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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/cpuidle/sysfs.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/cpuidle/sysfs.c')
-rw-r--r--drivers/cpuidle/sysfs.c718
1 files changed, 718 insertions, 0 deletions
diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c
new file mode 100644
index 000000000..d9b917529
--- /dev/null
+++ b/drivers/cpuidle/sysfs.c
@@ -0,0 +1,718 @@
+/*
+ * sysfs.c - sysfs support
+ *
+ * (C) 2006-2007 Shaohua Li <shaohua.li@intel.com>
+ *
+ * This code is licenced under the GPL.
+ */
+
+#include <linux/kernel.h>
+#include <linux/cpuidle.h>
+#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"
+
+static unsigned int sysfs_switch;
+static int __init cpuidle_sysfs_setup(char *unused)
+{
+ sysfs_switch = 1;
+ return 1;
+}
+__setup("cpuidle_sysfs_switch", cpuidle_sysfs_setup);
+
+static ssize_t show_available_governors(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t i = 0;
+ struct cpuidle_governor *tmp;
+
+ mutex_lock(&cpuidle_lock);
+ list_for_each_entry(tmp, &cpuidle_governors, governor_list) {
+ if (i >= (ssize_t) ((PAGE_SIZE/sizeof(char)) -
+ CPUIDLE_NAME_LEN - 2))
+ goto out;
+ i += scnprintf(&buf[i], CPUIDLE_NAME_LEN, "%s ", tmp->name);
+ }
+
+out:
+ i+= sprintf(&buf[i], "\n");
+ mutex_unlock(&cpuidle_lock);
+ return i;
+}
+
+static ssize_t show_current_driver(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t ret;
+ struct cpuidle_driver *drv;
+
+ spin_lock(&cpuidle_driver_lock);
+ drv = cpuidle_get_driver();
+ if (drv)
+ ret = sprintf(buf, "%s\n", drv->name);
+ else
+ ret = sprintf(buf, "none\n");
+ spin_unlock(&cpuidle_driver_lock);
+
+ return ret;
+}
+
+static ssize_t show_current_governor(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ ssize_t ret;
+
+ mutex_lock(&cpuidle_lock);
+ if (cpuidle_curr_governor)
+ ret = sprintf(buf, "%s\n", cpuidle_curr_governor->name);
+ else
+ ret = sprintf(buf, "none\n");
+ mutex_unlock(&cpuidle_lock);
+
+ return ret;
+}
+
+static ssize_t store_current_governor(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ char gov_name[CPUIDLE_NAME_LEN];
+ int ret = -EINVAL;
+ size_t len = count;
+ struct cpuidle_governor *gov;
+
+ if (!len || len >= sizeof(gov_name))
+ return -EINVAL;
+
+ memcpy(gov_name, buf, len);
+ gov_name[len] = '\0';
+ if (gov_name[len - 1] == '\n')
+ gov_name[--len] = '\0';
+
+ mutex_lock(&cpuidle_lock);
+
+ list_for_each_entry(gov, &cpuidle_governors, governor_list) {
+ if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) {
+ ret = cpuidle_switch_governor(gov);
+ break;
+ }
+ }
+
+ mutex_unlock(&cpuidle_lock);
+
+ if (ret)
+ return ret;
+ else
+ return count;
+}
+
+static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);
+static DEVICE_ATTR(current_governor_ro, 0444, show_current_governor, NULL);
+
+static struct attribute *cpuidle_default_attrs[] = {
+ &dev_attr_current_driver.attr,
+ &dev_attr_current_governor_ro.attr,
+ NULL
+};
+
+static DEVICE_ATTR(available_governors, 0444, show_available_governors, NULL);
+static DEVICE_ATTR(current_governor, 0644, show_current_governor,
+ store_current_governor);
+
+static struct attribute *cpuidle_switch_attrs[] = {
+ &dev_attr_available_governors.attr,
+ &dev_attr_current_driver.attr,
+ &dev_attr_current_governor.attr,
+ NULL
+};
+
+static struct attribute_group cpuidle_attr_group = {
+ .attrs = cpuidle_default_attrs,
+ .name = "cpuidle",
+};
+
+/**
+ * cpuidle_add_interface - add CPU global sysfs attributes
+ */
+int cpuidle_add_interface(struct device *dev)
+{
+ if (sysfs_switch)
+ cpuidle_attr_group.attrs = cpuidle_switch_attrs;
+
