[PATCH 3/4] drm/i915: Move timeline from GTT to ring

Chris Wilson chris at chris-wilson.co.uk
Fri Apr 20 11:35:30 UTC 2018


In the future, we want to move a request between engines. To achieve
this, we first realise that we have two timelines in effect here. The
first runs through the GTT is required for ordering vma access, which is
tracked currently by engine. The second is implied by sequential
execution of commands inside the ringbuffer. This timeline is one that
maps to userspace's expectations when submitting requests (i.e. given the
same context, batch A is executed before batch B). As the rings's
timelines map to userspace and the GTT timeline an implementation
detail, move the timeline from the GTT into the ring itself (per-context
in logical-ring-contexts/execlists, or a global per-engine timeline for
the shared ringbuffers in legacy submission.

The two timelines are still assumed to be equivalent at the moment (no
migrating requests between engines yet) and so we can simply move from
one to the other without adding extra ordering.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h               | 13 +----
 drivers/gpu/drm/i915/i915_gem.c               |  9 ++--
 drivers/gpu/drm/i915/i915_gem_context.c       | 15 +++++-
 drivers/gpu/drm/i915/i915_gem_context.h       |  2 +
 drivers/gpu/drm/i915/i915_gem_gtt.c           |  3 --
 drivers/gpu/drm/i915/i915_gem_gtt.h           |  1 -
 drivers/gpu/drm/i915/i915_gem_timeline.c      | 54 +++++++++++++++++--
 drivers/gpu/drm/i915/i915_gem_timeline.h      |  4 ++
 drivers/gpu/drm/i915/i915_request.c           | 15 +++---
 drivers/gpu/drm/i915/intel_engine_cs.c        |  3 +-
 drivers/gpu/drm/i915/intel_lrc.c              |  2 +-
 drivers/gpu/drm/i915/intel_ringbuffer.c       |  9 +++-
 drivers/gpu/drm/i915/intel_ringbuffer.h       |  5 +-
 drivers/gpu/drm/i915/selftests/mock_engine.c  |  3 +-
 .../gpu/drm/i915/selftests/mock_gem_device.c  |  4 +-
 drivers/gpu/drm/i915/selftests/mock_gtt.c     |  1 -
 16 files changed, 101 insertions(+), 42 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index e177d2bda87d..f3a898feaa91 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2055,7 +2055,8 @@ struct drm_i915_private {
 		void (*resume)(struct drm_i915_private *);
 		void (*cleanup_engine)(struct intel_engine_cs *engine);
 
-		struct i915_gem_timeline global_timeline;
+		struct i915_gem_timeline execution_timeline;
+		struct i915_gem_timeline legacy_timeline;
 		struct list_head timelines;
 		struct list_head rings;
 		u32 active_requests;
@@ -3229,16 +3230,6 @@ i915_gem_context_lookup(struct drm_i915_file_private *file_priv, u32 id)
 	return ctx;
 }
 
-static inline struct intel_timeline *
-i915_gem_context_lookup_timeline(struct i915_gem_context *ctx,
-				 struct intel_engine_cs *engine)
-{
-	struct i915_address_space *vm;
-
-	vm = ctx->ppgtt ? &ctx->ppgtt->base : &ctx->i915->ggtt.base;
-	return &vm->timeline.engine[engine->id];
-}
-
 int i915_perf_open_ioctl(struct drm_device *dev, void *data,
 			 struct drm_file *file);
 int i915_perf_add_config_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 906e2395c245..0c5aef67b302 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3109,10 +3109,10 @@ static void engine_skip_context(struct i915_request *request)
 {
 	struct intel_engine_cs *engine = request->engine;
 	struct i915_gem_context *hung_ctx = request->ctx;
-	struct intel_timeline *timeline;
+	struct intel_timeline *timeline = request->timeline;
 	unsigned long flags;
 
-	timeline = i915_gem_context_lookup_timeline(hung_ctx, engine);
+	GEM_BUG_ON(timeline == engine->timeline);
 
 	spin_lock_irqsave(&engine->timeline->lock, flags);
 	spin_lock(&timeline->lock);
@@ -3781,7 +3781,7 @@ int i915_gem_wait_for_idle(struct drm_i915_private *i915, unsigned int flags)
 
 		ret = wait_for_engines(i915);
 	} else {
-		ret = wait_for_timeline(&i915->gt.global_timeline, flags);
+		ret = wait_for_timeline(&i915->gt.execution_timeline, flags);
 	}
 
 	return ret;
@@ -5650,7 +5650,8 @@ void i915_gem_cleanup_early(struct drm_i915_private *dev_priv)
 	WARN_ON(dev_priv->mm.object_count);
 
 	mutex_lock(&dev_priv->drm.struct_mutex);
-	i915_gem_timeline_fini(&dev_priv->gt.global_timeline);
+	i915_gem_timeline_fini(&dev_priv->gt.legacy_timeline);
+	i915_gem_timeline_fini(&dev_priv->gt.execution_timeline);
 	WARN_ON(!list_empty(&dev_priv->gt.timelines));
 	mutex_unlock(&dev_priv->drm.struct_mutex);
 
