1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2015-2020 François Tigeot <ftigeot@wolfpond.org> 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 #ifndef _LINUX_BITOPS_H_ 30 #define _LINUX_BITOPS_H_ 31 32 #include <asm/types.h> 33 34 #define BIT(nr) (1UL << (nr)) 35 #define BIT_ULL(nb) (1ULL << (nb)) 36 #define BIT_MASK(n) (~0UL >> (BITS_PER_LONG - (n))) 37 #define BITS_TO_LONGS(n) howmany((n), BITS_PER_LONG) 38 #define BIT_WORD(nr) ((nr) / BITS_PER_LONG) 39 #define BITS_PER_BYTE 8 40 41 #include <asm/bitops.h> 42 43 #include <sys/types.h> 44 #include <sys/systm.h> 45 46 static inline int 47 __ffs(int mask) 48 { 49 return (ffs(mask) - 1); 50 } 51 52 static inline int 53 __fls(int mask) 54 { 55 return (fls(mask) - 1); 56 } 57 58 static inline int 59 __ffsl(long mask) 60 { 61 return (ffsl(mask) - 1); 62 } 63 64 static inline int 65 __flsl(long mask) 66 { 67 return (flsl(mask) - 1); 68 } 69 70 /* 71 * fls64 - find leftmost set bit in a 64-bit word 72 * 73 * Returns 0 if no bit is set or the bit 74 * position counted from 1 to 64 otherwise 75 */ 76 static inline int 77 fls64(__u64 x) 78 { 79 return flsl(x); 80 } 81 82 #define ffz(mask) __ffs(~(mask)) 83 84 static inline int get_count_order(unsigned int count) 85 { 86 int order; 87 88 order = fls(count) - 1; 89 if (count & (count - 1)) 90 order++; 91 return order; 92 } 93 94 static inline unsigned long 95 find_first_bit(unsigned long *addr, unsigned long size) 96 { 97 long mask; 98 int bit; 99 100 for (bit = 0; size >= BITS_PER_LONG; 101 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 102 if (*addr == 0) 103 continue; 104 return (bit + __ffsl(*addr)); 105 } 106 if (size) { 107 mask = (*addr) & BIT_MASK(size); 108 if (mask) 109 bit += __ffsl(mask); 110 else 111 bit += size; 112 } 113 return (bit); 114 } 115 116 static inline unsigned long 117 find_first_zero_bit(unsigned long *addr, unsigned long size) 118 { 119 long mask; 120 int bit; 121 122 for (bit = 0; size >= BITS_PER_LONG; 123 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 124 if (~(*addr) == 0) 125 continue; 126 return (bit + __ffsl(~(*addr))); 127 } 128 if (size) { 129 mask = ~(*addr) & BIT_MASK(size); 130 if (mask) 131 bit += __ffsl(mask); 132 else 133 bit += size; 134 } 135 return (bit); 136 } 137 138 static inline unsigned long 139 find_last_bit(unsigned long *addr, unsigned long size) 140 { 141 long mask; 142 int offs; 143 int bit; 144 int pos; 145 146 pos = size / BITS_PER_LONG; 147 offs = size % BITS_PER_LONG; 148 bit = BITS_PER_LONG * pos; 149 addr += pos; 150 if (offs) { 151 mask = (*addr) & BIT_MASK(offs); 152 if (mask) 153 return (bit + __flsl(mask)); 154 } 155 while (--pos) { 156 addr--; 157 bit -= BITS_PER_LONG; 158 if (*addr) 159 return (bit + __flsl(mask)); 160 } 161 return (size); 162 } 163 164 static inline unsigned long 165 find_next_bit(unsigned long *addr, unsigned long size, unsigned long offset) 166 { 167 long mask; 168 int offs; 169 int bit; 170 int pos; 171 172 if (offset >= size) 173 return (size); 174 pos = offset / BITS_PER_LONG; 175 offs = offset % BITS_PER_LONG; 176 bit = BITS_PER_LONG * pos; 177 addr += pos; 178 if (offs) { 179 mask = (*addr) & ~BIT_MASK(offs); 