[PATCH v19 03/30] drm/gem: Document locking rule of vmap and evict callbacks

From: Dmitry Osipenko
Date: Fri Jan 05 2024 - 13:47:35 EST


The vmap/vunmap/evict GEM callbacks are always invoked with a held GEM's
reservation lock. Document this locking rule for clarity.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
---
include/drm/drm_gem.h | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index f835fdee6a5e..021f64371056 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -156,7 +156,8 @@ struct drm_gem_object_funcs {
* @vmap:
*
* Returns a virtual address for the buffer. Used by the
- * drm_gem_dmabuf_vmap() helper.
+ * drm_gem_dmabuf_vmap() helper. Called with a held GEM reservation
+ * lock.
*
* This callback is optional.
*/
@@ -166,7 +167,8 @@ struct drm_gem_object_funcs {
* @vunmap:
*
* Releases the address previously returned by @vmap. Used by the
- * drm_gem_dmabuf_vunmap() helper.
+ * drm_gem_dmabuf_vunmap() helper. Called with a held GEM reservation
+ * lock.
*
* This callback is optional.
*/
@@ -189,7 +191,8 @@ struct drm_gem_object_funcs {
* @evict:
*
* Evicts gem object out from memory. Used by the drm_gem_object_evict()
- * helper. Returns 0 on success, -errno otherwise.
+ * helper. Returns 0 on success, -errno otherwise. Called with a held
+ * GEM reservation lock.
*
* This callback is optional.
*/
--
2.43.0