1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ARCH_MIPS_LOCAL_H
3 #define _ARCH_MIPS_LOCAL_H
4
5 #include <linux/percpu.h>
6 #include <linux/bitops.h>
7 #include <linux/atomic.h>
8 #include <asm/asm.h>
9 #include <asm/cmpxchg.h>
10 #include <asm/compiler.h>
11
12 typedef struct
13 {
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 if (kernel_uses_llsc) {
35 unsigned long temp;
36
37 __asm__ __volatile__(
38 " .set push \n"
39 " .set "MIPS_ISA_ARCH_LEVEL" \n"
40 __SYNC(full, loongson3_war) " \n"
41 "1:" __stringify(LONG_LL) " %1, %2 \n"
42 __stringify(LONG_ADDU) " %0, %1, %3 \n"
43 __stringify(LONG_SC) " %0, %2 \n"
44 __stringify(SC_BEQZ) " %0, 1b \n"
45 __stringify(LONG_ADDU) " %0, %1, %3 \n"
46 " .set pop \n"
47 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
48 : "Ir" (i), "m" (l->a.counter)
49 : "memory");
50 } else {
51 unsigned long flags;
52
53 local_irq_save(flags);
54 result = l->a.counter;
55 result += i;
56 l->a.counter = result;
57 local_irq_restore(flags);
58 }
59
60 return result;
61 }
62
63 static __inline__ long local_sub_return(long i, local_t * l)
64 {
65 unsigned long result;
66
67 if (kernel_uses_llsc) {
68 unsigned long temp;
69
70 __asm__ __volatile__(
71 " .set push \n"
72 " .set "MIPS_ISA_ARCH_LEVEL" \n"
73 __SYNC(full, loongson3_war) " \n"
74 "1:" __stringify(LONG_LL) " %1, %2 \n"
75 __stringify(LONG_SUBU) " %0, %1, %3 \n"
76 __stringify(LONG_SUBU) " %0, %1, %3 \n"
77 __stringify(LONG_SC) " %0, %2 \n"
78 __stringify(SC_BEQZ) " %0, 1b \n"
79 __stringify(LONG_SUBU) " %0, %1, %3 \n"
80 " .set pop \n"
81 : "=&r" (result), "=&r" (temp), "=m" (l->a.counter)
82 : "Ir" (i), "m" (l->a.counter)
83 : "memory");
84 } else {
85 unsigned long flags;
86
87 local_irq_save(flags);
88 result = l->a.counter;
89 result -= i;
90 l->a.counter = result;
91 local_irq_restore(flags);
92 }
93
94 return result;
95 }
96
97 static __inline__ long local_cmpxchg(local_t *l, long old, long new)
98 {
99 return cmpxchg_local(&l->a.counter, old, new);
100 }
101
102 static __inline__ bool local_try_cmpxchg(local_t *l, long *old, long new)
103 {
104 return try_cmpxchg_local(&l->a.counter,
105 (typeof(l->a.counter) *) old, new);
106 }
107
108 #define local_xchg(l, n) (atomic_long_xchg((&(l)->a), (n)))
109
110 /**
111 * local_add_unless - add unless the number is already a given value
112 * @l: pointer of type local_t
113 * @a: the amount to add to l...
114 * @u: ...unless l is equal to u.
115 *
116 * Atomically adds @a to @l, if @v was not already @u.
117 * Returns true if the addition was done.
118 */
119 static __inline__ bool
120 local_add_unless(local_t *l, long a, long u)
121 {
122 long c = local_read(l);
123
124 do {
125 if (unlikely(c == u))
126 return false;
127 } while (!local_try_cmpxchg(l, &c, c + a));
128
129 return true;
130 }
131
132 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
133
134 #define local_dec_return(l) local_sub_return(1, (l))
135 #define local_inc_return(l) local_add_return(1, (l))
136
137 /*
138 * local_sub_and_test - subtract value from variable and test result
139 * @i: integer value to subtract
140 * @l: pointer of type local_t
141 *
142 * Atomically subtracts @i from @l and returns
143 * true if the result is zero, or false for all
144 * other cases.
145 */
146 #define local_sub_and_test(i, l) (local_sub_return((i), (l)) == 0)
147
148 /*
149 * local_inc_and_test - increment and test
150 * @l: pointer of type local_t
151 *
152 * Atomically increments @l by 1
153 * and returns true if the result is zero, or false for all
154 * other cases.
155 */
156 #define local_inc_and_test(l) (local_inc_return(l) == 0)
157
158 /*
159 * local_dec_and_test - decrement by 1 and test
160 * @l: pointer of type local_t
161 *
162 * Atomically decrements @l by 1 and
163 * returns true if the result is 0, or false for all other
164 * cases.
165 */
166 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
167
168 /*
169 * local_add_negative - add and test if negative
170 * @l: pointer of type local_t
171 * @i: integer value to add
172 *
173 * Atomically adds @i to @l and returns true
174 * if the result is negative, or false when
175 * result is greater than or equal to zero.
176 */
177 #define local_add_negative(i, l) (local_add_return(i, (l)) < 0)
178
179 /* Use these for per-cpu local_t variables: on some archs they are
180 * much more efficient than these naive implementations. Note they take
181 * a variable, not an address.
182 */
183
184 #define __local_inc(l) ((l)->a.counter++)
185 #define __local_dec(l) ((l)->a.counter++)
186 #define __local_add(i, l) ((l)->a.counter+=(i))
187 #define __local_sub(i, l) ((l)->a.counter-=(i))
188
189 #endif /* _ARCH_MIPS_LOCAL_H */
190
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