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1 | // SPDX-License-Identifier: GPL-2.0-only | |
2 | /* | |
3 | * lib/bitmap.c | |
4 | * Helper functions for bitmap.h. | |
5 | */ | |
6 | ||
7 | #include <linux/bitmap.h> | |
8 | #include <linux/bitops.h> | |
9 | #include <linux/bug.h> | |
10 | #include <linux/ctype.h> | |
11 | #include <linux/device.h> | |
12 | #include <linux/errno.h> | |
13 | #include <linux/export.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/string.h> | |
18 | #include <linux/thread_info.h> | |
19 | #include <linux/uaccess.h> | |
20 | ||
21 | #include <asm/page.h> | |
22 | ||
23 | #include "kstrtox.h" | |
24 | ||
25 | /** | |
26 | * DOC: bitmap introduction | |
27 | * | |
28 | * bitmaps provide an array of bits, implemented using an | |
29 | * array of unsigned longs. The number of valid bits in a | |
30 | * given bitmap does _not_ need to be an exact multiple of | |
31 | * BITS_PER_LONG. | |
32 | * | |
33 | * The possible unused bits in the last, partially used word | |
34 | * of a bitmap are 'don't care'. The implementation makes | |
35 | * no particular effort to keep them zero. It ensures that | |
36 | * their value will not affect the results of any operation. | |
37 | * The bitmap operations that return Boolean (bitmap_empty, | |
38 | * for example) or scalar (bitmap_weight, for example) results | |
39 | * carefully filter out these unused bits from impacting their | |
40 | * results. | |
41 | * | |
42 | * The byte ordering of bitmaps is more natural on little | |
43 | * endian architectures. See the big-endian headers | |
44 | * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h | |
45 | * for the best explanations of this ordering. | |
46 | */ | |
47 | ||
48 | bool __bitmap_equal(const unsigned long *bitmap1, | |
49 | const unsigned long *bitmap2, unsigned int bits) | |
50 | { | |
51 | unsigned int k, lim = bits/BITS_PER_LONG; | |
52 | for (k = 0; k < lim; ++k) | |
53 | if (bitmap1[k] != bitmap2[k]) | |
54 | return false; | |
55 | ||
56 | if (bits % BITS_PER_LONG) | |
57 | if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
58 | return false; | |
59 | ||
60 | return true; | |
61 | } | |
62 | EXPORT_SYMBOL(__bitmap_equal); | |
63 | ||
64 | bool __bitmap_or_equal(const unsigned long *bitmap1, | |
65 | const unsigned long *bitmap2, | |
66 | const unsigned long *bitmap3, | |
67 | unsigned int bits) | |
68 | { | |
69 | unsigned int k, lim = bits / BITS_PER_LONG; | |
70 | unsigned long tmp; | |
71 | ||
72 | for (k = 0; k < lim; ++k) { | |
73 | if ((bitmap1[k] | bitmap2[k]) != bitmap3[k]) | |
74 | return false; | |
75 | } | |
76 | ||
77 | if (!(bits % BITS_PER_LONG)) | |
78 | return true; | |
79 | ||
80 | tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k]; | |
81 | return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0; | |
82 | } | |
83 | ||
84 | void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) | |
85 | { | |
86 | unsigned int k, lim = BITS_TO_LONGS(bits); | |
87 | for (k = 0; k < lim; ++k) | |
88 | dst[k] = ~src[k]; | |
89 | } | |
90 | EXPORT_SYMBOL(__bitmap_complement); | |
91 | ||
92 | /** | |
93 | * __bitmap_shift_right - logical right shift of the bits in a bitmap | |
94 | * @dst : destination bitmap | |
95 | * @src : source bitmap | |
96 | * @shift : shift by this many bits | |
97 | * @nbits : bitmap size, in bits | |
98 | * | |
99 | * Shifting right (dividing) means moving bits in the MS -> LS bit | |
100 | * direction. Zeros are fed into the vacated MS positions and the | |
101 | * LS bits shifted off the bottom are lost. | |
102 | */ | |
103 | void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, | |
104 | unsigned shift, unsigned nbits) | |
105 | { | |
106 | unsigned k, lim = BITS_TO_LONGS(nbits); | |
107 | unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; | |
108 | unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); | |
109 | for (k = 0; off + k < lim; ++k) { | |
110 | unsigned long upper, lower; | |
111 | ||
112 | /* | |
113 | * If shift is not word aligned, take lower rem bits of | |
114 | * word above and make them the top rem bits of result. | |
115 | */ | |
116 | if (!rem || off + k + 1 >= lim) | |
117 | upper = 0; | |
118 | else { | |
119 | upper = src[off + k + 1]; | |
120 | if (off + k + 1 == lim - 1) | |
121 | upper &= mask; | |
122 | upper <<= (BITS_PER_LONG - rem); | |
123 | } | |
124 | lower = src[off + k]; | |
125 | if (off + k == lim - 1) | |
126 | lower &= mask; | |
127 | lower >>= rem; | |
128 | dst[k] = lower | upper; | |
129 | } | |
130 | if (off) | |
131 | memset(&dst[lim - off], 0, off*sizeof(unsigned long)); | |
132 | } | |
133 | EXPORT_SYMBOL(__bitmap_shift_right); | |
134 | ||
135 | ||
136 | /** | |
137 | * __bitmap_shift_left - logical left shift of the bits in a bitmap | |
138 | * @dst : destination bitmap | |
139 | * @src : source bitmap | |
140 | * @shift : shift by this many bits | |
141 | * @nbits : bitmap size, in bits | |
142 | * | |
143 | * Shifting left (multiplying) means moving bits in the LS -> MS | |
144 | * direction. Zeros are fed into the vacated LS bit positions | |
145 | * and those MS bits shifted off the top are lost. | |
146 | */ | |
147 | ||
148 | void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, | |
149 | unsigned int shift, unsigned int nbits) | |
150 | { | |
151 | int k; | |
152 | unsigned int lim = BITS_TO_LONGS(nbits); | |
153 | unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; | |
154 | for (k = lim - off - 1; k >= 0; --k) { | |
155 | unsigned long upper, lower; | |
156 | ||
157 | /* | |
158 | * If shift is not word aligned, take upper rem bits of | |
159 | * word below and make them the bottom rem bits of result. | |
160 | */ | |
161 | if (rem && k > 0) | |
162 | lower = src[k - 1] >> (BITS_PER_LONG - rem); | |
163 | else | |
164 | lower = 0; | |
165 | upper = src[k] << rem; | |
166 | dst[k + off] = lower | upper; | |
167 | } | |
168 | if (off) | |
169 | memset(dst, 0, off*sizeof(unsigned long)); | |
170 | } | |
171 | EXPORT_SYMBOL(__bitmap_shift_left); | |
172 | ||
173 | /** | |
174 | * bitmap_cut() - remove bit region from bitmap and right shift remaining bits | |
175 | * @dst: destination bitmap, might overlap with src | |
176 | * @src: source bitmap | |
177 | * @first: start bit of region to be removed | |
178 | * @cut: number of bits to remove | |
179 | * @nbits: bitmap size, in bits | |
180 | * | |
181 | * Set the n-th bit of @dst iff the n-th bit of @src is set and | |
182 | * n is less than @first, or the m-th bit of @src is set for any | |
183 | * m such that @first <= n < nbits, and m = n + @cut. | |
184 | * | |
185 | * In pictures, example for a big-endian 32-bit architecture: | |
186 | * | |
187 | * The @src bitmap is:: | |
188 | * | |
189 | * 31 63 | |
190 | * | | | |
191 | * 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101 | |
192 | * | | | | | |
193 | * 16 14 0 32 | |
194 | * | |
195 | * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is:: | |
196 | * | |
197 | * 31 63 | |
198 | * | | | |
199 | * 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010 | |
200 | * | | | | |
201 | * 14 (bit 17 0 32 | |
202 | * from @src) | |
203 | * | |
204 | * Note that @dst and @src might overlap partially or entirely. | |
205 | * | |
206 | * This is implemented in the obvious way, with a shift and carry | |
207 | * step for each moved bit. Optimisation is left as an exercise | |
208 | * for the compiler. | |
209 | */ | |
