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 unsigned int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) 337 { 338 unsigned int k, lim = bits/BITS_PER_LONG, w = 0; 339 340 for (k = 0; k < lim; k++) 341 w += hweight_long(bitmap[k]); 342 343 if (bits % BITS_PER_LONG) 344 w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); 345 346 return w; 347 } 348 EXPORT_SYMBOL(__bitmap_weight); 349 350 void __bitmap_set(unsigned long *map, unsigned int start, int len) 351 { 352 unsigned long *p = map + BIT_WORD(start); 353 const unsigned int size = start + len; 354 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); 355 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); 356 357 while (len - bits_to_set >= 0) { 358 *p |= mask_to_set; 359 len -= bits_to_set; 360 bits_to_set = BITS_PER_LONG; 361 mask_to_set = ~0UL; 362 p++; 363 } 364 if (len) { 365 mask_to_set &= BITMAP_LAST_WORD_MASK(size); 366 *p |= mask_to_set; 367 } 368 } 369 EXPORT_SYMBOL(__bitmap_set); 370 371 void __bitmap_clear(unsigned long *map, unsigned int start, int len) 372 { 373 unsigned long *p = map + BIT_WORD(start); 374 const unsigned int size = start + len; 375 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); 376 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); 377 378 while (len - bits_to_clear >= 0) { 379 *p &= ~mask_to_clear; 380 len -= bits_to_clear; 381 bits_to_clear = BITS_PER_LONG; 382 mask_to_clear = ~0UL; 383 p++; 384 } 385 if (len) { 386 mask_to_clear &= BITMAP_LAST_WORD_MASK(size); 387 *p &= ~mask_to_clear; 388 } 389 } 390 EXPORT_SYMBOL(__bitmap_clear); 391 392 /** 393 * bitmap_find_next_zero_area_off - find a contiguous aligned zero area 394 * @map: The address to base the search on 395 * @size: The bitmap size in bits 396 * @start: The bitnumber to start searching at 397 * @nr: The number of zeroed bits we're looking for 398 * @align_mask: Alignment mask for zero area 399 * @align_offset: Alignment offset for zero area. 400 * 401 * The @align_mask should be one less than a power of 2; the effect is that 402 * the bit offset of all zero areas this function finds plus @align_offset 403 * is multiple of that power of 2. 404 */ 405 unsigned long bitmap_find_next_zero_area_off(unsigned long *map, 406 unsigned long size, 407 unsigned long start, 408 unsigned int nr, 409 unsigned long align_mask, 410 unsigned long align_offset) 411 { 412 unsigned long index, end, i; 413 again: 414 index = find_next_zero_bit(map, size, start); 415 416 /* Align allocation */ 417 index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; 418 419 end = index + nr; 420 if (end > size) 421 return end; 422 i = find_next_bit(map, end, index); 423 if (i < end) { 424 start = i + 1; 425 goto again; 426 } 427 return index; 428 } 429 EXPORT_SYMBOL(bitmap_find_next_zero_area_off); 430 431 /* 432 * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, 433 * second version by Paul Jackson, third by Joe Korty. 434 */ 435 436 /** 437 * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap 438 * 439 * @ubuf: pointer to user buffer containing string. 440 * @ulen: buffer size in bytes. If string is smaller than this 441 * then it must be terminated with a \0. 442 * @maskp: pointer to bitmap array that will contain result. 443 * @nmaskbits: size of bitmap, in bits. 444 */ 445 int bitmap_parse_user(const char __user *ubuf, 446 unsigned int ulen, unsigned long *maskp, 447 int nmaskbits) 448 { 449 char *buf; 450 int ret; 451 452 buf = memdup_user_nul(ubuf, ulen); 453 if (IS_ERR(buf)) 454 return PTR_ERR(buf); 455 456 ret = bitmap_parse(buf, UINT_MAX, maskp, nmaskbits); 457 458 kfree(buf); 459 return ret; 460 } 461 EXPORT_SYMBOL(bitmap_parse_user); 462 463 /** 464 * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string 465 * @list: indicates whether the bitmap must be list 466 * @buf: page aligned buffer into which string is placed 467 * @maskp: pointer to bitmap to convert 468 * @nmaskbits: size of bitmap, in bits 469 * 470 * Output format is a comma-separated list of decimal numbers and 471 * ranges if list is specified or hex digits grouped into comma-separated 472 * sets of 8 digits/set. Returns the number of characters written to buf. 473 * 474 * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned 475 * area and that sufficient storage remains at @buf to accommodate the 476 * bitmap_print_to_pagebuf() output. Returns the number of characters 477 * actually printed to @buf, excluding terminating '\0'. 