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> |
5aaba363 SH |
15 | |
16 | #include <asm/page.h> | |
1da177e4 LT |
17 | #include <asm/uaccess.h> |
18 | ||
19 | /* | |
20 | * bitmaps provide an array of bits, implemented using an an | |
21 | * array of unsigned longs. The number of valid bits in a | |
22 | * given bitmap does _not_ need to be an exact multiple of | |
23 | * BITS_PER_LONG. | |
24 | * | |
25 | * The possible unused bits in the last, partially used word | |
26 | * of a bitmap are 'don't care'. The implementation makes | |
27 | * no particular effort to keep them zero. It ensures that | |
28 | * their value will not affect the results of any operation. | |
29 | * The bitmap operations that return Boolean (bitmap_empty, | |
30 | * for example) or scalar (bitmap_weight, for example) results | |
31 | * carefully filter out these unused bits from impacting their | |
32 | * results. | |
33 | * | |
34 | * These operations actually hold to a slightly stronger rule: | |
35 | * if you don't input any bitmaps to these ops that have some | |
36 | * unused bits set, then they won't output any set unused bits | |
37 | * in output bitmaps. | |
38 | * | |
39 | * The byte ordering of bitmaps is more natural on little | |
40 | * endian architectures. See the big-endian headers | |
41 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h | |
42 | * for the best explanations of this ordering. | |
43 | */ | |
44 | ||
0679cc48 | 45 | int __bitmap_empty(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 46 | { |
0679cc48 | 47 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
48 | for (k = 0; k < lim; ++k) |
49 | if (bitmap[k]) | |
50 | return 0; | |
51 | ||
52 | if (bits % BITS_PER_LONG) | |
53 | if (bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) | |
54 | return 0; | |
55 | ||
56 | return 1; | |
57 | } | |
58 | EXPORT_SYMBOL(__bitmap_empty); | |
59 | ||
8397927c | 60 | int __bitmap_full(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 61 | { |
8397927c | 62 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
63 | for (k = 0; k < lim; ++k) |
64 | if (~bitmap[k]) | |
65 | return 0; | |
66 | ||
67 | if (bits % BITS_PER_LONG) | |
68 | if (~bitmap[k] & BITMAP_LAST_WORD_MASK(bits)) | |
69 | return 0; | |
70 | ||
71 | return 1; | |
72 | } | |
73 | EXPORT_SYMBOL(__bitmap_full); | |
74 | ||
75 | int __bitmap_equal(const unsigned long *bitmap1, | |
5e068069 | 76 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 77 | { |
5e068069 | 78 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
79 | for (k = 0; k < lim; ++k) |
80 | if (bitmap1[k] != bitmap2[k]) | |
81 | return 0; | |
82 | ||
83 | if (bits % BITS_PER_LONG) | |
84 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
85 | return 0; | |
86 | ||
87 | return 1; | |
88 | } | |
89 | EXPORT_SYMBOL(__bitmap_equal); | |
90 | ||
3d6684f4 | 91 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) |
1da177e4 | 92 | { |
3d6684f4 | 93 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
94 | for (k = 0; k < lim; ++k) |
95 | dst[k] = ~src[k]; | |
96 | ||
97 | if (bits % BITS_PER_LONG) | |
65b4ee62 | 98 | dst[k] = ~src[k]; |
1da177e4 LT |
99 | } |
100 | EXPORT_SYMBOL(__bitmap_complement); | |
101 | ||
72fd4a35 | 102 | /** |
1da177e4 | 103 | * __bitmap_shift_right - logical right shift of the bits in a bitmap |
05fb6bf0 RD |
104 | * @dst : destination bitmap |
105 | * @src : source bitmap | |
106 | * @shift : shift by this many bits | |
2fbad299 | 107 | * @nbits : bitmap size, in bits |
1da177e4 LT |
108 | * |
109 | * Shifting right (dividing) means moving bits in the MS -> LS bit | |
110 | * direction. Zeros are fed into the vacated MS positions and the | |
111 | * LS bits shifted off the bottom are lost. | |
112 | */ | |
2fbad299 RV |
113 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, |
114 | unsigned shift, unsigned nbits) | |
1da177e4 | 115 | { |
cfac1d08 | 116 | unsigned k, lim = BITS_TO_LONGS(nbits); |
2fbad299 | 117 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
cfac1d08 | 118 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); |
1da177e4 LT |
119 | for (k = 0; off + k < lim; ++k) { |
120 | unsigned long upper, lower; | |
121 | ||
122 | /* | |
123 | * If shift is not word aligned, take lower rem bits of | |
124 | * word above and make them the top rem bits of result. | |
125 | */ | |
126 | if (!rem || off + k + 1 >= lim) | |
127 | upper = 0; | |
128 | else { | |
129 | upper = src[off + k + 1]; | |
cfac1d08 | 130 | if (off + k + 1 == lim - 1) |
1da177e4 | 131 | upper &= mask; |
9d8a6b2a | 132 | upper <<= (BITS_PER_LONG - rem); |
1da177e4 LT |
133 | } |
134 | lower = src[off + k]; | |
cfac1d08 | 135 | if (off + k == lim - 1) |
1da177e4 | 136 | lower &= mask; |
9d8a6b2a RV |
137 | lower >>= rem; |
138 | dst[k] = lower | upper; | |
1da177e4 LT |
139 | } |
140 | if (off) | |
141 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); | |
142 | } | |
143 | EXPORT_SYMBOL(__bitmap_shift_right); | |
144 | ||
145 | ||
72fd4a35 | 146 | /** |
1da177e4 | 147 | * __bitmap_shift_left - logical left shift of the bits in a bitmap |
05fb6bf0 RD |
148 | * @dst : destination bitmap |
149 | * @src : source bitmap | |
150 | * @shift : shift by this many bits | |
dba94c25 | 151 | * @nbits : bitmap size, in bits |
1da177e4 LT |
152 | * |
153 | * Shifting left (multiplying) means moving bits in the LS -> MS | |
154 | * direction. Zeros are fed into the vacated LS bit positions | |
155 | * and those MS bits shifted off the top are lost. | |
156 | */ | |
157 | ||
dba94c25 RV |
158 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, |
159 | unsigned int shift, unsigned int nbits) | |
