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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> |
5aaba363 SH |
15 | |
16 | #include <asm/page.h> | |
1da177e4 LT |
17 | #include <asm/uaccess.h> |
18 | ||
19 | /* | |
20 | * bitmaps provide an array of bits, implemented using an an | |
21 | * array of unsigned longs. The number of valid bits in a | |
22 | * given bitmap does _not_ need to be an exact multiple of | |
23 | * BITS_PER_LONG. | |
24 | * | |
25 | * The possible unused bits in the last, partially used word | |
26 | * of a bitmap are 'don't care'. The implementation makes | |
27 | * no particular effort to keep them zero. It ensures that | |
28 | * their value will not affect the results of any operation. | |
29 | * The bitmap operations that return Boolean (bitmap_empty, | |
30 | * for example) or scalar (bitmap_weight, for example) results | |
31 | * carefully filter out these unused bits from impacting their | |
32 | * results. | |
33 | * | |
34 | * These operations actually hold to a slightly stronger rule: | |
35 | * if you don't input any bitmaps to these ops that have some | |
36 | * unused bits set, then they won't output any set unused bits | |
37 | * in output bitmaps. | |
38 | * | |
39 | * The byte ordering of bitmaps is more natural on little | |
40 | * endian architectures. See the big-endian headers | |
41 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h | |
42 | * for the best explanations of this ordering. | |
43 | */ | |
44 | ||
0679cc48 | 45 | int __bitmap_empty(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 46 | { |
0679cc48 | 47 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
48 | for (k = 0; k < lim; ++k) |
49 | if (bitmap[k]) | |
50 | return 0; | |
51 | ||
52 | if (bits % BITS_PER_LONG) | |
53 | if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) | |
54 | return 0; | |
55 | ||
56 | return 1; | |
57 | } | |
58 | EXPORT_SYMBOL(__bitmap_empty); | |
59 | ||
8397927c | 60 | int __bitmap_full(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 61 | { |
8397927c | 62 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
63 | for (k = 0; k < lim; ++k) |
64 | if (~bitmap[k]) | |
65 | return 0; | |
66 | ||
67 | if (bits % BITS_PER_LONG) | |
68 | if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) | |
69 | return 0; | |
70 | ||
71 | return 1; | |
72 | } | |
73 | EXPORT_SYMBOL(__bitmap_full); | |
74 | ||
75 | int __bitmap_equal(const unsigned long *bitmap1, | |
5e068069 | 76 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 77 | { |
5e068069 | 78 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
79 | for (k = 0; k < lim; ++k) |
80 | if (bitmap1[k] != bitmap2[k]) | |
81 | return 0; | |
82 | ||
83 | if (bits % BITS_PER_LONG) | |
84 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
85 | return 0; | |
86 | ||
87 | return 1; | |
88 | } | |
89 | EXPORT_SYMBOL(__bitmap_equal); | |
90 | ||
3d6684f4 | 91 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) |
1da177e4 | 92 | { |
3d6684f4 | 93 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
94 | for (k = 0; k < lim; ++k) |
95 | dst[k] = ~src[k]; | |
96 | ||
97 | if (bits % BITS_PER_LONG) | |
65b4ee62 | 98 | dst[k] = ~src[k]; |
1da177e4 LT |
99 | } |
100 | EXPORT_SYMBOL(__bitmap_complement); | |
101 | ||
72fd4a35 | 102 | /** |
1da177e4 | 103 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
05fb6bf0 RD |
104 | * @dst : destination bitmap |
105 | * @src : source bitmap | |
106 | * @shift : shift by this many bits | |
2fbad299 | 107 | * @nbits : bitmap size, in bits |
1da177e4 LT |
108 | * |
109 | * Shifting right (dividing) means moving bits in the MS -> LS bit | |
110 | * direction. Zeros are fed into the vacated MS positions and the | |
111 | * LS bits shifted off the bottom are lost. | |
112 | */ | |
2fbad299 RV |
113 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
114 | unsigned shift, unsigned nbits) | |
1da177e4 | 115 | { |
2fbad299 RV |
116 | unsigned k, lim = BITS_TO_LONGS(nbits), left = nbits % BITS_PER_LONG; |
117 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; | |
1da177e4 LT |
118 | unsigned long mask = (1UL << left) - 1; |
119 | for (k = 0; off + k < lim; ++k) { | |
120 | unsigned long upper, lower; | |
121 | ||
122 | /* | |
123 | * If shift is not word aligned, take lower rem bits of | |
124 | * word above and make them the top rem bits of result. | |
125 | */ | |
126 | if (!rem || off + k + 1 >= lim) | |
127 | upper = 0; | |
128 | else { | |
129 | upper = src[off + k + 1]; | |
130 | if (off + k + 1 == lim - 1 && left) | |
131 | upper &= mask; | |
9d8a6b2a | 132 | upper <<= (BITS_PER_LONG - rem); |
1da177e4 LT |
133 | } |
134 | lower = src[off + k]; | |
135 | if (left && off + k == lim - 1) | |
136 | lower &= mask; | |
9d8a6b2a RV |
137 | lower >>= rem; |
138 | dst[k] = lower | upper; | |
1da177e4 LT |
139 | } |
140 | if (off) | |
141 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); | |
142 | } | |
143 | EXPORT_SYMBOL(__bitmap_shift_right); | |
144 | ||
145 | ||
72fd4a35 | 146 | /** |
1da177e4 | 147 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
05fb6bf0 RD |
148 | * @dst : destination bitmap |
149 | * @src : source bitmap | |
150 | * @shift : shift by this many bits | |
151 | * @bits : bitmap size, in bits | |
1da177e4 LT |
152 | * |
153 | * Shifting left (multiplying) means moving bits in the LS -> MS | |
154 | * direction. Zeros are fed into the vacated LS bit positions | |
155 | * and those MS bits shifted off the top are lost. | |
156 | */ | |
157 | ||
158 | void __bitmap_shift_left(unsigned long *dst, | |
159 | const unsigned long *src, int shift, int bits) | |
160 | { | |
161 | int k, lim = BITS_TO_LONGS(bits), left = bits % BITS_PER_LONG; | |
162 | int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; | |
163 | for (k = lim - off - 1; k >= 0; --k) { | |
164 | unsigned long upper, lower; | |
165 | ||
166 | /* | |
167 | * If shift is not word aligned, take upper rem bits of | |
168 | * word below and make them the bottom rem bits of result. | |
169 | */ | |
170 | if (rem && k > 0) | |
171 | lower = src[k - 1]; | |
172 | else | |
