linux-kernel - [PATCH 1/2] lib: devres: Simplify API devm

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Message-Id: <20240918-fix_lib_devres-v1-1-e696ab5486e6@quicinc.com>
Date: Wed, 18 Sep 2024 22:48:13 +0800
From: Zijun Hu <zijun_hu@...oud.com>
To: Andrew Morton <akpm@...ux-foundation.org>, 
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Zijun Hu <zijun_hu@...oud.com>, linux-kernel@...r.kernel.org, 
 Zijun Hu <quic_zijuhu@...cinc.com>
Subject: [PATCH 1/2] lib: devres: Simplify API devm_iounmap()
 implementation

From: Zijun Hu <quic_zijuhu@...cinc.com>

Simplify devm_iounmap() implementation by dedicated API devres_release()
compared with current solution, namely, devres_destroy() + iounmap()
devres_release() has the following advantages:

- it is simpler if devm_iounmap()'s parameter @addr is valid, namely
  @addr was ever returned by one of devm_ioremap() variants.

- it can avoid unnecessary iounmap(@addr) if @addr is not valid.

Signed-off-by: Zijun Hu <quic_zijuhu@...cinc.com>
---
 lib/devres.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/devres.c b/lib/devres.c
index 4fc152de6d8b..68ffcd5d9358 100644
--- a/lib/devres.c
+++ b/lib/devres.c
@@ -115,9 +115,8 @@ EXPORT_SYMBOL(devm_ioremap_wc);
  */
 void devm_iounmap(struct device *dev, void __iomem *addr)
 {
-	WARN_ON(devres_destroy(dev, devm_ioremap_release, devm_ioremap_match,
+	WARN_ON(devres_release(dev, devm_ioremap_release, devm_ioremap_match,
 			       (__force void *)addr));
-	iounmap(addr);
 }
 EXPORT_SYMBOL(devm_iounmap);
 

-- 
2.34.1