mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-24 06:20:53 +07:00
1e474b28e7
In CONFIG_SMP=y kernels, smp_call_function_single() returns -ENXIO when invoked for a non-existent CPU. In contrast, in CONFIG_SMP=n kernels, a splat is emitted and smp_call_function_single() otherwise silently ignores its "cpu" argument, instead pretending that the caller intended to have something happen on CPU 0. Given that there is now code that expects smp_call_function_single() to return an error if a bad CPU was specified, this difference in semantics needs to be addressed. Bring the semantics of the CONFIG_SMP=n version of smp_call_function_single() into alignment with its CONFIG_SMP=y counterpart. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200205143409.GA7021@paulmck-ThinkPad-P72
110 lines
2.3 KiB
C
110 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Uniprocessor-only support functions. The counterpart to kernel/smp.c
|
|
*/
|
|
|
|
#include <linux/interrupt.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/export.h>
|
|
#include <linux/smp.h>
|
|
#include <linux/hypervisor.h>
|
|
|
|
int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
|
|
int wait)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (cpu != 0)
|
|
return -ENXIO;
|
|
|
|
local_irq_save(flags);
|
|
func(info);
|
|
local_irq_restore(flags);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(smp_call_function_single);
|
|
|
|
int smp_call_function_single_async(int cpu, call_single_data_t *csd)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
csd->func(csd->info);
|
|
local_irq_restore(flags);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(smp_call_function_single_async);
|
|
|
|
void on_each_cpu(smp_call_func_t func, void *info, int wait)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
func(info);
|
|
local_irq_restore(flags);
|
|
}
|
|
EXPORT_SYMBOL(on_each_cpu);
|
|
|
|
/*
|
|
* Note we still need to test the mask even for UP
|
|
* because we actually can get an empty mask from
|
|
* code that on SMP might call us without the local
|
|
* CPU in the mask.
|
|
*/
|
|
void on_each_cpu_mask(const struct cpumask *mask,
|
|
smp_call_func_t func, void *info, bool wait)
|
|
{
|
|
unsigned long flags;
|
|
|
|
if (cpumask_test_cpu(0, mask)) {
|
|
local_irq_save(flags);
|
|
func(info);
|
|
local_irq_restore(flags);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(on_each_cpu_mask);
|
|
|
|
/*
|
|
* Preemption is disabled here to make sure the cond_func is called under the
|
|
* same condtions in UP and SMP.
|
|
*/
|
|
void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
|
|
void *info, bool wait, const struct cpumask *mask)
|
|
{
|
|
unsigned long flags;
|
|
|
|
preempt_disable();
|
|
if (cond_func(0, info)) {
|
|
local_irq_save(flags);
|
|
func(info);
|
|
local_irq_restore(flags);
|
|
}
|
|
preempt_enable();
|
|
}
|
|
EXPORT_SYMBOL(on_each_cpu_cond_mask);
|
|
|
|
void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func,
|
|
void *info, bool wait)
|
|
{
|
|
on_each_cpu_cond_mask(cond_func, func, info, wait, NULL);
|
|
}
|
|
EXPORT_SYMBOL(on_each_cpu_cond);
|
|
|
|
int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par, bool phys)
|
|
{
|
|
int ret;
|
|
|
|
if (cpu != 0)
|
|
return -ENXIO;
|
|
|
|
if (phys)
|
|
hypervisor_pin_vcpu(0);
|
|
ret = func(par);
|
|
if (phys)
|
|
hypervisor_pin_vcpu(-1);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(smp_call_on_cpu);
|