Drivers are not supposed to call these functions directly when they
want to map/unamp a GEM in kernel space. They should instead go
through drm_gem_v[un]map[_unlocked]() that will forward the request
to drm_gem_object_funcs::v[un]map() which in turn will call
drm_gem_shmem_v[un]map().
Let's clarify that in the functions doc.
Signed-off-by: Boris Brezillon <boris.brezil...@collabora.com>
Cc: Daniel Vetter <dan...@ffwll.ch>
Cc: Thomas Zimmermann <tzimmerm...@suse.de>
Cc: Emil Velikov <emil.l.veli...@gmail.com>
Cc: Dmitry Osipenko <dmitry.osipe...@collabora.com>
---
drivers/gpu/drm/drm_gem_shmem_helper.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c
b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 2b8a32f6b656..daada172fe70 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -279,6 +279,11 @@ EXPORT_SYMBOL(drm_gem_shmem_unpin);
*
* Acquired mappings should be cleaned up by calling drm_gem_shmem_vunmap().
*
+ * This function is not meant to be used directly, but rather used as a helper
+ * to implement driver-specific versions of drm_gem_object_funcs::vmap(). If
+ * you need to vmap() a GEM object from your driver, use
+ * drm_gem_vmap[_unlocked]() instead.
+ *
* Returns:
* 0 on success or a negative error code on failure.
*/
@@ -348,6 +353,11 @@ EXPORT_SYMBOL(drm_gem_shmem_vmap);
*
* This function hides the differences between dma-buf imported and natively
* allocated objects.
+ *
+ * This function is not meant to be used directly, but rather used as a helper
+ * to implement driver-specific versions of drm_gem_object_funcs::vunmap(). If
+ * you need to vunmap() a GEM object from your driver, use
+ * drm_gem_vunmap[_unlocked]() instead.
*/
void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
struct iosys_map *map)
--
2.41.0