173 | lower = 0; | |
174 | upper = src[k]; | |
175 | if (left && k == lim - 1) | |
176 | upper &= (1UL << left) - 1; | |
ea5d05b3 JK |
177 | dst[k + off] = upper << rem; |
178 | if (rem) | |
179 | dst[k + off] |= lower >> (BITS_PER_LONG - rem); | |
1da177e4 LT |
180 | if (left && k + off == lim - 1) |
181 | dst[k + off] &= (1UL << left) - 1; | |
182 | } | |
183 | if (off) | |
184 | memset(dst, 0, off*sizeof(unsigned long)); | |
185 | } | |
186 | EXPORT_SYMBOL(__bitmap_shift_left); | |
187 | ||
f4b0373b | 188 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 189 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 190 | { |
2f9305eb | 191 | unsigned int k; |
7e5f97d1 | 192 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 193 | unsigned long result = 0; |
1da177e4 | 194 | |
7e5f97d1 | 195 | for (k = 0; k < lim; k++) |
f4b0373b | 196 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
7e5f97d1 RV |
197 | if (bits % BITS_PER_LONG) |
198 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & | |
199 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 200 | return result != 0; |
1da177e4 LT |
201 | } |
202 | EXPORT_SYMBOL(__bitmap_and); | |
203 | ||
204 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 205 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 206 | { |
2f9305eb RV |
207 | unsigned int k; |
208 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
209 | |
210 | for (k = 0; k < nr; k++) | |
211 | dst[k] = bitmap1[k] | bitmap2[k]; | |
212 | } | |
213 | EXPORT_SYMBOL(__bitmap_or); | |
214 | ||
215 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 216 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 217 | { |
2f9305eb RV |
218 | unsigned int k; |
219 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
220 | |
221 | for (k = 0; k < nr; k++) | |
222 | dst[k] = bitmap1[k] ^ bitmap2[k]; | |
223 | } | |
224 | EXPORT_SYMBOL(__bitmap_xor); | |
225 | ||
f4b0373b | 226 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 227 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 228 | { |
2f9305eb | 229 | unsigned int k; |
74e76531 | 230 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 231 | unsigned long result = 0; |
1da177e4 | 232 | |
74e76531 | 233 | for (k = 0; k < lim; k++) |
f4b0373b | 234 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
74e76531 RV |
235 | if (bits % BITS_PER_LONG) |
236 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & | |
237 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 238 | return result != 0; |
1da177e4 LT |
239 | } |
240 | EXPORT_SYMBOL(__bitmap_andnot); | |
241 | ||
242 | int __bitmap_intersects(const unsigned long *bitmap1, | |
6dfe9799 | 243 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 244 | { |
6dfe9799 | 245 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
246 | for (k = 0; k < lim; ++k) |
247 | if (bitmap1[k] & bitmap2[k]) | |
248 | return 1; | |
249 | ||
250 | if (bits % BITS_PER_LONG) | |
251 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
252 | return 1; | |
253 | return 0; | |
254 | } | |
255 | EXPORT_SYMBOL(__bitmap_intersects); | |
256 | ||
257 | int __bitmap_subset(const unsigned long *bitmap1, | |
5be20213 | 258 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 259 | { |
5be20213 | 260 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
261 | for (k = 0; k < lim; ++k) |
262 | if (bitmap1[k] & ~bitmap2[k]) | |
263 | return 0; | |
264 | ||
265 | if (bits % BITS_PER_LONG) | |
266 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
267 | return 0; | |
268 | return 1; | |
269 | } | |
270 | EXPORT_SYMBOL(__bitmap_subset); | |
271 | ||
877d9f3b | 272 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 273 | { |
877d9f3b RV |
274 | unsigned int k, lim = bits/BITS_PER_LONG; |
275 | int w = 0; | |
1da177e4 LT |
276 | |
277 | for (k = 0; k < lim; k++) | |
37d54111 | 278 | w += hweight_long(bitmap[k]); |
1da177e4 LT |
279 | |
280 | if (bits % BITS_PER_LONG) | |
37d54111 | 281 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
1da177e4 LT |
282 | |
283 | return w; | |
284 | } | |
1da177e4 LT |
285 | EXPORT_SYMBOL(__bitmap_weight); |
286 | ||
fb5ac542 | 287 | void bitmap_set(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
288 | { |
289 | unsigned long *p = map + BIT_WORD(start); | |
fb5ac542 | 290 | const unsigned int size = start + len; |
c1a2a962 AM |
291 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
292 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); | |
293 | ||
fb5ac542 | 294 | while (len - bits_to_set >= 0) { |
c1a2a962 | 295 | *p |= mask_to_set; |
fb5ac542 | 296 | len -= bits_to_set; |
c1a2a962 AM |
297 | bits_to_set = BITS_PER_LONG; |
298 | mask_to_set = ~0UL; | |
299 | p++; | |
300 | } | |
fb5ac542 | 301 | if (len) { |
c1a2a962 AM |
302 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
303 | *p |= mask_to_set; | |
304 | } | |
305 | } | |
306 | EXPORT_SYMBOL(bitmap_set); | |
307 | ||
154f5e38 | 308 | void bitmap_clear(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
309 | { |
310 | unsigned long *p = map + BIT_WORD(start); | |
154f5e38 | 311 | const unsigned int size = start + len; |
c1a2a962 AM |
312 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
313 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); | |
314 | ||
154f5e38 | 315 | while (len - bits_to_clear >= 0) { |
c1a2a962 | 316 | *p &= ~mask_to_clear; |
154f5e38 | 317 | len -= bits_to_clear; |
c1a2a962 AM |
318 | bits_to_clear = BITS_PER_LONG; |
319 | mask_to_clear = ~0UL; | |
320 | p++; | |
321 | } | |
154f5e38 | 322 | if (len) { |
c1a2a962 AM |
323 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
324 | *p &= ~mask_to_clear; | |
325 | } | |
326 | } | |
327 | EXPORT_SYMBOL(bitmap_clear); | |
328 | ||
5e19b013 MN |
329 | /** |
330 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area | |
c1a2a962 AM |
331 | * @map: The address to base the search on |
332 | * @size: The bitmap size in bits | |
333 | * @start: The bitnumber to start searching at | |
334 | * @nr: The number of zeroed bits we're looking for | |
335 | * @align_mask: Alignment mask for zero area | |
