redox/kernel/context/memory.rs
2016-09-11 21:35:02 -06:00

120 lines
3.7 KiB
Rust

use arch::paging::{ActivePageTable, Page, PageIter, VirtualAddress};
use arch::paging::entry::EntryFlags;
#[derive(Debug)]
pub struct Memory {
start: VirtualAddress,
size: usize,
flags: EntryFlags
}
impl Memory {
pub fn new(start: VirtualAddress, size: usize, flags: EntryFlags) -> Self {
let mut memory = Memory {
start: start,
size: size,
flags: flags
};
memory.map(true);
memory
}
pub fn start_address(&self) -> VirtualAddress {
self.start
}
pub fn size(&self) -> usize {
self.size
}
pub fn pages(&self) -> PageIter {
let start_page = Page::containing_address(self.start);
let end_page = Page::containing_address(VirtualAddress::new(self.start.get() + self.size - 1));
Page::range_inclusive(start_page, end_page)
}
pub fn map(&mut self, flush: bool) {
let mut active_table = unsafe { ActivePageTable::new() };
//TODO: Clear pages?
for page in self.pages() {
active_table.map(page, self.flags);
if flush {
active_table.flush(page);
}
}
}
pub fn unmap(&mut self, flush: bool) {
let mut active_table = unsafe { ActivePageTable::new() };
for page in self.pages() {
active_table.unmap(page);
if flush {
active_table.flush(page);
}
}
}
pub fn remap(&mut self, new_flags: EntryFlags, flush: bool) {
let mut active_table = unsafe { ActivePageTable::new() };
for page in self.pages() {
active_table.remap(page, new_flags);
if flush {
active_table.flush(page);
}
}
self.flags = new_flags;
}
pub fn resize(&mut self, new_size: usize, flush: bool) {
let mut active_table = unsafe { ActivePageTable::new() };
//TODO: Clear pages?
//TODO: Calculate page changes to minimize operations
if new_size > self.size {
let start_page = Page::containing_address(VirtualAddress::new(self.start.get() + self.size));
let end_page = Page::containing_address(VirtualAddress::new(self.start.get() + new_size - 1));
for page in Page::range_inclusive(start_page, end_page) {
//println!("Map {:X}", page.start_address().get());
if active_table.translate_page(page).is_none() {
//println!("Not found - mapping");
active_table.map(page, self.flags);
if flush {
active_table.flush(page);
}
} else {
//println!("Found - skipping {:X}", page.start_address().get());
}
}
} else if new_size < self.size {
let start_page = Page::containing_address(VirtualAddress::new(self.start.get() + new_size));
let end_page = Page::containing_address(VirtualAddress::new(self.start.get() + self.size - 1));
for page in Page::range_inclusive(start_page, end_page) {
//println!("Unmap {:X}", page.start_address().get());
if active_table.translate_page(page).is_some() {
//println!("Found - unmapping");
active_table.unmap(page);
if flush {
active_table.flush(page);
}
} else {
//println!("Not found - skipping {:X}", page.start_address().get());
}
}
}
self.size = new_size;
}
}
impl Drop for Memory {
fn drop(&mut self) {
self.unmap(true);
}
}