lkml.org 
[lkml]   [2013]   [Sep]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC PATCH 1/4] asm-generic: cmpxchg: implement dummy cmpxchg64_relaxed operation
Date
cmpxchg64_relaxed can be used to provide barrier-less semantics for a
64-bit cmpxchg operation in cases where the strong memory ordering is
not required.

This patch implements a dummy implementation for asm-generic, falling
back to the usual cmpxchg64 code.

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
include/asm-generic/cmpxchg.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/asm-generic/cmpxchg.h b/include/asm-generic/cmpxchg.h
index 811fb1e..298b9d4 100644
--- a/include/asm-generic/cmpxchg.h
+++ b/include/asm-generic/cmpxchg.h
@@ -102,7 +102,8 @@ unsigned long __xchg(unsigned long x, volatile void *ptr, int size)
#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
#endif

-#define cmpxchg(ptr, o, n) cmpxchg_local((ptr), (o), (n))
-#define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n))
+#define cmpxchg(ptr, o, n) cmpxchg_local((ptr), (o), (n))
+#define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n))
+#define cmpxchg64_relaxed(ptr, o, n) cmpxchg64((ptr), (o), (n))

#endif /* __ASM_GENERIC_CMPXCHG_H */
--
1.8.2.2


\
 
 \ /
  Last update: 2013-09-26 18:01    [W:0.058 / U:0.080 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site