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
  13typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
  14
  15/**
  16 * cpumask_bits - get the bits in a cpumask
  17 * @maskp: the struct cpumask *
  18 *
  19 * You should only assume nr_cpu_ids bits of this mask are valid.  This is
  20 * a macro so it's const-correct.
  21 */
  22#define cpumask_bits(maskp) ((maskp)->bits)
  23
  24#if NR_CPUS == 1
  25#define nr_cpu_ids              1
  26#else
  27extern int nr_cpu_ids;
  28#endif
  29
  30#ifdef CONFIG_CPUMASK_OFFSTACK
  31/* Assuming NR_CPUS is huge, a runtime limit is more efficient.  Also,
  32 * not all bits may be allocated. */
  33#define nr_cpumask_bits nr_cpu_ids
  34#else
  35#define nr_cpumask_bits NR_CPUS
  36#endif
  37
  38/*
  39 * The following particular system cpumasks and operations manage
  40 * possible, present, active and online cpus.
  41 *
  42 *     cpu_possible_mask- has bit 'cpu' set iff cpu is populatable
  43 *     cpu_present_mask - has bit 'cpu' set iff cpu is populated
  44 *     cpu_online_mask  - has bit 'cpu' set iff cpu available to scheduler
  45 *     cpu_active_mask  - has bit 'cpu' set iff cpu available to migration
  46 *
  47 *  If !CONFIG_HOTPLUG_CPU, present == possible, and active == online.
  48 *
  49 *  The cpu_possible_mask is fixed at boot time, as the set of CPU id's
  50 *  that it is possible might ever be plugged in at anytime during the
  51 *  life of that system boot.  The cpu_present_mask is dynamic(*),
  52 *  representing which CPUs are currently plugged in.  And
  53 *  cpu_online_mask is the dynamic subset of cpu_present_mask,
  54 *  indicating those CPUs available for scheduling.
  55 *
  56 *  If HOTPLUG is enabled, then cpu_possible_mask is forced to have
  57 *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
  58 *  ACPI reports present at boot.
  59 *
  60 *  If HOTPLUG is enabled, then cpu_present_mask varies dynamically,
  61 *  depending on what ACPI reports as currently plugged in, otherwise
  62 *  cpu_present_mask is just a copy of cpu_possible_mask.
  63 *
  64 *  (*) Well, cpu_present_mask is dynamic in the hotplug case.  If not
  65 *      hotplug, it's a copy of cpu_possible_mask, hence fixed at boot.
  66 *
  67 * Subtleties:
  68 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
  69 *    assumption that their single CPU is online.  The UP
  70 *    cpu_{online,possible,present}_masks are placebos.  Changing them
  71 *    will have no useful affect on the following num_*_cpus()
  72 *    and cpu_*() macros in the UP case.  This ugliness is a UP
  73 *    optimization - don't waste any instructions or memory references
  74 *    asking if you're online or how many CPUs there are if there is
  75 *    only one CPU.
