注册串口设备，创建字符设备框架(#290)

* 按照rust规范修改两个函数名称

* 修改一些函数句柄以符合rust规范

* 添加字符设备相关

* 添加字符设备相关文件

* 添加字符设备驱动框架代码

* 将串口注册

* 规范代码

kernel/src/driver/base/char/mod.rs

@@ -0,0 +1,285 @@
+use super::{
+    device::{mkdev, DeviceNumber, KObject},
+    map::{kobj_map, kobj_unmap, LockedKObjMap},
+};
+use crate::{filesystem::vfs::IndexNode, kerror, libs::spinlock::SpinLock, syscall::SystemError};
+use alloc::{sync::Arc, vec::Vec};
+use core::cmp::Ordering;
+
+const CHARDEV_MAJOR_HASH_SIZE: usize = 255;
+const CHARDEV_MAJOR_MAX: usize = 512;
+const MINOR_BITS: usize = 20;
+const MINOR_MASK: usize = 1 << MINOR_BITS - 1;
+/* Marks the bottom of the first segment of free char majors */
+const CHARDEV_MAJOR_DYN_END: usize = 234;
+/* Marks the top and bottom of the second segment of free char majors */
+const CHARDEV_MAJOR_DYN_EXT_START: usize = 511;
+const CHARDEV_MAJOR_DYN_EXT_END: usize = 384;
+
+lazy_static! {
+    // 全局字符设备号管理实例
+    pub static ref CHARDEVS: Arc<LockedChrDevs> = Arc::new(LockedChrDevs::default());
+
+    // 全局字符设备管理实例
+    pub static ref CDEVMAP: Arc<LockedKObjMap> = Arc::new(LockedKObjMap::default());
+}
+
+pub trait CharDevice: KObject {
+    /// @brief: 打开设备
+    /// @parameter: file: devfs inode
+    /// @return: 打开成功，返回OK(())，失败，返回错误代码
+    fn open(&self, file: Arc<dyn IndexNode>) -> Result<(), SystemError>;
+
+    /// @brief: 关闭设备
+    /// @parameter: file: devfs inode
+    /// @return: 关闭成功，返回OK(())，失败，返回错误代码
+    fn close(&self, file: Arc<dyn IndexNode>) -> Result<(), SystemError>;
+}
+
+// 管理字符设备号的map(加锁)
+pub struct LockedChrDevs(SpinLock<ChrDevs>);
+
+impl Default for LockedChrDevs {
+    fn default() -> Self {
+        LockedChrDevs(SpinLock::new(ChrDevs::default()))
+    }
+}
+
+// 管理字符设备号的map
+#[derive(Debug)]
+struct ChrDevs(Vec<Vec<CharDeviceStruct>>);
+
+impl Default for ChrDevs {
+    fn default() -> Self {
+        ChrDevs(vec![Vec::new(); CHARDEV_MAJOR_HASH_SIZE])
+    }
+}
+
+// 字符设备在系统中的实例，devfs通过该结构与实际字符设备进行联系
+#[allow(dead_code)]
+#[derive(Debug, Clone)]
+pub struct CharDeviceStruct {
+    dev_t: DeviceNumber, //起始设备号
+    minorct: usize,      // 次设备号数量
+    name: &'static str,  //字符设备名
+}
+
+impl CharDeviceStruct {
+    /// @brief: 创建实例
+    /// @parameter: dev_t: 设备号
+    ///             minorct: 次设备号数量
+    ///             name: 字符设备名
+    ///             char: 字符设备实例
+    /// @return: 实例
+    /// 
+    #[allow(dead_code)]
+    pub fn new(dev_t: DeviceNumber, minorct: usize, name: &'static str) -> Self {
+        Self {
+            dev_t,
+            minorct,
+            name,
+        }
+    }
+
+    /// @brief: 获取起始次设备号
+    /// @parameter: None
+    /// @return: 起始设备号
+    /// 
+    #[allow(dead_code)]
+    pub fn device_number(&self) -> DeviceNumber {
+        self.dev_t
+    }
+
+    /// @brief: 获取起始次设备号
+    /// @parameter: None
+    /// @return: 起始设备号
+    /// 
+    #[allow(dead_code)]
+    pub fn base_minor(&self) -> usize {
+        self.dev_t.minor()
+    }
+
+    /// @brief: 获取次设备号数量
+    /// @parameter: None
+    /// @return: 次设备号数量
+    #[allow(dead_code)]
+    pub fn minorct(&self) -> usize {
+        self.minorct
+    }
+}
+
+/// @brief 字符设备框架函数集
+pub struct CharDevOps;
+
+impl CharDevOps {
+    /// @brief: 主设备号转下标
+    /// @parameter: major: 主设备号
+    /// @return: 返回下标
+    #[allow(dead_code)]
+    fn major_to_index(major: usize) -> usize {
+        return major % CHARDEV_MAJOR_HASH_SIZE;
+    }
+
+    /// @brief: 动态获取主设备号
+    /// @parameter: None
+    /// @return: 如果成功，返回主设备号，否则，返回错误码 
+    #[allow(dead_code)]
+    fn find_dynamic_major() -> Result<usize, SystemError> {
+        let chardevs = CHARDEVS.0.lock();
+        // 寻找主设备号为234～255的设备
+        for index in (CHARDEV_MAJOR_DYN_END..CHARDEV_MAJOR_HASH_SIZE).rev() {
+            if let Some(item) = chardevs.0.get(index) {
+                if item.is_empty() {
+                    return Ok(index); // 返回可用的主设备号
+                }
+            }
+        }
+        // 寻找主设备号在384～511的设备
+        for index in (CHARDEV_MAJOR_DYN_EXT_END + 1..CHARDEV_MAJOR_DYN_EXT_START + 1).rev() {
+            if let Some(chardevss) = chardevs.0.get(Self::major_to_index(index)) {
+                let mut flag = true;
+                for item in chardevss {
+                    if item.device_number().major() == index {
+                        flag = false;
+                        break;
+                    }
+                }
+                if flag {
+                    // 如果数组中不存在主设备号等于index的设备
+                    return Ok(index); // 返回可用的主设备号
+                }
+            }
+        }
+        return Err(SystemError::EBUSY);
+    }
+
+    /// @brief: 注册设备号，该函数需要指定主设备号
