#ifndef __ASM_CMPXCHG_H #define __ASM_CMPXCHG_H #include <asm/alternative.h> /* Provides LOCK_PREFIX */ #define xchg(ptr,v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr)))) #define __xg(x) ((volatile long *)(x)) static inline void set_64bit(volatile unsigned long *ptr, unsigned long val) { *ptr = val; } #define _set_64bit set_64bit /* * Note: no "lock" prefix even on SMP: xchg always implies lock anyway * Note 2: xchg has side effect, so that attribute volatile is necessary, * but generally the primitive is invalid, *ptr is output argument. --ANK */ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size) { switch (size) { case 1: __asm__ __volatile__("xchgb %b0,%1" :"=q" (x) :"m" (*__xg(ptr)), "0" (x) :"memory"); break; case 2: __asm__ __volatile__("xchgw %w0,%1" :"=r" (x) :"m" (*__xg(ptr)), "0" (x) :"memory"); break; case 4: __asm__ __volatile__("xchgl %k0,%1" :"=r" (x) :"m" (*__xg(ptr)), "0" (x) :"memory"); break; case 8: __asm__ __volatile__("xchgq %0,%1" :"=r" (x) :"m" (*__xg(ptr)), "0" (x) :"memory"); break; } 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. */ #define __HAVE_ARCH_CMPXCHG 1 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) { unsigned long prev; switch (size) { case 1: __asm__ __volatile__(LOCK_PREFIX "cmpxchgb %b1,%2" : "=a"(prev) : "q"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; case 2: __asm__ __volatile__(LOCK_PREFIX "cmpxchgw %w1,%2" : "=a"(prev) : "r"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; case 4: __asm__ __volatile__(LOCK_PREFIX "cmpxchgl %k1,%2" : "=a"(prev) : "r"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; case 8: __asm__ __volatile__(LOCK_PREFIX "cmpxchgq %1,%2" : "=a"(prev) : "r"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; } return old; } static inline unsigned long __cmpxchg_local(volatile void *ptr, unsigned long old, unsigned long new, int size) { unsigned long prev; switch (size) { case 1: __asm__ __volatile__("cmpxchgb %b1,%2" : "=a"(prev) : "q"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; case 2: __asm__ __volatile__("cmpxchgw %w1,%2" : "=a"(prev) : "r"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; case 4: __asm__ __volatile__("cmpxchgl %k1,%2" : "=a"(prev) : "r"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; case 8: __asm__ __volatile__("cmpxchgq %1,%2" : "=a"(prev) : "r"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; } return old; } #define cmpxchg(ptr,o,n)\ ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\ (unsigned long)(n),sizeof(*(ptr)))) #define cmpxchg_local(ptr,o,n)\ ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\ (unsigned long)(n),sizeof(*(ptr)))) #endif