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/atomic.h> 14 #include <linux/bug.h> 15 16 /* Don't assign or return these: may not be this big! */ 17 typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t; 18 19 /** 20 * cpumask_bits - get the bits in a cpumask 21 * @maskp: the struct cpumask * 22 * 23 * You should only assume nr_cpu_ids bits of this mask are valid. This is 24 * a macro so it's const-correct. 25 */ 26 #define cpumask_bits(maskp) ((maskp)->bits) 27 28 /** 29 * cpumask_pr_args - printf args to output a cpumask 30 * @maskp: cpumask to be printed 31 * 32 * Can be used to provide arguments for '%*pb[l]' when printing a cpumask. 33 */ 34 #define cpumask_pr_args(maskp) nr_cpu_ids, cpumask_bits(maskp) 35 36 #if NR_CPUS == 1 37 #define nr_cpu_ids 1U 38 #else 39 extern unsigned int nr_cpu_ids; 40 #endif 41 42 #ifdef CONFIG_CPUMASK_OFFSTACK 43 /* Assuming NR_CPUS is huge, a runtime limit is more efficient. Also, 44 * not all bits may be allocated. */ 45 #define nr_cpumask_bits nr_cpu_ids 46 #else 47 #define nr_cpumask_bits ((unsigned int)NR_CPUS) 48 #endif 49 50 /* 51 * The following particular system cpumasks and operations manage 52 * possible, present, active and online cpus. 53 * 54 * cpu_possible_mask- has bit 'cpu' set iff cpu is populatable 55 * cpu_present_mask - has bit 'cpu' set iff cpu is populated 56 * cpu_online_mask - has bit 'cpu' set iff cpu available to scheduler 57 * cpu_active_mask - has bit 'cpu' set iff cpu available to migration 58 * 59 * If !CONFIG_HOTPLUG_CPU, present == possible, and active == online. 60 * 61 * The cpu_possible_mask is fixed at boot time, as the set of CPU id's 62 * that it is possible might ever be plugged in at anytime during the 63 * life of that system boot. The cpu_present_mask is dynamic(*), 64 * representing which CPUs are currently plugged in. And 65 * cpu_online_mask is the dynamic subset of cpu_present_mask, 66 * indicating those CPUs available for scheduling. 67 * 68 * If HOTPLUG is enabled, then cpu_possible_mask is forced to have 69 * all NR_CPUS bits set, otherwise it is just the set of CPUs that 70 * ACPI reports present at boot. 71 * 72 * If HOTPLUG is enabled, then cpu_present_mask varies dynamically, 73 * depending on what ACPI reports as currently plugged in, otherwise 74 * cpu_present_mask is just a copy of cpu_possible_mask. 75 * 76 * (*) Well, cpu_present_mask is dynamic in the hotplug case. If not 77 * hotplug, it's a copy of cpu_possible_mask, hence fixed at boot. 78 * 79 * Subtleties: 80 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode 81 * assumption that their single CPU is online. The UP 82 * cpu_{online,possible,present}_masks are placebos. Changing them 83 * will have no useful affect on the following num_*_cpus() 84 * and cpu_*() macros in the UP case. This ugliness is a UP 85 * optimization - don't waste any instructions or memory references 86 * asking if you're online or how many CPUs there are if there is 87 * only one CPU. 88 */ 89 90 extern struct cpumask __cpu_possible_mask; 91 extern struct cpumask __cpu_online_mask; 92 extern struct cpumask __cpu_present_mask; 93 extern struct cpumask __cpu_active_mask; 94 extern struct cpumask __cpu_dying_mask; 95 #define cpu_possible_mask ((const struct cpumask *)&__cpu_possible_mask) 96 #define cpu_online_mask ((const struct cpumask *)&__cpu_online_mask) 97 #define cpu_present_mask ((const struct cpumask *)&__cpu_present_mask) 98 #define cpu_active_mask ((const struct cpumask *)&__cpu_active_mask) 99 #define cpu_dying_mask ((const struct cpumask *)&__cpu_dying_mask) 100 101 extern atomic_t __num_online_cpus; 102 103 extern cpumask_t cpus_booted_once_mask; 104 105 static __always_inline void cpu_max_bits_warn(unsigned int cpu, unsigned int bits) 106 { 107 #ifdef CONFIG_DEBUG_PER_CPU_MAPS 108 WARN_ON_ONCE(cpu >= bits); 109 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */ 110 } 111 112 /* verify cpu argument to cpumask_* operators */ 113 static __always_inline unsigned int cpumask_check(unsigned int