  76 */
  77
  78extern const struct cpumask *const cpu_possible_mask;
  79extern const struct cpumask *const cpu_online_mask;
  80extern const struct cpumask *const cpu_present_mask;
  81extern const struct cpumask *const cpu_active_mask;
  82
  83#if NR_CPUS > 1
  84#define num_online_cpus()       cpumask_weight(cpu_online_mask)
  85#define num_possible_cpus()     cpumask_weight(cpu_possible_mask)
  86#define num_present_cpus()      cpumask_weight(cpu_present_mask)
  87#define cpu_online(cpu)         cpumask_test_cpu((cpu), cpu_online_mask)
  88#define cpu_possible(cpu)       cpumask_test_cpu((cpu), cpu_possible_mask)
  89#define cpu_present(cpu)        cpumask_test_cpu((cpu), cpu_present_mask)
  90#define cpu_active(cpu)         cpumask_test_cpu((cpu), cpu_active_mask)
  91#else
  92#define num_online_cpus()       1
  93#define num_possible_cpus()     1
  94#define num_present_cpus()      1
  95#define cpu_online(cpu)         ((cpu) == 0)
  96#define cpu_possible(cpu)       ((cpu) == 0)
  97#define cpu_present(cpu)        ((cpu) == 0)
  98#define cpu_active(cpu)         ((cpu) == 0)
  99#endif
 100
 101/* verify cpu argument to cpumask_* operators */
 102static inline unsigned int cpumask_check(unsigned int cpu)
 103{
 104#ifdef CONFIG_DEBUG_PER_CPU_MAPS
 105        WARN_ON_ONCE(cpu >= nr_cpumask_bits);
 106#endif /* CONFIG_DEBUG_PER_CPU_MAPS */
 107        return cpu;
 108}
 109
 110#if NR_CPUS == 1
 111/* Uniprocessor.  Assume all masks are "1". */
 112static inline unsigned int cpumask_first(const struct cpumask *srcp)
 113{
 114        return 0;
 115}
 116
 117/* Valid inputs for n are -1 and 0. */
 118static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 119{
 120        return n+1;
 121}
 122
 123static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 124{
 125        return n+1;
 126}
 127
 128static inline unsigned int cpumask_next_and(int n,
 129                                            const struct cpumask *srcp,
 130                                            const struct cpumask *andp)
 131{
 132        return n+1;
 133}
 134
 135/* cpu must be a valid cpu, ie 0, so there's no other choice. */
 136static inline unsigned int cpumask_any_but(const struct cpumask *mask,
 137                                           unsigned int cpu)
 138{
 139        return 1;
 140}
 141
 142#define for_each_cpu(cpu, mask)                 \
 143        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 144#define for_each_cpu_and(cpu, mask, and)        \
 145        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and)
 146#else
 147/**
 148 * cpumask_first - get the first cpu in a cpumask
 149 * @srcp: the cpumask pointer
 150 *
 151 * Returns >= nr_cpu_ids if no cpus set.
 152 */
 153static inline unsigned int cpumask_first(const struct cpumask *srcp)
 154{
 155        return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
 156}
 157
 158/**
 159 * cpumask_next - get the next cpu in a cpumask
 160 * @n: the cpu prior to the place to search (ie. return will be > @n)
 161 * @srcp: the cpumask pointer
 162 *
 163 * Returns >= nr_cpu_ids if no further cpus set.
 164 */
 165static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
 166{
 167        /* -1 is a legal arg here. */
 168        if (n != -1)
 169                cpumask_check(n);
 170        return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 171}
 172
 173/**
 174 * cpumask_next_zero - get the next unset cpu in a cpumask
 175 * @n: the cpu prior to the place to search (ie. return will be > @n)
 176 * @srcp: the cpumask pointer
 177 *
 178 * Returns >= nr_cpu_ids if no further cpus unset.
 179 */
 180static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
 181{
 182        /* -1 is a legal arg here. */
 183        if (n != -1)
 184                cpumask_check(n);
 185        return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
 186}
 187
 188int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
 189int cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
 190
 191/**
 192 * for_each_cpu - iterate over every cpu in a mask
 193 * @cpu: the (optionally unsigned) integer iterator
 194 * @mask: the cpumask pointer
 195 *
 196 * After the loop, cpu is >= nr_cpu_ids.
 197 */
 198#define for_each_cpu(cpu, mask)                         \
 199        for ((cpu) = -1;                                \
 200                (cpu) = cpumask_next((cpu), (mask)),    \
 201                (cpu) < nr_cpu_ids;)
 202
 203/**
 204 * for_each_cpu_and - iterate over every cpu in both masks
 205 * @cpu: the (optionally unsigned) integer iterator
 206 * @mask: the first cpumask pointer
 207 * @and: the second cpumask pointer
 208 *
 209 * This saves a temporary CPU mask in many places.  It is equivalent to:
 210 *      struct cpumask tmp;
 211 *      cpumask_and(&tmp, &mask, &and);
 212 *      for_each_cpu(cpu, &tmp)
 213 *              ...
 214 *
 215 * After the loop, cpu is >= nr_cpu_ids.
