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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)
172 lower = src[k - 1];
173 else
174 lower = 0;
175 upper = src[k];
176 if (left && k == lim - 1)
177 upper &= (1UL << left) - 1;
Jan Karaea5d05b2014-10-29 14:50:44 -0700178 dst[k + off] = upper << rem;
179 if (rem)
180 dst[k + off] |= lower >> (BITS_PER_LONG - rem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 if (left && k + off == lim - 1)
182 dst[k + off] &= (1UL << left) - 1;
183 }
184 if (off)
185 memset(dst, 0, off*sizeof(unsigned long));
186}
187EXPORT_SYMBOL(__bitmap_shift_left);
188
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700189int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700190 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700192 unsigned int k;
Rasmus Villemoes7e5f97d2014-08-06 16:10:22 -0700193 unsigned int lim = bits/BITS_PER_LONG;
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700194 unsigned long result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
Rasmus Villemoes7e5f97d2014-08-06 16:10:22 -0700196 for (k = 0; k < lim; k++)
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700197 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
Rasmus Villemoes7e5f97d2014-08-06 16:10:22 -0700198 if (bits % BITS_PER_LONG)
199 result |= (dst[k] = bitmap1[k] & bitmap2[k] &
200 BITMAP_LAST_WORD_MASK(bits));
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700201 return result != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202}
203EXPORT_SYMBOL(__bitmap_and);
204
205void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700206 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700208 unsigned int k;
209 unsigned int nr = BITS_TO_LONGS(bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
211 for (k = 0; k < nr; k++)
212 dst[k] = bitmap1[k] | bitmap2[k];
213}
214EXPORT_SYMBOL(__bitmap_or);
215
216void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700217 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700219 unsigned int k;
220 unsigned int nr = BITS_TO_LONGS(bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221
222 for (k = 0; k < nr; k++)
223 dst[k] = bitmap1[k] ^ bitmap2[k];
224}
225EXPORT_SYMBOL(__bitmap_xor);
226
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700227int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700228 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700230 unsigned int k;
Rasmus Villemoes74e76532014-08-06 16:10:24 -0700231 unsigned int lim = bits/BITS_PER_LONG;
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700232 unsigned long result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
Rasmus Villemoes74e76532014-08-06 16:10:24 -0700234 for (k = 0; k < lim; k++)
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700235 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
Rasmus Villemoes74e76532014-08-06 16:10:24 -0700236 if (bits % BITS_PER_LONG)
237 result |= (dst[k] = bitmap1[k] & ~bitmap2[k] &
238 BITMAP_LAST_WORD_MASK(bits));
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700239 return result != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240}
241EXPORT_SYMBOL(__bitmap_andnot);
242
243int __bitmap_intersects(const unsigned long *bitmap1,
Rasmus Villemoes6dfe9792014-08-06 16:10:01 -0700244 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245{
Rasmus Villemoes6dfe9792014-08-06 16:10:01 -0700246 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 for (k = 0; k < lim; ++k)
248 if (bitmap1[k] & bitmap2[k])
249 return 1;
250
251 if (bits % BITS_PER_LONG)
252 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
253 return 1;
254 return 0;
255}
256EXPORT_SYMBOL(__bitmap_intersects);
257
258int __bitmap_subset(const unsigned long *bitmap1,
Rasmus Villemoes5be20212014-08-06 16:10:03 -0700259 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260{
Rasmus Villemoes5be20212014-08-06 16:10:03 -0700261 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 for (k = 0; k < lim; ++k)
263 if (bitmap1[k] & ~bitmap2[k])
264 return 0;
265
266 if (bits % BITS_PER_LONG)
267 if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
268 return 0;
269 return 1;
270}
271EXPORT_SYMBOL(__bitmap_subset);
272
Rasmus Villemoes877d9f32014-08-06 16:10:05 -0700273int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274{
Rasmus Villemoes877d9f32014-08-06 16:10:05 -0700275 unsigned int k, lim = bits/BITS_PER_LONG;
276 int w = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277
278 for (k = 0; k < lim; k++)
Akinobu Mita37d54112006-03-26 01:39:56 -0800279 w += hweight_long(bitmap[k]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280
281 if (bits % BITS_PER_LONG)
Akinobu Mita37d54112006-03-26 01:39:56 -0800282 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283
284 return w;
285}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286EXPORT_SYMBOL(__bitmap_weight);
287
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700288void bitmap_set(unsigned long *map, unsigned int start, int len)
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800289{
290 unsigned long *p = map + BIT_WORD(start);
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700291 const unsigned int size = start + len;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800292 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
293 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
294
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700295 while (len - bits_to_set >= 0) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800296 *p |= mask_to_set;
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700297 len -= bits_to_set;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800298 bits_to_set = BITS_PER_LONG;
299 mask_to_set = ~0UL;
300 p++;
301 }
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700302 if (len) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800303 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
304 *p |= mask_to_set;
305 }
306}
307EXPORT_SYMBOL(bitmap_set);
308
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700309void bitmap_clear(unsigned long *map, unsigned int start, int len)
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800310{
311 unsigned long *p = map + BIT_WORD(start);
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700312 const unsigned int size = start + len;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800313 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
314 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
315
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700316 while (len - bits_to_clear >= 0) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800317 *p &= ~mask_to_clear;
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700318 len -= bits_to_clear;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800319 bits_to_clear = BITS_PER_LONG;
320 mask_to_clear = ~0UL;
321 p++;
322 }
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700323 if (len) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800324 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
325 *p &= ~mask_to_clear;
326 }
327}
328EXPORT_SYMBOL(bitmap_clear);
329
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800330/**
331 * bitmap_find_next_zero_area_off - find a contiguous aligned zero area
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800332 * @map: The address to base the search on
333 * @size: The bitmap size in bits
334 * @start: The bitnumber to start searching at
335 * @nr: The number of zeroed bits we're looking for
336 * @align_mask: Alignment mask for zero area
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800337 * @align_offset: Alignment offset for zero area.
