_engine_write_global_seqno(engine, 0);
 }
 
 void mock_engine_free(struct intel_engine_cs *engine)
diff --git a/drivers/gpu/drm/i915/selftests/mock_engine.h b/drivers/gpu/drm/i915/selftests/mock_engine.h
index 133d0c21790d..b9cc3a245f16 100644
--- a/drivers/gpu/drm/i915/selftests/mock_engine.h
+++ b/drivers/gpu/drm/i915/selftests/mock_engine.h
@@ -46,10 +46,4 @@ void mock_engine_flush(struct intel_engine_cs *engine);
 void mock_engine_reset(struct intel_engine_cs *engine);
 void mock_engine_free(struct intel_engine_cs *engine);
 
-static inline void mock_seqno_advance(struct intel_engine_cs *engine, u32 seqno)
-{
-	intel_write_status_page(engine, I915_GEM_HWS_INDEX, seqno);
-	intel_engine_wakeup(engine);
-}
-
 #endif /* !__MOCK_ENGINE_H__ */
-- 
cgit v1.2.3-59-g8ed1b


From 1413b2bc0717036a5a653eef20cc3ae4cc66501a Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 4 Feb 2019 15:01:01 +0000
Subject: drm/i915: Trim NEWCLIENT boosting

Limit the NEWCLIENT boost to only give its small priority boost to fresh
clients only that have no dependencies.

The idea for using NEWCLIENT boosting, commit b16c765122f9 ("drm/i915:
Priority boost for new clients"), is that short-lived streams are often
interactive and require lower latency -- and that by executing those
ahead of the long running hogs, the short-lived clients do little to
interfere with the system throughput by virtue of their short-lived
nature. However, we were only considering the client's own timeline for
determining whether or not it was a fresh stream. This allowed for
compositors to wake up before their vblank and bump all of its client
streams. However, in testing with media-bench this results in chaining
all cooperating contexts together preventing us from being able to
reorder contexts to reduce bubbles (pipeline stalls), overall increasing
latency, and reducing system throughput. The exact opposite of our
intent. The compromise of applying the NEWCLIENT boost to strictly fresh
clients (that do not wait upon anything else) should maintain the
"real-time response under load" characteristics of FQ_CODEL, without
locking together the long chains of dependencies across the system.

References: b16c765122f9 ("drm/i915: Priority boost for new clients")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190204150101.30759-1-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_request.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 9ed5baf157a3..9383a9fb4893 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -968,7 +968,7 @@ void i915_request_add(struct i915_request *request)
 		 * Allow interactive/synchronous clients to jump ahead of
 		 * the bulk clients. (FQ_CODEL)
 		 */
-		if (!prev || i915_request_completed(prev))
+		if (list_empty(&request->sched.signalers_list))
 			attr.priority |= I915_PRIORITY_NEWCLIENT;
 
 		engine->schedule(request, &attr);
-- 
cgit v1.2.3-59-g8ed1b


From 7810858412a0ab8b8ebb97d301dd601808968c88 Mon Sep 17 00:00:00 2001
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Date: Tue, 5 Feb 2019 09:50:30 +0000
Subject: drm/i915: Add timeline barrier support

Timeline barrier allows serialization between different timelines.

After calling i915_timeline_set_barrier with a request, all following
submissions on this timeline will be set up as depending on this request,
or barrier. Once the barrier has been completed it automatically gets
cleared and things continue as normal.

This facility will be used by the upcoming context SSEU code.

v2:
 * Assert barrier has been retired on timeline_fini. (Chris Wilson)
 * Fix mock_timeline.

v3:
 * Improved comment language. (Chris Wilson)

v4:
 * Maintain ordering with previous barriers set on the timeline.

v5:
 * Rebase.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190205095032.22673-3-tvrtko.ursulin@linux.intel.com
---
 drivers/gpu/drm/i915/i915_request.c            | 17 +++++++++++++++++
 drivers/gpu/drm/i915/i915_timeline.c           | 21 +++++++++++++++++++++
 drivers/gpu/drm/i915/i915_timeline.h           | 22 ++++++++++++++++++++++
 drivers/gpu/drm/i915/selftests/mock_timeline.c |  1 +
 4 files changed, 61 insertions(+)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 9383a9fb4893..6512630b59b8 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -526,6 +526,19 @@ out:
 	return kmem_cache_alloc(ce->gem_context->i915->requests, GFP_KERNEL);
 }
 
+static int add_barrier(struct i915_request *rq, struct i915_gem_active *active)
+{
+	struct i915_request *barrier =
+		i915_gem_active_raw(active, &rq->i915->drm.struct_mutex);
+
+	return barrier ? i915_request_await_dma_fence(rq, &barrier->fence) : 0;
+}
+
+static int add_timeline_barrier(struct i915_request *rq)
+{
+	return add_barrier(rq, &rq->timeline->barrier);
+}
+
 /**
  * i915_request_alloc - allocate a request structure
  *
@@ -668,6 +681,10 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	 */
 	rq->head = rq->ring->emit;
 
+	ret = add_timeline_barrier(rq);
+	if (ret)
+		goto err_unwind;
+
 	ret = engine->request_alloc(rq);
 	if (ret)
 		goto err_unwind;
diff --git a/drivers/gpu/drm/i915/i915_timeline.c b/drivers/gpu/drm/i915/i915_timeline.c
index 5ea3af393ffe..dcff3ae96683 100644
--- a/drivers/gpu/drm/i915/i915_timeline.c
+++ b/drivers/gpu/drm/i915/i915_timeline.c
@@ -163,6 +163,7 @@ int i915_timeline_init(struct drm_i915_private *i915,
 
 	spin_lock_init(&timeline->lock);
 
+	init_request_active(&timeline->barrier, NULL);
 	init_request_active(&timeline->last_request, NULL);
 	INIT_LIST_HEAD(&timeline->requests);
 
@@ -235,6 +236,7 @@ void i915_timeline_fini(struct i915_timeline *timeline)
 {
 	GEM_BUG_ON(timeline->pin_count);
 	GEM_BUG_ON(!list_empty(&timeline->requests));
+	GEM_BUG_ON(i915_gem_active_isset(&timeline->barrier));
 
 	i915_syncmap_free(&timeline->sync);
 	hwsp_free(timeline);
@@ -309,6 +311,25 @@ void i915_timeline_unpin(struct i915_timeline *tl)
 	__i915_vma_unpin(tl->hwsp_ggtt);
 }
 
+int i915_timeline_set_barrier(struct i915_timeline *tl, struct i915_request *rq)
+{
+	struct i915_request *old;
+	int err;
+
+	lockdep_assert_held(&rq->i915->drm.struct_mutex);
+
+	/* Must maintain ordering wrt existing barriers */
+	old = i915_gem_active_raw(&tl->barrier, &rq->i915->drm.struct_mutex);
+	if (old) {
+		err = i915_request_await_dma_fence(rq, &old->fence);
+		if (err)
+			return err;
+	}
+
+	i915_gem_active_set(&tl->barrier, rq);
+	return 0;
+}
+
 void __i915_timeline_free(struct kref *kref)
 {
 	struct i915_timeline *timeline =
diff --git a/drivers/gpu/drm/i915/i915_timeline.h b/drivers/gpu/drm/i915/i915_timeline.h
index 8caeb66d1cd5..d167e04073c5 100644
--- a/drivers/gpu/drm/i915/i915_timeline.h
+++ b/drivers/gpu/drm/i915/i915_timeline.h
@@ -74,6 +74,16 @@ struct i915_timeline {
 	 */
 	struct i915_syncmap *sync;
 
+	/**
+	 * Barrier provides the ability to serialize ordering between different
+	 * timelines.
+	 *
+	 * Users can call i915_timeline_set_barrier which will make all
+	 * subsequent submissions to this timeline be executed only after the
+	 * barrier has been completed.
+	 */
+	struct i915_gem_active barrier;
+
 	struct list_head link;
 	const char *name;
 	struct drm_i915_private *i915;
@@ -155,4 +165,16 @@ void i915_timelines_init(struct drm_i915_private *i915);
 void i915_timelines_park(struct drm_i915_private *i915);
 void i915_timelines_fini(struct drm_i915_private *i915);
 
+/**
+ * i915_timeline_set_barrier - orders submission between different timelines
+ * @timeline: timeline to set the barrier on
+ * @rq: request after which new submissions can proceed
+ *
+ * Sets the passed in request as the serialization point for all subsequent
+ * submissions on @timeline. Subsequent requests will not be submitted to GPU
+ * until the barrier has been completed.
+ */
+int i915_timeline_set_barrier(struct i915_timeline *timeline,
+			      struct i915_request *rq);
+
 #endif
diff --git a/drivers/gpu/drm/i915/selftests/mock_timeline.c b/drivers/gpu/drm/i915/selftests/mock_timeline.c
index cf39ccd9fc05..e5659aaa856d 100644
--- a/drivers/gpu/drm/i915/selftests/mock_timeline.c
+++ b/drivers/gpu/drm/i915/selftests/mock_timeline.c
@@ -15,6 +15,7 @@ void mock_timeline_init(struct i915_timeline *timeline, u64 context)
 
 	spin_lock_init(&timeline->lock);
 
