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 static inline void cpu_max_bits_warn(unsigned int cpu, unsigned int bits) 119 { 120 #ifdef CONFIG_DEBUG_PER_CPU_MAPS 121 WARN_ON_ONCE(cpu >= bits); 122 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */ 123 } 124 125 /* verify cpu argument to cpumask_* operators */ 126 static inline unsigned int cpumask_check(unsigned int cpu) 127 { 128 cpu_max_bits_warn(cpu, nr_cpumask_bits); 129 return cpu; 130 } 131 132 #if NR_CPUS == 1 133 /* Uniprocessor. Assume all masks are "1". */ 134 static inline unsigned int cpumask_first(const struct cpumask *srcp) 135 { 136 return 0; 137 } 138 139 static inline unsigned int cpumask_last(const struct cpumask *srcp) 140 { 141 return 0; 142 } 143 144 /* Valid inputs for n are -1 and 0. */ 145 static inline unsigned int cpumask_next(int n, const struct cpumask *srcp) 146 { 147 return n+1; 148 } 149 150 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp) 151 { 152 return n+1; 153 } 154 155 static inline unsigned int cpumask_next_and(int n, 156 const struct cpumask *srcp, 157 const struct cpumask *andp) 158 { 159 return n+1; 160 } 161 162 static inline unsigned int cpumask_next_wrap(int n, const struct cpumask *mask, 163 int start, bool wrap) 164 { 165 /* cpu0 unless stop condition, wrap and at cpu0, then nr_cpumask_bits */ 166 return (wrap && n == 0); 167 } 168 169 /* cpu must be a valid cpu, ie 0, so there's no other choice. */ 170 static inline unsigned int cpumask_any_but(const struct cpumask *mask, 171 unsigned int cpu) 172 { 173 return 1; 174 } 175 176 static inline unsigned int cpumask_local_spread(unsigned int i, int node) 177 { 178 return 0; 179 } 180 181 #define for_each_cpu(cpu, mask) \ 182 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask) 183 #define for_each_cpu_not(cpu, mask) \ 184 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask) 185 #define for_each_cpu_wrap(cpu, mask, start) \ 186 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)(start)) 187 #define for_each_cpu_and(cpu, mask, and) \ 188 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and) 189 #else 190 /** 191 * cpumask_first - get the first cpu in a cpumask 192 * @srcp: the cpumask pointer 193 * 194 * Returns >= nr_cpu_ids if no cpus set. 195 */ 196 static inline unsigned int cpumask_first(const struct cpumask *srcp) 197 { 198 return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits); 199 } 200 201 /** 202 * cpumask_last - get the last CPU in a cpumask 203 * @srcp: - the cpumask pointer 204 * 205 * Returns >= nr_cpumask_bits if no CPUs set. 206 */ 207 static inline unsigned int cpumask_last(const struct cpumask *srcp) 208 { 209 return find_last_bit(cpumask_bits(srcp), nr_cpumask_bits); 210 } 211 212 unsigned int cpumask_next(int n, const struct cpumask *srcp); 213 214 /** 215 * cpumask_next_zero - get the next unset cpu in a cpumask 216 * @n: the cpu prior to the place to search (ie. return will be > @n) 217 * @srcp: the cpumask pointer 218 * 219 * Returns >= nr_cpu_ids if no further cpus unset. 220 */ 221 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp) 222 { 223 /* -1 is a legal arg here. */ 224 if (n != -1) 225 cpumask_check(n); 226 return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1); 227 } 228 229 int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *); 230 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu); 231 unsigned int cpumask_local_spread(unsigned int i, int node); 232 233 /** 234 * for_each_cpu - iterate over every cpu in a mask 235 * @cpu: the (optionally unsigned) integer iterator 236 * @mask: the cpumask pointer 237 * 238 * After the loop, cpu is >= nr_cpu_ids. 239 */ 240 #define for_each_cpu(cpu, mask) \ 241 for ((cpu) = -1; \ 242 (cpu) = cpumask_next((cpu), (mask)), \ 243 (cpu) < nr_cpu_ids;) 244 245 /** 246 * for_each_cpu_not - iterate over every cpu in a complemented mask 247 * @cpu: the (optionally unsigned) integer