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