1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_BITOPS_H
3#define _LINUX_BITOPS_H
4#include <asm/types.h>
5#include <linux/bits.h>
6
7#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
8
9extern unsigned int __sw_hweight8(unsigned int w);
10extern unsigned int __sw_hweight16(unsigned int w);
11extern unsigned int __sw_hweight32(unsigned int w);
12extern unsigned long __sw_hweight64(__u64 w);
13
14/*
15 * Include this here because some architectures need generic_ffs/fls in
16 * scope
17 */
18#include <asm/bitops.h>
19
20#define for_each_set_bit(bit, addr, size) \
21 for ((bit) = find_first_bit((addr), (size)); \
22 (bit) < (size); \
23 (bit) = find_next_bit((addr), (size), (bit) + 1))
24
25/* same as for_each_set_bit() but use bit as value to start with */
26#define for_each_set_bit_from(bit, addr, size) \
27 for ((bit) = find_next_bit((addr), (size), (bit)); \
28 (bit) < (size); \
29 (bit) = find_next_bit((addr), (size), (bit) + 1))
30
31#define for_each_clear_bit(bit, addr, size) \
32 for ((bit) = find_first_zero_bit((addr), (size)); \
33 (bit) < (size); \
34 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
35
36/* same as for_each_clear_bit() but use bit as value to start with */
37#define for_each_clear_bit_from(bit, addr, size) \
38 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
39 (bit) < (size); \
40 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
41
42static inline int get_bitmask_order(unsigned int count)
43{
44 int order;
45
46 order = fls(count);
47 return order; /* We could be slightly more clever with -1 here... */
48}
49
50static __always_inline unsigned long hweight_long(unsigned long w)
51{
52 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
53}
54
55/**
56 * rol64 - rotate a 64-bit value left
57 * @word: value to rotate
58 * @shift: bits to roll
59 */
60static inline __u64 rol64(__u64 word, unsigned int shift)
61{
62 return (word << shift) | (word >> (64 - shift));
63}
64
65/**
66 * ror64 - rotate a 64-bit value right
67 * @word: value to rotate
68 * @shift: bits to roll
69 */
70static inline __u64 ror64(__u64 word, unsigned int shift)
71{
72 return (word >> shift) | (word << (64 - shift));
73}
74
75/**
76 * rol32 - rotate a 32-bit value left
77 * @word: value to rotate
78 * @shift: bits to roll
79 */
80static inline __u32 rol32(__u32 word, unsigned int shift)
81{
82 return (word << shift) | (word >> ((-shift) & 31));
83}
84
85/**
86 * ror32 - rotate a 32-bit value right
87 * @word: value to rotate
88 * @shift: bits to roll
89 */
90static inline __u32 ror32(__u32 word, unsigned int shift)
91{
92 return (word >> shift) | (word << (32 - shift));
93}
94
95/**
96 * rol16 - rotate a 16-bit value left
97 * @word: value to rotate
98 * @shift: bits to roll
99 */
100static inline __u16 rol16(__u16 word, unsigned int shift)
101{
102 return (word << shift) | (word >> (16 - shift));
103}
104
105/**
106 * ror16 - rotate a 16-bit value right
107 * @word: value to rotate
108 * @shift: bits to roll
109 */
110static inline __u16 ror16(__u16 word, unsigned int shift)
111{
112 return (word >> shift) | (word << (16 - shift));
113}
114
115/**
116 * rol8 - rotate an 8-bit value left
117 * @word: value to rotate
118 * @shift: bits to roll
119 */
120static inline __u8 rol8(__u8 word, unsigned int shift)
121{
122 return (word << shift) | (word >> (8 - shift));
123}
124
125/**
126 * ror8 - rotate an 8-bit value right
127 * @word: value to rotate
128 * @shift: bits to roll
129 */
130static inline __u8 ror8(__u8 word, unsigned int shift)
131{
132 return (word >> shift) | (word << (8 - shift));
133}
134
135/**
136 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
137 * @value: value to sign extend
138 * @index: 0 based bit index (0<=index<32) to sign bit
139 *
140 * This is safe to use for 16- and 8-bit types as well.
