LXR linux/include/linux/cpumask.h

   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.
   7 *
   8 * See detailed comments in the file linux/bitmap.h describing the
   9 * data type on which these cpumasks are based.
  10 *
  11 * For details of cpumask_scnprintf() and cpumask_parse_user(),
  12 * see bitmap_scnprintf() and bitmap_parse_user() in lib/bitmap.c.
  13 * For details of cpulist_scnprintf() and cpulist_parse(), see
  14 * bitmap_scnlistprintf() and bitmap_parselist(), also in bitmap.c.
  15 * For details of cpu_remap(), see bitmap_bitremap in lib/bitmap.c
  16 * For details of cpus_remap(), see bitmap_remap in lib/bitmap.c.
  17 * For details of cpus_onto(), see bitmap_onto in lib/bitmap.c.
  18 * For details of cpus_fold(), see bitmap_fold in lib/bitmap.c.
  19 *
  20 * The available cpumask operations are:
  21 *
  22 * void cpu_set(cpu, mask)              turn on bit 'cpu' in mask
  23 * void cpu_clear(cpu, mask)            turn off bit 'cpu' in mask
  24 * void cpus_setall(mask)               set all bits
  25 * void cpus_clear(mask)                clear all bits
  26 * int cpu_isset(cpu, mask)             true iff bit 'cpu' set in mask
  27 * int cpu_test_and_set(cpu, mask)      test and set bit 'cpu' in mask
  28 *
  29 * void cpus_and(dst, src1, src2)       dst = src1 & src2  [intersection]
  30 * void cpus_or(dst, src1, src2)        dst = src1 | src2  [union]
  31 * void cpus_xor(dst, src1, src2)       dst = src1 ^ src2
  32 * void cpus_andnot(dst, src1, src2)    dst = src1 & ~src2
  33 * void cpus_complement(dst, src)       dst = ~src
  34 *
  35 * int cpus_equal(mask1, mask2)         Does mask1 == mask2?
  36 * int cpus_intersects(mask1, mask2)    Do mask1 and mask2 intersect?
  37 * int cpus_subset(mask1, mask2)        Is mask1 a subset of mask2?
  38 * int cpus_empty(mask)                 Is mask empty (no bits sets)?
  39 * int cpus_full(mask)                  Is mask full (all bits sets)?
  40 * int cpus_weight(mask)                Hamming weigh - number of set bits
  41 *
  42 * void cpus_shift_right(dst, src, n)   Shift right
  43 * void cpus_shift_left(dst, src, n)    Shift left
  44 *
  45 * int first_cpu(mask)                  Number lowest set bit, or NR_CPUS
  46 * int next_cpu(cpu, mask)              Next cpu past 'cpu', or NR_CPUS
  47 *
  48 * cpumask_t cpumask_of_cpu(cpu)        Return cpumask with bit 'cpu' set
  49 * CPU_MASK_ALL                         Initializer - all bits set
  50 * CPU_MASK_NONE                        Initializer - no bits set
  51 * unsigned long *cpus_addr(mask)       Array of unsigned long's in mask
  52 *
  53 * int cpumask_scnprintf(buf, len, mask) Format cpumask for printing
  54 * int cpumask_parse_user(ubuf, ulen, mask)     Parse ascii string as cpumask
  55 * int cpulist_scnprintf(buf, len, mask) Format cpumask as list for printing
  56 * int cpulist_parse(buf, map)          Parse ascii string as cpulist
  57 * int cpu_remap(oldbit, old, new)      newbit = map(old, new)(oldbit)
  58 * void cpus_remap(dst, src, old, new)  *dst = map(old, new)(src)
  59 * void cpus_onto(dst, orig, relmap)    *dst = orig relative to relmap
  60 * void cpus_fold(dst, orig, sz)        dst bits = orig bits mod sz
  61 *
  62 * for_each_cpu_mask(cpu, mask)         for-loop cpu over mask
  63 *
  64 * int num_online_cpus()                Number of online CPUs
  65 * int num_possible_cpus()              Number of all possible CPUs
  66 * int num_present_cpus()               Number of present CPUs
  67 *
  68 * int cpu_online(cpu)                  Is some cpu online?
  69 * int cpu_possible(cpu)                Is some cpu possible?
  70 * int cpu_present(cpu)                 Is some cpu present (can schedule)?
