From 928a6f0d8c28dea5acbb23d1bbe77ab73087b552 Mon Sep 17 00:00:00 2001
From: Yifan Wu <shinbokuow@163.com>
Date: Wed, 8 Sep 2021 00:26:22 +0800
Subject: [PATCH] Remove spin::Mutex in frame_allocator and memory_set.

---
 os/Cargo.toml                |  1 -
 os/src/mm/frame_allocator.rs | 13 +++++++------
 os/src/mm/memory_set.rs      | 10 +++++-----
 os/src/mm/mod.rs             |  2 +-
 os/src/task/task.rs          |  4 ++--
 5 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/os/Cargo.toml b/os/Cargo.toml
index 588df758..f8cbacdc 100644
--- a/os/Cargo.toml
+++ b/os/Cargo.toml
@@ -10,7 +10,6 @@ edition = "2018"
 riscv = { git = "https://github.com/rcore-os/riscv", features = ["inline-asm"] }
 lazy_static = { version = "1.4.0", features = ["spin_no_std"] }
 buddy_system_allocator = "0.6"
-spin = "0.7.0"
 bitflags = "1.2.1"
 xmas-elf = "0.7.0"
 
diff --git a/os/src/mm/frame_allocator.rs b/os/src/mm/frame_allocator.rs
index c17385f1..34152355 100644
--- a/os/src/mm/frame_allocator.rs
+++ b/os/src/mm/frame_allocator.rs
@@ -1,6 +1,6 @@
 use super::{PhysAddr, PhysPageNum};
 use alloc::vec::Vec;
-use spin::Mutex;
+use crate::sync::UPSafeCell;
 use crate::config::MEMORY_END;
 use lazy_static::*;
 use core::fmt::{self, Debug, Formatter};
@@ -87,8 +87,9 @@ impl FrameAllocator for StackFrameAllocator {
 type FrameAllocatorImpl = StackFrameAllocator;
 
 lazy_static! {
-    pub static ref FRAME_ALLOCATOR: Mutex<FrameAllocatorImpl> =
-        Mutex::new(FrameAllocatorImpl::new());
+    pub static ref FRAME_ALLOCATOR: UPSafeCell<FrameAllocatorImpl> = unsafe {
+        UPSafeCell::new(FrameAllocatorImpl::new())
+    };
 }
 
 pub fn init_frame_allocator() {
@@ -96,20 +97,20 @@ pub fn init_frame_allocator() {
         fn ekernel();
     }
     FRAME_ALLOCATOR
-        .lock()
+        .exclusive_access()
         .init(PhysAddr::from(ekernel as usize).ceil(), PhysAddr::from(MEMORY_END).floor());
 }
 
 pub fn frame_alloc() -> Option<FrameTracker> {
     FRAME_ALLOCATOR
-        .lock()
+        .exclusive_access()
         .alloc()
         .map(|ppn| FrameTracker::new(ppn))
 }
 
 fn frame_dealloc(ppn: PhysPageNum) {
     FRAME_ALLOCATOR
-        .lock()
+        .exclusive_access()
         .dealloc(ppn);
 }
 
diff --git a/os/src/mm/memory_set.rs b/os/src/mm/memory_set.rs
index f2311509..ad3986a2 100644
--- a/os/src/mm/memory_set.rs
+++ b/os/src/mm/memory_set.rs
@@ -7,7 +7,7 @@ use alloc::vec::Vec;
 use riscv::register::satp;
 use alloc::sync::Arc;
 use lazy_static::*;
-use spin::Mutex;
+use crate::sync::UPSafeCell;
 use crate::config::{
     MEMORY_END,
     PAGE_SIZE,
@@ -30,9 +30,9 @@ extern "C" {
 }
 
 lazy_static! {
-    pub static ref KERNEL_SPACE: Arc<Mutex<MemorySet>> = Arc::new(Mutex::new(
-        MemorySet::new_kernel()
-    ));
+    pub static ref KERNEL_SPACE: Arc<UPSafeCell<MemorySet>> = Arc::new(unsafe {
+        UPSafeCell::new(MemorySet::new_kernel()
+    )});
 }
 
 pub struct MemorySet {
@@ -290,7 +290,7 @@ bitflags! {
 
 #[allow(unused)]
 pub fn remap_test() {
-    let mut kernel_space = KERNEL_SPACE.lock();
+    let mut kernel_space = KERNEL_SPACE.exclusive_access();
     let mid_text: VirtAddr = ((stext as usize + etext as usize) / 2).into();
     let mid_rodata: VirtAddr = ((srodata as usize + erodata as usize) / 2).into();
     let mid_data: VirtAddr = ((sdata as usize + edata as usize) / 2).into();
diff --git a/os/src/mm/mod.rs b/os/src/mm/mod.rs
index 04af2e12..bb04aea9 100644
--- a/os/src/mm/mod.rs
+++ b/os/src/mm/mod.rs
@@ -15,5 +15,5 @@ pub use memory_set::remap_test;
 pub fn init() {
     heap_allocator::init_heap();
     frame_allocator::init_frame_allocator();
-    KERNEL_SPACE.lock().activate();
+    KERNEL_SPACE.exclusive_access().activate();
 }
diff --git a/os/src/task/task.rs b/os/src/task/task.rs
index b08d82a9..47368db6 100644
--- a/os/src/task/task.rs
+++ b/os/src/task/task.rs
@@ -29,7 +29,7 @@ impl TaskControlBlock {
         // map a kernel-stack in kernel space
         let (kernel_stack_bottom, kernel_stack_top) = kernel_stack_position(app_id);
         KERNEL_SPACE
-            .lock()
+            .exclusive_access()
             .insert_framed_area(
                 kernel_stack_bottom.into(),
                 kernel_stack_top.into(),
@@ -47,7 +47,7 @@ impl TaskControlBlock {
         *trap_cx = TrapContext::app_init_context(
             entry_point,
             user_sp,
-            KERNEL_SPACE.lock().token(),
+            KERNEL_SPACE.exclusive_access().token(),
             kernel_stack_top,
             trap_handler as usize,
         );