5e19b013 | 336 | * @align_offset: Alignment offset for zero area. |
c1a2a962 AM |
337 | * |
338 | * The @align_mask should be one less than a power of 2; the effect is that | |
5e19b013 MN |
339 | * the bit offset of all zero areas this function finds plus @align_offset |
340 | * is multiple of that power of 2. | |
c1a2a962 | 341 | */ |
5e19b013 MN |
342 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map, |
343 | unsigned long size, | |
344 | unsigned long start, | |
345 | unsigned int nr, | |
346 | unsigned long align_mask, | |
347 | unsigned long align_offset) | |
c1a2a962 AM |
348 | { |
349 | unsigned long index, end, i; | |
350 | again: | |
351 | index = find_next_zero_bit(map, size, start); | |
352 | ||
353 | /* Align allocation */ | |
5e19b013 | 354 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; |
c1a2a962 AM |
355 | |
356 | end = index + nr; | |
357 | if (end > size) | |
358 | return end; | |
359 | i = find_next_bit(map, end, index); | |
360 | if (i < end) { | |
361 | start = i + 1; | |
362 | goto again; | |
363 | } | |
364 | return index; | |
365 | } | |
5e19b013 | 366 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off); |
c1a2a962 | 367 | |
1da177e4 | 368 | /* |
6d49e352 | 369 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
1da177e4 LT |
370 | * second version by Paul Jackson, third by Joe Korty. |
371 | */ | |
372 | ||
373 | #define CHUNKSZ 32 | |
374 | #define nbits_to_hold_value(val) fls(val) | |
1da177e4 LT |
375 | #define BASEDEC 10 /* fancier cpuset lists input in decimal */ |
376 | ||
377 | /** | |
378 | * bitmap_scnprintf - convert bitmap to an ASCII hex string. | |
379 | * @buf: byte buffer into which string is placed | |
380 | * @buflen: reserved size of @buf, in bytes | |
381 | * @maskp: pointer to bitmap to convert | |
382 | * @nmaskbits: size of bitmap, in bits | |
383 | * | |
384 | * Exactly @nmaskbits bits are displayed. Hex digits are grouped into | |
05a6c8a9 AM |
385 | * comma-separated sets of eight digits per set. Returns the number of |
386 | * characters which were written to *buf, excluding the trailing \0. | |
1da177e4 LT |
387 | */ |
388 | int bitmap_scnprintf(char *buf, unsigned int buflen, | |
389 | const unsigned long *maskp, int nmaskbits) | |
390 | { | |
391 | int i, word, bit, len = 0; | |
392 | unsigned long val; | |
393 | const char *sep = ""; | |
394 | int chunksz; | |
395 | u32 chunkmask; | |
396 | ||
397 | chunksz = nmaskbits & (CHUNKSZ - 1); | |
398 | if (chunksz == 0) | |
399 | chunksz = CHUNKSZ; | |
400 | ||
8c0e33c1 | 401 | i = ALIGN(nmaskbits, CHUNKSZ) - CHUNKSZ; |
1da177e4 LT |
402 | for (; i >= 0; i -= CHUNKSZ) { |
403 | chunkmask = ((1ULL << chunksz) - 1); | |
404 | word = i / BITS_PER_LONG; | |
405 | bit = i % BITS_PER_LONG; | |
406 | val = (maskp[word] >> bit) & chunkmask; | |
407 | len += scnprintf(buf+len, buflen-len, "%s%0*lx", sep, | |
408 | (chunksz+3)/4, val); | |
409 | chunksz = CHUNKSZ; | |
410 | sep = ","; | |
411 | } | |
412 | return len; | |
413 | } | |
414 | EXPORT_SYMBOL(bitmap_scnprintf); | |
415 | ||
416 | /** | |
01a3ee2b RC |
417 | * __bitmap_parse - convert an ASCII hex string into a bitmap. |
418 | * @buf: pointer to buffer containing string. | |
419 | * @buflen: buffer size in bytes. If string is smaller than this | |
1da177e4 | 420 | * then it must be terminated with a \0. |
01a3ee2b | 421 | * @is_user: location of buffer, 0 indicates kernel space |
1da177e4 LT |
422 | * @maskp: pointer to bitmap array that will contain result. |
423 | * @nmaskbits: size of bitmap, in bits. | |
424 | * | |
425 | * Commas group hex digits into chunks. Each chunk defines exactly 32 | |
426 | * bits of the resultant bitmask. No chunk may specify a value larger | |
6e1907ff RD |
427 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value |
428 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal | |
1da177e4 LT |
429 | * characters and for grouping errors such as "1,,5", ",44", "," and "". |
430 | * Leading and trailing whitespace accepted, but not embedded whitespace. | |
431 | */ | |
01a3ee2b RC |
432 | int __bitmap_parse(const char *buf, unsigned int buflen, |
433 | int is_user, unsigned long *maskp, | |
434 | int nmaskbits) | |
1da177e4 LT |
435 | { |
436 | int c, old_c, totaldigits, ndigits, nchunks, nbits; | |
437 | u32 chunk; | |
b9c321fd | 438 | const char __user __force *ubuf = (const char __user __force *)buf; |
1da177e4 LT |
439 | |
440 | bitmap_zero(maskp, nmaskbits); | |
441 | ||
442 | nchunks = nbits = totaldigits = c = 0; | |
443 | do { | |
444 | chunk = ndigits = 0; | |
445 | ||
446 | /* Get the next chunk of the bitmap */ | |
01a3ee2b | 447 | while (buflen) { |
1da177e4 | 448 | old_c = c; |
01a3ee2b RC |
449 | if (is_user) { |
450 | if (__get_user(c, ubuf++)) | |
451 | return -EFAULT; | |
452 | } | |
453 | else | |
454 | c = *buf++; | |
455 | buflen--; | |
1da177e4 LT |
456 | if (isspace(c)) |
457 | continue; | |
458 | ||
459 | /* | |
460 | * If the last character was a space and the current | |
461 | * character isn't '\0', we've got embedded whitespace. | |
462 | * This is a no-no, so throw an error. | |
463 | */ | |
464 | if (totaldigits && c && isspace(old_c)) | |
465 | return -EINVAL; | |
466 | ||
467 | /* A '\0' or a ',' signal the end of the chunk */ | |
468 | if (c == '\0' || c == ',') | |
469 | break; | |
470 | ||
471 | if (!isxdigit(c)) | |
472 | return -EINVAL; | |
473 | ||
474 | /* | |
475 | * Make sure there are at least 4 free bits in 'chunk'. | |
476 | * If not, this hexdigit will overflow 'chunk', so | |
477 | * throw an error. | |
478 | */ | |
479 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) | |
480 | return -EOVERFLOW; | |
481 | ||
66f1991b | 482 | chunk = (chunk << 4) | hex_to_bin(c); |
1da177e4 LT |
483 | ndigits++; totaldigits++; |
484 | } | |
485 | if (ndigits == 0) | |
486 | return -EINVAL; | |
487 | if (nchunks == 0 && chunk == 0) | |
488 | continue; | |
489 | ||
490 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); | |
491 | *maskp |= chunk; | |
492 | nchunks++; | |
493 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; | |
494 | if (nbits > nmaskbits) | |
