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 int on_each_cpu(smp_call_func_t func, void *info, int wait)
  26 {
  27         unsigned long flags;
  28
  29         local_irq_save(flags);
  30         func(info);
  31         local_irq_restore(flags);
  32         return 0;
  33 }
  34 EXPORT_SYMBOL(on_each_cpu);
  35
  36 /*
  37  * Note we still need to test the mask even for UP
  38  * because we actually can get an empty mask from
  39  * code that on SMP might call us without the local
  40  * CPU in the mask.
  41  */
  42 void on_each_cpu_mask(const struct cpumask *mask,
  43                       smp_call_func_t func, void *info, bool wait)
  44 {
  45         unsigned long flags;
  46
  47         if (cpumask_test_cpu(0, mask)) {
  48                 local_irq_save(flags);
  49                 func(info);
  50                 local_irq_restore(flags);
  51         }
  52 }
  53 EXPORT_SYMBOL(on_each_cpu_mask);
  54
  55 /*
  56  * Preemption is disabled here to make sure the cond_func is called under the
  57  * same condtions in UP and SMP.
  58  */
  59 void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  60                       smp_call_func_t func, void *info, bool wait,
  61                       gfp_t gfp_flags)
  62 {
  63         unsigned long flags;
  64
  65         preempt_disable();
  66         if (cond_func(0, info)) {
  67                 local_irq_save(flags);
  68                 func(info);
  69                 local_irq_restore(flags);
  70         }
  71         preempt_enable();
  72 }
  73 EXPORT_SYMBOL(on_each_cpu_cond);