linux/include/linux/cpumask.h
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   1#ifndef __LINUX_CPUMASK_H
   2#define __LINUX_CPUMASK_H
   3
   4/*
   5 * Cpumasks provide a bitmap suitable for representing the
   6 * set of CPU's in a system, one bit position per CPU number.  In general,
   7 * only nr_cpu_ids (<= NR_CPUS) bits are valid.
   8 */
   9#include <linux/kernel.h>
  10#include <linux/threads.h>
  11#include <linux/bitmap.h>
  12#include <linux/bug.h>
  13
  14typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
  15
  16/**
  17 * cpumask_bits - get the bits in a cpumask
  18 * @maskp: the struct cpumask *
  19 *
  20 * You should only assume nr_cpu_ids bits of this mask are valid.  This is
  21 * a macro so it's const-correct.
  22 */
  23#define cpumask_bits(maskp) ((maskp)->bits)
  24
  25#if NR_CPUS == 1
  26#define nr_cpu_ids              1
  27#else
  28extern int nr_cpu_ids;
  29#endif
  30
  31#ifdef CONFIG_CPUMASK_OFFSTACK
  32/* Assuming NR_CPUS is huge, a runtime limit is more efficient.  Also,
  33 * not all bits may be allocated. */
  34#define nr_cpumask_bits nr_cpu_ids
  35#else
  36#define nr_cpumask_bits NR_CPUS
  37#endif
  38
  39/*
  40 * The following particular system cpumasks and operations manage
  41 * possible, present, active and online cpus.
  42 *
  43 *     cpu_possible_mask- has bit 'cpu' set iff cpu is populatable
  44 *     cpu_present_mask - has bit 'cpu' set iff cpu is populated
  45 *     cpu_online_mask  - has bit 'cpu' set iff cpu available to scheduler
  46 *     cpu_active_mask  - has bit 'cpu' set iff cpu available to migration
  47 *
  48 *  If !CONFIG_HOTPLUG_CPU, present == possible, and active == online.
  49 *
  50 *  The cpu_possible_mask is fixed at boot time, as the set of CPU id's
  51 *  that it is possible might ever be plugged in at anytime during the
  52 *  life of that system boot.  The cpu_present_mask is dynamic(*),
  53 *  representing which CPUs are currently plugged in.  And
  54 *  cpu_online_mask is the dynamic subset of cpu_present_mask,
  55 *  indicating those CPUs available for scheduling.
  56 *
  57 *  If HOTPLUG is enabled, then cpu_possible_mask is forced to have
  58 *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
  59 *  ACPI reports present at boot.
  60 *
  61 *  If HOTPLUG is enabled, then cpu_present_mask varies dynamically,
  62 *  depending on what ACPI reports as currently plugged in, otherwise
  63 *  cpu_present_mask is just a copy of cpu_possible_mask.
  64 *
  65 *  (*) Well, cpu_present_mask is dynamic in the hotplug case.  If not
  66 *      hotplug, it's a copy of cpu_possible_mask, hence fixed at boot.
  67 *
  68 * Subtleties:
  69 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
  70 *    assumption that their single CPU is online.  The UP
  71 *    cpu_{online,possible,present}_masks are placebos.  Changing them
  72 *    will have no useful affect on the following num_*_cpus()
  73 *    and cpu_*() macros in the UP case.  This ugliness is a UP
  74 *    optimization - don't waste any instructions or memory references
  75 *    asking if you're online or how many CPUs there are if there is
  76 *    only one CPU.
