1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __LINUX_CPUMASK_H 3 #define __LINUX_CPUMASK_H 4 5 /* 6 * Cpumasks provide a bitmap suitable for representing the 7 * set of CPU's in a system, one bit position per CPU number. In general, 8 * only nr_cpu_ids (<= NR_CPUS) bits are valid. 9 */ 10 #include <linux/kernel.h> 11 #include <linux/threads.h> 12 #include <linux/bitmap.h> 13 #include <linux/bug.h> 14 15 /* Don't assign or return these: may not be this big! */ 16 typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t; 17 18 /** 19 * cpumask_bits - get the bits in a cpumask 20 * @maskp: the struct cpumask * 21 * 22 * You should only assume nr_cpu_ids bits of this mask are valid. This is 23 * a macro so it's const-correct. 24 */ 25 #define cpumask_bits(maskp) ((maskp)->bits) 26 27 /** 28 * cpumask_pr_args - printf args to output a cpumask 29 * @maskp: cpumask to be printed 30 * 31 * Can be used to provide arguments for '%*pb[l]' when printing a cpumask. 32 */ 33 #define cpumask_pr_args(maskp) nr_cpu_ids, cpumask_bits(maskp) 34 35 #if NR_CPUS == 1 36 #define nr_cpu_ids 1U 37 #else 38 extern unsigned int nr_cpu_ids; 39 #endif 40 41 #ifdef CONFIG_CPUMASK_OFFSTACK 42 /* Assuming NR_CPUS is huge, a runtime limit is more efficient. Also, 43 * not all bits may be allocated. */ 44 #define nr_cpumask_bits nr_cpu_ids 45 #else 46 #define nr_cpumask_bits ((unsigned int)NR_CPUS) 47 #endif 48 49 /* 50 * The following particular system cpumasks and operations manage 51 * possible, present, active and online cpus. 52 * 53 * cpu_possible_mask- has bit 'cpu' set iff cpu is populatable 54 * cpu_present_mask - has bit 'cpu' set iff cpu is populated 55 * cpu_online_mask - has bit 'cpu' set iff cpu available to scheduler 56 * cpu_active_mask - has bit 'cpu' set iff cpu available to migration 57 * 58 * If !CONFIG_HOTPLUG_CPU, present == possible, and active == online. 59 * 60 * The cpu_possible_mask is fixed at boot time, as the set of CPU id's 61 * that it is possible might ever be plugged in at anytime during the 62 * life of that system boot. The cpu_present_mask is dynamic(*), 63 * representing which CPUs are currently plugged in. And 64 * cpu_online_mask is the dynamic subset of cpu_present_mask, 65 * indicating those CPUs available for scheduling. 66 * 67 * If HOTPLUG is enabled, then cpu_possible_mask is forced to have 68 * all NR_CPUS bits set, otherwise it is just the set of CPUs that 69 * ACPI reports present at boot. 70 * 71 * If HOTPLUG is enabled, then cpu_present_mask varies dynamically, 72 * depending on what ACPI reports as currently plugged in, otherwise 73 * cpu_present_mask is just a copy of cpu_possible_mask. 74 * 75 * (*) Well, cpu_present_mask is dynamic in the hotplug case. If not 76 * hotplug, it's a copy of cpu_possible_mask, hence fixed at boot. 77 * 78 * Subtleties: 79 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode 80 * assumption that their single CPU is online. The UP 81 * cpu_{online,possible,present}_masks are placebos. Changing them 82 * will have no useful affect on the following num_*_cpus() 83 * and cpu_*() macros in the UP case. This ugliness is a UP 84 * optimization - don't waste any instructions or memory references 85 * asking if you're online or how many CPUs there are if there is 86 * only one CPU. 87 */ 88 89 extern struct cpumask __cpu_possible_mask; 90 extern struct cpumask __cpu_online_mask; 91 extern struct cpumask __cpu_present_mask; 92 extern struct cpumask __cpu_active_mask; 93 #define cpu_possible_mask ((const struct cpumask *)&__cpu_possible_mask) 94 #define cpu_online_mask ((const struct cpumask *)&__cpu_online_mask) 95 #define cpu_present_mask ((const struct cpumask *)&__cpu_present_mask) 96 #define cpu_active_mask ((const struct cpumask *)&__cpu_active_mask) 97 98 #if NR_CPUS > 1 99 #define num_online_cpus() cpumask_weight(cpu_online_mask) 100 #define num_possible_cpus() cpumask_weight(cpu_possible_mask) 101 #define num_present_cpus() cpumask_weight(cpu_present_mask) 