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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.  
  14. /* Don't assign or return these: may not be this big! */
  15. typedef struct cpumask { DECLARE_BITMAP(bits, NR_CPUS); } cpumask_t;
  16.  
  17. /**
  18.  * cpumask_bits - get the bits in a cpumask
  19.  * @maskp: the struct cpumask *
  20.  *
  21.  * You should only assume nr_cpu_ids bits of this mask are valid.  This is
  22.  * a macro so it's const-correct.
  23.  */
  24. #define cpumask_bits(maskp) ((maskp)->bits)
  25.  
  26. /**
  27.  * cpumask_pr_args - printf args to output a cpumask
  28.  * @maskp: cpumask to be printed
  29.  *
  30.  * Can be used to provide arguments for '%*pb[l]' when printing a cpumask.
  31.  */
  32. #define cpumask_pr_args(maskp)          nr_cpu_ids, cpumask_bits(maskp)
  33.  
  34. #if NR_CPUS == 1
  35. #define nr_cpu_ids              1
  36. #else
  37. extern int nr_cpu_ids;
  38. #endif
  39.  
  40. #ifdef CONFIG_CPUMASK_OFFSTACK
  41. /* Assuming NR_CPUS is huge, a runtime limit is more efficient.  Also,
  42.  * not all bits may be allocated. */
  43. #define nr_cpumask_bits nr_cpu_ids
  44. #else
  45. #define nr_cpumask_bits NR_CPUS
  46. #endif
  47.  
  48. /*
  49.  * The following particular system cpumasks and operations manage
  50.  * possible, present, active and online cpus.
  51.  *
  52.  *     cpu_possible_mask- has bit 'cpu' set iff cpu is populatable
  53.  *     cpu_present_mask - has bit 'cpu' set iff cpu is populated
  54.  *     cpu_online_mask  - has bit 'cpu' set iff cpu available to scheduler
  55.  *     cpu_active_mask  - has bit 'cpu' set iff cpu available to migration
  56.  *
  57.  *  If !CONFIG_HOTPLUG_CPU, present == possible, and active == online.
  58.  *
  59.  *  The cpu_possible_mask is fixed at boot time, as the set of CPU id's
  60.  *  that it is possible might ever be plugged in at anytime during the
  61.  *  life of that system boot.  The cpu_present_mask is dynamic(*),
  62.  *  representing which CPUs are currently plugged in.  And
  63.  *  cpu_online_mask is the dynamic subset of cpu_present_mask,
  64.  *  indicating those CPUs available for scheduling.
  65.  *
  66.  *  If HOTPLUG is enabled, then cpu_possible_mask is forced to have
  67.  *  all NR_CPUS bits set, otherwise it is just the set of CPUs that
  68.  *  ACPI reports present at boot.
  69.  *
  70.  *  If HOTPLUG is enabled, then cpu_present_mask varies dynamically,
  71.  *  depending on what ACPI reports as currently plugged in, otherwise
  72.  *  cpu_present_mask is just a copy of cpu_possible_mask.
  73.  *
  74.  *  (*) Well, cpu_present_mask is dynamic in the hotplug case.  If not
  75.  *      hotplug, it's a copy of cpu_possible_mask, hence fixed at boot.
  76.  *
  77.  * Subtleties:
  78.  * 1) UP arch's (NR_CPUS == 1, CONFIG_SMP not defined) hardcode
  79.  *    assumption that their single CPU is online.  The UP
  80.  *    cpu_{online,possible,present}_masks are placebos.  Changing them
  81.  *    will have no useful affect on the following num_*_cpus()
  82.  *    and cpu_*() macros in the UP case.  This ugliness is a UP
  83.  *    optimization - don't waste any instructions or memory references
  84.  *    asking if you're online or how many CPUs there are if there is
  85.  *    only one CPU.
  86.  */
  87.  
  88. extern const struct cpumask *const cpu_possible_mask;
  89. extern const struct cpumask *const cpu_online_mask;
  90. extern const struct cpumask *const cpu_present_mask;
  91. extern const struct cpumask *const cpu_active_mask;
  92.  
