diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-arm/atomic.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-arm/atomic.h')
-rw-r--r-- | include/asm-arm/atomic.h | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/include/asm-arm/atomic.h b/include/asm-arm/atomic.h new file mode 100644 index 000000000000..2885972b0855 --- /dev/null +++ b/include/asm-arm/atomic.h | |||
@@ -0,0 +1,165 @@ | |||
1 | /* | ||
2 | * linux/include/asm-arm/atomic.h | ||
3 | * | ||
4 | * Copyright (C) 1996 Russell King. | ||
5 | * Copyright (C) 2002 Deep Blue Solutions Ltd. | ||
6 | * | ||
7 | * This program is free software; you can redistribute it and/or modify | ||
8 | * it under the terms of the GNU General Public License version 2 as | ||
9 | * published by the Free Software Foundation. | ||
10 | */ | ||
11 | #ifndef __ASM_ARM_ATOMIC_H | ||
12 | #define __ASM_ARM_ATOMIC_H | ||
13 | |||
14 | #include <linux/config.h> | ||
15 | |||
16 | typedef struct { volatile int counter; } atomic_t; | ||
17 | |||
18 | #define ATOMIC_INIT(i) { (i) } | ||
19 | |||
20 | #ifdef __KERNEL__ | ||
21 | |||
22 | #define atomic_read(v) ((v)->counter) | ||
23 | |||
24 | #if __LINUX_ARM_ARCH__ >= 6 | ||
25 | |||
26 | /* | ||
27 | * ARMv6 UP and SMP safe atomic ops. We use load exclusive and | ||
28 | * store exclusive to ensure that these are atomic. We may loop | ||
29 | * to ensure that the update happens. Writing to 'v->counter' | ||
30 | * without using the following operations WILL break the atomic | ||
31 | * nature of these ops. | ||
32 | */ | ||
33 | static inline void atomic_set(atomic_t *v, int i) | ||
34 | { | ||
35 | unsigned long tmp; | ||
36 | |||
37 | __asm__ __volatile__("@ atomic_set\n" | ||
38 | "1: ldrex %0, [%1]\n" | ||
39 | " strex %0, %2, [%1]\n" | ||
40 | " teq %0, #0\n" | ||
41 | " bne 1b" | ||
42 | : "=&r" (tmp) | ||
43 | : "r" (&v->counter), "r" (i) | ||
44 | : "cc"); | ||
45 | } | ||
46 | |||
47 | static inline int atomic_add_return(int i, atomic_t *v) | ||
48 | { | ||
49 | unsigned long tmp; | ||
50 | int result; | ||
51 | |||
52 | __asm__ __volatile__("@ atomic_add_return\n" | ||
53 | "1: ldrex %0, [%2]\n" | ||
54 | " add %0, %0, %3\n" | ||
55 | " strex %1, %0, [%2]\n" | ||
56 | " teq %1, #0\n" | ||
57 | " bne 1b" | ||
58 | : "=&r" (result), "=&r" (tmp) | ||
59 | : "r" (&v->counter), "Ir" (i) | ||
60 | : "cc"); | ||
61 | |||
62 | return result; | ||
63 | } | ||
64 | |||
65 | static inline int atomic_sub_return(int i, atomic_t *v) | ||
66 | { | ||
67 | unsigned long tmp; | ||
68 | int result; | ||
69 | |||
70 | __asm__ __volatile__("@ atomic_sub_return\n" | ||
71 | "1: ldrex %0, [%2]\n" | ||
72 | " sub %0, %0, %3\n" | ||
73 | " strex %1, %0, [%2]\n" | ||
74 | " teq %1, #0\n" | ||
75 | " bne 1b" | ||
76 | : "=&r" (result), "=&r" (tmp) | ||
77 | : "r" (&v->counter), "Ir" (i) | ||
78 | : "cc"); | ||
79 | |||
80 | return result; | ||
81 | } | ||
82 | |||
83 | static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) | ||
84 | { | ||
85 | unsigned long tmp, tmp2; | ||
86 | |||
87 | __asm__ __volatile__("@ atomic_clear_mask\n" | ||
88 | "1: ldrex %0, %2\n" | ||
89 | " bic %0, %0, %3\n" | ||
90 | " strex %1, %0, %2\n" | ||
91 | " teq %1, #0\n" | ||
92 | " bne 1b" | ||
93 | : "=&r" (tmp), "=&r" (tmp2) | ||
94 | : "r" (addr), "Ir" (mask) | ||
95 | : "cc"); | ||
96 | } | ||
97 | |||
98 | #else /* ARM_ARCH_6 */ | ||
99 | |||
100 | #include <asm/system.h> | ||
101 | |||
102 | #ifdef CONFIG_SMP | ||
103 | #error SMP not supported on pre-ARMv6 CPUs | ||
104 | #endif | ||
105 | |||
106 | #define atomic_set(v,i) (((v)->counter) = (i)) | ||
107 | |||
108 | static inline int atomic_add_return(int i, atomic_t *v) | ||
109 | { | ||
110 | unsigned long flags; | ||
111 | int val; | ||
112 | |||
113 | local_irq_save(flags); | ||
114 | val = v->counter; | ||
115 | v->counter = val += i; | ||
116 | local_irq_restore(flags); | ||
117 | |||
118 | return val; | ||
119 | } | ||
120 | |||
121 | static inline int atomic_sub_return(int i, atomic_t *v) | ||
122 | { | ||
123 | unsigned long flags; | ||
124 | int val; | ||
125 | |||
126 | local_irq_save(flags); | ||
127 | val = v->counter; | ||
128 | v->counter = val -= i; | ||
129 | local_irq_restore(flags); | ||
130 | |||
131 | return val; | ||
132 | } | ||
133 | |||
134 | static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) | ||
135 | { | ||
136 | unsigned long flags; | ||
137 | |||
138 | local_irq_save(flags); | ||
139 | *addr &= ~mask; | ||
140 | local_irq_restore(flags); | ||
141 | } | ||
142 | |||
143 | #endif /* __LINUX_ARM_ARCH__ */ | ||
144 | |||
145 | #define atomic_add(i, v) (void) atomic_add_return(i, v) | ||
146 | #define atomic_inc(v) (void) atomic_add_return(1, v) | ||
147 | #define atomic_sub(i, v) (void) atomic_sub_return(i, v) | ||
148 | #define atomic_dec(v) (void) atomic_sub_return(1, v) | ||
149 | |||
150 | #define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0) | ||
151 | #define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0) | ||
152 | #define atomic_inc_return(v) (atomic_add_return(1, v)) | ||
153 | #define atomic_dec_return(v) (atomic_sub_return(1, v)) | ||
154 | #define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0) | ||
155 | |||
156 | #define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0) | ||
157 | |||
158 | /* Atomic operations are already serializing on ARM */ | ||
159 | #define smp_mb__before_atomic_dec() barrier() | ||
160 | #define smp_mb__after_atomic_dec() barrier() | ||
161 | #define smp_mb__before_atomic_inc() barrier() | ||
162 | #define smp_mb__after_atomic_inc() barrier() | ||
163 | |||
164 | #endif | ||
165 | #endif | ||