478 */ 479 int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, 480 int nmaskbits) 481 { 482 ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); 483 484 return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : 485 scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); 486 } 487 EXPORT_SYMBOL(bitmap_print_to_pagebuf); 488 489 /** 490 * bitmap_print_to_buf - convert bitmap to list or hex format ASCII string 491 * @list: indicates whether the bitmap must be list 492 * true: print in decimal list format 493 * false: print in hexadecimal bitmask format 494 * @buf: buffer into which string is placed 495 * @maskp: pointer to bitmap to convert 496 * @nmaskbits: size of bitmap, in bits 497 * @off: in the string from which we are copying, We copy to @buf 498 * @count: the maximum number of bytes to print 499 */ 500 static int bitmap_print_to_buf(bool list, char *buf, const unsigned long *maskp, 501 int nmaskbits, loff_t off, size_t count) 502 { 503 const char *fmt = list ? "%*pbl\n" : "%*pb\n"; 504 ssize_t size; 505 void *data; 506 507 data = kasprintf(GFP_KERNEL, fmt, nmaskbits, maskp); 508 if (!data) 509 return -ENOMEM; 510 511 size = memory_read_from_buffer(buf, count, &off, data, strlen(data) + 1); 512 kfree(data); 513 514 return size; 515 } 516 517 /** 518 * bitmap_print_bitmask_to_buf - convert bitmap to hex bitmask format ASCII string 519 * @buf: buffer into which string is placed 520 * @maskp: pointer to bitmap to convert 521 * @nmaskbits: size of bitmap, in bits 522 * @off: in the string from which we are copying, We copy to @buf 523 * @count: the maximum number of bytes to print 524 * 525 * The bitmap_print_to_pagebuf() is used indirectly via its cpumap wrapper 526 * cpumap_print_to_pagebuf() or directly by drivers to export hexadecimal 527 * bitmask and decimal list to userspace by sysfs ABI. 528 * Drivers might be using a normal attribute for this kind of ABIs. A 529 * normal attribute typically has show entry as below:: 530 * 531 * static ssize_t example_attribute_show(struct device *dev, 532 * struct device_attribute *attr, char *buf) 533 * { 534 * ... 535 * return bitmap_print_to_pagebuf(true, buf, &mask, nr_trig_max); 536 * } 537 * 538 * show entry of attribute has no offset and count parameters and this 539 * means the file is limited to one page only. 540 * bitmap_print_to_pagebuf() API works terribly well for this kind of 541 * normal attribute with buf parameter and without offset, count:: 542 * 543 * bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, 544 * int nmaskbits) 545 * { 546 * } 547 * 548 * The problem is once we have a large bitmap, we have a chance to get a 549 * bitmask or list more than one page. Especially for list, it could be 550 * as complex as 0,3,5,7,9,... We have no simple way to know it exact size. 551 * It turns out bin_attribute is a way to break this limit. bin_attribute 552 * has show entry as below:: 553 * 554 * static ssize_t 555 * example_bin_attribute_show(struct file *filp, struct kobject *kobj, 556 * struct bin_attribute *attr, char *buf, 557 * loff_t offset, size_t count) 558 * { 559 * ... 560 * } 561 * 562 * With the new offset and count parameters, this makes sysfs ABI be able 563 * to support file size more than one page. For example, offset could be 564 * >= 4096. 565 * bitmap_print_bitmask_to_buf(), bitmap_print_list_to_buf() wit their 566 * cpumap wrapper cpumap_print_bitmask_to_buf(), cpumap_print_list_to_buf() 567 * make those drivers be able to support large bitmask and list after they 568 * move to use bin_attribute. In result, we have to pass the corresponding 569 * parameters such as off, count from bin_attribute show entry to this API. 570 * 571 * The role of cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf() 572 * is similar with cpumap_print_to_pagebuf(), the difference is that 573 * bitmap_print_to_pagebuf() mainly serves sysfs attribute with the assumption 574 * the destination buffer is exactly one page and won't be more than one page. 575 * cpumap_print_bitmask_to_buf() and cpumap_print_list_to_buf(), on the other 576 * hand, mainly serves bin_attribute which doesn't work with exact one page, 577 * and it can break the size limit of converted decimal list and hexadecimal 578 * bitmask. 579 * 580 * WARNING! 581 * 582 * This function is not a replacement for sprintf() or bitmap_print_to_pagebuf(). 583 * It is intended to workaround sysfs limitations discussed above and should be 584 * used carefully in general case for the following reasons: 585 * 586 * - Time complexity is O(nbits^2/count), comparing to O(nbits) for snprintf(). 587 * - Memory complexity is O(nbits), comparing to O(1) for snprintf(). 588 * - @off and @count are NOT offset and number of bits to print. 589 * - If printing part of bitmap as list, the resulting string is not a correct 590 * list representation of bitmap. Particularly, some bits within or out of 591 * related interval may be erroneously set or unset. The format of the string 592 * may be broken, so bitmap_parselist-like parser may fail parsing it. 593 * - If printing the whole bitmap as list by parts, user must ensure the order 594 * of calls of the function such that the offset is incremented linearly. 595 * - If printing the whole bitmap as list by parts, user must keep bitmap 596 * unchanged between the very first and very last call. Otherwise concatenated 597 * result may be incorrect, and format may be broken. 598 * 599 * Returns the number of characters actually printed to @buf 600 */ 601 int bitmap_print_bitmask_to_buf(char *buf, const unsigned long *maskp, 602 int nmaskbits, loff_t off, size_t count) 603 { 604 return bitmap_print_to_buf(false, buf, maskp, nmaskbits, off, count); 605 } 606 EXPORT_SYMBOL(bitmap_print_bitmask_to_buf); 607 608 /** 609 * bitmap_print_list_to_buf - convert bitmap to decimal list format ASCII string 610 * @buf: buffer into which string is placed 611 * @maskp: pointer to bitmap to convert 612 * @nmaskbits: size of bitmap, in bits 613 * @off: in the string from which we are copying, We copy to @buf 614 * @count: the maximum number of bytes to print 615 * 616 * Everything is same with the above bitmap_print_bitmask_to_buf() except 617 * the print format. 