Merge tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull CPU hotplug notifiers registration fixes from Rafael Wysocki:
 "The purpose of this single series of commits from Srivatsa S Bhat
  (with a small piece from Gautham R Shenoy) touching multiple
  subsystems that use CPU hotplug notifiers is to provide a way to
  register them that will not lead to deadlocks with CPU online/offline
  operations as described in the changelog of commit 93ae4f978ca7f ("CPU
  hotplug: Provide lockless versions of callback registration
  functions").

  The first three commits in the series introduce the API and document
  it and the rest simply goes through the users of CPU hotplug notifiers
  and converts them to using the new method"

* tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits)
  net/iucv/iucv.c: Fix CPU hotplug callback registration
  net/core/flow.c: Fix CPU hotplug callback registration
  mm, zswap: Fix CPU hotplug callback registration
  mm, vmstat: Fix CPU hotplug callback registration
  profile: Fix CPU hotplug callback registration
  trace, ring-buffer: Fix CPU hotplug callback registration
  xen, balloon: Fix CPU hotplug callback registration
  hwmon, via-cputemp: Fix CPU hotplug callback registration
  hwmon, coretemp: Fix CPU hotplug callback registration
  thermal, x86-pkg-temp: Fix CPU hotplug callback registration
  octeon, watchdog: Fix CPU hotplug callback registration
  oprofile, nmi-timer: Fix CPU hotplug callback registration
  intel-idle: Fix CPU hotplug callback registration
  clocksource, dummy-timer: Fix CPU hotplug callback registration
  drivers/base/topology.c: Fix CPU hotplug callback registration
  acpi-cpufreq: Fix CPU hotplug callback registration
  zsmalloc: Fix CPU hotplug callback registration
  scsi, fcoe: Fix CPU hotplug callback registration
  scsi, bnx2fc: Fix CPU hotplug callback registration
  scsi, bnx2i: Fix CPU hotplug callback registration
  ...

2 files changed, 13 insertions, 5 deletions

diff --git a/arch/s390/kernel/cache.c b/arch/s390/kernel/cache.c
index 3a414c0f93ed..c0b03c28d157 100644
--- a/arch/s390/kernel/cache.c
+++ b/arch/s390/kernel/cache.c
@@ -378,9 +378,12 @@ static int __init cache_init(void)
         if (!test_facility(34))
                 return 0;
         cache_build_info();
+
+        cpu_notifier_register_begin();
         for_each_online_cpu(cpu)
                 cache_add_cpu(cpu);
-        hotcpu_notifier(cache_hotplug, 0);
+        __hotcpu_notifier(cache_hotplug, 0);
+        cpu_notifier_register_done();
         return 0;
 }
 device_initcall(cache_init);
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 8827883310dd..5a640b395bd4 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -1057,19 +1057,24 @@ static DEVICE_ATTR(rescan, 0200, NULL, rescan_store);
 
 static int __init s390_smp_init(void)
 {
-        int cpu, rc;
+        int cpu, rc = 0;
 
-        hotcpu_notifier(smp_cpu_notify, 0);
 #ifdef CONFIG_HOTPLUG_CPU
         rc = device_create_file(cpu_subsys.dev_root, &dev_attr_rescan);
         if (rc)
                 return rc;
 #endif
+        cpu_notifier_register_begin();
         for_each_present_cpu(cpu) {
                 rc = smp_add_present_cpu(cpu);
                 if (rc)
-                        return rc;
+                        goto out;
         }
-        return 0;
+
+        __hotcpu_notifier(smp_cpu_notify, 0);
+
+out:
+        cpu_notifier_register_done();
+        return rc;
 }
 subsys_initcall(s390_smp_init);