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powerpc/mpic: Fix regression caused by change of default IRQ affinity

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The Freescale implementation of MPIC only allows a single CPU destination
for non-IPI interrupts.  We add a flag to the mpic_init to distinquish
these variants of MPIC.  We pull in the irq_choose_cpu from sparc64 to
select a single CPU as the destination of the interrupt.

This is to deal with the fact that the default smp affinity was
changed by commit 1840475676 ("genirq:
Expose default irq affinity mask (take 3)") to be all CPUs.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Kumar Gala
2008-10-28 18:01:39 +00:00
committed by Paul Mackerras
parent f9226d572d
commit 3c10c9c45e
4 changed files with 61 additions and 6 deletions
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59
arch/powerpc/sysdev/mpic.c
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@ -563,6 +563,51 @@ static void __init mpic_scan_ht_pics(struct mpic *mpic)
#endif /* CONFIG_MPIC_U3_HT_IRQS */
#ifdef CONFIG_SMP
static int irq_choose_cpu(unsigned int virt_irq)
{
cpumask_t mask = irq_desc[virt_irq].affinity;
int cpuid;
if (cpus_equal(mask, CPU_MASK_ALL)) {
static int irq_rover;
static DEFINE_SPINLOCK(irq_rover_lock);
unsigned long flags;
/* Round-robin distribution... */
do_round_robin:
spin_lock_irqsave(&irq_rover_lock, flags);
while (!cpu_online(irq_rover)) {
if (++irq_rover >= NR_CPUS)
irq_rover = 0;
}
cpuid = irq_rover;
do {
if (++irq_rover >= NR_CPUS)
irq_rover = 0;
} while (!cpu_online(irq_rover));
spin_unlock_irqrestore(&irq_rover_lock, flags);
} else {
cpumask_t tmp;
cpus_and(tmp, cpu_online_map, mask);
if (cpus_empty(tmp))
goto do_round_robin;
cpuid = first_cpu(tmp);
}
return cpuid;
}
#else
static int irq_choose_cpu(unsigned int virt_irq)
{
return hard_smp_processor_id();
}
#endif
#define mpic_irq_to_hw(virq) ((unsigned int)irq_map[virq].hwirq)
@ -777,12 +822,18 @@ void mpic_set_affinity(unsigned int irq, cpumask_t cpumask)
struct mpic *mpic = mpic_from_irq(irq);
unsigned int src = mpic_irq_to_hw(irq);
cpumask_t tmp;
if (mpic->flags & MPIC_SINGLE_DEST_CPU) {
int cpuid = irq_choose_cpu(irq);
cpus_and(tmp, cpumask, cpu_online_map);
mpic_irq_write(src, MPIC_INFO(IRQ_DESTINATION), 1 << cpuid);
} else {
cpumask_t tmp;
mpic_irq_write(src, MPIC_INFO(IRQ_DESTINATION),
mpic_physmask(cpus_addr(tmp)[0]));
cpus_and(tmp, cpumask, cpu_online_map);
mpic_irq_write(src, MPIC_INFO(IRQ_DESTINATION),
mpic_physmask(cpus_addr(tmp)[0]));
}
}
static unsigned int mpic_type_to_vecpri(struct mpic *mpic, unsigned int type)