summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/include/asm/local.h
blob: c2410af6bfd954db83d41db7363bfc3d0ea5ec82 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
#ifndef _ARCH_POWERPC_LOCAL_H
#define _ARCH_POWERPC_LOCAL_H

#include <linux/percpu.h>
#include <asm/atomic.h>

typedef struct
{
	atomic_long_t a;
} local_t;

#define LOCAL_INIT(i)	{ ATOMIC_LONG_INIT(i) }

#define local_read(l)	atomic_long_read(&(l)->a)
#define local_set(l,i)	atomic_long_set(&(l)->a, (i))

#define local_add(i,l)	atomic_long_add((i),(&(l)->a))
#define local_sub(i,l)	atomic_long_sub((i),(&(l)->a))
#define local_inc(l)	atomic_long_inc(&(l)->a)
#define local_dec(l)	atomic_long_dec(&(l)->a)

static __inline__ long local_add_return(long a, local_t *l)
{
	long t;

	__asm__ __volatile__(
"1:"	PPC_LLARX(%0,0,%2,0) "			# local_add_return\n\
	add	%0,%1,%0\n"
	PPC405_ERR77(0,%2)
	PPC_STLCX	"%0,0,%2 \n\
	bne-	1b"
	: "=&r" (t)
	: "r" (a), "r" (&(l->a.counter))
	: "cc", "memory");

	return t;
}

#define local_add_negative(a, l)	(local_add_return((a), (l)) < 0)

static __inline__ long local_sub_return(long a, local_t *l)
{
	long t;

	__asm__ __volatile__(
"1:"	PPC_LLARX(%0,0,%2,0) "			# local_sub_return\n\
	subf	%0,%1,%0\n"
	PPC405_ERR77(0,%2)
	PPC_STLCX	"%0,0,%2 \n\
	bne-	1b"
	: "=&r" (t)
	: "r" (a), "r" (&(l->a.counter))
	: "cc", "memory");

	return t;
}

static __inline__ long local_inc_return(local_t *l)
{
	long t;

	__asm__ __volatile__(
"1:"	PPC_LLARX(%0,0,%1,0) "			# local_inc_return\n\
	addic	%0,%0,1\n"
	PPC405_ERR77(0,%1)
	PPC_STLCX	"%0,0,%1 \n\
	bne-	1b"
	: "=&r" (t)
	: "r" (&(l->a.counter))
	: "cc", "xer", "memory");

	return t;
}

/*
 * local_inc_and_test - increment and test
 * @l: pointer of type local_t
 *
 * Atomically increments @l by 1
 * and returns true if the result is zero, or false for all
 * other cases.
 */
#define local_inc_and_test(l) (local_inc_return(l) == 0)

static __inline__ long local_dec_return(local_t *l)
{
	long t;

	__asm__ __volatile__(
"1:"	PPC_LLARX(%0,0,%1,0) "			# local_dec_return\n\
	addic	%0,%0,-1\n"
	PPC405_ERR77(0,%1)
	PPC_STLCX	"%0,0,%1\n\
	bne-	1b"
	: "=&r" (t)
	: "r" (&(l->a.counter))
	: "cc", "xer", "memory");

	return t;
}

#define local_cmpxchg(l, o, n) \
	(cmpxchg_local(&((l)->a.counter), (o), (n)))
#define local_xchg(l, n) (xchg_local(&((l)->a.counter), (n)))

/**
 * local_add_unless - add unless the number is a given value
 * @l: pointer of type local_t
 * @a: the amount to add to v...
 * @u: ...unless v is equal to u.
 *
 * Atomically adds @a to @l, so long as it was not @u.
 * Returns non-zero if @l was not @u, and zero otherwise.
 */
static __inline__ int local_add_unless(local_t *l, long a, long u)
{
	long t;

	__asm__ __volatile__ (
"1:"	PPC_LLARX(%0,0,%1,0) "			# local_add_unless\n\
	cmpw	0,%0,%3 \n\
	beq-	2f \n\
	add	%0,%2,%0 \n"
	PPC405_ERR77(0,%2)
	PPC_STLCX	"%0,0,%1 \n\
	bne-	1b \n"
"	subf	%0,%2,%0 \n\
2:"
	: "=&r" (t)
	: "r" (&(l->a.counter)), "r" (a), "r" (u)
	: "cc", "memory");

	return t != u;
}

#define local_inc_not_zero(l) local_add_unless((l), 1, 0)

#define local_sub_and_test(a, l)	(local_sub_return((a), (l)) == 0)
#define local_dec_and_test(l)		(local_dec_return((l)) == 0)

/*
 * Atomically test *l and decrement if it is greater than 0.
 * The function returns the old value of *l minus 1.
 */
static __inline__ long local_dec_if_positive(local_t *l)
{
	long t;

	__asm__ __volatile__(
"1:"	PPC_LLARX(%0,0,%1,0) "			# local_dec_if_positive\n\
	cmpwi	%0,1\n\
	addi	%0,%0,-1\n\
	blt-	2f\n"
	PPC405_ERR77(0,%1)
	PPC_STLCX	"%0,0,%1\n\
	bne-	1b"
	"\n\
2:"	: "=&b" (t)
	: "r" (&(l->a.counter))
	: "cc", "memory");

	return t;
}

/* Use these for per-cpu local_t variables: on some archs they are
 * much more efficient than these naive implementations.  Note they take
 * a variable, not an address.
 */

#define __local_inc(l)		((l)->a.counter++)
#define __local_dec(l)		((l)->a.counter++)
#define __local_add(i,l)	((l)->a.counter+=(i))
#define __local_sub(i,l)	((l)->a.counter-=(i))

#endif /* _ARCH_POWERPC_LOCAL_H */