/* * 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: __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__ */