180 if (mask) 181 return (bit + __ffsl(mask)); 182 bit += BITS_PER_LONG; 183 addr++; 184 } 185 for (size -= bit; size >= BITS_PER_LONG; 186 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 187 if (*addr == 0) 188 continue; 189 return (bit + __ffsl(*addr)); 190 } 191 if (size) { 192 mask = (*addr) & BIT_MASK(size); 193 if (mask) 194 bit += __ffsl(mask); 195 else 196 bit += size; 197 } 198 return (bit); 199 } 200 201 static inline unsigned long 202 find_next_zero_bit(unsigned long *addr, unsigned long size, 203 unsigned long offset) 204 { 205 long mask; 206 int offs; 207 int bit; 208 int pos; 209 210 if (offset >= size) 211 return (size); 212 pos = offset / BITS_PER_LONG; 213 offs = offset % BITS_PER_LONG; 214 bit = BITS_PER_LONG * pos; 215 addr += pos; 216 if (offs) { 217 mask = ~(*addr) & ~BIT_MASK(offs); 218 if (mask) 219 return (bit + __ffsl(mask)); 220 bit += BITS_PER_LONG; 221 addr++; 222 } 223 for (size -= bit; size >= BITS_PER_LONG; 224 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 225 if (~(*addr) == 0) 226 continue; 227 return (bit + __ffsl(~(*addr))); 228 } 229 if (size) { 230 mask = ~(*addr) & BIT_MASK(size); 231 if (mask) 232 bit += __ffsl(mask); 233 else 234 bit += size; 235 } 236 return (bit); 237 } 238 239 static inline void 240 bitmap_zero(unsigned long *addr, int size) 241 { 242 int len; 243 244 len = BITS_TO_LONGS(size) * sizeof(long); 245 memset(addr, 0, len); 246 } 247 248 static inline void 249 bitmap_fill(unsigned long *addr, int size) 250 { 251 int tail; 252 int len; 253 254 len = (size / BITS_PER_LONG) * sizeof(long); 255 memset(addr, 0xff, len); 256 tail = size & (BITS_PER_LONG - 1); 257 if (tail) 258 addr[size / BITS_PER_LONG] = BIT_MASK(tail); 259 } 260 261 static inline int 262 bitmap_full(unsigned long *addr, int size) 263 { 264 long mask; 265 int tail; 266 int len; 267 int i; 268 269 len = size / BITS_PER_LONG; 270 for (i = 0; i < len; i++) 271 if (addr[i] != ~0UL) 272 return (0); 273 tail = size & (BITS_PER_LONG - 1); 274 if (tail) { 275 mask = BIT_MASK(tail); 276 if ((addr[i] & mask) != mask) 277 return (0); 278 } 279 return (1); 280 } 281 282 static inline int 283 bitmap_empty(unsigned long *addr, int size) 284 { 285 long mask; 286 int tail; 287 int len; 288 int i; 289 290 len = size / BITS_PER_LONG; 291 for (i = 0; i < len; i++) 292 if (addr[i] != 0) 293 return (0); 294 tail = size & (BITS_PER_LONG - 1); 295 if (tail) { 296 mask = BIT_MASK(tail); 297 if ((addr[i] & mask) != 0) 298 return (0); 299 } 300 return (1); 301 } 302 303 #define NBLONG (NBBY * sizeof(long)) 304 305 #define set_bit(i, a) \ 306 atomic_set_long(&((volatile long *)(a))[(i)/NBLONG], 1LU << ((i) % NBLONG)) 307 308 #define clear_bit(i, a) \ 309 atomic_clear_long(&((volatile long *)(a))[(i)/NBLONG], 1LU << ((i) % NBLONG)) 310 311 #define test_bit(i, a) \ 312 !!(atomic_load_acq_long(&((volatile long *)(a))[(i)/NBLONG]) & \ 313 (1LU << ((i) % NBLONG))) 314 315 static inline long 316 test_and_clear_bit(long bit, long *var) 317 { 318 long val; 319 320 var += bit / (sizeof(long) * NBBY); 321 bit %= sizeof(long) * NBBY; 322 bit = 1L << bit; 323 do { 324 val = *(volatile long *)var; 325 } while (atomic_cmpset_long(var, val, val & ~bit) == 0); 326 327 return !!