 216 */
 217#define for_each_cpu_and(cpu, mask, and)                                \
 218        for ((cpu) = -1;                                                \
 219                (cpu) = cpumask_next_and((cpu), (mask), (and)),         \
 220                (cpu) < nr_cpu_ids;)
 221#endif /* SMP */
 222
 223#define CPU_BITS_NONE                                           \
 224{                                                               \
 225        [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL                  \
 226}
 227
 228#define CPU_BITS_CPU0                                           \
 229{                                                               \
 230        [0] =  1UL                                              \
 231}
 232
 233/**
 234 * cpumask_set_cpu - set a cpu in a cpumask
 235 * @cpu: cpu number (< nr_cpu_ids)
 236 * @dstp: the cpumask pointer
 237 */
 238static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
 239{
 240        set_bit(cpumask_check(cpu), cpumask_bits(dstp));
 241}
 242
 243/**
 244 * cpumask_clear_cpu - clear a cpu in a cpumask
 245 * @cpu: cpu number (< nr_cpu_ids)
 246 * @dstp: the cpumask pointer
 247 */
 248static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
 249{
 250        clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
 251}
 252
 253/**
 254 * cpumask_test_cpu - test for a cpu in a cpumask
 255 * @cpu: cpu number (< nr_cpu_ids)
 256 * @cpumask: the cpumask pointer
 257 *
 258 * No static inline type checking - see Subtlety (1) above.
 259 */
 260#define cpumask_test_cpu(cpu, cpumask) \
 261        test_bit(cpumask_check(cpu), cpumask_bits((cpumask)))
 262
 263/**
 264 * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
 265 * @cpu: cpu number (< nr_cpu_ids)
 266 * @cpumask: the cpumask pointer
 267 *
 268 * test_and_set_bit wrapper for cpumasks.
 269 */
 270static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
 271{
 272        return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 273}
 274
 275/**
 276 * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask
 277 * @cpu: cpu number (< nr_cpu_ids)
 278 * @cpumask: the cpumask pointer
 279 *
 280 * test_and_clear_bit wrapper for cpumasks.
 281 */
 282static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
 283{
 284        return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask));
 285}
 286
 287/**
 288 * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
 289 * @dstp: the cpumask pointer
 290 */
 291static inline void cpumask_setall(struct cpumask *dstp)
 292{
 293        bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
 294}
 295
 296/**
 297 * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
 298 * @dstp: the cpumask pointer
 299 */
 300static inline void cpumask_clear(struct cpumask *dstp)
 301{
 302        bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits);
 303}
 304
 305/**
 306 * cpumask_and - *dstp = *src1p & *src2p
 307 * @dstp: the cpumask result
 308 * @src1p: the first input
 309 * @src2p: the second input
 310 */
 311static inline int cpumask_and(struct cpumask *dstp,
 312                               const struct cpumask *src1p,
 313                               const struct cpumask *src2p)
 314{
 315        return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
 316                                       cpumask_bits(src2p), nr_cpumask_bits);
 317}
 318
 319/**
 320 * cpumask_or - *dstp = *src1p | *src2p
 321 * @dstp: the cpumask result
 322 * @src1p: the first input
 323 * @src2p: the second input
 324 */
 325static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
 326                              const struct cpumask *src2p)
 327{
 328        bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
 329                                      cpumask_bits(src2p), nr_cpumask_bits);
 330}
 331
 332/**
 333 * cpumask_xor - *dstp = *src1p ^ *src2p
 334 * @dstp: the cpumask result
 335 * @src1p: the first input
 336 * @src2p: the second input
 337 */
 338static inline void cpumask_xor(struct cpumask *dstp,
 339                               const struct cpumask *src1p,
 340                               const struct cpumask *src2p)
 341{
 342        bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
 343                                       cpumask_bits(src2p), nr_cpumask_bits);
 344}
 345
 346/**
 347 * cpumask_andnot - *dstp = *src1p & ~*src2p
 348 * @dstp: the cpumask result
 349 * @src1p: the first input
 350 * @src2p: the second input
 351 */
 352static inline int cpumask_andnot(struct cpumask *dstp,
 353                                  const struct cpumask *src1p,