210 | void bitmap_cut(unsigned long *dst, const unsigned long *src, | |
211 | unsigned int first, unsigned int cut, unsigned int nbits) | |
212 | { | |
213 | unsigned int len = BITS_TO_LONGS(nbits); | |
214 | unsigned long keep = 0, carry; | |
215 | int i; | |
216 | ||
217 | if (first % BITS_PER_LONG) { | |
218 | keep = src[first / BITS_PER_LONG] & | |
219 | (~0UL >> (BITS_PER_LONG - first % BITS_PER_LONG)); | |
220 | } | |
221 | ||
222 | memmove(dst, src, len * sizeof(*dst)); | |
223 | ||
224 | while (cut--) { | |
225 | for (i = first / BITS_PER_LONG; i < len; i++) { | |
226 | if (i < len - 1) | |
227 | carry = dst[i + 1] & 1UL; | |
228 | else | |
229 | carry = 0; | |
230 | ||
231 | dst[i] = (dst[i] >> 1) | (carry << (BITS_PER_LONG - 1)); | |
232 | } | |
233 | } | |
234 | ||
235 | dst[first / BITS_PER_LONG] &= ~0UL << (first % BITS_PER_LONG); | |
236 | dst[first / BITS_PER_LONG] |= keep; | |
237 | } | |
238 | EXPORT_SYMBOL(bitmap_cut); | |
239 | ||
240 | bool __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, | |
241 | const unsigned long *bitmap2, unsigned int bits) | |
242 | { | |
243 | unsigned int k; | |
244 | unsigned int lim = bits/BITS_PER_LONG; | |
245 | unsigned long result = 0; | |
246 | ||
247 | for (k = 0; k < lim; k++) | |
248 | result |= (dst[k] = bitmap1[k] & bitmap2[k]); | |
249 | if (bits % BITS_PER_LONG) | |
250 | result |= (dst[k] = bitmap1[k] & bitmap2[k] & | |
251 | BITMAP_LAST_WORD_MASK(bits)); | |
252 | return result != 0; | |
253 | } | |
254 | EXPORT_SYMBOL(__bitmap_and); | |
255 | ||
256 | void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, | |
257 | const unsigned long *bitmap2, unsigned int bits) | |
258 | { | |
259 | unsigned int k; | |
260 | unsigned int nr = BITS_TO_LONGS(bits); | |
261 | ||
262 | for (k = 0; k < nr; k++) | |
263 | dst[k] = bitmap1[k] | bitmap2[k]; | |
264 | } | |
265 | EXPORT_SYMBOL(__bitmap_or); | |
266 | ||
267 | void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, | |
268 | const unsigned long *bitmap2, unsigned int bits) | |
269 | { | |
270 | unsigned int k; | |
271 | unsigned int nr = BITS_TO_LONGS(bits); | |
272 | ||
273 | for (k = 0; k < nr; k++) | |
274 | dst[k] = bitmap1[k] ^ bitmap2[k]; | |
275 | } | |
276 | EXPORT_SYMBOL(__bitmap_xor); | |
277 | ||
278 | bool __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, | |
279 | const unsigned long *bitmap2, unsigned int bits) | |
280 | { | |
281 | unsigned int k; | |
282 | unsigned int lim = bits/BITS_PER_LONG; | |
283 | unsigned long result = 0; | |
284 | ||
285 | for (k = 0; k < lim; k++) | |
286 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); | |
287 | if (bits % BITS_PER_LONG) | |
288 | result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & | |
289 | BITMAP_LAST_WORD_MASK(bits)); | |
290 | return result != 0; | |
291 | } | |
292 | EXPORT_SYMBOL(__bitmap_andnot); | |
293 | ||
294 | void __bitmap_replace(unsigned long *dst, | |
295 | const unsigned long *old, const unsigned long *new, | |
296 | const unsigned long *mask, unsigned int nbits) | |
297 | { | |
298 | unsigned int k; | |
299 | unsigned int nr = BITS_TO_LONGS(nbits); | |
300 | ||
301 | for (k = 0; k < nr; k++) | |
302 | dst[k] = (old[k] & ~mask[k]) | (new[k] & mask[k]); | |
303 | } | |
304 | EXPORT_SYMBOL(__bitmap_replace); | |
305 | ||
306 | bool __bitmap_intersects(const unsigned long *bitmap1, | |
307 | const unsigned long *bitmap2, unsigned int bits) | |
308 | { | |
309 | unsigned int k, lim = bits/BITS_PER_LONG; | |
310 | for (k = 0; k < lim; ++k) | |
311 | if (bitmap1[k] & bitmap2[k]) | |
312 | return true; | |
313 | ||
314 | if (bits % BITS_PER_LONG) | |
315 | if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
316 | return true; | |
317 | return false; | |
318 | } | |
319 | EXPORT_SYMBOL(__bitmap_intersects); | |
320 | ||
321 | bool __bitmap_subset(const unsigned long *bitmap1, | |
322 | const unsigned long *bitmap2, unsigned int bits) | |
323 | { | |
324 | unsigned int k, lim = bits/BITS_PER_LONG; | |
325 | for (k = 0; k < lim; ++k) | |
326 | if (bitmap1[k] & ~bitmap2[k]) | |
327 | return false; | |
328 | ||
329 | if (bits % BITS_PER_LONG) | |
330 | if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) | |
331 | return false; | |
332 | return true; | |
333 | } | |
334 | EXPORT_SYMBOL(__bitmap_subset); | |
335 | ||
336 | #define BITMAP_WEIGHT(FETCH, bits) \ | |
337 | ({ \ | |
338 | unsigned int __bits = (bits), idx, w = 0; \ | |
339 | \ | |
340 | for (idx = 0; idx < __bits / BITS_PER_LONG; idx++) \ | |
341 | w += hweight_long(FETCH); \ | |
342 | \ | |
343 | if (__bits % BITS_PER_LONG) \ | |
344 | w += hweight_long((FETCH) & BITMAP_LAST_WORD_MASK(__bits)); \ | |
345 | \ | |
346 | w; \ | |
347 | }) | |
348 | ||
349 | unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) | |
350 | { | |
351 | return BITMAP_WEIGHT(bitmap[idx], bits); | |
352 | } | |
353 | EXPORT_SYMBOL(__bitmap_weight); | |
354 | ||
355 | unsigned int __bitmap_weight_and(const unsigned long *bitmap1, | |
356 | const unsigned long *bitmap2, unsigned int bits) | |
357 | { | |
358 | return BITMAP_WEIGHT(bitmap1[idx] & bitmap2[idx], bits); | |
359 | } | |
360 | EXPORT_SYMBOL(__bitmap_weight_and); | |
361 | ||
362 | void __bitmap_set(unsigned long *map, unsigned int start, int len) | |
363 | { | |
364 | unsigned long *p = map + BIT_WORD(start); | |
365 | const unsigned int size = start + len; | |
366 | int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); | |
367 | unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); | |
368 | ||
369 | while (len - bits_to_set >= 0) { | |
370 | *p |= mask_to_set; | |
371 | len -= bits_to_set; | |
372 | bits_to_set = BITS_PER_LONG; | |
373 | mask_to_set = ~0UL; | |
374 | p++; | |
375 | } | |
376 | if (len) { | |
377 | mask_to_set &= BITMAP_LAST_WORD_MASK(size); | |
378 | *p |= mask_to_set; | |
379 | } | |
380 | } | |
381 | EXPORT_SYMBOL(__bitmap_set); | |
382 | ||
383 | void __bitmap_clear(unsigned long *map, unsigned int start, int len) | |
384 | { | |
385 | unsigned long *p = map + BIT_WORD(start); | |
386 | const unsigned int size = start + len; | |
387 | int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); | |
388 | unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); | |
389 | ||
390 | while (len - bits_to_clear >= 0) { | |
391 | *p &= ~mask_to_clear; | |
392 | len -= bits_to_clear; | |
393 | bits_to_clear = BITS_PER_LONG; | |
394 | mask_to_clear = ~0UL; | |
395 | p++; | |
396 | } | |
397 | if (len) { | |
398 | mask_to_clear &= BITMAP_LAST_WORD_MASK(size); | |
399 | *p &= ~mask_to_clear; | |
400 | } | |
401 | } | |
402 | EXPORT_SYMBOL(__bitmap_clear); | |
403 | ||
404 | /** | |
405 | * bitmap_find_next_zero_area_off - find a contiguous aligned zero area | |
406 | * @map: The address to base the search on | |
407 | * @size: The bitmap size in bits | |
408 | * @start: The bitnumber to start searching at | |
409 | * @nr: The number of zeroed bits we're looking for | |
410 | * @align_mask: Alignment mask for zero area | |
411 | * @align_offset: Alignment offset for zero area. | |
412 | * | |
413 | * The @align_mask should be one less than a power of 2; the effect is that | |
414 | * the bit offset of all zero areas this function finds plus @align_offset | |
415 | * is multiple of that power of 2. | |
416 | */ | |
417 | unsigned long bitmap_find_next_zero_area_off(unsigned long *map, | |
418 | unsigned long size, | |
419 | unsigned long start, | |
420 | unsigned int nr, | |