+	init_request_active(&timeline->barrier, NULL);
 	init_request_active(&timeline->last_request, NULL);
 	INIT_LIST_HEAD(&timeline->requests);
 
-- 
cgit v1.2.3-59-g8ed1b


From 21950ee7cc8f13c5350bda0cae22cdb7ac7e3058 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Tue, 5 Feb 2019 13:00:05 +0000
Subject: drm/i915: Pull i915_gem_active into the i915_active family

Looking forward, we need to break the struct_mutex dependency on
i915_gem_active. In the meantime, external use of i915_gem_active is
quite beguiling, little do new users suspect that it implies a barrier
as each request it tracks must be ordered wrt the previous one. As one
of many, it can be used to track activity across multiple timelines, a
shared fence, which fits our unordered request submission much better. We
need to steer external users away from the singular, exclusive fence
imposed by i915_gem_active to i915_active instead. As part of that
process, we move i915_gem_active out of i915_request.c into
i915_active.c to start separating the two concepts, and rename it to
i915_active_request (both to tie it to the concept of tracking just one
request, and to give it a longer, less appealing name).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190205130005.2807-5-chris@chris-wilson.co.uk
---
 drivers/gpu/drm/i915/i915_active.c             |  62 ++--
 drivers/gpu/drm/i915/i915_active.h             | 349 ++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_active_types.h       |  16 +-
 drivers/gpu/drm/i915/i915_debugfs.c            |   2 +-
 drivers/gpu/drm/i915/i915_gem.c                |  10 +-
 drivers/gpu/drm/i915/i915_gem_context.c        |  17 +-
 drivers/gpu/drm/i915/i915_gem_context.h        |   2 +-
 drivers/gpu/drm/i915/i915_gem_fence_reg.c      |   4 +-
 drivers/gpu/drm/i915/i915_gem_gtt.c            |   2 +-
 drivers/gpu/drm/i915/i915_gem_object.h         |   2 +-
 drivers/gpu/drm/i915/i915_gpu_error.c          |  10 +-
 drivers/gpu/drm/i915/i915_request.c            |  35 +--
 drivers/gpu/drm/i915/i915_request.h            | 383 -------------------------
 drivers/gpu/drm/i915/i915_reset.c              |   2 +-
 drivers/gpu/drm/i915/i915_timeline.c           |  25 +-
 drivers/gpu/drm/i915/i915_timeline.h           |  14 +-
 drivers/gpu/drm/i915/i915_vma.c                |  12 +-
 drivers/gpu/drm/i915/i915_vma.h                |   2 +-
 drivers/gpu/drm/i915/intel_engine_cs.c         |   2 +-
 drivers/gpu/drm/i915/intel_overlay.c           |  33 +--
 drivers/gpu/drm/i915/selftests/mock_timeline.c |   4 +-
 21 files changed, 480 insertions(+), 508 deletions(-)

(limited to 'drivers/gpu/drm/i915/i915_request.c')

diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
index 64661c41532b..215b6ff8aa73 100644
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -21,7 +21,7 @@ static struct i915_global_active {
 } global;
 
 struct active_node {
-	struct i915_gem_active base;
+	struct i915_active_request base;
 	struct i915_active *ref;
 	struct rb_node node;
 	u64 timeline;
@@ -33,7 +33,7 @@ __active_park(struct i915_active *ref)
 	struct active_node *it, *n;
 
 	rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node) {
-		GEM_BUG_ON(i915_gem_active_isset(&it->base));
+		GEM_BUG_ON(i915_active_request_isset(&it->base));
 		kmem_cache_free(global.slab_cache, it);
 	}
 	ref->tree = RB_ROOT;
@@ -53,18 +53,18 @@ __active_retire(struct i915_active *ref)
 }
 
 static void
-node_retire(struct i915_gem_active *base, struct i915_request *rq)
+node_retire(struct i915_active_request *base, struct i915_request *rq)
 {
 	__active_retire(container_of(base, struct active_node, base)->ref);
 }
 
 static void
-last_retire(struct i915_gem_active *base, struct i915_request *rq)
+last_retire(struct i915_active_request *base, struct i915_request *rq)
 {
 	__active_retire(container_of(base, struct i915_active, last));
 }
 
-static struct i915_gem_active *
+static struct i915_active_request *
 active_instance(struct i915_active *ref, u64 idx)
 {
 	struct active_node *node;
@@ -85,7 +85,7 @@ active_instance(struct i915_active *ref, u64 idx)
 	 * twice for the same timeline (as the older rbtree element will be
 	 * retired before the new request added to last).
 	 */
-	old = i915_gem_active_raw(&ref->last, BKL(ref));
+	old = i915_active_request_raw(&ref->last, BKL(ref));
 	if (!old || old->fence.context == idx)
 		goto out;
 
@@ -110,7 +110,7 @@ active_instance(struct i915_active *ref, u64 idx)
 	node = kmem_cache_alloc(global.slab_cache, GFP_KERNEL);
 
 	/* kmalloc may retire the ref->last (thanks shrinker)! */
-	if (unlikely(!i915_gem_active_raw(&ref->last, BKL(ref)))) {
+	if (unlikely(!i915_active_request_raw(&ref->last, BKL(ref)))) {
 		kmem_cache_free(global.slab_cache, node);
 		goto out;
 	}
@@ -118,7 +118,7 @@ active_instance(struct i915_active *ref, u64 idx)
 	if (unlikely(!node))
 		return ERR_PTR(-ENOMEM);
 
-	init_request_active(&node->base, node_retire);
+	i915_active_request_init(&node->base, NULL, node_retire);
 	node->ref = ref;
 	node->timeline = idx;
 
@@ -133,7 +133,7 @@ replace:
 	 * callback not two, and so much undo the active counting for the
 	 * overwritten slot.
 	 */
-	if (i915_gem_active_isset(&node->base)) {
+	if (i915_active_request_isset(&node->base)) {
 		/* Retire ourselves from the old rq->active_list */
 		__list_del_entry(&node->base.link);
 		ref->count--;
@@ -154,7 +154,7 @@ void i915_active_init(struct drm_i915_private *i915,
 	ref->i915 = i915;
 	ref->retire = retire;
 	ref->tree = RB_ROOT;
-	init_request_active(&ref->last, last_retire);
+	i915_active_request_init(&ref->last, NULL, last_retire);
 	ref->count = 0;
 }
 
@@ -162,15 +162,15 @@ int i915_active_ref(struct i915_active *ref,
 		    u64 timeline,
 		    struct i915_request *rq)
 {
-	struct i915_gem_active *active;
+	struct i915_active_request *active;
 
 	active = active_instance(ref, timeline);
 	if (IS_ERR(active))
 		return PTR_ERR(active);
 
-	if (!i915_gem_active_isset(active))
+	if (!i915_active_request_isset(active))
 		ref->count++;
-	i915_gem_active_set(active, rq);
+	__i915_active_request_set(active, rq);
 
 	GEM_BUG_ON(!ref->count);
 	return 0;
@@ -196,12 +196,12 @@ int i915_active_wait(struct i915_active *ref)
 	if (i915_active_acquire(ref))
 		goto out_release;
 
-	ret = i915_gem_active_retire(&ref->last, BKL(ref));
+	ret = i915_active_request_retire(&ref->last, BKL(ref));
 	if (ret)
 		goto out_release;
 
 	rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node) {
-		ret = i915_gem_active_retire(&it->base, BKL(ref));
+		ret = i915_active_request_retire(&it->base, BKL(ref));
 		if (ret)
 			break;
 	}
@@ -211,11 +211,11 @@ out_release:
 	return ret;
 }
 
-static int __i915_request_await_active(struct i915_request *rq,
-				       struct i915_gem_active *active)
+int i915_request_await_active_request(struct i915_request *rq,
+				      struct i915_active_request *active)
 {
 	struct i915_request *barrier =
-		i915_gem_active_raw(active, &rq->i915->drm.struct_mutex);
+		i915_active_request_raw(active, &rq->i915->drm.struct_mutex);
 
 	return barrier ? i915_request_await_dma_fence(rq, &barrier->fence) : 0;
 }
@@ -225,12 +225,12 @@ int i915_request_await_active(struct i915_request *rq, struct i915_active *ref)
 	struct active_node *it, *n;
 	int ret;
 
-	ret = __i915_request_await_active(rq, &ref->last);
+	ret = i915_request_await_active_request(rq, &ref->last);
 	if (ret)
 		return ret;
 
 	rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node) {
-		ret = __i915_request_await_active(rq, &it->base);
+		ret = i915_request_await_active_request(rq, &it->base);
 		if (ret)
 			return ret;
 	}
@@ -241,12 +241,32 @@ int i915_request_await_active(struct i915_request *rq, struct i915_active *ref)
 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
 void i915_active_fini(struct i915_active *ref)
 {
-	GEM_BUG_ON(i915_gem_active_isset(&ref->last));
+	GEM_BUG_ON(i915_active_request_isset(&ref->last));
 	GEM_BUG_ON(!RB_EMPTY_ROOT(&ref->tree));
 	GEM_BUG_ON(ref->count);
 }
 #endif
 