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800338 *
339 * The @align_mask should be one less than a power of 2; the effect is that
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800340 * the bit offset of all zero areas this function finds plus @align_offset
341 * is multiple of that power of 2.
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800342 */
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800343unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
344 unsigned long size,
345 unsigned long start,
346 unsigned int nr,
347 unsigned long align_mask,
348 unsigned long align_offset)
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800349{
350 unsigned long index, end, i;
351again:
352 index = find_next_zero_bit(map, size, start);
353
354 /* Align allocation */
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800355 index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800356
357 end = index + nr;
358 if (end > size)
359 return end;
360 i = find_next_bit(map, end, index);
361 if (i < end) {
362 start = i + 1;
363 goto again;
364 }
365 return index;
366}
Michal Nazarewicz5e19b012014-12-12 16:54:45 -0800367EXPORT_SYMBOL(bitmap_find_next_zero_area_off);
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800368
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369/*
Nadia Yvette Chambers6d49e352012-12-06 10:39:54 +0100370 * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 * second version by Paul Jackson, third by Joe Korty.
372 */
373
374#define CHUNKSZ 32
375#define nbits_to_hold_value(val) fls(val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376#define BASEDEC 10 /* fancier cpuset lists input in decimal */
377
378/**
379 * bitmap_scnprintf - convert bitmap to an ASCII hex string.
380 * @buf: byte buffer into which string is placed
381 * @buflen: reserved size of @buf, in bytes
382 * @maskp: pointer to bitmap to convert
383 * @nmaskbits: size of bitmap, in bits
384 *
385 * Exactly @nmaskbits bits are displayed. Hex digits are grouped into
Andrew Morton05a6c8a2012-05-29 15:07:32 -0700386 * comma-separated sets of eight digits per set. Returns the number of
387 * characters which were written to *buf, excluding the trailing \0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 */
389int bitmap_scnprintf(char *buf, unsigned int buflen,
390 const unsigned long *maskp, int nmaskbits)
391{
392 int i, word, bit, len = 0;
393 unsigned long val;
394 const char *sep = "";
395 int chunksz;
396 u32 chunkmask;
397
398 chunksz = nmaskbits & (CHUNKSZ - 1);
399 if (chunksz == 0)
400 chunksz = CHUNKSZ;
401
Nick Wilson8c0e33c2005-06-25 14:59:00 -0700402 i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 for (; i >= 0; i -= CHUNKSZ) {
404 chunkmask = ((1ULL << chunksz) - 1);
405 word = i / BITS_PER_LONG;
406 bit = i % BITS_PER_LONG;
407 val = (maskp[word] >> bit) & chunkmask;
408 len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep,
409 (chunksz+3)/4, val);
410 chunksz = CHUNKSZ;
411 sep = ",";
412 }
413 return len;
414}
415EXPORT_SYMBOL(bitmap_scnprintf);
416
417/**
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700418 * __bitmap_parse - convert an ASCII hex string into a bitmap.
419 * @buf: pointer to buffer containing string.
420 * @buflen: buffer size in bytes. If string is smaller than this
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 * then it must be terminated with a \0.
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700422 * @is_user: location of buffer, 0 indicates kernel space
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 * @maskp: pointer to bitmap array that will contain result.
424 * @nmaskbits: size of bitmap, in bits.
425 *
426 * Commas group hex digits into chunks. Each chunk defines exactly 32
427 * bits of the resultant bitmask. No chunk may specify a value larger
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700428 * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
429 * then leading 0-bits are prepended. %-EINVAL is returned for illegal
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 * characters and for grouping errors such as "1,,5", ",44", "," and "".
431 * Leading and trailing whitespace accepted, but not embedded whitespace.
432 */
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700433int __bitmap_parse(const char *buf, unsigned int buflen,
434 int is_user, unsigned long *maskp,
435 int nmaskbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436{
437 int c, old_c, totaldigits, ndigits, nchunks, nbits;
438 u32 chunk;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700439 const char __user __force *ubuf = (const char __user __force *)buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440
441 bitmap_zero(maskp, nmaskbits);
442
443 nchunks = nbits = totaldigits = c = 0;
444 do {
445 chunk = ndigits = 0;
446
447 /* Get the next chunk of the bitmap */
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700448 while (buflen) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 old_c = c;
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700450 if (is_user) {
451 if (__get_user(c, ubuf++))
452 return -EFAULT;
453 }
454 else
455 c = *buf++;
456 buflen--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 if (isspace(c))
458 continue;
459
460 /*
461 * If the last character was a space and the current
462 * character isn't '\0', we've got embedded whitespace.
463 * This is a no-no, so throw an error.
464 */
465 if (totaldigits && c && isspace(old_c))
466 return -EINVAL;
467
468 /* A '\0' or a ',' signal the end of the chunk */
469 if (c == '\0' || c == ',')
470 break;
471
472 if (!isxdigit(c))
473 return -EINVAL;
474
475 /*
476 * Make sure there are at least 4 free bits in 'chunk'.
