aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-x86/local_64.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-x86/local_64.h')
-rw-r--r--include/asm-x86/local_64.h222
1 files changed, 222 insertions, 0 deletions
diff --git a/include/asm-x86/local_64.h b/include/asm-x86/local_64.h
new file mode 100644
index 000000000000..e87492bb0693
--- /dev/null
+++ b/include/asm-x86/local_64.h
@@ -0,0 +1,222 @@
1#ifndef _ARCH_X8664_LOCAL_H
2#define _ARCH_X8664_LOCAL_H
3
4#include <linux/percpu.h>
5#include <asm/atomic.h>
6
7typedef struct
8{
9 atomic_long_t a;
10} local_t;
11
12#define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) }
13
14#define local_read(l) atomic_long_read(&(l)->a)
15#define local_set(l,i) atomic_long_set(&(l)->a, (i))
16
17static inline void local_inc(local_t *l)
18{
19 __asm__ __volatile__(
20 "incq %0"
21 :"=m" (l->a.counter)
22 :"m" (l->a.counter));
23}
24
25static inline void local_dec(local_t *l)
26{
27 __asm__ __volatile__(
28 "decq %0"
29 :"=m" (l->a.counter)
30 :"m" (l->a.counter));
31}
32
33static inline void local_add(long i, local_t *l)
34{
35 __asm__ __volatile__(
36 "addq %1,%0"
37 :"=m" (l->a.counter)
38 :"ir" (i), "m" (l->a.counter));
39}
40
41static inline void local_sub(long i, local_t *l)
42{
43 __asm__ __volatile__(
44 "subq %1,%0"
45 :"=m" (l->a.counter)
46 :"ir" (i), "m" (l->a.counter));
47}
48
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 */
58static __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 */
77static __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 */
96static __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 */
116static __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 */
134static __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
144static __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
182/* On x86-64 these are better than the atomic variants on SMP kernels
183 because they dont use a lock prefix. */
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 */
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. */
199#define cpu_local_wrap_v(l) \
200 ({ local_t res__; \
201 preempt_disable(); \
202 res__ = (l); \
203 preempt_enable(); \
204 res__; })
205#define cpu_local_wrap(l) \
206 ({ preempt_disable(); \
207 l; \
208 preempt_enable(); }) \
209
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)))
216
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))
221
222#endif /* _ARCH_X8664_LOCAL_H */