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1da177e4 LT |
1 | #ifndef _ARCH_I386_LOCAL_H |
2 | #define _ARCH_I386_LOCAL_H | |
3 | ||
4 | #include <linux/percpu.h> | |
a0752279 MD |
5 | #include <asm/system.h> |
6 | #include <asm/atomic.h> | |
1da177e4 LT |
7 | |
8 | typedef struct | |
9 | { | |
a0752279 | 10 | atomic_long_t a; |
1da177e4 LT |
11 | } local_t; |
12 | ||
a0752279 | 13 | #define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } |
1da177e4 | 14 | |
a0752279 MD |
15 | #define local_read(l) atomic_long_read(&(l)->a) |
16 | #define local_set(l,i) atomic_long_set(&(l)->a, (i)) | |
1da177e4 | 17 | |
a0752279 | 18 | static __inline__ void local_inc(local_t *l) |
1da177e4 LT |
19 | { |
20 | __asm__ __volatile__( | |
21 | "incl %0" | |
a0752279 | 22 | :"+m" (l->a.counter)); |
1da177e4 LT |
23 | } |
24 | ||
a0752279 | 25 | static __inline__ void local_dec(local_t *l) |
1da177e4 LT |
26 | { |
27 | __asm__ __volatile__( | |
28 | "decl %0" | |
a0752279 | 29 | :"+m" (l->a.counter)); |
1da177e4 LT |
30 | } |
31 | ||
a0752279 | 32 | static __inline__ void local_add(long i, local_t *l) |
1da177e4 LT |
33 | { |
34 | __asm__ __volatile__( | |
35 | "addl %1,%0" | |
a0752279 | 36 | :"+m" (l->a.counter) |
b862f3b0 | 37 | :"ir" (i)); |
1da177e4 LT |
38 | } |
39 | ||
a0752279 | 40 | static __inline__ void local_sub(long i, local_t *l) |
1da177e4 LT |
41 | { |
42 | __asm__ __volatile__( | |
43 | "subl %1,%0" | |
a0752279 | 44 | :"+m" (l->a.counter) |
b862f3b0 | 45 | :"ir" (i)); |
1da177e4 LT |
46 | } |
47 | ||
a0752279 MD |
48 | /** |
49 | * local_sub_and_test - subtract value from variable and test result | |
50 | * @i: integer value to subtract | |
51 | * @l: pointer of type local_t | |
52 | * | |
53 | * Atomically subtracts @i from @l and returns | |
54 | * true if the result is zero, or false for all | |
55 | * other cases. | |
56 | */ | |
57 | static __inline__ int local_sub_and_test(long i, local_t *l) | |
58 | { | |
59 | unsigned char c; | |
60 | ||
61 | __asm__ __volatile__( | |
62 | "subl %2,%0; sete %1" | |
63 | :"+m" (l->a.counter), "=qm" (c) | |
64 | :"ir" (i) : "memory"); | |
65 | return c; | |
66 | } | |
67 | ||
68 | /** | |
69 | * local_dec_and_test - decrement and test | |
70 | * @l: pointer of type local_t | |
71 | * | |
72 | * Atomically decrements @l by 1 and | |
73 | * returns true if the result is 0, or false for all other | |
74 | * cases. | |
75 | */ | |
76 | static __inline__ int local_dec_and_test(local_t *l) | |
77 | { | |
78 | unsigned char c; | |
79 | ||
80 | __asm__ __volatile__( | |
81 | "decl %0; sete %1" | |
82 | :"+m" (l->a.counter), "=qm" (c) | |
83 | : : "memory"); | |
84 | return c != 0; | |
85 | } | |
86 | ||
87 | /** | |
88 | * local_inc_and_test - increment and test | |
89 | * @l: pointer of type local_t | |
90 | * | |
91 | * Atomically increments @l by 1 | |
92 | * and returns true if the result is zero, or false for all | |
93 | * other cases. | |
94 | */ | |
95 | static __inline__ int local_inc_and_test(local_t *l) | |
96 | { | |
97 | unsigned char c; | |
98 | ||
99 | __asm__ __volatile__( | |
100 | "incl %0; sete %1" | |
101 | :"+m" (l->a.counter), "=qm" (c) | |
102 | : : "memory"); | |
103 | return c != 0; | |
104 | } | |
105 | ||
106 | /** | |
107 | * local_add_negative - add and test if negative | |
108 | * @l: pointer of type local_t | |
109 | * @i: integer value to add | |
110 | * | |
111 | * Atomically adds @i to @l and returns true | |
112 | * if the result is negative, or false when | |
113 | * result is greater than or equal to zero. | |
114 | */ | |
115 | static __inline__ int local_add_negative(long i, local_t *l) | |
116 | { | |
117 | unsigned char c; | |
118 | ||
119 | __asm__ __volatile__( | |
120 | "addl %2,%0; sets %1" | |
121 | :"+m" (l->a.counter), "=qm" (c) | |
122 | :"ir" (i) : "memory"); | |
123 | return c; | |
124 | } | |
125 | ||
126 | /** | |
127 | * local_add_return - add and return | |
128 | * @l: pointer of type local_t | |
129 | * @i: integer value to add | |
130 | * | |
