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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>
Sudeep Holla5aaba362014-09-30 14:48:22 +010015
16#include <asm/page.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <asm/uaccess.h>
18
19/*
20 * bitmaps provide an array of bits, implemented using an an
21 * array of unsigned longs. The number of valid bits in a
22 * given bitmap does _not_ need to be an exact multiple of
23 * BITS_PER_LONG.
24 *
25 * The possible unused bits in the last, partially used word
26 * of a bitmap are 'don't care'. The implementation makes
27 * no particular effort to keep them zero. It ensures that
28 * their value will not affect the results of any operation.
29 * The bitmap operations that return Boolean (bitmap_empty,
30 * for example) or scalar (bitmap_weight, for example) results
31 * carefully filter out these unused bits from impacting their
32 * results.
33 *
34 * These operations actually hold to a slightly stronger rule:
35 * if you don't input any bitmaps to these ops that have some
36 * unused bits set, then they won't output any set unused bits
37 * in output bitmaps.
38 *
39 * The byte ordering of bitmaps is more natural on little
40 * endian architectures. See the big-endian headers
41 * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
42 * for the best explanations of this ordering.
43 */
44
Rasmus Villemoes0679cc42014-08-06 16:09:49 -070045int __bitmap_empty(const unsigned long *bitmap, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -070046{
Rasmus Villemoes0679cc42014-08-06 16:09:49 -070047 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 for (k = 0; k < lim; ++k)
49 if (bitmap[k])
50 return 0;
51
52 if (bits % BITS_PER_LONG)
53 if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
54 return 0;
55
56 return 1;
57}
58EXPORT_SYMBOL(__bitmap_empty);
59
Rasmus Villemoes83979272014-08-06 16:09:51 -070060int __bitmap_full(const unsigned long *bitmap, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -070061{
Rasmus Villemoes83979272014-08-06 16:09:51 -070062 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 for (k = 0; k < lim; ++k)
64 if (~bitmap[k])
65 return 0;
66
67 if (bits % BITS_PER_LONG)
68 if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
69 return 0;
70
71 return 1;
72}
73EXPORT_SYMBOL(__bitmap_full);
74
75int __bitmap_equal(const unsigned long *bitmap1,
Rasmus Villemoes5e0680692014-08-06 16:09:53 -070076 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -070077{
Rasmus Villemoes5e0680692014-08-06 16:09:53 -070078 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 for (k = 0; k < lim; ++k)
80 if (bitmap1[k] != bitmap2[k])
81 return 0;
82
83 if (bits % BITS_PER_LONG)
84 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
85 return 0;
86
87 return 1;
88}
89EXPORT_SYMBOL(__bitmap_equal);
90
Rasmus Villemoes3d6684f2014-08-06 16:09:55 -070091void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -070092{
Rasmus Villemoes3d6684f2014-08-06 16:09:55 -070093 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 for (k = 0; k < lim; ++k)
95 dst[k] = ~src[k];
96
97 if (bits % BITS_PER_LONG)
Rasmus Villemoes65b4ee62014-08-06 16:09:57 -070098 dst[k] = ~src[k];
Linus Torvalds1da177e2005-04-16 15:20:36 -070099}
100EXPORT_SYMBOL(__bitmap_complement);
101
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800102/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 * __bitmap_shift_right - logical right shift of the bits in a bitmap
Randy Dunlap05fb6bf2007-02-28 20:12:13 -0800104 * @dst : destination bitmap
105 * @src : source bitmap
106 * @shift : shift by this many bits
Rasmus Villemoes2fbad292015-02-13 14:36:02 -0800107 * @nbits : bitmap size, in bits
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 *
109 * Shifting right (dividing) means moving bits in the MS -> LS bit
110 * direction. Zeros are fed into the vacated MS positions and the
111 * LS bits shifted off the bottom are lost.
112 */
Rasmus Villemoes2fbad292015-02-13 14:36:02 -0800113void __bitmap_shift_right(unsigned long *dst, const unsigned long *src,
114 unsigned shift, unsigned nbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115{
Rasmus Villemoescfac1d02015-02-13 14:36:10 -0800116 unsigned k, lim = BITS_TO_LONGS(nbits);
Rasmus Villemoes2fbad292015-02-13 14:36:02 -0800117 unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
Rasmus Villemoescfac1d02015-02-13 14:36:10 -0800118 unsigned long mask = BITMAP_LAST_WORD_MASK(nbits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119 for (k = 0; off + k < lim; ++k) {
120 unsigned long upper, lower;
121
122 /*
123 * If shift is not word aligned, take lower rem bits of
124 * word above and make them the top rem bits of result.
125 */
126 if (!rem || off + k + 1 >= lim)
127 upper = 0;
128 else {
129 upper = src[off + k + 1];
Rasmus Villemoescfac1d02015-02-13 14:36:10 -0800130 if (off + k + 1 == lim - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 upper &= mask;
Rasmus Villemoes9d8a6b22015-02-13 14:36:05 -0800132 upper <<= (BITS_PER_LONG - rem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 }
134 lower = src[off + k];
Rasmus Villemoescfac1d02015-02-13 14:36:10 -0800135 if (off + k == lim - 1)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 lower &= mask;
Rasmus Villemoes9d8a6b22015-02-13 14:36:05 -0800137 lower >>= rem;
138 dst[k] = lower | upper;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 }
140 if (off)
141 memset(&dst[lim - off], 0, off*sizeof(unsigned long));
142}
143EXPORT_SYMBOL(__bitmap_shift_right);
144
145
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800146/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 * __bitmap_shift_left - logical left shift of the bits in a bitmap
Randy Dunlap05fb6bf2007-02-28 20:12:13 -0800148 * @dst : destination bitmap
149 * @src : source bitmap
150 * @shift : shift by this many bits
Rasmus Villemoesdba94c22015-02-13 14:36:13 -0800151 * @nbits : bitmap size, in bits
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 *
153 * Shifting left (multiplying) means moving bits in the LS -> MS
154 * direction. Zeros are fed into the vacated LS bit positions
155 * and those MS bits shifted off the top are lost.