cpu) 114 { 115 cpu_max_bits_warn(cpu, nr_cpumask_bits); 116 return cpu; 117 } 118 119 /** 120 * cpumask_first - get the first cpu in a cpumask 121 * @srcp: the cpumask pointer 122 * 123 * Returns >= nr_cpu_ids if no cpus set. 124 */ 125 static inline unsigned int cpumask_first(const struct cpumask *srcp) 126 { 127 return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits); 128 } 129 130 /** 131 * cpumask_first_zero - get the first unset cpu in a cpumask 132 * @srcp: the cpumask pointer 133 * 134 * Returns >= nr_cpu_ids if all cpus are set. 135 */ 136 static inline unsigned int cpumask_first_zero(const struct cpumask *srcp) 137 { 138 return find_first_zero_bit(cpumask_bits(srcp), nr_cpumask_bits); 139 } 140 141 /** 142 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2 143 * @src1p: the first input 144 * @src2p: the second input 145 * 146 * Returns >= nr_cpu_ids if no cpus set in both. See also cpumask_next_and(). 147 */ 148 static inline 149 unsigned int cpumask_first_and(const struct cpumask *srcp1, const struct cpumask *srcp2) 150 { 151 return find_first_and_bit(cpumask_bits(srcp1), cpumask_bits(srcp2), nr_cpumask_bits); 152 } 153 154 /** 155 * cpumask_last - get the last CPU in a cpumask 156 * @srcp: - the cpumask pointer 157 * 158 * Returns >= nr_cpumask_bits if no CPUs set. 159 */ 160 static inline unsigned int cpumask_last(const struct cpumask *srcp) 161 { 162 return find_last_bit(cpumask_bits(srcp), nr_cpumask_bits); 163 } 164 165 unsigned int __pure cpumask_next(int n, const struct cpumask *srcp); 166 167 /** 168 * cpumask_next_zero - get the next unset cpu in a cpumask 169 * @n: the cpu prior to the place to search (ie. return will be > @n) 170 * @srcp: the cpumask pointer 171 * 172 * Returns >= nr_cpu_ids if no further cpus unset. 173 */ 174 static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp) 175 { 176 /* -1 is a legal arg here. */ 177 if (n != -1) 178 cpumask_check(n); 179 return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1); 180 } 181 182 int __pure cpumask_next_and(int n, const struct cpumask *, const struct cpumask *); 183 int __pure cpumask_any_but(const struct cpumask *mask, unsigned int cpu); 184 185 #if NR_CPUS == 1 186 /* Uniprocessor: there is only one valid CPU */ 187 static inline unsigned int cpumask_local_spread(unsigned int i, int node) 188 { 189 return 0; 190 } 191 192 static inline int cpumask_any_and_distribute(const struct cpumask *src1p, 193 const struct cpumask *src2p) { 194 return cpumask_first_and(src1p, src2p); 195 } 196 197 static inline int cpumask_any_distribute(const struct cpumask *srcp) 198 { 199 return cpumask_first(srcp); 200 } 201 #else 202 unsigned int cpumask_local_spread(unsigned int i, int node); 203 int cpumask_any_and_distribute(const struct cpumask *src1p, 204 const struct cpumask *src2p); 205 int cpumask_any_distribute(const struct cpumask *srcp); 206 #endif /* NR_CPUS */ 207 208 /** 209 * for_each_cpu - iterate over every cpu in a mask 210 * @cpu: the (optionally unsigned) integer iterator 211 * @mask: the cpumask pointer 212 * 213 * After the loop, cpu is >= nr_cpu_ids. 214 */ 215 #define for_each_cpu(cpu, mask) \ 216 for ((cpu) = -1; \ 217 (cpu) = cpumask_next((cpu), (mask)), \ 218 (cpu) < nr_cpu_ids;) 219 220 /** 221 * for_each_cpu_not - iterate over every cpu in a complemented mask 222 * @cpu: the (optionally unsigned) integer iterator 223 * @mask: the cpumask pointer 224 * 225 * After the loop, cpu is >= nr_cpu_ids. 226 */ 227 #define for_each_cpu_not(cpu, mask) \ 228 for ((cpu) = -1; \ 229 (cpu) = cpumask_next_zero((cpu), (mask)), \ 230 (cpu) < nr_cpu_ids;) 231 232 int __pure cpumask_next_wrap(int n, const struct cpumask *mask, int start, bool wrap); 233 234 /** 235 * for_each_cpu_wrap - iterate over every cpu in a mask, starting at a specified location 236 * @cpu: the (optionally unsigned) integer iterator 237 * @mask: the cpumask pointer 238 * @start: the start location 239 * 240 * The implementation does not assume any bit in @mask is set (including @start). 