lib/cpumask.c

   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
   7 int __first_cpu(const cpumask_t *srcp)
   8 {
   9         return min_t(int, NR_CPUS, find_first_bit(srcp->bits, NR_CPUS));
  10 }
  11 EXPORT_SYMBOL(__first_cpu);
  12
  13 int __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 }
  17 EXPORT_SYMBOL(__next_cpu);
  18
  19 #if NR_CPUS > 64
  20 int __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 }
  25 EXPORT_SYMBOL(__next_cpu_nr);
  26 #endif
  27
  28 int __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 }
  38 EXPORT_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  */
  48 int 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 }
  56 EXPORT_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  */
  66 int 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
  79 bool 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 }
  99 EXPORT_SYMBOL(alloc_cpumask_var);
 100
 101 void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
 102 {
 103         *mask = alloc_bootmem(cpumask_size());
 104 }
 105
 106 void free_cpumask_var(cpumask_var_t mask)
 107 {
 108         kfree(mask);
 109 }
 110 EXPORT_SYMBOL(free_cpumask_var);
 111
 112 void __init free_bootmem_cpumask_var(cpumask_var_t mask)
 113 {
 114         free_bootmem((unsigned long)mask, cpumask_size());
 115 }
 116 #endif