[PATCH AUTOSEL 4.19 165/237] powerpc/powernv: hold device_hotplug_lock when calling device_online()

[Sasha Levin]

From: David Hildenbrand <david at redhat.com>

[ Upstream commit cec1680591d6d5b10ecc10f370210089416e98af ]

device_online() should be called with device_hotplug_lock() held.

Link: http://lkml.kernel.org/r/20180925091457.28651-5-david@redhat.com
Signed-off-by: David Hildenbrand <david at redhat.com>
Reviewed-by: Pavel Tatashin <pavel.tatashin at microsoft.com>
Reviewed-by: Rashmica Gupta <rashmica.g at gmail.com>
Cc: Benjamin Herrenschmidt <benh at kernel.crashing.org>
Cc: Paul Mackerras <paulus at samba.org>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Rashmica Gupta <rashmica.g at gmail.com>
Cc: Balbir Singh <bsingharora at gmail.com>
Cc: Michael Neuling <mikey at neuling.org>
Cc: Boris Ostrovsky <boris.ostrovsky at oracle.com>
Cc: Dan Williams <dan.j.williams at intel.com>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: Haiyang Zhang <haiyangz at microsoft.com>
Cc: Heiko Carstens <heiko.carstens at de.ibm.com>
Cc: John Allen <jallen at linux.vnet.ibm.com>
Cc: Jonathan Corbet <corbet at lwn.net>
Cc: Joonsoo Kim <iamjoonsoo.kim at lge.com>
Cc: Juergen Gross <jgross at suse.com>
Cc: Kate Stewart <kstewart at linuxfoundation.org>
Cc: "K. Y. Srinivasan" <kys at microsoft.com>
Cc: Len Brown <lenb at kernel.org>
Cc: Martin Schwidefsky <schwidefsky at de.ibm.com>
Cc: Mathieu Malaterre <malat at debian.org>
Cc: Michal Hocko <mhocko at suse.com>
Cc: Nathan Fontenot <nfont at linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador at suse.de>
Cc: Philippe Ombredanne <pombredanne at nexb.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Cc: "Rafael J. Wysocki" <rjw at rjwysocki.net>
Cc: Stephen Hemminger <sthemmin at microsoft.com>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Vlastimil Babka <vbabka at suse.cz>
Cc: YASUAKI ISHIMATSU <yasu.isimatu at gmail.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 arch/powerpc/platforms/powernv/memtrace.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c
index 232bf5987f91d..dd3cc4632b9ae 100644
--- a/arch/powerpc/platforms/powernv/memtrace.c
+++ b/arch/powerpc/platforms/powernv/memtrace.c
@@ -244,9 +244,11 @@ static int memtrace_online(void)
 		 * we need to online the memory ourselves.
 		 */
 		if (!memhp_auto_online) {
+			lock_device_hotplug();
 			walk_memory_range(PFN_DOWN(ent->start),
 					  PFN_UP(ent->start + ent->size - 1),
 					  NULL, online_mem_block);
+			unlock_device_hotplug();
 		}
 
 		/*
-- 
2.20.1