477 * If not, this hexdigit will overflow 'chunk', so
478 * throw an error.
479 */
480 if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1))
481 return -EOVERFLOW;
482
Andy Shevchenko66f19912010-10-26 14:23:03 -0700483 chunk = (chunk << 4) | hex_to_bin(c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 ndigits++; totaldigits++;
485 }
486 if (ndigits == 0)
487 return -EINVAL;
488 if (nchunks == 0 && chunk == 0)
489 continue;
490
491 __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits);
492 *maskp |= chunk;
493 nchunks++;
494 nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
495 if (nbits > nmaskbits)
496 return -EOVERFLOW;
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700497 } while (buflen && c == ',');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498
499 return 0;
500}
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700501EXPORT_SYMBOL(__bitmap_parse);
502
503/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800504 * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700505 *
506 * @ubuf: pointer to user buffer containing string.
507 * @ulen: buffer size in bytes. If string is smaller than this
508 * then it must be terminated with a \0.
509 * @maskp: pointer to bitmap array that will contain result.
510 * @nmaskbits: size of bitmap, in bits.
511 *
512 * Wrapper for __bitmap_parse(), providing it with user buffer.
513 *
514 * We cannot have this as an inline function in bitmap.h because it needs
515 * linux/uaccess.h to get the access_ok() declaration and this causes
516 * cyclic dependencies.
517 */
518int bitmap_parse_user(const char __user *ubuf,
519 unsigned int ulen, unsigned long *maskp,
520 int nmaskbits)
521{
522 if (!access_ok(VERIFY_READ, ubuf, ulen))
523 return -EFAULT;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700524 return __bitmap_parse((const char __force *)ubuf,
525 ulen, 1, maskp, nmaskbits);
526
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700527}
528EXPORT_SYMBOL(bitmap_parse_user);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529
530/*
531 * bscnl_emit(buf, buflen, rbot, rtop, bp)
532 *
533 * Helper routine for bitmap_scnlistprintf(). Write decimal number
534 * or range to buf, suppressing output past buf+buflen, with optional
Andrew Morton05a6c8a2012-05-29 15:07:32 -0700535 * comma-prefix. Return len of what was written to *buf, excluding the
536 * trailing \0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 */
538static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len)
539{
540 if (len > 0)
541 len += scnprintf(buf + len, buflen - len, ",");
542 if (rbot == rtop)
543 len += scnprintf(buf + len, buflen - len, "%d", rbot);
544 else
545 len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop);
546 return len;
547}
548
549/**
550 * bitmap_scnlistprintf - convert bitmap to list format ASCII string
551 * @buf: byte buffer into which string is placed
552 * @buflen: reserved size of @buf, in bytes
553 * @maskp: pointer to bitmap to convert
554 * @nmaskbits: size of bitmap, in bits
555 *
556 * Output format is a comma-separated list of decimal numbers and
557 * ranges. Consecutively set bits are shown as two hyphen-separated
558 * decimal numbers, the smallest and largest bit numbers set in
559 * the range. Output format is compatible with the format
560 * accepted as input by bitmap_parselist().
561 *
Andrew Morton05a6c8a2012-05-29 15:07:32 -0700562 * The return value is the number of characters which were written to *buf
563 * excluding the trailing '\0', as per ISO C99's scnprintf.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 */
565int bitmap_scnlistprintf(char *buf, unsigned int buflen,
566 const unsigned long *maskp, int nmaskbits)
567{
568 int len = 0;
569 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
570 int cur, rbot, rtop;
571
Andi Kleen0b030c22007-11-05 14:50:56 -0800572 if (buflen == 0)
573 return 0;
574 buf[0] = 0;
575
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 rbot = cur = find_first_bit(maskp, nmaskbits);
577 while (cur < nmaskbits) {
578 rtop = cur;
579 cur = find_next_bit(maskp, nmaskbits, cur+1);
580 if (cur >= nmaskbits || cur > rtop + 1) {
581 len = bscnl_emit(buf, buflen, rbot, rtop, len);
582 rbot = cur;
583 }
584 }
585 return len;
586}
587EXPORT_SYMBOL(bitmap_scnlistprintf);
588
589/**
Sudeep Holla5aaba362014-09-30 14:48:22 +0100590 * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string
591 * @list: indicates whether the bitmap must be list
592 * @buf: page aligned buffer into which string is placed
593 * @maskp: pointer to bitmap to convert
594 * @nmaskbits: size of bitmap, in bits
595 *
596 * Output format is a comma-separated list of decimal numbers and
597 * ranges if list is specified or hex digits grouped into comma-separated
598 * sets of 8 digits/set. Returns the number of characters written to buf.
599 */
600int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp,
601 int nmaskbits)
602{
603 ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf - 2;
604 int n = 0;
605
606 if (len > 1) {
607 n = list ? bitmap_scnlistprintf(buf, len, maskp, nmaskbits) :
608 bitmap_scnprintf(buf, len, maskp, nmaskbits);
609 buf[n++] = '\n';
610 buf[n] = '\0';
611 }
612 return n;
613}
614EXPORT_SYMBOL(bitmap_print_to_pagebuf);
615
616/**
Mike Travis4b060422011-05-24 17:13:12 -0700617 * __bitmap_parselist - convert list format ASCII string to bitmap
Randy Dunlapb0825ee2011-06-15 15:08:10 -0700618 * @buf: read nul-terminated user string from this buffer
Mike Travis4b060422011-05-24 17:13:12 -0700619 * @buflen: buffer size in bytes. If string is smaller than this
620 * then it must be terminated with a \0.