156 */
157
Rasmus Villemoesdba94c22015-02-13 14:36:13 -0800158void __bitmap_shift_left(unsigned long *dst, const unsigned long *src,
159 unsigned int shift, unsigned int nbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160{
Rasmus Villemoesdba94c22015-02-13 14:36:13 -0800161 int k;
162 unsigned int lim = BITS_TO_LONGS(nbits), left = nbits % BITS_PER_LONG;
163 unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 for (k = lim - off - 1; k >= 0; --k) {
165 unsigned long upper, lower;
166
167 /*
168 * If shift is not word aligned, take upper rem bits of
169 * word below and make them the bottom rem bits of result.
170 */
171 if (rem && k > 0)
Rasmus Villemoes6d874ec2015-02-13 14:36:16 -0800172 lower = src[k - 1] >> (BITS_PER_LONG - rem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 else
174 lower = 0;
175 upper = src[k];
176 if (left && k == lim - 1)
177 upper &= (1UL << left) - 1;
Rasmus Villemoes6d874ec2015-02-13 14:36:16 -0800178 upper <<= rem;
179 dst[k + off] = lower | upper;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 if (left && k + off == lim - 1)
181 dst[k + off] &= (1UL << left) - 1;
182 }
183 if (off)
184 memset(dst, 0, off*sizeof(unsigned long));
185}
186EXPORT_SYMBOL(__bitmap_shift_left);
187
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700188int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700189 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700191 unsigned int k;
Rasmus Villemoes7e5f97d2014-08-06 16:10:22 -0700192 unsigned int lim = bits/BITS_PER_LONG;
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700193 unsigned long result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
Rasmus Villemoes7e5f97d2014-08-06 16:10:22 -0700195 for (k = 0; k < lim; k++)
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700196 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
Rasmus Villemoes7e5f97d2014-08-06 16:10:22 -0700197 if (bits % BITS_PER_LONG)
198 result |= (dst[k] = bitmap1[k] & bitmap2[k] &
199 BITMAP_LAST_WORD_MASK(bits));
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700200 return result != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201}
202EXPORT_SYMBOL(__bitmap_and);
203
204void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700205 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700207 unsigned int k;
208 unsigned int nr = BITS_TO_LONGS(bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
210 for (k = 0; k < nr; k++)
211 dst[k] = bitmap1[k] | bitmap2[k];
212}
213EXPORT_SYMBOL(__bitmap_or);
214
215void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700216 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700218 unsigned int k;
219 unsigned int nr = BITS_TO_LONGS(bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220
221 for (k = 0; k < nr; k++)
222 dst[k] = bitmap1[k] ^ bitmap2[k];
223}
224EXPORT_SYMBOL(__bitmap_xor);
225
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700226int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700227 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700229 unsigned int k;
Rasmus Villemoes74e76532014-08-06 16:10:24 -0700230 unsigned int lim = bits/BITS_PER_LONG;
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700231 unsigned long result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
Rasmus Villemoes74e76532014-08-06 16:10:24 -0700233 for (k = 0; k < lim; k++)
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700234 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
Rasmus Villemoes74e76532014-08-06 16:10:24 -0700235 if (bits % BITS_PER_LONG)
236 result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
237 BITMAP_LAST_WORD_MASK(bits));
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700238 return result != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239}
240EXPORT_SYMBOL(__bitmap_andnot);
241
242int __bitmap_intersects(const unsigned long *bitmap1,
Rasmus Villemoes6dfe9792014-08-06 16:10:01 -0700243 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244{
Rasmus Villemoes6dfe9792014-08-06 16:10:01 -0700245 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 for (k = 0; k < lim; ++k)
247 if (bitmap1[k] & bitmap2[k])
248 return 1;
249
250 if (bits % BITS_PER_LONG)
251 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
252 return 1;
253 return 0;
254}
255EXPORT_SYMBOL(__bitmap_intersects);
256
257int __bitmap_subset(const unsigned long *bitmap1,
Rasmus Villemoes5be20212014-08-06 16:10:03 -0700258 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259{
Rasmus Villemoes5be20212014-08-06 16:10:03 -0700260 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 for (k = 0; k < lim; ++k)
262 if (bitmap1[k] & ~bitmap2[k])
263 return 0;
264
265 if (bits % BITS_PER_LONG)
266 if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
267 return 0;
268 return 1;
269}
270EXPORT_SYMBOL(__bitmap_subset);
271
Rasmus Villemoes877d9f32014-08-06 16:10:05 -0700272int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273{
Rasmus Villemoes877d9f32014-08-06 16:10:05 -0700274 unsigned int k, lim = bits/BITS_PER_LONG;
275 int w = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276
277 for (k = 0; k < lim; k++)
Akinobu Mita37d54112006-03-26 01:39:56 -0800278 w += hweight_long(bitmap[k]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
280 if (bits % BITS_PER_LONG)
Akinobu Mita37d54112006-03-26 01:39:56 -0800281 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282
283 return w;
284}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285EXPORT_SYMBOL(__bitmap_weight);
286
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700287void bitmap_set(unsigned long *map, unsigned int start, int len)
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800288{
289 unsigned long *p = map + BIT_WORD(start);
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700290 const unsigned int size = start + len;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800291 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
292 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
293
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700294 while (len - bits_to_set >= 0) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800295 *p |= mask_to_set;
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700296 len -= bits_to_set;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800297 bits_to_set = BITS_PER_LONG;
298 mask_to_set = ~0UL;
299 p++;
300 }
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700301 if (len) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800302 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
303 *p |= mask_to_set;
304 }
305}
306EXPORT_SYMBOL(bitmap_set);
307
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700308void bitmap_clear(unsigned long *map, unsigned int start, int len)
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800309{
310 unsigned long *p = map + BIT_WORD(start);
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700311 const unsigned int size = start + len;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800312 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
313 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
314
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700315 while (len - bits_to_clear >= 0) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800316 *p &= ~mask_to_clear;
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700317 len -= bits_to_clear;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800318 bits_to_clear = BITS_PER_LONG;
319 mask_to_clear = ~0UL;
320 p++;
321 }
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700322 if (len) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800323 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
324 *p &= ~mask_to_clear;
325 }
326}
327EXPORT_SYMBOL(bitmap_clear);
328
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800329/**
330 * bitmap_find_next_zero_area_off - find a contiguous aligned zero area
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800331 * @map: The address to base the search on
332 * @size: The bitmap size in bits
333 * @start: The bitnumber to start searching at
334 * @nr: The number of zeroed bits we're looking for
335 * @align_mask: Alignment mask for zero area
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800336 * @align_offset: Alignment offset for zero area.
