saymrwulf/xous-core
1
0
Fork 0
mirror of https://github.com/saymrwulf/xous-core.git synced 2026-11-08 04:56:43 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

un-use the P bit in the page table

Browse source 
prep for re-allocating it to swap
This commit is contained in:
bunnie 2024-03-07 22:22:51 +08:00
parent 5c3edef519
commit a1cffed9cd
1 changed files with 3 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
kernel/src/arch/riscv/mem.rs
View file

@ -52,7 +52,7 @@ bitflags! {
const A = 0b00_0100_0000;
const D = 0b00_1000_0000;
const S = 0b01_0000_0000; // Shared page
const P = 0b10_0000_0000; // Previously writable
const P = 0b10_0000_0000; // swaP
}
}
@ -821,11 +821,8 @@ pub fn return_page_inner(
panic!("page wasn't shared in destination space");
}
// Clear the `SHARED` and `PREVIOUSLY-WRITABLE` bits, and set the `VALID` bit.
unsafe {
dest_entry
.write_volatile(dest_entry_value & !(MMUFlags::S | MMUFlags::P).bits() | MMUFlags::VALID.bits())
};
// Clear the `SHARED` bit, and set the `VALID` bit.
unsafe { dest_entry.write_volatile(dest_entry_value & !(MMUFlags::S).bits() | MMUFlags::VALID.bits()) };
unsafe { flush_mmu() };
// Swap back to our previous address space