495 | return -EOVERFLOW; | |
01a3ee2b | 496 | } while (buflen && c == ','); |
1da177e4 LT |
497 | |
498 | return 0; | |
499 | } | |
01a3ee2b RC |
500 | EXPORT_SYMBOL(__bitmap_parse); |
501 | ||
502 | /** | |
9a86e2ba | 503 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
01a3ee2b RC |
504 | * |
505 | * @ubuf: pointer to user buffer containing string. | |
506 | * @ulen: buffer size in bytes. If string is smaller than this | |
507 | * then it must be terminated with a \0. | |
508 | * @maskp: pointer to bitmap array that will contain result. | |
509 | * @nmaskbits: size of bitmap, in bits. | |
510 | * | |
511 | * Wrapper for __bitmap_parse(), providing it with user buffer. | |
512 | * | |
513 | * We cannot have this as an inline function in bitmap.h because it needs | |
514 | * linux/uaccess.h to get the access_ok() declaration and this causes | |
515 | * cyclic dependencies. | |
516 | */ | |
517 | int bitmap_parse_user(const char __user *ubuf, | |
518 | unsigned int ulen, unsigned long *maskp, | |
519 | int nmaskbits) | |
520 | { | |
521 | if (!access_ok(VERIFY_READ, ubuf, ulen)) | |
522 | return -EFAULT; | |
b9c321fd HS |
523 | return __bitmap_parse((const char __force *)ubuf, |
524 | ulen, 1, maskp, nmaskbits); | |
525 | ||
01a3ee2b RC |
526 | } |
527 | EXPORT_SYMBOL(bitmap_parse_user); | |
1da177e4 LT |
528 | |
529 | /* | |
530 | * bscnl_emit(buf, buflen, rbot, rtop, bp) | |
531 | * | |
532 | * Helper routine for bitmap_scnlistprintf(). Write decimal number | |
533 | * or range to buf, suppressing output past buf+buflen, with optional | |
05a6c8a9 AM |
534 | * comma-prefix. Return len of what was written to *buf, excluding the |
535 | * trailing \0. | |
1da177e4 LT |
536 | */ |
537 | static inline int bscnl_emit(char *buf, int buflen, int rbot, int rtop, int len) | |
538 | { | |
539 | if (len > 0) | |
540 | len += scnprintf(buf + len, buflen - len, ","); | |
541 | if (rbot == rtop) | |
542 | len += scnprintf(buf + len, buflen - len, "%d", rbot); | |
543 | else | |
544 | len += scnprintf(buf + len, buflen - len, "%d-%d", rbot, rtop); | |
545 | return len; | |
546 | } | |
547 | ||
548 | /** | |
549 | * bitmap_scnlistprintf - convert bitmap to list format ASCII string | |
550 | * @buf: byte buffer into which string is placed | |
551 | * @buflen: reserved size of @buf, in bytes | |
552 | * @maskp: pointer to bitmap to convert | |
553 | * @nmaskbits: size of bitmap, in bits | |
554 | * | |
555 | * Output format is a comma-separated list of decimal numbers and | |
556 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
557 | * decimal numbers, the smallest and largest bit numbers set in | |
558 | * the range. Output format is compatible with the format | |
559 | * accepted as input by bitmap_parselist(). | |
560 | * | |
05a6c8a9 AM |
561 | * The return value is the number of characters which were written to *buf |
562 | * excluding the trailing '\0', as per ISO C99's scnprintf. | |
1da177e4 LT |
563 | */ |
564 | int bitmap_scnlistprintf(char *buf, unsigned int buflen, | |
565 | const unsigned long *maskp, int nmaskbits) | |
566 | { | |
567 | int len = 0; | |
568 | /* current bit is 'cur', most recently seen range is [rbot, rtop] */ | |
569 | int cur, rbot, rtop; | |
570 | ||
0b030c2c AK |
571 | if (buflen == 0) |
572 | return 0; | |
573 | buf[0] = 0; | |
574 | ||
1da177e4 LT |
575 | rbot = cur = find_first_bit(maskp, nmaskbits); |
576 | while (cur < nmaskbits) { | |
577 | rtop = cur; | |
578 | cur = find_next_bit(maskp, nmaskbits, cur+1); | |
579 | if (cur >= nmaskbits || cur > rtop + 1) { | |
580 | len = bscnl_emit(buf, buflen, rbot, rtop, len); | |
581 | rbot = cur; | |
582 | } | |
583 | } | |
584 | return len; | |
585 | } | |
586 | EXPORT_SYMBOL(bitmap_scnlistprintf); | |
587 | ||
5aaba363 SH |
588 | /** |
589 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string | |
590 | * @list: indicates whether the bitmap must be list | |
591 | * @buf: page aligned buffer into which string is placed | |
592 | * @maskp: pointer to bitmap to convert | |
593 | * @nmaskbits: size of bitmap, in bits | |
594 | * | |
595 | * Output format is a comma-separated list of decimal numbers and | |
596 | * ranges if list is specified or hex digits grouped into comma-separated | |
597 | * sets of 8 digits/set. Returns the number of characters written to buf. | |
598 | */ | |
599 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, | |
600 | int nmaskbits) | |
601 | { | |
602 | ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf - 2; | |
603 | int n = 0; | |
604 | ||
605 | if (len > 1) { | |
606 | n = list ? bitmap_scnlistprintf(buf, len, maskp, nmaskbits) : | |
607 | bitmap_scnprintf(buf, len, maskp, nmaskbits); | |
608 | buf[n++] = '\n'; | |
609 | buf[n] = '\0'; | |
610 | } | |
611 | return n; | |
612 | } | |
613 | EXPORT_SYMBOL(bitmap_print_to_pagebuf); | |
614 | ||
1da177e4 | 615 | /** |
4b060420 | 616 | * __bitmap_parselist - convert list format ASCII string to bitmap |
b0825ee3 | 617 | * @buf: read nul-terminated user string from this buffer |
4b060420 MT |
618 | * @buflen: buffer size in bytes. If string is smaller than this |
619 | * then it must be terminated with a \0. | |
620 | * @is_user: location of buffer, 0 indicates kernel space | |
6e1907ff | 621 | * @maskp: write resulting mask here |
1da177e4 LT |
622 | * @nmaskbits: number of bits in mask to be written |
623 | * | |
624 | * Input format is a comma-separated list of decimal numbers and | |
625 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
626 | * decimal numbers, the smallest and largest bit numbers set in | |
627 | * the range. | |
628 | * | |
6e1907ff RD |
629 | * Returns 0 on success, -errno on invalid input strings. |
630 | * Error values: | |
631 | * %-EINVAL: second number in range smaller than first | |
632 | * %-EINVAL: invalid character in string | |
633 | * %-ERANGE: bit number specified too large for mask | |
1da177e4 | 634 | */ |
4b060420 MT |
635 | static int __bitmap_parselist(const char *buf, unsigned int buflen, |
636 | int is_user, unsigned long *maskp, | |
637 | int nmaskbits) | |
1da177e4 LT |
638 | { |
