We should disable sie before trapping back to user.

os/src/boards/qemu.rs

@@ -28,31 +28,18 @@ pub fn device_init() {
         plic.enable(hart_id, supervisor, intr_src_id);
         plic.set_priority(intr_src_id, 1);
     }
-    crate::println!(
-        "Hart0M threshold = {}",
-        plic.get_threshold(hart_id, IntrTargetPriority::Machine)
-    );
-    crate::println!(
-        "Hart0S threshold = {}",
-        plic.get_threshold(hart_id, IntrTargetPriority::Supervisor)
-    );
-    crate::println!("1 prio = {}", plic.get_priority(1));
-    crate::println!("10 prio = {}", plic.get_priority(10));
     unsafe {
         sie::set_sext();
     }
 }
 
 pub fn irq_handler() {
-    //crate::println!("->irq_handler");
     let mut plic = unsafe { PLIC::new(VIRT_PLIC) };
     let intr_src_id = plic.claim(0, IntrTargetPriority::Supervisor);
-    //crate::println!("intr_src={}", intr_src_id);
     match intr_src_id {
         1 => BLOCK_DEVICE.handle_irq(),
         10 => UART.handle_irq(),
         _ => panic!("unsupported IRQ {}", intr_src_id),
     }
     plic.complete(0, IntrTargetPriority::Supervisor, intr_src_id);
-    //crate::println!("irq_handler->");
 }

os/src/console.rs

@@ -7,8 +7,8 @@ struct Stdout;
 impl Write for Stdout {
     fn write_str(&mut self, s: &str) -> fmt::Result {
         for c in s.chars() {
-            //UART.write(c as u8);
-            console_putchar(c as usize);
+            UART.write(c as u8);
+            //console_putchar(c as usize);
         }
         Ok(())
     }

os/src/drivers/block/virtio_blk.rs

@@ -28,10 +28,17 @@ impl BlockDevice for VirtIOBlock {
         let nb = *DEV_NON_BLOCKING_ACCESS.exclusive_access();
         if nb {
             let mut resp = BlkResp::default();
+            /*
             let task_cx_ptr = self.virtio_blk.exclusive_session(|blk| {
                 let token = unsafe { blk.read_block_nb(block_id, buf, &mut resp).unwrap() };
                 self.condvars.get(&token).unwrap().wait_no_sched()
             });
+            */
+            let mut blk = self.virtio_blk.exclusive_access();
+            let token = unsafe { blk.read_block_nb(block_id, buf, &mut resp).unwrap() };
+            //println!("waiting on token {}", token);
+            let task_cx_ptr = self.condvars.get(&token).unwrap().wait_no_sched();
+            drop(blk);
             schedule(task_cx_ptr);
             assert_eq!(
                 resp.status(),
@@ -49,10 +56,16 @@ impl BlockDevice for VirtIOBlock {
         let nb = *DEV_NON_BLOCKING_ACCESS.exclusive_access();
         if nb {
             let mut resp = BlkResp::default();
+            /*
             let task_cx_ptr = self.virtio_blk.exclusive_session(|blk| {
                 let token = unsafe { blk.write_block_nb(block_id, buf, &mut resp).unwrap() };
                 self.condvars.get(&token).unwrap().wait_no_sched()
             });
+            */
+            let mut blk = self.virtio_blk.exclusive_access();
+            let token = unsafe { blk.write_block_nb(block_id, buf, &mut resp).unwrap() };
+            let task_cx_ptr = self.condvars.get(&token).unwrap().wait_no_sched();
+            drop(blk);
             schedule(task_cx_ptr);
             assert_eq!(
                 resp.status(),
@@ -68,6 +81,7 @@ impl BlockDevice for VirtIOBlock {
     }
     fn handle_irq(&self) {
         //println!("into handle_irq");
+        /*
         self.virtio_blk.exclusive_session(|blk| {
             //println!("not panic here");
             while let Ok(token) = blk.pop_used() {
@@ -75,6 +89,12 @@ impl BlockDevice for VirtIOBlock {
                 self.condvars.get(&token).unwrap().signal();
             }
         });
+        */
+        let mut blk = self.virtio_blk.exclusive_access();
+        while let Ok(token) = blk.pop_used() {
+            //println!("wakeup virtio.token {}", token);
+            self.condvars.get(&token).unwrap().signal();
+        }
     }
 }
 

