1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ARCH_POWERPC_LOCAL_H
3 #define _ARCH_POWERPC_LOCAL_H
4
5 #ifdef CONFIG_PPC_BOOK3S_64
6
7 #include <linux/percpu.h>
8 #include <linux/atomic.h>
9 #include <linux/irqflags.h>
10
11 #include <asm/hw_irq.h>
12
13 typedef struct
14 {
15 long v;
16 } local_t;
17
18 #define LOCAL_INIT(i) { (i) }
19
20 static __inline__ long local_read(const local_t *l)
21 {
22 return READ_ONCE(l->v);
23 }
24
25 static __inline__ void local_set(local_t *l, long i)
26 {
27 WRITE_ONCE(l->v, i);
28 }
29
30 #define LOCAL_OP(op, c_op) \
31 static __inline__ void local_##op(long i, local_t *l) \
32 { \
33 unsigned long flags; \
34 \
35 powerpc_local_irq_pmu_save(flags); \
36 l->v c_op i; \
37 powerpc_local_irq_pmu_restore(flags); \
38 }
39
40 #define LOCAL_OP_RETURN(op, c_op) \
41 static __inline__ long local_##op##_return(long a, local_t *l) \
42 { \
43 long t; \
44 unsigned long flags; \
45 \
46 powerpc_local_irq_pmu_save(flags); \
47 t = (l->v c_op a); \
48 powerpc_local_irq_pmu_restore(flags); \
49 \
50 return t; \
51 }
52
53 #define LOCAL_OPS(op, c_op) \
54 LOCAL_OP(op, c_op) \
55 LOCAL_OP_RETURN(op, c_op)
56
57 LOCAL_OPS(add, +=)
58 LOCAL_OPS(sub, -=)
59
60 #define local_add_negative(a, l) (local_add_return((a), (l)) < 0)
61 #define local_inc_return(l) local_add_return(1LL, l)
62 #define local_inc(l) local_inc_return(l)
63
64 /*
65 * local_inc_and_test - increment and test
66 * @l: pointer of type local_t
67 *
68 * Atomically increments @l by 1
69 * and returns true if the result is zero, or false for all
70 * other cases.
71 */
72 #define local_inc_and_test(l) (local_inc_return(l) == 0)
73
74 #define local_dec_return(l) local_sub_return(1LL, l)
75 #define local_dec(l) local_dec_return(l)
76 #define local_sub_and_test(a, l) (local_sub_return((a), (l)) == 0)
77 #define local_dec_and_test(l) (local_dec_return((l)) == 0)
78
79 static __inline__ long local_cmpxchg(local_t *l, long o, long n)
80 {
81 long t;
82 unsigned long flags;
83
84 powerpc_local_irq_pmu_save(flags);
85 t = l->v;
86 if (t == o)
87 l->v = n;
88 powerpc_local_irq_pmu_restore(flags);
89
90 return t;
91 }
92
93 static __inline__ bool local_try_cmpxchg(local_t *l, long *po, long n)
94 {
95 long o = *po, r;
96
97 r = local_cmpxchg(l, o, n);
98 if (unlikely(r != o))
99 *po = r;
100
101 return likely(r == o);
102 }
103
104 static __inline__ long local_xchg(local_t *l, long n)
105 {
106 long t;
107 unsigned long flags;
108
109 powerpc_local_irq_pmu_save(flags);
110 t = l->v;
111 l->v = n;
112 powerpc_local_irq_pmu_restore(flags);
113
114 return t;
115 }
116
117 /**
118 * local_add_unless - add unless the number is already a given value
119 * @l: pointer of type local_t
120 * @a: the amount to add to v...
121 * @u: ...unless v is equal to u.
122 *
123 * Atomically adds @a to @l, if @v was not already @u.
124 * Returns true if the addition was done.
125 */
126 static __inline__ bool local_add_unless(local_t *l, long a, long u)
127 {
128 unsigned long flags;
129 bool ret = false;
130
131 powerpc_local_irq_pmu_save(flags);
132 if (l->v != u) {
133 l->v += a;
134 ret = true;
135 }
136 powerpc_local_irq_pmu_restore(flags);
137
138 return ret;
139 }
140
141 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
142
143 /* Use these for per-cpu local_t variables: on some archs they are
144 * much more efficient than these naive implementations. Note they take
145 * a variable, not an address.
146 */
147
148 #define __local_inc(l) ((l)->v++)
149 #define __local_dec(l) ((l)->v++)
150 #define __local_add(i,l) ((l)->v+=(i))
151 #define __local_sub(i,l) ((l)->v-=(i))
152
153 #else /* CONFIG_PPC64 */
154
155 #include <asm-generic/local.h>
156
157 #endif /* CONFIG_PPC64 */
158
159 #endif /* _ARCH_POWERPC_LOCAL_H */
160
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