421 | unsigned long align_mask, | |
422 | unsigned long align_offset) | |
423 | { | |
424 | unsigned long index, end, i; | |
425 | again: | |
426 | index = find_next_zero_bit(map, size, start); | |
427 | ||
428 | /* Align allocation */ | |
429 | index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; | |
430 | ||
431 | end = index + nr; | |
432 | if (end > size) | |
433 | return end; | |
434 | i = find_next_bit(map, end, index); | |
435 | if (i < end) { | |
436 | start = i + 1; | |
437 | goto again; | |
438 | } | |
439 | return index; | |
440 | } | |
441 | EXPORT_SYMBOL(bitmap_find_next_zero_area_off); | |
442 | ||
443 | /* | |
444 | * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, | |
445 | * second version by Paul Jackson, third by Joe Korty. | |
446 | */ | |
447 | ||
448 | /** | |
449 | * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap | |
450 | * | |
451 | * @ubuf: pointer to user buffer containing string. | |
452 | * @ulen: buffer size in bytes. If string is smaller than this | |
453 | * then it must be terminated with a \0. | |
454 | * @maskp: pointer to bitmap array that will contain result. | |
455 | * @nmaskbits: size of bitmap, in bits. | |
456 | */ | |
457 | int bitmap_parse_user(const char __user *ubuf, | |
458 | unsigned int ulen, unsigned long *maskp, | |
459 | int nmaskbits) | |
460 | { | |
461 | char *buf; | |
462 | int ret; | |
463 | ||
464 | buf = memdup_user_nul(ubuf, ulen); | |
465 | if (IS_ERR(buf)) | |
466 | return PTR_ERR(buf); | |
467 | ||
468 | ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits); | |
469 | ||
470 | kfree(buf); | |
471 | return ret; | |
472 | } | |
473 | EXPORT_SYMBOL(bitmap_parse_user); | |
474 | ||
475 | /** | |
476 | * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string | |
477 | * @list: indicates whether the bitmap must be list | |
478 | * @buf: page aligned buffer into which string is placed | |
479 | * @maskp: pointer to bitmap to convert | |
480 | * @nmaskbits: size of bitmap, in bits | |
481 | * | |
482 | * Output format is a comma-separated list of decimal numbers and | |
483 | * ranges if list is specified or hex digits grouped into comma-separated | |
484 | * sets of 8 digits/set. Returns the number of characters written to buf. | |
485 | * | |
486 | * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned | |
487 | * area and that sufficient storage remains at @buf to accommodate the | |
488 | * bitmap_print_to_pagebuf() output. Returns the number of characters | |
489 | * actually printed to @buf, excluding terminating '\0'. | |
490 | */ | |
491 | int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, | |
492 | int nmaskbits) | |
493 | { | |
494 | ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); | |
495 | ||
496 | return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : | |
497 | scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); | |
498 | } | |
499 | EXPORT_SYMBOL(bitmap_print_to_pagebuf); | |
500 | ||
501 | /** | |
502 | * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string | |
503 | * @list: indicates whether the bitmap must be list | |
504 | * true: print in decimal list format | |
505 | * false: print in hexadecimal bitmask format | |
506 | * @buf: buffer into which string is placed | |
507 | * @maskp: pointer to bitmap to convert | |
508 | * @nmaskbits: size of bitmap, in bits | |
509 | * @off: in the string from which we are copying, We copy to @buf | |
510 | * @count: the maximum number of bytes to print | |
511 | */ | |
512 | static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, | |
513 | int nmaskbits, loff_t off, size_t count) | |
514 | { | |
515 | const char *fmt = list ? "%*pbl\n" : "%*pb\n"; | |
516 | ssize_t size; | |
517 | void *data; | |
518 | ||
519 | data = kasprintf(GFP_KERNEL, fmt, nmaskbits, maskp); | |
520 | if (!data) | |
521 | return -ENOMEM; | |
522 | ||
523 | size = memory_read_from_buffer(buf, count, &off, data, strlen(data) + 1); | |
524 | kfree(data); | |
525 | ||
526 | return size; | |
527 | } | |
528 | ||
529 | /** | |
530 | * bitmap_print_bitmask_to_buf - convert bitmap to hex bitmask format ASCII string | |
531 | * @buf: buffer into which string is placed | |
532 | * @maskp: pointer to bitmap to convert | |
533 | * @nmaskbits: size of bitmap, in bits | |
534 | * @off: in the string from which we are copying, We copy to @buf | |
535 | * @count: the maximum number of bytes to print | |
536 | * | |
537 | * The bitmap_print_to_pagebuf() is used indirectly via its cpumap wrapper | |
538 | * cpumap_print_to_pagebuf() or directly by drivers to export hexadecimal | |
539 | * bitmask and decimal list to userspace by sysfs ABI. | |
540 | * Drivers might be using a normal attribute for this kind of ABIs. A | |
541 | * normal attribute typically has show entry as below:: | |
542 | * | |
543 | * static ssize_t example_attribute_show(struct device *dev, | |
544 | * struct device_attribute *attr, char *buf) | |
545 | * { | |
546 | * ... | |
547 | * return bitmap_print_to_pagebuf(true, buf, &mask, nr_trig_max); | |
548 | * } | |
549 | * | |
550 | * show entry of attribute has no offset and count parameters and this | |
551 | * means the file is limited to one page only. | |
552 | * bitmap_print_to_pagebuf() API works terribly well for this kind of | |
553 | * normal attribute with buf parameter and without offset, count:: | |
554 | * | |
555 | * bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, | |
556 | * int nmaskbits) | |
557 | * { | |
558 | * } | |
559 | * | |
560 | * The problem is once we have a large bitmap, we have a chance to get a | |
561 | * bitmask or list more than one page. Especially for list, it could be | |
562 | * as complex as 0,3,5,7,9,... We have no simple way to know it exact size. | |
563 | * It turns out bin_attribute is a way to break this limit. bin_attribute | |
564 | * has show entry as below:: | |
565 | * | |
566 | * static ssize_t | |
567 | * example_bin_attribute_show(struct file *filp, struct kobject *kobj, | |
568 | * struct bin_attribute *attr, char *buf, | |
569 | * loff_t offset, size_t count) | |
570 | * { | |
571 | * ... | |
572 | * } | |
573 | * | |
574 | * With the new offset and count parameters, this makes sysfs ABI be able | |
575 | * to support file size more than one page. For example, offset could be | |
576 | * >= 4096. | |
577 | * bitmap_print_bitmask_to_buf(), bitmap_print_list_to_buf() wit their | |
578 | * cpumap wrapper cpumap_print_bitmask_to_buf(), cpumap_print_list_to_buf() | |
579 | * make those drivers be able to support large bitmask and list after they | |
580 | * move to use bin_attribute. In result, we have to pass the corresponding | |
581 | * parameters such as off, count from bin_attribute show entry to this API. | |
582 | * | |
583 | * The role of cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf() | |
584 | * is similar with cpumap_print_to_pagebuf(), the difference is that | |
585 | * bitmap_print_to_pagebuf() mainly serves sysfs attribute with the assumption | |
586 | * the destination buffer is exactly one page and won't be more than one page. | |
587 | * cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf(), on the other | |
588 | * hand, mainly serves bin_attribute which doesn't work with exact one page, | |
589 | * and it can break the size limit of converted decimal list and hexadecimal | |
590 | * bitmask. | |
591 | * | |
592 | * WARNING! | |
593 | * | |