 354                                  const struct cpumask *src2p)
 355{
 356        return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
 357                                          cpumask_bits(src2p), nr_cpumask_bits);
 358}
 359
 360/**
 361 * cpumask_complement - *dstp = ~*srcp
 362 * @dstp: the cpumask result
 363 * @srcp: the input to invert
 364 */
 365static inline void cpumask_complement(struct cpumask *dstp,
 366                                      const struct cpumask *srcp)
 367{
 368        bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
 369                                              nr_cpumask_bits);
 370}
 371
 372/**
 373 * cpumask_equal - *src1p == *src2p
 374 * @src1p: the first input
 375 * @src2p: the second input
 376 */
 377static inline bool cpumask_equal(const struct cpumask *src1p,
 378                                const struct cpumask *src2p)
 379{
 380        return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
 381                                                 nr_cpumask_bits);
 382}
 383
 384/**
 385 * cpumask_intersects - (*src1p & *src2p) != 0
 386 * @src1p: the first input
 387 * @src2p: the second input
 388 */
 389static inline bool cpumask_intersects(const struct cpumask *src1p,
 390                                     const struct cpumask *src2p)
 391{
 392        return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
 393                                                      nr_cpumask_bits);
 394}
 395
 396/**
 397 * cpumask_subset - (*src1p & ~*src2p) == 0
 398 * @src1p: the first input
 399 * @src2p: the second input
 400 */
 401static inline int cpumask_subset(const struct cpumask *src1p,
 402                                 const struct cpumask *src2p)
 403{
 404        return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
 405                                                  nr_cpumask_bits);
 406}
 407
 408/**
 409 * cpumask_empty - *srcp == 0
 410 * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
 411 */
 412static inline bool cpumask_empty(const struct cpumask *srcp)
 413{
 414        return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits);
 415}
 416
 417/**
 418 * cpumask_full - *srcp == 0xFFFFFFFF...
 419 * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
 420 */
 421static inline bool cpumask_full(const struct cpumask *srcp)
 422{
 423        return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
 424}
 425
 426/**
 427 * cpumask_weight - Count of bits in *srcp
 428 * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
 429 */
 430static inline unsigned int cpumask_weight(const struct cpumask *srcp)
 431{
 432        return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
 433}
 434
 435/**
 436 * cpumask_shift_right - *dstp = *srcp >> n
 437 * @dstp: the cpumask result
 438 * @srcp: the input to shift
 439 * @n: the number of bits to shift by
 440 */
 441static inline void cpumask_shift_right(struct cpumask *dstp,
 442                                       const struct cpumask *srcp, int n)
 443{
 444        bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n,
 445                                               nr_cpumask_bits);
 446}
 447
 448/**
 449 * cpumask_shift_left - *dstp = *srcp << n
 450 * @dstp: the cpumask result
 451 * @srcp: the input to shift
 452 * @n: the number of bits to shift by
 453 */
 454static inline void cpumask_shift_left(struct cpumask *dstp,
 455                                      const struct cpumask *srcp, int n)
 456{
 457        bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n,
 458                                              nr_cpumask_bits);
 459}
 460
 461/**
 462 * cpumask_copy - *dstp = *srcp
 463 * @dstp: the result
 464 * @srcp: the input cpumask
 465 */
 466static inline void cpumask_copy(struct cpumask *dstp,
 467                                const struct cpumask *srcp)
 468{
 469        bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
 470}
 471
 472/**
 473 * cpumask_any - pick a "random" cpu from *srcp
 474 * @srcp: the input cpumask
 475 *
 476 * Returns >= nr_cpu_ids if no cpus set.
 477 */
 478#define cpumask_any(srcp) cpumask_first(srcp)
 479
 480/**
 481 * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
 482 * @src1p: the first input
 483 * @src2p: the second input
 484 *
 485 * Returns >= nr_cpu_ids if no cpus set in both.  See also cpumask_next_and().
 486 */
 487#define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
 488
 489/**
 490 * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
 491 * @mask1: the first input cpumask
 492 * @mask2: the second input cpumask
 493 *
 494 * Returns >= nr_cpu_ids if no cpus set.