102 #define num_active_cpus() cpumask_weight(cpu_active_mask) 103 #define cpu_online(cpu) cpumask_test_cpu((cpu), cpu_online_mask) 104 #define cpu_possible(cpu) cpumask_test_cpu((cpu), cpu_possible_mask) 105 #define cpu_present(cpu) cpumask_test_cpu((cpu), cpu_present_mask) 106 #define cpu_active(cpu) cpumask_test_cpu((cpu), cpu_active_mask) 107 #else 108 #define num_online_cpus() 1U 109 #define num_possible_cpus() 1U 110 #define num_present_cpus() 1U 111 #define num_active_cpus() 1U 112 #define cpu_online(cpu) ((cpu) == 0) 113 #define cpu_possible(cpu) ((cpu) == 0) 114 #define cpu_present(cpu) ((cpu) == 0) 115 #define cpu_active(cpu) ((cpu) == 0) 116 #endif 117 118 /* verify cpu argument to cpumask_* operators */ 119 static inline unsigned int cpumask_check(unsigned int cpu) 120 { 121 #ifdef CONFIG_DEBUG_PER_CPU_MAPS 122 WARN_ON_ONCE(cpu >= nr_cpumask_bits); 123 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */ 124 return cpu; 125 } 126 127 #if NR_CPUS == 1 128 /* Uniprocessor. Assume all masks are "1". */ 129 static inline unsigned int cpumask_first(const struct cpumask *srcp) 130 { 131 return 0; 132 } 133 134 static inline unsigned int cpumask_last(const struct cpumask *srcp) 135 { 136 return 0; 137 } 138 139 /* Valid inputs for n are -1 and 0. */ 140 static inline unsigned int cpumask_next(int n, const struct cpumask *srcp) 141 { 142 return n+1; 143 } 144 145 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp) 146 { 147 return n+1; 148 } 149 150 static inline unsigned int cpumask_next_and(int n, 151 const struct cpumask *srcp, 152 const struct cpumask *andp) 153 { 154 return n+1; 155 } 156 157 /* cpu must be a valid cpu, ie 0, so there's no other choice. */ 158 static inline unsigned int cpumask_any_but(const struct cpumask *mask, 159 unsigned int cpu) 160 { 161 return 1; 162 } 163 164 static inline unsigned int cpumask_local_spread(unsigned int i, int node) 165 { 166 return 0; 167 } 168 169 #define for_each_cpu(cpu, mask) \ 170 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask) 171 #define for_each_cpu_not(cpu, mask) \ 172 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask) 173 #define for_each_cpu_and(cpu, mask, and) \ 174 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and) 175 #else 176 /** 177 * cpumask_first - get the first cpu in a cpumask 178 * @srcp: the cpumask pointer 179 * 180 * Returns >= nr_cpu_ids if no cpus set. 181 */ 182 static inline unsigned int cpumask_first(const struct cpumask *srcp) 183 { 184 return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits); 185 } 186 187 /** 188 * cpumask_last - get the last CPU in a cpumask 189 * @srcp: - the cpumask pointer 190 * 191 * Returns >= nr_cpumask_bits if no CPUs set. 192 */ 193 static inline unsigned int cpumask_last(const struct cpumask *srcp) 194 { 195 return find_last_bit(cpumask_bits(srcp), nr_cpumask_bits); 196 } 197 198 unsigned int cpumask_next(int n, const struct cpumask *srcp); 199 200 /** 201 * cpumask_next_zero - get the next unset cpu in a cpumask 202 * @n: the cpu prior to the place to search (ie. return will be > @n) 203 * @srcp: the cpumask pointer 204 * 205 * Returns >= nr_cpu_ids if no further cpus unset. 206 */ 207 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp) 208 { 209 /* -1 is a legal arg here. */ 210 if (n != -1) 211 cpumask_check(n); 212 return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1); 213 } 214 215 int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *); 216 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu); 217 unsigned int cpumask_local_spread(unsigned int i, int node); 218 219 /** 220 * for_each_cpu - iterate over every cpu in a mask 221 * @cpu: the (optionally unsigned) integer iterator 222 * @mask: the cpumask pointer 223 * 224 * After the loop, cpu is >= nr_cpu_ids. 225 */ 226 #define for_each_cpu(cpu, mask) \ 227 for ((cpu) = -1; \ 228 (cpu) = cpumask_next((cpu), (mask)), \ 229 (cpu) < nr_cpu_ids;) 230 231 /** 232 * for_each_cpu_not - iterate over every cpu in