[PATCH 06/11] timeline-

[Chris Wilson]

---
 drivers/gpu/drm/i915/i915_request.c           | 22 ++++++++++++-------
 drivers/gpu/drm/i915/i915_timeline.c          |  1 +
 drivers/gpu/drm/i915/i915_timeline.h          |  2 ++
 .../gpu/drm/i915/selftests/mock_timeline.c    |  1 +
 4 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index ea726d254397..53e85bc1e3d6 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -253,7 +253,7 @@ static void i915_request_retire(struct i915_request *request)
 		  hwsp_seqno(request),
 		  intel_engine_get_seqno(request->engine));
 
-	lockdep_assert_held(&request->i915->drm.struct_mutex);
+	lockdep_assert_held(&request->timeline->mutex);
 	GEM_BUG_ON(!i915_sw_fence_signaled(&request->submit));
 	GEM_BUG_ON(!i915_request_completed(request));
 
@@ -317,7 +317,7 @@ void i915_request_retire_upto(struct i915_request *rq)
 		  hwsp_seqno(rq),
 		  intel_engine_get_seqno(rq->engine));
 
-	lockdep_assert_held(&rq->i915->drm.struct_mutex);
+	lockdep_assert_held(&rq->timeline->mutex);
 	GEM_BUG_ON(!i915_request_completed(rq));
 
 	if (list_empty(&rq->ring_link))
@@ -513,6 +513,8 @@ static void ring_retire_requests(struct intel_ring *ring)
 {
 	struct i915_request *rq, *rn;
 
+	lockdep_assert_held(&ring->timeline->mutex);
+
 	list_for_each_entry_safe(rq, rn, &ring->request_list, ring_link) {
 		if (!i915_request_completed(rq))
 			break;
@@ -563,8 +565,6 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	struct intel_context *ce;
 	int ret;
 
-	lockdep_assert_held(&i915->drm.struct_mutex);
-
 	/*
 	 * Preempt contexts are reserved for exclusive use to inject a
 	 * preemption context switch. They are never to be used for any trivial
@@ -589,6 +589,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 		return ERR_CAST(ce);
 
 	reserve_gt(i915);
+	mutex_lock(&ce->ring->timeline->mutex);
 
 	/* Move our oldest request to the slab-cache (if not in use!) */
 	rq = list_first_entry(&ce->ring->request_list, typeof(*rq), ring_link);
@@ -715,6 +716,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 
 	kmem_cache_free(global.slab_requests, rq);
 err_unreserve:
+	mutex_unlock(&ce->ring->timeline->mutex);
 	unreserve_gt(i915);
 	intel_context_unpin(ce);
 	return ERR_PTR(ret);
@@ -1018,6 +1020,8 @@ void i915_request_add(struct i915_request *request)
 	 */
 	if (prev && i915_request_completed(prev))
 		i915_request_retire_upto(prev);
+
+	mutex_unlock(&request->timeline->mutex);
 }
 
 static unsigned long local_clock_us(unsigned int *cpu)
@@ -1192,13 +1196,15 @@ void i915_retire_requests(struct drm_i915_private *i915)
 {
 	struct intel_ring *ring, *tmp;
 
-	lockdep_assert_held(&i915->drm.struct_mutex);
-
-	if (!i915->gt.active_requests)
+	if (!READ_ONCE(i915->gt.active_requests))
 		return;
 
-	list_for_each_entry_safe(ring, tmp, &i915->gt.active_rings, active_link)
+	list_for_each_entry_safe(ring, tmp,
+				 &i915->gt.active_rings, active_link) {
+		mutex_lock(&ring->timeline->mutex);
 		ring_retire_requests(ring);
+		mutex_unlock(&ring->timeline->mutex);
+	}
 }
 
 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
diff --git a/drivers/gpu/drm/i915/i915_timeline.c b/drivers/gpu/drm/i915/i915_timeline.c
index b2202d2e58a2..87a80558da28 100644
--- a/drivers/gpu/drm/i915/i915_timeline.c
+++ b/drivers/gpu/drm/i915/i915_timeline.c
@@ -162,6 +162,7 @@ int i915_timeline_init(struct drm_i915_private *i915,
 	timeline->fence_context = dma_fence_context_alloc(1);
 
 	spin_lock_init(&timeline->lock);
+	mutex_init(&timeline->mutex);
 
 	INIT_ACTIVE_REQUEST(&timeline->barrier);
 	INIT_ACTIVE_REQUEST(&timeline->last_request);
diff --git a/drivers/gpu/drm/i915/i915_timeline.h b/drivers/gpu/drm/i915/i915_timeline.h
index 7bec7d2e45bf..36c3849f7108 100644
--- a/drivers/gpu/drm/i915/i915_timeline.h
+++ b/drivers/gpu/drm/i915/i915_timeline.h
@@ -44,6 +44,8 @@ struct i915_timeline {
 #define TIMELINE_CLIENT 0 /* default subclass */
 #define TIMELINE_ENGINE 1
 
+	struct mutex mutex; /* protects the flow of requests */
+
 	unsigned int pin_count;
 	const u32 *hwsp_seqno;
 	struct i915_vma *hwsp_ggtt;
diff --git a/drivers/gpu/drm/i915/selftests/mock_timeline.c b/drivers/gpu/drm/i915/selftests/mock_timeline.c
index d2de9ece2118..416d85233263 100644
--- a/drivers/gpu/drm/i915/selftests/mock_timeline.c
+++ b/drivers/gpu/drm/i915/selftests/mock_timeline.c
@@ -14,6 +14,7 @@ void mock_timeline_init(struct i915_timeline *timeline, u64 context)
 	timeline->fence_context = context;
 
 	spin_lock_init(&timeline->lock);
+	mutex_init(&timeline->mutex);
 
 	INIT_ACTIVE_REQUEST(&timeline->barrier);
 	INIT_ACTIVE_REQUEST(&timeline->last_request);
-- 
2.20.1