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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
9e5228ce PG |
2 | /* |
3 | * forked from parisc asm/atomic.h which was: | |
4 | * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org> | |
5 | * Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org> | |
6 | */ | |
7 | ||
8 | #ifndef _ASM_PARISC_CMPXCHG_H_ | |
9 | #define _ASM_PARISC_CMPXCHG_H_ | |
10 | ||
11 | /* This should get optimized out since it's never called. | |
12 | ** Or get a link error if xchg is used "wrong". | |
13 | */ | |
14 | extern void __xchg_called_with_bad_pointer(void); | |
15 | ||
16 | /* __xchg32/64 defined in arch/parisc/lib/bitops.c */ | |
17 | extern unsigned long __xchg8(char, char *); | |
18 | extern unsigned long __xchg32(int, int *); | |
19 | #ifdef CONFIG_64BIT | |
20 | extern unsigned long __xchg64(unsigned long, unsigned long *); | |
21 | #endif | |
22 | ||
23 | /* optimizer better get rid of switch since size is a constant */ | |
24 | static inline unsigned long | |
25 | __xchg(unsigned long x, __volatile__ void *ptr, int size) | |
26 | { | |
27 | switch (size) { | |
28 | #ifdef CONFIG_64BIT | |
29 | case 8: return __xchg64(x, (unsigned long *) ptr); | |
30 | #endif | |
31 | case 4: return __xchg32((int) x, (int *) ptr); | |
32 | case 1: return __xchg8((char) x, (char *) ptr); | |
33 | } | |
34 | __xchg_called_with_bad_pointer(); | |
35 | return x; | |
36 | } | |
37 | ||
38 | /* | |
39 | ** REVISIT - Abandoned use of LDCW in xchg() for now: | |
40 | ** o need to test sizeof(*ptr) to avoid clearing adjacent bytes | |
41 | ** o and while we are at it, could CONFIG_64BIT code use LDCD too? | |
42 | ** | |
43 | ** if (__builtin_constant_p(x) && (x == NULL)) | |
44 | ** if (((unsigned long)p & 0xf) == 0) | |
45 | ** return __ldcw(p); | |
46 | */ | |
47 | #define xchg(ptr, x) \ | |
48 | ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))) | |
49 | ||
9e5228ce PG |
50 | /* bug catcher for when unsupported size is used - won't link */ |
51 | extern void __cmpxchg_called_with_bad_pointer(void); | |
52 | ||
53 | /* __cmpxchg_u32/u64 defined in arch/parisc/lib/bitops.c */ | |
54 | extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old, | |
55 | unsigned int new_); | |
54b66800 | 56 | extern u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new_); |
9e5228ce PG |
57 | |
58 | /* don't worry...optimizer will get rid of most of this */ | |
59 | static inline unsigned long | |
60 | __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) | |
61 | { | |
62 | switch (size) { | |
63 | #ifdef CONFIG_64BIT | |
54b66800 | 64 | case 8: return __cmpxchg_u64((u64 *)ptr, old, new_); |
9e5228ce PG |
65 | #endif |
66 | case 4: return __cmpxchg_u32((unsigned int *)ptr, | |
67 | (unsigned int)old, (unsigned int)new_); | |
68 | } | |
69 | __cmpxchg_called_with_bad_pointer(); | |
70 | return old; | |
71 | } | |
72 | ||
73 | #define cmpxchg(ptr, o, n) \ | |
74 | ({ \ | |
75 | __typeof__(*(ptr)) _o_ = (o); \ | |
76 | __typeof__(*(ptr)) _n_ = (n); \ | |
77 | (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ | |
78 | (unsigned long)_n_, sizeof(*(ptr))); \ | |
79 | }) | |
80 | ||
81 | #include <asm-generic/cmpxchg-local.h> | |
82 | ||
83 | static inline unsigned long __cmpxchg_local(volatile void *ptr, | |
84 | unsigned long old, | |
85 | unsigned long new_, int size) | |
86 | { | |
87 | switch (size) { | |
88 | #ifdef CONFIG_64BIT | |
54b66800 | 89 | case 8: return __cmpxchg_u64((u64 *)ptr, old, new_); |
9e5228ce PG |
90 | #endif |
91 | case 4: return __cmpxchg_u32(ptr, old, new_); | |
92 | default: | |
93 | return __cmpxchg_local_generic(ptr, old, new_, size); | |
94 | } | |
95 | } | |
96 | ||
97 | /* | |
98 | * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make | |
99 | * them available. | |
100 | */ | |
101 | #define cmpxchg_local(ptr, o, n) \ | |
102 | ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \ | |
103 | (unsigned long)(n), sizeof(*(ptr)))) | |
104 | #ifdef CONFIG_64BIT | |
105 | #define cmpxchg64_local(ptr, o, n) \ | |
106 | ({ \ | |
107 | BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ | |
108 | cmpxchg_local((ptr), (o), (n)); \ | |
109 | }) | |
110 | #else | |
111 | #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) | |
112 | #endif | |
113 | ||
54b66800 HD |
114 | #define cmpxchg64(ptr, o, n) __cmpxchg_u64(ptr, o, n) |
115 | ||
9e5228ce | 116 | #endif /* _ASM_PARISC_CMPXCHG_H_ */ |