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	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}
 26EXPORT_SYMBOL(smp_call_function_single);
 27
 28int smp_call_function_single_async(int cpu, call_single_data_t *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}
 37EXPORT_SYMBOL(smp_call_function_single_async);
 38
 39void on_each_cpu(smp_call_func_t func, void *info, int wait)
 40{
 41	unsigned long flags;
 42
 43	local_irq_save(flags);
 44	func(info);
 45	local_irq_restore(flags);
 46}
 47EXPORT_SYMBOL(on_each_cpu);
 48
 49/*
 50 * Note we still need to test the mask even for UP
 51 * because we actually can get an empty mask from
 52 * code that on SMP might call us without the local
 53 * CPU in the mask.
 54 */
 55void on_each_cpu_mask(const struct cpumask *mask,
 56		      smp_call_func_t func, void *info, bool wait)
 57{
 58	unsigned long flags;
 59
 60	if (cpumask_test_cpu(0, mask)) {
 61		local_irq_save(flags);
 62		func(info);
 63		local_irq_restore(flags);
 64	}
 65}
 66EXPORT_SYMBOL(on_each_cpu_mask);
 67
 68/*
 69 * Preemption is disabled here to make sure the cond_func is called under the
 70 * same condtions in UP and SMP.
 71 */
 72void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
 73			   void *info, bool wait, 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(smp_cond_func_t cond_func, smp_call_func_t func,
 88		      void *info, bool wait)
 89{
 90	on_each_cpu_cond_mask(cond_func, func, info, wait, NULL);
 91}
 92EXPORT_SYMBOL(on_each_cpu_cond);
 93
 94int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)
 95{
 96	int ret;
 97
 98	if (cpu != 0)
 99		return -ENXIO;
100
101	if (phys)
102		hypervisor_pin_vcpu(0);
103	ret = func(par);
104	if (phys)
105		hypervisor_pin_vcpu(-1);
106
107	return ret;
108}
109EXPORT_SYMBOL_GPL(smp_call_on_cpu);