241 * 242 * After the loop, cpu is >= nr_cpu_ids. 243 */ 244 #define for_each_cpu_wrap(cpu, mask, start) \ 245 for ((cpu) = cpumask_next_wrap((start)-1, (mask), (start), false); \ 246 (cpu) < nr_cpumask_bits; \ 247 (cpu) = cpumask_next_wrap((cpu), (mask), (start), true)) 248 249 /** 250 * for_each_cpu_and - iterate over every cpu in both masks 251 * @cpu: the (optionally unsigned) integer iterator 252 * @mask1: the first cpumask pointer 253 * @mask2: the second cpumask pointer 254 * 255 * This saves a temporary CPU mask in many places. It is equivalent to: 256 * struct cpumask tmp; 257 * cpumask_and(&tmp, &mask1, &mask2); 258 * for_each_cpu(cpu, &tmp) 259 * ... 260 * 261 * After the loop, cpu is >= nr_cpu_ids. 262 */ 263 #define for_each_cpu_and(cpu, mask1, mask2) \ 264 for ((cpu) = -1; \ 265 (cpu) = cpumask_next_and((cpu), (mask1), (mask2)), \ 266 (cpu) < nr_cpu_ids;) 267 268 #define CPU_BITS_NONE \ 269 { \ 270 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 271 } 272 273 #define CPU_BITS_CPU0 \ 274 { \ 275 [0] = 1UL \ 276 } 277 278 /** 279 * cpumask_set_cpu - set a cpu in a cpumask 280 * @cpu: cpu number (< nr_cpu_ids) 281 * @dstp: the cpumask pointer 282 */ 283 static __always_inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 284 { 285 set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 286 } 287 288 static __always_inline void __cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp) 289 { 290 __set_bit(cpumask_check(cpu), cpumask_bits(dstp)); 291 } 292 293 294 /** 295 * cpumask_clear_cpu - clear a cpu in a cpumask 296 * @cpu: cpu number (< nr_cpu_ids) 297 * @dstp: the cpumask pointer 298 */ 299 static __always_inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp) 300 { 301 clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 302 } 303 304 static __always_inline void __cpumask_clear_cpu(int cpu, struct cpumask *dstp) 305 { 306 __clear_bit(cpumask_check(cpu), cpumask_bits(dstp)); 307 } 308 309 /** 310 * cpumask_test_cpu - test for a cpu in a cpumask 311 * @cpu: cpu number (< nr_cpu_ids) 312 * @cpumask: the cpumask pointer 313 * 314 * Returns 1 if @cpu is set in @cpumask, else returns 0 315 */ 316 static __always_inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask) 317 { 318 return test_bit(cpumask_check(cpu), cpumask_bits((cpumask))); 319 } 320 321 /** 322 * cpumask_test_and_set_cpu - atomically test and set 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 old bitmap of @cpumask, else returns 0 327 * 328 * test_and_set_bit wrapper for cpumasks. 329 */ 330 static __always_inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask) 331 { 332 return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 333 } 334 335 /** 336 * cpumask_test_and_clear_cpu - atomically test and clear 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_clear_bit wrapper for cpumasks. 343 */ 344 static __always_inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask) 345 { 346 return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask)); 347 } 348 349 /** 350 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask 351 * @dstp: the cpumask pointer 352 */ 353 static inline void cpumask_setall(struct cpumask *dstp) 354 { 355 bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits); 356 } 357 358 /** 359 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask 360 * @dstp: the cpumask pointer 361 */ 362 static inline void cpumask_clear(struct cpumask *dstp) 363 { 364 bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits); 365 } 366 367 /** 368 * cpumask_and - *dstp = *src1p & *src2p 369 * @dstp: the cpumask result 370 * @src1p: the first input 371 * @src2p: the second input 372 * 373 * If *@dstp is empty, returns 0, else returns 1 374 */ 375 static inline int cpumask_and(struct cpumask *dstp, 376 const struct cpumask *src1p, 377 const struct cpumask *src2p) 378 { 379 return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p), 380 cpumask_bits(src2p), nr_cpumask_bits); 381 } 382 383 /** 384 * cpumask_or - *dstp = *src1p | *src2p 385 * @dstp: the cpumask result 386 * @src1p: the first input 387 * @src2p: the second input 388 */ 389 static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p, 390 const struct cpumask *src2p) 391 { 392 bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p), 393 cpumask_bits(src2p), nr_cpumask_bits); 394 } 395 396 /** 397 * cpumask_xor - *dstp = *src1p ^ *src2p 398 * @dstp: the cpumask result 399 * @src1p: the first input 400 * @src2p: the second input 401 */ 402 static inline void cpumask_xor(struct cpumask *dstp, 403 const struct cpumask *src1p, 404 const struct cpumask *src2p) 405 { 406 bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p), 407 cpumask_bits(src2p), nr_cpumask_bits); 408 } 409 410 /** 411 * cpumask_andnot - *dstp = *src1p & ~*src2p 412 * @dstp: the cpumask result 413 * @src1p: the first input 414 * @src2p: the second input 415 * 416 * If *@dstp is empty, returns 0, else returns 1 417 */ 418 static inline int cpumask_andnot(struct cpumask *dstp, 419 const struct cpumask *src1p, 420 const struct cpumask *src2p) 421 { 422 return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p), 423 cpumask_bits(src2p), nr_cpumask_bits); 424 } 425 426 /** 427 * cpumask_complement - *dstp = ~*srcp 428 * @dstp: the cpumask result 429 * @srcp: the input to invert 430 */ 431 static inline void cpumask_complement(struct cpumask *dstp, 432 const struct cpumask *srcp) 433 { 434 bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp), 435 nr_cpumask_bits); 436 } 437 438 /** 439 * cpumask_equal - *src1p == *src2p 440 * @src1p: the first input 441 * @src2p: the second input 442 */ 443 static inline bool cpumask_equal(const struct cpumask *src1p, 444 const struct cpumask *src2p) 445 { 446 return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p), 447 nr_cpumask_bits); 448 } 449 450 /** 451 * cpumask_or_equal - *src1p | *src2p == *src3p 452 * @src1p: the first input 453 * @src2p: the second input 454 * @src3p: the third input 455 */ 456 static inline bool cpumask_or_equal(const struct cpumask *src1p, 457 const struct cpumask *src2p, 458 const struct cpumask *src3p) 459 { 460 return bitmap_or_equal(cpumask_bits(src1p), cpumask_bits(src2p), 461 cpumask_bits(src3p), 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_any_and - pick a "random" cpu from *mask1 & *mask2 564 * @mask1: the first input cpumask 565 * @mask2: the second input cpumask 566 * 567 * Returns >= nr_cpu_ids if no cpus set. 568 */ 569 #define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2)) 570 571 /** 572 * cpumask_of - the cpumask containing just a given cpu 573 * @cpu: the cpu (<= nr_cpu_ids) 574 */ 575 #define cpumask_of(cpu) (get_cpu_mask(cpu)) 576 577 /** 578 * cpumask_parse_user - extract a cpumask from a user string 579 * @buf: the buffer to extract from 580 * @len: the length of the buffer 581 * @dstp: the cpumask to set. 582 * 583 * Returns -errno, or 0 for success. 584 */ 585 static inline int cpumask_parse_user(const char __user *buf, int len, 586 struct cpumask *dstp) 587 { 588 return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits); 589 } 590 591 /** 592 * cpumask_parselist_user - extract a cpumask from a user string 593 * @buf: the buffer to extract from 594 * @len: the length of the buffer 595 * @dstp: the cpumask to set. 596 * 597 * Returns -errno, or 0 for success. 598 */ 599 static inline int cpumask_parselist_user(const char __user *buf, int len, 600 struct cpumask *dstp) 601 { 602 return bitmap_parselist_user(buf, len, cpumask_bits(dstp), 603 nr_cpumask_bits); 604 } 605 606 /** 607 * cpumask_parse - extract a cpumask from a string 608 * @buf: the buffer to extract from 609 * @dstp: the cpumask to set. 610 * 611 * Returns -errno, or 0 for success. 612 */ 613 static inline int cpumask_parse(const char *buf, struct cpumask *dstp) 614 { 615 return bitmap_parse(buf, UINT_MAX, cpumask_bits(dstp), nr_cpumask_bits); 616 } 617 618 /** 619 * cpulist_parse - extract a cpumask from a user string of ranges 620 * @buf: the buffer to extract from 621 * @dstp: the cpumask to set. 622 * 623 * Returns -errno, or 0 for success. 