Commit 0271cc48 authored by Dmitry Osipenko's avatar Dmitry Osipenko
Browse files

drm/shmem-helper: Switch drm_gem_shmem_vmap/vunmap to use pin/unpin 



The vmapped pages shall be pinned in memory and previously get/put_pages()
were implicitly hard-pinning/unpinning the pages. This will no longer be
the case with addition of memory shrinker because pages_use_count > 0 won't
determine anymore whether pages are hard-pinned (they will be soft-pinned),
while the new pages_pin_count will do the hard-pinning. Switch the
vmap/vunmap() to use pin/unpin() functions in a preparation of addition
of the memory shrinker support to drm-shmem.

Acked-by: default avatarMaxime Ripard <mripard@kernel.org>
Reviewed-by: default avatarBoris Brezillon <boris.brezillon@collabora.com>
Acked-by: default avatarThomas Zimmermann <tzimmermann@suse.d>
Signed-off-by: default avatarDmitry Osipenko <dmitry.osipenko@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250322212608.40511-10-dmitry.osipenko@collabora.com
parent 051b6646

drivers/gpu/drm/drm_gem_shmem_helper.c

+3 −3
Original line number Diff line number Diff line
@@ -360,7 +360,7 @@ int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem, 
			return 0;

		}



		ret = drm_gem_shmem_get_pages_locked(shmem);

		ret = drm_gem_shmem_pin_locked(shmem);

		if (ret)

			goto err_zero_use;
@@ -383,7 +383,7 @@ int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem, 


err_put_pages:

	if (!drm_gem_is_imported(obj))

		drm_gem_shmem_put_pages_locked(shmem);

		drm_gem_shmem_unpin_locked(shmem);

err_zero_use:

	shmem->vmap_use_count = 0;
@@ -420,7 +420,7 @@ void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem, 
			return;



		vunmap(shmem->vaddr);

		drm_gem_shmem_put_pages_locked(shmem);

		drm_gem_shmem_unpin_locked(shmem);

	}



	shmem->vaddr = NULL;

include/drm/drm_gem_shmem_helper.h

+1 −1
Original line number Diff line number Diff line
@@ -130,7 +130,7 @@ int drm_gem_shmem_madvise_locked(struct drm_gem_shmem_object *shmem, int madv); 
static inline bool drm_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem)

{

	return (shmem->madv > 0) &&

		!shmem->vmap_use_count && shmem->sgt &&

		!refcount_read(&shmem->pages_pin_count) && shmem->sgt &&

		!shmem->base.dma_buf && !drm_gem_is_imported(&shmem->base);

}