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