  71 *
  72 * int any_online_cpu(mask)             First online cpu in mask
  73 *
  74 * for_each_possible_cpu(cpu)           for-loop cpu over cpu_possible_map
  75 * for_each_online_cpu(cpu)             for-loop cpu over cpu_online_map
  76 * for_each_present_cpu(cpu)            for-loop cpu over cpu_present_map
  77 *
  78 * Subtlety:
  79 * 1) The 'type-checked' form of cpu_isset() causes gcc (3.3.2, anyway)
  80 *    to generate slightly worse code.  Note for example the additional
  81 *    40 lines of assembly code compiling the "for each possible cpu"
  82 *    loops buried in the disk_stat_read() macros calls when compiling
  83 *    drivers/block/genhd.c (arch i386, CONFIG_SMP=y).  So use a simple
  84 *    one-line #define for cpu_isset(), instead of wrapping an inline
  85 *    inside a macro, the way we do the other calls.
  86 */
  87
  88#include <linux/kernel.h>
  89#include <linux/threads.h>
  90#include <linux/bitmap.h>
  91
  92typedef struct { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
  93extern cpumask_t _unused_cpumask_arg_;
  94
  95#define cpu_set(cpu, dst) __cpu_set((cpu), &(dst))
  96static inline void __cpu_set(int cpu, volatile cpumask_t *dstp)
  97{
  98        set_bit(cpu, dstp->bits);
  99}
 100
 101#define cpu_clear(cpu, dst) __cpu_clear((cpu), &(dst))
 102static inline void __cpu_clear(int cpu, volatile cpumask_t *dstp)
 103{
 104        clear_bit(cpu, dstp->bits);
 105}
 106
 107#define cpus_setall(dst) __cpus_setall(&(dst), NR_CPUS)
 108static inline void __cpus_setall(cpumask_t *dstp, int nbits)
 109{
 110        bitmap_fill(dstp->bits, nbits);
 111}
 112
 113#define cpus_clear(dst) __cpus_clear(&(dst), NR_CPUS)
 114static inline void __cpus_clear(cpumask_t *dstp, int nbits)
 115{
 116        bitmap_zero(dstp->bits, nbits);
 117}
 118
 119/* No static inline type checking - see Subtlety (1) above. */
 120#define cpu_isset(cpu, cpumask) test_bit((cpu), (cpumask).bits)
 121
 122#define cpu_test_and_set(cpu, cpumask) __cpu_test_and_set((cpu), &(cpumask))
 123static inline int __cpu_test_and_set(int cpu, cpumask_t *addr)
 124{
 125        return test_and_set_bit(cpu, addr->bits);
 126}
 127
 128#define cpus_and(dst, src1, src2) __cpus_and(&(dst), &(src1), &(src2), NR_CPUS)
 129static inline void __cpus_and(cpumask_t *dstp, const cpumask_t *src1p,
 130                                        const cpumask_t *src2p, int nbits)
 131{
 132        bitmap_and(dstp->bits, src1p->bits, src2p->bits, nbits);
 133}
 134
 135#define cpus_or(dst, src1, src2) __cpus_or(&(dst), &(src1), &(src2), NR_CPUS)
 136static inline void __cpus_or(cpumask_t *dstp, const cpumask_t *src1p,
 137                                        const cpumask_t *src2p, int nbits)
 138{
 139        bitmap_or(dstp->bits, src1p->bits, src2p->bits, nbits);
 140}
 141
 142#define cpus_xor(dst, src1, src2) __cpus_xor(&(dst), &(src1), &(src2), NR_CPUS)
 143static inline void __cpus_xor(cpumask_t *dstp, const cpumask_t *src1p,
 144                                        const cpumask_t *src2p, int nbits)
 145{
 146        bitmap_xor(dstp->bits, src1p->bits, src2p->bits, nbits);
 147}
 148
 149#define cpus_andnot(dst, src1, src2) \
 150                                __cpus_andnot(&(dst), &(src1), &(src2), NR_CPUS)
 151static inline void __cpus_andnot(cpumask_t *dstp, const cpumask_t *src1p,
 152                                        const cpumask_t *src2p, int nbits)
 153{
 154        bitmap_andnot(dstp->bits, src1p->bits, src2p->bits, nbits);
 155}
 156
 157#define cpus_complement(dst, src) __cpus_complement(&(dst), &(src), NR_CPUS)
 158static inline void __cpus_complement(cpumask_t *dstp,
 159                                        const cpumask_t *srcp, int nbits)
 160{
 161        bitmap_complement(dstp->bits, srcp->bits, nbits);
 162}
 163
 164#define cpus_equal(src1, src2) __cpus_equal(&(src1), &(src2), NR_CPUS)
 165static inline int __cpus_equal(const cpumask_t *src1p,
 166                                        const cpumask_t *src2p, int nbits)
 167{