594 | * This function is not a replacement for sprintf() or bitmap_print_to_pagebuf(). | |
595 | * It is intended to workaround sysfs limitations discussed above and should be | |
596 | * used carefully in general case for the following reasons: | |
597 | * | |
598 | * - Time complexity is O(nbits^2/count), comparing to O(nbits) for snprintf(). | |
599 | * - Memory complexity is O(nbits), comparing to O(1) for snprintf(). | |
600 | * - @off and @count are NOT offset and number of bits to print. | |
601 | * - If printing part of bitmap as list, the resulting string is not a correct | |
602 | * list representation of bitmap. Particularly, some bits within or out of | |
603 | * related interval may be erroneously set or unset. The format of the string | |
604 | * may be broken, so bitmap_parselist-like parser may fail parsing it. | |
605 | * - If printing the whole bitmap as list by parts, user must ensure the order | |
606 | * of calls of the function such that the offset is incremented linearly. | |
607 | * - If printing the whole bitmap as list by parts, user must keep bitmap | |
608 | * unchanged between the very first and very last call. Otherwise concatenated | |
609 | * result may be incorrect, and format may be broken. | |
610 | * | |
611 | * Returns the number of characters actually printed to @buf | |
612 | */ | |
613 | int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, | |
614 | int nmaskbits, loff_t off, size_t count) | |
615 | { | |
616 | return bitmap_print_to_buf(false, buf, maskp, nmaskbits, off, count); | |
617 | } | |
618 | EXPORT_SYMBOL(bitmap_print_bitmask_to_buf); | |
619 | ||
620 | /** | |
621 | * bitmap_print_list_to_buf - convert bitmap to decimal list format ASCII string | |
622 | * @buf: buffer into which string is placed | |
623 | * @maskp: pointer to bitmap to convert | |
624 | * @nmaskbits: size of bitmap, in bits | |
625 | * @off: in the string from which we are copying, We copy to @buf | |
626 | * @count: the maximum number of bytes to print | |
627 | * | |
628 | * Everything is same with the above bitmap_print_bitmask_to_buf() except | |
629 | * the print format. | |
630 | */ | |
631 | int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, | |
632 | int nmaskbits, loff_t off, size_t count) | |
633 | { | |
634 | return bitmap_print_to_buf(true, buf, maskp, nmaskbits, off, count); | |
635 | } | |
636 | EXPORT_SYMBOL(bitmap_print_list_to_buf); | |
637 | ||
638 | /* | |
639 | * Region 9-38:4/10 describes the following bitmap structure: | |
640 | * 0 9 12 18 38 N | |
641 | * .........****......****......****.................. | |
642 | * ^ ^ ^ ^ ^ | |
643 | * start off group_len end nbits | |
644 | */ | |
645 | struct region { | |
646 | unsigned int start; | |
647 | unsigned int off; | |
648 | unsigned int group_len; | |
649 | unsigned int end; | |
650 | unsigned int nbits; | |
651 | }; | |
652 | ||
653 | static void bitmap_set_region(const struct region *r, unsigned long *bitmap) | |
654 | { | |
655 | unsigned int start; | |
656 | ||
657 | for (start = r->start; start <= r->end; start += r->group_len) | |
658 | bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); | |
659 | } | |
660 | ||
661 | static int bitmap_check_region(const struct region *r) | |
662 | { | |
663 | if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) | |
664 | return -EINVAL; | |
665 | ||
666 | if (r->end >= r->nbits) | |
667 | return -ERANGE; | |
668 | ||
669 | return 0; | |
670 | } | |
671 | ||
672 | static const char *bitmap_getnum(const char *str, unsigned int *num, | |
673 | unsigned int lastbit) | |
674 | { | |
675 | unsigned long long n; | |
676 | unsigned int len; | |
677 | ||
678 | if (str[0] == 'N') { | |
679 | *num = lastbit; | |
680 | return str + 1; | |
681 | } | |
682 | ||
683 | len = _parse_integer(str, 10, &n); | |
684 | if (!len) | |
685 | return ERR_PTR(-EINVAL); | |
686 | if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n) | |
687 | return ERR_PTR(-EOVERFLOW); | |
688 | ||
689 | *num = n; | |
690 | return str + len; | |
691 | } | |
692 | ||
693 | static inline bool end_of_str(char c) | |
694 | { | |
695 | return c == '\0' || c == '\n'; | |
696 | } | |
697 | ||
698 | static inline bool __end_of_region(char c) | |
699 | { | |
700 | return isspace(c) || c == ','; | |
701 | } | |
702 | ||
703 | static inline bool end_of_region(char c) | |
704 | { | |
705 | return __end_of_region(c) || end_of_str(c); | |
706 | } | |
707 | ||
708 | /* | |
709 | * The format allows commas and whitespaces at the beginning | |
710 | * of the region. | |
711 | */ | |
712 | static const char *bitmap_find_region(const char *str) | |
713 | { | |
714 | while (__end_of_region(*str)) | |
715 | str++; | |
716 | ||
717 | return end_of_str(*str) ? NULL : str; | |
718 | } | |
719 | ||
720 | static const char *bitmap_find_region_reverse(const char *start, const char *end) | |
721 | { | |
722 | while (start <= end && __end_of_region(*end)) | |
723 | end--; | |
724 | ||
725 | return end; | |
726 | } | |
727 | ||
728 | static const char *bitmap_parse_region(const char *str, struct region *r) | |
729 | { | |
730 | unsigned int lastbit = r->nbits - 1; | |
731 | ||
732 | if (!strncasecmp(str, "all", 3)) { | |
733 | r->start = 0; | |
734 | r->end = lastbit; | |
735 | str += 3; | |
736 | ||
737 | goto check_pattern; | |
738 | } | |
739 | ||
740 | str = bitmap_getnum(str, &r->start, lastbit); | |
741 | if (IS_ERR(str)) | |
742 | return str; | |
743 | ||
744 | if (end_of_region(*str)) | |
745 | goto no_end; | |
746 | ||
747 | if (*str != '-') | |
748 | return ERR_PTR(-EINVAL); | |
749 | ||
750 | str = bitmap_getnum(str + 1, &r->end, lastbit); | |
751 | if (IS_ERR(str)) | |
752 | return str; | |
753 | ||
754 | check_pattern: | |
755 | if (end_of_region(*str)) | |
756 | goto no_pattern; | |
757 | ||
758 | if (*str != ':') | |
759 | return ERR_PTR(-EINVAL); | |
760 | ||
761 | str = bitmap_getnum(str + 1, &r->off, lastbit); | |
762 | if (IS_ERR(str)) | |
763 | return str; | |
764 | ||
765 | if (*str != '/') | |
766 | return ERR_PTR(-EINVAL); | |
767 | ||
768 | return bitmap_getnum(str + 1, &r->group_len, lastbit); | |
769 | ||
770 | no_end: | |
771 | r->end = r->start; | |
772 | no_pattern: | |
773 | r->off = r->end + 1; | |
774 | r->group_len = r->end + 1; | |
775 | ||
776 | return end_of_str(*str) ? NULL : str; | |
777 | } | |
778 | ||
779 | /** | |
780 | * bitmap_parselist - convert list format ASCII string to bitmap | |
781 | * @buf: read user string from this buffer; must be terminated | |
782 | * with a \0 or \n. | |
783 | * @maskp: write resulting mask here | |
784 | * @nmaskbits: number of bits in mask to be written | |
785 | * | |
786 | * Input format is a comma-separated list of decimal numbers and | |
787 | * ranges. Consecutively set bits are shown as two hyphen-separated | |
788 | * decimal numbers, the smallest and largest bit numbers set in | |
789 | * the range. | |
790 | * Optionally each range can be postfixed to denote that only parts of it | |
791 | * should be set. The range will divided to groups of specific size. | |
792 | * From each group will be used only defined amount of bits. | |
793 | * Syntax: range:used_size/group_size | |
794 | * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 | |
795 | * The value 'N' can be used as a dynamically substituted token for the | |
796 | * maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is | |
797 | * dynamic, so if system changes cause the bitmap width to change, such | |