+int i915_active_request_set(struct i915_active_request *active,
+			    struct i915_request *rq)
+{
+	int err;
+
+	/* Must maintain ordering wrt previous active requests */
+	err = i915_request_await_active_request(rq, active);
+	if (err)
+		return err;
+
+	__i915_active_request_set(active, rq);
+	return 0;
+}
+
+void i915_active_retire_noop(struct i915_active_request *active,
+			     struct i915_request *request)
+{
+	/* Space left intentionally blank */
+}
+
 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
 #include "selftests/i915_active.c"
 #endif
diff --git a/drivers/gpu/drm/i915/i915_active.h b/drivers/gpu/drm/i915/i915_active.h
index 179b47aeec33..12b5c1d287d1 100644
--- a/drivers/gpu/drm/i915/i915_active.h
+++ b/drivers/gpu/drm/i915/i915_active.h
@@ -7,7 +7,354 @@
 #ifndef _I915_ACTIVE_H_
 #define _I915_ACTIVE_H_
 
+#include <linux/lockdep.h>
+
 #include "i915_active_types.h"
+#include "i915_request.h"
+
+/*
+ * We treat requests as fences. This is not be to confused with our
+ * "fence registers" but pipeline synchronisation objects ala GL_ARB_sync.
+ * We use the fences to synchronize access from the CPU with activity on the
+ * GPU, for example, we should not rewrite an object's PTE whilst the GPU
+ * is reading them. We also track fences at a higher level to provide
+ * implicit synchronisation around GEM objects, e.g. set-domain will wait
+ * for outstanding GPU rendering before marking the object ready for CPU
+ * access, or a pageflip will wait until the GPU is complete before showing
+ * the frame on the scanout.
+ *
+ * In order to use a fence, the object must track the fence it needs to
+ * serialise with. For example, GEM objects want to track both read and
+ * write access so that we can perform concurrent read operations between
+ * the CPU and GPU engines, as well as waiting for all rendering to
+ * complete, or waiting for the last GPU user of a "fence register". The
+ * object then embeds a #i915_active_request to track the most recent (in
+ * retirement order) request relevant for the desired mode of access.
+ * The #i915_active_request is updated with i915_active_request_set() to
+ * track the most recent fence request, typically this is done as part of
+ * i915_vma_move_to_active().
+ *
+ * When the #i915_active_request completes (is retired), it will
+ * signal its completion to the owner through a callback as well as mark
+ * itself as idle (i915_active_request.request == NULL). The owner
+ * can then perform any action, such as delayed freeing of an active
+ * resource including itself.
+ */
+
+void i915_active_retire_noop(struct i915_active_request *active,
+			     struct i915_request *request);
+
+/**
+ * i915_active_request_init - prepares the activity tracker for use
+ * @active - the active tracker
+ * @rq - initial request to track, can be NULL
+ * @func - a callback when then the tracker is retired (becomes idle),
+ *         can be NULL
+ *
+ * i915_active_request_init() prepares the embedded @active struct for use as
+ * an activity tracker, that is for tracking the last known active request
+ * associated with it. When the last request becomes idle, when it is retired
+ * after completion, the optional callback @func is invoked.
+ */
+static inline void
+i915_active_request_init(struct i915_active_request *active,
+			 struct i915_request *rq,
+			 i915_active_retire_fn retire)
+{
+	RCU_INIT_POINTER(active->request, rq);
+	INIT_LIST_HEAD(&active->link);
+	active->retire = retire ?: i915_active_retire_noop;
+}
+
+#define INIT_ACTIVE_REQUEST(name) i915_active_request_init((name), NULL, NULL)
+
+/**
+ * i915_active_request_set - updates the tracker to watch the current request
+ * @active - the active tracker
+ * @request - the request to watch
+ *
+ * __i915_active_request_set() watches the given @request for completion. Whilst
+ * that @request is busy, the @active reports busy. When that @request is
+ * retired, the @active tracker is updated to report idle.
+ */
+static inline void
+__i915_active_request_set(struct i915_active_request *active,
+			  struct i915_request *request)
+{
+	list_move(&active->link, &request->active_list);
+	rcu_assign_pointer(active->request, request);
+}
+
+int __must_check
+i915_active_request_set(struct i915_active_request *active,
+			struct i915_request *rq);
+
+/**
+ * i915_active_request_set_retire_fn - updates the retirement callback
+ * @active - the active tracker
+ * @fn - the routine called when the request is retired
+ * @mutex - struct_mutex used to guard retirements
+ *
+ * i915_active_request_set_retire_fn() updates the function pointer that
+ * is called when the final request associated with the @active tracker
+ * is retired.
+ */
+static inline void
+i915_active_request_set_retire_fn(struct i915_active_request *active,
+				  i915_active_retire_fn fn,
+				  struct mutex *mutex)
+{
+	lockdep_assert_held(mutex);
+	active->retire = fn ?: i915_active_retire_noop;
+}
+
+static inline struct i915_request *
+__i915_active_request_peek(const struct i915_active_request *active)
+{
+	/*
+	 * Inside the error capture (running with the driver in an unknown
+	 * state), we want to bend the rules slightly (a lot).
+	 *
+	 * Work is in progress to make it safer, in the meantime this keeps
+	 * the known issue from spamming the logs.
+	 */
+	return rcu_dereference_protected(active->request, 1);
+}
+
+/**
+ * i915_active_request_raw - return the active request
+ * @active - the active tracker
+ *
+ * i915_active_request_raw() returns the current request being tracked, or NULL.
+ * It does not obtain a reference on the request for the caller, so the caller
+ * must hold struct_mutex.
+ */
+static inline struct i915_request *
+i915_active_request_raw(const struct i915_active_request *active,
+			struct mutex *mutex)
+{
+	return rcu_dereference_protected(active->request,
+					 lockdep_is_held(mutex));
+}
+
+/**
+ * i915_active_request_peek - report the active request being monitored
+ * @active - the active tracker
+ *
+ * i915_active_request_peek() returns the current request being tracked if
+ * still active, or NULL. It does not obtain a reference on the request
+ * for the caller, so the caller must hold struct_mutex.
+ */
+static inline struct i915_request *
+i915_active_request_peek(const struct i915_active_request *active,
+			 struct mutex *mutex)
+{
+	struct i915_request *request;
+
+	request = i915_active_request_raw(active, mutex);
+	if (!request || i915_request_completed(request))
+		return NULL;
+
+	return request;
+}
+
+/**
+ * i915_active_request_get - return a reference to the active request
+ * @active - the active tracker
+ *
+ * i915_active_request_get() returns a reference to the active request, or NULL
+ * if the active tracker is idle. The caller must hold struct_mutex.
+ */
+static inline struct i915_request *
+i915_active_request_get(const struct i915_active_request *active,
+			struct mutex *mutex)
+{
+	return i915_request_get(i915_active_request_peek(active, mutex));
+}
+
+/**
+ * __i915_active_request_get_rcu - return a reference to the active request
+ * @active - the active tracker
+ *
+ * __i915_active_request_get() returns a reference to the active request,
+ * or NULL if the active tracker is idle. The caller must hold the RCU read
+ * lock, but the returned pointer is safe to use outside of RCU.
+ */
+static inline struct i915_request *
+__i915_active_request_get_rcu(const struct i915_active_request *active)
+{
+	/*
+	 * Performing a lockless retrieval of the active request is super
+	 * tricky. SLAB_TYPESAFE_BY_RCU merely guarantees that the backing
+	 * slab of request objects will not be freed whilst we hold the
+	 * RCU read lock. It does not guarantee that the request itself
+	 * will not be freed and then *reused*. Viz,
+	 *
+	 * Thread A			Thread B
+	 *
+	 * rq = active.request
+	 *				retire(rq) -> free(rq);
+	 *				(rq is now first on the slab freelist)
+	 *				active.request = NULL
+	 *
+	 *				rq = new submission on a new object
+	 * ref(rq)
+	 *
+	 * To prevent the request from being reused whilst the caller
+	 * uses it, we take a reference like normal. Whilst acquiring
+	 * the reference we check that it is not in a destroyed state
+	 * (refcnt == 0). That prevents the request being reallocated
+	 * whilst the caller holds on to it. To check that the request
+	 * was not reallocated as we acquired the reference we have to
+	 * check that our request remains the active request across
+	 * the lookup, in the same manner as a seqlock. The visibility
+	 * of the pointer versus the reference counting is controlled
+	 * by using RCU barriers (rcu_dereference and rcu_assign_pointer).
+	 *
+	 * In the middle of all that, we inspect whether the request is
+	 * complete. Retiring is lazy so the request may be completed long
+	 * before the active tracker is updated. Querying whether the
+	 * request is complete is far cheaper (as it involves no locked
+	 * instructions setting cachelines to exclusive) than acquiring
+	 * the reference, so we do it first. The RCU read lock ensures the
+	 * pointer dereference is valid, but does not ensure that the
+	 * seqno nor HWS is the right one! However, if the request was
+	 * reallocated, that means the active tracker's request was complete.
+	 * If the new request is also complete, then both are and we can
+	 * just report the active tracker is idle. If the new request is
+	 * incomplete, then we acquire a reference on it and check that
+	 * it remained the active request.
+	 *
+	 * It is then imperative that we do not zero the request on
+	 * reallocation, so that we can chase the dangling pointers!
+	 * See i915_request_alloc().
+	 */
+	do {
+		struct i915_request *request;
+
+		request = rcu_dereference(active->request);
+		if (!request || i915_request_completed(request))
+			return NULL;
+
+		/*
+		 * An especially silly compiler could decide to recompute the
+		 * result of i915_request_completed, more specifically
+		 * re-emit the load for request->fence.seqno. A race would catch
+		 * a later seqno value, which could flip the result from true to
+		 * false. Which means part of the instructions below might not
+		 * be executed, while later on instructions are executed. Due to
+		 * barriers within the refcounting the inconsistency can't reach
+		 * past the call to i915_request_get_rcu, but not executing
+		 * that while still executing i915_request_put() creates
+		 * havoc enough.  Prevent this with a compiler barrier.
+		 */
+		barrier();
+
+		request = i915_request_get_rcu(request);
+
+		/*
+		 * What stops the following rcu_access_pointer() from occurring
+		 * before the above i915_request_get_rcu()? If we were
+		 * to read the value before pausing to get the reference to
+		 * the request, we may not notice a change in the active
+		 * tracker.
+		 *
+		 * The rcu_access_pointer() is a mere compiler barrier, which
+		 * means both the CPU and compiler are free to perform the
+		 * memory read without constraint. The compiler only has to
+		 * ensure that any operations after the rcu_access_pointer()
+		 * occur afterwards in program order. This means the read may
+		 * be performed earlier by an out-of-order CPU, or adventurous
+		 * compiler.
+		 *
+		 * The atomic operation at the heart of
+		 * i915_request_get_rcu(), see dma_fence_get_rcu(), is
+		 * atomic_inc_not_zero() which is only a full memory barrier
+		 * when successful. That is, if i915_request_get_rcu()
+		 * returns the request (and so with the reference counted
+		 * incremented) then the following read for rcu_access_pointer()
+		 * must occur after the atomic operation and so confirm
+		 * that this request is the one currently being tracked.
+		 *
+		 * The corresponding write barrier is part of
+		 * rcu_assign_pointer().
+		 */
+		if (!request || request == rcu_access_pointer(active->request))
+			return rcu_pointer_handoff(request);
+
+		i915_request_put(request);
+	} while (1);
+}
+
+/**
+ * i915_active_request_get_unlocked - return a reference to the active request
+ * @active - the active tracker
+ *
+ * i915_active_request_get_unlocked() returns a reference to the active request,
+ * or NULL if the active tracker is idle. The reference is obtained under RCU,
+ * so no locking is required by the caller.
+ *
+ * The reference should be freed with i915_request_put().
+ */
+static inline struct i915_request *
+i915_active_request_get_unlocked(const struct i915_active_request *active)
+{
+	struct i915_request *request;
+
+	rcu_read_lock();
+	request = __i915_active_request_get_rcu(active);
+	rcu_read_unlock();
+
+	return request;
+}
+
+/**
+ * i915_active_request_isset - report whether the active tracker is assigned
+ * @active - the active tracker
+ *
+ * i915_active_request_isset() returns true if the active tracker is currently
+ * assigned to a request. Due to the lazy retiring, that request may be idle
+ * and this may report stale information.
+ */
+static inline bool
+i915_active_request_isset(const struct i915_active_request *active)
+{
+	return rcu_access_pointer(active->request);
+}
+
+/**
+ * i915_active_request_retire - waits until the request is retired
+ * @active - the active request on which to wait
+ *
+ * i915_active_request_retire() waits until the request is completed,
+ * and then ensures that at least the retirement handler for this
+ * @active tracker is called before returning. If the @active
+ * tracker is idle, the function returns immediately.
+ */
+static inline int __must_check
+i915_active_request_retire(struct i915_active_request *active,
+			   struct mutex *mutex)
+{
+	struct i915_request *request;
+	long ret;
+
+	request = i915_active_request_raw(active, mutex);
+	if (!request)
+		return 0;
+
+	ret = i915_request_wait(request,
+				I915_WAIT_INTERRUPTIBLE | I915_WAIT_LOCKED,
+				MAX_SCHEDULE_TIMEOUT);
+	if (ret < 0)
+		return ret;
+
+	list_del_init(&active->link);
+	RCU_INIT_POINTER(active->request, NULL);
+
+	active->retire(active, request);
+
+	return 0;
+}
 
