diff options
Diffstat (limited to 'arch/unicore32/include/asm/cmpxchg.h')
| -rw-r--r-- | arch/unicore32/include/asm/cmpxchg.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/arch/unicore32/include/asm/cmpxchg.h b/arch/unicore32/include/asm/cmpxchg.h new file mode 100644 index 00000000000..df4d5acfd19 --- /dev/null +++ b/arch/unicore32/include/asm/cmpxchg.h @@ -0,0 +1,61 @@ +/* + * Atomics xchg/cmpxchg for PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2012 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#ifndef __UNICORE_CMPXCHG_H__ +#define __UNICORE_CMPXCHG_H__ + +/* + * Generate a link failure on undefined symbol if the pointer points to a value + * of unsupported size. + */ +extern void __xchg_bad_pointer(void); + +static inline unsigned long __xchg(unsigned long x, volatile void *ptr, + int size) +{ + unsigned long ret; + + switch (size) { + case 1: + asm volatile("swapb %0, %1, [%2]" + : "=&r" (ret) + : "r" (x), "r" (ptr) + : "memory", "cc"); + break; + case 4: + asm volatile("swapw %0, %1, [%2]" + : "=&r" (ret) + : "r" (x), "r" (ptr) + : "memory", "cc"); + break; + default: + ret = __xchg_bad_pointer(); + } + + return ret; +} + +#define xchg(ptr, x) \ + ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), 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)) + +#include <asm-generic/cmpxchg.h> + +#endif /* __UNICORE_CMPXCHG_H__ */ |