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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * lib/bitmap.c
3 * Helper functions for bitmap.h.
4 *
5 * This source code is licensed under the GNU General Public License,
6 * Version 2. See the file COPYING for more details.
7 */
Paul Gortmaker8bc3bcc2011-11-16 21:29:17 -05008#include <linux/export.h>
9#include <linux/thread_info.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/ctype.h>
11#include <linux/errno.h>
12#include <linux/bitmap.h>
13#include <linux/bitops.h>
Paul Gortmaker50af5ea2012-01-20 18:35:53 -050014#include <linux/bug.h>
David Decotignye52bc7c2016-02-19 09:23:59 -050015#include <linux/kernel.h>
16#include <linux/string.h>
Andy Lutomirski13d4ea02016-07-14 13:22:57 -070017#include <linux/uaccess.h>
Sudeep Holla5aaba362014-09-30 14:48:22 +010018
19#include <asm/page.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
21/*
22 * bitmaps provide an array of bits, implemented using an an
23 * array of unsigned longs. The number of valid bits in a
24 * given bitmap does _not_ need to be an exact multiple of
25 * BITS_PER_LONG.
26 *
27 * The possible unused bits in the last, partially used word
28 * of a bitmap are 'don't care'. The implementation makes
29 * no particular effort to keep them zero. It ensures that
30 * their value will not affect the results of any operation.
31 * The bitmap operations that return Boolean (bitmap_empty,
32 * for example) or scalar (bitmap_weight, for example) results
33 * carefully filter out these unused bits from impacting their
34 * results.
35 *
36 * These operations actually hold to a slightly stronger rule:
37 * if you don't input any bitmaps to these ops that have some
38 * unused bits set, then they won't output any set unused bits
39 * in output bitmaps.
40 *
41 * The byte ordering of bitmaps is more natural on little
42 * endian architectures. See the big-endian headers
43 * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
44 * for the best explanations of this ordering.
45 */
46
Linus Torvalds1da177e2005-04-16 15:20:36 -070047int __bitmap_equal(const unsigned long *bitmap1,
Rasmus Villemoes5e0680692014-08-06 16:09:53 -070048 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -070049{
Rasmus Villemoes5e0680692014-08-06 16:09:53 -070050 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 for (k = 0; k < lim; ++k)
52 if (bitmap1[k] != bitmap2[k])
53 return 0;
54
55 if (bits % BITS_PER_LONG)
56 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
57 return 0;
58
59 return 1;
60}
61EXPORT_SYMBOL(__bitmap_equal);
62
Rasmus Villemoes3d6684f2014-08-06 16:09:55 -070063void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -070064{
Rasmus Villemoes3d6684f2014-08-06 16:09:55 -070065 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 for (k = 0; k < lim; ++k)
67 dst[k] = ~src[k];
68
69 if (bits % BITS_PER_LONG)
Rasmus Villemoes65b4ee62014-08-06 16:09:57 -070070 dst[k] = ~src[k];
Linus Torvalds1da177e2005-04-16 15:20:36 -070071}
72EXPORT_SYMBOL(__bitmap_complement);
73
Robert P. J. Day72fd4a32007-02-10 01:45:59 -080074/**
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 * __bitmap_shift_right - logical right shift of the bits in a bitmap
Randy Dunlap05fb6bf2007-02-28 20:12:13 -080076 * @dst : destination bitmap
77 * @src : source bitmap
78 * @shift : shift by this many bits
Rasmus Villemoes2fbad292015-02-13 14:36:02 -080079 * @nbits : bitmap size, in bits
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 *
81 * Shifting right (dividing) means moving bits in the MS -> LS bit
82 * direction. Zeros are fed into the vacated MS positions and the
83 * LS bits shifted off the bottom are lost.
84 */
Rasmus Villemoes2fbad292015-02-13 14:36:02 -080085void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
86 unsigned shift, unsigned nbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -070087{
Rasmus Villemoescfac1d02015-02-13 14:36:10 -080088 unsigned k, lim = BITS_TO_LONGS(nbits);
Rasmus Villemoes2fbad292015-02-13 14:36:02 -080089 unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
Rasmus Villemoescfac1d02015-02-13 14:36:10 -080090 unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 for (k = 0; off + k < lim; ++k) {
92 unsigned long upper, lower;
93
94 /*
95 * If shift is not word aligned, take lower rem bits of
96 * word above and make them the top rem bits of result.
97 */
98 if (!rem || off + k + 1 >= lim)
99 upper = 0;
100 else {
101 upper = src[off + k + 1];
Rasmus Villemoescfac1d02015-02-13 14:36:10 -0800102 if (off + k + 1 == lim - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 upper &= mask;
Rasmus Villemoes9d8a6b22015-02-13 14:36:05 -0800104 upper <<= (BITS_PER_LONG - rem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 }
106 lower = src[off + k];
Rasmus Villemoescfac1d02015-02-13 14:36:10 -0800107 if (off + k == lim - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 lower &= mask;
Rasmus Villemoes9d8a6b22015-02-13 14:36:05 -0800109 lower >>= rem;
110 dst[k] = lower | upper;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 }
112 if (off)
113 memset(&dst[lim - off], 0, off*sizeof(unsigned long));
114}
115EXPORT_SYMBOL(__bitmap_shift_right);
116
117
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800118/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 * __bitmap_shift_left - logical left shift of the bits in a bitmap
Randy Dunlap05fb6bf2007-02-28 20:12:13 -0800120 * @dst : destination bitmap
121 * @src : source bitmap
122 * @shift : shift by this many bits
Rasmus Villemoesdba94c22015-02-13 14:36:13 -0800123 * @nbits : bitmap size, in bits
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 *
125 * Shifting left (multiplying) means moving bits in the LS -> MS
126 * direction. Zeros are fed into the vacated LS bit positions
127 * and those MS bits shifted off the top are lost.
128 */
129
Rasmus Villemoesdba94c22015-02-13 14:36:13 -0800130void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
131 unsigned int shift, unsigned int nbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132{
Rasmus Villemoesdba94c22015-02-13 14:36:13 -0800133 int k;
Rasmus Villemoes7f590652015-02-13 14:36:19 -0800134 unsigned int lim = BITS_TO_LONGS(nbits);
Rasmus Villemoesdba94c22015-02-13 14:36:13 -0800135 unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 for (k = lim - off - 1; k >= 0; --k) {
137 unsigned long upper, lower;
138
139 /*
140 * If shift is not word aligned, take upper rem bits of
141 * word below and make them the bottom rem bits of result.
