Commit | Line | Data |
---|---|---|
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 DD |
15 | #include <linux/kernel.h> |
16 | #include <linux/string.h> | |
13d4ea09 | 17 | #include <linux/uaccess.h> |
5aaba363 SH |
18 | |
19 | #include <asm/page.h> | |
1da177e4 LT |
20 | |
21 | /* | |
22 | * bitmaps provide an array of bits, implemented using an an | |
23 | * array of unsigned longs. The number of valid bits in a | |
24 | * given bitmap does _not_ need to be an exact multiple of | |
25 | * BITS_PER_LONG. | |
26 | * | |
27 | * The possible unused bits in the last, partially used word | |
28 | * of a bitmap are 'don't care'. The implementation makes | |
29 | * no particular effort to keep them zero. It ensures that | |
30 | * their value will not affect the results of any operation. | |
31 | * The bitmap operations that return Boolean (bitmap_empty, | |
32 | * for example) or scalar (bitmap_weight, for example) results | |
33 | * carefully filter out these unused bits from impacting their | |
34 | * results. | |
35 | * | |
36 | * These operations actually hold to a slightly stronger rule: | |
37 | * if you don't input any bitmaps to these ops that have some | |
38 | * unused bits set, then they won't output any set unused bits | |
39 | * in output bitmaps. | |
40 | * | |
41 | * The byte ordering of bitmaps is more natural on little | |
42 | * endian architectures. See the big-endian headers | |
43 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h | |
44 | * for the best explanations of this ordering. | |
45 | */ | |
46 | ||
1da177e4 | 47 | int __bitmap_equal(const unsigned long *bitmap1, |
5e068069 | 48 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 49 | { |
5e068069 | 50 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
51 | for (k = 0; k < lim; ++k) |
52 | if (bitmap1[k] != bitmap2[k]) | |
53 | return 0; | |
54 | ||
55 | if (bits % BITS_PER_LONG) | |
56 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
57 | return 0; | |
58 | ||
59 | return 1; | |
60 | } | |
61 | EXPORT_SYMBOL(__bitmap_equal); | |
62 | ||
3d6684f4 | 63 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) |
1da177e4 | 64 | { |
3d6684f4 | 65 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
66 | for (k = 0; k < lim; ++k) |
67 | dst[k] = ~src[k]; | |
68 | ||
69 | if (bits % BITS_PER_LONG) | |
65b4ee62 | 70 | dst[k] = ~src[k]; |
1da177e4 LT |
71 | } |
72 | EXPORT_SYMBOL(__bitmap_complement); | |
73 | ||
72fd4a35 | 74 | /** |
1da177e4 | 75 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
05fb6bf0 RD |
76 | * @dst : destination bitmap |
77 | * @src : source bitmap | |
78 | * @shift : shift by this many bits | |
2fbad299 | 79 | * @nbits : bitmap size, in bits |
1da177e4 LT |
80 | * |
81 | * Shifting right (dividing) means moving bits in the MS -> LS bit | |
82 | * direction. Zeros are fed into the vacated MS positions and the | |
83 | * LS bits shifted off the bottom are lost. | |
84 | */ | |
2fbad299 RV |
85 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
86 | unsigned shift, unsigned nbits) | |
1da177e4 | 87 | { |
cfac1d08 | 88 | unsigned k, lim = BITS_TO_LONGS(nbits); |
2fbad299 | 89 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
cfac1d08 | 90 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); |
1da177e4 LT |
91 | for (k = 0; off + k < lim; ++k) { |
92 | unsigned long upper, lower; | |
93 | ||
94 | /* | |
95 | * If shift is not word aligned, take lower rem bits of | |
96 | * word above and make them the top rem bits of result. | |
97 | */ | |
98 | if (!rem || off + k + 1 >= lim) | |
99 | upper = 0; | |
100 | else { | |
101 | upper = src[off + k + 1]; | |
cfac1d08 | 102 | if (off + k + 1 == lim - 1) |
1da177e4 | 103 | upper &= mask; |
9d8a6b2a | 104 | upper <<= (BITS_PER_LONG - rem); |
1da177e4 LT |
105 | } |
106 | lower = src[off + k]; | |
cfac1d08 | 107 | if (off + k == lim - 1) |
1da177e4 | 108 | lower &= mask; |
9d8a6b2a RV |
109 | lower >>= rem; |
110 | dst[k] = lower | upper; | |
1da177e4 LT |
111 | } |
112 | if (off) | |
113 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); | |
114 | } | |
115 | EXPORT_SYMBOL(__bitmap_shift_right); | |
116 | ||
117 | ||
72fd4a35 | 118 | /** |
1da177e4 | 119 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
05fb6bf0 RD |
120 | * @dst : destination bitmap |
121 | * @src : source bitmap | |
122 | * @shift : shift by this many bits | |
dba94c25 | 123 | * @nbits : bitmap size, in bits |
1da177e4 LT |
124 | * |
125 | * Shifting left (multiplying) means moving bits in the LS -> MS | |
126 | * direction. Zeros are fed into the vacated LS bit positions | |
127 | * and those MS bits shifted off the top are lost. | |
128 | */ | |
129 | ||
dba94c25 RV |
130 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, |
131 | unsigned int shift, unsigned int nbits) | |
1da177e4 | 132 | { |
dba94c25 | 133 | int k; |
7f590657 | 134 | unsigned int lim = BITS_TO_LONGS(nbits); |
dba94c25 | 135 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
1da177e4 LT |
136 | for (k = lim - off - 1; k >= 0; --k) { |
137 | unsigned long upper, lower; | |
138 | ||
139 | /* | |
140 | * If shift is not word aligned, take upper rem bits of | |
141 | * word below and make them the bottom rem bits of result. | |
142 | */ | |
143 | if (rem && k > 0) | |
6d874eca | 144 | lower = src[k - 1] >> (BITS_PER_LONG - rem); |
1da177e4 LT |
145 | else |
146 | lower = 0; | |
7f590657 | 147 | upper = src[k] << rem; |
6d874eca | 148 | dst[k + off] = lower | upper; |
1da177e4 LT |
149 | } |
150 | if (off) | |
151 | memset(dst, 0, off*sizeof(unsigned long)); | |
152 | } | |
153 | EXPORT_SYMBOL(__bitmap_shift_left); | |
154 | ||
f4b0373b | 155 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 156 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 157 | { |
2f9305eb | 158 | unsigned int k; |
7e5f97d1 | 159 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 160 | unsigned long result = 0; |
1da177e4 | 161 | |
7e5f97d1 | 162 | for (k = 0; k < lim; k++) |
f4b0373b | 163 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
7e5f97d1 RV |
164 | if (bits % BITS_PER_LONG) |
165 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & | |
166 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 167 | return result != 0; |
