1 files changed, 26 insertions, 40 deletions

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 0f17ad8585d7..b03771d4787c 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -28,6 +28,7 @@
 #include <linux/cpu.h>
 #include <linux/completion.h>
 #include <linux/mutex.h>
+#include <linux/syscore_ops.h>
 
 #include <trace/events/power.h>
 
@@ -1340,35 +1341,31 @@ out:
 }
 EXPORT_SYMBOL(cpufreq_get);
 
+static struct sysdev_driver cpufreq_sysdev_driver = {
+        .add            = cpufreq_add_dev,
+        .remove         = cpufreq_remove_dev,
+};
+
 
 /**
- *      cpufreq_suspend - let the low level driver prepare for suspend
+ * cpufreq_bp_suspend - Prepare the boot CPU for system suspend.
+ *
+ * This function is only executed for the boot processor.  The other CPUs
+ * have been put offline by means of CPU hotplug.
  */
-
-static int cpufreq_suspend(struct sys_device *sysdev, pm_message_t pmsg)
+static int cpufreq_bp_suspend(void)
 {
         int ret = 0;
 
-        int cpu = sysdev->id;
+        int cpu = smp_processor_id();
         struct cpufreq_policy *cpu_policy;
 
         dprintk("suspending cpu %u\n", cpu);
 
-        if (!cpu_online(cpu))
-                return 0;
-
-        /* we may be lax here as interrupts are off. Nonetheless
-         * we need to grab the correct cpu policy, as to check
-         * whether we really run on this CPU.
-         */
-
+        /* If there's no policy for the boot CPU, we have nothing to do. */
         cpu_policy = cpufreq_cpu_get(cpu);
         if (!cpu_policy)
-                return -EINVAL;
-
-        /* only handle each CPU group once */
-        if (unlikely(cpu_policy->cpu != cpu))
-                goto out;
+                return 0;
 
         if (cpufreq_driver->suspend) {
                 ret = cpufreq_driver->suspend(cpu_policy);
@@ -1377,13 +1374,12 @@ static int cpufreq_suspend(struct sys_device *sysdev, pm_message_t pmsg)
                                         "step on CPU %u\n", cpu_policy->cpu);
         }
 
-out:
         cpufreq_cpu_put(cpu_policy);
         return ret;
 }
 
 /**
- *      cpufreq_resume -  restore proper CPU frequency handling after resume
+ * cpufreq_bp_resume - Restore proper frequency handling of the boot CPU.
  *
  *      1.) resume CPUfreq hardware support (cpufreq_driver->resume())
  *      2.) schedule call cpufreq_update_policy() ASAP as interrupts are
@@ -1391,31 +1387,23 @@ out:
  *          what we believe it to be. This is a bit later than when it
  *          should be, but nonethteless it's better than calling
  *          cpufreq_driver->get() here which might re-enable interrupts...
+ *
+ * This function is only executed for the boot CPU.  The other CPUs have not
+ * been turned on yet.
  */
-static int cpufreq_resume(struct sys_device *sysdev)
+static void cpufreq_bp_resume(void)
 {
         int ret = 0;
 
-        int cpu = sysdev->id;
+        int cpu = smp_processor_id();
         struct cpufreq_policy *cpu_policy;
 
         dprintk("resuming cpu %u\n", cpu);
 
-        if (!cpu_online(cpu))
-                return 0;
-
-        /* we may be lax here as interrupts are off. Nonetheless
-         * we need to grab the correct cpu policy, as to check
-         * whether we really run on this CPU.
-         */
-
+        /* If there's no policy for the boot CPU, we have nothing to do. */
         cpu_policy = cpufreq_cpu_get(cpu);
         if (!cpu_policy)
-                return -EINVAL;
-
-        /* only handle each CPU group once */
-        if (unlikely(cpu_policy->cpu != cpu))
-                goto fail;
+                return;
 
         if (cpufreq_driver->resume) {
                 ret = cpufreq_driver->resume(cpu_policy);
@@ -1430,14 +1418,11 @@ static int cpufreq_resume(struct sys_device *sysdev)
 
 fail:
         cpufreq_cpu_put(cpu_policy);
-        return ret;
 }
 
-static struct sysdev_driver cpufreq_sysdev_driver = {
-        .add            = cpufreq_add_dev,
-        .remove         = cpufreq_remove_dev,
-        .suspend        = cpufreq_suspend,
-        .resume         = cpufreq_resume,
+static struct syscore_ops cpufreq_syscore_ops = {
+        .suspend        = cpufreq_bp_suspend,
+        .resume         = cpufreq_bp_resume,
 };
 
 
@@ -2002,6 +1987,7 @@ static int __init cpufreq_core_init(void)
         cpufreq_global_kobject = kobject_create_and_add("cpufreq",
                                                 &cpu_sysdev_class.kset.kobj);
         BUG_ON(!cpufreq_global_kobject);
+        register_syscore_ops(&cpufreq_syscore_ops);
 
         return 0;
 }