  77 */
  78
  79extern const struct cpumask *const cpu_possible_mask;
  80extern const struct cpumask *const cpu_online_mask;
  81extern const struct cpumask *const cpu_present_mask;
  82extern const struct cpumask *const cpu_active_mask;
  83
  84#if NR_CPUS > 1
  85#define num_online_cpus()       cpumask_weight(cpu_online_mask)
  86#define num_possible_cpus()     cpumask_weight(cpu_possible_mask)
  87#define num_present_cpus()      cpumask_weight(cpu_present_mask)
  88#define num_active_cpus()       cpumask_weight(cpu_active_mask)
  89#define cpu_online(cpu)         cpumask_test_cpu((cpu), cpu_online_mask)
  90#define cpu_possible(cpu)       cpumask_test_cpu((cpu), cpu_possible_mask)
  91#define cpu_present(cpu)        cpumask_test_cpu((cpu), cpu_present_mask)
  92#define cpu_active(cpu)         cpumask_test_cpu((cpu), cpu_active_mask)
  93#else
  94#define num_online_cpus()       1U
  95#define num_possible_cpus()     1U
  96#define num_present_cpus()      1U
  97#define num_active_cpus()       1U
  98#define cpu_online(cpu)         ((cpu) == 0)
  99#define cpu_possible(cpu)       ((cpu) == 0)
 100#define cpu_present(cpu)        ((cpu) == 0)
 101#define cpu_active(cpu)         ((cpu) == 0)
 102#endif
 103
 104/* verify cpu argument to cpumask_* operators */
 105static inline unsigned int cpumask_check(unsigned int cpu)
 106{
 107#ifdef CONFIG_DEBUG_PER_CPU_MAPS
 108        WARN_ON_ONCE(cpu >= nr_cpumask_bits);
 109#endif /* CONFIG_DEBUG_PER_CPU_MAPS */
 110        return cpu;
 111}
 112
 113#if NR_CPUS == 1
 114/* Uniprocessor.  Assume all masks are "1". */
 115static inline unsigned int cpumask_first(const struct cpumask *srcp)
 116{
 117        return 0;
 118}
 119
 120/* Valid inputs for n are -1 and 0. */
 121static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 122{
 123        return n+1;
 124}
 125
 126static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 127{
 128        return n+1;
 129}
 130
 131static inline unsigned int cpumask_next_and(int n,
 132                                            const struct cpumask *srcp,
 133                                            const struct cpumask *andp)
 134{
 135        return n+1;
 136}
 137
 138/* cpu must be a valid cpu, ie 0, so there's no other choice. */
 139static inline unsigned int cpumask_any_but(const struct cpumask *mask,
 140                                           unsigned int cpu)
 141{
 142        return 1;
 143}
 144
 145#define for_each_cpu(cpu, mask)                 \
 146        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 147#define for_each_cpu_not(cpu, mask)             \
 148        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 149#define for_each_cpu_and(cpu, mask, and)        \
 150        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and)
 151#else
 152/**
 153 * cpumask_first - get the first cpu in a cpumask
 154 * @srcp: the cpumask pointer
 155 *
 156 * Returns >= nr_cpu_ids if no cpus set.
 157 */
 158static inline unsigned int cpumask_first(const struct cpumask *srcp)
 159{
 160        return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
 161}
 162
 163/**
 164 * cpumask_next - get the next cpu in a cpumask
 165 * @n: the cpu prior to the place to search (ie. return will be > @n)
 166 * @srcp: the cpumask pointer
 167 *
 168 * Returns >= nr_cpu_ids if no further cpus set.
 169 */
 170static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 171{
 172        /* -1 is a legal arg here. */
 173        if (n != -1)
 174                cpumask_check(n);
 175        return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 176}
 177
 178/**
 179 * cpumask_next_zero - get the next unset cpu in a cpumask
 180 * @n: the cpu prior to the place to search (ie. return will be > @n)
 181 * @srcp: the cpumask pointer
 182 *
 183 * Returns >= nr_cpu_ids if no further cpus unset.
 184 */
 185static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 186{
 187        /* -1 is a legal arg here. */
 188        if (n != -1)
 189                cpumask_check(n);
 190        return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 191}
 192
 193int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
 194int cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
 195
 196/**
 197 * for_each_cpu - iterate over every cpu in a mask
 198 * @cpu: the (optionally unsigned) integer iterator
 199 * @mask: the cpumask pointer
 200 *
 201 * After the loop, cpu is >= nr_cpu_ids.
 202 */
 203#define for_each_cpu(cpu, mask)                         \
 204        for ((cpu) = -1;                                \
 205                (cpu) = cpumask_next((cpu), (mask)),    \
 206                (cpu) < nr_cpu_ids;)
 207
 208/**
 209 * for_each_cpu_not - iterate over every cpu in a complemented 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_not(cpu, mask)                             \
 216        for ((cpu) = -1;                                        \
 217                (cpu) = cpumask_next_zero((cpu), (mask)),       \
 218                (cpu) < nr_cpu_ids;)
 219
 220/**
 221 * for_each_cpu_and - iterate over every cpu in both masks
 222 * @cpu: the (optionally unsigned) integer iterator
 223 * @mask: the first cpumask pointer
 224 * @and: the second cpumask pointer
 225 *
 226 * This saves a temporary CPU mask in many places.  It is equivalent to:
 227 *      struct cpumask tmp;
 228 *      cpumask_and(&tmp, &mask, &and);
 229 *      for_each_cpu(cpu, &tmp)
 230 *              ...
 231 *
 232 * After the loop, cpu is >= nr_cpu_ids.
 233 */
 234#define for_each_cpu_and(cpu, mask, and)                                \
 235        for ((cpu) = -1;                                                \
 236                (cpu) = cpumask_next_and((cpu), (mask), (and)),         \
 237                (cpu) < nr_cpu_ids;)
 238#endif /* SMP */
 239
 240#define CPU_BITS_NONE                                           \
 241{                                                               \
 242        [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL                  \
 243}
 244
 245#define CPU_BITS_CPU0                                           \
 246{                                                               \
 247        [0] =  1UL                                              \
 248}
 249
 250/**
 251 * cpumask_set_cpu - set a cpu in a cpumask
 252 * @cpu: cpu number (< nr_cpu_ids)
 253 * @dstp: the cpumask pointer
 254 */
 255static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
 256{
 257        set_bit(cpumask_check(cpu), cpumask_bits(dstp));
 258}
 259
 260/**
 261 * cpumask_clear_cpu - clear a cpu in a cpumask
 262 * @cpu: cpu number (< nr_cpu_ids)
 263 * @dstp: the cpumask pointer
 264 */
 265static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
 266{
 267        clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
 268}
 269
 270/**
 271 * cpumask_test_cpu - test for a cpu in a cpumask
 272 * @cpu: cpu number (< nr_cpu_ids)
 273 * @cpumask: the cpumask pointer
 274 *
 275 * Returns 1 if @cpu is set in @cpumask, else returns 0
 276 *
 277 * No static inline type checking - see Subtlety (1) above.
 278 */
 279#define cpumask_test_cpu(cpu, cpumask) \
 280        test_bit(cpumask_check(cpu), cpumask_bits((cpumask)))
 281
 282/**
 283 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
 284 * @cpu: cpu number (< nr_cpu_ids)
 285 * @cpumask: the cpumask pointer
 286 *
 287 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
 288 *
 289 * test_and_set_bit wrapper for cpumasks.
 290 */
 291static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
 292{
 293        return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 294}
 295
 296/**
 297 * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask
 298 * @cpu: cpu number (< nr_cpu_ids)
 299 * @cpumask: the cpumask pointer
 300 *
 301 * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
 302 *
 303 * test_and_clear_bit wrapper for cpumasks.