 168        return bitmap_equal(src1p->bits, src2p->bits, nbits);
 169}
 170
 171#define cpus_intersects(src1, src2) __cpus_intersects(&(src1), &(src2), NR_CPUS)
 172static inline int __cpus_intersects(const cpumask_t *src1p,
 173                                        const cpumask_t *src2p, int nbits)
 174{
 175        return bitmap_intersects(src1p->bits, src2p->bits, nbits);
 176}
 177
 178#define cpus_subset(src1, src2) __cpus_subset(&(src1), &(src2), NR_CPUS)
 179static inline int __cpus_subset(const cpumask_t *src1p,
 180                                        const cpumask_t *src2p, int nbits)
 181{
 182        return bitmap_subset(src1p->bits, src2p->bits, nbits);
 183}
 184
 185#define cpus_empty(src) __cpus_empty(&(src), NR_CPUS)
 186static inline int __cpus_empty(const cpumask_t *srcp, int nbits)
 187{
 188        return bitmap_empty(srcp->bits, nbits);
 189}
 190
 191#define cpus_full(cpumask) __cpus_full(&(cpumask), NR_CPUS)
 192static inline int __cpus_full(const cpumask_t *srcp, int nbits)
 193{
 194        return bitmap_full(srcp->bits, nbits);
 195}
 196
 197#define cpus_weight(cpumask) __cpus_weight(&(cpumask), NR_CPUS)
 198static inline int __cpus_weight(const cpumask_t *srcp, int nbits)
 199{
 200        return bitmap_weight(srcp->bits, nbits);
 201}
 202
 203#define cpus_shift_right(dst, src, n) \
 204                        __cpus_shift_right(&(dst), &(src), (n), NR_CPUS)
 205static inline void __cpus_shift_right(cpumask_t *dstp,
 206                                        const cpumask_t *srcp, int n, int nbits)
 207{
 208        bitmap_shift_right(dstp->bits, srcp->bits, n, nbits);
 209}
 210
 211#define cpus_shift_left(dst, src, n) \
 212                        __cpus_shift_left(&(dst), &(src), (n), NR_CPUS)
 213static inline void __cpus_shift_left(cpumask_t *dstp,
 214                                        const cpumask_t *srcp, int n, int nbits)
 215{
 216        bitmap_shift_left(dstp->bits, srcp->bits, n, nbits);
 217}
 218
 219#ifdef CONFIG_SMP
 220int __first_cpu(const cpumask_t *srcp);
 221#define first_cpu(src) __first_cpu(&(src))
 222int __next_cpu(int n, const cpumask_t *srcp);
 223#define next_cpu(n, src) __next_cpu((n), &(src))
 224#else
 225#define first_cpu(src)          ({ (void)(src); 0; })
 226#define next_cpu(n, src)        ({ (void)(src); 1; })
 227#endif
 228
 229#ifdef CONFIG_HAVE_CPUMASK_OF_CPU_MAP
 230extern cpumask_t *cpumask_of_cpu_map;
 231#define cpumask_of_cpu(cpu)    (cpumask_of_cpu_map[cpu])
 232
 233#else
 234#define cpumask_of_cpu(cpu)                                             \
 235(*({                                                                    \
 236        typeof(_unused_cpumask_arg_) m;                                 \
 237        if (sizeof(m) == sizeof(unsigned long)) {                       \
 238                m.bits[0] = 1UL<<(cpu);                                 \
 239        } else {                                                        \
 240                cpus_clear(m);                                          \
 241                cpu_set((cpu), m);                                      \
 242        }                                                               \
 243        &m;                                                             \
 244}))
 245#endif
 246
 247#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
 248
 249#if NR_CPUS <= BITS_PER_LONG
 250
 251#define CPU_MASK_ALL                                                    \
 252(cpumask_t) { {                                                         \
 253        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 254} }
 255
 256#define CPU_MASK_ALL_PTR        (&CPU_MASK_ALL)
 257
 258#else
 259
 260#define CPU_MASK_ALL                                                    \
 261(cpumask_t) { {                                                         \
 262        [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
 263        [BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD                 \
 264} }
 265
 266/* cpu_mask_all is in init/main.c */
