linux-kernel - [PATCH 4/5] regmap: Wrap maple tree locking

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Message-Id: <20240822-b4-regmap-maple-nolock-v1-4-d5e6dbae3396@kernel.org>
Date: Thu, 22 Aug 2024 20:13:38 +0100
From: Mark Brown <broonie@...nel.org>
To: "Liam R. Howlett" <Liam.Howlett@...cle.com>
Cc: Cristian Ciocaltea <cristian.ciocaltea@...labora.com>, 
 maple-tree@...ts.infradead.org, linux-mm@...ck.org, 
 linux-kernel@...r.kernel.org, Mark Brown <broonie@...nel.org>
Subject: [PATCH 4/5] regmap: Wrap maple tree locking

In preparation for using the regmap lock when available with the maple
tree lock wrap all the maple tree locking with some local functions and
only do the maple tree locking if the maple tree has it's own lock.

Signed-off-by: Mark Brown <broonie@...nel.org>
---
 drivers/base/regmap/regcache-maple.c | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/base/regmap/regcache-maple.c b/drivers/base/regmap/regcache-maple.c
index 2dea9d259c49..d2de3eba1646 100644
--- a/drivers/base/regmap/regcache-maple.c
+++ b/drivers/base/regmap/regcache-maple.c
@@ -13,6 +13,18 @@
 
 #include "internal.h"
 
+static inline void regmap_mas_lock(struct ma_state *mas)
+{
+	if (!mt_external_lock(mas->tree))
+		mas_lock(mas);
+}
+
+static inline void regmap_mas_unlock(struct ma_state *mas)
+{
+	if (!mt_external_lock(mas->tree))
+		mas_unlock(mas);
+}
+
 static int regcache_maple_read(struct regmap *map,
 			       unsigned int reg, unsigned int *value)
 {
@@ -89,12 +101,12 @@ static int regcache_maple_write(struct regmap *map, unsigned int reg,
 	 * is redundant, but we need to take it due to lockdep asserts
 	 * in the maple tree code.
 	 */
-	mas_lock(&mas);
+	regmap_mas_lock(&mas);
 
 	mas_set_range(&mas, index, last);
 	ret = mas_store_gfp(&mas, entry, map->alloc_flags);
 
-	mas_unlock(&mas);
+	regmap_mas_unlock(&mas);
 
 	if (ret == 0) {
 		kfree(lower);
@@ -118,7 +130,7 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
 	lower = NULL;
 	upper = NULL;
 
-	mas_lock(&mas);
+	regmap_mas_lock(&mas);
 
 	mas_for_each(&mas, entry, max) {
 		/*
@@ -126,7 +138,7 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
 		 * Maple lock is redundant, but we need to take it due
 		 * to lockdep asserts in the maple tree code.
 		 */
-		mas_unlock(&mas);
+		regmap_mas_unlock(&mas);
 
 		/* Do we need to save any of this entry? */
 		if (mas.index < min) {
@@ -156,7 +168,7 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
 		}
 
 		kfree(entry);
-		mas_lock(&mas);
+		regmap_mas_lock(&mas);
 		mas_erase(&mas);
 
 		/* Insert new nodes with the saved data */
@@ -178,7 +190,7 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
 	}
 
 out:
-	mas_unlock(&mas);
+	regmap_mas_unlock(&mas);
 out_unlocked:
 	kfree(lower);
 	kfree(upper);
@@ -300,11 +312,11 @@ static int regcache_maple_exit(struct regmap *map)
 	if (!mt)
 		return 0;
 
-	mas_lock(&mas);
+	regmap_mas_lock(&mas);
 	mas_for_each(&mas, entry, UINT_MAX)
 		kfree(entry);
 	__mt_destroy(mt);
-	mas_unlock(&mas);
+	regmap_mas_unlock(&mas);
 
 	kfree(mt);
 	map->cache = NULL;
@@ -327,13 +339,13 @@ static int regcache_maple_insert_block(struct regmap *map, int first,
 	for (i = 0; i < last - first + 1; i++)
 		entry[i] = map->reg_defaults[first + i].def;
 
-	mas_lock(&mas);
+	regmap_mas_lock(&mas);
 
 	mas_set_range(&mas, map->reg_defaults[first].reg,
 		      map->reg_defaults[last].reg);
 	ret = mas_store_gfp(&mas, entry, map->alloc_flags);
 
-	mas_unlock(&mas);
+	regmap_mas_unlock(&mas);
 
 	if (ret)
 		kfree(entry);

-- 
2.39.2