From 24dc64c1ba5c3ef0463d59fef6df09336754188d Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Wed, 26 Sep 2018 15:57:46 +0200 Subject: [PATCH] drm/ttm: Export ttm_bo_get_unless_zero() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Export ttm_bo_get_unless_zero() to be used when looking up buffer objects that are removed from the lookup structure in the destructor. Signed-off-by: Thomas Hellstrom Reviewed-by: Sinclair Yeh Reviewed-by: Christian König --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 3 +-- include/drm/ttm/ttm_bo_api.h | 18 ++++++++++++++++++ 2 files changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 6fe91c1b692d..a1d977fbade5 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -409,8 +409,7 @@ static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev, node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages); if (likely(node)) { bo = container_of(node, struct ttm_buffer_object, vma_node); - if (!kref_get_unless_zero(&bo->kref)) - bo = NULL; + bo = ttm_bo_get_unless_zero(bo); } drm_vma_offset_unlock_lookup(&bdev->vma_manager); diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 8c19470785e2..3fc4854dce49 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -312,6 +312,24 @@ ttm_bo_reference(struct ttm_buffer_object *bo) return bo; } +/** + * ttm_bo_get_unless_zero - reference a struct ttm_buffer_object unless + * its refcount has already reached zero. + * @bo: The buffer object. + * + * Used to reference a TTM buffer object in lookups where the object is removed + * from the lookup structure during the destructor and for RCU lookups. + * + * Returns: @bo if the referencing was successful, NULL otherwise. + */ +static inline __must_check struct ttm_buffer_object * +ttm_bo_get_unless_zero(struct ttm_buffer_object *bo) +{ + if (!kref_get_unless_zero(&bo->kref)) + return NULL; + return bo; +} + /** * ttm_bo_wait - wait for buffer idle. * -- 2.30.2