summaryrefslogtreecommitdiffstats
path: root/arch/m68k/include/asm/atomic.h
blob: e993e2860ee141ec711a5115ccbee577dad35b58 (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
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ARCH_M68K_ATOMIC__
#define __ARCH_M68K_ATOMIC__

#include <linux/types.h>
#include <linux/irqflags.h>
#include <asm/cmpxchg.h>
#include <asm/barrier.h>

/*
 * Atomic operations that C can't guarantee us.  Useful for
 * resource counting etc..
 */

/*
 * We do not have SMP m68k systems, so we don't have to deal with that.
 */

#define ATOMIC_INIT(i)	{ (i) }

#define atomic_read(v)		READ_ONCE((v)->counter)
#define atomic_set(v, i)	WRITE_ONCE(((v)->counter), (i))

/*
 * The ColdFire parts cannot do some immediate to memory operations,
 * so for them we do not specify the "i" asm constraint.
 */
#ifdef CONFIG_COLDFIRE
#define	ASM_DI	"d"
#else
#define	ASM_DI	"di"
#endif

#define ATOMIC_OP(op, c_op, asm_op)					\
static inline void atomic_##op(int i, atomic_t *v)			\
{									\
	__asm__ __volatile__(#asm_op "l %1,%0" : "+m" (*v) : ASM_DI (i));\
}									\

#ifdef CONFIG_RMW_INSNS

#define ATOMIC_OP_RETURN(op, c_op, asm_op)				\
static inline int atomic_##op##_return(int i, atomic_t *v)		\
{									\
	int t, tmp;							\
									\
	__asm__ __volatile__(						\
			"1:	movel %2,%1\n"				\
			"	" #asm_op "l %3,%1\n"			\
			"	casl %2,%1,%0\n"			\
			"	jne 1b"					\
			: "+m" (*v), "=&d" (t), "=&d" (tmp)		\
			: "g" (i), "2" (atomic_read(v)));		\
	return t;							\
}

#define ATOMIC_FETCH_OP(op, c_op, asm_op)				\
static inline int atomic_fetch_##op(int i, atomic_t *v)			\
{									\
	int t, tmp;							\
									\
	__asm__ __volatile__(						\
			"1:	movel %2,%1\n"				\
			"	" #asm_op "l %3,%1\n"			\
			"	casl %2,%1,%0\n"			\
			"	jne 1b"					\
			: "+m" (*v), "=&d" (t), "=&d" (tmp)		\
			: "g" (i), "2" (atomic_read(v)));		\
	return tmp;							\
}

#else

#define ATOMIC_OP_RETURN(op, c_op, asm_op)				\
static inline int atomic_##op##_return(int i, atomic_t * v)		\
{									\
	unsigned long flags;						\
	int t;								\
									\
	local_irq_save(flags);						\
	t = (v->counter c_op i);					\
	local_irq_restore(flags);					\
									\
	return t;							\
}

#define ATOMIC_FETCH_OP(op, c_op, asm_op)				\
static inline int atomic_fetch_##op(int i, atomic_t * v)		\
{									\
	unsigned long flags;						\
	int t;								\
									\
	local_irq_save(flags);						\
	t = v->counter;							\
	v->counter c_op i;						\
	local_irq_restore(flags);					\
									\
	return t;							\
}

#endif /* CONFIG_RMW_INSNS */

#define ATOMIC_OPS(op, c_op, asm_op)					\
	ATOMIC_OP(op, c_op, asm_op)					\
	ATOMIC_OP_RETURN(op, c_op, asm_op)				\
	ATOMIC_FETCH_OP(op, c_op, asm_op)

ATOMIC_OPS(add, +=, add)
ATOMIC_OPS(sub, -=, sub)

#undef ATOMIC_OPS
#define ATOMIC_OPS(op, c_op, asm_op)					\
	ATOMIC_OP(op, c_op, asm_op)					\
	ATOMIC_FETCH_OP(op, c_op, asm_op)

ATOMIC_OPS(and, &=, and)
ATOMIC_OPS(or, |=, or)
ATOMIC_OPS(xor, ^=, eor)

#undef ATOMIC_OPS
#undef ATOMIC_FETCH_OP
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP

static inline void atomic_inc(atomic_t *v)
{
	__asm__ __volatile__("addql #1,%0" : "+m" (*v));
}

static inline void atomic_dec(atomic_t *v)
{
	__asm__ __volatile__("subql #1,%0" : "+m" (*v));
}

static inline int atomic_dec_and_test(atomic_t *v)
{
	char c;
	__asm__ __volatile__("subql #1,%1; seq %0" : "=d" (c), "+m" (*v));
	return c != 0;
}

static inline int atomic_dec_and_test_lt(atomic_t *v)
{
	char c;
	__asm__ __volatile__(
		"subql #1,%1; slt %0"
		: "=d" (c), "=m" (*v)
		: "m" (*v));
	return c != 0;
}

static inline int atomic_inc_and_test(atomic_t *v)
{
	char c;
	__asm__ __volatile__("addql #1,%1; seq %0" : "=d" (c), "+m" (*v));
	return c != 0;
}

#ifdef CONFIG_RMW_INSNS

#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))

#else /* !CONFIG_RMW_INSNS */

static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
{
	unsigned long flags;
	int prev;

	local_irq_save(flags);
	prev = atomic_read(v);
	if (prev == old)
		atomic_set(v, new);
	local_irq_restore(flags);
	return prev;
}

static inline int atomic_xchg(atomic_t *v, int new)
{
	unsigned long flags;
	int prev;

	local_irq_save(flags);
	prev = atomic_read(v);
	atomic_set(v, new);
	local_irq_restore(flags);
	return prev;
}

#endif /* !CONFIG_RMW_INSNS */

#define atomic_dec_return(v)	atomic_sub_return(1, (v))
#define atomic_inc_return(v)	atomic_add_return(1, (v))

static inline int atomic_sub_and_test(int i, atomic_t *v)
{
	char c;
	__asm__ __volatile__("subl %2,%1; seq %0"
			     : "=d" (c), "+m" (*v)
			     : ASM_DI (i));
	return c != 0;
}

static inline int atomic_add_negative(int i, atomic_t *v)
{
	char c;
	__asm__ __volatile__("addl %2,%1; smi %0"
			     : "=d" (c), "+m" (*v)
			     : ASM_DI (i));
	return c != 0;
}

static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
{
	int c, old;
	c = atomic_read(v);
	for (;;) {
		if (unlikely(c == (u)))
			break;
		old = atomic_cmpxchg((v), c, c + (a));
		if (likely(old == c))
			break;
		c = old;
	}
	return c;
}

#endif /* __ARCH_M68K_ATOMIC __ */
OpenPOWER on IntegriCloud