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authorAnton Arapov <anton@redhat.com>2012-06-08 12:58:00 +0200
committerAnton Arapov <anton@redhat.com>2012-06-08 12:58:00 +0200
commit6792a3f47a2e42d7164292bf7f1a55cfc4c91652 (patch)
treeb90c002bfbbeaec92f5d8a2383dcabf6524016f7 /arch/sparc/include/asm/cmpxchg_64.h
parentfe2895d3d55146cac65b273c0f83e2c7e543cd0e (diff)
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fedora kernel: b920e9b748c595f970bf80ede7832d39f8d567dav3.4.1-2
Signed-off-by: Anton Arapov <anton@redhat.com>
Diffstat (limited to 'arch/sparc/include/asm/cmpxchg_64.h')
-rw-r--r--arch/sparc/include/asm/cmpxchg_64.h145
1 files changed, 145 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/cmpxchg_64.h b/arch/sparc/include/asm/cmpxchg_64.h
new file mode 100644
index 00000000000..b30eb37294c
--- /dev/null
+++ b/arch/sparc/include/asm/cmpxchg_64.h
@@ -0,0 +1,145 @@
+/* 64-bit atomic xchg() and cmpxchg() definitions.
+ *
+ * Copyright (C) 1996, 1997, 2000 David S. Miller (davem@redhat.com)
+ */
+
+#ifndef __ARCH_SPARC64_CMPXCHG__
+#define __ARCH_SPARC64_CMPXCHG__
+
+static inline unsigned long xchg32(__volatile__ unsigned int *m, unsigned int val)
+{
+ unsigned long tmp1, tmp2;
+
+ __asm__ __volatile__(
+" mov %0, %1\n"
+"1: lduw [%4], %2\n"
+" cas [%4], %2, %0\n"
+" cmp %2, %0\n"
+" bne,a,pn %%icc, 1b\n"
+" mov %1, %0\n"
+ : "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
+ : "0" (val), "r" (m)
+ : "cc", "memory");
+ return val;
+}
+
+static inline unsigned long xchg64(__volatile__ unsigned long *m, unsigned long val)
+{
+ unsigned long tmp1, tmp2;
+
+ __asm__ __volatile__(
+" mov %0, %1\n"
+"1: ldx [%4], %2\n"
+" casx [%4], %2, %0\n"
+" cmp %2, %0\n"
+" bne,a,pn %%xcc, 1b\n"
+" mov %1, %0\n"
+ : "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
+ : "0" (val), "r" (m)
+ : "cc", "memory");
+ return val;
+}
+
+#define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
+
+extern void __xchg_called_with_bad_pointer(void);
+
+static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr,
+ int size)
+{
+ switch (size) {
+ case 4:
+ return xchg32(ptr, x);
+ case 8:
+ return xchg64(ptr, x);
+ }
+ __xchg_called_with_bad_pointer();
+ return x;
+}
+
+/*
+ * Atomic compare and exchange. Compare OLD with MEM, if identical,
+ * store NEW in MEM. Return the initial value in MEM. Success is
+ * indicated by comparing RETURN with OLD.
+ */
+
+#include <asm-generic/cmpxchg-local.h>
+
+#define __HAVE_ARCH_CMPXCHG 1
+
+static inline unsigned long
+__cmpxchg_u32(volatile int *m, int old, int new)
+{
+ __asm__ __volatile__("cas [%2], %3, %0"
+ : "=&r" (new)
+ : "0" (new), "r" (m), "r" (old)
+ : "memory");
+
+ return new;
+}
+
+static inline unsigned long
+__cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new)
+{
+ __asm__ __volatile__("casx [%2], %3, %0"
+ : "=&r" (new)
+ : "0" (new), "r" (m), "r" (old)
+ : "memory");
+
+ return new;
+}
+
+/* This function doesn't exist, so you'll get a linker error
+ if something tries to do an invalid cmpxchg(). */
+extern void __cmpxchg_called_with_bad_pointer(void);
+
+static inline unsigned long
+__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
+{
+ switch (size) {
+ case 4:
+ return __cmpxchg_u32(ptr, old, new);
+ case 8:
+ return __cmpxchg_u64(ptr, old, new);
+ }
+ __cmpxchg_called_with_bad_pointer();
+ 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))); \
+ })
+
+/*
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * them available.
+ */
+
+static inline unsigned long __cmpxchg_local(volatile void *ptr,
+ unsigned long old,
+ unsigned long new, int size)
+{
+ switch (size) {
+ case 4:
+ case 8: return __cmpxchg(ptr, old, new, size);
+ default:
+ return __cmpxchg_local_generic(ptr, old, new, size);
+ }
+
+ return old;
+}
+
+#define cmpxchg_local(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
+ (unsigned long)(n), sizeof(*(ptr))))
+#define cmpxchg64_local(ptr, o, n) \
+ ({ \
+ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
+ cmpxchg_local((ptr), (o), (n)); \
+ })
+
+#endif /* __ARCH_SPARC64_CMPXCHG__ */