[patch 03/23] Add cmpxchg_local to arm

Mathieu Desnoyers
2007-08-20T20:23:40Z

[-- Attachment #1: add-cmpxchg-local-to-arm.patch --]
[-- Type: text/plain, Size: 2207 bytes --]

Use the new generic cmpxchg_local (disables interrupt). Also use the generic
cmpxchg as fallback if SMP is not set.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: clameter@sgi.com
CC: rmk@arm.linux.org.uk
---
include/asm-arm/system.h | 43 +++++++++++--------------------------------
1 file changed, 11 insertions(+), 32 deletions(-)

Index: linux-2.6-lttng/include/asm-arm/system.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-arm/system.h 2007-08-07 11:03:37.000000000 -0400
+++ linux-2.6-lttng/include/asm-arm/system.h 2007-08-07 11:19:40.000000000 -0400
@@ -350,40 +350,19 @@ static inline unsigned long __xchg(unsig
extern void disable_hlt(void);
extern void enable_hlt(void);

-#ifndef CONFIG_SMP
+#include <asm-generic/cmpxchg-local.h>
+
/*
- * Atomic compare and exchange.
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * then available.
*/
-#define __HAVE_ARCH_CMPXCHG 1
-
-extern unsigned long wrong_size_cmpxchg(volatile void *ptr);
-
-static inline unsigned long __cmpxchg(volatile void *ptr,
- unsigned long old,
- unsigned long new, int size)
-{
- unsigned long flags, prev;
- volatile unsigned long *p = ptr;
-
- if (size == 4) {
- local_irq_save(flags);
- prev = *p;
- if (prev == old)
- *p = new;
- local_irq_restore(flags);
- return prev;
- } else
- return wrong_size_cmpxchg(ptr);
-}
-
-#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 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))
+
+#ifndef CONFIG_SMP
+#include <asm-generic/cmpxchg.h>
#endif

#endif /* __ASSEMBLY__ */