142 */
143 if (rem && k > 0)
Rasmus Villemoes6d874ec2015-02-13 14:36:16 -0800144 lower = src[k - 1] >> (BITS_PER_LONG - rem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 else
146 lower = 0;
Rasmus Villemoes7f590652015-02-13 14:36:19 -0800147 upper = src[k] << rem;
Rasmus Villemoes6d874ec2015-02-13 14:36:16 -0800148 dst[k + off] = lower | upper;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 }
150 if (off)
151 memset(dst, 0, off*sizeof(unsigned long));
152}
153EXPORT_SYMBOL(__bitmap_shift_left);
154
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700155int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700156 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700158 unsigned int k;
Rasmus Villemoes7e5f97d2014-08-06 16:10:22 -0700159 unsigned int lim = bits/BITS_PER_LONG;
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700160 unsigned long result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
Rasmus Villemoes7e5f97d2014-08-06 16:10:22 -0700162 for (k = 0; k < lim; k++)
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700163 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
Rasmus Villemoes7e5f97d2014-08-06 16:10:22 -0700164 if (bits % BITS_PER_LONG)
165 result |= (dst[k] = bitmap1[k] & bitmap2[k] &
166 BITMAP_LAST_WORD_MASK(bits));
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700167 return result != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168}
169EXPORT_SYMBOL(__bitmap_and);
170
171void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700172 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700174 unsigned int k;
175 unsigned int nr = BITS_TO_LONGS(bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
177 for (k = 0; k < nr; k++)
178 dst[k] = bitmap1[k] | bitmap2[k];
179}
180EXPORT_SYMBOL(__bitmap_or);
181
182void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700183 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700185 unsigned int k;
186 unsigned int nr = BITS_TO_LONGS(bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
188 for (k = 0; k < nr; k++)
189 dst[k] = bitmap1[k] ^ bitmap2[k];
190}
191EXPORT_SYMBOL(__bitmap_xor);
192
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700193int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700194 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700196 unsigned int k;
Rasmus Villemoes74e76532014-08-06 16:10:24 -0700197 unsigned int lim = bits/BITS_PER_LONG;
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700198 unsigned long result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
Rasmus Villemoes74e76532014-08-06 16:10:24 -0700200 for (k = 0; k < lim; k++)
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700201 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
Rasmus Villemoes74e76532014-08-06 16:10:24 -0700202 if (bits % BITS_PER_LONG)
203 result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
204 BITMAP_LAST_WORD_MASK(bits));
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700205 return result != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206}
207EXPORT_SYMBOL(__bitmap_andnot);
208
209int __bitmap_intersects(const unsigned long *bitmap1,
Rasmus Villemoes6dfe9792014-08-06 16:10:01 -0700210 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211{
Rasmus Villemoes6dfe9792014-08-06 16:10:01 -0700212 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 for (k = 0; k < lim; ++k)
214 if (bitmap1[k] & bitmap2[k])
215 return 1;
216
217 if (bits % BITS_PER_LONG)
218 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
219 return 1;
220 return 0;
221}
222EXPORT_SYMBOL(__bitmap_intersects);
223
224int __bitmap_subset(const unsigned long *bitmap1,
Rasmus Villemoes5be20212014-08-06 16:10:03 -0700225 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226{
Rasmus Villemoes5be20212014-08-06 16:10:03 -0700227 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 for (k = 0; k < lim; ++k)
229 if (bitmap1[k] & ~bitmap2[k])
230 return 0;
231
232 if (bits % BITS_PER_LONG)
233 if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
234 return 0;
235 return 1;
236}
237EXPORT_SYMBOL(__bitmap_subset);
238
Rasmus Villemoes877d9f32014-08-06 16:10:05 -0700239int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240{
Rasmus Villemoes877d9f32014-08-06 16:10:05 -0700241 unsigned int k, lim = bits/BITS_PER_LONG;
242 int w = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
244 for (k = 0; k < lim; k++)
Akinobu Mita37d54112006-03-26 01:39:56 -0800245 w += hweight_long(bitmap[k]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
247 if (bits % BITS_PER_LONG)
Akinobu Mita37d54112006-03-26 01:39:56 -0800248 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
250 return w;
251}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252EXPORT_SYMBOL(__bitmap_weight);
253
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700254void bitmap_set(unsigned long *map, unsigned int start, int len)
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800255{
256 unsigned long *p = map + BIT_WORD(start);
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700257 const unsigned int size = start + len;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800258 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
259 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
260
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700261 while (len - bits_to_set >= 0) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800262 *p |= mask_to_set;
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700263 len -= bits_to_set;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800264 bits_to_set = BITS_PER_LONG;
265 mask_to_set = ~0UL;
266 p++;
267 }
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700268 if (len) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800269 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
270 *p |= mask_to_set;
271 }
272}
273EXPORT_SYMBOL(bitmap_set);
274
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700275void bitmap_clear(unsigned long *map, unsigned int start, int len)
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800276{
277 unsigned long *p = map + BIT_WORD(start);
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700278 const unsigned int size = start + len;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800279 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
280 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
281
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700282 while (len - bits_to_clear >= 0) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800283 *p &= ~mask_to_clear;
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700284 len -= bits_to_clear;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800285 bits_to_clear = BITS_PER_LONG;
286 mask_to_clear = ~0UL;
287 p++;
288 }
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700289 if (len) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800290 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
291 *p &= ~mask_to_clear;
292 }
293}
294EXPORT_SYMBOL(bitmap_clear);
295
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800296/**
297 * bitmap_find_next_zero_area_off - find a contiguous aligned zero area
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800298 * @map: The address to base the search on
299 * @size: The bitmap size in bits
300 * @start: The bitnumber to start searching at
301 * @nr: The number of zeroed bits we're looking for
302 * @align_mask: Alignment mask for zero area
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800303 * @align_offset: Alignment offset for zero area.
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800304 *
305 * The @align_mask should be one less than a power of 2; the effect is that
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800306 * the bit offset of all zero areas this function finds plus @align_offset
307 * is multiple of that power of 2.