 304 */
 305static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
 306{
 307        return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 308}
 309
 310/**
 311 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
 312 * @dstp: the cpumask pointer
 313 */
 314static inline void cpumask_setall(struct cpumask *dstp)
 315{
 316        bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
 317}
 318
 319/**
 320 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
 321 * @dstp: the cpumask pointer
 322 */
 323static inline void cpumask_clear(struct cpumask *dstp)
 324{
 325        bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits);
 326}
 327
 328/**
 329 * cpumask_and - *dstp = *src1p & *src2p
 330 * @dstp: the cpumask result
 331 * @src1p: the first input
 332 * @src2p: the second input
 333 *
 334 * If *@dstp is empty, returns 0, else returns 1
 335 */
 336static inline int cpumask_and(struct cpumask *dstp,
 337                               const struct cpumask *src1p,
 338                               const struct cpumask *src2p)
 339{
 340        return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
 341                                       cpumask_bits(src2p), nr_cpumask_bits);
 342}
 343
 344/**
 345 * cpumask_or - *dstp = *src1p | *src2p
 346 * @dstp: the cpumask result
 347 * @src1p: the first input
 348 * @src2p: the second input
 349 */
 350static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
 351                              const struct cpumask *src2p)
 352{
 353        bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
 354                                      cpumask_bits(src2p), nr_cpumask_bits);
 355}
 356
 357/**
 358 * cpumask_xor - *dstp = *src1p ^ *src2p
 359 * @dstp: the cpumask result
 360 * @src1p: the first input
 361 * @src2p: the second input
 362 */
 363static inline void cpumask_xor(struct cpumask *dstp,
 364                               const struct cpumask *src1p,
 365                               const struct cpumask *src2p)
 366{
 367        bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
 368                                       cpumask_bits(src2p), nr_cpumask_bits);
 369}
 370
 371/**
 372 * cpumask_andnot - *dstp = *src1p & ~*src2p
 373 * @dstp: the cpumask result
 374 * @src1p: the first input
 375 * @src2p: the second input
 376 *
 377 * If *@dstp is empty, returns 0, else returns 1
 378 */
 379static inline int cpumask_andnot(struct cpumask *dstp,
 380                                  const struct cpumask *src1p,
 381                                  const struct cpumask *src2p)
 382{
 383        return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
 384                                          cpumask_bits(src2p), nr_cpumask_bits);
 385}
 386
 387/**
 388 * cpumask_complement - *dstp = ~*srcp
 389 * @dstp: the cpumask result
 390 * @srcp: the input to invert
 391 */
 392static inline void cpumask_complement(struct cpumask *dstp,
 393                                      const struct cpumask *srcp)
 394{
 395        bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
 396                                              nr_cpumask_bits);
 397}
 398
 399/**
 400 * cpumask_equal - *src1p == *src2p
 401 * @src1p: the first input
 402 * @src2p: the second input
 403 */
 404static inline bool cpumask_equal(const struct cpumask *src1p,
 405                                const struct cpumask *src2p)
 406{
 407        return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
 408                                                 nr_cpumask_bits);
 409}
 410
 411/**
 412 * cpumask_intersects - (*src1p & *src2p) != 0
 413 * @src1p: the first input
 414 * @src2p: the second input
 415 */
 416static inline bool cpumask_intersects(const struct cpumask *src1p,
 417                                     const struct cpumask *src2p)
 418{
 419        return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
 420                                                      nr_cpumask_bits);
 421}
 422
 423/**
 424 * cpumask_subset - (*src1p & ~*src2p) == 0
 425 * @src1p: the first input
 426 * @src2p: the second input
 427 *
 428 * Returns 1 if *@src1p is a subset of *@src2p, else returns 0
 429 */
 430static inline int cpumask_subset(const struct cpumask *src1p,
 431                                 const struct cpumask *src2p)
 432{
 433        return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
 434                                                  nr_cpumask_bits);
 435}
 436
 437/**
 438 * cpumask_empty - *srcp == 0
 439 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
 440 */
 441static inline bool cpumask_empty(const struct cpumask *srcp)
 442{
 443        return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits);
 444}
 445
 446/**
 447 * cpumask_full - *srcp == 0xFFFFFFFF...
