7 files changed, 37 insertions, 7 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 4d5d059bcab9..cb346ab7afb0 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3101,7 +3101,7 @@ static inline void i915_gem_object_unpin_map(struct drm_i915_gem_object *obj)
 int __must_check i915_mutex_lock_interruptible(struct drm_device *dev);
 int i915_gem_object_sync(struct drm_i915_gem_object *obj,
 			 struct intel_engine_cs *to,
-			 struct drm_i915_gem_request **to_req);
+			 struct drm_i915_gem_request **to_req, bool to_batch);
 void i915_vma_move_to_active(struct i915_vma *vma,
 			     struct drm_i915_gem_request *req);
 int i915_gem_dumb_create(struct drm_file *file_priv,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 30f5d3fd08dc..47f57dbd2b6b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3658,7 +3658,7 @@ static int
 __i915_gem_object_sync(struct drm_i915_gem_object *obj,
 		       struct intel_engine_cs *to,
 		       struct drm_i915_gem_request *from_req,
-		       struct drm_i915_gem_request **to_req)
+		       struct drm_i915_gem_request **to_req, bool to_batch)
 {
 	struct intel_engine_cs *from;
 	int ret;
@@ -3670,6 +3670,14 @@ __i915_gem_object_sync(struct drm_i915_gem_object *obj,
 	if (i915_gem_request_completed(from_req))
 		return 0;
 
+	/*
+	 * The scheduler will manage inter-ring object dependencies
+	 * as long as both to and from requests are scheduler managed
+	 * (i.e. batch buffers).
+	 */
+	if (to_batch && i915_scheduler_is_request_batch_buffer(from_req))
+		return 0;
+
 	if (!i915_semaphore_is_enabled(obj->base.dev)) {
 		struct drm_i915_private *i915 = to_i915(obj->base.dev);
 		uint32_t flags;
@@ -3728,6 +3736,8 @@ __i915_gem_object_sync(struct drm_i915_gem_object *obj,
  * @to_req: request we wish to use the object for. See below.
  *          This will be allocated and returned if a request is
  *          required but not passed in.
+ * @to_batch: is the sync request on behalf of batch buffer submission?
+ * If so then the scheduler can (potentially) manage the synchronisation.
  *
  * This code is meant to abstract object synchronization with the GPU.
  * Calling with NULL implies synchronizing the object with the CPU
@@ -3758,7 +3768,7 @@ __i915_gem_object_sync(struct drm_i915_gem_object *obj,
 int
 i915_gem_object_sync(struct drm_i915_gem_object *obj,
 		     struct intel_engine_cs *to,
-		     struct drm_i915_gem_request **to_req)
+		     struct drm_i915_gem_request **to_req, bool to_batch)
 {
 	const bool readonly = obj->base.pending_write_domain == 0;
 	struct drm_i915_gem_request *req[I915_NUM_ENGINES];
@@ -3780,7 +3790,7 @@ i915_gem_object_sync(struct drm_i915_gem_object *obj,
 				req[n++] = obj->last_read_req[i];
 	}
 	for (i = 0; i < n; i++) {
-		ret = __i915_gem_object_sync(obj, to, req[i], to_req);
+		ret = __i915_gem_object_sync(obj, to, req[i], to_req, to_batch);
 		if (ret)
 			return ret;
 	}
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 54175d8c71c9..c1205f096451 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -954,7 +954,7 @@ i915_gem_execbuffer_move_to_gpu(struct drm_i915_gem_request *req,
 		struct drm_i915_gem_object *obj = vma->obj;
 
 		if (obj->active & other_rings) {
-			ret = i915_gem_object_sync(obj, req->engine, &req);
+			ret = i915_gem_object_sync(obj, req->engine, &req, true);
 			if (ret)
 				return ret;
 		}
diff --git a/drivers/gpu/drm/i915/i915_scheduler.c b/drivers/gpu/drm/i915/i915_scheduler.c
index d1f819c95750..46953609bb38 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.c
+++ b/drivers/gpu/drm/i915/i915_scheduler.c
@@ -1346,6 +1346,25 @@ bool i915_scheduler_is_mutex_required(struct drm_i915_gem_request *req)
 }
 
 /**
+ * i915_scheduler_is_request_batch_buffer - is this request related to a
+ * batch buffer object?
+ * @req: request to be queried
+ *
+ * Returns true if the given request is for a batch buffer. False means it
+ * is for something else - page flip, context initialisation, etc.
+ */
+bool i915_scheduler_is_request_batch_buffer(struct drm_i915_gem_request *req)
+{
+	if (req->scheduler_qe == NULL)
+		return false;
+
+	if (req->scheduler_qe->params.batch_obj == NULL)
+		return false;
+
+	return true;
+}
+
+/**
  * i915_scheduler_closefile - notify the scheduler that a DRM file handle
  * has been closed.
  * @dev: DRM device
diff --git a/drivers/gpu/drm/i915/i915_scheduler.h b/drivers/gpu/drm/i915/i915_scheduler.h
index 0017b40f1314..da80f792e566 100644
--- a/drivers/gpu/drm/i915/i915_scheduler.h
+++ b/drivers/gpu/drm/i915/i915_scheduler.h
@@ -151,6 +151,7 @@ int i915_scheduler_flush(struct intel_engine_cs *engine, bool is_locked);
 int i915_scheduler_flush_stamp(struct intel_engine_cs *engine,
 			       unsigned long stamp, bool is_locked);
 bool i915_scheduler_is_mutex_required(struct drm_i915_gem_request *req);
+bool i915_scheduler_is_request_batch_buffer(struct drm_i915_gem_request *req);
 int i915_scheduler_query_stats(struct intel_engine_cs *engine,
 			       struct i915_scheduler_stats_nodes *stats);
 bool i915_scheduler_file_queue_wait(struct drm_file *file,
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 54274d3ec601..c2b1d5fd0a10 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -11604,7 +11604,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 	 * into the display plane and skip any waits.
 	 */
 	if (!mmio_flip) {
-		ret = i915_gem_object_sync(obj, engine, &request);
+		ret = i915_gem_object_sync(obj, engine, &request, false);
 		if (ret)
 			goto cleanup_pending;
 	}
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 02808f71ee82..c1263e6f8946 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -698,7 +698,7 @@ static int execlists_move_to_gpu(struct drm_i915_gem_request *req,
 		struct drm_i915_gem_object *obj = vma->obj;
 
 		if (obj->active & other_rings) {
-			ret = i915_gem_object_sync(obj, req->engine, &req);
+			ret = i915_gem_object_sync(obj, req->engine, &req, true);
 			if (ret)
 				return ret;
 		}