+    /// @parameter: from: 主设备号
+    ///             count: 次设备号数量
+    ///             name: 字符设备名
+    /// @return: 如果注册成功，返回设备号，否则，返回错误码
+    #[allow(dead_code)]
+    pub fn register_chardev_region(
+        from: DeviceNumber,
+        count: usize,
+        name: &'static str,
+    ) -> Result<DeviceNumber, SystemError> {
+        Self::__register_chardev_region(from, count, name)
+    }
+
+    /// @brief: 注册设备号，该函数自动分配主设备号
+    /// @parameter: baseminor: 主设备号
+    ///             count: 次设备号数量
+    ///             name: 字符设备名
+    /// @return: 如果注册成功，返回，否则，返回false 
+    #[allow(dead_code)]
+    pub fn alloc_chardev_region(
+        baseminor: usize,
+        count: usize,
+        name: &'static str,
+    ) -> Result<DeviceNumber, SystemError> {
+        Self::__register_chardev_region(mkdev(0, baseminor), count, name)
+    }
+
+    /// @brief: 注册设备号
+    /// @parameter: device_number: 设备号，主设备号如果为0，则动态分配
+    ///             minorct: 次设备号数量
+    ///             name: 字符设备名
+    /// @return: 如果注册成功，返回设备号，否则，返回错误码
+    fn __register_chardev_region(
+        device_number: DeviceNumber,
+        minorct: usize,
+        name: &'static str,
+    ) -> Result<DeviceNumber, SystemError> {
+        let mut major = device_number.major();
+        let baseminor = device_number.minor();
+        if major >= CHARDEV_MAJOR_MAX {
+            kerror!(
+                "CHARDEV {} major requested {} is greater than the maximum {}\n",
+                name,
+                major,
+                CHARDEV_MAJOR_MAX - 1
+            );
+        }
+        if minorct > MINOR_MASK + 1 - baseminor {
+            kerror!("CHARDEV {} minor range requested ({}-{}) is out of range of maximum range ({}-{}) for a single major\n",
+                name, baseminor, baseminor + minorct - 1, 0, MINOR_MASK);
+        }
+        let chardev = CharDeviceStruct::new(mkdev(major, baseminor), minorct, name);
+        if major == 0 {
+            // 如果主设备号为0,则自动分配主设备号
+            major = Self::find_dynamic_major().expect("Find synamic major error.\n");
+        }
+        if let Some(items) = CHARDEVS.0.lock().0.get_mut(Self::major_to_index(major)) {
+            let mut insert_index: usize = 0;
+            for (index, item) in items.iter().enumerate() {
+                insert_index = index;
+                match item.device_number().major().cmp(&major) {
+                    Ordering::Less => continue,
+                    Ordering::Greater => {
+                        break; // 大于则向后插入
+                    }
+                    Ordering::Equal => {
+                        if item.device_number().minor() + item.minorct() <= baseminor {
+                            continue; // 下一个主设备号大于或者次设备号大于被插入的次设备号最大值
+                        }
+                        if item.base_minor() >= baseminor + minorct {
+                            break; // 在此处插入
+                        }
+                        return Err(SystemError::EBUSY); // 存在重合的次设备号
+                    }
+                }
+            }
+            items.insert(insert_index, chardev);
+        }
+        return Ok(mkdev(major, baseminor));
+    }
+
+    /// @brief: 注销设备号
+    /// @parameter: major: 主设备号，如果为0，动态分配
+    ///             baseminor: 起始次设备号
+    ///             minorct: 次设备号数量
+    /// @return: 如果注销成功，返回()，否则，返回错误码
+    fn __unregister_chardev_region(
+        device_number: DeviceNumber,
+        minorct: usize,
+    ) -> Result<(), SystemError> {
+        if let Some(items) = CHARDEVS
+            .0
+            .lock()
+            .0
+            .get_mut(Self::major_to_index(device_number.major()))
+        {
+            for (index, item) in items.iter().enumerate() {
+                if item.device_number() == device_number && item.minorct() == minorct {
+                    // 设备号和数量都相等
+                    items.remove(index);
+                    return Ok(());
+                }
+            }
+        }
+        return Err(SystemError::EBUSY);
+    }
+
+    /// @brief: 字符设备注册
+    /// @parameter: cdev: 字符设备实例
+    ///             dev_t: 字符设备号
+    ///             range: 次设备号范围
+    /// @return: none
+    #[allow(dead_code)]
+    pub fn cdev_add(cdev: Arc<dyn CharDevice>, dev_t: DeviceNumber, range: usize) {
+        if Into::<usize>::into(dev_t) == 0 {
+            kerror!("Device number can't be 0!\n");
+        }
+        kobj_map(CDEVMAP.clone(), dev_t, range, cdev);
+    }
+
+    /// @brief: 字符设备注销
+    /// @parameter: dev_t: 字符设备号
+    ///             range: 次设备号范围
+    /// @return: none
+    #[allow(dead_code)]
+    pub fn cdev_del(dev_t: DeviceNumber, range: usize) {
+        kobj_unmap(CDEVMAP.clone(), dev_t, range);
+    }
+}