1da177e4 | 160 | { |
dba94c25 | 161 | int k; |
7f590657 | 162 | unsigned int lim = BITS_TO_LONGS(nbits); |
dba94c25 | 163 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; |
1da177e4 LT |
164 | for (k = lim - off - 1; k >= 0; --k) { |
165 | unsigned long upper, lower; | |
166 | ||
167 | /* | |
168 | * If shift is not word aligned, take upper rem bits of | |
169 | * word below and make them the bottom rem bits of result. | |
170 | */ | |
171 | if (rem && k > 0) | |
6d874eca | 172 | lower = src[k - 1] >> (BITS_PER_LONG - rem); |
1da177e4 LT |
173 | else |
174 | lower = 0; | |
7f590657 | 175 | upper = src[k] << rem; |
6d874eca | 176 | dst[k + off] = lower | upper; |
1da177e4 LT |
177 | } |
178 | if (off) | |
179 | memset(dst, 0, off*sizeof(unsigned long)); | |
180 | } | |
181 | EXPORT_SYMBOL(__bitmap_shift_left); | |
182 | ||
f4b0373b | 183 | int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 184 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 185 | { |
2f9305eb | 186 | unsigned int k; |
7e5f97d1 | 187 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 188 | unsigned long result = 0; |
1da177e4 | 189 | |
7e5f97d1 | 190 | for (k = 0; k < lim; k++) |
f4b0373b | 191 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); |
7e5f97d1 RV |
192 | if (bits % BITS_PER_LONG) |
193 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & | |
194 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 195 | return result != 0; |
1da177e4 LT |
196 | } |
197 | EXPORT_SYMBOL(__bitmap_and); | |
198 | ||
199 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 200 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 201 | { |
2f9305eb RV |
202 | unsigned int k; |
203 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
204 | |
205 | for (k = 0; k < nr; k++) | |
206 | dst[k] = bitmap1[k] | bitmap2[k]; | |
207 | } | |
208 | EXPORT_SYMBOL(__bitmap_or); | |
209 | ||
210 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
2f9305eb | 211 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 212 | { |
2f9305eb RV |
213 | unsigned int k; |
214 | unsigned int nr = BITS_TO_LONGS(bits); | |
1da177e4 LT |
215 | |
216 | for (k = 0; k < nr; k++) | |
217 | dst[k] = bitmap1[k] ^ bitmap2[k]; | |
218 | } | |
219 | EXPORT_SYMBOL(__bitmap_xor); | |
220 | ||
f4b0373b | 221 | int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, |
2f9305eb | 222 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 223 | { |
2f9305eb | 224 | unsigned int k; |
74e76531 | 225 | unsigned int lim = bits/BITS_PER_LONG; |
f4b0373b | 226 | unsigned long result = 0; |
1da177e4 | 227 | |
74e76531 | 228 | for (k = 0; k < lim; k++) |
f4b0373b | 229 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); |
74e76531 RV |
230 | if (bits % BITS_PER_LONG) |
231 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & | |
232 | BITMAP_LAST_WORD_MASK(bits)); | |
f4b0373b | 233 | return result != 0; |
1da177e4 LT |
234 | } |
235 | EXPORT_SYMBOL(__bitmap_andnot); | |
236 | ||
237 | int __bitmap_intersects(const unsigned long *bitmap1, | |
6dfe9799 | 238 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 239 | { |
6dfe9799 | 240 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
241 | for (k = 0; k < lim; ++k) |
242 | if (bitmap1[k] & bitmap2[k]) | |
243 | return 1; | |
244 | ||
245 | if (bits % BITS_PER_LONG) | |
246 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
247 | return 1; | |
248 | return 0; | |
249 | } | |
250 | EXPORT_SYMBOL(__bitmap_intersects); | |
251 | ||
252 | int __bitmap_subset(const unsigned long *bitmap1, | |
5be20213 | 253 | const unsigned long *bitmap2, unsigned int bits) |
1da177e4 | 254 | { |
5be20213 | 255 | unsigned int k, lim = bits/BITS_PER_LONG; |
1da177e4 LT |
256 | for (k = 0; k < lim; ++k) |
257 | if (bitmap1[k] & ~bitmap2[k]) | |
258 | return 0; | |
259 | ||
260 | if (bits % BITS_PER_LONG) | |
261 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
262 | return 0; | |
263 | return 1; | |
264 | } | |
265 | EXPORT_SYMBOL(__bitmap_subset); | |
266 | ||
877d9f3b | 267 | int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) |
1da177e4 | 268 | { |
877d9f3b RV |
269 | unsigned int k, lim = bits/BITS_PER_LONG; |
270 | int w = 0; | |
1da177e4 LT |
271 | |
272 | for (k = 0; k < lim; k++) | |
37d54111 | 273 | w += hweight_long(bitmap[k]); |
1da177e4 LT |
274 | |
275 | if (bits % BITS_PER_LONG) | |
37d54111 | 276 | w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); |
1da177e4 LT |
277 | |
278 | return w; | |
279 | } | |
1da177e4 LT |
280 | EXPORT_SYMBOL(__bitmap_weight); |
281 | ||
fb5ac542 | 282 | void bitmap_set(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
283 | { |
284 | unsigned long *p = map + BIT_WORD(start); | |
fb5ac542 | 285 | const unsigned int size = start + len; |
c1a2a962 AM |
286 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); |
287 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); | |
288 | ||
fb5ac542 | 289 | while (len - bits_to_set >= 0) { |
c1a2a962 | 290 | *p |= mask_to_set; |
fb5ac542 | 291 | len -= bits_to_set; |
c1a2a962 AM |
292 | bits_to_set = BITS_PER_LONG; |
293 | mask_to_set = ~0UL; | |
294 | p++; | |
295 | } | |
fb5ac542 | 296 | if (len) { |
c1a2a962 AM |
297 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); |
298 | *p |= mask_to_set; | |
299 | } | |
300 | } | |
301 | EXPORT_SYMBOL(bitmap_set); | |
302 | ||
154f5e38 | 303 | void bitmap_clear(unsigned long *map, unsigned int start, int len) |
c1a2a962 AM |
304 | { |
305 | unsigned long *p = map + BIT_WORD(start); | |
154f5e38 | 306 | const unsigned int size = start + len; |
c1a2a962 AM |
