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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
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 | */ | |
8bc3bcc9 PG |
8 | #include <linux/export.h> |
9 | #include <linux/thread_info.h> | |
1da177e4 LT |
10 | #include <linux/ctype.h> |
11 | #include <linux/errno.h> | |
12 | #include <linux/bitmap.h> | |
13 | #include <linux/bitops.h> | |
50af5ead | 14 | #include <linux/bug.h> |
e52bc7c2 | 15 | #include <linux/kernel.h> |
b2917089 | 16 | #include <linux/slab.h> |
e9983f65 | 17 | #include <linux/mm.h> |
e52bc7c2 | 18 | #include <linux/string.h> |
13d4ea09 | 19 | #include <linux/uaccess.h> |
5aaba363 SH |
20 | |
21 | #include <asm/page.h> | |
1da177e4 | 22 | |
7d7363e4 RD |
23 | /** |
24 | * DOC: bitmap introduction | |
25 | * | |
1da177e4 LT |
26 | * bitmaps provide an array of bits, implemented using an an |
27 | * array of unsigned longs. The number of valid bits in a | |
28 | * given bitmap does _not_ need to be an exact multiple of | |
29 | * BITS_PER_LONG. | |
30 | * | |
31 | * The possible unused bits in the last, partially used word | |
32 | * of a bitmap are 'don't care'. The implementation makes | |
33 | * no particular effort to keep them zero. It ensures that | |
34 | * their value will not affect the results of any operation. | |
35 | * The bitmap operations that return Boolean (bitmap_empty, | |
36 | * for example) or scalar (bitmap_weight, for example) results | |
37 | * carefully filter out these unused bits from impacting their | |
38 | * results. | |
39 | * | |
40 | * These operations actually hold to a slightly stronger rule: | |
41 | * if you don't input any bitmaps to these ops that have some | |
42 | * unused bits set, then they won't output any set unused bits | |
43 | * in output bitmaps. | |
44 | * | |
45 | * The byte ordering of bitmaps is more natural on little | |
46 | * endian architectures. See the big-endian headers | |
47 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h | |
48 | * for the best explanations of this ordering. | |
49 | */ | |
50 | ||
1da177e4 | 51 | int __bitmap_equal(const unsigned long *bitmap1, |
5e068069 | 52 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 53 | { |
5e068069 | 54 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
55 | for (k = 0; k < lim; ++k) |
56 | if (bitmap1[k] != bitmap2[k]) | |
57 | return 0; | |
58 | ||
59 | if (bits % BITS_PER_LONG) | |
60 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
61 | return 0; | |
62 | ||
63 | return 1; | |
64 | } | |
65 | EXPORT_SYMBOL(__bitmap_equal); | |
66 | ||
3d6684f4 | 67 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) |
1da177e4 | 68 | { |
3d6684f4 | 69 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
70 | for (k = 0; k < lim; ++k) |
71 | dst[k] = ~src[k]; | |
72 | ||
73 | if (bits % BITS_PER_LONG) | |
65b4ee62 | 74 | dst[k] = ~src[k]; |
1da177e4 LT |
75 | } |
76 | EXPORT_SYMBOL(__bitmap_complement); | |
77 | ||
72fd4a35 | 78 | /** |
1da177e4 | 79 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
05fb6bf0 RD |
80 | * @dst : destination bitmap |
81 | * @src : source bitmap | |
82 | * @shift : shift by this many bits | |
2fbad299 | 83 | * @nbits : bitmap size, in bits |
1da177e4 LT |
84 | * |
85 | * Shifting right (dividing) means moving bits in the MS -> LS bit | |
86 | * direction. Zeros are fed into the vacated MS positions and the | |
87 | * LS bits shifted off the bottom are lost. | |
88 | */ | |
2fbad299 RV |
89 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
90 | unsigned shift, unsigned nbits) | |
1da177e4 | 91 | { |
cfac1d08 | 92 | unsigned k, lim = BITS_TO_LONGS(nbits); |
2fbad299 | 93 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
cfac1d08 | 94 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); |
1da177e4 LT |
95 | for (k = 0; off + k < lim; ++k) { |
96 | unsigned long upper, lower; | |
97 | ||
98 | /* | |
99 | * If shift is not word aligned, take lower rem bits of | |
100 | * word above and make them the top rem bits of result. | |
101 | */ | |
102 | if (!rem || off + k + 1 >= lim) | |
103 | upper = 0; | |
104 | else { | |
105 | upper = src[off + k + 1]; | |
cfac1d08 | 106 | if (off + k + 1 == lim - 1) |
1da177e4 | 107 | upper &= mask; |
9d8a6b2a | 108 | upper <<= (BITS_PER_LONG - rem); |
1da177e4 LT |
109 | } |
110 | lower = src[off + k]; | |
cfac1d08 | 111 | if (off + k == lim - 1) |
1da177e4 | 112 | lower &= mask; |
9d8a6b2a RV |
113 | lower >>= rem; |
114 | dst[k] = lower | upper; | |
1da177e4 LT |
115 | } |
116 | if (off) | |
117 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); | |
118 | } | |
119 | EXPORT_SYMBOL(__bitmap_shift_right); | |
120 | ||
121 | ||
72fd4a35 | 122 | /** |
1da177e4 | 123 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
05fb6bf0 RD |
124 | * @dst : destination bitmap |
125 | * @src : source bitmap | |
126 | * @shift : shift by this many bits | |
dba94c25 | 127 | * @nbits : bitmap size, in bits |
1da177e4 LT |
128 | * |
129 | * Shifting left (multiplying) means moving bits in the LS -> MS | |
130 | * direction. Zeros are fed into the vacated LS bit positions | |
131 | * and those MS bits shifted off the top are lost. | |
132 | */ | |
133 | ||
dba94c25 RV |
134 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, |
135 | unsigned int shift, unsigned int nbits) | |
1da177e4 | 136 | { |
dba94c25 | 137 | int k; |
7f590657 | 138 | unsigned int lim = BITS_TO_LONGS(nbits); |
dba94c25 | 139 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
1da177e4 LT |
140 | for (k = lim - off - 1; k >= 0; --k) { |
141 | unsigned long upper, lower; | |
142 | ||
143 | /* | |
144 | * If shift is not word aligned, take upper rem bits of | |
145 | * word below and make them the bottom rem bits of result. | |
146 | */ | |
147 | if (rem && k > 0) | |
6d874eca | 148 | lower = src[k - 1] >> (BITS_PER_LONG - rem); |
1da177e4 LT |
149 | else |
150 | lower = 0; | |
7f590657 | 151 | upper = src[k] << rem; |
6d874eca | 152 | dst[k + off] = lower | upper; |
1da177e4 LT |
153 | } |
154 | if (off) | |
155 | memset(dst, 0, off*sizeof(unsigned long)); | |
156 | } | |
157 | EXPORT_SYMBOL(__bitmap_shift_left); | |
158 | ||
f4b0373b | 159 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 160 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 161 | { |
2f9305eb | 162 | unsigned int k; |