1da177e4 LT |
168 | } |
169 | EXPORT_SYMBOL(__bitmap_and); | |
170 | ||
171 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 172 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 173 | { |
2f9305eb RV |
174 | unsigned int k; |
175 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
176 | |
177 | for (k = 0; k < nr; k++) | |
178 | dst[k] = bitmap1[k] | bitmap2[k]; | |
179 | } | |
180 | EXPORT_SYMBOL(__bitmap_or); | |
181 | ||
182 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 183 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 184 | { |
2f9305eb RV |
185 | unsigned int k; |
186 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
187 | |
188 | for (k = 0; k < nr; k++) | |
189 | dst[k] = bitmap1[k] ^ bitmap2[k]; | |
190 | } | |
191 | EXPORT_SYMBOL(__bitmap_xor); | |
192 | ||
f4b0373b | 193 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 194 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 195 | { |
2f9305eb | 196 | unsigned int k; |
74e76531 | 197 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 198 | unsigned long result = 0; |
1da177e4 | 199 | |
74e76531 | 200 | for (k = 0; k < lim; k++) |
f4b0373b | 201 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
74e76531 RV |
202 | if (bits % BITS_PER_LONG) |
203 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & | |
204 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 205 | return result != 0; |
1da177e4 LT |
206 | } |
207 | EXPORT_SYMBOL(__bitmap_andnot); | |
208 | ||
209 | int __bitmap_intersects(const unsigned long *bitmap1, | |
6dfe9799 | 210 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 211 | { |
6dfe9799 | 212 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
213 | for (k = 0; k < lim; ++k) |
214 | if (bitmap1[k] & bitmap2[k]) | |
215 | return 1; | |
216 | ||
217 | if (bits % BITS_PER_LONG) | |
218 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
219 | return 1; | |
220 | return 0; | |
221 | } | |
222 | EXPORT_SYMBOL(__bitmap_intersects); | |
223 | ||
224 | int __bitmap_subset(const unsigned long *bitmap1, | |
5be20213 | 225 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 226 | { |
5be20213 | 227 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
228 | for (k = 0; k < lim; ++k) |
229 | if (bitmap1[k] & ~bitmap2[k]) | |
230 | return 0; | |
231 | ||
232 | if (bits % BITS_PER_LONG) | |
233 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
234 | return 0; | |
235 | return 1; | |
236 | } | |
237 | EXPORT_SYMBOL(__bitmap_subset); | |
238 | ||
877d9f3b | 239 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 240 | { |
877d9f3b RV |
241 | unsigned int k, lim = bits/BITS_PER_LONG; |
242 | int w = 0; | |
1da177e4 LT |
243 | |
244 | for (k = 0; k < lim; k++) | |
37d54111 | 245 | w += hweight_long(bitmap[k]); |
1da177e4 LT |
246 | |
247 | if (bits % BITS_PER_LONG) | |
37d54111 | 248 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
1da177e4 LT |
249 | |
250 | return w; | |
251 | } | |
1da177e4 LT |
252 | EXPORT_SYMBOL(__bitmap_weight); |
253 | ||
e5af323c | 254 | void __bitmap_set(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
255 | { |
256 | unsigned long *p = map + BIT_WORD(start); | |
fb5ac542 | 257 | const unsigned int size = start + len; |
c1a2a962 AM |
258 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
259 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); | |
260 | ||
fb5ac542 | 261 | while (len - bits_to_set >= 0) { |
c1a2a962 | 262 | *p |= mask_to_set; |
fb5ac542 | 263 | len -= bits_to_set; |
c1a2a962 AM |
264 | bits_to_set = BITS_PER_LONG; |
265 | mask_to_set = ~0UL; | |
266 | p++; | |
267 | } | |
fb5ac542 | 268 | if (len) { |
c1a2a962 AM |
269 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
270 | *p |= mask_to_set; | |
271 | } | |
272 | } | |
e5af323c | 273 | EXPORT_SYMBOL(__bitmap_set); |
c1a2a962 | 274 | |
e5af323c | 275 | void __bitmap_clear(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
276 | { |
277 | unsigned long *p = map + BIT_WORD(start); | |
154f5e38 | 278 | const unsigned int size = start + len; |
c1a2a962 AM |
279 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
280 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); | |
281 | ||
154f5e38 | 282 | while (len - bits_to_clear >= 0) { |
c1a2a962 | 283 | *p &= ~mask_to_clear; |
154f5e38 | 284 | len -= bits_to_clear; |
c1a2a962 AM |
285 | bits_to_clear = BITS_PER_LONG; |
286 | mask_to_clear = ~0UL; | |
287 | p++; | |
288 | } | |
154f5e38 | 289 | if (len) { |
c1a2a962 AM |
290 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
291 | *p &= ~mask_to_clear; | |
292 | } | |
293 | } | |
e5af323c | 294 | EXPORT_SYMBOL(__bitmap_clear); |
c1a2a962 | 295 | |
5e19b013 MN |
296 | /** |
297 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area | |
c1a2a962 AM |
298 | * @map: The address to base the search on |
299 | * @size: The bitmap size in bits | |
300 | * @start: The bitnumber to start searching at | |
301 | * @nr: The number of zeroed bits we're looking for | |
302 | * @align_mask: Alignment mask for zero area | |
5e19b013 | 303 | * @align_offset: Alignment offset for zero area. |
c1a2a962 AM |
304 | * |
305 | * The @align_mask should be one less than a power of 2; the effect is that | |
5e19b013 MN |
306 | * the bit offset of all zero areas this function finds plus @align_offset |
307 | * is multiple of that power of 2. | |
c1a2a962 | 308 | */ |
5e19b013 MN |
309 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map, |
310 | unsigned long size, | |
311 | unsigned long start, | |
312 | unsigned int nr, | |
313 | unsigned long align_mask, | |
314 | unsigned long align_offset) | |
c1a2a962 AM |
315 | { |
316 | unsigned long index, end, i; | |
317 | again: | |
318 | index = find_next_zero_bit(map, size, start); | |
319 | ||
320 | /* Align allocation */ | |
5e19b013 | 321 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; |
c1a2a962 AM |
322 | |
323 | end = index + nr; | |
324 | if (end > size) | |
325 | return end; | |
326 | i = find_next_bit(map, end, index); | |
327 | if (i < end) { | |
328 | start = i + 1; | |
329 | goto again; | |
330 | } | |
331 | return index; | |
332 | } | |
5e19b013 | 333 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off); |
