Commit 122020af authored by Chris Wilson's avatar Chris Wilson Committed by Daniel Vetter
Browse files

dma-buf: Provide wrappers for reservation's lock 



Joonas complained that writing ww_mutex_lock(&resv->lock, ctx) was too
intrusive compared to reservation_object_lock(resv, ctx);

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: default avatarAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20161115154642.31850-1-chris@chris-wilson.co.uk
parent 7da0e124

include/linux/reservation.h

+34 −0
Original line number Diff line number Diff line
@@ -144,6 +144,40 @@ reservation_object_get_list(struct reservation_object *obj) 
					 reservation_object_held(obj));

}



/**

 * reservation_object_lock - lock the reservation object

 * @obj: the reservation object

 * @ctx: the locking context

 *

 * Locks the reservation object for exclusive access and modification. Note,

 * that the lock is only against other writers, readers will run concurrently

 * with a writer under RCU. The seqlock is used to notify readers if they

 * overlap with a writer.

 *

 * As the reservation object may be locked by multiple parties in an

 * undefined order, a #ww_acquire_ctx is passed to unwind if a cycle

 * is detected. See ww_mutex_lock() and ww_acquire_init(). A reservation

 * object may be locked by itself by passing NULL as @ctx.

 */

static inline int

reservation_object_lock(struct reservation_object *obj,

			struct ww_acquire_ctx *ctx)

{

	return ww_mutex_lock(&obj->lock, ctx);

}



/**

 * reservation_object_unlock - unlock the reservation object

 * @obj: the reservation object

 *

 * Unlocks the reservation object following exclusive access.

 */

static inline void

reservation_object_unlock(struct reservation_object *obj)

{

	ww_mutex_unlock(&obj->lock);

}



/**

 * reservation_object_get_excl - get the reservation object's

 * exclusive fence, with update-side lock held