618 */ 619 int bitmap_print_list_to_buf(char *buf, const unsigned long *maskp, 620 int nmaskbits, loff_t off, size_t count) 621 { 622 return bitmap_print_to_buf(true, buf, maskp, nmaskbits, off, count); 623 } 624 EXPORT_SYMBOL(bitmap_print_list_to_buf); 625 626 /* 627 * Region 9-38:4/10 describes the following bitmap structure: 628 * 0 9 12 18 38 N 629 * .........****......****......****.................. 630 * ^ ^ ^ ^ ^ 631 * start off group_len end nbits 632 */ 633 struct region { 634 unsigned int start; 635 unsigned int off; 636 unsigned int group_len; 637 unsigned int end; 638 unsigned int nbits; 639 }; 640 641 static void bitmap_set_region(const struct region *r, unsigned long *bitmap) 642 { 643 unsigned int start; 644 645 for (start = r->start; start <= r->end; start += r->group_len) 646 bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); 647 } 648 649 static int bitmap_check_region(const struct region *r) 650 { 651 if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) 652 return -EINVAL; 653 654 if (r->end >= r->nbits) 655 return -ERANGE; 656 657 return 0; 658 } 659 660 static const char *bitmap_getnum(const char *str, unsigned int *num, 661 unsigned int lastbit) 662 { 663 unsigned long long n; 664 unsigned int len; 665 666 if (str[0] == 'N') { 667 *num = lastbit; 668 return str + 1; 669 } 670 671 len = _parse_integer(str, 10, &n); 672 if (!len) 673 return ERR_PTR(-EINVAL); 674 if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n) 675 return ERR_PTR(-EOVERFLOW); 676 677 *num = n; 678 return str + len; 679 } 680 681 static inline bool end_of_str(char c) 682 { 683 return c == '\0' || c == '\n'; 684 } 685 686 static inline bool __end_of_region(char c) 687 { 688 return isspace(c) || c == ','; 689 } 690 691 static inline bool end_of_region(char c) 692 { 693 return __end_of_region(c) || end_of_str(c); 694 } 695 696 /* 697 * The format allows commas and whitespaces at the beginning 698 * of the region. 699 */ 700 static const char *bitmap_find_region(const char *str) 701 { 702 while (__end_of_region(*str)) 703 str++; 704 705 return end_of_str(*str) ? NULL : str; 706 } 707 708 static const char *bitmap_find_region_reverse(const char *start, const char *end) 709 { 710 while (start <= end && __end_of_region(*end)) 711 end--; 712 713 return end; 714 } 715 716 static const char *bitmap_parse_region(const char *str, struct region *r) 717 { 718 unsigned int lastbit = r->nbits - 1; 719 720 if (!strncasecmp(str, "all", 3)) { 721 r->start = 0; 722 r->end = lastbit; 723 str += 3; 724 725 goto check_pattern; 726 } 727 728 str = bitmap_getnum(str, &r->start, lastbit); 729 if (IS_ERR(str)) 730 return str; 731 732 if (end_of_region(*str)) 733 goto no_end; 734 735 if (*str != '-') 736 return ERR_PTR(-EINVAL); 737 738 str = bitmap_getnum(str + 1, &r->end, lastbit); 739 if (IS_ERR(str)) 740 return str; 741 742 check_pattern: 743 if (end_of_region(*str)) 744 goto no_pattern; 745 746 if (*str != ':') 747 return ERR_PTR(-EINVAL); 748 749 str = bitmap_getnum(str + 1, &r->off, lastbit); 750 if (IS_ERR(str)) 751 return str; 752 753 if (*str != '/') 754 return ERR_PTR(-EINVAL); 755 756 return bitmap_getnum(str + 1, &r->group_len, lastbit); 757 758 no_end: 759 r->end = r->start; 760 no_pattern: 761 r->off = r->end + 1; 762 r->group_len = r->end + 1; 763 764 return end_of_str(*str) ? NULL : str; 765 } 766 767 /** 768 * bitmap_parselist - convert list format ASCII string to bitmap 769 * @buf: read user string from this buffer; must be terminated 770 * with a \0 or \n. 771 * @maskp: write resulting mask here 772 * @nmaskbits: number of bits in mask to be written 773 * 774 * Input format is a comma-separated list of decimal numbers and 775 * ranges. Consecutively set bits are shown as two hyphen-separated 776 * decimal numbers, the smallest and largest bit numbers set in 777 * the range. 778 * Optionally each range can be postfixed to denote that only parts of it 779 * should be set. The range will divided to groups of specific size. 780 * From each group will be used only defined amount of bits. 781 * Syntax: range:used_size/group_size 782 * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 783 * The value 'N' can be used as a dynamically substituted token for the 784 * maximum allowed value; i.e (nmaskbits - 1). Keep in mind that it is 785 * dynamic, so if system changes cause the bitmap width to change, such 786 * as more cores in a CPU list, then any ranges using N will also change. 