 448 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
 449 */
 450static inline bool cpumask_full(const struct cpumask *srcp)
 451{
 452        return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
 453}
 454
 455/**
 456 * cpumask_weight - Count of bits in *srcp
 457 * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
 458 */
 459static inline unsigned int cpumask_weight(const struct cpumask *srcp)
 460{
 461        return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
 462}
 463
 464/**
 465 * cpumask_shift_right - *dstp = *srcp >> n
 466 * @dstp: the cpumask result
 467 * @srcp: the input to shift
 468 * @n: the number of bits to shift by
 469 */
 470static inline void cpumask_shift_right(struct cpumask *dstp,
 471                                       const struct cpumask *srcp, int n)
 472{
 473        bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n,
 474                                               nr_cpumask_bits);
 475}
 476
 477/**
 478 * cpumask_shift_left - *dstp = *srcp << n
 479 * @dstp: the cpumask result
 480 * @srcp: the input to shift
 481 * @n: the number of bits to shift by
 482 */
 483static inline void cpumask_shift_left(struct cpumask *dstp,
 484                                      const struct cpumask *srcp, int n)
 485{
 486        bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n,
 487                                              nr_cpumask_bits);
 488}
 489
 490/**
 491 * cpumask_copy - *dstp = *srcp
 492 * @dstp: the result
 493 * @srcp: the input cpumask
 494 */
 495static inline void cpumask_copy(struct cpumask *dstp,
 496                                const struct cpumask *srcp)
 497{
 498        bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
 499}
 500
 501/**
 502 * cpumask_any - pick a "random" cpu from *srcp
 503 * @srcp: the input cpumask
 504 *
 505 * Returns >= nr_cpu_ids if no cpus set.
 506 */
 507#define cpumask_any(srcp) cpumask_first(srcp)
 508
 509/**
 510 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
 511 * @src1p: the first input
 512 * @src2p: the second input
 513 *
 514 * Returns >= nr_cpu_ids if no cpus set in both.  See also cpumask_next_and().
 515 */
 516#define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
 517
 518/**
 519 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
 520 * @mask1: the first input cpumask
 521 * @mask2: the second input cpumask
 522 *
 523 * Returns >= nr_cpu_ids if no cpus set.
 524 */
 525#define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
 526
 527/**
 528 * cpumask_of - the cpumask containing just a given cpu
 529 * @cpu: the cpu (<= nr_cpu_ids)
 530 */
 531#define cpumask_of(cpu) (get_cpu_mask(cpu))
 532
 533/**
 534 * cpumask_scnprintf - print a cpumask into a string as comma-separated hex
 535 * @buf: the buffer to sprintf into
 536 * @len: the length of the buffer
 537 * @srcp: the cpumask to print
 538 *
 539 * If len is zero, returns zero.  Otherwise returns the length of the
 540 * (nul-terminated) @buf string.
 541 */
 542static inline int cpumask_scnprintf(char *buf, int len,
 543                                    const struct cpumask *srcp)
 544{
 545        return bitmap_scnprintf(buf, len, cpumask_bits(srcp), nr_cpumask_bits);
 546}
 547
 548/**
 549 * cpumask_parse_user - extract a cpumask from a user string
 550 * @buf: the buffer to extract from
 551 * @len: the length of the buffer
 552 * @dstp: the cpumask to set.
 553 *
 554 * Returns -errno, or 0 for success.
 555 */
 556static inline int cpumask_parse_user(const char __user *buf, int len,
 557                                     struct cpumask *dstp)
 558{
 559        return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
 560}
 561
 562/**
 563 * cpumask_parselist_user - extract a cpumask from a user string
 564 * @buf: the buffer to extract from
 565 * @len: the length of the buffer
 566 * @dstp: the cpumask to set.
 567 *
 568 * Returns -errno, or 0 for success.
