You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
111 lines
4.0 KiB
111 lines
4.0 KiB
use super::{Page, ENTRY_COUNT, EntryFlags};
|
|
use super::table::{self, Table, Level4, Level1};
|
|
use memory::*;
|
|
use core::ptr::Unique;
|
|
|
|
pub struct Mapper {
|
|
p4: Unique<Table<Level4>>,
|
|
}
|
|
|
|
impl Mapper {
|
|
pub unsafe fn new() -> Mapper {
|
|
Mapper {
|
|
p4: Unique::new_unchecked(table::P4),
|
|
}
|
|
}
|
|
|
|
pub fn p4(&self) -> &Table<Level4> {
|
|
unsafe { self.p4.as_ref() }
|
|
}
|
|
|
|
pub fn p4_mut(&mut self) -> &mut Table<Level4> {
|
|
unsafe { self.p4.as_mut() }
|
|
}
|
|
|
|
pub fn translate(&self, virtual_address: VirtAddr) -> Option<PhysAddr> {
|
|
let offset = virtual_address % PAGE_SIZE;
|
|
self.translate_page(Page::of_addr(virtual_address))
|
|
.map(|frame| PhysAddr((frame.start_address().get() + offset) as u64))
|
|
}
|
|
|
|
pub fn translate_page(&self, page: Page) -> Option<Frame> {
|
|
let p3 = self.p4().next_table(page.p4_index());
|
|
|
|
let huge_page = || {
|
|
p3.and_then(|p3| {
|
|
let p3_entry = &p3[page.p3_index()];
|
|
// 1GiB page?
|
|
if let Some(start_frame) = p3_entry.pointed_frame() {
|
|
if p3_entry.flags().contains(EntryFlags::HUGE_PAGE) {
|
|
// address must be 1GiB aligned
|
|
assert_eq!(start_frame.start_address().get() % (ENTRY_COUNT * ENTRY_COUNT * PAGE_SIZE), 0);
|
|
return Some(Frame::of_addr(
|
|
start_frame.start_address().get() +
|
|
(page.p2_index() * ENTRY_COUNT + page.p1_index()) * PAGE_SIZE
|
|
));
|
|
}
|
|
}
|
|
if let Some(p2) = p3.next_table(page.p3_index()) {
|
|
let p2_entry = &p2[page.p2_index()];
|
|
// 2MiB page?
|
|
if let Some(start_frame) = p2_entry.pointed_frame() {
|
|
if p2_entry.flags().contains(EntryFlags::HUGE_PAGE) {
|
|
// address must be 2MiB aligned
|
|
assert_eq!(start_frame.start_address().get() % ENTRY_COUNT, 0);
|
|
return Some(Frame::of_addr(
|
|
start_frame.start_address().get() + page.p1_index() * PAGE_SIZE
|
|
));
|
|
}
|
|
}
|
|
}
|
|
None
|
|
})
|
|
};
|
|
|
|
p3.and_then(|p3| p3.next_table(page.p3_index()))
|
|
.and_then(|p2| p2.next_table(page.p2_index()))
|
|
.and_then(|p1| p1[page.p1_index()].pointed_frame())
|
|
.or_else(huge_page)
|
|
}
|
|
|
|
pub fn map_to(&mut self, page: Page, frame: Frame, flags: EntryFlags)
|
|
{
|
|
let p4 = self.p4_mut();
|
|
let mut p3 = p4.next_table_create(page.p4_index());
|
|
let mut p2 = p3.next_table_create(page.p3_index());
|
|
let mut p1 = p2.next_table_create(page.p2_index());
|
|
|
|
assert!(p1[page.p1_index()].is_unused());
|
|
// TODO: Remove USER_ACCESSIBLE
|
|
p1[page.p1_index()].set(frame, flags | EntryFlags::PRESENT | EntryFlags::USER_ACCESSIBLE);
|
|
}
|
|
|
|
pub fn map(&mut self, page: Page, flags: EntryFlags)
|
|
{
|
|
self.map_to(page, alloc_frame(), flags)
|
|
}
|
|
|
|
pub fn identity_map(&mut self, frame: Frame, flags: EntryFlags)
|
|
{
|
|
let page = Page::of_addr(frame.start_address().to_identity_virtual());
|
|
self.map_to(page, frame, flags)
|
|
}
|
|
|
|
pub fn unmap(&mut self, page: Page)
|
|
{
|
|
use x86_64::instructions::tlb;
|
|
use x86_64::VirtualAddress;
|
|
|
|
assert!(self.translate(page.start_address()).is_some());
|
|
|
|
let p1 = self.p4_mut()
|
|
.next_table_mut(page.p4_index())
|
|
.and_then(|p3| p3.next_table_mut(page.p3_index()))
|
|
.and_then(|p2| p2.next_table_mut(page.p2_index()))
|
|
.expect("mapping code does not support huge pages");
|
|
let frame = p1[page.p1_index()].pointed_frame().unwrap();
|
|
p1[page.p1_index()].set_unused();
|
|
tlb::flush(VirtualAddress(page.start_address()));
|
|
// TODO free p(1,2,3) table if empty
|
|
}
|
|
} |