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800337 *
338 * The @align_mask should be one less than a power of 2; the effect is that
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800339 * the bit offset of all zero areas this function finds plus @align_offset
340 * is multiple of that power of 2.
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800341 */
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800342unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
343 unsigned long size,
344 unsigned long start,
345 unsigned int nr,
346 unsigned long align_mask,
347 unsigned long align_offset)
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800348{
349 unsigned long index, end, i;
350again:
351 index = find_next_zero_bit(map, size, start);
352
353 /* Align allocation */
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800354 index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800355
356 end = index + nr;
357 if (end > size)
358 return end;
359 i = find_next_bit(map, end, index);
360 if (i < end) {
361 start = i + 1;
362 goto again;
363 }
364 return index;
365}
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800366EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800367
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368/*
Nadia Yvette Chambers6d49e352012-12-06 10:39:54 +0100369 * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370 * second version by Paul Jackson, third by Joe Korty.
371 */
372
373#define CHUNKSZ 32
374#define nbits_to_hold_value(val) fls(val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375#define BASEDEC 10 /* fancier cpuset lists input in decimal */
376
377/**
378 * bitmap_scnprintf - convert bitmap to an ASCII hex string.
379 * @buf: byte buffer into which string is placed
380 * @buflen: reserved size of @buf, in bytes
381 * @maskp: pointer to bitmap to convert
382 * @nmaskbits: size of bitmap, in bits
383 *
384 * Exactly @nmaskbits bits are displayed. Hex digits are grouped into
Andrew Morton05a6c8a2012-05-29 15:07:32 -0700385 * comma-separated sets of eight digits per set. Returns the number of
386 * characters which were written to *buf, excluding the trailing \0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 */
388int bitmap_scnprintf(char *buf, unsigned int buflen,
389 const unsigned long *maskp, int nmaskbits)
390{
391 int i, word, bit, len = 0;
392 unsigned long val;
393 const char *sep = "";
394 int chunksz;
395 u32 chunkmask;
396
397 chunksz = nmaskbits & (CHUNKSZ - 1);
398 if (chunksz == 0)
399 chunksz = CHUNKSZ;
400
Nick Wilson8c0e33c2005-06-25 14:59:00 -0700401 i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 for (; i >= 0; i -= CHUNKSZ) {
403 chunkmask = ((1ULL << chunksz) - 1);
404 word = i / BITS_PER_LONG;
405 bit = i % BITS_PER_LONG;
406 val = (maskp[word] >> bit) & chunkmask;
407 len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep,
408 (chunksz+3)/4, val);
409 chunksz = CHUNKSZ;
410 sep = ",";
411 }
412 return len;
413}
414EXPORT_SYMBOL(bitmap_scnprintf);
415
416/**
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700417 * __bitmap_parse - convert an ASCII hex string into a bitmap.
418 * @buf: pointer to buffer containing string.
419 * @buflen: buffer size in bytes. If string is smaller than this
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 * then it must be terminated with a \0.
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700421 * @is_user: location of buffer, 0 indicates kernel space
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 * @maskp: pointer to bitmap array that will contain result.
423 * @nmaskbits: size of bitmap, in bits.
424 *
425 * Commas group hex digits into chunks. Each chunk defines exactly 32
426 * bits of the resultant bitmask. No chunk may specify a value larger
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700427 * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
428 * then leading 0-bits are prepended. %-EINVAL is returned for illegal
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 * characters and for grouping errors such as "1,,5", ",44", "," and "".
430 * Leading and trailing whitespace accepted, but not embedded whitespace.
431 */
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700432int __bitmap_parse(const char *buf, unsigned int buflen,
433 int is_user, unsigned long *maskp,
434 int nmaskbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435{
436 int c, old_c, totaldigits, ndigits, nchunks, nbits;
437 u32 chunk;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700438 const char __user __force *ubuf = (const char __user __force *)buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439
440 bitmap_zero(maskp, nmaskbits);
441
442 nchunks = nbits = totaldigits = c = 0;
443 do {
444 chunk = ndigits = 0;
445
446 /* Get the next chunk of the bitmap */
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700447 while (buflen) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 old_c = c;
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700449 if (is_user) {
450 if (__get_user(c, ubuf++))
451 return -EFAULT;
452 }
453 else
454 c = *buf++;
455 buflen--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 if (isspace(c))
457 continue;
458
459 /*
460 * If the last character was a space and the current
461 * character isn't '\0', we've got embedded whitespace.
462 * This is a no-no, so throw an error.
463 */
464 if (totaldigits && c && isspace(old_c))
465 return -EINVAL;
466
467 /* A '\0' or a ',' signal the end of the chunk */
468 if (c == '\0' || c == ',')
469 break;
470
471 if (!isxdigit(c))
472 return -EINVAL;
473
474 /*
475 * Make sure there are at least 4 free bits in 'chunk'.
476 * If not, this hexdigit will overflow 'chunk', so
477 * throw an error.
478 */
479 if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1))
480 return -EOVERFLOW;
481
Andy Shevchenko66f19912010-10-26 14:23:03 -0700482 chunk = (chunk << 4) | hex_to_bin(c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 ndigits++; totaldigits++;
484 }
485 if (ndigits == 0)
486 return -EINVAL;
487 if (nchunks == 0 && chunk == 0)
488 continue;
489
490 __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits);
491 *maskp |= chunk;
492 nchunks++;
493 nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
494 if (nbits > nmaskbits)
495 return -EOVERFLOW;
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700496 } while (buflen && c == ',');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497
498 return 0;
499}
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700500EXPORT_SYMBOL(__bitmap_parse);
501
502/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800503 * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700504 *
505 * @ubuf: pointer to user buffer containing string.
506 * @ulen: buffer size in bytes. If string is smaller than this
507 * then it must be terminated with a \0.