c1a2a962 | 334 | |
1da177e4 | 335 | /* |
6d49e352 | 336 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
1da177e4 LT |
337 | * second version by Paul Jackson, third by Joe Korty. |
338 | */ | |
339 | ||
340 | #define CHUNKSZ 32 | |
341 | #define nbits_to_hold_value(val) fls(val) | |
1da177e4 LT |
342 | #define BASEDEC 10 /* fancier cpuset lists input in decimal */ |
343 | ||
1da177e4 | 344 | /** |
01a3ee2b RC |
345 | * __bitmap_parse - convert an ASCII hex string into a bitmap. |
346 | * @buf: pointer to buffer containing string. | |
347 | * @buflen: buffer size in bytes. If string is smaller than this | |
1da177e4 | 348 | * then it must be terminated with a \0. |
01a3ee2b | 349 | * @is_user: location of buffer, 0 indicates kernel space |
1da177e4 LT |
350 | * @maskp: pointer to bitmap array that will contain result. |
351 | * @nmaskbits: size of bitmap, in bits. | |
352 | * | |
353 | * Commas group hex digits into chunks. Each chunk defines exactly 32 | |
354 | * bits of the resultant bitmask. No chunk may specify a value larger | |
6e1907ff RD |
355 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value |
356 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal | |
1da177e4 LT |
357 | * characters and for grouping errors such as "1,,5", ",44", "," and "". |
358 | * Leading and trailing whitespace accepted, but not embedded whitespace. | |
359 | */ | |
01a3ee2b RC |
360 | int __bitmap_parse(const char *buf, unsigned int buflen, |
361 | int is_user, unsigned long *maskp, | |
362 | int nmaskbits) | |
1da177e4 LT |
363 | { |
364 | int c, old_c, totaldigits, ndigits, nchunks, nbits; | |
365 | u32 chunk; | |
b9c321fd | 366 | const char __user __force *ubuf = (const char __user __force *)buf; |
1da177e4 LT |
367 | |
368 | bitmap_zero(maskp, nmaskbits); | |
369 | ||
370 | nchunks = nbits = totaldigits = c = 0; | |
371 | do { | |
d21c3d4d PX |
372 | chunk = 0; |
373 | ndigits = totaldigits; | |
1da177e4 LT |
374 | |
375 | /* Get the next chunk of the bitmap */ | |
01a3ee2b | 376 | while (buflen) { |
1da177e4 | 377 | old_c = c; |
01a3ee2b RC |
378 | if (is_user) { |
379 | if (__get_user(c, ubuf++)) | |
380 | return -EFAULT; | |
381 | } | |
382 | else | |
383 | c = *buf++; | |
384 | buflen--; | |
1da177e4 LT |
385 | if (isspace(c)) |
386 | continue; | |
387 | ||
388 | /* | |
389 | * If the last character was a space and the current | |
390 | * character isn't '\0', we've got embedded whitespace. | |
391 | * This is a no-no, so throw an error. | |
392 | */ | |
393 | if (totaldigits && c && isspace(old_c)) | |
394 | return -EINVAL; | |
395 | ||
396 | /* A '\0' or a ',' signal the end of the chunk */ | |
397 | if (c == '\0' || c == ',') | |
398 | break; | |
399 | ||
400 | if (!isxdigit(c)) | |
401 | return -EINVAL; | |
402 | ||
403 | /* | |
404 | * Make sure there are at least 4 free bits in 'chunk'. | |
405 | * If not, this hexdigit will overflow 'chunk', so | |
406 | * throw an error. | |
407 | */ | |
408 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) | |
409 | return -EOVERFLOW; | |
410 | ||
66f1991b | 411 | chunk = (chunk << 4) | hex_to_bin(c); |
d21c3d4d | 412 | totaldigits++; |
1da177e4 | 413 | } |
d21c3d4d | 414 | if (ndigits == totaldigits) |
1da177e4 LT |
415 | return -EINVAL; |
416 | if (nchunks == 0 && chunk == 0) | |
417 | continue; | |
418 | ||
419 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); | |
420 | *maskp |= chunk; | |
421 | nchunks++; | |
422 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; | |
423 | if (nbits > nmaskbits) | |
424 | return -EOVERFLOW; | |
01a3ee2b | 425 | } while (buflen && c == ','); |
1da177e4 LT |
426 | |
427 | return 0; | |
428 | } | |
01a3ee2b RC |
429 | EXPORT_SYMBOL(__bitmap_parse); |
430 | ||
431 | /** | |
9a86e2ba | 432 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
01a3ee2b RC |
433 | * |
434 | * @ubuf: pointer to user buffer containing string. | |
435 | * @ulen: buffer size in bytes. If string is smaller than this | |
436 | * then it must be terminated with a \0. | |
437 | * @maskp: pointer to bitmap array that will contain result. | |
438 | * @nmaskbits: size of bitmap, in bits. | |
439 | * | |
440 | * Wrapper for __bitmap_parse(), providing it with user buffer. | |
441 | * | |
442 | * We cannot have this as an inline function in bitmap.h because it needs | |
443 | * linux/uaccess.h to get the access_ok() declaration and this causes | |
444 | * cyclic dependencies. | |
445 | */ | |
446 | int bitmap_parse_user(const char __user *ubuf, | |
447 | unsigned int ulen, unsigned long *maskp, | |
448 | int nmaskbits) | |
449 | { | |
450 | if (!access_ok(VERIFY_READ, ubuf, ulen)) | |
451 | return -EFAULT; | |
b9c321fd HS |
452 | return __bitmap_parse((const char __force *)ubuf, |
453 | ulen, 1, maskp, nmaskbits); | |
454 | ||
01a3ee2b RC |
455 | } |
456 | EXPORT_SYMBOL(bitmap_parse_user); | |
1da177e4 | 457 | |
5aaba363 SH |
458 | /** |
459 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string | |
460 | * @list: indicates whether the bitmap must be list | |
461 | * @buf: page aligned buffer into which string is placed | |
462 | * @maskp: pointer to bitmap to convert | |
463 | * @nmaskbits: size of bitmap, in bits | |
464 | * | |
465 | * Output format is a comma-separated list of decimal numbers and | |
466 | * ranges if list is specified or hex digits grouped into comma-separated | |
467 | * sets of 8 digits/set. Returns the number of characters written to buf. | |
9cf79d11 SH |
468 | * |
469 | * It is assumed that @buf is a pointer into a PAGE_SIZE area and that | |
470 | * sufficient storage remains at @buf to accommodate the | |
471 | * bitmap_print_to_pagebuf() output. | |
5aaba363 SH |
472 | */ |
473 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, | |
474 | int nmaskbits) | |
475 | { | |
9cf79d11 | 476 | ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf; |
5aaba363 SH |
477 | int n = 0; |
478 | ||
9cf79d11 SH |
479 | if (len > 1) |
480 | n = list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : | |
481 | scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); | |
5aaba363 SH |
482 | return n; |
483 | } | |
484 | EXPORT_SYMBOL(bitmap_print_to_pagebuf); | |
485 | ||
1da177e4 | 486 | /** |
