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_wrap(cpu, mask, start) \ 174 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)(start)) 175 #define for_each_cpu_and(cpu, mask, and) \ 176 for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and) 177 #else 178 /** 179 * cpumask_first - get the first cpu in a cpumask 180 * @srcp: the cpumask pointer 181 * 182 * Returns >= nr_cpu_ids if no cpus set. 183 */ 184 static inline unsigned int cpumask_first(const struct cpumask *srcp) 185 { 186 return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits); 187 } 188 189 /** 190 * cpumask_last - get the last CPU in a cpumask 191 * @srcp: - the cpumask pointer 192 * 193 * Returns >= nr_cpumask_bits if no CPUs set. 194 */ 195 static inline unsigned int cpumask_last(const struct cpumask *srcp) 196 { 197 return find_last_bit(cpumask_bits(srcp), nr_cpumask_bits); 198 } 199 200 unsigned int cpumask_next(int n, const struct cpumask *srcp); 201 202 /** 203 * cpumask_next_zero - get the next unset cpu in a cpumask 204 * @n: the cpu prior to the place to search (ie. return will be > @n) 205 * @srcp: the cpumask pointer 206 * 207 * Returns >= nr_cpu_ids if no further cpus unset. 208 */ 209 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp) 210 { 211 /* -1 is a legal arg here. */ 212 if (n != -1) 213 cpumask_check(n); 214 return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1); 215 } 216 217 int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *); 218 int cpumask_any_but(const struct cpumask *mask, unsigned int cpu); 219 unsigned int cpumask_local_spread(unsigned int i, int node); 220 221 /** 222 * for_each_cpu - iterate over every cpu in a mask 223 * @cpu: the (optionally unsigned) integer iterator 224 * @mask: the cpumask pointer 225 * 226 * After the loop, cpu is >= nr_cpu_ids. 227 */ 228 #define for_each_cpu(cpu, mask) \ 229 for ((cpu) = -1; \ 230 (cpu) = cpumask_next((cpu), (mask)), \ 231 (cpu) < nr_cpu_ids;) 232 233 /** 234 * for_each_cpu_not - iterate over every cpu in a complemented 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_not(cpu, mask) \ 241 for ((cpu) = -1; \ 242 (cpu) = cpumask_next_zero((cpu), (mask)), \ 243 (cpu) < nr_cpu_ids;) 244 245 extern int cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap); 246 247 /** 248 * for_each_cpu_wrap - iterate over every cpu in a mask, starting at a specified location 249 * @cpu: the (optionally unsigned) integer iterator 250 * @mask: the cpumask poiter 251 * @start: the start location 252 * 253 * The implementation does not assume any bit in @mask is set (including @start). 254 * 255 * After the loop, cpu is >= nr_cpu_ids. 256 */ 257 #define for_each_cpu_wrap(cpu, mask, start) \ 258 for ((cpu) = cpumask_next_wrap((start)-1, (mask), (start), false); \ 259 (cpu) < nr_cpumask_bits; \ 260 (cpu) = cpumask_next_wrap((cpu), (mask), (start), true)) 261 262 /** 263 * for_each_cpu_and - iterate over every cpu in both masks 264 * @cpu: the (optionally unsigned) integer iterator 265 * @mask: the first cpumask pointer 266 * @and: the second cpumask pointer 267 * 268 * This saves a temporary CPU mask in many places. It is equivalent to: 269 * struct cpumask tmp; 270 * cpumask_and(&tmp, &mask, &and); 271 * for_each_cpu(cpu, &tmp) 272 * ... 273 * 274 * After the loop, cpu is >= nr_cpu_ids. 275 */ 276 #define for_each_cpu_and(cpu, mask, and) \ 277 for ((cpu) = -1; \ 278 (cpu) = cpumask_next_and((cpu), (mask), (and)), \ 279 (cpu) < nr_cpu_ids;) 280 #endif /* SMP */ 281 282 #define CPU_BITS_NONE \ 283 { \ 284 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 285 } 286 287 #define CPU_BITS_CPU0 \ 288 { \ 289 [0] = 1UL \ 290 } 291 292 /** 293 * cpumask_set_cpu - set a cpu in a cpumask 294 * @cpu: cpu number (< nr_cpu_ids) 295 * @dstp: the cpumask pointer 296 */ 297 static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 298 { 299 set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 300 } 301 302 static inline void __cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 303 { 304 __set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 305 } 306 307 308 /** 309 * cpumask_clear_cpu - clear a cpu in a cpumask 310 * @cpu: cpu number (< nr_cpu_ids) 311 * @dstp: the cpumask pointer 312 */ 313 static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp) 314 { 315 clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 316 } 317 318 static inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp) 319 { 320 __clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 321 } 322 323 /** 324 * cpumask_test_cpu - test for a cpu in a cpumask 325 * @cpu: cpu number (< nr_cpu_ids) 326 * @cpumask: the cpumask pointer 327 * 328 * Returns 1 if @cpu is set in @cpumask, else returns 0 329 */ 330 static inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask) 331 { 332 return test_bit(cpumask_check(cpu), cpumask_bits((cpumask))); 333 } 334 335 /** 336 * cpumask_test_and_set_cpu - atomically test and set 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 old bitmap of @cpumask, else returns 0 341 * 342 * test_and_set_bit wrapper for cpumasks. 343 */ 344 static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask) 345 { 346 return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 347 } 348 349 /** 350 * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask 351 * @cpu: cpu number (< nr_cpu_ids) 352 * @cpumask: the cpumask pointer 353 * 354 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0 355 * 356 * test_and_clear_bit wrapper for cpumasks. 357 */ 358 static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask) 359 { 360 return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 361 } 362 363 /** 364 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask 365 * @dstp: the cpumask pointer 366 */ 367 static inline void cpumask_setall(struct cpumask *dstp) 368 { 369 bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits); 370 } 371 372 /** 373 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask 374 * @dstp: the cpumask pointer 375 */ 376 static inline void cpumask_clear(struct cpumask *dstp) 377 { 378 bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits); 379 } 380 381 /** 382 * cpumask_and - *dstp = *src1p & *src2p 383 * @dstp: the cpumask result 384 * @src1p: the first input 385 * @src2p: the second input 386 * 387 * If *@dstp is empty, returns 0, else returns 1 388 */ 389 static inline int cpumask_and(struct cpumask *dstp, 390 const struct cpumask *src1p, 391 const struct cpumask *src2p) 392 { 393 return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p), 394 cpumask_bits(src2p), nr_cpumask_bits); 395 } 396 397 /** 398 * cpumask_or - *dstp = *src1p | *src2p 399 * @dstp: the cpumask result 400 * @src1p: the first input 401 * @src2p: the second input 402 */ 403 static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p, 404 const struct cpumask *src2p) 405 { 406 bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p), 407 cpumask_bits(src2p), nr_cpumask_bits); 408 } 409 410 /** 411 * cpumask_xor - *dstp = *src1p ^ *src2p 412 * @dstp: the cpumask result 413 * @src1p: the first input 414 * @src2p: the second input 415 */ 416 static inline void cpumask_xor(struct cpumask *dstp, 417 const struct cpumask *src1p, 418 const struct cpumask *src2p) 419 { 420 bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p), 421 cpumask_bits(src2p), nr_cpumask_bits); 422 } 423 424 /** 425 * cpumask_andnot - *dstp = *src1p & ~*src2p 426 * @dstp: the cpumask result 427 * @src1p: the first input 428 * @src2p: the second input 429 * 430 * If *@dstp is empty, returns 0, else returns 1 431 */ 432 static inline int cpumask_andnot(struct cpumask *dstp, 433 const struct cpumask *src1p, 434 const struct cpumask *src2p) 435 { 436 return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p), 437 cpumask_bits(src2p), nr_cpumask_bits); 438 } 439 440 /** 441 * cpumask_complement - *dstp = ~*srcp 442 * @dstp: the cpumask result 443 * @srcp: the input to invert 444 */ 445 static inline void cpumask_complement(struct cpumask *dstp, 446 const struct cpumask *srcp) 447 { 448 bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp), 449 nr_cpumask_bits); 450 } 451 452 /** 453 * cpumask_equal - *src1p == *src2p 454 * @src1p: the first input 455 * @src2p: the second input 456 */ 457 static inline bool cpumask_equal(const struct cpumask *src1p, 458 const struct cpumask *src2p) 459 { 460 return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p), 461 nr_cpumask_bits); 462 } 463 464 /** 465 * cpumask_intersects - (*src1p & *src2p) != 0 466 * @src1p: the first input 467 * @src2p: the second input 468 */ 469 static inline bool cpumask_intersects(const struct cpumask *src1p, 470 const struct cpumask *src2p) 471 { 472 