508 * @maskp: pointer to bitmap array that will contain result.
509 * @nmaskbits: size of bitmap, in bits.
510 *
511 * Wrapper for __bitmap_parse(), providing it with user buffer.
512 *
513 * We cannot have this as an inline function in bitmap.h because it needs
514 * linux/uaccess.h to get the access_ok() declaration and this causes
515 * cyclic dependencies.
516 */
517int bitmap_parse_user(const char __user *ubuf,
518 unsigned int ulen, unsigned long *maskp,
519 int nmaskbits)
520{
521 if (!access_ok(VERIFY_READ, ubuf, ulen))
522 return -EFAULT;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700523 return __bitmap_parse((const char __force *)ubuf,
524 ulen, 1, maskp, nmaskbits);
525
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700526}
527EXPORT_SYMBOL(bitmap_parse_user);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528
529/*
530 * bscnl_emit(buf, buflen, rbot, rtop, bp)
531 *
532 * Helper routine for bitmap_scnlistprintf(). Write decimal number
533 * or range to buf, suppressing output past buf+buflen, with optional
Andrew Morton05a6c8a2012-05-29 15:07:32 -0700534 * comma-prefix. Return len of what was written to *buf, excluding the
535 * trailing \0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 */
537static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len)
538{
539 if (len > 0)
540 len += scnprintf(buf + len, buflen - len, ",");
541 if (rbot == rtop)
542 len += scnprintf(buf + len, buflen - len, "%d", rbot);
543 else
544 len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop);
545 return len;
546}
547
548/**
549 * bitmap_scnlistprintf - convert bitmap to list format ASCII string
550 * @buf: byte buffer into which string is placed
551 * @buflen: reserved size of @buf, in bytes
552 * @maskp: pointer to bitmap to convert
553 * @nmaskbits: size of bitmap, in bits
554 *
555 * Output format is a comma-separated list of decimal numbers and
556 * ranges. Consecutively set bits are shown as two hyphen-separated
557 * decimal numbers, the smallest and largest bit numbers set in
558 * the range. Output format is compatible with the format
559 * accepted as input by bitmap_parselist().
560 *
Andrew Morton05a6c8a2012-05-29 15:07:32 -0700561 * The return value is the number of characters which were written to *buf
562 * excluding the trailing '\0', as per ISO C99's scnprintf.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 */
564int bitmap_scnlistprintf(char *buf, unsigned int buflen,
565 const unsigned long *maskp, int nmaskbits)
566{
567 int len = 0;
568 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
569 int cur, rbot, rtop;
570
Andi Kleen0b030c22007-11-05 14:50:56 -0800571 if (buflen == 0)
572 return 0;
573 buf[0] = 0;
574
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 rbot = cur = find_first_bit(maskp, nmaskbits);
576 while (cur < nmaskbits) {
577 rtop = cur;
578 cur = find_next_bit(maskp, nmaskbits, cur+1);
579 if (cur >= nmaskbits || cur > rtop + 1) {
580 len = bscnl_emit(buf, buflen, rbot, rtop, len);
581 rbot = cur;
582 }
583 }
584 return len;
585}
586EXPORT_SYMBOL(bitmap_scnlistprintf);
587
588/**
Sudeep Holla5aaba362014-09-30 14:48:22 +0100589 * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string
590 * @list: indicates whether the bitmap must be list
591 * @buf: page aligned buffer into which string is placed
592 * @maskp: pointer to bitmap to convert
593 * @nmaskbits: size of bitmap, in bits
594 *
595 * Output format is a comma-separated list of decimal numbers and
596 * ranges if list is specified or hex digits grouped into comma-separated
597 * sets of 8 digits/set. Returns the number of characters written to buf.
598 */
599int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
600 int nmaskbits)
601{
602 ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf - 2;
603 int n = 0;
604
605 if (len > 1) {
606 n = list ? bitmap_scnlistprintf(buf, len, maskp, nmaskbits) :
607 bitmap_scnprintf(buf, len, maskp, nmaskbits);
608 buf[n++] = '\n';
609 buf[n] = '\0';
610 }
611 return n;
612}
613EXPORT_SYMBOL(bitmap_print_to_pagebuf);
614
615/**
Mike Travis4b060422011-05-24 17:13:12 -0700616 * __bitmap_parselist - convert list format ASCII string to bitmap
Randy Dunlapb0825ee2011-06-15 15:08:10 -0700617 * @buf: read nul-terminated user string from this buffer
Mike Travis4b060422011-05-24 17:13:12 -0700618 * @buflen: buffer size in bytes. If string is smaller than this
619 * then it must be terminated with a \0.
620 * @is_user: location of buffer, 0 indicates kernel space
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700621 * @maskp: write resulting mask here
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 * @nmaskbits: number of bits in mask to be written
623 *
624 * Input format is a comma-separated list of decimal numbers and
625 * ranges. Consecutively set bits are shown as two hyphen-separated
626 * decimal numbers, the smallest and largest bit numbers set in
627 * the range.
628 *
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700629 * Returns 0 on success, -errno on invalid input strings.
630 * Error values:
631 * %-EINVAL: second number in range smaller than first
632 * %-EINVAL: invalid character in string
633 * %-ERANGE: bit number specified too large for mask
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 */
Mike Travis4b060422011-05-24 17:13:12 -0700635static int __bitmap_parselist(const char *buf, unsigned int buflen,
636 int is_user, unsigned long *maskp,
637 int nmaskbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638{
639 unsigned a, b;
Mike Travis4b060422011-05-24 17:13:12 -0700640 int c, old_c, totaldigits;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700641 const char __user __force *ubuf = (const char __user __force *)buf;
Mike Travis4b060422011-05-24 17:13:12 -0700642 int exp_digit, in_range;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643
Mike Travis4b060422011-05-24 17:13:12 -0700644 totaldigits = c = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 bitmap_zero(maskp, nmaskbits);
646 do {
Mike Travis4b060422011-05-24 17:13:12 -0700647 exp_digit = 1;
648 in_range = 0;
649 a = b = 0;
650
651 /* Get the next cpu# or a range of cpu#'s */
652 while (buflen) {
653 old_c = c;
654 if (is_user) {
655 if (__get_user(c, ubuf++))
656 return -EFAULT;
657 } else
658 c = *buf++;
659 buflen--;
660 if (isspace(c))
661 continue;
662
663 /*
664 * If the last character was a space and the current
665 * character isn't '\0', we've got embedded whitespace.
