regmap: Fixes for v7.3

The main thing here is a fix for lockdep warnings with MMIO regmaps that
 use a raw spinlock and a cache, some other lockdep fixes we'd done for
 the benefit of the maple tree on sleeping buses meant that we were doing
 allocations for those MMIO regmaps under a raw spinlock.  While fixing
 that Michael Reeves also noticed that the debugfs files were briefly
 available without the cache structures backing them.
 
 There's also a fix for interrupt freeing on error in regmap-irq which
 had been hanging around because it's not super urgent.
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Merge tag 'regmap-fix-v7.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap fixes from Mark Brown:
 "The main thing here is a fix for lockdep warnings with MMIO regmaps
  that use a raw spinlock and a cache, some other lockdep fixes we'd
  done for the benefit of the maple tree on sleeping buses meant that we
  were doing allocations for those MMIO regmaps under a raw spinlock.

  While fixing that Michael Reeves also noticed that the debugfs files
  were briefly available without the cache structures backing them.

  There's also a fix for interrupt freeing on error in regmap-irq which
  had been hanging around because it's not super urgent"

* tag 'regmap-fix-v7.3-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: Drop map lock during cache init and exit
  regmap: Remove debugfs before cache teardown
  regmap: irq: Free the irqdomain we create

drivers/base/regmap/regcache-maple.c

@@ -312,16 +312,21 @@ static void regcache_maple_exit(struct regmap *map)
 	struct maple_tree *mt = map->cache;
 	MA_STATE(mas, mt, 0, UINT_MAX);
 	unsigned int *entry;
+	unsigned long flags;
 
 	/* if we've already been called then just return */
 	if (!mt)
 		return;
 
-	mas_lock(&mas);
+	/*
+	 * Register access may take the Maple lock from hard IRQ context, so
+	 * preserve its IRQ-safe lockdep state during teardown.
+	 */
+	mas_lock_irqsave(&mas, flags);
 	mas_for_each(&mas, entry, UINT_MAX)
 		kfree(entry);
 	__mt_destroy(mt);
-	mas_unlock(&mas);
+	mas_unlock_irqrestore(&mas, flags);
 
 	kfree(mt);
 	map->cache = NULL;

drivers/base/regmap/regcache.c

@@ -225,9 +225,7 @@ int regcache_init(struct regmap *map, const struct regmap_config *config)
 	if (map->cache_ops->init) {
 		dev_dbg(map->dev, "Initializing %s cache\n",
 			map->cache_ops->name);
-		map->lock(map->lock_arg);
 		ret = map->cache_ops->init(map);
-		map->unlock(map->lock_arg);
 		if (ret)
 			goto err_free_reg_defaults;
 	}
@@ -259,9 +257,7 @@ int regcache_init(struct regmap *map, const struct regmap_config *config)
 err_exit:
 	if (map->cache_ops->exit) {
 		dev_dbg(map->dev, "Destroying %s cache\n", map->cache_ops->name);
-		map->lock(map->lock_arg);
 		map->cache_ops->exit(map);
-		map->unlock(map->lock_arg);
 	}
 err_free_reg_defaults:
 	kfree(map->reg_defaults);
@@ -281,9 +277,7 @@ void regcache_exit(struct regmap *map)
 	if (map->cache_ops->exit) {
 		dev_dbg(map->dev, "Destroying %s cache\n",
 			map->cache_ops->name);
-		map->lock(map->lock_arg);
 		map->cache_ops->exit(map);
-		map->unlock(map->lock_arg);
 	}
 
 	kfree(map->reg_defaults);

drivers/base/regmap/regmap-debugfs.c

@@ -664,6 +664,7 @@ void regmap_debugfs_exit(struct regmap *map)
 {
 	if (map->debugfs) {
 		debugfs_remove_recursive(map->debugfs);
+		map->debugfs = NULL;
 		mutex_lock(&map->cache_lock);
 		regmap_debugfs_free_dump_cache(map);
 		mutex_unlock(&map->cache_lock);

drivers/base/regmap/regmap-irq.c

@@ -963,7 +963,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 	return 0;
 
 err_domain:
-	/* Should really dispose of the domain but... */
+	irq_domain_remove(d->domain);
 err_mutex:
 	mutex_destroy(&d->lock);
 	lockdep_unregister_key(&d->lock_key);

drivers/base/regmap/regmap.c

@@ -1422,8 +1422,8 @@ int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
 {
 	int ret;
 
-	regcache_exit(map);
 	regmap_debugfs_exit(map);
+	regcache_exit(map);
 
 	map->max_register = config->max_register;
 	map->max_register_is_set = map->max_register ?: config->max_register_is_0;
@@ -1440,12 +1440,16 @@ int regmap_reinit_cache(struct regmap *map, const struct regmap_config *config)
 	if (ret)
 		return ret;
 
-	regmap_debugfs_init(map);
-
 	map->cache_bypass = false;
 	map->cache_only = false;
 
-	return regcache_init(map, config);
+	ret = regcache_init(map, config);
+	if (ret)
+		return ret;
+
+	regmap_debugfs_init(map);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(regmap_reinit_cache);
 
@@ -1459,9 +1463,8 @@ void regmap_exit(struct regmap *map)
 	struct regmap_async *async;
 
 	regmap_detach_dev(map->dev, map);
-	regcache_exit(map);
-
 	regmap_debugfs_exit(map);
+	regcache_exit(map);
 	regmap_range_exit(map);
 	if (map->bus && map->bus->free_context)
 		map->bus->free_context(map->bus_context);

include/linux/maple_tree.h

@@ -507,9 +507,13 @@ struct ma_wr_state {
 };
 
 #define mas_lock(mas)           spin_lock(&((mas)->tree->ma_lock))
+#define mas_lock_irqsave(mas, flags) \
+		spin_lock_irqsave(&((mas)->tree->ma_lock), flags)
 #define mas_lock_nested(mas, subclass) \
 		spin_lock_nested(&((mas)->tree->ma_lock), subclass)
 #define mas_unlock(mas)         spin_unlock(&((mas)->tree->ma_lock))
+#define mas_unlock_irqrestore(mas, flags) \
+		spin_unlock_irqrestore(&((mas)->tree->ma_lock), flags)
 
 /*
  * Special values for ma_state.node.