From cc56939802fb4c9548be53563387a0700baeec82 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@kaod.org>
Date: Wed, 4 Oct 2017 11:15:05 +0200
Subject: [PATCH] powerpc/xive: Clear XIVE internal structures when a CPU is
 removed
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References: fate#322438
Patch-mainline: v4.14-rc4
Git-commit: cc56939802fb4c9548be53563387a0700baeec82

Commit eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE
interrupt controller") introduced support for the XIVE exploitation
mode of the P9 interrupt controller on the pseries platform.

At that time, support for CPU removal was not complete on PowerVM and
CPU hot unplug remained untested. It appears that some cleanups of the
XIVE internal structures are required before releasing the CPU,
without which the kernel crashes in a RTAS call doing the CPU
isolation.

These changes fix the crash by deconfiguring the IPI interrupt source
and clearing the event queues of the CPU when it is removed.

Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller")
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 arch/powerpc/sysdev/xive/common.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index f387318678b9..a3b8d7d1316e 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -1402,6 +1402,14 @@ void xive_teardown_cpu(void)
 
 	if (xive_ops->teardown_cpu)
 		xive_ops->teardown_cpu(cpu, xc);
+
+#ifdef CONFIG_SMP
+	/* Get rid of IPI */
+	xive_cleanup_cpu_ipi(cpu, xc);
+#endif
+
+	/* Disable and free the queues */
+	xive_cleanup_cpu_queues(cpu, xc);
 }
 
 void xive_kexec_teardown_cpu(int secondary)
-- 
2.10.2