7e5f97d1 | 163 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 164 | unsigned long result = 0; |
1da177e4 | 165 | |
7e5f97d1 | 166 | for (k = 0; k < lim; k++) |
f4b0373b | 167 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
7e5f97d1 RV |
168 | if (bits % BITS_PER_LONG) |
169 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & | |
170 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 171 | return result != 0; |
1da177e4 LT |
172 | } |
173 | EXPORT_SYMBOL(__bitmap_and); | |
174 | ||
175 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 176 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 177 | { |
2f9305eb RV |
178 | unsigned int k; |
179 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
180 | |
181 | for (k = 0; k < nr; k++) | |
182 | dst[k] = bitmap1[k] | bitmap2[k]; | |
183 | } | |
184 | EXPORT_SYMBOL(__bitmap_or); | |
185 | ||
186 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 187 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 188 | { |
2f9305eb RV |
189 | unsigned int k; |
190 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
191 | |
192 | for (k = 0; k < nr; k++) | |
193 | dst[k] = bitmap1[k] ^ bitmap2[k]; | |
194 | } | |
195 | EXPORT_SYMBOL(__bitmap_xor); | |
196 | ||
f4b0373b | 197 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 198 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 199 | { |
2f9305eb | 200 | unsigned int k; |
74e76531 | 201 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 202 | unsigned long result = 0; |
1da177e4 | 203 | |
74e76531 | 204 | for (k = 0; k < lim; k++) |
f4b0373b | 205 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
74e76531 RV |
206 | if (bits % BITS_PER_LONG) |
207 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & | |
208 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 209 | return result != 0; |
1da177e4 LT |
210 | } |
211 | EXPORT_SYMBOL(__bitmap_andnot); | |
212 | ||
213 | int __bitmap_intersects(const unsigned long *bitmap1, | |
6dfe9799 | 214 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 215 | { |
6dfe9799 | 216 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
217 | for (k = 0; k < lim; ++k) |
218 | if (bitmap1[k] & bitmap2[k]) | |
219 | return 1; | |
220 | ||
221 | if (bits % BITS_PER_LONG) | |
222 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
223 | return 1; | |
224 | return 0; | |
225 | } | |
226 | EXPORT_SYMBOL(__bitmap_intersects); | |
227 | ||
228 | int __bitmap_subset(const unsigned long *bitmap1, | |
5be20213 | 229 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 230 | { |
5be20213 | 231 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
232 | for (k = 0; k < lim; ++k) |
233 | if (bitmap1[k] & ~bitmap2[k]) | |
234 | return 0; | |
235 | ||
236 | if (bits % BITS_PER_LONG) | |
237 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
238 | return 0; | |
239 | return 1; | |
240 | } | |
241 | EXPORT_SYMBOL(__bitmap_subset); | |
242 | ||
877d9f3b | 243 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 244 | { |
877d9f3b RV |
245 | unsigned int k, lim = bits/BITS_PER_LONG; |
246 | int w = 0; | |
1da177e4 LT |
247 | |
248 | for (k = 0; k < lim; k++) | |
37d54111 | 249 | w += hweight_long(bitmap[k]); |
1da177e4 LT |
250 | |
251 | if (bits % BITS_PER_LONG) | |
37d54111 | 252 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
1da177e4 LT |
253 | |
254 | return w; | |
255 | } | |
1da177e4 LT |
256 | EXPORT_SYMBOL(__bitmap_weight); |
257 | ||
e5af323c | 258 | void __bitmap_set(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
259 | { |
260 | unsigned long *p = map + BIT_WORD(start); | |
fb5ac542 | 261 | const unsigned int size = start + len; |
c1a2a962 AM |
262 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
263 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); | |
264 | ||
fb5ac542 | 265 | while (len - bits_to_set >= 0) { |
c1a2a962 | 266 | *p |= mask_to_set; |
fb5ac542 | 267 | len -= bits_to_set; |
c1a2a962 AM |
268 | bits_to_set = BITS_PER_LONG; |
269 | mask_to_set = ~0UL; | |
270 | p++; | |
271 | } | |
fb5ac542 | 272 | if (len) { |
c1a2a962 AM |
273 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
274 | *p |= mask_to_set; | |
275 | } | |
276 | } | |
e5af323c | 277 | EXPORT_SYMBOL(__bitmap_set); |
c1a2a962 | 278 | |
e5af323c | 279 | void __bitmap_clear(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
280 | { |
281 | unsigned long *p = map + BIT_WORD(start); | |
154f5e38 | 282 | const unsigned int size = start + len; |
c1a2a962 AM |
283 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
284 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); | |
285 | ||
154f5e38 | 286 | while (len - bits_to_clear >= 0) { |
c1a2a962 | 287 | *p &= ~mask_to_clear; |
154f5e38 | 288 | len -= bits_to_clear; |
c1a2a962 AM |
289 | bits_to_clear = BITS_PER_LONG; |
290 | mask_to_clear = ~0UL; | |
291 | p++; | |
292 | } | |
154f5e38 | 293 | if (len) { |
c1a2a962 AM |
294 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
295 | *p &= ~mask_to_clear; | |
296 | } | |
297 | } | |
e5af323c | 298 | EXPORT_SYMBOL(__bitmap_clear); |
c1a2a962 | 299 | |
5e19b013 MN |
300 | /** |
301 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area | |
c1a2a962 AM |
302 | * @map: The address to base the search on |
303 | * @size: The bitmap size in bits | |
304 | * @start: The bitnumber to start searching at | |
305 | * @nr: The number of zeroed bits we're looking for | |
306 | * @align_mask: Alignment mask for zero area | |
5e19b013 | 307 | * @align_offset: Alignment offset for zero area. |
c1a2a962 AM |
308 | * |
309 | * The @align_mask should be one less than a power of 2; the effect is that | |
5e19b013 MN |
310 | * the bit offset of all zero areas this function finds plus @align_offset |
311 | * is multiple of that power of 2. | |
c1a2a962 | 312 | */ |
5e19b013 MN |
313 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map, |
314 | unsigned long size, | |
315 | unsigned long start, | |
316 | unsigned int nr, | |
317 | unsigned long align_mask, | |
318 | unsigned long align_offset) | |
c1a2a962 AM |
319 | { |
320 | unsigned long index, end, i; | |
321 | again: | |
322 | index = find_next_zero_bit(map, size, start); | |
323 | ||
324 | /* Align allocation */ | |
5e19b013 | 325 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; |
c1a2a962 AM |
326 | |
327 | end = index + nr; | |
328 | if (end > size) | |
329 | return end; | |
