bitops.h revision 300490
1/*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013-2015 Mellanox Technologies, Ltd. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice unmodified, this list of conditions, and the following 13 * disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * $FreeBSD: head/sys/compat/linuxkpi/common/include/linux/bitops.h 300490 2016-05-23 11:41:35Z hselasky $ 30 */ 31#ifndef _LINUX_BITOPS_H_ 32#define _LINUX_BITOPS_H_ 33 34#include <sys/types.h> 35#include <sys/systm.h> 36#include <sys/errno.h> 37 38#define BIT(nr) (1UL << (nr)) 39#ifdef __LP64__ 40#define BITS_PER_LONG 64 41#else 42#define BITS_PER_LONG 32 43#endif 44#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG)) 45#define BITMAP_LAST_WORD_MASK(n) (~0UL >> (BITS_PER_LONG - (n))) 46#define BITS_TO_LONGS(n) howmany((n), BITS_PER_LONG) 47#define BIT_MASK(nr) (1UL << ((nr) & (BITS_PER_LONG - 1))) 48#define BIT_WORD(nr) ((nr) / BITS_PER_LONG) 49#define GENMASK(h, l) (((~0UL) >> (BITS_PER_LONG - (h) - 1)) & ((~0UL) << (l))) 50#define BITS_PER_BYTE 8 51 52static inline int 53__ffs(int mask) 54{ 55 return (ffs(mask) - 1); 56} 57 58static inline int 59__fls(int mask) 60{ 61 return (fls(mask) - 1); 62} 63 64static inline int 65__ffsl(long mask) 66{ 67 return (ffsl(mask) - 1); 68} 69 70static inline int 71__flsl(long mask) 72{ 73 return (flsl(mask) - 1); 74} 75 76 77#define ffz(mask) __ffs(~(mask)) 78 79static inline int get_count_order(unsigned int count) 80{ 81 int order; 82 83 order = fls(count) - 1; 84 if (count & (count - 1)) 85 order++; 86 return order; 87} 88 89static inline unsigned long 90find_first_bit(unsigned long *addr, unsigned long size) 91{ 92 long mask; 93 int bit; 94 95 for (bit = 0; size >= BITS_PER_LONG; 96 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 97 if (*addr == 0) 98 continue; 99 return (bit + __ffsl(*addr)); 100 } 101 if (size) { 102 mask = (*addr) & BITMAP_LAST_WORD_MASK(size); 103 if (mask) 104 bit += __ffsl(mask); 105 else 106 bit += size; 107 } 108 return (bit); 109} 110 111static inline unsigned long 112find_first_zero_bit(unsigned long *addr, unsigned long size) 113{ 114 long mask; 115 int bit; 116 117 for (bit = 0; size >= BITS_PER_LONG; 118 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 119 if (~(*addr) == 0) 120 continue; 121 return (bit + __ffsl(~(*addr))); 122 } 123 if (size) { 124 mask = ~(*addr) & BITMAP_LAST_WORD_MASK(size); 125 if (mask) 126 bit += __ffsl(mask); 127 else 128 bit += size; 129 } 130 return (bit); 131} 132 133static inline unsigned long 134find_last_bit(unsigned long *addr, unsigned long size) 135{ 136 long mask; 137 int offs; 138 int bit; 139 int pos; 140 141 pos = size / BITS_PER_LONG; 142 offs = size % BITS_PER_LONG; 143 bit = BITS_PER_LONG * pos; 144 addr += pos; 145 if (offs) { 146 mask = (*addr) & BITMAP_LAST_WORD_MASK(offs); 147 if (mask) 148 return (bit + __flsl(mask)); 149 } 150 while (pos--) { 151 addr--; 152 bit -= BITS_PER_LONG; 153 if (*addr) 154 return (bit + __flsl(*addr)); 155 } 156 return (size); 157} 158 159static inline unsigned long 160find_next_bit(unsigned long *addr, unsigned long size, unsigned long offset) 161{ 162 long mask; 163 int offs; 164 int bit; 165 int pos; 166 167 if (offset >= size) 168 return (size); 169 pos = offset / BITS_PER_LONG; 170 offs = offset % BITS_PER_LONG; 171 bit = BITS_PER_LONG * pos; 172 addr += pos; 173 if (offs) { 174 mask = (*addr) & ~BITMAP_LAST_WORD_MASK(offs); 175 if (mask) 176 return (bit + __ffsl(mask)); 177 if (size - bit <= BITS_PER_LONG) 178 return (size); 179 bit += BITS_PER_LONG; 180 addr++; 181 } 182 for (size -= bit; size >= BITS_PER_LONG; 183 