639 | unsigned a, b; | |
4b060420 | 640 | int c, old_c, totaldigits; |
b9c321fd | 641 | const char __user __force *ubuf = (const char __user __force *)buf; |
4b060420 | 642 | int exp_digit, in_range; |
1da177e4 | 643 | |
4b060420 | 644 | totaldigits = c = 0; |
1da177e4 LT |
645 | bitmap_zero(maskp, nmaskbits); |
646 | do { | |
4b060420 MT |
647 | exp_digit = 1; |
648 | in_range = 0; | |
649 | a = b = 0; | |
650 | ||
651 | /* Get the next cpu# or a range of cpu#'s */ | |
652 | while (buflen) { | |
653 | old_c = c; | |
654 | if (is_user) { | |
655 | if (__get_user(c, ubuf++)) | |
656 | return -EFAULT; | |
657 | } else | |
658 | c = *buf++; | |
659 | buflen--; | |
660 | if (isspace(c)) | |
661 | continue; | |
662 | ||
663 | /* | |
664 | * If the last character was a space and the current | |
665 | * character isn't '\0', we've got embedded whitespace. | |
666 | * This is a no-no, so throw an error. | |
667 | */ | |
668 | if (totaldigits && c && isspace(old_c)) | |
669 | return -EINVAL; | |
670 | ||
671 | /* A '\0' or a ',' signal the end of a cpu# or range */ | |
672 | if (c == '\0' || c == ',') | |
673 | break; | |
674 | ||
675 | if (c == '-') { | |
676 | if (exp_digit || in_range) | |
677 | return -EINVAL; | |
678 | b = 0; | |
679 | in_range = 1; | |
680 | exp_digit = 1; | |
681 | continue; | |
682 | } | |
683 | ||
684 | if (!isdigit(c)) | |
1da177e4 | 685 | return -EINVAL; |
4b060420 MT |
686 | |
687 | b = b * 10 + (c - '0'); | |
688 | if (!in_range) | |
689 | a = b; | |
690 | exp_digit = 0; | |
691 | totaldigits++; | |
1da177e4 LT |
692 | } |
693 | if (!(a <= b)) | |
694 | return -EINVAL; | |
695 | if (b >= nmaskbits) | |
696 | return -ERANGE; | |
697 | while (a <= b) { | |
698 | set_bit(a, maskp); | |
699 | a++; | |
700 | } | |
4b060420 | 701 | } while (buflen && c == ','); |
1da177e4 LT |
702 | return 0; |
703 | } | |
4b060420 MT |
704 | |
705 | int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) | |
706 | { | |
bc5be182 RV |
707 | char *nl = strchrnul(bp, '\n'); |
708 | int len = nl - bp; | |
4b060420 MT |
709 | |
710 | return __bitmap_parselist(bp, len, 0, maskp, nmaskbits); | |
711 | } | |
1da177e4 LT |
712 | EXPORT_SYMBOL(bitmap_parselist); |
713 | ||
4b060420 MT |
714 | |
715 | /** | |
716 | * bitmap_parselist_user() | |
717 | * | |
718 | * @ubuf: pointer to user buffer containing string. | |
719 | * @ulen: buffer size in bytes. If string is smaller than this | |
720 | * then it must be terminated with a \0. | |
721 | * @maskp: pointer to bitmap array that will contain result. | |
722 | * @nmaskbits: size of bitmap, in bits. | |
723 | * | |
724 | * Wrapper for bitmap_parselist(), providing it with user buffer. | |
725 | * | |
726 | * We cannot have this as an inline function in bitmap.h because it needs | |
727 | * linux/uaccess.h to get the access_ok() declaration and this causes | |
728 | * cyclic dependencies. | |
729 | */ | |
730 | int bitmap_parselist_user(const char __user *ubuf, | |
731 | unsigned int ulen, unsigned long *maskp, | |
732 | int nmaskbits) | |
733 | { | |
734 | if (!access_ok(VERIFY_READ, ubuf, ulen)) | |
735 | return -EFAULT; | |
b9c321fd | 736 | return __bitmap_parselist((const char __force *)ubuf, |
4b060420 MT |
737 | ulen, 1, maskp, nmaskbits); |
738 | } | |
739 | EXPORT_SYMBOL(bitmap_parselist_user); | |
740 | ||
741 | ||
72fd4a35 | 742 | /** |
9a86e2ba | 743 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
fb5eeeee | 744 | * @buf: pointer to a bitmap |
df1d80a9 RV |
745 | * @pos: a bit position in @buf (0 <= @pos < @nbits) |
746 | * @nbits: number of valid bit positions in @buf | |
fb5eeeee | 747 | * |
df1d80a9 | 748 | * Map the bit at position @pos in @buf (of length @nbits) to the |
fb5eeeee | 749 | * ordinal of which set bit it is. If it is not set or if @pos |
96b7f341 | 750 | * is not a valid bit position, map to -1. |
fb5eeeee PJ |
751 | * |
752 | * If for example, just bits 4 through 7 are set in @buf, then @pos | |
753 | * values 4 through 7 will get mapped to 0 through 3, respectively, | |
a8551748 | 754 | * and other @pos values will get mapped to -1. When @pos value 7 |
fb5eeeee PJ |
755 | * gets mapped to (returns) @ord value 3 in this example, that means |
756 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. | |
757 | * | |
758 | * The bit positions 0 through @bits are valid positions in @buf. | |
759 | */ | |
df1d80a9 | 760 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) |
fb5eeeee | 761 | { |
df1d80a9 | 762 | if (pos >= nbits || !test_bit(pos, buf)) |
96b7f341 | 763 | return -1; |
fb5eeeee | 764 | |
df1d80a9 | 765 | return __bitmap_weight(buf, pos); |
fb5eeeee PJ |
766 | } |
767 | ||
768 | /** | |
9a86e2ba | 769 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
fb5eeeee PJ |
770 | * @buf: pointer to bitmap |
771 | * @ord: ordinal bit position (n-th set bit, n >= 0) | |
f6a1f5db | 772 | * @nbits: number of valid bit positions in @buf |
fb5eeeee PJ |
773 | * |
774 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. | |
f6a1f5db RV |
775 | * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord |
776 | * >= weight(buf), returns @nbits. | |
fb5eeeee PJ |
777 | * |
778 | * If for example, just bits 4 through 7 are set in @buf, then @ord | |
779 | * values 0 through 3 will get mapped to 4 through 7, respectively, | |
f6a1f5db | 780 | * and all other @ord values returns @nbits. When @ord value 3 |
fb5eeeee PJ |
781 | * gets mapped to (returns) @pos value 7 in this example, that means |
782 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. | |
783 | * | |
f6a1f5db | 784 | * The bit positions 0 through @nbits-1 are valid positions in @buf. |
fb5eeeee | 785 | */ |
f6a1f5db | 786 | unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) |
fb5eeeee | 787 | { |
f6a1f5db | 788 | unsigned int pos; |
fb5eeeee | 789 | |
f6a1f5db RV |
790 | for (pos = find_first_bit(buf, nbits); |
791 | pos < nbits && ord; | |
792 | pos = find_next_bit(buf, nbits, pos + 1)) | |
793 | ord--; | |
fb5eeeee PJ |
794 | |
795 | return pos; | |
796 | } | |
797 | ||
798 | /** | |
799 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap | |
