powerpc: Optimise smp_wmb

Change 2d1b202762 ("powerpc: Fixup
lwsync at runtime") removed __SUBARCH_HAS_LWSYNC, causing smp_wmb to
revert back to eieio for all CPUs.  This restores the behaviour
intorduced in 74f0609526 ("powerpc:
Optimise smp_wmb on 64-bit processors").

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Nick Piggin 2008-11-11 17:50:48 +00:00 committed by Paul Mackerras
parent a4e22f02f5
commit 46d075be58
2 changed files with 6 additions and 2 deletions

View file

@ -5,6 +5,10 @@
#include <linux/stringify.h>
#include <asm/feature-fixups.h>
#if defined(__powerpc64__) || defined(CONFIG_PPC_E500MC)
#define __SUBARCH_HAS_LWSYNC
#endif
#ifndef __ASSEMBLY__
extern unsigned int __start___lwsync_fixup, __stop___lwsync_fixup;
extern void do_lwsync_fixups(unsigned long value, void *fixup_start,

View file

@ -45,14 +45,14 @@
#ifdef CONFIG_SMP
#ifdef __SUBARCH_HAS_LWSYNC
# define SMPWMB lwsync
# define SMPWMB LWSYNC
#else
# define SMPWMB eieio
#endif
#define smp_mb() mb()
#define smp_rmb() rmb()
#define smp_wmb() __asm__ __volatile__ (__stringify(SMPWMB) : : :"memory")
#define smp_wmb() __asm__ __volatile__ (stringify_in_c(SMPWMB) : : :"memory")
#define smp_read_barrier_depends() read_barrier_depends()
#else
#define smp_mb() barrier()