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 184 if (*addr == 0) 185 continue; 186 return (bit + __ffsl(*addr)); 187 } 188 if (size) { 189 mask = (*addr) & BITMAP_LAST_WORD_MASK(size); 190 if (mask) 191 bit += __ffsl(mask); 192 else 193 bit += size; 194 } 195 return (bit); 196} 197 198static inline unsigned long 199find_next_zero_bit(unsigned long *addr, unsigned long size, 200 unsigned long offset) 201{ 202 long mask; 203 int offs; 204 int bit; 205 int pos; 206 207 if (offset >= size) 208 return (size); 209 pos = offset / BITS_PER_LONG; 210 offs = offset % BITS_PER_LONG; 211 bit = BITS_PER_LONG * pos; 212 addr += pos; 213 if (offs) { 214 mask = ~(*addr) & ~BITMAP_LAST_WORD_MASK(offs); 215 if (mask) 216 return (bit + __ffsl(mask)); 217 if (size - bit <= BITS_PER_LONG) 218 return (size); 219 bit += BITS_PER_LONG; 220 addr++; 221 } 222 for (size -= bit; size >= BITS_PER_LONG; 223 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 224 if (~(*addr) == 0) 225 continue; 226 return (bit + __ffsl(~(*addr))); 227 } 228 if (size) { 229 mask = ~(*addr) & BITMAP_LAST_WORD_MASK(size); 230 if (mask) 231 bit += __ffsl(mask); 232 else 233 bit += size; 234 } 235 return (bit); 236} 237 238static inline void 239bitmap_zero(unsigned long *addr, int size) 240{ 241 int len; 242 243 len = BITS_TO_LONGS(size) * sizeof(long); 244 memset(addr, 0, len); 245} 246 247static inline void 248bitmap_fill(unsigned long *addr, int size) 249{ 250 int tail; 251 int len; 252 253 len = (size / BITS_PER_LONG) * sizeof(long); 254 memset(addr, 0xff, len); 255 tail = size & (BITS_PER_LONG - 1); 256 if (tail) 257 addr[size / BITS_PER_LONG] = BITMAP_LAST_WORD_MASK(tail); 258} 259 260static inline int 261bitmap_full(unsigned long *addr, int size) 262{ 263 unsigned long mask; 264 int tail; 265 int len; 266 int i; 267 268 len = size / BITS_PER_LONG; 269 for (i = 0; i < len; i++) 270 if (addr[i] != ~0UL) 271 return (0); 272 tail = size & (BITS_PER_LONG - 1); 273 if (tail) { 274 mask = BITMAP_LAST_WORD_MASK(tail); 275 if ((addr[i] & mask) != mask) 276 return (0); 277 } 278 return (1); 279} 280 281static inline int 282bitmap_empty(unsigned long *addr, int size) 283{ 284 unsigned long mask; 285 int tail; 286 int len; 287 int i; 288 289 len = size / BITS_PER_LONG; 290 for (i = 0; i < len; i++) 291 if (addr[i] != 0) 292 return (0); 293 tail = size & (BITS_PER_LONG - 1); 294 if (tail) { 295 mask = BITMAP_LAST_WORD_MASK(tail); 296 if ((addr[i] & mask) != 0) 297 return (0); 298 } 299 return (1); 300} 301 302#define __set_bit(i, a) \ 303 atomic_set_long(&((volatile long *)(a))[BIT_WORD(i)], BIT_MASK(i)) 304 305#define set_bit(i, a) \ 306 atomic_set_long(&((volatile long *)(a))[BIT_WORD(i)], BIT_MASK(i)) 307 308#define __clear_bit(i, a) \ 309 atomic_clear_long(&((volatile long *)(a))[BIT_WORD(i)], BIT_MASK(i)) 310 311#define clear_bit(i, a) \ 312 atomic_clear_long(&((volatile long *)(a))[BIT_WORD(i)], BIT_MASK(i)) 313 314#define test_bit(i, a) \ 315 !!(atomic_load_acq_long(&((volatile long *)(a))[BIT_WORD(i)]) & \ 316 BIT_MASK(i)) 317 318static inline long 319test_and_clear_bit(long bit, long *var) 320{ 321 long val; 322 323 var += BIT_WORD(bit); 324 bit %= BITS_PER_LONG; 325 bit = (1UL << bit); 326 do { 327 val = *(volatile long *)var; 328 } while (atomic_cmpset_long(var, val, val & ~bit) == 0); 329 330 return !!(val & bit); 331} 332 333static inline long 334test_and_set_bit(long bit, long *var) 335{ 336 long val; 337 338 var += BIT_WORD(bit); 339 bit %= BITS_PER_LONG; 340 bit = (1UL << bit); 341 do { 342 val = *(volatile long *)var; 343 } while (atomic_cmpset_long(var, val, val | bit) == 0); 344 345 return !!