[patch 23/23] Add cmpxchg_local to xtensa

From: Mathieu Desnoyers
Date: Mon Aug 20 2007 - 16:23:21 EST


Use the architecture specific __cmpxchg_u32 for 32 bits cmpxchg)_local. Else,
use the new generic cmpxchg_local (disables interrupt).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
CC: clameter@xxxxxxx
chris@xxxxxxxxxx
---
include/asm-xtensa/system.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)

Index: linux-2.6-lttng/include/asm-xtensa/system.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-xtensa/system.h 2007-07-23 11:29:18.000000000 -0400
+++ linux-2.6-lttng/include/asm-xtensa/system.h 2007-07-23 11:32:32.000000000 -0400
@@ -156,8 +156,30 @@ __cmpxchg(volatile void *ptr, unsigned l
(unsigned long)_n_, sizeof (*(ptr))); \
})

+#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 4:
+ return __cmpxchg_u32(ptr, old, new);
+ 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_generic((ptr), (unsigned long)(o), \
+ (unsigned long)(n), sizeof(*(ptr)))
+#define cmpxchg64_local(ptr,o,n) __cmpxchg64_local_generic((ptr), (o), (n))

/*
* xchg_u32

--
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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