Merge tag 'regmap-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap updates from Mark Brown:
 "Another small update for regmap, we have one new feature plus a little
  bit of cleanup:

   - Support for sparseness information in the flat cache, allowing
     users that really need the performance properties it provides to
     benefit from the interface and startup time improvements that
     sparsness provides without needing to go all the way to a more
     fancy data structure

   - Cleanup work from Andy Shevchenko, refactoring the cache interface
     in preparation for some future stuff he's working on"

* tag 'regmap-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: sdw-mbq: Reorder regmap_mbq_context struct for better packing
  regmap: i3c: Use ARRAY_SIZE()
  regcache: maple: Split ->populate() from ->init()
  regcache: flat: Split ->populate() from ->init()
  regcache: flat: Remove unneeded check and error message for -ENOMEM
  regcache: rbtree: Split ->populate() from ->init()
  regcache: Add ->populate() callback to separate from ->init()
  regmap: warn users about uninitialized flat cache
  regmap: add flat cache with sparse validity

8 files changed, 175 insertions, 59 deletions

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 6f31240ee4a9..1477329410ec 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -186,6 +186,7 @@ struct regcache_ops {
 	enum regcache_type type;
 	int (*init)(struct regmap *map);
 	int (*exit)(struct regmap *map);
+	int (*populate)(struct regmap *map);
 #ifdef CONFIG_DEBUG_FS
 	void (*debugfs_init)(struct regmap *map);
 #endif
@@ -288,6 +289,7 @@ enum regmap_endian regmap_get_val_endian(struct device *dev,
 					 const struct regmap_bus *bus,
 					 const struct regmap_config *config);
 
+extern struct regcache_ops regcache_flat_sparse_ops;
 extern struct regcache_ops regcache_rbtree_ops;
 extern struct regcache_ops regcache_maple_ops;
 extern struct regcache_ops regcache_flat_ops;
diff --git a/drivers/base/regmap/regcache-flat.c b/drivers/base/regmap/regcache-flat.c
index f36d3618b67c..53cc59c84e2f 100644
--- a/drivers/base/regmap/regcache-flat.c
+++ b/drivers/base/regmap/regcache-flat.c
@@ -6,7 +6,11 @@
 //
 // Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
 #include <linux/device.h>
+#include <linux/limits.h>
+#include <linux/overflow.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 
@@ -18,46 +22,92 @@ static inline unsigned int regcache_flat_get_index(const struct regmap *map,
 	return regcache_get_index_by_order(map, reg);
 }
 
+struct regcache_flat_data {
+	unsigned long *valid;
+	unsigned int data[];
+};
+
 static int regcache_flat_init(struct regmap *map)
 {
-	int i;
-	unsigned int *cache;
+	unsigned int cache_size;
+	struct regcache_flat_data *cache;
 
 	if (!map || map->reg_stride_order < 0 || !map->max_register_is_set)
 		return -EINVAL;
 
-	map->cache = kcalloc(regcache_flat_get_index(map, map->max_register)
-			     + 1, sizeof(unsigned int), map->alloc_flags);
-	if (!map->cache)
+	cache_size = regcache_flat_get_index(map, map->max_register) + 1;
+	cache = kzalloc(struct_size(cache, data, cache_size), map->alloc_flags);
+	if (!cache)
 		return -ENOMEM;
 
-	cache = map->cache;
+	cache->valid = bitmap_zalloc(cache_size, map->alloc_flags);
+	if (!cache->valid)
+		goto err_free;
+
+	map->cache = cache;
+
+	return 0;
+
+err_free:
+	kfree(cache);
+	return -ENOMEM;
+}
+
+static int regcache_flat_exit(struct regmap *map)
+{
+	struct regcache_flat_data *cache = map->cache;
+
+	if (cache)
+		bitmap_free(cache->valid);
+
+	kfree(cache);
+	map->cache = NULL;
+
+	return 0;
+}
+
+static int regcache_flat_populate(struct regmap *map)
+{
+	struct regcache_flat_data *cache = map->cache;
+	unsigned int i;
 