624 */ 625 static inline int cpulist_parse(const char *buf, struct cpumask *dstp) 626 { 627 return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits); 628 } 629 630 /** 631 * cpumask_size - size to allocate for a 'struct cpumask' in bytes 632 */ 633 static inline unsigned int cpumask_size(void) 634 { 635 return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long); 636 } 637 638 /* 639 * cpumask_var_t: struct cpumask for stack usage. 640 * 641 * Oh, the wicked games we play! In order to make kernel coding a 642 * little more difficult, we typedef cpumask_var_t to an array or a 643 * pointer: doing &mask on an array is a noop, so it still works. 644 * 645 * ie. 646 * cpumask_var_t tmpmask; 647 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 648 * return -ENOMEM; 649 * 650 * ... use 'tmpmask' like a normal struct cpumask * ... 651 * 652 * free_cpumask_var(tmpmask); 653 * 654 * 655 * However, one notable exception is there. alloc_cpumask_var() allocates 656 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has 657 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t. 658 * 659 * cpumask_var_t tmpmask; 660 * if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) 661 * return -ENOMEM; 662 * 663 * var = *tmpmask; 664 * 665 * This code makes NR_CPUS length memcopy and brings to a memory corruption. 666 * cpumask_copy() provide safe copy functionality. 667 * 668 * Note that there is another evil here: If you define a cpumask_var_t 669 * as a percpu variable then the way to obtain the address of the cpumask 670 * structure differently influences what this_cpu_* operation needs to be 671 * used. Please use this_cpu_cpumask_var_t in those cases. The direct use 672 * of this_cpu_ptr() or this_cpu_read() will lead to failures when the 673 * other type of cpumask_var_t implementation is configured. 674 * 675 * Please also note that __cpumask_var_read_mostly can be used to declare 676 * a cpumask_var_t variable itself (not its content) as read mostly. 677 */ 678 #ifdef CONFIG_CPUMASK_OFFSTACK 679 typedef struct cpumask *cpumask_var_t; 680 681 #define this_cpu_cpumask_var_ptr(x) this_cpu_read(x) 682 #define __cpumask_var_read_mostly __read_mostly 683 684 bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 685 bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 686 bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node); 687 bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags); 688 void alloc_bootmem_cpumask_var(cpumask_var_t *mask); 689 void free_cpumask_var(cpumask_var_t mask); 690 void free_bootmem_cpumask_var(cpumask_var_t mask); 691 692 static inline bool cpumask_available(cpumask_var_t mask) 693 { 694 return mask != NULL; 695 } 696 697 #else 698 typedef struct cpumask cpumask_var_t[1]; 699 700 #define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x) 701 #define __cpumask_var_read_mostly 702 703 static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 704 { 705 return true; 706 } 707 708 static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 709 int node) 710 { 711 return true; 712 } 713 714 static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) 715 { 716 cpumask_clear(*mask); 717 return true; 718 } 719 720 static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, 721 int node) 722 { 723 cpumask_clear(*mask); 724 return true; 725 } 726 727 static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask) 728 { 729 } 730 731 static inline void free_cpumask_var(cpumask_var_t mask) 732 { 733 } 734 735 static inline void free_bootmem_cpumask_var(cpumask_var_t mask) 736 { 737 } 738 739 static inline bool cpumask_available(cpumask_var_t mask) 740 { 741 return true; 742 } 743 #endif /* CONFIG_CPUMASK_OFFSTACK */ 744 745 /* It's common to want to use cpu_all_mask in struct member initializers, 746 * so it has to refer to an address rather than a pointer. */ 747 extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS); 