linux-kernel - [PATCH] regmap: use IS_ALIGNED instead of % to improve the performance

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Message-Id: <1450259132-23850-1-git-send-email-lixiubo@cmss.chinamobile.com>
Date:	Wed, 16 Dec 2015 17:45:32 +0800
From:	Xiubo Li <lixiubo@...s.chinamobile.com>
To:	broonie@...nel.org
Cc:	gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org,
	Xiubo Li <lixiubo@...s.chinamobile.com>
Subject: [PATCH] regmap: use IS_ALIGNED instead of % to improve the performance

The stride value should always equal to 2^n, so we can use bit
rotation instead of % to improve the performance.

Signed-off-by: Xiubo Li <lixiubo@...s.chinamobile.com>
---
 drivers/base/regmap/regmap.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index d27fe2f..ee54e84 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1607,7 +1607,7 @@ int regmap_write(struct regmap *map, unsigned int reg, unsigned int val)
 {
 	int ret;
 
-	if (reg % map->reg_stride)
+	if (!IS_ALIGNED(reg, map->reg_stride))
 		return -EINVAL;
 
 	map->lock(map->lock_arg);
@@ -1634,7 +1634,7 @@ int regmap_write_async(struct regmap *map, unsigned int reg, unsigned int val)
 {
 	int ret;
 
-	if (reg % map->reg_stride)
+	if (!IS_ALIGNED(reg, map->reg_stride))
 		return -EINVAL;
 
 	map->lock(map->lock_arg);
@@ -1808,7 +1808,7 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val,
 
 	if (map->bus && !map->format.parse_inplace)
 		return -EINVAL;
-	if (reg % map->reg_stride)
+	if (!IS_ALIGNED(reg, map->reg_stride))
 		return -EINVAL;
 
 	/*
@@ -2077,7 +2077,7 @@ static int _regmap_multi_reg_write(struct regmap *map,
 			int reg = regs[i].reg;
 			if (!map->writeable_reg(map->dev, reg))
 				return -EINVAL;
-			if (reg % map->reg_stride)
+			if (!IS_ALIGNED(reg, map->reg_stride))
 				return -EINVAL;
 		}
 
@@ -2227,7 +2227,7 @@ int regmap_raw_write_async(struct regmap *map, unsigned int reg,
 
 	if (val_len % map->format.val_bytes)
 		return -EINVAL;
-	if (reg % map->reg_stride)
+	if (!IS_ALIGNED(reg, map->reg_stride))
 		return -EINVAL;
 
 	map->lock(map->lock_arg);
@@ -2354,7 +2354,7 @@ int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val)
 {
 	int ret;
 
-	if (reg % map->reg_stride)
+	if (!IS_ALIGNED(reg, map->reg_stride))
 		return -EINVAL;
 
 	map->lock(map->lock_arg);
@@ -2390,7 +2390,7 @@ int regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
 		return -EINVAL;
 	if (val_len % map->format.val_bytes)
 		return -EINVAL;
-	if (reg % map->reg_stride)
+	if (!IS_ALIGNED(reg, map->reg_stride))
 		return -EINVAL;
 	if (val_count == 0)
 		return -EINVAL;
@@ -2508,7 +2508,7 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 	size_t val_bytes = map->format.val_bytes;
 	bool vol = regmap_volatile_range(map, reg, val_count);
 
-	if (reg % map->reg_stride)
+	if (!IS_ALIGNED(reg, map->reg_stride))
 		return -EINVAL;
 
 	if (map->bus && map->format.parse_inplace && (vol || map->cache_type == REGCACHE_NONE)) {
-- 
1.8.3.1



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