fb5eeeee | 800 | * @dst: remapped result |
96b7f341 | 801 | * @src: subset to be remapped |
fb5eeeee PJ |
802 | * @old: defines domain of map |
803 | * @new: defines range of map | |
9814ec13 | 804 | * @nbits: number of bits in each of these bitmaps |
fb5eeeee PJ |
805 | * |
806 | * Let @old and @new define a mapping of bit positions, such that | |
807 | * whatever position is held by the n-th set bit in @old is mapped | |
808 | * to the n-th set bit in @new. In the more general case, allowing | |
809 | * for the possibility that the weight 'w' of @new is less than the | |
810 | * weight of @old, map the position of the n-th set bit in @old to | |
811 | * the position of the m-th set bit in @new, where m == n % w. | |
812 | * | |
96b7f341 PJ |
813 | * If either of the @old and @new bitmaps are empty, or if @src and |
814 | * @dst point to the same location, then this routine copies @src | |
815 | * to @dst. | |
fb5eeeee | 816 | * |
96b7f341 PJ |
817 | * The positions of unset bits in @old are mapped to themselves |
818 | * (the identify map). | |
fb5eeeee PJ |
819 | * |
820 | * Apply the above specified mapping to @src, placing the result in | |
821 | * @dst, clearing any bits previously set in @dst. | |
822 | * | |
fb5eeeee PJ |
823 | * For example, lets say that @old has bits 4 through 7 set, and |
824 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
825 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
826 | * bit positions unchanged. So if say @src comes into this routine |
827 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, | |
828 | * 13 and 15 set. | |
fb5eeeee PJ |
829 | */ |
830 | void bitmap_remap(unsigned long *dst, const unsigned long *src, | |
831 | const unsigned long *old, const unsigned long *new, | |
9814ec13 | 832 | unsigned int nbits) |
fb5eeeee | 833 | { |
9814ec13 | 834 | unsigned int oldbit, w; |
fb5eeeee | 835 | |
fb5eeeee PJ |
836 | if (dst == src) /* following doesn't handle inplace remaps */ |
837 | return; | |
9814ec13 | 838 | bitmap_zero(dst, nbits); |
96b7f341 | 839 | |
9814ec13 RV |
840 | w = bitmap_weight(new, nbits); |
841 | for_each_set_bit(oldbit, src, nbits) { | |
842 | int n = bitmap_pos_to_ord(old, oldbit, nbits); | |
08564fb7 | 843 | |
96b7f341 PJ |
844 | if (n < 0 || w == 0) |
845 | set_bit(oldbit, dst); /* identity map */ | |
846 | else | |
9814ec13 | 847 | set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); |
fb5eeeee PJ |
848 | } |
849 | } | |
850 | EXPORT_SYMBOL(bitmap_remap); | |
851 | ||
852 | /** | |
853 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit | |
6e1907ff RD |
854 | * @oldbit: bit position to be mapped |
855 | * @old: defines domain of map | |
856 | * @new: defines range of map | |
857 | * @bits: number of bits in each of these bitmaps | |
fb5eeeee PJ |
858 | * |
859 | * Let @old and @new define a mapping of bit positions, such that | |
860 | * whatever position is held by the n-th set bit in @old is mapped | |
861 | * to the n-th set bit in @new. In the more general case, allowing | |
862 | * for the possibility that the weight 'w' of @new is less than the | |
863 | * weight of @old, map the position of the n-th set bit in @old to | |
864 | * the position of the m-th set bit in @new, where m == n % w. | |
865 | * | |
96b7f341 PJ |
866 | * The positions of unset bits in @old are mapped to themselves |
867 | * (the identify map). | |
fb5eeeee PJ |
868 | * |
869 | * Apply the above specified mapping to bit position @oldbit, returning | |
870 | * the new bit position. | |
871 | * | |
872 | * For example, lets say that @old has bits 4 through 7 set, and | |
873 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
874 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
875 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
876 | * returns 13. | |
fb5eeeee PJ |
877 | */ |
878 | int bitmap_bitremap(int oldbit, const unsigned long *old, | |
879 | const unsigned long *new, int bits) | |
880 | { | |
96b7f341 PJ |
881 | int w = bitmap_weight(new, bits); |
882 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
883 | if (n < 0 || w == 0) | |
884 | return oldbit; | |
885 | else | |
886 | return bitmap_ord_to_pos(new, n % w, bits); | |
fb5eeeee PJ |
887 | } |
888 | EXPORT_SYMBOL(bitmap_bitremap); | |
889 | ||
7ea931c9 PJ |
890 | /** |
891 | * bitmap_onto - translate one bitmap relative to another | |
892 | * @dst: resulting translated bitmap | |
893 | * @orig: original untranslated bitmap | |
894 | * @relmap: bitmap relative to which translated | |
895 | * @bits: number of bits in each of these bitmaps | |
896 | * | |
897 | * Set the n-th bit of @dst iff there exists some m such that the | |
898 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and | |
899 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. | |
900 | * (If you understood the previous sentence the first time your | |
901 | * read it, you're overqualified for your current job.) | |
902 | * | |
903 | * In other words, @orig is mapped onto (surjectively) @dst, | |
da3dae54 | 904 | * using the map { <n, m> | the n-th bit of @relmap is the |
7ea931c9 PJ |
905 | * m-th set bit of @relmap }. |
906 | * | |
907 | * Any set bits in @orig above bit number W, where W is the | |
908 | * weight of (number of set bits in) @relmap are mapped nowhere. | |
909 | * In particular, if for all bits m set in @orig, m >= W, then | |
910 | * @dst will end up empty. In situations where the possibility | |
911 | * of such an empty result is not desired, one way to avoid it is | |
912 | * to use the bitmap_fold() operator, below, to first fold the | |
913 | * @orig bitmap over itself so that all its set bits x are in the | |
914 | * range 0 <= x < W. The bitmap_fold() operator does this by | |
915 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. | |
916 | * | |
917 | * Example [1] for bitmap_onto(): | |
918 | * Let's say @relmap has bits 30-39 set, and @orig has bits | |
919 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, | |
920 | * @dst will have bits 31, 33, 35, 37 and 39 set. | |
921 | * | |
922 | * When bit 0 is set in @orig, it means turn on the bit in | |
