Kset和Kobject

/**
 * struct bus_type_private - structure to hold the private to the driver core portions of the bus_type structure.
 *
 * @subsys - the struct kset that defines this bus.  This is the main kobject
 * @drivers_kset - the list of drivers associated with this bus
 * @devices_kset - the list of devices associated with this bus
 * @klist_devices - the klist to iterate over the @devices_kset
 * @klist_drivers - the klist to iterate over the @drivers_kset
 * @bus_notifier - the bus notifier list for anything that cares about things
 * on this bus.
 * @bus - pointer back to the struct bus_type that this structure is associated
 * with.
 *
 * This structure is the one that is the actual kobject allowing struct
 * bus_type to be statically allocated safely.  Nothing outside of the driver
 * core should ever touch these fields.
 */
struct bus_type_private {
struct kset subsys;  //用来描述总线的kset。
struct kset *drivers_kset; //和bus_type相关的驱动的kset集合
struct kset *devices_kset;//和bus_type相关的设备的kset集合
struct klist klist_devices;
struct klist klist_drivers;
struct blocking_notifier_head bus_notifier;
unsigned int drivers_autoprobe:1;
struct bus_type *bus;

};

/*bus_type结构体用来描述总线。*/

struct bus_type {
const char *name;
struct bus_attribute*bus_attrs;
struct device_attribute*dev_attrs;
struct driver_attribute*drv_attrs;


int (*match)(struct device *dev, struct device_driver *drv);
int (*uevent)(struct device *dev, struct kobj_uevent_env *env);
int (*probe)(struct device *dev);
int (*remove)(struct device *dev);
void (*shutdown)(struct device *dev);


int (*suspend)(struct device *dev, pm_message_t state);
int (*resume)(struct device *dev);


const struct dev_pm_ops *pm;


struct bus_type_private *p;//这个私有指针包含了kset
};

Sysfs文件系统是一个类 似于proc文件系统的特殊文件系统，用于将系统中的设备组织成层次结构，并向用户模式程序提供详细的内核数据结构信息。

Kobject 是Linux 2.6引入的新的设备管理机制，在内核中由struct kobject表示。通过这个数据结构使所有设备在底层都具有统一的接口，kobject提供基本的对象管理，是构成Linux2.6设备模型的核心结 构，它与sysfs文件系统紧密关联，每个在内核中注册的kobject对象都对应于sysfs文件系统中的一个目录。Kobject是组成设备模型的基 本结构。类似于C++中的基类，它嵌入于更大的对象的对象中--所谓的容器--用来描述设备模型的组件。如bus,devices, drivers 都是典型的容器。这些容器就是通过kobject连接起来了，形成了一个树状结构。这个树状结构就与/sys向对应。