create helper function to get next page table

anubis-rs · Jan 25, 2024 · 32d3d85 · 32d3d85
1 parent fc6b265
commit 32d3d85
Showing 1 changed file with 8 additions and 4 deletions.
diff --git a/xernel/kernel/src/mem/paging.rs b/xernel/kernel/src/mem/paging.rs
@@ -9,7 +9,7 @@ use limine::KernelAddressRequest;
 use x86_64::{
     align_down,
     registers::control::{Cr3, Cr3Flags},
-    structures::paging::{Page, PageSize, Size1GiB, Size2MiB, Size4KiB},
+    structures::paging::{Page, PageSize, PageTableIndex, Size1GiB, Size2MiB, Size4KiB},
 };
 use x86_64::{
     structures::paging::{PageTable, PageTableFlags, PhysFrame},
@@ -294,6 +294,10 @@ impl Pagemap {
         }
     }
 
+    unsafe fn get_next_pt(pt: *mut PageTable, pt_index: PageTableIndex) -> *mut PageTable {
+        (*pt)[pt_index].addr().as_u64() as *mut PageTable
+    }
+
     /// Only works with 4KiB pages
     pub fn translate(&self, virt: VirtAddr) -> Option<PhysAddr> {
         let pml4 = self.page_table;
@@ -303,19 +307,19 @@ impl Pagemap {
                 return None;
             }
 
-            let pml3 = (*pml4)[virt.p4_index()].addr().as_u64() as *mut PageTable;
+            let pml3 = Self::get_next_pt(pml4, virt.p4_index());
 
             if !(*pml3)[virt.p3_index()].flags().contains(PageTableFlags::PRESENT) {
                 return None;
             }
 
-            let pml2 = (*pml3)[virt.p3_index()].addr().as_u64() as *mut PageTable;
+            let pml2 = Self::get_next_pt(pml3, virt.p3_index());
 
             if !(*pml2)[virt.p2_index()].flags().contains(PageTableFlags::PRESENT) {
                 return None;
             }
 
-            let pml1 = (*pml2)[virt.p2_index()].addr().as_u64() as *mut PageTable;
+            let pml1 = Self::get_next_pt(pml2, virt.p2_index());
 
             if !(*pml1)[virt.p1_index()].flags().contains(PageTableFlags::PRESENT) {
                 return None;