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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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <asm/uaccess.h>
16
17/*
18 * bitmaps provide an array of bits, implemented using an an
19 * array of unsigned longs. The number of valid bits in a
20 * given bitmap does _not_ need to be an exact multiple of
21 * BITS_PER_LONG.
22 *
23 * The possible unused bits in the last, partially used word
24 * of a bitmap are 'don't care'. The implementation makes
25 * no particular effort to keep them zero. It ensures that
26 * their value will not affect the results of any operation.
27 * The bitmap operations that return Boolean (bitmap_empty,
28 * for example) or scalar (bitmap_weight, for example) results
29 * carefully filter out these unused bits from impacting their
30 * results.
31 *
32 * These operations actually hold to a slightly stronger rule:
33 * if you don't input any bitmaps to these ops that have some
34 * unused bits set, then they won't output any set unused bits
35 * in output bitmaps.
36 *
37 * The byte ordering of bitmaps is more natural on little
38 * endian architectures. See the big-endian headers
39 * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h
40 * for the best explanations of this ordering.
41 */
42
Rasmus Villemoes0679cc42014-08-06 16:09:49 -070043int __bitmap_empty(const unsigned long *bitmap, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -070044{
Rasmus Villemoes0679cc42014-08-06 16:09:49 -070045 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 for (k = 0; k < lim; ++k)
47 if (bitmap[k])
48 return 0;
49
50 if (bits % BITS_PER_LONG)
51 if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
52 return 0;
53
54 return 1;
55}
56EXPORT_SYMBOL(__bitmap_empty);
57
Rasmus Villemoes83979272014-08-06 16:09:51 -070058int __bitmap_full(const unsigned long *bitmap, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -070059{
Rasmus Villemoes83979272014-08-06 16:09:51 -070060 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 for (k = 0; k < lim; ++k)
62 if (~bitmap[k])
63 return 0;
64
65 if (bits % BITS_PER_LONG)
66 if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits))
67 return 0;
68
69 return 1;
70}
71EXPORT_SYMBOL(__bitmap_full);
72
73int __bitmap_equal(const unsigned long *bitmap1,
Rasmus Villemoes5e0680692014-08-06 16:09:53 -070074 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -070075{
Rasmus Villemoes5e0680692014-08-06 16:09:53 -070076 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 for (k = 0; k < lim; ++k)
78 if (bitmap1[k] != bitmap2[k])
79 return 0;
80
81 if (bits % BITS_PER_LONG)
82 if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
83 return 0;
84
85 return 1;
86}
87EXPORT_SYMBOL(__bitmap_equal);
88
Rasmus Villemoes3d6684f2014-08-06 16:09:55 -070089void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -070090{
Rasmus Villemoes3d6684f2014-08-06 16:09:55 -070091 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 for (k = 0; k < lim; ++k)
93 dst[k] = ~src[k];
94
95 if (bits % BITS_PER_LONG)
Rasmus Villemoes65b4ee62014-08-06 16:09:57 -070096 dst[k] = ~src[k];
Linus Torvalds1da177e2005-04-16 15:20:36 -070097}
98EXPORT_SYMBOL(__bitmap_complement);
99
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800100/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 * __bitmap_shift_right - logical right shift of the bits in a bitmap
Randy Dunlap05fb6bf2007-02-28 20:12:13 -0800102 * @dst : destination bitmap
103 * @src : source bitmap
104 * @shift : shift by this many bits
105 * @bits : bitmap size, in bits
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 *
107 * Shifting right (dividing) means moving bits in the MS -> LS bit
108 * direction. Zeros are fed into the vacated MS positions and the
109 * LS bits shifted off the bottom are lost.
110 */
111void __bitmap_shift_right(unsigned long *dst,
112 const unsigned long *src, int shift, int bits)
113{
114 int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
115 int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
116 unsigned long mask = (1UL << left) - 1;
117 for (k = 0; off + k < lim; ++k) {
118 unsigned long upper, lower;
119
120 /*
121 * If shift is not word aligned, take lower rem bits of
122 * word above and make them the top rem bits of result.
123 */
124 if (!rem || off + k + 1 >= lim)
125 upper = 0;
126 else {
127 upper = src[off + k + 1];
128 if (off + k + 1 == lim - 1 && left)
129 upper &= mask;
130 }
131 lower = src[off + k];
132 if (left && off + k == lim - 1)
133 lower &= mask;
134 dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem;
135 if (left && k == lim - 1)
136 dst[k] &= mask;
137 }
138 if (off)
139 memset(&dst[lim - off], 0, off*sizeof(unsigned long));
140}
141EXPORT_SYMBOL(__bitmap_shift_right);
142
143
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800144/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 * __bitmap_shift_left - logical left shift of the bits in a bitmap
Randy Dunlap05fb6bf2007-02-28 20:12:13 -0800146 * @dst : destination bitmap
147 * @src : source bitmap
148 * @shift : shift by this many bits
149 * @bits : bitmap size, in bits
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 *
151 * Shifting left (multiplying) means moving bits in the LS -> MS
152 * direction. Zeros are fed into the vacated LS bit positions
153 * and those MS bits shifted off the top are lost.
154 */
155
156void __bitmap_shift_left(unsigned long *dst,
157 const unsigned long *src, int shift, int bits)
158{
159 int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG;
160 int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG;
161 for (k = lim - off - 1; k >= 0; --k) {
162 unsigned long upper, lower;
163
164 /*
165 * If shift is not word aligned, take upper rem bits of
166 * word below and make them the bottom rem bits of result.