 569 */
 570static inline int cpumask_parselist_user(const char __user *buf, int len,
 571                                     struct cpumask *dstp)
 572{
 573        return bitmap_parselist_user(buf, len, cpumask_bits(dstp),
 574                                                        nr_cpumask_bits);
 575}
 576
 577/**
 578 * cpulist_scnprintf - print a cpumask into a string as comma-separated list
 579 * @buf: the buffer to sprintf into
 580 * @len: the length of the buffer
 581 * @srcp: the cpumask to print
 582 *
 583 * If len is zero, returns zero.  Otherwise returns the length of the
 584 * (nul-terminated) @buf string.
 585 */
 586static inline int cpulist_scnprintf(char *buf, int len,
 587                                    const struct cpumask *srcp)
 588{
 589        return bitmap_scnlistprintf(buf, len, cpumask_bits(srcp),
 590                                    nr_cpumask_bits);
 591}
 592
 593/**
 594 * cpulist_parse - extract a cpumask from a user string of ranges
 595 * @buf: the buffer to extract from
 596 * @dstp: the cpumask to set.
 597 *
 598 * Returns -errno, or 0 for success.
 599 */
 600static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
 601{
 602        return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits);
 603}
 604
 605/**
 606 * cpumask_size - size to allocate for a 'struct cpumask' in bytes
 607 *
 608 * This will eventually be a runtime variable, depending on nr_cpu_ids.
 609 */
 610static inline size_t cpumask_size(void)
 611{
 612        /* FIXME: Once all cpumask assignments are eliminated, this
 613         * can be nr_cpumask_bits */
 614        return BITS_TO_LONGS(NR_CPUS) * sizeof(long);
 615}
 616
 617/*
 618 * cpumask_var_t: struct cpumask for stack usage.
 619 *
 620 * Oh, the wicked games we play!  In order to make kernel coding a
 621 * little more difficult, we typedef cpumask_var_t to an array or a
 622 * pointer: doing &mask on an array is a noop, so it still works.
 623 *
 624 * ie.
 625 *      cpumask_var_t tmpmask;
 626 *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
 627 *              return -ENOMEM;
 628 *
 629 *        ... use 'tmpmask' like a normal struct cpumask * ...
 630 *
 631 *      free_cpumask_var(tmpmask);
 632 *
 633 *
 634 * However, one notable exception is there. alloc_cpumask_var() allocates
 635 * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has
 636 * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t.
 637 *
 638 *      cpumask_var_t tmpmask;
 639 *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
 640 *              return -ENOMEM;
 641 *
 642 *      var = *tmpmask;
 643 *
 644 * This code makes NR_CPUS length memcopy and brings to a memory corruption.
 645 * cpumask_copy() provide safe copy functionality.
 646 */
 647#ifdef CONFIG_CPUMASK_OFFSTACK
 648typedef struct cpumask *cpumask_var_t;
 649
 650bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
 651bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
 652bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
 653bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
 654void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
 655void free_cpumask_var(cpumask_var_t mask);
 656void free_bootmem_cpumask_var(cpumask_var_t mask);
 657
 658#else
 659typedef struct cpumask cpumask_var_t[1];
 660
 661static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
 662{
 663        return true;
 664}
 665
 666static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
 667                                          int node)
 668{
 669        return true;
 670}
 671
 672static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
 673{
 674        cpumask_clear(*mask);
 675        return true;
 676}
 677
 678static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
 679                                          int node)
 680{
 681        cpumask_clear(*mask);
 682        return true;
 683}
 684
 685static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask)
 686{
 687}
 688
 689static inline void free_cpumask_var(cpumask_var_t mask)
 690{
 691}
 692
 693static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
 694{
 695}
 696#endif /* CONFIG_CPUMASK_OFFSTACK */
 697
 698/* It's common to want to use cpu_all_mask in struct member initializers,
 699 * so it has to refer to an address rather than a pointer. */
 700extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
 701#define cpu_all_mask to_cpumask(cpu_all_bits)
 702
 703/* First bits of cpu_bit_bitmap are in fact unset. */
 704#define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
 705
 706#define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
 707#define for_each_online_cpu(cpu)   for_each_cpu((cpu), cpu_online_mask)
 708#define for_each_present_cpu(cpu)  for_each_cpu((cpu), cpu_present_mask)
 709
 710/* Wrappers for arch boot code to manipulate normally-constant masks */
 711void set_cpu_possible(unsigned int cpu, bool possible);
 712void set_cpu_present(unsigned int cpu, bool present);
 713void set_cpu_online(unsigned int cpu, bool online);
 714void set_cpu_active(unsigned int cpu, bool active);
 715void init_cpu_present(const struct cpumask *src);
 716void init_cpu_possible(const struct cpumask *src);
 717void init_cpu_online(const struct cpumask *src);
 718
 719/**
 720 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
 721 * @bitmap: the bitmap
 722 *
 723 * There are a few places where cpumask_var_t isn't appropriate and
 724 * static cpumasks must be used (eg. very early boot), yet we don't
 725 * expose the definition of 'struct cpumask'.