798 | * as more cores in a CPU list, then any ranges using N will also change. | |
799 | * | |
800 | * Returns: 0 on success, -errno on invalid input strings. Error values: | |
801 | * | |
802 | * - ``-EINVAL``: wrong region format | |
803 | * - ``-EINVAL``: invalid character in string | |
804 | * - ``-ERANGE``: bit number specified too large for mask | |
805 | * - ``-EOVERFLOW``: integer overflow in the input parameters | |
806 | */ | |
807 | int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) | |
808 | { | |
809 | struct region r; | |
810 | long ret; | |
811 | ||
812 | r.nbits = nmaskbits; | |
813 | bitmap_zero(maskp, r.nbits); | |
814 | ||
815 | while (buf) { | |
816 | buf = bitmap_find_region(buf); | |
817 | if (buf == NULL) | |
818 | return 0; | |
819 | ||
820 | buf = bitmap_parse_region(buf, &r); | |
821 | if (IS_ERR(buf)) | |
822 | return PTR_ERR(buf); | |
823 | ||
824 | ret = bitmap_check_region(&r); | |
825 | if (ret) | |
826 | return ret; | |
827 | ||
828 | bitmap_set_region(&r, maskp); | |
829 | } | |
830 | ||
831 | return 0; | |
832 | } | |
833 | EXPORT_SYMBOL(bitmap_parselist); | |
834 | ||
835 | ||
836 | /** | |
837 | * bitmap_parselist_user() - convert user buffer's list format ASCII | |
838 | * string to bitmap | |
839 | * | |
840 | * @ubuf: pointer to user buffer containing string. | |
841 | * @ulen: buffer size in bytes. If string is smaller than this | |
842 | * then it must be terminated with a \0. | |
843 | * @maskp: pointer to bitmap array that will contain result. | |
844 | * @nmaskbits: size of bitmap, in bits. | |
845 | * | |
846 | * Wrapper for bitmap_parselist(), providing it with user buffer. | |
847 | */ | |
848 | int bitmap_parselist_user(const char __user *ubuf, | |
849 | unsigned int ulen, unsigned long *maskp, | |
850 | int nmaskbits) | |
851 | { | |
852 | char *buf; | |
853 | int ret; | |
854 | ||
855 | buf = memdup_user_nul(ubuf, ulen); | |
856 | if (IS_ERR(buf)) | |
857 | return PTR_ERR(buf); | |
858 | ||
859 | ret = bitmap_parselist(buf, maskp, nmaskbits); | |
860 | ||
861 | kfree(buf); | |
862 | return ret; | |
863 | } | |
864 | EXPORT_SYMBOL(bitmap_parselist_user); | |
865 | ||
866 | static const char *bitmap_get_x32_reverse(const char *start, | |
867 | const char *end, u32 *num) | |
868 | { | |
869 | u32 ret = 0; | |
870 | int c, i; | |
871 | ||
872 | for (i = 0; i < 32; i += 4) { | |
873 | c = hex_to_bin(*end--); | |
874 | if (c < 0) | |
875 | return ERR_PTR(-EINVAL); | |
876 | ||
877 | ret |= c << i; | |
878 | ||
879 | if (start > end || __end_of_region(*end)) | |
880 | goto out; | |
881 | } | |
882 | ||
883 | if (hex_to_bin(*end--) >= 0) | |
884 | return ERR_PTR(-EOVERFLOW); | |
885 | out: | |
886 | *num = ret; | |
887 | return end; | |
888 | } | |
889 | ||
890 | /** | |
891 | * bitmap_parse - convert an ASCII hex string into a bitmap. | |
892 | * @start: pointer to buffer containing string. | |
893 | * @buflen: buffer size in bytes. If string is smaller than this | |
894 | * then it must be terminated with a \0 or \n. In that case, | |
895 | * UINT_MAX may be provided instead of string length. | |
896 | * @maskp: pointer to bitmap array that will contain result. | |
897 | * @nmaskbits: size of bitmap, in bits. | |
898 | * | |
899 | * Commas group hex digits into chunks. Each chunk defines exactly 32 | |
900 | * bits of the resultant bitmask. No chunk may specify a value larger | |
901 | * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value | |
902 | * then leading 0-bits are prepended. %-EINVAL is returned for illegal | |
903 | * characters. Grouping such as "1,,5", ",44", "," or "" is allowed. | |
904 | * Leading, embedded and trailing whitespace accepted. | |
905 | */ | |
906 | int bitmap_parse(const char *start, unsigned int buflen, | |
907 | unsigned long *maskp, int nmaskbits) | |
908 | { | |
909 | const char *end = strnchrnul(start, buflen, '\n') - 1; | |
910 | int chunks = BITS_TO_U32(nmaskbits); | |
911 | u32 *bitmap = (u32 *)maskp; | |
912 | int unset_bit; | |
913 | int chunk; | |
914 | ||
915 | for (chunk = 0; ; chunk++) { | |
916 | end = bitmap_find_region_reverse(start, end); | |
917 | if (start > end) | |
918 | break; | |
919 | ||
920 | if (!chunks--) | |
921 | return -EOVERFLOW; | |
922 | ||
923 | #if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN) | |
924 | end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]); | |
925 | #else | |
926 | end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]); | |
927 | #endif | |
928 | if (IS_ERR(end)) | |
929 | return PTR_ERR(end); | |
930 | } | |
931 | ||
932 | unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32; | |
933 | if (unset_bit < nmaskbits) { | |
934 | bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit); | |
935 | return 0; | |
936 | } | |
937 | ||
938 | if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit) | |
939 | return -EOVERFLOW; | |
940 | ||
941 | return 0; | |
942 | } | |
943 | EXPORT_SYMBOL(bitmap_parse); | |
944 | ||
945 | /** | |
946 | * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap | |
947 | * @buf: pointer to a bitmap | |
948 | * @pos: a bit position in @buf (0 <= @pos < @nbits) | |
949 | * @nbits: number of valid bit positions in @buf | |
950 | * | |
951 | * Map the bit at position @pos in @buf (of length @nbits) to the | |
952 | * ordinal of which set bit it is. If it is not set or if @pos | |
953 | * is not a valid bit position, map to -1. | |
954 | * | |
955 | * If for example, just bits 4 through 7 are set in @buf, then @pos | |
956 | * values 4 through 7 will get mapped to 0 through 3, respectively, | |
957 | * and other @pos values will get mapped to -1. When @pos value 7 | |
958 | * gets mapped to (returns) @ord value 3 in this example, that means | |
959 | * that bit 7 is the 3rd (starting with 0th) set bit in @buf. | |
960 | * | |
961 | * The bit positions 0 through @bits are valid positions in @buf. | |
962 | */ | |
963 | static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) | |
964 | { | |
965 | if (pos >= nbits || !test_bit(pos, buf)) | |
966 | return -1; | |
967 | ||
968 | return bitmap_weight(buf, pos); | |
969 | } | |
970 | ||
971 | /** | |
972 | * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap | |
973 | * @dst: remapped result | |
974 | * @src: subset to be remapped | |
975 | * @old: defines domain of map | |
976 | * @new: defines range of map | |
977 | * @nbits: number of bits in each of these bitmaps | |
978 | * | |
979 | * Let @old and @new define a mapping of bit positions, such that | |
980 | * whatever position is held by the n-th set bit in @old is mapped | |
981 | * to the n-th set bit in @new. In the more general case, allowing | |
982 | * for the possibility that the weight 'w' of @new is less than the | |
983 | * weight of @old, map the position of the n-th set bit in @old to | |
984 | * the position of the m-th set bit in @new, where m == n % w. | |
985 | * | |
986 | * If either of the @old and @new bitmaps are empty, or if @src and | |
987 | * @dst point to the same location, then this routine copies @src | |
988 | * to @dst. | |
989 | * | |
990 | * The positions of unset bits in @old are mapped to themselves | |
991 | * (the identify map). | |
992 | * | |
993 | * Apply the above specified mapping to @src, placing the result in | |
994 | * @dst, clearing any bits previously set in @dst. | |
995 | * | |
996 | * For example, lets say that @old has bits 4 through 7 set, and | |
