Mem: Fix issues with page tables and impl invlpg

corigan01 · Jan 20, 2025 · fd33038 · fd33038
1 parent 8d90a45
commit fd33038
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Showing 4 changed files with 56 additions and 30 deletions.
diff --git a/crates/mem/src/addr.rs b/crates/mem/src/addr.rs
@@ -186,6 +186,7 @@ macro_rules! make_addr {
 
         impl<A: AlignmentTo> $ident<A> {
             /// Force a value as an addr.
+            #[inline]
             pub const unsafe fn new_unchecked(value: usize) -> Self {
                Self {
                   addr: value,

diff --git a/crates/mem/src/page.rs b/crates/mem/src/page.rs
@@ -213,6 +213,7 @@ impl<S: PagingStructureSize> VirtPage<S> {
     }
 
     /// Get the address that this page represents.
+    #[inline]
     pub const fn addr(&self) -> VirtAddr {
         // We know this is safe because we are of this alignment
         unsafe { VirtAddr::new_unchecked(self.id * S::N_BYTES) }

diff --git a/crates/mem/src/paging.rs b/crates/mem/src/paging.rs
@@ -86,7 +86,13 @@ impl Clone for Virt2PhysMapping {
 /// Flush this page from the TLB
 #[inline]
 pub unsafe fn flush_tlb(page: VirtPage) {
-    todo!()
+    unsafe {
+        core::arch::asm!(
+            "invlpg [rax]",
+            in("rax") page.addr().addr(),
+            options(nostack)
+        )
+    }
 }
 
 /// Returns the indexes into the page tables that would give this virtual address.
@@ -351,7 +357,7 @@ impl Virt2PhysMapping {
                     let page_entry = lower.table.get(lvl1_index);
 
                     // Make sure we don't override unless we are told to
-                    if entry.is_present_set() && !options.is_overwrite_set() {
+                    if page_entry.is_present_set() && !options.is_overwrite_set() {
                         return Some(PageCorrelationError::PageAlreadyMapped);
                     }
 
@@ -982,6 +988,34 @@ impl SafePageMapLvl1 {
 }
 
 impl core::fmt::Debug for Virt2PhysMapping {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        let mapping_lock = self.mapping.read();
+
+        let Some(_) = mapping_lock.as_ref() else {
+            writeln!(f, "Virt2PhysMapping ?? (Empty)")?;
+            return Ok(());
+        };
+
+        write!(f, "Virt2PhysMapping (",)?;
+
+        if self.is_loaded() {
+            write!(f, "Current")?;
+        } else {
+            write!(
+                f,
+                "Not Loaded, refs={}",
+                self.mapping
+                    .read()
+                    .as_ref()
+                    .map(|inner| Arc::strong_count(inner))
+                    .unwrap_or(0)
+            )?;
+        }
+        writeln!(f, ")")
+    }
+}
+
+impl core::fmt::Display for Virt2PhysMapping {
     fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         let mapping_lock = self.mapping.read();
 

diff --git a/kernel/src/main.rs b/kernel/src/main.rs
@@ -101,36 +101,26 @@ fn main(kbh: &KernelBootHeader) {
     );
     mem::pmm::set_physical_memory_manager(pmm);
 
+    logln!("Attached virt2phys provider!");
     init_virt2phys_provider();
+
     let new_tables = Virt2PhysMapping::empty();
-    new_tables
-        .correlate_page(
-            mem::page::VirtPage::new(10),
-            PhysPage::new(1),
-            VmOptions::none()
-                .set_no_tlb_flush_flag(true)
-                .set_increase_perm_flag(true),
-            mem::paging::VmPermissions::none()
-                .set_read_flag(true)
-                .set_write_flag(true)
-                .set_exec_flag(true),
-        )
-        .unwrap();
-    new_tables
-        .correlate_page(
-            mem::page::VirtPage::new(51224),
-            PhysPage::new(2),
-            VmOptions::none()
-                .set_no_tlb_flush_flag(true)
-                .set_increase_perm_flag(true),
-            mem::paging::VmPermissions::none()
-                .set_read_flag(true)
-                .set_write_flag(true)
-                .set_exec_flag(true)
-                .set_user_flag(true),
-        )
-        .unwrap();
-    logln!("Page tables:\n{new_tables:#?}");
+    for i in 0..1024 {
+        new_tables
+            .correlate_page(
+                mem::page::VirtPage::new(10 + i),
+                PhysPage::new(1 + i),
+                VmOptions::none()
+                    .set_no_tlb_flush_flag(false)
+                    .set_increase_perm_flag(true),
+                mem::paging::VmPermissions::none()
+                    .set_read_flag(true)
+                    .set_write_flag(true)
+                    .set_exec_flag(true),
+            )
+            .unwrap();
+    }
+    // logln!("Page tables:\n{new_tables:#?}");
 
     logln!("Init VirtMemoryManager");
     let kernel_process = unsafe { VmProcess::new_from_bootloader() };