kernel/up.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Uniprocessor-only support functions.  The counterpart to kernel/smp.c
   4  */
   5
   6 #include <linux/interrupt.h>
   7 #include <linux/kernel.h>
   8 #include <linux/export.h>
   9 #include <linux/smp.h>
  10 #include <linux/hypervisor.h>
  11
  12 int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
  13                                 int wait)
  14 {
  15         unsigned long flags;
  16
  17         if (cpu != 0)
  18                 return -ENXIO;
  19
  20         local_irq_save(flags);
  21         func(info);
  22         local_irq_restore(flags);
  23
  24         return 0;
  25 }
  26 EXPORT_SYMBOL(smp_call_function_single);
  27
  28 int smp_call_function_single_async(int cpu, struct __call_single_data *csd)
  29 {
  30         unsigned long flags;
  31
  32         local_irq_save(flags);
  33         csd->func(csd->info);
  34         local_irq_restore(flags);
  35         return 0;
  36 }
  37 EXPORT_SYMBOL(smp_call_function_single_async);
  38
  39 /*
  40  * Preemption is disabled here to make sure the cond_func is called under the
  41  * same conditions in UP and SMP.
  42  */
  43 void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
  44                            void *info, bool wait, const struct cpumask *mask)
  45 {
  46         unsigned long flags;
  47
  48         preempt_disable();
  49         if ((!cond_func || cond_func(0, info)) && cpumask_test_cpu(0, mask)) {
  50                 local_irq_save(flags);
  51                 func(info);
  52                 local_irq_restore(flags);
  53         }
  54         preempt_enable();
  55 }
  56 EXPORT_SYMBOL(on_each_cpu_cond_mask);
  57
  58 int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)
  59 {
  60         int ret;
  61
  62         if (cpu != 0)
  63                 return -ENXIO;
  64
  65         if (phys)
  66                 hypervisor_pin_vcpu(0);
  67         ret = func(par);
  68         if (phys)
  69                 hypervisor_pin_vcpu(-1);
  70
  71         return ret;
  72 }
  73 EXPORT_SYMBOL_GPL(smp_call_on_cpu);