923 | * @dst corresponding to whatever is the first bit (if any) | |
924 | * that is turned on in @relmap. Since bit 0 was off in the | |
925 | * above example, we leave off that bit (bit 30) in @dst. | |
926 | * | |
927 | * When bit 1 is set in @orig (as in the above example), it | |
928 | * means turn on the bit in @dst corresponding to whatever | |
929 | * is the second bit that is turned on in @relmap. The second | |
930 | * bit in @relmap that was turned on in the above example was | |
931 | * bit 31, so we turned on bit 31 in @dst. | |
932 | * | |
933 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, | |
934 | * because they were the 4th, 6th, 8th and 10th set bits | |
935 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of | |
936 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. | |
937 | * | |
938 | * When bit 11 is set in @orig, it means turn on the bit in | |
25985edc | 939 | * @dst corresponding to whatever is the twelfth bit that is |
7ea931c9 PJ |
940 | * turned on in @relmap. In the above example, there were |
941 | * only ten bits turned on in @relmap (30..39), so that bit | |
942 | * 11 was set in @orig had no affect on @dst. | |
943 | * | |
944 | * Example [2] for bitmap_fold() + bitmap_onto(): | |
945 | * Let's say @relmap has these ten bits set: | |
946 | * 40 41 42 43 45 48 53 61 74 95 | |
947 | * (for the curious, that's 40 plus the first ten terms of the | |
948 | * Fibonacci sequence.) | |
949 | * | |
950 | * Further lets say we use the following code, invoking | |
951 | * bitmap_fold() then bitmap_onto, as suggested above to | |
da3dae54 | 952 | * avoid the possibility of an empty @dst result: |
7ea931c9 PJ |
953 | * |
954 | * unsigned long *tmp; // a temporary bitmap's bits | |
955 | * | |
956 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); | |
957 | * bitmap_onto(dst, tmp, relmap, bits); | |
958 | * | |
959 | * Then this table shows what various values of @dst would be, for | |
960 | * various @orig's. I list the zero-based positions of each set bit. | |
961 | * The tmp column shows the intermediate result, as computed by | |
962 | * using bitmap_fold() to fold the @orig bitmap modulo ten | |
963 | * (the weight of @relmap). | |
964 | * | |
965 | * @orig tmp @dst | |
966 | * 0 0 40 | |
967 | * 1 1 41 | |
968 | * 9 9 95 | |
969 | * 10 0 40 (*) | |
970 | * 1 3 5 7 1 3 5 7 41 43 48 61 | |
971 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 | |
972 | * 0 9 18 27 0 9 8 7 40 61 74 95 | |
973 | * 0 10 20 30 0 40 | |
974 | * 0 11 22 33 0 1 2 3 40 41 42 43 | |
975 | * 0 12 24 36 0 2 4 6 40 42 45 53 | |
976 | * 78 102 211 1 2 8 41 42 74 (*) | |
977 | * | |
978 | * (*) For these marked lines, if we hadn't first done bitmap_fold() | |
979 | * into tmp, then the @dst result would have been empty. | |
980 | * | |
981 | * If either of @orig or @relmap is empty (no set bits), then @dst | |
982 | * will be returned empty. | |
983 | * | |
984 | * If (as explained above) the only set bits in @orig are in positions | |
985 | * m where m >= W, (where W is the weight of @relmap) then @dst will | |
986 | * once again be returned empty. | |
987 | * | |
988 | * All bits in @dst not set by the above rule are cleared. | |
989 | */ | |
990 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, | |
eb569883 | 991 | const unsigned long *relmap, unsigned int bits) |
7ea931c9 | 992 | { |
eb569883 | 993 | unsigned int n, m; /* same meaning as in above comment */ |
7ea931c9 PJ |
994 | |
995 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
996 | return; | |
997 | bitmap_zero(dst, bits); | |
998 | ||
999 | /* | |
1000 | * The following code is a more efficient, but less | |
1001 | * obvious, equivalent to the loop: | |
1002 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { | |
1003 | * n = bitmap_ord_to_pos(orig, m, bits); | |
1004 | * if (test_bit(m, orig)) | |
1005 | * set_bit(n, dst); | |
1006 | * } | |
1007 | */ | |
1008 | ||
1009 | m = 0; | |
08564fb7 | 1010 | for_each_set_bit(n, relmap, bits) { |
7ea931c9 PJ |
1011 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
1012 | if (test_bit(m, orig)) | |
1013 | set_bit(n, dst); | |
1014 | m++; | |
1015 | } | |
1016 | } | |
1017 | EXPORT_SYMBOL(bitmap_onto); | |
1018 | ||
1019 | /** | |
1020 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size | |
1021 | * @dst: resulting smaller bitmap | |
1022 | * @orig: original larger bitmap | |
1023 | * @sz: specified size | |
b26ad583 | 1024 | * @nbits: number of bits in each of these bitmaps |
7ea931c9 PJ |
1025 | * |
1026 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. | |
1027 | * Clear all other bits in @dst. See further the comment and | |
1028 | * Example [2] for bitmap_onto() for why and how to use this. | |
1029 | */ | |
1030 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, | |
b26ad583 | 1031 | unsigned int sz, unsigned int nbits) |
7ea931c9 | 1032 | { |
b26ad583 | 1033 | unsigned int oldbit; |
7ea931c9 PJ |
1034 | |
1035 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
1036 | return; | |
b26ad583 | 1037 | bitmap_zero(dst, nbits); |
7ea931c9 | 1038 | |
b26ad583 | 1039 | for_each_set_bit(oldbit, orig, nbits) |
7ea931c9 PJ |
1040 | set_bit(oldbit % sz, dst); |
1041 | } | |
1042 | EXPORT_SYMBOL(bitmap_fold); | |
1043 | ||
3cf64b93 PJ |
1044 | /* |
1045 | * Common code for bitmap_*_region() routines. | |
1046 | * bitmap: array of unsigned longs corresponding to the bitmap | |
1047 | * pos: the beginning of the region | |
1048 | * order: region size (log base 2 of number of bits) | |
1049 | * reg_op: operation(s) to perform on that region of bitmap | |
1da177e4 | 1050 | * |
3cf64b93 PJ |
1051 | * Can set, verify and/or release a region of bits in a bitmap, |
1052 | * depending on which combination of REG_OP_* flag bits is set. | |
1da177e4 | 1053 | * |
3cf64b93 PJ |
1054 | * A region of a bitmap is a sequence of bits in the bitmap, of |
1055 | * some size '1 << order' (a power of two), aligned to that same | |
1056 | * '1 << order' power of two. | |
1057 | * | |
1058 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). | |
1059 | * Returns 0 in all other cases and reg_ops. | |
