feat(mm): add PageRangeBox, PageBox, FrameBox

Author: mkroening

src/mm/mod.rs

@@ -54,9 +54,9 @@ use hermit_sync::{Lazy, RawInterruptTicketMutex};
 pub use memory_addresses::{PhysAddr, VirtAddr};
 use talc::{ErrOnOom, Span, Talc, Talck};
 
-pub use self::page_range_alloc::PageRangeAllocator;
-pub use self::physicalmem::FrameAlloc;
-pub use self::virtualmem::PageAlloc;
+pub use self::page_range_alloc::{PageRangeAllocator, PageRangeBox};
+pub use self::physicalmem::{FrameAlloc, FrameBox};
+pub use self::virtualmem::{PageAlloc, PageBox};
 #[cfg(any(target_arch = "x86_64", target_arch = "riscv64"))]
 use crate::arch::mm::paging::HugePageSize;
 pub use crate::arch::mm::paging::virtual_to_physical;

src/mm/page_range_alloc.rs

@@ -1,4 +1,7 @@
 use core::alloc::AllocError;
+use core::marker::PhantomData;
+use core::mem::ManuallyDrop;
+use core::ops::Deref;
 
 use free_list::{PageLayout, PageRange};
 
@@ -19,3 +22,37 @@ pub trait PageRangeAllocator {
 	/// - `range` must described a range of pages _currently allocated_ via this allocator.
 	unsafe fn deallocate(range: PageRange);
 }
+
+pub struct PageRangeBox<A: PageRangeAllocator>(PageRange, PhantomData<A>);
+
+impl<A: PageRangeAllocator> PageRangeBox<A> {
+	pub fn new(layout: PageLayout) -> Result<Self, AllocError> {
+		let range = A::allocate(layout)?;
+		Ok(Self(range, PhantomData))
+	}
+
+	pub unsafe fn from_raw(range: PageRange) -> Self {
+		Self(range, PhantomData)
+	}
+
+	pub fn into_raw(b: Self) -> PageRange {
+		let b = ManuallyDrop::new(b);
+		**b
+	}
+}
+
+impl<A: PageRangeAllocator> Drop for PageRangeBox<A> {
+	fn drop(&mut self) {
+		unsafe {
+			A::deallocate(self.0);
+		}
+	}
+}
+
+impl<A: PageRangeAllocator> Deref for PageRangeBox<A> {
+	type Target = PageRange;
+
+	fn deref(&self) -> &Self::Target {
+		&self.0
+	}
+}

src/mm/physicalmem.rs

@@ -11,8 +11,8 @@ use memory_addresses::{PhysAddr, VirtAddr};
 use crate::arch::mm::paging::PageTableEntryFlagsExt;
 use crate::arch::mm::paging::{self, HugePageSize, PageSize, PageTableEntryFlags};
 use crate::env;
-use crate::mm::PageRangeAllocator;
 use crate::mm::device_alloc::DeviceAlloc;
+use crate::mm::{PageRangeAllocator, PageRangeBox};
 
 static PHYSICAL_FREE_LIST: InterruptTicketMutex<FreeList<16>> =
 	InterruptTicketMutex::new(FreeList::new());
@@ -53,6 +53,8 @@ impl fmt::Display for FrameAlloc {
 	}
 }
 
+pub type FrameBox = PageRangeBox<FrameAlloc>;
+
 pub fn total_memory_size() -> usize {
 	TOTAL_MEMORY.load(Ordering::Relaxed)
 }

src/mm/virtualmem.rs

@@ -5,7 +5,7 @@ use free_list::{FreeList, PageLayout, PageRange};
 use hermit_sync::InterruptTicketMutex;
 use memory_addresses::VirtAddr;
 
-use crate::mm::PageRangeAllocator;
+use crate::mm::{PageRangeAllocator, PageRangeBox};
 
 static KERNEL_FREE_LIST: InterruptTicketMutex<FreeList<16>> =
 	InterruptTicketMutex::new(FreeList::new());
@@ -45,6 +45,8 @@ impl fmt::Display for PageAlloc {
 	}
 }
 
+pub type PageBox = PageRangeBox<PageAlloc>;
+
 fn init() {
 	let range = PageRange::new(
 		kernel_heap_end().as_usize().div_ceil(2),