307 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); |
308 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); | |
309 | ||
154f5e38 | 310 | while (len - bits_to_clear >= 0) { |
c1a2a962 | 311 | *p &= ~mask_to_clear; |
154f5e38 | 312 | len -= bits_to_clear; |
c1a2a962 AM |
313 | bits_to_clear = BITS_PER_LONG; |
314 | mask_to_clear = ~0UL; | |
315 | p++; | |
316 | } | |
154f5e38 | 317 | if (len) { |
c1a2a962 AM |
318 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); |
319 | *p &= ~mask_to_clear; | |
320 | } | |
321 | } | |
322 | EXPORT_SYMBOL(bitmap_clear); | |
323 | ||
5e19b013 MN |
324 | /** |
325 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area | |
c1a2a962 AM |
326 | * @map: The address to base the search on |
327 | * @size: The bitmap size in bits | |
328 | * @start: The bitnumber to start searching at | |
329 | * @nr: The number of zeroed bits we're looking for | |
330 | * @align_mask: Alignment mask for zero area | |
5e19b013 | 331 | * @align_offset: Alignment offset for zero area. |
c1a2a962 AM |
332 | * |
333 | * The @align_mask should be one less than a power of 2; the effect is that | |
5e19b013 MN |
334 | * the bit offset of all zero areas this function finds plus @align_offset |
335 | * is multiple of that power of 2. | |
c1a2a962 | 336 | */ |
5e19b013 MN |
337 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map, |
338 | unsigned long size, | |
339 | unsigned long start, | |
340 | unsigned int nr, | |
341 | unsigned long align_mask, | |
342 | unsigned long align_offset) | |
c1a2a962 AM |
343 | { |
344 | unsigned long index, end, i; | |
345 | again: | |
346 | index = find_next_zero_bit(map, size, start); | |
347 | ||
348 | /* Align allocation */ | |
5e19b013 | 349 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; |
c1a2a962 AM |
350 | |
351 | end = index + nr; | |
352 | if (end > size) | |
353 | return end; | |
354 | i = find_next_bit(map, end, index); | |
355 | if (i < end) { | |
356 | start = i + 1; | |
357 | goto again; | |
358 | } | |
359 | return index; | |
360 | } | |
5e19b013 | 361 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off); |
c1a2a962 | 362 | |
1da177e4 | 363 | /* |
6d49e352 | 364 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, |
1da177e4 LT |
365 | * second version by Paul Jackson, third by Joe Korty. |
366 | */ | |
367 | ||
368 | #define CHUNKSZ 32 | |
369 | #define nbits_to_hold_value(val) fls(val) | |
1da177e4 LT |
370 | #define BASEDEC 10 /* fancier cpuset lists input in decimal */ |
371 | ||
1da177e4 | 372 | /** |
01a3ee2b RC |
373 | * __bitmap_parse - convert an ASCII hex string into a bitmap. |
374 | * @buf: pointer to buffer containing string. | |
375 | * @buflen: buffer size in bytes. If string is smaller than this | |
1da177e4 | 376 | * then it must be terminated with a \0. |
01a3ee2b | 377 | * @is_user: location of buffer, 0 indicates kernel space |
1da177e4 LT |
378 | * @maskp: pointer to bitmap array that will contain result. |
379 | * @nmaskbits: size of bitmap, in bits. | |
380 | * | |
381 | * Commas group hex digits into chunks. Each chunk defines exactly 32 | |
382 | * bits of the resultant bitmask. No chunk may specify a value larger | |
6e1907ff RD |
383 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value |
384 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal | |
1da177e4 LT |
385 | * characters and for grouping errors such as "1,,5", ",44", "," and "". |
386 | * Leading and trailing whitespace accepted, but not embedded whitespace. | |
387 | */ | |
01a3ee2b RC |
388 | int __bitmap_parse(const char *buf, unsigned int buflen, |
389 | int is_user, unsigned long *maskp, | |
390 | int nmaskbits) | |
1da177e4 LT |
391 | { |
392 | int c, old_c, totaldigits, ndigits, nchunks, nbits; | |
393 | u32 chunk; | |
b9c321fd | 394 | const char __user __force *ubuf = (const char __user __force *)buf; |
1da177e4 LT |
395 | |
396 | bitmap_zero(maskp, nmaskbits); | |
397 | ||
398 | nchunks = nbits = totaldigits = c = 0; | |
399 | do { | |
400 | chunk = ndigits = 0; | |
401 | ||
402 | /* Get the next chunk of the bitmap */ | |
01a3ee2b | 403 | while (buflen) { |
1da177e4 | 404 | old_c = c; |
01a3ee2b RC |
405 | if (is_user) { |
406 | if (__get_user(c, ubuf++)) | |
407 | return -EFAULT; | |
408 | } | |
409 | else | |
410 | c = *buf++; | |
411 | buflen--; | |
1da177e4 LT |
412 | if (isspace(c)) |
413 | continue; | |
414 | ||
415 | /* | |
416 | * If the last character was a space and the current | |
417 | * character isn't '\0', we've got embedded whitespace. | |
418 | * This is a no-no, so throw an error. | |
419 | */ | |
420 | if (totaldigits && c && isspace(old_c)) | |
421 | return -EINVAL; | |
422 | ||
423 | /* A '\0' or a ',' signal the end of the chunk */ | |
424 | if (c == '\0' || c == ',') | |
425 | break; | |
426 | ||
427 | if (!isxdigit(c)) | |
428 | return -EINVAL; | |
429 | ||
430 | /* | |
431 | * Make sure there are at least 4 free bits in 'chunk'. | |
432 | * If not, this hexdigit will overflow 'chunk', so | |
433 | * throw an error. | |
434 | */ | |
435 | if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) | |
436 | return -EOVERFLOW; | |
437 | ||
66f1991b | 438 | chunk = (chunk << 4) | hex_to_bin(c); |
1da177e4 LT |
439 | ndigits++; totaldigits++; |
440 | } | |
441 | if (ndigits == 0) | |
442 | return -EINVAL; | |
443 | if (nchunks == 0 && chunk == 0) | |
444 | continue; | |
445 | ||
446 | __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); | |
447 | *maskp |= chunk; | |
448 | nchunks++; | |
449 | nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; | |
450 | if (nbits > nmaskbits) | |
451 | return -EOVERFLOW; | |