+ return sysfs_create_group(&dev->kobj, &cpuidle_attr_group);
+}
+
+/**
+ * cpuidle_remove_interface - remove CPU global sysfs attributes
+ */
+void cpuidle_remove_interface(struct device *dev)
+{
+ sysfs_remove_group(&dev->kobj, &cpuidle_attr_group);
+}
+
+struct cpuidle_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct cpuidle_device *, char *);
+ ssize_t (*store)(struct cpuidle_device *, const char *, size_t count);
+};
+
+#define define_one_ro(_name, show) \
+ static struct cpuidle_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
+#define define_one_rw(_name, show, store) \
+ static struct cpuidle_attr attr_##_name = __ATTR(_name, 0644, show, store)
+
+#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 = to_cpuidle_device(kobj);
+ struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
+
+ if (cattr->show) {
+ mutex_lock(&cpuidle_lock);
+ ret = cattr->show(dev, buf);
+ mutex_unlock(&cpuidle_lock);
+ }
+ return ret;
+}
+
+static ssize_t cpuidle_store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret = -EIO;
+ struct cpuidle_device *dev = to_cpuidle_device(kobj);
+ struct cpuidle_attr *cattr = attr_to_cpuidleattr(attr);
+
+ if (cattr->store) {
+ mutex_lock(&cpuidle_lock);
+ ret = cattr->store(dev, buf, count);
+ mutex_unlock(&cpuidle_lock);
+ }
+ return ret;
+}
+
+static const struct sysfs_ops cpuidle_sysfs_ops = {
+ .show = cpuidle_show,
+ .store = cpuidle_store,
+};
+
+static void cpuidle_sysfs_release(struct kobject *kobj)
+{
+ struct cpuidle_device_kobj *kdev =
+ container_of(kobj, struct cpuidle_device_kobj, kobj);
+
+ complete(&kdev->kobj_unregister);
+}
+
+static struct kobj_type ktype_cpuidle = {
+ .sysfs_ops = &cpuidle_sysfs_ops,
+ .release = cpuidle_sysfs_release,
+};
+
+struct cpuidle_state_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct cpuidle_state *, \
+ struct cpuidle_state_usage *, char *);
+ ssize_t (*store)(struct cpuidle_state *, \
+ struct cpuidle_state_usage *, const char *, size_t);
+};
+
+#define define_one_state_ro(_name, show) \
+static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0444, show, NULL)
+
+#define define_one_state_rw(_name, show, store) \
+static struct cpuidle_state_attr attr_##_name = __ATTR(_name, 0644, show, store)
+
+#define define_show_state_function(_name) \
+static ssize_t show_state_##_name(struct cpuidle_state *state, \
+ struct cpuidle_state_usage *state_usage, char *buf) \
+{ \
+ return sprintf(buf, "%u\n", state->_name);\
+}
+
+#define define_store_state_ull_function(_name) \
+static ssize_t store_state_##_name(struct cpuidle_state *state, \
+ struct cpuidle_state_usage *state_usage, \
+ const char *buf, size_t size) \
+{ \
+ unsigned long long value; \
+ int err; \
+ if (!capable(CAP_SYS_ADMIN)) \
+ return -EPERM; \
+ err = kstrtoull(buf, 0, &value); \
+ if (err) \
+ return err; \
+ if (value) \
+ state_usage->_name = 1; \
+ else \
+ state_usage->_name = 0; \
+ return size; \
+}
+
+#define define_show_state_ull_function(_name) \
+static ssize_t show_state_##_name(struct cpuidle_state *state, \
+ struct cpuidle_state_usage *state_usage, \
+ char *buf) \
+{ \
+ return sprintf(buf, "%llu\n", state_usage->_name);\
+}
+
+#define define_show_state_str_function(_name) \
+static ssize_t show_state_##_name(struct cpuidle_state *state, \
+ struct cpuidle_state_usage *state_usage, \
+ char *buf) \
+{ \
+ if (state->_name[0] == '\0')\
+ return sprintf(buf, "<null>\n");\
+ return sprintf(buf, "%s\n", state->_name);\
+}
+
+define_show_state_function(exit_latency)
+define_show_state_function(target_residency)
+define_show_state_function(power_usage)
+define_show_state_ull_function(usage)
+define_show_state_ull_function(time)