os/src/drivers/chardev/ns16550a.rs

@@ -146,15 +146,15 @@ impl<const BASE_ADDR: usize> NS16550a<BASE_ADDR> {
 
 impl<const BASE_ADDR: usize> CharDevice for NS16550a<BASE_ADDR> {
     fn read(&self) -> u8 {
-        println!("NS16550a::read");
+        //println!("NS16550a::read");
         loop {
             let mut inner = self.inner.exclusive_access();
             if let Some(ch) = inner.read_buffer.pop_front() {
                 return ch;
             } else {
-                println!("no ch yet!");
                 let task_cx_ptr = self.condvar.wait_no_sched();
                 drop(inner);
+                //println!("before scheduling");
                 schedule(task_cx_ptr);
             }
         }
@@ -167,7 +167,7 @@ impl<const BASE_ADDR: usize> CharDevice for NS16550a<BASE_ADDR> {
         let mut inner = self.inner.exclusive_access();
         let mut count = 0;
         while let Some(ch) = inner.ns16550a.read() {
-            println!("got {}", ch as char);
+            //println!("got {}", ch as char);
             count += 1;
             inner.read_buffer.push_back(ch);
         }

os/src/fs/stdio.rs

@@ -14,7 +14,7 @@ impl File for Stdin {
     }
     fn read(&self, mut user_buf: UserBuffer) -> usize {
         assert_eq!(user_buf.len(), 1);
-        println!("before UART.read() in Stdin::read()");
+        //println!("before UART.read() in Stdin::read()");
         let ch = UART.read();
         unsafe {
             user_buf.buffers[0].as_mut_ptr().write_volatile(ch);

os/src/sync/condvar.rs

@@ -36,9 +36,14 @@ impl Condvar {
     }
 
     pub fn wait_no_sched(&self) -> *mut TaskContext {
+        /*
         self.inner.exclusive_session(|inner| {
             inner.wait_queue.push_back(current_task().unwrap());
         });
+        */
+        let mut inner = self.inner.exclusive_access();
+        inner.wait_queue.push_back(current_task().unwrap());
+        drop(inner);
         block_current_task()
     }
 

os/src/sync/up.rs

@@ -3,6 +3,7 @@ use core::ops::{Deref, DerefMut};
 use riscv::register::sstatus;
 use lazy_static::*;
 
+/*
 /// Wrap a static data structure inside it so that we are
 /// able to access it without any `unsafe`.
 ///
@@ -30,6 +31,7 @@ impl<T> UPSafeCell<T> {
         self.inner.borrow_mut()
     }
 }
+*/
 
 pub struct UPSafeCellRaw<T> {
     inner: UnsafeCell<T>,
@@ -105,10 +107,12 @@ impl<T> UPIntrFreeCell<T> {
         UPIntrRefMut(Some(self.inner.borrow_mut()))
     }
 
+    /*
     pub fn exclusive_session<F, V>(&self, f: F) -> V where F: FnOnce(&mut T) -> V {
         let mut inner = self.exclusive_access();
         f(inner.deref_mut())
     }
+    */
 }
 
 impl<'a, T> Drop for UPIntrRefMut<'a, T> {

os/src/trap/mod.rs

@@ -50,6 +50,12 @@ fn enable_supervisor_interrupt() {
     }
 }
 
+fn disable_supervisor_interrupt() {
+    unsafe {
+        sstatus::clear_sie(); 
+    }
+}
+
 #[no_mangle]
 pub fn trap_handler() -> ! {
     set_kernel_trap_entry();
@@ -62,8 +68,6 @@ pub fn trap_handler() -> ! {
             let mut cx = current_trap_cx();
             cx.sepc += 4;
             
-            //println!("syscall id={}", cx.x[17]);
-            //println!("after setting sstatus.sie");
             enable_supervisor_interrupt();
 
             // get system call return value
@@ -117,6 +121,7 @@ pub fn trap_handler() -> ! {
 
 #[no_mangle]
 pub fn trap_return() -> ! {
+    disable_supervisor_interrupt();
     set_user_trap_entry();
     let trap_cx_user_va = current_trap_cx_user_va();
     let user_satp = current_user_token();
@@ -139,17 +144,7 @@ pub fn trap_return() -> ! {
 }
 
 #[no_mangle]
-pub fn trap_from_kernel(trap_cx: &TrapContext) {
-    /*
-    use riscv::register::sepc;
-    println!("a trap {:?} from kernel!", scause::read().cause());
-    println!("stval = {:#x}, sepc = {:#x}", stval::read(), sepc::read());
-    //panic!("a trap {:?} from kernel!", scause::read().cause());
-    */
-    //panic!("a trap {:?} from kernel!", scause::read().cause());
-    //println!("->trap_from_kernel");
-    //println!("a trap {:?} from kernel!", scause::read().cause());
-    //println!("sepc = {:#x}", trap_cx.sepc);
+pub fn trap_from_kernel(_trap_cx: &TrapContext) {
     let scause = scause::read();
     let stval = stval::read();
     match scause.cause() {
@@ -169,7 +164,6 @@ pub fn trap_from_kernel(trap_cx: &TrapContext) {
             );
         },
     }
-    //println!("trap_from_kernel->");
 }
 
 pub use context::TrapContext;