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
Cc: linux-kernel@vger.kernel.org, torvalds@linux-foundation.org,
Paul Burton <paul.burton@mips.com>
Subject: [RFC][PATCH 1/5] mips/atomic: Fix cmpxchg64 barriers
Date: Wed, 24 Apr 2019 14:36:57 +0200 [thread overview]
Message-ID: <20190424124421.579563933@infradead.org> (raw)
In-Reply-To: 20190424123656.484227701@infradead.org
There were no memory barriers on cmpxchg64() _at_all_. Fix this.
Cc: Paul Burton <paul.burton@mips.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/mips/include/asm/cmpxchg.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/arch/mips/include/asm/cmpxchg.h
+++ b/arch/mips/include/asm/cmpxchg.h
@@ -290,9 +290,11 @@ 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:[~2019-04-24 12:48 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-24 12:36 [RFC][PATCH 0/5] atomic: Fixes to smp_mb__{before,after}_atomic() and mips Peter Zijlstra
2019-04-24 12:36 ` Peter Zijlstra [this message]
2019-04-24 21:00 ` [RFC][PATCH 1/5] mips/atomic: Fix cmpxchg64 barriers Paul Burton
2019-04-25 6:59 ` Peter Zijlstra
2019-04-24 12:36 ` [RFC][PATCH 2/5] mips/atomic: Fix loongson_llsc_mb() wreckage Peter Zijlstra
2019-04-24 12:59 ` Peter Zijlstra
2019-04-24 21:18 ` Paul Burton
2019-04-25 4:58 ` huangpei
2019-04-25 7:33 ` Peter Zijlstra
2019-04-25 9:09 ` Peter Zijlstra
2019-04-25 12:14 ` huangpei
2019-04-25 9:12 ` Peter Zijlstra
2019-05-14 15:58 ` Peter Zijlstra
2019-05-14 16:10 ` Linus Torvalds
2019-05-14 16:56 ` Peter Zijlstra
2019-05-14 17:07 ` Linus Torvalds
2019-05-15 13:50 ` huangpei
2019-04-25 11:32 ` huangpei
2019-04-25 12:26 ` Peter Zijlstra
2019-04-25 12:51 ` huangpei
2019-04-25 13:31 ` Peter Zijlstra
2019-04-26 2:57 ` huangpei
2019-05-14 15:46 ` Peter Zijlstra
2019-04-25 16:12 ` Linus Torvalds
2019-04-25 7:15 ` Peter Zijlstra
2019-04-24 12:36 ` [RFC][PATCH 3/5] mips/atomic: Optimize loongson3_llsc_mb() Peter Zijlstra
2019-04-24 12:37 ` [RFC][PATCH 4/5] mips/atomic: Fix smp_mb__{before,after}_atomic() Peter Zijlstra
2019-04-24 21:24 ` Paul Burton
2019-04-25 7:34 ` Peter Zijlstra
2019-04-24 12:37 ` [RFC][PATCH 5/5] x86/atomic: " Peter Zijlstra
2019-04-24 13:41 ` Will Deacon
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