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1#ifndef __ASM_SH_CMPXCHG_H
2#define __ASM_SH_CMPXCHG_H
3
4/*
5 * Atomic operations that C can't guarantee us. Useful for
6 * resource counting etc..
7 */
8
9#include <linux/compiler.h>
10#include <linux/types.h>
11
12#if defined(CONFIG_GUSA_RB)
13#include <asm/cmpxchg-grb.h>
14#elif defined(CONFIG_CPU_SH4A)
15#include <asm/cmpxchg-llsc.h>
16#else
17#include <asm/cmpxchg-irq.h>
18#endif
19
20extern void __xchg_called_with_bad_pointer(void);
21
22#define __xchg(ptr, x, size) \
23({ \
24 unsigned long __xchg__res; \
25 volatile void *__xchg_ptr = (ptr); \
26 switch (size) { \
27 case 4: \
28 __xchg__res = xchg_u32(__xchg_ptr, x); \
29 break; \
30 case 2: \
31 __xchg__res = xchg_u16(__xchg_ptr, x); \
32 break; \
33 case 1: \
34 __xchg__res = xchg_u8(__xchg_ptr, x); \
35 break; \
36 default: \
37 __xchg_called_with_bad_pointer(); \
38 __xchg__res = x; \
39 break; \
40 } \
41 \
42 __xchg__res; \
43})
44
45#define xchg(ptr,x) \
46 ((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
47
48/* This function doesn't exist, so you'll get a linker error
49 * if something tries to do an invalid cmpxchg(). */
50extern void __cmpxchg_called_with_bad_pointer(void);
51
52static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
53 unsigned long new, int size)
54{
55 switch (size) {
56 case 4:
57 return __cmpxchg_u32(ptr, old, new);
58 }
59 __cmpxchg_called_with_bad_pointer();
60 return old;
61}
62
63#define cmpxchg(ptr,o,n) \
64 ({ \
65 __typeof__(*(ptr)) _o_ = (o); \
66 __typeof__(*(ptr)) _n_ = (n); \
67 (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
68 (unsigned long)_n_, sizeof(*(ptr))); \
69 })
70
71#endif /* __ASM_SH_CMPXCHG_H */