regmap: core: Introduce register stride order
Since the register stride should always equal to 2^N, and bit rotation is
much faster than multiplication and division. So introducing the stride
order and using bit rotation to get the offset of the register from the
index to improve the performance.
Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index ee54e84..29d526e 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -19,6 +19,7 @@
#include <linux/rbtree.h>
#include <linux/sched.h>
#include <linux/delay.h>
+#include <linux/log2.h>
#define CREATE_TRACE_POINTS
#include "trace.h"
@@ -638,6 +639,10 @@
map->reg_stride = config->reg_stride;
else
map->reg_stride = 1;
+ if (is_power_of_2(map->reg_stride))
+ map->reg_stride_order = ilog2(map->reg_stride);
+ else
+ map->reg_stride_order = -1;
map->use_single_read = config->use_single_rw || !bus || !bus->read;
map->use_single_write = config->use_single_rw || !bus || !bus->write;
map->can_multi_write = config->can_multi_write && bus && bus->write;
@@ -1308,7 +1313,7 @@
if (map->writeable_reg)
for (i = 0; i < val_len / map->format.val_bytes; i++)
if (!map->writeable_reg(map->dev,
- reg + (i * map->reg_stride)))
+ reg + regmap_get_offset(map, i)))
return -EINVAL;
if (!map->cache_bypass && map->format.parse_val) {
@@ -1316,7 +1321,8 @@
int val_bytes = map->format.val_bytes;
for (i = 0; i < val_len / val_bytes; i++) {
ival = map->format.parse_val(val + (i * val_bytes));
- ret = regcache_write(map, reg + (i * map->reg_stride),
+ ret = regcache_write(map,
+ reg + regmap_get_offset(map, i),
ival);
if (ret) {
dev_err(map->dev,
@@ -1846,8 +1852,9 @@
goto out;
}
- ret = _regmap_write(map, reg + (i * map->reg_stride),
- ival);
+ ret = _regmap_write(map,
+ reg + regmap_get_offset(map, i),
+ ival);
if (ret != 0)
goto out;
}
@@ -2416,7 +2423,7 @@
* cost as we expect to hit the cache.
*/
for (i = 0; i < val_count; i++) {
- ret = _regmap_read(map, reg + (i * map->reg_stride),
+ ret = _regmap_read(map, reg + regmap_get_offset(map, i),
&v);
if (ret != 0)
goto out;
@@ -2568,7 +2575,7 @@
} else {
for (i = 0; i < val_count; i++) {
unsigned int ival;
- ret = regmap_read(map, reg + (i * map->reg_stride),
+ ret = regmap_read(map, reg + regmap_get_offset(map, i),
&ival);
if (ret != 0)
return ret;