LXR linux/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
  12int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
  13                                int wait)
  14{
  15        unsigned long flags;
  16
  17        WARN_ON(cpu != 0);
  18
  19        local_irq_save(flags);
  20        func(info);
  21        local_irq_restore(flags);
  22
  23        return 0;
  24}
  25EXPORT_SYMBOL(smp_call_function_single);
  26
  27int smp_call_function_single_async(int cpu, call_single_data_t *csd)
  28{
  29        unsigned long flags;
  30
  31        local_irq_save(flags);
  32        csd->func(csd->info);
  33        local_irq_restore(flags);
  34        return 0;
  35}
  36EXPORT_SYMBOL(smp_call_function_single_async);
  37
  38void on_each_cpu(smp_call_func_t func, void *info, int wait)
  39{
  40        unsigned long flags;
  41
  42        local_irq_save(flags);
  43        func(info);
  44        local_irq_restore(flags);
  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_mask(bool (*cond_func)(int cpu, void *info),
  72                           smp_call_func_t func, void *info, bool wait,
  73                           gfp_t gfp_flags, const struct cpumask *mask)
  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_mask);
  86
  87void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
  88                      smp_call_func_t func, void *info, bool wait,
  89                      gfp_t gfp_flags)
  90{
  91        on_each_cpu_cond_mask(cond_func, func, info, wait, gfp_flags, NULL);
  92}
  93EXPORT_SYMBOL(on_each_cpu_cond);
  94
  95int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)
  96{
  97        int ret;
  98
  99        if (cpu != 0)
 100                return -ENXIO;
 101
 102        if (phys)
 103                hypervisor_pin_vcpu(0);
 104        ret = func(par);
 105        if (phys)
 106                hypervisor_pin_vcpu(-1);
 107
 108        return ret;
 109}
 110EXPORT_SYMBOL_GPL(smp_call_on_cpu);
 111