feat(mm): 添加slab内存分配器 (DragonOS-Community#683)

feat(mm): 添加slab内存分配器 
---------

Co-authored-by: longjin <[email protected]>

kernel/Cargo.toml

@@ -52,6 +52,7 @@ fdt = "=0.1.5"
 uefi = { version = "=0.26.0", features = ["alloc"] }
 uefi-raw = "=0.5.0"
 paste = "=1.0.14"
+slabmalloc = { path = "crates/rust-slabmalloc" }
 
 
 # target为x86_64时，使用下面的依赖

kernel/crates/rust-slabmalloc/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "slabmalloc"
+version = "0.11.0"
+edition = "2018"
+
+[features]
+unstable = []
+default = [ "unstable" ]
+
+[dependencies]
+log = "0.4"
+
+[target.'cfg(unix)'.dev-dependencies]
+rand = "0.8"
+env_logger = "0.9"
+spin = "0.9.8"

kernel/crates/rust-slabmalloc/src/lib.rs

@@ -0,0 +1,79 @@
+//! A slab allocator implementation for objects less than a page-size (4 KiB or 2MiB).
+//!
+//! # Overview
+//!
+//! The organization is as follows:
+//!
+//!  * A `ZoneAllocator` manages many `SCAllocator` and can
+//!    satisfy requests for different allocation sizes.
+//!  * A `SCAllocator` allocates objects of exactly one size.
+//!    It stores the objects and meta-data in one or multiple `AllocablePage` objects.
+//!  * A trait `AllocablePage` that defines the page-type from which we allocate objects.
+//!
+//! Lastly, it provides two default `AllocablePage` implementations `ObjectPage` and `LargeObjectPage`:
+//!  * A `ObjectPage` that is 4 KiB in size and contains allocated objects and associated meta-data.
+//!  * A `LargeObjectPage` that is 2 MiB in size and contains allocated objects and associated meta-data.
+//!
+//!
+//! # Implementing GlobalAlloc
+//! See the [global alloc](https://github.com/gz/rust-slabmalloc/tree/master/examples/global_alloc.rs) example.
+#![allow(unused_features)]
+#![cfg_attr(feature = "unstable", feature(const_mut_refs))]
+#![no_std]
+#![crate_name = "slabmalloc"]
+#![crate_type = "lib"]
+#![feature(new_uninit)]
+#![feature(maybe_uninit_as_bytes)]
+
+extern crate alloc;
+
+mod pages;
+mod sc;
+mod zone;
+
+pub use pages::*;
+pub use sc::*;
+pub use zone::*;
+
+use core::alloc::Layout;
+use core::fmt;
+use core::ptr::{self, NonNull};
+
+use log::trace;
+
+/// How many bytes in the page are used by allocator meta-data.
+const OBJECT_PAGE_METADATA_OVERHEAD: usize = 80;
+
+/// How many bytes a [`ObjectPage`] is.
+const OBJECT_PAGE_SIZE: usize = 4096;
+
+type VAddr = usize;
+
+/// Error that can be returned for `allocation` and `deallocation` requests.
+#[derive(Debug)]
+pub enum AllocationError {
+    /// Can't satisfy the allocation request for Layout because the allocator
+    /// does not have enough memory (you may be able to `refill` it).
+    OutOfMemory,
+    /// Allocator can't deal with the provided size of the Layout.
+    InvalidLayout,
+}
+
+/// Allocator trait to be implemented by users of slabmalloc to provide memory to slabmalloc.
+///
+/// # Safety
+/// Needs to adhere to safety requirements of a rust allocator (see GlobalAlloc et. al.).
+pub unsafe trait Allocator<'a> {
+    fn allocate(&mut self, layout: Layout) -> Result<NonNull<u8>, AllocationError>;
+    fn deallocate(&mut self, ptr: NonNull<u8>, layout: Layout) -> Result<(), AllocationError>;
+
+    /// Refill the allocator with a [`ObjectPage`].
+    ///
+    /// # Safety
+    /// TBD (this API needs to change anyways, likely new page should be a raw pointer)
+    unsafe fn refill(
+        &mut self,
+        layout: Layout,
+        new_page: &'a mut ObjectPage<'a>,
+    ) -> Result<(), AllocationError>;
+}