drm/i915: Remove redundant i915_request_await_object in blit clears

One i915_request_await_object is enough and we keep the one under the
object lock so it is final.

At the same time move async clflushing setup under the same locked
section and consolidate common code into a helper function.

v2:
 * Emit initial breadcrumbs after aways are set up. (Chris)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michael J. Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200615151449.32605-1-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/gem/i915_gem_object_blt.c

@@ -126,6 +126,17 @@ void intel_emit_vma_release(struct intel_context *ce, struct i915_vma *vma)
 	intel_engine_pm_put(ce->engine);
 }
 
+static int
+move_obj_to_gpu(struct drm_i915_gem_object *obj,
+		struct i915_request *rq,
+		bool write)
+{
+	if (obj->cache_dirty & ~obj->cache_coherent)
+		i915_gem_clflush_object(obj, 0);
+
+	return i915_request_await_object(rq, obj, write);
+}
+
 int i915_gem_object_fill_blt(struct drm_i915_gem_object *obj,
 			     struct intel_context *ce,
 			     u32 value)
@@ -143,12 +154,6 @@ int i915_gem_object_fill_blt(struct drm_i915_gem_object *obj,
 	if (unlikely(err))
 		return err;
 
-	if (obj->cache_dirty & ~obj->cache_coherent) {
-		i915_gem_object_lock(obj);
-		i915_gem_clflush_object(obj, 0);
-		i915_gem_object_unlock(obj);
-	}
-
 	batch = intel_emit_vma_fill_blt(ce, vma, value);
 	if (IS_ERR(batch)) {
 		err = PTR_ERR(batch);
@@ -165,27 +170,22 @@ int i915_gem_object_fill_blt(struct drm_i915_gem_object *obj,
 	if (unlikely(err))
 		goto out_request;
 
-	err = i915_request_await_object(rq, obj, true);
-	if (unlikely(err))
-		goto out_request;
-
-	if (ce->engine->emit_init_breadcrumb) {
-		err = ce->engine->emit_init_breadcrumb(rq);
-		if (unlikely(err))
-			goto out_request;
-	}
-
 	i915_vma_lock(vma);
-	err = i915_request_await_object(rq, vma->obj, true);
+	err = move_obj_to_gpu(vma->obj, rq, true);
 	if (err == 0)
 		err = i915_vma_move_to_active(vma, rq, EXEC_OBJECT_WRITE);
 	i915_vma_unlock(vma);
 	if (unlikely(err))
 		goto out_request;
 
-	err = ce->engine->emit_bb_start(rq,
-					batch->node.start, batch->node.size,
-					0);
+	if (ce->engine->emit_init_breadcrumb)
+		err = ce->engine->emit_init_breadcrumb(rq);
+
+	if (likely(!err))
+		err = ce->engine->emit_bb_start(rq,
+						batch->node.start,
+						batch->node.size,
+						0);
 out_request:
 	if (unlikely(err))
 		i915_request_set_error_once(rq, err);
@@ -317,16 +317,6 @@ struct i915_vma *intel_emit_vma_copy_blt(struct intel_context *ce,
 	return ERR_PTR(err);
 }
 
-static int move_to_gpu(struct i915_vma *vma, struct i915_request *rq, bool write)
-{
-	struct drm_i915_gem_object *obj = vma->obj;
-
-	if (obj->cache_dirty & ~obj->cache_coherent)
-		i915_gem_clflush_object(obj, 0);
-
-	return i915_request_await_object(rq, obj, write);
-}
-
 int i915_gem_object_copy_blt(struct drm_i915_gem_object *src,
 			     struct drm_i915_gem_object *dst,
 			     struct intel_context *ce)
@@ -375,7 +365,7 @@ int i915_gem_object_copy_blt(struct drm_i915_gem_object *src,
 		goto out_request;
 
 	for (i = 0; i < ARRAY_SIZE(vma); i++) {
-		err = move_to_gpu(vma[i], rq, i);
+		err = move_obj_to_gpu(vma[i]->obj, rq, i);
 		if (unlikely(err))
 			goto out_unlock;
 	}