1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2015-2017 François Tigeot 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 <sys/types.h> 33 #include <sys/systm.h> 34 35 #include <asm/types.h> 36 37 #define BIT(nr) (1UL << (nr)) 38 #define BITS_PER_LONG 64 39 #define BIT_MASK(n) (~0UL >> (BITS_PER_LONG - (n))) 40 #define BITS_TO_LONGS(n) howmany((n), BITS_PER_LONG) 41 #define BIT_WORD(nr) ((nr) / BITS_PER_LONG) 42 #define BITS_PER_BYTE 8 43 44 static inline int 45 __ffs(int mask) 46 { 47 return (ffs(mask) - 1); 48 } 49 50 static inline int 51 __fls(int mask) 52 { 53 return (fls(mask) - 1); 54 } 55 56 static inline int 57 __ffsl(long mask) 58 { 59 return (ffsl(mask) - 1); 60 } 61 62 static inline int 63 __flsl(long mask) 64 { 65 return (flsl(mask) - 1); 66 } 67 68 69 #define ffz(mask) __ffs(~(mask)) 70 71 static inline int get_count_order(unsigned int count) 72 { 73 int order; 74 75 order = fls(count) - 1; 76 if (count & (count - 1)) 77 order++; 78 return order; 79 } 80 81 static inline unsigned long 82 find_first_bit(unsigned long *addr, unsigned long size) 83 { 84 long mask; 85 int bit; 86 87 for (bit = 0; size >= BITS_PER_LONG; 88 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 89 if (*addr == 0) 90 continue; 91 return (bit + __ffsl(*addr)); 92 } 93 if (size) { 94 mask = (*addr) & BIT_MASK(size); 95 if (mask) 96 bit += __ffsl(mask); 97 else 98 bit += size; 99 } 100 return (bit); 101 } 102 103 static inline unsigned long 104 find_first_zero_bit(unsigned long *addr, unsigned long size) 105 { 106 long mask; 107 int bit; 108 109 for (bit = 0; size >= BITS_PER_LONG; 110 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 111 if (~(*addr) == 0) 112 continue; 113 return (bit + __ffsl(~(*addr))); 114 } 115 if (size) { 116 mask = ~(*addr) & BIT_MASK(size); 117 if (mask) 118 bit += __ffsl(mask); 119 else 120 bit += size; 121 } 122 return (bit); 123 } 124 125 static inline unsigned long 126 find_last_bit(unsigned long *addr, unsigned long size) 127 { 128 long mask; 129 int offs; 130 int bit; 131 int pos; 132 133 pos = size / BITS_PER_LONG; 134 offs = size % BITS_PER_LONG; 135 bit = BITS_PER_LONG * pos; 136 addr += pos; 137 if (offs) { 138 mask = (*addr) & BIT_MASK(offs); 139 if (mask) 140 return (bit + __flsl(mask)); 141 } 142 while (--pos) { 143 addr--; 144 bit -= BITS_PER_LONG; 145 if (*addr) 146 return (bit + __flsl(mask)); 147 } 148 return (size); 149 } 150 151 static inline unsigned long 152 find_next_bit(unsigned long *addr, unsigned long size, unsigned long offset) 153 { 154 long mask; 155 int offs; 156 int bit; 157 int pos; 158 159 if (offset >= size) 160 return (size); 161 pos = offset / BITS_PER_LONG; 162 offs = offset % BITS_PER_LONG; 163 bit = BITS_PER_LONG * pos; 164 addr += pos; 165 if (offs) { 166 mask = (*addr) & ~BIT_MASK(offs); 167 if (mask) 168 return (bit + __ffsl(mask)); 169 bit += BITS_PER_LONG; 170 addr++; 171 } 172 for (size -= bit; size >= BITS_PER_LONG; 173 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 174 if (*addr == 0) 175 continue; 176 return (bit + __ffsl(*addr)); 177 } 178 if (size) { 179 mask = (*addr) & BIT_MASK(size); 180 if (mask) 181 bit += __ffsl(mask); 182 else 183 bit += size; 184 } 185 return (bit); 186 } 187 188 static inline unsigned long 189 find_next_zero_bit(unsigned long *addr, unsigned long size, 190 unsigned long offset) 191 { 192 long mask; 193 int offs; 194 int bit; 195 int pos; 196 197 if (offset >= size) 198 return (size); 199 pos = offset / BITS_PER_LONG; 200 offs = offset % BITS_PER_LONG; 201 bit = BITS_PER_LONG * pos; 202 addr += pos; 203 if (offs) { 204 mask = ~(*addr) & ~BIT_MASK(offs); 205 if (mask) 206 return (bit + __ffsl(mask)); 207 bit += BITS_PER_LONG; 208 addr++; 209 } 210 for (size -= bit; size >= BITS_PER_LONG; 211 size -= BITS_PER_LONG, bit += BITS_PER_LONG, addr++) { 212 if (~(*addr) == 0) 213 continue; 214 return (bit + __ffsl(~(*addr))); 215 } 216 if (size) { 217 mask = ~(*addr) & BIT_MASK(size); 218 if (mask) 219 bit += __ffsl(mask); 220 else 221 