 /*
  * GPU activity tracking
@@ -47,6 +394,8 @@ int i915_active_wait(struct i915_active *ref);
 
 int i915_request_await_active(struct i915_request *rq,
 			      struct i915_active *ref);
+int i915_request_await_active_request(struct i915_request *rq,
+				      struct i915_active_request *active);
 
 bool i915_active_acquire(struct i915_active *ref);
 
diff --git a/drivers/gpu/drm/i915/i915_active_types.h b/drivers/gpu/drm/i915/i915_active_types.h
index 411e502ed8dd..b679253b53a5 100644
--- a/drivers/gpu/drm/i915/i915_active_types.h
+++ b/drivers/gpu/drm/i915/i915_active_types.h
@@ -8,16 +8,26 @@
 #define _I915_ACTIVE_TYPES_H_
 
 #include <linux/rbtree.h>
-
-#include "i915_request.h"
+#include <linux/rcupdate.h>
 
 struct drm_i915_private;
+struct i915_active_request;
+struct i915_request;
+
+typedef void (*i915_active_retire_fn)(struct i915_active_request *,
+				      struct i915_request *);
+
+struct i915_active_request {
+	struct i915_request __rcu *request;
+	struct list_head link;
+	i915_active_retire_fn retire;
+};
 
 struct i915_active {
 	struct drm_i915_private *i915;
 
 	struct rb_root tree;
-	struct i915_gem_active last;
+	struct i915_active_request last;
 	unsigned int count;
 
 	void (*retire)(struct i915_active *ref);
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index bf3073e63af8..c48733a15e63 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -206,7 +206,7 @@ describe_obj(struct seq_file *m, struct drm_i915_gem_object *obj)
 		if (vma->fence)
 			seq_printf(m, " , fence: %d%s",
 				   vma->fence->id,
-				   i915_gem_active_isset(&vma->last_fence) ? "*" : "");
+				   i915_active_request_isset(&vma->last_fence) ? "*" : "");
 		seq_puts(m, ")");
 	}
 	if (obj->stolen)
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index d92e7ab0005e..52b5a24be42b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3018,7 +3018,7 @@ static void assert_kernel_context_is_current(struct drm_i915_private *i915)
 
 	GEM_BUG_ON(i915->gt.active_requests);
 	for_each_engine(engine, i915, id) {
-		GEM_BUG_ON(__i915_gem_active_peek(&engine->timeline.last_request));
+		GEM_BUG_ON(__i915_active_request_peek(&engine->timeline.last_request));
 		GEM_BUG_ON(engine->last_retired_context !=
 			   to_intel_context(i915->kernel_context, engine));
 	}
@@ -3264,7 +3264,7 @@ wait_for_timelines(struct drm_i915_private *i915,
 	list_for_each_entry(tl, &gt->active_list, link) {
 		struct i915_request *rq;
 
-		rq = i915_gem_active_get_unlocked(&tl->last_request);
+		rq = i915_active_request_get_unlocked(&tl->last_request);
 		if (!rq)
 			continue;
 
@@ -4165,7 +4165,8 @@ out:
 }
 
 static void
-frontbuffer_retire(struct i915_gem_active *active, struct i915_request *request)
+frontbuffer_retire(struct i915_active_request *active,
+		   struct i915_request *request)
 {
 	struct drm_i915_gem_object *obj =
 		container_of(active, typeof(*obj), frontbuffer_write);
@@ -4192,7 +4193,8 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj,
 	obj->resv = &obj->__builtin_resv;
 
 	obj->frontbuffer_ggtt_origin = ORIGIN_GTT;
-	init_request_active(&obj->frontbuffer_write, frontbuffer_retire);
+	i915_active_request_init(&obj->frontbuffer_write,
+				 NULL, frontbuffer_retire);
 
 	obj->mm.madv = I915_MADV_WILLNEED;
 	INIT_RADIX_TREE(&obj->mm.get_page.radix, GFP_KERNEL | __GFP_NOWARN);
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 93ab287f44b6..280813a4bf82 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -322,7 +322,7 @@ static u32 default_desc_template(const struct drm_i915_private *i915,
 	return desc;
 }
 
-static void intel_context_retire(struct i915_gem_active *active,
+static void intel_context_retire(struct i915_active_request *active,
 				 struct i915_request *rq)
 {
 	struct intel_context *ce =
@@ -344,7 +344,8 @@ intel_context_init(struct intel_context *ce,
 	/* Use the whole device by default */
 	ce->sseu = intel_device_default_sseu(ctx->i915);
 
-	init_request_active(&ce->active_tracker, intel_context_retire);
+	i915_active_request_init(&ce->active_tracker,
+				 NULL, intel_context_retire);
 }
 
 static struct i915_gem_context *
@@ -668,8 +669,8 @@ last_request_on_engine(struct i915_timeline *timeline,
 