621 * @is_user: location of buffer, 0 indicates kernel space
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700622 * @maskp: write resulting mask here
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 * @nmaskbits: number of bits in mask to be written
624 *
625 * Input format is a comma-separated list of decimal numbers and
626 * ranges. Consecutively set bits are shown as two hyphen-separated
627 * decimal numbers, the smallest and largest bit numbers set in
628 * the range.
629 *
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700630 * Returns 0 on success, -errno on invalid input strings.
631 * Error values:
632 * %-EINVAL: second number in range smaller than first
633 * %-EINVAL: invalid character in string
634 * %-ERANGE: bit number specified too large for mask
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 */
Mike Travis4b060422011-05-24 17:13:12 -0700636static int __bitmap_parselist(const char *buf, unsigned int buflen,
637 int is_user, unsigned long *maskp,
638 int nmaskbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639{
640 unsigned a, b;
Mike Travis4b060422011-05-24 17:13:12 -0700641 int c, old_c, totaldigits;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700642 const char __user __force *ubuf = (const char __user __force *)buf;
Mike Travis4b060422011-05-24 17:13:12 -0700643 int exp_digit, in_range;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644
Mike Travis4b060422011-05-24 17:13:12 -0700645 totaldigits = c = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 bitmap_zero(maskp, nmaskbits);
647 do {
Mike Travis4b060422011-05-24 17:13:12 -0700648 exp_digit = 1;
649 in_range = 0;
650 a = b = 0;
651
652 /* Get the next cpu# or a range of cpu#'s */
653 while (buflen) {
654 old_c = c;
655 if (is_user) {
656 if (__get_user(c, ubuf++))
657 return -EFAULT;
658 } else
659 c = *buf++;
660 buflen--;
661 if (isspace(c))
662 continue;
663
664 /*
665 * If the last character was a space and the current
666 * character isn't '\0', we've got embedded whitespace.
667 * This is a no-no, so throw an error.
668 */
669 if (totaldigits && c && isspace(old_c))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 return -EINVAL;
Mike Travis4b060422011-05-24 17:13:12 -0700671
672 /* A '\0' or a ',' signal the end of a cpu# or range */
673 if (c == '\0' || c == ',')
674 break;
675
676 if (c == '-') {
677 if (exp_digit || in_range)
678 return -EINVAL;
679 b = 0;
680 in_range = 1;
681 exp_digit = 1;
682 continue;
683 }
684
685 if (!isdigit(c))
686 return -EINVAL;
687
688 b = b * 10 + (c - '0');
689 if (!in_range)
690 a = b;
691 exp_digit = 0;
692 totaldigits++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 }
694 if (!(a <= b))
695 return -EINVAL;
696 if (b >= nmaskbits)
697 return -ERANGE;
698 while (a <= b) {
699 set_bit(a, maskp);
700 a++;
701 }
Mike Travis4b060422011-05-24 17:13:12 -0700702 } while (buflen && c == ',');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 return 0;
704}
Mike Travis4b060422011-05-24 17:13:12 -0700705
706int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
707{
Rasmus Villemoesbc5be182014-08-06 16:10:12 -0700708 char *nl = strchrnul(bp, '\n');
709 int len = nl - bp;
Mike Travis4b060422011-05-24 17:13:12 -0700710
711 return __bitmap_parselist(bp, len, 0, maskp, nmaskbits);
712}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713EXPORT_SYMBOL(bitmap_parselist);
714
Mike Travis4b060422011-05-24 17:13:12 -0700715
716/**
717 * bitmap_parselist_user()
718 *
719 * @ubuf: pointer to user buffer containing string.
720 * @ulen: buffer size in bytes. If string is smaller than this
721 * then it must be terminated with a \0.
722 * @maskp: pointer to bitmap array that will contain result.
723 * @nmaskbits: size of bitmap, in bits.
724 *
725 * Wrapper for bitmap_parselist(), providing it with user buffer.
726 *
727 * We cannot have this as an inline function in bitmap.h because it needs
728 * linux/uaccess.h to get the access_ok() declaration and this causes
729 * cyclic dependencies.
730 */
731int bitmap_parselist_user(const char __user *ubuf,
732 unsigned int ulen, unsigned long *maskp,
733 int nmaskbits)
734{
735 if (!access_ok(VERIFY_READ, ubuf, ulen))
736 return -EFAULT;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700737 return __bitmap_parselist((const char __force *)ubuf,
Mike Travis4b060422011-05-24 17:13:12 -0700738 ulen, 1, maskp, nmaskbits);
739}
740EXPORT_SYMBOL(bitmap_parselist_user);
741
742
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800743/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800744 * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800745 * @buf: pointer to a bitmap
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800746 * @pos: a bit position in @buf (0 <= @pos < @nbits)
747 * @nbits: number of valid bit positions in @buf
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800748 *
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800749 * Map the bit at position @pos in @buf (of length @nbits) to the
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800750 * ordinal of which set bit it is. If it is not set or if @pos
Paul Jackson96b7f342006-01-08 01:01:46 -0800751 * is not a valid bit position, map to -1.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800752 *
753 * If for example, just bits 4 through 7 are set in @buf, then @pos
754 * values 4 through 7 will get mapped to 0 through 3, respectively,
Rasmus Villemoesa8551742014-08-06 16:10:14 -0700755 * and other @pos values will get mapped to -1. When @pos value 7
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800756 * gets mapped to (returns) @ord value 3 in this example, that means
757 * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
758 *
759 * The bit positions 0 through @bits are valid positions in @buf.
