xref: /linux/arch/powerpc/include/asm/local.h (revision 4c630f307455c06f99bdeca7f7a1ab5318604fe0)
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 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, so long as it was not @u.
124  * Returns non-zero if @l was not @u, and zero otherwise.
125  */
126 static __inline__ int local_add_unless(local_t *l, long a, long u)
127 {
128 	unsigned long flags;
129 	int ret = 0;
130 
131 	powerpc_local_irq_pmu_save(flags);
132 	if (l->v != u) {
133 		l->v += a;
134 		ret = 1;
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