 	GEM_BUG_ON(timeline == &engine->timeline);
 
-	rq = i915_gem_active_raw(&timeline->last_request,
-				 &engine->i915->drm.struct_mutex);
+	rq = i915_active_request_raw(&timeline->last_request,
+				     &engine->i915->drm.struct_mutex);
 	if (rq && rq->engine == engine) {
 		GEM_TRACE("last request for %s on engine %s: %llx:%llu\n",
 			  timeline->name, engine->name,
@@ -1015,8 +1016,8 @@ gen8_modify_rpcs_gpu(struct intel_context *ce,
 	}
 
 	/* Queue this switch after all other activity by this context. */
-	prev = i915_gem_active_raw(&ce->ring->timeline->last_request,
-				   &i915->drm.struct_mutex);
+	prev = i915_active_request_raw(&ce->ring->timeline->last_request,
+				       &i915->drm.struct_mutex);
 	if (prev && !i915_request_completed(prev)) {
 		ret = i915_request_await_dma_fence(rq, &prev->fence);
 		if (ret < 0)
@@ -1039,9 +1040,9 @@ gen8_modify_rpcs_gpu(struct intel_context *ce,
 	 * But we only need to take one pin on the account of it. Or in other
 	 * words transfer the pinned ce object to tracked active request.
 	 */
-	if (!i915_gem_active_isset(&ce->active_tracker))
+	if (!i915_active_request_isset(&ce->active_tracker))
 		__intel_context_pin(ce);
-	i915_gem_active_set(&ce->active_tracker, rq);
+	__i915_active_request_set(&ce->active_tracker, rq);
 
 out_add:
 	i915_request_add(rq);
diff --git a/drivers/gpu/drm/i915/i915_gem_context.h b/drivers/gpu/drm/i915/i915_gem_context.h
index 92ad5272e57f..ca150a764c24 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/i915_gem_context.h
@@ -187,7 +187,7 @@ struct i915_gem_context {
 		 * active_tracker: Active tracker for the external rq activity
 		 * on this intel_context object.
 		 */
-		struct i915_gem_active active_tracker;
+		struct i915_active_request active_tracker;
 
 		const struct intel_context_ops *ops;
 
diff --git a/drivers/gpu/drm/i915/i915_gem_fence_reg.c b/drivers/gpu/drm/i915/i915_gem_fence_reg.c
index 46e259661294..e037e94792f3 100644
--- a/drivers/gpu/drm/i915/i915_gem_fence_reg.c
+++ b/drivers/gpu/drm/i915/i915_gem_fence_reg.c
@@ -223,7 +223,7 @@ static int fence_update(struct drm_i915_fence_reg *fence,
 			 i915_gem_object_get_tiling(vma->obj)))
 			return -EINVAL;
 
-		ret = i915_gem_active_retire(&vma->last_fence,
+		ret = i915_active_request_retire(&vma->last_fence,
 					     &vma->obj->base.dev->struct_mutex);
 		if (ret)
 			return ret;
@@ -232,7 +232,7 @@ static int fence_update(struct drm_i915_fence_reg *fence,
 	if (fence->vma) {
 		struct i915_vma *old = fence->vma;
 
-		ret = i915_gem_active_retire(&old->last_fence,
+		ret = i915_active_request_retire(&old->last_fence,
 					     &old->obj->base.dev->struct_mutex);
 		if (ret)
 			return ret;
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index e625659c03a2..d646d37eec2f 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1918,7 +1918,7 @@ static struct i915_vma *pd_vma_create(struct gen6_hw_ppgtt *ppgtt, int size)
 		return ERR_PTR(-ENOMEM);
 
 	i915_active_init(i915, &vma->active, NULL);
-	init_request_active(&vma->last_fence, NULL);
+	INIT_ACTIVE_REQUEST(&vma->last_fence);
 
 	vma->vm = &ggtt->vm;
 	vma->ops = &pd_vma_ops;
diff --git a/drivers/gpu/drm/i915/i915_gem_object.h b/drivers/gpu/drm/i915/i915_gem_object.h
index 73fec917d097..fab040331cdb 100644
--- a/drivers/gpu/drm/i915/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/i915_gem_object.h
@@ -175,7 +175,7 @@ struct drm_i915_gem_object {
 
 	atomic_t frontbuffer_bits;
 	unsigned int frontbuffer_ggtt_origin; /* write once */
-	struct i915_gem_active frontbuffer_write;
+	struct i915_active_request frontbuffer_write;
 
 	/** Current tiling stride for the object, if it's tiled. */
 	unsigned int tiling_and_stride;
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 6e2e5ed2bd0a..9a65341fec09 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1062,23 +1062,23 @@ i915_error_object_create(struct drm_i915_private *i915,
 }
 
 /* The error capture is special as tries to run underneath the normal
- * locking rules - so we use the raw version of the i915_gem_active lookup.
+ * locking rules - so we use the raw version of the i915_active_request lookup.
  */
 static inline u32
-__active_get_seqno(struct i915_gem_active *active)
+__active_get_seqno(struct i915_active_request *active)
 {
 	struct i915_request *request;
 
-	request = __i915_gem_active_peek(active);
+	request = __i915_active_request_peek(active);
 	return request ? request->global_seqno : 0;
 }
 
 static inline int
-__active_get_engine_id(struct i915_gem_active *active)
+__active_get_engine_id(struct i915_active_request *active)
 {
 	struct i915_request *request;
 
-	request = __i915_gem_active_peek(active);
+	request = __i915_active_request_peek(active);
 	return request ? request->engine->id : -1;
 }
 
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 6512630b59b8..c2a5c48c7541 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -29,6 +29,7 @@
 #include <linux/sched/signal.h>
 
 #include "i915_drv.h"
+#include "i915_active.h"
 #include "i915_reset.h"
 
 static const char *i915_fence_get_driver_name(struct dma_fence *fence)
@@ -125,12 +126,6 @@ static void unreserve_gt(struct drm_i915_private *i915)
 		i915_gem_park(i915);
 }
 
-void i915_gem_retire_noop(struct i915_gem_active *active,
-			  struct i915_request *request)
-{
-	/* Space left intentionally blank */
-}
-
 static void advance_ring(struct i915_request *request)
 {
 	struct intel_ring *ring = request->ring;
@@ -244,7 +239,7 @@ static void __retire_engine_upto(struct intel_engine_cs *engine,
 
 static void i915_request_retire(struct i915_request *request)
 {
-	struct i915_gem_active *active, *next;
+	struct i915_active_request *active, *next;
 
 	GEM_TRACE("%s fence %llx:%lld, global=%d, current %d:%d\n",
 		  request->engine->name,
@@ -278,10 +273,10 @@ static void i915_request_retire(struct i915_request *request)
 		 * we may spend an inordinate amount of time simply handling
 		 * the retirement of requests and processing their callbacks.
 		 * Of which, this loop itself is particularly hot due to the
-		 * cache misses when jumping around the list of i915_gem_active.
-		 * So we try to keep this loop as streamlined as possible and
-		 * also prefetch the next i915_gem_active to try and hide
-		 * the likely cache miss.
+		 * cache misses when jumping around the list of
+		 * i915_active_request.  So we try to keep this loop as
+		 * streamlined as possible and also prefetch the next
+		 * i915_active_request to try and hide the likely cache miss.
 		 */
 		prefetchw(next);
 
@@ -526,17 +521,9 @@ out:
 	return kmem_cache_alloc(ce->gem_context->i915->requests, GFP_KERNEL);
 }
 
-static int add_barrier(struct i915_request *rq, struct i915_gem_active *active)
-{
-	struct i915_request *barrier =
-		i915_gem_active_raw(active, &rq->i915->drm.struct_mutex);
-
-	return barrier ? i915_request_await_dma_fence(rq, &barrier->fence) : 0;
-}
-
 static int add_timeline_barrier(struct i915_request *rq)
 {
-	return add_barrier(rq, &rq->timeline->barrier);
+	return i915_request_await_active_request(rq, &rq->timeline->barrier);
 }
 
 /**
@@ -595,7 +582,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	 * We use RCU to look up requests in flight. The lookups may
 	 * race with the request being allocated from the slab freelist.
 	 * That is the request we are writing to here, may be in the process
-	 * of being read by __i915_gem_active_get_rcu(). As such,
+	 * of being read by __i915_active_request_get_rcu(). As such,
 	 * we have to be very careful when overwriting the contents. During
 	 * the RCU lookup, we change chase the request->engine pointer,
 	 * read the request->global_seqno and increment the reference count.
@@ -937,8 +924,8 @@ void i915_request_add(struct i915_request *request)
 	 * see a more recent value in the hws than we are tracking.
 	 */
 
-	prev = i915_gem_active_raw(&timeline->last_request,
-				   &request->i915->drm.struct_mutex);
+	prev = i915_active_request_raw(&timeline->last_request,
+				       &request->i915->drm.struct_mutex);
 	if (prev && !i915_request_completed(prev)) {
 		i915_sw_fence_await_sw_fence(&request->submit, &prev->submit,
 					     &request->submitq);
@@ -954,7 +941,7 @@ void i915_request_add(struct i915_request *request)
 	spin_unlock_irq(&timeline->lock);
 