760 */
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800761static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800762{
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800763 if (pos >= nbits || !test_bit(pos, buf))
Paul Jackson96b7f342006-01-08 01:01:46 -0800764 return -1;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800765
Rasmus Villemoesdf1d80a2015-02-12 15:02:07 -0800766 return __bitmap_weight(buf, pos);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800767}
768
769/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800770 * bitmap_ord_to_pos - find position of n-th set bit in bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800771 * @buf: pointer to bitmap
772 * @ord: ordinal bit position (n-th set bit, n >= 0)
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800773 * @nbits: number of valid bit positions in @buf
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800774 *
775 * Map the ordinal offset of bit @ord in @buf to its position in @buf.
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800776 * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord
777 * >= weight(buf), returns @nbits.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800778 *
779 * If for example, just bits 4 through 7 are set in @buf, then @ord
780 * values 0 through 3 will get mapped to 4 through 7, respectively,
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800781 * and all other @ord values returns @nbits. When @ord value 3
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800782 * gets mapped to (returns) @pos value 7 in this example, that means
783 * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
784 *
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800785 * The bit positions 0 through @nbits-1 are valid positions in @buf.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800786 */
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800787unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits)
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800788{
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800789 unsigned int pos;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800790
Rasmus Villemoesf6a1f5d2015-02-12 15:02:10 -0800791 for (pos = find_first_bit(buf, nbits);
792 pos < nbits && ord;
793 pos = find_next_bit(buf, nbits, pos + 1))
794 ord--;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800795
796 return pos;
797}
798
799/**
800 * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800801 * @dst: remapped result
Paul Jackson96b7f342006-01-08 01:01:46 -0800802 * @src: subset to be remapped
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800803 * @old: defines domain of map
804 * @new: defines range of map
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800805 * @nbits: number of bits in each of these bitmaps
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800806 *
807 * Let @old and @new define a mapping of bit positions, such that
808 * whatever position is held by the n-th set bit in @old is mapped
809 * to the n-th set bit in @new. In the more general case, allowing
810 * for the possibility that the weight 'w' of @new is less than the
811 * weight of @old, map the position of the n-th set bit in @old to
812 * the position of the m-th set bit in @new, where m == n % w.
813 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800814 * If either of the @old and @new bitmaps are empty, or if @src and
815 * @dst point to the same location, then this routine copies @src
816 * to @dst.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800817 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800818 * The positions of unset bits in @old are mapped to themselves
819 * (the identify map).
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800820 *
821 * Apply the above specified mapping to @src, placing the result in
822 * @dst, clearing any bits previously set in @dst.
823 *
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800824 * For example, lets say that @old has bits 4 through 7 set, and
825 * @new has bits 12 through 15 set. This defines the mapping of bit
826 * 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 -0800827 * bit positions unchanged. So if say @src comes into this routine
828 * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
829 * 13 and 15 set.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800830 */
831void bitmap_remap(unsigned long *dst, const unsigned long *src,
832 const unsigned long *old, const unsigned long *new,
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800833 unsigned int nbits)
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800834{
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800835 unsigned int oldbit, w;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800836
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800837 if (dst == src) /* following doesn't handle inplace remaps */
838 return;
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800839 bitmap_zero(dst, nbits);
Paul Jackson96b7f342006-01-08 01:01:46 -0800840
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800841 w = bitmap_weight(new, nbits);
842 for_each_set_bit(oldbit, src, nbits) {
843 int n = bitmap_pos_to_ord(old, oldbit, nbits);
Akinobu Mita08564fb2010-03-05 13:43:18 -0800844
Paul Jackson96b7f342006-01-08 01:01:46 -0800845 if (n < 0 || w == 0)
846 set_bit(oldbit, dst); /* identity map */
847 else
Rasmus Villemoes9814ec12015-02-12 15:02:13 -0800848 set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800849 }
850}
851EXPORT_SYMBOL(bitmap_remap);
852
853/**
854 * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700855 * @oldbit: bit position to be mapped
856 * @old: defines domain of map
857 * @new: defines range of map
858 * @bits: number of bits in each of these bitmaps
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800859 *
860 * Let @old and @new define a mapping of bit positions, such that
861 * whatever position is held by the n-th set bit in @old is mapped
862 * to the n-th set bit in @new. In the more general case, allowing
863 * for the possibility that the weight 'w' of @new is less than the
864 * weight of @old, map the position of the n-th set bit in @old to
865 * the position of the m-th set bit in @new, where m == n % w.
866 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800867 * The positions of unset bits in @old are mapped to themselves
868 * (the identify map).
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800869 *
870 * Apply the above specified mapping to bit position @oldbit, returning
871 * the new bit position.
