Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1#ifndef __LINUX_BITMAP_H
2#define __LINUX_BITMAP_H
3
4#ifndef __ASSEMBLY__
5
6#include <linux/types.h>
7#include <linux/bitops.h>
8#include <linux/string.h>
9#include <linux/kernel.h>
10
11/*
12 * bitmaps provide bit arrays that consume one or more unsigned
13 * longs. The bitmap interface and available operations are listed
14 * here, in bitmap.h
15 *
16 * Function implementations generic to all architectures are in
17 * lib/bitmap.c. Functions implementations that are architecture
18 * specific are in various include/asm-<arch>/bitops.h headers
19 * and other arch/<arch> specific files.
20 *
21 * See lib/bitmap.c for more details.
22 */
23
24/*
25 * The available bitmap operations and their rough meaning in the
26 * case that the bitmap is a single unsigned long are thus:
27 *
28 * Note that nbits should be always a compile time evaluable constant.
29 * Otherwise many inlines will generate horrible code.
30 *
31 * bitmap_zero(dst, nbits) *dst = 0UL
32 * bitmap_fill(dst, nbits) *dst = ~0UL
33 * bitmap_copy(dst, src, nbits) *dst = *src
34 * bitmap_and(dst, src1, src2, nbits) *dst = *src1 & *src2
35 * bitmap_or(dst, src1, src2, nbits) *dst = *src1 | *src2
36 * bitmap_xor(dst, src1, src2, nbits) *dst = *src1 ^ *src2
37 * bitmap_andnot(dst, src1, src2, nbits) *dst = *src1 & ~(*src2)
38 * bitmap_complement(dst, src, nbits) *dst = ~(*src)
39 * bitmap_equal(src1, src2, nbits) Are *src1 and *src2 equal?
40 * bitmap_intersects(src1, src2, nbits) Do *src1 and *src2 overlap?
41 * bitmap_subset(src1, src2, nbits) Is *src1 a subset of *src2?
42 * bitmap_empty(src, nbits) Are all bits zero in *src?
43 * bitmap_full(src, nbits) Are all bits set in *src?
44 * bitmap_weight(src, nbits) Hamming Weight: number set bits
45 * bitmap_set(dst, pos, nbits) Set specified bit area
46 * bitmap_clear(dst, pos, nbits) Clear specified bit area
47 * bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
48 * bitmap_find_next_zero_area_off(buf, len, pos, n, mask) as above
49 * bitmap_shift_right(dst, src, n, nbits) *dst = *src >> n
50 * bitmap_shift_left(dst, src, n, nbits) *dst = *src << n
51 * bitmap_remap(dst, src, old, new, nbits) *dst = map(old, new)(src)
52 * bitmap_bitremap(oldbit, old, new, nbits) newbit = map(old, new)(oldbit)
53 * bitmap_onto(dst, orig, relmap, nbits) *dst = orig relative to relmap
54 * bitmap_fold(dst, orig, sz, nbits) dst bits = orig bits mod sz
55 * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf
56 * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf
57 * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf
58 * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf
59 * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region
60 * bitmap_release_region(bitmap, pos, order) Free specified bit region
61 * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region
62 * bitmap_from_u32array(dst, nbits, buf, nwords) *dst = *buf (nwords 32b words)
63 * bitmap_to_u32array(buf, nwords, src, nbits) *buf = *dst (nwords 32b words)
64 */
65
66/*
67 * Also the following operations in asm/bitops.h apply to bitmaps.
68 *
69 * set_bit(bit, addr) *addr |= bit
70 * clear_bit(bit, addr) *addr &= ~bit
71 * change_bit(bit, addr) *addr ^= bit
72 * test_bit(bit, addr) Is bit set in *addr?
