posix-clock: Fix return code on the poll method's error path

[pandora-kernel.git] / kernel / cpu.c

diff --git a/kernel/cpu.c b/kernel/cpu.c
index aa39dd7..82c91f1 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -10,7 +10,7 @@
 #include <linux/sched.h>
 #include <linux/unistd.h>
 #include <linux/cpu.h>
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/kthread.h>
 #include <linux/stop_machine.h>
 #include <linux/mutex.h>
@@ -124,6 +124,27 @@ static void cpu_hotplug_done(void)
        mutex_unlock(&cpu_hotplug.lock);
 }
 
+/*
+ * Wait for currently running CPU hotplug operations to complete (if any) and
+ * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects
+ * the 'cpu_hotplug_disabled' flag. The same lock is also acquired by the
+ * hotplug path before performing hotplug operations. So acquiring that lock
+ * guarantees mutual exclusion from any currently running hotplug operations.
+ */
+void cpu_hotplug_disable(void)
+{
+       cpu_maps_update_begin();
+       cpu_hotplug_disabled = 1;
+       cpu_maps_update_done();
+}
+
+void cpu_hotplug_enable(void)
+{
+       cpu_maps_update_begin();
+       cpu_hotplug_disabled = 0;
+       cpu_maps_update_done();
+}
+
 #else /* #if CONFIG_HOTPLUG_CPU */
 static void cpu_hotplug_begin(void) {}
 static void cpu_hotplug_done(void) {}
@@ -478,36 +499,6 @@ static int alloc_frozen_cpus(void)
 }
 core_initcall(alloc_frozen_cpus);
 
-/*
- * Prevent regular CPU hotplug from racing with the freezer, by disabling CPU
- * hotplug when tasks are about to be frozen. Also, don't allow the freezer
- * to continue until any currently running CPU hotplug operation gets
- * completed.
- * To modify the 'cpu_hotplug_disabled' flag, we need to acquire the
- * 'cpu_add_remove_lock'. And this same lock is also taken by the regular
- * CPU hotplug path and released only after it is complete. Thus, we
- * (and hence the freezer) will block here until any currently running CPU
- * hotplug operation gets completed.
- */
-void cpu_hotplug_disable_before_freeze(void)
-{
-       cpu_maps_update_begin();
-       cpu_hotplug_disabled = 1;
-       cpu_maps_update_done();
-}
-
-
-/*
- * When tasks have been thawed, re-enable regular CPU hotplug (which had been
- * disabled while beginning to freeze tasks).
- */
-void cpu_hotplug_enable_after_thaw(void)
-{
-       cpu_maps_update_begin();
-       cpu_hotplug_disabled = 0;
-       cpu_maps_update_done();
-}
-
 /*
  * When callbacks for CPU hotplug notifications are being executed, we must
  * ensure that the state of the system with respect to the tasks being frozen
@@ -527,12 +518,12 @@ cpu_hotplug_pm_callback(struct notifier_block *nb,
 
        case PM_SUSPEND_PREPARE:
        case PM_HIBERNATION_PREPARE:
-               cpu_hotplug_disable_before_freeze();
+               cpu_hotplug_disable();
                break;
 
        case PM_POST_SUSPEND:
        case PM_POST_HIBERNATION:
-               cpu_hotplug_enable_after_thaw();
+               cpu_hotplug_enable();
                break;
 
        default: