powerpc: hard disable irqs in smp_send_stop loop

The hard lockup watchdog can fire under local_irq_disable
on platforms with irq soft masking.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index db88660..e16ec7b 100644 (file)
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -574,9 +574,10 @@ static void stop_this_cpu(void *dummy)
        /* Remove this CPU */
        set_cpu_online(smp_processor_id(), false);
 
-       local_irq_disable();
+       hard_irq_disable();
+       spin_begin();
        while (1)
-               ;
+               spin_cpu_relax();
 }
 
 void smp_send_stop(void)