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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright 1995, Russell King.
4 * Various bits and pieces copyrights include:
5 * Linus Torvalds (test_bit).
6 * Big endian support: Copyright 2001, Nicolas Pitre
7 * reworked by rmk.
8 *
9 * bit 0 is the LSB of an "unsigned long" quantity.
10 *
11 * Please note that the code in this file should never be included
12 * from user space. Many of these are not implemented in assembler
13 * since they would be too costly. Also, they require privileged
14 * instructions (which are not available from user mode) to ensure
15 * that they are atomic.
16 */
17
18#ifndef __ASM_ARM_BITOPS_H
19#define __ASM_ARM_BITOPS_H
20
21#ifdef __KERNEL__
22
23#ifndef _LINUX_BITOPS_H
24#error only <linux/bitops.h> can be included directly
25#endif
26
27#include <linux/compiler.h>
28#include <linux/irqflags.h>
29#include <asm/barrier.h>
30
31/*
32 * These functions are the basis of our bit ops.
33 *
34 * First, the atomic bitops. These use native endian.
35 */
36static inline void ____atomic_set_bit(unsigned int bit, volatile unsigned long *p)
37{
38 unsigned long flags;
39 unsigned long mask = BIT_MASK(bit);
40
41 p += BIT_WORD(bit);
42
43 raw_local_irq_save(flags);
44 *p |= mask;
45 raw_local_irq_restore(flags);
46}
47
48static inline void ____atomic_clear_bit(unsigned int bit, volatile unsigned long *p)
49{
50 unsigned long flags;
51 unsigned long mask = BIT_MASK(bit);
52
53 p += BIT_WORD(bit);
54
55 raw_local_irq_save(flags);
56 *p &= ~mask;
57 raw_local_irq_restore(flags);
58}
59
60static inline void ____atomic_change_bit(unsigned int bit, volatile unsigned long *p)
61{
62 unsigned long flags;
63 unsigned long mask = BIT_MASK(bit);
64
65 p += BIT_WORD(bit);
66
67 raw_local_irq_save(flags);
68 *p ^= mask;
69 raw_local_irq_restore(flags);
70}
71
72static inline int
73____atomic_test_and_set_bit(unsigned int bit, volatile unsigned long *p)
74{
75 unsigned long flags;
76 unsigned int res;
77 unsigned long mask = BIT_MASK(bit);
78
79 p += BIT_WORD(bit);
80
81 raw_local_irq_save(flags);
82 res = *p;
83 *p = res | mask;
84 raw_local_irq_restore(flags);
85
86 return (res & mask) != 0;
87}
88
89static inline int
90____atomic_test_and_clear_bit(unsigned int bit, volatile unsigned long *p)
91{
92 unsigned long flags;
93 unsigned int res;
94 unsigned long mask = BIT_MASK(bit);
95
96 p += BIT_WORD(bit);
97
98 raw_local_irq_save(flags);
99 res = *p;
100 *p = res & ~mask;
101 raw_local_irq_restore(flags);
102
103 return (res & mask) != 0;
104}
105
106static inline int
107____atomic_test_and_change_bit(unsigned int bit, volatile unsigned long *p)
108{
109 unsigned long flags;
110 unsigned int res;
111 unsigned long mask = BIT_MASK(bit);
112
113 p += BIT_WORD(bit);
114
115 raw_local_irq_save(flags);
116 res = *p;
117 *p = res ^ mask;
118 raw_local_irq_restore(flags);
119
120 return (res & mask) != 0;
121}
122
123#include <asm-generic/bitops/non-atomic.h>
124
125/*
126 * A note about Endian-ness.
127 * -------------------------
128 *
129 * When the ARM is put into big endian mode via CR15, the processor
130 * merely swaps the order of bytes within words, thus:
131 *
132 * ------------ physical data bus bits -----------
133 * D31 ... D24 D23 ... D16 D15 ... D8 D7 ... D0
134 * little byte 3 byte 2 byte 1 byte 0
135 * big byte 0 byte 1 byte 2 byte 3
136 *
137 * This means that reading a 32-bit word at address 0 returns the same
138 * value irrespective of the endian mode bit.
139 *
140 * Peripheral devices should be connected with the data bus reversed in
141 * "Big Endian" mode. ARM Application Note 61 is applicable, and is
142 * available from http://www.arm.com/.
143 *
144 * The following assumes that the data bus connectivity for big endian
145 * mode has been followed.
146 *
147 * Note that bit 0 is defined to be 32-bit word bit 0, not byte 0 bit 0.
148 */
149
150/*
151 * Native endian assembly bitops. nr = 0 -> word 0 bit 0.
152 */
153extern void _set_bit(int nr, volatile unsigned long * p);
154extern void _clear_bit(int nr, volatile unsigned long * p);
155extern void _change_bit(int nr, volatile unsigned long * p);
156extern int _test_and_set_bit(int nr, volatile unsigned long * p);
157extern int _test_and_clear_bit(int nr, volatile unsigned long * p);
158extern int _test_and_change_bit(int nr, volatile unsigned long * p);
159
160/*
161 * Little endian assembly bitops. nr = 0 -> byte 0 bit 0.