01a3ee2b | 452 | } while (buflen && c == ','); |
1da177e4 LT |
453 | |
454 | return 0; | |
455 | } | |
01a3ee2b RC |
456 | EXPORT_SYMBOL(__bitmap_parse); |
457 | ||
458 | /** | |
9a86e2ba | 459 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap |
01a3ee2b RC |
460 | * |
461 | * @ubuf: pointer to user buffer containing string. | |
462 | * @ulen: buffer size in bytes. If string is smaller than this | |
463 | * then it must be terminated with a \0. | |
464 | * @maskp: pointer to bitmap array that will contain result. | |
465 | * @nmaskbits: size of bitmap, in bits. | |
466 | * | |
467 | * Wrapper for __bitmap_parse(), providing it with user buffer. | |
468 | * | |
469 | * We cannot have this as an inline function in bitmap.h because it needs | |
470 | * linux/uaccess.h to get the access_ok() declaration and this causes | |
471 | * cyclic dependencies. | |
472 | */ | |
473 | int bitmap_parse_user(const char __user *ubuf, | |
474 | unsigned int ulen, unsigned long *maskp, | |
475 | int nmaskbits) | |
476 | { | |
477 | if (!access_ok(VERIFY_READ, ubuf, ulen)) | |
478 | return -EFAULT; | |
b9c321fd HS |
479 | return __bitmap_parse((const char __force *)ubuf, |
480 | ulen, 1, maskp, nmaskbits); | |
481 | ||
01a3ee2b RC |
482 | } |
483 | EXPORT_SYMBOL(bitmap_parse_user); | |
1da177e4 | 484 | |
5aaba363 SH |
485 | /** |
486 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string | |
487 | * @list: indicates whether the bitmap must be list | |
488 | * @buf: page aligned buffer into which string is placed | |
489 | * @maskp: pointer to bitmap to convert | |
490 | * @nmaskbits: size of bitmap, in bits | |
491 | * | |
492 | * Output format is a comma-separated list of decimal numbers and | |
493 | * ranges if list is specified or hex digits grouped into comma-separated | |
494 | * sets of 8 digits/set. Returns the number of characters written to buf. | |
495 | */ | |
496 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, | |
497 | int nmaskbits) | |
498 | { | |
499 | ptrdiff_t len = PTR_ALIGN(buf + PAGE_SIZE - 1, PAGE_SIZE) - buf - 2; | |
500 | int n = 0; | |
501 | ||
502 | if (len > 1) { | |
4a0792b0 TH |
503 | n = list ? scnprintf(buf, len, "%*pbl", nmaskbits, maskp) : |
504 | scnprintf(buf, len, "%*pb", nmaskbits, maskp); | |
5aaba363 SH |
505 | buf[n++] = '\n'; |
506 | buf[n] = '\0'; | |
507 | } | |
508 | return n; | |
509 | } | |
510 | EXPORT_SYMBOL(bitmap_print_to_pagebuf); | |
511 | ||
1da177e4 | 512 | /** |
4b060420 | 513 | * __bitmap_parselist - convert list format ASCII string to bitmap |
b0825ee3 | 514 | * @buf: read nul-terminated user string from this buffer |
4b060420 MT |
515 | * @buflen: buffer size in bytes. If string is smaller than this |
516 | * then it must be terminated with a \0. | |
517 | * @is_user: location of buffer, 0 indicates kernel space | |
6e1907ff | 518 | * @maskp: write resulting mask here |
1da177e4 LT |
519 | * @nmaskbits: number of bits in mask to be written |
520 | * | |
521 | * Input format is a comma-separated list of decimal numbers and | |
522 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
523 | * decimal numbers, the smallest and largest bit numbers set in | |
524 | * the range. | |
525 | * | |
6e1907ff RD |
526 | * Returns 0 on success, -errno on invalid input strings. |
527 | * Error values: | |
528 | * %-EINVAL: second number in range smaller than first | |
529 | * %-EINVAL: invalid character in string | |
530 | * %-ERANGE: bit number specified too large for mask | |
1da177e4 | 531 | */ |
4b060420 MT |
532 | static int __bitmap_parselist(const char *buf, unsigned int buflen, |
533 | int is_user, unsigned long *maskp, | |
534 | int nmaskbits) | |
1da177e4 LT |
535 | { |
536 | unsigned a, b; | |
4b060420 | 537 | int c, old_c, totaldigits; |
b9c321fd | 538 | const char __user __force *ubuf = (const char __user __force *)buf; |
4b060420 | 539 | int exp_digit, in_range; |
1da177e4 | 540 | |
4b060420 | 541 | totaldigits = c = 0; |
1da177e4 LT |
542 | bitmap_zero(maskp, nmaskbits); |
543 | do { | |
4b060420 MT |
544 | exp_digit = 1; |
545 | in_range = 0; | |
546 | a = b = 0; | |
547 | ||
548 | /* Get the next cpu# or a range of cpu#'s */ | |
549 | while (buflen) { | |
550 | old_c = c; | |
551 | if (is_user) { | |
552 | if (__get_user(c, ubuf++)) | |
553 | return -EFAULT; | |
554 | } else | |
555 | c = *buf++; | |
556 | buflen--; | |
557 | if (isspace(c)) | |
558 | continue; | |
559 | ||
560 | /* | |
561 | * If the last character was a space and the current | |
562 | * character isn't '\0', we've got embedded whitespace. | |
563 | * This is a no-no, so throw an error. | |
564 | */ | |
565 | if (totaldigits && c && isspace(old_c)) | |
566 | return -EINVAL; | |
567 | ||
568 | /* A '\0' or a ',' signal the end of a cpu# or range */ | |
569 | if (c == '\0' || c == ',') | |
570 | break; | |
571 | ||
572 | if (c == '-') { | |
573 | if (exp_digit || in_range) | |
574 | return -EINVAL; | |
575 | b = 0; | |
576 | in_range = 1; | |
577 | exp_digit = 1; | |
578 | continue; | |
579 | } | |
580 | ||
581 | if (!isdigit(c)) | |
1da177e4 | 582 | return -EINVAL; |
4b060420 MT |
583 | |
584 | b = b * 10 + (c - '0'); | |
585 | if (!in_range) | |
586 | a = b; | |
587 | exp_digit = 0; | |
588 | totaldigits++; | |
1da177e4 LT |
589 | } |
590 | if (!(a <= b)) | |
591 | return -EINVAL; | |
592 | if (b >= nmaskbits) | |
593 | return -ERANGE; | |
594 | while (a <= b) { | |
595 | set_bit(a, maskp); | |
596 | a++; | |
597 | } | |
4b060420 | 598 | } while (buflen && c == ','); |
1da177e4 LT |
599 | return 0; |
600 | } | |
4b060420 MT |
601 | |
602 | int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) | |
603 | { | |
