Merge pull request #832 from stlankes/talc

fix mapping of 1GB pages
hermit-os · Aug 9, 2023 · 2fda1c6 · 2fda1c6
2 parents e1a0707 + 9fcce94
commit 2fda1c6
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Showing 4 changed files with 64 additions and 25 deletions.
diff --git a/src/arch/aarch64/kernel/processor.rs b/src/arch/aarch64/kernel/processor.rs
@@ -152,6 +152,7 @@ pub fn get_timestamp() -> u64 {
 }
 
 #[inline]
+#[allow(dead_code)]
 pub fn supports_1gib_pages() -> bool {
 	false
 }

diff --git a/src/arch/aarch64/mm/paging.rs b/src/arch/aarch64/mm/paging.rs
@@ -601,7 +601,9 @@ pub fn map<S: PageSize>(
 	root_pagetable.map_pages(range, physical_address, flags);
 }
 
-pub fn map_heap<S: PageSize>(virt_addr: VirtAddr, count: usize) {
+/// Maps `count` pages at address `virt_addr`. If the allocation of a physical memory failed,
+/// the number of successfull mapped pages are returned as error value.
+pub fn map_heap<S: PageSize>(virt_addr: VirtAddr, count: usize) -> Result<(), usize> {
 	let flags = {
 		let mut flags = PageTableEntryFlags::empty();
 		flags.normal().writable().execute_disable();
@@ -610,10 +612,13 @@ pub fn map_heap<S: PageSize>(virt_addr: VirtAddr, count: usize) {
 
 	let virt_addrs = (0..count).map(|n| virt_addr + n * S::SIZE as usize);
 
-	for virt_addr in virt_addrs {
-		let phys_addr = physicalmem::allocate_aligned(S::SIZE as usize, S::SIZE as usize).unwrap();
+	for (map_counter, virt_addr) in virt_addrs.enumerate() {
+		let phys_addr = physicalmem::allocate_aligned(S::SIZE as usize, S::SIZE as usize)
+			.map_err(|_| map_counter)?;
 		map::<S>(virt_addr, phys_addr, 1, flags);
 	}
+
+	Ok(())
 }
 
 pub fn unmap<S: PageSize>(virtual_address: VirtAddr, count: usize) {

diff --git a/src/arch/x86_64/mm/paging.rs b/src/arch/x86_64/mm/paging.rs
@@ -138,7 +138,9 @@ pub fn map<S>(
 	}
 }
 
-pub fn map_heap<S: PageSize>(virt_addr: VirtAddr, count: usize)
+/// Maps `count` pages at address `virt_addr`. If the allocation of a physical memory failed,
+/// the number of successfull mapped pages are returned as error value.
+pub fn map_heap<S: PageSize>(virt_addr: VirtAddr, count: usize) -> Result<(), usize>
 where
 	S: PageSize + Debug,
 	RecursivePageTable<'static>: Mapper<S>,
@@ -151,10 +153,13 @@ where
 
 	let virt_addrs = (0..count).map(|n| virt_addr + n * S::SIZE as usize);
 
-	for virt_addr in virt_addrs {
-		let phys_addr = physicalmem::allocate_aligned(S::SIZE as usize, S::SIZE as usize).unwrap();
+	for (map_counter, virt_addr) in virt_addrs.enumerate() {
+		let phys_addr = physicalmem::allocate_aligned(S::SIZE as usize, S::SIZE as usize)
+			.map_err(|_| map_counter)?;
 		map::<S>(virt_addr, phys_addr, 1, flags);
 	}
+
+	Ok(())
 }
 
 #[cfg(feature = "acpi")]

diff --git a/src/mm/mod.rs b/src/mm/mod.rs
@@ -9,11 +9,11 @@ use hermit_sync::Lazy;
 #[cfg(feature = "newlib")]
 use hermit_sync::OnceCell;
 
+#[cfg(target_arch = "x86_64")]
+use crate::arch::mm::paging::HugePageSize;
 #[cfg(target_arch = "x86_64")]
 use crate::arch::mm::paging::PageTableEntryFlagsExt;
-use crate::arch::mm::paging::{
-	BasePageSize, HugePageSize, LargePageSize, PageSize, PageTableEntryFlags,
-};
+use crate::arch::mm::paging::{BasePageSize, LargePageSize, PageSize, PageTableEntryFlags};
 use crate::arch::mm::physicalmem::total_memory_size;
 #[cfg(feature = "newlib")]
 use crate::arch::mm::virtualmem::kernel_heap_end;
@@ -82,6 +82,7 @@ pub(crate) fn init() {
 	let reserved_space = (npage_3tables + npage_2tables + npage_1tables)
 		* BasePageSize::SIZE as usize
 		+ LargePageSize::SIZE as usize;
+	#[cfg(target_arch = "x86_64")]
 	let has_1gib_pages = arch::processor::supports_1gib_pages();
 	let has_2mib_pages = arch::processor::supports_2mib_pages();
 
