projects/linux·blob v4.12 · refs

275 lines · 6.7 KiB

1#ifndef _LINUX_BITOPS_H
2#define _LINUX_BITOPS_H
3#include <asm/types.h>
4
5#ifdef __KERNEL__
6#define BIT(nr) (1UL << (nr))
7#define BIT_ULL(nr) (1ULL << (nr))
8#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
9#define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
10#define BIT_ULL_MASK(nr) (1ULL << ((nr) % BITS_PER_LONG_LONG))
11#define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG)
12#define BITS_PER_BYTE 8
13#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long))
14#endif
15
16/*
17 * Create a contiguous bitmask starting at bit position @l and ending at
18 * position @h. For example
19 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
20 */
21#define GENMASK(h, l) \
22 (((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
23
24#define GENMASK_ULL(h, l) \
25 (((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
26
27extern unsigned int __sw_hweight8(unsigned int w);
28extern unsigned int __sw_hweight16(unsigned int w);
29extern unsigned int __sw_hweight32(unsigned int w);
30extern unsigned long __sw_hweight64(__u64 w);
31
32/*
33 * Include this here because some architectures need generic_ffs/fls in
34 * scope
35 */
36#include <asm/bitops.h>
37
38#define for_each_set_bit(bit, addr, size) \
39 for ((bit) = find_first_bit((addr), (size)); \
40 (bit) < (size); \
41 (bit) = find_next_bit((addr), (size), (bit) + 1))
42
43/* same as for_each_set_bit() but use bit as value to start with */
44#define for_each_set_bit_from(bit, addr, size) \
45 for ((bit) = find_next_bit((addr), (size), (bit)); \
46 (bit) < (size); \
47 (bit) = find_next_bit((addr), (size), (bit) + 1))
48
49#define for_each_clear_bit(bit, addr, size) \
50 for ((bit) = find_first_zero_bit((addr), (size)); \
51 (bit) < (size); \
52 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
53
54/* same as for_each_clear_bit() but use bit as value to start with */
55#define for_each_clear_bit_from(bit, addr, size) \
56 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
57 (bit) < (size); \
58 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
59
60static inline int get_bitmask_order(unsigned int count)
61{
62 int order;
63
64 order = fls(count);
65 return order; /* We could be slightly more clever with -1 here... */
66}
67
68static __always_inline unsigned long hweight_long(unsigned long w)
69{
70 return sizeof(w) == 4 ? hweight32(w) : hweight64(w);
71}
72
73/**
74 * rol64 - rotate a 64-bit value left
75 * @word: value to rotate
76 * @shift: bits to roll
77 */
78static inline __u64 rol64(__u64 word, unsigned int shift)
79{
80 return (word << shift) | (word >> (64 - shift));
81}
82
83/**
84 * ror64 - rotate a 64-bit value right
85 * @word: value to rotate
86 * @shift: bits to roll
87 */
88static inline __u64 ror64(__u64 word, unsigned int shift)
89{
90 return (word >> shift) | (word << (64 - shift));
91}
92
93/**
94 * rol32 - rotate a 32-bit value left
95 * @word: value to rotate
96 * @shift: bits to roll
97 */
98static inline __u32 rol32(__u32 word, unsigned int shift)
99{
100 return (word << shift) | (word >> ((-shift) & 31));
101}
102
103/**
104 * ror32 - rotate a 32-bit value right
105 * @word: value to rotate
106 * @shift: bits to roll
107 */
108static inline __u32 ror32(__u32 word, unsigned int shift)
109{
110 return (word >> shift) | (word << (32 - shift));
111}
112
113/**
114 * rol16 - rotate a 16-bit value left
115 * @word: value to rotate
116 * @shift: bits to roll
117 */
118static inline __u16 rol16(__u16 word, unsigned int shift)
119{
120 return (word << shift) | (word >> (16 - shift));
121}
122
123/**
124 * ror16 - rotate a 16-bit value right
125 * @word: value to rotate
126 * @shift: bits to roll
127 */
128static inline __u16 ror16(__u16 word, unsigned int shift)
129{
130 return (word >> shift) | (word << (16 - shift));
131}
132
133/**
134 * rol8 - rotate an 8-bit value left
135 * @word: value to rotate
136 * @shift: bits to roll
137 */
138static inline __u8 rol8(__u8 word, unsigned int shift)
139{
140 return (word << shift) | (word >> (8 - shift));
141}
142
143/**
144 * ror8 - rotate an 8-bit value right
145 * @word: value to rotate
146 * @shift: bits to roll
147 */
148static inline __u8 ror8(__u8 word, unsigned int shift)
149{
150 return (word >> shift) | (word << (8 - shift));
151}
152
153/**
154 * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit
155 * @value: value to sign extend
156 * @index: 0 based bit index (0<=index<32) to sign bit
157 *
158 * This is safe to use for 16- and 8-bit types as well.