666 * This is a no-no, so throw an error.
667 */
668 if (totaldigits && c && isspace(old_c))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 return -EINVAL;
Mike Travis4b060422011-05-24 17:13:12 -0700670
671 /* A '\0' or a ',' signal the end of a cpu# or range */
672 if (c == '\0' || c == ',')
673 break;
674
675 if (c == '-') {
676 if (exp_digit || in_range)
677 return -EINVAL;
678 b = 0;
679 in_range = 1;
680 exp_digit = 1;
681 continue;
682 }
683
684 if (!isdigit(c))
685 return -EINVAL;
686
687 b = b * 10 + (c - '0');
688 if (!in_range)
689 a = b;
690 exp_digit = 0;
691 totaldigits++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 }
693 if (!(a <= b))
694 return -EINVAL;
695 if (b >= nmaskbits)
696 return -ERANGE;
697 while (a <= b) {
698 set_bit(a, maskp);
699 a++;
700 }
Mike Travis4b060422011-05-24 17:13:12 -0700701 } while (buflen && c == ',');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 return 0;
703}
Mike Travis4b060422011-05-24 17:13:12 -0700704
705int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
706{
Rasmus Villemoesbc5be182014-08-06 16:10:12 -0700707 char *nl = strchrnul(bp, '\n');
708 int len = nl - bp;
Mike Travis4b060422011-05-24 17:13:12 -0700709
710 return __bitmap_parselist(bp, len, 0, maskp, nmaskbits);
711}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712EXPORT_SYMBOL(bitmap_parselist);
713
Mike Travis4b060422011-05-24 17:13:12 -0700714
715/**
716 * bitmap_parselist_user()
717 *
718 * @ubuf: pointer to user buffer containing string.
719 * @ulen: buffer size in bytes. If string is smaller than this
720 * then it must be terminated with a \0.
721 * @maskp: pointer to bitmap array that will contain result.
722 * @nmaskbits: size of bitmap, in bits.
723 *
724 * Wrapper for bitmap_parselist(), providing it with user buffer.
725 *
726 * We cannot have this as an inline function in bitmap.h because it needs
727 * linux/uaccess.h to get the access_ok() declaration and this causes
728 * cyclic dependencies.
729 */
730int bitmap_parselist_user(const char __user *ubuf,
731 unsigned int ulen, unsigned long *maskp,
732 int nmaskbits)
733{
734 if (!access_ok(VERIFY_READ, ubuf, ulen))
735 return -EFAULT;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700736 return __bitmap_parselist((const char __force *)ubuf,
Mike Travis4b060422011-05-24 17:13:12 -0700737 ulen, 1, maskp, nmaskbits);
738}
739EXPORT_SYMBOL(bitmap_parselist_user);
740
741
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800742/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800743 * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800744 * @buf: pointer to a bitmap
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800745 * @pos: a bit position in @buf (0 <= @pos < @nbits)
746 * @nbits: number of valid bit positions in @buf
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800747 *
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800748 * Map the bit at position @pos in @buf (of length @nbits) to the
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800749 * ordinal of which set bit it is. If it is not set or if @pos
Paul Jackson96b7f342006-01-08 01:01:46 -0800750 * is not a valid bit position, map to -1.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800751 *
752 * If for example, just bits 4 through 7 are set in @buf, then @pos
753 * values 4 through 7 will get mapped to 0 through 3, respectively,
Rasmus Villemoesa8551742014-08-06 16:10:14 -0700754 * and other @pos values will get mapped to -1. When @pos value 7
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800755 * gets mapped to (returns) @ord value 3 in this example, that means
756 * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
757 *
758 * The bit positions 0 through @bits are valid positions in @buf.
759 */
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800760static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800761{
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800762 if (pos >= nbits || !test_bit(pos, buf))
Paul Jackson96b7f342006-01-08 01:01:46 -0800763 return -1;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800764
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800765 return __bitmap_weight(buf, pos);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800766}
767
768/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800769 * bitmap_ord_to_pos - find position of n-th set bit in bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800770 * @buf: pointer to bitmap
771 * @ord: ordinal bit position (n-th set bit, n >= 0)
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800772 * @nbits: number of valid bit positions in @buf
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800773 *
774 * Map the ordinal offset of bit @ord in @buf to its position in @buf.
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800775 * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
776 * >= weight(buf), returns @nbits.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800777 *
778 * If for example, just bits 4 through 7 are set in @buf, then @ord
779 * values 0 through 3 will get mapped to 4 through 7, respectively,
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800780 * and all other @ord values returns @nbits. When @ord value 3
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800781 * gets mapped to (returns) @pos value 7 in this example, that means
782 * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
783 *
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800784 * The bit positions 0 through @nbits-1 are valid positions in @buf.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800785 */
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800786unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800787{
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800788 unsigned int pos;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800789
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800790 for (pos = find_first_bit(buf, nbits);
791 pos < nbits && ord;
792 pos = find_next_bit(buf, nbits, pos + 1))
793 ord--;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800794
795 return pos;
796}
797
798/**
799 * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800800 * @dst: remapped result
Paul Jackson96b7f342006-01-08 01:01:46 -0800801 * @src: subset to be remapped
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800802 * @old: defines domain of map
803 * @new: defines range of map
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800804 * @nbits: number of bits in each of these bitmaps
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800805 *
806 * Let @old and @new define a mapping of bit positions, such that
807 * whatever position is held by the n-th set bit in @old is mapped
808 * to the n-th set bit in @new. In the more general case, allowing
809 * for the possibility that the weight 'w' of @new is less than the
810 * weight of @old, map the position of the n-th set bit in @old to
811 * the position of the m-th set bit in @new, where m == n % w.
812 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800813 * If either of the @old and @new bitmaps are empty, or if @src and
814 * @dst point to the same location, then this routine copies @src
815 * to @dst.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800816 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800817 * The positions of unset bits in @old are mapped to themselves
818 * (the identify map).
