From 15c9f43622e40fac8797df33c2caa703a5ffb14f Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Thu, 13 Apr 2017 19:24:20 +0200
Subject: [PATCH] Add an (unfinished) `unmap` method
---
src/memory/paging/mod.rs | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/src/memory/paging/mod.rs b/src/memory/paging/mod.rs
index 55e4825..a19264e 100644
--- a/src/memory/paging/mod.rs
+++ b/src/memory/paging/mod.rs
@@ -134,4 +134,20 @@ impl ActivePageTable {
let page = Page::containing_address(frame.start_address());
self.map_to(page, frame, flags, allocator)
}
+
+ fn unmap<A>(&mut self, page: Page, allocator: &mut A)
+ where A: FrameAllocator
+ {
+ 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();
+ // TODO free p(1,2,3) table if empty
+ allocator.deallocate_frame(frame);
+ }
}