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>
* 2 as published by the Free Software Foundation.
*/
+#include <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/smp.h>
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();