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800308 */
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800309unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
310 unsigned long size,
311 unsigned long start,
312 unsigned int nr,
313 unsigned long align_mask,
314 unsigned long align_offset)
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800315{
316 unsigned long index, end, i;
317again:
318 index = find_next_zero_bit(map, size, start);
319
320 /* Align allocation */
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800321 index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800322
323 end = index + nr;
324 if (end > size)
325 return end;
326 i = find_next_bit(map, end, index);
327 if (i < end) {
328 start = i + 1;
329 goto again;
330 }
331 return index;
332}
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800333EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335/*
Nadia Yvette Chambers6d49e352012-12-06 10:39:54 +0100336 * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 * second version by Paul Jackson, third by Joe Korty.
338 */
339
340#define CHUNKSZ 32
341#define nbits_to_hold_value(val) fls(val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342#define BASEDEC 10 /* fancier cpuset lists input in decimal */
343
344/**
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700345 * __bitmap_parse - convert an ASCII hex string into a bitmap.
346 * @buf: pointer to buffer containing string.
347 * @buflen: buffer size in bytes. If string is smaller than this
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 * then it must be terminated with a \0.
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700349 * @is_user: location of buffer, 0 indicates kernel space
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 * @maskp: pointer to bitmap array that will contain result.
351 * @nmaskbits: size of bitmap, in bits.
352 *
353 * Commas group hex digits into chunks. Each chunk defines exactly 32
354 * bits of the resultant bitmask. No chunk may specify a value larger
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700355 * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
356 * then leading 0-bits are prepended. %-EINVAL is returned for illegal
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357 * characters and for grouping errors such as "1,,5", ",44", "," and "".
358 * Leading and trailing whitespace accepted, but not embedded whitespace.
359 */
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700360int __bitmap_parse(const char *buf, unsigned int buflen,
361 int is_user, unsigned long *maskp,
362 int nmaskbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363{
364 int c, old_c, totaldigits, ndigits, nchunks, nbits;
365 u32 chunk;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700366 const char __user __force *ubuf = (const char __user __force *)buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367
368 bitmap_zero(maskp, nmaskbits);
369
370 nchunks = nbits = totaldigits = c = 0;
371 do {
Pan Xinhuid21c3d42015-09-09 15:37:02 -0700372 chunk = 0;
373 ndigits = totaldigits;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374
375 /* Get the next chunk of the bitmap */
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700376 while (buflen) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 old_c = c;
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700378 if (is_user) {
379 if (__get_user(c, ubuf++))
380 return -EFAULT;
381 }
382 else
383 c = *buf++;
384 buflen--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 if (isspace(c))
386 continue;
387
388 /*
389 * If the last character was a space and the current
390 * character isn't '\0', we've got embedded whitespace.
391 * This is a no-no, so throw an error.
392 */
393 if (totaldigits && c && isspace(old_c))
394 return -EINVAL;
395
396 /* A '\0' or a ',' signal the end of the chunk */
397 if (c == '\0' || c == ',')
398 break;
399
400 if (!isxdigit(c))
401 return -EINVAL;
402
403 /*
404 * Make sure there are at least 4 free bits in 'chunk'.
405 * If not, this hexdigit will overflow 'chunk', so
406 * throw an error.
407 */
408 if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1))
409 return -EOVERFLOW;
410
Andy Shevchenko66f19912010-10-26 14:23:03 -0700411 chunk = (chunk << 4) | hex_to_bin(c);
Pan Xinhuid21c3d42015-09-09 15:37:02 -0700412 totaldigits++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 }
Pan Xinhuid21c3d42015-09-09 15:37:02 -0700414 if (ndigits == totaldigits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 return -EINVAL;
416 if (nchunks == 0 && chunk == 0)
417 continue;
418
419 __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits);
420 *maskp |= chunk;
421 nchunks++;
422 nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
423 if (nbits > nmaskbits)
424 return -EOVERFLOW;
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700425 } while (buflen && c == ',');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
427 return 0;
428}
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700429EXPORT_SYMBOL(__bitmap_parse);
430
431/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800432 * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700433 *
434 * @ubuf: pointer to user buffer containing string.
435 * @ulen: buffer size in bytes. If string is smaller than this
436 * then it must be terminated with a \0.
437 * @maskp: pointer to bitmap array that will contain result.
438 * @nmaskbits: size of bitmap, in bits.
439 *
440 * Wrapper for __bitmap_parse(), providing it with user buffer.
441 *
442 * We cannot have this as an inline function in bitmap.h because it needs
443 * linux/uaccess.h to get the access_ok() declaration and this causes
444 * cyclic dependencies.
445 */
446int bitmap_parse_user(const char __user *ubuf,
447 unsigned int ulen, unsigned long *maskp,
448 int nmaskbits)
449{
450 if (!access_ok(VERIFY_READ, ubuf, ulen))
451 return -EFAULT;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700452 return __bitmap_parse((const char __force *)ubuf,
453 ulen, 1, maskp, nmaskbits);
454
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700455}
456EXPORT_SYMBOL(bitmap_parse_user);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458/**
Sudeep Holla5aaba362014-09-30 14:48:22 +0100459 * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string
460 * @list: indicates whether the bitmap must be list
461 * @buf: page aligned buffer into which string is placed
462 * @maskp: pointer to bitmap to convert
463 * @nmaskbits: size of bitmap, in bits
464 *
465 * Output format is a comma-separated list of decimal numbers and
466 * ranges if list is specified or hex digits grouped into comma-separated
467 * sets of 8 digits/set. Returns the number of characters written to buf.
Sudeep Holla9cf79d12015-06-25 15:02:17 -0700468 *
469 * It is assumed that @buf is a pointer into a PAGE_SIZE area and that
470 * sufficient storage remains at @buf to accommodate the
471 * bitmap_print_to_pagebuf() output.