 	GEM_BUG_ON(timeline->seqno != request->fence.seqno);
-	i915_gem_active_set(&timeline->last_request, request);
+	__i915_active_request_set(&timeline->last_request, request);
 
 	list_add_tail(&request->ring_link, &ring->request_list);
 	if (list_is_first(&request->ring_link, &ring->request_list)) {
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index 3cffb96203b9..40f3e8dcbdd5 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -403,387 +403,4 @@ static inline void i915_request_mark_complete(struct i915_request *rq)
 
 void i915_retire_requests(struct drm_i915_private *i915);
 
-/*
- * We treat requests as fences. This is not be to confused with our
- * "fence registers" but pipeline synchronisation objects ala GL_ARB_sync.
- * We use the fences to synchronize access from the CPU with activity on the
- * GPU, for example, we should not rewrite an object's PTE whilst the GPU
- * is reading them. We also track fences at a higher level to provide
- * implicit synchronisation around GEM objects, e.g. set-domain will wait
- * for outstanding GPU rendering before marking the object ready for CPU
- * access, or a pageflip will wait until the GPU is complete before showing
- * the frame on the scanout.
- *
- * In order to use a fence, the object must track the fence it needs to
- * serialise with. For example, GEM objects want to track both read and
- * write access so that we can perform concurrent read operations between
- * the CPU and GPU engines, as well as waiting for all rendering to
- * complete, or waiting for the last GPU user of a "fence register". The
- * object then embeds a #i915_gem_active to track the most recent (in
- * retirement order) request relevant for the desired mode of access.
- * The #i915_gem_active is updated with i915_gem_active_set() to track the
- * most recent fence request, typically this is done as part of
- * i915_vma_move_to_active().
- *
- * When the #i915_gem_active completes (is retired), it will
- * signal its completion to the owner through a callback as well as mark
- * itself as idle (i915_gem_active.request == NULL). The owner
- * can then perform any action, such as delayed freeing of an active
- * resource including itself.
- */
-struct i915_gem_active;
-
-typedef void (*i915_gem_retire_fn)(struct i915_gem_active *,
-				   struct i915_request *);
-
-struct i915_gem_active {
-	struct i915_request __rcu *request;
-	struct list_head link;
-	i915_gem_retire_fn retire;
-};
-
-void i915_gem_retire_noop(struct i915_gem_active *,
-			  struct i915_request *request);
-
-/**
- * init_request_active - prepares the activity tracker for use
- * @active - the active tracker
- * @func - a callback when then the tracker is retired (becomes idle),
- *         can be NULL
- *
- * init_request_active() prepares the embedded @active struct for use as
- * an activity tracker, that is for tracking the last known active request
- * associated with it. When the last request becomes idle, when it is retired
- * after completion, the optional callback @func is invoked.
- */
-static inline void
-init_request_active(struct i915_gem_active *active,
-		    i915_gem_retire_fn retire)
-{
-	RCU_INIT_POINTER(active->request, NULL);
-	INIT_LIST_HEAD(&active->link);
-	active->retire = retire ?: i915_gem_retire_noop;
-}
-
-/**
- * i915_gem_active_set - updates the tracker to watch the current request
- * @active - the active tracker
- * @request - the request to watch
- *
- * i915_gem_active_set() watches the given @request for completion. Whilst
- * that @request is busy, the @active reports busy. When that @request is
- * retired, the @active tracker is updated to report idle.
- */
-static inline void
-i915_gem_active_set(struct i915_gem_active *active,
-		    struct i915_request *request)
-{
-	list_move(&active->link, &request->active_list);
-	rcu_assign_pointer(active->request, request);
-}
-
-/**
- * i915_gem_active_set_retire_fn - updates the retirement callback
- * @active - the active tracker
- * @fn - the routine called when the request is retired
- * @mutex - struct_mutex used to guard retirements
- *
- * i915_gem_active_set_retire_fn() updates the function pointer that
- * is called when the final request associated with the @active tracker
- * is retired.
- */
-static inline void
-i915_gem_active_set_retire_fn(struct i915_gem_active *active,
-			      i915_gem_retire_fn fn,
-			      struct mutex *mutex)
-{
-	lockdep_assert_held(mutex);
-	active->retire = fn ?: i915_gem_retire_noop;
-}
-
-static inline struct i915_request *
-__i915_gem_active_peek(const struct i915_gem_active *active)
-{
-	/*
-	 * Inside the error capture (running with the driver in an unknown
-	 * state), we want to bend the rules slightly (a lot).
-	 *
-	 * Work is in progress to make it safer, in the meantime this keeps
-	 * the known issue from spamming the logs.
-	 */
-	return rcu_dereference_protected(active->request, 1);
-}
-
-/**
- * i915_gem_active_raw - return the active request
- * @active - the active tracker
- *
- * i915_gem_active_raw() returns the current request being tracked, or NULL.
- * It does not obtain a reference on the request for the caller, so the caller
- * must hold struct_mutex.
- */
-static inline struct i915_request *
-i915_gem_active_raw(const struct i915_gem_active *active, struct mutex *mutex)
-{
-	return rcu_dereference_protected(active->request,
-					 lockdep_is_held(mutex));
-}
-
-/**
- * i915_gem_active_peek - report the active request being monitored
- * @active - the active tracker
- *
- * i915_gem_active_peek() returns the current request being tracked if
- * still active, or NULL. It does not obtain a reference on the request
- * for the caller, so the caller must hold struct_mutex.
- */
-static inline struct i915_request *
-i915_gem_active_peek(const struct i915_gem_active *active, struct mutex *mutex)
-{
-	struct i915_request *request;
-
-	request = i915_gem_active_raw(active, mutex);
-	if (!request || i915_request_completed(request))
-		return NULL;
-
-	return request;
-}
-
-/**
- * i915_gem_active_get - return a reference to the active request
- * @active - the active tracker
- *
- * i915_gem_active_get() returns a reference to the active request, or NULL
- * if the active tracker is idle. The caller must hold struct_mutex.
- */
-static inline struct i915_request *
-i915_gem_active_get(const struct i915_gem_active *active, struct mutex *mutex)
-{
-	return i915_request_get(i915_gem_active_peek(active, mutex));
-}
-
-/**
- * __i915_gem_active_get_rcu - return a reference to the active request
- * @active - the active tracker
- *
- * __i915_gem_active_get() returns a reference to the active request, or NULL
- * if the active tracker is idle. The caller must hold the RCU read lock, but
- * the returned pointer is safe to use outside of RCU.
- */
-static inline struct i915_request *
-__i915_gem_active_get_rcu(const struct i915_gem_active *active)
-{
-	/*
-	 * Performing a lockless retrieval of the active request is super
-	 * tricky. SLAB_TYPESAFE_BY_RCU merely guarantees that the backing
-	 * slab of request objects will not be freed whilst we hold the
-	 * RCU read lock. It does not guarantee that the request itself
-	 * will not be freed and then *reused*. Viz,
-	 *
-	 * Thread A			Thread B
-	 *
-	 * rq = active.request
-	 *				retire(rq) -> free(rq);
-	 *				(rq is now first on the slab freelist)
-	 *				active.request = NULL
-	 *
-	 *				rq = new submission on a new object
-	 * ref(rq)
-	 *
-	 * To prevent the request from being reused whilst the caller
-	 * uses it, we take a reference like normal. Whilst acquiring
-	 * the reference we check that it is not in a destroyed state
-	 * (refcnt == 0). That prevents the request being reallocated
-	 * whilst the caller holds on to it. To check that the request
-	 * was not reallocated as we acquired the reference we have to
-	 * check that our request remains the active request across
-	 * the lookup, in the same manner as a seqlock. The visibility
-	 * of the pointer versus the reference counting is controlled
-	 * by using RCU barriers (rcu_dereference and rcu_assign_pointer).
-	 *
-	 * In the middle of all that, we inspect whether the request is
-	 * complete. Retiring is lazy so the request may be completed long
-	 * before the active tracker is updated. Querying whether the
-	 * request is complete is far cheaper (as it involves no locked
-	 * instructions setting cachelines to exclusive) than acquiring
-	 * the reference, so we do it first. The RCU read lock ensures the
-	 * pointer dereference is valid, but does not ensure that the
-	 * seqno nor HWS is the right one! However, if the request was
-	 * reallocated, that means the active tracker's request was complete.
-	 * If the new request is also complete, then both are and we can
-	 * just report the active tracker is idle. If the new request is
-	 * incomplete, then we acquire a reference on it and check that
-	 * it remained the active request.
-	 *
-	 * It is then imperative that we do not zero the request on
-	 * reallocation, so that we can chase the dangling pointers!
-	 * See i915_request_alloc().
-	 */
-	do {
-		struct i915_request *request;
-
-		request = rcu_dereference(active->request);
-		if (!request || i915_request_completed(request))
-			return NULL;
-
-		/*
-		 * An especially silly compiler could decide to recompute the
-		 * result of i915_request_completed, more specifically
-		 * re-emit the load for request->fence.seqno. A race would catch
-		 * a later seqno value, which could flip the result from true to
-		 * false. Which means part of the instructions below might not
-		 * be executed, while later on instructions are executed. Due to
-		 * barriers within the refcounting the inconsistency can't reach
-		 * past the call to i915_request_get_rcu, but not executing
-		 * that while still executing i915_request_put() creates
-		 * havoc enough.  Prevent this with a compiler barrier.
-		 */
-		barrier();
-
-		request = i915_request_get_rcu(request);
-
-		/*
-		 * What stops the following rcu_access_pointer() from occurring
-		 * before the above i915_request_get_rcu()? If we were
-		 * to read the value before pausing to get the reference to
-		 * the request, we may not notice a change in the active
-		 * tracker.
-		 *
-		 * The rcu_access_pointer() is a mere compiler barrier, which
-		 * means both the CPU and compiler are free to perform the
-		 * memory read without constraint. The compiler only has to
-		 * ensure that any operations after the rcu_access_pointer()
-		 * occur afterwards in program order. This means the read may
-		 * be performed earlier by an out-of-order CPU, or adventurous
-		 * compiler.
-		 *
-		 * The atomic operation at the heart of
-		 * i915_request_get_rcu(), see dma_fence_get_rcu(), is
-		 * atomic_inc_not_zero() which is only a full memory barrier
-		 * when successful. That is, if i915_request_get_rcu()
-		 * returns the request (and so with the reference counted
-		 * incremented) then the following read for rcu_access_pointer()
-		 * must occur after the atomic operation and so confirm
-		 * that this request is the one currently being tracked.
-		 *
-		 * The corresponding write barrier is part of
-		 * rcu_assign_pointer().
-		 */
-		if (!request || request == rcu_access_pointer(active->request))
-			return rcu_pointer_handoff(request);
-
-		i915_request_put(request);
-	} while (1);
-}
-
-/**
- * i915_gem_active_get_unlocked - return a reference to the active request
- * @active - the active tracker
- *
- * i915_gem_active_get_unlocked() returns a reference to the active request,
- * or NULL if the active tracker is idle. The reference is obtained under RCU,
- * so no locking is required by the caller.
- *
- * The reference should be freed with i915_request_put().
- */
-static inline struct i915_request *
-i915_gem_active_get_unlocked(const struct i915_gem_active *active)
-{
-	struct i915_request *request;
-
-	rcu_read_lock();
-	request = __i915_gem_active_get_rcu(active);
-	rcu_read_unlock();
-
-	return request;
-}
-
-/**
- * i915_gem_active_isset - report whether the active tracker is assigned
- * @active - the active tracker
- *
- * i915_gem_active_isset() returns true if the active tracker is currently
- * assigned to a request. Due to the lazy retiring, that request may be idle
- * and this may report stale information.
- */
-static inline bool
-i915_gem_active_isset(const struct i915_gem_active *active)
-{
-	return rcu_access_pointer(active->request);
-}
-
-/**
- * i915_gem_active_wait - waits until the request is completed
- * @active - the active request on which to wait
- * @flags - how to wait
- * @timeout - how long to wait at most
- * @rps - userspace client to charge for a waitboost
- *
- * i915_gem_active_wait() waits until the request is completed before
- * returning, without requiring any locks to be held. Note that it does not
- * retire any requests before returning.
- *
- * This function relies on RCU in order to acquire the reference to the active
- * request without holding any locks. See __i915_gem_active_get_rcu() for the
- * glory details on how that is managed. Once the reference is acquired, we
- * can then wait upon the request, and afterwards release our reference,
- * free of any locking.
- *
- * This function wraps i915_request_wait(), see it for the full details on
- * the arguments.
- *
- * Returns 0 if successful, or a negative error code.
- */
-static inline int
-i915_gem_active_wait(const struct i915_gem_active *active, unsigned int flags)
-{
-	struct i915_request *request;
-	long ret = 0;
-
-	request = i915_gem_active_get_unlocked(active);
-	if (request) {
-		ret = i915_request_wait(request, flags, MAX_SCHEDULE_TIMEOUT);
-		i915_request_put(request);
-	}
-
-	return ret < 0 ? ret : 0;
-}
-
-/**
- * i915_gem_active_retire - waits until the request is retired
- * @active - the active request on which to wait
- *
- * i915_gem_active_retire() waits until the request is completed,
- * and then ensures that at least the retirement handler for this
- * @active tracker is called before returning. If the @active
- * tracker is idle, the function returns immediately.
- */
-static inline int __must_check
-i915_gem_active_retire(struct i915_gem_active *active,
-		       struct mutex *mutex)
-{
-	struct i915_request *request;
-	long ret;
-
-	request = i915_gem_active_raw(active, mutex);
-	if (!request)
-		return 0;
-
-	ret = i915_request_wait(request,
-				I915_WAIT_INTERRUPTIBLE | I915_WAIT_LOCKED,
-				MAX_SCHEDULE_TIMEOUT);
-	if (ret < 0)
-		return ret;
-
-	list_del_init(&active->link);
-	RCU_INIT_POINTER(active->request, NULL);
-
-	active->retire(active, request);
-
-	return 0;
-}
-
-#define for_each_active(mask, idx) \
-	for (; mask ? idx = ffs(mask) - 1, 1 : 0; mask &= ~BIT(idx))
-
 #endif /* I915_REQUEST_H */
diff --git a/drivers/gpu/drm/i915/i915_reset.c b/drivers/gpu/drm/i915/i915_reset.c
index 4462007a681c..0e0ddf2e6815 100644
--- a/drivers/gpu/drm/i915/i915_reset.c
+++ b/drivers/gpu/drm/i915/i915_reset.c
@@ -862,7 +862,7 @@ bool i915_gem_unset_wedged(struct drm_i915_private *i915)
 		struct i915_request *rq;
 		long timeout;
 
