Add alignment to all aperture allocation requests.

When pinning buffers, or using execbuffer, allow the application to specify
the necessary aperture allocation alignment constraints.

2 files changed, 21 insertions, 10 deletions

diff --git a/linux-core/i915_gem.c b/linux-core/i915_gem.c
index 335f0618..30e67742 100644
--- a/linux-core/i915_gem.c
+++ b/linux-core/i915_gem.c
@@ -96,21 +96,26 @@ i915_gem_object_unbind(struct drm_device *dev, struct drm_gem_object *obj)
  * Finds free space in the GTT aperture and binds the object there.
  */
 static int
-i915_gem_object_bind_to_gtt(struct drm_device *dev, struct drm_gem_object *obj)
+i915_gem_object_bind_to_gtt(struct drm_device *dev, struct drm_gem_object *obj, unsigned alignment)
 {
 	drm_i915_private_t *dev_priv = dev->dev_private;
 	struct drm_i915_gem_object *obj_priv = obj->driver_private;
 	struct drm_memrange_node *free_space;
 	int page_count, i;
 
+	if (alignment == 0)
+		alignment = PAGE_SIZE;
+	if (alignment & (PAGE_SIZE - 1))
+		return -EINVAL;
+
 	free_space = drm_memrange_search_free(&dev_priv->mm.gtt_space,
 					      obj->size,
-					      PAGE_SIZE, 0);
+					      alignment, 0);
 	if (free_space == NULL)
 		return -ENOMEM;
 	obj_priv->gtt_space = drm_memrange_get_block(free_space,
 						     obj->size,
-						     PAGE_SIZE);
+						     alignment);
 	if (obj_priv->gtt_space == NULL)
 		return -ENOMEM;
 
@@ -173,7 +178,7 @@ i915_gem_reloc_and_validate_object(struct drm_device *dev,
 
 	/* Choose the GTT offset for our buffer and put it there. */
 	if (obj_priv->gtt_space == NULL) {
-		i915_gem_object_bind_to_gtt(dev, obj);
+		i915_gem_object_bind_to_gtt(dev, obj, (unsigned) entry->alignment);
 		if (obj_priv->gtt_space == NULL)
 			return -ENOMEM;
 	}
@@ -367,7 +372,7 @@ i915_gem_pin_ioctl(struct drm_device *dev, void *data,
 		return -EINVAL;
 	}
 
-	ret = i915_gem_object_bind_to_gtt(dev, obj);
+	ret = i915_gem_object_bind_to_gtt(dev, obj, (unsigned) args->alignment);
 	if (ret != 0) {
 		DRM_ERROR("Failure to bind in i915_gem_pin_ioctl(): %d\n",
 			  ret);
diff --git a/shared-core/i915_drm.h b/shared-core/i915_drm.h
index 91461c41..0c64e866 100644
--- a/shared-core/i915_drm.h
+++ b/shared-core/i915_drm.h
@@ -451,15 +451,18 @@ struct drm_i915_gem_validate_entry {
 	 * operation.
 	 */
 	uint32_t buffer_handle;
+	
+	/** List of relocations to be performed on this buffer */
+	uint32_t relocation_count;
+	uint64_t relocs_ptr;	/* struct drm_i915_gem_relocation_entry *relocs */
+	
+	/** Required alignment in graphics aperture */
+	uint64_t alignment;
 	/**
 	 * Returned value of the updated offset of the buffer, for future
 	 * presumed_offset writes.
 	 */
-	uint32_t buffer_offset;
-	/** List of relocations to be performed on this buffer */
-	uint64_t relocs_ptr;	/* struct drm_i915_gem_relocation_entry *relocs */
-	uint32_t relocation_count;
-	uint32_t pad;
+	uint64_t buffer_offset;
 };
 
 struct drm_i915_gem_execbuffer {
@@ -488,6 +491,9 @@ struct drm_i915_gem_pin {
 	/** Handle of the buffer to be pinned. */
 	uint32_t handle;
 	uint32_t pad;
+	
+	/** alignment required within the aperture */
+	uint64_t alignment;
 
 	/** Returned GTT offset of the buffer. */
 	uint64_t offset;