 726 *
 727 * This does the conversion, and can be used as a constant initializer.
 728 */
 729#define to_cpumask(bitmap)                                              \
 730        ((struct cpumask *)(1 ? (bitmap)                                \
 731                            : (void *)sizeof(__check_is_bitmap(bitmap))))
 732
 733static inline int __check_is_bitmap(const unsigned long *bitmap)
 734{
 735        return 1;
 736}
 737
 738/*
 739 * Special-case data structure for "single bit set only" constant CPU masks.
 740 *
 741 * We pre-generate all the 64 (or 32) possible bit positions, with enough
 742 * padding to the left and the right, and return the constant pointer
 743 * appropriately offset.
 744 */
 745extern const unsigned long
 746        cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
 747
 748static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
 749{
 750        const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
 751        p -= cpu / BITS_PER_LONG;
 752        return to_cpumask(p);
 753}
 754
 755#define cpu_is_offline(cpu)     unlikely(!cpu_online(cpu))
 756
 757#if NR_CPUS <= BITS_PER_LONG
 758#define CPU_BITS_ALL                                            \
 759{                                                               \
 760        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
 761}
 762
 763#else /* NR_CPUS > BITS_PER_LONG */
 764
 765#define CPU_BITS_ALL                                            \
 766{                                                               \
 767        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                \
 768        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD         \
 769}
 770#endif /* NR_CPUS > BITS_PER_LONG */
 771
 772/*
 773 *
 774 * From here down, all obsolete.  Use cpumask_ variants!
 775 *
 776 */
 777#ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
 778#define cpumask_of_cpu(cpu) (*get_cpu_mask(cpu))
 779
 780#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
 781
 782#if NR_CPUS <= BITS_PER_LONG
 783
 784#define CPU_MASK_ALL                                                    \
 785(cpumask_t) { {                                                         \
 786        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 787} }
 788
 789#else
 790
 791#define CPU_MASK_ALL                                                    \
 792(cpumask_t) { {                                                         \
 793        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
 794        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 795} }
 796
 797#endif
 798
 799#define CPU_MASK_NONE                                                   \
 800(cpumask_t) { {                                                         \
 801        [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
 802} }
 803
 804#define CPU_MASK_CPU0                                                   \
 805(cpumask_t) { {                                                         \
 806        [0] =  1UL                                                      \
 807} }
 808
 809#if NR_CPUS == 1
 810#define first_cpu(src)          ({ (void)(src); 0; })
 811#define next_cpu(n, src)        ({ (void)(src); 1; })
 812#define any_online_cpu(mask)    0
 813#define for_each_cpu_mask(cpu, mask)    \
 814        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 815#else /* NR_CPUS > 1 */
 816int __first_cpu(const cpumask_t *srcp);
 817int __next_cpu(int n, const cpumask_t *srcp);
 818
 819#define first_cpu(src)          __first_cpu(&(src))
 820#define next_cpu(n, src)        __next_cpu((n), &(src))
 821#define any_online_cpu(mask) cpumask_any_and(&mask, cpu_online_mask)
 822#define for_each_cpu_mask(cpu, mask)                    \
 823        for ((cpu) = -1;                                \
 824                (cpu) = next_cpu((cpu), (mask)),        \
 825                (cpu) < NR_CPUS; )
 826#endif /* SMP */
 827
 828#if NR_CPUS <= 64
 829
 830#define for_each_cpu_mask_nr(cpu, mask) for_each_cpu_mask(cpu, mask)
 831
 832#else /* NR_CPUS > 64 */
 833
 834int __next_cpu_nr(int n, const cpumask_t *srcp);
 835#define for_each_cpu_mask_nr(cpu, mask)                 \
 836        for ((cpu) = -1;                                \