73 * test_and_set_bit(bit, addr) Set bit and return old value
74 * test_and_clear_bit(bit, addr) Clear bit and return old value
75 * test_and_change_bit(bit, addr) Change bit and return old value
76 * find_first_zero_bit(addr, nbits) Position first zero bit in *addr
77 * find_first_bit(addr, nbits) Position first set bit in *addr
78 * find_next_zero_bit(addr, nbits, bit) Position next zero bit in *addr >= bit
79 * find_next_bit(addr, nbits, bit) Position next set bit in *addr >= bit
80 */
81
82/*
83 * The DECLARE_BITMAP(name,bits) macro, in linux/types.h, can be used
84 * to declare an array named 'name' of just enough unsigned longs to
85 * contain all bit positions from 0 to 'bits' - 1.
86 */
87
88/*
89 * lib/bitmap.c provides these functions:
90 */
91
92extern int __bitmap_empty(const unsigned long *bitmap, unsigned int nbits);
93extern int __bitmap_full(const unsigned long *bitmap, unsigned int nbits);
94extern int __bitmap_equal(const unsigned long *bitmap1,
95 const unsigned long *bitmap2, unsigned int nbits);
96extern void __bitmap_complement(unsigned long *dst, const unsigned long *src,
97 unsigned int nbits);
98extern void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
99 unsigned int shift, unsigned int nbits);
100extern void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
101 unsigned int shift, unsigned int nbits);
102extern int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
103 const unsigned long *bitmap2, unsigned int nbits);
104extern void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
105 const unsigned long *bitmap2, unsigned int nbits);
106extern void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
107 const unsigned long *bitmap2, unsigned int nbits);
108extern int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
109 const unsigned long *bitmap2, unsigned int nbits);
110extern int __bitmap_intersects(const unsigned long *bitmap1,
111 const unsigned long *bitmap2, unsigned int nbits);
112extern int __bitmap_subset(const unsigned long *bitmap1,
113 const unsigned long *bitmap2, unsigned int nbits);
114extern int __bitmap_weight(const unsigned long *bitmap, unsigned int nbits);
115extern void __bitmap_set(unsigned long *map, unsigned int start, int len);
116extern void __bitmap_clear(unsigned long *map, unsigned int start, int len);
117
118extern unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
119 unsigned long size,
120 unsigned long start,
121 unsigned int nr,
122 unsigned long align_mask,
123 unsigned long align_offset);
124
125/**
126 * bitmap_find_next_zero_area - find a contiguous aligned zero area
127 * @map: The address to base the search on
128 * @size: The bitmap size in bits
129 * @start: The bitnumber to start searching at
130 * @nr: The number of zeroed bits we're looking for
131 * @align_mask: Alignment mask for zero area
132 *
133 * The @align_mask should be one less than a power of 2; the effect is that
134 * the bit offset of all zero areas this function finds is multiples of that
135 * power of 2. A @align_mask of 0 means no alignment is required.
136 */
137static inline unsigned long
138bitmap_find_next_zero_area(unsigned long *map,
139 unsigned long size,
140 unsigned long start,
141 unsigned int nr,
142 unsigned long align_mask)
143{
144 return bitmap_find_next_zero_area_off(map, size, start, nr,
145 align_mask, 0);
146}
147
148extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,
149 unsigned long *dst, int nbits);
150extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen,
151 unsigned long *dst, int nbits);
152extern int bitmap_parselist(const char *buf, unsigned long *maskp,
153 int nmaskbits);
154extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen,
155 unsigned long *dst, int nbits);
156extern void bitmap_remap(unsigned long *dst, const unsigned long *src,