 	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;
+		cache->data[index] = map->reg_defaults[i].def;
+		__set_bit(index, cache->valid);
 	}
 
 	return 0;
 }
 
-static int regcache_flat_exit(struct regmap *map)
+static int regcache_flat_read(struct regmap *map,
+			      unsigned int reg, unsigned int *value)
 {
-	kfree(map->cache);
-	map->cache = NULL;
+	struct regcache_flat_data *cache = map->cache;
+	unsigned int index = regcache_flat_get_index(map, reg);
+
+	/* legacy behavior: ignore validity, but warn the user */
+	if (unlikely(!test_bit(index, cache->valid)))
+		dev_warn_once(map->dev,
+			"using zero-initialized flat cache, this may cause unexpected behavior");
+
+	*value = cache->data[index];
 
 	return 0;
 }
 
-static int regcache_flat_read(struct regmap *map,
-			      unsigned int reg, unsigned int *value)
+static int regcache_flat_sparse_read(struct regmap *map,
+				     unsigned int reg, unsigned int *value)
 {
-	unsigned int *cache = map->cache;
+	struct regcache_flat_data *cache = map->cache;
 	unsigned int index = regcache_flat_get_index(map, reg);
 
-	*value = cache[index];
+	if (unlikely(!test_bit(index, cache->valid)))
+		return -ENOENT;
+
+	*value = cache->data[index];
 
 	return 0;
 }
@@ -65,10 +115,23 @@ static int regcache_flat_read(struct regmap *map,
 static int regcache_flat_write(struct regmap *map, unsigned int reg,
 			       unsigned int value)
 {
-	unsigned int *cache = map->cache;
+	struct regcache_flat_data *cache = map->cache;
 	unsigned int index = regcache_flat_get_index(map, reg);
 
-	cache[index] = value;
+	cache->data[index] = value;
+	__set_bit(index, cache->valid);
+
+	return 0;
+}
+
+static int regcache_flat_drop(struct regmap *map, unsigned int min,
+			      unsigned int max)
+{
+	struct regcache_flat_data *cache = map->cache;
+	unsigned int bitmap_min = regcache_flat_get_index(map, min);
+	unsigned int bitmap_max = regcache_flat_get_index(map, max);
+
+	bitmap_clear(cache->valid, bitmap_min, bitmap_max + 1 - bitmap_min);
 
 	return 0;
 }
@@ -78,6 +141,18 @@ struct regcache_ops regcache_flat_ops = {
 	.name = "flat",
 	.init = regcache_flat_init,
 	.exit = regcache_flat_exit,
+	.populate = regcache_flat_populate,
 	.read = regcache_flat_read,
 	.write = regcache_flat_write,
 };
+
+struct regcache_ops regcache_flat_sparse_ops = {
+	.type = REGCACHE_FLAT_S,
+	.name = "flat-sparse",
+	.init = regcache_flat_init,
+	.exit = regcache_flat_exit,
+	.populate = regcache_flat_populate,
+	.read = regcache_flat_sparse_read,
+	.write = regcache_flat_write,
+	.drop = regcache_flat_drop,
+};
diff --git a/drivers/base/regmap/regcache-maple.c b/drivers/base/regmap/regcache-maple.c
index 2319c30283a6..ca1c72b68f31 100644
--- a/drivers/base/regmap/regcache-maple.c
+++ b/drivers/base/regmap/regcache-maple.c
@@ -289,6 +289,23 @@ out:
 	return ret;
 }
 
+static int regcache_maple_init(struct regmap *map)
+{
+	struct maple_tree *mt;
+
+	mt = kmalloc(sizeof(*mt), map->alloc_flags);
+	if (!mt)
+		return -ENOMEM;
+	map->cache = mt;
+
+	mt_init(mt);
+
+	if (!mt_external_lock(mt) && map->lock_key)
+		lockdep_set_class_and_subclass(&mt->ma_lock, map->lock_key, 1);
+
+	return 0;
+}
+
 static int regcache_maple_exit(struct regmap *map)
 {
 	struct maple_tree *mt = map->cache;
@@ -340,26 +357,12 @@ static int regcache_maple_insert_block(struct regmap *map, int first,
 	return ret;
 }
 
-static int regcache_maple_init(struct regmap *map)
+static int regcache_maple_populate(struct regmap *map)
 {
-	struct maple_tree *mt;
 	int i;
 	int ret;
 	int range_start;
 