872 *
873 * For example, lets say that @old has bits 4 through 7 set, and
874 * @new has bits 12 through 15 set. This defines the mapping of bit
875 * 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 -0800876 * bit positions unchanged. So if say @oldbit is 5, then this routine
877 * returns 13.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800878 */
879int bitmap_bitremap(int oldbit, const unsigned long *old,
880 const unsigned long *new, int bits)
881{
Paul Jackson96b7f342006-01-08 01:01:46 -0800882 int w = bitmap_weight(new, bits);
883 int n = bitmap_pos_to_ord(old, oldbit, bits);
884 if (n < 0 || w == 0)
885 return oldbit;
886 else
887 return bitmap_ord_to_pos(new, n % w, bits);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800888}
889EXPORT_SYMBOL(bitmap_bitremap);
890
Paul Jackson7ea931c2008-04-28 02:12:29 -0700891/**
892 * bitmap_onto - translate one bitmap relative to another
893 * @dst: resulting translated bitmap
894 * @orig: original untranslated bitmap
895 * @relmap: bitmap relative to which translated
896 * @bits: number of bits in each of these bitmaps
897 *
898 * Set the n-th bit of @dst iff there exists some m such that the
899 * n-th bit of @relmap is set, the m-th bit of @orig is set, and
900 * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
901 * (If you understood the previous sentence the first time your
902 * read it, you're overqualified for your current job.)
903 *
904 * In other words, @orig is mapped onto (surjectively) @dst,
Masanari Iidada3dae52014-09-09 01:27:23 +0900905 * using the map { <n, m> | the n-th bit of @relmap is the
Paul Jackson7ea931c2008-04-28 02:12:29 -0700906 * m-th set bit of @relmap }.
907 *
908 * Any set bits in @orig above bit number W, where W is the
909 * weight of (number of set bits in) @relmap are mapped nowhere.
910 * In particular, if for all bits m set in @orig, m >= W, then
911 * @dst will end up empty. In situations where the possibility
912 * of such an empty result is not desired, one way to avoid it is
913 * to use the bitmap_fold() operator, below, to first fold the
914 * @orig bitmap over itself so that all its set bits x are in the
915 * range 0 <= x < W. The bitmap_fold() operator does this by
916 * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
917 *
918 * Example [1] for bitmap_onto():
919 * Let's say @relmap has bits 30-39 set, and @orig has bits
920 * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
921 * @dst will have bits 31, 33, 35, 37 and 39 set.
922 *
923 * When bit 0 is set in @orig, it means turn on the bit in
924 * @dst corresponding to whatever is the first bit (if any)
925 * that is turned on in @relmap. Since bit 0 was off in the
926 * above example, we leave off that bit (bit 30) in @dst.
927 *
928 * When bit 1 is set in @orig (as in the above example), it
929 * means turn on the bit in @dst corresponding to whatever
930 * is the second bit that is turned on in @relmap. The second
931 * bit in @relmap that was turned on in the above example was
932 * bit 31, so we turned on bit 31 in @dst.
933 *
934 * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
935 * because they were the 4th, 6th, 8th and 10th set bits
936 * set in @relmap, and the 4th, 6th, 8th and 10th bits of
937 * @orig (i.e. bits 3, 5, 7 and 9) were also set.
938 *
939 * When bit 11 is set in @orig, it means turn on the bit in
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300940 * @dst corresponding to whatever is the twelfth bit that is
Paul Jackson7ea931c2008-04-28 02:12:29 -0700941 * turned on in @relmap. In the above example, there were
942 * only ten bits turned on in @relmap (30..39), so that bit
943 * 11 was set in @orig had no affect on @dst.
944 *
945 * Example [2] for bitmap_fold() + bitmap_onto():
946 * Let's say @relmap has these ten bits set:
947 * 40 41 42 43 45 48 53 61 74 95
948 * (for the curious, that's 40 plus the first ten terms of the
949 * Fibonacci sequence.)
950 *
951 * Further lets say we use the following code, invoking
952 * bitmap_fold() then bitmap_onto, as suggested above to
Masanari Iidada3dae52014-09-09 01:27:23 +0900953 * avoid the possibility of an empty @dst result:
Paul Jackson7ea931c2008-04-28 02:12:29 -0700954 *
955 * unsigned long *tmp; // a temporary bitmap's bits
956 *
957 * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
958 * bitmap_onto(dst, tmp, relmap, bits);
959 *
960 * Then this table shows what various values of @dst would be, for
961 * various @orig's. I list the zero-based positions of each set bit.
962 * The tmp column shows the intermediate result, as computed by
963 * using bitmap_fold() to fold the @orig bitmap modulo ten
964 * (the weight of @relmap).
965 *
966 * @orig tmp @dst
967 * 0 0 40
968 * 1 1 41
969 * 9 9 95
970 * 10 0 40 (*)
971 * 1 3 5 7 1 3 5 7 41 43 48 61
972 * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
973 * 0 9 18 27 0 9 8 7 40 61 74 95
974 * 0 10 20 30 0 40
975 * 0 11 22 33 0 1 2 3 40 41 42 43
976 * 0 12 24 36 0 2 4 6 40 42 45 53
977 * 78 102 211 1 2 8 41 42 74 (*)
978 *
979 * (*) For these marked lines, if we hadn't first done bitmap_fold()
980 * into tmp, then the @dst result would have been empty.
981 *
982 * If either of @orig or @relmap is empty (no set bits), then @dst
983 * will be returned empty.
984 *
985 * If (as explained above) the only set bits in @orig are in positions
986 * m where m >= W, (where W is the weight of @relmap) then @dst will
987 * once again be returned empty.
