使用Rust重构CFS调度器 (#131)

* 新建调度器的文件

* 把softirq vector移动到c文件中（原来在.h)

* 将进程切换方式改为“中断返回时切换”

* new:使用rust重构CFS

* 删除已经在smp中废弃的HPET中断转发函数

* 代码格式化

* 删除多余的dunce依赖

kernel/src/arch/x86_64/Makefile

@@ -18,5 +18,6 @@ $(kernel_arch_x86_64_subdirs): ECHO
 all: $(kernel_arch_x86_64_objs) $(kernel_arch_x86_64_subdirs)
 
 
+
 clean:
 	echo "Done."

kernel/src/arch/x86_64/context.rs

@@ -0,0 +1,19 @@
+use crate::include::bindings::bindings::{process_control_block, switch_proc};
+
+use core::sync::atomic::compiler_fence;
+
+/// @brief 切换进程的上下文（没有切换页表的动作）
+///
+/// @param next 下一个进程的pcb
+/// @param trap_frame 中断上下文的栈帧
+#[inline(always)]
+pub fn switch_process(
+    prev: &'static mut process_control_block,
+    next: &'static mut process_control_block,
+) {
+    compiler_fence(core::sync::atomic::Ordering::SeqCst);
+    unsafe {
+        switch_proc(prev, next);
+    }
+    compiler_fence(core::sync::atomic::Ordering::SeqCst);
+}

kernel/src/arch/x86_64/mm/barrier.rs

@@ -0,0 +1,23 @@
+#![allow(dead_code)]
+use core::arch::asm;
+
+#[inline(always)]
+pub fn mfence(){
+    unsafe{
+        asm!("mfence");
+    }
+}
+
+#[inline(always)]
+pub fn lfence(){
+    unsafe{
+        asm!("lfence");
+    }
+}
+
+#[inline(always)]
+pub fn sfence(){
+    unsafe{
+        asm!("sfence");
+    }
+}

kernel/src/arch/x86_64/mm/mod.rs

@@ -0,0 +1,28 @@
+pub mod barrier;
+use crate::include::bindings::bindings::process_control_block;
+
+use core::arch::asm;
+use core::ptr::read_volatile;
+
+use self::barrier::mfence;
+
+/// @brief 切换进程的页表
+///
+/// @param 下一个进程的pcb。将会把它的页表切换进来。
+///
+/// @return 下一个进程的pcb(把它return的目的主要是为了归还所有权)
+#[inline(always)]
+#[allow(dead_code)]
+pub fn switch_mm(
+    next_pcb: &'static mut process_control_block,
+) -> &'static mut process_control_block {
+    mfence();
+    // kdebug!("to get pml4t");
+    let pml4t = unsafe { read_volatile(&next_pcb.mm.as_ref().unwrap().pgd) };
+    
+    unsafe {
+        asm!("mov cr3, {}", in(reg) pml4t);
+    }
+    mfence();
+    return next_pcb;
+}

kernel/src/arch/x86_64/mod.rs

@@ -1,4 +1,7 @@
 #[macro_use]
 pub mod asm;
 pub mod cpu;
-pub mod interrupt;
+pub mod interrupt;
+pub mod mm;
+pub mod context;
+pub mod sched;

kernel/src/arch/x86_64/sched.rs

@@ -0,0 +1,10 @@
+use crate::include::bindings::bindings::{enter_syscall_int, SYS_SCHED};
+
+/// @brief 若内核代码不处在中断上下文中，那么将可以使用本函数，发起一个sys_sched系统调用，然后运行调度器。
+/// 由于只能在中断上下文中进行进程切换，因此需要发起一个系统调用SYS_SCHED。
+#[no_mangle]
+pub extern "C" fn sched() {
+    unsafe {
+        enter_syscall_int(SYS_SCHED.into(), 0, 0, 0, 0, 0, 0, 0, 0);
+    }
+}