From: Nick Desaulniers <nick.desaulniers@gmail.com>
To: will.deacon@arm.com
Cc: natechancellor@gmail.com,
Nick Desaulniers <nick.desaulniers@gmail.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Jens Axboe <axboe@kernel.dk>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] arm64: io: specify asm operand width for __iormb()
Date: Wed, 28 Nov 2018 20:19:10 -0800 [thread overview]
Message-ID: <20181129041912.5918-1-nick.desaulniers@gmail.com> (raw)
Fixes the warning produced from Clang:
./include/asm-generic/io.h:711:9: warning: value size does not match
register size specified by the constraint and modifier
[-Wasm-operand-widths]
return readl(addr);
^
./arch/arm64/include/asm/io.h:149:58: note: expanded from macro 'readl'
^
./include/asm-generic/io.h:711:9: note: use constraint modifier "w"
./arch/arm64/include/asm/io.h:149:50: note: expanded from macro 'readl'
^
./arch/arm64/include/asm/io.h:118:25: note: expanded from macro '__iormb'
asm volatile("eor %w0, %1, %1\n" \
^
Though we disable Clang's integrated assembler with -no-integrated-as,
it still tries to do some validation of assembler constraints.
While __iormb() is type agnostic to operand widths for argument v, its
lone use is to zero'd out via eor (exclusive or).
Fixes commit 6460d3201471 ("arm64: io: Ensure calls to delay routines
are ordered against prior readX()")
Link: https://github.com/ClangBuiltLinux/continuous-integration/issues/78
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Nick Desaulniers <nick.desaulniers@gmail.com>
---
Side note: is it not correct to cite SHAs from linux-next in "Fixes
commit ..." lines? I guess we can drop it.
Link to regression build:
https://travis-ci.com/ClangBuiltLinux/continuous-integration/builds/92799938
Link to build w/ this patch:
https://travis-ci.com/ClangBuiltLinux/continuous-integration/builds/92935901
arch/arm64/include/asm/io.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index d42d00d8d5b6..dbdebf81162b 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -115,7 +115,7 @@ static inline u64 __raw_readq(const volatile void __iomem *addr)
* later instructions. This ensures that a subsequent call to \
* udelay() will be ordered due to the ISB in get_cycles(). \
*/ \
- asm volatile("eor %0, %1, %1\n" \
+ asm volatile("eor %0, %x1, %x1\n" \
"cbnz %0, ." \
: "=r" (tmp) : "r" (v) : "memory"); \
})
--
2.17.1
next reply other threads:[~2018-11-29 4:19 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-29 4:19 Nick Desaulniers [this message]
2018-11-29 9:03 ` [PATCH] arm64: io: specify asm operand width for __iormb() Julien Thierry
2018-11-29 10:49 ` Will Deacon
2018-11-29 16:10 ` Nathan Chancellor
2018-11-29 16:13 ` Will Deacon
2018-11-29 16:17 ` Nathan Chancellor
2018-11-29 16:37 ` Will Deacon
2018-11-29 16:14 ` Russell King - ARM Linux
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