4b060420 | 487 | * __bitmap_parselist - convert list format ASCII string to bitmap |
b0825ee3 | 488 | * @buf: read nul-terminated user string from this buffer |
4b060420 MT |
489 | * @buflen: buffer size in bytes. If string is smaller than this |
490 | * then it must be terminated with a \0. | |
491 | * @is_user: location of buffer, 0 indicates kernel space | |
6e1907ff | 492 | * @maskp: write resulting mask here |
1da177e4 LT |
493 | * @nmaskbits: number of bits in mask to be written |
494 | * | |
495 | * Input format is a comma-separated list of decimal numbers and | |
496 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
497 | * decimal numbers, the smallest and largest bit numbers set in | |
498 | * the range. | |
2d13e6ca NC |
499 | * Optionally each range can be postfixed to denote that only parts of it |
500 | * should be set. The range will divided to groups of specific size. | |
501 | * From each group will be used only defined amount of bits. | |
502 | * Syntax: range:used_size/group_size | |
503 | * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 | |
1da177e4 | 504 | * |
40bf19a8 MCC |
505 | * Returns: 0 on success, -errno on invalid input strings. Error values: |
506 | * | |
507 | * - ``-EINVAL``: second number in range smaller than first | |
508 | * - ``-EINVAL``: invalid character in string | |
509 | * - ``-ERANGE``: bit number specified too large for mask | |
1da177e4 | 510 | */ |
4b060420 MT |
511 | static int __bitmap_parselist(const char *buf, unsigned int buflen, |
512 | int is_user, unsigned long *maskp, | |
513 | int nmaskbits) | |
1da177e4 | 514 | { |
2d13e6ca | 515 | unsigned int a, b, old_a, old_b; |
0a5ce083 | 516 | unsigned int group_size, used_size, off; |
9bf98f16 | 517 | int c, old_c, totaldigits, ndigits; |
b9c321fd | 518 | const char __user __force *ubuf = (const char __user __force *)buf; |
2d13e6ca | 519 | int at_start, in_range, in_partial_range; |
1da177e4 | 520 | |
4b060420 | 521 | totaldigits = c = 0; |
2d13e6ca NC |
522 | old_a = old_b = 0; |
523 | group_size = used_size = 0; | |
1da177e4 LT |
524 | bitmap_zero(maskp, nmaskbits); |
525 | do { | |
2528a8b8 | 526 | at_start = 1; |
4b060420 | 527 | in_range = 0; |
2d13e6ca | 528 | in_partial_range = 0; |
4b060420 | 529 | a = b = 0; |
9bf98f16 | 530 | ndigits = totaldigits; |
4b060420 MT |
531 | |
532 | /* Get the next cpu# or a range of cpu#'s */ | |
533 | while (buflen) { | |
534 | old_c = c; | |
535 | if (is_user) { | |
536 | if (__get_user(c, ubuf++)) | |
537 | return -EFAULT; | |
538 | } else | |
539 | c = *buf++; | |
540 | buflen--; | |
541 | if (isspace(c)) | |
542 | continue; | |
543 | ||
4b060420 MT |
544 | /* A '\0' or a ',' signal the end of a cpu# or range */ |
545 | if (c == '\0' || c == ',') | |
546 | break; | |
9bf98f16 PX |
547 | /* |
548 | * whitespaces between digits are not allowed, | |
549 | * but it's ok if whitespaces are on head or tail. | |
550 | * when old_c is whilespace, | |
551 | * if totaldigits == ndigits, whitespace is on head. | |
552 | * if whitespace is on tail, it should not run here. | |
553 | * as c was ',' or '\0', | |
554 | * the last code line has broken the current loop. | |
555 | */ | |
556 | if ((totaldigits != ndigits) && isspace(old_c)) | |
557 | return -EINVAL; | |
4b060420 | 558 | |
2d13e6ca NC |
559 | if (c == '/') { |
560 | used_size = a; | |
561 | at_start = 1; | |
562 | in_range = 0; | |
563 | a = b = 0; | |
564 | continue; | |
565 | } | |
566 | ||
567 | if (c == ':') { | |
568 | old_a = a; | |
569 | old_b = b; | |
570 | at_start = 1; | |
571 | in_range = 0; | |
572 | in_partial_range = 1; | |
573 | a = b = 0; | |
574 | continue; | |
575 | } | |
576 | ||
4b060420 | 577 | if (c == '-') { |
2528a8b8 | 578 | if (at_start || in_range) |
4b060420 MT |
579 | return -EINVAL; |
580 | b = 0; | |
581 | in_range = 1; | |
d9282cb6 | 582 | at_start = 1; |
4b060420 MT |
583 | continue; |
584 | } | |
585 | ||
586 | if (!isdigit(c)) | |
1da177e4 | 587 | return -EINVAL; |
4b060420 MT |
588 | |
589 | b = b * 10 + (c - '0'); | |
590 | if (!in_range) | |
591 | a = b; | |
2528a8b8 | 592 | at_start = 0; |
4b060420 | 593 | totaldigits++; |
1da177e4 | 594 | } |
9bf98f16 PX |
595 | if (ndigits == totaldigits) |
596 | continue; | |
2d13e6ca NC |
597 | if (in_partial_range) { |
598 | group_size = a; | |
599 | a = old_a; | |
600 | b = old_b; | |
601 | old_a = old_b = 0; | |
0a5ce083 YN |
602 | } else { |
603 | used_size = group_size = b - a + 1; | |
2d13e6ca | 604 | } |
d9282cb6 PX |
605 | /* if no digit is after '-', it's wrong*/ |
606 | if (at_start && in_range) | |
607 | return -EINVAL; | |
a333a284 | 608 | if (!(a <= b) || group_size == 0 || !(used_size <= group_size)) |
1da177e4 LT |
609 | return -EINVAL; |
610 | if (b >= nmaskbits) | |
611 | return -ERANGE; | |
9bf98f16 | 612 | while (a <= b) { |
0a5ce083 YN |
613 | off = min(b - a + 1, used_size); |
614 | bitmap_set(maskp, a, off); | |
615 | a += group_size; | |
1da177e4 | 616 | } |
4b060420 | 617 | } while (buflen && c == ','); |
1da177e4 LT |
618 | return 0; |
619 | } | |
4b060420 MT |
620 | |
621 | int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) | |
622 | { | |
bc5be182 RV |
623 | char *nl = strchrnul(bp, '\n'); |
624 | int len = nl - bp; | |
4b060420 MT |
625 | |
626 | return __bitmap_parselist(bp, len, 0, maskp, nmaskbits); | |
627 | } | |
1da177e4 LT |
628 | EXPORT_SYMBOL(bitmap_parselist); |
629 | ||
4b060420 MT |
630 | |
631 | /** | |
632 | * bitmap_parselist_user() | |
633 | * | |
634 | * @ubuf: pointer to user buffer containing string. | |
635 | * @ulen: buffer size in bytes. If string is smaller than this | |
636 | * then it must be terminated with a \0. | |
637 | * @maskp: pointer to bitmap array that will contain result. | |
638 | * @nmaskbits: size of bitmap, in bits. | |
639 | * | |
640 | * Wrapper for bitmap_parselist(), providing it with user buffer. | |
641 | * | |
642 | * We cannot have this as an inline function in bitmap.h because it needs | |
643 | * linux/uaccess.h to get the access_ok() declaration and this causes | |
644 | * cyclic dependencies. | |
645 | */ | |
646 | int bitmap_parselist_user(const char __user *ubuf, | |
647 | unsigned int ulen, unsigned long *maskp, | |
648 | int nmaskbits) | |