  93. #if NR_CPUS > 1
  94. #define num_online_cpus()       cpumask_weight(cpu_online_mask)
  95. #define num_possible_cpus()     cpumask_weight(cpu_possible_mask)
  96. #define num_present_cpus()      cpumask_weight(cpu_present_mask)
  97. #define num_active_cpus()       cpumask_weight(cpu_active_mask)
  98. #define cpu_online(cpu)         cpumask_test_cpu((cpu), cpu_online_mask)
  99. #define cpu_possible(cpu)       cpumask_test_cpu((cpu), cpu_possible_mask)
  100. #define cpu_present(cpu)        cpumask_test_cpu((cpu), cpu_present_mask)
  101. #define cpu_active(cpu)         cpumask_test_cpu((cpu), cpu_active_mask)
  102. #else
  103. #define num_online_cpus()       1U
  104. #define num_possible_cpus()     1U
  105. #define num_present_cpus()      1U
  106. #define num_active_cpus()       1U
  107. #define cpu_online(cpu)         ((cpu) == 0)
  108. #define cpu_possible(cpu)       ((cpu) == 0)
  109. #define cpu_present(cpu)        ((cpu) == 0)
  110. #define cpu_active(cpu)         ((cpu) == 0)
  111. #endif
  112.  
  113. /* verify cpu argument to cpumask_* operators */
  114. static inline unsigned int cpumask_check(unsigned int cpu)
  115. {
  116. #ifdef CONFIG_DEBUG_PER_CPU_MAPS
  117.         WARN_ON_ONCE(cpu >= nr_cpumask_bits);
  118. #endif /* CONFIG_DEBUG_PER_CPU_MAPS */
  119.         return cpu;
  120. }
  121.  
  122. #if NR_CPUS == 1
  123. /* Uniprocessor.  Assume all masks are "1". */
  124. static inline unsigned int cpumask_first(const struct cpumask *srcp)
  125. {
  126.         return 0;
  127. }
  128.  
  129. /* Valid inputs for n are -1 and 0. */
  130. static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
  131. {
  132.         return n+1;
  133. }
  134.  
  135. static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
  136. {
  137.         return n+1;
  138. }
  139.  
  140. static inline unsigned int cpumask_next_and(int n,
  141.                                             const struct cpumask *srcp,
  142.                                             const struct cpumask *andp)
  143. {
  144.         return n+1;
  145. }
  146.  
  147. /* cpu must be a valid cpu, ie 0, so there's no other choice. */
  148. static inline unsigned int cpumask_any_but(const struct cpumask *mask,
  149.                                            unsigned int cpu)
  150. {
  151.         return 1;
  152. }
  153.  
  154. static inline unsigned int cpumask_local_spread(unsigned int i, int node)
  155. {
  156.         return 0;
  157. }
  158.  
  159. #define for_each_cpu(cpu, mask)                 \
  160.         for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
  161. #define for_each_cpu_not(cpu, mask)             \
  162.         for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)
  163. #define for_each_cpu_and(cpu, mask, and)        \
  164.         for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask, (void)and)
  165. #else
  166. /**
  167.  * cpumask_first - get the first cpu in a cpumask
  168.  * @srcp: the cpumask pointer
  169.  *
  170.  * Returns >= nr_cpu_ids if no cpus set.
  171.  */
  172. static inline unsigned int cpumask_first(const struct cpumask *srcp)
  173. {
  174.         return find_first_bit(cpumask_bits(srcp), nr_cpumask_bits);
  175. }
  176.  
  177. /**
  178.  * cpumask_next - get the next cpu in a cpumask
  179.  * @n: the cpu prior to the place to search (ie. return will be > @n)
  180.  * @srcp: the cpumask pointer
  181.  *
  182.  * Returns >= nr_cpu_ids if no further cpus set.
  183.  */
  184. static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
  185. {
  186.         /* -1 is a legal arg here. */
  187.         if (n != -1)
  188.                 cpumask_check(n);
  189.         return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
  190. }
  191.  
