linux/lib/cpumask.c
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   1#include <linux/kernel.h>
   2#include <linux/bitops.h>
   3#include <linux/cpumask.h>
   4#include <linux/module.h>
   5#include <linux/bootmem.h>
   6
   7int __first_cpu(const cpumask_t *srcp)
   8{
   9        return min_t(int, NR_CPUS, find_first_bit(srcp->bits, NR_CPUS));
  10}
  11EXPORT_SYMBOL(__first_cpu);
  12
  13int __next_cpu(int n, const cpumask_t *srcp)
  14{
  15        return min_t(int, NR_CPUS, find_next_bit(srcp->bits, NR_CPUS, n+1));
  16}
  17EXPORT_SYMBOL(__next_cpu);
  18
  19#if NR_CPUS > 64
  20int __next_cpu_nr(int n, const cpumask_t *srcp)
  21{
  22        return min_t(int, nr_cpu_ids,
  23                                find_next_bit(srcp->bits, nr_cpu_ids, n+1));
  24}
  25EXPORT_SYMBOL(__next_cpu_nr);
  26#endif
  27
  28int __any_online_cpu(const cpumask_t *mask)
  29{
  30        int cpu;
  31
  32        for_each_cpu_mask(cpu, *mask) {
  33                if (cpu_online(cpu))
  34                        break;
  35        }
  36        return cpu;
  37}
  38EXPORT_SYMBOL(__any_online_cpu);
  39
  40/**
  41 * cpumask_next_and - get the next cpu in *src1p & *src2p
  42 * @n: the cpu prior to the place to search (ie. return will be > @n)
  43 * @src1p: the first cpumask pointer
  44 * @src2p: the second cpumask pointer
  45 *
  46 * Returns >= nr_cpu_ids if no further cpus set in both.
  47 */
  48int cpumask_next_and(int n, const struct cpumask *src1p,
  49                     const struct cpumask *src2p)
  50{
  51        while ((n = cpumask_next(n, src1p)) < nr_cpu_ids)
  52                if (cpumask_test_cpu(n, src2p))
  53                        break;
  54        return n;
  55}
  56EXPORT_SYMBOL(cpumask_next_and);
  57
  58/**
  59 * cpumask_any_but - return a "random" in a cpumask, but not this one.
  60 * @mask: the cpumask to search
  61 * @cpu: the cpu to ignore.
  62 *
  63 * Often used to find any cpu but smp_processor_id() in a mask.
  64 * Returns >= nr_cpu_ids if no cpus set.
  65 */
  66int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
  67{
  68        unsigned int i;
  69
  70        cpumask_check(cpu);
  71        for_each_cpu(i, mask)
  72                if (i != cpu)
  73                        break;
  74        return i;
  75}
  76
  77/* These are not inline because of header tangles. */
  78#ifdef CONFIG_CPUMASK_OFFSTACK
  79bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
  80{
  81        if (likely(slab_is_available()))
  82                *mask = kmalloc(cpumask_size(), flags);
  83        else {
  84#ifdef CONFIG_DEBUG_PER_CPU_MAPS
  85                printk(KERN_ERR
  86                        "=> alloc_cpumask_var: kmalloc not available!\n");
  87                dump_stack();
  88#endif
  89                *mask = NULL;
  90        }
  91#ifdef CONFIG_DEBUG_PER_CPU_MAPS
  92        if (!*mask) {
  93                printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
  94                dump_stack();
  95        }
  96#endif
  97        return *mask != NULL;
  98}
  99EXPORT_SYMBOL(alloc_cpumask_var);
 100
 101void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
 102{
 103        *mask = alloc_bootmem(cpumask_size());
 104}
 105
 106void free_cpumask_var(cpumask_var_t mask)
 107{
 108        kfree(mask);
 109}
 110EXPORT_SYMBOL(free_cpumask_var);
 111
 112void __init free_bootmem_cpumask_var(cpumask_var_t mask)
 113{
 114        free_bootmem((unsigned long)mask, cpumask_size());
 115}
 116#endif
 117