ACPI: Reevaluate C/P/T states when a cpu becomes online

Reevaluate C/P/T states when a cpu becomes online. This avoids
the caching of the broadcast information in the clockevents layer.

Signed-off-by: Venkatesh Pallipadi <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Cc: Len Brown <[e-mail]>

drivers/acpi/processor_core.c

···
 	return;
 }
 
+static int acpi_cpu_soft_notify(struct notifier_block *nfb,
+		unsigned long action, void *hcpu)
+{
+	unsigned int cpu = (unsigned long)hcpu;
+	struct acpi_processor *pr = processors[cpu];
+
+	if (action == CPU_ONLINE && pr) {
+		acpi_processor_ppc_has_changed(pr);
+		acpi_processor_cst_has_changed(pr);
+		acpi_processor_tstate_has_changed(pr);
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block acpi_cpu_notifier =
+{
+	    .notifier_call = acpi_cpu_soft_notify,
+};
+
 static int acpi_processor_add(struct acpi_device *device)
 {
 	struct acpi_processor *pr = NULL;
···
 			    ACPI_UINT32_MAX,
 			    processor_walk_namespace_cb, &action, NULL);
 #endif
+	register_hotcpu_notifier(&acpi_cpu_notifier);
 }
 
 static
···
 			    ACPI_UINT32_MAX,
 			    processor_walk_namespace_cb, &action, NULL);
 #endif
+	unregister_hotcpu_notifier(&acpi_cpu_notifier);
 }
 
 /*