-		rq = i915_gem_active_get_unlocked(&tl->last_request);
+		rq = i915_active_request_get_unlocked(&tl->last_request);
 		if (!rq)
 			continue;
 
diff --git a/drivers/gpu/drm/i915/i915_timeline.c b/drivers/gpu/drm/i915/i915_timeline.c
index dcff3ae96683..b2202d2e58a2 100644
--- a/drivers/gpu/drm/i915/i915_timeline.c
+++ b/drivers/gpu/drm/i915/i915_timeline.c
@@ -163,8 +163,8 @@ int i915_timeline_init(struct drm_i915_private *i915,
 
 	spin_lock_init(&timeline->lock);
 
-	init_request_active(&timeline->barrier, NULL);
-	init_request_active(&timeline->last_request, NULL);
+	INIT_ACTIVE_REQUEST(&timeline->barrier);
+	INIT_ACTIVE_REQUEST(&timeline->last_request);
 	INIT_LIST_HEAD(&timeline->requests);
 
 	i915_syncmap_init(&timeline->sync);
@@ -236,7 +236,7 @@ void i915_timeline_fini(struct i915_timeline *timeline)
 {
 	GEM_BUG_ON(timeline->pin_count);
 	GEM_BUG_ON(!list_empty(&timeline->requests));
-	GEM_BUG_ON(i915_gem_active_isset(&timeline->barrier));
+	GEM_BUG_ON(i915_active_request_isset(&timeline->barrier));
 
 	i915_syncmap_free(&timeline->sync);
 	hwsp_free(timeline);
@@ -311,25 +311,6 @@ void i915_timeline_unpin(struct i915_timeline *tl)
 	__i915_vma_unpin(tl->hwsp_ggtt);
 }
 
-int i915_timeline_set_barrier(struct i915_timeline *tl, struct i915_request *rq)
-{
-	struct i915_request *old;
-	int err;
-
-	lockdep_assert_held(&rq->i915->drm.struct_mutex);
-
-	/* Must maintain ordering wrt existing barriers */
-	old = i915_gem_active_raw(&tl->barrier, &rq->i915->drm.struct_mutex);
-	if (old) {
-		err = i915_request_await_dma_fence(rq, &old->fence);
-		if (err)
-			return err;
-	}
-
-	i915_gem_active_set(&tl->barrier, rq);
-	return 0;
-}
-
 void __i915_timeline_free(struct kref *kref)
 {
 	struct i915_timeline *timeline =
diff --git a/drivers/gpu/drm/i915/i915_timeline.h b/drivers/gpu/drm/i915/i915_timeline.h
index d167e04073c5..7bec7d2e45bf 100644
--- a/drivers/gpu/drm/i915/i915_timeline.h
+++ b/drivers/gpu/drm/i915/i915_timeline.h
@@ -28,6 +28,7 @@
 #include <linux/list.h>
 #include <linux/kref.h>
 
+#include "i915_active.h"
 #include "i915_request.h"
 #include "i915_syncmap.h"
 #include "i915_utils.h"
@@ -58,10 +59,10 @@ struct i915_timeline {
 
 	/* Contains an RCU guarded pointer to the last request. No reference is
 	 * held to the request, users must carefully acquire a reference to
-	 * the request using i915_gem_active_get_request_rcu(), or hold the
+	 * the request using i915_active_request_get_request_rcu(), or hold the
 	 * struct_mutex.
 	 */
-	struct i915_gem_active last_request;
+	struct i915_active_request last_request;
 
