powerpc/mpic: Disable preemption when calling mpic_processor_id()

Otherwise, we get a debug traceback due to the use of
smp_processor_id() (or get_paca()) inside hard_smp_processor_id().
mpic_host_map() is just looking for a default CPU, so it doesn't matter
if we migrate after getting the CPU ID.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 1be54faf60dd8be75f9f149101733c4c1c92f299..bdcb8588e4926c42130935a0ef33d2d19cab4b99 100644 (file)
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -1088,8 +1088,14 @@ static int mpic_host_map(struct irq_domain *h, unsigned int virq,
         * is done here.
         */
        if (!mpic_is_ipi(mpic, hw) && (mpic->flags & MPIC_NO_RESET)) {
+               int cpu;
+
+               preempt_disable();
+               cpu = mpic_processor_id(mpic);
+               preempt_enable();
+
                mpic_set_vector(virq, hw);
-               mpic_set_destination(virq, mpic_processor_id(mpic));
+               mpic_set_destination(virq, cpu);
                mpic_irq_set_priority(virq, 8);
        }