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authorNathan Lynch <nathanl@linux.ibm.com>2019-06-12 07:45:05 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2019-06-15 09:52:07 +0300
commite59a175faa8df9d674247946f2a5a9c29c835725 (patch)
treec8823e071f0321cf58c616f2235b8926111a219b /arch/powerpc/platforms/pseries/mobility.c
parentd4aa219a074a5abaf95a756b9f0d190b5c03a945 (diff)
downloadlinux-e59a175faa8df9d674247946f2a5a9c29c835725.tar.xz
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: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel") Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/platforms/pseries/mobility.c')
-rw-r--r--arch/powerpc/platforms/pseries/mobility.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index 88925f8ca8a0..edc1ec408589 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 <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/smp.h>
@@ -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();