 495 */
 496#define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
 497
 498/**
 499 * cpumask_of - the cpumask containing just a given cpu
 500 * @cpu: the cpu (<= nr_cpu_ids)
 501 */
 502#define cpumask_of(cpu) (get_cpu_mask(cpu))
 503
 504/**
 505 * cpumask_scnprintf - print a cpumask into a string as comma-separated hex
 506 * @buf: the buffer to sprintf into
 507 * @len: the length of the buffer
 508 * @srcp: the cpumask to print
 509 *
 510 * If len is zero, returns zero.  Otherwise returns the length of the
 511 * (nul-terminated) @buf string.
 512 */
 513static inline int cpumask_scnprintf(char *buf, int len,
 514                                    const struct cpumask *srcp)
 515{
 516        return bitmap_scnprintf(buf, len, cpumask_bits(srcp), nr_cpumask_bits);
 517}
 518
 519/**
 520 * cpumask_parse_user - extract a cpumask from a user string
 521 * @buf: the buffer to extract from
 522 * @len: the length of the buffer
 523 * @dstp: the cpumask to set.
 524 *
 525 * Returns -errno, or 0 for success.
 526 */
 527static inline int cpumask_parse_user(const char __user *buf, int len,
 528                                     struct cpumask *dstp)
 529{
 530        return bitmap_parse_user(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
 531}
 532
 533/**
 534 * cpulist_scnprintf - print a cpumask into a string as comma-separated list
 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 cpulist_scnprintf(char *buf, int len,
 543                                    const struct cpumask *srcp)
 544{
 545        return bitmap_scnlistprintf(buf, len, cpumask_bits(srcp),
 546                                    nr_cpumask_bits);
 547}
 548
 549/**
 550 * cpulist_parse_user - extract a cpumask from a user string of ranges
 551 * @buf: the buffer to extract from
 552 * @len: the length of the buffer
 553 * @dstp: the cpumask to set.
 554 *
 555 * Returns -errno, or 0 for success.
 556 */
 557static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
 558{
 559        return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits);
 560}
 561
 562/**
 563 * cpumask_size - size to allocate for a 'struct cpumask' in bytes
 564 *
 565 * This will eventually be a runtime variable, depending on nr_cpu_ids.
 566 */
 567static inline size_t cpumask_size(void)
 568{
 569        /* FIXME: Once all cpumask assignments are eliminated, this
 570         * can be nr_cpumask_bits */
 571        return BITS_TO_LONGS(NR_CPUS) * sizeof(long);
 572}
 573
 574/*
 575 * cpumask_var_t: struct cpumask for stack usage.
 576 *
 577 * Oh, the wicked games we play!  In order to make kernel coding a
 578 * little more difficult, we typedef cpumask_var_t to an array or a
 579 * pointer: doing &mask on an array is a noop, so it still works.
 580 *
 581 * ie.
 582 *      cpumask_var_t tmpmask;
 583 *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
 584 *              return -ENOMEM;
 585 *
 586 *        ... use 'tmpmask' like a normal struct cpumask * ...
 587 *
 588 *      free_cpumask_var(tmpmask);
 589 */
 590#ifdef CONFIG_CPUMASK_OFFSTACK
 591typedef struct cpumask *cpumask_var_t;
 592
 593bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
 594bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
 595bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
 596bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
 597void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
 598void free_cpumask_var(cpumask_var_t mask);
 599void free_bootmem_cpumask_var(cpumask_var_t mask);
 600
 601#else
 602typedef struct cpumask cpumask_var_t[1];
 603
 604static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
 605{
 606        return true;
 607}
 608
 609static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
 610                                          int node)
 611{
 612        return true;
 613}
 614
 615static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
 616{
 617        cpumask_clear(*mask);
 618        return true;
 619}
 620
 621static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
 622                                          int node)
 623{
 624        cpumask_clear(*mask);
 625        return true;
 626}
 627
 628static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask)
 629{
 630}
 631
 632static inline void free_cpumask_var(cpumask_var_t mask)
 633{
 634}
 635
 636static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
 637{
 638}
 639#endif /* CONFIG_CPUMASK_OFFSTACK */
 640
 641/* It's common to want to use cpu_all_mask in struct member initializers,
 642 * so it has to refer to an address rather than a pointer. */
 643extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
 644#define cpu_all_mask to_cpumask(cpu_all_bits)
 645
 646/* First bits of cpu_bit_bitmap are in fact unset. */
 647#define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
 648
 649#define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
 650#define for_each_online_cpu(cpu)   for_each_cpu((cpu), cpu_online_mask)
 651#define for_each_present_cpu(cpu)  for_each_cpu((cpu), cpu_present_mask)
 652
 653/* Wrappers for arch boot code to manipulate normally-constant masks */
 654void set_cpu_possible(unsigned int cpu, bool possible);
 655void set_cpu_present(unsigned int cpu, bool present);
 656void set_cpu_online(unsigned int cpu, bool online);
 657void set_cpu_active(unsigned int cpu, bool active);
 658void init_cpu_present(const struct cpumask *src);
 659void init_cpu_possible(const struct cpumask *src);
 660void init_cpu_online(const struct cpumask *src);
 661
 662/**
 663 * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
 664 * @bitmap: the bitmap
 665 *
 666 * There are a few places where cpumask_var_t isn't appropriate and
 667 * static cpumasks must be used (eg. very early boot), yet we don't
 668 * expose the definition of 'struct cpumask'.
