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authorXiubo Li <lixiubo@cmss.chinamobile.com>2016-01-04 13:00:35 +0300
committerMark Brown <broonie@kernel.org>2016-02-19 19:12:32 +0300
commitce11020f0e82dbb18eb59b6f6ce92cc0410b353e (patch)
treefd4032d2861d5d06187419cb156cdcb5c47a577b /drivers/base
parent8b31ec5572f812acac36f3d02944ade76a8f51b9 (diff)
downloadlinux-ce11020f0e82dbb18eb59b6f6ce92cc0410b353e.tar.xz
regcache: flat: Introduce register strider order
Here we introduce regcache_flat_get_index(), which using register stride order and bit rotation, will save some memory spaces for flat cache. Though this will also lost some access performance, since the bit rotation is used to get the index of the cache array, and this could be ingored for memory I/O accessing. Signed-off-by: Xiubo Li <lixiubo@cmss.chinamobile.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/regmap/regcache-flat.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/base/regmap/regcache-flat.c b/drivers/base/regmap/regcache-flat.c
index 686c9e0b930e..3ee72550b1e3 100644
--- a/drivers/base/regmap/regcache-flat.c
+++ b/drivers/base/regmap/regcache-flat.c
@@ -16,20 +16,30 @@
#include "internal.h"
+static inline unsigned int regcache_flat_get_index(const struct regmap *map,
+ unsigned int reg)
+{
+ return regcache_get_index_by_order(map, reg);
+}
+
static int regcache_flat_init(struct regmap *map)
{
int i;
unsigned int *cache;
- map->cache = kcalloc(map->max_register + 1, sizeof(unsigned int),
- GFP_KERNEL);
+ if (!map || map->reg_stride_order < 0)
+ return -EINVAL;
+
+ map->cache = kcalloc(regcache_flat_get_index(map, map->max_register)
+ + 1, sizeof(unsigned int), GFP_KERNEL);
if (!map->cache)
return -ENOMEM;
cache = map->cache;
for (i = 0; i < map->num_reg_defaults; i++)
- cache[map->reg_defaults[i].reg] = map->reg_defaults[i].def;
+ cache[regcache_flat_get_index(map, map->reg_defaults[i].reg)] =
+ map->reg_defaults[i].def;
return 0;
}
@@ -47,7 +57,7 @@ static int regcache_flat_read(struct regmap *map,
{
unsigned int *cache = map->cache;
- *value = cache[reg];
+ *value = cache[regcache_flat_get_index(map, reg)];
return 0;
}
@@ -57,7 +67,7 @@ static int regcache_flat_write(struct regmap *map, unsigned int reg,
{
unsigned int *cache = map->cache;
- cache[reg] = value;
+ cache[regcache_flat_get_index(map, reg)] = value;
return 0;
}