bc5be182 RV |
604 | char *nl = strchrnul(bp, '\n'); |
605 | int len = nl - bp; | |
4b060420 MT |
606 | |
607 | return __bitmap_parselist(bp, len, 0, maskp, nmaskbits); | |
608 | } | |
1da177e4 LT |
609 | EXPORT_SYMBOL(bitmap_parselist); |
610 | ||
4b060420 MT |
611 | |
612 | /** | |
613 | * bitmap_parselist_user() | |
614 | * | |
615 | * @ubuf: pointer to user buffer containing string. | |
616 | * @ulen: buffer size in bytes. If string is smaller than this | |
617 | * then it must be terminated with a \0. | |
618 | * @maskp: pointer to bitmap array that will contain result. | |
619 | * @nmaskbits: size of bitmap, in bits. | |
620 | * | |
621 | * Wrapper for bitmap_parselist(), providing it with user buffer. | |
622 | * | |
623 | * We cannot have this as an inline function in bitmap.h because it needs | |
624 | * linux/uaccess.h to get the access_ok() declaration and this causes | |
625 | * cyclic dependencies. | |
626 | */ | |
627 | int bitmap_parselist_user(const char __user *ubuf, | |
628 | unsigned int ulen, unsigned long *maskp, | |
629 | int nmaskbits) | |
630 | { | |
631 | if (!access_ok(VERIFY_READ, ubuf, ulen)) | |
632 | return -EFAULT; | |
b9c321fd | 633 | return __bitmap_parselist((const char __force *)ubuf, |
4b060420 MT |
634 | ulen, 1, maskp, nmaskbits); |
635 | } | |
636 | EXPORT_SYMBOL(bitmap_parselist_user); | |
637 | ||
638 | ||
72fd4a35 | 639 | /** |
9a86e2ba | 640 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap |
fb5eeeee | 641 | * @buf: pointer to a bitmap |
df1d80a9 RV |
642 | * @pos: a bit position in @buf (0 <= @pos < @nbits) |
643 | * @nbits: number of valid bit positions in @buf | |
fb5eeeee | 644 | * |
df1d80a9 | 645 | * Map the bit at position @pos in @buf (of length @nbits) to the |
fb5eeeee | 646 | * ordinal of which set bit it is. If it is not set or if @pos |
96b7f341 | 647 | * is not a valid bit position, map to -1. |
fb5eeeee PJ |
648 | * |
649 | * If for example, just bits 4 through 7 are set in @buf, then @pos | |
650 | * values 4 through 7 will get mapped to 0 through 3, respectively, | |
a8551748 | 651 | * and other @pos values will get mapped to -1. When @pos value 7 |
fb5eeeee PJ |
652 | * gets mapped to (returns) @ord value 3 in this example, that means |
653 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. | |
654 | * | |
655 | * The bit positions 0 through @bits are valid positions in @buf. | |
656 | */ | |
df1d80a9 | 657 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) |
fb5eeeee | 658 | { |
df1d80a9 | 659 | if (pos >= nbits || !test_bit(pos, buf)) |
96b7f341 | 660 | return -1; |
fb5eeeee | 661 | |
df1d80a9 | 662 | return __bitmap_weight(buf, pos); |
fb5eeeee PJ |
663 | } |
664 | ||
665 | /** | |
9a86e2ba | 666 | * bitmap_ord_to_pos - find position of n-th set bit in bitmap |
fb5eeeee PJ |
667 | * @buf: pointer to bitmap |
668 | * @ord: ordinal bit position (n-th set bit, n >= 0) | |
f6a1f5db | 669 | * @nbits: number of valid bit positions in @buf |
fb5eeeee PJ |
670 | * |
671 | * Map the ordinal offset of bit @ord in @buf to its position in @buf. | |
f6a1f5db RV |
672 | * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord |
673 | * >= weight(buf), returns @nbits. | |
fb5eeeee PJ |
674 | * |
675 | * If for example, just bits 4 through 7 are set in @buf, then @ord | |
676 | * values 0 through 3 will get mapped to 4 through 7, respectively, | |
f6a1f5db | 677 | * and all other @ord values returns @nbits. When @ord value 3 |
fb5eeeee PJ |
678 | * gets mapped to (returns) @pos value 7 in this example, that means |
679 | * that the 3rd set bit (starting with 0th) is at position 7 in @buf. | |
680 | * | |
f6a1f5db | 681 | * The bit positions 0 through @nbits-1 are valid positions in @buf. |
fb5eeeee | 682 | */ |
f6a1f5db | 683 | unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) |
fb5eeeee | 684 | { |
f6a1f5db | 685 | unsigned int pos; |
fb5eeeee | 686 | |
f6a1f5db RV |
687 | for (pos = find_first_bit(buf, nbits); |
688 | pos < nbits && ord; | |
689 | pos = find_next_bit(buf, nbits, pos + 1)) | |
690 | ord--; | |
fb5eeeee PJ |
691 | |
692 | return pos; | |
693 | } | |
694 | ||
695 | /** | |
696 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap | |
fb5eeeee | 697 | * @dst: remapped result |
96b7f341 | 698 | * @src: subset to be remapped |
fb5eeeee PJ |
699 | * @old: defines domain of map |
700 | * @new: defines range of map | |
9814ec13 | 701 | * @nbits: number of bits in each of these bitmaps |
fb5eeeee PJ |
702 | * |
703 | * Let @old and @new define a mapping of bit positions, such that | |
704 | * whatever position is held by the n-th set bit in @old is mapped | |
705 | * to the n-th set bit in @new. In the more general case, allowing | |
706 | * for the possibility that the weight 'w' of @new is less than the | |
707 | * weight of @old, map the position of the n-th set bit in @old to | |
708 | * the position of the m-th set bit in @new, where m == n % w. | |
709 | * | |
96b7f341 PJ |
710 | * If either of the @old and @new bitmaps are empty, or if @src and |
711 | * @dst point to the same location, then this routine copies @src | |
712 | * to @dst. | |
fb5eeeee | 713 | * |
96b7f341 PJ |
714 | * The positions of unset bits in @old are mapped to themselves |
715 | * (the identify map). | |
fb5eeeee PJ |
716 | * |
717 | * Apply the above specified mapping to @src, placing the result in | |
718 | * @dst, clearing any bits previously set in @dst. | |
719 | * | |
fb5eeeee PJ |
720 | * For example, lets say that @old has bits 4 through 7 set, and |
721 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
722 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