649 | { | |
650 | if (!access_ok(VERIFY_READ, ubuf, ulen)) | |
651 | return -EFAULT; | |
b9c321fd | 652 | return __bitmap_parselist((const char __force *)ubuf, |
4b060420 MT |
653 | ulen, 1, maskp, nmaskbits); |
654 | } | |
655 | EXPORT_SYMBOL(bitmap_parselist_user); | |
656 | ||
657 | ||
72fd4a35 | 658 | /** |
9a86e2ba | 659 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
fb5eeeee | 660 | * @buf: pointer to a bitmap |
df1d80a9 RV |
661 | * @pos: a bit position in @buf (0 <= @pos < @nbits) |
662 | * @nbits: number of valid bit positions in @buf | |
fb5eeeee | 663 | * |
df1d80a9 | 664 | * Map the bit at position @pos in @buf (of length @nbits) to the |
fb5eeeee | 665 | * ordinal of which set bit it is. If it is not set or if @pos |
96b7f341 | 666 | * is not a valid bit position, map to -1. |
fb5eeeee PJ |
667 | * |
668 | * If for example, just bits 4 through 7 are set in @buf, then @pos | |
669 | * values 4 through 7 will get mapped to 0 through 3, respectively, | |
a8551748 | 670 | * and other @pos values will get mapped to -1. When @pos value 7 |
fb5eeeee PJ |
671 | * gets mapped to (returns) @ord value 3 in this example, that means |
672 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. | |
673 | * | |
674 | * The bit positions 0 through @bits are valid positions in @buf. | |
675 | */ | |
df1d80a9 | 676 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) |
fb5eeeee | 677 | { |
df1d80a9 | 678 | if (pos >= nbits || !test_bit(pos, buf)) |
96b7f341 | 679 | return -1; |
fb5eeeee | 680 | |
df1d80a9 | 681 | return __bitmap_weight(buf, pos); |
fb5eeeee PJ |
682 | } |
683 | ||
684 | /** | |
9a86e2ba | 685 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
fb5eeeee PJ |
686 | * @buf: pointer to bitmap |
687 | * @ord: ordinal bit position (n-th set bit, n >= 0) | |
f6a1f5db | 688 | * @nbits: number of valid bit positions in @buf |
fb5eeeee PJ |
689 | * |
690 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. | |
f6a1f5db RV |
691 | * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord |
692 | * >= weight(buf), returns @nbits. | |
fb5eeeee PJ |
693 | * |
694 | * If for example, just bits 4 through 7 are set in @buf, then @ord | |
695 | * values 0 through 3 will get mapped to 4 through 7, respectively, | |
f6a1f5db | 696 | * and all other @ord values returns @nbits. When @ord value 3 |
fb5eeeee PJ |
697 | * gets mapped to (returns) @pos value 7 in this example, that means |
698 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. | |
699 | * | |
f6a1f5db | 700 | * The bit positions 0 through @nbits-1 are valid positions in @buf. |
fb5eeeee | 701 | */ |
f6a1f5db | 702 | unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) |
fb5eeeee | 703 | { |
f6a1f5db | 704 | unsigned int pos; |
fb5eeeee | 705 | |
f6a1f5db RV |
706 | for (pos = find_first_bit(buf, nbits); |
707 | pos < nbits && ord; | |
708 | pos = find_next_bit(buf, nbits, pos + 1)) | |
709 | ord--; | |
fb5eeeee PJ |
710 | |
711 | return pos; | |
712 | } | |
713 | ||
714 | /** | |
715 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap | |
fb5eeeee | 716 | * @dst: remapped result |
96b7f341 | 717 | * @src: subset to be remapped |
fb5eeeee PJ |
718 | * @old: defines domain of map |
719 | * @new: defines range of map | |
9814ec13 | 720 | * @nbits: number of bits in each of these bitmaps |
fb5eeeee PJ |
721 | * |
722 | * Let @old and @new define a mapping of bit positions, such that | |
723 | * whatever position is held by the n-th set bit in @old is mapped | |
724 | * to the n-th set bit in @new. In the more general case, allowing | |
725 | * for the possibility that the weight 'w' of @new is less than the | |
726 | * weight of @old, map the position of the n-th set bit in @old to | |
727 | * the position of the m-th set bit in @new, where m == n % w. | |
728 | * | |
96b7f341 PJ |
729 | * If either of the @old and @new bitmaps are empty, or if @src and |
730 | * @dst point to the same location, then this routine copies @src | |
731 | * to @dst. | |
fb5eeeee | 732 | * |
96b7f341 PJ |
733 | * The positions of unset bits in @old are mapped to themselves |
734 | * (the identify map). | |
fb5eeeee PJ |
735 | * |
736 | * Apply the above specified mapping to @src, placing the result in | |
737 | * @dst, clearing any bits previously set in @dst. | |
738 | * | |
fb5eeeee PJ |
739 | * For example, lets say that @old has bits 4 through 7 set, and |
740 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
741 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
742 | * bit positions unchanged. So if say @src comes into this routine |
743 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, | |
744 | * 13 and 15 set. | |
fb5eeeee PJ |
745 | */ |
746 | void bitmap_remap(unsigned long *dst, const unsigned long *src, | |
747 | const unsigned long *old, const unsigned long *new, | |
9814ec13 | 748 | unsigned int nbits) |
fb5eeeee | 749 | { |
9814ec13 | 750 | unsigned int oldbit, w; |
fb5eeeee | 751 | |
fb5eeeee PJ |
752 | if (dst == src) /* following doesn't handle inplace remaps */ |
753 | return; | |
9814ec13 | 754 | bitmap_zero(dst, nbits); |
96b7f341 | 755 | |
9814ec13 RV |
756 | w = bitmap_weight(new, nbits); |
757 | for_each_set_bit(oldbit, src, nbits) { | |
758 | int n = bitmap_pos_to_ord(old, oldbit, nbits); | |
08564fb7 | 759 | |
96b7f341 PJ |
760 | if (n < 0 || w == 0) |
761 | set_bit(oldbit, dst); /* identity map */ | |
762 | else | |
9814ec13 | 763 | set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); |
fb5eeeee PJ |
764 | } |
765 | } | |
766 | EXPORT_SYMBOL(bitmap_remap); | |
767 | ||
768 | /** | |
769 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit | |
6e1907ff RD |
770 | * @oldbit: bit position to be mapped |
771 | * @old: defines domain of map | |
772 | * @new: defines range of map | |
773 | * @bits: number of bits in each of these bitmaps | |
fb5eeeee PJ |
774 | * |
775 | * Let @old and @new define a mapping of bit positions, such that | |
776 | * whatever position is held by the n-th set bit in @old is mapped | |
777 | * to the n-th set bit in @new. In the more general case, allowing | |
778 | * for the possibility that the weight 'w' of @new is less than the | |
779 | * weight of @old, map the position of the n-th set bit in @old to | |
