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-rw-r--r--include/asm-powerpc/system.h26
1 files changed, 17 insertions, 9 deletions
diff --git a/include/asm-powerpc/system.h b/include/asm-powerpc/system.h
index d075725..4c9f522 100644
--- a/include/asm-powerpc/system.h
+++ b/include/asm-powerpc/system.h
@@ -39,7 +39,6 @@
#define read_barrier_depends() do { } while(0)
#define set_mb(var, value) do { var = value; mb(); } while (0)
-#define set_wmb(var, value) do { var = value; wmb(); } while (0)
#ifdef __KERNEL__
#ifdef CONFIG_SMP
@@ -54,6 +53,15 @@
#define smp_read_barrier_depends() do { } while(0)
#endif /* CONFIG_SMP */
+/*
+ * This is a barrier which prevents following instructions from being
+ * started until the value of the argument x is known. For example, if
+ * x is a variable loaded from memory, this prevents following
+ * instructions from being executed until the load has been performed.
+ */
+#define data_barrier(x) \
+ asm volatile("twi 0,%0,0; isync" : : "r" (x) : "memory");
+
struct task_struct;
struct pt_regs;
@@ -220,8 +228,8 @@ __xchg_u32(volatile void *p, unsigned long val)
" stwcx. %3,0,%2 \n\
bne- 1b"
ISYNC_ON_SMP
- : "=&r" (prev), "=m" (*(volatile unsigned int *)p)
- : "r" (p), "r" (val), "m" (*(volatile unsigned int *)p)
+ : "=&r" (prev), "+m" (*(volatile unsigned int *)p)
+ : "r" (p), "r" (val)
: "cc", "memory");
return prev;
@@ -240,8 +248,8 @@ __xchg_u64(volatile void *p, unsigned long val)
" stdcx. %3,0,%2 \n\
bne- 1b"
ISYNC_ON_SMP
- : "=&r" (prev), "=m" (*(volatile unsigned long *)p)
- : "r" (p), "r" (val), "m" (*(volatile unsigned long *)p)
+ : "=&r" (prev), "+m" (*(volatile unsigned long *)p)
+ : "r" (p), "r" (val)
: "cc", "memory");
return prev;
@@ -299,8 +307,8 @@ __cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new)
ISYNC_ON_SMP
"\n\
2:"
- : "=&r" (prev), "=m" (*p)
- : "r" (p), "r" (old), "r" (new), "m" (*p)
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
: "cc", "memory");
return prev;
@@ -322,8 +330,8 @@ __cmpxchg_u64(volatile unsigned long *p, unsigned long old, unsigned long new)
ISYNC_ON_SMP
"\n\
2:"
- : "=&r" (prev), "=m" (*p)
- : "r" (p), "r" (old), "r" (new), "m" (*p)
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
: "cc", "memory");
return prev;
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