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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 */ | |
2a7d4eed JDA |
17 | extern unsigned long __xchg8(char, volatile char *); |
18 | extern unsigned long __xchg32(int, volatile int *); | |
9e5228ce | 19 | #ifdef CONFIG_64BIT |
2a7d4eed | 20 | extern unsigned long __xchg64(unsigned long, volatile unsigned long *); |
9e5228ce PG |
21 | #endif |
22 | ||
23 | /* optimizer better get rid of switch since size is a constant */ | |
24 | static inline unsigned long | |
06855063 | 25 | __arch_xchg(unsigned long x, volatile void *ptr, int size) |
9e5228ce PG |
26 | { |
27 | switch (size) { | |
28 | #ifdef CONFIG_64BIT | |
2a7d4eed | 29 | case 8: return __xchg64(x, (volatile unsigned long *) ptr); |
9e5228ce | 30 | #endif |
2a7d4eed JDA |
31 | case 4: return __xchg32((int) x, (volatile int *) ptr); |
32 | case 1: return __xchg8((char) x, (volatile char *) ptr); | |
9e5228ce PG |
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 | */ | |
329c161b | 47 | #define arch_xchg(ptr, x) \ |
75cf9797 HD |
48 | ({ \ |
49 | __typeof__(*(ptr)) __ret; \ | |
50 | __typeof__(*(ptr)) _x_ = (x); \ | |
51 | __ret = (__typeof__(*(ptr))) \ | |
06855063 | 52 | __arch_xchg((unsigned long)_x_, (ptr), sizeof(*(ptr))); \ |
75cf9797 HD |
53 | __ret; \ |
54 | }) | |
9e5228ce | 55 | |
9e5228ce PG |
56 | /* bug catcher for when unsupported size is used - won't link */ |
57 | extern void __cmpxchg_called_with_bad_pointer(void); | |
58 | ||
d428032b AV |
59 | /* __cmpxchg_u... defined in arch/parisc/lib/bitops.c */ |
60 | extern u8 __cmpxchg_u8(volatile u8 *ptr, u8 old, u8 new_); | |
61 | extern u16 __cmpxchg_u16(volatile u16 *ptr, u16 old, u16 new_); | |
29b8e53c | 62 | extern u32 __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_); |
54b66800 | 63 | extern u64 __cmpxchg_u64(volatile u64 *ptr, u64 old, u64 new_); |
9e5228ce PG |
64 | |
65 | /* don't worry...optimizer will get rid of most of this */ | |
66 | static inline unsigned long | |
67 | __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) | |
68 | { | |
d428032b | 69 | return |
9e5228ce | 70 | #ifdef CONFIG_64BIT |
d428032b | 71 | size == 8 ? __cmpxchg_u64(ptr, old, new_) : |
9e5228ce | 72 | #endif |
d428032b AV |
73 | size == 4 ? __cmpxchg_u32(ptr, old, new_) : |
74 | size == 2 ? __cmpxchg_u16(ptr, old, new_) : | |
75 | size == 1 ? __cmpxchg_u8(ptr, old, new_) : | |
76 | (__cmpxchg_called_with_bad_pointer(), old); | |
9e5228ce PG |
77 | } |
78 | ||
329c161b | 79 | #define arch_cmpxchg(ptr, o, n) \ |
9e5228ce PG |
80 | ({ \ |
81 | __typeof__(*(ptr)) _o_ = (o); \ | |
82 | __typeof__(*(ptr)) _n_ = (n); \ | |
83 | (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ | |
84 | (unsigned long)_n_, sizeof(*(ptr))); \ | |
85 | }) | |
86 | ||
87 | #include <asm-generic/cmpxchg-local.h> | |
88 | ||
89 | static inline unsigned long __cmpxchg_local(volatile void *ptr, | |
90 | unsigned long old, | |
91 | unsigned long new_, int size) | |
92 | { | |
93 | switch (size) { | |
94 | #ifdef CONFIG_64BIT | |
54b66800 | 95 | case 8: return __cmpxchg_u64((u64 *)ptr, old, new_); |
9e5228ce PG |
96 | #endif |
97 | case 4: return __cmpxchg_u32(ptr, old, new_); | |
98 | default: | |
6988631b | 99 | return __generic_cmpxchg_local(ptr, old, new_, size); |
9e5228ce PG |
100 | } |
101 | } | |
102 | ||
103 | /* | |
104 | * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make | |
105 | * them available. | |
106 | */ | |
329c161b | 107 | #define arch_cmpxchg_local(ptr, o, n) \ |
9e5228ce PG |
108 | ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \ |
109 | (unsigned long)(n), sizeof(*(ptr)))) | |
110 | #ifdef CONFIG_64BIT | |
329c161b | 111 | #define arch_cmpxchg64_local(ptr, o, n) \ |
9e5228ce PG |
112 | ({ \ |
113 | BUILD_BUG_ON(sizeof(*(ptr)) != 8); \ | |
114 | cmpxchg_local((ptr), (o), (n)); \ | |
115 | }) | |
116 | #else | |
329c161b | 117 | #define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n)) |
9e5228ce PG |
118 | #endif |
119 | ||
329c161b | 120 | #define arch_cmpxchg64(ptr, o, n) __cmpxchg_u64(ptr, o, n) |
54b66800 | 121 | |
9e5228ce | 122 | #endif /* _ASM_PARISC_CMPXCHG_H_ */ |