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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 */
28extern 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 */
71extern 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) \
143do { \
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 */