PM: domains: create debugfs nodes when adding power domains

debugfs nodes were created in genpd_debug_init alled in late_initcall
preventing power domains registered though loadable modules to have
a debugfs entry.

Create/remove debugfs nodes when the power domain is added/removed
to/from the internal gpd_list.
Signed-off-by: Thierry Strudel <tstrudel@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/base/power/domain.c

@@ -21,6 +21,7 @@
 #include <linux/suspend.h>
 #include <linux/export.h>
 #include <linux/cpu.h>
+#include <linux/debugfs.h>
 
 #include "power.h"
 
@@ -210,6 +211,18 @@ static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
 }
 
 #ifdef CONFIG_DEBUG_FS
+static struct dentry *genpd_debugfs_dir;
+
+static void genpd_debug_add(struct generic_pm_domain *genpd);
+
+static void genpd_debug_remove(struct generic_pm_domain *genpd)
+{
+	struct dentry *d;
+
+	d = debugfs_lookup(genpd->name, genpd_debugfs_dir);
+	debugfs_remove(d);
+}
+
 static void genpd_update_accounting(struct generic_pm_domain *genpd)
 {
 	ktime_t delta, now;
@@ -234,6 +247,8 @@ static void genpd_update_accounting(struct generic_pm_domain *genpd)
 	genpd->accounting_time = now;
 }
 #else
+static inline void genpd_debug_add(struct generic_pm_domain *genpd) {}
+static inline void genpd_debug_remove(struct generic_pm_domain *genpd) {}
 static inline void genpd_update_accounting(struct generic_pm_domain *genpd) {}
 #endif
 
@@ -1954,6 +1969,7 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
 
 	mutex_lock(&gpd_list_lock);
 	list_add(&genpd->gpd_list_node, &gpd_list);
+	genpd_debug_add(genpd);
 	mutex_unlock(&gpd_list_lock);
 
 	return 0;
@@ -1987,6 +2003,7 @@ static int genpd_remove(struct generic_pm_domain *genpd)
 		kfree(link);
 	}
 
+	genpd_debug_remove(genpd);
 	list_del(&genpd->gpd_list_node);
 	genpd_unlock(genpd);
 	cancel_work_sync(&genpd->power_off_work);
@@ -2893,14 +2910,6 @@ core_initcall(genpd_bus_init);
 /***        debugfs support        ***/
 
 #ifdef CONFIG_DEBUG_FS
-#include <linux/pm.h>
-#include <linux/device.h>
-#include <linux/debugfs.h>
-#include <linux/seq_file.h>
-#include <linux/init.h>
-#include <linux/kobject.h>
-static struct dentry *genpd_debugfs_dir;
-
 /*
  * TODO: This function is a slightly modified version of rtpm_status_show
  * from sysfs.c, so generalize it.
@@ -3177,9 +3186,34 @@ DEFINE_SHOW_ATTRIBUTE(total_idle_time);
 DEFINE_SHOW_ATTRIBUTE(devices);
 DEFINE_SHOW_ATTRIBUTE(perf_state);
 
-static int __init genpd_debug_init(void)
+static void genpd_debug_add(struct generic_pm_domain *genpd)
 {
 	struct dentry *d;
+
+	if (!genpd_debugfs_dir)
+		return;
+
+	d = debugfs_create_dir(genpd->name, genpd_debugfs_dir);
+
+	debugfs_create_file("current_state", 0444,
+			    d, genpd, &status_fops);
+	debugfs_create_file("sub_domains", 0444,
+			    d, genpd, &sub_domains_fops);
+	debugfs_create_file("idle_states", 0444,
+			    d, genpd, &idle_states_fops);
+	debugfs_create_file("active_time", 0444,
+			    d, genpd, &active_time_fops);
+	debugfs_create_file("total_idle_time", 0444,
+			    d, genpd, &total_idle_time_fops);
+	debugfs_create_file("devices", 0444,
+			    d, genpd, &devices_fops);
+	if (genpd->set_performance_state)
+		debugfs_create_file("perf_state", 0444,
+				    d, genpd, &perf_state_fops);
+}
+
+static int __init genpd_debug_init(void)
+{
 	struct generic_pm_domain *genpd;
 
 	genpd_debugfs_dir = debugfs_create_dir("pm_genpd", NULL);
@@ -3187,25 +3221,8 @@ static int __init genpd_debug_init(void)
 	debugfs_create_file("pm_genpd_summary", S_IRUGO, genpd_debugfs_dir,
 			    NULL, &summary_fops);
 
-	list_for_each_entry(genpd, &gpd_list, gpd_list_node) {
-		d = debugfs_create_dir(genpd->name, genpd_debugfs_dir);
-
-		debugfs_create_file("current_state", 0444,
-				d, genpd, &status_fops);
-		debugfs_create_file("sub_domains", 0444,
-				d, genpd, &sub_domains_fops);
-		debugfs_create_file("idle_states", 0444,
-				d, genpd, &idle_states_fops);
-		debugfs_create_file("active_time", 0444,
-				d, genpd, &active_time_fops);
-		debugfs_create_file("total_idle_time", 0444,
-				d, genpd, &total_idle_time_fops);
-		debugfs_create_file("devices", 0444,
-				d, genpd, &devices_fops);
-		if (genpd->set_performance_state)
-			debugfs_create_file("perf_state", 0444,
-					    d, genpd, &perf_state_fops);
-	}
+	list_for_each_entry(genpd, &gpd_list, gpd_list_node)
+		genpd_debug_add(genpd);
 
 	return 0;
 }