cpuidle: Make cpuidle's sysfs directory dynamically allocated

The cpuidle sysfs code is designed to have a single instance of per CPU cpuidle directory. It is not possible to remove the sysfs entry and create it again. This is not a problem with the current code but future changes will add CPU hotplug support to enable/disable the device, so it will need to remove the sysfs entry like other subsystems do. That won't be possible without this change, because the kobj is a static object which can't be reused for kobj_init_and_add(). Add cpuidle_device_kobj to be allocated dynamically when adding/removing a sysfs entry which is consistent with the other cpuidle's sysfs entries. An added benefit is that the sysfs code is now more self-contained and the includes needed for sysfs can be moved from cpuidle.h directly into sysfs.c so as to reduce the total number of headers dragged along with cpuidle.h. [rjw: Changelog] Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

cpuidle: Make cpuidle's sysfs directory dynamically allocated
The cpuidle sysfs code is designed to have a single instance of per CPU cpuidle directory. It is not possible to remove the sysfs entry and create it again. This is not a problem with the current code but future changes will add CPU hotplug support to enable/disable the device, so it will need to remove the sysfs entry like other subsystems do. That won't be possible without this change, because the kobj is a static object which can't be reused for kobj_init_and_add(). Add cpuidle_device_kobj to be allocated dynamically when adding/removing a sysfs entry which is consistent with the other cpuidle's sysfs entries. An added benefit is that the sysfs code is now more self-contained and the includes needed for sysfs can be moved from cpuidle.h directly into sysfs.c so as to reduce the total number of headers dragged along with cpuidle.h. [rjw: Changelog] Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Daniel Lezcano · Rafael J. Wysocki
1 parent f89ae89e27
Showing 2 changed files with 51 additions and 19 deletions Side-by-side Diff
drivers/cpuidle/sysfs.c
include/linux/cpuidle.h
@@ -11,8 +11,10 @@
 #include <linux/sysfs.h>
 #include <linux/slab.h>
 #include <linux/cpu.h>
+#include <linux/completion.h>
 #include <linux/capability.h>
 #include <linux/device.h>
+#include <linux/kobject.h>
  
 #include "cpuidle.h"
  
  
  
@@ -167,14 +169,27 @@
 #define define_one_rw(_name, show, store) \
 	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
  
-#define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
 #define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
  
+struct cpuidle_device_kobj {
+	struct cpuidle_device *dev;
+	struct completion kobj_unregister;
+	struct kobject kobj;
+};
+
+static inline struct cpuidle_device *to_cpuidle_device(struct kobject *kobj)
+{
+	struct cpuidle_device_kobj *kdev =
+		container_of(kobj, struct cpuidle_device_kobj, kobj);
+
+	return kdev->dev;
+}
+
 static ssize_t cpuidle_show(struct kobject *kobj, struct attribute *attr,
 			    char *buf)
 {
 	int ret = -EIO;
-	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
+	struct cpuidle_device *dev = to_cpuidle_device(kobj);
 	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
  
 	if (cattr->show) {
@@ -189,7 +204,7 @@
 			     const char *buf, size_t count)
 {
 	int ret = -EIO;
-	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
+	struct cpuidle_device *dev = to_cpuidle_device(kobj);
 	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
  
 	if (cattr->store) {
  
@@ -207,9 +222,10 @@
  
 static void cpuidle_sysfs_release(struct kobject *kobj)
 {
-	struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
+	struct cpuidle_device_kobj *kdev =
+		container_of(kobj, struct cpuidle_device_kobj, kobj);
  
-	complete(&dev->kobj_unregister);
+	complete(&kdev->kobj_unregister);
 }
  
 static struct kobj_type ktype_cpuidle = {
@@ -377,6 +393,7 @@
 {
 	int i, ret = -ENOMEM;
 	struct cpuidle_state_kobj *kobj;
+	struct cpuidle_device_kobj *kdev = device->kobj_dev;
 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
  
 	/* state statistics */
@@ -389,7 +406,7 @@
 		init_completion(&kobj->kobj_unregister);
  
 		ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
-					   &device->kobj, "state%d", i);
+					   &kdev->kobj, "state%d", i);
 		if (ret) {
 			kfree(kobj);
 			goto error_state;
@@ -506,6 +523,7 @@
 static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
 {
 	struct cpuidle_driver_kobj *kdrv;
+	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
 	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
 	int ret;
  
@@ -517,7 +535,7 @@
 	init_completion(&kdrv->kobj_unregister);
  