787 * 788 * Returns: 0 on success, -errno on invalid input strings. Error values: 789 * 790 * - ``-EINVAL``: wrong region format 791 * - ``-EINVAL``: invalid character in string 792 * - ``-ERANGE``: bit number specified too large for mask 793 * - ``-EOVERFLOW``: integer overflow in the input parameters 794 */ 795 int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) 796 { 797 struct region r; 798 long ret; 799 800 r.nbits = nmaskbits; 801 bitmap_zero(maskp, r.nbits); 802 803 while (buf) { 804 buf = bitmap_find_region(buf); 805 if (buf == NULL) 806 return 0; 807 808 buf = bitmap_parse_region(buf, &r); 809 if (IS_ERR(buf)) 810 return PTR_ERR(buf); 811 812 ret = bitmap_check_region(&r); 813 if (ret) 814 return ret; 815 816 bitmap_set_region(&r, maskp); 817 } 818 819 return 0; 820 } 821 EXPORT_SYMBOL(bitmap_parselist); 822 823 824 /** 825 * bitmap_parselist_user() - convert user buffer's list format ASCII 826 * string to bitmap 827 * 828 * @ubuf: pointer to user buffer containing string. 829 * @ulen: buffer size in bytes. If string is smaller than this 830 * then it must be terminated with a \0. 831 * @maskp: pointer to bitmap array that will contain result. 832 * @nmaskbits: size of bitmap, in bits. 833 * 834 * Wrapper for bitmap_parselist(), providing it with user buffer. 835 */ 836 int bitmap_parselist_user(const char __user *ubuf, 837 unsigned int ulen, unsigned long *maskp, 838 int nmaskbits) 839 { 840 char *buf; 841 int ret; 842 843 buf = memdup_user_nul(ubuf, ulen); 844 if (IS_ERR(buf)) 845 return PTR_ERR(buf); 846 847 ret = bitmap_parselist(buf, maskp, nmaskbits); 848 849 kfree(buf); 850 return ret; 851 } 852 EXPORT_SYMBOL(bitmap_parselist_user); 853 854 static const char *bitmap_get_x32_reverse(const char *start, 855 const char *end, u32 *num) 856 { 857 u32 ret = 0; 858 int c, i; 859 860 for (i = 0; i < 32; i += 4) { 861 c = hex_to_bin(*end--); 862 if (c < 0) 863 return ERR_PTR(-EINVAL); 864 865 ret |= c << i; 866 867 if (start > end || __end_of_region(*end)) 868 goto out; 869 } 870 871 if (hex_to_bin(*end--) >= 0) 872 return ERR_PTR(-EOVERFLOW); 873 out: 874 *num = ret; 875 return end; 876 } 877 878 /** 879 * bitmap_parse - convert an ASCII hex string into a bitmap. 880 * @start: pointer to buffer containing string. 881 * @buflen: buffer size in bytes. If string is smaller than this 882 * then it must be terminated with a \0 or \n. In that case, 883 * UINT_MAX may be provided instead of string length. 884 * @maskp: pointer to bitmap array that will contain result. 885 * @nmaskbits: size of bitmap, in bits. 886 * 887 * Commas group hex digits into chunks. Each chunk defines exactly 32 888 * bits of the resultant bitmask. No chunk may specify a value larger 889 * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value 890 * then leading 0-bits are prepended. %-EINVAL is returned for illegal 891 * characters. Grouping such as "1,,5", ",44", "," or "" is allowed. 892 * Leading, embedded and trailing whitespace accepted. 893 */ 894 int bitmap_parse(const char *start, unsigned int buflen, 895 unsigned long *maskp, int nmaskbits) 896 { 897 const char *end = strnchrnul(start, buflen, '\n') - 1; 898 int chunks = BITS_TO_U32(nmaskbits); 899 u32 *bitmap = (u32 *)maskp; 900 int unset_bit; 901 int chunk; 902 903 for (chunk = 0; ; chunk++) { 904 end = bitmap_find_region_reverse(start, end); 905 if (start > end) 906 break; 907 908 if (!chunks--) 909 return -EOVERFLOW; 910 911 #if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN) 912 end = bitmap_get_x32_reverse(start, end, &bitmap[chunk ^ 1]); 913 #else 914 end = bitmap_get_x32_reverse(start, end, &bitmap[chunk]); 915 #endif 916 if (IS_ERR(end)) 917 return PTR_ERR(end); 918 } 919 920 unset_bit = (BITS_TO_U32(nmaskbits) - chunks) * 32; 921 if (unset_bit < nmaskbits) { 922 bitmap_clear(maskp, unset_bit, nmaskbits - unset_bit); 923 return 0; 924 } 925 926 if (find_next_bit(maskp, unset_bit, nmaskbits) != unset_bit) 927 return -EOVERFLOW; 928 929 return 0; 930 } 931 EXPORT_SYMBOL(bitmap_parse); 932 933 /** 934 * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap 935 * @buf: pointer to a bitmap 936 * @pos: a bit position in @buf (0 <= @pos < @nbits) 937 * @nbits: number of valid bit positions in @buf 938 * 939 * Map the bit at position @pos in @buf (of length @nbits) to the 940 * ordinal of which set bit it is. If it is not set or if @pos 941 * is not a valid bit position, map to -1. 942 * 943 * If for example, just bits 4 through 7 are set in @buf, then @pos 944 * values 4 through 7 will get mapped to 0 through 3, respectively, 945 * and other @pos values will get mapped to -1. When @pos value 7 946 * gets mapped to (returns) @ord value 3 in this example, that means 947 * that bit 7 is the 3rd (starting with 0th) set bit in @buf. 948 * 949 * The bit positions 0 through @bits are valid positions in @buf. 950 */ 951 static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) 952 { 953 if (pos >= nbits || !test_bit(pos, buf)) 954 return -1; 955 956 return __bitmap_weight(buf, pos); 957 } 958 959 /** 960 * bitmap_ord_to_pos - find position of n-th set bit in bitmap 961 * @buf: pointer to bitmap 962 * @ord: ordinal bit position (n-th set bit, n >= 0) 963 * @nbits: number of valid bit positions in @buf 964 * 965 * Map the ordinal offset of bit @ord in @buf to its position in @buf. 966 * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord 967 * >= weight(buf), returns @nbits. 