+define_show_state_str_function(name)
+define_show_state_str_function(desc)
+define_show_state_ull_function(disable)
+define_store_state_ull_function(disable)
+
+define_one_state_ro(name, show_state_name);
+define_one_state_ro(desc, show_state_desc);
+define_one_state_ro(latency, show_state_exit_latency);
+define_one_state_ro(residency, show_state_target_residency);
+define_one_state_ro(power, show_state_power_usage);
+define_one_state_ro(usage, show_state_usage);
+define_one_state_ro(time, show_state_time);
+define_one_state_rw(disable, show_state_disable, store_state_disable);
+
+static struct attribute *cpuidle_state_default_attrs[] = {
+ &attr_name.attr,
+ &attr_desc.attr,
+ &attr_latency.attr,
+ &attr_residency.attr,
+ &attr_power.attr,
+ &attr_usage.attr,
+ &attr_time.attr,
+ &attr_disable.attr,
+ NULL
+};
+
+struct cpuidle_state_kobj {
+ struct cpuidle_state *state;
+ struct cpuidle_state_usage *state_usage;
+ struct completion kobj_unregister;
+ struct kobject kobj;
+};
+
+#ifdef CONFIG_SUSPEND
+#define define_show_state_s2idle_ull_function(_name) \
+static ssize_t show_state_s2idle_##_name(struct cpuidle_state *state, \
+ struct cpuidle_state_usage *state_usage, \
+ char *buf) \
+{ \
+ return sprintf(buf, "%llu\n", state_usage->s2idle_##_name);\
+}
+
+define_show_state_s2idle_ull_function(usage);
+define_show_state_s2idle_ull_function(time);
+
+#define define_one_state_s2idle_ro(_name, show) \
+static struct cpuidle_state_attr attr_s2idle_##_name = \
+ __ATTR(_name, 0444, show, NULL)
+
+define_one_state_s2idle_ro(usage, show_state_s2idle_usage);
+define_one_state_s2idle_ro(time, show_state_s2idle_time);
+
+static struct attribute *cpuidle_state_s2idle_attrs[] = {
+ &attr_s2idle_usage.attr,
+ &attr_s2idle_time.attr,
+ NULL
+};
+
+static const struct attribute_group cpuidle_state_s2idle_group = {
+ .name = "s2idle",
+ .attrs = cpuidle_state_s2idle_attrs,
+};
+
+static void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
+{
+ int ret;
+
+ if (!kobj->state->enter_s2idle)
+ return;
+
+ ret = sysfs_create_group(&kobj->kobj, &cpuidle_state_s2idle_group);
+ if (ret)
+ pr_debug("%s: sysfs attribute group not created\n", __func__);
+}
+
+static void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj)
+{
+ if (kobj->state->enter_s2idle)
+ sysfs_remove_group(&kobj->kobj, &cpuidle_state_s2idle_group);
+}
+#else
+static inline void cpuidle_add_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
+static inline void cpuidle_remove_s2idle_attr_group(struct cpuidle_state_kobj *kobj) { }
+#endif /* CONFIG_SUSPEND */
+
+#define kobj_to_state_obj(k) container_of(k, struct cpuidle_state_kobj, kobj)
+#define kobj_to_state(k) (kobj_to_state_obj(k)->state)
+#define kobj_to_state_usage(k) (kobj_to_state_obj(k)->state_usage)
+#define attr_to_stateattr(a) container_of(a, struct cpuidle_state_attr, attr)
+
+static ssize_t cpuidle_state_show(struct kobject *kobj, struct attribute *attr,
+ char * buf)
+{
+ int ret = -EIO;
+ struct cpuidle_state *state = kobj_to_state(kobj);
+ struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
+ struct cpuidle_state_attr * cattr = attr_to_stateattr(attr);
+
+ if (cattr->show)
+ ret = cattr->show(state, state_usage, buf);
+
+ return ret;
+}
+
+static ssize_t cpuidle_state_store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t size)
+{
+ int ret = -EIO;
+ struct cpuidle_state *state = kobj_to_state(kobj);
+ struct cpuidle_state_usage *state_usage = kobj_to_state_usage(kobj);
+ struct cpuidle_state_attr *cattr = attr_to_stateattr(attr);
+
+ if (cattr->store)
+ ret = cattr->store(state, state_usage, buf, size);
+
+ return ret;
+}
+