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800819 *
820 * Apply the above specified mapping to @src, placing the result in
821 * @dst, clearing any bits previously set in @dst.
822 *
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800823 * For example, lets say that @old has bits 4 through 7 set, and
824 * @new has bits 12 through 15 set. This defines the mapping of bit
825 * 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 -0800826 * bit positions unchanged. So if say @src comes into this routine
827 * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
828 * 13 and 15 set.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800829 */
830void bitmap_remap(unsigned long *dst, const unsigned long *src,
831 const unsigned long *old, const unsigned long *new,
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800832 unsigned int nbits)
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800833{
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800834 unsigned int oldbit, w;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800835
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800836 if (dst == src) /* following doesn't handle inplace remaps */
837 return;
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800838 bitmap_zero(dst, nbits);
Paul Jackson96b7f342006-01-08 01:01:46 -0800839
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800840 w = bitmap_weight(new, nbits);
841 for_each_set_bit(oldbit, src, nbits) {
842 int n = bitmap_pos_to_ord(old, oldbit, nbits);
Akinobu Mita08564fb2010-03-05 13:43:18 -0800843
Paul Jackson96b7f342006-01-08 01:01:46 -0800844 if (n < 0 || w == 0)
845 set_bit(oldbit, dst); /* identity map */
846 else
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800847 set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800848 }
849}
850EXPORT_SYMBOL(bitmap_remap);
851
852/**
853 * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700854 * @oldbit: bit position to be mapped
855 * @old: defines domain of map
856 * @new: defines range of map
857 * @bits: number of bits in each of these bitmaps
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800858 *
859 * Let @old and @new define a mapping of bit positions, such that
860 * whatever position is held by the n-th set bit in @old is mapped
861 * to the n-th set bit in @new. In the more general case, allowing
862 * for the possibility that the weight 'w' of @new is less than the
863 * weight of @old, map the position of the n-th set bit in @old to
864 * the position of the m-th set bit in @new, where m == n % w.
865 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800866 * The positions of unset bits in @old are mapped to themselves
867 * (the identify map).
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800868 *
869 * Apply the above specified mapping to bit position @oldbit, returning
870 * the new bit position.
871 *
872 * For example, lets say that @old has bits 4 through 7 set, and
873 * @new has bits 12 through 15 set. This defines the mapping of bit
874 * 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 -0800875 * bit positions unchanged. So if say @oldbit is 5, then this routine
876 * returns 13.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800877 */
878int bitmap_bitremap(int oldbit, const unsigned long *old,
879 const unsigned long *new, int bits)
880{
Paul Jackson96b7f342006-01-08 01:01:46 -0800881 int w = bitmap_weight(new, bits);
882 int n = bitmap_pos_to_ord(old, oldbit, bits);
883 if (n < 0 || w == 0)
884 return oldbit;
885 else
886 return bitmap_ord_to_pos(new, n % w, bits);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800887}
888EXPORT_SYMBOL(bitmap_bitremap);
889
Paul Jackson7ea931c2008-04-28 02:12:29 -0700890/**
891 * bitmap_onto - translate one bitmap relative to another
892 * @dst: resulting translated bitmap
893 * @orig: original untranslated bitmap
894 * @relmap: bitmap relative to which translated
895 * @bits: number of bits in each of these bitmaps
896 *
897 * Set the n-th bit of @dst iff there exists some m such that the
898 * n-th bit of @relmap is set, the m-th bit of @orig is set, and
899 * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
900 * (If you understood the previous sentence the first time your
901 * read it, you're overqualified for your current job.)
902 *
903 * In other words, @orig is mapped onto (surjectively) @dst,
Masanari Iidada3dae52014-09-09 01:27:23 +0900904 * using the map { <n, m> | the n-th bit of @relmap is the
Paul Jackson7ea931c2008-04-28 02:12:29 -0700905 * m-th set bit of @relmap }.
906 *
907 * Any set bits in @orig above bit number W, where W is the
908 * weight of (number of set bits in) @relmap are mapped nowhere.
909 * In particular, if for all bits m set in @orig, m >= W, then
910 * @dst will end up empty. In situations where the possibility
911 * of such an empty result is not desired, one way to avoid it is
912 * to use the bitmap_fold() operator, below, to first fold the
913 * @orig bitmap over itself so that all its set bits x are in the
914 * range 0 <= x < W. The bitmap_fold() operator does this by
915 * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
916 *
917 * Example [1] for bitmap_onto():
918 * Let's say @relmap has bits 30-39 set, and @orig has bits
919 * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
920 * @dst will have bits 31, 33, 35, 37 and 39 set.
921 *
922 * When bit 0 is set in @orig, it means turn on the bit in
923 * @dst corresponding to whatever is the first bit (if any)
924 * that is turned on in @relmap. Since bit 0 was off in the
925 * above example, we leave off that bit (bit 30) in @dst.
926 *
927 * When bit 1 is set in @orig (as in the above example), it
928 * means turn on the bit in @dst corresponding to whatever
929 * is the second bit that is turned on in @relmap. The second
930 * bit in @relmap that was turned on in the above example was
931 * bit 31, so we turned on bit 31 in @dst.
932 *
933 * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
934 * because they were the 4th, 6th, 8th and 10th set bits
935 * set in @relmap, and the 4th, 6th, 8th and 10th bits of
936 * @orig (i.e. bits 3, 5, 7 and 9) were also set.
937 *
938 * When bit 11 is set in @orig, it means turn on the bit in
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300939 * @dst corresponding to whatever is the twelfth bit that is
Paul Jackson7ea931c2008-04-28 02:12:29 -0700940 * turned on in @relmap. In the above example, there were
941 * only ten bits turned on in @relmap (30..39), so that bit
942 * 11 was set in @orig had no affect on @dst.
943 *
944 * Example [2] for bitmap_fold() + bitmap_onto():
945 * Let's say @relmap has these ten bits set:
946 * 40 41 42 43 45 48 53 61 74 95
947 * (for the curious, that's 40 plus the first ten terms of the
948 * Fibonacci sequence.)