780 | * the position of the m-th set bit in @new, where m == n % w. | |
781 | * | |
96b7f341 PJ |
782 | * The positions of unset bits in @old are mapped to themselves |
783 | * (the identify map). | |
fb5eeeee PJ |
784 | * |
785 | * Apply the above specified mapping to bit position @oldbit, returning | |
786 | * the new bit position. | |
787 | * | |
788 | * For example, lets say that @old has bits 4 through 7 set, and | |
789 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
790 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
791 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
792 | * returns 13. | |
fb5eeeee PJ |
793 | */ |
794 | int bitmap_bitremap(int oldbit, const unsigned long *old, | |
795 | const unsigned long *new, int bits) | |
796 | { | |
96b7f341 PJ |
797 | int w = bitmap_weight(new, bits); |
798 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
799 | if (n < 0 || w == 0) | |
800 | return oldbit; | |
801 | else | |
802 | return bitmap_ord_to_pos(new, n % w, bits); | |
fb5eeeee PJ |
803 | } |
804 | EXPORT_SYMBOL(bitmap_bitremap); | |
805 | ||
7ea931c9 PJ |
806 | /** |
807 | * bitmap_onto - translate one bitmap relative to another | |
808 | * @dst: resulting translated bitmap | |
809 | * @orig: original untranslated bitmap | |
810 | * @relmap: bitmap relative to which translated | |
811 | * @bits: number of bits in each of these bitmaps | |
812 | * | |
813 | * Set the n-th bit of @dst iff there exists some m such that the | |
814 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and | |
815 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. | |
816 | * (If you understood the previous sentence the first time your | |
817 | * read it, you're overqualified for your current job.) | |
818 | * | |
819 | * In other words, @orig is mapped onto (surjectively) @dst, | |
da3dae54 | 820 | * using the map { <n, m> | the n-th bit of @relmap is the |
7ea931c9 PJ |
821 | * m-th set bit of @relmap }. |
822 | * | |
823 | * Any set bits in @orig above bit number W, where W is the | |
824 | * weight of (number of set bits in) @relmap are mapped nowhere. | |
825 | * In particular, if for all bits m set in @orig, m >= W, then | |
826 | * @dst will end up empty. In situations where the possibility | |
827 | * of such an empty result is not desired, one way to avoid it is | |
828 | * to use the bitmap_fold() operator, below, to first fold the | |
829 | * @orig bitmap over itself so that all its set bits x are in the | |
830 | * range 0 <= x < W. The bitmap_fold() operator does this by | |
831 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. | |
832 | * | |
833 | * Example [1] for bitmap_onto(): | |
834 | * Let's say @relmap has bits 30-39 set, and @orig has bits | |
835 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, | |
836 | * @dst will have bits 31, 33, 35, 37 and 39 set. | |
837 | * | |
838 | * When bit 0 is set in @orig, it means turn on the bit in | |
839 | * @dst corresponding to whatever is the first bit (if any) | |
840 | * that is turned on in @relmap. Since bit 0 was off in the | |
841 | * above example, we leave off that bit (bit 30) in @dst. | |
842 | * | |
843 | * When bit 1 is set in @orig (as in the above example), it | |
844 | * means turn on the bit in @dst corresponding to whatever | |
845 | * is the second bit that is turned on in @relmap. The second | |
846 | * bit in @relmap that was turned on in the above example was | |
847 | * bit 31, so we turned on bit 31 in @dst. | |
848 | * | |
849 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, | |
850 | * because they were the 4th, 6th, 8th and 10th set bits | |
851 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of | |
852 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. | |
853 | * | |
854 | * When bit 11 is set in @orig, it means turn on the bit in | |
25985edc | 855 | * @dst corresponding to whatever is the twelfth bit that is |
7ea931c9 PJ |
856 | * turned on in @relmap. In the above example, there were |
857 | * only ten bits turned on in @relmap (30..39), so that bit | |
858 | * 11 was set in @orig had no affect on @dst. | |
859 | * | |
860 | * Example [2] for bitmap_fold() + bitmap_onto(): | |
40bf19a8 MCC |
861 | * Let's say @relmap has these ten bits set:: |
862 | * | |
7ea931c9 | 863 | * 40 41 42 43 45 48 53 61 74 95 |
40bf19a8 | 864 | * |
7ea931c9 PJ |
865 | * (for the curious, that's 40 plus the first ten terms of the |
866 | * Fibonacci sequence.) | |
867 | * | |
868 | * Further lets say we use the following code, invoking | |
869 | * bitmap_fold() then bitmap_onto, as suggested above to | |
40bf19a8 | 870 | * avoid the possibility of an empty @dst result:: |
7ea931c9 PJ |
871 | * |
872 | * unsigned long *tmp; // a temporary bitmap's bits | |
873 | * | |
874 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); | |
875 | * bitmap_onto(dst, tmp, relmap, bits); | |
876 | * | |
877 | * Then this table shows what various values of @dst would be, for | |
878 | * various @orig's. I list the zero-based positions of each set bit. | |
879 | * The tmp column shows the intermediate result, as computed by | |
880 | * using bitmap_fold() to fold the @orig bitmap modulo ten | |
40bf19a8 | 881 | * (the weight of @relmap): |
7ea931c9 | 882 | * |
40bf19a8 | 883 | * =============== ============== ================= |
7ea931c9 PJ |
884 | * @orig tmp @dst |
885 | * 0 0 40 | |
886 | * 1 1 41 | |
887 | * 9 9 95 | |
40bf19a8 | 888 | * 10 0 40 [#f1]_ |
7ea931c9 PJ |
889 | * 1 3 5 7 1 3 5 7 41 43 48 61 |
890 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 | |
891 | * 0 9 18 27 0 9 8 7 40 61 74 95 | |
892 | * 0 10 20 30 0 40 | |
893 | * 0 11 22 33 0 1 2 3 40 41 42 43 | |
894 | * 0 12 24 36 0 2 4 6 40 42 45 53 | |
40bf19a8 MCC |
895 | * 78 102 211 1 2 8 41 42 74 [#f1]_ |
896 | * =============== ============== ================= | |
897 | * | |
898 | * .. [#f1] | |
7ea931c9 | 899 | * |
40bf19a8 | 900 | * For these marked lines, if we hadn't first done bitmap_fold() |
7ea931c9 PJ |
901 | * into tmp, then the @dst result would have been empty. |
902 | * | |
903 | * If either of @orig or @relmap is empty (no set bits), then @dst | |
904 | * will be returned empty. | |
905 | * | |