bit += size; 222 } 223 return (bit); 224 } 225 226 static inline void 227 bitmap_zero(unsigned long *addr, int size) 228 { 229 int len; 230 231 len = BITS_TO_LONGS(size) * sizeof(long); 232 memset(addr, 0, len); 233 } 234 235 static inline void 236 bitmap_fill(unsigned long *addr, int size) 237 { 238 int tail; 239 int len; 240 241 len = (size / BITS_PER_LONG) * sizeof(long); 242 memset(addr, 0xff, len); 243 tail = size & (BITS_PER_LONG - 1); 244 if (tail) 245 addr[size / BITS_PER_LONG] = BIT_MASK(tail); 246 } 247 248 static inline int 249 bitmap_full(unsigned long *addr, int size) 250 { 251 long mask; 252 int tail; 253 int len; 254 int i; 255 256 len = size / BITS_PER_LONG; 257 for (i = 0; i < len; i++) 258 if (addr[i] != ~0UL) 259 return (0); 260 tail = size & (BITS_PER_LONG - 1); 261 if (tail) { 262 mask = BIT_MASK(tail); 263 if ((addr[i] & mask) != mask) 264 return (0); 265 } 266 return (1); 267 } 268 269 static inline int 270 bitmap_empty(unsigned long *addr, int size) 271 { 272 long mask; 273 int tail; 274 int len; 275 int i; 276 277 len = size / BITS_PER_LONG; 278 for (i = 0; i < len; i++) 279 if (addr[i] != 0) 280 return (0); 281 tail = size & (BITS_PER_LONG - 1); 282 if (tail) { 283 mask = BIT_MASK(tail); 284 if ((addr[i] & mask) != 0) 285 return (0); 286 } 287 return (1); 288 } 289 290 #define NBLONG (NBBY * sizeof(long)) 291 292 #define set_bit(i, a) \ 293 atomic_set_long(&((volatile long *)(a))[(i)/NBLONG], 1LU << ((i) % NBLONG)) 294 295 #define clear_bit(i, a) \ 296 atomic_clear_long(&((volatile long *)(a))[(i)/NBLONG], 1LU << ((i) % NBLONG)) 297 298 #define test_bit(i, a) \ 299 !!(atomic_load_acq_long(&((volatile long *)(a))[(i)/NBLONG]) & \ 300 (1LU << ((i) % NBLONG))) 301 302 static inline long 303 test_and_clear_bit(long bit, long *var) 304 { 305 long val; 306 307 var += bit / (sizeof(long) * NBBY); 308 bit %= sizeof(long) * NBBY; 309 bit = 1L << bit; 310 do { 311 val = *(volatile long *)var; 312 } while (atomic_cmpset_long(var, val, val & ~bit) == 0); 313 314 return !!(val & bit); 315 } 316 317 static inline unsigned long 318 __test_and_clear_bit(unsigned int bit, volatile unsigned long *ptr) 319 { 320 const unsigned int units = (sizeof(*ptr) * NBBY); 321 volatile unsigned long *const p = &ptr[bit / units]; 322 const unsigned long mask = (1UL << (bit % units)); 323 unsigned long v; 324 325 v = *p; 326 *p &= ~mask; 327 328 return ((v & mask) != 0); 329 } 330 331 static inline long 332 test_and_set_bit(long bit, volatile unsigned long *var) 333 { 334 long val; 335 336 var += bit / (sizeof(long) * NBBY); 337 bit %= sizeof(long) * NBBY; 338 bit = 1L << bit; 339 do { 340 val = *(volatile long *)var; 341 } while (atomic_cmpset_long(var, val, val | bit) == 0); 342 343 return !!(val & bit); 344 } 345 346 347 #define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG)) 348 #define BITMAP_LAST_WORD_MASK(nbits) \ 349 ( \ 350 ((nbits) % BITS_PER_LONG) ? \ 351 (1UL<<((nbits) % BITS_PER_LONG))-1 : ~0UL \ 352 ) 353 354 355 static inline void 356 bitmap_set(unsigned long *map, int start, int nr) 357 { 358 unsigned long *p = map + BIT_WORD(start); 359 const int size = start + nr; 360 int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); 361 unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); 362 363 while (nr - bits_to_set >= 0) { 364 *p |= mask_to_set; 365 nr -= bits_to_set; 366 bits_to_set = BITS_PER_LONG; 367 mask_to_set = ~0UL; 368 p++; 369 } 370 if (nr) { 371 mask_to_set &= BITMAP_LAST_WORD_MASK(size); 372 *p |= mask_to_set; 373 } 374 } 375 376 static inline void 377 bitmap_clear(unsigned long *map, int start, int nr) 378 { 379 unsigned long *p = map + BIT_WORD(start); 380 const int size = start + nr; 381 int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); 382 unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); 383 384 while (nr - bits_to_clear >= 0) { 385 *p &= ~mask_to_clear; 386 nr -= bits_to_clear; 387 bits_to_clear = BITS_PER_LONG; 388 mask_to_clear = ~0UL; 389 p++; 390 } 391 if (nr) { 392 mask_to_clear &= BITMAP_LAST_WORD_MASK(size); 393 *p &= ~mask_to_clear; 394 } 395 } 396 397 enum { 398 REG_OP_ISFREE, /* true if region is all zero bits */ 399 REG_OP_ALLOC, /* set all bits in region */ 400 REG_OP_RELEASE, /* clear all bits in region */ 401 }; 402 403 static int __reg_op(unsigned long *bitmap, int pos, int order, int reg_op) 404 { 405 int nbits_reg; /* number of bits in region */ 406 int index; /* index first long of region in bitmap */ 407 int offset; /* bit offset region in bitmap[index] */ 408 int nlongs_reg; /* num longs spanned by region in bitmap */ 409 int nbitsinlong; /* num bits of region in each spanned long */ 410 unsigned long mask; /* bitmask for one long of region */ 411 int i; /* scans bitmap by longs */ 412 int ret = 0; /* return value */ 413 414 /* 415 * Either nlongs_reg == 1 (for small orders that fit in one long) 416 * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) 417 */ 418 nbits_reg = 1 << order; 419 index = pos / BITS_PER_LONG; 420 offset = pos - (index * BITS_PER_LONG); 421 nlongs_reg = BITS_TO_LONGS(nbits_reg); 422 nbitsinlong = min(nbits_reg, BITS_PER_LONG); 423 424 /* 425 * Can't do "mask = (1UL << nbitsinlong) - 1", as that 426 * overflows if nbitsinlong == BITS_PER_LONG. 427 */ 428 mask = (1UL << (nbitsinlong - 1)); 429 mask += mask - 1; 430 mask <<= offset; 431 432 switch (reg_op) { 433 case REG_OP_ISFREE: 434 for (i = 0; i < nlongs_reg; i++) { 435 if (bitmap[index + i] & mask) 436 goto done; 437 } 438 ret = 1; /* all bits in region free (zero) */ 439 break; 440 441 case REG_OP_ALLOC: 442 for (i = 0; i < nlongs_reg; i++) 443 bitmap[index + i] |= mask; 444 break; 445 446 case REG_OP_RELEASE: 447 for (i = 0; i < nlongs_reg; i++) 448 bitmap[index + i] &= ~mask; 449 break; 450 } 451 done: 452 return ret; 453 } 454 455 /** 456 * bitmap_find_free_region - find a contiguous aligned mem region 457 * @bitmap: array of unsigned longs corresponding to the bitmap 458 * @bits: number of bits in the bitmap 459 * @order: region size (log base 2 of number of bits) to find 460 * 461 * Find a region of free (zero) bits in a @bitmap of @bits bits and 462 * allocate them (set them to one). Only consider regions of length 463 * a power (@order) of two, aligned to that power of two, which 464 * makes the search algorithm much faster. 465 * 466 * Return the bit offset in bitmap of the allocated region, 467 * or -errno on failure. 468 */ 469 static inline int 470 bitmap_find_free_region(unsigned long *bitmap, int bits, int order) 471 { 472 int pos, end; /* scans bitmap by regions of size order */ 473 474 for (pos = 0 ; (end = pos + (1 << order)) <= bits; pos = end) { 475 if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) 476 continue; 477 __reg_op(bitmap, pos, order, REG_OP_ALLOC); 478 return pos; 479 } 480 return -ENOMEM; 481 } 482 483 /** 484 * bitmap_release_region - release allocated bitmap region 485 * @bitmap: array of unsigned longs corresponding to the bitmap 486 * @pos: beginning of bit region to release 487 * @order: region size (log base 2 of number of bits) to release 488 * 489 * This is the complement to __bitmap_find_free_region() and releases 490 * the found region (by clearing it in the bitmap). 491 * 492 * No return value. 493 */ 494 static inline void 495 bitmap_release_region(unsigned long *bitmap, int pos, int order) 496 { 497 __reg_op(bitmap, pos, order, REG_OP_RELEASE); 498 } 499 500 /* Returns a contiguous bitmask from bits h to l */ 501 #define GENMASK(h, l) \ 502 (((~0UL) >> (BITS_PER_LONG - (h) - 1)) & ((~0UL) << (l))) 503 504 #include <asm/bitops/non-atomic.h> 505 #include <asm/bitops/const_hweight.h> 506 507 #define for_each_set_bit(bit, addr, size) \ 508 for ((bit) = find_first_bit((addr), (size)); \ 509 (bit) < (size); \ 510 (bit) = find_next_bit((addr), (size), (bit) + 1)) 511 512 513 static inline int64_t 514 sign_extend64(uint64_t value, int index) 515 { 516 uint8_t shift = 63 - index; 517 return (int64_t)(value << shift) >> shift; 518 } 519 520 #endif /* _LINUX_BITOPS_H_ */ 521