Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

Pull two powerpc fixes from Ben Herrenschmidt:
 "Here's a pair of powerpc fixes for 3.15 which are also going to
  stable.

  One's a fix for building with newer binutils (the problem currently
  only affects the BookE kernels but the affected macro might come back
  into use on BookS platforms at any time).  Unfortunately, the binutils
  maintainer did a backward incompatible change to a construct that we
  use so we have to add Makefile check.

  The other one is a fix for CPUs getting stuck in kexec when running
  single threaded.  Since we routinely use kexec on power (including in
  our newer bootloaders), I deemed that important enough"

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc, kexec: Fix "Processor X is stuck" issue during kexec from ST mode
  powerpc: Fix 64 bit builds with binutils 2.24

1 files changed, 8 insertions, 0 deletions

diff --git a/kernel/kexec.c b/kernel/kexec.c
index c8380ad203bc..28c57069ef68 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1683,6 +1683,14 @@ int kernel_kexec(void)
                 kexec_in_progress = true;
                 kernel_restart_prepare(NULL);
                 migrate_to_reboot_cpu();
+
+                /*
+                 * migrate_to_reboot_cpu() disables CPU hotplug assuming that
+                 * no further code needs to use CPU hotplug (which is true in
+                 * the reboot case). However, the kexec path depends on using
+                 * CPU hotplug again; so re-enable it here.
+                 */
+                cpu_hotplug_enable();
                 printk(KERN_EMERG "Starting new kernel\n");
                 machine_shutdown();
         }