powerpc/xive: Ensure active irqd when setting affinity

Ensure irqd is active before attempting to set affinity. This should
make the set affinity code more robust. For instance, this prevents
these messages seen on a 4.12 based kernel when taking cpus offline:

   [  123.053037264,3] XIVE[ IC 00  ] ISN 2 lead to invalid IVE !
   [   77.885859] xive: Error -6 reconfiguring irq 17
   [   77.885862] IRQ17: set affinity failed(-6).

That particular case has been fixed in 4.13-rc1 by commit
91f26cb4cd3c ("genirq/cpuhotplug: Do not migrated shutdown irqs").

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index 6595462b1fc8e8dcef978d00fa2ac0ed7dfc2433..2708d423d8b92f299dbff2e6cdb461e6a6c83df5 100644 (file)
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -672,6 +672,10 @@ static int xive_irq_set_affinity(struct irq_data *d,
        if (cpumask_any_and(cpumask, cpu_online_mask) >= nr_cpu_ids)
                return -EINVAL;
 
+       /* Don't do anything if the interrupt isn't started */
+       if (!irqd_is_started(d))
+               return IRQ_SET_MASK_OK;
+
        /*
         * If existing target is already in the new mask, and is
         * online then do nothing.