1#![allow(clippy::missing_safety_doc)]
2
3#[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd)]
4pub struct PhysicalAddress(pub usize);
5
6#[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd)]
7pub struct VirtualAddress(pub usize);
8
9pub trait Mapper {
10 unsafe fn map_aligned(&mut self, address: PhysicalAddress, size: usize) -> Result<VirtualAddress, &'static str>;
11 unsafe fn unmap_aligned(&mut self, address: VirtualAddress, size: usize) -> Result<(), &'static str>;
12 fn page_size(&self) -> usize;
13
14 unsafe fn map(&mut self, address: PhysicalAddress, size: usize) -> Result<VirtualAddress, &'static str> {
15 let page_size = self.page_size();
16 let page = address.0/page_size;
17 let aligned_address = PhysicalAddress(page * page_size);
18 let offset = address.0 - aligned_address.0;
19 let pages = (offset + size + page_size - 1) / page_size;
20 let aligned_size = pages * page_size;
21 let virtual_address = self.map_aligned(aligned_address, aligned_size)?;
22 Ok(VirtualAddress(virtual_address.0 + offset))
23 }
24
25 unsafe fn unmap(&mut self, address: VirtualAddress, size: usize) -> Result<(), &'static str> {
26 let page_size = self.page_size();
27 let page = address.0/page_size;
28 let aligned_address = VirtualAddress(page * page_size);
29 let offset = address.0 - aligned_address.0;
30 let pages = (offset + size + page_size - 1) / page_size;
31 let aligned_size = pages * page_size;
32 self.unmap_aligned(aligned_address, aligned_size)
33 }
34}