 	ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
-				   &dev->kobj, "driver");
+				   &kdev->kobj, "driver");
 	if (ret) {
 		kfree(kdrv);
 		return ret;
  
  
@@ -586,16 +604,28 @@
  */
 int cpuidle_add_sysfs(struct cpuidle_device *dev)
 {
+	struct cpuidle_device_kobj *kdev;
 	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
 	int error;
  
-	init_completion(&dev->kobj_unregister);
+	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
+	if (!kdev)
+		return -ENOMEM;
+	kdev->dev = dev;
+	dev->kobj_dev = kdev;
  
-	error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
-				     "cpuidle");
-	if (!error)
-		kobject_uevent(&dev->kobj, KOBJ_ADD);
-	return error;
+	init_completion(&kdev->kobj_unregister);
+
+	error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
+				   "cpuidle");
+	if (error) {
+		kfree(kdev);
+		return error;
+	}
+
+	kobject_uevent(&kdev->kobj, KOBJ_ADD);
+
+	return 0;
 }
  
 /**
@@ -604,7 +634,10 @@
  */
 void cpuidle_remove_sysfs(struct cpuidle_device *dev)
 {
-	kobject_put(&dev->kobj);
-	wait_for_completion(&dev->kobj_unregister);
+	struct cpuidle_device_kobj *kdev = dev->kobj_dev;
+
+	kobject_put(&kdev->kobj);
+	wait_for_completion(&kdev->kobj_unregister);
+	kfree(kdev);
 }
@@ -13,8 +13,6 @@
  
 #include <linux/percpu.h>
 #include <linux/list.h>
-#include <linux/kobject.h>
-#include <linux/completion.h>
 #include <linux/hrtimer.h>
  
 #define CPUIDLE_STATE_MAX	10
@@ -61,6 +59,8 @@
  
 #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
  
+struct cpuidle_device_kobj;
+
 struct cpuidle_device {
 	unsigned int		registered:1;
 	unsigned int		enabled:1;
  
@@ -71,9 +71,8 @@
 	struct cpuidle_state_usage	states_usage[CPUIDLE_STATE_MAX];
 	struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
 	struct cpuidle_driver_kobj *kobj_driver;
+	struct cpuidle_device_kobj *kobj_dev;
 	struct list_head 	device_list;
-	struct kobject		kobj;
-	struct completion	kobj_unregister;
  