157 const unsigned long *old, const unsigned long *new, unsigned int nbits);
158extern int bitmap_bitremap(int oldbit,
159 const unsigned long *old, const unsigned long *new, int bits);
160extern void bitmap_onto(unsigned long *dst, const unsigned long *orig,
161 const unsigned long *relmap, unsigned int bits);
162extern void bitmap_fold(unsigned long *dst, const unsigned long *orig,
163 unsigned int sz, unsigned int nbits);
164extern int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order);
165extern void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order);
166extern int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order);
167extern unsigned int bitmap_from_u32array(unsigned long *bitmap,
168 unsigned int nbits,
169 const u32 *buf,
170 unsigned int nwords);
171extern unsigned int bitmap_to_u32array(u32 *buf,
172 unsigned int nwords,
173 const unsigned long *bitmap,
174 unsigned int nbits);
175#ifdef __BIG_ENDIAN
176extern void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits);
177#else
178#define bitmap_copy_le bitmap_copy
179#endif
180extern unsigned int bitmap_ord_to_pos(const unsigned long *bitmap, unsigned int ord, unsigned int nbits);
181extern int bitmap_print_to_pagebuf(bool list, char *buf,
182 const unsigned long *maskp, int nmaskbits);
183
184#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) & (BITS_PER_LONG - 1)))
185#define BITMAP_LAST_WORD_MASK(nbits) (~0UL >> (-(nbits) & (BITS_PER_LONG - 1)))
186
187#define small_const_nbits(nbits) \
188 (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG)
189
190static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
191{
192 if (small_const_nbits(nbits))
193 *dst = 0UL;
194 else {
195 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
196 memset(dst, 0, len);
197 }
198}
199
200static inline void bitmap_fill(unsigned long *dst, unsigned int nbits)
201{
202 unsigned int nlongs = BITS_TO_LONGS(nbits);
203 if (!small_const_nbits(nbits)) {
204 unsigned int len = (nlongs - 1) * sizeof(unsigned long);
205 memset(dst, 0xff, len);
206 }
207 dst[nlongs - 1] = BITMAP_LAST_WORD_MASK(nbits);
208}
209
210static inline void bitmap_copy(unsigned long *dst, const unsigned long *src,
211 unsigned int nbits)
212{
213 if (small_const_nbits(nbits))
214 *dst = *src;
215 else {
216 unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
217 memcpy(dst, src, len);
218 }
219}
220
221static inline int bitmap_and(unsigned long *dst, const unsigned long *src1,
222 const unsigned long *src2, unsigned int nbits)
223{
224 if (small_const_nbits(nbits))
225 return (*dst = *src1 & *src2 & BITMAP_LAST_WORD_MASK(nbits)) != 0;
226 return __bitmap_and(dst, src1, src2, nbits);
227}
228
229static inline void bitmap_or(unsigned long *dst, const unsigned long *src1,
230 const unsigned long *src2, unsigned int nbits)
231{
232 if (small_const_nbits(nbits))
233 *dst = *src1 | *src2;
234 else
235 __bitmap_or(dst, src1, src2, nbits);
236}
237
238static inline void bitmap_xor(unsigned long *dst, const unsigned long *src1,
239 const unsigned long *src2, unsigned int nbits)
240{
241 if (small_const_nbits(nbits))
242 *dst = *src1 ^ *src2;
243 else
244 __bitmap_xor(dst, src1, src2, nbits);
245}
246
247static inline int bitmap_andnot(unsigned long *dst, const unsigned long *src1,
248 const unsigned long *src2, unsigned int nbits)
249{
250 if (small_const_nbits(nbits))
251 return (*dst = *src1 & ~(*src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
252 return __bitmap_andnot(dst, src1, src2, nbits);
253}
254
255static inline void bitmap_complement(unsigned long *dst, const unsigned long *src,
256 unsigned int nbits)
257{
258 if (small_const_nbits(nbits))
259 *dst = ~(*src);
260 else
261 __bitmap_complement(dst, src, nbits);
262}
263
264static inline int bitmap_equal(const unsigned long *src1,
