drm/i915: Skip the sanity checks if the current relocation is valid

If the presumed_offset as feed to userspace and returned to the kernel
from a previous execbuffer is still valid, then we do not need to rewrite
the relocation entry and may skip the offset sanity checks.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index c60ca32..dea9ac0 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3128,6 +3128,21 @@ i915_gem_object_pin_and_relocate(struct drm_gem_object *obj,
                }
                target_obj_priv = target_obj->driver_private;
 
+#if WATCH_RELOC
+               DRM_INFO("%s: obj %p offset %08x target %d "
+                        "read %08x write %08x gtt %08x "
+                        "presumed %08x delta %08x\n",
+                        __func__,
+                        obj,
+                        (int) reloc->offset,
+                        (int) reloc->target_handle,
+                        (int) reloc->read_domains,
+                        (int) reloc->write_domain,
+                        (int) target_obj_priv->gtt_offset,
+                        (int) reloc->presumed_offset,
+                        reloc->delta);
+#endif
+
                /* The target buffer should have appeared before us in the
                 * exec_object list, so it should have a GTT space bound by now.
                 */
@@ -3139,35 +3154,7 @@ i915_gem_object_pin_and_relocate(struct drm_gem_object *obj,
                        return -EINVAL;
                }
 
-               if (reloc->offset > obj->size - 4) {
-                       DRM_ERROR("Relocation beyond object bounds: "
-                                 "obj %p target %d offset %d size %d.\n",
-                                 obj, reloc->target_handle,
-                                 (int) reloc->offset, (int) obj->size);
-                       drm_gem_object_unreference(target_obj);
-                       i915_gem_object_unpin(obj);
-                       return -EINVAL;
-               }
-               if (reloc->offset & 3) {
-                       DRM_ERROR("Relocation not 4-byte aligned: "
-                                 "obj %p target %d offset %d.\n",
-                                 obj, reloc->target_handle,
-                                 (int) reloc->offset);
-                       drm_gem_object_unreference(target_obj);
-                       i915_gem_object_unpin(obj);
-                       return -EINVAL;
-               }
-
-               if (reloc->delta >= target_obj->size) {
-                       DRM_ERROR("Relocation beyond target object bounds: "
-                                 "obj %p target %d delta %d size %d.\n",
-                                 obj, reloc->target_handle,
-                                 (int) reloc->delta, (int) target_obj->size);
-                       drm_gem_object_unreference(target_obj);
-                       i915_gem_object_unpin(obj);
-                       return -EINVAL;
-               }
-
+               /* Validate that the target is in a valid r/w GPU domain */
                if (reloc->write_domain & I915_GEM_DOMAIN_CPU ||
                    reloc->read_domains & I915_GEM_DOMAIN_CPU) {
                        DRM_ERROR("reloc with read/write CPU domains: "
@@ -3181,7 +3168,6 @@ i915_gem_object_pin_and_relocate(struct drm_gem_object *obj,
                        i915_gem_object_unpin(obj);
                        return -EINVAL;
                }
-
                if (reloc->write_domain && target_obj->pending_write_domain &&
                    reloc->write_domain != target_obj->pending_write_domain) {
                        DRM_ERROR("Write domain conflict: "
@@ -3196,21 +3182,6 @@ i915_gem_object_pin_and_relocate(struct drm_gem_object *obj,
                        return -EINVAL;
                }
 
-#if WATCH_RELOC
-               DRM_INFO("%s: obj %p offset %08x target %d "
-                        "read %08x write %08x gtt %08x "
-                        "presumed %08x delta %08x\n",
-                        __func__,
-                        obj,
-                        (int) reloc->offset,
-                        (int) reloc->target_handle,
-                        (int) reloc->read_domains,
-                        (int) reloc->write_domain,
-                        (int) target_obj_priv->gtt_offset,
-                        (int) reloc->presumed_offset,
-                        reloc->delta);
-#endif
-
                target_obj->pending_read_domains |= reloc->read_domains;
                target_obj->pending_write_domain |= reloc->write_domain;
 
@@ -3222,6 +3193,37 @@ i915_gem_object_pin_and_relocate(struct drm_gem_object *obj,
                        continue;
                }
 
+               /* Check that the relocation address is valid... */
+               if (reloc->offset > obj->size - 4) {
+                       DRM_ERROR("Relocation beyond object bounds: "
+                                 "obj %p target %d offset %d size %d.\n",
+                                 obj, reloc->target_handle,
+                                 (int) reloc->offset, (int) obj->size);
+                       drm_gem_object_unreference(target_obj);
+                       i915_gem_object_unpin(obj);
+                       return -EINVAL;
+               }
+               if (reloc->offset & 3) {
+                       DRM_ERROR("Relocation not 4-byte aligned: "
+                                 "obj %p target %d offset %d.\n",
+                                 obj, reloc->target_handle,
+                                 (int) reloc->offset);
+                       drm_gem_object_unreference(target_obj);
+                       i915_gem_object_unpin(obj);
+                       return -EINVAL;
+               }
+
+               /* and points to somewhere within the target object. */
+               if (reloc->delta >= target_obj->size) {
+                       DRM_ERROR("Relocation beyond target object bounds: "
+                                 "obj %p target %d delta %d size %d.\n",
+                                 obj, reloc->target_handle,
+                                 (int) reloc->delta, (int) target_obj->size);
+                       drm_gem_object_unreference(target_obj);
+                       i915_gem_object_unpin(obj);
+                       return -EINVAL;
+               }
+
                ret = i915_gem_object_set_to_gtt_domain(obj, 1);
                if (ret != 0) {
                        drm_gem_object_unreference(target_obj);