kernel/up.c

   1 /*
   2  * Uniprocessor-only support functions.  The counterpart to kernel/smp.c
   3  */
   4
   5 #include <linux/interrupt.h>
   6 #include <linux/kernel.h>
   7 #include <linux/export.h>
   8 #include <linux/smp.h>
   9
  10 int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
  11                                 int wait)
  12 {
  13         unsigned long flags;
  14
  15         WARN_ON(cpu != 0);
  16
  17         local_irq_save(flags);
  18         func(info);
  19         local_irq_restore(flags);
  20
  21         return 0;
  22 }
  23 EXPORT_SYMBOL(smp_call_function_single);
  24
  25 void __smp_call_function_single(int cpu, struct call_single_data *csd,
  26                                 int wait)
  27 {
  28         unsigned long flags;
  29
  30         local_irq_save(flags);
  31         csd->func(csd->info);
  32         local_irq_restore(flags);
  33 }
  34 EXPORT_SYMBOL(__smp_call_function_single);
  35
  36 int on_each_cpu(smp_call_func_t func, void *info, int wait)
  37 {
  38         unsigned long flags;
  39
  40         local_irq_save(flags);
  41         func(info);
  42         local_irq_restore(flags);
  43         return 0;
  44 }
  45 EXPORT_SYMBOL(on_each_cpu);
  46
  47 /*
  48  * Note we still need to test the mask even for UP
  49  * because we actually can get an empty mask from
  50  * code that on SMP might call us without the local
  51  * CPU in the mask.
  52  */
  53 void on_each_cpu_mask(const struct cpumask *mask,
  54                       smp_call_func_t func, void *info, bool wait)
  55 {
  56         unsigned long flags;
  57
  58         if (cpumask_test_cpu(0, mask)) {
  59                 local_irq_save(flags);
  60                 func(info);
  61                 local_irq_restore(flags);
  62         }
  63 }
  64 EXPORT_SYMBOL(on_each_cpu_mask);
  65
  66 /*
  67  * Preemption is disabled here to make sure the cond_func is called under the
  68  * same condtions in UP and SMP.
  69  */
  70 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  71                       smp_call_func_t func, void *info, bool wait,
  72                       gfp_t gfp_flags)
  73 {
  74         unsigned long flags;
  75
  76         preempt_disable();
  77         if (cond_func(0, info)) {
  78                 local_irq_save(flags);
  79                 func(info);
  80                 local_irq_restore(flags);
  81         }
  82         preempt_enable();
  83 }
  84 EXPORT_SYMBOL(on_each_cpu_cond);