[patch 22/28] Add cmpxchg_local to s390

Mathieu Desnoyers
2007-10-30T19:22:40Z

[-- Attachment #1: add-cmpxchg-local-to-s390.patch --]
[-- Type: text/plain, Size: 1873 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 | 34 ++++++++++++++++++++++++++++++++++
1 file changed, 34 insertions(+)

Index: linux-2.6-lttng/include/asm-s390/system.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-s390/system.h 2007-08-27 11:46:43.000000000 -0400
+++ linux-2.6-lttng/include/asm-s390/system.h 2007-08-27 11:48:38.000000000 -0400
@@ -355,6 +355,40 @@ __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) 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.