a complemented mask 233 * @cpu: the (optionally unsigned) integer iterator 234 * @mask: the cpumask pointer 235 * 236 * After the loop, cpu is >= nr_cpu_ids. 237 */ 238 #define for_each_cpu_not(cpu, mask) \ 239 for ((cpu) = -1; \ 240 (cpu) = cpumask_next_zero((cpu), (mask)), \ 241 (cpu) < nr_cpu_ids;) 242 243 extern int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap); 244 245 /** 246 * for_each_cpu_wrap - iterate over every cpu in a mask, starting at a specified location 247 * @cpu: the (optionally unsigned) integer iterator 248 * @mask: the cpumask poiter 249 * @start: the start location 250 * 251 * The implementation does not assume any bit in @mask is set (including @start). 252 * 253 * After the loop, cpu is >= nr_cpu_ids. 254 */ 255 #define for_each_cpu_wrap(cpu, mask, start) \ 256 for ((cpu) = cpumask_next_wrap((start)-1, (mask), (start), false); \ 257 (cpu) < nr_cpumask_bits; \ 258 (cpu) = cpumask_next_wrap((cpu), (mask), (start), true)) 259 260 /** 261 * for_each_cpu_and - iterate over every cpu in both masks 262 * @cpu: the (optionally unsigned) integer iterator 263 * @mask: the first cpumask pointer 264 * @and: the second cpumask pointer 265 * 266 * This saves a temporary CPU mask in many places. It is equivalent to: 267 * struct cpumask tmp; 268 * cpumask_and(&tmp, &mask, &and); 269 * for_each_cpu(cpu, &tmp) 270 * ... 271 * 272 * After the loop, cpu is >= nr_cpu_ids. 273 */ 274 #define for_each_cpu_and(cpu, mask, and) \ 275 for ((cpu) = -1; \ 276 (cpu) = cpumask_next_and((cpu), (mask), (and)), \ 277 (cpu) < nr_cpu_ids;) 278 #endif /* SMP */ 279 280 #define CPU_BITS_NONE \ 281 { \ 282 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 283 } 284 285 #define CPU_BITS_CPU0 \ 286 { \ 287 [0] = 1UL \ 288 } 289 290 /** 291 * cpumask_set_cpu - set a cpu in a cpumask 292 * @cpu: cpu number (< nr_cpu_ids) 293 * @dstp: the cpumask pointer 294 */ 295 static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 296 { 297 set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 298 } 299 300 static inline void __cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 301 { 302 __set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 303 } 304 305 306 /** 307 * cpumask_clear_cpu - clear a cpu in a cpumask 308 * @cpu: cpu number (< nr_cpu_ids) 309 * @dstp: the cpumask pointer 310 */ 311 static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp) 312 { 313 clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 314 } 315 316 static inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp) 317 { 318 __clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 319 } 320 321 /** 322 * cpumask_test_cpu - test for a cpu in a cpumask 323 * @cpu: cpu number (< nr_cpu_ids) 324 * @cpumask: the cpumask pointer 325 * 326 * Returns 1 if @cpu is set in @cpumask, else returns 0 327 */ 328 static inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask) 329 { 330 return test_bit(cpumask_check(cpu), cpumask_bits((cpumask))); 331 } 332 333 /** 334 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask 335 * @cpu: cpu number (< nr_cpu_ids) 336 * @cpumask: the cpumask pointer 337 * 338 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0 339 * 340 * test_and_set_bit wrapper for cpumasks. 341 */ 342 static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask) 343 { 344 return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 345 } 346 347 /** 348 * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask 349 * @cpu: cpu number (< nr_cpu_ids) 350 * @cpumask: the cpumask pointer 351 * 352 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0 353 * 354 * test_and_clear_bit wrapper for cpumasks. 