 	/**
 	 * We track the most recent seqno that we wait on in every context so
@@ -82,7 +83,7 @@ struct i915_timeline {
 	 * subsequent submissions to this timeline be executed only after the
 	 * barrier has been completed.
 	 */
-	struct i915_gem_active barrier;
+	struct i915_active_request barrier;
 
 	struct list_head link;
 	const char *name;
@@ -174,7 +175,10 @@ void i915_timelines_fini(struct drm_i915_private *i915);
  * submissions on @timeline. Subsequent requests will not be submitted to GPU
  * until the barrier has been completed.
  */
-int i915_timeline_set_barrier(struct i915_timeline *timeline,
-			      struct i915_request *rq);
+static inline int
+i915_timeline_set_barrier(struct i915_timeline *tl, struct i915_request *rq)
+{
+	return i915_active_request_set(&tl->barrier, rq);
+}
 
 #endif
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index d4772061e642..b713bed20c38 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -120,7 +120,7 @@ vma_create(struct drm_i915_gem_object *obj,
 		return ERR_PTR(-ENOMEM);
 
 	i915_active_init(vm->i915, &vma->active, __i915_vma_retire);
-	init_request_active(&vma->last_fence, NULL);
+	INIT_ACTIVE_REQUEST(&vma->last_fence);
 
 	vma->vm = vm;
 	vma->ops = &vm->vma_ops;
@@ -808,7 +808,7 @@ static void __i915_vma_destroy(struct i915_vma *vma)
 	GEM_BUG_ON(vma->node.allocated);
 	GEM_BUG_ON(vma->fence);
 
-	GEM_BUG_ON(i915_gem_active_isset(&vma->last_fence));
+	GEM_BUG_ON(i915_active_request_isset(&vma->last_fence));
 
 	mutex_lock(&vma->vm->mutex);
 	list_del(&vma->vm_link);
@@ -942,14 +942,14 @@ int i915_vma_move_to_active(struct i915_vma *vma,
 		obj->write_domain = I915_GEM_DOMAIN_RENDER;
 
 		if (intel_fb_obj_invalidate(obj, ORIGIN_CS))
-			i915_gem_active_set(&obj->frontbuffer_write, rq);
+			__i915_active_request_set(&obj->frontbuffer_write, rq);
 
 		obj->read_domains = 0;
 	}
 	obj->read_domains |= I915_GEM_GPU_DOMAINS;
 
 	if (flags & EXEC_OBJECT_NEEDS_FENCE)
-		i915_gem_active_set(&vma->last_fence, rq);
+		__i915_active_request_set(&vma->last_fence, rq);
 
 	export_fence(vma, rq, flags);
 	return 0;
@@ -986,8 +986,8 @@ int i915_vma_unbind(struct i915_vma *vma)
 		if (ret)
 			goto unpin;
 
-		ret = i915_gem_active_retire(&vma->last_fence,
-					     &vma->vm->i915->drm.struct_mutex);
+		ret = i915_active_request_retire(&vma->last_fence,
+					      &vma->vm->i915->drm.struct_mutex);
 unpin:
 		__i915_vma_unpin(vma);
 		if (ret)
diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 3c03d4569481..7c742027f866 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -110,7 +110,7 @@ struct i915_vma {
 #define I915_VMA_GGTT_WRITE	BIT(15)
 
 	struct i915_active active;
-	struct i915_gem_active last_fence;
+	struct i915_active_request last_fence;
 
 	/**
 	 * Support different GGTT views into the same object.
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 71c01eb13af1..49fa43ff02ba 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1086,7 +1086,7 @@ bool intel_engine_has_kernel_context(const struct intel_engine_cs *engine)
 	 * the last request that remains in the timeline. When idle, it is
 	 * the last executed context as tracked by retirement.
 	 */
-	rq = __i915_gem_active_peek(&engine->timeline.last_request);
+	rq = __i915_active_request_peek(&engine->timeline.last_request);
 	if (rq)
 		return rq->hw_context == kernel_context;
 	else
diff --git a/drivers/gpu/drm/i915/intel_overlay.c b/drivers/gpu/drm/i915/intel_overlay.c
index f68c7975006c..fc2e283d326b 100644
--- a/drivers/gpu/drm/i915/intel_overlay.c
+++ b/drivers/gpu/drm/i915/intel_overlay.c
@@ -184,7 +184,7 @@ struct intel_overlay {
 	struct overlay_registers __iomem *regs;
 	u32 flip_addr;
 	/* flip handling */
-	struct i915_gem_active last_flip;
+	struct i915_active_request last_flip;
 };
 
 static void i830_overlay_clock_gating(struct drm_i915_private *dev_priv,
@@ -212,23 +212,23 @@ static void i830_overlay_clock_gating(struct drm_i915_private *dev_priv,
 
 static void intel_overlay_submit_request(struct intel_overlay *overlay,
 					 struct i915_request *rq,
-					 i915_gem_retire_fn retire)
+					 i915_active_retire_fn retire)
 {
-	GEM_BUG_ON(i915_gem_active_peek(&overlay->last_flip,
-					&overlay->i915->drm.struct_mutex));
-	i915_gem_active_set_retire_fn(&overlay->last_flip, retire,
-				      &overlay->i915->drm.struct_mutex);
-	i915_gem_active_set(&overlay->last_flip, rq);
+	GEM_BUG_ON(i915_active_request_peek(&overlay->last_flip,
+					    &overlay->i915->drm.struct_mutex));
+	i915_active_request_set_retire_fn(&overlay->last_flip, retire,
+					  &overlay->i915->drm.struct_mutex);
+	__i915_active_request_set(&overlay->last_flip, rq);
 	i915_request_add(rq);
 }
 
 static int intel_overlay_do_wait_request(struct intel_overlay *overlay,
 					 struct i915_request *rq,
-					 i915_gem_retire_fn retire)
+					 i915_active_retire_fn retire)
 {
 	intel_overlay_submit_request(overlay, rq, retire);
-	return i915_gem_active_retire(&overlay->last_flip,
-				      &overlay->i915->drm.struct_mutex);
+	return i915_active_request_retire(&overlay->last_flip,
+					  &overlay->i915->drm.struct_mutex);
 }
 
 static struct i915_request *alloc_request(struct intel_overlay *overlay)
@@ -349,8 +349,9 @@ static void intel_overlay_release_old_vma(struct intel_overlay *overlay)
 	i915_vma_put(vma);
 }
 
-static void intel_overlay_release_old_vid_tail(struct i915_gem_active *active,
-					       struct i915_request *rq)
+static void
+intel_overlay_release_old_vid_tail(struct i915_active_request *active,
+				   struct i915_request *rq)
 {
 	struct intel_overlay *overlay =
 		container_of(active, typeof(*overlay), last_flip);
@@ -358,7 +359,7 @@ static void intel_overlay_release_old_vid_tail(struct i915_gem_active *active,
 	intel_overlay_release_old_vma(overlay);
 }
 
-static void intel_overlay_off_tail(struct i915_gem_active *active,
+static void intel_overlay_off_tail(struct i915_active_request *active,
 				   struct i915_request *rq)
 {
 	struct intel_overlay *overlay =
@@ -421,8 +422,8 @@ static int intel_overlay_off(struct intel_overlay *overlay)
  * We have to be careful not to repeat work forever an make forward progess. */
 static int intel_overlay_recover_from_interrupt(struct intel_overlay *overlay)
 {
-	return i915_gem_active_retire(&overlay->last_flip,
-				      &overlay->i915->drm.struct_mutex);
+	return i915_active_request_retire(&overlay->last_flip,
+					  &overlay->i915->drm.struct_mutex);
 }
 
 /* Wait for pending overlay flip and release old frame.
@@ -1355,7 +1356,7 @@ void intel_overlay_setup(struct drm_i915_private *dev_priv)
 	overlay->contrast = 75;
 	overlay->saturation = 146;
 
-	init_request_active(&overlay->last_flip, NULL);
+	INIT_ACTIVE_REQUEST(&overlay->last_flip);
 
 	mutex_lock(&dev_priv->drm.struct_mutex);
 
diff --git a/drivers/gpu/drm/i915/selftests/mock_timeline.c b/drivers/gpu/drm/i915/selftests/mock_timeline.c
index e5659aaa856d..d2de9ece2118 100644
--- a/drivers/gpu/drm/i915/selftests/mock_timeline.c
+++ b/drivers/gpu/drm/i915/selftests/mock_timeline.c
@@ -15,8 +15,8 @@ void mock_timeline_init(struct i915_timeline *timeline, u64 context)
 
 	spin_lock_init(&timeline->lock);
 
-	init_request_active(&timeline->barrier, NULL);
-	init_request_active(&timeline->last_request, NULL);
+	INIT_ACTIVE_REQUEST(&timeline->barrier);
+	INIT_ACTIVE_REQUEST(&timeline->last_request);
 	INIT_LIST_HEAD(&timeline->requests);
 
 	i915_syncmap_init(&timeline->sync);
-- 
cgit v1.2.3-59-g8ed1b