iterator 248 * @mask: the cpumask pointer 249 * 250 * After the loop, cpu is >= nr_cpu_ids. 251 */ 252 #define for_each_cpu_not(cpu, mask) \ 253 for ((cpu) = -1; \ 254 (cpu) = cpumask_next_zero((cpu), (mask)), \ 255 (cpu) < nr_cpu_ids;) 256 257 extern int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap); 258 259 /** 260 * for_each_cpu_wrap - iterate over every cpu in a mask, starting at a specified location 261 * @cpu: the (optionally unsigned) integer iterator 262 * @mask: the cpumask poiter 263 * @start: the start location 264 * 265 * The implementation does not assume any bit in @mask is set (including @start). 266 * 267 * After the loop, cpu is >= nr_cpu_ids. 268 */ 269 #define for_each_cpu_wrap(cpu, mask, start) \ 270 for ((cpu) = cpumask_next_wrap((start)-1, (mask), (start), false); \ 271 (cpu) < nr_cpumask_bits; \ 272 (cpu) = cpumask_next_wrap((cpu), (mask), (start), true)) 273 274 /** 275 * for_each_cpu_and - iterate over every cpu in both masks 276 * @cpu: the (optionally unsigned) integer iterator 277 * @mask: the first cpumask pointer 278 * @and: the second cpumask pointer 279 * 280 * This saves a temporary CPU mask in many places. It is equivalent to: 281 * struct cpumask tmp; 282 * cpumask_and(&tmp, &mask, &and); 283 * for_each_cpu(cpu, &tmp) 284 * ... 285 * 286 * After the loop, cpu is >= nr_cpu_ids. 287 */ 288 #define for_each_cpu_and(cpu, mask, and) \ 289 for ((cpu) = -1; \ 290 (cpu) = cpumask_next_and((cpu), (mask), (and)), \ 291 (cpu) < nr_cpu_ids;) 292 #endif /* SMP */ 293 294 #define CPU_BITS_NONE \ 295 { \ 296 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 297 } 298 299 #define CPU_BITS_CPU0 \ 300 { \ 301 [0] = 1UL \ 302 } 303 304 /** 305 * cpumask_set_cpu - set a cpu in a cpumask 306 * @cpu: cpu number (< nr_cpu_ids) 307 * @dstp: the cpumask pointer 308 */ 309 static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 310 { 311 set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 312 } 313 314 static inline void __cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 315 { 316 __set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 317 } 318 319 320 /** 321 * cpumask_clear_cpu - clear a cpu in a cpumask 322 * @cpu: cpu number (< nr_cpu_ids) 323 * @dstp: the cpumask pointer 324 */ 325 static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp) 326 { 327 clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 328 } 329 330 static inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp) 331 { 332 __clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 333 } 334 335 /** 336 * cpumask_test_cpu - test for a cpu in a cpumask 337 * @cpu: cpu number (< nr_cpu_ids) 338 * @cpumask: the cpumask pointer 339 * 340 * Returns 1 if @cpu is set in @cpumask, else returns 0 341 */ 342 static inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask) 343 { 344 return test_bit(cpumask_check(cpu), cpumask_bits((cpumask))); 345 } 346 347 /** 348 * cpumask_test_and_set_cpu - atomically test and set 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_set_bit wrapper for cpumasks. 355 */ 356 static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask) 357 { 358 return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 359 } 360 361 /** 362 * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask 363 * @cpu: cpu number (< nr_cpu_ids) 364 * @cpumask: the cpumask pointer 365 * 366 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0 367 * 368 * test_and_clear_bit wrapper for cpumasks. 