330 | i = find_next_bit(map, end, index); | |
331 | if (i < end) { | |
332 | start = i + 1; | |
333 | goto again; | |
334 | } | |
335 | return index; | |
336 | } | |
5e19b013 | 337 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off); |
c1a2a962 | 338 | |
1da177e4 | 339 | /* |
6d49e352 | 340 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
1da177e4 LT |
341 | * second version by Paul Jackson, third by Joe Korty. |
342 | */ | |
343 | ||
344 | #define CHUNKSZ 32 | |
345 | #define nbits_to_hold_value(val) fls(val) | |
1da177e4 LT |
346 | #define BASEDEC 10 /* fancier cpuset lists input in decimal */ |
347 | ||
1da177e4 | 348 | /** |
01a3ee2b RC |
349 | * __bitmap_parse - convert an ASCII hex string into a bitmap. |
350 | * @buf: pointer to buffer containing string. | |
351 | * @buflen: buffer size in bytes. If string is smaller than this | |
1da177e4 | 352 | * then it must be terminated with a \0. |
01a3ee2b | 353 | * @is_user: location of buffer, 0 indicates kernel space |
1da177e4 LT |
354 | * @maskp: pointer to bitmap array that will contain result. |
355 | * @nmaskbits: size of bitmap, in bits. | |
356 | * | |
357 | * Commas group hex digits into chunks. Each chunk defines exactly 32 | |
358 | * bits of the resultant bitmask. No chunk may specify a value larger | |
6e1907ff RD |
359 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value |
360 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal | |
1da177e4 LT |
361 | * characters and for grouping errors such as "1,,5", ",44", "," and "". |
362 | * Leading and trailing whitespace accepted, but not embedded whitespace. | |
363 | */ | |
01a3ee2b RC |
364 | int __bitmap_parse(const char *buf, unsigned int buflen, |
365 | int is_user, unsigned long *maskp, | |
366 | int nmaskbits) | |
1da177e4 LT |
367 | { |
368 | int c, old_c, totaldigits, ndigits, nchunks, nbits; | |
369 | u32 chunk; | |
b9c321fd | 370 | const char __user __force *ubuf = (const char __user __force *)buf; |
1da177e4 LT |
371 | |
372 | bitmap_zero(maskp, nmaskbits); | |
373 | ||
374 | nchunks = nbits = totaldigits = c = 0; | |
375 | do { | |
d21c3d4d PX |
376 | chunk = 0; |
377 | ndigits = totaldigits; | |
1da177e4 LT |
378 | |
379 | /* Get the next chunk of the bitmap */ | |
01a3ee2b | 380 | while (buflen) { |
1da177e4 | 381 | old_c = c; |
01a3ee2b RC |
382 | if (is_user) { |
383 | if (__get_user(c, ubuf++)) | |
384 | return -EFAULT; | |
385 | } | |
386 | else | |
387 | c = *buf++; | |
388 | buflen--; | |
1da177e4 LT |
389 | if (isspace(c)) |
390 | continue; | |
391 | ||
392 | /* | |
393 | * If the last character was a space and the current | |
394 | * character isn't '\0', we've got embedded whitespace. | |
395 | * This is a no-no, so throw an error. | |
396 | */ | |
397 | if (totaldigits && c && isspace(old_c)) | |
398 | return -EINVAL; | |
399 | ||
400 | /* A '\0' or a ',' signal the end of the chunk */ | |
401 | if (c == '\0' || c == ',') | |
402 | break; | |
403 | ||
404 | if (!isxdigit(c)) | |
405 | return -EINVAL; | |
406 | ||
407 | /* | |
408 | * Make sure there are at least 4 free bits in 'chunk'. | |
409 | * If not, this hexdigit will overflow 'chunk', so | |
410 | * throw an error. | |
411 | */ | |
412 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) | |
413 | return -EOVERFLOW; | |
414 | ||
66f1991b | 415 | chunk = (chunk << 4) | hex_to_bin(c); |
d21c3d4d | 416 | totaldigits++; |
1da177e4 | 417 | } |
d21c3d4d | 418 | if (ndigits == totaldigits) |
1da177e4 LT |
419 | return -EINVAL; |
420 | if (nchunks == 0 && chunk == 0) | |
421 | continue; | |
422 | ||
423 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); | |
424 | *maskp |= chunk; | |
425 | nchunks++; | |
426 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; | |
427 | if (nbits > nmaskbits) | |
428 | return -EOVERFLOW; | |
01a3ee2b | 429 | } while (buflen && c == ','); |
1da177e4 LT |
430 | |
431 | return 0; | |
432 | } | |
01a3ee2b RC |
433 | EXPORT_SYMBOL(__bitmap_parse); |
434 | ||
435 | /** | |
9a86e2ba | 436 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
01a3ee2b RC |
437 | * |
438 | * @ubuf: pointer to user buffer containing string. | |
439 | * @ulen: buffer size in bytes. If string is smaller than this | |
440 | * then it must be terminated with a \0. | |
441 | * @maskp: pointer to bitmap array that will contain result. | |
442 | * @nmaskbits: size of bitmap, in bits. | |
443 | * | |
444 | * Wrapper for __bitmap_parse(), providing it with user buffer. | |
445 | * | |
446 | * We cannot have this as an inline function in bitmap.h because it needs | |
447 | * linux/uaccess.h to get the access_ok() declaration and this causes | |
448 | * cyclic dependencies. | |
449 | */ | |
450 | int bitmap_parse_user(const char __user *ubuf, | |
451 | unsigned int ulen, unsigned long *maskp, | |
452 | int nmaskbits) | |
453 | { | |
454 | if (!access_ok(VERIFY_READ, ubuf, ulen)) | |
455 | return -EFAULT; | |
b9c321fd HS |
456 | return __bitmap_parse((const char __force *)ubuf, |
457 | ulen, 1, maskp, nmaskbits); | |
458 | ||
01a3ee2b RC |
459 | } |
460 | EXPORT_SYMBOL(bitmap_parse_user); | |
1da177e4 | 461 | |
5aaba363 SH |
462 | /** |
463 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string | |
464 | * @list: indicates whether the bitmap must be list | |
465 | * @buf: page aligned buffer into which string is placed | |
466 | * @maskp: pointer to bitmap to convert | |
467 | * @nmaskbits: size of bitmap, in bits | |
468 | * | |
469 | * Output format is a comma-separated list of decimal numbers and | |
470 | * ranges if list is specified or hex digits grouped into comma-separated | |
471 | * sets of 8 digits/set. Returns the number of characters written to buf. | |
9cf79d11 | 472 | * |
e9983f65 RV |
473 | * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned |
474 | * area and that sufficient storage remains at @buf to accommodate the | |
475 | * bitmap_print_to_pagebuf() output. Returns the number of characters | |
476 | * actually printed to @buf, excluding terminating '\0'. | |
5aaba363 SH |
477 | */ |
478 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, | |
479 | int nmaskbits) | |
480 | { | |
e9983f65 | 481 | ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); |
5aaba363 SH |
482 | int n = 0; |
483 | ||
9cf79d11 SH |
484 | if (len > 1) |
485 | n = list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : | |
