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1da177e4 LT |
1 | #ifndef _ARCH_X8664_LOCAL_H |
2 | #define _ARCH_X8664_LOCAL_H | |
3 | ||
4 | #include <linux/percpu.h> | |
c343c14a | 5 | #include <asm/atomic.h> |
1da177e4 LT |
6 | |
7 | typedef struct | |
8 | { | |
c343c14a | 9 | atomic_long_t a; |
1da177e4 LT |
10 | } local_t; |
11 | ||
c343c14a | 12 | #define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } |
1da177e4 | 13 | |
c343c14a MD |
14 | #define local_read(l) atomic_long_read(&(l)->a) |
15 | #define local_set(l,i) atomic_long_set(&(l)->a, (i)) | |
1da177e4 | 16 | |
c343c14a | 17 | static inline void local_inc(local_t *l) |
1da177e4 LT |
18 | { |
19 | __asm__ __volatile__( | |
94949436 | 20 | "incq %0" |
c343c14a MD |
21 | :"=m" (l->a.counter) |
22 | :"m" (l->a.counter)); | |
1da177e4 LT |
23 | } |
24 | ||
c343c14a | 25 | static inline void local_dec(local_t *l) |
1da177e4 LT |
26 | { |
27 | __asm__ __volatile__( | |
94949436 | 28 | "decq %0" |
c343c14a MD |
29 | :"=m" (l->a.counter) |
30 | :"m" (l->a.counter)); | |
1da177e4 LT |
31 | } |
32 | ||
c343c14a | 33 | static inline void local_add(long i, local_t *l) |
1da177e4 LT |
34 | { |
35 | __asm__ __volatile__( | |
94949436 | 36 | "addq %1,%0" |
c343c14a MD |
37 | :"=m" (l->a.counter) |
38 | :"ir" (i), "m" (l->a.counter)); | |
1da177e4 LT |
39 | } |
40 | ||
c343c14a | 41 | static inline void local_sub(long i, local_t *l) |
1da177e4 LT |
42 | { |
43 | __asm__ __volatile__( | |
94949436 | 44 | "subq %1,%0" |
c343c14a MD |
45 | :"=m" (l->a.counter) |
46 | :"ir" (i), "m" (l->a.counter)); | |
1da177e4 LT |
47 | } |
48 | ||
c343c14a MD |
49 | /** |
50 | * local_sub_and_test - subtract value from variable and test result | |
51 | * @i: integer value to subtract | |
52 | * @l: pointer to type local_t | |
53 | * | |
54 | * Atomically subtracts @i from @l and returns | |
55 | * true if the result is zero, or false for all | |
56 | * other cases. | |
57 | */ | |
58 | static __inline__ int local_sub_and_test(long i, local_t *l) | |
59 | { | |
60 | unsigned char c; | |
61 | ||
62 | __asm__ __volatile__( | |
63 | "subq %2,%0; sete %1" | |
64 | :"=m" (l->a.counter), "=qm" (c) | |
65 | :"ir" (i), "m" (l->a.counter) : "memory"); | |
66 | return c; | |
67 | } | |
68 | ||
69 | /** | |
70 | * local_dec_and_test - decrement and test | |
71 | * @l: pointer to type local_t | |
72 | * | |
73 | * Atomically decrements @l by 1 and | |
74 | * returns true if the result is 0, or false for all other | |
75 | * cases. | |
76 | */ | |
77 | static __inline__ int local_dec_and_test(local_t *l) | |
78 | { | |
79 | unsigned char c; | |
80 | ||
81 | __asm__ __volatile__( | |
82 | "decq %0; sete %1" | |
83 | :"=m" (l->a.counter), "=qm" (c) | |
84 | :"m" (l->a.counter) : "memory"); | |
85 | return c != 0; | |
86 | } | |
87 | ||
88 | /** | |
89 | * local_inc_and_test - increment and test | |
90 | * @l: pointer to type local_t | |
91 | * | |
92 | * Atomically increments @l by 1 | |
93 | * and returns true if the result is zero, or false for all | |
94 | * other cases. | |
95 | */ | |
96 | static __inline__ int local_inc_and_test(local_t *l) | |
97 | { | |
98 | unsigned char c; | |
99 | ||
100 | __asm__ __volatile__( | |
101 | "incq %0; sete %1" | |
102 | :"=m" (l->a.counter), "=qm" (c) | |
103 | :"m" (l->a.counter) : "memory"); | |
104 | return c != 0; | |
105 | } | |
106 | ||
107 | /** | |
108 | * local_add_negative - add and test if negative | |
109 | * @i: integer value to add | |
110 | * @l: pointer to type local_t | |
111 | * | |
112 | * Atomically adds @i to @l and returns true | |
113 | * if the result is negative, or false when | |
114 | * result is greater than or equal to zero. | |
115 | */ | |
116 | static __inline__ int local_add_negative(long i, local_t *l) | |
117 | { | |
118 | unsigned char c; | |
119 | ||
120 | __asm__ __volatile__( | |
121 | "addq %2,%0; sets %1" | |
122 | :"=m" (l->a.counter), "=qm" (c) | |
123 | :"ir" (i), "m" (l->a.counter) : "memory"); | |
