From: David Howells <dhowells@redhat.com>
Date: Thu, 10 Apr 2008 15:11:05 +0000 (+0100)
Subject: FRV: Don't make smp_{r, w, }mb() interpolate MEMBAR when CONFIG_SMP=n [try #2]
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f17520e1f19172057328e50ffed01a42534921e9;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git

FRV: Don't make smp_{r, w, }mb() interpolate MEMBAR when CONFIG_SMP=n [try #2]

Don't make smp_{r,w,}mb() interpolate a MEMBAR instruction when CONFIG_SMP=n as
SMP memory barries on UP systems should interpolate a compiler barrier only.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/include/asm-frv/system.h b/include/asm-frv/system.h
index 2c57f4734746..30a67a9da11a 100644
--- a/include/asm-frv/system.h
+++ b/include/asm-frv/system.h
@@ -179,14 +179,23 @@ do {							\
 #define mb()			asm volatile ("membar" : : :"memory")
 #define rmb()			asm volatile ("membar" : : :"memory")
 #define wmb()			asm volatile ("membar" : : :"memory")
-#define set_mb(var, value)	do { var = value; mb(); } while (0)
+#define read_barrier_depends()	barrier()
 
-#define smp_mb()		mb()
-#define smp_rmb()		rmb()
-#define smp_wmb()		wmb()
-
-#define read_barrier_depends()		do {} while(0)
+#ifdef CONFIG_SMP
+#define smp_mb()			mb()
+#define smp_rmb()			rmb()
+#define smp_wmb()			wmb()
 #define smp_read_barrier_depends()	read_barrier_depends()
+#define set_mb(var, value) \
+	do { xchg(&var, (value)); } while (0)
+#else
+#define smp_mb()			barrier()
+#define smp_rmb()			barrier()
+#define smp_wmb()			barrier()
+#define smp_read_barrier_depends()	do {} while(0)
+#define set_mb(var, value) \
+	do { var = (value); barrier(); } while (0)
+#endif
 
 #define HARD_RESET_NOW()			\
 do {						\