Extend Sv39PageTable/Sv48PageTable to support nested page tables al…

…so (#7)

* extend sv pagetables to support nested page tables also

* simplify code

* remove a mis-commited file

page_table_multiarch/src/arch/riscv.rs

@@ -14,38 +14,55 @@ fn riscv_flush_tlb(vaddr: Option<memory_addr::VirtAddr>) {
     }
 }
 
+/// A virtual address that can be used in RISC-V Sv39 and Sv48 page tables.
+pub trait SvVirtAddr: memory_addr::MemoryAddr + Send + Sync {
+    /// Flush the TLB.
+    fn flush_tlb(vaddr: Option<Self>);
+}
+
+impl SvVirtAddr for memory_addr::VirtAddr {
+    #[inline]
+    fn flush_tlb(vaddr: Option<Self>) {
+        riscv_flush_tlb(vaddr.map(|vaddr| vaddr.into()))
+    }
+}
+
 /// Metadata of RISC-V Sv39 page tables.
-pub struct Sv39MetaData;
+pub struct Sv39MetaData<VA: SvVirtAddr> {
+    _virt_addr: core::marker::PhantomData<VA>,
+}
 
 /// Metadata of RISC-V Sv48 page tables.
-pub struct Sv48MetaData;
+pub struct Sv48MetaData<VA: SvVirtAddr> {
+    _virt_addr: core::marker::PhantomData<VA>,
+}
 
-impl PagingMetaData for Sv39MetaData {
+impl<VA: SvVirtAddr> PagingMetaData for Sv39MetaData<VA> {
     const LEVELS: usize = 3;
     const PA_MAX_BITS: usize = 56;
     const VA_MAX_BITS: usize = 39;
-    type VirtAddr = memory_addr::VirtAddr;
+    type VirtAddr = VA;
 
     #[inline]
-    fn flush_tlb(vaddr: Option<memory_addr::VirtAddr>) {
-        riscv_flush_tlb(vaddr)
+    fn flush_tlb(vaddr: Option<VA>) {
+        <VA as SvVirtAddr>::flush_tlb(vaddr);
     }
 }
 
-impl PagingMetaData for Sv48MetaData {
+impl<VA: SvVirtAddr> PagingMetaData for Sv48MetaData<VA> {
     const LEVELS: usize = 4;
     const PA_MAX_BITS: usize = 56;
     const VA_MAX_BITS: usize = 48;
-    type VirtAddr = memory_addr::VirtAddr;
+    type VirtAddr = VA;
 
     #[inline]
-    fn flush_tlb(vaddr: Option<memory_addr::VirtAddr>) {
-        riscv_flush_tlb(vaddr)
+    fn flush_tlb(vaddr: Option<VA>) {
+        <VA as SvVirtAddr>::flush_tlb(vaddr);
     }
 }
 
 /// Sv39: Page-Based 39-bit (3 levels) Virtual-Memory System.
-pub type Sv39PageTable<H> = PageTable64<Sv39MetaData, Rv64PTE, H>;
+pub type Sv39PageTable<H> = PageTable64<Sv39MetaData<memory_addr::VirtAddr>, Rv64PTE, H>;
 
 /// Sv48: Page-Based 48-bit (4 levels) Virtual-Memory System.
-pub type Sv48PageTable<H> = PageTable64<Sv48MetaData, Rv64PTE, H>;
+pub type Sv48PageTable<H> = PageTable64<Sv48MetaData<memory_addr::VirtAddr>, Rv64PTE, H>;