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authorMark Brown <broonie@opensource.wolfsonmicro.com>2012-12-11 01:24:29 +0900
committerMark Brown <broonie@opensource.wolfsonmicro.com>2012-12-11 01:29:47 +0900
commit5166b7c006eeb4f6becc0822974d8da259484ba1 (patch)
treeb28c4098a5b75a34efd8262efcc99fdf8d586365 /drivers/base
parentafab2f7b21b042bcbffb1e82f78243382a122d70 (diff)
downloadlinux-5166b7c006eeb4f6becc0822974d8da259484ba1.tar.bz2
regmap: debugfs: Cache offsets of valid regions for dump
Avoid doing a linear scan of the entire register map for each read() of the debugfs register dump by recording the offsets where valid registers exist when we first read the registers file. This assumes the set of valid registers never changes, if this is not the case invalidation of the cache will be required. This could be further improved for large blocks of contiguous registers by calculating the register we will read from within the block - currently we do a linear scan of the block. An rbtree may also be worthwhile. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/regmap/internal.h10
-rw-r--r--drivers/base/regmap/regmap-debugfs.c67
2 files changed, 63 insertions, 14 deletions
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 1abcd27e2d0f..9c3b0e7a6c7d 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -15,10 +15,18 @@
#include <linux/regmap.h>
#include <linux/fs.h>
+#include <linux/list.h>
struct regmap;
struct regcache_ops;
+struct regmap_debugfs_off_cache {
+ struct list_head list;
+ off_t min;
+ off_t max;
+ unsigned int base_reg;
+};
+
struct regmap_format {
size_t buf_size;
size_t reg_bytes;
@@ -54,6 +62,8 @@ struct regmap {
unsigned int debugfs_reg_len;
unsigned int debugfs_val_len;
unsigned int debugfs_tot_len;
+
+ struct list_head debugfs_off_cache;
#endif
unsigned int max_register;
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index 749a1dc5bbfb..07aad786f817 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -65,25 +65,53 @@ static unsigned int regmap_debugfs_get_dump_start(struct regmap *map,
loff_t from,
loff_t *pos)
{
- loff_t p = *pos;
- unsigned int i;
-
- for (i = base; i <= map->max_register; i += map->reg_stride) {
- if (!regmap_readable(map, i))
- continue;
-
- if (regmap_precious(map, i))
- continue;
+ struct regmap_debugfs_off_cache *c = NULL;
+ loff_t p = 0;
+ unsigned int i, ret;
+
+ /*
+ * If we don't have a cache build one so we don't have to do a
+ * linear scan each time.
+ */
+ if (list_empty(&map->debugfs_off_cache)) {
+ for (i = base; i <= map->max_register; i += map->reg_stride) {
+ /* Skip unprinted registers, closing off cache entry */
+ if (!regmap_readable(map, i) ||
+ regmap_precious(map, i)) {
+ if (c) {
+ c->max = p - 1;
+ list_add_tail(&c->list,
+ &map->debugfs_off_cache);
+ c = NULL;
+ }
+
+ continue;
+ }
+
+ /* No cache entry? Start a new one */
+ if (!c) {
+ c = kzalloc(sizeof(*c), GFP_KERNEL);
+ if (!c)
+ break;
+ c->min = p;
+ c->base_reg = i;
+ }
+
+ p += map->debugfs_tot_len;
+ }
+ }
- if (i >= from) {
- *pos = p;
- return i;
+ /* Find the relevant block */
+ list_for_each_entry(c, &map->debugfs_off_cache, list) {
+ if (*pos >= c->min && *pos <= c->max) {
+ *pos = c->min;
+ return c->base_reg;
}
- p += map->debugfs_tot_len;
+ ret = c->max;
}
- return base;
+ return ret;
}
static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from,
@@ -309,6 +337,8 @@ void regmap_debugfs_init(struct regmap *map, const char *name)
struct rb_node *next;
struct regmap_range_node *range_node;
+ INIT_LIST_HEAD(&map->debugfs_off_cache);
+
if (name) {
map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
dev_name(map->dev), name);
@@ -357,7 +387,16 @@ void regmap_debugfs_init(struct regmap *map, const char *name)
void regmap_debugfs_exit(struct regmap *map)
{
+ struct regmap_debugfs_off_cache *c;
+
debugfs_remove_recursive(map->debugfs);
+ while (!list_empty(&map->debugfs_off_cache)) {
+ c = list_first_entry(&map->debugfs_off_cache,
+ struct regmap_debugfs_off_cache,
+ list);
+ list_del(&c->list);
+ kfree(c);
+ }
kfree(map->debugfs_name);
}