===================================================================
@@ -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_de
"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_dev
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;
}