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gerrit.nordix.org / codeaurora / cp-linux / 8d8f6542b666daf5e87de156590e635c2c4da0c0 / . / arch / ia64 / include / uapi / asm / cmpxchg.h
blob: a0e3620f8f133f7ea798ae9458abf10cc168f3c3 [file] [log] [blame]
Kyle Swenson8d8f6542021-03-15 11:02:55 -0600[diff] [blame^]1#ifndef _ASM_IA64_CMPXCHG_H
2#define _ASM_IA64_CMPXCHG_H
3
4/*
5 * Compare/Exchange, forked from asm/intrinsics.h
6 * which was:
7 *
8 * Copyright (C) 2002-2003 Hewlett-Packard Co
9 * David Mosberger-Tang <davidm@hpl.hp.com>
10 */
11
12#ifndef __ASSEMBLY__
13
14#include <linux/types.h>
15/* include compiler specific intrinsics */
16#include <asm/ia64regs.h>
17#ifdef __INTEL_COMPILER
18# include <asm/intel_intrin.h>
19#else
20# include <asm/gcc_intrin.h>
21#endif
22
23/*
24 * This function doesn't exist, so you'll get a linker error if
25 * something tries to do an invalid xchg().
26 */
27extern void ia64_xchg_called_with_bad_pointer(void);
28
29#define __xchg(x, ptr, size) \
30({ \
31 unsigned long __xchg_result; \
32 \
33 switch (size) { \
34 case 1: \
35 __xchg_result = ia64_xchg1((__u8 *)ptr, x); \
36 break; \
37 \
38 case 2: \
39 __xchg_result = ia64_xchg2((__u16 *)ptr, x); \
40 break; \
41 \
42 case 4: \
43 __xchg_result = ia64_xchg4((__u32 *)ptr, x); \
44 break; \
45 \
46 case 8: \
47 __xchg_result = ia64_xchg8((__u64 *)ptr, x); \
48 break; \
49 default: \
50 ia64_xchg_called_with_bad_pointer(); \
51 } \
52 __xchg_result; \
53})
54
55#define xchg(ptr, x) \
56((__typeof__(*(ptr))) __xchg((unsigned long) (x), (ptr), sizeof(*(ptr))))
57
58/*
59 * Atomic compare and exchange. Compare OLD with MEM, if identical,
60 * store NEW in MEM. Return the initial value in MEM. Success is
61 * indicated by comparing RETURN with OLD.
62 */
63
64/*
65 * This function doesn't exist, so you'll get a linker error
66 * if something tries to do an invalid cmpxchg().
67 */
68extern long ia64_cmpxchg_called_with_bad_pointer(void);
69
70#define ia64_cmpxchg(sem, ptr, old, new, size) \
71({ \
72 __u64 _o_, _r_; \
73 \
74 switch (size) { \
75 case 1: \
76 _o_ = (__u8) (long) (old); \
77 break; \
78 case 2: \
79 _o_ = (__u16) (long) (old); \
80 break; \
81 case 4: \
82 _o_ = (__u32) (long) (old); \
83 break; \
84 case 8: \
85 _o_ = (__u64) (long) (old); \
86 break; \
87 default: \
88 break; \
89 } \
90 switch (size) { \
91 case 1: \
92 _r_ = ia64_cmpxchg1_##sem((__u8 *) ptr, new, _o_); \
93 break; \
94 \
95 case 2: \
96 _r_ = ia64_cmpxchg2_##sem((__u16 *) ptr, new, _o_); \
97 break; \
98 \
99 case 4: \
100 _r_ = ia64_cmpxchg4_##sem((__u32 *) ptr, new, _o_); \
101 break; \
102 \
103 case 8: \
104 _r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); \
105 break; \
106 \
107 default: \
108 _r_ = ia64_cmpxchg_called_with_bad_pointer(); \
109 break; \
110 } \
111 (__typeof__(old)) _r_; \
112})
113
114#define cmpxchg_acq(ptr, o, n) \
115 ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr)))
116#define cmpxchg_rel(ptr, o, n) \
117 ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr)))
118
119/*
120 * Worse still - early processor implementations actually just ignored
121 * the acquire/release and did a full fence all the time. Unfortunately
122 * this meant a lot of badly written code that used .acq when they really
123 * wanted .rel became legacy out in the wild - so when we made a cpu
124 * that strictly did the .acq or .rel ... all that code started breaking - so
125 * we had to back-pedal and keep the "legacy" behavior of a full fence :-(
126 */
127
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
135#ifdef CONFIG_IA64_DEBUG_CMPXCHG
136# define CMPXCHG_BUGCHECK_DECL int _cmpxchg_bugcheck_count = 128;
137# define CMPXCHG_BUGCHECK(v) \
138do { \
139 if (_cmpxchg_bugcheck_count-- <= 0) { \
140 void *ip; \
141 extern int printk(const char *fmt, ...); \
142 ip = (void *) ia64_getreg(_IA64_REG_IP); \
143 printk("CMPXCHG_BUGCHECK: stuck at %p on word %p\n", ip, (v));\
144 break; \
145 } \
146} while (0)
147#else /* !CONFIG_IA64_DEBUG_CMPXCHG */
148# define CMPXCHG_BUGCHECK_DECL
149# define CMPXCHG_BUGCHECK(v)
150#endif /* !CONFIG_IA64_DEBUG_CMPXCHG */
151
152#endif /* !__ASSEMBLY__ */
153
154#endif /* _ASM_IA64_CMPXCHG_H */