[PATCH AUTOSEL 4.4 12/35] powerpc/pseries/mobility: prevent cpu hotplug during DT update
sashal at kernel.org
Fri Jul 19 14:14:00 AEST 2019
From: Nathan Lynch <nathanl at linux.ibm.com>
[ Upstream commit e59a175faa8df9d674247946f2a5a9c29c835725 ]
CPU online/offline code paths are sensitive to parts of the device
tree (various cpu node properties, cache nodes) that can be changed as
a result of a migration.
Prevent CPU hotplug while the device tree potentially is inconsistent.
Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel")
Signed-off-by: Nathan Lynch <nathanl at linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego at linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Sasha Levin <sashal at kernel.org>
arch/powerpc/platforms/pseries/mobility.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index c773396d0969..fcd1a32267c4 100644
@@ -9,6 +9,7 @@
* 2 as published by the Free Software Foundation.
@@ -309,11 +310,19 @@ void post_mobility_fixup(void)
printk(KERN_ERR "Post-mobility activate-fw failed: %d\n", rc);
+ * We don't want CPUs to go online/offline while the device
+ * tree is being updated.
rc = pseries_devicetree_update(MIGRATION_SCOPE);
printk(KERN_ERR "Post-mobility device tree update "
"failed: %d\n", rc);
/* Possibly switch to a new RFI flush type */
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