(val & bit); 346} 347 348static inline void 349bitmap_set(unsigned long *map, int start, int nr) 350{ 351 unsigned long *p = map + BIT_WORD(start); 352 const int size = start + nr; 353 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); 354 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); 355 356 while (nr - bits_to_set >= 0) { 357 *p |= mask_to_set; 358 nr -= bits_to_set; 359 bits_to_set = BITS_PER_LONG; 360 mask_to_set = ~0UL; 361 p++; 362 } 363 if (nr) { 364 mask_to_set &= BITMAP_LAST_WORD_MASK(size); 365 *p |= mask_to_set; 366 } 367} 368 369static inline void 370bitmap_clear(unsigned long *map, int start, int nr) 371{ 372 unsigned long *p = map + BIT_WORD(start); 373 const int size = start + nr; 374 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); 375 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); 376 377 while (nr - bits_to_clear >= 0) { 378 *p &= ~mask_to_clear; 379 nr -= bits_to_clear; 380 bits_to_clear = BITS_PER_LONG; 381 mask_to_clear = ~0UL; 382 p++; 383 } 384 if (nr) { 385 mask_to_clear &= BITMAP_LAST_WORD_MASK(size); 386 *p &= ~mask_to_clear; 387 } 388} 389 390enum { 391 REG_OP_ISFREE, 392 REG_OP_ALLOC, 393 REG_OP_RELEASE, 394}; 395 396static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op) 397{ 398 int nbits_reg; 399 int index; 400 int offset; 401 int nlongs_reg; 402 int nbitsinlong; 403 unsigned long mask; 404 int i; 405 int ret = 0; 406 407 nbits_reg = 1 << order; 408 index = pos / BITS_PER_LONG; 409 offset = pos - (index * BITS_PER_LONG); 410 nlongs_reg = BITS_TO_LONGS(nbits_reg); 411 nbitsinlong = min(nbits_reg, BITS_PER_LONG); 412 413 mask = (1UL << (nbitsinlong - 1)); 414 mask += mask - 1; 415 mask <<= offset; 416 417 switch (reg_op) { 418 case REG_OP_ISFREE: 419 for (i = 0; i < nlongs_reg; i++) { 420 if (bitmap[index + i] & mask) 421 goto done; 422 } 423 ret = 1; 424 break; 425 426 case REG_OP_ALLOC: 427 for (i = 0; i < nlongs_reg; i++) 428 bitmap[index + i] |= mask; 429 break; 430 431 case REG_OP_RELEASE: 432 for (i = 0; i < nlongs_reg; i++) 433 bitmap[index + i] &= ~mask; 434 break; 435 } 436done: 437 return ret; 438} 439 440static inline int 441bitmap_find_free_region(unsigned long *bitmap, int bits, int order) 442{ 443 int pos; 444 int end; 445 446 for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) { 447 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) 448 continue; 449 __reg_op(bitmap, pos, order, REG_OP_ALLOC); 450 return pos; 451 } 452 return -ENOMEM; 453} 454 455static inline int 456bitmap_allocate_region(unsigned long *bitmap, int pos, int order) 457{ 458 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) 459 return -EBUSY; 460 __reg_op(bitmap, pos, order, REG_OP_ALLOC); 461 return 0; 462} 463 464static inline void 465bitmap_release_region(unsigned long *bitmap, int pos, int order) 466{ 467 __reg_op(bitmap, pos, order, REG_OP_RELEASE); 468} 469 470#define for_each_set_bit(bit, addr, size) \ 471 for ((bit) = find_first_bit((addr), (size)); \ 472 (bit) < (size); \ 473 (bit) = find_next_bit((addr), (size), (bit) + 1)) 474 475static inline unsigned 476bitmap_weight(unsigned long *bitmap, unsigned nbits) 477{ 478 unsigned bit; 479 unsigned retval = 0; 480 481 for_each_set_bit(bit, bitmap, nbits) 482 retval++; 483 return (retval); 484} 485 486static inline int 487bitmap_equal(const unsigned long *pa, 488 const unsigned long *pb, unsigned bits) 489{ 490 unsigned x; 491 unsigned y = bits / BITS_PER_LONG; 492 493 for (x = 0; x != y; x++) { 494 if (pa[x] != pb[x]) 495 return (0); 496 } 497 498 y = bits % BITS_PER_LONG; 499 if (y != 0) { 500 if ((pa[x] ^ pb[x]) & BITMAP_LAST_WORD_MASK(y)) 501 return (0); 502 } 503 return (1); 504} 505 506#endif /* _LINUX_BITOPS_H_ */ 507