From: Peter Zijlstra <peterz@infradead.org>
To: stern@rowland.harvard.edu, akiyks@gmail.com,
andrea.parri@amarulasolutions.com, boqun.feng@gmail.com,
dlustig@nvidia.com, dhowells@redhat.com, j.alglave@ucl.ac.uk,
luc.maranget@inria.fr, npiggin@gmail.com, paulmck@linux.ibm.com,
peterz@infradead.org, will.deacon@arm.com, paul.burton@mips.com
Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org
Subject: [PATCH v2 1/4] mips/atomic: Fix cmpxchg64 barriers
Date: Thu, 13 Jun 2019 15:43:18 +0200 [thread overview]
Message-ID: <20190613134932.853419066@infradead.org> (raw)
In-Reply-To: 20190613134317.734881240@infradead.org
There were no memory barriers on the 32bit implementation of
cmpxchg64(). Fix this.
Cc: Paul Burton <paul.burton@mips.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/mips/include/asm/cmpxchg.h | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/arch/mips/include/asm/cmpxchg.h
+++ b/arch/mips/include/asm/cmpxchg.h
@@ -290,10 +290,13 @@ static inline unsigned long __cmpxchg64(
* will cause a build error unless cpu_has_64bits is a \
* compile-time constant 1. \
*/ \
- if (cpu_has_64bits && kernel_uses_llsc) \
+ if (cpu_has_64bits && kernel_uses_llsc) { \
+ smp_mb__before_llsc(); \
__res = __cmpxchg64((ptr), __old, __new); \
- else \
+ smp_llsc_mb(); \
+ } else { \
__res = __cmpxchg64_unsupported(); \
+ } \
\
__res; \
})
next prev parent reply other threads:[~2019-06-13 15:11 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-13 13:43 [PATCH v2 0/4] atomic: Fixes to smp_mb__{before,after}_atomic() and mips Peter Zijlstra
2019-06-13 13:43 ` Peter Zijlstra [this message]
2019-06-13 13:43 ` [PATCH v2 2/4] mips/atomic: Fix loongson_llsc_mb() wreckage Peter Zijlstra
2019-06-13 13:43 ` [PATCH v2 3/4] mips/atomic: Fix smp_mb__{before,after}_atomic() Peter Zijlstra
2019-06-13 13:43 ` [PATCH v2 4/4] x86/atomic: " Peter Zijlstra
2019-06-13 14:02 ` Will Deacon
2019-06-13 14:25 ` [PATCH v2 0/4] atomic: Fixes to smp_mb__{before,after}_atomic() and mips David Howells
2019-06-13 16:58 ` Alan Stern
2019-06-13 18:00 ` Peter Zijlstra
2019-06-13 16:32 ` Paul Burton
2019-06-13 17:48 ` Peter Zijlstra
2019-08-31 9:00 ` Peter Zijlstra
2019-08-31 10:02 ` Paul Burton
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