167 */
168 if (rem && k > 0)
169 lower = src[k - 1];
170 else
171 lower = 0;
172 upper = src[k];
173 if (left && k == lim - 1)
174 upper &= (1UL << left) - 1;
175 dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem;
176 if (left && k + off == lim - 1)
177 dst[k + off] &= (1UL << left) - 1;
178 }
179 if (off)
180 memset(dst, 0, off*sizeof(unsigned long));
181}
182EXPORT_SYMBOL(__bitmap_shift_left);
183
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700184int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700185 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700187 unsigned int k;
188 unsigned int nr = BITS_TO_LONGS(bits);
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700189 unsigned long result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190
191 for (k = 0; k < nr; k++)
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700192 result |= (dst[k] = bitmap1[k] & bitmap2[k]);
193 return result != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194}
195EXPORT_SYMBOL(__bitmap_and);
196
197void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700198 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700200 unsigned int k;
201 unsigned int nr = BITS_TO_LONGS(bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
203 for (k = 0; k < nr; k++)
204 dst[k] = bitmap1[k] | bitmap2[k];
205}
206EXPORT_SYMBOL(__bitmap_or);
207
208void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700209 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700211 unsigned int k;
212 unsigned int nr = BITS_TO_LONGS(bits);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
214 for (k = 0; k < nr; k++)
215 dst[k] = bitmap1[k] ^ bitmap2[k];
216}
217EXPORT_SYMBOL(__bitmap_xor);
218
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700219int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1,
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700220 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221{
Rasmus Villemoes2f9305e2014-08-06 16:09:59 -0700222 unsigned int k;
223 unsigned int nr = BITS_TO_LONGS(bits);
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700224 unsigned long result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
226 for (k = 0; k < nr; k++)
Linus Torvaldsf4b03732009-08-21 09:26:15 -0700227 result |= (dst[k] = bitmap1[k] & ~bitmap2[k]);
228 return result != 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229}
230EXPORT_SYMBOL(__bitmap_andnot);
231
232int __bitmap_intersects(const unsigned long *bitmap1,
Rasmus Villemoes6dfe9792014-08-06 16:10:01 -0700233 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234{
Rasmus Villemoes6dfe9792014-08-06 16:10:01 -0700235 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 for (k = 0; k < lim; ++k)
237 if (bitmap1[k] & bitmap2[k])
238 return 1;
239
240 if (bits % BITS_PER_LONG)
241 if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
242 return 1;
243 return 0;
244}
245EXPORT_SYMBOL(__bitmap_intersects);
246
247int __bitmap_subset(const unsigned long *bitmap1,
Rasmus Villemoes5be20212014-08-06 16:10:03 -0700248 const unsigned long *bitmap2, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249{
Rasmus Villemoes5be20212014-08-06 16:10:03 -0700250 unsigned int k, lim = bits/BITS_PER_LONG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 for (k = 0; k < lim; ++k)
252 if (bitmap1[k] & ~bitmap2[k])
253 return 0;
254
255 if (bits % BITS_PER_LONG)
256 if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits))
257 return 0;
258 return 1;
259}
260EXPORT_SYMBOL(__bitmap_subset);
261
Rasmus Villemoes877d9f32014-08-06 16:10:05 -0700262int __bitmap_weight(const unsigned long *bitmap, unsigned int bits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263{
Rasmus Villemoes877d9f32014-08-06 16:10:05 -0700264 unsigned int k, lim = bits/BITS_PER_LONG;
265 int w = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
267 for (k = 0; k < lim; k++)
Akinobu Mita37d54112006-03-26 01:39:56 -0800268 w += hweight_long(bitmap[k]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
270 if (bits % BITS_PER_LONG)
Akinobu Mita37d54112006-03-26 01:39:56 -0800271 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
273 return w;
274}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275EXPORT_SYMBOL(__bitmap_weight);
276
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700277void bitmap_set(unsigned long *map, unsigned int start, int len)
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800278{
279 unsigned long *p = map + BIT_WORD(start);
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700280 const unsigned int size = start + len;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800281 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
282 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
283
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700284 while (len - bits_to_set >= 0) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800285 *p |= mask_to_set;
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700286 len -= bits_to_set;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800287 bits_to_set = BITS_PER_LONG;
288 mask_to_set = ~0UL;
289 p++;
290 }
Rasmus Villemoesfb5ac542014-08-06 16:10:07 -0700291 if (len) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800292 mask_to_set &= BITMAP_LAST_WORD_MASK(size);
293 *p |= mask_to_set;
294 }
295}
296EXPORT_SYMBOL(bitmap_set);
297
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700298void bitmap_clear(unsigned long *map, unsigned int start, int len)
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800299{
300 unsigned long *p = map + BIT_WORD(start);
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700301 const unsigned int size = start + len;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800302 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
303 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
304
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700305 while (len - bits_to_clear >= 0) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800306 *p &= ~mask_to_clear;
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700307 len -= bits_to_clear;
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800308 bits_to_clear = BITS_PER_LONG;
309 mask_to_clear = ~0UL;
310 p++;
311 }
Rasmus Villemoes154f5e32014-08-06 16:10:10 -0700312 if (len) {
Akinobu Mitac1a2a962009-12-15 16:48:25 -0800313 mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
314 *p &= ~mask_to_clear;
315 }
316}
317EXPORT_SYMBOL(bitmap_clear);
318
319/*
320 * bitmap_find_next_zero_area - find a contiguous aligned zero area
321 * @map: The address to base the search on
322 * @size: The bitmap size in bits
323 * @start: The bitnumber to start searching at
324 * @nr: The number of zeroed bits we're looking for
325 * @align_mask: Alignment mask for zero area
326 *
327 * The @align_mask should be one less than a power of 2; the effect is that
328 * the bit offset of all zero areas this function finds is multiples of that
329 * power of 2. A @align_mask of 0 means no alignment is required.
330 */
331unsigned long bitmap_find_next_zero_area(unsigned long *map,
332 unsigned long size,
333 unsigned long start,
334 unsigned int nr,
335 unsigned long align_mask)
336{
337 unsigned long index, end, i;
338again:
339 index = find_next_zero_bit(map, size, start);
340
341 /* Align allocation */
342 index = __ALIGN_MASK(index, align_mask);
343
344 end = index + nr;
345 if (end > size)
346 return end;
347 i = find_next_bit(map, end, index);
348 if (i < end) {
349 start = i + 1;
350 goto again;
351 }
352 return index;
353}
354EXPORT_SYMBOL(bitmap_find_next_zero_area);
355
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356/*
Nadia Yvette Chambers6d49e352012-12-06 10:39:54 +0100357 * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 * second version by Paul Jackson, third by Joe Korty.