131 | * Atomically adds @i to @l and returns @i + @l | |
132 | */ | |
133 | static __inline__ long local_add_return(long i, local_t *l) | |
134 | { | |
135 | long __i; | |
136 | #ifdef CONFIG_M386 | |
137 | unsigned long flags; | |
138 | if(unlikely(boot_cpu_data.x86==3)) | |
139 | goto no_xadd; | |
140 | #endif | |
141 | /* Modern 486+ processor */ | |
142 | __i = i; | |
143 | __asm__ __volatile__( | |
144 | "xaddl %0, %1;" | |
145 | :"+r" (i), "+m" (l->a.counter) | |
146 | : : "memory"); | |
147 | return i + __i; | |
148 | ||
149 | #ifdef CONFIG_M386 | |
150 | no_xadd: /* Legacy 386 processor */ | |
151 | local_irq_save(flags); | |
152 | __i = local_read(l); | |
153 | local_set(l, i + __i); | |
154 | local_irq_restore(flags); | |
155 | return i + __i; | |
156 | #endif | |
157 | } | |
158 | ||
159 | static __inline__ long local_sub_return(long i, local_t *l) | |
160 | { | |
161 | return local_add_return(-i,l); | |
162 | } | |
163 | ||
164 | #define local_inc_return(l) (local_add_return(1,l)) | |
165 | #define local_dec_return(l) (local_sub_return(1,l)) | |
166 | ||
167 | #define local_cmpxchg(l, o, n) \ | |
168 | (cmpxchg_local(&((l)->a.counter), (o), (n))) | |
169 | /* Always has a lock prefix */ | |
170 | #define local_xchg(l, n) (xchg(&((l)->a.counter), (n))) | |
171 | ||
172 | /** | |
173 | * local_add_unless - add unless the number is a given value | |
174 | * @l: pointer of type local_t | |
175 | * @a: the amount to add to l... | |
176 | * @u: ...unless l is equal to u. | |
177 | * | |
178 | * Atomically adds @a to @l, so long as it was not @u. | |
179 | * Returns non-zero if @l was not @u, and zero otherwise. | |
180 | */ | |
181 | #define local_add_unless(l, a, u) \ | |
182 | ({ \ | |
183 | long c, old; \ | |
184 | c = local_read(l); \ | |
185 | for (;;) { \ | |
186 | if (unlikely(c == (u))) \ | |
187 | break; \ | |
188 | old = local_cmpxchg((l), c, c + (a)); \ | |
189 | if (likely(old == c)) \ | |
190 | break; \ | |
191 | c = old; \ | |
192 | } \ | |
193 | c != (u); \ | |
194 | }) | |
195 | #define local_inc_not_zero(l) local_add_unless((l), 1, 0) | |
196 | ||
1da177e4 LT |
197 | /* On x86, these are no better than the atomic variants. */ |
198 | #define __local_inc(l) local_inc(l) | |
199 | #define __local_dec(l) local_dec(l) | |
200 | #define __local_add(i,l) local_add((i),(l)) | |
201 | #define __local_sub(i,l) local_sub((i),(l)) | |
202 | ||
203 | /* Use these for per-cpu local_t variables: on some archs they are | |
204 | * much more efficient than these naive implementations. Note they take | |
205 | * a variable, not an address. | |
206 | */ | |
da531125 AK |
207 | |
208 | /* Need to disable preemption for the cpu local counters otherwise we could | |
209 | still access a variable of a previous CPU in a non atomic way. */ | |
a0752279 | 210 | #define cpu_local_wrap_v(l) \ |
da531125 AK |
211 | ({ local_t res__; \ |
212 | preempt_disable(); \ | |
a0752279 | 213 | res__ = (l); \ |
da531125 AK |
214 | preempt_enable(); \ |
215 | res__; }) | |
a0752279 | 216 | #define cpu_local_wrap(l) \ |
da531125 | 217 | ({ preempt_disable(); \ |
a0752279 | 218 | l; \ |
da531125 AK |
219 | preempt_enable(); }) \ |
220 | ||
a0752279 MD |
221 | #define cpu_local_read(l) cpu_local_wrap_v(local_read(&__get_cpu_var(l))) |
222 | #define cpu_local_set(l, i) cpu_local_wrap(local_set(&__get_cpu_var(l), (i))) | |
223 | #define cpu_local_inc(l) cpu_local_wrap(local_inc(&__get_cpu_var(l))) | |
224 | #define cpu_local_dec(l) cpu_local_wrap(local_dec(&__get_cpu_var(l))) | |
225 | #define cpu_local_add(i, l) cpu_local_wrap(local_add((i), &__get_cpu_var(l))) | |
226 | #define cpu_local_sub(i, l) cpu_local_wrap(local_sub((i), &__get_cpu_var(l))) | |
227 | ||
228 | #define __cpu_local_inc(l) cpu_local_inc(l) | |
229 | #define __cpu_local_dec(l) cpu_local_dec(l) | |
230 | #define __cpu_local_add(i, l) cpu_local_add((i), (l)) | |
231 | #define __cpu_local_sub(i, l) cpu_local_sub((i), (l)) | |
1da177e4 LT |
232 | |
233 | #endif /* _ARCH_I386_LOCAL_H */ |