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 74435affe23f..58b185abe652 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -122,6 +122,7 @@ static void i915_gem_context_free(struct i915_gem_context *ctx)
 	lockdep_assert_held(&ctx->i915->drm.struct_mutex);
 	GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
 
+	i915_gem_timeline_free(ctx->timeline);
 	i915_ppgtt_put(ctx->ppgtt);
 
 	for (i = 0; i < I915_NUM_ENGINES; i++) {
@@ -376,6 +377,18 @@ i915_gem_create_context(struct drm_i915_private *dev_priv,
 		ctx->desc_template = default_desc_template(dev_priv, ppgtt);
 	}
 
+	if (HAS_EXECLISTS(dev_priv)) {
+		struct i915_gem_timeline *timeline;
+
+		timeline = i915_gem_timeline_create(dev_priv, ctx->name);
+		if (IS_ERR(timeline)) {
+			__destroy_hw_context(ctx, file_priv);
+			return ERR_CAST(timeline);
+		}
+
+		ctx->timeline = timeline;
+	}
+
 	trace_i915_context_create(ctx);
 
 	return ctx;
@@ -584,7 +597,7 @@ static bool engine_has_idle_kernel_context(struct intel_engine_cs *engine)
 	list_for_each_entry(timeline, &engine->i915->gt.timelines, link) {
 		struct intel_timeline *tl;
 
-		if (timeline == &engine->i915->gt.global_timeline)
+		if (timeline == &engine->i915->gt.execution_timeline)
 			continue;
 
 		tl = &timeline->engine[engine->id];
diff --git a/drivers/gpu/drm/i915/i915_gem_context.h b/drivers/gpu/drm/i915/i915_gem_context.h
index b12a8a8c5af9..140edcb424df 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.h
+++ b/drivers/gpu/drm/i915/i915_gem_context.h
@@ -58,6 +58,8 @@ struct i915_gem_context {
 	/** file_priv: owning file descriptor */
 	struct drm_i915_file_private *file_priv;
 
+	struct i915_gem_timeline *timeline;
+
 	/**
 	 * @ppgtt: unique address space (GTT)
 	 *
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 21d72f695adb..e9d828324f67 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -2111,8 +2111,6 @@ static void i915_address_space_init(struct i915_address_space *vm,
 				    struct drm_i915_private *dev_priv,
 				    const char *name)
 {
-	i915_gem_timeline_init(dev_priv, &vm->timeline, name);
-
 	drm_mm_init(&vm->mm, 0, vm->total);
 	vm->mm.head_node.color = I915_COLOR_UNEVICTABLE;
 
@@ -2129,7 +2127,6 @@ static void i915_address_space_fini(struct i915_address_space *vm)
 	if (pagevec_count(&vm->free_pages))
 		vm_free_pages_release(vm, true);
 
-	i915_gem_timeline_fini(&vm->timeline);
 	drm_mm_takedown(&vm->mm);
 	list_del(&vm->global_link);
 }
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 6efc017e8bb3..98107925de48 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -257,7 +257,6 @@ struct i915_pml4 {
 
 struct i915_address_space {
 	struct drm_mm mm;
-	struct i915_gem_timeline timeline;
 	struct drm_i915_private *i915;
 	struct device *dma;
 	/* Every address space belongs to a struct file - except for the global
diff --git a/drivers/gpu/drm/i915/i915_gem_timeline.c b/drivers/gpu/drm/i915/i915_gem_timeline.c
index e9fd87604067..24f4068cc137 100644
--- a/drivers/gpu/drm/i915/i915_gem_timeline.c
+++ b/drivers/gpu/drm/i915/i915_gem_timeline.c
@@ -95,12 +95,28 @@ int i915_gem_timeline_init(struct drm_i915_private *i915,
 
 int i915_gem_timeline_init__global(struct drm_i915_private *i915)
 {
-	static struct lock_class_key class;
+	static struct lock_class_key class1, class2;
+	int err;
+
+	err = __i915_gem_timeline_init(i915,
+				       &i915->gt.execution_timeline,
+				       "[execution]", &class1,
+				       "i915_execution_timeline");
+	if (err)
+		return err;
+
+	err = __i915_gem_timeline_init(i915,
+				       &i915->gt.legacy_timeline,
+				       "[global]", &class2,
+				       "i915_global_timeline");
+	if (err)
+		goto err_exec_timeline;
+
+	return 0;
 