return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p), 473 nr_cpumask_bits); 474 } 475 476 /** 477 * cpumask_subset - (*src1p & ~*src2p) == 0 478 * @src1p: the first input 479 * @src2p: the second input 480 * 481 * Returns 1 if *@src1p is a subset of *@src2p, else returns 0 482 */ 483 static inline int cpumask_subset(const struct cpumask *src1p, 484 const struct cpumask *src2p) 485 { 486 return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p), 487 nr_cpumask_bits); 488 } 489 490 /** 491 * cpumask_empty - *srcp == 0 492 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear. 493 */ 494 static inline bool cpumask_empty(const struct cpumask *srcp) 495 { 496 return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits); 497 } 498 499 /** 500 * cpumask_full - *srcp == 0xFFFFFFFF... 501 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set. 502 */ 503 static inline bool cpumask_full(const struct cpumask *srcp) 504 { 505 return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits); 506 } 507 508 /** 509 * cpumask_weight - Count of bits in *srcp 510 * @srcp: the cpumask to count bits (< nr_cpu_ids) in. 511 */ 512 static inline unsigned int cpumask_weight(const struct cpumask *srcp) 513 { 514 return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits); 515 } 516 517 /** 518 * cpumask_shift_right - *dstp = *srcp >> n 519 * @dstp: the cpumask result 520 * @srcp: the input to shift 521 * @n: the number of bits to shift by 522 */ 523 static inline void cpumask_shift_right(struct cpumask *dstp, 524 const struct cpumask *srcp, int n) 525 { 526 bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n, 527 nr_cpumask_bits); 528 } 529 530 /** 531 * cpumask_shift_left - *dstp = *srcp << n 532 * @dstp: the cpumask result 533 * @srcp: the input to shift 534 * @n: the number of bits to shift by 535 */ 536 static inline void cpumask_shift_left(struct cpumask *dstp, 537 const struct cpumask *srcp, int n) 538 { 539 bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n, 540 nr_cpumask_bits); 541 } 542 543 /** 544 * cpumask_copy - *dstp = *srcp 545 * @dstp: the result 546 * @srcp: the input cpumask 547 */ 548 static inline void cpumask_copy(struct cpumask *dstp, 549 const struct cpumask *srcp) 550 { 551 bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits); 552 } 553 554 /** 555 * cpumask_any - pick a "random" cpu from *srcp 556 * @srcp: the input cpumask 557 * 558 * Returns >= nr_cpu_ids if no cpus set. 559 */ 560 #define cpumask_any(srcp) cpumask_first(srcp) 561 562 /** 563 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2 564 * @src1p: the first input 565 * @src2p: the second input 566 * 567 * Returns >= nr_cpu_ids if no cpus set in both. See also cpumask_next_and(). 568 */ 569 #define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p)) 570 571 /** 572 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2 573 * @mask1: the first input cpumask 574 * @mask2: the second input cpumask 575 * 576 * Returns >= nr_cpu_ids if no cpus set. 577 */ 578 #define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2)) 579 580 /** 581 * cpumask_of - the cpumask containing just a given cpu 582 * @cpu: the cpu (<= nr_cpu_ids) 583 */ 584 #define cpumask_of(cpu) (get_cpu_mask(cpu)) 585 586 /** 587 * cpumask_parse_user - extract a cpumask from a user string 588 * @buf: the buffer to extract from 589 * @len: the length of the buffer 590 * @dstp: the cpumask to set. 591 * 592 * Returns -errno, or 0 for success. 593 */ 594 static inline int cpumask_parse_user(const char __user *buf, int len, 595 struct cpumask *dstp) 596 { 597 return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits); 598 } 599 600 /** 601 * cpumask_parselist_user - extract a cpumask from a user string 602 * @buf: the buffer to extract from 603 * @len: the length of the buffer 604 * @dstp: the cpumask to set. 605 * 606 * Returns -errno, or 0 for success. 607 */ 608 static inline int cpumask_parselist_user(const char __user *buf, int len, 609 struct cpumask *dstp) 610 { 611 return bitmap_parselist_user(buf, len, cpumask_bits(dstp), 612 nr_cpumask_bits); 613 } 614 615 /** 616 * cpumask_parse - extract a cpumask from a string 617 * @buf: the buffer to extract from 618 * @dstp: the cpumask to set. 619 * 620 * Returns -errno, or 0 for success. 