linux-kernel - [PATCH 1/2] asm-generic/io.h: suppress endianness warnings for readq() and writeq()

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Date:   Mon,  9 Jan 2023 15:11:52 +0200
From:   Vladimir Oltean <vladimir.oltean@....com>
To:     Arnd Bergmann <arnd@...db.de>
Cc:     linux-arch@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] asm-generic/io.h: suppress endianness warnings for readq() and writeq()

Commit c1d55d50139b ("asm-generic/io.h: Fix sparse warnings on
big-endian architectures") missed fixing the 64-bit accessors.

Arnd explains in the attached link why the casts are necessary, even if
__raw_readq() and __raw_writeq() do not take endian-specific types.

Link: https://lore.kernel.org/lkml/9105d6fc-880b-4734-857d-e3d30b87ccf6@app.fastmail.com/
Suggested-by: Arnd Bergmann <arnd@...db.de>
Signed-off-by: Vladimir Oltean <vladimir.oltean@....com>
---
 include/asm-generic/io.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 4c44a29b5e8e..d78c3056c98f 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -236,7 +236,7 @@ static inline u64 readq(const volatile void __iomem *addr)
 
 	log_read_mmio(64, addr, _THIS_IP_, _RET_IP_);
 	__io_br();
-	val = __le64_to_cpu(__raw_readq(addr));
+	val = __le64_to_cpu((__le64 __force)__raw_readq(addr));
 	__io_ar(val);
 	log_post_read_mmio(val, 64, addr, _THIS_IP_, _RET_IP_);
 	return val;
@@ -287,7 +287,7 @@ static inline void writeq(u64 value, volatile void __iomem *addr)
 {
 	log_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
 	__io_bw();
-	__raw_writeq(__cpu_to_le64(value), addr);
+	__raw_writeq((u64 __force)__cpu_to_le64(value), addr);
 	__io_aw();
 	log_post_write_mmio(value, 64, addr, _THIS_IP_, _RET_IP_);
 }
-- 
2.34.1