summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/include/asm/cmpxchg.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/include/asm/cmpxchg.h')
-rw-r--r--arch/powerpc/include/asm/cmpxchg.h309
1 files changed, 309 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/cmpxchg.h b/arch/powerpc/include/asm/cmpxchg.h
new file mode 100644
index 000000000000..e245aab7f191
--- /dev/null
+++ b/arch/powerpc/include/asm/cmpxchg.h
@@ -0,0 +1,309 @@
+#ifndef _ASM_POWERPC_CMPXCHG_H_
+#define _ASM_POWERPC_CMPXCHG_H_
+
+#ifdef __KERNEL__
+#include <linux/compiler.h>
+#include <asm/synch.h>
+#include <asm/asm-compat.h>
+
+/*
+ * Atomic exchange
+ *
+ * Changes the memory location '*ptr' to be val and returns
+ * the previous value stored there.
+ */
+static __always_inline unsigned long
+__xchg_u32(volatile void *p, unsigned long val)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__(
+ PPC_RELEASE_BARRIER
+"1: lwarx %0,0,%2 \n"
+ PPC405_ERR77(0,%2)
+" stwcx. %3,0,%2 \n\
+ bne- 1b"
+ PPC_ACQUIRE_BARRIER
+ : "=&r" (prev), "+m" (*(volatile unsigned int *)p)
+ : "r" (p), "r" (val)
+ : "cc", "memory");
+
+ return prev;
+}
+
+/*
+ * Atomic exchange
+ *
+ * Changes the memory location '*ptr' to be val and returns
+ * the previous value stored there.
+ */
+static __always_inline unsigned long
+__xchg_u32_local(volatile void *p, unsigned long val)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__(
+"1: lwarx %0,0,%2 \n"
+ PPC405_ERR77(0,%2)
+" stwcx. %3,0,%2 \n\
+ bne- 1b"
+ : "=&r" (prev), "+m" (*(volatile unsigned int *)p)
+ : "r" (p), "r" (val)
+ : "cc", "memory");
+
+ return prev;
+}
+
+#ifdef CONFIG_PPC64
+static __always_inline unsigned long
+__xchg_u64(volatile void *p, unsigned long val)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__(
+ PPC_RELEASE_BARRIER
+"1: ldarx %0,0,%2 \n"
+ PPC405_ERR77(0,%2)
+" stdcx. %3,0,%2 \n\
+ bne- 1b"
+ PPC_ACQUIRE_BARRIER
+ : "=&r" (prev), "+m" (*(volatile unsigned long *)p)
+ : "r" (p), "r" (val)
+ : "cc", "memory");
+
+ return prev;
+}
+
+static __always_inline unsigned long
+__xchg_u64_local(volatile void *p, unsigned long val)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__(
+"1: ldarx %0,0,%2 \n"
+ PPC405_ERR77(0,%2)
+" stdcx. %3,0,%2 \n\
+ bne- 1b"
+ : "=&r" (prev), "+m" (*(volatile unsigned long *)p)
+ : "r" (p), "r" (val)
+ : "cc", "memory");
+
+ return prev;
+}
+#endif
+
+/*
+ * This function doesn't exist, so you'll get a linker error
+ * if something tries to do an invalid xchg().
+ */
+extern void __xchg_called_with_bad_pointer(void);
+
+static __always_inline unsigned long
+__xchg(volatile void *ptr, unsigned long x, unsigned int size)
+{
+ switch (size) {
+ case 4:
+ return __xchg_u32(ptr, x);
+#ifdef CONFIG_PPC64
+ case 8:
+ return __xchg_u64(ptr, x);
+#endif
+ }
+ __xchg_called_with_bad_pointer();
+ return x;
+}
+
+static __always_inline unsigned long
+__xchg_local(volatile void *ptr, unsigned long x, unsigned int size)
+{
+ switch (size) {
+ case 4:
+ return __xchg_u32_local(ptr, x);
+#ifdef CONFIG_PPC64
+ case 8:
+ return __xchg_u64_local(ptr, x);
+#endif
+ }
+ __xchg_called_with_bad_pointer();
+ return x;
+}
+#define xchg(ptr,x) \
+ ({ \
+ __typeof__(*(ptr)) _x_ = (x); \
+ (__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_, sizeof(*(ptr))); \
+ })
+
+#define xchg_local(ptr,x) \
+ ({ \
+ __typeof__(*(ptr)) _x_ = (x); \
+ (__typeof__(*(ptr))) __xchg_local((ptr), \
+ (unsigned long)_x_, sizeof(*(ptr))); \
+ })
+
+/*
+ * Compare and exchange - if *p == old, set it to new,
+ * and return the old value of *p.