748 #define cpu_all_mask to_cpumask(cpu_all_bits) 749 750 /* First bits of cpu_bit_bitmap are in fact unset. */ 751 #define cpu_none_mask to_cpumask(cpu_bit_bitmap[0]) 752 753 #if NR_CPUS == 1 754 /* Uniprocessor: the possible/online/present masks are always "1" */ 755 #define for_each_possible_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++) 756 #define for_each_online_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++) 757 #define for_each_present_cpu(cpu) for ((cpu) = 0; (cpu) < 1; (cpu)++) 758 #else 759 #define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask) 760 #define for_each_online_cpu(cpu) for_each_cpu((cpu), cpu_online_mask) 761 #define for_each_present_cpu(cpu) for_each_cpu((cpu), cpu_present_mask) 762 #endif 763 764 /* Wrappers for arch boot code to manipulate normally-constant masks */ 765 void init_cpu_present(const struct cpumask *src); 766 void init_cpu_possible(const struct cpumask *src); 767 void init_cpu_online(const struct cpumask *src); 768 769 static inline void reset_cpu_possible_mask(void) 770 { 771 bitmap_zero(cpumask_bits(&__cpu_possible_mask), NR_CPUS); 772 } 773 774 static inline void 775 set_cpu_possible(unsigned int cpu, bool possible) 776 { 777 if (possible) 778 cpumask_set_cpu(cpu, &__cpu_possible_mask); 779 else 780 cpumask_clear_cpu(cpu, &__cpu_possible_mask); 781 } 782 783 static inline void 784 set_cpu_present(unsigned int cpu, bool present) 785 { 786 if (present) 787 cpumask_set_cpu(cpu, &__cpu_present_mask); 788 else 789 cpumask_clear_cpu(cpu, &__cpu_present_mask); 790 } 791 792 void set_cpu_online(unsigned int cpu, bool online); 793 794 static inline void 795 set_cpu_active(unsigned int cpu, bool active) 796 { 797 if (active) 798 cpumask_set_cpu(cpu, &__cpu_active_mask); 799 else 800 cpumask_clear_cpu(cpu, &__cpu_active_mask); 801 } 802 803 static inline void 804 set_cpu_dying(unsigned int cpu, bool dying) 805 { 806 if (dying) 807 cpumask_set_cpu(cpu, &__cpu_dying_mask); 808 else 809 cpumask_clear_cpu(cpu, &__cpu_dying_mask); 810 } 811 812 /** 813 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask * 814 * @bitmap: the bitmap 815 * 816 * There are a few places where cpumask_var_t isn't appropriate and 817 * static cpumasks must be used (eg. very early boot), yet we don't 818 * expose the definition of 'struct cpumask'. 819 * 820 * This does the conversion, and can be used as a constant initializer. 821 */ 822 #define to_cpumask(bitmap) \ 823 ((struct cpumask *)(1 ? (bitmap) \ 824 : (void *)sizeof(__check_is_bitmap(bitmap)))) 825 826 static inline int __check_is_bitmap(const unsigned long *bitmap) 827 { 828 return 1; 829 } 830 831 /* 832 * Special-case data structure for "single bit set only" constant CPU masks. 833 * 834 * We pre-generate all the 64 (or 32) possible bit positions, with enough 835 * padding to the left and the right, and return the constant pointer 836 * appropriately offset. 837 */ 838 extern const unsigned long 839 cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)]; 840 841 static inline const struct cpumask *get_cpu_mask(unsigned int cpu) 842 { 843 const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG]; 844 p -= cpu / BITS_PER_LONG; 845 return to_cpumask(p); 846 } 847 848 #if NR_CPUS > 1 849 /** 850 * num_online_cpus() - Read the number of online CPUs 851 * 852 * Despite the fact that __num_online_cpus is of type atomic_t, this 853 * interface gives only a momentary snapshot and is not protected against 854 * concurrent CPU hotplug operations unless invoked from a cpuhp_lock held 855 * region. 