powerpc/mpic: Fix regression caused by change of default IRQ affinity
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 18404756765c713a0be4eb1082920c04822ce588 ("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>
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 8e3478c..f6299cc 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -563,6 +563,51 @@
#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 @@
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)