355 */ 356 static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask) 357 { 358 return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 359 } 360 361 /** 362 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask 363 * @dstp: the cpumask pointer 364 */ 365 static inline void cpumask_setall(struct cpumask *dstp) 366 { 367 bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits); 368 } 369 370 /** 371 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask 372 * @dstp: the cpumask pointer 373 */ 374 static inline void cpumask_clear(struct cpumask *dstp) 375 { 376 bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits); 377 } 378 379 /** 380 * cpumask_and - *dstp = *src1p & *src2p 381 * @dstp: the cpumask result 382 * @src1p: the first input 383 * @src2p: the second input 384 * 385 * If *@dstp is empty, returns 0, else returns 1 386 */ 387 static inline int cpumask_and(struct cpumask *dstp, 388 const struct cpumask *src1p, 389 const struct cpumask *src2p) 390 { 391 return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p), 392 cpumask_bits(src2p), nr_cpumask_bits); 393 } 394 395 /** 396 * cpumask_or - *dstp = *src1p | *src2p 397 * @dstp: the cpumask result 398 * @src1p: the first input 399 * @src2p: the second input 400 */ 401 static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p, 402 const struct cpumask *src2p) 403 { 404 bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p), 405 cpumask_bits(src2p), nr_cpumask_bits); 406 } 407 408 /** 409 * cpumask_xor - *dstp = *src1p ^ *src2p 410 * @dstp: the cpumask result 411 * @src1p: the first input 412 * @src2p: the second input 413 */ 414 static inline void cpumask_xor(struct cpumask *dstp, 415 const struct cpumask *src1p, 416 const struct cpumask *src2p) 417 { 418 bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p), 419 cpumask_bits(src2p), nr_cpumask_bits); 420 } 421 422 /** 423 * cpumask_andnot - *dstp = *src1p & ~*src2p 424 * @dstp: the cpumask result 425 * @src1p: the first input 426 * @src2p: the second input 427 * 428 * If *@dstp is empty, returns 0, else returns 1 429 */ 430 static inline int cpumask_andnot(struct cpumask *dstp, 431 const struct cpumask *src1p, 432 const struct cpumask *src2p) 433 { 434 return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p), 435 cpumask_bits(src2p), nr_cpumask_bits); 436 } 437 438 /** 439 * cpumask_complement - *dstp = ~*srcp 440 * @dstp: the cpumask result 441 * @srcp: the input to invert 442 */ 443 static inline void cpumask_complement(struct cpumask *dstp, 444 const struct cpumask *srcp) 445 { 446 bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp), 447 nr_cpumask_bits); 448 } 449 450 /** 451 * cpumask_equal - *src1p == *src2p 452 * @src1p: the first input 453 * @src2p: the second input 454 */ 455 static inline bool cpumask_equal(const struct cpumask *src1p, 456 const struct cpumask *src2p) 457 { 458 return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p), 459 nr_cpumask_bits); 460 } 461 462 /** 463 * cpumask_intersects - (*src1p & *src2p) != 0 464 * @src1p: the first input 465 * @src2p: the second input 466 */ 467 static inline bool cpumask_intersects(const struct cpumask *src1p, 468 const struct cpumask *src2p) 469 { 470 return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p), 471 nr_cpumask_bits); 472 } 473 474 /** 475 * cpumask_subset - (*src1p & ~*src2p) == 0 476 * @src1p: the first input 477 * @src2p: the second input 478 * 479 * Returns 1 if *@src1p is a subset of *@src2p, else returns 0 480 */ 481 static inline int cpumask_subset(const struct cpumask *src1p, 482 const struct cpumask *src2p) 483 { 484 return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p), 485 nr_cpumask_bits); 486 } 487 488 /** 489 * cpumask_empty - *srcp == 0 490 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear. 491 */ 492 static inline bool cpumask_empty(const struct cpumask *srcp) 493 { 494 return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits); 495 } 496 497 /** 498 * cpumask_full - *srcp == 0xFFFFFFFF... 