static void nmi_shootdown_cpus(void)
{
unsigned long msecs;
local_irq_disable();
crashing_cpu = smp_processor_id();
local_irq_count(crashing_cpu) = 0;
atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
/* Would it be better to replace the trap vector here? */
set_nmi_callback(crash_nmi_callback);
/* Ensure the new callback function is set before sending out the NMI. */
wmb();
smp_send_nmi_allbutself();
msecs = 1000; /* Wait at most a second for the other cpus to stop */
while ( (atomic_read(&waiting_for_crash_ipi) > 0) && msecs )
{
mdelay(1);
msecs--;
}
__stop_this_cpu();
disable_IO_APIC();
local_irq_enable();
}
/*
* Stop all CPUs and turn off local APICs and the IO-APIC, so other OSs see a
* clean IRQ state.
*/
void smp_send_stop(void)
{
int timeout = 10;
smp_call_function(stop_this_cpu, NULL, 0);
/* Wait 10ms for all other CPUs to go offline. */
while ( (num_online_cpus() > 1) && (timeout-- > 0) )
mdelay(1);
local_irq_disable();
__stop_this_cpu();
disable_IO_APIC();
hpet_disable();
local_irq_enable();
}
static void nmi_shootdown_cpus(void)
{
unsigned long msecs;
local_irq_disable();
if ( hpet_broadcast_is_available() )
hpet_disable_legacy_broadcast();
crashing_cpu = smp_processor_id();
local_irq_count(crashing_cpu) = 0;
atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
/* Would it be better to replace the trap vector here? */
set_nmi_callback(crash_nmi_callback);
/* Ensure the new callback function is set before sending out the NMI. */
wmb();
smp_send_nmi_allbutself();
msecs = 1000; /* Wait at most a second for the other cpus to stop */
while ( (atomic_read(&waiting_for_crash_ipi) > 0) && msecs )
{
mdelay(1);
msecs--;
}
/* Crash shutdown any IOMMU functionality as the crashdump kernel is not
* happy when booting if interrupt/dma remapping is still enabled */
iommu_crash_shutdown();
__stop_this_cpu();
/* This is a bit of a hack due to the problems with the x2apic_enabled
* variable, but we can't do any better without a significant refactoring
* of the APIC code */
x2apic_enabled = (current_local_apic_mode() == APIC_MODE_X2APIC);
disable_IO_APIC();
hpet_disable();
}
static int crash_nmi_callback(struct cpu_user_regs *regs, int cpu)
{
/* Don't do anything if this handler is invoked on crashing cpu.
* Otherwise, system will completely hang. Crashing cpu can get
* an NMI if system was initially booted with nmi_watchdog parameter.
*/
if ( cpu == crashing_cpu )
return 1;
local_irq_disable();
kexec_crash_save_cpu();
__stop_this_cpu();
atomic_dec(&waiting_for_crash_ipi);
for ( ; ; )
halt();
return 1;
}
static void stop_this_cpu(void *dummy)
{
__stop_this_cpu();
for ( ; ; )
halt();
}