 #ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
 	int			safe_state_index;
...	...	@@ -11,8 +11,10 @@
11	11	#include <linux/sysfs.h>
12	12	#include <linux/slab.h>
13	13	#include <linux/cpu.h>
	14	+#include <linux/completion.h>
14	15	#include <linux/capability.h>
15	16	#include <linux/device.h>
	17	+#include <linux/kobject.h>
16	18
17	19	#include "cpuidle.h"
18	20
19	21
20	22
...	...	@@ -167,14 +169,27 @@
167	169	#define define_one_rw(_name, show, store) \
168	170	static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
169	171
170		-#define kobj_to_cpuidledev(k) container_of(k, struct cpuidle_device, kobj)
171	172	#define attr_to_cpuidleattr(a) container_of(a, struct cpuidle_attr, attr)
172	173
	174	+struct cpuidle_device_kobj {
	175	+ struct cpuidle_device *dev;
	176	+ struct completion kobj_unregister;
	177	+ struct kobject kobj;
	178	+};
	179	+
	180	+static inline struct cpuidle_device to_cpuidle_device(struct kobject kobj)
	181	+{
	182	+ struct cpuidle_device_kobj *kdev =
	183	+ container_of(kobj, struct cpuidle_device_kobj, kobj);
	184	+
	185	+ return kdev->dev;
	186	+}
	187	+
173	188	static ssize_t cpuidle_show(struct kobject kobj, struct attribute attr,
174	189	char *buf)
175	190	{
176	191	int ret = -EIO;
177		- struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
	192	+ struct cpuidle_device *dev = to_cpuidle_device(kobj);
178	193	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
179	194
180	195	if (cattr->show) {
...	...	@@ -189,7 +204,7 @@
189	204	const char *buf, size_t count)
190	205	{
191	206	int ret = -EIO;
192		- struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
	207	+ struct cpuidle_device *dev = to_cpuidle_device(kobj);
193	208	struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
194	209
195	210	if (cattr->store) {
196	211
...	...	@@ -207,9 +222,10 @@
207	222
208	223	static void cpuidle_sysfs_release(struct kobject *kobj)
209	224	{
210		- struct cpuidle_device *dev = kobj_to_cpuidledev(kobj);
	225	+ struct cpuidle_device_kobj *kdev =
	226	+ container_of(kobj, struct cpuidle_device_kobj, kobj);
211	227
212		- complete(&dev->kobj_unregister);
	228	+ complete(&kdev->kobj_unregister);
213	229	}
214	230
215	231	static struct kobj_type ktype_cpuidle = {
...	...	@@ -377,6 +393,7 @@
377	393	{
378	394	int i, ret = -ENOMEM;
379	395	struct cpuidle_state_kobj *kobj;
	396	+ struct cpuidle_device_kobj *kdev = device->kobj_dev;
380	397	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
381	398
382	399	/* state statistics */
...	...	@@ -389,7 +406,7 @@
389	406	init_completion(&kobj->kobj_unregister);
390	407
391	408	ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
392		- &device->kobj, "state%d", i);
	409	+ &kdev->kobj, "state%d", i);
393	410	if (ret) {
394	411	kfree(kobj);
395	412	goto error_state;
...	...	@@ -506,6 +523,7 @@
506	523	static int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
507	524	{
508	525	struct cpuidle_driver_kobj *kdrv;
	526	+ struct cpuidle_device_kobj *kdev = dev->kobj_dev;
509	527	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
510	528	int ret;
511	529
...	...	@@ -517,7 +535,7 @@
517	535	init_completion(&kdrv->kobj_unregister);
518	536
519	537	ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
520		- &dev->kobj, "driver");
	538	+ &kdev->kobj, "driver");
521	539	if (ret) {
522	540	kfree(kdrv);
523	541	return ret;
524	542
525	543
...	...	@@ -586,16 +604,28 @@
586	604	*/
587	605	int cpuidle_add_sysfs(struct cpuidle_device *dev)
588	606	{
	607	+ struct cpuidle_device_kobj *kdev;
589	608	struct device *cpu_dev = get_cpu_device((unsigned long)dev->cpu);
590	609	int error;
591	610
592		- init_completion(&dev->kobj_unregister);
	611	+ kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
	612	+ if (!kdev)
	613	+ return -ENOMEM;
	614	+ kdev->dev = dev;
	615	+ dev->kobj_dev = kdev;
593	616
594		- error = kobject_init_and_add(&dev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
595		- "cpuidle");
596		- if (!error)
597		- kobject_uevent(&dev->kobj, KOBJ_ADD);
598		- return error;
	617	+ init_completion(&kdev->kobj_unregister);
	618	+
	619	+ error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
	620	+ "cpuidle");
	621	+ if (error) {
	622	+ kfree(kdev);
	623	+ return error;
	624	+ }
	625	+
	626	+ kobject_uevent(&kdev->kobj, KOBJ_ADD);
	627	+
	628	+ return 0;
599	629	}
600	630
601	631	/**
...	...	@@ -604,7 +634,10 @@
604	634	*/
605	635	void cpuidle_remove_sysfs(struct cpuidle_device *dev)
606	636	{
607		- kobject_put(&dev->kobj);
608		- wait_for_completion(&dev->kobj_unregister);
	637	+ struct cpuidle_device_kobj *kdev = dev->kobj_dev;
	638	+
	639	+ kobject_put(&kdev->kobj);
	640	+ wait_for_completion(&kdev->kobj_unregister);
	641	+ kfree(kdev);
609	642	}
...	...	@@ -13,8 +13,6 @@
13	13
14	14	#include <linux/percpu.h>
15	15	#include <linux/list.h>
16		-#include <linux/kobject.h>
17		-#include <linux/completion.h>
18	16	#include <linux/hrtimer.h>
19	17
20	18	#define CPUIDLE_STATE_MAX 10
...	...	@@ -61,6 +59,8 @@
61	59
62	60	#define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000)
63	61
	62	+struct cpuidle_device_kobj;
	63	+
64	64	struct cpuidle_device {
65	65	unsigned int registered:1;
66	66	unsigned int enabled:1;
67	67
...	...	@@ -71,9 +71,8 @@
71	71	struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX];
72	72	struct cpuidle_state_kobj *kobjs[CPUIDLE_STATE_MAX];
73	73	struct cpuidle_driver_kobj *kobj_driver;
	74	+ struct cpuidle_device_kobj *kobj_dev;
74	75	struct list_head device_list;
75		- struct kobject kobj;
76		- struct completion kobj_unregister;
77	76
78	77	#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
79	78	int safe_state_index;