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