aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mn10300/include/asm/atomic.h
blob: cadeb1e2cdfcfa1f473ac44f1e63a3a81b0c2fa9 (plain) (blame)
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
230
231
232
233
234
235
236
237
238
239
240
/* MN10300 Atomic counter operations
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */
#ifndef _ASM_ATOMIC_H
#define _ASM_ATOMIC_H

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

#ifndef CONFIG_SMP
#include <asm-generic/atomic.h>
#else

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

#define ATOMIC_INIT(i)	{ (i) }

#ifdef __KERNEL__

/**
 * atomic_read - read atomic variable
 * @v: pointer of type atomic_t
 *
 * Atomically reads the value of @v.  Note that the guaranteed
 * useful range of an atomic_t is only 24 bits.
 */
#define atomic_read(v)	(ACCESS_ONCE((v)->counter))

/**
 * atomic_set - set atomic variable
 * @v: pointer of type atomic_t
 * @i: required value
 *
 * Atomically sets the value of @v to @i.  Note that the guaranteed
 * useful range of an atomic_t is only 24 bits.
 */
#define atomic_set(v, i) (((v)->counter) = (i))

/**
 * atomic_add_return - add integer to atomic variable
 * @i: integer value to add
 * @v: pointer of type atomic_t
 *
 * Atomically adds @i to @v and returns the result
 * Note that the guaranteed useful range of an atomic_t is only 24 bits.
 */
static inline int atomic_add_return(int i, atomic_t *v)
{
	int retval;
#ifdef CONFIG_SMP
	int status;

	asm volatile(
		"1:	mov	%4,(_AAR,%3)	\n"
		"	mov	(_ADR,%3),%1	\n"
		"	add	%5,%1		\n"
		"	mov	%1,(_ADR,%3)	\n"
		"	mov	(_ADR,%3),%0	\n"	/* flush */
		"	mov	(_ASR,%3),%0	\n"
		"	or	%0,%0		\n"
		"	bne	1b		\n"
		: "=&r"(status), "=&r"(retval), "=m"(v->counter)
		: "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i)
		: "memory", "cc");

#else
	unsigned long flags;

	flags = arch_local_cli_save();
	retval = v->counter;
	retval += i;
	v->counter = retval;
	arch_local_irq_restore(flags);
#endif
	return retval;
}

/**
 * atomic_sub_return - subtract integer from atomic variable
 * @i: integer value to subtract
 * @v: pointer of type atomic_t
 *
 * Atomically subtracts @i from @v and returns the result
 * Note that the guaranteed useful range of an atomic_t is only 24 bits.
 */
static inline int atomic_sub_return(int i, atomic_t *v)
{
	int retval;
#ifdef CONFIG_SMP
	int status;

	asm volatile(
		"1:	mov	%4,(_AAR,%3)	\n"
		"	mov	(_ADR,%3),%1	\n"
		"	sub	%5,%1		\n"
		"	mov	%1,(_ADR,%3)	\n"
		"	mov	(_ADR,%3),%0	\n"	/* flush */
		"	mov	(_ASR,%3),%0	\n"
		"	or	%0,%0		\n"
		"	bne	1b		\n"
		: "=&r"(status), "=&r"(retval), "=m"(v->counter)
		: "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i)
		: "memory", "cc");

#else
	unsigned long flags;
	flags = arch_local_cli_save();
	retval = v->counter;
	retval -= i;
	v->counter = retval;
	arch_local_irq_restore(flags);
#endif
	return retval;
}

static inline int atomic_add_negative(int i, atomic_t *v)
{
	return atomic_add_return(i, v) < 0;
}

static inline void atomic_add(int i, atomic_t *v)
{
	atomic_add_return(i, v);
}

static inline void atomic_sub(int i, atomic_t *v)
{
	atomic_sub_return(i, v);
}

static inline void atomic_inc(atomic_t *v)
{
	atomic_add_return(1, v);
}

static inline void atomic_dec(atomic_t *v)
{
	atomic_sub_return(1, v);
}

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

#define atomic_sub_and_test(i, v)	(atomic_sub_return((i), (v)) == 0)
#define atomic_dec_and_test(v)		(atomic_sub_return(1, (v)) == 0)
#define atomic_inc_and_test(v)		(atomic_add_return(1, (v)) == 0)

#define __atomic_add_unless(v, a, u)				\
({								\
	int c, old;						\
	c = atomic_read(v);					\
	while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \
		c = old;					\
	c;							\
})

#define atomic_xchg(ptr, v)		(xchg(&(ptr)->counter, (v)))
#define atomic_cmpxchg(v, old, new)	(cmpxchg(&((v)->counter), (old), (new)))

/**
 * atomic_clear_mask - Atomically clear bits in memory
 * @mask: Mask of the bits to be cleared
 * @v: pointer to word in memory
 *
 * Atomically clears the bits set in mask from the memory word specified.
 */
static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr)
{
#ifdef CONFIG_SMP
	int status;

	asm volatile(
		"1:	mov	%3,(_AAR,%2)	\n"
		"	mov	(_ADR,%2),%0	\n"
		"	and	%4,%0		\n"
		"	mov	%0,(_ADR,%2)	\n"
		"	mov	(_ADR,%2),%0	\n"	/* flush */
		"	mov	(_ASR,%2),%0	\n"
		"	or	%0,%0		\n"
		"	bne	1b		\n"
		: "=&r"(status), "=m"(*addr)
		: "a"(ATOMIC_OPS_BASE_ADDR), "r"(addr), "r"(~mask)
		: "memory", "cc");
#else
	unsigned long flags;

	mask = ~mask;
	flags = arch_local_cli_save();
	*addr &= mask;
	arch_local_irq_restore(flags);
#endif
}

/**
 * atomic_set_mask - Atomically set bits in memory
 * @mask: Mask of the bits to be set
 * @v: pointer to word in memory
 *
 * Atomically sets the bits set in mask from the memory word specified.
 */
static inline void atomic_set_mask(unsigned long mask, unsigned long *addr)
{
#ifdef CONFIG_SMP
	int status;

	asm volatile(
		"1:	mov	%3,(_AAR,%2)	\n"
		"	mov	(_ADR,%2),%0	\n"
		"	or	%4,%0		\n"
		"	mov	%0,(_ADR,%2)	\n"
		"	mov	(_ADR,%2),%0	\n"	/* flush */
		"	mov	(_ASR,%2),%0	\n"
		"	or	%0,%0		\n"
		"	bne	1b		\n"
		: "=&r"(status), "=m"(*addr)
		: "a"(ATOMIC_OPS_BASE_ADDR), "r"(addr), "r"(mask)
		: "memory", "cc");
#else
	unsigned long flags;

	flags = arch_local_cli_save();
	*addr |= mask;
	arch_local_irq_restore(flags);
#endif
}

#endif /* __KERNEL__ */
#endif /* CONFIG_SMP */
#endif /* _ASM_ATOMIC_H */