906 | * If (as explained above) the only set bits in @orig are in positions | |
907 | * m where m >= W, (where W is the weight of @relmap) then @dst will | |
908 | * once again be returned empty. | |
909 | * | |
910 | * All bits in @dst not set by the above rule are cleared. | |
911 | */ | |
912 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, | |
eb569883 | 913 | const unsigned long *relmap, unsigned int bits) |
7ea931c9 | 914 | { |
eb569883 | 915 | unsigned int n, m; /* same meaning as in above comment */ |
7ea931c9 PJ |
916 | |
917 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
918 | return; | |
919 | bitmap_zero(dst, bits); | |
920 | ||
921 | /* | |
922 | * The following code is a more efficient, but less | |
923 | * obvious, equivalent to the loop: | |
924 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { | |
925 | * n = bitmap_ord_to_pos(orig, m, bits); | |
926 | * if (test_bit(m, orig)) | |
927 | * set_bit(n, dst); | |
928 | * } | |
929 | */ | |
930 | ||
931 | m = 0; | |
08564fb7 | 932 | for_each_set_bit(n, relmap, bits) { |
7ea931c9 PJ |
933 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
934 | if (test_bit(m, orig)) | |
935 | set_bit(n, dst); | |
936 | m++; | |
937 | } | |
938 | } | |
939 | EXPORT_SYMBOL(bitmap_onto); | |
940 | ||
941 | /** | |
942 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size | |
943 | * @dst: resulting smaller bitmap | |
944 | * @orig: original larger bitmap | |
945 | * @sz: specified size | |
b26ad583 | 946 | * @nbits: number of bits in each of these bitmaps |
7ea931c9 PJ |
947 | * |
948 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. | |
949 | * Clear all other bits in @dst. See further the comment and | |
950 | * Example [2] for bitmap_onto() for why and how to use this. | |
951 | */ | |
952 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, | |
b26ad583 | 953 | unsigned int sz, unsigned int nbits) |
7ea931c9 | 954 | { |
b26ad583 | 955 | unsigned int oldbit; |
7ea931c9 PJ |
956 | |
957 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
958 | return; | |
b26ad583 | 959 | bitmap_zero(dst, nbits); |
7ea931c9 | 960 | |
b26ad583 | 961 | for_each_set_bit(oldbit, orig, nbits) |
7ea931c9 PJ |
962 | set_bit(oldbit % sz, dst); |
963 | } | |
964 | EXPORT_SYMBOL(bitmap_fold); | |
965 | ||
3cf64b93 PJ |
966 | /* |
967 | * Common code for bitmap_*_region() routines. | |
968 | * bitmap: array of unsigned longs corresponding to the bitmap | |
969 | * pos: the beginning of the region | |
970 | * order: region size (log base 2 of number of bits) | |
971 | * reg_op: operation(s) to perform on that region of bitmap | |
1da177e4 | 972 | * |
3cf64b93 PJ |
973 | * Can set, verify and/or release a region of bits in a bitmap, |
974 | * depending on which combination of REG_OP_* flag bits is set. | |
1da177e4 | 975 | * |
3cf64b93 PJ |
976 | * A region of a bitmap is a sequence of bits in the bitmap, of |
977 | * some size '1 << order' (a power of two), aligned to that same | |
978 | * '1 << order' power of two. | |
979 | * | |
980 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). | |
981 | * Returns 0 in all other cases and reg_ops. | |
1da177e4 | 982 | */ |
3cf64b93 PJ |
983 | |
984 | enum { | |
985 | REG_OP_ISFREE, /* true if region is all zero bits */ | |
986 | REG_OP_ALLOC, /* set all bits in region */ | |
987 | REG_OP_RELEASE, /* clear all bits in region */ | |
988 | }; | |
989 | ||
9279d328 | 990 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) |
1da177e4 | 991 | { |
3cf64b93 PJ |
992 | int nbits_reg; /* number of bits in region */ |
993 | int index; /* index first long of region in bitmap */ | |
994 | int offset; /* bit offset region in bitmap[index] */ | |
995 | int nlongs_reg; /* num longs spanned by region in bitmap */ | |
74373c6a | 996 | int nbitsinlong; /* num bits of region in each spanned long */ |
3cf64b93 | 997 | unsigned long mask; /* bitmask for one long of region */ |
74373c6a | 998 | int i; /* scans bitmap by longs */ |
3cf64b93 | 999 | int ret = 0; /* return value */ |
74373c6a | 1000 | |
3cf64b93 PJ |
1001 | /* |
1002 | * Either nlongs_reg == 1 (for small orders that fit in one long) | |
1003 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) | |
1004 | */ | |
1005 | nbits_reg = 1 << order; | |
1006 | index = pos / BITS_PER_LONG; | |
1007 | offset = pos - (index * BITS_PER_LONG); | |
1008 | nlongs_reg = BITS_TO_LONGS(nbits_reg); | |
1009 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); | |
1da177e4 | 1010 | |
3cf64b93 PJ |
1011 | /* |
1012 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that | |
1013 | * overflows if nbitsinlong == BITS_PER_LONG. | |
1014 | */ | |
74373c6a | 1015 | mask = (1UL << (nbitsinlong - 1)); |
1da177e4 | 1016 | mask += mask - 1; |
3cf64b93 | 1017 | mask <<= offset; |
1da177e4 | 1018 | |
3cf64b93 PJ |
1019 | switch (reg_op) { |
1020 | case REG_OP_ISFREE: | |
1021 | for (i = 0; i < nlongs_reg; i++) { | |
1022 | if (bitmap[index + i] & mask) | |
1023 | goto done; | |
1024 | } | |
1025 | ret = 1; /* all bits in region free (zero) */ | |
1026 | break; | |
1027 | ||
1028 | case REG_OP_ALLOC: | |
1029 | for (i = 0; i < nlongs_reg; i++) | |
1030 | bitmap[index + i] |= mask; | |
1031 | break; | |
1032 | ||
1033 | case REG_OP_RELEASE: | |
1034 | for (i = 0; i < nlongs_reg; i++) | |
1035 | bitmap[index + i] &= ~mask; | |
1036 | break; | |
1da177e4 | 1037 | } |
3cf64b93 PJ |
1038 | done: |
1039 | return ret; | |
1040 | } | |
1041 | ||
1042 | /** | |
1043 | * bitmap_find_free_region - find a contiguous aligned mem region | |
1044 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
1045 | * @bits: number of bits in the bitmap | |
1046 | * @order: region size (log base 2 of number of bits) to find | |
1047 | * | |
1048 | * Find a region of free (zero) bits in a @bitmap of @bits bits and | |
1049 | * allocate them (set them to one). Only consider regions of length | |
1050 | * a power (@order) of two, aligned to that power of two, which | |
1051 | * makes the search algorithm much faster. | |
1052 | * | |
1053 | * Return the bit offset in bitmap of the allocated region, | |
1054 | * or -errno on failure. | |
1055 | */ | |
9279d328 | 1056 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) |