369 */ 370 static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask) 371 { 372 return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 373 } 374 375 /** 376 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask 377 * @dstp: the cpumask pointer 378 */ 379 static inline void cpumask_setall(struct cpumask *dstp) 380 { 381 bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits); 382 } 383 384 /** 385 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask 386 * @dstp: the cpumask pointer 387 */ 388 static inline void cpumask_clear(struct cpumask *dstp) 389 { 390 bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits); 391 } 392 393 /** 394 * cpumask_and - *dstp = *src1p & *src2p 395 * @dstp: the cpumask result 396 * @src1p: the first input 397 * @src2p: the second input 398 * 399 * If *@dstp is empty, returns 0, else returns 1 400 */ 401 static inline int cpumask_and(struct cpumask *dstp, 402 const struct cpumask *src1p, 403 const struct cpumask *src2p) 404 { 405 return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p), 406 cpumask_bits(src2p), nr_cpumask_bits); 407 } 408 409 /** 410 * cpumask_or - *dstp = *src1p | *src2p 411 * @dstp: the cpumask result 412 * @src1p: the first input 413 * @src2p: the second input 414 */ 415 static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p, 416 const struct cpumask *src2p) 417 { 418 bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p), 419 cpumask_bits(src2p), nr_cpumask_bits); 420 } 421 422 /** 423 * cpumask_xor - *dstp = *src1p ^ *src2p 424 * @dstp: the cpumask result 425 * @src1p: the first input 426 * @src2p: the second input 427 */ 428 static inline void cpumask_xor(struct cpumask *dstp, 429 const struct cpumask *src1p, 430 const struct cpumask *src2p) 431 { 432 bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p), 433 cpumask_bits(src2p), nr_cpumask_bits); 434 } 435 436 /** 437 * cpumask_andnot - *dstp = *src1p & ~*src2p 438 * @dstp: the cpumask result 439 * @src1p: the first input 440 * @src2p: the second input 441 * 442 * If *@dstp is empty, returns 0, else returns 1 443 */ 444 static inline int cpumask_andnot(struct cpumask *dstp, 445 const struct cpumask *src1p, 446 const struct cpumask *src2p) 447 { 448 return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p), 449 cpumask_bits(src2p), nr_cpumask_bits); 450 } 451 452 /** 453 * cpumask_complement - *dstp = ~*srcp 454 * @dstp: the cpumask result 455 * @srcp: the input to invert 456 */ 457 static inline void cpumask_complement(struct cpumask *dstp, 458 const struct cpumask *srcp) 459 { 460 bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp), 461 nr_cpumask_bits); 462 } 463 464 /** 465 * cpumask_equal - *src1p == *src2p 466 * @src1p: the first input 467 * @src2p: the second input 468 */ 469 static inline bool cpumask_equal(const struct cpumask *src1p, 470 const struct cpumask *src2p) 471 { 472 return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p), 473 nr_cpumask_bits); 474 } 475 476 /** 477 * cpumask_intersects - (*src1p & *src2p) != 0 478 * @src1p: the first input 479 * @src2p: the second input 480 */ 481 static inline bool cpumask_intersects(const struct cpumask *src1p, 482 const struct cpumask *src2p) 483 { 484 return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p), 485 nr_cpumask_bits); 486 } 487 488 /** 489 * cpumask_subset - (*src1p & ~*src2p) == 0 490 * @src1p: the first input 491 * @src2p: the second input 492 * 493 * Returns 1 if *@src1p is a subset of *@src2p, else returns 0 494 */ 495 static inline int cpumask_subset(const struct cpumask *src1p, 496 const struct cpumask *src2p) 497 { 498 return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p), 499 nr_cpumask_bits); 500 } 501 502 /** 503 * cpumask_empty - *srcp == 0 504 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear. 505 */ 506 static inline bool cpumask_empty(const struct cpumask *srcp) 507 { 508 return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits); 509 } 510 511 /** 512 * cpumask_full - *srcp == 0xFFFFFFFF... 