1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef _ASM_IA64_CMPXCHG_H 3 #define _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 #define xchg(ptr, x) \ 57 ((__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr)))) 58 59 /* 60 * Atomic compare and exchange. Compare OLD with MEM, if identical, 61 * store NEW in MEM. Return the initial value in MEM. Success is 62 * indicated by comparing RETURN with OLD. 63 */ 64 65 /* 66 * This function doesn't exist, so you'll get a linker error 67 * if something tries to do an invalid cmpxchg(). 68 */ 69 extern long ia64_cmpxchg_called_with_bad_pointer(void); 70 71 #define ia64_cmpxchg(sem, ptr, old, new, size) \ 72 ({ \ 73 __u64 _o_, _r_; \ 74 \ 75 switch (size) { \ 76 case 1: \ 77 _o_ = (__u8) (long) (old); \ 78 break; \ 79 case 2: \ 80 _o_ = (__u16) (long) (old); \ 81 break; \ 82 case 4: \ 83 _o_ = (__u32) (long) (old); \ 84 break; \ 85 case 8: \ 86 _o_ = (__u64) (long) (old); \ 87 break; \ 88 default: \ 89 break; \ 90 } \ 91 switch (size) { \ 92 case 1: \ 93 _r_ = ia64_cmpxchg1_##sem((__u8 *) ptr, new, _o_); \ 94 break; \ 95 \ 96 case 2: \ 97 _r_ = ia64_cmpxchg2_##sem((__u16 *) ptr, new, _o_); \ 98 break; \ 99 \ 100 case 4: \ 101 _r_ = ia64_cmpxchg4_##sem((__u32 *) ptr, new, _o_); \ 102 break; \ 103 \ 104 case 8: \ 105 _r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); \ 106 break; \ 107 \ 108 default: \ 109 _r_ = ia64_cmpxchg_called_with_bad_pointer(); \ 110 break; \ 111 } \ 112 (__typeof__(old)) _r_; \ 113 }) 114 115 #define cmpxchg_acq(ptr, o, n) \ 116 ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr))) 117 #define cmpxchg_rel(ptr, o, n) \ 118 ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr))) 119 120 /* 121 * Worse still - early processor implementations actually just ignored 122 * the acquire/release and did a full fence all the time. Unfortunately 123 * this meant a lot of badly written code that used .acq when they really 124 * wanted .rel became legacy out in the wild - so when we made a cpu 125 * that strictly did the .acq or .rel ... all that code started breaking - so 126 * we had to back-pedal and keep the "legacy" behavior of a full fence :-( 127 */ 128 129 /* for compatibility with other platforms: */ 130 #define cmpxchg(ptr, o, n) cmpxchg_acq((ptr), (o), (n)) 131 #define cmpxchg64(ptr, o, n) cmpxchg_acq((ptr), (o), (n)) 132 133 #define cmpxchg_local cmpxchg 134 #define cmpxchg64_local cmpxchg64 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 /* _ASM_IA64_CMPXCHG_H */ 156