486 | scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); | |
5aaba363 SH |
487 | return n; |
488 | } | |
489 | EXPORT_SYMBOL(bitmap_print_to_pagebuf); | |
490 | ||
1da177e4 | 491 | /** |
4b060420 | 492 | * __bitmap_parselist - convert list format ASCII string to bitmap |
b0825ee3 | 493 | * @buf: read nul-terminated user string from this buffer |
4b060420 MT |
494 | * @buflen: buffer size in bytes. If string is smaller than this |
495 | * then it must be terminated with a \0. | |
496 | * @is_user: location of buffer, 0 indicates kernel space | |
6e1907ff | 497 | * @maskp: write resulting mask here |
1da177e4 LT |
498 | * @nmaskbits: number of bits in mask to be written |
499 | * | |
500 | * Input format is a comma-separated list of decimal numbers and | |
501 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
502 | * decimal numbers, the smallest and largest bit numbers set in | |
503 | * the range. | |
2d13e6ca NC |
504 | * Optionally each range can be postfixed to denote that only parts of it |
505 | * should be set. The range will divided to groups of specific size. | |
506 | * From each group will be used only defined amount of bits. | |
507 | * Syntax: range:used_size/group_size | |
508 | * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 | |
1da177e4 | 509 | * |
40bf19a8 MCC |
510 | * Returns: 0 on success, -errno on invalid input strings. Error values: |
511 | * | |
512 | * - ``-EINVAL``: second number in range smaller than first | |
513 | * - ``-EINVAL``: invalid character in string | |
514 | * - ``-ERANGE``: bit number specified too large for mask | |
1da177e4 | 515 | */ |
4b060420 MT |
516 | static int __bitmap_parselist(const char *buf, unsigned int buflen, |
517 | int is_user, unsigned long *maskp, | |
518 | int nmaskbits) | |
1da177e4 | 519 | { |
2d13e6ca | 520 | unsigned int a, b, old_a, old_b; |
0a5ce083 | 521 | unsigned int group_size, used_size, off; |
9bf98f16 | 522 | int c, old_c, totaldigits, ndigits; |
b9c321fd | 523 | const char __user __force *ubuf = (const char __user __force *)buf; |
2d13e6ca | 524 | int at_start, in_range, in_partial_range; |
1da177e4 | 525 | |
4b060420 | 526 | totaldigits = c = 0; |
2d13e6ca NC |
527 | old_a = old_b = 0; |
528 | group_size = used_size = 0; | |
1da177e4 LT |
529 | bitmap_zero(maskp, nmaskbits); |
530 | do { | |
2528a8b8 | 531 | at_start = 1; |
4b060420 | 532 | in_range = 0; |
2d13e6ca | 533 | in_partial_range = 0; |
4b060420 | 534 | a = b = 0; |
9bf98f16 | 535 | ndigits = totaldigits; |
4b060420 MT |
536 | |
537 | /* Get the next cpu# or a range of cpu#'s */ | |
538 | while (buflen) { | |
539 | old_c = c; | |
540 | if (is_user) { | |
541 | if (__get_user(c, ubuf++)) | |
542 | return -EFAULT; | |
543 | } else | |
544 | c = *buf++; | |
545 | buflen--; | |
546 | if (isspace(c)) | |
547 | continue; | |
548 | ||
4b060420 MT |
549 | /* A '\0' or a ',' signal the end of a cpu# or range */ |
550 | if (c == '\0' || c == ',') | |
551 | break; | |
9bf98f16 PX |
552 | /* |
553 | * whitespaces between digits are not allowed, | |
554 | * but it's ok if whitespaces are on head or tail. | |
555 | * when old_c is whilespace, | |
556 | * if totaldigits == ndigits, whitespace is on head. | |
557 | * if whitespace is on tail, it should not run here. | |
558 | * as c was ',' or '\0', | |
559 | * the last code line has broken the current loop. | |
560 | */ | |
561 | if ((totaldigits != ndigits) && isspace(old_c)) | |
562 | return -EINVAL; | |
4b060420 | 563 | |
2d13e6ca NC |
564 | if (c == '/') { |
565 | used_size = a; | |
566 | at_start = 1; | |
567 | in_range = 0; | |
568 | a = b = 0; | |
569 | continue; | |
570 | } | |
571 | ||
572 | if (c == ':') { | |
573 | old_a = a; | |
574 | old_b = b; | |
575 | at_start = 1; | |
576 | in_range = 0; | |
577 | in_partial_range = 1; | |
578 | a = b = 0; | |
579 | continue; | |
580 | } | |
581 | ||
4b060420 | 582 | if (c == '-') { |
2528a8b8 | 583 | if (at_start || in_range) |
4b060420 MT |
584 | return -EINVAL; |
585 | b = 0; | |
586 | in_range = 1; | |
d9282cb6 | 587 | at_start = 1; |
4b060420 MT |
588 | continue; |
589 | } | |
590 | ||
591 | if (!isdigit(c)) | |
1da177e4 | 592 | return -EINVAL; |
4b060420 MT |
593 | |
594 | b = b * 10 + (c - '0'); | |
595 | if (!in_range) | |
596 | a = b; | |
2528a8b8 | 597 | at_start = 0; |
4b060420 | 598 | totaldigits++; |
1da177e4 | 599 | } |
9bf98f16 PX |
600 | if (ndigits == totaldigits) |
601 | continue; | |
2d13e6ca NC |
602 | if (in_partial_range) { |
603 | group_size = a; | |
604 | a = old_a; | |
605 | b = old_b; | |
606 | old_a = old_b = 0; | |
0a5ce083 YN |
607 | } else { |
608 | used_size = group_size = b - a + 1; | |
2d13e6ca | 609 | } |
d9282cb6 PX |
610 | /* if no digit is after '-', it's wrong*/ |
611 | if (at_start && in_range) | |
612 | return -EINVAL; | |
dad4f5a6 | 613 | if (!(a <= b) || group_size == 0 || !(used_size <= group_size)) |
1da177e4 LT |
614 | return -EINVAL; |
615 | if (b >= nmaskbits) | |
616 | return -ERANGE; | |
9bf98f16 | 617 | while (a <= b) { |
0a5ce083 YN |
618 | off = min(b - a + 1, used_size); |
619 | bitmap_set(maskp, a, off); | |
620 | a += group_size; | |
1da177e4 | 621 | } |
4b060420 | 622 | } while (buflen && c == ','); |
1da177e4 LT |
623 | return 0; |
624 | } | |
4b060420 MT |
625 | |
626 | int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) | |
627 | { | |
bc5be182 RV |
628 | char *nl = strchrnul(bp, '\n'); |
629 | int len = nl - bp; | |
4b060420 MT |
630 | |
631 | return __bitmap_parselist(bp, len, 0, maskp, nmaskbits); | |
632 | } | |
1da177e4 LT |
633 | EXPORT_SYMBOL(bitmap_parselist); |
634 | ||
4b060420 MT |
635 | |
636 | /** | |
637 | * bitmap_parselist_user() | |
638 | * | |
639 | * @ubuf: pointer to user buffer containing string. | |
640 | * @ulen: buffer size in bytes. If string is smaller than this | |
641 | * then it must be terminated with a \0. | |
642 | * @maskp: pointer to bitmap array that will contain result. | |
643 | * @nmaskbits: size of bitmap, in bits. | |
644 | * | |
645 | * Wrapper for bitmap_parselist(), providing it with user buffer. | |
646 | * | |
647 | * We cannot have this as an inline function in bitmap.h because it needs | |
648 | * linux/uaccess.h to get the access_ok() declaration and this causes | |
649 | * cyclic dependencies. | |
650 | */ | |
651 | int bitmap_parselist_user(const char __user *ubuf, | |
652 | unsigned int ulen, unsigned long *maskp, | |
653 | int nmaskbits) | |