  192. /**
  193.  * cpumask_next_zero - get the next unset cpu in a cpumask
  194.  * @n: the cpu prior to the place to search (ie. return will be > @n)
  195.  * @srcp: the cpumask pointer
  196.  *
  197.  * Returns >= nr_cpu_ids if no further cpus unset.
  198.  */
  199. static inline unsigned int cpumask_next_zero(int n, const struct cpumask *srcp)
  200. {
  201.         /* -1 is a legal arg here. */
  202.         if (n != -1)
  203.                 cpumask_check(n);
  204.         return find_next_zero_bit(cpumask_bits(srcp), nr_cpumask_bits, n+1);
  205. }
  206.  
  207. int cpumask_next_and(int n, const struct cpumask *, const struct cpumask *);
  208. int cpumask_any_but(const struct cpumask *mask, unsigned int cpu);
  209. unsigned int cpumask_local_spread(unsigned int i, int node);
  210.  
  211. /**
  212.  * for_each_cpu - iterate over every cpu in a mask
  213.  * @cpu: the (optionally unsigned) integer iterator
  214.  * @mask: the cpumask pointer
  215.  *
  216.  * After the loop, cpu is >= nr_cpu_ids.
  217.  */
  218. #define for_each_cpu(cpu, mask)                         \
  219.         for ((cpu) = -1;                                \
  220.                 (cpu) = cpumask_next((cpu), (mask)),    \
  221.                 (cpu) < nr_cpu_ids;)
  222.  
  223. /**
  224.  * for_each_cpu_not - iterate over every cpu in a complemented mask
  225.  * @cpu: the (optionally unsigned) integer iterator
  226.  * @mask: the cpumask pointer
  227.  *
  228.  * After the loop, cpu is >= nr_cpu_ids.
  229.  */
  230. #define for_each_cpu_not(cpu, mask)                             \
  231.         for ((cpu) = -1;                                        \
  232.                 (cpu) = cpumask_next_zero((cpu), (mask)),       \
  233.                 (cpu) < nr_cpu_ids;)
  234.  
  235. /**
  236.  * for_each_cpu_and - iterate over every cpu in both masks
  237.  * @cpu: the (optionally unsigned) integer iterator
  238.  * @mask: the first cpumask pointer
  239.  * @and: the second cpumask pointer
  240.  *
  241.  * This saves a temporary CPU mask in many places.  It is equivalent to:
  242.  *      struct cpumask tmp;
  243.  *      cpumask_and(&tmp, &mask, &and);
  244.  *      for_each_cpu(cpu, &tmp)
  245.  *              ...
  246.  *
  247.  * After the loop, cpu is >= nr_cpu_ids.
  248.  */
  249. #define for_each_cpu_and(cpu, mask, and)                                \
  250.         for ((cpu) = -1;                                                \
  251.                 (cpu) = cpumask_next_and((cpu), (mask), (and)),         \
  252.                 (cpu) < nr_cpu_ids;)
  253. #endif /* SMP */
  254.  
  255. #define CPU_BITS_NONE                                           \
  256. {                                                               \
  257.         [0 ... BITS_TO_LONGS(NR_CPUS)-1] = 0UL                  \
  258. }
  259.  
  260. #define CPU_BITS_CPU0                                           \
  261. {                                                               \
  262.         [0] =  1UL                                              \
  263. }
  264.  
  265. /**
  266.  * cpumask_set_cpu - set a cpu in a cpumask
  267.  * @cpu: cpu number (< nr_cpu_ids)
  268.  * @dstp: the cpumask pointer
  269.  */
  270. static inline void cpumask_set_cpu(unsigned int cpu, struct cpumask *dstp)
  271. {
  272.         set_bit(cpumask_check(cpu), cpumask_bits(dstp));
  273. }
  274.  
  275. /**
  276.  * cpumask_clear_cpu - clear a cpu in a cpumask
  277.  * @cpu: cpu number (< nr_cpu_ids)
  278.  * @dstp: the cpumask pointer
  279.  */
  280. static inline void cpumask_clear_cpu(int cpu, struct cpumask *dstp)
  281. {
  282.         clear_bit(cpumask_check(cpu), cpumask_bits(dstp));
  283. }
  284.  