+static const struct sysfs_ops cpuidle_state_sysfs_ops = {
+ .show = cpuidle_state_show,
+ .store = cpuidle_state_store,
+};
+
+static void cpuidle_state_sysfs_release(struct kobject *kobj)
+{
+ struct cpuidle_state_kobj *state_obj = kobj_to_state_obj(kobj);
+
+ complete(&state_obj->kobj_unregister);
+}
+
+static struct kobj_type ktype_state_cpuidle = {
+ .sysfs_ops = &cpuidle_state_sysfs_ops,
+ .default_attrs = cpuidle_state_default_attrs,
+ .release = cpuidle_state_sysfs_release,
+};
+
+static inline void cpuidle_free_state_kobj(struct cpuidle_device *device, int i)
+{
+ cpuidle_remove_s2idle_attr_group(device->kobjs[i]);
+ kobject_put(&device->kobjs[i]->kobj);
+ wait_for_completion(&device->kobjs[i]->kobj_unregister);
+ kfree(device->kobjs[i]);
+ device->kobjs[i] = NULL;
+}
+
+/**
+ * cpuidle_add_state_sysfs - adds cpuidle states sysfs attributes
+ * @device: the target device
+ */
+static int cpuidle_add_state_sysfs(struct cpuidle_device *device)
+{
+ 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 */
+ for (i = 0; i < drv->state_count; i++) {
+ kobj = kzalloc(sizeof(struct cpuidle_state_kobj), GFP_KERNEL);
+ if (!kobj) {
+ ret = -ENOMEM;
+ goto error_state;
+ }
+ kobj->state = &drv->states[i];
+ kobj->state_usage = &device->states_usage[i];
+ init_completion(&kobj->kobj_unregister);
+
+ ret = kobject_init_and_add(&kobj->kobj, &ktype_state_cpuidle,
+ &kdev->kobj, "state%d", i);
+ if (ret) {
+ kobject_put(&kobj->kobj);
+ kfree(kobj);
+ goto error_state;
+ }
+ cpuidle_add_s2idle_attr_group(kobj);
+ kobject_uevent(&kobj->kobj, KOBJ_ADD);
+ device->kobjs[i] = kobj;
+ }
+
+ return 0;
+
+error_state:
+ for (i = i - 1; i >= 0; i--)
+ cpuidle_free_state_kobj(device, i);
+ return ret;
+}
+
+/**
+ * cpuidle_remove_driver_sysfs - removes the cpuidle states sysfs attributes
+ * @device: the target device
+ */
+static void cpuidle_remove_state_sysfs(struct cpuidle_device *device)
+{
+ struct cpuidle_driver *drv = cpuidle_get_cpu_driver(device);
+ int i;
+
+ for (i = 0; i < drv->state_count; i++)
+ cpuidle_free_state_kobj(device, i);
+}
+
+#ifdef CONFIG_CPU_IDLE_MULTIPLE_DRIVERS
+#define kobj_to_driver_kobj(k) container_of(k, struct cpuidle_driver_kobj, kobj)
+#define attr_to_driver_attr(a) container_of(a, struct cpuidle_driver_attr, attr)
+
+#define define_one_driver_ro(_name, show) \
+ static struct cpuidle_driver_attr attr_driver_##_name = \
+ __ATTR(_name, 0444, show, NULL)
+
+struct cpuidle_driver_kobj {
+ struct cpuidle_driver *drv;
+ struct completion kobj_unregister;
+ struct kobject kobj;
+};
+
+struct cpuidle_driver_attr {
+ struct attribute attr;
+ ssize_t (*show)(struct cpuidle_driver *, char *);
+ ssize_t (*store)(struct cpuidle_driver *, const char *, size_t);
+};
+
+static ssize_t show_driver_name(struct cpuidle_driver *drv, char *buf)
+{
+ ssize_t ret;
+
+ spin_lock(&cpuidle_driver_lock);
+ ret = sprintf(buf, "%s\n", drv ? drv->name : "none");
+ spin_unlock(&cpuidle_driver_lock);
+
+ return ret;
+}
+
+static void cpuidle_driver_sysfs_release(struct kobject *kobj)
+{
+ struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
+ complete(&driver_kobj->kobj_unregister);
+}
+
+static ssize_t cpuidle_driver_show(struct kobject *kobj, struct attribute *attr,
+ char *buf)
+{
+ int ret = -EIO;
+ struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
+ struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
+
+ if (dattr->show)
+ ret = dattr->show(driver_kobj->drv, buf);
+
+ return ret;
+}
+
+static ssize_t cpuidle_driver_store(struct kobject *kobj, struct attribute *attr,
+ const char *buf, size_t size)
+{
+ int ret = -EIO;
+ struct cpuidle_driver_kobj *driver_kobj = kobj_to_driver_kobj(kobj);
