regmap: Provide debugfs dump of the rbtree cache data
Show the register ranges we have in each rbtree node in debugfs, plus
some statistics on how big each node is and the total number of nodes.
It may also be worth collecting data on the ranges of dirty registers
to see if there's much mileage in trying to coalesce writes on sync.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index e71320f..7767cbb 100644
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -11,7 +11,9 @@
*/
#include <linux/slab.h>
+#include <linux/debugfs.h>
#include <linux/rbtree.h>
+#include <linux/seq_file.h>
#include "internal.h"
@@ -125,6 +127,51 @@
return 1;
}
+#ifdef CONFIG_DEBUG_FS
+static int rbtree_show(struct seq_file *s, void *ignored)
+{
+ struct regmap *map = s->private;
+ struct regcache_rbtree_ctx *rbtree_ctx = map->cache;
+ struct regcache_rbtree_node *n;
+ struct rb_node *node;
+ unsigned int base, top;
+ int nodes = 0;
+ int registers = 0;
+
+ mutex_lock(&map->lock);
+
+ for (node = rb_first(&rbtree_ctx->root); node != NULL;
+ node = rb_next(node)) {
+ n = container_of(node, struct regcache_rbtree_node, node);
+
+ regcache_rbtree_get_base_top_reg(n, &base, &top);
+ seq_printf(s, "%x-%x (%d)\n", base, top, top - base + 1);
+
+ nodes++;
+ registers += top - base + 1;
+ }
+
+ seq_printf(s, "%d nodes, %d registers, average %d registers\n",
+ nodes, registers, registers / nodes);
+
+ mutex_unlock(&map->lock);
+
+ return 0;
+}
+
+static int rbtree_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, rbtree_show, inode->i_private);
+}
+
+static const struct file_operations rbtree_fops = {
+ .open = rbtree_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+#endif
+
static int regcache_rbtree_init(struct regmap *map)
{
struct regcache_rbtree_ctx *rbtree_ctx;
@@ -147,6 +194,8 @@
goto err;
}
+ debugfs_create_file("rbtree", 0400, map->debugfs, map, &rbtree_fops);
+
return 0;
err: