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 --- sound/soc/soc-cache.c | 37 +++++++++++++++++++++++++++++++++++++ 1 files changed, 37 insertions(+), 0 deletions(-)
diff --git a/sound/soc/soc-cache.c b/sound/soc/soc-cache.c index b72f591..73656f6 100644 --- a/sound/soc/soc-cache.c +++ b/sound/soc/soc-cache.c @@ -492,6 +492,7 @@ 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( @@ -668,11 +669,28 @@ 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; @@ -680,6 +698,7 @@ 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) @@ -701,6 +720,7 @@ 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; } } @@ -723,6 +743,7 @@ 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; @@ -733,13 +754,28 @@ 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; @@ -790,6 +826,7 @@ 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;