Sudeep Holla5aaba362014-09-30 14:48:22 +0100472 */
473int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
474 int nmaskbits)
475{
Sudeep Holla9cf79d12015-06-25 15:02:17 -0700476 ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf;
Sudeep Holla5aaba362014-09-30 14:48:22 +0100477 int n = 0;
478
Sudeep Holla9cf79d12015-06-25 15:02:17 -0700479 if (len > 1)
480 n = list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) :
481 scnprintf(buf, len, "%*pb\n", nmaskbits, maskp);
Sudeep Holla5aaba362014-09-30 14:48:22 +0100482 return n;
483}
484EXPORT_SYMBOL(bitmap_print_to_pagebuf);
485
486/**
Mike Travis4b060422011-05-24 17:13:12 -0700487 * __bitmap_parselist - convert list format ASCII string to bitmap
Randy Dunlapb0825ee2011-06-15 15:08:10 -0700488 * @buf: read nul-terminated user string from this buffer
Mike Travis4b060422011-05-24 17:13:12 -0700489 * @buflen: buffer size in bytes. If string is smaller than this
490 * then it must be terminated with a \0.
491 * @is_user: location of buffer, 0 indicates kernel space
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700492 * @maskp: write resulting mask here
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 * @nmaskbits: number of bits in mask to be written
494 *
495 * Input format is a comma-separated list of decimal numbers and
496 * ranges. Consecutively set bits are shown as two hyphen-separated
497 * decimal numbers, the smallest and largest bit numbers set in
498 * the range.
499 *
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700500 * Returns 0 on success, -errno on invalid input strings.
501 * Error values:
502 * %-EINVAL: second number in range smaller than first
503 * %-EINVAL: invalid character in string
504 * %-ERANGE: bit number specified too large for mask
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 */
Mike Travis4b060422011-05-24 17:13:12 -0700506static int __bitmap_parselist(const char *buf, unsigned int buflen,
507 int is_user, unsigned long *maskp,
508 int nmaskbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509{
510 unsigned a, b;
Pan Xinhui9bf98f12015-09-09 15:37:08 -0700511 int c, old_c, totaldigits, ndigits;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700512 const char __user __force *ubuf = (const char __user __force *)buf;
Chris Metcalf2528a8b2015-06-25 15:02:08 -0700513 int at_start, in_range;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514
Mike Travis4b060422011-05-24 17:13:12 -0700515 totaldigits = c = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 bitmap_zero(maskp, nmaskbits);
517 do {
Chris Metcalf2528a8b2015-06-25 15:02:08 -0700518 at_start = 1;
Mike Travis4b060422011-05-24 17:13:12 -0700519 in_range = 0;
520 a = b = 0;
Pan Xinhui9bf98f12015-09-09 15:37:08 -0700521 ndigits = totaldigits;
Mike Travis4b060422011-05-24 17:13:12 -0700522
523 /* Get the next cpu# or a range of cpu#'s */
524 while (buflen) {
525 old_c = c;
526 if (is_user) {
527 if (__get_user(c, ubuf++))
528 return -EFAULT;
529 } else
530 c = *buf++;
531 buflen--;
532 if (isspace(c))
533 continue;
534
Mike Travis4b060422011-05-24 17:13:12 -0700535 /* A '\0' or a ',' signal the end of a cpu# or range */
536 if (c == '\0' || c == ',')
537 break;
Pan Xinhui9bf98f12015-09-09 15:37:08 -0700538 /*
539 * whitespaces between digits are not allowed,
540 * but it's ok if whitespaces are on head or tail.
541 * when old_c is whilespace,
542 * if totaldigits == ndigits, whitespace is on head.
543 * if whitespace is on tail, it should not run here.
544 * as c was ',' or '\0',
545 * the last code line has broken the current loop.
546 */
547 if ((totaldigits != ndigits) && isspace(old_c))
548 return -EINVAL;
Mike Travis4b060422011-05-24 17:13:12 -0700549
550 if (c == '-') {
Chris Metcalf2528a8b2015-06-25 15:02:08 -0700551 if (at_start || in_range)
Mike Travis4b060422011-05-24 17:13:12 -0700552 return -EINVAL;
553 b = 0;
554 in_range = 1;
Pan Xinhuid9282cb2015-09-09 15:37:05 -0700555 at_start = 1;
Mike Travis4b060422011-05-24 17:13:12 -0700556 continue;
557 }
558
559 if (!isdigit(c))
560 return -EINVAL;
561
562 b = b * 10 + (c - '0');
563 if (!in_range)
564 a = b;
Chris Metcalf2528a8b2015-06-25 15:02:08 -0700565 at_start = 0;
Mike Travis4b060422011-05-24 17:13:12 -0700566 totaldigits++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 }
Pan Xinhui9bf98f12015-09-09 15:37:08 -0700568 if (ndigits == totaldigits)
569 continue;
Pan Xinhuid9282cb2015-09-09 15:37:05 -0700570 /* if no digit is after '-', it's wrong*/
571 if (at_start && in_range)
572 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 if (!(a <= b))
574 return -EINVAL;
575 if (b >= nmaskbits)
576 return -ERANGE;
Pan Xinhui9bf98f12015-09-09 15:37:08 -0700577 while (a <= b) {
578 set_bit(a, maskp);
579 a++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 }
Mike Travis4b060422011-05-24 17:13:12 -0700581 } while (buflen && c == ',');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 return 0;
583}
Mike Travis4b060422011-05-24 17:13:12 -0700584
585int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
586{
Rasmus Villemoesbc5be182014-08-06 16:10:12 -0700587 char *nl = strchrnul(bp, '\n');
588 int len = nl - bp;
Mike Travis4b060422011-05-24 17:13:12 -0700589
590 return __bitmap_parselist(bp, len, 0, maskp, nmaskbits);
591}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592EXPORT_SYMBOL(bitmap_parselist);
593
Mike Travis4b060422011-05-24 17:13:12 -0700594
595/**
596 * bitmap_parselist_user()
597 *
598 * @ubuf: pointer to user buffer containing string.
599 * @ulen: buffer size in bytes. If string is smaller than this
600 * then it must be terminated with a \0.
601 * @maskp: pointer to bitmap array that will contain result.
602 * @nmaskbits: size of bitmap, in bits.
603 *
604 * Wrapper for bitmap_parselist(), providing it with user buffer.
605 *
606 * We cannot have this as an inline function in bitmap.h because it needs
607 * linux/uaccess.h to get the access_ok() declaration and this causes
608 * cyclic dependencies.