(val & bit); 328 } 329 330 static inline unsigned long 331 __test_and_clear_bit(unsigned int bit, volatile unsigned long *ptr) 332 { 333 const unsigned int units = (sizeof(*ptr) * NBBY); 334 volatile unsigned long *const p = &ptr[bit / units]; 335 const unsigned long mask = (1UL << (bit % units)); 336 unsigned long v; 337 338 v = *p; 339 *p &= ~mask; 340 341 return ((v & mask) != 0); 342 } 343 344 static inline long 345 test_and_set_bit(long bit, volatile unsigned long *var) 346 { 347 long val; 348 349 var += bit / (sizeof(long) * NBBY); 350 bit %= sizeof(long) * NBBY; 351 bit = 1L << bit; 352 do { 353 val = *(volatile long *)var; 354 } while (atomic_cmpset_long(var, val, val | bit) == 0); 355 356 return !!(val & bit); 357 } 358 359 360 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG)) 361 #define BITMAP_LAST_WORD_MASK(nbits) \ 362 ( \ 363 ((nbits) % BITS_PER_LONG) ? \ 364 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL \ 365 ) 366 367 368 static inline void 369 bitmap_set(unsigned long *map, int start, int nr) 370 { 371 unsigned long *p = map + BIT_WORD(start); 372 const int size = start + nr; 373 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); 374 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); 375 376 while (nr - bits_to_set >= 0) { 377 *p |= mask_to_set; 378 nr -= bits_to_set; 379 bits_to_set = BITS_PER_LONG; 380 mask_to_set = ~0UL; 381 p++; 382 } 383 if (nr) { 384 mask_to_set &= BITMAP_LAST_WORD_MASK(size); 385 *p |= mask_to_set; 386 } 387 } 388 389 static inline void 390 bitmap_clear(unsigned long *map, int start, int nr) 391 { 392 unsigned long *p = map + BIT_WORD(start); 393 const int size = start + nr; 394 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); 395 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); 396 397 while (nr - bits_to_clear >= 0) { 398 *p &= ~mask_to_clear; 399 nr -= bits_to_clear; 400 bits_to_clear = BITS_PER_LONG; 401 mask_to_clear = ~0UL; 402 p++; 403 } 404 if (nr) { 405 mask_to_clear &= BITMAP_LAST_WORD_MASK(size); 406 *p &= ~mask_to_clear; 407 } 408 } 409 410 enum { 411 REG_OP_ISFREE, /* true if region is all zero bits */ 412 REG_OP_ALLOC, /* set all bits in region */ 413 REG_OP_RELEASE, /* clear all bits in region */ 414 }; 415 416 static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op) 417 { 418 int nbits_reg; /* number of bits in region */ 419 int index; /* index first long of region in bitmap */ 420 int offset; /* bit offset region in bitmap[index] */ 421 int nlongs_reg; /* num longs spanned by region in bitmap */ 422 int nbitsinlong; /* num bits of region in each spanned long */ 423 unsigned long mask; /* bitmask for one long of region */ 424 int i; /* scans bitmap by longs */ 425 int ret = 0; /* return value */ 426 427 /* 428 * Either nlongs_reg == 1 (for small orders that fit in one long) 429 * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) 430 */ 431 nbits_reg = 1 << order; 432 index = pos / BITS_PER_LONG; 433 offset = pos - (index * BITS_PER_LONG); 434 nlongs_reg = BITS_TO_LONGS(nbits_reg); 435 nbitsinlong = min(nbits_reg, BITS_PER_LONG); 436 437 /* 438 * Can't do "mask = (1UL << nbitsinlong) - 1", as that 439 * overflows if nbitsinlong == BITS_PER_LONG. 440 */ 441 mask = (1UL << (nbitsinlong - 1)); 442 mask += mask - 1; 443 mask <<= offset; 444 445 switch (reg_op) { 446 case REG_OP_ISFREE: 447 for (i = 0; i < nlongs_reg; i++) { 448 if (bitmap[index + i] & mask) 449 goto done; 450 } 451 ret = 1; /* all bits in region free (zero) */ 452 break; 453 454 case REG_OP_ALLOC: 455 for (i = 0; i < nlongs_reg; i++) 456 bitmap[index + i] |= mask; 457 break; 458 459 case REG_OP_RELEASE: 460 for (i = 0; i < nlongs_reg; i++) 461 bitmap[index + i] &= ~mask; 462 break; 463 } 464 done: 465 return ret; 466 } 467 468 /** 469 * bitmap_find_free_region - find a contiguous aligned mem region 470 * @bitmap: array of unsigned longs corresponding to the bitmap 471 * @bits: number of bits in the bitmap 472 * @order: region size (log base 2 of number of bits) to find 473 * 474 * Find a region of free (zero) bits in a @bitmap of @bits bits and 475 * allocate them (set them to one). Only consider regions of length 476 * a power (@order) of two, aligned to that power of two, which 477 * makes the search algorithm much faster. 478 * 479 * Return the bit offset in bitmap of the allocated region, 480 * or -errno on failure. 481 */ 482 static inline int 483 bitmap_find_free_region(unsigned long *bitmap, int bits, int order) 484 { 485 int pos, end; /* scans bitmap by regions of size order */ 486 487 for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) { 488 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) 489 continue; 490 __reg_op(bitmap, pos, order, REG_OP_ALLOC); 491 return pos; 492 } 493 return -ENOMEM; 494 } 495 496 /** 497 * bitmap_release_region - release allocated bitmap region 498 * @bitmap: array of unsigned longs corresponding to the bitmap 499 * @pos: beginning of bit region to release 500 * @order: region size (log base 2 of number of bits) to release 501 * 502 * This is the complement to __bitmap_find_free_region() and releases 503 * the found region (by clearing it in the bitmap). 504 * 505 * No return value. 506 */ 507 static inline void 508 bitmap_release_region(unsigned long *bitmap, int pos, int order) 509 { 510 __reg_op(bitmap, pos, order, REG_OP_RELEASE); 511 } 512 513 /* Returns a contiguous bitmask from bits h to l */ 514 #define GENMASK(h, l) \ 515 (((~0UL) >> (BITS_PER_LONG - (h) - 1)) & ((~0UL) << (l))) 516 517 #define GENMASK_ULL(h, l) \ 518 (((~0ULL) >> (BITS_PER_LONG_LONG - 1 - (h))) & ((~0ULL) << (l))) 519 520 #include <asm/bitops/non-atomic.h> 521 #include <asm/bitops/const_hweight.h> 522 523 #define for_each_set_bit(bit, addr, size) \ 524 for ((bit) = find_first_bit((addr), (size)); \ 525 (bit) < (size); \ 526 (bit) = find_next_bit((addr), (size), (bit) + 1)) 527 528 #define for_each_clear_bit(bit, addr, size) \ 529 for ((bit) = find_first_zero_bit((addr), (size)); \ 530 (bit) < (size); \ 531 (bit) = find_next_zero_bit((addr), (size), (bit) + 1)) 532 533 static inline int64_t 534 sign_extend64(uint64_t value, int index) 535 { 536 uint8_t shift = 63 - index; 537 return (int64_t)(value << shift) >> shift; 538 } 539 540 #endif /* _LINUX_BITOPS_H_ */ 541