int generic_cpu_disable(void)
{
unsigned int cpu = smp_processor_id();
if (cpu == boot_cpuid)
return -EBUSY;
set_cpu_online(cpu, false);
#ifdef CONFIG_PPC64
vdso_data->processorCount--;
#endif
/* Update affinity of all IRQs previously aimed at this CPU */
irq_migrate_all_off_this_cpu();
/*
* Depending on the details of the interrupt controller, it's possible
* that one of the interrupts we just migrated away from this CPU is
* actually already pending on this CPU. If we leave it in that state
* the interrupt will never be EOI'ed, and will never fire again. So
* temporarily enable interrupts here, to allow any pending interrupt to
* be received (and EOI'ed), before we take this CPU offline.
*/
local_irq_enable();
mdelay(1);
local_irq_disable();
return 0;
}
/* A cpu has been removed from cpu_online_mask. Reset irq affinities. */
void fixup_irqs(void)
{
unsigned int irr, vector;
struct irq_desc *desc;
struct irq_data *data;
struct irq_chip *chip;
irq_migrate_all_off_this_cpu();
/*
* We can remove mdelay() and then send spuriuous interrupts to
* new cpu targets for all the irqs that were handled previously by
* this cpu. While it works, I have seen spurious interrupt messages
* (nothing wrong but still...).
*
* So for now, retain mdelay(1) and check the IRR and then send those
* interrupts to new targets as this cpu is already offlined...
*/
mdelay(1);
/*
* We can walk the vector array of this cpu without holding
* vector_lock because the cpu is already marked !online, so
* nothing else will touch it.
*/
for (vector = FIRST_EXTERNAL_VECTOR; vector < NR_VECTORS; vector++) {
if (IS_ERR_OR_NULL(__this_cpu_read(vector_irq[vector])))
continue;
irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
if (irr & (1 << (vector % 32))) {
desc = __this_cpu_read(vector_irq[vector]);
raw_spin_lock(&desc->lock);
data = irq_desc_get_irq_data(desc);
chip = irq_data_get_irq_chip(data);
if (chip->irq_retrigger) {
chip->irq_retrigger(data);
__this_cpu_write(vector_irq[vector], VECTOR_RETRIGGERED);
}
raw_spin_unlock(&desc->lock);
}
if (__this_cpu_read(vector_irq[vector]) != VECTOR_RETRIGGERED)
__this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
}
}
/*
* __cpu_disable runs on the processor to be shutdown.
*/
int __cpu_disable(void)
{
unsigned int cpu = smp_processor_id();
int ret;
ret = op_cpu_disable(cpu);
if (ret)
return ret;
/*
* Take this CPU offline. Once we clear this, we can't return,
* and we must not schedule until we're ready to give up the cpu.
*/
set_cpu_online(cpu, false);
/*
* OK - migrate IRQs away from this CPU
*/
irq_migrate_all_off_this_cpu();
return 0;
}
