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-i386/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-i386/atomic.h')
-rw-r--r-- | include/asm-i386/atomic.h | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/include/asm-i386/atomic.h b/include/asm-i386/atomic.h new file mode 100644 index 000000000000..509720be772a --- /dev/null +++ b/include/asm-i386/atomic.h | |||
@@ -0,0 +1,236 @@ | |||
1 | #ifndef __ARCH_I386_ATOMIC__ | ||
2 | #define __ARCH_I386_ATOMIC__ | ||
3 | |||
4 | #include <linux/config.h> | ||
5 | #include <linux/compiler.h> | ||
6 | #include <asm/processor.h> | ||
7 | |||
8 | /* | ||
9 | * Atomic operations that C can't guarantee us. Useful for | ||
10 | * resource counting etc.. | ||
11 | */ | ||
12 | |||
13 | #ifdef CONFIG_SMP | ||
14 | #define LOCK "lock ; " | ||
15 | #else | ||
16 | #define LOCK "" | ||
17 | #endif | ||
18 | |||
19 | /* | ||
20 | * Make sure gcc doesn't try to be clever and move things around | ||
21 | * on us. We need to use _exactly_ the address the user gave us, | ||
22 | * not some alias that contains the same information. | ||
23 | */ | ||
24 | typedef struct { volatile int counter; } atomic_t; | ||
25 | |||
26 | #define ATOMIC_INIT(i) { (i) } | ||
27 | |||
28 | /** | ||
29 | * atomic_read - read atomic variable | ||
30 | * @v: pointer of type atomic_t | ||
31 | * | ||
32 | * Atomically reads the value of @v. | ||
33 | */ | ||
34 | #define atomic_read(v) ((v)->counter) | ||
35 | |||
36 | /** | ||
37 | * atomic_set - set atomic variable | ||
38 | * @v: pointer of type atomic_t | ||
39 | * @i: required value | ||
40 | * | ||
41 | * Atomically sets the value of @v to @i. | ||
42 | */ | ||
43 | #define atomic_set(v,i) (((v)->counter) = (i)) | ||
44 | |||
45 | /** | ||
46 | * atomic_add - add integer to atomic variable | ||
47 | * @i: integer value to add | ||
48 | * @v: pointer of type atomic_t | ||
49 | * | ||
50 | * Atomically adds @i to @v. | ||
51 | */ | ||
52 | static __inline__ void atomic_add(int i, atomic_t *v) | ||
53 | { | ||
54 | __asm__ __volatile__( | ||
55 | LOCK "addl %1,%0" | ||
56 | :"=m" (v->counter) | ||
57 | :"ir" (i), "m" (v->counter)); | ||
58 | } | ||
59 | |||
60 | /** | ||
61 | * atomic_sub - subtract the atomic variable | ||
62 | * @i: integer value to subtract | ||
63 | * @v: pointer of type atomic_t | ||
64 | * | ||
65 | * Atomically subtracts @i from @v. | ||
66 | */ | ||
67 | static __inline__ void atomic_sub(int i, atomic_t *v) | ||
68 | { | ||
69 | __asm__ __volatile__( | ||
70 | LOCK "subl %1,%0" | ||
71 | :"=m" (v->counter) | ||
72 | :"ir" (i), "m" (v->counter)); | ||
73 | } | ||
74 | |||
75 | /** | ||
76 | * atomic_sub_and_test - subtract value from variable and test result | ||
77 | * @i: integer value to subtract | ||
78 | * @v: pointer of type atomic_t | ||
79 | * | ||
80 | * Atomically subtracts @i from @v and returns | ||
81 | * true if the result is zero, or false for all | ||
82 | * other cases. | ||
83 | */ | ||
84 | static __inline__ int atomic_sub_and_test(int i, atomic_t *v) | ||
85 | { | ||
86 | unsigned char c; | ||
87 | |||
88 | __asm__ __volatile__( | ||
89 | LOCK "subl %2,%0; sete %1" | ||
90 | :"=m" (v->counter), "=qm" (c) | ||
91 | :"ir" (i), "m" (v->counter) : "memory"); | ||
92 | return c; | ||
93 | } | ||
94 | |||
95 | /** | ||
96 | * atomic_inc - increment atomic variable | ||
97 | * @v: pointer of type atomic_t | ||
98 | * | ||
99 | * Atomically increments @v by 1. | ||
100 | */ | ||
101 | static __inline__ void atomic_inc(atomic_t *v) | ||
102 | { | ||
103 | __asm__ __volatile__( | ||
104 | LOCK "incl %0" | ||
105 | :"=m" (v->counter) | ||
106 | :"m" (v->counter)); | ||
107 | } | ||
108 | |||
109 | /** | ||
110 | * atomic_dec - decrement atomic variable | ||
111 | * @v: pointer of type atomic_t | ||
112 | * | ||
113 | * Atomically decrements @v by 1. | ||
114 | */ | ||
115 | static __inline__ void atomic_dec(atomic_t *v) | ||
116 | { | ||
117 | __asm__ __volatile__( | ||
