xref: /openbmc/linux/arch/powerpc/include/asm/local.h (revision be709d48)
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(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__ long local_xchg(local_t *l, long n)
94 {
95 	long t;
96 	unsigned long flags;
97 
98 	powerpc_local_irq_pmu_save(flags);
99 	t = l->v;
100 	l->v = n;
101 	powerpc_local_irq_pmu_restore(flags);
102 
103 	return t;
104 }
105 
106 /**
107  * local_add_unless - add unless the number is a given value
108  * @l: pointer of type local_t
109  * @a: the amount to add to v...
110  * @u: ...unless v is equal to u.
111  *
112  * Atomically adds @a to @l, so long as it was not @u.
113  * Returns non-zero if @l was not @u, and zero otherwise.
114  */
115 static __inline__ int local_add_unless(local_t *l, long a, long u)
116 {
117 	unsigned long flags;
118 	int ret = 0;
119 
120 	powerpc_local_irq_pmu_save(flags);
121 	if (l->v != u) {
122 		l->v += a;
123 		ret = 1;
124 	}
125 	powerpc_local_irq_pmu_restore(flags);
126 
127 	return ret;
128 }
129 
130 #define local_inc_not_zero(l)		local_add_unless((l), 1, 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)->v++)
138 #define __local_dec(l)		((l)->v++)
139 #define __local_add(i,l)	((l)->v+=(i))
140 #define __local_sub(i,l)	((l)->v-=(i))
141 
142 #else /* CONFIG_PPC64 */
143 
144 #include <asm-generic/local.h>
145 
146 #endif /* CONFIG_PPC64 */
147 
148 #endif /* _ARCH_POWERPC_LOCAL_H */
149