1/* 2 * forked from parisc asm/atomic.h which was: 3 * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org> 4 * Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org> 5 */ 6 7#ifndef _ASM_PARISC_CMPXCHG_H_ 8#define _ASM_PARISC_CMPXCHG_H_ 9 10/* This should get optimized out since it's never called. 11** Or get a link error if xchg is used "wrong". 12*/ 13extern void __xchg_called_with_bad_pointer(void); 14 15/* __xchg32/64 defined in arch/parisc/lib/bitops.c */ 16extern unsigned long __xchg8(char, char *); 17extern unsigned long __xchg32(int, int *); 18#ifdef CONFIG_64BIT 19extern unsigned long __xchg64(unsigned long, unsigned long *); 20#endif 21 22/* optimizer better get rid of switch since size is a constant */ 23static inline unsigned long 24__xchg(unsigned long x, __volatile__ void *ptr, int size) 25{ 26 switch (size) { 27#ifdef CONFIG_64BIT 28 case 8: return __xchg64(x, (unsigned long *) ptr); 29#endif 30 case 4: return __xchg32((int) x, (int *) ptr); 31 case 1: return __xchg8((char) x, (char *) ptr); 32 } 33 __xchg_called_with_bad_pointer(); 34 return x; 35} 36 37/* 38** REVISIT - Abandoned use of LDCW in xchg() for now: 39** o need to test sizeof(*ptr) to avoid clearing adjacent bytes 40** o and while we are at it, could CONFIG_64BIT code use LDCD too? 41** 42** if (__builtin_constant_p(x) && (x == NULL)) 43** if (((unsigned long)p & 0xf) == 0) 44** return __ldcw(p); 45*/ 46#define xchg(ptr, x) \ 47 ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))) 48 49#define __HAVE_ARCH_CMPXCHG 1 50 51/* bug catcher for when unsupported size is used - won't link */ 52extern void __cmpxchg_called_with_bad_pointer(void); 53 54/* __cmpxchg_u32/u64 defined in arch/parisc/lib/bitops.c */ 55extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old, 56 unsigned int new_); 57extern unsigned long __cmpxchg_u64(volatile unsigned long *ptr, 58 unsigned long old, unsigned long new_); 59 60/* don't worry...optimizer will get rid of most of this */ 61static inline unsigned long 62__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) 63{ 64 switch (size) { 65#ifdef CONFIG_64BIT 66 case 8: return __cmpxchg_u64((unsigned long *)ptr, old, new_); 67#endif 68 case 4: return __cmpxchg_u32((unsigned int *)ptr, 69 (unsigned int)old, (unsigned int)new_); 70 } 71 __cmpxchg_called_with_bad_pointer(); 72 return old; 73} 74 75#define cmpxchg(ptr, o, n) \ 76({ \ 77 __typeof__(*(ptr)) _o_ = (o); \ 78 __typeof__(*(ptr)) _n_ = (n); \ 79 (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ 80 (unsigned long)_n_, sizeof(*(ptr))); \ 81}) 82 83#include <asm-generic/cmpxchg-local.h> 84 85static inline unsigned long __cmpxchg_local(volatile void *ptr, 86 unsigned long old, 87 unsigned long new_, int size) 88{ 89 switch (size) { 90#ifdef CONFIG_64BIT 91 case 8: return __cmpxchg_u64((unsigned long *)ptr, old, new_); 92#endif 93 case 4: return __cmpxchg_u32(ptr, old, new_); 94 default: 95 return __cmpxchg_local_generic(ptr, old, new_, size); 96 } 97} 98 99/* 100 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make 101 * them available. 102 */ 103#define cmpxchg_local(ptr, o, n) \ 104 ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \ 105 (unsigned long)(n), sizeof(*(ptr)))) 106#ifdef CONFIG_64BIT 107#define cmpxchg64_local(ptr, o, n) \ 108({ \ 109 BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ 110 cmpxchg_local((ptr), (o), (n)); \ 111}) 112#else 113#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) 114#endif 115 116#endif /* _ASM_PARISC_CMPXCHG_H_ */ 117