654 | { | |
655 | if (!access_ok(VERIFY_READ, ubuf, ulen)) | |
656 | return -EFAULT; | |
b9c321fd | 657 | return __bitmap_parselist((const char __force *)ubuf, |
4b060420 MT |
658 | ulen, 1, maskp, nmaskbits); |
659 | } | |
660 | EXPORT_SYMBOL(bitmap_parselist_user); | |
661 | ||
662 | ||
72fd4a35 | 663 | /** |
9a86e2ba | 664 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
fb5eeeee | 665 | * @buf: pointer to a bitmap |
df1d80a9 RV |
666 | * @pos: a bit position in @buf (0 <= @pos < @nbits) |
667 | * @nbits: number of valid bit positions in @buf | |
fb5eeeee | 668 | * |
df1d80a9 | 669 | * Map the bit at position @pos in @buf (of length @nbits) to the |
fb5eeeee | 670 | * ordinal of which set bit it is. If it is not set or if @pos |
96b7f341 | 671 | * is not a valid bit position, map to -1. |
fb5eeeee PJ |
672 | * |
673 | * If for example, just bits 4 through 7 are set in @buf, then @pos | |
674 | * values 4 through 7 will get mapped to 0 through 3, respectively, | |
a8551748 | 675 | * and other @pos values will get mapped to -1. When @pos value 7 |
fb5eeeee PJ |
676 | * gets mapped to (returns) @ord value 3 in this example, that means |
677 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. | |
678 | * | |
679 | * The bit positions 0 through @bits are valid positions in @buf. | |
680 | */ | |
df1d80a9 | 681 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) |
fb5eeeee | 682 | { |
df1d80a9 | 683 | if (pos >= nbits || !test_bit(pos, buf)) |
96b7f341 | 684 | return -1; |
fb5eeeee | 685 | |
df1d80a9 | 686 | return __bitmap_weight(buf, pos); |
fb5eeeee PJ |
687 | } |
688 | ||
689 | /** | |
9a86e2ba | 690 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
fb5eeeee PJ |
691 | * @buf: pointer to bitmap |
692 | * @ord: ordinal bit position (n-th set bit, n >= 0) | |
f6a1f5db | 693 | * @nbits: number of valid bit positions in @buf |
fb5eeeee PJ |
694 | * |
695 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. | |
f6a1f5db RV |
696 | * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord |
697 | * >= weight(buf), returns @nbits. | |
fb5eeeee PJ |
698 | * |
699 | * If for example, just bits 4 through 7 are set in @buf, then @ord | |
700 | * values 0 through 3 will get mapped to 4 through 7, respectively, | |
f6a1f5db | 701 | * and all other @ord values returns @nbits. When @ord value 3 |
fb5eeeee PJ |
702 | * gets mapped to (returns) @pos value 7 in this example, that means |
703 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. | |
704 | * | |
f6a1f5db | 705 | * The bit positions 0 through @nbits-1 are valid positions in @buf. |
fb5eeeee | 706 | */ |
f6a1f5db | 707 | unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) |
fb5eeeee | 708 | { |
f6a1f5db | 709 | unsigned int pos; |
fb5eeeee | 710 | |
f6a1f5db RV |
711 | for (pos = find_first_bit(buf, nbits); |
712 | pos < nbits && ord; | |
713 | pos = find_next_bit(buf, nbits, pos + 1)) | |
714 | ord--; | |
fb5eeeee PJ |
715 | |
716 | return pos; | |
717 | } | |
718 | ||
719 | /** | |
720 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap | |
fb5eeeee | 721 | * @dst: remapped result |
96b7f341 | 722 | * @src: subset to be remapped |
fb5eeeee PJ |
723 | * @old: defines domain of map |
724 | * @new: defines range of map | |
9814ec13 | 725 | * @nbits: number of bits in each of these bitmaps |
fb5eeeee PJ |
726 | * |
727 | * Let @old and @new define a mapping of bit positions, such that | |
728 | * whatever position is held by the n-th set bit in @old is mapped | |
729 | * to the n-th set bit in @new. In the more general case, allowing | |
730 | * for the possibility that the weight 'w' of @new is less than the | |
731 | * weight of @old, map the position of the n-th set bit in @old to | |
732 | * the position of the m-th set bit in @new, where m == n % w. | |
733 | * | |
96b7f341 PJ |
734 | * If either of the @old and @new bitmaps are empty, or if @src and |
735 | * @dst point to the same location, then this routine copies @src | |
736 | * to @dst. | |
fb5eeeee | 737 | * |
96b7f341 PJ |
738 | * The positions of unset bits in @old are mapped to themselves |
739 | * (the identify map). | |
fb5eeeee PJ |
740 | * |
741 | * Apply the above specified mapping to @src, placing the result in | |
742 | * @dst, clearing any bits previously set in @dst. | |
743 | * | |
fb5eeeee PJ |
744 | * For example, lets say that @old has bits 4 through 7 set, and |
745 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
746 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
747 | * bit positions unchanged. So if say @src comes into this routine |
748 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, | |
749 | * 13 and 15 set. | |
fb5eeeee PJ |
750 | */ |
751 | void bitmap_remap(unsigned long *dst, const unsigned long *src, | |
752 | const unsigned long *old, const unsigned long *new, | |
9814ec13 | 753 | unsigned int nbits) |
fb5eeeee | 754 | { |
9814ec13 | 755 | unsigned int oldbit, w; |
fb5eeeee | 756 | |
fb5eeeee PJ |
757 | if (dst == src) /* following doesn't handle inplace remaps */ |
758 | return; | |
9814ec13 | 759 | bitmap_zero(dst, nbits); |
96b7f341 | 760 | |
9814ec13 RV |
761 | w = bitmap_weight(new, nbits); |
762 | for_each_set_bit(oldbit, src, nbits) { | |
763 | int n = bitmap_pos_to_ord(old, oldbit, nbits); | |
08564fb7 | 764 | |
96b7f341 PJ |
765 | if (n < 0 || w == 0) |
766 | set_bit(oldbit, dst); /* identity map */ | |
767 | else | |
9814ec13 | 768 | set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); |
fb5eeeee PJ |
769 | } |
770 | } | |
771 | EXPORT_SYMBOL(bitmap_remap); | |
772 | ||
773 | /** | |
774 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit | |
6e1907ff RD |
775 | * @oldbit: bit position to be mapped |
776 | * @old: defines domain of map | |
777 | * @new: defines range of map | |
778 | * @bits: number of bits in each of these bitmaps | |
fb5eeeee PJ |
779 | * |
780 | * Let @old and @new define a mapping of bit positions, such that | |
781 | * whatever position is held by the n-th set bit in @old is mapped | |
782 | * to the n-th set bit in @new. In the more general case, allowing | |
783 | * for the possibility that the weight 'w' of @new is less than the | |
784 | * weight of @old, map the position of the n-th set bit in @old to | |
785 | * the position of the m-th set bit in @new, where m == n % w. | |
786 | * | |
96b7f341 PJ |