949 *
950 * Further lets say we use the following code, invoking
951 * bitmap_fold() then bitmap_onto, as suggested above to
Masanari Iidada3dae52014-09-09 01:27:23 +0900952 * avoid the possibility of an empty @dst result:
Paul Jackson7ea931c2008-04-28 02:12:29 -0700953 *
954 * unsigned long *tmp; // a temporary bitmap's bits
955 *
956 * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
957 * bitmap_onto(dst, tmp, relmap, bits);
958 *
959 * Then this table shows what various values of @dst would be, for
960 * various @orig's. I list the zero-based positions of each set bit.
961 * The tmp column shows the intermediate result, as computed by
962 * using bitmap_fold() to fold the @orig bitmap modulo ten
963 * (the weight of @relmap).
964 *
965 * @orig tmp @dst
966 * 0 0 40
967 * 1 1 41
968 * 9 9 95
969 * 10 0 40 (*)
970 * 1 3 5 7 1 3 5 7 41 43 48 61
971 * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
972 * 0 9 18 27 0 9 8 7 40 61 74 95
973 * 0 10 20 30 0 40
974 * 0 11 22 33 0 1 2 3 40 41 42 43
975 * 0 12 24 36 0 2 4 6 40 42 45 53
976 * 78 102 211 1 2 8 41 42 74 (*)
977 *
978 * (*) For these marked lines, if we hadn't first done bitmap_fold()
979 * into tmp, then the @dst result would have been empty.
980 *
981 * If either of @orig or @relmap is empty (no set bits), then @dst
982 * will be returned empty.
983 *
984 * If (as explained above) the only set bits in @orig are in positions
985 * m where m >= W, (where W is the weight of @relmap) then @dst will
986 * once again be returned empty.
987 *
988 * All bits in @dst not set by the above rule are cleared.
989 */
990void bitmap_onto(unsigned long *dst, const unsigned long *orig,
Rasmus Villemoeseb569882015-02-12 15:02:01 -0800991 const unsigned long *relmap, unsigned int bits)
Paul Jackson7ea931c2008-04-28 02:12:29 -0700992{
Rasmus Villemoeseb569882015-02-12 15:02:01 -0800993 unsigned int n, m; /* same meaning as in above comment */
Paul Jackson7ea931c2008-04-28 02:12:29 -0700994
995 if (dst == orig) /* following doesn't handle inplace mappings */
996 return;
997 bitmap_zero(dst, bits);
998
999 /*
1000 * The following code is a more efficient, but less
1001 * obvious, equivalent to the loop:
1002 * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
1003 * n = bitmap_ord_to_pos(orig, m, bits);
1004 * if (test_bit(m, orig))
1005 * set_bit(n, dst);
1006 * }
1007 */
1008
1009 m = 0;
Akinobu Mita08564fb2010-03-05 13:43:18 -08001010 for_each_set_bit(n, relmap, bits) {
Paul Jackson7ea931c2008-04-28 02:12:29 -07001011 /* m == bitmap_pos_to_ord(relmap, n, bits) */
1012 if (test_bit(m, orig))
1013 set_bit(n, dst);
1014 m++;
1015 }
1016}
1017EXPORT_SYMBOL(bitmap_onto);
1018
1019/**
1020 * bitmap_fold - fold larger bitmap into smaller, modulo specified size
1021 * @dst: resulting smaller bitmap
1022 * @orig: original larger bitmap
1023 * @sz: specified size
Rasmus Villemoesb26ad582015-02-12 15:02:04 -08001024 * @nbits: number of bits in each of these bitmaps
Paul Jackson7ea931c2008-04-28 02:12:29 -07001025 *
1026 * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
1027 * Clear all other bits in @dst. See further the comment and
1028 * Example [2] for bitmap_onto() for why and how to use this.
1029 */
1030void bitmap_fold(unsigned long *dst, const unsigned long *orig,
Rasmus Villemoesb26ad582015-02-12 15:02:04 -08001031 unsigned int sz, unsigned int nbits)
Paul Jackson7ea931c2008-04-28 02:12:29 -07001032{
Rasmus Villemoesb26ad582015-02-12 15:02:04 -08001033 unsigned int oldbit;
Paul Jackson7ea931c2008-04-28 02:12:29 -07001034
1035 if (dst == orig) /* following doesn't handle inplace mappings */
1036 return;
Rasmus Villemoesb26ad582015-02-12 15:02:04 -08001037 bitmap_zero(dst, nbits);
Paul Jackson7ea931c2008-04-28 02:12:29 -07001038
Rasmus Villemoesb26ad582015-02-12 15:02:04 -08001039 for_each_set_bit(oldbit, orig, nbits)
Paul Jackson7ea931c2008-04-28 02:12:29 -07001040 set_bit(oldbit % sz, dst);
1041}
1042EXPORT_SYMBOL(bitmap_fold);
1043
Paul Jackson3cf64b92006-03-24 03:15:46 -08001044/*
1045 * Common code for bitmap_*_region() routines.
1046 * bitmap: array of unsigned longs corresponding to the bitmap
1047 * pos: the beginning of the region
1048 * order: region size (log base 2 of number of bits)
1049 * reg_op: operation(s) to perform on that region of bitmap
1050 *
1051 * Can set, verify and/or release a region of bits in a bitmap,
1052 * depending on which combination of REG_OP_* flag bits is set.
1053 *
1054 * A region of a bitmap is a sequence of bits in the bitmap, of
1055 * some size '1 << order' (a power of two), aligned to that same
1056 * '1 << order' power of two.
1057 *
1058 * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
1059 * Returns 0 in all other cases and reg_ops.
