ACPI: Fix broken extctnl mechanism.

Fn arch_acpi_processor_init_extcntl need to be called before any acpi_processor init stuff, otherwise many special paths for xen-cpu-idle & xen-cpu-freq can't get executed. So keep arch_acpi_processor_init_extcntl call in processor_extcntl_init and call it very early, move other stuff of processor_extcntl_init into a new fn processor_extcntl_prepare.

Signed-off-by: Wei Gang <gang.wei@intel.com>

diff -r d25b46565529 drivers/acpi/processor_core.c
--- a/drivers/acpi/processor_core.c	Wed Jul 23 14:21:58 2008 +0100
+++ b/drivers/acpi/processor_core.c	Fri Jul 25 19:02:25 2008 +0800
@@ -526,6 +526,7 @@ static int acpi_processor_start(struct a
 	acpi_status status = AE_OK;
 	struct acpi_processor *pr;
 
+	processor_extcntl_init();
 
 	pr = acpi_driver_data(device);
 
@@ -579,7 +580,7 @@ static int acpi_processor_start(struct a
 
 	acpi_processor_power_init(pr, device);
 
-	result = processor_extcntl_init(pr);
+	result = processor_extcntl_prepare(pr);
 	if (result)
 		goto end;
 
diff -r d25b46565529 drivers/acpi/processor_extcntl.c
--- a/drivers/acpi/processor_extcntl.c	Wed Jul 23 14:21:58 2008 +0100
+++ b/drivers/acpi/processor_extcntl.c	Fri Jul 25 19:02:25 2008 +0800
@@ -105,13 +105,28 @@ int processor_notify_external(struct acp
 }
 
 /*
+ * External control logic can decide to grab full or part of physical
+ * processor control bits. Take a VMM for example, physical processors
+ * are owned by VMM and thus existence information like hotplug is
+ * always required to be notified to VMM. Similar is processor idle
+ * state which is also necessarily controlled by VMM. But for other
+ * control bits like performance/throttle states, VMM may choose to
+ * control or not upon its own policy.
+ */
+void processor_extcntl_init(void)
+{
+	if (!processor_extcntl_ops)
+		arch_acpi_processor_init_extcntl(&processor_extcntl_ops);
+}
+
+/*
  * This is called from ACPI processor init, and targeted to hold
  * some tricky housekeeping jobs to satisfy external control model.
  * For example, we may put dependency parse stub here for idle
  * and performance state. Those information may be not available
  * if splitting from dom0 control logic like cpufreq driver.
  */
-int __cpuinit processor_extcntl_init(struct acpi_processor *pr)
+int processor_extcntl_prepare(struct acpi_processor *pr)
 {
 	/* parse cstate dependency information */
 	if (processor_pm_external())
@@ -120,18 +135,6 @@ int __cpuinit processor_extcntl_init(str
 	/* Initialize performance states */
 	if (processor_pmperf_external())
 		processor_extcntl_get_performance(pr);
-
-	/*
-	 * External control logic can decide to grab full or part of physical
-	 * processor control bits. Take a VMM for example, physical processors
-	 * are owned by VMM and thus existence information like hotplug is
-	 * always required to be notified to VMM. Similar is processor idle
-	 * state which is also necessarily controlled by VMM. But for other
-	 * control bits like performance/throttle states, VMM may choose to
-	 * control or not upon its own policy.
-	 */
-	if (!processor_extcntl_ops)
-		arch_acpi_processor_init_extcntl(&processor_extcntl_ops);
 
 	return 0;
 }
diff -r d25b46565529 include/acpi/processor.h
--- a/include/acpi/processor.h	Wed Jul 23 14:21:58 2008 +0100
+++ b/include/acpi/processor.h	Fri Jul 25 19:02:25 2008 +0800
@@ -351,7 +351,8 @@ static inline int processor_pmthr_extern
 
 extern int processor_notify_external(struct acpi_processor *pr,
 			int event, int type);
-extern int processor_extcntl_init(struct acpi_processor *pr);
+extern void processor_extcntl_init(void);
+extern int processor_extcntl_prepare(struct acpi_processor *pr);
 extern int acpi_processor_get_performance_info(struct acpi_processor *pr);
 extern int acpi_processor_get_psd(struct acpi_processor *pr);
 void arch_acpi_processor_init_extcntl(const struct processor_extcntl_ops **);
@@ -365,7 +366,8 @@ static inline int processor_notify_exter
 {
 	return 0;
 }
-static inline int processor_extcntl_init(struct acpi_processor *pr)
+static inline void processor_extcntl_init(void) {}
+static inline int processor_extcntl_prepare(struct acpi_processor *pr)
 {
 	return 0;
 }