968 * 969 * If for example, just bits 4 through 7 are set in @buf, then @ord 970 * values 0 through 3 will get mapped to 4 through 7, respectively, 971 * and all other @ord values returns @nbits. When @ord value 3 972 * gets mapped to (returns) @pos value 7 in this example, that means 973 * that the 3rd set bit (starting with 0th) is at position 7 in @buf. 974 * 975 * The bit positions 0 through @nbits-1 are valid positions in @buf. 976 */ 977 unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) 978 { 979 unsigned int pos; 980 981 for (pos = find_first_bit(buf, nbits); 982 pos < nbits && ord; 983 pos = find_next_bit(buf, nbits, pos + 1)) 984 ord--; 985 986 return pos; 987 } 988 989 /** 990 * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap 991 * @dst: remapped result 992 * @src: subset to be remapped 993 * @old: defines domain of map 994 * @new: defines range of map 995 * @nbits: number of bits in each of these bitmaps 996 * 997 * Let @old and @new define a mapping of bit positions, such that 998 * whatever position is held by the n-th set bit in @old is mapped 999 * to the n-th set bit in @new. In the more general case, allowing 1000 * for the possibility that the weight 'w' of @new is less than the 1001 * weight of @old, map the position of the n-th set bit in @old to 1002 * the position of the m-th set bit in @new, where m == n % w. 1003 * 1004 * If either of the @old and @new bitmaps are empty, or if @src and 1005 * @dst point to the same location, then this routine copies @src 1006 * to @dst. 1007 * 1008 * The positions of unset bits in @old are mapped to themselves 1009 * (the identify map). 1010 * 1011 * Apply the above specified mapping to @src, placing the result in 1012 * @dst, clearing any bits previously set in @dst. 1013 * 1014 * For example, lets say that @old has bits 4 through 7 set, and 1015 * @new has bits 12 through 15 set. This defines the mapping of bit 1016 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other 1017 * bit positions unchanged. So if say @src comes into this routine 1018 * with bits 1, 5 and 7 set, then @dst should leave with bits 1, 1019 * 13 and 15 set. 1020 */ 1021 void bitmap_remap(unsigned long *dst, const unsigned long *src, 1022 const unsigned long *old, const unsigned long *new, 1023 unsigned int nbits) 1024 { 1025 unsigned int oldbit, w; 1026 1027 if (dst == src) /* following doesn't handle inplace remaps */ 1028 return; 1029 bitmap_zero(dst, nbits); 1030 1031 w = bitmap_weight(new, nbits); 1032 for_each_set_bit(oldbit, src, nbits) { 1033 int n = bitmap_pos_to_ord(old, oldbit, nbits); 1034 1035 if (n < 0 || w == 0) 1036 set_bit(oldbit, dst); /* identity map */ 1037 else 1038 set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); 1039 } 1040 } 1041 EXPORT_SYMBOL(bitmap_remap); 1042 1043 /** 1044 * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit 1045 * @oldbit: bit position to be mapped 1046 * @old: defines domain of map 1047 * @new: defines range of map 1048 * @bits: number of bits in each of these bitmaps 1049 * 1050 * Let @old and @new define a mapping of bit positions, such that 1051 * whatever position is held by the n-th set bit in @old is mapped 1052 * to the n-th set bit in @new. In the more general case, allowing 1053 * for the possibility that the weight 'w' of @new is less than the 1054 * weight of @old, map the position of the n-th set bit in @old to 1055 * the position of the m-th set bit in @new, where m == n % w. 1056 * 1057 * The positions of unset bits in @old are mapped to themselves 1058 * (the identify map). 1059 * 1060 * Apply the above specified mapping to bit position @oldbit, returning 1061 * the new bit position. 1062 * 1063 * For example, lets say that @old has bits 4 through 7 set, and 1064 * @new has bits 12 through 15 set. This defines the mapping of bit 1065 * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other 1066 * bit positions unchanged. So if say @oldbit is 5, then this routine 1067 * returns 13. 1068 */ 1069 int bitmap_bitremap(int oldbit, const unsigned long *old, 1070 const unsigned long *new, int bits) 1071 { 1072 int w = bitmap_weight(new, bits); 1073 int n = bitmap_pos_to_ord(old, oldbit, bits); 1074 if (n < 0 || w == 0) 1075 return oldbit; 1076 else 1077 return bitmap_ord_to_pos(new, n % w, bits); 1078 } 1079 EXPORT_SYMBOL(bitmap_bitremap); 1080 1081 #ifdef CONFIG_NUMA 1082 /** 1083 * bitmap_onto - translate one bitmap relative to another 1084 * @dst: resulting translated bitmap 1085 * @orig: original untranslated bitmap 1086 * @relmap: bitmap relative to which translated 1087 * @bits: number of bits in each of these bitmaps 1088 * 1089 * Set the n-th bit of @dst iff there exists some m such that the 1090 * n-th bit of @relmap is set, the m-th bit of @orig is set, and 1091 * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. 1092 * (If you understood the previous sentence the first time your 1093 * read it, you're overqualified for your current job.) 1094 * 1095 * In other words, @orig is mapped onto (surjectively) @dst, 1096 * using the map { <n, m> | the n-th bit of @relmap is the 1097 * m-th set bit of @relmap }. 1098 * 1099 * Any set bits in @orig above bit number W, where W is the 1100 * weight of (number of set bits in) @relmap are mapped nowhere. 