159 */
160static inline __s32 sign_extend32(__u32 value, int index)
161{
162 __u8 shift = 31 - index;
163 return (__s32)(value << shift) >> shift;
164}
165
166/**
167 * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit
168 * @value: value to sign extend
169 * @index: 0 based bit index (0<=index<64) to sign bit
170 */
171static inline __s64 sign_extend64(__u64 value, int index)
172{
173 __u8 shift = 63 - index;
174 return (__s64)(value << shift) >> shift;
175}
176
177static inline unsigned fls_long(unsigned long l)
178{
179 if (sizeof(l) == 4)
180 return fls(l);
181 return fls64(l);
182}
183
184static inline int get_count_order(unsigned int count)
185{
186 int order;
187
188 order = fls(count) - 1;
189 if (count & (count - 1))
190 order++;
191 return order;
192}
193
194/**
195 * get_count_order_long - get order after rounding @l up to power of 2
196 * @l: parameter
197 *
198 * it is same as get_count_order() but with long type parameter
199 */
200static inline int get_count_order_long(unsigned long l)
201{
202 if (l == 0UL)
203 return -1;
204 else if (l & (l - 1UL))
205 return (int)fls_long(l);
206 else
207 return (int)fls_long(l) - 1;
208}
209
210/**
211 * __ffs64 - find first set bit in a 64 bit word
212 * @word: The 64 bit word
213 *
214 * On 64 bit arches this is a synomyn for __ffs
215 * The result is not defined if no bits are set, so check that @word
216 * is non-zero before calling this.
217 */
218static inline unsigned long __ffs64(u64 word)
219{
220#if BITS_PER_LONG == 32
221 if (((u32)word) == 0UL)
222 return __ffs((u32)(word >> 32)) + 32;
223#elif BITS_PER_LONG != 64
224#error BITS_PER_LONG not 32 or 64
225#endif
226 return __ffs((unsigned long)word);
227}
228
229#ifdef __KERNEL__
230
231#ifndef set_mask_bits
232#define set_mask_bits(ptr, _mask, _bits) \
233({ \
234 const typeof(*ptr) mask = (_mask), bits = (_bits); \
235 typeof(*ptr) old, new; \
236 \
237 do { \
238 old = ACCESS_ONCE(*ptr); \
239 new = (old & ~mask) | bits; \
240 } while (cmpxchg(ptr, old, new) != old); \
241 \
242 new; \
243})
244#endif
245
246#ifndef bit_clear_unless
247#define bit_clear_unless(ptr, _clear, _test) \
248({ \
249 const typeof(*ptr) clear = (_clear), test = (_test); \
250 typeof(*ptr) old, new; \
251 \
252 do { \
253 old = ACCESS_ONCE(*ptr); \
254 new = old & ~clear; \
255 } while (!(old & test) && \
256 cmpxchg(ptr, old, new) != old); \
257 \
258 !(old & test); \
259})
260#endif
261
262#ifndef find_last_bit
263/**
264 * find_last_bit - find the last set bit in a memory region
265 * @addr: The address to start the search at
266 * @size: The number of bits to search
267 *
268 * Returns the bit number of the last set bit, or size.
269 */
270extern unsigned long find_last_bit(const unsigned long *addr,
271 unsigned long size);
272#endif
273
274#endif /* __KERNEL__ */
275#endif