[patch 25/28] Add cmpxchg_local to sparc, move __cmpxchg to system.h

From: Mathieu Desnoyers
Date: Tue Oct 30 2007 - 15:21:43 EST


Move cmpxchg and add cmpxchg_local to system.h.
Use the new generic cmpxchg_local (disables interrupt).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
CC: clameter@xxxxxxx
CC: wli@xxxxxxxxxxxxxx
CC: sparclinux@xxxxxxxxxxxxxxx
---
include/asm-sparc/atomic.h | 36 ----------------------------------
include/asm-sparc/system.h | 47 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 47 insertions(+), 36 deletions(-)

Index: linux-2.6-lttng/include/asm-sparc/atomic.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-sparc/atomic.h 2007-08-10 19:36:01.000000000 -0400
+++ linux-2.6-lttng/include/asm-sparc/atomic.h 2007-08-10 19:42:47.000000000 -0400
@@ -17,42 +17,6 @@ typedef struct { volatile int counter; }

#ifdef __KERNEL__

-/* Emulate cmpxchg() the same way we emulate atomics,
- * by hashing the object address and indexing into an array
- * of spinlocks to get a bit of performance...
- *
- * See arch/sparc/lib/atomic32.c for implementation.
- *
- * Cribbed from <asm-parisc/atomic.h>
- */
-#define __HAVE_ARCH_CMPXCHG 1
-
-/* bug catcher for when unsupported size is used - won't link */
-extern void __cmpxchg_called_with_bad_pointer(void);
-/* we only need to support cmpxchg of a u32 on sparc */
-extern unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);
-
-/* don't worry...optimizer will get rid of most of this */
-static __inline__ unsigned long
-__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
-{
- switch(size) {
- case 4:
- return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_);
- default:
- __cmpxchg_called_with_bad_pointer();
- break;
- }
- return old;
-}
-
-#define cmpxchg(ptr,o,n) ({ \
- __typeof__(*(ptr)) _o_ = (o); \
- __typeof__(*(ptr)) _n_ = (n); \
- (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
- (unsigned long)_n_, sizeof(*(ptr))); \
-})
-
#define ATOMIC_INIT(i) { (i) }

extern int __atomic_add_return(int, atomic_t *);
Index: linux-2.6-lttng/include/asm-sparc/system.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-sparc/system.h 2007-08-10 19:43:08.000000000 -0400
+++ linux-2.6-lttng/include/asm-sparc/system.h 2007-08-10 19:43:42.000000000 -0400
@@ -245,6 +245,53 @@ static __inline__ unsigned long __xchg(u
return x;
}

+/* Emulate cmpxchg() the same way we emulate atomics,
+ * by hashing the object address and indexing into an array
+ * of spinlocks to get a bit of performance...
+ *
+ * See arch/sparc/lib/atomic32.c for implementation.
+ *
+ * Cribbed from <asm-parisc/atomic.h>
+ */
+#define __HAVE_ARCH_CMPXCHG 1
+
+/* bug catcher for when unsupported size is used - won't link */
+extern void __cmpxchg_called_with_bad_pointer(void);
+/* we only need to support cmpxchg of a u32 on sparc */
+extern unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_);
+
+/* don't worry...optimizer will get rid of most of this */
+static __inline__ unsigned long
+__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
+{
+ switch(size) {
+ case 4:
+ return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_);
+ default:
+ __cmpxchg_called_with_bad_pointer();
+ break;
+ }
+ return old;
+}
+
+#define cmpxchg(ptr,o,n) ({ \
+ __typeof__(*(ptr)) _o_ = (o); \
+ __typeof__(*(ptr)) _n_ = (n); \
+ (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
+ (unsigned long)_n_, sizeof(*(ptr))); \
+})
+
+#include <asm-generic/cmpxchg-local.h>
+
+/*
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * them available.
+ */
+#define cmpxchg_local(ptr,o,n) \
+ (__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o), \
+ (unsigned long)(n), sizeof(*(ptr)))
+#define cmpxchg64_local(ptr,o,n) __cmpxchg64_local_generic((ptr), (o), (n))
+
extern void die_if_kernel(char *str, struct pt_regs *regs) __attribute__ ((noreturn));

#endif /* __KERNEL__ */

--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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