1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
4 */
5 #ifndef _ARCH_LOONGARCH_LOCAL_H
6 #define _ARCH_LOONGARCH_LOCAL_H
7
8 #include <linux/percpu.h>
9 #include <linux/bitops.h>
10 #include <linux/atomic.h>
11 #include <asm/cmpxchg.h>
12
13 typedef struct {
14 atomic_long_t a;
15 } local_t;
16
17 #define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) }
18
19 #define local_read(l) atomic_long_read(&(l)->a)
20 #define local_set(l, i) atomic_long_set(&(l)->a, (i))
21
22 #define local_add(i, l) atomic_long_add((i), (&(l)->a))
23 #define local_sub(i, l) atomic_long_sub((i), (&(l)->a))
24 #define local_inc(l) atomic_long_inc(&(l)->a)
25 #define local_dec(l) atomic_long_dec(&(l)->a)
26
27 /*
28 * Same as above, but return the result value
29 */
30 static inline long local_add_return(long i, local_t *l)
31 {
32 unsigned long result;
33
34 __asm__ __volatile__(
35 " " __AMADD " %1, %2, %0 \n"
36 : "+ZB" (l->a.counter), "=&r" (result)
37 : "r" (i)
38 : "memory");
39 result = result + i;
40
41 return result;
42 }
43
44 static inline long local_sub_return(long i, local_t *l)
45 {
46 unsigned long result;
47
48 __asm__ __volatile__(
49 " " __AMADD "%1, %2, %0 \n"
50 : "+ZB" (l->a.counter), "=&r" (result)
51 : "r" (-i)
52 : "memory");
53
54 result = result - i;
55
56 return result;
57 }
58
59 static inline long local_cmpxchg(local_t *l, long old, long new)
60 {
61 return cmpxchg_local(&l->a.counter, old, new);
62 }
63
64 static inline bool local_try_cmpxchg(local_t *l, long *old, long new)
65 {
66 return try_cmpxchg_local(&l->a.counter,
67 (typeof(l->a.counter) *) old, new);
68 }
69
70 #define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
71
72 /**
73 * local_add_unless - add unless the number is already a given value
74 * @l: pointer of type local_t
75 * @a: the amount to add to l...
76 * @u: ...unless l is equal to u.
77 *
78 * Atomically adds @a to @l, if @v was not already @u.
79 * Returns true if the addition was done.
80 */
81 static inline bool
82 local_add_unless(local_t *l, long a, long u)
83 {
84 long c = local_read(l);
85
86 do {
87 if (unlikely(c == u))
88 return false;
89 } while (!local_try_cmpxchg(l, &c, c + a));
90
91 return true;
92 }
93
94 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
95
96 #define local_dec_return(l) local_sub_return(1, (l))
97 #define local_inc_return(l) local_add_return(1, (l))
98
99 /*
100 * local_sub_and_test - subtract value from variable and test result
101 * @i: integer value to subtract
102 * @l: pointer of type local_t
103 *
104 * Atomically subtracts @i from @l and returns
105 * true if the result is zero, or false for all
106 * other cases.
107 */
108 #define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
109
110 /*
111 * local_inc_and_test - increment and test
112 * @l: pointer of type local_t
113 *
114 * Atomically increments @l by 1
115 * and returns true if the result is zero, or false for all
116 * other cases.
117 */
118 #define local_inc_and_test(l) (local_inc_return(l) == 0)
119
120 /*
121 * local_dec_and_test - decrement by 1 and test
122 * @l: pointer of type local_t
123 *
124 * Atomically decrements @l by 1 and
125 * returns true if the result is 0, or false for all other
126 * cases.
127 */
128 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
129
130 /*
131 * local_add_negative - add and test if negative
132 * @l: pointer of type local_t
133 * @i: integer value to add
134 *
135 * Atomically adds @i to @l and returns true
136 * if the result is negative, or false when
137 * result is greater than or equal to zero.
138 */
139 #define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
140
141 /* Use these for per-cpu local_t variables: on some archs they are
142 * much more efficient than these naive implementations. Note they take
143 * a variable, not an address.
144 */
145
146 #define __local_inc(l) ((l)->a.counter++)
147 #define __local_dec(l) ((l)->a.counter++)
148 #define __local_add(i, l) ((l)->a.counter += (i))
149 #define __local_sub(i, l) ((l)->a.counter -= (i))
150
151 #endif /* _ARCH_LOONGARCH_LOCAL_H */
152
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