 837                (cpu) = __next_cpu_nr((cpu), &(mask)),  \
 838                (cpu) < nr_cpu_ids; )
 839
 840#endif /* NR_CPUS > 64 */
 841
 842#define cpus_addr(src) ((src).bits)
 843
 844#define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
 845static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
 846{
 847        set_bit(cpu, dstp->bits);
 848}
 849
 850#define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
 851static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
 852{
 853        clear_bit(cpu, dstp->bits);
 854}
 855
 856#define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
 857static inline void __cpus_setall(cpumask_t *dstp, int nbits)
 858{
 859        bitmap_fill(dstp->bits, nbits);
 860}
 861
 862#define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
 863static inline void __cpus_clear(cpumask_t *dstp, int nbits)
 864{
 865        bitmap_zero(dstp->bits, nbits);
 866}
 867
 868/* No static inline type checking - see Subtlety (1) above. */
 869#define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
 870
 871#define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
 872static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
 873{
 874        return test_and_set_bit(cpu, addr->bits);
 875}
 876
 877#define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
 878static inline int __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
 879                                        const cpumask_t *src2p, int nbits)
 880{
 881        return bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
 882}
 883
 884#define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
 885static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
 886                                        const cpumask_t *src2p, int nbits)
 887{
 888        bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
 889}
 890
 891#define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
 892static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
 893                                        const cpumask_t *src2p, int nbits)
 894{
 895        bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
 896}
 897
 898#define cpus_andnot(dst, src1, src2) \
 899                                __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
 900static inline int __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
 901                                        const cpumask_t *src2p, int nbits)
 902{
 903        return bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
 904}
 905
 906#define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
 907static inline int __cpus_equal(const cpumask_t *src1p,
 908                                        const cpumask_t *src2p, int nbits)
 909{
 910        return bitmap_equal(src1p->bits, src2p->bits, nbits);
 911}
 912
 913#define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
 914static inline int __cpus_intersects(const cpumask_t *src1p,
 915                                        const cpumask_t *src2p, int nbits)
 916{
 917        return bitmap_intersects(src1p->bits, src2p->bits, nbits);
 918}
 919
 920#define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
 921static inline int __cpus_subset(const cpumask_t *src1p,
 922                                        const cpumask_t *src2p, int nbits)
 923{
 924        return bitmap_subset(src1p->bits, src2p->bits, nbits);
 925}
 926
 927#define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
 928static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
 929{
 930        return bitmap_empty(srcp->bits, nbits);
 931}
 932
 933#define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
 934static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
 935{
 936        return bitmap_weight(srcp->bits, nbits);
 937}
 938
 939#define cpus_shift_left(dst, src, n) \
 940                        __cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
 941static inline void __cpus_shift_left(cpumask_t *dstp,
 942                                        const cpumask_t *srcp, int n, int nbits)
 943{
 944        bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
 945}
 946#endif /* !CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS */
 947
 948#endif /* __LINUX_CPUMASK_H */
 949
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