-	mt = kmalloc(sizeof(*mt), map->alloc_flags);
-	if (!mt)
-		return -ENOMEM;
-	map->cache = mt;
-
-	mt_init(mt);
-
-	if (!mt_external_lock(mt) && map->lock_key)
-		lockdep_set_class_and_subclass(&mt->ma_lock, map->lock_key, 1);
-
-	if (!map->num_reg_defaults)
-		return 0;
-
 	range_start = 0;
 
 	/* Scan for ranges of contiguous registers */
@@ -369,23 +372,14 @@ static int regcache_maple_init(struct regmap *map)
 			ret = regcache_maple_insert_block(map, range_start,
 							  i - 1);
 			if (ret != 0)
-				goto err;
+				return ret;
 
 			range_start = i;
 		}
 	}
 
 	/* Add the last block */
-	ret = regcache_maple_insert_block(map, range_start,
-					  map->num_reg_defaults - 1);
-	if (ret != 0)
-		goto err;
-
-	return 0;
-
-err:
-	regcache_maple_exit(map);
-	return ret;
+	return regcache_maple_insert_block(map, range_start, map->num_reg_defaults - 1);
 }
 
 struct regcache_ops regcache_maple_ops = {
@@ -393,6 +387,7 @@ struct regcache_ops regcache_maple_ops = {
 	.name = "maple",
 	.init = regcache_maple_init,
 	.exit = regcache_maple_exit,
+	.populate = regcache_maple_populate,
 	.read = regcache_maple_read,
 	.write = regcache_maple_write,
 	.drop = regcache_maple_drop,
diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index a9d17f316e55..3344b82c3799 100644
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -184,8 +184,6 @@ static void rbtree_debugfs_init(struct regmap *map)
 static int regcache_rbtree_init(struct regmap *map)
 {
 	struct regcache_rbtree_ctx *rbtree_ctx;
-	int i;
-	int ret;
 
 	map->cache = kmalloc(sizeof *rbtree_ctx, map->alloc_flags);
 	if (!map->cache)
@@ -195,19 +193,7 @@ static int regcache_rbtree_init(struct regmap *map)
 	rbtree_ctx->root = RB_ROOT;
 	rbtree_ctx->cached_rbnode = NULL;
 
-	for (i = 0; i < map->num_reg_defaults; i++) {
-		ret = regcache_rbtree_write(map,
-					    map->reg_defaults[i].reg,
-					    map->reg_defaults[i].def);
-		if (ret)
-			goto err;
-	}
-
 	return 0;
-
-err:
-	regcache_rbtree_exit(map);
-	return ret;
 }
 
 static int regcache_rbtree_exit(struct regmap *map)
@@ -239,6 +225,22 @@ static int regcache_rbtree_exit(struct regmap *map)
 	return 0;
 }
 
+static int regcache_rbtree_populate(struct regmap *map)
+{
+	unsigned int i;
+	int ret;
+
+	for (i = 0; i < map->num_reg_defaults; i++) {
+		ret = regcache_rbtree_write(map,
+					    map->reg_defaults[i].reg,
+					    map->reg_defaults[i].def);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 static int regcache_rbtree_read(struct regmap *map,
 				unsigned int reg, unsigned int *value)
 {
@@ -546,6 +548,7 @@ struct regcache_ops regcache_rbtree_ops = {
 	.name = "rbtree",
 	.init = regcache_rbtree_init,
 	.exit = regcache_rbtree_exit,
+	.populate = regcache_rbtree_populate,
 #ifdef CONFIG_DEBUG_FS
 	.debugfs_init = rbtree_debugfs_init,
 #endif
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index c7650fa434ad..319c342bf5a0 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -16,6 +16,7 @@
 #include "internal.h"
 
 static const struct regcache_ops *cache_types[] = {
+	&regcache_flat_sparse_ops,
 	&regcache_rbtree_ops,
 	&regcache_maple_ops,
 	&regcache_flat_ops,
@@ -221,8 +222,24 @@ int regcache_init(struct regmap *map, const struct regmap_config *config)
 		if (ret)
 			goto err_free;
 	}
+
+	if (map->num_reg_defaults && map->cache_ops->populate) {
+		dev_dbg(map->dev, "Populating %s cache\n", map->cache_ops->name);
+		map->lock(map->lock_arg);
+		ret = map->cache_ops->populate(map);
+		map->unlock(map->lock_arg);
+		if (ret)
+			goto err_exit;
+	}
 	return 0;
 