723 | * bit positions unchanged. So if say @src comes into this routine |
724 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, | |
725 | * 13 and 15 set. | |
fb5eeeee PJ |
726 | */ |
727 | void bitmap_remap(unsigned long *dst, const unsigned long *src, | |
728 | const unsigned long *old, const unsigned long *new, | |
9814ec13 | 729 | unsigned int nbits) |
fb5eeeee | 730 | { |
9814ec13 | 731 | unsigned int oldbit, w; |
fb5eeeee | 732 | |
fb5eeeee PJ |
733 | if (dst == src) /* following doesn't handle inplace remaps */ |
734 | return; | |
9814ec13 | 735 | bitmap_zero(dst, nbits); |
96b7f341 | 736 | |
9814ec13 RV |
737 | w = bitmap_weight(new, nbits); |
738 | for_each_set_bit(oldbit, src, nbits) { | |
739 | int n = bitmap_pos_to_ord(old, oldbit, nbits); | |
08564fb7 | 740 | |
96b7f341 PJ |
741 | if (n < 0 || w == 0) |
742 | set_bit(oldbit, dst); /* identity map */ | |
743 | else | |
9814ec13 | 744 | set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); |
fb5eeeee PJ |
745 | } |
746 | } | |
747 | EXPORT_SYMBOL(bitmap_remap); | |
748 | ||
749 | /** | |
750 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit | |
6e1907ff RD |
751 | * @oldbit: bit position to be mapped |
752 | * @old: defines domain of map | |
753 | * @new: defines range of map | |
754 | * @bits: number of bits in each of these bitmaps | |
fb5eeeee PJ |
755 | * |
756 | * Let @old and @new define a mapping of bit positions, such that | |
757 | * whatever position is held by the n-th set bit in @old is mapped | |
758 | * to the n-th set bit in @new. In the more general case, allowing | |
759 | * for the possibility that the weight 'w' of @new is less than the | |
760 | * weight of @old, map the position of the n-th set bit in @old to | |
761 | * the position of the m-th set bit in @new, where m == n % w. | |
762 | * | |
96b7f341 PJ |
763 | * The positions of unset bits in @old are mapped to themselves |
764 | * (the identify map). | |
fb5eeeee PJ |
765 | * |
766 | * Apply the above specified mapping to bit position @oldbit, returning | |
767 | * the new bit position. | |
768 | * | |
769 | * For example, lets say that @old has bits 4 through 7 set, and | |
770 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
771 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
96b7f341 PJ |
772 | * bit positions unchanged. So if say @oldbit is 5, then this routine |
773 | * returns 13. | |
fb5eeeee PJ |
774 | */ |
775 | int bitmap_bitremap(int oldbit, const unsigned long *old, | |
776 | const unsigned long *new, int bits) | |
777 | { | |
96b7f341 PJ |
778 | int w = bitmap_weight(new, bits); |
779 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
780 | if (n < 0 || w == 0) | |
781 | return oldbit; | |
782 | else | |
783 | return bitmap_ord_to_pos(new, n % w, bits); | |
fb5eeeee PJ |
784 | } |
785 | EXPORT_SYMBOL(bitmap_bitremap); | |
786 | ||
7ea931c9 PJ |
787 | /** |
788 | * bitmap_onto - translate one bitmap relative to another | |
789 | * @dst: resulting translated bitmap | |
790 | * @orig: original untranslated bitmap | |
791 | * @relmap: bitmap relative to which translated | |
792 | * @bits: number of bits in each of these bitmaps | |
793 | * | |
794 | * Set the n-th bit of @dst iff there exists some m such that the | |
795 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and | |
796 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. | |
797 | * (If you understood the previous sentence the first time your | |
798 | * read it, you're overqualified for your current job.) | |
799 | * | |
800 | * In other words, @orig is mapped onto (surjectively) @dst, | |
da3dae54 | 801 | * using the map { <n, m> | the n-th bit of @relmap is the |
7ea931c9 PJ |
802 | * m-th set bit of @relmap }. |
803 | * | |
804 | * Any set bits in @orig above bit number W, where W is the | |
805 | * weight of (number of set bits in) @relmap are mapped nowhere. | |
806 | * In particular, if for all bits m set in @orig, m >= W, then | |
807 | * @dst will end up empty. In situations where the possibility | |
808 | * of such an empty result is not desired, one way to avoid it is | |
809 | * to use the bitmap_fold() operator, below, to first fold the | |
810 | * @orig bitmap over itself so that all its set bits x are in the | |
811 | * range 0 <= x < W. The bitmap_fold() operator does this by | |
812 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. | |
813 | * | |
814 | * Example [1] for bitmap_onto(): | |
815 | * Let's say @relmap has bits 30-39 set, and @orig has bits | |
816 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, | |
817 | * @dst will have bits 31, 33, 35, 37 and 39 set. | |
818 | * | |
819 | * When bit 0 is set in @orig, it means turn on the bit in | |
820 | * @dst corresponding to whatever is the first bit (if any) | |
821 | * that is turned on in @relmap. Since bit 0 was off in the | |
822 | * above example, we leave off that bit (bit 30) in @dst. | |
823 | * | |
824 | * When bit 1 is set in @orig (as in the above example), it | |
825 | * means turn on the bit in @dst corresponding to whatever | |
826 | * is the second bit that is turned on in @relmap. The second | |
827 | * bit in @relmap that was turned on in the above example was | |
828 | * bit 31, so we turned on bit 31 in @dst. | |
829 | * | |
830 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, | |
831 | * because they were the 4th, 6th, 8th and 10th set bits | |
832 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of | |
833 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. | |
834 | * | |
835 | * When bit 11 is set in @orig, it means turn on the bit in | |
