1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef _UAPI_ASM_IA64_CMPXCHG_H 3 #define _UAPI_ASM_IA64_CMPXCHG_H 4 5 /* 6 * Compare/Exchange, forked from asm/intrinsics.h 7 * which was: 8 * 9 * Copyright (C) 2002-2003 Hewlett-Packard Co 10 * David Mosberger-Tang <davidm@hpl.hp.com> 11 */ 12 13 #ifndef __ASSEMBLY__ 14 15 #include <linux/types.h> 16 /* include compiler specific intrinsics */ 17 #include <asm/ia64regs.h> 18 #include <asm/gcc_intrin.h> 19 20 /* 21 * This function doesn't exist, so you'll get a linker error if 22 * something tries to do an invalid xchg(). 23 */ 24 extern void ia64_xchg_called_with_bad_pointer(void); 25 26 #define __arch_xchg(x, ptr, size) \ 27 ({ \ 28 unsigned long __xchg_result; \ 29 \ 30 switch (size) { \ 31 case 1: \ 32 __xchg_result = ia64_xchg1((__u8 __force *)ptr, x); \ 33 break; \ 34 \ 35 case 2: \ 36 __xchg_result = ia64_xchg2((__u16 __force *)ptr, x); \ 37 break; \ 38 \ 39 case 4: \ 40 __xchg_result = ia64_xchg4((__u32 __force *)ptr, x); \ 41 break; \ 42 \ 43 case 8: \ 44 __xchg_result = ia64_xchg8((__u64 __force *)ptr, x); \ 45 break; \ 46 default: \ 47 ia64_xchg_called_with_bad_pointer(); \ 48 } \ 49 (__typeof__ (*(ptr)) __force) __xchg_result; \ 50 }) 51 52 #ifndef __KERNEL__ 53 #define xchg(ptr, x) \ 54 ({(__typeof__(*(ptr))) __arch_xchg((unsigned long) (x), (ptr), sizeof(*(ptr)));}) 55 #endif 56 57 /* 58 * Atomic compare and exchange. Compare OLD with MEM, if identical, 59 * store NEW in MEM. Return the initial value in MEM. Success is 60 * indicated by comparing RETURN with OLD. 61 */ 62 63 /* 64 * This function doesn't exist, so you'll get a linker error 65 * if something tries to do an invalid cmpxchg(). 66 */ 67 extern long ia64_cmpxchg_called_with_bad_pointer(void); 68 69 #define ia64_cmpxchg(sem, ptr, old, new, size) \ 70 ({ \ 71 __u64 _o_, _r_; \ 72 \ 73 switch (size) { \ 74 case 1: \ 75 _o_ = (__u8) (long __force) (old); \ 76 break; \ 77 case 2: \ 78 _o_ = (__u16) (long __force) (old); \ 79 break; \ 80 case 4: \ 81 _o_ = (__u32) (long __force) (old); \ 82 break; \ 83 case 8: \ 84 _o_ = (__u64) (long __force) (old); \ 85 break; \ 86 default: \ 87 break; \ 88 } \ 89 switch (size) { \ 90 case 1: \ 91 _r_ = ia64_cmpxchg1_##sem((__u8 __force *) ptr, new, _o_); \ 92 break; \ 93 \ 94 case 2: \ 95 _r_ = ia64_cmpxchg2_##sem((__u16 __force *) ptr, new, _o_); \ 96 break; \ 97 \ 98 case 4: \ 99 _r_ = ia64_cmpxchg4_##sem((__u32 __force *) ptr, new, _o_); \ 100 break; \ 101 \ 102 case 8: \ 103 _r_ = ia64_cmpxchg8_##sem((__u64 __force *) ptr, new, _o_); \ 104 break; \ 105 \ 106 default: \ 107 _r_ = ia64_cmpxchg_called_with_bad_pointer(); \ 108 break; \ 109 } \ 110 (__typeof__(old) __force) _r_; \ 111 }) 112 113 #define cmpxchg_acq(ptr, o, n) \ 114 ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr))) 115 #define cmpxchg_rel(ptr, o, n) \ 116 ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr))) 117 118 /* 119 * Worse still - early processor implementations actually just ignored 120 * the acquire/release and did a full fence all the time. Unfortunately 121 * this meant a lot of badly written code that used .acq when they really 122 * wanted .rel became legacy out in the wild - so when we made a cpu 123 * that strictly did the .acq or .rel ... all that code started breaking - so 124 * we had to back-pedal and keep the "legacy" behavior of a full fence :-( 125 */ 126 127 #ifndef __KERNEL__ 128 /* for compatibility with other platforms: */ 129 #define cmpxchg(ptr, o, n) cmpxchg_acq((ptr), (o), (n)) 130 #define cmpxchg64(ptr, o, n) cmpxchg_acq((ptr), (o), (n)) 131 132 #define cmpxchg_local cmpxchg 133 #define cmpxchg64_local cmpxchg64 134 #endif 135 136 #ifdef CONFIG_IA64_DEBUG_CMPXCHG 137 # define CMPXCHG_BUGCHECK_DECL int _cmpxchg_bugcheck_count = 128; 138 # define CMPXCHG_BUGCHECK(v) \ 139 do { \ 140 if (_cmpxchg_bugcheck_count-- <= 0) { \ 141 void *ip; \ 142 extern int _printk(const char *fmt, ...); \ 143 ip = (void *) ia64_getreg(_IA64_REG_IP); \ 144 _printk("CMPXCHG_BUGCHECK: stuck at %p on word %p\n", ip, (v));\ 145 break; \ 146 } \ 147 } while (0) 148 #else /* !CONFIG_IA64_DEBUG_CMPXCHG */ 149 # define CMPXCHG_BUGCHECK_DECL 150 # define CMPXCHG_BUGCHECK(v) 151 #endif /* !CONFIG_IA64_DEBUG_CMPXCHG */ 152 153 #endif /* !__ASSEMBLY__ */ 154 155 #endif /* _UAPI_ASM_IA64_CMPXCHG_H */ 156