359 */
360
361#define CHUNKSZ 32
362#define nbits_to_hold_value(val) fls(val)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363#define BASEDEC 10 /* fancier cpuset lists input in decimal */
364
365/**
366 * bitmap_scnprintf - convert bitmap to an ASCII hex string.
367 * @buf: byte buffer into which string is placed
368 * @buflen: reserved size of @buf, in bytes
369 * @maskp: pointer to bitmap to convert
370 * @nmaskbits: size of bitmap, in bits
371 *
372 * Exactly @nmaskbits bits are displayed. Hex digits are grouped into
Andrew Morton05a6c8a2012-05-29 15:07:32 -0700373 * comma-separated sets of eight digits per set. Returns the number of
374 * characters which were written to *buf, excluding the trailing \0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 */
376int bitmap_scnprintf(char *buf, unsigned int buflen,
377 const unsigned long *maskp, int nmaskbits)
378{
379 int i, word, bit, len = 0;
380 unsigned long val;
381 const char *sep = "";
382 int chunksz;
383 u32 chunkmask;
384
385 chunksz = nmaskbits & (CHUNKSZ - 1);
386 if (chunksz == 0)
387 chunksz = CHUNKSZ;
388
Nick Wilson8c0e33c2005-06-25 14:59:00 -0700389 i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 for (; i >= 0; i -= CHUNKSZ) {
391 chunkmask = ((1ULL << chunksz) - 1);
392 word = i / BITS_PER_LONG;
393 bit = i % BITS_PER_LONG;
394 val = (maskp[word] >> bit) & chunkmask;
395 len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep,
396 (chunksz+3)/4, val);
397 chunksz = CHUNKSZ;
398 sep = ",";
399 }
400 return len;
401}
402EXPORT_SYMBOL(bitmap_scnprintf);
403
404/**
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700405 * __bitmap_parse - convert an ASCII hex string into a bitmap.
406 * @buf: pointer to buffer containing string.
407 * @buflen: buffer size in bytes. If string is smaller than this
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 * then it must be terminated with a \0.
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700409 * @is_user: location of buffer, 0 indicates kernel space
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 * @maskp: pointer to bitmap array that will contain result.
411 * @nmaskbits: size of bitmap, in bits.
412 *
413 * Commas group hex digits into chunks. Each chunk defines exactly 32
414 * bits of the resultant bitmask. No chunk may specify a value larger
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700415 * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value
416 * then leading 0-bits are prepended. %-EINVAL is returned for illegal
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 * characters and for grouping errors such as "1,,5", ",44", "," and "".
418 * Leading and trailing whitespace accepted, but not embedded whitespace.
419 */
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700420int __bitmap_parse(const char *buf, unsigned int buflen,
421 int is_user, unsigned long *maskp,
422 int nmaskbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423{
424 int c, old_c, totaldigits, ndigits, nchunks, nbits;
425 u32 chunk;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700426 const char __user __force *ubuf = (const char __user __force *)buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427
428 bitmap_zero(maskp, nmaskbits);
429
430 nchunks = nbits = totaldigits = c = 0;
431 do {
432 chunk = ndigits = 0;
433
434 /* Get the next chunk of the bitmap */
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700435 while (buflen) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 old_c = c;
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700437 if (is_user) {
438 if (__get_user(c, ubuf++))
439 return -EFAULT;
440 }
441 else
442 c = *buf++;
443 buflen--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 if (isspace(c))
445 continue;
446
447 /*
448 * If the last character was a space and the current
449 * character isn't '\0', we've got embedded whitespace.
450 * This is a no-no, so throw an error.
451 */
452 if (totaldigits && c && isspace(old_c))
453 return -EINVAL;
454
455 /* A '\0' or a ',' signal the end of the chunk */
456 if (c == '\0' || c == ',')
457 break;
458
459 if (!isxdigit(c))
460 return -EINVAL;
461
462 /*
463 * Make sure there are at least 4 free bits in 'chunk'.
464 * If not, this hexdigit will overflow 'chunk', so
465 * throw an error.
466 */
467 if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1))
468 return -EOVERFLOW;
469
Andy Shevchenko66f19912010-10-26 14:23:03 -0700470 chunk = (chunk << 4) | hex_to_bin(c);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 ndigits++; totaldigits++;
472 }
473 if (ndigits == 0)
474 return -EINVAL;
475 if (nchunks == 0 && chunk == 0)
476 continue;
477
478 __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits);
479 *maskp |= chunk;
480 nchunks++;
481 nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ;
482 if (nbits > nmaskbits)
483 return -EOVERFLOW;
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700484 } while (buflen && c == ',');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485
486 return 0;
487}
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700488EXPORT_SYMBOL(__bitmap_parse);
489
490/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800491 * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700492 *
493 * @ubuf: pointer to user buffer containing string.
494 * @ulen: buffer size in bytes. If string is smaller than this
495 * then it must be terminated with a \0.
496 * @maskp: pointer to bitmap array that will contain result.
497 * @nmaskbits: size of bitmap, in bits.
498 *
499 * Wrapper for __bitmap_parse(), providing it with user buffer.
500 *
501 * We cannot have this as an inline function in bitmap.h because it needs
502 * linux/uaccess.h to get the access_ok() declaration and this causes
503 * cyclic dependencies.