997 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
998 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
999 | * bit positions unchanged. So if say @src comes into this routine | |
1000 | * with bits 1, 5 and 7 set, then @dst should leave with bits 1, | |
1001 | * 13 and 15 set. | |
1002 | */ | |
1003 | void bitmap_remap(unsigned long *dst, const unsigned long *src, | |
1004 | const unsigned long *old, const unsigned long *new, | |
1005 | unsigned int nbits) | |
1006 | { | |
1007 | unsigned int oldbit, w; | |
1008 | ||
1009 | if (dst == src) /* following doesn't handle inplace remaps */ | |
1010 | return; | |
1011 | bitmap_zero(dst, nbits); | |
1012 | ||
1013 | w = bitmap_weight(new, nbits); | |
1014 | for_each_set_bit(oldbit, src, nbits) { | |
1015 | int n = bitmap_pos_to_ord(old, oldbit, nbits); | |
1016 | ||
1017 | if (n < 0 || w == 0) | |
1018 | set_bit(oldbit, dst); /* identity map */ | |
1019 | else | |
1020 | set_bit(find_nth_bit(new, nbits, n % w), dst); | |
1021 | } | |
1022 | } | |
1023 | EXPORT_SYMBOL(bitmap_remap); | |
1024 | ||
1025 | /** | |
1026 | * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit | |
1027 | * @oldbit: bit position to be mapped | |
1028 | * @old: defines domain of map | |
1029 | * @new: defines range of map | |
1030 | * @bits: number of bits in each of these bitmaps | |
1031 | * | |
1032 | * Let @old and @new define a mapping of bit positions, such that | |
1033 | * whatever position is held by the n-th set bit in @old is mapped | |
1034 | * to the n-th set bit in @new. In the more general case, allowing | |
1035 | * for the possibility that the weight 'w' of @new is less than the | |
1036 | * weight of @old, map the position of the n-th set bit in @old to | |
1037 | * the position of the m-th set bit in @new, where m == n % w. | |
1038 | * | |
1039 | * The positions of unset bits in @old are mapped to themselves | |
1040 | * (the identify map). | |
1041 | * | |
1042 | * Apply the above specified mapping to bit position @oldbit, returning | |
1043 | * the new bit position. | |
1044 | * | |
1045 | * For example, lets say that @old has bits 4 through 7 set, and | |
1046 | * @new has bits 12 through 15 set. This defines the mapping of bit | |
1047 | * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other | |
1048 | * bit positions unchanged. So if say @oldbit is 5, then this routine | |
1049 | * returns 13. | |
1050 | */ | |
1051 | int bitmap_bitremap(int oldbit, const unsigned long *old, | |
1052 | const unsigned long *new, int bits) | |
1053 | { | |
1054 | int w = bitmap_weight(new, bits); | |
1055 | int n = bitmap_pos_to_ord(old, oldbit, bits); | |
1056 | if (n < 0 || w == 0) | |
1057 | return oldbit; | |
1058 | else | |
1059 | return find_nth_bit(new, bits, n % w); | |
1060 | } | |
1061 | EXPORT_SYMBOL(bitmap_bitremap); | |
1062 | ||
1063 | #ifdef CONFIG_NUMA | |
1064 | /** | |
1065 | * bitmap_onto - translate one bitmap relative to another | |
1066 | * @dst: resulting translated bitmap | |
1067 | * @orig: original untranslated bitmap | |
1068 | * @relmap: bitmap relative to which translated | |
1069 | * @bits: number of bits in each of these bitmaps | |
1070 | * | |
1071 | * Set the n-th bit of @dst iff there exists some m such that the | |
1072 | * n-th bit of @relmap is set, the m-th bit of @orig is set, and | |
1073 | * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. | |
1074 | * (If you understood the previous sentence the first time your | |
1075 | * read it, you're overqualified for your current job.) | |
1076 | * | |
1077 | * In other words, @orig is mapped onto (surjectively) @dst, | |
1078 | * using the map { <n, m> | the n-th bit of @relmap is the | |
1079 | * m-th set bit of @relmap }. | |
1080 | * | |
1081 | * Any set bits in @orig above bit number W, where W is the | |
1082 | * weight of (number of set bits in) @relmap are mapped nowhere. | |
1083 | * In particular, if for all bits m set in @orig, m >= W, then | |
1084 | * @dst will end up empty. In situations where the possibility | |
1085 | * of such an empty result is not desired, one way to avoid it is | |
1086 | * to use the bitmap_fold() operator, below, to first fold the | |
1087 | * @orig bitmap over itself so that all its set bits x are in the | |
1088 | * range 0 <= x < W. The bitmap_fold() operator does this by | |
1089 | * setting the bit (m % W) in @dst, for each bit (m) set in @orig. | |
1090 | * | |
1091 | * Example [1] for bitmap_onto(): | |
1092 | * Let's say @relmap has bits 30-39 set, and @orig has bits | |
1093 | * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, | |
1094 | * @dst will have bits 31, 33, 35, 37 and 39 set. | |
1095 | * | |
1096 | * When bit 0 is set in @orig, it means turn on the bit in | |
1097 | * @dst corresponding to whatever is the first bit (if any) | |
1098 | * that is turned on in @relmap. Since bit 0 was off in the | |
1099 | * above example, we leave off that bit (bit 30) in @dst. | |
1100 | * | |
1101 | * When bit 1 is set in @orig (as in the above example), it | |
1102 | * means turn on the bit in @dst corresponding to whatever | |
1103 | * is the second bit that is turned on in @relmap. The second | |
1104 | * bit in @relmap that was turned on in the above example was | |
1105 | * bit 31, so we turned on bit 31 in @dst. | |
1106 | * | |
1107 | * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, | |
1108 | * because they were the 4th, 6th, 8th and 10th set bits | |
1109 | * set in @relmap, and the 4th, 6th, 8th and 10th bits of | |
1110 | * @orig (i.e. bits 3, 5, 7 and 9) were also set. | |
1111 | * | |
1112 | * When bit 11 is set in @orig, it means turn on the bit in | |
1113 | * @dst corresponding to whatever is the twelfth bit that is | |
1114 | * turned on in @relmap. In the above example, there were | |
1115 | * only ten bits turned on in @relmap (30..39), so that bit | |
1116 | * 11 was set in @orig had no affect on @dst. | |
1117 | * | |
1118 | * Example [2] for bitmap_fold() + bitmap_onto(): | |
1119 | * Let's say @relmap has these ten bits set:: | |
1120 | * | |
1121 | * 40 41 42 43 45 48 53 61 74 95 | |
1122 | * | |
1123 | * (for the curious, that's 40 plus the first ten terms of the | |
1124 | * Fibonacci sequence.) | |
1125 | * | |
1126 | * Further lets say we use the following code, invoking | |
1127 | * bitmap_fold() then bitmap_onto, as suggested above to | |
1128 | * avoid the possibility of an empty @dst result:: | |
1129 | * | |
1130 | * unsigned long *tmp; // a temporary bitmap's bits | |
1131 | * | |
1132 | * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); | |
1133 | * bitmap_onto(dst, tmp, relmap, bits); | |
1134 | * | |
1135 | * Then this table shows what various values of @dst would be, for | |
1136 | * various @orig's. I list the zero-based positions of each set bit. | |
1137 | * The tmp column shows the intermediate result, as computed by | |
1138 | * using bitmap_fold() to fold the @orig bitmap modulo ten | |
1139 | * (the weight of @relmap): | |
1140 | * | |
1141 | * =============== ============== ================= | |
1142 | * @orig tmp @dst | |
1143 | * 0 0 40 | |
1144 | * 1 1 41 | |
1145 | * 9 9 95 | |
1146 | * 10 0 40 [#f1]_ | |
1147 | * 1 3 5 7 1 3 5 7 41 43 48 61 | |
1148 | * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 | |
1149 | * 0 9 18 27 0 9 8 7 40 61 74 95 | |
1150 | * 0 10 20 30 0 40 | |
1151 | * 0 11 22 33 0 1 2 3 40 41 42 43 | |
1152 | * 0 12 24 36 0 2 4 6 40 42 45 53 | |