1101 * In particular, if for all bits m set in @orig, m >= W, then 1102 * @dst will end up empty. In situations where the possibility 1103 * of such an empty result is not desired, one way to avoid it is 1104 * to use the bitmap_fold() operator, below, to first fold the 1105 * @orig bitmap over itself so that all its set bits x are in the 1106 * range 0 <= x < W. The bitmap_fold() operator does this by 1107 * setting the bit (m % W) in @dst, for each bit (m) set in @orig. 1108 * 1109 * Example [1] for bitmap_onto(): 1110 * Let's say @relmap has bits 30-39 set, and @orig has bits 1111 * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, 1112 * @dst will have bits 31, 33, 35, 37 and 39 set. 1113 * 1114 * When bit 0 is set in @orig, it means turn on the bit in 1115 * @dst corresponding to whatever is the first bit (if any) 1116 * that is turned on in @relmap. Since bit 0 was off in the 1117 * above example, we leave off that bit (bit 30) in @dst. 1118 * 1119 * When bit 1 is set in @orig (as in the above example), it 1120 * means turn on the bit in @dst corresponding to whatever 1121 * is the second bit that is turned on in @relmap. The second 1122 * bit in @relmap that was turned on in the above example was 1123 * bit 31, so we turned on bit 31 in @dst. 1124 * 1125 * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, 1126 * because they were the 4th, 6th, 8th and 10th set bits 1127 * set in @relmap, and the 4th, 6th, 8th and 10th bits of 1128 * @orig (i.e. bits 3, 5, 7 and 9) were also set. 1129 * 1130 * When bit 11 is set in @orig, it means turn on the bit in 1131 * @dst corresponding to whatever is the twelfth bit that is 1132 * turned on in @relmap. In the above example, there were 1133 * only ten bits turned on in @relmap (30..39), so that bit 1134 * 11 was set in @orig had no affect on @dst. 1135 * 1136 * Example [2] for bitmap_fold() + bitmap_onto(): 1137 * Let's say @relmap has these ten bits set:: 1138 * 1139 * 40 41 42 43 45 48 53 61 74 95 1140 * 1141 * (for the curious, that's 40 plus the first ten terms of the 1142 * Fibonacci sequence.) 1143 * 1144 * Further lets say we use the following code, invoking 1145 * bitmap_fold() then bitmap_onto, as suggested above to 1146 * avoid the possibility of an empty @dst result:: 1147 * 1148 * unsigned long *tmp; // a temporary bitmap's bits 1149 * 1150 * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); 1151 * bitmap_onto(dst, tmp, relmap, bits); 1152 * 1153 * Then this table shows what various values of @dst would be, for 1154 * various @orig's. I list the zero-based positions of each set bit. 1155 * The tmp column shows the intermediate result, as computed by 1156 * using bitmap_fold() to fold the @orig bitmap modulo ten 1157 * (the weight of @relmap): 1158 * 1159 * =============== ============== ================= 1160 * @orig tmp @dst 1161 * 0 0 40 1162 * 1 1 41 1163 * 9 9 95 1164 * 10 0 40 [#f1]_ 1165 * 1 3 5 7 1 3 5 7 41 43 48 61 1166 * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 1167 * 0 9 18 27 0 9 8 7 40 61 74 95 1168 * 0 10 20 30 0 40 1169 * 0 11 22 33 0 1 2 3 40 41 42 43 1170 * 0 12 24 36 0 2 4 6 40 42 45 53 1171 * 78 102 211 1 2 8 41 42 74 [#f1]_ 1172 * =============== ============== ================= 1173 * 1174 * .. [#f1] 1175 * 1176 * For these marked lines, if we hadn't first done bitmap_fold() 1177 * into tmp, then the @dst result would have been empty. 1178 * 1179 * If either of @orig or @relmap is empty (no set bits), then @dst 1180 * will be returned empty. 1181 * 1182 * If (as explained above) the only set bits in @orig are in positions 1183 * m where m >= W, (where W is the weight of @relmap) then @dst will 1184 * once again be returned empty. 1185 * 1186 * All bits in @dst not set by the above rule are cleared. 1187 */ 1188 void bitmap_onto(unsigned long *dst, const unsigned long *orig, 1189 const unsigned long *relmap, unsigned int bits) 1190 { 1191 unsigned int n, m; /* same meaning as in above comment */ 1192 1193 if (dst == orig) /* following doesn't handle inplace mappings */ 1194 return; 1195 bitmap_zero(dst, bits); 1196 1197 /* 1198 * The following code is a more efficient, but less 1199 * obvious, equivalent to the loop: 1200 * for (m = 0; m < bitmap_weight(relmap, bits); m++) { 1201 * n = bitmap_ord_to_pos(orig, m, bits); 1202 * if (test_bit(m, orig)) 1203 * set_bit(n, dst); 1204 * } 1205 */ 1206 1207 m = 0; 1208 for_each_set_bit(n, relmap, bits) { 1209 /* m == bitmap_pos_to_ord(relmap, n, bits) */ 1210 if (test_bit(m, orig)) 1211 set_bit(n, dst); 1212 m++; 1213 } 1214 } 1215 1216 /** 1217 * bitmap_fold - fold larger bitmap into smaller, modulo specified size 1218 * @dst: resulting smaller bitmap 1219 * @orig: original larger bitmap 1220 * @sz: specified size 1221 * @nbits: number of bits in each of these bitmaps 1222 * 1223 * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. 1224 * Clear all other bits in @dst. See further the comment and 1225 * Example [2] for bitmap_onto() for why and how to use this. 1226 */ 1227 void bitmap_fold(unsigned long *dst, const unsigned long *orig, 1228 unsigned int sz, unsigned int nbits) 1229 { 1230 unsigned int oldbit; 1231 1232 if (dst == orig) /* following doesn't handle inplace mappings */ 1233 return; 1234 bitmap_zero(dst, nbits); 1235 1236 for_each_set_bit(oldbit, orig, nbits) 1237 set_bit(oldbit % sz, dst); 1238 } 1239 #endif /* CONFIG_NUMA */ 1240 1241 /* 1242 * Common code for bitmap_*_region() routines. 