  285. /**
  286.  * cpumask_test_cpu - test for a cpu in a cpumask
  287.  * @cpu: cpu number (< nr_cpu_ids)
  288.  * @cpumask: the cpumask pointer
  289.  *
  290.  * Returns 1 if @cpu is set in @cpumask, else returns 0
  291.  */
  292. static inline int cpumask_test_cpu(int cpu, const struct cpumask *cpumask)
  293. {
  294.         return test_bit(cpumask_check(cpu), cpumask_bits((cpumask)));
  295. }
  296.  
  297. /**
  298.  * cpumask_test_and_set_cpu - atomically test and set a cpu in a cpumask
  299.  * @cpu: cpu number (< nr_cpu_ids)
  300.  * @cpumask: the cpumask pointer
  301.  *
  302.  * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
  303.  *
  304.  * test_and_set_bit wrapper for cpumasks.
  305.  */
  306. static inline int cpumask_test_and_set_cpu(int cpu, struct cpumask *cpumask)
  307. {
  308.         return test_and_set_bit(cpumask_check(cpu), cpumask_bits(cpumask));
  309. }
  310.  
  311. /**
  312.  * cpumask_test_and_clear_cpu - atomically test and clear a cpu in a cpumask
  313.  * @cpu: cpu number (< nr_cpu_ids)
  314.  * @cpumask: the cpumask pointer
  315.  *
  316.  * Returns 1 if @cpu is set in old bitmap of @cpumask, else returns 0
  317.  *
  318.  * test_and_clear_bit wrapper for cpumasks.
  319.  */
  320. static inline int cpumask_test_and_clear_cpu(int cpu, struct cpumask *cpumask)
  321. {
  322.         return test_and_clear_bit(cpumask_check(cpu), cpumask_bits(cpumask));
  323. }
  324.  
  325. /**
  326.  * cpumask_setall - set all cpus (< nr_cpu_ids) in a cpumask
  327.  * @dstp: the cpumask pointer
  328.  */
  329. static inline void cpumask_setall(struct cpumask *dstp)
  330. {
  331.         bitmap_fill(cpumask_bits(dstp), nr_cpumask_bits);
  332. }
  333.  
  334. /**
  335.  * cpumask_clear - clear all cpus (< nr_cpu_ids) in a cpumask
  336.  * @dstp: the cpumask pointer
  337.  */
  338. static inline void cpumask_clear(struct cpumask *dstp)
  339. {
  340.         bitmap_zero(cpumask_bits(dstp), nr_cpumask_bits);
  341. }
  342.  
  343. /**
  344.  * cpumask_and - *dstp = *src1p & *src2p
  345.  * @dstp: the cpumask result
  346.  * @src1p: the first input
  347.  * @src2p: the second input
  348.  *
  349.  * If *@dstp is empty, returns 0, else returns 1
  350.  */
  351. static inline int cpumask_and(struct cpumask *dstp,
  352.                                const struct cpumask *src1p,
  353.                                const struct cpumask *src2p)
  354. {
  355.         return bitmap_and(cpumask_bits(dstp), cpumask_bits(src1p),
  356.                                        cpumask_bits(src2p), nr_cpumask_bits);
  357. }
  358.  
  359. /**
  360.  * cpumask_or - *dstp = *src1p | *src2p
  361.  * @dstp: the cpumask result
  362.  * @src1p: the first input
  363.  * @src2p: the second input
  364.  */
  365. static inline void cpumask_or(struct cpumask *dstp, const struct cpumask *src1p,
  366.                               const struct cpumask *src2p)
  367. {
  368.         bitmap_or(cpumask_bits(dstp), cpumask_bits(src1p),
  369.                                       cpumask_bits(src2p), nr_cpumask_bits);
  370. }
  371.  
  372. /**
  373.  * cpumask_xor - *dstp = *src1p ^ *src2p
  374.  * @dstp: the cpumask result
  375.  * @src1p: the first input
  376.  * @src2p: the second input
  377.  */
  378. static inline void cpumask_xor(struct cpumask *dstp,
  379.                                const struct cpumask *src1p,
  380.                                const struct cpumask *src2p)
  381. {
  382.         bitmap_xor(cpumask_bits(dstp), cpumask_bits(src1p),
  383.                                        cpumask_bits(src2p), nr_cpumask_bits);
  384. }
  385.  