609 */
610int bitmap_parselist_user(const char __user *ubuf,
611 unsigned int ulen, unsigned long *maskp,
612 int nmaskbits)
613{
614 if (!access_ok(VERIFY_READ, ubuf, ulen))
615 return -EFAULT;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700616 return __bitmap_parselist((const char __force *)ubuf,
Mike Travis4b060422011-05-24 17:13:12 -0700617 ulen, 1, maskp, nmaskbits);
618}
619EXPORT_SYMBOL(bitmap_parselist_user);
620
621
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800622/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800623 * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800624 * @buf: pointer to a bitmap
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800625 * @pos: a bit position in @buf (0 <= @pos < @nbits)
626 * @nbits: number of valid bit positions in @buf
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800627 *
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800628 * Map the bit at position @pos in @buf (of length @nbits) to the
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800629 * ordinal of which set bit it is. If it is not set or if @pos
Paul Jackson96b7f342006-01-08 01:01:46 -0800630 * is not a valid bit position, map to -1.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800631 *
632 * If for example, just bits 4 through 7 are set in @buf, then @pos
633 * values 4 through 7 will get mapped to 0 through 3, respectively,
Rasmus Villemoesa8551742014-08-06 16:10:14 -0700634 * and other @pos values will get mapped to -1. When @pos value 7
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800635 * gets mapped to (returns) @ord value 3 in this example, that means
636 * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
637 *
638 * The bit positions 0 through @bits are valid positions in @buf.
639 */
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800640static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800641{
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800642 if (pos >= nbits || !test_bit(pos, buf))
Paul Jackson96b7f342006-01-08 01:01:46 -0800643 return -1;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800644
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800645 return __bitmap_weight(buf, pos);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800646}
647
648/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800649 * bitmap_ord_to_pos - find position of n-th set bit in bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800650 * @buf: pointer to bitmap
651 * @ord: ordinal bit position (n-th set bit, n >= 0)
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800652 * @nbits: number of valid bit positions in @buf
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800653 *
654 * Map the ordinal offset of bit @ord in @buf to its position in @buf.
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800655 * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
656 * >= weight(buf), returns @nbits.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800657 *
658 * If for example, just bits 4 through 7 are set in @buf, then @ord
659 * values 0 through 3 will get mapped to 4 through 7, respectively,
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800660 * and all other @ord values returns @nbits. When @ord value 3
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800661 * gets mapped to (returns) @pos value 7 in this example, that means
662 * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
663 *
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800664 * The bit positions 0 through @nbits-1 are valid positions in @buf.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800665 */
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800666unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800667{
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800668 unsigned int pos;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800669
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800670 for (pos = find_first_bit(buf, nbits);
671 pos < nbits && ord;
672 pos = find_next_bit(buf, nbits, pos + 1))
673 ord--;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800674
675 return pos;
676}
677
678/**
679 * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800680 * @dst: remapped result
Paul Jackson96b7f342006-01-08 01:01:46 -0800681 * @src: subset to be remapped
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800682 * @old: defines domain of map
683 * @new: defines range of map
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800684 * @nbits: number of bits in each of these bitmaps
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800685 *
686 * Let @old and @new define a mapping of bit positions, such that
687 * whatever position is held by the n-th set bit in @old is mapped
688 * to the n-th set bit in @new. In the more general case, allowing
689 * for the possibility that the weight 'w' of @new is less than the
690 * weight of @old, map the position of the n-th set bit in @old to
691 * the position of the m-th set bit in @new, where m == n % w.
692 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800693 * If either of the @old and @new bitmaps are empty, or if @src and
694 * @dst point to the same location, then this routine copies @src
695 * to @dst.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800696 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800697 * The positions of unset bits in @old are mapped to themselves
698 * (the identify map).
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800699 *
700 * Apply the above specified mapping to @src, placing the result in
701 * @dst, clearing any bits previously set in @dst.
702 *
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800703 * For example, lets say that @old has bits 4 through 7 set, and
704 * @new has bits 12 through 15 set. This defines the mapping of bit
705 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
Paul Jackson96b7f342006-01-08 01:01:46 -0800706 * bit positions unchanged. So if say @src comes into this routine
707 * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
708 * 13 and 15 set.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800709 */
710void bitmap_remap(unsigned long *dst, const unsigned long *src,
711 const unsigned long *old, const unsigned long *new,
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800712 unsigned int nbits)
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800713{
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800714 unsigned int oldbit, w;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800715
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800716 if (dst == src) /* following doesn't handle inplace remaps */
717 return;
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800718 bitmap_zero(dst, nbits);
Paul Jackson96b7f342006-01-08 01:01:46 -0800719
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800720 w = bitmap_weight(new, nbits);
721 for_each_set_bit(oldbit, src, nbits) {
722 int n = bitmap_pos_to_ord(old, oldbit, nbits);
Akinobu Mita08564fb2010-03-05 13:43:18 -0800723
Paul Jackson96b7f342006-01-08 01:01:46 -0800724 if (n < 0 || w == 0)
725 set_bit(oldbit, dst); /* identity map */
726 else
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800727 set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800728 }
729}
730EXPORT_SYMBOL(bitmap_remap);
731
732/**
733 * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700734 * @oldbit: bit position to be mapped
735 * @old: defines domain of map
736 * @new: defines range of map
737 * @bits: number of bits in each of these bitmaps
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800738 *
739 * Let @old and @new define a mapping of bit positions, such that
740 * whatever position is held by the n-th set bit in @old is mapped
741 * to the n-th set bit in @new. In the more general case, allowing
742 * for the possibility that the weight 'w' of @new is less than the
743 * weight of @old, map the position of the n-th set bit in @old to
744 * the position of the m-th set bit in @new, where m == n % w.
745 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800746 * The positions of unset bits in @old are mapped to themselves
747 * (the identify map).
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800748 *
749 * Apply the above specified mapping to bit position @oldbit, returning
750 * the new bit position.
751 *
752 * For example, lets say that @old has bits 4 through 7 set, and
753 * @new has bits 12 through 15 set. This defines the mapping of bit
754 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other
Paul Jackson96b7f342006-01-08 01:01:46 -0800755 * bit positions unchanged. So if say @oldbit is 5, then this routine
756 * returns 13.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800757 */
758int bitmap_bitremap(int oldbit, const unsigned long *old,
759 const unsigned long *new, int bits)
760{
Paul Jackson96b7f342006-01-08 01:01:46 -0800761 int w = bitmap_weight(new, bits);
762 int n = bitmap_pos_to_ord(old, oldbit, bits);
763 if (n < 0 || w == 0)
764 return oldbit;
765 else
766 return bitmap_ord_to_pos(new, n % w, bits);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800767}
768EXPORT_SYMBOL(bitmap_bitremap);
769
Paul Jackson7ea931c2008-04-28 02:12:29 -0700770/**
771 * bitmap_onto - translate one bitmap relative to another
772 * @dst: resulting translated bitmap
773 * @orig: original untranslated bitmap
774 * @relmap: bitmap relative to which translated
775 * @bits: number of bits in each of these bitmaps
776 *
777 * Set the n-th bit of @dst iff there exists some m such that the
778 * n-th bit of @relmap is set, the m-th bit of @orig is set, and
779 * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
780 * (If you understood the previous sentence the first time your
781 * read it, you're overqualified for your current job.)
