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1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ALPHA_LOCAL_H
3 #define _ALPHA_LOCAL_H
4 
5 #include <linux/percpu.h>
6 #include <linux/atomic.h>
7 
8 typedef struct
9 {
10 	atomic_long_t a;
11 } local_t;
12 
13 #define LOCAL_INIT(i)	{ ATOMIC_LONG_INIT(i) }
14 #define local_read(l)	atomic_long_read(&(l)->a)
15 #define local_set(l,i)	atomic_long_set(&(l)->a, (i))
16 #define local_inc(l)	atomic_long_inc(&(l)->a)
17 #define local_dec(l)	atomic_long_dec(&(l)->a)
18 #define local_add(i,l)	atomic_long_add((i),(&(l)->a))
19 #define local_sub(i,l)	atomic_long_sub((i),(&(l)->a))
20 
local_add_return(long i,local_t * l)21 static __inline__ long local_add_return(long i, local_t * l)
22 {
23 	long temp, result;
24 	__asm__ __volatile__(
25 	"1:	ldq_l %0,%1\n"
26 	"	addq %0,%3,%2\n"
27 	"	addq %0,%3,%0\n"
28 	"	stq_c %0,%1\n"
29 	"	beq %0,2f\n"
30 	".subsection 2\n"
31 	"2:	br 1b\n"
32 	".previous"
33 	:"=&r" (temp), "=m" (l->a.counter), "=&r" (result)
34 	:"Ir" (i), "m" (l->a.counter) : "memory");
35 	return result;
36 }
37 
local_sub_return(long i,local_t * l)38 static __inline__ long local_sub_return(long i, local_t * l)
39 {
40 	long temp, result;
41 	__asm__ __volatile__(
42 	"1:	ldq_l %0,%1\n"
43 	"	subq %0,%3,%2\n"
44 	"	subq %0,%3,%0\n"
45 	"	stq_c %0,%1\n"
46 	"	beq %0,2f\n"
47 	".subsection 2\n"
48 	"2:	br 1b\n"
49 	".previous"
50 	:"=&r" (temp), "=m" (l->a.counter), "=&r" (result)
51 	:"Ir" (i), "m" (l->a.counter) : "memory");
52 	return result;
53 }
54 
55 #define local_cmpxchg(l, o, n) \
56 	(cmpxchg_local(&((l)->a.counter), (o), (n)))
57 #define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n)))
58 
59 /**
60  * local_add_unless - add unless the number is a given value
61  * @l: pointer of type local_t
62  * @a: the amount to add to l...
63  * @u: ...unless l is equal to u.
64  *
65  * Atomically adds @a to @l, so long as it was not @u.
66  * Returns non-zero if @l was not @u, and zero otherwise.
67  */
68 #define local_add_unless(l, a, u)				\
69 ({								\
70 	long c, old;						\
71 	c = local_read(l);					\
72 	for (;;) {						\
73 		if (unlikely(c == (u)))				\
74 			break;					\
75 		old = local_cmpxchg((l), c, c + (a));	\
76 		if (likely(old == c))				\
77 			break;					\
78 		c = old;					\
79 	}							\
80 	c != (u);						\
81 })
82 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
83 
84 #define local_add_negative(a, l) (local_add_return((a), (l)) < 0)
85 
86 #define local_dec_return(l) local_sub_return(1,(l))
87 
88 #define local_inc_return(l) local_add_return(1,(l))
89 
90 #define local_sub_and_test(i,l) (local_sub_return((i), (l)) == 0)
91 
92 #define local_inc_and_test(l) (local_add_return(1, (l)) == 0)
93 
94 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
95 
96 /* Verify if faster than atomic ops */
97 #define __local_inc(l)		((l)->a.counter++)
98 #define __local_dec(l)		((l)->a.counter++)
99 #define __local_add(i,l)	((l)->a.counter+=(i))
100 #define __local_sub(i,l)	((l)->a.counter-=(i))
101 
102 #endif /* _ALPHA_LOCAL_H */
103