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cmpxchg.h
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1 /* xchg and cmpxchg operation emulation for FR-V
2  *
3  * For an explanation of how atomic ops work in this arch, see:
4  * Documentation/frv/atomic-ops.txt
5  *
6  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
7  * Written by David Howells ([email protected])
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * as published by the Free Software Foundation; either version
12  * 2 of the License, or (at your option) any later version.
13  */
14 #ifndef _ASM_CMPXCHG_H
15 #define _ASM_CMPXCHG_H
16 
17 #include <linux/types.h>
18 
19 /*****************************************************************************/
20 /*
21  * exchange value with memory
22  */
23 extern uint64_t __xchg_64(uint64_t i, volatile void *v);
24 
25 #ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
26 
27 #define xchg(ptr, x) \
28 ({ \
29  __typeof__(ptr) __xg_ptr = (ptr); \
30  __typeof__(*(ptr)) __xg_orig; \
31  \
32  switch (sizeof(__xg_orig)) { \
33  case 4: \
34  asm volatile( \
35  "swap%I0 %M0,%1" \
36  : "+m"(*__xg_ptr), "=r"(__xg_orig) \
37  : "1"(x) \
38  : "memory" \
39  ); \
40  break; \
41  \
42  default: \
43  __xg_orig = (__typeof__(__xg_orig))0; \
44  asm volatile("break"); \
45  break; \
46  } \
47  \
48  __xg_orig; \
49 })
50 
51 #else
52 
53 extern uint32_t __xchg_32(uint32_t i, volatile void *v);
54 
55 #define xchg(ptr, x) \
56 ({ \
57  __typeof__(ptr) __xg_ptr = (ptr); \
58  __typeof__(*(ptr)) __xg_orig; \
59  \
60  switch (sizeof(__xg_orig)) { \
61  case 4: __xg_orig = (__typeof__(*(ptr))) __xchg_32((uint32_t) x, __xg_ptr); break; \
62  default: \
63  __xg_orig = (__typeof__(__xg_orig))0; \
64  asm volatile("break"); \
65  break; \
66  } \
67  __xg_orig; \
68 })
69 
70 #endif
71 
72 #define tas(ptr) (xchg((ptr), 1))
73 
74 /*****************************************************************************/
75 /*
76  * compare and conditionally exchange value with memory
77  * - if (*ptr == test) then orig = *ptr; *ptr = test;
78  * - if (*ptr != test) then orig = *ptr;
79  */
80 extern uint64_t __cmpxchg_64(uint64_t test, uint64_t new, volatile uint64_t *v);
81 
82 #ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
83 
84 #define cmpxchg(ptr, test, new) \
85 ({ \
86  __typeof__(ptr) __xg_ptr = (ptr); \
87  __typeof__(*(ptr)) __xg_orig, __xg_tmp; \
88  __typeof__(*(ptr)) __xg_test = (test); \
89  __typeof__(*(ptr)) __xg_new = (new); \
90  \
91  switch (sizeof(__xg_orig)) { \
92  case 4: \
93  asm volatile( \
94  "0: \n" \
95  " orcc gr0,gr0,gr0,icc3 \n" \
96  " ckeq icc3,cc7 \n" \
97  " ld.p %M0,%1 \n" \
98  " orcr cc7,cc7,cc3 \n" \
99  " sub%I4cc %1,%4,%2,icc0 \n" \
100  " bne icc0,#0,1f \n" \
101  " cst.p %3,%M0 ,cc3,#1 \n" \
102  " corcc gr29,gr29,gr0 ,cc3,#1 \n" \
103  " beq icc3,#0,0b \n" \
104  "1: \n" \
105  : "+U"(*__xg_ptr), "=&r"(__xg_orig), "=&r"(__xg_tmp) \
106  : "r"(__xg_new), "NPr"(__xg_test) \
107  : "memory", "cc7", "cc3", "icc3", "icc0" \
108  ); \
109  break; \
110  \
111  default: \
112  __xg_orig = (__typeof__(__xg_orig))0; \
113  asm volatile("break"); \
114  break; \
115  } \
116  \
117  __xg_orig; \
118 })
119 
120 #else
121 
122 extern uint32_t __cmpxchg_32(uint32_t *v, uint32_t test, uint32_t new);
123 
124 #define cmpxchg(ptr, test, new) \
125 ({ \
126  __typeof__(ptr) __xg_ptr = (ptr); \
127  __typeof__(*(ptr)) __xg_orig; \
128  __typeof__(*(ptr)) __xg_test = (test); \
129  __typeof__(*(ptr)) __xg_new = (new); \
130  \
131  switch (sizeof(__xg_orig)) { \
132  case 4: __xg_orig = (__force __typeof__(*ptr)) \
133  __cmpxchg_32((__force uint32_t *)__xg_ptr, \
134  (__force uint32_t)__xg_test, \
135  (__force uint32_t)__xg_new); break; \
136  default: \
137  __xg_orig = (__typeof__(__xg_orig))0; \
138  asm volatile("break"); \
139  break; \
140  } \
141  \
142  __xg_orig; \
143 })
144 
145 #endif
146 
147 #include <asm-generic/cmpxchg-local.h>
148 
149 static inline unsigned long __cmpxchg_local(volatile void *ptr,
150  unsigned long old,
151  unsigned long new, int size)
152 {
153  switch (size) {
154  case 4:
155  return cmpxchg((unsigned long *)ptr, old, new);
156  default:
157  return __cmpxchg_local_generic(ptr, old, new, size);
158  }
159 
160  return old;
161 }
162 
163 /*
164  * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
165  * them available.
166  */
167 #define cmpxchg_local(ptr, o, n) \
168  ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
169  (unsigned long)(n), sizeof(*(ptr))))
170 #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
171 
172 #endif /* _ASM_CMPXCHG_H */
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