782 *
783 * In other words, @orig is mapped onto (surjectively) @dst,
Masanari Iidada3dae52014-09-09 01:27:23 +0900784 * using the map { <n, m> | the n-th bit of @relmap is the
Paul Jackson7ea931c2008-04-28 02:12:29 -0700785 * m-th set bit of @relmap }.
786 *
787 * Any set bits in @orig above bit number W, where W is the
788 * weight of (number of set bits in) @relmap are mapped nowhere.
789 * In particular, if for all bits m set in @orig, m >= W, then
790 * @dst will end up empty. In situations where the possibility
791 * of such an empty result is not desired, one way to avoid it is
792 * to use the bitmap_fold() operator, below, to first fold the
793 * @orig bitmap over itself so that all its set bits x are in the
794 * range 0 <= x < W. The bitmap_fold() operator does this by
795 * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
796 *
797 * Example [1] for bitmap_onto():
798 * Let's say @relmap has bits 30-39 set, and @orig has bits
799 * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
800 * @dst will have bits 31, 33, 35, 37 and 39 set.
801 *
802 * When bit 0 is set in @orig, it means turn on the bit in
803 * @dst corresponding to whatever is the first bit (if any)
804 * that is turned on in @relmap. Since bit 0 was off in the
805 * above example, we leave off that bit (bit 30) in @dst.
806 *
807 * When bit 1 is set in @orig (as in the above example), it
808 * means turn on the bit in @dst corresponding to whatever
809 * is the second bit that is turned on in @relmap. The second
810 * bit in @relmap that was turned on in the above example was
811 * bit 31, so we turned on bit 31 in @dst.
812 *
813 * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
814 * because they were the 4th, 6th, 8th and 10th set bits
815 * set in @relmap, and the 4th, 6th, 8th and 10th bits of
816 * @orig (i.e. bits 3, 5, 7 and 9) were also set.
817 *
818 * When bit 11 is set in @orig, it means turn on the bit in
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300819 * @dst corresponding to whatever is the twelfth bit that is
Paul Jackson7ea931c2008-04-28 02:12:29 -0700820 * turned on in @relmap. In the above example, there were
821 * only ten bits turned on in @relmap (30..39), so that bit
822 * 11 was set in @orig had no affect on @dst.
823 *
824 * Example [2] for bitmap_fold() + bitmap_onto():
825 * Let's say @relmap has these ten bits set:
826 * 40 41 42 43 45 48 53 61 74 95
827 * (for the curious, that's 40 plus the first ten terms of the
828 * Fibonacci sequence.)
829 *
830 * Further lets say we use the following code, invoking
831 * bitmap_fold() then bitmap_onto, as suggested above to
Masanari Iidada3dae52014-09-09 01:27:23 +0900832 * avoid the possibility of an empty @dst result:
Paul Jackson7ea931c2008-04-28 02:12:29 -0700833 *
834 * unsigned long *tmp; // a temporary bitmap's bits
835 *
836 * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
837 * bitmap_onto(dst, tmp, relmap, bits);
838 *
839 * Then this table shows what various values of @dst would be, for
840 * various @orig's. I list the zero-based positions of each set bit.
841 * The tmp column shows the intermediate result, as computed by
842 * using bitmap_fold() to fold the @orig bitmap modulo ten
843 * (the weight of @relmap).
844 *
845 * @orig tmp @dst
846 * 0 0 40
847 * 1 1 41
848 * 9 9 95
849 * 10 0 40 (*)
850 * 1 3 5 7 1 3 5 7 41 43 48 61
851 * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
852 * 0 9 18 27 0 9 8 7 40 61 74 95
853 * 0 10 20 30 0 40
854 * 0 11 22 33 0 1 2 3 40 41 42 43
855 * 0 12 24 36 0 2 4 6 40 42 45 53
856 * 78 102 211 1 2 8 41 42 74 (*)
857 *
858 * (*) For these marked lines, if we hadn't first done bitmap_fold()
859 * into tmp, then the @dst result would have been empty.
860 *
861 * If either of @orig or @relmap is empty (no set bits), then @dst
862 * will be returned empty.
863 *
864 * If (as explained above) the only set bits in @orig are in positions
865 * m where m >= W, (where W is the weight of @relmap) then @dst will
866 * once again be returned empty.
867 *
868 * All bits in @dst not set by the above rule are cleared.
869 */
870void bitmap_onto(unsigned long *dst, const unsigned long *orig,
Rasmus Villemoeseb569882015-02-12 15:02:01 -0800871 const unsigned long *relmap, unsigned int bits)
Paul Jackson7ea931c2008-04-28 02:12:29 -0700872{
Rasmus Villemoeseb569882015-02-12 15:02:01 -0800873 unsigned int n, m; /* same meaning as in above comment */
Paul Jackson7ea931c2008-04-28 02:12:29 -0700874
875 if (dst == orig) /* following doesn't handle inplace mappings */
876 return;
877 bitmap_zero(dst, bits);
878
879 /*
880 * The following code is a more efficient, but less
881 * obvious, equivalent to the loop:
882 * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
883 * n = bitmap_ord_to_pos(orig, m, bits);
884 * if (test_bit(m, orig))
885 * set_bit(n, dst);
886 * }
887 */
888
889 m = 0;
Akinobu Mita08564fb2010-03-05 13:43:18 -0800890 for_each_set_bit(n, relmap, bits) {
Paul Jackson7ea931c2008-04-28 02:12:29 -0700891 /* m == bitmap_pos_to_ord(relmap, n, bits) */
892 if (test_bit(m, orig))
893 set_bit(n, dst);
894 m++;
895 }
896}
897EXPORT_SYMBOL(bitmap_onto);
898
899/**
900 * bitmap_fold - fold larger bitmap into smaller, modulo specified size
901 * @dst: resulting smaller bitmap
902 * @orig: original larger bitmap
903 * @sz: specified size
Rasmus Villemoesb26ad582015-02-12 15:02:04 -0800904 * @nbits: number of bits in each of these bitmaps
Paul Jackson7ea931c2008-04-28 02:12:29 -0700905 *
906 * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
907 * Clear all other bits in @dst. See further the comment and
908 * Example [2] for bitmap_onto() for why and how to use this.