513 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set. 514 */ 515 static inline bool cpumask_full(const struct cpumask *srcp) 516 { 517 return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits); 518 } 519 520 /** 521 * cpumask_weight - Count of bits in *srcp 522 * @srcp: the cpumask to count bits (< nr_cpu_ids) in. 523 */ 524 static inline unsigned int cpumask_weight(const struct cpumask *srcp) 525 { 526 return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits); 527 } 528 529 /** 530 * cpumask_shift_right - *dstp = *srcp >> n 531 * @dstp: the cpumask result 532 * @srcp: the input to shift 533 * @n: the number of bits to shift by 534 */ 535 static inline void cpumask_shift_right(struct cpumask *dstp, 536 const struct cpumask *srcp, int n) 537 { 538 bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n, 539 nr_cpumask_bits); 540 } 541 542 /** 543 * cpumask_shift_left - *dstp = *srcp << n 544 * @dstp: the cpumask result 545 * @srcp: the input to shift 546 * @n: the number of bits to shift by 547 */ 548 static inline void cpumask_shift_left(struct cpumask *dstp, 549 const struct cpumask *srcp, int n) 550 { 551 bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n, 552 nr_cpumask_bits); 553 } 554 555 /** 556 * cpumask_copy - *dstp = *srcp 557 * @dstp: the result 558 * @srcp: the input cpumask 559 */ 560 static inline void cpumask_copy(struct cpumask *dstp, 561 const struct cpumask *srcp) 562 { 563 bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits); 564 } 565 566 /** 567 * cpumask_any - pick a "random" cpu from *srcp 568 * @srcp: the input cpumask 569 * 570 * Returns >= nr_cpu_ids if no cpus set. 571 */ 572 #define cpumask_any(srcp) cpumask_first(srcp) 573 574 /** 575 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2 576 * @src1p: the first input 577 * @src2p: the second input 578 * 579 * Returns >= nr_cpu_ids if no cpus set in both. See also cpumask_next_and(). 580 */ 581 #define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p)) 582 583 /** 584 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2 585 * @mask1: the first input cpumask 586 * @mask2: the second input cpumask 587 * 588 * Returns >= nr_cpu_ids if no cpus set. 589 */ 590 #define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2)) 591 592 /** 593 * cpumask_of - the cpumask containing just a given cpu 594 * @cpu: the cpu (<= nr_cpu_ids) 595 */ 596 #define cpumask_of(cpu) (get_cpu_mask(cpu)) 597 598 /** 599 * cpumask_parse_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_parse_user(const char __user *buf, int len, 607 struct cpumask *dstp) 608 { 609 return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits); 610 } 611 612 /** 613 * cpumask_parselist_user - extract a cpumask from a user string 614 * @buf: the buffer to extract from 615 * @len: the length of the buffer 616 * @dstp: the cpumask to set. 617 * 618 * Returns -errno, or 0 for success. 619 */ 620 static inline int cpumask_parselist_user(const char __user *buf, int len, 621 struct cpumask *dstp) 622 { 623 return bitmap_parselist_user(buf, len, cpumask_bits(dstp), 624 nr_cpumask_bits); 625 } 626 627 /** 628 * cpumask_parse - extract a cpumask from a string 629 * @buf: the buffer to extract from 630 * @dstp: the cpumask to set. 631 * 632 * Returns -errno, or 0 for success. 633 */ 634 static inline int cpumask_parse(const char *buf, struct cpumask *dstp) 635 { 636 unsigned int len = strchrnul(buf, '\n') - buf; 637 638 return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits); 639 } 640 641 /** 642 * cpulist_parse - extract a cpumask from a user string of ranges 643 * @buf: the buffer to extract from 644 * @dstp: the cpumask to set. 645 * 646 * Returns -errno, or 0 for success. 647 */ 648 static inline int cpulist_parse(const char *buf, struct cpumask *dstp) 649 { 650 return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits); 651 } 652 653 /** 654 * cpumask_size - size to allocate for a 'struct cpumask' in bytes 655 */ 656 static inline unsigned int cpumask_size(void) 657 { 658 return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long); 659 } 660 661 /* 662 * cpumask_var_t: struct cpumask for stack usage. 