25985edc | 836 | * @dst corresponding to whatever is the twelfth bit that is |
7ea931c9 PJ |
837 | * turned on in @relmap. In the above example, there were |
838 | * only ten bits turned on in @relmap (30..39), so that bit | |
839 | * 11 was set in @orig had no affect on @dst. | |
840 | * | |
841 | * Example [2] for bitmap_fold() + bitmap_onto(): | |
842 | * Let's say @relmap has these ten bits set: | |
843 | * 40 41 42 43 45 48 53 61 74 95 | |
844 | * (for the curious, that's 40 plus the first ten terms of the | |
845 | * Fibonacci sequence.) | |
846 | * | |
847 | * Further lets say we use the following code, invoking | |
848 | * bitmap_fold() then bitmap_onto, as suggested above to | |
da3dae54 | 849 | * avoid the possibility of an empty @dst result: |
7ea931c9 PJ |
850 | * |
851 | * unsigned long *tmp; // a temporary bitmap's bits | |
852 | * | |
853 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); | |
854 | * bitmap_onto(dst, tmp, relmap, bits); | |
855 | * | |
856 | * Then this table shows what various values of @dst would be, for | |
857 | * various @orig's. I list the zero-based positions of each set bit. | |
858 | * The tmp column shows the intermediate result, as computed by | |
859 | * using bitmap_fold() to fold the @orig bitmap modulo ten | |
860 | * (the weight of @relmap). | |
861 | * | |
862 | * @orig tmp @dst | |
863 | * 0 0 40 | |
864 | * 1 1 41 | |
865 | * 9 9 95 | |
866 | * 10 0 40 (*) | |
867 | * 1 3 5 7 1 3 5 7 41 43 48 61 | |
868 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 | |
869 | * 0 9 18 27 0 9 8 7 40 61 74 95 | |
870 | * 0 10 20 30 0 40 | |
871 | * 0 11 22 33 0 1 2 3 40 41 42 43 | |
872 | * 0 12 24 36 0 2 4 6 40 42 45 53 | |
873 | * 78 102 211 1 2 8 41 42 74 (*) | |
874 | * | |
875 | * (*) For these marked lines, if we hadn't first done bitmap_fold() | |
876 | * into tmp, then the @dst result would have been empty. | |
877 | * | |
878 | * If either of @orig or @relmap is empty (no set bits), then @dst | |
879 | * will be returned empty. | |
880 | * | |
881 | * If (as explained above) the only set bits in @orig are in positions | |
882 | * m where m >= W, (where W is the weight of @relmap) then @dst will | |
883 | * once again be returned empty. | |
884 | * | |
885 | * All bits in @dst not set by the above rule are cleared. | |
886 | */ | |
887 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, | |
eb569883 | 888 | const unsigned long *relmap, unsigned int bits) |
7ea931c9 | 889 | { |
eb569883 | 890 | unsigned int n, m; /* same meaning as in above comment */ |
7ea931c9 PJ |
891 | |
892 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
893 | return; | |
894 | bitmap_zero(dst, bits); | |
895 | ||
896 | /* | |
897 | * The following code is a more efficient, but less | |
898 | * obvious, equivalent to the loop: | |
899 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { | |
900 | * n = bitmap_ord_to_pos(orig, m, bits); | |
901 | * if (test_bit(m, orig)) | |
902 | * set_bit(n, dst); | |
903 | * } | |
904 | */ | |
905 | ||
906 | m = 0; | |
08564fb7 | 907 | for_each_set_bit(n, relmap, bits) { |
7ea931c9 PJ |
908 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ |
909 | if (test_bit(m, orig)) | |
910 | set_bit(n, dst); | |
911 | m++; | |
912 | } | |
913 | } | |
914 | EXPORT_SYMBOL(bitmap_onto); | |
915 | ||
916 | /** | |
917 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size | |
918 | * @dst: resulting smaller bitmap | |
919 | * @orig: original larger bitmap | |
920 | * @sz: specified size | |
b26ad583 | 921 | * @nbits: number of bits in each of these bitmaps |
7ea931c9 PJ |
922 | * |
923 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. | |
924 | * Clear all other bits in @dst. See further the comment and | |
925 | * Example [2] for bitmap_onto() for why and how to use this. | |
926 | */ | |
927 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, | |
b26ad583 | 928 | unsigned int sz, unsigned int nbits) |
7ea931c9 | 929 | { |
b26ad583 | 930 | unsigned int oldbit; |
7ea931c9 PJ |
931 | |
932 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
933 | return; | |
b26ad583 | 934 | bitmap_zero(dst, nbits); |
7ea931c9 | 935 | |
b26ad583 | 936 | for_each_set_bit(oldbit, orig, nbits) |
7ea931c9 PJ |
937 | set_bit(oldbit % sz, dst); |
938 | } | |
939 | EXPORT_SYMBOL(bitmap_fold); | |
940 | ||
3cf64b93 PJ |
941 | /* |
942 | * Common code for bitmap_*_region() routines. | |
943 | * bitmap: array of unsigned longs corresponding to the bitmap | |
944 | * pos: the beginning of the region | |
945 | * order: region size (log base 2 of number of bits) | |
946 | * reg_op: operation(s) to perform on that region of bitmap | |
1da177e4 | 947 | * |
3cf64b93 PJ |
948 | * Can set, verify and/or release a region of bits in a bitmap, |
949 | * depending on which combination of REG_OP_* flag bits is set. | |
1da177e4 | 950 | * |
3cf64b93 PJ |
951 | * A region of a bitmap is a sequence of bits in the bitmap, of |
952 | * some size '1 << order' (a power of two), aligned to that same | |
953 | * '1 << order' power of two. | |
954 | * | |
955 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). | |
956 | * Returns 0 in all other cases and reg_ops. | |
1da177e4 | 957 | */ |
3cf64b93 PJ |
958 | |
959 | enum { | |
960 | REG_OP_ISFREE, /* true if region is all zero bits */ | |
961 | REG_OP_ALLOC, /* set all bits in region */ | |
962 | REG_OP_RELEASE, /* clear all bits in region */ | |
963 | }; | |
964 | ||
9279d328 | 965 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) |
1da177e4 | 966 | { |
3cf64b93 PJ |
967 | int nbits_reg; /* number of bits in region */ |
968 | int index; /* index first long of region in bitmap */ | |
