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5638f993 HH |
1 | #ifndef _ARCH_LOCAL_H |
2 | #define _ARCH_LOCAL_H | |
3 | ||
4 | #include <linux/percpu.h> | |
5 | ||
6 | #include <asm/system.h> | |
7 | #include <asm/atomic.h> | |
8 | #include <asm/asm.h> | |
9 | ||
01c57fb6 | 10 | typedef struct { |
5638f993 HH |
11 | atomic_long_t a; |
12 | } local_t; | |
13 | ||
14 | #define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } | |
15 | ||
16 | #define local_read(l) atomic_long_read(&(l)->a) | |
01c57fb6 | 17 | #define local_set(l, i) atomic_long_set(&(l)->a, (i)) |
5638f993 HH |
18 | |
19 | static inline void local_inc(local_t *l) | |
20 | { | |
69cde651 JP |
21 | asm volatile(_ASM_INC "%0" |
22 | : "+m" (l->a.counter)); | |
5638f993 HH |
23 | } |
24 | ||
25 | static inline void local_dec(local_t *l) | |
26 | { | |
69cde651 JP |
27 | asm volatile(_ASM_DEC "%0" |
28 | : "+m" (l->a.counter)); | |
5638f993 HH |
29 | } |
30 | ||
31 | static inline void local_add(long i, local_t *l) | |
32 | { | |
69cde651 JP |
33 | asm volatile(_ASM_ADD "%1,%0" |
34 | : "+m" (l->a.counter) | |
35 | : "ir" (i)); | |
5638f993 HH |
36 | } |
37 | ||
38 | static inline void local_sub(long i, local_t *l) | |
39 | { | |
69cde651 JP |
40 | asm volatile(_ASM_SUB "%1,%0" |
41 | : "+m" (l->a.counter) | |
42 | : "ir" (i)); | |
5638f993 HH |
43 | } |
44 | ||
45 | /** | |
46 | * local_sub_and_test - subtract value from variable and test result | |
47 | * @i: integer value to subtract | |
48 | * @l: pointer to type local_t | |
49 | * | |
50 | * Atomically subtracts @i from @l and returns | |
51 | * true if the result is zero, or false for all | |
52 | * other cases. | |
53 | */ | |
54 | static inline int local_sub_and_test(long i, local_t *l) | |
55 | { | |
56 | unsigned char c; | |
57 | ||
69cde651 JP |
58 | asm volatile(_ASM_SUB "%2,%0; sete %1" |
59 | : "+m" (l->a.counter), "=qm" (c) | |
60 | : "ir" (i) : "memory"); | |
5638f993 HH |
61 | return c; |
62 | } | |
63 | ||
64 | /** | |
65 | * local_dec_and_test - decrement and test | |
66 | * @l: pointer to type local_t | |
67 | * | |
68 | * Atomically decrements @l by 1 and | |
69 | * returns true if the result is 0, or false for all other | |
70 | * cases. | |
71 | */ | |
72 | static inline int local_dec_and_test(local_t *l) | |
73 | { | |
74 | unsigned char c; | |
75 | ||
69cde651 JP |
76 | asm volatile(_ASM_DEC "%0; sete %1" |
77 | : "+m" (l->a.counter), "=qm" (c) | |
78 | : : "memory"); | |
5638f993 HH |
79 | return c != 0; |
80 | } | |
81 | ||
82 | /** | |
83 | * local_inc_and_test - increment and test | |
84 | * @l: pointer to type local_t | |
85 | * | |
86 | * Atomically increments @l by 1 | |
87 | * and returns true if the result is zero, or false for all | |
88 | * other cases. | |
89 | */ | |
90 | static inline int local_inc_and_test(local_t *l) | |
91 | { | |
92 | unsigned char c; | |
93 | ||
69cde651 JP |
94 | asm volatile(_ASM_INC "%0; sete %1" |
95 | : "+m" (l->a.counter), "=qm" (c) | |
96 | : : "memory"); | |
5638f993 HH |
97 | return c != 0; |
98 | } | |
99 | ||
100 | /** | |
101 | * local_add_negative - add and test if negative | |
102 | * @i: integer value to add | |
103 | * @l: pointer to type local_t | |
104 | * | |
105 | * Atomically adds @i to @l and returns true | |
106 | * if the result is negative, or false when | |
107 | * result is greater than or equal to zero. | |
108 | */ | |
109 | static inline int local_add_negative(long i, local_t *l) | |
110 | { | |
111 | unsigned char c; | |
112 | ||
69cde651 JP |
113 | asm volatile(_ASM_ADD "%2,%0; sets %1" |
114 | : "+m" (l->a.counter), "=qm" (c) | |
115 | : "ir" (i) : "memory"); | |
5638f993 HH |
116 | return c; |
117 | } | |
118 | ||
119 | /** | |
120 | * local_add_return - add and return | |
121 | * @i: integer value to add | |
122 | * @l: pointer to type local_t | |
123 | * | |
124 | * Atomically adds @i to @l and returns @i + @l | |
125 | */ | |
126 | static inline long local_add_return(long i, local_t *l) | |
127 | { | |
128 | long __i; | |
129 | #ifdef CONFIG_M386 | |
130 | unsigned long flags; | |
01c57fb6 | 131 | if (unlikely(boot_cpu_data.x86 <= 3)) |
