drm/ttm: use ffs in ttm_mem_type_from_place

A bit pointless to search for the first bit set manually.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index c2a30bd..fc6217d 100644 (file)
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -57,14 +57,14 @@ static struct attribute ttm_bo_count = {
 static inline int ttm_mem_type_from_place(const struct ttm_place *place,
                                          uint32_t *mem_type)
 {
-       int i;
+       int pos;
 
-       for (i = 0; i <= TTM_PL_PRIV5; i++)
-               if (place->flags & (1 << i)) {
-                       *mem_type = i;
-                       return 0;
-               }
-       return -EINVAL;
+       pos = ffs(place->flags & TTM_PL_MASK_MEM);
+       if (unlikely(!pos))
+               return -EINVAL;
+
+       *mem_type = pos - 1;
+       return 0;
 }
 
 static void ttm_mem_type_debug(struct ttm_bo_device *bdev, int mem_type)