1 files changed, 60 insertions, 32 deletions

diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c
index 09ed90c0ba00..832cb6b1e9bd 100644
--- a/drivers/gpu/drm/i915/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c
@@ -23,12 +23,11 @@
  */
 
 #include <linux/kthread.h>
+#include <trace/events/dma_fence.h>
 #include <uapi/linux/sched/types.h>
 
 #include "i915_drv.h"
 
-#define task_asleep(tsk) ((tsk)->state & TASK_NORMAL && !(tsk)->on_rq)
-
 static void irq_enable(struct intel_engine_cs *engine)
 {
 	if (!engine->irq_enable)
@@ -82,9 +81,39 @@ 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)
+static bool
+__dma_fence_signal(struct dma_fence *fence)
+{
+	return !test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags);
+}
+
+static void
+__dma_fence_signal__timestamp(struct dma_fence *fence, ktime_t timestamp)
+{
+	fence->timestamp = timestamp;
+	set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags);
+	trace_dma_fence_signaled(fence);
+}
+
+static void
+__dma_fence_signal__notify(struct dma_fence *fence)
+{
+	struct dma_fence_cb *cur, *tmp;
+
+	lockdep_assert_held(fence->lock);
+	lockdep_assert_irqs_disabled();
+
+	list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) {
+		INIT_LIST_HEAD(&cur->node);
+		cur->func(fence, cur);
+	}
+	INIT_LIST_HEAD(&fence->cb_list);
+}
+
+void intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine)
 {
 	struct intel_breadcrumbs *b = &engine->breadcrumbs;
+	const ktime_t timestamp = ktime_get();
 	struct intel_context *ce, *cn;
 	struct list_head *pos, *next;
 	LIST_HEAD(signal);
@@ -106,6 +135,10 @@ bool intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine)
 
 			GEM_BUG_ON(!test_bit(I915_FENCE_FLAG_SIGNAL,
 					     &rq->fence.flags));
+			clear_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags);
+
+			if (!__dma_fence_signal(&rq->fence))
+				continue;
 
 			/*
 			 * Queue for execution after dropping the signaling
@@ -113,14 +146,6 @@ bool intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine)
 			 * more signalers to the same context or engine.
 			 */
 			i915_request_get(rq);
-
-			/*
-			 * We may race with direct invocation of
-			 * dma_fence_signal(), e.g. i915_request_retire(),
-			 * so we need to acquire our reference to the request
-			 * before we cancel the breadcrumb.
-			 */
-			clear_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags);
 			list_add_tail(&rq->signal_link, &signal);
 		}
 
@@ -143,22 +168,21 @@ bool intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine)
 		struct i915_request *rq =
 			list_entry(pos, typeof(*rq), signal_link);
 
-		dma_fence_signal(&rq->fence);
+		__dma_fence_signal__timestamp(&rq->fence, timestamp);
+
+		spin_lock(&rq->lock);
+		__dma_fence_signal__notify(&rq->fence);
+		spin_unlock(&rq->lock);
+
 		i915_request_put(rq);
 	}
-
-	return !list_empty(&signal);
 }
 
-bool intel_engine_signal_breadcrumbs(struct intel_engine_cs *engine)
+void intel_engine_signal_breadcrumbs(struct intel_engine_cs *engine)
 {
-	bool result;
-
 	local_irq_disable();
-	result = intel_engine_breadcrumbs_irq(engine);
+	intel_engine_breadcrumbs_irq(engine);
 	local_irq_enable();
-
-	return result;
 }
 
 static void signal_irq_work(struct irq_work *work)
@@ -251,19 +275,17 @@ void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine)
 
 bool i915_request_enable_breadcrumb(struct i915_request *rq)
 {
-	struct intel_breadcrumbs *b = &rq->engine->breadcrumbs;
+	lockdep_assert_held(&rq->lock);
+	lockdep_assert_irqs_disabled();
 
-	GEM_BUG_ON(test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags));
-
-	if (!test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags))
-		return true;
-
-	spin_lock(&b->irq_lock);
-	if (test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags) &&
-	    !__request_completed(rq)) {
+	if (test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags)) {
+		struct intel_breadcrumbs *b = &rq->engine->breadcrumbs;
 		struct intel_context *ce = rq->hw_context;
 		struct list_head *pos;
 
+		spin_lock(&b->irq_lock);
+		GEM_BUG_ON(test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags));
+
 		__intel_breadcrumbs_arm_irq(b);
 
 		/*
@@ -292,8 +314,8 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq)
 			list_move_tail(&ce->signal_link, &b->signalers);
 
 		set_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags);
+		spin_unlock(&b->irq_lock);
 	}
-	spin_unlock(&b->irq_lock);
 
 	return !__request_completed(rq);
 }
@@ -302,9 +324,15 @@ void i915_request_cancel_breadcrumb(struct i915_request *rq)
 {
 	struct intel_breadcrumbs *b = &rq->engine->breadcrumbs;
 
-	if (!test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags))
-		return;
+	lockdep_assert_held(&rq->lock);
+	lockdep_assert_irqs_disabled();
 
+	/*
+	 * We must wait for b->irq_lock so that we know the interrupt handler
+	 * has released its reference to the intel_context and has completed
+	 * the DMA_FENCE_FLAG_SIGNALED_BIT/I915_FENCE_FLAG_SIGNAL dance (if
+	 * required).
+	 */
 	spin_lock(&b->irq_lock);
 	if (test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags)) {
 		struct intel_context *ce = rq->hw_context;