+err_exit:
+	if (map->cache_ops->exit) {
+		dev_dbg(map->dev, "Destroying %s cache\n", map->cache_ops->name);
+		map->lock(map->lock_arg);
+		ret = map->cache_ops->exit(map);
+		map->unlock(map->lock_arg);
+	}
 err_free:
 	kfree(map->reg_defaults);
 	if (map->cache_free)
diff --git a/drivers/base/regmap/regmap-i3c.c b/drivers/base/regmap/regmap-i3c.c
index b5300b7c477e..6a0f6c826980 100644
--- a/drivers/base/regmap/regmap-i3c.c
+++ b/drivers/base/regmap/regmap-i3c.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 // Copyright (c) 2018 Synopsys, Inc. and/or its affiliates.
 
+#include <linux/array_size.h>
 #include <linux/regmap.h>
 #include <linux/i3c/device.h>
 #include <linux/i3c/master.h>
@@ -18,7 +19,7 @@ static int regmap_i3c_write(void *context, const void *data, size_t count)
 		},
 	};
 
-	return i3c_device_do_priv_xfers(i3c, xfers, 1);
+	return i3c_device_do_priv_xfers(i3c, xfers, ARRAY_SIZE(xfers));
 }
 
 static int regmap_i3c_read(void *context,
@@ -37,7 +38,7 @@ static int regmap_i3c_read(void *context,
 	xfers[1].len = val_size;
 	xfers[1].data.in = val;
 
-	return i3c_device_do_priv_xfers(i3c, xfers, 2);
+	return i3c_device_do_priv_xfers(i3c, xfers, ARRAY_SIZE(xfers));
 }
 
 static const struct regmap_bus regmap_i3c = {
diff --git a/drivers/base/regmap/regmap-kunit.c b/drivers/base/regmap/regmap-kunit.c
index 95c5bf2a78ee..f6fc5ed016da 100644
--- a/drivers/base/regmap/regmap-kunit.c
+++ b/drivers/base/regmap/regmap-kunit.c
@@ -54,6 +54,8 @@ static const char *regcache_type_name(enum regcache_type type)
 		return "none";
 	case REGCACHE_FLAT:
 		return "flat";
+	case REGCACHE_FLAT_S:
+		return "flat-sparse";
 	case REGCACHE_RBTREE:
 		return "rbtree";
 	case REGCACHE_MAPLE:
@@ -93,6 +95,8 @@ static const struct regmap_test_param regcache_types_list[] = {
 	{ .cache = REGCACHE_NONE, .fast_io = true },
 	{ .cache = REGCACHE_FLAT },
 	{ .cache = REGCACHE_FLAT, .fast_io = true },
+	{ .cache = REGCACHE_FLAT_S },
+	{ .cache = REGCACHE_FLAT_S, .fast_io = true },
 	{ .cache = REGCACHE_RBTREE },
 	{ .cache = REGCACHE_RBTREE, .fast_io = true },
 	{ .cache = REGCACHE_MAPLE },
@@ -104,6 +108,8 @@ KUNIT_ARRAY_PARAM(regcache_types, regcache_types_list, param_to_desc);
 static const struct regmap_test_param real_cache_types_only_list[] = {
 	{ .cache = REGCACHE_FLAT },
 	{ .cache = REGCACHE_FLAT, .fast_io = true },
+	{ .cache = REGCACHE_FLAT_S },
+	{ .cache = REGCACHE_FLAT_S, .fast_io = true },
 	{ .cache = REGCACHE_RBTREE },
 	{ .cache = REGCACHE_RBTREE, .fast_io = true },
 	{ .cache = REGCACHE_MAPLE },
@@ -119,6 +125,12 @@ static const struct regmap_test_param real_cache_types_list[] = {
 	{ .cache = REGCACHE_FLAT,   .from_reg = 0x2002 },
 	{ .cache = REGCACHE_FLAT,   .from_reg = 0x2003 },
 	{ .cache = REGCACHE_FLAT,   .from_reg = 0x2004 },
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0 },
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0, .fast_io = true },
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0x2001 },
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0x2002 },
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0x2003 },
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0x2004 },
 	{ .cache = REGCACHE_RBTREE, .from_reg = 0 },
 	{ .cache = REGCACHE_RBTREE, .from_reg = 0, .fast_io = true },
 	{ .cache = REGCACHE_RBTREE, .from_reg = 0x2001 },
@@ -136,6 +148,12 @@ static const struct regmap_test_param real_cache_types_list[] = {
 KUNIT_ARRAY_PARAM(real_cache_types, real_cache_types_list, param_to_desc);
 
