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cmpxchg.h
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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 <[email protected]>
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  */
27 extern 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 #define __HAVE_ARCH_CMPXCHG 1
65 
66 /*
67  * This function doesn't exist, so you'll get a linker error
68  * if something tries to do an invalid cmpxchg().
69  */
70 extern long ia64_cmpxchg_called_with_bad_pointer(void);
71 
72 #define ia64_cmpxchg(sem, ptr, old, new, size) \
73 ({ \
74  __u64 _o_, _r_; \
75  \
76  switch (size) { \
77  case 1: \
78  _o_ = (__u8) (long) (old); \
79  break; \
80  case 2: \
81  _o_ = (__u16) (long) (old); \
82  break; \
83  case 4: \
84  _o_ = (__u32) (long) (old); \
85  break; \
86  case 8: \
87  _o_ = (__u64) (long) (old); \
88  break; \
89  default: \
90  break; \
91  } \
92  switch (size) { \
93  case 1: \
94  _r_ = ia64_cmpxchg1_##sem((__u8 *) ptr, new, _o_); \
95  break; \
96  \
97  case 2: \
98  _r_ = ia64_cmpxchg2_##sem((__u16 *) ptr, new, _o_); \
99  break; \
100  \
101  case 4: \
102  _r_ = ia64_cmpxchg4_##sem((__u32 *) ptr, new, _o_); \
103  break; \
104  \
105  case 8: \
106  _r_ = ia64_cmpxchg8_##sem((__u64 *) ptr, new, _o_); \
107  break; \
108  \
109  default: \
110  _r_ = ia64_cmpxchg_called_with_bad_pointer(); \
111  break; \
112  } \
113  (__typeof__(old)) _r_; \
114 })
115 
116 #define cmpxchg_acq(ptr, o, n) \
117  ia64_cmpxchg(acq, (ptr), (o), (n), sizeof(*(ptr)))
118 #define cmpxchg_rel(ptr, o, n) \
119  ia64_cmpxchg(rel, (ptr), (o), (n), sizeof(*(ptr)))
120 
121 /* for compatibility with other platforms: */
122 #define cmpxchg(ptr, o, n) cmpxchg_acq((ptr), (o), (n))
123 #define cmpxchg64(ptr, o, n) cmpxchg_acq((ptr), (o), (n))
124 
125 #define cmpxchg_local cmpxchg
126 #define cmpxchg64_local cmpxchg64
127 
128 #ifdef CONFIG_IA64_DEBUG_CMPXCHG
129 # define CMPXCHG_BUGCHECK_DECL int _cmpxchg_bugcheck_count = 128;
130 # define CMPXCHG_BUGCHECK(v) \
131 do { \
132  if (_cmpxchg_bugcheck_count-- <= 0) { \
133  void *ip; \
134  extern int printk(const char *fmt, ...); \
135  ip = (void *) ia64_getreg(_IA64_REG_IP); \
136  printk("CMPXCHG_BUGCHECK: stuck at %p on word %p\n", ip, (v));\
137  break; \
138  } \
139 } while (0)
140 #else /* !CONFIG_IA64_DEBUG_CMPXCHG */
141 # define CMPXCHG_BUGCHECK_DECL
142 # define CMPXCHG_BUGCHECK(v)
143 #endif /* !CONFIG_IA64_DEBUG_CMPXCHG */
144 
145 #endif /* !__ASSEMBLY__ */
146 
147 #endif /* _ASM_IA64_CMPXCHG_H */
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