988 *
989 * All bits in @dst not set by the above rule are cleared.
990 */
991void bitmap_onto(unsigned long *dst, const unsigned long *orig,
Rasmus Villemoeseb569882015-02-12 15:02:01 -0800992 const unsigned long *relmap, unsigned int bits)
Paul Jackson7ea931c2008-04-28 02:12:29 -0700993{
Rasmus Villemoeseb569882015-02-12 15:02:01 -0800994 unsigned int n, m; /* same meaning as in above comment */
Paul Jackson7ea931c2008-04-28 02:12:29 -0700995
996 if (dst == orig) /* following doesn't handle inplace mappings */
997 return;
998 bitmap_zero(dst, bits);
999
1000 /*
1001 * The following code is a more efficient, but less
1002 * obvious, equivalent to the loop:
1003 * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
1004 * n = bitmap_ord_to_pos(orig, m, bits);
1005 * if (test_bit(m, orig))
1006 * set_bit(n, dst);
1007 * }
1008 */
1009
1010 m = 0;
Akinobu Mita08564fb2010-03-05 13:43:18 -08001011 for_each_set_bit(n, relmap, bits) {
Paul Jackson7ea931c2008-04-28 02:12:29 -07001012 /* m == bitmap_pos_to_ord(relmap, n, bits) */
1013 if (test_bit(m, orig))
1014 set_bit(n, dst);
1015 m++;
1016 }
1017}
1018EXPORT_SYMBOL(bitmap_onto);
1019
1020/**
1021 * bitmap_fold - fold larger bitmap into smaller, modulo specified size
1022 * @dst: resulting smaller bitmap
1023 * @orig: original larger bitmap
1024 * @sz: specified size
Rasmus Villemoesb26ad582015-02-12 15:02:04 -08001025 * @nbits: number of bits in each of these bitmaps
Paul Jackson7ea931c2008-04-28 02:12:29 -07001026 *
1027 * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
1028 * Clear all other bits in @dst. See further the comment and
1029 * Example [2] for bitmap_onto() for why and how to use this.
1030 */
1031void bitmap_fold(unsigned long *dst, const unsigned long *orig,
Rasmus Villemoesb26ad582015-02-12 15:02:04 -08001032 unsigned int sz, unsigned int nbits)
Paul Jackson7ea931c2008-04-28 02:12:29 -07001033{
Rasmus Villemoesb26ad582015-02-12 15:02:04 -08001034 unsigned int oldbit;
Paul Jackson7ea931c2008-04-28 02:12:29 -07001035
1036 if (dst == orig) /* following doesn't handle inplace mappings */
1037 return;
Rasmus Villemoesb26ad582015-02-12 15:02:04 -08001038 bitmap_zero(dst, nbits);
Paul Jackson7ea931c2008-04-28 02:12:29 -07001039
Rasmus Villemoesb26ad582015-02-12 15:02:04 -08001040 for_each_set_bit(oldbit, orig, nbits)
Paul Jackson7ea931c2008-04-28 02:12:29 -07001041 set_bit(oldbit % sz, dst);
1042}
1043EXPORT_SYMBOL(bitmap_fold);
1044
Paul Jackson3cf64b92006-03-24 03:15:46 -08001045/*
1046 * Common code for bitmap_*_region() routines.
1047 * bitmap: array of unsigned longs corresponding to the bitmap
1048 * pos: the beginning of the region
1049 * order: region size (log base 2 of number of bits)
1050 * reg_op: operation(s) to perform on that region of bitmap
1051 *
1052 * Can set, verify and/or release a region of bits in a bitmap,
1053 * depending on which combination of REG_OP_* flag bits is set.
1054 *
1055 * A region of a bitmap is a sequence of bits in the bitmap, of
1056 * some size '1 << order' (a power of two), aligned to that same
1057 * '1 << order' power of two.
1058 *
1059 * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
1060 * Returns 0 in all other cases and reg_ops.
1061 */
1062
1063enum {
1064 REG_OP_ISFREE, /* true if region is all zero bits */
1065 REG_OP_ALLOC, /* set all bits in region */
1066 REG_OP_RELEASE, /* clear all bits in region */
1067};
1068
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001069static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op)
Paul Jackson3cf64b92006-03-24 03:15:46 -08001070{
1071 int nbits_reg; /* number of bits in region */
1072 int index; /* index first long of region in bitmap */
1073 int offset; /* bit offset region in bitmap[index] */
1074 int nlongs_reg; /* num longs spanned by region in bitmap */
1075 int nbitsinlong; /* num bits of region in each spanned long */
1076 unsigned long mask; /* bitmask for one long of region */
1077 int i; /* scans bitmap by longs */
1078 int ret = 0; /* return value */
1079
1080 /*
1081 * Either nlongs_reg == 1 (for small orders that fit in one long)
1082 * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
1083 */
1084 nbits_reg = 1 << order;
1085 index = pos / BITS_PER_LONG;
1086 offset = pos - (index * BITS_PER_LONG);
1087 nlongs_reg = BITS_TO_LONGS(nbits_reg);
1088 nbitsinlong = min(nbits_reg, BITS_PER_LONG);
1089
1090 /*
1091 * Can't do "mask = (1UL << nbitsinlong) - 1", as that
1092 * overflows if nbitsinlong == BITS_PER_LONG.