 static const struct regmap_test_param sparse_cache_types_list[] = {
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0 },
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0, .fast_io = true },
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0x2001 },
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0x2002 },
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0x2003 },
+	{ .cache = REGCACHE_FLAT_S, .from_reg = 0x2004 },
 	{ .cache = REGCACHE_RBTREE, .from_reg = 0 },
 	{ .cache = REGCACHE_RBTREE, .from_reg = 0, .fast_io = true },
 	{ .cache = REGCACHE_RBTREE, .from_reg = 0x2001 },
@@ -1597,6 +1615,8 @@ static const struct regmap_test_param raw_types_list[] = {
 	{ .cache = REGCACHE_NONE,   .val_endian = REGMAP_ENDIAN_BIG },
 	{ .cache = REGCACHE_FLAT,   .val_endian = REGMAP_ENDIAN_LITTLE },
 	{ .cache = REGCACHE_FLAT,   .val_endian = REGMAP_ENDIAN_BIG },
+	{ .cache = REGCACHE_FLAT_S, .val_endian = REGMAP_ENDIAN_LITTLE },
+	{ .cache = REGCACHE_FLAT_S, .val_endian = REGMAP_ENDIAN_BIG },
 	{ .cache = REGCACHE_RBTREE, .val_endian = REGMAP_ENDIAN_LITTLE },
 	{ .cache = REGCACHE_RBTREE, .val_endian = REGMAP_ENDIAN_BIG },
 	{ .cache = REGCACHE_MAPLE,  .val_endian = REGMAP_ENDIAN_LITTLE },
@@ -1608,6 +1628,8 @@ KUNIT_ARRAY_PARAM(raw_test_types, raw_types_list, param_to_desc);
 static const struct regmap_test_param raw_cache_types_list[] = {
 	{ .cache = REGCACHE_FLAT,   .val_endian = REGMAP_ENDIAN_LITTLE },
 	{ .cache = REGCACHE_FLAT,   .val_endian = REGMAP_ENDIAN_BIG },
+	{ .cache = REGCACHE_FLAT_S, .val_endian = REGMAP_ENDIAN_LITTLE },
+	{ .cache = REGCACHE_FLAT_S, .val_endian = REGMAP_ENDIAN_BIG },
 	{ .cache = REGCACHE_RBTREE, .val_endian = REGMAP_ENDIAN_LITTLE },
 	{ .cache = REGCACHE_RBTREE, .val_endian = REGMAP_ENDIAN_BIG },
 	{ .cache = REGCACHE_MAPLE,  .val_endian = REGMAP_ENDIAN_LITTLE },
diff --git a/drivers/base/regmap/regmap-sdw-mbq.c b/drivers/base/regmap/regmap-sdw-mbq.c
index 8b7d34a6080d..6a61629f5f89 100644
--- a/drivers/base/regmap/regmap-sdw-mbq.c
+++ b/drivers/base/regmap/regmap-sdw-mbq.c
@@ -17,10 +17,11 @@ struct regmap_mbq_context {
 	struct device *dev;
 	struct sdw_slave *sdw;
 
+	bool (*readable_reg)(struct device *dev, unsigned int reg);
+
 	struct regmap_sdw_mbq_cfg cfg;
 
 	int val_size;
-	bool (*readable_reg)(struct device *dev, unsigned int reg);
 };
 
 static int regmap_sdw_mbq_size(struct regmap_mbq_context *ctx, unsigned int reg)