1060 */
1061
1062enum {
1063 REG_OP_ISFREE, /* true if region is all zero bits */
1064 REG_OP_ALLOC, /* set all bits in region */
1065 REG_OP_RELEASE, /* clear all bits in region */
1066};
1067
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001068static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op)
Paul Jackson3cf64b92006-03-24 03:15:46 -08001069{
1070 int nbits_reg; /* number of bits in region */
1071 int index; /* index first long of region in bitmap */
1072 int offset; /* bit offset region in bitmap[index] */
1073 int nlongs_reg; /* num longs spanned by region in bitmap */
1074 int nbitsinlong; /* num bits of region in each spanned long */
1075 unsigned long mask; /* bitmask for one long of region */
1076 int i; /* scans bitmap by longs */
1077 int ret = 0; /* return value */
1078
1079 /*
1080 * Either nlongs_reg == 1 (for small orders that fit in one long)
1081 * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
1082 */
1083 nbits_reg = 1 << order;
1084 index = pos / BITS_PER_LONG;
1085 offset = pos - (index * BITS_PER_LONG);
1086 nlongs_reg = BITS_TO_LONGS(nbits_reg);
1087 nbitsinlong = min(nbits_reg, BITS_PER_LONG);
1088
1089 /*
1090 * Can't do "mask = (1UL << nbitsinlong) - 1", as that
1091 * overflows if nbitsinlong == BITS_PER_LONG.
1092 */
1093 mask = (1UL << (nbitsinlong - 1));
1094 mask += mask - 1;
1095 mask <<= offset;
1096
1097 switch (reg_op) {
1098 case REG_OP_ISFREE:
1099 for (i = 0; i < nlongs_reg; i++) {
1100 if (bitmap[index + i] & mask)
1101 goto done;
1102 }
1103 ret = 1; /* all bits in region free (zero) */
1104 break;
1105
1106 case REG_OP_ALLOC:
1107 for (i = 0; i < nlongs_reg; i++)
1108 bitmap[index + i] |= mask;
1109 break;
1110
1111 case REG_OP_RELEASE:
1112 for (i = 0; i < nlongs_reg; i++)
1113 bitmap[index + i] &= ~mask;
1114 break;
1115 }
1116done:
1117 return ret;
1118}
1119
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120/**
Paul Jackson87e24802006-03-24 03:15:44 -08001121 * bitmap_find_free_region - find a contiguous aligned mem region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001122 * @bitmap: array of unsigned longs corresponding to the bitmap
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123 * @bits: number of bits in the bitmap
Paul Jackson3cf64b92006-03-24 03:15:46 -08001124 * @order: region size (log base 2 of number of bits) to find
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125 *
Paul Jackson3cf64b92006-03-24 03:15:46 -08001126 * Find a region of free (zero) bits in a @bitmap of @bits bits and
1127 * allocate them (set them to one). Only consider regions of length
1128 * a power (@order) of two, aligned to that power of two, which
Paul Jackson87e24802006-03-24 03:15:44 -08001129 * makes the search algorithm much faster.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130 *
Paul Jackson3cf64b92006-03-24 03:15:46 -08001131 * Return the bit offset in bitmap of the allocated region,
Paul Jackson87e24802006-03-24 03:15:44 -08001132 * or -errno on failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001134int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135{
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001136 unsigned int pos, end; /* scans bitmap by regions of size order */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001138 for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) {
Linus Torvaldsaa8e4fc2009-03-12 19:32:51 -07001139 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1140 continue;
1141 __reg_op(bitmap, pos, order, REG_OP_ALLOC);
1142 return pos;
1143 }
1144 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145}
1146EXPORT_SYMBOL(bitmap_find_free_region);
1147
1148/**
Paul Jackson87e24802006-03-24 03:15:44 -08001149 * bitmap_release_region - release allocated bitmap region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001150 * @bitmap: array of unsigned longs corresponding to the bitmap
1151 * @pos: beginning of bit region to release
1152 * @order: region size (log base 2 of number of bits) to release
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08001154 * This is the complement to __bitmap_find_free_region() and releases
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155 * the found region (by clearing it in the bitmap).
Paul Jackson3cf64b92006-03-24 03:15:46 -08001156 *
1157 * No return value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001159void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160{
Paul Jackson3cf64b92006-03-24 03:15:46 -08001161 __reg_op(bitmap, pos, order, REG_OP_RELEASE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162}
1163EXPORT_SYMBOL(bitmap_release_region);
1164
Paul Jackson87e24802006-03-24 03:15:44 -08001165/**
1166 * bitmap_allocate_region - allocate bitmap region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001167 * @bitmap: array of unsigned longs corresponding to the bitmap
1168 * @pos: beginning of bit region to allocate
1169 * @order: region size (log base 2 of number of bits) to allocate
Paul Jackson87e24802006-03-24 03:15:44 -08001170 *
1171 * Allocate (set bits in) a specified region of a bitmap.
Paul Jackson3cf64b92006-03-24 03:15:46 -08001172 *
Randy Dunlap6e1907ff2006-06-25 05:48:57 -07001173 * Return 0 on success, or %-EBUSY if specified region wasn't
Paul Jackson87e24802006-03-24 03:15:44 -08001174 * free (not all bits were zero).
1175 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001176int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177{
Paul Jackson3cf64b92006-03-24 03:15:46 -08001178 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1179 return -EBUSY;
Rasmus Villemoes2ac521d2014-08-06 16:10:18 -07001180 return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001181}
1182EXPORT_SYMBOL(bitmap_allocate_region);
David Vrabelccbe3292008-09-17 16:34:03 +01001183
1184/**
1185 * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
1186 * @dst: destination buffer
1187 * @src: bitmap to copy
1188 * @nbits: number of bits in the bitmap
1189 *
1190 * Require nbits % BITS_PER_LONG == 0.
1191 */
Rasmus Villemoese8f24272015-02-13 14:36:00 -08001192#ifdef __BIG_ENDIAN
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001193void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits)
David Vrabelccbe3292008-09-17 16:34:03 +01001194{
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001195 unsigned int i;
David Vrabelccbe3292008-09-17 16:34:03 +01001196
1197 for (i = 0; i < nbits/BITS_PER_LONG; i++) {
1198 if (BITS_PER_LONG == 64)
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001199 dst[i] = cpu_to_le64(src[i]);
David Vrabelccbe3292008-09-17 16:34:03 +01001200 else
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001201 dst[i] = cpu_to_le32(src[i]);
David Vrabelccbe3292008-09-17 16:34:03 +01001202 }
1203}
1204EXPORT_SYMBOL(bitmap_copy_le);
Rasmus Villemoese8f24272015-02-13 14:36:00 -08001205#endif