162 */
163unsigned long _find_first_zero_bit_le(const unsigned long *p, unsigned long size);
164unsigned long _find_next_zero_bit_le(const unsigned long *p,
165 unsigned long size, unsigned long offset);
166unsigned long _find_first_bit_le(const unsigned long *p, unsigned long size);
167unsigned long _find_next_bit_le(const unsigned long *p, unsigned long size, unsigned long offset);
168
169/*
170 * Big endian assembly bitops. nr = 0 -> byte 3 bit 0.
171 */
172unsigned long _find_first_zero_bit_be(const unsigned long *p, unsigned long size);
173unsigned long _find_next_zero_bit_be(const unsigned long *p,
174 unsigned long size, unsigned long offset);
175unsigned long _find_first_bit_be(const unsigned long *p, unsigned long size);
176unsigned long _find_next_bit_be(const unsigned long *p, unsigned long size, unsigned long offset);
177
178#ifndef CONFIG_SMP
179/*
180 * The __* form of bitops are non-atomic and may be reordered.
181 */
182#define ATOMIC_BITOP(name,nr,p) \
183 (__builtin_constant_p(nr) ? ____atomic_##name(nr, p) : _##name(nr,p))
184#else
185#define ATOMIC_BITOP(name,nr,p) _##name(nr,p)
186#endif
187
188/*
189 * Native endian atomic definitions.
190 */
191#define set_bit(nr,p) ATOMIC_BITOP(set_bit,nr,p)
192#define clear_bit(nr,p) ATOMIC_BITOP(clear_bit,nr,p)
193#define change_bit(nr,p) ATOMIC_BITOP(change_bit,nr,p)
194#define test_and_set_bit(nr,p) ATOMIC_BITOP(test_and_set_bit,nr,p)
195#define test_and_clear_bit(nr,p) ATOMIC_BITOP(test_and_clear_bit,nr,p)
196#define test_and_change_bit(nr,p) ATOMIC_BITOP(test_and_change_bit,nr,p)
197
198#ifndef __ARMEB__
199/*
200 * These are the little endian, atomic definitions.
201 */
202#define find_first_zero_bit(p,sz) _find_first_zero_bit_le(p,sz)
203#define find_next_zero_bit(p,sz,off) _find_next_zero_bit_le(p,sz,off)
204#define find_first_bit(p,sz) _find_first_bit_le(p,sz)
205#define find_next_bit(p,sz,off) _find_next_bit_le(p,sz,off)
206
207#else
208/*
209 * These are the big endian, atomic definitions.
210 */
211#define find_first_zero_bit(p,sz) _find_first_zero_bit_be(p,sz)
212#define find_next_zero_bit(p,sz,off) _find_next_zero_bit_be(p,sz,off)
213#define find_first_bit(p,sz) _find_first_bit_be(p,sz)
214#define find_next_bit(p,sz,off) _find_next_bit_be(p,sz,off)
215
216#endif
217
218#if __LINUX_ARM_ARCH__ < 5
219
220#include <asm-generic/bitops/__fls.h>
221#include <asm-generic/bitops/__ffs.h>
222#include <asm-generic/bitops/fls.h>
223#include <asm-generic/bitops/ffs.h>
224
225#else
226
227/*
228 * On ARMv5 and above, the gcc built-ins may rely on the clz instruction
229 * and produce optimal inlined code in all cases. On ARMv7 it is even
230 * better by also using the rbit instruction.
231 */
232#include <asm-generic/bitops/builtin-__fls.h>
233#include <asm-generic/bitops/builtin-__ffs.h>
234#include <asm-generic/bitops/builtin-fls.h>
235#include <asm-generic/bitops/builtin-ffs.h>
236
237#endif
238
239#include <asm-generic/bitops/ffz.h>
240
241#include <asm-generic/bitops/fls64.h>
242
243#include <asm-generic/bitops/sched.h>
244#include <asm-generic/bitops/hweight.h>
245#include <asm-generic/bitops/lock.h>
246
247#ifdef __ARMEB__
248
249static inline int find_first_zero_bit_le(const void *p, unsigned size)
250{
251 return _find_first_zero_bit_le(p, size);
252}
253#define find_first_zero_bit_le find_first_zero_bit_le
254
255static inline int find_next_zero_bit_le(const void *p, int size, int offset)
256{
257 return _find_next_zero_bit_le(p, size, offset);
258}
259#define find_next_zero_bit_le find_next_zero_bit_le
260
261static inline int find_next_bit_le(const void *p, int size, int offset)
262{
263 return _find_next_bit_le(p, size, offset);
264}
265#define find_next_bit_le find_next_bit_le
266
267#endif
268
269#include <asm-generic/bitops/le.h>
270
271/*
272 * Ext2 is defined to use little-endian byte ordering.
273 */
274#include <asm-generic/bitops/ext2-atomic-setbit.h>
275
276#endif /* __KERNEL__ */
277
278#endif /* _ARM_BITOPS_H */