909 */
910void bitmap_fold(unsigned long *dst, const unsigned long *orig,
Rasmus Villemoesb26ad582015-02-12 15:02:04 -0800911 unsigned int sz, unsigned int nbits)
Paul Jackson7ea931c2008-04-28 02:12:29 -0700912{
Rasmus Villemoesb26ad582015-02-12 15:02:04 -0800913 unsigned int oldbit;
Paul Jackson7ea931c2008-04-28 02:12:29 -0700914
915 if (dst == orig) /* following doesn't handle inplace mappings */
916 return;
Rasmus Villemoesb26ad582015-02-12 15:02:04 -0800917 bitmap_zero(dst, nbits);
Paul Jackson7ea931c2008-04-28 02:12:29 -0700918
Rasmus Villemoesb26ad582015-02-12 15:02:04 -0800919 for_each_set_bit(oldbit, orig, nbits)
Paul Jackson7ea931c2008-04-28 02:12:29 -0700920 set_bit(oldbit % sz, dst);
921}
922EXPORT_SYMBOL(bitmap_fold);
923
Paul Jackson3cf64b92006-03-24 03:15:46 -0800924/*
925 * Common code for bitmap_*_region() routines.
926 * bitmap: array of unsigned longs corresponding to the bitmap
927 * pos: the beginning of the region
928 * order: region size (log base 2 of number of bits)
929 * reg_op: operation(s) to perform on that region of bitmap
930 *
931 * Can set, verify and/or release a region of bits in a bitmap,
932 * depending on which combination of REG_OP_* flag bits is set.
933 *
934 * A region of a bitmap is a sequence of bits in the bitmap, of
935 * some size '1 << order' (a power of two), aligned to that same
936 * '1 << order' power of two.
937 *
938 * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
939 * Returns 0 in all other cases and reg_ops.
940 */
941
942enum {
943 REG_OP_ISFREE, /* true if region is all zero bits */
944 REG_OP_ALLOC, /* set all bits in region */
945 REG_OP_RELEASE, /* clear all bits in region */
946};
947
Rasmus Villemoes9279d322014-08-06 16:10:16 -0700948static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op)
Paul Jackson3cf64b92006-03-24 03:15:46 -0800949{
950 int nbits_reg; /* number of bits in region */
951 int index; /* index first long of region in bitmap */
952 int offset; /* bit offset region in bitmap[index] */
953 int nlongs_reg; /* num longs spanned by region in bitmap */
954 int nbitsinlong; /* num bits of region in each spanned long */
955 unsigned long mask; /* bitmask for one long of region */
956 int i; /* scans bitmap by longs */
957 int ret = 0; /* return value */
958
959 /*
960 * Either nlongs_reg == 1 (for small orders that fit in one long)
961 * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
962 */
963 nbits_reg = 1 << order;
964 index = pos / BITS_PER_LONG;
965 offset = pos - (index * BITS_PER_LONG);
966 nlongs_reg = BITS_TO_LONGS(nbits_reg);
967 nbitsinlong = min(nbits_reg, BITS_PER_LONG);
968
969 /*
970 * Can't do "mask = (1UL << nbitsinlong) - 1", as that
971 * overflows if nbitsinlong == BITS_PER_LONG.
972 */
973 mask = (1UL << (nbitsinlong - 1));
974 mask += mask - 1;
975 mask <<= offset;
976
977 switch (reg_op) {
978 case REG_OP_ISFREE:
979 for (i = 0; i < nlongs_reg; i++) {
980 if (bitmap[index + i] & mask)
981 goto done;
982 }
983 ret = 1; /* all bits in region free (zero) */
984 break;
985
986 case REG_OP_ALLOC:
987 for (i = 0; i < nlongs_reg; i++)
988 bitmap[index + i] |= mask;
989 break;
990
991 case REG_OP_RELEASE:
992 for (i = 0; i < nlongs_reg; i++)
993 bitmap[index + i] &= ~mask;
994 break;
995 }
996done:
997 return ret;
998}
999
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000/**
Paul Jackson87e24802006-03-24 03:15:44 -08001001 * bitmap_find_free_region - find a contiguous aligned mem region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001002 * @bitmap: array of unsigned longs corresponding to the bitmap
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 * @bits: number of bits in the bitmap
Paul Jackson3cf64b92006-03-24 03:15:46 -08001004 * @order: region size (log base 2 of number of bits) to find
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 *
Paul Jackson3cf64b92006-03-24 03:15:46 -08001006 * Find a region of free (zero) bits in a @bitmap of @bits bits and
1007 * allocate them (set them to one). Only consider regions of length
1008 * a power (@order) of two, aligned to that power of two, which
Paul Jackson87e24802006-03-24 03:15:44 -08001009 * makes the search algorithm much faster.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010 *
Paul Jackson3cf64b92006-03-24 03:15:46 -08001011 * Return the bit offset in bitmap of the allocated region,
Paul Jackson87e24802006-03-24 03:15:44 -08001012 * or -errno on failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001014int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015{
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001016 unsigned int pos, end; /* scans bitmap by regions of size order */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001018 for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) {
Linus Torvaldsaa8e4fc2009-03-12 19:32:51 -07001019 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1020 continue;
1021 __reg_op(bitmap, pos, order, REG_OP_ALLOC);
1022 return pos;
1023 }
1024 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025}
1026EXPORT_SYMBOL(bitmap_find_free_region);
1027
1028/**
Paul Jackson87e24802006-03-24 03:15:44 -08001029 * bitmap_release_region - release allocated bitmap region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001030 * @bitmap: array of unsigned longs corresponding to the bitmap
1031 * @pos: beginning of bit region to release
1032 * @order: region size (log base 2 of number of bits) to release
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08001034 * This is the complement to __bitmap_find_free_region() and releases
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 * the found region (by clearing it in the bitmap).