  386. /**
  387.  * cpumask_andnot - *dstp = *src1p & ~*src2p
  388.  * @dstp: the cpumask result
  389.  * @src1p: the first input
  390.  * @src2p: the second input
  391.  *
  392.  * If *@dstp is empty, returns 0, else returns 1
  393.  */
  394. static inline int cpumask_andnot(struct cpumask *dstp,
  395.                                   const struct cpumask *src1p,
  396.                                   const struct cpumask *src2p)
  397. {
  398.         return bitmap_andnot(cpumask_bits(dstp), cpumask_bits(src1p),
  399.                                           cpumask_bits(src2p), nr_cpumask_bits);
  400. }
  401.  
  402. /**
  403.  * cpumask_complement - *dstp = ~*srcp
  404.  * @dstp: the cpumask result
  405.  * @srcp: the input to invert
  406.  */
  407. static inline void cpumask_complement(struct cpumask *dstp,
  408.                                       const struct cpumask *srcp)
  409. {
  410.         bitmap_complement(cpumask_bits(dstp), cpumask_bits(srcp),
  411.                                               nr_cpumask_bits);
  412. }
  413.  
  414. /**
  415.  * cpumask_equal - *src1p == *src2p
  416.  * @src1p: the first input
  417.  * @src2p: the second input
  418.  */
  419. static inline bool cpumask_equal(const struct cpumask *src1p,
  420.                                 const struct cpumask *src2p)
  421. {
  422.         return bitmap_equal(cpumask_bits(src1p), cpumask_bits(src2p),
  423.                                                  nr_cpumask_bits);
  424. }
  425.  
  426. /**
  427.  * cpumask_intersects - (*src1p & *src2p) != 0
  428.  * @src1p: the first input
  429.  * @src2p: the second input
  430.  */
  431. static inline bool cpumask_intersects(const struct cpumask *src1p,
  432.                                      const struct cpumask *src2p)
  433. {
  434.         return bitmap_intersects(cpumask_bits(src1p), cpumask_bits(src2p),
  435.                                                       nr_cpumask_bits);
  436. }
  437.  
  438. /**
  439.  * cpumask_subset - (*src1p & ~*src2p) == 0
  440.  * @src1p: the first input
  441.  * @src2p: the second input
  442.  *
  443.  * Returns 1 if *@src1p is a subset of *@src2p, else returns 0
  444.  */
  445. static inline int cpumask_subset(const struct cpumask *src1p,
  446.                                  const struct cpumask *src2p)
  447. {
  448.         return bitmap_subset(cpumask_bits(src1p), cpumask_bits(src2p),
  449.                                                   nr_cpumask_bits);
  450. }
  451.  
  452. /**
  453.  * cpumask_empty - *srcp == 0
  454.  * @srcp: the cpumask to that all cpus < nr_cpu_ids are clear.
  455.  */
  456. static inline bool cpumask_empty(const struct cpumask *srcp)
  457. {
  458.         return bitmap_empty(cpumask_bits(srcp), nr_cpumask_bits);
  459. }
  460.  
  461. /**
  462.  * cpumask_full - *srcp == 0xFFFFFFFF...
  463.  * @srcp: the cpumask to that all cpus < nr_cpu_ids are set.
  464.  */
  465. static inline bool cpumask_full(const struct cpumask *srcp)
  466. {
  467.         return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
  468. }
  469.  
  470. /**
  471.  * cpumask_weight - Count of bits in *srcp
  472.  * @srcp: the cpumask to count bits (< nr_cpu_ids) in.
  473.  */
  474. static inline unsigned int cpumask_weight(const struct cpumask *srcp)
  475. {
  476.         return bitmap_weight(cpumask_bits(srcp), nr_cpumask_bits);
  477. }
  478.  
