LXR linux/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#include <linux/hypervisor.h>
  10
  11int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
  12                                int wait)
  13{
  14        unsigned long flags;
  15
  16        WARN_ON(cpu != 0);
  17
  18        local_irq_save(flags);
  19        func(info);
  20        local_irq_restore(flags);
  21
  22        return 0;
  23}
  24EXPORT_SYMBOL(smp_call_function_single);
  25
  26int smp_call_function_single_async(int cpu, call_single_data_t *csd)
  27{
  28        unsigned long flags;
  29
  30        local_irq_save(flags);
  31        csd->func(csd->info);
  32        local_irq_restore(flags);
  33        return 0;
  34}
  35EXPORT_SYMBOL(smp_call_function_single_async);
  36
  37int on_each_cpu(smp_call_func_t func, void *info, int wait)
  38{
  39        unsigned long flags;
  40
  41        local_irq_save(flags);
  42        func(info);
  43        local_irq_restore(flags);
  44        return 0;
  45}
  46EXPORT_SYMBOL(on_each_cpu);
  47
  48/*
  49 * Note we still need to test the mask even for UP
  50 * because we actually can get an empty mask from
  51 * code that on SMP might call us without the local
  52 * CPU in the mask.
  53 */
  54void on_each_cpu_mask(const struct cpumask *mask,
  55                      smp_call_func_t func, void *info, bool wait)
  56{
  57        unsigned long flags;
  58
  59        if (cpumask_test_cpu(0, mask)) {
  60                local_irq_save(flags);
  61                func(info);
  62                local_irq_restore(flags);
  63        }
  64}
  65EXPORT_SYMBOL(on_each_cpu_mask);
  66
  67/*
  68 * Preemption is disabled here to make sure the cond_func is called under the
  69 * same condtions in UP and SMP.
  70 */
  71void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  72                      smp_call_func_t func, void *info, bool wait,
  73                      gfp_t gfp_flags)
  74{
  75        unsigned long flags;
  76
  77        preempt_disable();
  78        if (cond_func(0, info)) {
  79                local_irq_save(flags);
  80                func(info);
  81                local_irq_restore(flags);
  82        }
  83        preempt_enable();
  84}
  85EXPORT_SYMBOL(on_each_cpu_cond);
  86
  87int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)
  88{
  89        int ret;
  90
  91        if (cpu != 0)
  92                return -ENXIO;
  93
  94        if (phys)
  95                hypervisor_pin_vcpu(0);
  96        ret = func(par);
  97        if (phys)
  98                hypervisor_pin_vcpu(-1);
  99
 100        return ret;
 101}
 102EXPORT_SYMBOL_GPL(smp_call_on_cpu);
 103