 267extern cpumask_t cpu_mask_all;
 268#define CPU_MASK_ALL_PTR        (&cpu_mask_all)
 269
 270#endif
 271
 272#define CPU_MASK_NONE                                                   \
 273(cpumask_t) { {                                                         \
 274        [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
 275} }
 276
 277#define CPU_MASK_CPU0                                                   \
 278(cpumask_t) { {                                                         \
 279        [0] =  1UL                                                      \
 280} }
 281
 282#define cpus_addr(src) ((src).bits)
 283
 284#define cpumask_scnprintf(buf, len, src) \
 285                        __cpumask_scnprintf((buf), (len), &(src), NR_CPUS)
 286static inline int __cpumask_scnprintf(char *buf, int len,
 287                                        const cpumask_t *srcp, int nbits)
 288{
 289        return bitmap_scnprintf(buf, len, srcp->bits, nbits);
 290}
 291
 292#define cpumask_parse_user(ubuf, ulen, dst) \
 293                        __cpumask_parse_user((ubuf), (ulen), &(dst), NR_CPUS)
 294static inline int __cpumask_parse_user(const char __user *buf, int len,
 295                                        cpumask_t *dstp, int nbits)
 296{
 297        return bitmap_parse_user(buf, len, dstp->bits, nbits);
 298}
 299
 300#define cpulist_scnprintf(buf, len, src) \
 301                        __cpulist_scnprintf((buf), (len), &(src), NR_CPUS)
 302static inline int __cpulist_scnprintf(char *buf, int len,
 303                                        const cpumask_t *srcp, int nbits)
 304{
 305        return bitmap_scnlistprintf(buf, len, srcp->bits, nbits);
 306}
 307
 308#define cpulist_parse(buf, dst) __cpulist_parse((buf), &(dst), NR_CPUS)
 309static inline int __cpulist_parse(const char *buf, cpumask_t *dstp, int nbits)
 310{
 311        return bitmap_parselist(buf, dstp->bits, nbits);
 312}
 313
 314#define cpu_remap(oldbit, old, new) \
 315                __cpu_remap((oldbit), &(old), &(new), NR_CPUS)
 316static inline int __cpu_remap(int oldbit,
 317                const cpumask_t *oldp, const cpumask_t *newp, int nbits)
 318{
 319        return bitmap_bitremap(oldbit, oldp->bits, newp->bits, nbits);
 320}
 321
 322#define cpus_remap(dst, src, old, new) \
 323                __cpus_remap(&(dst), &(src), &(old), &(new), NR_CPUS)
 324static inline void __cpus_remap(cpumask_t *dstp, const cpumask_t *srcp,
 325                const cpumask_t *oldp, const cpumask_t *newp, int nbits)
 326{
 327        bitmap_remap(dstp->bits, srcp->bits, oldp->bits, newp->bits, nbits);
 328}
 329
 330#define cpus_onto(dst, orig, relmap) \
 331                __cpus_onto(&(dst), &(orig), &(relmap), NR_CPUS)
 332static inline void __cpus_onto(cpumask_t *dstp, const cpumask_t *origp,
 333                const cpumask_t *relmapp, int nbits)
 334{
 335        bitmap_onto(dstp->bits, origp->bits, relmapp->bits, nbits);
 336}
 337
 338#define cpus_fold(dst, orig, sz) \
 339                __cpus_fold(&(dst), &(orig), sz, NR_CPUS)
 340static inline void __cpus_fold(cpumask_t *dstp, const cpumask_t *origp,
 341                int sz, int nbits)
 342{
 343        bitmap_fold(dstp->bits, origp->bits, sz, nbits);
 344}
 345
 346#if NR_CPUS > 1
 347#define for_each_cpu_mask(cpu, mask)            \
 348        for ((cpu) = first_cpu(mask);           \
 349                (cpu) < NR_CPUS;                \
 350                (cpu) = next_cpu((cpu), (mask)))
 351#else /* NR_CPUS == 1 */
 352#define for_each_cpu_mask(cpu, mask)            \
 353        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
 354#endif /* NR_CPUS */
 355
 356#define next_cpu_nr(n, src)             next_cpu(n, src)
 357#define cpus_weight_nr(cpumask)         cpus_weight(cpumask)
 358#define for_each_cpu_mask_nr(cpu, mask) for_each_cpu_mask(cpu, mask)
 359
 360/*
 361 * The following particular system cpumasks and operations manage
 362 * possible, present and online cpus.  Each of them is a fixed size
 363 * bitmap of size NR_CPUS.
