From 2bf7bfa002fdccdeaf8a5720be64e7d5bb7ae958 Mon Sep 17 00:00:00 2001 From: Nathan Lynch Date: Tue, 11 Jun 2019 23:45:05 -0500 Subject: [PATCH] powerpc/pseries/mobility: prevent cpu hotplug during DT update 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: 9b6e2c7b9681 ("powerpc/pseries: Partition migration in the kernel") Signed-off-by: Nathan Lynch Reviewed-by: Gautham R. Shenoy Signed-off-by: Michael Ellerman --- 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 88925f8ca8a09..edc1ec4085893 100644 --- a/arch/powerpc/platforms/pseries/mobility.c +++ b/arch/powerpc/platforms/pseries/mobility.c @@ -9,6 +9,7 @@ * 2 as published by the Free Software Foundation. */ +#include #include #include #include @@ -338,11 +339,19 @@ void post_mobility_fixup(void) if (rc) 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. + */ + cpus_read_lock(); + rc = pseries_devicetree_update(MIGRATION_SCOPE); if (rc) printk(KERN_ERR "Post-mobility device tree update " "failed: %d\n", rc); + cpus_read_unlock(); + /* Possibly switch to a new RFI flush type */ pseries_setup_rfi_flush(); -- 2.39.5