856 */ 857 static inline unsigned int num_online_cpus(void) 858 { 859 return atomic_read(&__num_online_cpus); 860 } 861 #define num_possible_cpus() cpumask_weight(cpu_possible_mask) 862 #define num_present_cpus() cpumask_weight(cpu_present_mask) 863 #define num_active_cpus() cpumask_weight(cpu_active_mask) 864 865 static inline bool cpu_online(unsigned int cpu) 866 { 867 return cpumask_test_cpu(cpu, cpu_online_mask); 868 } 869 870 static inline bool cpu_possible(unsigned int cpu) 871 { 872 return cpumask_test_cpu(cpu, cpu_possible_mask); 873 } 874 875 static inline bool cpu_present(unsigned int cpu) 876 { 877 return cpumask_test_cpu(cpu, cpu_present_mask); 878 } 879 880 static inline bool cpu_active(unsigned int cpu) 881 { 882 return cpumask_test_cpu(cpu, cpu_active_mask); 883 } 884 885 static inline bool cpu_dying(unsigned int cpu) 886 { 887 return cpumask_test_cpu(cpu, cpu_dying_mask); 888 } 889 890 #else 891 892 #define num_online_cpus() 1U 893 #define num_possible_cpus() 1U 894 #define num_present_cpus() 1U 895 #define num_active_cpus() 1U 896 897 static inline bool cpu_online(unsigned int cpu) 898 { 899 return cpu == 0; 900 } 901 902 static inline bool cpu_possible(unsigned int cpu) 903 { 904 return cpu == 0; 905 } 906 907 static inline bool cpu_present(unsigned int cpu) 908 { 909 return cpu == 0; 910 } 911 912 static inline bool cpu_active(unsigned int cpu) 913 { 914 return cpu == 0; 915 } 916 917 static inline bool cpu_dying(unsigned int cpu) 918 { 919 return false; 920 } 921 922 #endif /* NR_CPUS > 1 */ 923 924 #define cpu_is_offline(cpu) unlikely(!cpu_online(cpu)) 925 926 #if NR_CPUS <= BITS_PER_LONG 927 #define CPU_BITS_ALL \ 928 { \ 929 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 930 } 931 932 #else /* NR_CPUS > BITS_PER_LONG */ 933 934 #define CPU_BITS_ALL \ 935 { \ 936 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 937 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 938 } 939 #endif /* NR_CPUS > BITS_PER_LONG */ 940 941 /** 942 * cpumap_print_to_pagebuf - copies the cpumask into the buffer either 943 * as comma-separated list of cpus or hex values of cpumask 944 * @list: indicates whether the cpumap must be list 945 * @mask: the cpumask to copy 946 * @buf: the buffer to copy into 947 * 948 * Returns the length of the (null-terminated) @buf string, zero if 949 * nothing is copied. 950 */ 951 static inline ssize_t 952 cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask) 953 { 954 return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask), 955 nr_cpu_ids); 956 } 957 958 /** 959 * cpumap_print_bitmask_to_buf - copies the cpumask into the buffer as 960 * hex values of cpumask 961 * 962 * @buf: the buffer to copy into 963 * @mask: the cpumask to copy 964 * @off: in the string from which we are copying, we copy to @buf 965 * @count: the maximum number of bytes to print 966 * 967 * The function prints the cpumask into the buffer as hex values of 968 * cpumask; Typically used by bin_attribute to export cpumask bitmask 969 * ABI. 970 * 971 * Returns the length of how many bytes have been copied, excluding 972 * terminating '\0'. 973 */ 974 static inline ssize_t 975 cpumap_print_bitmask_to_buf(char *buf, const struct cpumask *mask, 976 loff_t off, size_t count) 977 { 978 return bitmap_print_bitmask_to_buf(buf, cpumask_bits(mask), 979 nr_cpu_ids, off, count) - 1; 980 } 981 982 /** 983 * cpumap_print_list_to_buf - copies the cpumask into the buffer as 984 * comma-separated list of cpus 985 * 986 * Everything is same with the above cpumap_print_bitmask_to_buf() 987 * except the print format. 988 */ 989 static inline ssize_t 990 cpumap_print_list_to_buf(char *buf, const struct cpumask *mask, 991 loff_t off, size_t count) 992 { 993 return bitmap_print_list_to_buf(buf, cpumask_bits(mask), 994 nr_cpu_ids, off, count) - 1; 995 } 996 997 #if NR_CPUS <= BITS_PER_LONG 998 #define CPU_MASK_ALL \ 999 (cpumask_t) { { \ 1000 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 1001 } } 1002 #else 1003 #define CPU_MASK_ALL \ 1004 (cpumask_t) { { \ 1005 [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL, \ 1006 [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS) \ 1007 } } 1008 #endif /* NR_CPUS > BITS_PER_LONG */ 1009 1010 #define CPU_MASK_NONE \ 1011 (cpumask_t) { { \ 1012 [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL \ 1013 } } 1014 1015 #define CPU_MASK_CPU0 \ 1016 (cpumask_t) { { \ 1017 [0] = 1UL \ 1018 } } 1019 1020 #endif /* __LINUX_CPUMASK_H */ 1021