[PATCH] ppc64: fix for kexec boot issue

The kexec boot is not successful on some power machines since all CPUs are
getting removed from global interrupt queue (GIQ) before kexec boot.  Some
systems always expect at least one CPU in GIQ.  Hence, this patch will make
sure that only secondary CPUs are removed from GIQ.

Signed-off-by: Haren Myneni <hbabu@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 16 insertions, 15 deletions

diff --git a/arch/ppc64/kernel/xics.c b/arch/ppc64/kernel/xics.c
index 677c4450984..d9dc6f28d05 100644
--- a/arch/ppc64/kernel/xics.c
+++ b/arch/ppc64/kernel/xics.c
@@ -647,29 +647,30 @@ static void xics_set_affinity(unsigned int virq, cpumask_t cpumask)
 	}
 }
 
-void xics_teardown_cpu(void)
+void xics_teardown_cpu(int secondary)
 {
 	int cpu = smp_processor_id();
-	int status;
 
 	ops->cppr_info(cpu, 0x00);
 	iosync();
 
 	/*
-	 * we need to EOI the IPI if we got here from kexec down IPI
-	 *
-	 * xics doesn't care if we duplicate an EOI as long as we
-	 * don't EOI and raise priority.
-	 *
-	 * probably need to check all the other interrupts too
-	 * should we be flagging idle loop instead?
-	 * or creating some task to be scheduled?
+	 * Some machines need to have at least one cpu in the GIQ,
+	 * so leave the master cpu in the group.
 	 */
-	ops->xirr_info_set(cpu, XICS_IPI);
-
-	status = rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
-		(1UL << interrupt_server_size) - 1 - default_distrib_server, 0);
-	WARN_ON(status != 0);
+	if (secondary) {
+		/*
+		 * we need to EOI the IPI if we got here from kexec down IPI
+		 *
+		 * probably need to check all the other interrupts too
+		 * should we be flagging idle loop instead?
+		 * or creating some task to be scheduled?
+		 */
+		ops->xirr_info_set(cpu, XICS_IPI);
+		rtas_set_indicator(GLOBAL_INTERRUPT_QUEUE,
+			(1UL << interrupt_server_size) - 1 -
+			default_distrib_server, 0);
+	}
 }
 
 #ifdef CONFIG_HOTPLUG_CPU