diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 95d46a5..b01fe59 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -126,6 +126,9 @@
 	void *cache;
 	u32 cache_dirty;
 
+	unsigned long *cache_present;
+	unsigned int cache_present_nbits;
+
 	struct reg_default *patch;
 	int patch_regs;
 
@@ -201,6 +204,16 @@
 bool regcache_set_val(struct regmap *map, void *base, unsigned int idx,
 		      unsigned int val);
 int regcache_lookup_reg(struct regmap *map, unsigned int reg);
+int regcache_set_reg_present(struct regmap *map, unsigned int reg);
+
+static inline bool regcache_reg_present(struct regmap *map, unsigned int reg)
+{
+	if (!map->cache_present)
+		return true;
+	if (reg > map->cache_present_nbits)
+		return false;
+	return map->cache_present[BIT_WORD(reg)] & BIT_MASK(reg);
+}
 
 int _regmap_raw_write(struct regmap *map, unsigned int reg,
 		      const void *val, size_t val_len, bool async);
diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index 382a6de..00c3506 100644
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -36,8 +36,6 @@
 struct regcache_rbtree_ctx {
 	struct rb_root root;
 	struct regcache_rbtree_node *cached_rbnode;
-	unsigned long *reg_present;
-	unsigned int reg_present_nbits;
 };
 
 static inline void regcache_rbtree_get_base_top_reg(
@@ -154,7 +152,7 @@
 	map->lock(map);
 
 	mem_size = sizeof(*rbtree_ctx);
-	mem_size += BITS_TO_LONGS(rbtree_ctx->reg_present_nbits) * sizeof(long);
+	mem_size += BITS_TO_LONGS(map->cache_present_nbits) * sizeof(long);
 
 	for (node = rb_first(&rbtree_ctx->root); node != NULL;
 	     node = rb_next(node)) {
@@ -205,44 +203,6 @@
 }
 #endif
 
-static int enlarge_reg_present_bitmap(struct regmap *map, unsigned int reg)
-{
-	struct regcache_rbtree_ctx *rbtree_ctx;
-	unsigned long *reg_present;
-	unsigned int reg_present_size;
-	unsigned int nregs;
-	int i;
-
-	rbtree_ctx = map->cache;
-	nregs = reg + 1;
-	reg_present_size = BITS_TO_LONGS(nregs);
-	reg_present_size *= sizeof(long);
-
-	if (!rbtree_ctx->reg_present) {
-		reg_present = kmalloc(reg_present_size, GFP_KERNEL);
-		if (!reg_present)
-			return -ENOMEM;
-		bitmap_zero(reg_present, nregs);
-		rbtree_ctx->reg_present = reg_present;
-		rbtree_ctx->reg_present_nbits = nregs;
-		return 0;
-	}
-
-	if (nregs > rbtree_ctx->reg_present_nbits) {
-		reg_present = krealloc(rbtree_ctx->reg_present,
-				       reg_present_size, GFP_KERNEL);
-		if (!reg_present)
-			return -ENOMEM;
-		for (i = 0; i < nregs; i++)
-			if (i >= rbtree_ctx->reg_present_nbits)
-				clear_bit(i, reg_present);
-		rbtree_ctx->reg_present = reg_present;
-		rbtree_ctx->reg_present_nbits = nregs;
-	}
-
-	return 0;
-}
-
 static int regcache_rbtree_init(struct regmap *map)
 {
 	struct regcache_rbtree_ctx *rbtree_ctx;
@@ -256,8 +216,6 @@
 	rbtree_ctx = map->cache;
 	rbtree_ctx->root = RB_ROOT;
 	rbtree_ctx->cached_rbnode = NULL;
-	rbtree_ctx->reg_present = NULL;
-	rbtree_ctx->reg_present_nbits = 0;
 
 	for (i = 0; i < map->num_reg_defaults; i++) {
 		ret = regcache_rbtree_write(map,
@@ -287,8 +245,6 @@
 	if (!rbtree_ctx)
 		return 0;
 
-	kfree(rbtree_ctx->reg_present);
-
 	/* free up the rbtree */
 	next = rb_first(&rbtree_ctx->root);
 	while (next) {
@@ -306,17 +262,6 @@
 	return 0;
 }
 
-static int regcache_reg_present(struct regmap *map, unsigned int reg)
-{
-	struct regcache_rbtree_ctx *rbtree_ctx;
-
-	rbtree_ctx = map->cache;
-	if (!(rbtree_ctx->reg_present[BIT_WORD(reg)] & BIT_MASK(reg)))
-		return 0;
-	return 1;
-
-}
-
 static int regcache_rbtree_read(struct regmap *map,
 				unsigned int reg, unsigned int *value)
 {
@@ -378,10 +323,9 @@
 
 	rbtree_ctx = map->cache;
 	/* update the reg_present bitmap, make space if necessary */
-	ret = enlarge_reg_present_bitmap(map, reg);
+	ret = regcache_set_reg_present(map, reg);
 	if (ret < 0)
 		return ret;
-	set_bit(reg, rbtree_ctx->reg_present);
 
 	/* if we can't locate it in the cached rbnode we'll have
 	 * to traverse the rbtree looking for it.
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 229c804..0fedf4f 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -121,6 +121,8 @@
 	map->reg_defaults_raw = config->reg_defaults_raw;
 	map->cache_word_size = DIV_ROUND_UP(config->val_bits, 8);
 	map->cache_size_raw = map->cache_word_size * config->num_reg_defaults_raw;
+	map->cache_present = NULL;
+	map->cache_present_nbits = 0;
 
 	map->cache = NULL;
 	map->cache_ops = cache_types[i];
@@ -179,6 +181,7 @@
 
 	BUG_ON(!map->cache_ops);
 
+	kfree(map->cache_present);
 	kfree(map->reg_defaults);
 	if (map->cache_free)
 		kfree(map->reg_defaults_raw);
@@ -415,6 +418,42 @@
 }
 EXPORT_SYMBOL_GPL(regcache_cache_bypass);
 
+int regcache_set_reg_present(struct regmap *map, unsigned int reg)
+{
+	unsigned long *cache_present;
+	unsigned int cache_present_size;
+	unsigned int nregs;
+	int i;
+
+	nregs = reg + 1;
+	cache_present_size = BITS_TO_LONGS(nregs);
+	cache_present_size *= sizeof(long);
+
+	if (!map->cache_present) {
+		cache_present = kmalloc(cache_present_size, GFP_KERNEL);
+		if (!cache_present)
+			return -ENOMEM;
+		bitmap_zero(cache_present, nregs);
+		map->cache_present = cache_present;
+		map->cache_present_nbits = nregs;
+	}
+
+	if (nregs > map->cache_present_nbits) {
+		cache_present = krealloc(map->cache_present,
+					 cache_present_size, GFP_KERNEL);
+		if (!cache_present)
+			return -ENOMEM;
+		for (i = 0; i < nregs; i++)
+			if (i >= map->cache_present_nbits)
+				clear_bit(i, cache_present);
+		map->cache_present = cache_present;
+		map->cache_present_nbits = nregs;
+	}
+
+	set_bit(reg, map->cache_present);
+	return 0;
+}
+
 bool regcache_set_val(struct regmap *map, void *base, unsigned int idx,
 		      unsigned int val)
 {