[patch 22/28] Add cmpxchg_local to s390

Mathieu Desnoyers
2007-10-31T22:50:49Z

[-- Attachment #1: add-cmpxchg-local-to-s390.patch --]
[-- Type: text/plain, Size: 2401 bytes --]

Use the standard __cmpxchg for every type that can be updated atomically.
Use the new generic cmpxchg_local (disables interrupt) for other types.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: clameter@sgi.com
CC: schwidefsky@de.ibm.com
CC: linux390@de.ibm.com
---
include/asm-s390/system.h | 44 +++++++++++++++++++++++++++++++++++++++++---
1 file changed, 41 insertions(+), 3 deletions(-)

Index: linux-2.6-lttng/include/asm-s390/system.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-s390/system.h 2007-10-31 17:32:43.000000000 -0400
+++ linux-2.6-lttng/include/asm-s390/system.h 2007-10-31 18:26:02.000000000 -0400
@@ -201,9 +201,9 @@ static inline unsigned long __xchg(unsig

#define __HAVE_ARCH_CMPXCHG 1

-#define cmpxchg(ptr,o,n)\
- ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
- (unsigned long)(n),sizeof(*(ptr))))
+#define cmpxchg(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
+ (unsigned long)(n), sizeof(*(ptr))))

extern void __cmpxchg_called_with_bad_pointer(void);

@@ -355,6 +355,44 @@ __cmpxchg(volatile void *ptr, unsigned l

#include <linux/irqflags.h>

+#include <asm-generic/cmpxchg-local.h>
+
+static inline unsigned long __cmpxchg_local(volatile void *ptr,
+ unsigned long old,
+ unsigned long new, int size)
+{
+ switch (size) {
+ case 1:
+ case 2:
+ case 4:
+#ifdef __s390x__
+ case 8:
+#endif
+ return __cmpxchg(ptr, old, new, size);
+ default:
+ return __cmpxchg_local_generic(ptr, old, new, size);
+ }
+
+ return old;
+}
+
+/*
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * them available.
+ */
+#define cmpxchg_local(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
+ (unsigned long)(n), sizeof(*(ptr))))
+#ifdef __s390x__
+#define cmpxchg64_local(ptr, o, n) \
+ ({ \
+ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
+ cmpxchg_local((ptr), (o), (n)); \
+ })
+#else
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+#endif
+
/*
* Use to set psw mask except for the first byte which
* won't be changed by this function.