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 (dhowells@redhat.com)
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
__cmpxchg_local(volatile void * ptr,unsigned long old,unsigned long new,int size)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 */
173