265 const unsigned long *src2, unsigned int nbits)
266{
267 if (small_const_nbits(nbits))
268 return !((*src1 ^ *src2) & BITMAP_LAST_WORD_MASK(nbits));
269 if (__builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
270 return !memcmp(src1, src2, nbits / 8);
271 return __bitmap_equal(src1, src2, nbits);
272}
273
274static inline int bitmap_intersects(const unsigned long *src1,
275 const unsigned long *src2, unsigned int nbits)
276{
277 if (small_const_nbits(nbits))
278 return ((*src1 & *src2) & BITMAP_LAST_WORD_MASK(nbits)) != 0;
279 else
280 return __bitmap_intersects(src1, src2, nbits);
281}
282
283static inline int bitmap_subset(const unsigned long *src1,
284 const unsigned long *src2, unsigned int nbits)
285{
286 if (small_const_nbits(nbits))
287 return ! ((*src1 & ~(*src2)) & BITMAP_LAST_WORD_MASK(nbits));
288 else
289 return __bitmap_subset(src1, src2, nbits);
290}
291
292static inline int bitmap_empty(const unsigned long *src, unsigned nbits)
293{
294 if (small_const_nbits(nbits))
295 return ! (*src & BITMAP_LAST_WORD_MASK(nbits));
296
297 return find_first_bit(src, nbits) == nbits;
298}
299
300static inline int bitmap_full(const unsigned long *src, unsigned int nbits)
301{
302 if (small_const_nbits(nbits))
303 return ! (~(*src) & BITMAP_LAST_WORD_MASK(nbits));
304
305 return find_first_zero_bit(src, nbits) == nbits;
306}
307
308static __always_inline int bitmap_weight(const unsigned long *src, unsigned int nbits)
309{
310 if (small_const_nbits(nbits))
311 return hweight_long(*src & BITMAP_LAST_WORD_MASK(nbits));
312 return __bitmap_weight(src, nbits);
313}
314
315static __always_inline void bitmap_set(unsigned long *map, unsigned int start,
316 unsigned int nbits)
317{
318 if (__builtin_constant_p(nbits) && nbits == 1)
319 __set_bit(start, map);
320 else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) &&
321 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
322 memset((char *)map + start / 8, 0xff, nbits / 8);
323 else
324 __bitmap_set(map, start, nbits);
325}
326
327static __always_inline void bitmap_clear(unsigned long *map, unsigned int start,
328 unsigned int nbits)
329{
330 if (__builtin_constant_p(nbits) && nbits == 1)
331 __clear_bit(start, map);
332 else if (__builtin_constant_p(start & 7) && IS_ALIGNED(start, 8) &&
333 __builtin_constant_p(nbits & 7) && IS_ALIGNED(nbits, 8))
334 memset((char *)map + start / 8, 0, nbits / 8);
335 else
336 __bitmap_clear(map, start, nbits);
337}
338
339static inline void bitmap_shift_right(unsigned long *dst, const unsigned long *src,
340 unsigned int shift, int nbits)
341{
342 if (small_const_nbits(nbits))
343 *dst = (*src & BITMAP_LAST_WORD_MASK(nbits)) >> shift;
344 else
345 __bitmap_shift_right(dst, src, shift, nbits);
346}
347
348static inline void bitmap_shift_left(unsigned long *dst, const unsigned long *src,
349 unsigned int shift, unsigned int nbits)
350{
351 if (small_const_nbits(nbits))
352 *dst = (*src << shift) & BITMAP_LAST_WORD_MASK(nbits);
353 else
354 __bitmap_shift_left(dst, src, shift, nbits);
355}
356
357static inline int bitmap_parse(const char *buf, unsigned int buflen,
358 unsigned long *maskp, int nmaskbits)
359{
360 return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);
361}
362
363/*
364 * bitmap_from_u64 - Check and swap words within u64.
365 * @mask: source bitmap
366 * @dst: destination bitmap
367 *
368 * In 32-bit Big Endian kernel, when using (u32 *)(&val)[*]
369 * to read u64 mask, we will get the wrong word.
370 * That is "(u32 *)(&val)[0]" gets the upper 32 bits,
371 * but we expect the lower 32-bits of u64.
372 */
373static inline void bitmap_from_u64(unsigned long *dst, u64 mask)
374{
375 dst[0] = mask & ULONG_MAX;
376
377 if (sizeof(mask) > sizeof(unsigned long))
378 dst[1] = mask >> 32;
379}
380
381#endif /* __ASSEMBLY__ */
382
383#endif /* __LINUX_BITMAP_H */