powerpc/64: Fix smp_wmb barrier definition use use lwsync consistently

commit 0bfdf598900fd62869659f360d3387ed80eb71cf upstream.

asm/barrier.h is not always included after asm/synch.h, which meant
it was missing __SUBARCH_HAS_LWSYNC, so in some files smp_wmb() would
be eieio when it should be lwsync. kernel/time/hrtimer.c is one case.

__SUBARCH_HAS_LWSYNC is only used in one place, so just fold it in
to where it's used. Previously with my small simulator config, 377
instances of eieio in the tree. After this patch there are 55.

Fixes: 46d075be585e ("powerpc: Optimise smp_wmb")
Cc: stable@vger.kernel.org # v2.6.29+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h
index bab79a110c7b05ceb8a4320efe4290257e186250..7c63ec5d4fa9b9007411770347b80491a95d6c08 100644 (file)
--- a/arch/powerpc/include/asm/barrier.h
+++ b/arch/powerpc/include/asm/barrier.h
@@ -39,7 +39,8 @@
 
 #ifdef CONFIG_SMP
 
-#ifdef __SUBARCH_HAS_LWSYNC
+/* The sub-arch has lwsync */
+#if defined(__powerpc64__) || defined(CONFIG_PPC_E500MC)
 #    define SMPWMB      LWSYNC
 #else
 #    define SMPWMB      eieio

diff --git a/arch/powerpc/include/asm/synch.h b/arch/powerpc/include/asm/synch.h
index e682a7143edb767826705243df3613cc85e305ab..e344d98239a76b3b0207d067b65cbcd5b9cb8006 100644 (file)
--- a/arch/powerpc/include/asm/synch.h
+++ b/arch/powerpc/include/asm/synch.h
@@ -5,10 +5,6 @@
 #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,