1243 * bitmap: array of unsigned longs corresponding to the bitmap 1244 * pos: the beginning of the region 1245 * order: region size (log base 2 of number of bits) 1246 * reg_op: operation(s) to perform on that region of bitmap 1247 * 1248 * Can set, verify and/or release a region of bits in a bitmap, 1249 * depending on which combination of REG_OP_* flag bits is set. 1250 * 1251 * A region of a bitmap is a sequence of bits in the bitmap, of 1252 * some size '1 << order' (a power of two), aligned to that same 1253 * '1 << order' power of two. 1254 * 1255 * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). 1256 * Returns 0 in all other cases and reg_ops. 1257 */ 1258 1259 enum { 1260 REG_OP_ISFREE, /* true if region is all zero bits */ 1261 REG_OP_ALLOC, /* set all bits in region */ 1262 REG_OP_RELEASE, /* clear all bits in region */ 1263 }; 1264 1265 static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) 1266 { 1267 int nbits_reg; /* number of bits in region */ 1268 int index; /* index first long of region in bitmap */ 1269 int offset; /* bit offset region in bitmap[index] */ 1270 int nlongs_reg; /* num longs spanned by region in bitmap */ 1271 int nbitsinlong; /* num bits of region in each spanned long */ 1272 unsigned long mask; /* bitmask for one long of region */ 1273 int i; /* scans bitmap by longs */ 1274 int ret = 0; /* return value */ 1275 1276 /* 1277 * Either nlongs_reg == 1 (for small orders that fit in one long) 1278 * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) 1279 */ 1280 nbits_reg = 1 << order; 1281 index = pos / BITS_PER_LONG; 1282 offset = pos - (index * BITS_PER_LONG); 1283 nlongs_reg = BITS_TO_LONGS(nbits_reg); 1284 nbitsinlong = min(nbits_reg, BITS_PER_LONG); 1285 1286 /* 1287 * Can't do "mask = (1UL << nbitsinlong) - 1", as that 1288 * overflows if nbitsinlong == BITS_PER_LONG. 1289 */ 1290 mask = (1UL << (nbitsinlong - 1)); 1291 mask += mask - 1; 1292 mask <<= offset; 1293 1294 switch (reg_op) { 1295 case REG_OP_ISFREE: 1296 for (i = 0; i < nlongs_reg; i++) { 1297 if (bitmap[index + i] & mask) 1298 goto done; 1299 } 1300 ret = 1; /* all bits in region free (zero) */ 1301 break; 1302 1303 case REG_OP_ALLOC: 1304 for (i = 0; i < nlongs_reg; i++) 1305 bitmap[index + i] |= mask; 1306 break; 1307 1308 case REG_OP_RELEASE: 1309 for (i = 0; i < nlongs_reg; i++) 1310 bitmap[index + i] &= ~mask; 1311 break; 1312 } 1313 done: 1314 return ret; 1315 } 1316 1317 /** 1318 * bitmap_find_free_region - find a contiguous aligned mem region 1319 * @bitmap: array of unsigned longs corresponding to the bitmap 1320 * @bits: number of bits in the bitmap 1321 * @order: region size (log base 2 of number of bits) to find 1322 * 1323 * Find a region of free (zero) bits in a @bitmap of @bits bits and 1324 * allocate them (set them to one). Only consider regions of length 1325 * a power (@order) of two, aligned to that power of two, which 1326 * makes the search algorithm much faster. 1327 * 1328 * Return the bit offset in bitmap of the allocated region, 1329 * or -errno on failure. 1330 */ 1331 int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) 1332 { 1333 unsigned int pos, end; /* scans bitmap by regions of size order */ 1334 1335 for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { 1336 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) 1337 continue; 1338 __reg_op(bitmap, pos, order, REG_OP_ALLOC); 1339 return pos; 1340 } 1341 return -ENOMEM; 1342 } 1343 EXPORT_SYMBOL(bitmap_find_free_region); 1344 1345 /** 1346 * bitmap_release_region - release allocated bitmap region 1347 * @bitmap: array of unsigned longs corresponding to the bitmap 1348 * @pos: beginning of bit region to release 1349 * @order: region size (log base 2 of number of bits) to release 1350 * 1351 * This is the complement to __bitmap_find_free_region() and releases 1352 * the found region (by clearing it in the bitmap). 1353 * 1354 * No return value. 1355 */ 1356 void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) 1357 { 1358 __reg_op(bitmap, pos, order, REG_OP_RELEASE); 1359 } 1360 EXPORT_SYMBOL(bitmap_release_region); 1361 1362 /** 1363 * bitmap_allocate_region - allocate bitmap region 1364 * @bitmap: array of unsigned longs corresponding to the bitmap 1365 * @pos: beginning of bit region to allocate 1366 * @order: region size (log base 2 of number of bits) to allocate 1367 * 1368 * Allocate (set bits in) a specified region of a bitmap. 1369 * 1370 * Return 0 on success, or %-EBUSY if specified region wasn't 1371 * free (not all bits were zero). 1372 */ 1373 int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) 1374 { 1375 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) 1376 return -EBUSY; 1377 return __reg_op(bitmap, pos, order, REG_OP_ALLOC); 1378 } 1379 EXPORT_SYMBOL(bitmap_allocate_region); 1380 1381 /** 1382 * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. 1383 * @dst: destination buffer 1384 * @src: bitmap to copy 1385 * @nbits: number of bits in the bitmap 1386 * 1387 * Require nbits % BITS_PER_LONG == 0. 