[Intel-gfx] [PATCH 2/2] drm/i915: Drop i915_gem_obj_is_pinned() from set-cache-level

[Chris Wilson]

Since the remove of the pin-ioctl, we only care about not changing the
cache level on buffers pinned to the hardware as indicated by
obj->pin_display. So we can safely replace i915_gem_object_is_pinned()
here with a plain obj->pin_display check. During rebinding, we will check
sanity checks in case vma->pin_count is erroneously set.

At the same time, we can micro-optimise GTT mmap() behaviour since we
only need to relinquish the mmaps before Sandybridge.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_gem.c | 40 ++++++++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index d4a3bdf0c5b6..2b8ed7a2faab 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3629,31 +3629,34 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
 {
 	struct drm_device *dev = obj->base.dev;
 	struct i915_vma *vma, *next;
+	bool bound = false;
 	int ret = 0;
 
 	if (obj->cache_level == cache_level)
 		goto out;
 
-	if (i915_gem_obj_is_pinned(obj)) {
-		DRM_DEBUG("can not change the cache level of pinned objects\n");
-		return -EBUSY;
-	}
-
 	list_for_each_entry_safe(vma, next, &obj->vma_list, vma_link) {
+		if (!drm_mm_node_allocated(&vma->node))
+			continue;
+
+		if (vma->pin_count) {
+			DRM_DEBUG("can not change the cache level of pinned objects\n");
+			return -EBUSY;
+		}
+
 		if (!i915_gem_valid_gtt_space(vma, cache_level)) {
 			ret = i915_vma_unbind(vma);
 			if (ret)
 				return ret;
-		}
+		} else
+			bound = true;
 	}
 
-	if (i915_gem_obj_bound_any(obj)) {
+	if (bound) {
 		ret = i915_gem_object_wait_rendering(obj, false);
 		if (ret)
 			return ret;
 
-		i915_gem_object_finish_gtt(obj);
-
 		/* Before SandyBridge, you could not use tiling or fence
 		 * registers with snooped memory, so relinquish any fences
 		 * currently pointing to our region in the aperture.
@@ -3664,13 +3667,18 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
 				return ret;
 		}
 
-		list_for_each_entry(vma, &obj->vma_list, vma_link)
-			if (drm_mm_node_allocated(&vma->node)) {
-				ret = i915_vma_bind(vma, cache_level,
-						    PIN_UPDATE);
-				if (ret)
-					return ret;
-			}
+		/* Access to snoopable pages through the GTT is incoherent. */
+		if (cache_level != I915_CACHE_NONE && !HAS_LLC(dev))
+			i915_gem_release_mmap(obj);
+
+		list_for_each_entry(vma, &obj->vma_list, vma_link) {
+			if (!drm_mm_node_allocated(&vma->node))
+				continue;
+
+			ret = i915_vma_bind(vma, cache_level, PIN_UPDATE);
+			if (ret)
+				return ret;
+		}
 	}
 
 	list_for_each_entry(vma, &obj->vma_list, vma_link)
-- 
2.6.0