141 */
142static inline __s32 sign_extend32(__u32 value, int index)
143{
144 __u8 shift = 31 - index;
145 return (__s32)(value << shift) >> shift;
146}
147
148/**
149 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
150 * @value: value to sign extend
151 * @index: 0 based bit index (0<=index<64) to sign bit
152 */
153static inline __s64 sign_extend64(__u64 value, int index)
154{
155 __u8 shift = 63 - index;
156 return (__s64)(value << shift) >> shift;
157}
158
159static inline unsigned fls_long(unsigned long l)
160{
161 if (sizeof(l) == 4)
162 return fls(l);
163 return fls64(l);
164}
165
166static inline int get_count_order(unsigned int count)
167{
168 int order;
169
170 order = fls(count) - 1;
171 if (count & (count - 1))
172 order++;
173 return order;
174}
175
176/**
177 * get_count_order_long - get order after rounding @l up to power of 2
178 * @l: parameter
179 *
180 * it is same as get_count_order() but with long type parameter
181 */
182static inline int get_count_order_long(unsigned long l)
183{
184 if (l == 0UL)
185 return -1;
186 else if (l & (l - 1UL))
187 return (int)fls_long(l);
188 else
189 return (int)fls_long(l) - 1;
190}
191
192/**
193 * __ffs64 - find first set bit in a 64 bit word
194 * @word: The 64 bit word
195 *
196 * On 64 bit arches this is a synomyn for __ffs
197 * The result is not defined if no bits are set, so check that @word
198 * is non-zero before calling this.
199 */
200static inline unsigned long __ffs64(u64 word)
201{
202#if BITS_PER_LONG == 32
203 if (((u32)word) == 0UL)
204 return __ffs((u32)(word >> 32)) + 32;
205#elif BITS_PER_LONG != 64
206#error BITS_PER_LONG not 32 or 64
207#endif
208 return __ffs((unsigned long)word);
209}
210
211/**
212 * assign_bit - Assign value to a bit in memory
213 * @nr: the bit to set
214 * @addr: the address to start counting from
215 * @value: the value to assign
216 */
217static __always_inline void assign_bit(long nr, volatile unsigned long *addr,
218 bool value)
219{
220 if (value)
221 set_bit(nr, addr);
222 else
223 clear_bit(nr, addr);
224}
225
226static __always_inline void __assign_bit(long nr, volatile unsigned long *addr,
227 bool value)
228{
229 if (value)
230 __set_bit(nr, addr);
231 else
232 __clear_bit(nr, addr);
233}
234
235#ifdef __KERNEL__
236
237#ifndef set_mask_bits
238#define set_mask_bits(ptr, _mask, _bits) \
239({ \
240 const typeof(*ptr) mask = (_mask), bits = (_bits); \
241 typeof(*ptr) old, new; \
242 \
243 do { \
244 old = READ_ONCE(*ptr); \
245 new = (old & ~mask) | bits; \
246 } while (cmpxchg(ptr, old, new) != old); \
247 \
248 new; \
249})
250#endif
251
252#ifndef bit_clear_unless
253#define bit_clear_unless(ptr, _clear, _test) \
254({ \
255 const typeof(*ptr) clear = (_clear), test = (_test); \
256 typeof(*ptr) old, new; \
257 \
258 do { \
259 old = READ_ONCE(*ptr); \
260 new = old & ~clear; \
261 } while (!(old & test) && \
262 cmpxchg(ptr, old, new) != old); \
263 \
264 !(old & test); \
265})
266#endif
267
268#ifndef find_last_bit
269/**
270 * find_last_bit - find the last set bit in a memory region
271 * @addr: The address to start the search at
272 * @size: The number of bits to search
273 *
274 * Returns the bit number of the last set bit, or size.
275 */
276extern unsigned long find_last_bit(const unsigned long *addr,
277 unsigned long size);
278#endif
279
280#endif /* __KERNEL__ */
281#endif
282