  479. /**
  480.  * cpumask_shift_right - *dstp = *srcp >> n
  481.  * @dstp: the cpumask result
  482.  * @srcp: the input to shift
  483.  * @n: the number of bits to shift by
  484.  */
  485. static inline void cpumask_shift_right(struct cpumask *dstp,
  486.                                        const struct cpumask *srcp, int n)
  487. {
  488.         bitmap_shift_right(cpumask_bits(dstp), cpumask_bits(srcp), n,
  489.                                                nr_cpumask_bits);
  490. }
  491.  
  492. /**
  493.  * cpumask_shift_left - *dstp = *srcp << n
  494.  * @dstp: the cpumask result
  495.  * @srcp: the input to shift
  496.  * @n: the number of bits to shift by
  497.  */
  498. static inline void cpumask_shift_left(struct cpumask *dstp,
  499.                                       const struct cpumask *srcp, int n)
  500. {
  501.         bitmap_shift_left(cpumask_bits(dstp), cpumask_bits(srcp), n,
  502.                                               nr_cpumask_bits);
  503. }
  504.  
  505. /**
  506.  * cpumask_copy - *dstp = *srcp
  507.  * @dstp: the result
  508.  * @srcp: the input cpumask
  509.  */
  510. static inline void cpumask_copy(struct cpumask *dstp,
  511.                                 const struct cpumask *srcp)
  512. {
  513.         bitmap_copy(cpumask_bits(dstp), cpumask_bits(srcp), nr_cpumask_bits);
  514. }
  515.  
  516. /**
  517.  * cpumask_any - pick a "random" cpu from *srcp
  518.  * @srcp: the input cpumask
  519.  *
  520.  * Returns >= nr_cpu_ids if no cpus set.
  521.  */
  522. #define cpumask_any(srcp) cpumask_first(srcp)
  523.  
  524. /**
  525.  * cpumask_first_and - return the first cpu from *srcp1 & *srcp2
  526.  * @src1p: the first input
  527.  * @src2p: the second input
  528.  *
  529.  * Returns >= nr_cpu_ids if no cpus set in both.  See also cpumask_next_and().
  530.  */
  531. #define cpumask_first_and(src1p, src2p) cpumask_next_and(-1, (src1p), (src2p))
  532.  
  533. /**
  534.  * cpumask_any_and - pick a "random" cpu from *mask1 & *mask2
  535.  * @mask1: the first input cpumask
  536.  * @mask2: the second input cpumask
  537.  *
  538.  * Returns >= nr_cpu_ids if no cpus set.
  539.  */
  540. #define cpumask_any_and(mask1, mask2) cpumask_first_and((mask1), (mask2))
  541.  
  542. /**
  543.  * cpumask_of - the cpumask containing just a given cpu
  544.  * @cpu: the cpu (<= nr_cpu_ids)
  545.  */
  546. #define cpumask_of(cpu) (get_cpu_mask(cpu))
  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.  */
  556. static 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.  */
  570. static 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.  * cpumask_parse - extract a cpumask from from a string
  579.  * @buf: the buffer to extract from
  580.  * @dstp: the cpumask to set.
  581.  *
  582.  * Returns -errno, or 0 for success.
  583.  */
  584. static inline int cpumask_parse(const char *buf, struct cpumask *dstp)
  585. {
  586.         char *nl = strchr(buf, '\n');
  587.         unsigned int len = nl ? (unsigned int)(nl - buf) : strlen(buf);
  588.  
  589.         return bitmap_parse(buf, len, cpumask_bits(dstp), nr_cpumask_bits);
  590. }
  591.  
  592. /**
  593.  * cpulist_parse - extract a cpumask from a user string of ranges
  594.  * @buf: the buffer to extract from
  595.  * @dstp: the cpumask to set.
  596.  *
  597.  * Returns -errno, or 0 for success.
  598.  */
  599. static inline int cpulist_parse(const char *buf, struct cpumask *dstp)
  600. {
  601.         return bitmap_parselist(buf, cpumask_bits(dstp), nr_cpumask_bits);
  602. }
  603.  
  604. /**
  605.  * cpumask_size - size to allocate for a 'struct cpumask' in bytes
  606.  *
  607.  * This will eventually be a runtime variable, depending on nr_cpu_ids.
