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Commit 75ef8b3b authored by Rob Clark's avatar Rob Clark Committed by Dave Airlie
Browse files

drm/gem: add functions for mmap offset creation 



Signed-off-by: default avatarRob Clark <rob@ti.com>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 302a8e8b

drivers/gpu/drm/drm_gem.c

+88 −0
Original line number Diff line number Diff line
@@ -285,6 +285,94 @@ drm_gem_handle_create(struct drm_file *file_priv, 
}

EXPORT_SYMBOL(drm_gem_handle_create);





/**

 * drm_gem_free_mmap_offset - release a fake mmap offset for an object

 * @obj: obj in question

 *

 * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().

 */

void

drm_gem_free_mmap_offset(struct drm_gem_object *obj)

{

	struct drm_device *dev = obj->dev;

	struct drm_gem_mm *mm = dev->mm_private;

	struct drm_map_list *list = &obj->map_list;



	drm_ht_remove_item(&mm->offset_hash, &list->hash);

	drm_mm_put_block(list->file_offset_node);

	kfree(list->map);

	list->map = NULL;

}

EXPORT_SYMBOL(drm_gem_free_mmap_offset);



/**

 * drm_gem_create_mmap_offset - create a fake mmap offset for an object

 * @obj: obj in question

 *

 * GEM memory mapping works by handing back to userspace a fake mmap offset

 * it can use in a subsequent mmap(2) call.  The DRM core code then looks

 * up the object based on the offset and sets up the various memory mapping

 * structures.

 *

 * This routine allocates and attaches a fake offset for @obj.

 */

int

drm_gem_create_mmap_offset(struct drm_gem_object *obj)

{

	struct drm_device *dev = obj->dev;

	struct drm_gem_mm *mm = dev->mm_private;

	struct drm_map_list *list;

	struct drm_local_map *map;

	int ret = 0;



	/* Set the object up for mmap'ing */

	list = &obj->map_list;

	list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL);

	if (!list->map)

		return -ENOMEM;



	map = list->map;

	map->type = _DRM_GEM;

	map->size = obj->size;

	map->handle = obj;



	/* Get a DRM GEM mmap offset allocated... */

	list->file_offset_node = drm_mm_search_free(&mm->offset_manager,

			obj->size / PAGE_SIZE, 0, 0);



	if (!list->file_offset_node) {

		DRM_ERROR("failed to allocate offset for bo %d\n", obj->name);

		ret = -ENOSPC;

		goto out_free_list;

	}



	list->file_offset_node = drm_mm_get_block(list->file_offset_node,

			obj->size / PAGE_SIZE, 0);

	if (!list->file_offset_node) {

		ret = -ENOMEM;

		goto out_free_list;

	}



	list->hash.key = list->file_offset_node->start;

	ret = drm_ht_insert_item(&mm->offset_hash, &list->hash);

	if (ret) {

		DRM_ERROR("failed to add to map hash\n");

		goto out_free_mm;

	}



	return 0;



out_free_mm:

	drm_mm_put_block(list->file_offset_node);

out_free_list:

	kfree(list->map);

	list->map = NULL;



	return ret;

}

EXPORT_SYMBOL(drm_gem_create_mmap_offset);



/** Returns a reference to the object named by the handle. */

struct drm_gem_object *

drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,

include/drm/drmP.h

+3 −0
Original line number Diff line number Diff line
@@ -1624,6 +1624,9 @@ drm_gem_object_handle_unreference_unlocked(struct drm_gem_object *obj) 
	drm_gem_object_unreference_unlocked(obj);

}



void drm_gem_free_mmap_offset(struct drm_gem_object *obj);

int drm_gem_create_mmap_offset(struct drm_gem_object *obj);



struct drm_gem_object *drm_gem_object_lookup(struct drm_device *dev,

					     struct drm_file *filp,

					     u32 handle);