Skip to content

Only perform a single TLB flush after identity mapping #265

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Sep 25, 2022
Merged

Only perform a single TLB flush after identity mapping #265

Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
14c63aa
Only perform a single TLB flush after identity mapping
hawkw Sep 23, 2022
3bb5b8e
Merge branch 'main' into eliza/flush-all
phil-opp Sep 25, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 11 additions & 2 deletions src/bin/bios.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -117,19 +117,28 @@ fn bootloader_main(
PhysFrame::containing_address(PhysAddr::new(GIGABYTE));
let end_frame = PhysFrame::containing_address(PhysAddr::new(max_phys_addr - 1));
for frame in PhysFrame::range_inclusive(start_frame, end_frame) {
unsafe {
let flusher = unsafe {
bootloader_page_table
.identity_map(
frame,
PageTableFlags::PRESENT | PageTableFlags::WRITABLE,
&mut frame_allocator,
)
.unwrap()
.flush()
};
// skip flushing the entry from the TLB for now, as we will
// flush the entire TLB at the end of the loop.
flusher.ignore();
}
}

// once all the physical memory is mapped, flush the TLB by reloading the
// CR3 register.
//
// we perform a single flush here rather than flushing each individual entry as
// it's mapped using `invlpg`, for efficiency.
x86_64::instructions::tlb::flush_all();

let framebuffer_addr = PhysAddr::new(unsafe { VBEModeInfo_physbaseptr }.into());
let mut error = None;
let framebuffer_info = unsafe {
Expand Down