1388 */ 1389 #ifdef __BIG_ENDIAN 1390 void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) 1391 { 1392 unsigned int i; 1393 1394 for (i = 0; i < nbits/BITS_PER_LONG; i++) { 1395 if (BITS_PER_LONG == 64) 1396 dst[i] = cpu_to_le64(src[i]); 1397 else 1398 dst[i] = cpu_to_le32(src[i]); 1399 } 1400 } 1401 EXPORT_SYMBOL(bitmap_copy_le); 1402 #endif 1403 1404 unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) 1405 { 1406 return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), 1407 flags); 1408 } 1409 EXPORT_SYMBOL(bitmap_alloc); 1410 1411 unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags) 1412 { 1413 return bitmap_alloc(nbits, flags | __GFP_ZERO); 1414 } 1415 EXPORT_SYMBOL(bitmap_zalloc); 1416 1417 unsigned long *bitmap_alloc_node(unsigned int nbits, gfp_t flags, int node) 1418 { 1419 return kmalloc_array_node(BITS_TO_LONGS(nbits), sizeof(unsigned long), 1420 flags, node); 1421 } 1422 EXPORT_SYMBOL(bitmap_alloc_node); 1423 1424 unsigned long *bitmap_zalloc_node(unsigned int nbits, gfp_t flags, int node) 1425 { 1426 return bitmap_alloc_node(nbits, flags | __GFP_ZERO, node); 1427 } 1428 EXPORT_SYMBOL(bitmap_zalloc_node); 1429 1430 void bitmap_free(const unsigned long *bitmap) 1431 { 1432 kfree(bitmap); 1433 } 1434 EXPORT_SYMBOL(bitmap_free); 1435 1436 static void devm_bitmap_free(void *data) 1437 { 1438 unsigned long *bitmap = data; 1439 1440 bitmap_free(bitmap); 1441 } 1442 1443 unsigned long *devm_bitmap_alloc(struct device *dev, 1444 unsigned int nbits, gfp_t flags) 1445 { 1446 unsigned long *bitmap; 1447 int ret; 1448 1449 bitmap = bitmap_alloc(nbits, flags); 1450 if (!bitmap) 1451 return NULL; 1452 1453 ret = devm_add_action_or_reset(dev, devm_bitmap_free, bitmap); 1454 if (ret) 1455 return NULL; 1456 1457 return bitmap; 1458 } 1459 EXPORT_SYMBOL_GPL(devm_bitmap_alloc); 1460 1461 unsigned long *devm_bitmap_zalloc(struct device *dev, 1462 unsigned int nbits, gfp_t flags) 1463 { 1464 return devm_bitmap_alloc(dev, nbits, flags | __GFP_ZERO); 1465 } 1466 EXPORT_SYMBOL_GPL(devm_bitmap_zalloc); 1467 1468 #if BITS_PER_LONG == 64 1469 /** 1470 * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap 1471 * @bitmap: array of unsigned longs, the destination bitmap 1472 * @buf: array of u32 (in host byte order), the source bitmap 1473 * @nbits: number of bits in @bitmap 1474 */ 1475 void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits) 1476 { 1477 unsigned int i, halfwords; 1478 1479 halfwords = DIV_ROUND_UP(nbits, 32); 1480 for (i = 0; i < halfwords; i++) { 1481 bitmap[i/2] = (unsigned long) buf[i]; 1482 if (++i < halfwords) 1483 bitmap[i/2] |= ((unsigned long) buf[i]) << 32; 1484 } 1485 1486 /* Clear tail bits in last word beyond nbits. */ 1487 if (nbits % BITS_PER_LONG) 1488 bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits); 1489 } 1490 EXPORT_SYMBOL(bitmap_from_arr32); 1491 1492 /** 1493 * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits 1494 * @buf: array of u32 (in host byte order), the dest bitmap 1495 * @bitmap: array of unsigned longs, the source bitmap 1496 * @nbits: number of bits in @bitmap 1497 */ 1498 void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits) 1499 { 1500 unsigned int i, halfwords; 1501 1502 halfwords = DIV_ROUND_UP(nbits, 32); 1503 for (i = 0; i < halfwords; i++) { 1504 buf[i] = (u32) (bitmap[i/2] & UINT_MAX); 1505 if (++i < halfwords) 1506 buf[i] = (u32) (bitmap[i/2] >> 32); 1507 } 1508 1509 /* Clear tail bits in last element of array beyond nbits. */ 1510 if (nbits % BITS_PER_LONG) 1511 buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31)); 1512 } 1513 EXPORT_SYMBOL(bitmap_to_arr32); 1514 #endif 1515 1516 #if (BITS_PER_LONG == 32) && defined(__BIG_ENDIAN) 1517 /** 1518 * bitmap_from_arr64 - copy the contents of u64 array of bits to bitmap 1519 * @bitmap: array of unsigned longs, the destination bitmap 1520 * @buf: array of u64 (in host byte order), the source bitmap 1521 * @nbits: number of bits in @bitmap 1522 */ 1523 void bitmap_from_arr64(unsigned long *bitmap, const u64 *buf, unsigned int nbits) 1524 { 1525 int n; 1526 1527 for (n = nbits; n > 0; n -= 64) { 1528 u64 val = *buf++; 1529 1530 *bitmap++ = val; 1531 if (n > 32) 1532 *bitmap++ = val >> 32; 1533 } 1534 1535 /* 1536 * Clear tail bits in the last word beyond nbits. 1537 * 1538 * Negative index is OK because here we point to the word next 1539 * to the last word of the bitmap, except for nbits == 0, which 1540 * is tested implicitly. 1541 */ 1542 if (nbits % BITS_PER_LONG) 1543 bitmap[-1] &= BITMAP_LAST_WORD_MASK(nbits); 1544 } 1545 EXPORT_SYMBOL(bitmap_from_arr64); 1546 1547 /** 1548 * bitmap_to_arr64 - copy the contents of bitmap to a u64 array of bits 1549 * @buf: array of u64 (in host byte order), the dest bitmap 1550 * @bitmap: array of unsigned longs, the source bitmap 1551 * @nbits: number of bits in @bitmap 1552 */ 1553 void bitmap_to_arr64(u64 *buf, const unsigned long *bitmap, unsigned int nbits) 1554 { 1555 const unsigned long *end = bitmap + BITS_TO_LONGS(nbits); 1556 1557 while (bitmap < end) { 1558 *buf = *bitmap++; 1559 if (bitmap < end) 1560 *buf |= (u64)(*bitmap++) << 32; 1561 buf++; 1562 } 1563 1564 /* Clear tail bits in the last element of array beyond nbits. */ 1565 if (nbits % 64) 1566 buf[-1] &= GENMASK_ULL((nbits - 1) % 64, 0); 1567 } 1568 EXPORT_SYMBOL(bitmap_to_arr64); 1569 #endif 1570