1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * forked from parisc asm/atomic.h which was: 4 * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org> 5 * Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org> 6 */ 7 8#ifndef _ASM_PARISC_CMPXCHG_H_ 9#define _ASM_PARISC_CMPXCHG_H_ 10 11/* This should get optimized out since it's never called. 12** Or get a link error if xchg is used "wrong". 13*/ 14extern void __xchg_called_with_bad_pointer(void); 15 16/* __xchg32/64 defined in arch/parisc/lib/bitops.c */ 17extern unsigned long __xchg8(char, volatile char *); 18extern unsigned long __xchg32(int, volatile int *); 19#ifdef CONFIG_64BIT 20extern unsigned long __xchg64(unsigned long, volatile unsigned long *); 21#endif 22 23/* optimizer better get rid of switch since size is a constant */ 24static inline unsigned long 25__arch_xchg(unsigned long x, volatile void *ptr, int size) 26{ 27 switch (size) { 28#ifdef CONFIG_64BIT 29 case 8: return __xchg64(x, (volatile unsigned long *) ptr); 30#endif 31 case 4: return __xchg32((int) x, (volatile int *) ptr); 32 case 1: return __xchg8((char) x, (volatile char *) ptr); 33 } 34 __xchg_called_with_bad_pointer(); 35 return x; 36} 37 38/* 39** REVISIT - Abandoned use of LDCW in xchg() for now: 40** o need to test sizeof(*ptr) to avoid clearing adjacent bytes 41** o and while we are at it, could CONFIG_64BIT code use LDCD too? 42** 43** if (__builtin_constant_p(x) && (x == NULL)) 44** if (((unsigned long)p & 0xf) == 0) 45** return __ldcw(p); 46*/ 47#define arch_xchg(ptr, x) \ 48({ \ 49 __typeof__(*(ptr)) __ret; \ 50 __typeof__(*(ptr)) _x_ = (x); \ 51 __ret = (__typeof__(*(ptr))) \ 52 __arch_xchg((unsigned long)_x_, (ptr), sizeof(*(ptr))); \ 53 __ret; \ 54}) 55 56/* bug catcher for when unsupported size is used - won't link */ 57extern void __cmpxchg_called_with_bad_pointer(void); 58 59/* __cmpxchg_u... defined in arch/parisc/lib/bitops.c */ 60extern u8 __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 new_); 61extern u16 __cmpxchg_u16(volatile u16 *ptr, u16 old, u16 new_); 62extern u32 __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_); 63extern u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new_); 64 65/* don't worry...optimizer will get rid of most of this */ 66static inline unsigned long 67__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) 68{ 69 return 70#ifdef CONFIG_64BIT 71 size == 8 ? __cmpxchg_u64(ptr, old, new_) : 72#endif 73 size == 4 ? __cmpxchg_u32(ptr, old, new_) : 74 size == 2 ? __cmpxchg_u16(ptr, old, new_) : 75 size == 1 ? __cmpxchg_u8(ptr, old, new_) : 76 (__cmpxchg_called_with_bad_pointer(), old); 77} 78 79#define arch_cmpxchg(ptr, o, n) \ 80({ \ 81 __typeof__(*(ptr)) _o_ = (o); \ 82 __typeof__(*(ptr)) _n_ = (n); \ 83 (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ 84 (unsigned long)_n_, sizeof(*(ptr))); \ 85}) 86 87#include <asm-generic/cmpxchg-local.h> 88 89static inline unsigned long __cmpxchg_local(volatile void *ptr, 90 unsigned long old, 91 unsigned long new_, int size) 92{ 93 switch (size) { 94#ifdef CONFIG_64BIT 95 case 8: return __cmpxchg_u64((u64 *)ptr, old, new_); 96#endif 97 case 4: return __cmpxchg_u32(ptr, old, new_); 98 default: 99 return __generic_cmpxchg_local(ptr, old, new_, size); 100 } 101} 102 103/* 104 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make 105 * them available. 106 */ 107#define arch_cmpxchg_local(ptr, o, n) \ 108 ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \ 109 (unsigned long)(n), sizeof(*(ptr)))) 110#ifdef CONFIG_64BIT 111#define arch_cmpxchg64_local(ptr, o, n) \ 112({ \ 113 BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ 114 cmpxchg_local((ptr), (o), (n)); \ 115}) 116#else 117#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n)) 118#endif 119 120#define arch_cmpxchg64(ptr, o, n) __cmpxchg_u64(ptr, o, n) 121 122#endif /* _ASM_PARISC_CMPXCHG_H_ */ 123