-	return __i915_gem_timeline_init(i915,
-					&i915->gt.global_timeline,
-					"[execution]",
-					&class, "&global_timeline->lock");
+err_exec_timeline:
+	i915_gem_timeline_fini(&i915->gt.execution_timeline);
+	return err;
 }
 
 /**
@@ -148,6 +164,34 @@ void i915_gem_timeline_fini(struct i915_gem_timeline *timeline)
 	kfree(timeline->name);
 }
 
+struct i915_gem_timeline *
+i915_gem_timeline_create(struct drm_i915_private *i915, const char *name)
+{
+	struct i915_gem_timeline *timeline;
+	int err;
+
+	timeline = kzalloc(sizeof(*timeline), GFP_KERNEL);
+	if (!timeline)
+		return ERR_PTR(-ENOMEM);
+
+	err = i915_gem_timeline_init(i915, timeline, name);
+	if (err) {
+		kfree(timeline);
+		return ERR_PTR(err);
+	}
+
+	return timeline;
+}
+
+void i915_gem_timeline_free(struct i915_gem_timeline *timeline)
+{
+	if (!timeline)
+		return;
+
+	i915_gem_timeline_fini(timeline);
+	kfree(timeline);
+}
+
 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
 #include "selftests/mock_timeline.c"
 #include "selftests/i915_gem_timeline.c"
diff --git a/drivers/gpu/drm/i915/i915_gem_timeline.h b/drivers/gpu/drm/i915/i915_gem_timeline.h
index 6e82119e2cd8..780ed465c4fc 100644
--- a/drivers/gpu/drm/i915/i915_gem_timeline.h
+++ b/drivers/gpu/drm/i915/i915_gem_timeline.h
@@ -90,6 +90,10 @@ int i915_gem_timeline_init__global(struct drm_i915_private *i915);
 void i915_gem_timelines_park(struct drm_i915_private *i915);
 void i915_gem_timeline_fini(struct i915_gem_timeline *tl);
 
+struct i915_gem_timeline *
+i915_gem_timeline_create(struct drm_i915_private *i915, const char *name);
+void i915_gem_timeline_free(struct i915_gem_timeline *timeline);
+
 static inline int __intel_timeline_sync_set(struct intel_timeline *tl,
 					    u64 context, u32 seqno)
 {
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 0bf949ec9f1a..844de5481788 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -638,6 +638,7 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 	if (IS_ERR(ring))
 		return ERR_CAST(ring);
 	GEM_BUG_ON(!ring);
+	GEM_BUG_ON(ring->timeline == engine->timeline);
 
 	ret = reserve_engine(engine);
 	if (ret)
@@ -710,8 +711,12 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 		}
 	}
 
-	rq->timeline = i915_gem_context_lookup_timeline(ctx, engine);
-	GEM_BUG_ON(rq->timeline == engine->timeline);
+	INIT_LIST_HEAD(&rq->active_list);
+	rq->i915 = i915;
+	rq->engine = engine;
+	rq->ctx = ctx;
+	rq->ring = ring;
+	rq->timeline = ring->timeline;
 
 	spin_lock_init(&rq->lock);
 	dma_fence_init(&rq->fence,
@@ -726,12 +731,6 @@ i915_request_alloc(struct intel_engine_cs *engine, struct i915_gem_context *ctx)
 
 	i915_sched_node_init(&rq->sched);
 
-	INIT_LIST_HEAD(&rq->active_list);
-	rq->i915 = i915;
-	rq->engine = engine;
-	rq->ctx = ctx;
-	rq->ring = ring;
-
 	/* No zalloc, must clear what we need by hand */
 	rq->global_seqno = 0;
 	rq->signaling.wait.seqno = 0;
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index a55a849b81b6..d44a8eb83379 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -453,7 +453,8 @@ void intel_engine_init_global_seqno(struct intel_engine_cs *engine, u32 seqno)
 
 static void intel_engine_init_timeline(struct intel_engine_cs *engine)
 {
-	engine->timeline = &engine->i915->gt.global_timeline.engine[engine->id];
+	engine->timeline =
+		&engine->i915->gt.execution_timeline.engine[engine->id];
 }
 
 static void intel_engine_init_batch_pool(struct intel_engine_cs *engine)
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 029901a8fa38..fd3539034665 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -2584,7 +2584,7 @@ static int execlists_context_deferred_alloc(struct i915_gem_context *ctx,
 		goto error_deref_obj;
 	}
 
