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authorNick Piggin <npiggin@suse.de>2008-05-21 10:12:31 -0400
committerPaul Mackerras <paulus@samba.org>2008-06-30 08:30:25 -0400
commit74f0609526afddd88bef40b651da24f3167b10b2 (patch)
treebe6d04cbc81d37957f484b4085113765c9903e4c /include/asm-powerpc
parente9a4b6a3f6592862a67837e80aad3f50468857a6 (diff)
powerpc: Optimise smp_wmb on 64-bit processors
For 64-bit processors, lwsync is the recommended method of store/store ordering on caching enabled memory. For those subarchs which have lwsync, use it rather than eieio for smp_wmb. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'include/asm-powerpc')
-rw-r--r--include/asm-powerpc/system.h13
1 files changed, 10 insertions, 3 deletions
diff --git a/include/asm-powerpc/system.h b/include/asm-powerpc/system.h
index d1ced5029c42..145b70f6d22b 100644
--- a/include/asm-powerpc/system.h
+++ b/include/asm-powerpc/system.h
@@ -30,8 +30,8 @@
30 * 30 *
31 * For wmb(), we use sync since wmb is used in drivers to order 31 * For wmb(), we use sync since wmb is used in drivers to order
32 * stores to system memory with respect to writes to the device. 32 * stores to system memory with respect to writes to the device.
33 * However, smp_wmb() can be a lighter-weight eieio barrier on 33 * However, smp_wmb() can be a lighter-weight lwsync or eieio barrier
34 * SMP since it is only used to order updates to system memory. 34 * on SMP since it is only used to order updates to system memory.
35 */ 35 */
36#define mb() __asm__ __volatile__ ("sync" : : : "memory") 36#define mb() __asm__ __volatile__ ("sync" : : : "memory")
37#define rmb() __asm__ __volatile__ ("sync" : : : "memory") 37#define rmb() __asm__ __volatile__ ("sync" : : : "memory")
@@ -43,9 +43,16 @@
43#ifdef __KERNEL__ 43#ifdef __KERNEL__
44#define AT_VECTOR_SIZE_ARCH 6 /* entries in ARCH_DLINFO */ 44#define AT_VECTOR_SIZE_ARCH 6 /* entries in ARCH_DLINFO */
45#ifdef CONFIG_SMP 45#ifdef CONFIG_SMP
46
47#ifdef __SUBARCH_HAS_LWSYNC
48# define SMPWMB lwsync
49#else
50# define SMPWMB eieio
51#endif
52
46#define smp_mb() mb() 53#define smp_mb() mb()
47#define smp_rmb() rmb() 54#define smp_rmb() rmb()
48#define smp_wmb() eieio() 55#define smp_wmb() __asm__ __volatile__ (__stringify(SMPWMB) : : :"memory")
49#define smp_read_barrier_depends() read_barrier_depends() 56#define smp_read_barrier_depends() read_barrier_depends()
50#else 57#else
51#define smp_mb() barrier() 58#define smp_mb() barrier()