[Intel-gfx] [PATCH] drm/i915: Broaden application of set-domain(GTT)

[Chris Wilson]

Previously, this was restricted to only operate on bound objects - to
make pointer access through the GTT to the object coherent with writes
to and from the GPU. A second usecase is drm_intel_bo_wait_rendering()
which at present does not function unless the object also happens to
be bound into the GGTT (on current systems that is becoming increasingly
rare, especially for the typical requests from mesa). A third usecase is
a future patch wishing to extend the coverage of the GTT domain to
include objects not bound into the GGTT but still in its coherent cache
domain. For the latter pair of requests, we need to operate on the
object regardless of its bind state.

Cc: Akash Goel <akash.goel at intel.com>
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index a2251d9dc134..cee6fdfe8e05 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1506,18 +1506,10 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data,
 	if (ret)
 		goto unref;
 
-	if (read_domains & I915_GEM_DOMAIN_GTT) {
+	if (read_domains & I915_GEM_DOMAIN_GTT)
 		ret = i915_gem_object_set_to_gtt_domain(obj, write_domain != 0);
-
-		/* Silently promote "you're not bound, there was nothing to do"
-		 * to success, since the client was just asking us to
-		 * make sure everything was done.
-		 */
-		if (ret == -EINVAL)
-			ret = 0;
-	} else {
+	else
 		ret = i915_gem_object_set_to_cpu_domain(obj, write_domain != 0);
-	}
 
 unref:
 	drm_gem_object_unreference(&obj->base);
@@ -3474,14 +3466,10 @@ i915_gem_object_flush_cpu_write_domain(struct drm_i915_gem_object *obj,
 int
 i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
 {
-	struct i915_vma *vma = i915_gem_obj_to_ggtt(obj);
 	uint32_t old_write_domain, old_read_domains;
+	struct i915_vma *vma;
 	int ret;
 
-	/* Not valid to be called on unbound objects. */
-	if (vma == NULL)
-		return -EINVAL;
-
 	if (obj->base.write_domain == I915_GEM_DOMAIN_GTT)
 		return 0;
 
@@ -3518,7 +3506,10 @@ i915_gem_object_set_to_gtt_domain(struct drm_i915_gem_object *obj, bool write)
 					    old_write_domain);
 
 	/* And bump the LRU for this access */
-	if (i915_gem_object_is_inactive(obj))
+	vma = i915_gem_obj_to_ggtt(obj);
+	if (vma &&
+	    drm_mm_node_allocated(&vma->node) &&
+	    i915_gem_object_is_inactive(obj))
 		list_move_tail(&vma->mm_list,
 			       &to_i915(obj->base.dev)->gtt.base.inactive_list);
 
-- 
2.1.1