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
|
/*
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef _ASM_RISCV_BITOPS_H
#define _ASM_RISCV_BITOPS_H
#ifndef _LINUX_BITOPS_H
#error "Only <linux/bitops.h> can be included directly"
#endif /* _LINUX_BITOPS_H */
#include <linux/compiler.h>
#include <linux/irqflags.h>
#include <asm/barrier.h>
#include <asm/bitsperlong.h>
#ifndef smp_mb__before_clear_bit
#define smp_mb__before_clear_bit() smp_mb()
#define smp_mb__after_clear_bit() smp_mb()
#endif /* smp_mb__before_clear_bit */
#include <asm-generic/bitops/__ffs.h>
#include <asm-generic/bitops/ffz.h>
#include <asm-generic/bitops/fls.h>
#include <asm-generic/bitops/__fls.h>
#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/find.h>
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/ffs.h>
#include <asm-generic/bitops/hweight.h>
#if (BITS_PER_LONG == 64)
#define __AMO(op) "amo" #op ".d"
#elif (BITS_PER_LONG == 32)
#define __AMO(op) "amo" #op ".w"
#else
#error "Unexpected BITS_PER_LONG"
#endif
#define __test_and_op_bit_ord(op, mod, nr, addr, ord) \
({ \
unsigned long __res, __mask; \
__mask = BIT_MASK(nr); \
__asm__ __volatile__ ( \
__AMO(op) #ord " %0, %2, %1" \
: "=r" (__res), "+A" (addr[BIT_WORD(nr)]) \
: "r" (mod(__mask)) \
: "memory"); \
((__res & __mask) != 0); \
})
#define __op_bit_ord(op, mod, nr, addr, ord) \
__asm__ __volatile__ ( \
__AMO(op) #ord " zero, %1, %0" \
: "+A" (addr[BIT_WORD(nr)]) \
: "r" (mod(BIT_MASK(nr))) \
: "memory");
#define __test_and_op_bit(op, mod, nr, addr) \
__test_and_op_bit_ord(op, mod, nr, addr, .aqrl)
#define __op_bit(op, mod, nr, addr) \
__op_bit_ord(op, mod, nr, addr, )
/* Bitmask modifiers */
#define __NOP(x) (x)
#define __NOT(x) (~(x))
/**
* test_and_set_bit - Set a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*
* This operation may be reordered on other architectures than x86.
*/
static inline int test_and_set_bit(int nr, volatile unsigned long *addr)
{
return __test_and_op_bit(or, __NOP, nr, addr);
}
/**
* test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to clear
* @addr: Address to count from
*
* This operation can be reordered on other architectures other than x86.
*/
static inline int test_and_clear_bit(int nr, volatile unsigned long *addr)
{
return __test_and_op_bit(and, __NOT, nr, addr);
}
/**
* test_and_change_bit - Change a bit and return its old value
* @nr: Bit to change
* @addr: Address to count from
*
* This operation is atomic and cannot be reordered.
* It also implies a memory barrier.
*/
static inline int test_and_change_bit(int nr, volatile unsigned long *addr)
{
return __test_and_op_bit(xor, __NOP, nr, addr);
}
/**
* set_bit - Atomically set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
* Note: there are no guarantees that this function will not be reordered
* on non x86 architectures, so if you are writing portable code,
* make sure not to rely on its reordering guarantees.
*
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
static inline void set_bit(int nr, volatile unsigned long *addr)
{
__op_bit(or, __NOP, nr, addr);
}
/**
* clear_bit - Clears a bit in memory
* @nr: Bit to clear
* @addr: Address to start counting from
*
* Note: there are no guarantees that this function will not be reordered
* on non x86 architectures, so if you are writing portable code,
* make sure not to rely on its reordering guarantees.
*/
static inline void clear_bit(int nr, volatile unsigned long *addr)
{
__op_bit(and, __NOT, nr, addr);
}
/**
* change_bit - Toggle a bit in memory
* @nr: Bit to change
* @addr: Address to start counting from
*
* change_bit() may be reordered on other architectures than x86.
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
static inline void change_bit(int nr, volatile unsigned long *addr)
{
__op_bit(xor, __NOP, nr, addr);
}
/**
* test_and_set_bit_lock - Set a bit and return its old value, for lock
* @nr: Bit to set
* @addr: Address to count from
*
* This operation is atomic and provides acquire barrier semantics.
* It can be used to implement bit locks.
*/
static inline int test_and_set_bit_lock(
unsigned long nr, volatile unsigned long *addr)
{
return __test_and_op_bit_ord(or, __NOP, nr, addr, .aq);
}
/**
* clear_bit_unlock - Clear a bit in memory, for unlock
* @nr: the bit to set
* @addr: the address to start counting from
*
* This operation is atomic and provides release barrier semantics.
*/
static inline void clear_bit_unlock(
unsigned long nr, volatile unsigned long *addr)
{
__op_bit_ord(and, __NOT, nr, addr, .rl);
}
/**
* __clear_bit_unlock - Clear a bit in memory, for unlock
* @nr: the bit to set
* @addr: the address to start counting from
*
* This operation is like clear_bit_unlock, however it is not atomic.
* It does provide release barrier semantics so it can be used to unlock
* a bit lock, however it would only be used if no other CPU can modify
* any bits in the memory until the lock is released (a good example is
* if the bit lock itself protects access to the other bits in the word).
*
* On RISC-V systems there seems to be no benefit to taking advantage of the
* non-atomic property here: it's a lot more instructions and we still have to
* provide release semantics anyway.
*/
static inline void __clear_bit_unlock(
unsigned long nr, volatile unsigned long *addr)
{
clear_bit_unlock(nr, addr);
}
#undef __test_and_op_bit
#undef __op_bit
#undef __NOP
#undef __NOT
#undef __AMO
#include <asm-generic/bitops/non-atomic.h>
#include <asm-generic/bitops/le.h>
#include <asm-generic/bitops/ext2-atomic.h>
#endif /* _ASM_RISCV_BITOPS_H */
|
