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Commit c117aa4d authored by Rob Herring's avatar Rob Herring
Browse files

drm: Add a drm_gem_objects_lookup helper 



Similar to the single handle drm_gem_object_lookup(),
drm_gem_objects_lookup() takes an array of handles and returns an array
of GEM objects.

v2:
- Take the userspace pointer directly and allocate the array.
- Expand the function documentation.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: Sean Paul <sean@poorly.run>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Acked-by: default avatarAlyssa Rosenzweig <alyssa@rosenzweig.io>
Acked-by: default avatarTomeu Vizoso <tomeu.vizoso@collabora.com>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190409205427.6943-3-robh@kernel.org
parent d08d42de

drivers/gpu/drm/drm_gem.c

+83 −10
Original line number Diff line number Diff line
@@ -646,6 +646,85 @@ void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages, 
}

EXPORT_SYMBOL(drm_gem_put_pages);



static int objects_lookup(struct drm_file *filp, u32 *handle, int count,

			  struct drm_gem_object **objs)

{

	int i, ret = 0;

	struct drm_gem_object *obj;



	spin_lock(&filp->table_lock);



	for (i = 0; i < count; i++) {

		/* Check if we currently have a reference on the object */

		obj = idr_find(&filp->object_idr, handle[i]);

		if (!obj) {

			ret = -ENOENT;

			break;

		}

		drm_gem_object_get(obj);

		objs[i] = obj;

	}

	spin_unlock(&filp->table_lock);



	return ret;

}



/**

 * drm_gem_objects_lookup - look up GEM objects from an array of handles

 * @filp: DRM file private date

 * @bo_handles: user pointer to array of userspace handle

 * @count: size of handle array

 * @objs_out: returned pointer to array of drm_gem_object pointers

 *

 * Takes an array of userspace handles and returns a newly allocated array of

 * GEM objects.

 *

 * For a single handle lookup, use drm_gem_object_lookup().

 *

 * Returns:

 *

 * @objs filled in with GEM object pointers. Returned GEM objects need to be

 * released with drm_gem_object_put(). -ENOENT is returned on a lookup

 * failure. 0 is returned on success.

 *

 */

int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,

			   int count, struct drm_gem_object ***objs_out)

{

	int ret;

	u32 *handles;

	struct drm_gem_object **objs;



	if (!count)

		return 0;



	objs = kvmalloc_array(count, sizeof(struct drm_gem_object *),

			     GFP_KERNEL | __GFP_ZERO);

	if (!objs)

		return -ENOMEM;



	handles = kvmalloc_array(count, sizeof(u32), GFP_KERNEL);

	if (!handles) {

		ret = -ENOMEM;

		goto out;

	}



	if (copy_from_user(handles, bo_handles, count * sizeof(u32))) {

		ret = -EFAULT;

		DRM_DEBUG("Failed to copy in GEM handles\n");

		goto out;

	}



	ret = objects_lookup(filp, handles, count, objs);

	*objs_out = objs;



out:

	kvfree(handles);

	return ret;



}

EXPORT_SYMBOL(drm_gem_objects_lookup);



/**

 * drm_gem_object_lookup - look up a GEM object from its handle

 * @filp: DRM file private date
@@ -655,21 +734,15 @@ EXPORT_SYMBOL(drm_gem_put_pages); 
 *

 * A reference to the object named by the handle if such exists on @filp, NULL

 * otherwise.

 *

 * If looking up an array of handles, use drm_gem_objects_lookup().

 */

struct drm_gem_object *

drm_gem_object_lookup(struct drm_file *filp, u32 handle)

{

	struct drm_gem_object *obj;



	spin_lock(&filp->table_lock);



	/* Check if we currently have a reference on the object */

	obj = idr_find(&filp->object_idr, handle);

	if (obj)

		drm_gem_object_get(obj);



	spin_unlock(&filp->table_lock);

	struct drm_gem_object *obj = NULL;



	objects_lookup(filp, &handle, 1, &obj);

	return obj;

}

EXPORT_SYMBOL(drm_gem_object_lookup);

include/drm/drm_gem.h

+2 −0
Original line number Diff line number Diff line
@@ -381,6 +381,8 @@ struct page **drm_gem_get_pages(struct drm_gem_object *obj); 
void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,

		bool dirty, bool accessed);



int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,

			   int count, struct drm_gem_object ***objs_out);

struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);

long drm_gem_reservation_object_wait(struct drm_file *filep, u32 handle,

				    bool wait_all, unsigned long timeout);