 669 *
 670 * This does the conversion, and can be used as a constant initializer.
 671 */
 672#define to_cpumask(bitmap)                                              \
 673        ((struct cpumask *)(1 ? (bitmap)                                \
 674                            : (void *)sizeof(__check_is_bitmap(bitmap))))
 675
 676static inline int __check_is_bitmap(const unsigned long *bitmap)
 677{
 678        return 1;
 679}
 680
 681/*
 682 * Special-case data structure for "single bit set only" constant CPU masks.
 683 *
 684 * We pre-generate all the 64 (or 32) possible bit positions, with enough
 685 * padding to the left and the right, and return the constant pointer
 686 * appropriately offset.
 687 */
 688extern const unsigned long
 689        cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
 690
 691static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
 692{
 693        const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
 694        p -= cpu / BITS_PER_LONG;
 695        return to_cpumask(p);
 696}
 697
 698#define cpu_is_offline(cpu)     unlikely(!cpu_online(cpu))
 699
 700#if NR_CPUS <= BITS_PER_LONG
 701#define CPU_BITS_ALL                                            \
 702{                                                               \
 703        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD \
 704}
 705
 706#else /* NR_CPUS > BITS_PER_LONG */
 707
 708#define CPU_BITS_ALL                                            \
 709{                                                               \
 710        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                \
 711        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD         \
 712}
 713#endif /* NR_CPUS > BITS_PER_LONG */
 714
 715/*
 716 *
 717 * From here down, all obsolete.  Use cpumask_ variants!
 718 *
 719 */
 720#ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
 721/* These strip const, as traditionally they weren't const. */
 722#define cpu_possible_map        (*(cpumask_t *)cpu_possible_mask)
 723#define cpu_online_map          (*(cpumask_t *)cpu_online_mask)
 724#define cpu_present_map         (*(cpumask_t *)cpu_present_mask)
 725#define cpu_active_map          (*(cpumask_t *)cpu_active_mask)
 726
 727#define cpumask_of_cpu(cpu) (*get_cpu_mask(cpu))
 728
 729#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
 730
 731#if NR_CPUS <= BITS_PER_LONG
 732
 733#define CPU_MASK_ALL                                                    \
 734(cpumask_t) { {                                                         \
 735        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 736} }
 737
 738#else
 739
 740#define CPU_MASK_ALL                                                    \
 741(cpumask_t) { {                                                         \
 742        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
 743        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 744} }
 745
 746#endif
 747
 748#define CPU_MASK_NONE                                                   \
 749(cpumask_t) { {                                                         \
 750        [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
 751} }
 752
 753#define CPU_MASK_CPU0                                                   \
 754(cpumask_t) { {                                                         \
 755        [0] =  1UL                                                      \
 756} }
 757
 758#if NR_CPUS == 1
 759#define first_cpu(src)          ({ (void)(src); 0; })
 760#define next_cpu(n, src)        ({ (void)(src); 1; })
 761#define any_online_cpu(mask)    0
 762#define for_each_cpu_mask(cpu, mask)    \
 763        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 764#else /* NR_CPUS > 1 */
 765int __first_cpu(const cpumask_t *srcp);
 766int __next_cpu(int n, const cpumask_t *srcp);
 767int __any_online_cpu(const cpumask_t *mask);
 768
 769#define first_cpu(src)          __first_cpu(&(src))
 770#define next_cpu(n, src)        __next_cpu((n), &(src))
 771#define any_online_cpu(mask) __any_online_cpu(&(mask))
 772#define for_each_cpu_mask(cpu, mask)                    \
 773        for ((cpu) = -1;                                \
 774                (cpu) = next_cpu((cpu), (mask)),        \
 775                (cpu) < NR_CPUS; )
 776#endif /* SMP */
 777
 778#if NR_CPUS <= 64
 779
 780#define for_each_cpu_mask_nr(cpu, mask) for_each_cpu_mask(cpu, mask)
 781
 782#else /* NR_CPUS > 64 */
