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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
d550bbd4 DH |
2 | /* 32-bit atomic xchg() and cmpxchg() definitions. |
3 | * | |
4 | * Copyright (C) 1996 David S. Miller (davem@davemloft.net) | |
5 | * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com.au) | |
6 | * Copyright (C) 2007 Kyle McMartin (kyle@parisc-linux.org) | |
7 | * | |
8 | * Additions by Keith M Wesolowski (wesolows@foobazco.org) based | |
9 | * on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>. | |
10 | */ | |
11 | ||
12 | #ifndef __ARCH_SPARC_CMPXCHG__ | |
13 | #define __ARCH_SPARC_CMPXCHG__ | |
14 | ||
1a17fdc4 | 15 | unsigned long __xchg_u32(volatile u32 *m, u32 new); |
f05a6865 | 16 | void __xchg_called_with_bad_pointer(void); |
d550bbd4 DH |
17 | |
18 | static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr, int size) | |
19 | { | |
20 | switch (size) { | |
21 | case 4: | |
1a17fdc4 | 22 | return __xchg_u32(ptr, x); |
d550bbd4 DH |
23 | } |
24 | __xchg_called_with_bad_pointer(); | |
25 | return x; | |
26 | } | |
27 | ||
28 | #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr)))) | |
29 | ||
30 | /* Emulate cmpxchg() the same way we emulate atomics, | |
31 | * by hashing the object address and indexing into an array | |
32 | * of spinlocks to get a bit of performance... | |
33 | * | |
34 | * See arch/sparc/lib/atomic32.c for implementation. | |
35 | * | |
36 | * Cribbed from <asm-parisc/atomic.h> | |
37 | */ | |
d550bbd4 DH |
38 | |
39 | /* bug catcher for when unsupported size is used - won't link */ | |
f05a6865 | 40 | void __cmpxchg_called_with_bad_pointer(void); |
d550bbd4 | 41 | /* we only need to support cmpxchg of a u32 on sparc */ |
f05a6865 | 42 | unsigned long __cmpxchg_u32(volatile u32 *m, u32 old, u32 new_); |
d550bbd4 DH |
43 | |
44 | /* don't worry...optimizer will get rid of most of this */ | |
45 | static inline unsigned long | |
46 | __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size) | |
47 | { | |
48 | switch (size) { | |
49 | case 4: | |
50 | return __cmpxchg_u32((u32 *)ptr, (u32)old, (u32)new_); | |
51 | default: | |
52 | __cmpxchg_called_with_bad_pointer(); | |
53 | break; | |
54 | } | |
55 | return old; | |
56 | } | |
57 | ||
58 | #define cmpxchg(ptr, o, n) \ | |
59 | ({ \ | |
60 | __typeof__(*(ptr)) _o_ = (o); \ | |
61 | __typeof__(*(ptr)) _n_ = (n); \ | |
62 | (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \ | |
63 | (unsigned long)_n_, sizeof(*(ptr))); \ | |
64 | }) | |
65 | ||
66 | #include <asm-generic/cmpxchg-local.h> | |
67 | ||
68 | /* | |
69 | * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make | |
70 | * them available. | |
71 | */ | |
72 | #define cmpxchg_local(ptr, o, n) \ | |
73 | ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\ | |
74 | (unsigned long)(n), sizeof(*(ptr)))) | |
75 | #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) | |
76 | ||
77 | #endif /* __ARCH_SPARC_CMPXCHG__ */ |