[PATCH 1/4] drm/ttm: use ffs in ttm_mem_type_from_place

Christian König deathsimple at vodafone.de
Mon Sep 12 11:46:41 UTC 2016


From: Christian König <christian.koenig at amd.com>

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

Signed-off-by: Christian König <christian.koenig at amd.com>
---
 drivers/gpu/drm/ttm/ttm_bo.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index bc37f02..531cc97 100644
--- 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)
-- 
2.5.0



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