+ struct cpuidle_driver_attr *dattr = attr_to_driver_attr(attr);
+
+ if (dattr->store)
+ ret = dattr->store(driver_kobj->drv, buf, size);
+
+ return ret;
+}
+
+define_one_driver_ro(name, show_driver_name);
+
+static const struct sysfs_ops cpuidle_driver_sysfs_ops = {
+ .show = cpuidle_driver_show,
+ .store = cpuidle_driver_store,
+};
+
+static struct attribute *cpuidle_driver_default_attrs[] = {
+ &attr_driver_name.attr,
+ NULL
+};
+
+static struct kobj_type ktype_driver_cpuidle = {
+ .sysfs_ops = &cpuidle_driver_sysfs_ops,
+ .default_attrs = cpuidle_driver_default_attrs,
+ .release = cpuidle_driver_sysfs_release,
+};
+
+/**
+ * cpuidle_add_driver_sysfs - adds the driver name sysfs attribute
+ * @device: the target device
+ */
+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;
+
+ kdrv = kzalloc(sizeof(*kdrv), GFP_KERNEL);
+ if (!kdrv)
+ return -ENOMEM;
+
+ kdrv->drv = drv;
+ init_completion(&kdrv->kobj_unregister);
+
+ ret = kobject_init_and_add(&kdrv->kobj, &ktype_driver_cpuidle,
+ &kdev->kobj, "driver");
+ if (ret) {
+ kobject_put(&kdrv->kobj);
+ kfree(kdrv);
+ return ret;
+ }
+
+ kobject_uevent(&kdrv->kobj, KOBJ_ADD);
+ dev->kobj_driver = kdrv;
+
+ return ret;
+}
+
+/**
+ * cpuidle_remove_driver_sysfs - removes the driver name sysfs attribute
+ * @device: the target device
+ */
+static void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
+{
+ struct cpuidle_driver_kobj *kdrv = dev->kobj_driver;
+ kobject_put(&kdrv->kobj);
+ wait_for_completion(&kdrv->kobj_unregister);
+ kfree(kdrv);
+}
+#else
+static inline int cpuidle_add_driver_sysfs(struct cpuidle_device *dev)
+{
+ return 0;
+}
+
+static inline void cpuidle_remove_driver_sysfs(struct cpuidle_device *dev)
+{
+ ;
+}
+#endif
+
+/**
+ * cpuidle_add_device_sysfs - adds device specific sysfs attributes
+ * @device: the target device
+ */
+int cpuidle_add_device_sysfs(struct cpuidle_device *device)
+{
+ int ret;
+
+ ret = cpuidle_add_state_sysfs(device);
+ if (ret)
+ return ret;
+
+ ret = cpuidle_add_driver_sysfs(device);
+ if (ret)
+ cpuidle_remove_state_sysfs(device);
+ return ret;
+}
+
+/**
+ * cpuidle_remove_device_sysfs : removes device specific sysfs attributes
+ * @device : the target device
+ */
+void cpuidle_remove_device_sysfs(struct cpuidle_device *device)
+{
+ cpuidle_remove_driver_sysfs(device);
+ cpuidle_remove_state_sysfs(device);
+}
+
+/**
+ * cpuidle_add_sysfs - creates a sysfs instance for the target device
+ * @dev: the target device
+ */
+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;
+
+ /*
+ * Return if cpu_device is not setup for this CPU.
+ *
+ * This could happen if the arch did not set up cpu_device
+ * since this CPU is not in cpu_present mask and the
+ * driver did not send a correct CPU mask during registration.
+ * Without this check we would end up passing bogus
+ * value for &cpu_dev->kobj in kobject_init_and_add()
+ */
+ if (!cpu_dev)
+ return -ENODEV;
+
+ kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
+ if (!kdev)
+ return -ENOMEM;
+ kdev->dev = dev;
+
+ init_completion(&kdev->kobj_unregister);
+
+ error = kobject_init_and_add(&kdev->kobj, &ktype_cpuidle, &cpu_dev->kobj,
+ "cpuidle");
+ if (error) {
+ kobject_put(&kdev->kobj);
+ kfree(kdev);
+ return error;
+ }
+
+ dev->kobj_dev = kdev;
+ kobject_uevent(&kdev->kobj, KOBJ_ADD);
+
+ return 0;
+}
+
+/**
+ * cpuidle_remove_sysfs - deletes a sysfs instance on the target device
+ * @dev: the target device
+ */
+void cpuidle_remove_sysfs(struct cpuidle_device *dev)
+{
+ struct cpuidle_device_kobj *kdev = dev->kobj_dev;
+
+ kobject_put(&kdev->kobj);
+ wait_for_completion(&kdev->kobj_unregister);
+ kfree(kdev);
+}