504 */
505int bitmap_parse_user(const char __user *ubuf,
506 unsigned int ulen, unsigned long *maskp,
507 int nmaskbits)
508{
509 if (!access_ok(VERIFY_READ, ubuf, ulen))
510 return -EFAULT;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700511 return __bitmap_parse((const char __force *)ubuf,
512 ulen, 1, maskp, nmaskbits);
513
Reinette Chatre01a3ee22006-10-11 01:21:55 -0700514}
515EXPORT_SYMBOL(bitmap_parse_user);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
517/*
518 * bscnl_emit(buf, buflen, rbot, rtop, bp)
519 *
520 * Helper routine for bitmap_scnlistprintf(). Write decimal number
521 * or range to buf, suppressing output past buf+buflen, with optional
Andrew Morton05a6c8a2012-05-29 15:07:32 -0700522 * comma-prefix. Return len of what was written to *buf, excluding the
523 * trailing \0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 */
525static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len)
526{
527 if (len > 0)
528 len += scnprintf(buf + len, buflen - len, ",");
529 if (rbot == rtop)
530 len += scnprintf(buf + len, buflen - len, "%d", rbot);
531 else
532 len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop);
533 return len;
534}
535
536/**
537 * bitmap_scnlistprintf - convert bitmap to list format ASCII string
538 * @buf: byte buffer into which string is placed
539 * @buflen: reserved size of @buf, in bytes
540 * @maskp: pointer to bitmap to convert
541 * @nmaskbits: size of bitmap, in bits
542 *
543 * Output format is a comma-separated list of decimal numbers and
544 * ranges. Consecutively set bits are shown as two hyphen-separated
545 * decimal numbers, the smallest and largest bit numbers set in
546 * the range. Output format is compatible with the format
547 * accepted as input by bitmap_parselist().
548 *
Andrew Morton05a6c8a2012-05-29 15:07:32 -0700549 * The return value is the number of characters which were written to *buf
550 * excluding the trailing '\0', as per ISO C99's scnprintf.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551 */
552int bitmap_scnlistprintf(char *buf, unsigned int buflen,
553 const unsigned long *maskp, int nmaskbits)
554{
555 int len = 0;
556 /* current bit is 'cur', most recently seen range is [rbot, rtop] */
557 int cur, rbot, rtop;
558
Andi Kleen0b030c22007-11-05 14:50:56 -0800559 if (buflen == 0)
560 return 0;
561 buf[0] = 0;
562
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 rbot = cur = find_first_bit(maskp, nmaskbits);
564 while (cur < nmaskbits) {
565 rtop = cur;
566 cur = find_next_bit(maskp, nmaskbits, cur+1);
567 if (cur >= nmaskbits || cur > rtop + 1) {
568 len = bscnl_emit(buf, buflen, rbot, rtop, len);
569 rbot = cur;
570 }
571 }
572 return len;
573}
574EXPORT_SYMBOL(bitmap_scnlistprintf);
575
576/**
Mike Travis4b060422011-05-24 17:13:12 -0700577 * __bitmap_parselist - convert list format ASCII string to bitmap
Randy Dunlapb0825ee2011-06-15 15:08:10 -0700578 * @buf: read nul-terminated user string from this buffer
Mike Travis4b060422011-05-24 17:13:12 -0700579 * @buflen: buffer size in bytes. If string is smaller than this
580 * then it must be terminated with a \0.
581 * @is_user: location of buffer, 0 indicates kernel space
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700582 * @maskp: write resulting mask here
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 * @nmaskbits: number of bits in mask to be written
584 *
585 * Input format is a comma-separated list of decimal numbers and
586 * ranges. Consecutively set bits are shown as two hyphen-separated
587 * decimal numbers, the smallest and largest bit numbers set in
588 * the range.
589 *
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700590 * Returns 0 on success, -errno on invalid input strings.
591 * Error values:
592 * %-EINVAL: second number in range smaller than first
593 * %-EINVAL: invalid character in string
594 * %-ERANGE: bit number specified too large for mask
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 */
Mike Travis4b060422011-05-24 17:13:12 -0700596static int __bitmap_parselist(const char *buf, unsigned int buflen,
597 int is_user, unsigned long *maskp,
598 int nmaskbits)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599{
600 unsigned a, b;
Mike Travis4b060422011-05-24 17:13:12 -0700601 int c, old_c, totaldigits;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700602 const char __user __force *ubuf = (const char __user __force *)buf;
Mike Travis4b060422011-05-24 17:13:12 -0700603 int exp_digit, in_range;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604
Mike Travis4b060422011-05-24 17:13:12 -0700605 totaldigits = c = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 bitmap_zero(maskp, nmaskbits);
607 do {
Mike Travis4b060422011-05-24 17:13:12 -0700608 exp_digit = 1;
609 in_range = 0;
610 a = b = 0;
611
612 /* Get the next cpu# or a range of cpu#'s */
613 while (buflen) {
614 old_c = c;
615 if (is_user) {
616 if (__get_user(c, ubuf++))
617 return -EFAULT;
618 } else
619 c = *buf++;
620 buflen--;
621 if (isspace(c))
622 continue;
623
624 /*
625 * If the last character was a space and the current
626 * character isn't '\0', we've got embedded whitespace.
627 * This is a no-no, so throw an error.
628 */
629 if (totaldigits && c && isspace(old_c))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 return -EINVAL;
Mike Travis4b060422011-05-24 17:13:12 -0700631
632 /* A '\0' or a ',' signal the end of a cpu# or range */
633 if (c == '\0' || c == ',')
634 break;
635
636 if (c == '-') {
637 if (exp_digit || in_range)
638 return -EINVAL;
639 b = 0;
640 in_range = 1;
641 exp_digit = 1;
642 continue;
643 }
644
645 if (!isdigit(c))
646 return -EINVAL;
647
648 b = b * 10 + (c - '0');
649 if (!in_range)
650 a = b;
651 exp_digit = 0;
652 totaldigits++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 }
654 if (!(a <= b))
655 return -EINVAL;
656 if (b >= nmaskbits)
657 return -ERANGE;
658 while (a <= b) {
659 set_bit(a, maskp);
660 a++;
661 }
Mike Travis4b060422011-05-24 17:13:12 -0700662 } while (buflen && c == ',');
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 return 0;
664}
Mike Travis4b060422011-05-24 17:13:12 -0700665
666int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits)
667{
Rasmus Villemoesbc5be182014-08-06 16:10:12 -0700668 char *nl = strchrnul(bp, '\n');
669 int len = nl - bp;
Mike Travis4b060422011-05-24 17:13:12 -0700670
671 return __bitmap_parselist(bp, len, 0, maskp, nmaskbits);
672}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673EXPORT_SYMBOL(bitmap_parselist);
674
Mike Travis4b060422011-05-24 17:13:12 -0700675
676/**
677 * bitmap_parselist_user()
678 *
679 * @ubuf: pointer to user buffer containing string.
