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 #ifdef __INTEL_COMPILER 19 # include <asm/intel_intrin.h> 20 #else 21 # include <asm/gcc_intrin.h> 22 #endif 23 24 /* 25 * This function doesn't exist, so you'll get a linker error if 26 * something tries to do an invalid xchg(). 27 */ 28 extern void ia64_xchg_called_with_bad_pointer(void); 29 30 #define __xchg(x, ptr, size) \ 31 ({ \ 32 unsigned long __xchg_result; \ 33 \ 34 switch (size) { \ 35 case 1: \ 36 __xchg_result = ia64_xchg1((__u8 *)ptr, x); \ 37 break; \ 38 \ 39 case 2: \ 40 __xchg_result = ia64_xchg2((__u16 *)ptr, x); \ 41 break; \ 42 \ 43 case 4: \ 44 __xchg_result = ia64_xchg4((__u32 *)ptr, x); \ 45 break; \ 46 \ 47 case 8: \ 48 __xchg_result = ia64_xchg8((__u64 *)ptr, x); \ 49 break; \ 50 default: \ 51 ia64_xchg_called_with_bad_pointer(); \ 52 } \ 53 __xchg_result; \ 54 }) 55 56 #ifndef __KERNEL__ 57 #define xchg(ptr, x) \ 58 ({(__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr)));}) 59 #endif 60 61 /* 62 * Atomic compare and exchange. Compare OLD with MEM, if identical, 63 * store NEW in MEM. Return the initial value in MEM. Success is 64 * indicated by comparing RETURN with OLD. 65 */ 66 67 /* 68 * This function doesn't exist, so you'll get a linker error 69 * if something tries to do an invalid cmpxchg(). 70 */ 71 extern long ia64_cmpxchg_called_with_bad_pointer(void); 72 73 #define ia64_cmpxchg(sem, ptr, old, new, size) \ 74 ({ \ 75 __u64 _o_, _r_; \ 76 \ 77 switch (size) { \ 78 case 1: \ 79 _o_ = (__u8) (long) (old); \ 80 break; \ 81 case 2: \ 82 _o_ = (__u16) (long) (old); \ 83 break; \ 84 case 4: \ 85 _o_ = (__u32) (long) (old); \ 86 break; \ 87 case 8: \ 88 _o_ = (__u64) (long) (old); \ 89 break; \ 90 default: \ 91 break; \ 92 } \ 93 switch (size) { \ 94 case 1: \ 95 _r_ = ia64_cmpxchg1_##sem((__u8 *) ptr, new, _o_); \ 96 break; \ 97 \ 98 case 2: \ 99 _r_ = ia64_cmpxchg2_##sem((__u16 *) ptr, new, _o_); \ 100 break; \ 101 \ 102 case 4: \ 103 _r_ = ia64_cmpxchg4_##sem((__u32 *) ptr, new, _o_); \ 104 break; \ 105 \ 106 case 8: \ 107 _r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); \ 108 break; \ 109 \ 110 default: \ 111 _r_ = ia64_cmpxchg_called_with_bad_pointer(); \ 112 break; \ 113 } \ 114 (__typeof__(old)) _r_; \ 115 }) 116 117 #define cmpxchg_acq(ptr, o, n) \ 118 ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr))) 119 #define cmpxchg_rel(ptr, o, n) \ 120 ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr))) 121 122 /* 123 * Worse still - early processor implementations actually just ignored 124 * the acquire/release and did a full fence all the time. Unfortunately 125 * this meant a lot of badly written code that used .acq when they really 126 * wanted .rel became legacy out in the wild - so when we made a cpu 127 * that strictly did the .acq or .rel ... all that code started breaking - so 128 * we had to back-pedal and keep the "legacy" behavior of a full fence :-( 129 */ 130 131 #ifndef __KERNEL__ 132 /* for compatibility with other platforms: */ 133 #define cmpxchg(ptr, o, n) cmpxchg_acq((ptr), (o), (n)) 134 #define cmpxchg64(ptr, o, n) cmpxchg_acq((ptr), (o), (n)) 135 136 #define cmpxchg_local cmpxchg 137 #define cmpxchg64_local cmpxchg64 138 #endif 139 140 #ifdef CONFIG_IA64_DEBUG_CMPXCHG 141 # define CMPXCHG_BUGCHECK_DECL int _cmpxchg_bugcheck_count = 128; 142 # define CMPXCHG_BUGCHECK(v) \ 143 do { \ 144 if (_cmpxchg_bugcheck_count-- <= 0) { \ 145 void *ip; \ 146 extern int _printk(const char *fmt, ...); \ 147 ip = (void *) ia64_getreg(_IA64_REG_IP); \ 148 _printk("CMPXCHG_BUGCHECK: stuck at %p on word %p\n", ip, (v));\ 149 break; \ 150 } \ 151 } while (0) 152 #else /* !CONFIG_IA64_DEBUG_CMPXCHG */ 153 # define CMPXCHG_BUGCHECK_DECL 154 # define CMPXCHG_BUGCHECK(v) 155 #endif /* !CONFIG_IA64_DEBUG_CMPXCHG */ 156 157 #endif /* !__ASSEMBLY__ */ 158 159 #endif /* _UAPI_ASM_IA64_CMPXCHG_H */ 160