 783
 784int __next_cpu_nr(int n, const cpumask_t *srcp);
 785#define for_each_cpu_mask_nr(cpu, mask)                 \
 786        for ((cpu) = -1;                                \
 787                (cpu) = __next_cpu_nr((cpu), &(mask)),  \
 788                (cpu) < nr_cpu_ids; )
 789
 790#endif /* NR_CPUS > 64 */
 791
 792#define cpus_addr(src) ((src).bits)
 793
 794#define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
 795static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
 796{
 797        set_bit(cpu, dstp->bits);
 798}
 799
 800#define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
 801static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
 802{
 803        clear_bit(cpu, dstp->bits);
 804}
 805
 806#define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
 807static inline void __cpus_setall(cpumask_t *dstp, int nbits)
 808{
 809        bitmap_fill(dstp->bits, nbits);
 810}
 811
 812#define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
 813static inline void __cpus_clear(cpumask_t *dstp, int nbits)
 814{
 815        bitmap_zero(dstp->bits, nbits);
 816}
 817
 818/* No static inline type checking - see Subtlety (1) above. */
 819#define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
 820
 821#define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
 822static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
 823{
 824        return test_and_set_bit(cpu, addr->bits);
 825}
 826
 827#define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
 828static inline int __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
 829                                        const cpumask_t *src2p, int nbits)
 830{
 831        return bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
 832}
 833
 834#define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
 835static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
 836                                        const cpumask_t *src2p, int nbits)
 837{
 838        bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
 839}
 840
 841#define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
 842static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
 843                                        const cpumask_t *src2p, int nbits)
 844{
 845        bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
 846}
 847
 848#define cpus_andnot(dst, src1, src2) \
 849                                __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
 850static inline int __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
 851                                        const cpumask_t *src2p, int nbits)
 852{
 853        return bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
 854}
 855
 856#define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
 857static inline int __cpus_equal(const cpumask_t *src1p,
 858                                        const cpumask_t *src2p, int nbits)
 859{
 860        return bitmap_equal(src1p->bits, src2p->bits, nbits);
 861}
 862
 863#define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
 864static inline int __cpus_intersects(const cpumask_t *src1p,
 865                                        const cpumask_t *src2p, int nbits)
 866{
 867        return bitmap_intersects(src1p->bits, src2p->bits, nbits);
 868}
 869
 870#define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
 871static inline int __cpus_subset(const cpumask_t *src1p,
 872                                        const cpumask_t *src2p, int nbits)
 873{
 874        return bitmap_subset(src1p->bits, src2p->bits, nbits);
 875}
 876
 877#define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
 878static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
 879{
 880        return bitmap_empty(srcp->bits, nbits);
 881}
 882
 883#define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
 884static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
 885{
 886        return bitmap_weight(srcp->bits, nbits);
 887}
 888
 889#define cpus_shift_left(dst, src, n) \
 890                        __cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
 891static inline void __cpus_shift_left(cpumask_t *dstp,
 892                                        const cpumask_t *srcp, int n, int nbits)
 893{
 894        bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
 895}
 896#endif /* !CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS */
 897
 898#endif /* __LINUX_CPUMASK_H */
 899