499 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set. 500 */ 501 static inline bool cpumask_full(const struct cpumask *srcp) 502 { 503 return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits); 504 } 505 506 /** 507 * cpumask_weight - Count of bits in *srcp 508 * @srcp: the cpumask to count bits (< nr_cpu_ids) in. 509 */ 510 static inline unsigned int cpumask_weight(const struct cpumask *srcp) 511 { 512 return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits); 513 } 514 515 /** 516 * cpumask_shift_right - *dstp = *srcp >> n 517 * @dstp: the cpumask result 518 * @srcp: the input to shift 519 * @n: the number of bits to shift by 520 */ 521 static inline void cpumask_shift_right(struct cpumask *dstp, 522 const struct cpumask *srcp, int n) 523 { 524 bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n, 525 nr_cpumask_bits); 526 } 527 528 /** 529 * cpumask_shift_left - *dstp = *srcp << n 530 * @dstp: the cpumask result 531 * @srcp: the input to shift 532 * @n: the number of bits to shift by 533 */ 534 static inline void cpumask_shift_left(struct cpumask *dstp, 535 const struct cpumask *srcp, int n) 536 { 537 bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n, 538 nr_cpumask_bits); 539 } 540 541 /** 542 * cpumask_copy - *dstp = *srcp 543 * @dstp: the result 544 * @srcp: the input cpumask 545 */ 546 static inline void cpumask_copy(struct cpumask *dstp, 547 const struct cpumask *srcp) 548 { 549 bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits); 550 } 551 552 /** 553 * cpumask_any - pick a "random" cpu from *srcp 554 * @srcp: the input cpumask 555 * 556 * Returns >= nr_cpu_ids if no cpus set. 557 */ 558 #define cpumask_any(srcp) cpumask_first(srcp) 559 560 /** 561 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2 562 * @src1p: the first input 563 * @src2p: the second input 564 * 565 * Returns >= nr_cpu_ids if no cpus set in both. See also cpumask_next_and(). 566 */ 567 #define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p)) 568 569 /** 570 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2 571 * @mask1: the first input cpumask 572 * @mask2: the second input cpumask 573 * 574 * Returns >= nr_cpu_ids if no cpus set. 575 */ 576 #define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2)) 577 578 /** 579 * cpumask_of - the cpumask containing just a given cpu 580 * @cpu: the cpu (<= nr_cpu_ids) 581 */ 582 #define cpumask_of(cpu) (get_cpu_mask(cpu)) 583 584 /** 585 * cpumask_parse_user - extract a cpumask from a user string 586 * @buf: the buffer to extract from 587 * @len: the length of the buffer 588 * @dstp: the cpumask to set. 589 * 590 * Returns -errno, or 0 for success. 591 */ 592 static inline int cpumask_parse_user(const char __user *buf, int len, 593 struct cpumask *dstp) 594 { 595 return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits); 596 } 597 598 /** 599 * cpumask_parselist_user - extract a cpumask from a user string 600 * @buf: the buffer to extract from 601 * @len: the length of the buffer 602 * @dstp: the cpumask to set. 603 * 604 * Returns -errno, or 0 for success. 605 */ 606 static inline int cpumask_parselist_user(const char __user *buf, int len, 607 struct cpumask *dstp) 608 { 609 return bitmap_parselist_user(buf, len, cpumask_bits(dstp), 610 nr_cpumask_bits); 611 } 612 613 /** 614 * cpumask_parse - extract a cpumask from a string 615 * @buf: the buffer to extract from 616 * @dstp: the cpumask to set. 617 * 618 * Returns -errno, or 0 for success. 619 */ 620 static inline int cpumask_parse(const char *buf, struct cpumask *dstp) 621 { 622 char *nl = strchr(buf, '\n'); 623 unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf); 624 625 return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits); 626 } 627 628 /** 629 * cpulist_parse - extract a cpumask from a user string of ranges 630 * @buf: the buffer to extract from 631 * @dstp: the cpumask to set. 632 * 633 * Returns -errno, or 0 for success. 634 */ 635 static inline int cpulist_parse(const char *buf, struct cpumask *dstp) 636 { 637 return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits); 638 } 639 640 /** 641 * cpumask_size - size to allocate for a 'struct cpumask' in bytes 642 */ 643 static inline size_t cpumask_size(void) 644 { 645 return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long); 646 } 647 648 /* 649 * cpumask_var_t: struct cpumask for stack usage. 