Paul Jackson3cf64b92006-03-24 03:15:46 -08001036 *
1037 * No return value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001039void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040{
Paul Jackson3cf64b92006-03-24 03:15:46 -08001041 __reg_op(bitmap, pos, order, REG_OP_RELEASE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001042}
1043EXPORT_SYMBOL(bitmap_release_region);
1044
Paul Jackson87e24802006-03-24 03:15:44 -08001045/**
1046 * bitmap_allocate_region - allocate bitmap region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001047 * @bitmap: array of unsigned longs corresponding to the bitmap
1048 * @pos: beginning of bit region to allocate
1049 * @order: region size (log base 2 of number of bits) to allocate
Paul Jackson87e24802006-03-24 03:15:44 -08001050 *
1051 * Allocate (set bits in) a specified region of a bitmap.
Paul Jackson3cf64b92006-03-24 03:15:46 -08001052 *
Randy Dunlap6e1907ff2006-06-25 05:48:57 -07001053 * Return 0 on success, or %-EBUSY if specified region wasn't
Paul Jackson87e24802006-03-24 03:15:44 -08001054 * free (not all bits were zero).
1055 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001056int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001057{
Paul Jackson3cf64b92006-03-24 03:15:46 -08001058 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1059 return -EBUSY;
Rasmus Villemoes2ac521d2014-08-06 16:10:18 -07001060 return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061}
1062EXPORT_SYMBOL(bitmap_allocate_region);
David Vrabelccbe3292008-09-17 16:34:03 +01001063
1064/**
David Decotignye52bc7c2016-02-19 09:23:59 -05001065 * bitmap_from_u32array - copy the contents of a u32 array of bits to bitmap
1066 * @bitmap: array of unsigned longs, the destination bitmap, non NULL
1067 * @nbits: number of bits in @bitmap
1068 * @buf: array of u32 (in host byte order), the source bitmap, non NULL
1069 * @nwords: number of u32 words in @buf
1070 *
1071 * copy min(nbits, 32*nwords) bits from @buf to @bitmap, remaining
1072 * bits between nword and nbits in @bitmap (if any) are cleared. In
1073 * last word of @bitmap, the bits beyond nbits (if any) are kept
1074 * unchanged.
1075 *
1076 * Return the number of bits effectively copied.
1077 */
1078unsigned int
1079bitmap_from_u32array(unsigned long *bitmap, unsigned int nbits,
1080 const u32 *buf, unsigned int nwords)
1081{
1082 unsigned int dst_idx, src_idx;
1083
1084 for (src_idx = dst_idx = 0; dst_idx < BITS_TO_LONGS(nbits); ++dst_idx) {
1085 unsigned long part = 0;
1086
1087 if (src_idx < nwords)
1088 part = buf[src_idx++];
1089
1090#if BITS_PER_LONG == 64
1091 if (src_idx < nwords)
1092 part |= ((unsigned long) buf[src_idx++]) << 32;
1093#endif
1094
1095 if (dst_idx < nbits/BITS_PER_LONG)
1096 bitmap[dst_idx] = part;
1097 else {
1098 unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
1099
1100 bitmap[dst_idx] = (bitmap[dst_idx] & ~mask)
1101 | (part & mask);
1102 }
1103 }
1104
1105 return min_t(unsigned int, nbits, 32*nwords);
1106}
1107EXPORT_SYMBOL(bitmap_from_u32array);
1108
1109/**
1110 * bitmap_to_u32array - copy the contents of bitmap to a u32 array of bits
1111 * @buf: array of u32 (in host byte order), the dest bitmap, non NULL
1112 * @nwords: number of u32 words in @buf
1113 * @bitmap: array of unsigned longs, the source bitmap, non NULL
1114 * @nbits: number of bits in @bitmap
1115 *
1116 * copy min(nbits, 32*nwords) bits from @bitmap to @buf. Remaining
1117 * bits after nbits in @buf (if any) are cleared.
1118 *
1119 * Return the number of bits effectively copied.
1120 */
1121unsigned int
1122bitmap_to_u32array(u32 *buf, unsigned int nwords,
1123 const unsigned long *bitmap, unsigned int nbits)
1124{
1125 unsigned int dst_idx = 0, src_idx = 0;
1126
1127 while (dst_idx < nwords) {
1128 unsigned long part = 0;
1129
1130 if (src_idx < BITS_TO_LONGS(nbits)) {
1131 part = bitmap[src_idx];
1132 if (src_idx >= nbits/BITS_PER_LONG)
1133 part &= BITMAP_LAST_WORD_MASK(nbits);
1134 src_idx++;
1135 }
1136
1137 buf[dst_idx++] = part & 0xffffffffUL;
1138
1139#if BITS_PER_LONG == 64
1140 if (dst_idx < nwords) {
1141 part >>= 32;
1142 buf[dst_idx++] = part & 0xffffffffUL;
1143 }
1144#endif
1145 }
1146
1147 return min_t(unsigned int, nbits, 32*nwords);
1148}
1149EXPORT_SYMBOL(bitmap_to_u32array);
1150
1151/**
David Vrabelccbe3292008-09-17 16:34:03 +01001152 * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
1153 * @dst: destination buffer
1154 * @src: bitmap to copy
1155 * @nbits: number of bits in the bitmap
1156 *
1157 * Require nbits % BITS_PER_LONG == 0.
1158 */
Rasmus Villemoese8f24272015-02-13 14:36:00 -08001159#ifdef __BIG_ENDIAN
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001160void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits)
David Vrabelccbe3292008-09-17 16:34:03 +01001161{
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001162 unsigned int i;
David Vrabelccbe3292008-09-17 16:34:03 +01001163
1164 for (i = 0; i < nbits/BITS_PER_LONG; i++) {
1165 if (BITS_PER_LONG == 64)
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001166 dst[i] = cpu_to_le64(src[i]);
David Vrabelccbe3292008-09-17 16:34:03 +01001167 else
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001168 dst[i] = cpu_to_le32(src[i]);
David Vrabelccbe3292008-09-17 16:34:03 +01001169 }
1170}
1171EXPORT_SYMBOL(bitmap_copy_le);
Rasmus Villemoese8f24272015-02-13 14:36:00 -08001172#endif