Author: nwhitehorn
Date: Sun Apr 22 22:27:35 2012
New Revision: 234590
URL: http://svn.freebsd.org/changeset/base/234590
Log:
Provide a clearer split between read/write and acquire/release barriers.
This should really, actually be correct now.
Modified:
head/sys/powerpc/include/atomic.h
Modified: head/sys/powerpc/include/atomic.h
==============================================================================
--- head/sys/powerpc/include/atomic.h Sun Apr 22 21:55:19 2012
(r234589)
+++ head/sys/powerpc/include/atomic.h Sun Apr 22 22:27:35 2012
(r234590)
@@ -38,20 +38,25 @@
/* NOTE: lwsync is equivalent to sync on systems without lwsync */
#define mb() __asm __volatile("lwsync" : : : "memory")
+#ifdef __powerpc64__
+#define rmb() __asm __volatile("lwsync" : : : "memory")
#define wmb() __asm __volatile("lwsync" : : : "memory")
+#else
#define rmb() __asm __volatile("lwsync" : : : "memory")
+#define wmb() __asm __volatile("eieio" : : : "memory")
+#endif
/*
- * The __ATOMIC_XMB() macros provide memory barriers only in conjunction
+ * The __ATOMIC_REL/ACQ() macros provide memory barriers only in conjunction
* with the atomic lXarx/stXcx. sequences below. See Appendix B.2 of Book II
* of the architecture manual.
*/
#ifdef __powerpc64__
-#define __ATOMIC_WMB() __asm __volatile("lwsync" : : : "memory")
-#define __ATOMIC_RMB() __asm __volatile("lwsync" : : : "memory")
+#define __ATOMIC_REL() __asm __volatile("lwsync" : : : "memory")
+#define __ATOMIC_ACQ() __asm __volatile("lwsync" : : : "memory")
#else
-#define __ATOMIC_WMB() __asm __volatile("eieio" : : : "memory")
-#define __ATOMIC_RMB() __asm __volatile("isync" : : : "memory")
+#define __ATOMIC_REL() __asm __volatile("lwsync" : : : "memory")
+#define __ATOMIC_ACQ() __asm __volatile("isync" : : : "memory")
#endif
/*
@@ -105,13 +110,13 @@
atomic_add_acq_##type(volatile u_##type *p, u_##type v) { \
u_##type t; \
__atomic_add_##type(p, v, t); \
- __ATOMIC_RMB(); \
+ __ATOMIC_ACQ(); \
} \
\
static __inline void \
atomic_add_rel_##type(volatile u_##type *p, u_##type v) { \
u_##type t; \
- __ATOMIC_WMB(); \
+ __ATOMIC_REL(); \
__atomic_add_##type(p, v, t); \
} \
/* _ATOMIC_ADD */
@@ -191,13 +196,13 @@ _ATOMIC_ADD(long)
atomic_clear_acq_##type(volatile u_##type *p, u_##type v) { \
u_##type t; \
__atomic_clear_##type(p, v, t); \
- __ATOMIC_RMB(); \
+ __ATOMIC_ACQ(); \
} \
\
static __inline void \
atomic_clear_rel_##type(volatile u_##type *p, u_##type v) { \
u_##type t; \
- __ATOMIC_WMB(); \
+ __ATOMIC_REL(); \
__atomic_clear_##type(p, v, t); \
} \
/* _ATOMIC_CLEAR */
@@ -293,13 +298,13 @@ _ATOMIC_CLEAR(long)
atomic_set_acq_##type(volatile u_##type *p, u_##type v) { \
u_##type t; \
__atomic_set_##type(p, v, t); \
- __ATOMIC_RMB(); \
+ __ATOMIC_ACQ(); \
} \
\
static __inline void \
atomic_set_rel_##type(volatile u_##type *p, u_##type v) { \
u_##type t; \
- __ATOMIC_WMB(); \
+ __ATOMIC_REL(); \
__atomic_set_##type(p, v, t); \
} \
/* _ATOMIC_SET */
@@ -379,13 +384,13 @@ _ATOMIC_SET(long)
atomic_subtract_acq_##type(volatile u_##type *p, u_##type v) { \
u_##type t; \
__atomic_subtract_##type(p, v, t); \
- __ATOMIC_RMB(); \
+ __ATOMIC_ACQ(); \
} \
\
static __inline void \
atomic_subtract_rel_##type(volatile u_##type *p, u_##type v) { \
u_##type t; \
- __ATOMIC_WMB(); \
+ __ATOMIC_REL(); \
__atomic_subtract_##type(p, v, t); \
} \
/* _ATOMIC_SUBTRACT */
@@ -492,14 +497,14 @@ atomic_load_acq_##TYPE(volatile u_##TYPE
u_##TYPE v; \
\
v = *p; \
- rmb(); \
+ mb(); \
return (v); \
} \
\
static __inline void \
atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v) \
{ \
- wmb(); \
+ mb(); \
*p = v; \
}
@@ -609,14 +614,14 @@ atomic_cmpset_acq_int(volatile u_int *p,
int retval;
retval = atomic_cmpset_int(p, cmpval, newval);
- __ATOMIC_RMB();
+ __ATOMIC_ACQ();
return (retval);
}
static __inline int
atomic_cmpset_rel_int(volatile u_int *p, u_int cmpval, u_int newval)
{
- wmb();
+ __ATOMIC_REL();
return (atomic_cmpset_int(p, cmpval, newval));
}
@@ -626,14 +631,14 @@ atomic_cmpset_acq_long(volatile u_long *
u_long retval;
retval = atomic_cmpset_long(p, cmpval, newval);
- __ATOMIC_RMB();
+ __ATOMIC_ACQ();
return (retval);
}
static __inline int
atomic_cmpset_rel_long(volatile u_long *p, u_long cmpval, u_long newval)
{
- wmb();
+ __ATOMIC_REL();
return (atomic_cmpset_long(p, cmpval, newval));
}
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