663 * 664 * Oh, the wicked games we play! In order to make kernel coding a 665 * little more difficult, we typedef cpumask_var_t to an array or a 666 * pointer: doing &mask on an array is a noop, so it still works. 667 * 668 * ie. 669 * cpumask_var_t tmpmask; 670 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 671 * return -ENOMEM; 672 * 673 * ... use 'tmpmask' like a normal struct cpumask * ... 674 * 675 * free_cpumask_var(tmpmask); 676 * 677 * 678 * However, one notable exception is there. alloc_cpumask_var() allocates 679 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has 680 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t. 681 * 682 * cpumask_var_t tmpmask; 683 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 684 * return -ENOMEM; 685 * 686 * var = *tmpmask; 687 * 688 * This code makes NR_CPUS length memcopy and brings to a memory corruption. 689 * cpumask_copy() provide safe copy functionality. 690 * 691 * Note that there is another evil here: If you define a cpumask_var_t 692 * as a percpu variable then the way to obtain the address of the cpumask 693 * structure differently influences what this_cpu_* operation needs to be 694 * used. Please use this_cpu_cpumask_var_t in those cases. The direct use 695 * of this_cpu_ptr() or this_cpu_read() will lead to failures when the 696 * other type of cpumask_var_t implementation is configured. 697 * 698 * Please also note that __cpumask_var_read_mostly can be used to declare 699 * a cpumask_var_t variable itself (not its content) as read mostly. 700 */ 701 #ifdef CONFIG_CPUMASK_OFFSTACK 702 typedef struct cpumask *cpumask_var_t; 703 704 #define this_cpu_cpumask_var_ptr(x) this_cpu_read(x) 705 #define __cpumask_var_read_mostly __read_mostly 706 707 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 708 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 709 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 710 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 711 void alloc_bootmem_cpumask_var(cpumask_var_t *mask); 712 void free_cpumask_var(cpumask_var_t mask); 713 void free_bootmem_cpumask_var(cpumask_var_t mask); 714 715 static inline bool cpumask_available(cpumask_var_t mask) 716 { 717 return mask != NULL; 718 } 719 720 #else 721 typedef struct cpumask cpumask_var_t[1]; 722 723 #define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x) 724 #define __cpumask_var_read_mostly 725 726 static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 727 { 728 return true; 729 } 730 731 static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 732 int node) 733 { 734 return true; 735 } 736 737 static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 738 { 739 cpumask_clear(*mask); 740 return true; 741 } 742 743 static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 744 int node) 745 { 746 cpumask_clear(*mask); 747 return true; 748 } 749 750 static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask) 751 { 752 } 753 754 static inline void free_cpumask_var(cpumask_var_t mask) 755 { 756 } 757 758 static inline void free_bootmem_cpumask_var(cpumask_var_t mask) 759 { 760 } 761 762 static inline bool cpumask_available(cpumask_var_t mask) 763 { 764 return true; 765 } 766 #endif /* CONFIG_CPUMASK_OFFSTACK */ 767 768 /* It's common to want to use cpu_all_mask in struct member initializers, 769 * so it has to refer to an address rather than a pointer. */ 770 extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS); 771 #define cpu_all_mask to_cpumask(cpu_all_bits) 772 773 /* First bits of cpu_bit_bitmap are in fact unset. */ 774 #define cpu_none_mask to_cpumask(cpu_bit_bitmap[0]) 775 776 #define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask) 777 #define for_each_online_cpu(cpu) for_each_cpu((cpu), cpu_online_mask) 778 #define for_each_present_cpu(cpu) for_each_cpu((cpu), cpu_present_mask) 779 780 /* Wrappers for arch boot code to manipulate normally-constant masks */ 781 void init_cpu_present(const struct cpumask *src); 