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author | Andrea Parri <parri.andrea@gmail.com> | 2018-02-22 10:24:29 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2018-02-23 08:38:15 +0100 |
commit | 79d442461df7478cdd0c50d9b8a76f431f150fa3 (patch) | |
tree | 53ec8c34409ef60806faae9ee2bdff17c301875f /arch/alpha/include/asm/xchg.h | |
parent | locking/xchg/alpha: Add unconditional memory barrier to cmpxchg() (diff) | |
download | linux-dev-79d442461df7478cdd0c50d9b8a76f431f150fa3.tar.xz linux-dev-79d442461df7478cdd0c50d9b8a76f431f150fa3.zip |
locking/xchg/alpha: Clean up barrier usage by using smp_mb() in place of __ASM__MB
Replace each occurrence of __ASM__MB with a (trailing) smp_mb() in
xchg(), cmpxchg(), and remove the now unused __ASM__MB definitions;
this improves readability, with no additional synchronization cost.
Suggested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-alpha@vger.kernel.org
Link: http://lkml.kernel.org/r/1519291469-5702-1-git-send-email-parri.andrea@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/alpha/include/asm/xchg.h')
-rw-r--r-- | arch/alpha/include/asm/xchg.h | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/arch/alpha/include/asm/xchg.h b/arch/alpha/include/asm/xchg.h index e2660866ce97..e1facf6fc244 100644 --- a/arch/alpha/include/asm/xchg.h +++ b/arch/alpha/include/asm/xchg.h @@ -28,12 +28,12 @@ ____xchg(_u8, volatile char *m, unsigned long val) " or %1,%2,%2\n" " stq_c %2,0(%3)\n" " beq %2,2f\n" - __ASM__MB ".subsection 2\n" "2: br 1b\n" ".previous" : "=&r" (ret), "=&r" (val), "=&r" (tmp), "=&r" (addr64) : "r" ((long)m), "1" (val) : "memory"); + smp_mb(); return ret; } @@ -52,12 +52,12 @@ ____xchg(_u16, volatile short *m, unsigned long val) " or %1,%2,%2\n" " stq_c %2,0(%3)\n" " beq %2,2f\n" - __ASM__MB ".subsection 2\n" "2: br 1b\n" ".previous" : "=&r" (ret), "=&r" (val), "=&r" (tmp), "=&r" (addr64) : "r" ((long)m), "1" (val) : "memory"); + smp_mb(); return ret; } @@ -72,12 +72,12 @@ ____xchg(_u32, volatile int *m, unsigned long val) " bis $31,%3,%1\n" " stl_c %1,%2\n" " beq %1,2f\n" - __ASM__MB ".subsection 2\n" "2: br 1b\n" ".previous" : "=&r" (val), "=&r" (dummy), "=m" (*m) : "rI" (val), "m" (*m) : "memory"); + smp_mb(); return val; } @@ -92,12 +92,12 @@ ____xchg(_u64, volatile long *m, unsigned long val) " bis $31,%3,%1\n" " stq_c %1,%2\n" " beq %1,2f\n" - __ASM__MB ".subsection 2\n" "2: br 1b\n" ".previous" : "=&r" (val), "=&r" (dummy), "=m" (*m) : "rI" (val), "m" (*m) : "memory"); + smp_mb(); return val; } @@ -150,12 +150,12 @@ ____cmpxchg(_u8, volatile char *m, unsigned char old, unsigned char new) " stq_c %2,0(%4)\n" " beq %2,3f\n" "2:\n" - __ASM__MB ".subsection 2\n" "3: br 1b\n" ".previous" : "=&r" (prev), "=&r" (new), "=&r" (tmp), "=&r" (cmp), "=&r" (addr64) : "r" ((long)m), "Ir" (old), "1" (new) : "memory"); + smp_mb(); return prev; } @@ -177,12 +177,12 @@ ____cmpxchg(_u16, volatile short *m, unsigned short old, unsigned short new) " stq_c %2,0(%4)\n" " beq %2,3f\n" "2:\n" - __ASM__MB ".subsection 2\n" "3: br 1b\n" ".previous" : "=&r" (prev), "=&r" (new), "=&r" (tmp), "=&r" (cmp), "=&r" (addr64) : "r" ((long)m), "Ir" (old), "1" (new) : "memory"); + smp_mb(); return prev; } @@ -200,12 +200,12 @@ ____cmpxchg(_u32, volatile int *m, int old, int new) " stl_c %1,%2\n" " beq %1,3f\n" "2:\n" - __ASM__MB ".subsection 2\n" "3: br 1b\n" ".previous" : "=&r"(prev), "=&r"(cmp), "=m"(*m) : "r"((long) old), "r"(new), "m"(*m) : "memory"); + smp_mb(); return prev; } @@ -223,12 +223,12 @@ ____cmpxchg(_u64, volatile long *m, unsigned long old, unsigned long new) " stq_c %1,%2\n" " beq %1,3f\n" "2:\n" - __ASM__MB ".subsection 2\n" "3: br 1b\n" ".previous" : "=&r"(prev), "=&r"(cmp), "=m"(*m) : "r"((long) old), "r"(new), "m"(*m) : "memory"); + smp_mb(); return prev; } |