621 */ 622 static inline int cpumask_parse(const char *buf, struct cpumask *dstp) 623 { 624 char *nl = strchr(buf, '\n'); 625 unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf); 626 627 return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits); 628 } 629 630 /** 631 * cpulist_parse - extract a cpumask from a user string of ranges 632 * @buf: the buffer to extract from 633 * @dstp: the cpumask to set. 634 * 635 * Returns -errno, or 0 for success. 636 */ 637 static inline int cpulist_parse(const char *buf, struct cpumask *dstp) 638 { 639 return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits); 640 } 641 642 /** 643 * cpumask_size - size to allocate for a 'struct cpumask' in bytes 644 */ 645 static inline unsigned int cpumask_size(void) 646 { 647 return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long); 648 } 649 650 /* 651 * cpumask_var_t: struct cpumask for stack usage. 652 * 653 * Oh, the wicked games we play! In order to make kernel coding a 654 * little more difficult, we typedef cpumask_var_t to an array or a 655 * pointer: doing &mask on an array is a noop, so it still works. 656 * 657 * ie. 658 * cpumask_var_t tmpmask; 659 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 660 * return -ENOMEM; 661 * 662 * ... use 'tmpmask' like a normal struct cpumask * ... 663 * 664 * free_cpumask_var(tmpmask); 665 * 666 * 667 * However, one notable exception is there. alloc_cpumask_var() allocates 668 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has 669 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t. 670 * 671 * cpumask_var_t tmpmask; 672 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 673 * return -ENOMEM; 674 * 675 * var = *tmpmask; 676 * 677 * This code makes NR_CPUS length memcopy and brings to a memory corruption. 678 * cpumask_copy() provide safe copy functionality. 679 * 680 * Note that there is another evil here: If you define a cpumask_var_t 681 * as a percpu variable then the way to obtain the address of the cpumask 682 * structure differently influences what this_cpu_* operation needs to be 683 * used. Please use this_cpu_cpumask_var_t in those cases. The direct use 684 * of this_cpu_ptr() or this_cpu_read() will lead to failures when the 685 * other type of cpumask_var_t implementation is configured. 686 * 687 * Please also note that __cpumask_var_read_mostly can be used to declare 688 * a cpumask_var_t variable itself (not its content) as read mostly. 689 */ 690 #ifdef CONFIG_CPUMASK_OFFSTACK 691 typedef struct cpumask *cpumask_var_t; 692 693 #define this_cpu_cpumask_var_ptr(x) this_cpu_read(x) 694 #define __cpumask_var_read_mostly __read_mostly 695 696 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 697 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 698 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 699 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 700 void alloc_bootmem_cpumask_var(cpumask_var_t *mask); 701 void free_cpumask_var(cpumask_var_t mask); 702 void free_bootmem_cpumask_var(cpumask_var_t mask); 703 704 static inline bool cpumask_available(cpumask_var_t mask) 705 { 706 return mask != NULL; 707 } 708 709 #else 710 typedef struct cpumask cpumask_var_t[1]; 711 712 #define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x) 713 #define __cpumask_var_read_mostly 714 715 static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 716 { 717 return true; 718 } 719 720 static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 721 int node) 722 { 723 return true; 724 } 725 726 static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 727 { 728 cpumask_clear(*mask); 729 return true; 730 } 731 732 static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 733 int node) 734 { 735 cpumask_clear(*mask); 736 return true; 737 } 738 739 static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask) 740 { 741 } 742 743 static inline void free_cpumask_var(cpumask_var_t mask) 744 { 745 } 746 747 static inline void free_bootmem_cpumask_var(cpumask_var_t mask) 748 { 749 } 750 751 static inline bool cpumask_available(cpumask_var_t mask) 752 { 753 return true; 754 } 755 #endif /* CONFIG_CPUMASK_OFFSTACK */ 756 757 /* It's common to want to use cpu_all_mask in struct member initializers, 758 * so it has to refer to an address rather than a pointer. */ 759 extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS); 760 #define cpu_all_mask to_cpumask(cpu_all_bits) 761 762 /* First bits