  608.  */
  609. static inline size_t cpumask_size(void)
  610. {
  611.         return BITS_TO_LONGS(nr_cpumask_bits) * sizeof(long);
  612. }
  613.  
  614. /*
  615.  * cpumask_var_t: struct cpumask for stack usage.
  616.  *
  617.  * Oh, the wicked games we play!  In order to make kernel coding a
  618.  * little more difficult, we typedef cpumask_var_t to an array or a
  619.  * pointer: doing &mask on an array is a noop, so it still works.
  620.  *
  621.  * ie.
  622.  *      cpumask_var_t tmpmask;
  623.  *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
  624.  *              return -ENOMEM;
  625.  *
  626.  *        ... use 'tmpmask' like a normal struct cpumask * ...
  627.  *
  628.  *      free_cpumask_var(tmpmask);
  629.  *
  630.  *
  631.  * However, one notable exception is there. alloc_cpumask_var() allocates
  632.  * only nr_cpumask_bits bits (in the other hand, real cpumask_t always has
  633.  * NR_CPUS bits). Therefore you don't have to dereference cpumask_var_t.
  634.  *
  635.  *      cpumask_var_t tmpmask;
  636.  *      if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL))
  637.  *              return -ENOMEM;
  638.  *
  639.  *      var = *tmpmask;
  640.  *
  641.  * This code makes NR_CPUS length memcopy and brings to a memory corruption.
  642.  * cpumask_copy() provide safe copy functionality.
  643.  *
  644.  * Note that there is another evil here: If you define a cpumask_var_t
  645.  * as a percpu variable then the way to obtain the address of the cpumask
  646.  * structure differently influences what this_cpu_* operation needs to be
  647.  * used. Please use this_cpu_cpumask_var_t in those cases. The direct use
  648.  * of this_cpu_ptr() or this_cpu_read() will lead to failures when the
  649.  * other type of cpumask_var_t implementation is configured.
  650.  */
  651. #ifdef CONFIG_CPUMASK_OFFSTACK
  652. typedef struct cpumask *cpumask_var_t;
  653.  
  654. #define this_cpu_cpumask_var_ptr(x) this_cpu_read(x)
  655.  
  656. bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
  657. bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
  658. bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
  659. bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
  660. void alloc_bootmem_cpumask_var(cpumask_var_t *mask);
  661. void free_cpumask_var(cpumask_var_t mask);
  662. void free_bootmem_cpumask_var(cpumask_var_t mask);
  663.  
  664. #else
  665. typedef struct cpumask cpumask_var_t[1];
  666.  
  667. #define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x)
  668.  
  669. static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
  670. {
  671.         return true;
  672. }
  673.  
  674. static inline bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
  675.                                           int node)
  676. {
  677.         return true;
  678. }
  679.  
  680. static inline bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
  681. {
  682.         cpumask_clear(*mask);
  683.         return true;
  684. }
  685.  
  686. static inline bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags,
  687.                                           int node)
  688. {
  689.         cpumask_clear(*mask);
  690.         return true;
  691. }
  692.  
  693. static inline void alloc_bootmem_cpumask_var(cpumask_var_t *mask)
  694. {
  695. }
  696.  
  697. static inline void free_cpumask_var(cpumask_var_t mask)
  698. {
  699. }
  700.  
  701. static inline void free_bootmem_cpumask_var(cpumask_var_t mask)
  702. {
  703. }
  704. #endif /* CONFIG_CPUMASK_OFFSTACK */
  705.  
  706. /* It's common to want to use cpu_all_mask in struct member initializers,
  707.  * so it has to refer to an address rather than a pointer. */
  708. extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);
  709. #define cpu_all_mask to_cpumask(cpu_all_bits)
  710.  
  711. /* First bits of cpu_bit_bitmap are in fact unset. */
  712. #define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
  713.  
  714. #define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
  715. #define for_each_online_cpu(cpu)   for_each_cpu((cpu), cpu_online_mask)
  716. #define for_each_present_cpu(cpu)  for_each_cpu((cpu), cpu_present_mask)
  717.  