118 | LOCK "decl %0" | ||
119 | :"=m" (v->counter) | ||
120 | :"m" (v->counter)); | ||
121 | } | ||
122 | |||
123 | /** | ||
124 | * atomic_dec_and_test - decrement and test | ||
125 | * @v: pointer of type atomic_t | ||
126 | * | ||
127 | * Atomically decrements @v by 1 and | ||
128 | * returns true if the result is 0, or false for all other | ||
129 | * cases. | ||
130 | */ | ||
131 | static __inline__ int atomic_dec_and_test(atomic_t *v) | ||
132 | { | ||
133 | unsigned char c; | ||
134 | |||
135 | __asm__ __volatile__( | ||
136 | LOCK "decl %0; sete %1" | ||
137 | :"=m" (v->counter), "=qm" (c) | ||
138 | :"m" (v->counter) : "memory"); | ||
139 | return c != 0; | ||
140 | } | ||
141 | |||
142 | /** | ||
143 | * atomic_inc_and_test - increment and test | ||
144 | * @v: pointer of type atomic_t | ||
145 | * | ||
146 | * Atomically increments @v by 1 | ||
147 | * and returns true if the result is zero, or false for all | ||
148 | * other cases. | ||
149 | */ | ||
150 | static __inline__ int atomic_inc_and_test(atomic_t *v) | ||
151 | { | ||
152 | unsigned char c; | ||
153 | |||
154 | __asm__ __volatile__( | ||
155 | LOCK "incl %0; sete %1" | ||
156 | :"=m" (v->counter), "=qm" (c) | ||
157 | :"m" (v->counter) : "memory"); | ||
158 | return c != 0; | ||
159 | } | ||
160 | |||
161 | /** | ||
162 | * atomic_add_negative - add and test if negative | ||
163 | * @v: pointer of type atomic_t | ||
164 | * @i: integer value to add | ||
165 | * | ||
166 | * Atomically adds @i to @v and returns true | ||
167 | * if the result is negative, or false when | ||
168 | * result is greater than or equal to zero. | ||
169 | */ | ||
170 | static __inline__ int atomic_add_negative(int i, atomic_t *v) | ||
171 | { | ||
172 | unsigned char c; | ||
173 | |||
174 | __asm__ __volatile__( | ||
175 | LOCK "addl %2,%0; sets %1" | ||
176 | :"=m" (v->counter), "=qm" (c) | ||
177 | :"ir" (i), "m" (v->counter) : "memory"); | ||
178 | return c; | ||
179 | } | ||
180 | |||
181 | /** | ||
182 | * atomic_add_return - add and return | ||
183 | * @v: pointer of type atomic_t | ||
184 | * @i: integer value to add | ||
185 | * | ||
186 | * Atomically adds @i to @v and returns @i + @v | ||
187 | */ | ||
188 | static __inline__ int atomic_add_return(int i, atomic_t *v) | ||
189 | { | ||
190 | int __i; | ||
191 | #ifdef CONFIG_M386 | ||
192 | if(unlikely(boot_cpu_data.x86==3)) | ||
193 | goto no_xadd; | ||
194 | #endif | ||
195 | /* Modern 486+ processor */ | ||
196 | __i = i; | ||
197 | __asm__ __volatile__( | ||
198 | LOCK "xaddl %0, %1;" | ||
199 | :"=r"(i) | ||
200 | :"m"(v->counter), "0"(i)); | ||
201 | return i + __i; | ||
202 | |||
203 | #ifdef CONFIG_M386 | ||
204 | no_xadd: /* Legacy 386 processor */ | ||
205 | local_irq_disable(); | ||
206 | __i = atomic_read(v); | ||
207 | atomic_set(v, i + __i); | ||
208 | local_irq_enable(); | ||
209 | return i + __i; | ||
210 | #endif | ||
211 | } | ||
212 | |||
213 | static __inline__ int atomic_sub_return(int i, atomic_t *v) | ||
214 | { | ||
215 | return atomic_add_return(-i,v); | ||
216 | } | ||
217 | |||
218 | #define atomic_inc_return(v) (atomic_add_return(1,v)) | ||
219 | #define atomic_dec_return(v) (atomic_sub_return(1,v)) | ||
220 | |||
221 | /* These are x86-specific, used by some header files */ | ||
222 | #define atomic_clear_mask(mask, addr) \ | ||
223 | __asm__ __volatile__(LOCK "andl %0,%1" \ | ||
224 | : : "r" (~(mask)),"m" (*addr) : "memory") | ||
225 | |||
226 | #define atomic_set_mask(mask, addr) \ | ||
227 | __asm__ __volatile__(LOCK "orl %0,%1" \ | ||
228 | : : "r" (mask),"m" (*(addr)) : "memory") | ||
229 | |||
230 | /* Atomic operations are already serializing on x86 */ | ||
231 | #define smp_mb__before_atomic_dec() barrier() | ||
232 | #define smp_mb__after_atomic_dec() barrier() | ||
233 | #define smp_mb__before_atomic_inc() barrier() | ||
234 | #define smp_mb__after_atomic_inc() barrier() | ||
235 | |||
236 | #endif | ||