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ASoC: soc-cache: Cache a pointer to the last accessed rbnode

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Whenever we are doing a read or a write through the rbtree code, we'll
cache a pointer to the rbnode.  To avoid looking up the register
everytime we do a read or a write, we first check if it can be found in
the cached register block, otherwise we traverse the rbtree and finally
cache the rbnode for future use.

Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
This commit is contained in:
Dimitris Papastamos 2011-05-19 13:45:30 +01:00 committed by Mark Brown
parent 0944cc392e
commit 7e146b5586
1 changed files with 37 additions and 0 deletions
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37
sound/soc/soc-cache.c
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@ -604,6 +604,7 @@ struct snd_soc_rbtree_node {
struct snd_soc_rbtree_ctx {
struct rb_root root;
struct snd_soc_rbtree_node *cached_rbnode;
};
static inline void snd_soc_rbtree_get_base_top_reg(
@ -780,11 +781,28 @@ static int snd_soc_rbtree_cache_write(struct snd_soc_codec *codec,
struct rb_node *node;
unsigned int val;
unsigned int reg_tmp;
unsigned int base_reg, top_reg;
unsigned int pos;
int i;
int ret;
rbtree_ctx = codec->reg_cache;
/* look up the required register in the cached rbnode */
rbnode = rbtree_ctx->cached_rbnode;
if (rbnode) {
snd_soc_rbtree_get_base_top_reg(rbnode, &base_reg, &top_reg);
if (reg >= base_reg && reg <= top_reg) {
reg_tmp = reg - base_reg;
val = snd_soc_rbtree_get_register(rbnode, reg_tmp);
if (val == value)
return 0;
snd_soc_rbtree_set_register(rbnode, reg_tmp, value);
return 0;
}
}
/* if we can't locate it in the cached rbnode we'll have
* to traverse the rbtree looking for it.
*/
rbnode = snd_soc_rbtree_lookup(&rbtree_ctx->root, reg);
if (rbnode) {
reg_tmp = reg - rbnode->base_reg;
@ -792,6 +810,7 @@ static int snd_soc_rbtree_cache_write(struct snd_soc_codec *codec,
if (val == value)
return 0;
snd_soc_rbtree_set_register(rbnode, reg_tmp, value);
rbtree_ctx->cached_rbnode = rbnode;
} else {
/* bail out early, no need to create the rbnode yet */
if (!value)
@ -813,6 +832,7 @@ static int snd_soc_rbtree_cache_write(struct snd_soc_codec *codec,
reg, value);
if (ret)
return ret;
rbtree_ctx->cached_rbnode = rbnode_tmp;
return 0;
}
}
@ -835,6 +855,7 @@ static int snd_soc_rbtree_cache_write(struct snd_soc_codec *codec,
}
snd_soc_rbtree_set_register(rbnode, 0, value);
snd_soc_rbtree_insert(&rbtree_ctx->root, rbnode);
rbtree_ctx->cached_rbnode = rbnode;
}
return 0;
@ -845,13 +866,28 @@ static int snd_soc_rbtree_cache_read(struct snd_soc_codec *codec,
{
struct snd_soc_rbtree_ctx *rbtree_ctx;
struct snd_soc_rbtree_node *rbnode;
unsigned int base_reg, top_reg;
unsigned int reg_tmp;
rbtree_ctx = codec->reg_cache;
/* look up the required register in the cached rbnode */
rbnode = rbtree_ctx->cached_rbnode;
if (rbnode) {
snd_soc_rbtree_get_base_top_reg(rbnode, &base_reg, &top_reg);
if (reg >= base_reg && reg <= top_reg) {
reg_tmp = reg - base_reg;
*value = snd_soc_rbtree_get_register(rbnode, reg_tmp);
return 0;
}
}
/* if we can't locate it in the cached rbnode we'll have
* to traverse the rbtree looking for it.
*/
rbnode = snd_soc_rbtree_lookup(&rbtree_ctx->root, reg);
if (rbnode) {
reg_tmp = reg - rbnode->base_reg;
*value = snd_soc_rbtree_get_register(rbnode, reg_tmp);
rbtree_ctx->cached_rbnode = rbnode;
} else {
/* uninitialized registers default to 0 */
*value = 0;
@ -902,6 +938,7 @@ static int snd_soc_rbtree_cache_init(struct snd_soc_codec *codec)
rbtree_ctx = codec->reg_cache;
rbtree_ctx->root = RB_ROOT;
rbtree_ctx->cached_rbnode = NULL;
if (!codec->reg_def_copy)
return 0;