 364 *
 365 *  #ifdef CONFIG_HOTPLUG_CPU
 366 *     cpu_possible_map - has bit 'cpu' set iff cpu is populatable
 367 *     cpu_present_map  - has bit 'cpu' set iff cpu is populated
 368 *     cpu_online_map   - has bit 'cpu' set iff cpu available to scheduler
 369 *  #else
 370 *     cpu_possible_map - has bit 'cpu' set iff cpu is populated
 371 *     cpu_present_map  - copy of cpu_possible_map
 372 *     cpu_online_map   - has bit 'cpu' set iff cpu available to scheduler
 373 *  #endif
 374 *
 375 *  In either case, NR_CPUS is fixed at compile time, as the static
 376 *  size of these bitmaps.  The cpu_possible_map is fixed at boot
 377 *  time, as the set of CPU id's that it is possible might ever
 378 *  be plugged in at anytime during the life of that system boot.
 379 *  The cpu_present_map is dynamic(*), representing which CPUs
 380 *  are currently plugged in.  And cpu_online_map is the dynamic
 381 *  subset of cpu_present_map, indicating those CPUs available
 382 *  for scheduling.
 383 *
 384 *  If HOTPLUG is enabled, then cpu_possible_map is forced to have
 385 *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
 386 *  ACPI reports present at boot.
 387 *
 388 *  If HOTPLUG is enabled, then cpu_present_map varies dynamically,
 389 *  depending on what ACPI reports as currently plugged in, otherwise
 390 *  cpu_present_map is just a copy of cpu_possible_map.
 391 *
 392 *  (*) Well, cpu_present_map is dynamic in the hotplug case.  If not
 393 *      hotplug, it's a copy of cpu_possible_map, hence fixed at boot.
 394 *
 395 * Subtleties:
 396 * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
 397 *    assumption that their single CPU is online.  The UP
 398 *    cpu_{online,possible,present}_maps are placebos.  Changing them
 399 *    will have no useful affect on the following num_*_cpus()
 400 *    and cpu_*() macros in the UP case.  This ugliness is a UP
 401 *    optimization - don't waste any instructions or memory references
 402 *    asking if you're online or how many CPUs there are if there is
 403 *    only one CPU.
 404 * 2) Most SMP arch's #define some of these maps to be some
 405 *    other map specific to that arch.  Therefore, the following
 406 *    must be #define macros, not inlines.  To see why, examine
 407 *    the assembly code produced by the following.  Note that
 408 *    set1() writes phys_x_map, but set2() writes x_map:
 409 *        int x_map, phys_x_map;
 410 *        #define set1(a) x_map = a
 411 *        inline void set2(int a) { x_map = a; }
 412 *        #define x_map phys_x_map
 413 *        main(){ set1(3); set2(5); }
 414 */
 415
 416extern cpumask_t cpu_possible_map;
 417extern cpumask_t cpu_online_map;
 418extern cpumask_t cpu_present_map;
 419
 420#if NR_CPUS > 1
 421#define num_online_cpus()       cpus_weight(cpu_online_map)
 422#define num_possible_cpus()     cpus_weight(cpu_possible_map)
 423#define num_present_cpus()      cpus_weight(cpu_present_map)
 424#define cpu_online(cpu)         cpu_isset((cpu), cpu_online_map)
 425#define cpu_possible(cpu)       cpu_isset((cpu), cpu_possible_map)
 426#define cpu_present(cpu)        cpu_isset((cpu), cpu_present_map)
 427#else
 428#define num_online_cpus()       1
 429#define num_possible_cpus()     1
 430#define num_present_cpus()      1
 431#define cpu_online(cpu)         ((cpu) == 0)
 432#define cpu_possible(cpu)       ((cpu) == 0)
 433#define cpu_present(cpu)        ((cpu) == 0)
 434#endif
 435
 436#define cpu_is_offline(cpu)     unlikely(!cpu_online(cpu))
 437
 438#ifdef CONFIG_SMP
 439extern int nr_cpu_ids;
 440#define any_online_cpu(mask) __any_online_cpu(&(mask))
 441int __any_online_cpu(const cpumask_t *mask);
 442#else
 443#define nr_cpu_ids                      1
 444#define any_online_cpu(mask)            0
 445#endif
 446
 447#define for_each_possible_cpu(cpu)  for_each_cpu_mask((cpu), cpu_possible_map)
 448#define for_each_online_cpu(cpu)  for_each_cpu_mask((cpu), cpu_online_map)
 449#define for_each_present_cpu(cpu) for_each_cpu_mask((cpu), cpu_present_map)
 450
 451#endif /* __LINUX_CPUMASK_H */
 452