680 * @ulen: buffer size in bytes. If string is smaller than this
681 * then it must be terminated with a \0.
682 * @maskp: pointer to bitmap array that will contain result.
683 * @nmaskbits: size of bitmap, in bits.
684 *
685 * Wrapper for bitmap_parselist(), providing it with user buffer.
686 *
687 * We cannot have this as an inline function in bitmap.h because it needs
688 * linux/uaccess.h to get the access_ok() declaration and this causes
689 * cyclic dependencies.
690 */
691int bitmap_parselist_user(const char __user *ubuf,
692 unsigned int ulen, unsigned long *maskp,
693 int nmaskbits)
694{
695 if (!access_ok(VERIFY_READ, ubuf, ulen))
696 return -EFAULT;
H Hartley Sweetenb9c321f2011-10-31 17:12:32 -0700697 return __bitmap_parselist((const char __force *)ubuf,
Mike Travis4b060422011-05-24 17:13:12 -0700698 ulen, 1, maskp, nmaskbits);
699}
700EXPORT_SYMBOL(bitmap_parselist_user);
701
702
Robert P. J. Day72fd4a32007-02-10 01:45:59 -0800703/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800704 * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800705 * @buf: pointer to a bitmap
706 * @pos: a bit position in @buf (0 <= @pos < @bits)
707 * @bits: number of valid bit positions in @buf
708 *
709 * Map the bit at position @pos in @buf (of length @bits) to the
710 * ordinal of which set bit it is. If it is not set or if @pos
Paul Jackson96b7f342006-01-08 01:01:46 -0800711 * is not a valid bit position, map to -1.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800712 *
713 * If for example, just bits 4 through 7 are set in @buf, then @pos
714 * values 4 through 7 will get mapped to 0 through 3, respectively,
Rasmus Villemoesa8551742014-08-06 16:10:14 -0700715 * and other @pos values will get mapped to -1. When @pos value 7
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800716 * gets mapped to (returns) @ord value 3 in this example, that means
717 * that bit 7 is the 3rd (starting with 0th) set bit in @buf.
718 *
719 * The bit positions 0 through @bits are valid positions in @buf.
720 */
721static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits)
722{
Paul Jackson96b7f342006-01-08 01:01:46 -0800723 int i, ord;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800724
Paul Jackson96b7f342006-01-08 01:01:46 -0800725 if (pos < 0 || pos >= bits || !test_bit(pos, buf))
726 return -1;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800727
Paul Jackson96b7f342006-01-08 01:01:46 -0800728 i = find_first_bit(buf, bits);
729 ord = 0;
730 while (i < pos) {
731 i = find_next_bit(buf, bits, i + 1);
732 ord++;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800733 }
Paul Jackson96b7f342006-01-08 01:01:46 -0800734 BUG_ON(i != pos);
735
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800736 return ord;
737}
738
739/**
Ben Hutchings9a86e2b2010-03-05 13:43:17 -0800740 * bitmap_ord_to_pos - find position of n-th set bit in bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800741 * @buf: pointer to bitmap
742 * @ord: ordinal bit position (n-th set bit, n >= 0)
743 * @bits: number of valid bit positions in @buf
744 *
745 * Map the ordinal offset of bit @ord in @buf to its position in @buf.
Paul Jackson96b7f342006-01-08 01:01:46 -0800746 * Value of @ord should be in range 0 <= @ord < weight(buf), else
747 * results are undefined.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800748 *
749 * If for example, just bits 4 through 7 are set in @buf, then @ord
750 * values 0 through 3 will get mapped to 4 through 7, respectively,
Paul Jackson96b7f342006-01-08 01:01:46 -0800751 * and all other @ord values return undefined values. When @ord value 3
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800752 * gets mapped to (returns) @pos value 7 in this example, that means
753 * that the 3rd set bit (starting with 0th) is at position 7 in @buf.
754 *
755 * The bit positions 0 through @bits are valid positions in @buf.
756 */
Michal Hocko778d3b02011-07-26 16:08:30 -0700757int bitmap_ord_to_pos(const unsigned long *buf, int ord, int bits)
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800758{
759 int pos = 0;
760
761 if (ord >= 0 && ord < bits) {
762 int i;
763
764 for (i = find_first_bit(buf, bits);
765 i < bits && ord > 0;
766 i = find_next_bit(buf, bits, i + 1))
767 ord--;
768 if (i < bits && ord == 0)
769 pos = i;
770 }
771
772 return pos;
773}
774
775/**
776 * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800777 * @dst: remapped result
Paul Jackson96b7f342006-01-08 01:01:46 -0800778 * @src: subset to be remapped
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800779 * @old: defines domain of map
780 * @new: defines range of map
781 * @bits: number of bits in each of these bitmaps
782 *
783 * Let @old and @new define a mapping of bit positions, such that
784 * whatever position is held by the n-th set bit in @old is mapped
785 * to the n-th set bit in @new. In the more general case, allowing
786 * for the possibility that the weight 'w' of @new is less than the
787 * weight of @old, map the position of the n-th set bit in @old to
788 * the position of the m-th set bit in @new, where m == n % w.
789 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800790 * If either of the @old and @new bitmaps are empty, or if @src and
791 * @dst point to the same location, then this routine copies @src
792 * to @dst.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800793 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800794 * The positions of unset bits in @old are mapped to themselves
795 * (the identify map).
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800796 *
797 * Apply the above specified mapping to @src, placing the result in
798 * @dst, clearing any bits previously set in @dst.