-	ring = intel_engine_create_ring(engine, ctx->ring_size);
+	ring = intel_engine_create_ring(engine, ctx->timeline, ctx->ring_size);
 	if (IS_ERR(ring)) {
 		ret = PTR_ERR(ring);
 		goto error_deref_obj;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 792a2ca95872..a4b2691dac52 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1117,7 +1117,9 @@ intel_ring_create_vma(struct drm_i915_private *dev_priv, int size)
 }
 
 struct intel_ring *
-intel_engine_create_ring(struct intel_engine_cs *engine, int size)
+intel_engine_create_ring(struct intel_engine_cs *engine,
+			 struct i915_gem_timeline *timeline,
+			 int size)
 {
 	struct intel_ring *ring;
 	struct i915_vma *vma;
@@ -1131,6 +1133,7 @@ intel_engine_create_ring(struct intel_engine_cs *engine, int size)
 		return ERR_PTR(-ENOMEM);
 
 	INIT_LIST_HEAD(&ring->request_list);
+	ring->timeline = &timeline->engine[engine->id];
 
 	ring->size = size;
 	/* Workaround an erratum on the i830 which causes a hang if
@@ -1331,7 +1334,9 @@ static int intel_init_ring_buffer(struct intel_engine_cs *engine)
 	if (err)
 		goto err;
 
-	ring = intel_engine_create_ring(engine, 32 * PAGE_SIZE);
+	ring = intel_engine_create_ring(engine,
+					&engine->i915->gt.legacy_timeline,
+					32 * PAGE_SIZE);
 	if (IS_ERR(ring)) {
 		err = PTR_ERR(ring);
 		goto err;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index d816f8dea245..3debe7172dff 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -128,6 +128,7 @@ struct intel_ring {
 	struct i915_vma *vma;
 	void *vaddr;
 
+	struct intel_timeline *timeline;
 	struct list_head request_list;
 	struct list_head link;
 
@@ -767,7 +768,9 @@ intel_write_status_page(struct intel_engine_cs *engine, int reg, u32 value)
 #define CNL_HWS_CSB_WRITE_INDEX		0x2f
 
 struct intel_ring *
-intel_engine_create_ring(struct intel_engine_cs *engine, int size);
+intel_engine_create_ring(struct intel_engine_cs *engine,
+			 struct i915_gem_timeline *timeline,
+			 int size);
 int intel_ring_pin(struct intel_ring *ring,
 		   struct drm_i915_private *i915,
 		   unsigned int offset_bias);
diff --git a/drivers/gpu/drm/i915/selftests/mock_engine.c b/drivers/gpu/drm/i915/selftests/mock_engine.c
index 78a89efa1119..705c338217e1 100644
--- a/drivers/gpu/drm/i915/selftests/mock_engine.c
+++ b/drivers/gpu/drm/i915/selftests/mock_engine.c
@@ -174,8 +174,7 @@ struct intel_engine_cs *mock_engine(struct drm_i915_private *i915,
 	engine->base.emit_breadcrumb = mock_emit_breadcrumb;
 	engine->base.submit_request = mock_submit_request;
 
-	engine->base.timeline =
-		&i915->gt.global_timeline.engine[engine->base.id];
+	intel_engine_init_timeline(&engine->base);
 
 	intel_engine_init_breadcrumbs(&engine->base);
 	engine->base.breadcrumbs.mock = true; /* prevent touching HW for irqs */
diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
index 4215f48e4a1c..81d771447771 100644
--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
@@ -72,7 +72,9 @@ static void mock_device_release(struct drm_device *dev)
 
 	mutex_lock(&i915->drm.struct_mutex);
 	mock_fini_ggtt(i915);
-	i915_gem_timeline_fini(&i915->gt.global_timeline);
+	i915_gem_timeline_fini(&i915->gt.legacy_timeline);
+	i915_gem_timeline_fini(&i915->gt.execution_timeline);
+	WARN_ON(!list_empty(&i915->gt.timelines));
 	mutex_unlock(&i915->drm.struct_mutex);
 
 	destroy_workqueue(i915->wq);
diff --git a/drivers/gpu/drm/i915/selftests/mock_gtt.c b/drivers/gpu/drm/i915/selftests/mock_gtt.c
index e96873f96116..36c112088940 100644
--- a/drivers/gpu/drm/i915/selftests/mock_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gtt.c
@@ -76,7 +76,6 @@ mock_ppgtt(struct drm_i915_private *i915,
 
 	INIT_LIST_HEAD(&ppgtt->base.global_link);
 	drm_mm_init(&ppgtt->base.mm, 0, ppgtt->base.total);
-	i915_gem_timeline_init(i915, &ppgtt->base.timeline, name);
 
 	ppgtt->base.clear_range = nop_clear_range;
 	ppgtt->base.insert_page = mock_insert_page;
-- 
2.17.0



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