1093 */
1094 mask = (1UL << (nbitsinlong - 1));
1095 mask += mask - 1;
1096 mask <<= offset;
1097
1098 switch (reg_op) {
1099 case REG_OP_ISFREE:
1100 for (i = 0; i < nlongs_reg; i++) {
1101 if (bitmap[index + i] & mask)
1102 goto done;
1103 }
1104 ret = 1; /* all bits in region free (zero) */
1105 break;
1106
1107 case REG_OP_ALLOC:
1108 for (i = 0; i < nlongs_reg; i++)
1109 bitmap[index + i] |= mask;
1110 break;
1111
1112 case REG_OP_RELEASE:
1113 for (i = 0; i < nlongs_reg; i++)
1114 bitmap[index + i] &= ~mask;
1115 break;
1116 }
1117done:
1118 return ret;
1119}
1120
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121/**
Paul Jackson87e24802006-03-24 03:15:44 -08001122 * bitmap_find_free_region - find a contiguous aligned mem region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001123 * @bitmap: array of unsigned longs corresponding to the bitmap
Linus Torvalds1da177e2005-04-16 15:20:36 -07001124 * @bits: number of bits in the bitmap
Paul Jackson3cf64b92006-03-24 03:15:46 -08001125 * @order: region size (log base 2 of number of bits) to find
Linus Torvalds1da177e2005-04-16 15:20:36 -07001126 *
Paul Jackson3cf64b92006-03-24 03:15:46 -08001127 * Find a region of free (zero) bits in a @bitmap of @bits bits and
1128 * allocate them (set them to one). Only consider regions of length
1129 * a power (@order) of two, aligned to that power of two, which
Paul Jackson87e24802006-03-24 03:15:44 -08001130 * makes the search algorithm much faster.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131 *
Paul Jackson3cf64b92006-03-24 03:15:46 -08001132 * Return the bit offset in bitmap of the allocated region,
Paul Jackson87e24802006-03-24 03:15:44 -08001133 * or -errno on failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001135int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136{
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001137 unsigned int pos, end; /* scans bitmap by regions of size order */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001139 for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) {
Linus Torvaldsaa8e4fc2009-03-12 19:32:51 -07001140 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1141 continue;
1142 __reg_op(bitmap, pos, order, REG_OP_ALLOC);
1143 return pos;
1144 }
1145 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146}
1147EXPORT_SYMBOL(bitmap_find_free_region);
1148
1149/**
Paul Jackson87e24802006-03-24 03:15:44 -08001150 * bitmap_release_region - release allocated bitmap region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001151 * @bitmap: array of unsigned longs corresponding to the bitmap
1152 * @pos: beginning of bit region to release
1153 * @order: region size (log base 2 of number of bits) to release
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08001155 * This is the complement to __bitmap_find_free_region() and releases
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 * the found region (by clearing it in the bitmap).
Paul Jackson3cf64b92006-03-24 03:15:46 -08001157 *
1158 * No return value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001160void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161{
Paul Jackson3cf64b92006-03-24 03:15:46 -08001162 __reg_op(bitmap, pos, order, REG_OP_RELEASE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163}
1164EXPORT_SYMBOL(bitmap_release_region);
1165
Paul Jackson87e24802006-03-24 03:15:44 -08001166/**
1167 * bitmap_allocate_region - allocate bitmap region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001168 * @bitmap: array of unsigned longs corresponding to the bitmap
1169 * @pos: beginning of bit region to allocate
1170 * @order: region size (log base 2 of number of bits) to allocate
Paul Jackson87e24802006-03-24 03:15:44 -08001171 *
1172 * Allocate (set bits in) a specified region of a bitmap.
Paul Jackson3cf64b92006-03-24 03:15:46 -08001173 *
Randy Dunlap6e1907ff2006-06-25 05:48:57 -07001174 * Return 0 on success, or %-EBUSY if specified region wasn't
Paul Jackson87e24802006-03-24 03:15:44 -08001175 * free (not all bits were zero).
1176 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001177int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178{
Paul Jackson3cf64b92006-03-24 03:15:46 -08001179 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1180 return -EBUSY;
Rasmus Villemoes2ac521d2014-08-06 16:10:18 -07001181 return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182}
1183EXPORT_SYMBOL(bitmap_allocate_region);
David Vrabelccbe3292008-09-17 16:34:03 +01001184
1185/**
1186 * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
1187 * @dst: destination buffer
1188 * @src: bitmap to copy
1189 * @nbits: number of bits in the bitmap
1190 *
1191 * Require nbits % BITS_PER_LONG == 0.
1192 */
Rasmus Villemoese8f24272015-02-13 14:36:00 -08001193#ifdef __BIG_ENDIAN
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001194void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits)
David Vrabelccbe3292008-09-17 16:34:03 +01001195{
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001196 unsigned int i;
David Vrabelccbe3292008-09-17 16:34:03 +01001197
1198 for (i = 0; i < nbits/BITS_PER_LONG; i++) {
1199 if (BITS_PER_LONG == 64)
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001200 dst[i] = cpu_to_le64(src[i]);
David Vrabelccbe3292008-09-17 16:34:03 +01001201 else
Rasmus Villemoes9b6c2d22015-02-13 14:35:57 -08001202 dst[i] = cpu_to_le32(src[i]);
David Vrabelccbe3292008-09-17 16:34:03 +01001203 }
1204}
1205EXPORT_SYMBOL(bitmap_copy_le);
Rasmus Villemoese8f24272015-02-13 14:36:00 -08001206#endif