ACPI: Reevaluate whether the T-state is supported or not after cpu is online/offline

After one CPU is offlined, it is unnecessary to switch T-state for it.
So it will be better that the throttling is disabled after the cpu
is offline.
At the same time after one cpu is online, we should check whether
the T-state is supported and then set the corresponding T-state
flag.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 1b62102..55192ac 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -324,6 +324,12 @@
 int acpi_processor_get_throttling_info(struct acpi_processor *pr);
 extern int acpi_processor_set_throttling(struct acpi_processor *pr,
 					 int state, bool force);
+/*
+ * Reevaluate whether the T-state is invalid after one cpu is
+ * onlined/offlined. In such case the flags.throttling will be updated.
+ */
+extern void acpi_processor_reevaluate_tstate(struct acpi_processor *pr,
+			unsigned long action);
 extern const struct file_operations acpi_processor_throttling_fops;
 extern void acpi_processor_throttling_init(void);
 /* in processor_idle.c */