1da177e4 | 1060 | */ |
3cf64b93 PJ |
1061 | |
1062 | enum { | |
1063 | REG_OP_ISFREE, /* true if region is all zero bits */ | |
1064 | REG_OP_ALLOC, /* set all bits in region */ | |
1065 | REG_OP_RELEASE, /* clear all bits in region */ | |
1066 | }; | |
1067 | ||
9279d328 | 1068 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) |
1da177e4 | 1069 | { |
3cf64b93 PJ |
1070 | int nbits_reg; /* number of bits in region */ |
1071 | int index; /* index first long of region in bitmap */ | |
1072 | int offset; /* bit offset region in bitmap[index] */ | |
1073 | int nlongs_reg; /* num longs spanned by region in bitmap */ | |
74373c6a | 1074 | int nbitsinlong; /* num bits of region in each spanned long */ |
3cf64b93 | 1075 | unsigned long mask; /* bitmask for one long of region */ |
74373c6a | 1076 | int i; /* scans bitmap by longs */ |
3cf64b93 | 1077 | int ret = 0; /* return value */ |
74373c6a | 1078 | |
3cf64b93 PJ |
1079 | /* |
1080 | * Either nlongs_reg == 1 (for small orders that fit in one long) | |
1081 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) | |
1082 | */ | |
1083 | nbits_reg = 1 << order; | |
1084 | index = pos / BITS_PER_LONG; | |
1085 | offset = pos - (index * BITS_PER_LONG); | |
1086 | nlongs_reg = BITS_TO_LONGS(nbits_reg); | |
1087 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); | |
1da177e4 | 1088 | |
3cf64b93 PJ |
1089 | /* |
1090 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that | |
1091 | * overflows if nbitsinlong == BITS_PER_LONG. | |
1092 | */ | |
74373c6a | 1093 | mask = (1UL << (nbitsinlong - 1)); |
1da177e4 | 1094 | mask += mask - 1; |
3cf64b93 | 1095 | mask <<= offset; |
1da177e4 | 1096 | |
3cf64b93 PJ |
1097 | switch (reg_op) { |
1098 | case REG_OP_ISFREE: | |
1099 | for (i = 0; i < nlongs_reg; i++) { | |
1100 | if (bitmap[index + i] & mask) | |
1101 | goto done; | |
1102 | } | |
1103 | ret = 1; /* all bits in region free (zero) */ | |
1104 | break; | |
1105 | ||
1106 | case REG_OP_ALLOC: | |
1107 | for (i = 0; i < nlongs_reg; i++) | |
1108 | bitmap[index + i] |= mask; | |
1109 | break; | |
1110 | ||
1111 | case REG_OP_RELEASE: | |
1112 | for (i = 0; i < nlongs_reg; i++) | |
1113 | bitmap[index + i] &= ~mask; | |
1114 | break; | |
1da177e4 | 1115 | } |
3cf64b93 PJ |
1116 | done: |
1117 | return ret; | |
1118 | } | |
1119 | ||
1120 | /** | |
1121 | * bitmap_find_free_region - find a contiguous aligned mem region | |
1122 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
1123 | * @bits: number of bits in the bitmap | |
1124 | * @order: region size (log base 2 of number of bits) to find | |
1125 | * | |
1126 | * Find a region of free (zero) bits in a @bitmap of @bits bits and | |
1127 | * allocate them (set them to one). Only consider regions of length | |
1128 | * a power (@order) of two, aligned to that power of two, which | |
1129 | * makes the search algorithm much faster. | |
1130 | * | |
1131 | * Return the bit offset in bitmap of the allocated region, | |
1132 | * or -errno on failure. | |
1133 | */ | |
9279d328 | 1134 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) |
3cf64b93 | 1135 | { |
9279d328 | 1136 | unsigned int pos, end; /* scans bitmap by regions of size order */ |
aa8e4fc6 | 1137 | |
9279d328 | 1138 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { |
aa8e4fc6 LT |
1139 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1140 | continue; | |
1141 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
1142 | return pos; | |
1143 | } | |
1144 | return -ENOMEM; | |
1da177e4 LT |
1145 | } |
1146 | EXPORT_SYMBOL(bitmap_find_free_region); | |
1147 | ||
1148 | /** | |
87e24802 | 1149 | * bitmap_release_region - release allocated bitmap region |
3cf64b93 PJ |
1150 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1151 | * @pos: beginning of bit region to release | |
1152 | * @order: region size (log base 2 of number of bits) to release | |
1da177e4 | 1153 | * |
72fd4a35 | 1154 | * This is the complement to __bitmap_find_free_region() and releases |
1da177e4 | 1155 | * the found region (by clearing it in the bitmap). |
3cf64b93 PJ |
1156 | * |
1157 | * No return value. | |
1da177e4 | 1158 | */ |
9279d328 | 1159 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1160 | { |
3cf64b93 | 1161 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1da177e4 LT |
1162 | } |
1163 | EXPORT_SYMBOL(bitmap_release_region); | |
1164 | ||
87e24802 PJ |
1165 | /** |
1166 | * bitmap_allocate_region - allocate bitmap region | |
3cf64b93 PJ |
1167 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1168 | * @pos: beginning of bit region to allocate | |
1169 | * @order: region size (log base 2 of number of bits) to allocate | |
87e24802 PJ |
1170 | * |
1171 | * Allocate (set bits in) a specified region of a bitmap. | |
3cf64b93 | 1172 | * |
6e1907ff | 1173 | * Return 0 on success, or %-EBUSY if specified region wasn't |
87e24802 PJ |
1174 | * free (not all bits were zero). |
1175 | */ | |
9279d328 | 1176 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1177 | { |
3cf64b93 PJ |
1178 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1179 | return -EBUSY; | |
2ac521d3 | 1180 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1da177e4 LT |
1181 | } |
1182 | EXPORT_SYMBOL(bitmap_allocate_region); | |
ccbe329b DV |
1183 | |
1184 | /** | |
1185 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. | |
1186 | * @dst: destination buffer | |
1187 | * @src: bitmap to copy | |
1188 | * @nbits: number of bits in the bitmap | |
1189 | * | |
1190 | * Require nbits % BITS_PER_LONG == 0. | |
1191 | */ | |
e8f24278 | 1192 | #ifdef __BIG_ENDIAN |
9b6c2d2e | 1193 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) |
ccbe329b | 1194 | { |
9b6c2d2e | 1195 | unsigned int i; |
ccbe329b DV |
1196 | |
1197 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { | |
1198 | if (BITS_PER_LONG == 64) | |
9b6c2d2e | 1199 | dst[i] = cpu_to_le64(src[i]); |
ccbe329b | 1200 | else |
9b6c2d2e | 1201 | dst[i] = cpu_to_le32(src[i]); |
ccbe329b DV |
1202 | } |
1203 | } | |
1204 | EXPORT_SYMBOL(bitmap_copy_le); | |
e8f24278 | 1205 | #endif |