Add cmpxchg_local to sparc, move __cmpxchg to system.h
Move cmpxchg and add cmpxchg_local to system.h.
Use the new generic cmpxchg_local (disables interrupt).
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/asm-sparc/system.h b/include/asm-sparc/system.h
index 2655d14..45e47c1 100644
--- a/include/asm-sparc/system.h
+++ b/include/asm-sparc/system.h
@@ -225,6 +225,54 @@
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__ */