787 | * The positions of unset bits in @old are mapped to themselves |
788 | * (the identify map). | |
fb5eeeee PJ |
789 | * |
790 | * Apply the above specified mapping to bit position @oldbit, returning | |
791 | * the new bit position. | |
792 | * | |
793 | * For example, lets say that @old has bits 4 through 7 set, and | |
794 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
795 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
796 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
797 | * returns 13. | |
fb5eeeee PJ |
798 | */ |
799 | int bitmap_bitremap(int oldbit, const unsigned long *old, | |
800 | const unsigned long *new, int bits) | |
801 | { | |
96b7f341 PJ |
802 | int w = bitmap_weight(new, bits); |
803 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
804 | if (n < 0 || w == 0) | |
805 | return oldbit; | |
806 | else | |
807 | return bitmap_ord_to_pos(new, n % w, bits); | |
fb5eeeee PJ |
808 | } |
809 | EXPORT_SYMBOL(bitmap_bitremap); | |
810 | ||
7ea931c9 PJ |
811 | /** |
812 | * bitmap_onto - translate one bitmap relative to another | |
813 | * @dst: resulting translated bitmap | |
814 | * @orig: original untranslated bitmap | |
815 | * @relmap: bitmap relative to which translated | |
816 | * @bits: number of bits in each of these bitmaps | |
817 | * | |
818 | * Set the n-th bit of @dst iff there exists some m such that the | |
819 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and | |
820 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. | |
821 | * (If you understood the previous sentence the first time your | |
822 | * read it, you're overqualified for your current job.) | |
823 | * | |
824 | * In other words, @orig is mapped onto (surjectively) @dst, | |
da3dae54 | 825 | * using the map { <n, m> | the n-th bit of @relmap is the |
7ea931c9 PJ |
826 | * m-th set bit of @relmap }. |
827 | * | |
828 | * Any set bits in @orig above bit number W, where W is the | |
829 | * weight of (number of set bits in) @relmap are mapped nowhere. | |
830 | * In particular, if for all bits m set in @orig, m >= W, then | |
831 | * @dst will end up empty. In situations where the possibility | |
832 | * of such an empty result is not desired, one way to avoid it is | |
833 | * to use the bitmap_fold() operator, below, to first fold the | |
834 | * @orig bitmap over itself so that all its set bits x are in the | |
835 | * range 0 <= x < W. The bitmap_fold() operator does this by | |
836 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. | |
837 | * | |
838 | * Example [1] for bitmap_onto(): | |
839 | * Let's say @relmap has bits 30-39 set, and @orig has bits | |
840 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, | |
841 | * @dst will have bits 31, 33, 35, 37 and 39 set. | |
842 | * | |
843 | * When bit 0 is set in @orig, it means turn on the bit in | |
844 | * @dst corresponding to whatever is the first bit (if any) | |
845 | * that is turned on in @relmap. Since bit 0 was off in the | |
846 | * above example, we leave off that bit (bit 30) in @dst. | |
847 | * | |
848 | * When bit 1 is set in @orig (as in the above example), it | |
849 | * means turn on the bit in @dst corresponding to whatever | |
850 | * is the second bit that is turned on in @relmap. The second | |
851 | * bit in @relmap that was turned on in the above example was | |
852 | * bit 31, so we turned on bit 31 in @dst. | |
853 | * | |
854 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, | |
855 | * because they were the 4th, 6th, 8th and 10th set bits | |
856 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of | |
857 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. | |
858 | * | |
859 | * When bit 11 is set in @orig, it means turn on the bit in | |
25985edc | 860 | * @dst corresponding to whatever is the twelfth bit that is |
7ea931c9 PJ |
861 | * turned on in @relmap. In the above example, there were |
862 | * only ten bits turned on in @relmap (30..39), so that bit | |
863 | * 11 was set in @orig had no affect on @dst. | |
864 | * | |
865 | * Example [2] for bitmap_fold() + bitmap_onto(): | |
40bf19a8 MCC |
866 | * Let's say @relmap has these ten bits set:: |
867 | * | |
7ea931c9 | 868 | * 40 41 42 43 45 48 53 61 74 95 |
40bf19a8 | 869 | * |
7ea931c9 PJ |
870 | * (for the curious, that's 40 plus the first ten terms of the |
871 | * Fibonacci sequence.) | |
872 | * | |
873 | * Further lets say we use the following code, invoking | |
874 | * bitmap_fold() then bitmap_onto, as suggested above to | |
40bf19a8 | 875 | * avoid the possibility of an empty @dst result:: |
7ea931c9 PJ |
876 | * |
877 | * unsigned long *tmp; // a temporary bitmap's bits | |
878 | * | |
879 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); | |
880 | * bitmap_onto(dst, tmp, relmap, bits); | |
881 | * | |
882 | * Then this table shows what various values of @dst would be, for | |
883 | * various @orig's. I list the zero-based positions of each set bit. | |
884 | * The tmp column shows the intermediate result, as computed by | |
885 | * using bitmap_fold() to fold the @orig bitmap modulo ten | |
40bf19a8 | 886 | * (the weight of @relmap): |
7ea931c9 | 887 | * |
40bf19a8 | 888 | * =============== ============== ================= |
7ea931c9 PJ |
889 | * @orig tmp @dst |
890 | * 0 0 40 | |
891 | * 1 1 41 | |
892 | * 9 9 95 | |
40bf19a8 | 893 | * 10 0 40 [#f1]_ |
7ea931c9 PJ |
894 | * 1 3 5 7 1 3 5 7 41 43 48 61 |
895 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 | |
896 | * 0 9 18 27 0 9 8 7 40 61 74 95 | |
897 | * 0 10 20 30 0 40 | |
898 | * 0 11 22 33 0 1 2 3 40 41 42 43 | |
899 | * 0 12 24 36 0 2 4 6 40 42 45 53 | |
40bf19a8 MCC |
900 | * 78 102 211 1 2 8 41 42 74 [#f1]_ |
901 | * =============== ============== ================= | |
902 | * | |
903 | * .. [#f1] | |
7ea931c9 | 904 | * |
40bf19a8 | 905 | * For these marked lines, if we hadn't first done bitmap_fold() |
7ea931c9 PJ |
906 | * into tmp, then the @dst result would have been empty. |
907 | * | |
908 | * If either of @orig or @relmap is empty (no set bits), then @dst | |
909 | * will be returned empty. | |
910 | * | |
911 | * If (as explained above) the only set bits in @orig are in positions | |
912 | * m where m >= W, (where W is the weight of @relmap) then @dst will | |
913 | * once again be returned empty. | |
914 | * | |
915 | * All bits in @dst not set by the above rule are cleared. | |
916 | */ | |