1153 | * 78 102 211 1 2 8 41 42 74 [#f1]_ | |
1154 | * =============== ============== ================= | |
1155 | * | |
1156 | * .. [#f1] | |
1157 | * | |
1158 | * For these marked lines, if we hadn't first done bitmap_fold() | |
1159 | * into tmp, then the @dst result would have been empty. | |
1160 | * | |
1161 | * If either of @orig or @relmap is empty (no set bits), then @dst | |
1162 | * will be returned empty. | |
1163 | * | |
1164 | * If (as explained above) the only set bits in @orig are in positions | |
1165 | * m where m >= W, (where W is the weight of @relmap) then @dst will | |
1166 | * once again be returned empty. | |
1167 | * | |
1168 | * All bits in @dst not set by the above rule are cleared. | |
1169 | */ | |
1170 | void bitmap_onto(unsigned long *dst, const unsigned long *orig, | |
1171 | const unsigned long *relmap, unsigned int bits) | |
1172 | { | |
1173 | unsigned int n, m; /* same meaning as in above comment */ | |
1174 | ||
1175 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
1176 | return; | |
1177 | bitmap_zero(dst, bits); | |
1178 | ||
1179 | /* | |
1180 | * The following code is a more efficient, but less | |
1181 | * obvious, equivalent to the loop: | |
1182 | * for (m = 0; m < bitmap_weight(relmap, bits); m++) { | |
1183 | * n = find_nth_bit(orig, bits, m); | |
1184 | * if (test_bit(m, orig)) | |
1185 | * set_bit(n, dst); | |
1186 | * } | |
1187 | */ | |
1188 | ||
1189 | m = 0; | |
1190 | for_each_set_bit(n, relmap, bits) { | |
1191 | /* m == bitmap_pos_to_ord(relmap, n, bits) */ | |
1192 | if (test_bit(m, orig)) | |
1193 | set_bit(n, dst); | |
1194 | m++; | |
1195 | } | |
1196 | } | |
1197 | ||
1198 | /** | |
1199 | * bitmap_fold - fold larger bitmap into smaller, modulo specified size | |
1200 | * @dst: resulting smaller bitmap | |
1201 | * @orig: original larger bitmap | |
1202 | * @sz: specified size | |
1203 | * @nbits: number of bits in each of these bitmaps | |
1204 | * | |
1205 | * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. | |
1206 | * Clear all other bits in @dst. See further the comment and | |
1207 | * Example [2] for bitmap_onto() for why and how to use this. | |
1208 | */ | |
1209 | void bitmap_fold(unsigned long *dst, const unsigned long *orig, | |
1210 | unsigned int sz, unsigned int nbits) | |
1211 | { | |
1212 | unsigned int oldbit; | |
1213 | ||
1214 | if (dst == orig) /* following doesn't handle inplace mappings */ | |
1215 | return; | |
1216 | bitmap_zero(dst, nbits); | |
1217 | ||
1218 | for_each_set_bit(oldbit, orig, nbits) | |
1219 | set_bit(oldbit % sz, dst); | |
1220 | } | |
1221 | #endif /* CONFIG_NUMA */ | |
1222 | ||
1223 | /* | |
1224 | * Common code for bitmap_*_region() routines. | |
1225 | * bitmap: array of unsigned longs corresponding to the bitmap | |
1226 | * pos: the beginning of the region | |
1227 | * order: region size (log base 2 of number of bits) | |
1228 | * reg_op: operation(s) to perform on that region of bitmap | |
1229 | * | |
1230 | * Can set, verify and/or release a region of bits in a bitmap, | |
1231 | * depending on which combination of REG_OP_* flag bits is set. | |
1232 | * | |
1233 | * A region of a bitmap is a sequence of bits in the bitmap, of | |
1234 | * some size '1 << order' (a power of two), aligned to that same | |
1235 | * '1 << order' power of two. | |
1236 | * | |
1237 | * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). | |
1238 | * Returns 0 in all other cases and reg_ops. | |
1239 | */ | |
1240 | ||
1241 | enum { | |
1242 | REG_OP_ISFREE, /* true if region is all zero bits */ | |
1243 | REG_OP_ALLOC, /* set all bits in region */ | |
1244 | REG_OP_RELEASE, /* clear all bits in region */ | |
1245 | }; | |
1246 | ||
1247 | static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) | |
1248 | { | |
1249 | int nbits_reg; /* number of bits in region */ | |
1250 | int index; /* index first long of region in bitmap */ | |
1251 | int offset; /* bit offset region in bitmap[index] */ | |
1252 | int nlongs_reg; /* num longs spanned by region in bitmap */ | |
1253 | int nbitsinlong; /* num bits of region in each spanned long */ | |
1254 | unsigned long mask; /* bitmask for one long of region */ | |
1255 | int i; /* scans bitmap by longs */ | |
1256 | int ret = 0; /* return value */ | |
1257 | ||
1258 | /* | |
1259 | * Either nlongs_reg == 1 (for small orders that fit in one long) | |
1260 | * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) | |
1261 | */ | |
1262 | nbits_reg = 1 << order; | |
1263 | index = pos / BITS_PER_LONG; | |
1264 | offset = pos - (index * BITS_PER_LONG); | |
1265 | nlongs_reg = BITS_TO_LONGS(nbits_reg); | |
1266 | nbitsinlong = min(nbits_reg, BITS_PER_LONG); | |
1267 | ||
1268 | /* | |
1269 | * Can't do "mask = (1UL << nbitsinlong) - 1", as that | |
1270 | * overflows if nbitsinlong == BITS_PER_LONG. | |
1271 | */ | |
1272 | mask = (1UL << (nbitsinlong - 1)); | |
1273 | mask += mask - 1; | |
1274 | mask <<= offset; | |
1275 | ||
1276 | switch (reg_op) { | |
1277 | case REG_OP_ISFREE: | |
1278 | for (i = 0; i < nlongs_reg; i++) { | |
1279 | if (bitmap[index + i] & mask) | |
1280 | goto done; | |
1281 | } | |
1282 | ret = 1; /* all bits in region free (zero) */ | |
1283 | break; | |
1284 | ||
1285 | case REG_OP_ALLOC: | |
1286 | for (i = 0; i < nlongs_reg; i++) | |
1287 | bitmap[index + i] |= mask; | |
1288 | break; | |
1289 | ||
1290 | case REG_OP_RELEASE: | |
1291 | for (i = 0; i < nlongs_reg; i++) | |
1292 | bitmap[index + i] &= ~mask; | |
1293 | break; | |
1294 | } | |
1295 | done: | |
1296 | return ret; | |
1297 | } | |
1298 | ||
1299 | /** | |
1300 | * bitmap_find_free_region - find a contiguous aligned mem region | |
1301 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
1302 | * @bits: number of bits in the bitmap | |
1303 | * @order: region size (log base 2 of number of bits) to find | |
1304 | * | |
1305 | * Find a region of free (zero) bits in a @bitmap of @bits bits and | |
1306 | * allocate them (set them to one). Only consider regions of length | |
1307 | * a power (@order) of two, aligned to that power of two, which | |
1308 | * makes the search algorithm much faster. | |
1309 | * | |
1310 | * Return the bit offset in bitmap of the allocated region, | |
1311 | * or -errno on failure. | |
1312 | */ | |
1313 | int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) | |
1314 | { | |
1315 | unsigned int pos, end; /* scans bitmap by regions of size order */ | |
1316 | ||
1317 | for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { | |
1318 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) | |
1319 | continue; | |
1320 | __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
1321 | return pos; | |
1322 | } | |
1323 | return -ENOMEM; | |
1324 | } | |
1325 | EXPORT_SYMBOL(bitmap_find_free_region); | |
1326 | ||
1327 | /** | |
1328 | * bitmap_release_region - release allocated bitmap region | |
1329 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
1330 | * @pos: beginning of bit region to release | |
1331 | * @order: region size (log base 2 of number of bits) to release | |
1332 | * | |
1333 | * This is the complement to __bitmap_find_free_region() and releases | |
1334 | * the found region (by clearing it in the bitmap). | |
1335 | * | |
1336 | * No return value. | |
1337 | */ | |
1338 | void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) | |
1339 | { | |
1340 | __reg_op(bitmap, pos, order, REG_OP_RELEASE); | |
1341 | } | |