799 *
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800800 * For example, lets say that @old has bits 4 through 7 set, and
801 * @new has bits 12 through 15 set. This defines the mapping of bit
802 * 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 -0800803 * bit positions unchanged. So if say @src comes into this routine
804 * with bits 1, 5 and 7 set, then @dst should leave with bits 1,
805 * 13 and 15 set.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800806 */
807void bitmap_remap(unsigned long *dst, const unsigned long *src,
808 const unsigned long *old, const unsigned long *new,
809 int bits)
810{
Paul Jackson96b7f342006-01-08 01:01:46 -0800811 int oldbit, w;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800812
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800813 if (dst == src) /* following doesn't handle inplace remaps */
814 return;
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800815 bitmap_zero(dst, bits);
Paul Jackson96b7f342006-01-08 01:01:46 -0800816
817 w = bitmap_weight(new, bits);
Akinobu Mita08564fb2010-03-05 13:43:18 -0800818 for_each_set_bit(oldbit, src, bits) {
Paul Jackson96b7f342006-01-08 01:01:46 -0800819 int n = bitmap_pos_to_ord(old, oldbit, bits);
Akinobu Mita08564fb2010-03-05 13:43:18 -0800820
Paul Jackson96b7f342006-01-08 01:01:46 -0800821 if (n < 0 || w == 0)
822 set_bit(oldbit, dst); /* identity map */
823 else
824 set_bit(bitmap_ord_to_pos(new, n % w, bits), dst);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800825 }
826}
827EXPORT_SYMBOL(bitmap_remap);
828
829/**
830 * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit
Randy Dunlap6e1907ff2006-06-25 05:48:57 -0700831 * @oldbit: bit position to be mapped
832 * @old: defines domain of map
833 * @new: defines range of map
834 * @bits: number of bits in each of these bitmaps
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800835 *
836 * Let @old and @new define a mapping of bit positions, such that
837 * whatever position is held by the n-th set bit in @old is mapped
838 * to the n-th set bit in @new. In the more general case, allowing
839 * for the possibility that the weight 'w' of @new is less than the
840 * weight of @old, map the position of the n-th set bit in @old to
841 * the position of the m-th set bit in @new, where m == n % w.
842 *
Paul Jackson96b7f342006-01-08 01:01:46 -0800843 * The positions of unset bits in @old are mapped to themselves
844 * (the identify map).
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800845 *
846 * Apply the above specified mapping to bit position @oldbit, returning
847 * the new bit position.
848 *
849 * For example, lets say that @old has bits 4 through 7 set, and
850 * @new has bits 12 through 15 set. This defines the mapping of bit
851 * 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 -0800852 * bit positions unchanged. So if say @oldbit is 5, then this routine
853 * returns 13.
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800854 */
855int bitmap_bitremap(int oldbit, const unsigned long *old,
856 const unsigned long *new, int bits)
857{
Paul Jackson96b7f342006-01-08 01:01:46 -0800858 int w = bitmap_weight(new, bits);
859 int n = bitmap_pos_to_ord(old, oldbit, bits);
860 if (n < 0 || w == 0)
861 return oldbit;
862 else
863 return bitmap_ord_to_pos(new, n % w, bits);
Paul Jacksonfb5eeee2005-10-30 15:02:33 -0800864}
865EXPORT_SYMBOL(bitmap_bitremap);
866
Paul Jackson7ea931c2008-04-28 02:12:29 -0700867/**
868 * bitmap_onto - translate one bitmap relative to another
869 * @dst: resulting translated bitmap
870 * @orig: original untranslated bitmap
871 * @relmap: bitmap relative to which translated
872 * @bits: number of bits in each of these bitmaps
873 *
874 * Set the n-th bit of @dst iff there exists some m such that the
875 * n-th bit of @relmap is set, the m-th bit of @orig is set, and
876 * the n-th bit of @relmap is also the m-th _set_ bit of @relmap.
877 * (If you understood the previous sentence the first time your
878 * read it, you're overqualified for your current job.)
879 *
880 * In other words, @orig is mapped onto (surjectively) @dst,
881 * using the the map { <n, m> | the n-th bit of @relmap is the
882 * m-th set bit of @relmap }.
883 *
884 * Any set bits in @orig above bit number W, where W is the
885 * weight of (number of set bits in) @relmap are mapped nowhere.
886 * In particular, if for all bits m set in @orig, m >= W, then
887 * @dst will end up empty. In situations where the possibility
888 * of such an empty result is not desired, one way to avoid it is
889 * to use the bitmap_fold() operator, below, to first fold the
890 * @orig bitmap over itself so that all its set bits x are in the
891 * range 0 <= x < W. The bitmap_fold() operator does this by
892 * setting the bit (m % W) in @dst, for each bit (m) set in @orig.
893 *
894 * Example [1] for bitmap_onto():
895 * Let's say @relmap has bits 30-39 set, and @orig has bits
896 * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine,
897 * @dst will have bits 31, 33, 35, 37 and 39 set.
898 *
899 * When bit 0 is set in @orig, it means turn on the bit in
900 * @dst corresponding to whatever is the first bit (if any)
901 * that is turned on in @relmap. Since bit 0 was off in the
902 * above example, we leave off that bit (bit 30) in @dst.
903 *
904 * When bit 1 is set in @orig (as in the above example), it
905 * means turn on the bit in @dst corresponding to whatever
906 * is the second bit that is turned on in @relmap. The second
907 * bit in @relmap that was turned on in the above example was
908 * bit 31, so we turned on bit 31 in @dst.
909 *
910 * Similarly, we turned on bits 33, 35, 37 and 39 in @dst,
911 * because they were the 4th, 6th, 8th and 10th set bits
912 * set in @relmap, and the 4th, 6th, 8th and 10th bits of
913 * @orig (i.e. bits 3, 5, 7 and 9) were also set.