124 | return c; | |
125 | } | |
126 | ||
127 | /** | |
128 | * local_add_return - add and return | |
129 | * @i: integer value to add | |
130 | * @l: pointer to type local_t | |
131 | * | |
132 | * Atomically adds @i to @l and returns @i + @l | |
133 | */ | |
134 | static __inline__ long local_add_return(long i, local_t *l) | |
135 | { | |
136 | long __i = i; | |
137 | __asm__ __volatile__( | |
138 | "xaddq %0, %1;" | |
139 | :"+r" (i), "+m" (l->a.counter) | |
140 | : : "memory"); | |
141 | return i + __i; | |
142 | } | |
143 | ||
144 | static __inline__ long local_sub_return(long i, local_t *l) | |
145 | { | |
146 | return local_add_return(-i,l); | |
147 | } | |
148 | ||
149 | #define local_inc_return(l) (local_add_return(1,l)) | |
150 | #define local_dec_return(l) (local_sub_return(1,l)) | |
151 | ||
152 | #define local_cmpxchg(l, o, n) \ | |
153 | (cmpxchg_local(&((l)->a.counter), (o), (n))) | |
154 | /* Always has a lock prefix */ | |
155 | #define local_xchg(l, n) (xchg(&((l)->a.counter), (n))) | |
156 | ||
157 | /** | |
158 | * atomic_up_add_unless - add unless the number is a given value | |
159 | * @l: pointer of type local_t | |
160 | * @a: the amount to add to l... | |
161 | * @u: ...unless l is equal to u. | |
162 | * | |
163 | * Atomically adds @a to @l, so long as it was not @u. | |
164 | * Returns non-zero if @l was not @u, and zero otherwise. | |
165 | */ | |
166 | #define local_add_unless(l, a, u) \ | |
167 | ({ \ | |
168 | long c, old; \ | |
169 | c = local_read(l); \ | |
170 | for (;;) { \ | |
171 | if (unlikely(c == (u))) \ | |
172 | break; \ | |
173 | old = local_cmpxchg((l), c, c + (a)); \ | |
174 | if (likely(old == c)) \ | |
175 | break; \ | |
176 | c = old; \ | |
177 | } \ | |
178 | c != (u); \ | |
179 | }) | |
180 | #define local_inc_not_zero(l) local_add_unless((l), 1, 0) | |
181 | ||
1c173409 AK |
182 | /* On x86-64 these are better than the atomic variants on SMP kernels |
183 | because they dont use a lock prefix. */ | |
1da177e4 LT |
184 | #define __local_inc(l) local_inc(l) |
185 | #define __local_dec(l) local_dec(l) | |
186 | #define __local_add(i,l) local_add((i),(l)) | |
187 | #define __local_sub(i,l) local_sub((i),(l)) | |
188 | ||
189 | /* Use these for per-cpu local_t variables: on some archs they are | |
190 | * much more efficient than these naive implementations. Note they take | |
191 | * a variable, not an address. | |
192 | * | |
193 | * This could be done better if we moved the per cpu data directly | |
194 | * after GS. | |
195 | */ | |
da531125 AK |
196 | |
197 | /* Need to disable preemption for the cpu local counters otherwise we could | |
198 | still access a variable of a previous CPU in a non atomic way. */ | |
c343c14a | 199 | #define cpu_local_wrap_v(l) \ |
da531125 AK |
200 | ({ local_t res__; \ |
201 | preempt_disable(); \ | |
c343c14a | 202 | res__ = (l); \ |
da531125 AK |
203 | preempt_enable(); \ |
204 | res__; }) | |
c343c14a | 205 | #define cpu_local_wrap(l) \ |
da531125 | 206 | ({ preempt_disable(); \ |
c343c14a | 207 | l; \ |
da531125 AK |
208 | preempt_enable(); }) \ |
209 | ||
c343c14a MD |
210 | #define cpu_local_read(l) cpu_local_wrap_v(local_read(&__get_cpu_var(l))) |
211 | #define cpu_local_set(l, i) cpu_local_wrap(local_set(&__get_cpu_var(l), (i))) | |
212 | #define cpu_local_inc(l) cpu_local_wrap(local_inc(&__get_cpu_var(l))) | |
213 | #define cpu_local_dec(l) cpu_local_wrap(local_dec(&__get_cpu_var(l))) | |
214 | #define cpu_local_add(i, l) cpu_local_wrap(local_add((i), &__get_cpu_var(l))) | |
215 | #define cpu_local_sub(i, l) cpu_local_wrap(local_sub((i), &__get_cpu_var(l))) | |
1da177e4 | 216 | |
c343c14a MD |
217 | #define __cpu_local_inc(l) cpu_local_inc(l) |
218 | #define __cpu_local_dec(l) cpu_local_dec(l) | |
219 | #define __cpu_local_add(i, l) cpu_local_add((i), (l)) | |
220 | #define __cpu_local_sub(i, l) cpu_local_sub((i), (l)) | |
1da177e4 | 221 | |
c343c14a | 222 | #endif /* _ARCH_X8664_LOCAL_H */ |