  718. /* Wrappers for arch boot code to manipulate normally-constant masks */
  719. void set_cpu_possible(unsigned int cpu, bool possible);
  720. void set_cpu_present(unsigned int cpu, bool present);
  721. void set_cpu_online(unsigned int cpu, bool online);
  722. void set_cpu_active(unsigned int cpu, bool active);
  723. void init_cpu_present(const struct cpumask *src);
  724. void init_cpu_possible(const struct cpumask *src);
  725. void init_cpu_online(const struct cpumask *src);
  726.  
  727. /**
  728.  * to_cpumask - convert an NR_CPUS bitmap to a struct cpumask *
  729.  * @bitmap: the bitmap
  730.  *
  731.  * There are a few places where cpumask_var_t isn't appropriate and
  732.  * static cpumasks must be used (eg. very early boot), yet we don't
  733.  * expose the definition of 'struct cpumask'.
  734.  *
  735.  * This does the conversion, and can be used as a constant initializer.
  736.  */
  737. #define to_cpumask(bitmap)                                              \
  738.         ((struct cpumask *)(1 ? (bitmap)                                \
  739.                             : (void *)sizeof(__check_is_bitmap(bitmap))))
  740.  
  741. static inline int __check_is_bitmap(const unsigned long *bitmap)
  742. {
  743.         return 1;
  744. }
  745.  
  746. /*
  747.  * Special-case data structure for "single bit set only" constant CPU masks.
  748.  *
  749.  * We pre-generate all the 64 (or 32) possible bit positions, with enough
  750.  * padding to the left and the right, and return the constant pointer
  751.  * appropriately offset.
  752.  */
  753. extern const unsigned long
  754.         cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)];
  755.  
  756. static inline const struct cpumask *get_cpu_mask(unsigned int cpu)
  757. {
  758.         const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
  759.         p -= cpu / BITS_PER_LONG;
  760.         return to_cpumask(p);
  761. }
  762.  
  763. #define cpu_is_offline(cpu)     unlikely(!cpu_online(cpu))
  764.  
  765. #if NR_CPUS <= BITS_PER_LONG
  766. #define CPU_BITS_ALL                                            \
  767. {                                                               \
  768.         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
  769. }
  770.  
  771. #else /* NR_CPUS > BITS_PER_LONG */
  772.  
  773. #define CPU_BITS_ALL                                            \
  774. {                                                               \
  775.         [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                \
  776.         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
  777. }
  778. #endif /* NR_CPUS > BITS_PER_LONG */
  779.  
  780. /**
  781.  * cpumap_print_to_pagebuf  - copies the cpumask into the buffer either
  782.  *      as comma-separated list of cpus or hex values of cpumask
  783.  * @list: indicates whether the cpumap must be list
  784.  * @mask: the cpumask to copy
  785.  * @buf: the buffer to copy into
  786.  *
  787.  * Returns the length of the (null-terminated) @buf string, zero if
  788.  * nothing is copied.
  789.  */
  790. static inline ssize_t
  791. cpumap_print_to_pagebuf(bool list, char *buf, const struct cpumask *mask)
  792. {
  793.         return bitmap_print_to_pagebuf(list, buf, cpumask_bits(mask),
  794.                                       nr_cpu_ids);
  795. }
  796.  
  797. #if NR_CPUS <= BITS_PER_LONG
  798. #define CPU_MASK_ALL                                                    \
  799. (cpumask_t) { {                                                         \
  800.         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
  801. } }
  802. #else
  803. #define CPU_MASK_ALL                                                    \
  804. (cpumask_t) { {                                                         \
  805.         [0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,                        \
  806.         [BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)     \
  807. } }
  808. #endif /* NR_CPUS > BITS_PER_LONG */
  809.  
  810. #define CPU_MASK_NONE                                                   \
  811. (cpumask_t) { {                                                         \
  812.         [0 ... BITS_TO_LONGS(NR_CPUS)-1] =  0UL                         \
  813. } }
  814.  
  815. #define CPU_MASK_CPU0                                                   \
  816. (cpumask_t) { {                                                         \
  817.         [0] =  1UL                                                      \
  818. } }
  819.  
  820. #endif /* __LINUX_CPUMASK_H */
  821.