650 * 651 * Oh, the wicked games we play! In order to make kernel coding a 652 * little more difficult, we typedef cpumask_var_t to an array or a 653 * pointer: doing &mask on an array is a noop, so it still works. 654 * 655 * ie. 656 * cpumask_var_t tmpmask; 657 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 658 * return -ENOMEM; 659 * 660 * ... use 'tmpmask' like a normal struct cpumask * ... 661 * 662 * free_cpumask_var(tmpmask); 663 * 664 * 665 * However, one notable exception is there. alloc_cpumask_var() allocates 666 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has 667 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t. 668 * 669 * cpumask_var_t tmpmask; 670 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 671 * return -ENOMEM; 672 * 673 * var = *tmpmask; 674 * 675 * This code makes NR_CPUS length memcopy and brings to a memory corruption. 676 * cpumask_copy() provide safe copy functionality. 677 * 678 * Note that there is another evil here: If you define a cpumask_var_t 679 * as a percpu variable then the way to obtain the address of the cpumask 680 * structure differently influences what this_cpu_* operation needs to be 681 * used. Please use this_cpu_cpumask_var_t in those cases. The direct use 682 * of this_cpu_ptr() or this_cpu_read() will lead to failures when the 683 * other type of cpumask_var_t implementation is configured. 684 * 685 * Please also note that __cpumask_var_read_mostly can be used to declare 686 * a cpumask_var_t variable itself (not its content) as read mostly. 687 */ 688 #ifdef CONFIG_CPUMASK_OFFSTACK 689 typedef struct cpumask *cpumask_var_t; 690 691 #define this_cpu_cpumask_var_ptr(x) this_cpu_read(x) 692 #define __cpumask_var_read_mostly __read_mostly 693 694 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 695 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 696 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 697 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 698 void alloc_bootmem_cpumask_var(cpumask_var_t *mask); 699 void free_cpumask_var(cpumask_var_t mask); 700 void free_bootmem_cpumask_var(cpumask_var_t mask); 701 702 static inline bool cpumask_available(cpumask_var_t mask) 703 { 704 return mask != NULL; 705 } 706 707 #else 708 typedef struct cpumask cpumask_var_t[1]; 709 710 #define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x) 711 #define __cpumask_var_read_mostly 712 713 static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 714 { 715 return true; 716 } 717 718 static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 719 int node) 720 { 721 return true; 722 } 723 724 static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 725 { 726 cpumask_clear(*mask); 727 return true; 728 } 729 730 static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 731 int node) 732 { 733 cpumask_clear(*mask); 734 return true; 735 } 736 737 static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask) 738 { 739 } 740 741 static inline void free_cpumask_var(cpumask_var_t mask) 742 { 743 } 744 745 static inline void free_bootmem_cpumask_var(cpumask_var_t mask) 746 { 747 } 748 749 static inline bool cpumask_available(cpumask_var_t mask) 750 { 751 return true; 752 } 753 #endif /* CONFIG_CPUMASK_OFFSTACK */ 754 755 /* It's common to want to use cpu_all_mask in struct member initializers, 756 * so it has to refer to an address rather than a pointer. */ 757 extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS); 758 #define cpu_all_mask to_cpumask(cpu_all_bits) 759 760 /* First bits of cpu_bit_bitmap are in fact unset. */ 761 #define cpu_none_mask to_cpumask(cpu_bit_bitmap[0]) 762 763 #define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask) 764 #define for_each_online_cpu(cpu) for_each_cpu((cpu), cpu_online_mask) 765 #define for_each_present_cpu(cpu) for_each_cpu((cpu), cpu_present_mask) 766 767 /* Wrappers for arch boot code to manipulate