@@ -154,10 +155,15 @@ pub(crate) fn init() {
 		#[cfg(target_arch = "x86_64")]
 		if has_1gib_pages && virt_size > HugePageSize::SIZE as usize {
 			// Mount large pages to the next huge page boundary
-			map_addr = virt_addr.align_up_to_huge_page();
-			map_size = virt_size - (map_addr - virt_addr).as_usize();
-			let npages = (map_addr - virt_addr).as_usize() / LargePageSize::SIZE as usize;
-			paging::map_heap::<LargePageSize>(virt_addr, npages);
+			let npages = (virt_addr.align_up_to_huge_page().as_usize() - virt_addr.as_usize())
+				/ LargePageSize::SIZE as usize;
+			if let Err(n) = paging::map_heap::<LargePageSize>(virt_addr, npages) {
+				map_addr = virt_addr + n * LargePageSize::SIZE as usize;
+				map_size = virt_size - (map_addr - virt_addr).as_usize();
+			} else {
+				map_addr = virt_addr.align_up_to_huge_page();
+				map_size = virt_size - (map_addr - virt_addr).as_usize();
+			}
 		} else {
 			map_addr = virt_addr;
 			map_size = virt_size;
@@ -170,28 +176,50 @@ pub(crate) fn init() {
 		}
 	}
 
+	#[cfg(target_arch = "x86_64")]
 	if has_1gib_pages
 		&& map_size > HugePageSize::SIZE as usize
-		&& map_addr.as_usize().align_down(HugePageSize::SIZE as usize) == 0
+		&& map_addr.is_aligned(HugePageSize::SIZE)
 	{
 		let size = map_size.align_down(HugePageSize::SIZE as usize);
-		paging::map_heap::<HugePageSize>(map_addr, size / HugePageSize::SIZE as usize);
-		map_size -= size;
-		map_addr += size;
+		if let Err(num_pages) =
+			paging::map_heap::<HugePageSize>(map_addr, size / HugePageSize::SIZE as usize)
+		{
+			map_size -= num_pages * HugePageSize::SIZE as usize;
+			map_addr += num_pages * HugePageSize::SIZE as usize;
+		} else {
+			map_size -= size;
+			map_addr += size;
+		}
 	}
 
-	if has_2mib_pages && map_size > LargePageSize::SIZE as usize {
+	if has_2mib_pages
+		&& map_size > LargePageSize::SIZE as usize
+		&& map_addr.is_aligned(LargePageSize::SIZE)
+	{
 		let size = map_size.align_down(LargePageSize::SIZE as usize);
-		paging::map_heap::<LargePageSize>(map_addr, size / LargePageSize::SIZE as usize);
-		map_size -= size;
-		map_addr += size;
+		if let Err(num_pages) =
+			paging::map_heap::<LargePageSize>(map_addr, size / LargePageSize::SIZE as usize)
+		{
+			map_size -= num_pages * LargePageSize::SIZE as usize;
+			map_addr += num_pages * LargePageSize::SIZE as usize;
+		} else {
+			map_size -= size;
+			map_addr += size;
+		}
 	}
 
-	if map_size > BasePageSize::SIZE as usize {
+	if map_size > BasePageSize::SIZE as usize && map_addr.is_aligned(BasePageSize::SIZE) {
 		let size = map_size.align_down(BasePageSize::SIZE as usize);
-		paging::map_heap::<BasePageSize>(map_addr, size / BasePageSize::SIZE as usize);
-		map_size -= size;
-		map_addr += size;
+		if let Err(num_pages) =
+			paging::map_heap::<BasePageSize>(map_addr, size / BasePageSize::SIZE as usize)
+		{
+			map_size -= num_pages * BasePageSize::SIZE as usize;
+			map_addr += num_pages * BasePageSize::SIZE as usize;
+		} else {
+			map_size -= size;
+			map_addr += size;
+		}
 	}
 
 	let heap_end_addr = map_addr;