1342 | EXPORT_SYMBOL(bitmap_release_region); | |
1343 | ||
1344 | /** | |
1345 | * bitmap_allocate_region - allocate bitmap region | |
1346 | * @bitmap: array of unsigned longs corresponding to the bitmap | |
1347 | * @pos: beginning of bit region to allocate | |
1348 | * @order: region size (log base 2 of number of bits) to allocate | |
1349 | * | |
1350 | * Allocate (set bits in) a specified region of a bitmap. | |
1351 | * | |
1352 | * Return 0 on success, or %-EBUSY if specified region wasn't | |
1353 | * free (not all bits were zero). | |
1354 | */ | |
1355 | int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) | |
1356 | { | |
1357 | if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) | |
1358 | return -EBUSY; | |
1359 | return __reg_op(bitmap, pos, order, REG_OP_ALLOC); | |
1360 | } | |
1361 | EXPORT_SYMBOL(bitmap_allocate_region); | |
1362 | ||
1363 | /** | |
1364 | * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. | |
1365 | * @dst: destination buffer | |
1366 | * @src: bitmap to copy | |
1367 | * @nbits: number of bits in the bitmap | |
1368 | * | |
1369 | * Require nbits % BITS_PER_LONG == 0. | |
1370 | */ | |
1371 | #ifdef __BIG_ENDIAN | |
1372 | void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) | |
1373 | { | |
1374 | unsigned int i; | |
1375 | ||
1376 | for (i = 0; i < nbits/BITS_PER_LONG; i++) { | |
1377 | if (BITS_PER_LONG == 64) | |
1378 | dst[i] = cpu_to_le64(src[i]); | |
1379 | else | |
1380 | dst[i] = cpu_to_le32(src[i]); | |
1381 | } | |
1382 | } | |
1383 | EXPORT_SYMBOL(bitmap_copy_le); | |
1384 | #endif | |
1385 | ||
1386 | unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) | |
1387 | { | |
1388 | return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), | |
1389 | flags); | |
1390 | } | |
1391 | EXPORT_SYMBOL(bitmap_alloc); | |
1392 | ||
1393 | unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags) | |
1394 | { | |
1395 | return bitmap_alloc(nbits, flags | __GFP_ZERO); | |
1396 | } | |
1397 | EXPORT_SYMBOL(bitmap_zalloc); | |
1398 | ||
1399 | unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node) | |
1400 | { | |
1401 | return kmalloc_array_node(BITS_TO_LONGS(nbits), sizeof(unsigned long), | |
1402 | flags, node); | |
1403 | } | |
1404 | EXPORT_SYMBOL(bitmap_alloc_node); | |
1405 | ||
1406 | unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node) | |
1407 | { | |
1408 | return bitmap_alloc_node(nbits, flags | __GFP_ZERO, node); | |
1409 | } | |
1410 | EXPORT_SYMBOL(bitmap_zalloc_node); | |
1411 | ||
1412 | void bitmap_free(const unsigned long *bitmap) | |
1413 | { | |
1414 | kfree(bitmap); | |
1415 | } | |
1416 | EXPORT_SYMBOL(bitmap_free); | |
1417 | ||
1418 | static void devm_bitmap_free(void *data) | |
1419 | { | |
1420 | unsigned long *bitmap = data; | |
1421 | ||
1422 | bitmap_free(bitmap); | |
1423 | } | |
1424 | ||
1425 | unsigned long *devm_bitmap_alloc(struct device *dev, | |
1426 | unsigned int nbits, gfp_t flags) | |
1427 | { | |
1428 | unsigned long *bitmap; | |
1429 | int ret; | |
1430 | ||
1431 | bitmap = bitmap_alloc(nbits, flags); | |
1432 | if (!bitmap) | |
1433 | return NULL; | |
1434 | ||
1435 | ret = devm_add_action_or_reset(dev, devm_bitmap_free, bitmap); | |
1436 | if (ret) | |
1437 | return NULL; | |
1438 | ||
1439 | return bitmap; | |
1440 | } | |
1441 | EXPORT_SYMBOL_GPL(devm_bitmap_alloc); | |
1442 | ||
1443 | unsigned long *devm_bitmap_zalloc(struct device *dev, | |
1444 | unsigned int nbits, gfp_t flags) | |
1445 | { | |
1446 | return devm_bitmap_alloc(dev, nbits, flags | __GFP_ZERO); | |
1447 | } | |
1448 | EXPORT_SYMBOL_GPL(devm_bitmap_zalloc); | |
1449 | ||
1450 | #if BITS_PER_LONG == 64 | |
1451 | /** | |
1452 | * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap | |
1453 | * @bitmap: array of unsigned longs, the destination bitmap | |
1454 | * @buf: array of u32 (in host byte order), the source bitmap | |
1455 | * @nbits: number of bits in @bitmap | |
1456 | */ | |
1457 | void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits) | |
1458 | { | |
1459 | unsigned int i, halfwords; | |
1460 | ||
1461 | halfwords = DIV_ROUND_UP(nbits, 32); | |
1462 | for (i = 0; i < halfwords; i++) { | |
1463 | bitmap[i/2] = (unsigned long) buf[i]; | |
1464 | if (++i < halfwords) | |
1465 | bitmap[i/2] |= ((unsigned long) buf[i]) << 32; | |
1466 | } | |
1467 | ||
1468 | /* Clear tail bits in last word beyond nbits. */ | |
1469 | if (nbits % BITS_PER_LONG) | |
1470 | bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits); | |
1471 | } | |
1472 | EXPORT_SYMBOL(bitmap_from_arr32); | |
1473 | ||
1474 | /** | |
1475 | * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits | |
1476 | * @buf: array of u32 (in host byte order), the dest bitmap | |
1477 | * @bitmap: array of unsigned longs, the source bitmap | |
1478 | * @nbits: number of bits in @bitmap | |
1479 | */ | |
1480 | void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits) | |
1481 | { | |
1482 | unsigned int i, halfwords; | |
1483 | ||
1484 | halfwords = DIV_ROUND_UP(nbits, 32); | |
1485 | for (i = 0; i < halfwords; i++) { | |
1486 | buf[i] = (u32) (bitmap[i/2] & UINT_MAX); | |
1487 | if (++i < halfwords) | |
1488 | buf[i] = (u32) (bitmap[i/2] >> 32); | |
1489 | } | |
1490 | ||
1491 | /* Clear tail bits in last element of array beyond nbits. */ | |
1492 | if (nbits % BITS_PER_LONG) | |
1493 | buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31)); | |
1494 | } | |
1495 | EXPORT_SYMBOL(bitmap_to_arr32); | |
1496 | #endif | |
1497 | ||
1498 | #if BITS_PER_LONG == 32 | |
1499 | /** | |
1500 | * bitmap_from_arr64 - copy the contents of u64 array of bits to bitmap | |
1501 | * @bitmap: array of unsigned longs, the destination bitmap | |
1502 | * @buf: array of u64 (in host byte order), the source bitmap | |
1503 | * @nbits: number of bits in @bitmap | |
1504 | */ | |
1505 | void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits) | |
1506 | { | |
1507 | int n; | |
1508 | ||
1509 | for (n = nbits; n > 0; n -= 64) { | |
1510 | u64 val = *buf++; | |
1511 | ||
1512 | *bitmap++ = val; | |
1513 | if (n > 32) | |
1514 | *bitmap++ = val >> 32; | |
1515 | } | |
1516 | ||
1517 | /* | |
1518 | * Clear tail bits in the last word beyond nbits. | |
1519 | * | |
1520 | * Negative index is OK because here we point to the word next | |
1521 | * to the last word of the bitmap, except for nbits == 0, which | |
1522 | * is tested implicitly. | |
1523 | */ | |
1524 | if (nbits % BITS_PER_LONG) | |
1525 | bitmap[-1] &= BITMAP_LAST_WORD_MASK(nbits); | |
1526 | } | |
1527 | EXPORT_SYMBOL(bitmap_from_arr64); | |
1528 | ||
1529 | /** | |
1530 | * bitmap_to_arr64 - copy the contents of bitmap to a u64 array of bits | |
1531 | * @buf: array of u64 (in host byte order), the dest bitmap | |
1532 | * @bitmap: array of unsigned longs, the source bitmap | |
1533 | * @nbits: number of bits in @bitmap | |
1534 | */ | |
1535 | void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits) | |
1536 | { | |
1537 | const unsigned long *end = bitmap + BITS_TO_LONGS(nbits); | |
1538 | ||
1539 | while (bitmap < end) { | |
1540 | *buf = *bitmap++; | |
1541 | if (bitmap < end) | |
1542 | *buf |= (u64)(*bitmap++) << 32; | |
1543 | buf++; | |
1544 | } | |
1545 | ||
1546 | /* Clear tail bits in the last element of array beyond nbits. */ | |
1547 | if (nbits % 64) | |
1548 | buf[-1] &= GENMASK_ULL((nbits - 1) % 64, 0); | |
1549 | } | |
1550 | EXPORT_SYMBOL(bitmap_to_arr64); | |
1551 | #endif |