powerpc/powernv: Fix oops on P9 DD1 in cause_ipi()

[karo-tx-linux.git] / arch / powerpc / sysdev / xics / xics-common.c

diff --git a/arch/powerpc/sysdev/xics/xics-common.c b/arch/powerpc/sysdev/xics/xics-common.c
index 69d858e51ac76f121741337031465cb1fd1ccebb..ffe138b8b9dc458646aaa45b79f1c18410a56c74 100644 (file)
--- a/arch/powerpc/sysdev/xics/xics-common.c
+++ b/arch/powerpc/sysdev/xics/xics-common.c
@@ -20,6 +20,7 @@
 #include <linux/of.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
+#include <linux/delay.h>
 
 #include <asm/prom.h>
 #include <asm/io.h>
@@ -142,11 +143,11 @@ static void xics_request_ipi(void)
 
 void __init xics_smp_probe(void)
 {
-       /* Setup cause_ipi callback  based on which ICP is used */
-       smp_ops->cause_ipi = icp_ops->cause_ipi;
-
        /* Register all the IPIs */
        xics_request_ipi();
+
+       /* Setup cause_ipi callback based on which ICP is used */
+       smp_ops->cause_ipi = icp_ops->cause_ipi;
 }
 
 #endif /* CONFIG_SMP */
@@ -198,9 +199,6 @@ void xics_migrate_irqs_away(void)
        /* Remove ourselves from the global interrupt queue */
        xics_set_cpu_giq(xics_default_distrib_server, 0);
 
-       /* Allow IPIs again... */
-       icp_ops->set_priority(DEFAULT_PRIORITY);
-
        for_each_irq_desc(virq, desc) {
                struct irq_chip *chip;
                long server;
@@ -255,6 +253,19 @@ void xics_migrate_irqs_away(void)
 unlock:
                raw_spin_unlock_irqrestore(&desc->lock, flags);
        }
+
+       /* Allow "sufficient" time to drop any inflight IRQ's */
+       mdelay(5);
+
+       /*
+        * Allow IPIs again. This is done at the very end, after migrating all
+        * interrupts, the expectation is that we'll only get woken up by an IPI
+        * interrupt beyond this point, but leave externals masked just to be
+        * safe. If we're using icp-opal this may actually allow all
+        * interrupts anyway, but that should be OK.
+        */
+       icp_ops->set_priority(DEFAULT_PRIORITY);
+
 }
 #endif /* CONFIG_HOTPLUG_CPU */