914 *
915 * When bit 11 is set in @orig, it means turn on the bit in
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300916 * @dst corresponding to whatever is the twelfth bit that is
Paul Jackson7ea931c2008-04-28 02:12:29 -0700917 * turned on in @relmap. In the above example, there were
918 * only ten bits turned on in @relmap (30..39), so that bit
919 * 11 was set in @orig had no affect on @dst.
920 *
921 * Example [2] for bitmap_fold() + bitmap_onto():
922 * Let's say @relmap has these ten bits set:
923 * 40 41 42 43 45 48 53 61 74 95
924 * (for the curious, that's 40 plus the first ten terms of the
925 * Fibonacci sequence.)
926 *
927 * Further lets say we use the following code, invoking
928 * bitmap_fold() then bitmap_onto, as suggested above to
929 * avoid the possitility of an empty @dst result:
930 *
931 * unsigned long *tmp; // a temporary bitmap's bits
932 *
933 * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits);
934 * bitmap_onto(dst, tmp, relmap, bits);
935 *
936 * Then this table shows what various values of @dst would be, for
937 * various @orig's. I list the zero-based positions of each set bit.
938 * The tmp column shows the intermediate result, as computed by
939 * using bitmap_fold() to fold the @orig bitmap modulo ten
940 * (the weight of @relmap).
941 *
942 * @orig tmp @dst
943 * 0 0 40
944 * 1 1 41
945 * 9 9 95
946 * 10 0 40 (*)
947 * 1 3 5 7 1 3 5 7 41 43 48 61
948 * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45
949 * 0 9 18 27 0 9 8 7 40 61 74 95
950 * 0 10 20 30 0 40
951 * 0 11 22 33 0 1 2 3 40 41 42 43
952 * 0 12 24 36 0 2 4 6 40 42 45 53
953 * 78 102 211 1 2 8 41 42 74 (*)
954 *
955 * (*) For these marked lines, if we hadn't first done bitmap_fold()
956 * into tmp, then the @dst result would have been empty.
957 *
958 * If either of @orig or @relmap is empty (no set bits), then @dst
959 * will be returned empty.
960 *
961 * If (as explained above) the only set bits in @orig are in positions
962 * m where m >= W, (where W is the weight of @relmap) then @dst will
963 * once again be returned empty.
964 *
965 * All bits in @dst not set by the above rule are cleared.
966 */
967void bitmap_onto(unsigned long *dst, const unsigned long *orig,
968 const unsigned long *relmap, int bits)
969{
970 int n, m; /* same meaning as in above comment */
971
972 if (dst == orig) /* following doesn't handle inplace mappings */
973 return;
974 bitmap_zero(dst, bits);
975
976 /*
977 * The following code is a more efficient, but less
978 * obvious, equivalent to the loop:
979 * for (m = 0; m < bitmap_weight(relmap, bits); m++) {
980 * n = bitmap_ord_to_pos(orig, m, bits);
981 * if (test_bit(m, orig))
982 * set_bit(n, dst);
983 * }
984 */
985
986 m = 0;
Akinobu Mita08564fb2010-03-05 13:43:18 -0800987 for_each_set_bit(n, relmap, bits) {
Paul Jackson7ea931c2008-04-28 02:12:29 -0700988 /* m == bitmap_pos_to_ord(relmap, n, bits) */
989 if (test_bit(m, orig))
990 set_bit(n, dst);
991 m++;
992 }
993}
994EXPORT_SYMBOL(bitmap_onto);
995
996/**
997 * bitmap_fold - fold larger bitmap into smaller, modulo specified size
998 * @dst: resulting smaller bitmap
999 * @orig: original larger bitmap
1000 * @sz: specified size
1001 * @bits: number of bits in each of these bitmaps
1002 *
1003 * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst.
1004 * Clear all other bits in @dst. See further the comment and
1005 * Example [2] for bitmap_onto() for why and how to use this.
1006 */
1007void bitmap_fold(unsigned long *dst, const unsigned long *orig,
1008 int sz, int bits)
1009{
1010 int oldbit;
1011
1012 if (dst == orig) /* following doesn't handle inplace mappings */
1013 return;
1014 bitmap_zero(dst, bits);
1015
Akinobu Mita08564fb2010-03-05 13:43:18 -08001016 for_each_set_bit(oldbit, orig, bits)
Paul Jackson7ea931c2008-04-28 02:12:29 -07001017 set_bit(oldbit % sz, dst);
1018}
1019EXPORT_SYMBOL(bitmap_fold);
1020
Paul Jackson3cf64b92006-03-24 03:15:46 -08001021/*
1022 * Common code for bitmap_*_region() routines.
1023 * bitmap: array of unsigned longs corresponding to the bitmap
1024 * pos: the beginning of the region
1025 * order: region size (log base 2 of number of bits)
1026 * reg_op: operation(s) to perform on that region of bitmap
1027 *
1028 * Can set, verify and/or release a region of bits in a bitmap,
1029 * depending on which combination of REG_OP_* flag bits is set.
1030 *
1031 * A region of a bitmap is a sequence of bits in the bitmap, of
1032 * some size '1 << order' (a power of two), aligned to that same
1033 * '1 << order' power of two.
1034 *
1035 * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits).
1036 * Returns 0 in all other cases and reg_ops.
1037 */
1038
1039enum {
1040 REG_OP_ISFREE, /* true if region is all zero bits */
1041 REG_OP_ALLOC, /* set all bits in region */
1042 REG_OP_RELEASE, /* clear all bits in region */
1043};
1044
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001045static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op)
Paul Jackson3cf64b92006-03-24 03:15:46 -08001046{
1047 int nbits_reg; /* number of bits in region */
1048 int index; /* index first long of region in bitmap */
1049 int offset; /* bit offset region in bitmap[index] */
1050 int nlongs_reg; /* num longs spanned by region in bitmap */
1051 int nbitsinlong; /* num bits of region in each spanned long */
1052 unsigned long mask; /* bitmask for one long of region */
1053 int i; /* scans bitmap by longs */
1054 int ret = 0; /* return value */
1055
1056 /*
1057 * Either nlongs_reg == 1 (for small orders that fit in one long)
1058 * or (offset == 0 && mask == ~0UL) (for larger multiword orders.)