5638f993 | 132 | goto no_xadd; |
96a388de | 133 | #endif |
5638f993 HH |
134 | /* Modern 486+ processor */ |
135 | __i = i; | |
69cde651 JP |
136 | asm volatile(_ASM_XADD "%0, %1;" |
137 | : "+r" (i), "+m" (l->a.counter) | |
138 | : : "memory"); | |
5638f993 HH |
139 | return i + __i; |
140 | ||
141 | #ifdef CONFIG_M386 | |
142 | no_xadd: /* Legacy 386 processor */ | |
143 | local_irq_save(flags); | |
144 | __i = local_read(l); | |
145 | local_set(l, i + __i); | |
146 | local_irq_restore(flags); | |
147 | return i + __i; | |
148 | #endif | |
149 | } | |
150 | ||
151 | static inline long local_sub_return(long i, local_t *l) | |
152 | { | |
01c57fb6 | 153 | return local_add_return(-i, l); |
5638f993 HH |
154 | } |
155 | ||
01c57fb6 HH |
156 | #define local_inc_return(l) (local_add_return(1, l)) |
157 | #define local_dec_return(l) (local_sub_return(1, l)) | |
5638f993 HH |
158 | |
159 | #define local_cmpxchg(l, o, n) \ | |
160 | (cmpxchg_local(&((l)->a.counter), (o), (n))) | |
161 | /* Always has a lock prefix */ | |
162 | #define local_xchg(l, n) (xchg(&((l)->a.counter), (n))) | |
163 | ||
164 | /** | |
165 | * local_add_unless - add unless the number is a given value | |
166 | * @l: pointer of type local_t | |
167 | * @a: the amount to add to l... | |
168 | * @u: ...unless l is equal to u. | |
169 | * | |
170 | * Atomically adds @a to @l, so long as it was not @u. | |
171 | * Returns non-zero if @l was not @u, and zero otherwise. | |
172 | */ | |
173 | #define local_add_unless(l, a, u) \ | |
174 | ({ \ | |
175 | long c, old; \ | |
69cde651 | 176 | c = local_read((l)); \ |
5638f993 HH |
177 | for (;;) { \ |
178 | if (unlikely(c == (u))) \ | |
179 | break; \ | |
69cde651 | 180 | old = local_cmpxchg((l), c, c + (a)); \ |
5638f993 HH |
181 | if (likely(old == c)) \ |
182 | break; \ | |
183 | c = old; \ | |
184 | } \ | |
185 | c != (u); \ | |
186 | }) | |
187 | #define local_inc_not_zero(l) local_add_unless((l), 1, 0) | |
188 | ||
189 | /* On x86_32, these are no better than the atomic variants. | |
190 | * On x86-64 these are better than the atomic variants on SMP kernels | |
191 | * because they dont use a lock prefix. | |
192 | */ | |
193 | #define __local_inc(l) local_inc(l) | |
194 | #define __local_dec(l) local_dec(l) | |
01c57fb6 HH |
195 | #define __local_add(i, l) local_add((i), (l)) |
196 | #define __local_sub(i, l) local_sub((i), (l)) | |
5638f993 HH |
197 | |
198 | /* Use these for per-cpu local_t variables: on some archs they are | |
199 | * much more efficient than these naive implementations. Note they take | |
200 | * a variable, not an address. | |
201 | * | |
202 | * X86_64: This could be done better if we moved the per cpu data directly | |
203 | * after GS. | |
204 | */ | |
205 | ||
206 | /* Need to disable preemption for the cpu local counters otherwise we could | |
207 | still access a variable of a previous CPU in a non atomic way. */ | |
69cde651 JP |
208 | #define cpu_local_wrap_v(l) \ |
209 | ({ \ | |
210 | local_t res__; \ | |
211 | preempt_disable(); \ | |
212 | res__ = (l); \ | |
213 | preempt_enable(); \ | |
214 | res__; \ | |
215 | }) | |
5638f993 | 216 | #define cpu_local_wrap(l) \ |
69cde651 JP |
217 | ({ \ |
218 | preempt_disable(); \ | |
219 | (l); \ | |
220 | preempt_enable(); \ | |
221 | }) \ | |
222 | ||
223 | #define cpu_local_read(l) cpu_local_wrap_v(local_read(&__get_cpu_var((l)))) | |
224 | #define cpu_local_set(l, i) cpu_local_wrap(local_set(&__get_cpu_var((l)), (i))) | |
225 | #define cpu_local_inc(l) cpu_local_wrap(local_inc(&__get_cpu_var((l)))) | |
226 | #define cpu_local_dec(l) cpu_local_wrap(local_dec(&__get_cpu_var((l)))) | |
227 | #define cpu_local_add(i, l) cpu_local_wrap(local_add((i), &__get_cpu_var((l)))) | |
228 | #define cpu_local_sub(i, l) cpu_local_wrap(local_sub((i), &__get_cpu_var((l)))) | |
229 | ||
230 | #define __cpu_local_inc(l) cpu_local_inc((l)) | |
231 | #define __cpu_local_dec(l) cpu_local_dec((l)) | |
5638f993 HH |
232 | #define __cpu_local_add(i, l) cpu_local_add((i), (l)) |
233 | #define __cpu_local_sub(i, l) cpu_local_sub((i), (l)) | |
234 | ||
235 | #endif /* _ARCH_LOCAL_H */ |