4 files changed, 55 insertions, 10 deletions

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 8641183cac2f..53785e0e297a 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -77,6 +77,7 @@ struct regmap {
 	int async_ret;
 
 #ifdef CONFIG_DEBUG_FS
+	bool debugfs_disable;
 	struct dentry *debugfs;
 	const char *debugfs_name;
 
@@ -215,10 +216,17 @@ struct regmap_field {
 extern void regmap_debugfs_initcall(void);
 extern void regmap_debugfs_init(struct regmap *map, const char *name);
 extern void regmap_debugfs_exit(struct regmap *map);
+
+static inline void regmap_debugfs_disable(struct regmap *map)
+{
+	map->debugfs_disable = true;
+}
+
 #else
 static inline void regmap_debugfs_initcall(void) { }
 static inline void regmap_debugfs_init(struct regmap *map, const char *name) { }
 static inline void regmap_debugfs_exit(struct regmap *map) { }
+static inline void regmap_debugfs_disable(struct regmap *map) { }
 #endif
 
 /* regcache core declarations */
diff --git a/drivers/base/regmap/regcache-flat.c b/drivers/base/regmap/regcache-flat.c
index 4d2e50bfc726..bc6cd88b8cc6 100644
--- a/drivers/base/regmap/regcache-flat.c
+++ b/drivers/base/regmap/regcache-flat.c
@@ -37,9 +37,12 @@ static int regcache_flat_init(struct regmap *map)
 
 	cache = map->cache;
 
-	for (i = 0; i < map->num_reg_defaults; i++)
-		cache[regcache_flat_get_index(map, map->reg_defaults[i].reg)] =
-				map->reg_defaults[i].def;
+	for (i = 0; i < map->num_reg_defaults; i++) {
+		unsigned int reg = map->reg_defaults[i].reg;
+		unsigned int index = regcache_flat_get_index(map, reg);
+
+		cache[index] = map->reg_defaults[i].def;
+	}
 
 	return 0;
 }
@@ -56,8 +59,9 @@ static int regcache_flat_read(struct regmap *map,
 			      unsigned int reg, unsigned int *value)
 {
 	unsigned int *cache = map->cache;
+	unsigned int index = regcache_flat_get_index(map, reg);
 
-	*value = cache[regcache_flat_get_index(map, reg)];
+	*value = cache[index];
 
 	return 0;
 }
@@ -66,8 +70,9 @@ static int regcache_flat_write(struct regmap *map, unsigned int reg,
 			       unsigned int value)
 {
 	unsigned int *cache = map->cache;
+	unsigned int index = regcache_flat_get_index(map, reg);
 
-	cache[regcache_flat_get_index(map, reg)] = value;
+	cache[index] = value;
 
 	return 0;
 }
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index 36ce3511c733..f3266334063e 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -529,6 +529,18 @@ void regmap_debugfs_init(struct regmap *map, const char *name)
 	struct regmap_range_node *range_node;
 	const char *devname = "dummy";
 
+	/*
+	 * Userspace can initiate reads from the hardware over debugfs.
+	 * Normally internal regmap structures and buffers are protected with
+	 * a mutex or a spinlock, but if the regmap owner decided to disable
+	 * all locking mechanisms, this is no longer the case. For safety:
+	 * don't create the debugfs entries if locking is disabled.
+	 */
+	if (map->debugfs_disable) {
+		dev_dbg(map->dev, "regmap locking disabled - not creating debugfs entries\n");
+		return;
+	}
+
 	/* If we don't have the debugfs root yet, postpone init */
 	if (!regmap_debugfs_root) {
 		struct regmap_debugfs_node *node;
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index d23a5c99b639..be55e5a0e38c 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -457,6 +457,11 @@ static void regmap_unlock_hwlock_irqrestore(void *__map)
 	hwspin_unlock_irqrestore(map->hwlock, &map->spinlock_flags);
 }
 
+static void regmap_lock_unlock_none(void *__map)
+{
+
+}
+
 static void regmap_lock_mutex(void *__map)
 {
 	struct regmap *map = __map;
@@ -667,7 +672,18 @@ struct regmap *__regmap_init(struct device *dev,
 		goto err;
 	}
 
-	if (config->lock && config->unlock) {
+	if (config->name) {
+		map->name = kstrdup_const(config->name, GFP_KERNEL);
+		if (!map->name) {
+			ret = -ENOMEM;
+			goto err_map;
+		}
+	}
+
+	if (config->disable_locking) {
+		map->lock = map->unlock = regmap_lock_unlock_none;
+		regmap_debugfs_disable(map);
+	} else if (config->lock && config->unlock) {
 		map->lock = config->lock;
 		map->unlock = config->unlock;
 		map->lock_arg = config->lock_arg;
@@ -675,7 +691,7 @@ struct regmap *__regmap_init(struct device *dev,
 		map->hwlock = hwspin_lock_request_specific(config->hwlock_id);
 		if (!map->hwlock) {
 			ret = -ENXIO;
-			goto err_map;
+			goto err_name;
 		}
 
 		switch (config->hwlock_mode) {
@@ -755,7 +771,6 @@ struct regmap *__regmap_init(struct device *dev,
 	map->volatile_reg = config->volatile_reg;
 	map->precious_reg = config->precious_reg;
 	map->cache_type = config->cache_type;
-	map->name = config->name;
 
 	spin_lock_init(&map->async_lock);
 	INIT_LIST_HEAD(&map->async_list);
@@ -1111,6 +1126,8 @@ err_range:
 err_hwlock:
 	if (map->hwlock)
 		hwspin_lock_free(map->hwlock);
+err_name:
+	kfree_const(map->name);
 err_map:
 	kfree(map);
 err:
@@ -1300,6 +1317,7 @@ void regmap_exit(struct regmap *map)
 	}
 	if (map->hwlock)
 		hwspin_lock_free(map->hwlock);
+	kfree_const(map->name);
 	kfree(map);
 }
 EXPORT_SYMBOL_GPL(regmap_exit);
@@ -2416,13 +2434,15 @@ static int _regmap_bus_read(void *context, unsigned int reg,
 {
 	int ret;
 	struct regmap *map = context;
+	void *work_val = map->work_buf + map->format.reg_bytes +
+		map->format.pad_bytes;
 
 	if (!map->format.parse_val)
 		return -EINVAL;
 
-	ret = _regmap_raw_read(map, reg, map->work_buf, map->format.val_bytes);
+	ret = _regmap_raw_read(map, reg, work_val, map->format.val_bytes);
 	if (ret == 0)
-		*val = map->format.parse_val(map->work_buf);
+		*val = map->format.parse_val(work_val);
 
 	return ret;
 }