917 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, | |
eb569883 | 918 | const unsigned long *relmap, unsigned int bits) |
7ea931c9 | 919 | { |
eb569883 | 920 | unsigned int n, m; /* same meaning as in above comment */ |
7ea931c9 PJ |
921 | |
922 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
923 | return; | |
924 | bitmap_zero(dst, bits); | |
925 | ||
926 | /* | |
927 | * The following code is a more efficient, but less | |
928 | * obvious, equivalent to the loop: | |
929 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { | |
930 | * n = bitmap_ord_to_pos(orig, m, bits); | |
931 | * if (test_bit(m, orig)) | |
932 | * set_bit(n, dst); | |
933 | * } | |
934 | */ | |
935 | ||
936 | m = 0; | |
08564fb7 | 937 | for_each_set_bit(n, relmap, bits) { |
7ea931c9 PJ |
938 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
939 | if (test_bit(m, orig)) | |
940 | set_bit(n, dst); | |
941 | m++; | |
942 | } | |
943 | } | |
944 | EXPORT_SYMBOL(bitmap_onto); | |
945 | ||
946 | /** | |
947 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size | |
948 | * @dst: resulting smaller bitmap | |
949 | * @orig: original larger bitmap | |
950 | * @sz: specified size | |
b26ad583 | 951 | * @nbits: number of bits in each of these bitmaps |
7ea931c9 PJ |
952 | * |
953 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. | |
954 | * Clear all other bits in @dst. See further the comment and | |
955 | * Example [2] for bitmap_onto() for why and how to use this. | |
956 | */ | |
957 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, | |
b26ad583 | 958 | unsigned int sz, unsigned int nbits) |
7ea931c9 | 959 | { |
b26ad583 | 960 | unsigned int oldbit; |
7ea931c9 PJ |
961 | |
962 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
963 | return; | |
b26ad583 | 964 | bitmap_zero(dst, nbits); |
7ea931c9 | 965 | |
b26ad583 | 966 | for_each_set_bit(oldbit, orig, nbits) |
7ea931c9 PJ |
967 | set_bit(oldbit % sz, dst); |
968 | } | |
969 | EXPORT_SYMBOL(bitmap_fold); | |
970 | ||
3cf64b93 PJ |
971 | /* |
972 | * Common code for bitmap_*_region() routines. | |
973 | * bitmap: array of unsigned longs corresponding to the bitmap | |
974 | * pos: the beginning of the region | |
975 | * order: region size (log base 2 of number of bits) | |
976 | * reg_op: operation(s) to perform on that region of bitmap | |
1da177e4 | 977 | * |
3cf64b93 PJ |
978 | * Can set, verify and/or release a region of bits in a bitmap, |
979 | * depending on which combination of REG_OP_* flag bits is set. | |
1da177e4 | 980 | * |
3cf64b93 PJ |
981 | * A region of a bitmap is a sequence of bits in the bitmap, of |
982 | * some size '1 << order' (a power of two), aligned to that same | |
983 | * '1 << order' power of two. | |
984 | * | |
985 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). | |
986 | * Returns 0 in all other cases and reg_ops. | |
1da177e4 | 987 | */ |
3cf64b93 PJ |
988 | |
989 | enum { | |
990 | REG_OP_ISFREE, /* true if region is all zero bits */ | |
991 | REG_OP_ALLOC, /* set all bits in region */ | |
992 | REG_OP_RELEASE, /* clear all bits in region */ | |
993 | }; | |
994 | ||
9279d328 | 995 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) |
1da177e4 | 996 | { |
3cf64b93 PJ |
997 | int nbits_reg; /* number of bits in region */ |
998 | int index; /* index first long of region in bitmap */ | |
999 | int offset; /* bit offset region in bitmap[index] */ | |
1000 | int nlongs_reg; /* num longs spanned by region in bitmap */ | |
74373c6a | 1001 | int nbitsinlong; /* num bits of region in each spanned long */ |
3cf64b93 | 1002 | unsigned long mask; /* bitmask for one long of region */ |
74373c6a | 1003 | int i; /* scans bitmap by longs */ |
3cf64b93 | 1004 | int ret = 0; /* return value */ |
74373c6a | 1005 | |
3cf64b93 PJ |
1006 | /* |
1007 | * Either nlongs_reg == 1 (for small orders that fit in one long) | |
1008 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) | |
1009 | */ | |
1010 | nbits_reg = 1 << order; | |
1011 | index = pos / BITS_PER_LONG; | |
1012 | offset = pos - (index * BITS_PER_LONG); | |
1013 | nlongs_reg = BITS_TO_LONGS(nbits_reg); | |
1014 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); | |
1da177e4 | 1015 | |
3cf64b93 PJ |
1016 | /* |
1017 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that | |
1018 | * overflows if nbitsinlong == BITS_PER_LONG. | |
1019 | */ | |
74373c6a | 1020 | mask = (1UL << (nbitsinlong - 1)); |
1da177e4 | 1021 | mask += mask - 1; |
3cf64b93 | 1022 | mask <<= offset; |
1da177e4 | 1023 | |
3cf64b93 PJ |
1024 | switch (reg_op) { |
1025 | case REG_OP_ISFREE: | |
1026 | for (i = 0; i < nlongs_reg; i++) { | |
1027 | if (bitmap[index + i] & mask) | |
1028 | goto done; | |
1029 | } | |
1030 | ret = 1; /* all bits in region free (zero) */ | |
1031 | break; | |
1032 | ||
1033 | case REG_OP_ALLOC: | |
1034 | for (i = 0; i < nlongs_reg; i++) | |
1035 | bitmap[index + i] |= mask; | |
1036 | break; | |
1037 | ||
1038 | case REG_OP_RELEASE: | |
1039 | for (i = 0; i < nlongs_reg; i++) | |
1040 | bitmap[index + i] &= ~mask; | |
1041 | break; | |
1da177e4 | 1042 | } |
3cf64b93 PJ |
1043 | done: |
1044 | return ret; | |
1045 | } | |
1046 | ||
1047 | /** | |
1048 | * bitmap_find_free_region - find a contiguous aligned mem region | |
1049 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
1050 | * @bits: number of bits in the bitmap | |
1051 | * @order: region size (log base 2 of number of bits) to find | |
1052 | * | |
1053 | * Find a region of free (zero) bits in a @bitmap of @bits bits and | |
1054 | * allocate them (set them to one). Only consider regions of length | |
1055 | * a power (@order) of two, aligned to that power of two, which | |
1056 | * makes the search algorithm much faster. | |
1057 | * | |
1058 | * Return the bit offset in bitmap of the allocated region, | |
1059 | * or -errno on failure. | |
1060 | */ | |
9279d328 | 1061 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) |
3cf64b93 | 1062 | { |
9279d328 | 1063 | unsigned int pos, end; /* scans bitmap by regions of size order */ |
aa8e4fc6 | 1064 | |
9279d328 | 1065 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { |
aa8e4fc6 LT |
1066 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1067 | continue; | |
1068 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
1069 | return pos; | |
1070 | } | |
1071 | return -ENOMEM; | |
1da177e4 LT |
1072 | } |
