xref: /openbmc/linux/arch/alpha/include/asm/local.h (revision 9cfc5c90)
1 #ifndef _ALPHA_LOCAL_H
2 #define _ALPHA_LOCAL_H
3 
4 #include <linux/percpu.h>
5 #include <linux/atomic.h>
6 
7 typedef struct
8 {
9 	atomic_long_t a;
10 } local_t;
11 
12 #define LOCAL_INIT(i)	{ ATOMIC_LONG_INIT(i) }
13 #define local_read(l)	atomic_long_read(&(l)->a)
14 #define local_set(l,i)	atomic_long_set(&(l)->a, (i))
15 #define local_inc(l)	atomic_long_inc(&(l)->a)
16 #define local_dec(l)	atomic_long_dec(&(l)->a)
17 #define local_add(i,l)	atomic_long_add((i),(&(l)->a))
18 #define local_sub(i,l)	atomic_long_sub((i),(&(l)->a))
19 
20 static __inline__ long local_add_return(long i, local_t * l)
21 {
22 	long temp, result;
23 	__asm__ __volatile__(
24 	"1:	ldq_l %0,%1\n"
25 	"	addq %0,%3,%2\n"
26 	"	addq %0,%3,%0\n"
27 	"	stq_c %0,%1\n"
28 	"	beq %0,2f\n"
29 	".subsection 2\n"
30 	"2:	br 1b\n"
31 	".previous"
32 	:"=&r" (temp), "=m" (l->a.counter), "=&r" (result)
33 	:"Ir" (i), "m" (l->a.counter) : "memory");
34 	return result;
35 }
36 
37 static __inline__ long local_sub_return(long i, local_t * l)
38 {
39 	long temp, result;
40 	__asm__ __volatile__(
41 	"1:	ldq_l %0,%1\n"
42 	"	subq %0,%3,%2\n"
43 	"	subq %0,%3,%0\n"
44 	"	stq_c %0,%1\n"
45 	"	beq %0,2f\n"
46 	".subsection 2\n"
47 	"2:	br 1b\n"
48 	".previous"
49 	:"=&r" (temp), "=m" (l->a.counter), "=&r" (result)
50 	:"Ir" (i), "m" (l->a.counter) : "memory");
51 	return result;
52 }
53 
54 #define local_cmpxchg(l, o, n) \
55 	(cmpxchg_local(&((l)->a.counter), (o), (n)))
56 #define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n)))
57 
58 /**
59  * local_add_unless - add unless the number is a given value
60  * @l: pointer of type local_t
61  * @a: the amount to add to l...
62  * @u: ...unless l is equal to u.
63  *
64  * Atomically adds @a to @l, so long as it was not @u.
65  * Returns non-zero if @l was not @u, and zero otherwise.
66  */
67 #define local_add_unless(l, a, u)				\
68 ({								\
69 	long c, old;						\
70 	c = local_read(l);					\
71 	for (;;) {						\
72 		if (unlikely(c == (u)))				\
73 			break;					\
74 		old = local_cmpxchg((l), c, c + (a));	\
75 		if (likely(old == c))				\
76 			break;					\
77 		c = old;					\
78 	}							\
79 	c != (u);						\
80 })
81 #define local_inc_not_zero(l) local_add_unless((l), 1, 0)
82 
83 #define local_add_negative(a, l) (local_add_return((a), (l)) < 0)
84 
85 #define local_dec_return(l) local_sub_return(1,(l))
86 
87 #define local_inc_return(l) local_add_return(1,(l))
88 
89 #define local_sub_and_test(i,l) (local_sub_return((i), (l)) == 0)
90 
91 #define local_inc_and_test(l) (local_add_return(1, (l)) == 0)
92 
93 #define local_dec_and_test(l) (local_sub_return(1, (l)) == 0)
94 
95 /* Verify if faster than atomic ops */
96 #define __local_inc(l)		((l)->a.counter++)
97 #define __local_dec(l)		((l)->a.counter++)
98 #define __local_add(i,l)	((l)->a.counter+=(i))
99 #define __local_sub(i,l)	((l)->a.counter-=(i))
100 
101 #endif /* _ALPHA_LOCAL_H */
102