969 | int offset; /* bit offset region in bitmap[index] */ | |
970 | int nlongs_reg; /* num longs spanned by region in bitmap */ | |
74373c6a | 971 | int nbitsinlong; /* num bits of region in each spanned long */ |
3cf64b93 | 972 | unsigned long mask; /* bitmask for one long of region */ |
74373c6a | 973 | int i; /* scans bitmap by longs */ |
3cf64b93 | 974 | int ret = 0; /* return value */ |
74373c6a | 975 | |
3cf64b93 PJ |
976 | /* |
977 | * Either nlongs_reg == 1 (for small orders that fit in one long) | |
978 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) | |
979 | */ | |
980 | nbits_reg = 1 << order; | |
981 | index = pos / BITS_PER_LONG; | |
982 | offset = pos - (index * BITS_PER_LONG); | |
983 | nlongs_reg = BITS_TO_LONGS(nbits_reg); | |
984 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); | |
1da177e4 | 985 | |
3cf64b93 PJ |
986 | /* |
987 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that | |
988 | * overflows if nbitsinlong == BITS_PER_LONG. | |
989 | */ | |
74373c6a | 990 | mask = (1UL << (nbitsinlong - 1)); |
1da177e4 | 991 | mask += mask - 1; |
3cf64b93 | 992 | mask <<= offset; |
1da177e4 | 993 | |
3cf64b93 PJ |
994 | switch (reg_op) { |
995 | case REG_OP_ISFREE: | |
996 | for (i = 0; i < nlongs_reg; i++) { | |
997 | if (bitmap[index + i] & mask) | |
998 | goto done; | |
999 | } | |
1000 | ret = 1; /* all bits in region free (zero) */ | |
1001 | break; | |
1002 | ||
1003 | case REG_OP_ALLOC: | |
1004 | for (i = 0; i < nlongs_reg; i++) | |
1005 | bitmap[index + i] |= mask; | |
1006 | break; | |
1007 | ||
1008 | case REG_OP_RELEASE: | |
1009 | for (i = 0; i < nlongs_reg; i++) | |
1010 | bitmap[index + i] &= ~mask; | |
1011 | break; | |
1da177e4 | 1012 | } |
3cf64b93 PJ |
1013 | done: |
1014 | return ret; | |
1015 | } | |
1016 | ||
1017 | /** | |
1018 | * bitmap_find_free_region - find a contiguous aligned mem region | |
1019 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
1020 | * @bits: number of bits in the bitmap | |
1021 | * @order: region size (log base 2 of number of bits) to find | |
1022 | * | |
1023 | * Find a region of free (zero) bits in a @bitmap of @bits bits and | |
1024 | * allocate them (set them to one). Only consider regions of length | |
1025 | * a power (@order) of two, aligned to that power of two, which | |
1026 | * makes the search algorithm much faster. | |
1027 | * | |
1028 | * Return the bit offset in bitmap of the allocated region, | |
1029 | * or -errno on failure. | |
1030 | */ | |
9279d328 | 1031 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) |
3cf64b93 | 1032 | { |
9279d328 | 1033 | unsigned int pos, end; /* scans bitmap by regions of size order */ |
aa8e4fc6 | 1034 | |
9279d328 | 1035 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { |
aa8e4fc6 LT |
1036 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1037 | continue; | |
1038 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
1039 | return pos; | |
1040 | } | |
1041 | return -ENOMEM; | |
1da177e4 LT |
1042 | } |
1043 | EXPORT_SYMBOL(bitmap_find_free_region); | |
1044 | ||
1045 | /** | |
87e24802 | 1046 | * bitmap_release_region - release allocated bitmap region |
3cf64b93 PJ |
1047 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1048 | * @pos: beginning of bit region to release | |
1049 | * @order: region size (log base 2 of number of bits) to release | |
1da177e4 | 1050 | * |
72fd4a35 | 1051 | * This is the complement to __bitmap_find_free_region() and releases |
1da177e4 | 1052 | * the found region (by clearing it in the bitmap). |
3cf64b93 PJ |
1053 | * |
1054 | * No return value. | |
1da177e4 | 1055 | */ |
9279d328 | 1056 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1057 | { |
3cf64b93 | 1058 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); |
1da177e4 LT |
1059 | } |
1060 | EXPORT_SYMBOL(bitmap_release_region); | |
1061 | ||
87e24802 PJ |
1062 | /** |
1063 | * bitmap_allocate_region - allocate bitmap region | |
3cf64b93 PJ |
1064 | * @bitmap: array of unsigned longs corresponding to the bitmap |
1065 | * @pos: beginning of bit region to allocate | |
1066 | * @order: region size (log base 2 of number of bits) to allocate | |
87e24802 PJ |
1067 | * |
1068 | * Allocate (set bits in) a specified region of a bitmap. | |
3cf64b93 | 1069 | * |
6e1907ff | 1070 | * Return 0 on success, or %-EBUSY if specified region wasn't |
87e24802 PJ |
1071 | * free (not all bits were zero). |
1072 | */ | |
9279d328 | 1073 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) |
1da177e4 | 1074 | { |
3cf64b93 PJ |
1075 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) |
1076 | return -EBUSY; | |
2ac521d3 | 1077 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC); |
1da177e4 LT |
1078 | } |
1079 | EXPORT_SYMBOL(bitmap_allocate_region); | |
ccbe329b DV |
1080 | |
1081 | /** | |
1082 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. | |
1083 | * @dst: destination buffer | |
1084 | * @src: bitmap to copy | |
1085 | * @nbits: number of bits in the bitmap | |
1086 | * | |
1087 | * Require nbits % BITS_PER_LONG == 0. | |
1088 | */ | |
e8f24278 | 1089 | #ifdef __BIG_ENDIAN |
9b6c2d2e | 1090 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) |
ccbe329b | 1091 | { |
9b6c2d2e | 1092 | unsigned int i; |
ccbe329b DV |
1093 | |
1094 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { | |
1095 | if (BITS_PER_LONG == 64) | |
9b6c2d2e | 1096 | dst[i] = cpu_to_le64(src[i]); |
ccbe329b | 1097 | else |
9b6c2d2e | 1098 | dst[i] = cpu_to_le32(src[i]); |
ccbe329b DV |
1099 | } |
1100 | } | |
1101 | EXPORT_SYMBOL(bitmap_copy_le); | |
e8f24278 | 1102 | #endif |