1073 | EXPORT_SYMBOL(bitmap_find_free_region); | |
1074 | ||
1075 | /** | |
87e24802 | 1076 | * bitmap_release_region - release allocated bitmap region |
3cf64b93 PJ |
1077 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1078 | * @pos: beginning of bit region to release | |
1079 | * @order: region size (log base 2 of number of bits) to release | |
1da177e4 | 1080 | * |
72fd4a35 | 1081 | * This is the complement to __bitmap_find_free_region() and releases |
1da177e4 | 1082 | * the found region (by clearing it in the bitmap). |
3cf64b93 PJ |
1083 | * |
1084 | * No return value. | |
1da177e4 | 1085 | */ |
9279d328 | 1086 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1087 | { |
3cf64b93 | 1088 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1da177e4 LT |
1089 | } |
1090 | EXPORT_SYMBOL(bitmap_release_region); | |
1091 | ||
87e24802 PJ |
1092 | /** |
1093 | * bitmap_allocate_region - allocate bitmap region | |
3cf64b93 PJ |
1094 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1095 | * @pos: beginning of bit region to allocate | |
1096 | * @order: region size (log base 2 of number of bits) to allocate | |
87e24802 PJ |
1097 | * |
1098 | * Allocate (set bits in) a specified region of a bitmap. | |
3cf64b93 | 1099 | * |
6e1907ff | 1100 | * Return 0 on success, or %-EBUSY if specified region wasn't |
87e24802 PJ |
1101 | * free (not all bits were zero). |
1102 | */ | |
9279d328 | 1103 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1104 | { |
3cf64b93 PJ |
1105 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1106 | return -EBUSY; | |
2ac521d3 | 1107 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1da177e4 LT |
1108 | } |
1109 | EXPORT_SYMBOL(bitmap_allocate_region); | |
ccbe329b | 1110 | |
e52bc7c2 DD |
1111 | /** |
1112 | * bitmap_from_u32array - copy the contents of a u32 array of bits to bitmap | |
1113 | * @bitmap: array of unsigned longs, the destination bitmap, non NULL | |
1114 | * @nbits: number of bits in @bitmap | |
1115 | * @buf: array of u32 (in host byte order), the source bitmap, non NULL | |
1116 | * @nwords: number of u32 words in @buf | |
1117 | * | |
1118 | * copy min(nbits, 32*nwords) bits from @buf to @bitmap, remaining | |
1119 | * bits between nword and nbits in @bitmap (if any) are cleared. In | |
1120 | * last word of @bitmap, the bits beyond nbits (if any) are kept | |
1121 | * unchanged. | |
1122 | * | |
1123 | * Return the number of bits effectively copied. | |
1124 | */ | |
1125 | unsigned int | |
1126 | bitmap_from_u32array(unsigned long *bitmap, unsigned int nbits, | |
1127 | const u32 *buf, unsigned int nwords) | |
1128 | { | |
1129 | unsigned int dst_idx, src_idx; | |
1130 | ||
1131 | for (src_idx = dst_idx = 0; dst_idx < BITS_TO_LONGS(nbits); ++dst_idx) { | |
1132 | unsigned long part = 0; | |
1133 | ||
1134 | if (src_idx < nwords) | |
1135 | part = buf[src_idx++]; | |
1136 | ||
1137 | #if BITS_PER_LONG == 64 | |
1138 | if (src_idx < nwords) | |
1139 | part |= ((unsigned long) buf[src_idx++]) << 32; | |
1140 | #endif | |
1141 | ||
1142 | if (dst_idx < nbits/BITS_PER_LONG) | |
1143 | bitmap[dst_idx] = part; | |
1144 | else { | |
1145 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); | |
1146 | ||
1147 | bitmap[dst_idx] = (bitmap[dst_idx] & ~mask) | |
1148 | | (part & mask); | |
1149 | } | |
1150 | } | |
1151 | ||
1152 | return min_t(unsigned int, nbits, 32*nwords); | |
1153 | } | |
1154 | EXPORT_SYMBOL(bitmap_from_u32array); | |
1155 | ||
1156 | /** | |
1157 | * bitmap_to_u32array - copy the contents of bitmap to a u32 array of bits | |
1158 | * @buf: array of u32 (in host byte order), the dest bitmap, non NULL | |
1159 | * @nwords: number of u32 words in @buf | |
1160 | * @bitmap: array of unsigned longs, the source bitmap, non NULL | |
1161 | * @nbits: number of bits in @bitmap | |
1162 | * | |
1163 | * copy min(nbits, 32*nwords) bits from @bitmap to @buf. Remaining | |
1164 | * bits after nbits in @buf (if any) are cleared. | |
1165 | * | |
1166 | * Return the number of bits effectively copied. | |
1167 | */ | |
1168 | unsigned int | |
1169 | bitmap_to_u32array(u32 *buf, unsigned int nwords, | |
1170 | const unsigned long *bitmap, unsigned int nbits) | |
1171 | { | |
1172 | unsigned int dst_idx = 0, src_idx = 0; | |
1173 | ||
1174 | while (dst_idx < nwords) { | |
1175 | unsigned long part = 0; | |
1176 | ||
1177 | if (src_idx < BITS_TO_LONGS(nbits)) { | |
1178 | part = bitmap[src_idx]; | |
1179 | if (src_idx >= nbits/BITS_PER_LONG) | |
1180 | part &= BITMAP_LAST_WORD_MASK(nbits); | |
1181 | src_idx++; | |
1182 | } | |
1183 | ||
1184 | buf[dst_idx++] = part & 0xffffffffUL; | |
1185 | ||
1186 | #if BITS_PER_LONG == 64 | |
1187 | if (dst_idx < nwords) { | |
1188 | part >>= 32; | |
1189 | buf[dst_idx++] = part & 0xffffffffUL; | |
1190 | } | |
1191 | #endif | |
1192 | } | |
1193 | ||
1194 | return min_t(unsigned int, nbits, 32*nwords); | |
1195 | } | |
1196 | EXPORT_SYMBOL(bitmap_to_u32array); | |
1197 | ||
ccbe329b DV |
1198 | /** |
1199 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. | |
1200 | * @dst: destination buffer | |
1201 | * @src: bitmap to copy | |
1202 | * @nbits: number of bits in the bitmap | |
1203 | * | |
1204 | * Require nbits % BITS_PER_LONG == 0. | |
1205 | */ | |
e8f24278 | 1206 | #ifdef __BIG_ENDIAN |
9b6c2d2e | 1207 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) |
ccbe329b | 1208 | { |
9b6c2d2e | 1209 | unsigned int i; |
ccbe329b DV |
1210 | |
1211 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { | |
1212 | if (BITS_PER_LONG == 64) | |
9b6c2d2e | 1213 | dst[i] = cpu_to_le64(src[i]); |
ccbe329b | 1214 | else |
9b6c2d2e | 1215 | dst[i] = cpu_to_le32(src[i]); |
ccbe329b DV |
1216 | } |
1217 | } | |
1218 | EXPORT_SYMBOL(bitmap_copy_le); | |
e8f24278 | 1219 | #endif |
b2917089 AS |
1220 | |
1221 | unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) | |
1222 | { | |
1223 | return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), | |
1224 | flags); | |
1225 | } | |
1226 | EXPORT_SYMBOL(bitmap_alloc); | |
1227 | ||
1228 | unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags) | |
1229 | { | |
1230 | return bitmap_alloc(nbits, flags | __GFP_ZERO); | |
1231 | } | |
1232 | EXPORT_SYMBOL(bitmap_zalloc); | |
1233 | ||
1234 | void bitmap_free(const unsigned long *bitmap) | |
1235 | { | |
1236 | kfree(bitmap); | |
1237 | } | |
1238 | EXPORT_SYMBOL(bitmap_free); |