Merged PR #87

os/src/drivers/bus/mod.rs

@@ -0,0 +1 @@
+pub mod virtio;

os/src/drivers/bus/virtio.rs

@@ -0,0 +1,52 @@
+use alloc::vec::Vec;
+use crate::mm::{
+    frame_alloc, frame_dealloc, kernel_token, FrameTracker, PageTable, PhysAddr, PhysPageNum,
+    StepByOne, VirtAddr,
+};
+use crate::sync::UPIntrFreeCell;
+use lazy_static::*;
+use virtio_drivers::Hal;
+
+lazy_static! {
+    static ref QUEUE_FRAMES: UPIntrFreeCell<Vec<FrameTracker>> =
+        unsafe { UPIntrFreeCell::new(Vec::new()) };
+}
+
+pub struct VirtioHal;
+
+impl Hal for VirtioHal {
+    fn dma_alloc(pages: usize) -> usize {
+        let mut ppn_base = PhysPageNum(0);
+        for i in 0..pages {
+            let frame = frame_alloc().unwrap();
+            if i == 0 {
+                ppn_base = frame.ppn;
+            }
+            assert_eq!(frame.ppn.0, ppn_base.0 + i);
+            QUEUE_FRAMES.exclusive_access().push(frame);
+        }
+        let pa: PhysAddr = ppn_base.into();
+        pa.0
+    }
+
+    fn dma_dealloc(pa: usize, pages: usize) -> i32 {
+        let pa = PhysAddr::from(pa);
+        let mut ppn_base: PhysPageNum = pa.into();
+        for _ in 0..pages {
+            frame_dealloc(ppn_base);
+            ppn_base.step();
+        }
+        0
+    }
+
+    fn phys_to_virt(addr: usize) -> usize {
+        addr
+    }
+
+    fn virt_to_phys(vaddr: usize) -> usize {
+        PageTable::from_token(kernel_token())
+            .translate_va(VirtAddr::from(vaddr))
+            .unwrap()
+            .0
+    }
+}