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1da177e4 LT |
1 | /* atomic.h: atomic operation emulation for FR-V |
2 | * | |
3 | * For an explanation of how atomic ops work in this arch, see: | |
0868ff7a | 4 | * Documentation/frv/atomic-ops.txt |
1da177e4 LT |
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_ATOMIC_H | |
15 | #define _ASM_ATOMIC_H | |
16 | ||
1da177e4 LT |
17 | #include <linux/types.h> |
18 | #include <asm/spr-regs.h> | |
2856f5e3 | 19 | #include <asm/system.h> |
1da177e4 LT |
20 | |
21 | #ifdef CONFIG_SMP | |
22 | #error not SMP safe | |
23 | #endif | |
24 | ||
25 | /* | |
26 | * Atomic operations that C can't guarantee us. Useful for | |
27 | * resource counting etc.. | |
28 | * | |
29 | * We do not have SMP systems, so we don't have to deal with that. | |
30 | */ | |
31 | ||
32 | /* Atomic operations are already serializing */ | |
33 | #define smp_mb__before_atomic_dec() barrier() | |
34 | #define smp_mb__after_atomic_dec() barrier() | |
35 | #define smp_mb__before_atomic_inc() barrier() | |
36 | #define smp_mb__after_atomic_inc() barrier() | |
37 | ||
38 | typedef struct { | |
39 | int counter; | |
40 | } atomic_t; | |
41 | ||
42 | #define ATOMIC_INIT(i) { (i) } | |
43 | #define atomic_read(v) ((v)->counter) | |
44 | #define atomic_set(v, i) (((v)->counter) = (i)) | |
45 | ||
46 | #ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS | |
47 | static inline int atomic_add_return(int i, atomic_t *v) | |
48 | { | |
49 | unsigned long val; | |
50 | ||
51 | asm("0: \n" | |
52 | " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */ | |
53 | " ckeq icc3,cc7 \n" | |
54 | " ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */ | |
55 | " orcr cc7,cc7,cc3 \n" /* set CC3 to true */ | |
56 | " add%I2 %1,%2,%1 \n" | |
57 | " cst.p %1,%M0 ,cc3,#1 \n" | |
58 | " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */ | |
59 | " beq icc3,#0,0b \n" | |
60 | : "+U"(v->counter), "=&r"(val) | |
61 | : "NPr"(i) | |
62 | : "memory", "cc7", "cc3", "icc3" | |
63 | ); | |
64 | ||
65 | return val; | |
66 | } | |
67 | ||
68 | static inline int atomic_sub_return(int i, atomic_t *v) | |
69 | { | |
70 | unsigned long val; | |
71 | ||
72 | asm("0: \n" | |
73 | " orcc gr0,gr0,gr0,icc3 \n" /* set ICC3.Z */ | |
74 | " ckeq icc3,cc7 \n" | |
75 | " ld.p %M0,%1 \n" /* LD.P/ORCR must be atomic */ | |
76 | " orcr cc7,cc7,cc3 \n" /* set CC3 to true */ | |
77 | " sub%I2 %1,%2,%1 \n" | |
78 | " cst.p %1,%M0 ,cc3,#1 \n" | |
79 | " corcc gr29,gr29,gr0 ,cc3,#1 \n" /* clear ICC3.Z if store happens */ | |
80 | " beq icc3,#0,0b \n" | |
81 | : "+U"(v->counter), "=&r"(val) | |
82 | : "NPr"(i) | |
83 | : "memory", "cc7", "cc3", "icc3" | |
84 | ); | |
85 | ||
86 | return val; | |
87 | } | |
88 | ||
89 | #else | |
90 | ||
91 | extern int atomic_add_return(int i, atomic_t *v); | |
92 | extern int atomic_sub_return(int i, atomic_t *v); | |
93 | ||
94 | #endif | |
95 | ||
96 | static inline int atomic_add_negative(int i, atomic_t *v) | |
97 | { | |
98 | return atomic_add_return(i, v) < 0; | |
99 | } | |
100 | ||
101 | static inline void atomic_add(int i, atomic_t *v) | |
102 | { | |
103 | atomic_add_return(i, v); | |
