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.brezillon@xxxxxxxxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> Cc: Emil Velikov <emil.l.velikov@xxxxxxxxx> Cc: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx> --- 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
