linux/kernel/up.c
Juergen Gross df8ce9d78a smp: Add function to execute a function synchronously on a CPU
On some hardware models (e.g. Dell Studio 1555 laptop) some hardware
related functions (e.g. SMIs) are to be executed on physical CPU 0
only. Instead of open coding such a functionality multiple times in
the kernel add a service function for this purpose. This will enable
the possibility to take special measures in virtualized environments
like Xen, too.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Douglas_Warzecha@dell.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akataria@vmware.com
Cc: boris.ostrovsky@oracle.com
Cc: chrisw@sous-sol.org
Cc: david.vrabel@citrix.com
Cc: hpa@zytor.com
Cc: jdelvare@suse.com
Cc: jeremy@goop.org
Cc: linux@roeck-us.net
Cc: pali.rohar@gmail.com
Cc: rusty@rustcorp.com.au
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1472453327-19050-4-git-send-email-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-09-05 13:52:39 +02:00

102 lines
2 KiB
C

/*
* 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;
WARN_ON(cpu != 0);
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, struct call_single_data *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);
int 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);
return 0;
}
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(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags)
{
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);
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);