782 void init_cpu_possible(const struct cpumask *src); 783 void init_cpu_online(const struct cpumask *src); 784 785 static inline void reset_cpu_possible_mask(void) 786 { 787 bitmap_zero(cpumask_bits(&__cpu_possible_mask), NR_CPUS); 788 } 789 790 static inline void 791 set_cpu_possible(unsigned int cpu, bool possible) 792 { 793 if (possible) 794 cpumask_set_cpu(cpu, &__cpu_possible_mask); 795 else 796 cpumask_clear_cpu(cpu, &__cpu_possible_mask); 797 } 798 799 static inline void 800 set_cpu_present(unsigned int cpu, bool present) 801 { 802 if (present) 803 cpumask_set_cpu(cpu, &__cpu_present_mask); 804 else 805 cpumask_clear_cpu(cpu, &__cpu_present_mask); 806 } 807 808 static inline void 809 set_cpu_online(unsigned int cpu, bool online) 810 { 811 if (online) 812 cpumask_set_cpu(cpu, &__cpu_online_mask); 813 else 814 cpumask_clear_cpu(cpu, &__cpu_online_mask); 815 } 816 817 static inline void 818 set_cpu_active(unsigned int cpu, bool active) 819 { 820 if (active) 821 cpumask_set_cpu(cpu, &__cpu_active_mask); 822 else 823 cpumask_clear_cpu(cpu, &__cpu_active_mask); 824 } 825 826 827 /** 828 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask * 829 * @bitmap: the bitmap 830 * 831 * There are a few places where cpumask_var_t isn't appropriate and 832 * static cpumasks must be used (eg. very early boot), yet we don't 833 * expose the definition of 'struct cpumask'. 834 * 835 * This does the conversion, and can be used as a constant initializer. 836 */ 837 #define to_cpumask(bitmap) \ 838 ((struct cpumask *)(1 ? (bitmap) \ 839 : (void *)sizeof(__check_is_bitmap(bitmap)))) 840 841 static inline int __check_is_bitmap(const unsigned long *bitmap) 842 { 843 return 1; 844 } 845 846 /* 847 * Special-case data structure for "single bit set only" constant CPU masks. 848 * 849 * We pre-generate all the 64 (or 32) possible bit positions, with enough 850 * padding to the left and the right, and return the constant pointer 851 * appropriately offset. 852 */ 853 extern const unsigned long 854 cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)]; 855 856 static inline const struct cpumask *get_cpu_mask(unsigned int cpu) 857 { 858 const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG]; 859 p -= cpu / BITS_PER_LONG; 860 return to_cpumask(p); 861 } 862 863 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) 864 865 #if NR_CPUS <= BITS_PER_LONG 866 #define CPU_BITS_ALL \ 867 { \ 868 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 869 } 870 871 #else /* NR_CPUS > BITS_PER_LONG */ 872 873 #define CPU_BITS_ALL \ 874 { \ 875 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 876 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 877 } 878 #endif /* NR_CPUS > BITS_PER_LONG */ 879 880 /** 881 * cpumap_print_to_pagebuf - copies the cpumask into the buffer either 882 * as comma-separated list of cpus or hex values of cpumask 883 * @list: indicates whether the cpumap must be list 884 * @mask: the cpumask to copy 885 * @buf: the buffer to copy into 886 * 887 * Returns the length of the (null-terminated) @buf string, zero if 888 * nothing is copied. 889 */ 890 static inline ssize_t 891 cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask) 892 { 893 return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask), 894 nr_cpu_ids); 895 } 896 897 #if NR_CPUS <= BITS_PER_LONG 898 #define CPU_MASK_ALL \ 899 (cpumask_t) { { \ 900 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 901 } } 902 #else 903 #define CPU_MASK_ALL \ 904 (cpumask_t) { { \ 905 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 906 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 907 } } 908 #endif /* NR_CPUS > BITS_PER_LONG */ 909 910 #define CPU_MASK_NONE \ 911 (cpumask_t) { { \ 912 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 913 } } 914 915 #define CPU_MASK_CPU0 \ 916 (cpumask_t) { { \ 917 [0] = 1UL \ 918 } } 919 920 #endif /* __LINUX_CPUMASK_H */ 921