Implement TLB maintenance
Invalidate TLB entries after changing descriptor to invalid and
implement break-before-make sequence when changing translation table
entries.
Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I8e384de306c185315a1d189c01ff275ac646d539
diff --git a/src/descriptor.rs b/src/descriptor.rs
index bf10380..24ed8df 100644
--- a/src/descriptor.rs
+++ b/src/descriptor.rs
@@ -202,9 +202,17 @@
self.set(Self::INVALID_DESCRIPTOR_VALUE)
}
+ /// Set block or invalid descriptor to invalid
+ pub fn set_block_or_invalid_descriptor_to_invalid(&mut self, level: usize) {
+ assert!(level <= 3);
+ assert!(DescriptorType::Table != self.get_descriptor_type(level));
+
+ self.set(Self::INVALID_DESCRIPTOR_VALUE)
+ }
+
/// Set table descriptor
///
- /// **Unsafe**: The caller has to ensure that the passed next level table has the same life as
+ /// Safety: The caller has to ensure that the passed next level table has the same life as
/// the descriptor.
pub unsafe fn set_table_descriptor(
&mut self,
@@ -232,7 +240,7 @@
/// Get next level table
///
- /// **Unsafe**: The returned next level table is based on the address read from the descriptor.
+ /// Safety: The returned next level table is based on the address read from the descriptor.
/// The caller has to ensure that no other references are being used of the table.
pub unsafe fn get_next_level_table(&self, level: usize) -> &[Descriptor] {
assert!(level <= 2);
@@ -245,7 +253,7 @@
/// Get mutable next level table
///
- /// **Unsafe**: The returned next level table is based on the address read from the descriptor.
+ /// Safety: The returned next level table is based on the address read from the descriptor.
/// The caller has to ensure that no other references are being used of the table.
pub unsafe fn get_next_level_table_mut(&mut self, level: usize) -> &mut [Descriptor] {
assert!(level <= 2);
@@ -285,7 +293,13 @@
/// Set raw descriptor value
fn set(&mut self, value: u64) {
- unsafe { ptr::write_volatile(self.cell.get(), value) }
+ // Safety: The cell should point to a valid address and the assembly code is just a data
+ // barrier.
+ unsafe {
+ ptr::write_volatile(self.cell.get(), value);
+ #[cfg(target_arch = "aarch64")]
+ core::arch::asm!("dsb nsh");
+ }
}
/// Modify raw descriptor value
@@ -556,6 +570,23 @@
}
#[test]
+ fn test_descriptor_block_or_invalid_block_to_invalid() {
+ let mut descriptor = Descriptor {
+ cell: UnsafeCell::new(0),
+ };
+
+ descriptor.set_block_or_invalid_descriptor_to_invalid(0);
+ assert_eq!(0, descriptor.get());
+
+ let mut descriptor = Descriptor {
+ cell: UnsafeCell::new(3),
+ };
+
+ descriptor.set_block_or_invalid_descriptor_to_invalid(3);
+ assert_eq!(0, descriptor.get());
+ }
+
+ #[test]
#[should_panic]
fn test_descriptor_level3_to_table() {
let mut next_level_table = [Descriptor {