1059 */
1060 nbits_reg = 1 << order;
1061 index = pos / BITS_PER_LONG;
1062 offset = pos - (index * BITS_PER_LONG);
1063 nlongs_reg = BITS_TO_LONGS(nbits_reg);
1064 nbitsinlong = min(nbits_reg, BITS_PER_LONG);
1065
1066 /*
1067 * Can't do "mask = (1UL << nbitsinlong) - 1", as that
1068 * overflows if nbitsinlong == BITS_PER_LONG.
1069 */
1070 mask = (1UL << (nbitsinlong - 1));
1071 mask += mask - 1;
1072 mask <<= offset;
1073
1074 switch (reg_op) {
1075 case REG_OP_ISFREE:
1076 for (i = 0; i < nlongs_reg; i++) {
1077 if (bitmap[index + i] & mask)
1078 goto done;
1079 }
1080 ret = 1; /* all bits in region free (zero) */
1081 break;
1082
1083 case REG_OP_ALLOC:
1084 for (i = 0; i < nlongs_reg; i++)
1085 bitmap[index + i] |= mask;
1086 break;
1087
1088 case REG_OP_RELEASE:
1089 for (i = 0; i < nlongs_reg; i++)
1090 bitmap[index + i] &= ~mask;
1091 break;
1092 }
1093done:
1094 return ret;
1095}
1096
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097/**
Paul Jackson87e24802006-03-24 03:15:44 -08001098 * bitmap_find_free_region - find a contiguous aligned mem region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001099 * @bitmap: array of unsigned longs corresponding to the bitmap
Linus Torvalds1da177e2005-04-16 15:20:36 -07001100 * @bits: number of bits in the bitmap
Paul Jackson3cf64b92006-03-24 03:15:46 -08001101 * @order: region size (log base 2 of number of bits) to find
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 *
Paul Jackson3cf64b92006-03-24 03:15:46 -08001103 * Find a region of free (zero) bits in a @bitmap of @bits bits and
1104 * allocate them (set them to one). Only consider regions of length
1105 * a power (@order) of two, aligned to that power of two, which
Paul Jackson87e24802006-03-24 03:15:44 -08001106 * makes the search algorithm much faster.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001107 *
Paul Jackson3cf64b92006-03-24 03:15:46 -08001108 * Return the bit offset in bitmap of the allocated region,
Paul Jackson87e24802006-03-24 03:15:44 -08001109 * or -errno on failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001111int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112{
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001113 unsigned int pos, end; /* scans bitmap by regions of size order */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001115 for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) {
Linus Torvaldsaa8e4fc2009-03-12 19:32:51 -07001116 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1117 continue;
1118 __reg_op(bitmap, pos, order, REG_OP_ALLOC);
1119 return pos;
1120 }
1121 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122}
1123EXPORT_SYMBOL(bitmap_find_free_region);
1124
1125/**
Paul Jackson87e24802006-03-24 03:15:44 -08001126 * bitmap_release_region - release allocated bitmap region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001127 * @bitmap: array of unsigned longs corresponding to the bitmap
1128 * @pos: beginning of bit region to release
1129 * @order: region size (log base 2 of number of bits) to release
Linus Torvalds1da177e2005-04-16 15:20:36 -07001130 *
Robert P. J. Day72fd4a32007-02-10 01:45:59 -08001131 * This is the complement to __bitmap_find_free_region() and releases
Linus Torvalds1da177e2005-04-16 15:20:36 -07001132 * the found region (by clearing it in the bitmap).
Paul Jackson3cf64b92006-03-24 03:15:46 -08001133 *
1134 * No return value.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001136void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137{
Paul Jackson3cf64b92006-03-24 03:15:46 -08001138 __reg_op(bitmap, pos, order, REG_OP_RELEASE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139}
1140EXPORT_SYMBOL(bitmap_release_region);
1141
Paul Jackson87e24802006-03-24 03:15:44 -08001142/**
1143 * bitmap_allocate_region - allocate bitmap region
Paul Jackson3cf64b92006-03-24 03:15:46 -08001144 * @bitmap: array of unsigned longs corresponding to the bitmap
1145 * @pos: beginning of bit region to allocate
1146 * @order: region size (log base 2 of number of bits) to allocate
Paul Jackson87e24802006-03-24 03:15:44 -08001147 *
1148 * Allocate (set bits in) a specified region of a bitmap.
Paul Jackson3cf64b92006-03-24 03:15:46 -08001149 *
Randy Dunlap6e1907ff2006-06-25 05:48:57 -07001150 * Return 0 on success, or %-EBUSY if specified region wasn't
Paul Jackson87e24802006-03-24 03:15:44 -08001151 * free (not all bits were zero).
1152 */
Rasmus Villemoes9279d322014-08-06 16:10:16 -07001153int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154{
Paul Jackson3cf64b92006-03-24 03:15:46 -08001155 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
1156 return -EBUSY;
Rasmus Villemoes2ac521d2014-08-06 16:10:18 -07001157 return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158}
1159EXPORT_SYMBOL(bitmap_allocate_region);
David Vrabelccbe3292008-09-17 16:34:03 +01001160
1161/**
1162 * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order.
1163 * @dst: destination buffer
1164 * @src: bitmap to copy
1165 * @nbits: number of bits in the bitmap
1166 *
1167 * Require nbits % BITS_PER_LONG == 0.
1168 */
1169void bitmap_copy_le(void *dst, const unsigned long *src, int nbits)
1170{
1171 unsigned long *d = dst;
1172 int i;
1173
1174 for (i = 0; i < nbits/BITS_PER_LONG; i++) {
1175 if (BITS_PER_LONG == 64)
1176 d[i] = cpu_to_le64(src[i]);
1177 else
1178 d[i] = cpu_to_le32(src[i]);
1179 }
1180}
1181EXPORT_SYMBOL(bitmap_copy_le);