3cf64b93 | 1057 | { |
9279d328 | 1058 | unsigned int pos, end; /* scans bitmap by regions of size order */ |
aa8e4fc6 | 1059 | |
9279d328 | 1060 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { |
aa8e4fc6 LT |
1061 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1062 | continue; | |
1063 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
1064 | return pos; | |
1065 | } | |
1066 | return -ENOMEM; | |
1da177e4 LT |
1067 | } |
1068 | EXPORT_SYMBOL(bitmap_find_free_region); | |
1069 | ||
1070 | /** | |
87e24802 | 1071 | * bitmap_release_region - release allocated bitmap region |
3cf64b93 PJ |
1072 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1073 | * @pos: beginning of bit region to release | |
1074 | * @order: region size (log base 2 of number of bits) to release | |
1da177e4 | 1075 | * |
72fd4a35 | 1076 | * This is the complement to __bitmap_find_free_region() and releases |
1da177e4 | 1077 | * the found region (by clearing it in the bitmap). |
3cf64b93 PJ |
1078 | * |
1079 | * No return value. | |
1da177e4 | 1080 | */ |
9279d328 | 1081 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1082 | { |
3cf64b93 | 1083 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1da177e4 LT |
1084 | } |
1085 | EXPORT_SYMBOL(bitmap_release_region); | |
1086 | ||
87e24802 PJ |
1087 | /** |
1088 | * bitmap_allocate_region - allocate bitmap region | |
3cf64b93 PJ |
1089 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1090 | * @pos: beginning of bit region to allocate | |
1091 | * @order: region size (log base 2 of number of bits) to allocate | |
87e24802 PJ |
1092 | * |
1093 | * Allocate (set bits in) a specified region of a bitmap. | |
3cf64b93 | 1094 | * |
6e1907ff | 1095 | * Return 0 on success, or %-EBUSY if specified region wasn't |
87e24802 PJ |
1096 | * free (not all bits were zero). |
1097 | */ | |
9279d328 | 1098 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1099 | { |
3cf64b93 PJ |
1100 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1101 | return -EBUSY; | |
2ac521d3 | 1102 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1da177e4 LT |
1103 | } |
1104 | EXPORT_SYMBOL(bitmap_allocate_region); | |
ccbe329b | 1105 | |
e52bc7c2 DD |
1106 | /** |
1107 | * bitmap_from_u32array - copy the contents of a u32 array of bits to bitmap | |
1108 | * @bitmap: array of unsigned longs, the destination bitmap, non NULL | |
1109 | * @nbits: number of bits in @bitmap | |
1110 | * @buf: array of u32 (in host byte order), the source bitmap, non NULL | |
1111 | * @nwords: number of u32 words in @buf | |
1112 | * | |
1113 | * copy min(nbits, 32*nwords) bits from @buf to @bitmap, remaining | |
1114 | * bits between nword and nbits in @bitmap (if any) are cleared. In | |
1115 | * last word of @bitmap, the bits beyond nbits (if any) are kept | |
1116 | * unchanged. | |
1117 | * | |
1118 | * Return the number of bits effectively copied. | |
1119 | */ | |
1120 | unsigned int | |
1121 | bitmap_from_u32array(unsigned long *bitmap, unsigned int nbits, | |
1122 | const u32 *buf, unsigned int nwords) | |
1123 | { | |
1124 | unsigned int dst_idx, src_idx; | |
1125 | ||
1126 | for (src_idx = dst_idx = 0; dst_idx < BITS_TO_LONGS(nbits); ++dst_idx) { | |
1127 | unsigned long part = 0; | |
1128 | ||
1129 | if (src_idx < nwords) | |
1130 | part = buf[src_idx++]; | |
1131 | ||
1132 | #if BITS_PER_LONG == 64 | |
1133 | if (src_idx < nwords) | |
1134 | part |= ((unsigned long) buf[src_idx++]) << 32; | |
1135 | #endif | |
1136 | ||
1137 | if (dst_idx < nbits/BITS_PER_LONG) | |
1138 | bitmap[dst_idx] = part; | |
1139 | else { | |
1140 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); | |
1141 | ||
1142 | bitmap[dst_idx] = (bitmap[dst_idx] & ~mask) | |
1143 | | (part & mask); | |
1144 | } | |
1145 | } | |
1146 | ||
1147 | return min_t(unsigned int, nbits, 32*nwords); | |
1148 | } | |
1149 | EXPORT_SYMBOL(bitmap_from_u32array); | |
1150 | ||
1151 | /** | |
1152 | * bitmap_to_u32array - copy the contents of bitmap to a u32 array of bits | |
1153 | * @buf: array of u32 (in host byte order), the dest bitmap, non NULL | |
1154 | * @nwords: number of u32 words in @buf | |
1155 | * @bitmap: array of unsigned longs, the source bitmap, non NULL | |
1156 | * @nbits: number of bits in @bitmap | |
1157 | * | |
1158 | * copy min(nbits, 32*nwords) bits from @bitmap to @buf. Remaining | |
1159 | * bits after nbits in @buf (if any) are cleared. | |
1160 | * | |
1161 | * Return the number of bits effectively copied. | |
1162 | */ | |
1163 | unsigned int | |
1164 | bitmap_to_u32array(u32 *buf, unsigned int nwords, | |
1165 | const unsigned long *bitmap, unsigned int nbits) | |
1166 | { | |
1167 | unsigned int dst_idx = 0, src_idx = 0; | |
1168 | ||
1169 | while (dst_idx < nwords) { | |
1170 | unsigned long part = 0; | |
1171 | ||
1172 | if (src_idx < BITS_TO_LONGS(nbits)) { | |
1173 | part = bitmap[src_idx]; | |
1174 | if (src_idx >= nbits/BITS_PER_LONG) | |
1175 | part &= BITMAP_LAST_WORD_MASK(nbits); | |
1176 | src_idx++; | |
1177 | } | |
1178 | ||
1179 | buf[dst_idx++] = part & 0xffffffffUL; | |
1180 | ||
1181 | #if BITS_PER_LONG == 64 | |
1182 | if (dst_idx < nwords) { | |
1183 | part >>= 32; | |
1184 | buf[dst_idx++] = part & 0xffffffffUL; | |
1185 | } | |
1186 | #endif | |
1187 | } | |
1188 | ||
1189 | return min_t(unsigned int, nbits, 32*nwords); | |
1190 | } | |
1191 | EXPORT_SYMBOL(bitmap_to_u32array); | |
1192 | ||
ccbe329b DV |
1193 | /** |
1194 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. | |
1195 | * @dst: destination buffer | |
1196 | * @src: bitmap to copy | |
1197 | * @nbits: number of bits in the bitmap | |
1198 | * | |
1199 | * Require nbits % BITS_PER_LONG == 0. | |
1200 | */ | |
e8f24278 | 1201 | #ifdef __BIG_ENDIAN |
9b6c2d2e | 1202 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) |
ccbe329b | 1203 | { |
9b6c2d2e | 1204 | unsigned int i; |
ccbe329b DV |
1205 | |
1206 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { | |
1207 | if (BITS_PER_LONG == 64) | |
9b6c2d2e | 1208 | dst[i] = cpu_to_le64(src[i]); |
ccbe329b | 1209 | else |
9b6c2d2e | 1210 | dst[i] = cpu_to_le32(src[i]); |
ccbe329b DV |
1211 | } |
1212 | } | |
1213 | EXPORT_SYMBOL(bitmap_copy_le); | |
e8f24278 | 1214 | #endif |