normally-constant masks */ 768 void init_cpu_present(const struct cpumask *src); 769 void init_cpu_possible(const struct cpumask *src); 770 void init_cpu_online(const struct cpumask *src); 771 772 static inline void reset_cpu_possible_mask(void) 773 { 774 bitmap_zero(cpumask_bits(&__cpu_possible_mask), NR_CPUS); 775 } 776 777 static inline void 778 set_cpu_possible(unsigned int cpu, bool possible) 779 { 780 if (possible) 781 cpumask_set_cpu(cpu, &__cpu_possible_mask); 782 else 783 cpumask_clear_cpu(cpu, &__cpu_possible_mask); 784 } 785 786 static inline void 787 set_cpu_present(unsigned int cpu, bool present) 788 { 789 if (present) 790 cpumask_set_cpu(cpu, &__cpu_present_mask); 791 else 792 cpumask_clear_cpu(cpu, &__cpu_present_mask); 793 } 794 795 static inline void 796 set_cpu_online(unsigned int cpu, bool online) 797 { 798 if (online) 799 cpumask_set_cpu(cpu, &__cpu_online_mask); 800 else 801 cpumask_clear_cpu(cpu, &__cpu_online_mask); 802 } 803 804 static inline void 805 set_cpu_active(unsigned int cpu, bool active) 806 { 807 if (active) 808 cpumask_set_cpu(cpu, &__cpu_active_mask); 809 else 810 cpumask_clear_cpu(cpu, &__cpu_active_mask); 811 } 812 813 814 /** 815 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask * 816 * @bitmap: the bitmap 817 * 818 * There are a few places where cpumask_var_t isn't appropriate and 819 * static cpumasks must be used (eg. very early boot), yet we don't 820 * expose the definition of 'struct cpumask'. 821 * 822 * This does the conversion, and can be used as a constant initializer. 823 */ 824 #define to_cpumask(bitmap) \ 825 ((struct cpumask *)(1 ? (bitmap) \ 826 : (void *)sizeof(__check_is_bitmap(bitmap)))) 827 828 static inline int __check_is_bitmap(const unsigned long *bitmap) 829 { 830 return 1; 831 } 832 833 /* 834 * Special-case data structure for "single bit set only" constant CPU masks. 835 * 836 * We pre-generate all the 64 (or 32) possible bit positions, with enough 837 * padding to the left and the right, and return the constant pointer 838 * appropriately offset. 839 */ 840 extern const unsigned long 841 cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)]; 842 843 static inline const struct cpumask *get_cpu_mask(unsigned int cpu) 844 { 845 const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG]; 846 p -= cpu / BITS_PER_LONG; 847 return to_cpumask(p); 848 } 849 850 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) 851 852 #if NR_CPUS <= BITS_PER_LONG 853 #define CPU_BITS_ALL \ 854 { \ 855 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 856 } 857 858 #else /* NR_CPUS > BITS_PER_LONG */ 859 860 #define CPU_BITS_ALL \ 861 { \ 862 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 863 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 864 } 865 #endif /* NR_CPUS > BITS_PER_LONG */ 866 867 /** 868 * cpumap_print_to_pagebuf - copies the cpumask into the buffer either 869 * as comma-separated list of cpus or hex values of cpumask 870 * @list: indicates whether the cpumap must be list 871 * @mask: the cpumask to copy 872 * @buf: the buffer to copy into 873 * 874 * Returns the length of the (null-terminated) @buf string, zero if 875 * nothing is copied. 876 */ 877 static inline ssize_t 878 cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask) 879 { 880 return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask), 881 nr_cpu_ids); 882 } 883 884 #if NR_CPUS <= BITS_PER_LONG 885 #define CPU_MASK_ALL \ 886 (cpumask_t) { { \ 887 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 888 } } 889 #else 890 #define CPU_MASK_ALL \ 891 (cpumask_t) { { \ 892 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 893 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 894 } } 895 #endif /* NR_CPUS > BITS_PER_LONG */ 896 897 #define CPU_MASK_NONE \ 898 (cpumask_t) { { \ 899 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 900 } } 901 902 #define CPU_MASK_CPU0 \ 903 (cpumask_t) { { \ 904 [0] = 1UL \ 905 } } 906 907 #endif /* __LINUX_CPUMASK_H */ 908