+ */
+#define __HAVE_ARCH_CMPXCHG 1
+
+static __always_inline unsigned long
+__cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new)
+{
+ unsigned int prev;
+
+ __asm__ __volatile__ (
+ PPC_RELEASE_BARRIER
+"1: lwarx %0,0,%2 # __cmpxchg_u32\n\
+ cmpw 0,%0,%3\n\
+ bne- 2f\n"
+ PPC405_ERR77(0,%2)
+" stwcx. %4,0,%2\n\
+ bne- 1b"
+ PPC_ACQUIRE_BARRIER
+ "\n\
+2:"
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
+ : "cc", "memory");
+
+ return prev;
+}
+
+static __always_inline unsigned long
+__cmpxchg_u32_local(volatile unsigned int *p, unsigned long old,
+ unsigned long new)
+{
+ unsigned int prev;
+
+ __asm__ __volatile__ (
+"1: lwarx %0,0,%2 # __cmpxchg_u32\n\
+ cmpw 0,%0,%3\n\
+ bne- 2f\n"
+ PPC405_ERR77(0,%2)
+" stwcx. %4,0,%2\n\
+ bne- 1b"
+ "\n\
+2:"
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
+ : "cc", "memory");
+
+ return prev;
+}
+
+#ifdef CONFIG_PPC64
+static __always_inline unsigned long
+__cmpxchg_u64(volatile unsigned long *p, unsigned long old, unsigned long new)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__ (
+ PPC_RELEASE_BARRIER
+"1: ldarx %0,0,%2 # __cmpxchg_u64\n\
+ cmpd 0,%0,%3\n\
+ bne- 2f\n\
+ stdcx. %4,0,%2\n\
+ bne- 1b"
+ PPC_ACQUIRE_BARRIER
+ "\n\
+2:"
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
+ : "cc", "memory");
+
+ return prev;
+}
+
+static __always_inline unsigned long
+__cmpxchg_u64_local(volatile unsigned long *p, unsigned long old,
+ unsigned long new)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__ (
+"1: ldarx %0,0,%2 # __cmpxchg_u64\n\
+ cmpd 0,%0,%3\n\
+ bne- 2f\n\
+ stdcx. %4,0,%2\n\
+ bne- 1b"
+ "\n\
+2:"
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
+ : "cc", "memory");
+
+ return prev;
+}
+#endif
+
+/* 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 __always_inline unsigned long
+__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
+ unsigned int size)
+{
+ switch (size) {
+ case 4:
+ return __cmpxchg_u32(ptr, old, new);
+#ifdef CONFIG_PPC64
+ case 8:
+ return __cmpxchg_u64(ptr, old, new);
+#endif
+ }
+ __cmpxchg_called_with_bad_pointer();
+ return old;
+}
+
+static __always_inline unsigned long
+__cmpxchg_local(volatile void *ptr, unsigned long old, unsigned long new,
+ unsigned int size)
+{
+ switch (size) {
+ case 4:
+ return __cmpxchg_u32_local(ptr, old, new);
+#ifdef CONFIG_PPC64
+ case 8:
+ return __cmpxchg_u64_local(ptr, old, new);
+#endif
+ }
+ __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))); \
+ })
+
+
+#define cmpxchg_local(ptr, o, n) \
+ ({ \
+ __typeof__(*(ptr)) _o_ = (o); \
+ __typeof__(*(ptr)) _n_ = (n); \
+ (__typeof__(*(ptr))) __cmpxchg_local((ptr), (unsigned long)_o_, \
+ (unsigned long)_n_, sizeof(*(ptr))); \
+ })
+
+#ifdef CONFIG_PPC64
+#define cmpxchg64(ptr, o, n) \
+ ({ \
+ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
+ cmpxchg((ptr), (o), (n)); \
+ })
+#define cmpxchg64_local(ptr, o, n) \
+ ({ \
+ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
+ cmpxchg_local((ptr), (o), (n)); \
+ })
+#else
+#include <asm-generic/cmpxchg-local.h>
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+#endif
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_CMPXCHG_H_ */
OpenPOWER on IntegriCloud