104 | } | |
105 | ||
106 | static inline void atomic_sub(int i, atomic_t *v) | |
107 | { | |
108 | atomic_sub_return(i, v); | |
109 | } | |
110 | ||
111 | static inline void atomic_inc(atomic_t *v) | |
112 | { | |
113 | atomic_add_return(1, v); | |
114 | } | |
115 | ||
116 | static inline void atomic_dec(atomic_t *v) | |
117 | { | |
118 | atomic_sub_return(1, v); | |
119 | } | |
120 | ||
121 | #define atomic_dec_return(v) atomic_sub_return(1, (v)) | |
122 | #define atomic_inc_return(v) atomic_add_return(1, (v)) | |
123 | ||
124 | #define atomic_sub_and_test(i,v) (atomic_sub_return((i), (v)) == 0) | |
125 | #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) | |
126 | #define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) | |
127 | ||
1da177e4 LT |
128 | /*****************************************************************************/ |
129 | /* | |
130 | * exchange value with memory | |
131 | */ | |
132 | #ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS | |
133 | ||
134 | #define xchg(ptr, x) \ | |
135 | ({ \ | |
136 | __typeof__(ptr) __xg_ptr = (ptr); \ | |
137 | __typeof__(*(ptr)) __xg_orig; \ | |
138 | \ | |
139 | switch (sizeof(__xg_orig)) { \ | |
1da177e4 LT |
140 | case 4: \ |
141 | asm volatile( \ | |
68f624fc DH |
142 | "swap%I0 %M0,%1" \ |
143 | : "+m"(*__xg_ptr), "=r"(__xg_orig) \ | |
144 | : "1"(x) \ | |
2fa9e7e2 | 145 | : "memory" \ |
1da177e4 LT |
146 | ); \ |
147 | break; \ | |
148 | \ | |
149 | default: \ | |
7f788435 | 150 | __xg_orig = (__typeof__(__xg_orig))0; \ |
1da177e4 LT |
151 | asm volatile("break"); \ |
152 | break; \ | |
153 | } \ | |
154 | \ | |
155 | __xg_orig; \ | |
156 | }) | |
157 | ||
158 | #else | |
159 | ||
1da177e4 LT |
160 | extern uint32_t __xchg_32(uint32_t i, volatile void *v); |
161 | ||
162 | #define xchg(ptr, x) \ | |
163 | ({ \ | |
164 | __typeof__(ptr) __xg_ptr = (ptr); \ | |
165 | __typeof__(*(ptr)) __xg_orig; \ | |
166 | \ | |
167 | switch (sizeof(__xg_orig)) { \ | |
1da177e4 LT |
168 | case 4: __xg_orig = (__typeof__(*(ptr))) __xchg_32((uint32_t) x, __xg_ptr); break; \ |
169 | default: \ | |
7f788435 | 170 | __xg_orig = (__typeof__(__xg_orig))0; \ |
1da177e4 LT |
171 | asm volatile("break"); \ |
172 | break; \ | |
173 | } \ | |
174 | __xg_orig; \ | |
175 | }) | |
176 | ||
177 | #endif | |
178 | ||
179 | #define tas(ptr) (xchg((ptr), 1)) | |
180 | ||
2fa9e7e2 | 181 | #define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), old, new)) |
ffbf670f | 182 | #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) |
4a6dae6d | 183 | |
2856f5e3 MD |
184 | static __inline__ int atomic_add_unless(atomic_t *v, int a, int u) |
185 | { | |
186 | int c, old; | |
187 | c = atomic_read(v); | |
188 | for (;;) { | |
189 | if (unlikely(c == (u))) | |
190 | break; | |
191 | old = atomic_cmpxchg((v), c, c + (a)); | |
192 | if (likely(old == c)) | |
193 | break; | |
194 | c = old; | |
195 | } | |
196 | return c != (u); | |
197 | } | |
2fa9e7e2 | 198 | |
8426e1f6 NP |
199 | #define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) |
200 | ||
d3cb4871 | 201 | #include <asm-generic/atomic.h> |
1da177e4 | 202 | #endif /* _ASM_ATOMIC_H */ |