drm/i915: Remove i915->kernel_context

Allocate only an internal intel_context for the kernel_context, forgoing
a global GEM context for internal use as we only require a separate
address space (for our own protection).

Now having weaned GT from requiring ce->gem_context, we can stop
referencing it entirely. This also means we no longer have to create random
and unnecessary GEM contexts for internal use.

GEM contexts are now entirely for tracking GEM clients, and intel_context
the execution environment on the GPU.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@intel.com>
Acked-by: Andi Shyti <andi.shyti@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191221160324.1073045-1-chris@chris-wilson.co.uk

1 files changed, 11 insertions, 7 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_requests.c b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
index 0d1bca787288..063f863ee21c 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_requests.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_requests.c
@@ -8,6 +8,7 @@
 
 #include "i915_drv.h" /* for_each_engine() */
 #include "i915_request.h"
+#include "intel_engine_heartbeat.h"
 #include "intel_gt.h"
 #include "intel_gt_pm.h"
 #include "intel_gt_requests.h"
@@ -27,8 +28,10 @@ static void flush_submission(struct intel_gt *gt)
 	struct intel_engine_cs *engine;
 	enum intel_engine_id id;
 
-	for_each_engine(engine, gt, id)
+	for_each_engine(engine, gt, id) {
 		intel_engine_flush_submission(engine);
+		flush_work(&engine->retire_work);
+	}
 }
 
 static void engine_retire(struct work_struct *work)
@@ -117,10 +120,9 @@ long intel_gt_retire_requests_timeout(struct intel_gt *gt, long timeout)
 
 	spin_lock(&timelines->lock);
 	list_for_each_entry_safe(tl, tn, &timelines->active_list, link) {
-		if (!mutex_trylock(&tl->mutex)) {
-			active_count++; /* report busy to caller, try again? */
+		active_count++; /* report busy to caller, try again? */
+		if (!mutex_trylock(&tl->mutex))
 			continue;
-		}
 
 		intel_timeline_get(tl);
 		GEM_BUG_ON(!atomic_read(&tl->active_count));
@@ -145,10 +147,10 @@ long intel_gt_retire_requests_timeout(struct intel_gt *gt, long timeout)
 
 		/* Resume iteration after dropping lock */
 		list_safe_reset_next(tl, tn, link);
-		if (atomic_dec_and_test(&tl->active_count))
+		if (atomic_dec_and_test(&tl->active_count)) {
 			list_del(&tl->link);
-		else
-			active_count += !!rcu_access_pointer(tl->last_request.fence);
+			active_count--;
+		}
 
 		mutex_unlock(&tl->mutex);
 
@@ -163,6 +165,8 @@ long intel_gt_retire_requests_timeout(struct intel_gt *gt, long timeout)
 	list_for_each_entry_safe(tl, tn, &free, link)
 		__intel_timeline_free(&tl->kref);
 
+	flush_submission(gt);
+
 	return active_count ? timeout : 0;
 }