增加x87FPU支持 (#212)

* remove `ret_from_syscall`
*修复ps2键盘驱动程序inode在进程fork的时候导致死锁的问题.
*更新: VFS每次拷贝文件描述符的时候,都会去调用inode的open函数

---------

Co-authored-by: longjin <longjin@RinGoTek.cn>

kernel/src/driver/keyboard/ps2_keyboard.rs

@@ -1,3 +1,5 @@
+use core::sync::atomic::AtomicI32;
+
 use alloc::sync::{Arc, Weak};
 
 use crate::{
@@ -6,13 +8,12 @@ use crate::{
         vfs::{core::generate_inode_id, file::FileMode, FileType, IndexNode, Metadata, PollStatus},
     },
     include::bindings::bindings::{vfs_file_operations_t, vfs_file_t, vfs_index_node_t, ENOTSUP},
-    kdebug,
-    libs::spinlock::SpinLock,
+    libs::rwlock::RwLock,
     time::TimeSpec,
 };
 
 #[derive(Debug)]
-pub struct LockedPS2KeyBoardInode(SpinLock<PS2KeyBoardInode>);
+pub struct LockedPS2KeyBoardInode(RwLock<PS2KeyBoardInode>, AtomicI32); // self.1 用来记录有多少个文件打开了这个inode
 
 #[derive(Debug)]
 pub struct PS2KeyBoardInode {
@@ -53,8 +54,11 @@ impl LockedPS2KeyBoardInode {
             },
         };
 
-        let result = Arc::new(LockedPS2KeyBoardInode(SpinLock::new(inode)));
-        result.0.lock().self_ref = Arc::downgrade(&result);
+        let result = Arc::new(LockedPS2KeyBoardInode(
+            RwLock::new(inode),
+            AtomicI32::new(0),
+        ));
+        result.0.write().self_ref = Arc::downgrade(&result);
 
         return result;
     }
@@ -62,7 +66,7 @@ impl LockedPS2KeyBoardInode {
 
 impl DeviceINode for LockedPS2KeyBoardInode {
     fn set_fs(&self, fs: Weak<DevFS>) {
-        self.0.lock().fs = fs;
+        self.0.write().fs = fs;
     }
 }
 
@@ -80,7 +84,7 @@ impl IndexNode for LockedPS2KeyBoardInode {
         buf: &mut [u8],
         _data: &mut crate::filesystem::vfs::FilePrivateData,
     ) -> Result<usize, i32> {
-        let guard = self.0.lock();
+        let guard = self.0.read();
         let func = guard.f_ops.read.unwrap();
         let r = unsafe {
             func(
@@ -108,16 +112,24 @@ impl IndexNode for LockedPS2KeyBoardInode {
         _data: &mut crate::filesystem::vfs::FilePrivateData,
         _mode: &FileMode,
     ) -> Result<(), i32> {
-        let guard = self.0.lock();
-        let func = guard.f_ops.open.unwrap();
-        let _ = unsafe { func(0 as *mut vfs_index_node_t, 0 as *mut vfs_file_t) };
+        let prev_ref_count = self.1.fetch_add(1, core::sync::atomic::Ordering::SeqCst);
+        if prev_ref_count == 0 {
+            // 第一次打开，需要初始化
+            let guard = self.0.write();
+            let func = guard.f_ops.open.unwrap();
+            let _ = unsafe { func(0 as *mut vfs_index_node_t, 0 as *mut vfs_file_t) };
+        }
         return Ok(());
     }
 
     fn close(&self, _data: &mut crate::filesystem::vfs::FilePrivateData) -> Result<(), i32> {
-        let guard = self.0.lock();
-        let func = guard.f_ops.close.unwrap();
-        let _ = unsafe { func(0 as *mut vfs_index_node_t, 0 as *mut vfs_file_t) };
+        let prev_ref_count = self.1.fetch_sub(1, core::sync::atomic::Ordering::SeqCst);
+        if prev_ref_count == 1 {
+            // 最后一次关闭，需要释放
+            let guard = self.0.write();
+            let func = guard.f_ops.close.unwrap();
+            let _ = unsafe { func(0 as *mut vfs_index_node_t, 0 as *mut vfs_file_t) };
+        }
         return Ok(());
     }
 
@@ -128,11 +140,11 @@ impl IndexNode for LockedPS2KeyBoardInode {
     }
 
     fn metadata(&self) -> Result<Metadata, i32> {
-        return Ok(self.0.lock().metadata.clone());
+        return Ok(self.0.read().metadata.clone());
     }
 
     fn set_metadata(&self, metadata: &Metadata) -> Result<(), i32> {
-        let mut inode = self.0.lock();
+        let mut inode = self.0.write();
         inode.metadata.atime = metadata.atime;
         inode.metadata.mtime = metadata.mtime;
         inode.metadata.ctime = metadata.ctime;
@@ -144,7 +156,7 @@ impl IndexNode for LockedPS2KeyBoardInode {
     }
 
     fn fs(&self) -> alloc::sync::Arc<dyn crate::filesystem::vfs::FileSystem> {
-        return self.0.lock().fs.upgrade().unwrap();
+        return self.0.read().fs.upgrade().unwrap();
     }
 
     fn as_any_ref(&self) -> &dyn core::any::Any {