of cpu_bit_bitmap are in fact unset. */ 763 #define cpu_none_mask to_cpumask(cpu_bit_bitmap[0]) 764 765 #define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask) 766 #define for_each_online_cpu(cpu) for_each_cpu((cpu), cpu_online_mask) 767 #define for_each_present_cpu(cpu) for_each_cpu((cpu), cpu_present_mask) 768 769 /* Wrappers for arch boot code to manipulate normally-constant masks */ 770 void init_cpu_present(const struct cpumask *src); 771 void init_cpu_possible(const struct cpumask *src); 772 void init_cpu_online(const struct cpumask *src); 773 774 static inline void reset_cpu_possible_mask(void) 775 { 776 bitmap_zero(cpumask_bits(&__cpu_possible_mask), NR_CPUS); 777 } 778 779 static inline void 780 set_cpu_possible(unsigned int cpu, bool possible) 781 { 782 if (possible) 783 cpumask_set_cpu(cpu, &__cpu_possible_mask); 784 else 785 cpumask_clear_cpu(cpu, &__cpu_possible_mask); 786 } 787 788 static inline void 789 set_cpu_present(unsigned int cpu, bool present) 790 { 791 if (present) 792 cpumask_set_cpu(cpu, &__cpu_present_mask); 793 else 794 cpumask_clear_cpu(cpu, &__cpu_present_mask); 795 } 796 797 static inline void 798 set_cpu_online(unsigned int cpu, bool online) 799 { 800 if (online) 801 cpumask_set_cpu(cpu, &__cpu_online_mask); 802 else 803 cpumask_clear_cpu(cpu, &__cpu_online_mask); 804 } 805 806 static inline void 807 set_cpu_active(unsigned int cpu, bool active) 808 { 809 if (active) 810 cpumask_set_cpu(cpu, &__cpu_active_mask); 811 else 812 cpumask_clear_cpu(cpu, &__cpu_active_mask); 813 } 814 815 816 /** 817 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask * 818 * @bitmap: the bitmap 819 * 820 * There are a few places where cpumask_var_t isn't appropriate and 821 * static cpumasks must be used (eg. very early boot), yet we don't 822 * expose the definition of 'struct cpumask'. 823 * 824 * This does the conversion, and can be used as a constant initializer. 825 */ 826 #define to_cpumask(bitmap) \ 827 ((struct cpumask *)(1 ? (bitmap) \ 828 : (void *)sizeof(__check_is_bitmap(bitmap)))) 829 830 static inline int __check_is_bitmap(const unsigned long *bitmap) 831 { 832 return 1; 833 } 834 835 /* 836 * Special-case data structure for "single bit set only" constant CPU masks. 837 * 838 * We pre-generate all the 64 (or 32) possible bit positions, with enough 839 * padding to the left and the right, and return the constant pointer 840 * appropriately offset. 841 */ 842 extern const unsigned long 843 cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)]; 844 845 static inline const struct cpumask *get_cpu_mask(unsigned int cpu) 846 { 847 const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG]; 848 p -= cpu / BITS_PER_LONG; 849 return to_cpumask(p); 850 } 851 852 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) 853 854 #if NR_CPUS <= BITS_PER_LONG 855 #define CPU_BITS_ALL \ 856 { \ 857 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 858 } 859 860 #else /* NR_CPUS > BITS_PER_LONG */ 861 862 #define CPU_BITS_ALL \ 863 { \ 864 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 865 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 866 } 867 #endif /* NR_CPUS > BITS_PER_LONG */ 868 869 /** 870 * cpumap_print_to_pagebuf - copies the cpumask into the buffer either 871 * as comma-separated list of cpus or hex values of cpumask 872 * @list: indicates whether the cpumap must be list 873 * @mask: the cpumask to copy 874 * @buf: the buffer to copy into 875 * 876 * Returns the length of the (null-terminated) @buf string, zero if 877 * nothing is copied. 878 */ 879 static inline ssize_t 880 cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask) 881 { 882 return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask), 883 nr_cpu_ids); 884 } 885 886 #if NR_CPUS <= BITS_PER_LONG 887 #define CPU_MASK_ALL \ 888 (cpumask_t) { { \ 889 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 890 } } 891 #else 892 #define CPU_MASK_ALL \ 893 (cpumask_t) { { \ 894 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 895 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 896 } } 897 #endif /* NR_CPUS > BITS_PER_LONG */ 898 899 #define CPU_MASK_NONE \ 900 (cpumask_t) { { \ 901 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 902 } } 903 904 #define CPU_MASK_CPU0 \ 905 (cpumask_t) { { \ 906 [0] = 1UL \ 907 } } 908 909 #endif /* __LINUX_CPUMASK_H */ 910