feature: 增加early io remap的fixmap功能 (#495)

允许在内存管理初始化之前,使用fixmap功能,映射一些物理内存,并记录.

kernel/Cargo.toml

@@ -23,7 +23,7 @@ backtrace = []
 
 # 运行时依赖项
 [dependencies]
-acpi = { git = "https://git.mirrors.dragonos.org/DragonOS-Community/acpi-rs.git", rev = "fb69243dcf" }
+acpi = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/acpi-rs.git", rev = "fb69243dcf" }
 atomic_enum = "0.2.0"
 bit_field = "0.10"
 bitfield-struct = "0.5.3"
@@ -39,12 +39,12 @@ klog_types = { path = "crates/klog_types" }
 linkme = "0.2"
 num = { version = "0.4.0", default-features = false }
 num-derive = "0.3"
-num-traits = { git = "https://git.mirrors.dragonos.org/DragonOS-Community/num-traits.git", rev="1597c1c", default-features = false }
+num-traits = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/num-traits.git", rev="1597c1c", default-features = false }
 raw-cpuid = "11.0.1"
-smoltcp = { git = "https://git.mirrors.dragonos.org/DragonOS-Community/smoltcp.git", rev = "9027825", default-features = false, features = ["log", "alloc",  "socket-raw", "socket-udp", "socket-tcp", "socket-icmp", "socket-dhcpv4", "socket-dns", "proto-ipv4", "proto-ipv6"]}
+smoltcp = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/smoltcp.git", rev = "9027825", default-features = false, features = ["log", "alloc",  "socket-raw", "socket-udp", "socket-tcp", "socket-icmp", "socket-dhcpv4", "socket-dns", "proto-ipv4", "proto-ipv6"]}
 system_error = { path = "crates/system_error" }
 unified-init = { path = "crates/unified-init" }
-virtio-drivers = { git = "https://git.mirrors.dragonos.org/DragonOS-Community/virtio-drivers.git", rev = "f1d1cbb" }
+virtio-drivers = { git = "https://git.mirrors.dragonos.org.cn/DragonOS-Community/virtio-drivers.git", rev = "f1d1cbb" }
 fdt = "0.1.5"
 
 # target为x86_64时，使用下面的依赖

kernel/src/arch/riscv64/mm/mod.rs

@@ -11,7 +11,7 @@ pub(super) mod init;
 
 pub type PageMapper = crate::mm::page::PageMapper<RiscV64MMArch, LockedFrameAllocator>;
 
-/// RiscV64的内存管理架构结构体
+/// RiscV64的内存管理架构结构体(sv39)
 #[derive(Debug, Clone, Copy, Hash)]
 pub struct RiscV64MMArch;
 
@@ -53,6 +53,11 @@ impl MemoryManagementArch for RiscV64MMArch {
 
     const USER_STACK_START: crate::mm::VirtAddr = VirtAddr::new(0x0000_001f_ffa0_0000);
 
+    /// 在距离sv39的顶端还有1G的位置，设置为FIXMAP的起始地址
+    const FIXMAP_START_VADDR: VirtAddr = VirtAddr::new(0xffff_ffff_8000_0000);
+    /// 设置1MB的fixmap空间
+    const FIXMAP_SIZE: usize = 256 * 4096;
+
     unsafe fn init() {
         todo!()
     }

kernel/src/arch/x86_64/mm/mod.rs

@@ -115,6 +115,10 @@ impl MemoryManagementArch for X86_64MMArch {
     const USER_BRK_START: VirtAddr = VirtAddr::new(0x700000000000);
     const USER_STACK_START: VirtAddr = VirtAddr::new(0x6ffff0a00000);
 
+    const FIXMAP_START_VADDR: VirtAddr = VirtAddr::new(0xffffb00000000000);
+    /// 设置FIXMAP区域大小为1M
+    const FIXMAP_SIZE: usize = 256 * 4096;
+
     /// @brief 获取物理内存区域
     unsafe fn init() {
         extern "C" {

kernel/src/mm/early_ioremap.rs

@@ -0,0 +1,169 @@
+use system_error::SystemError;
+
+use crate::{
+    arch::MMArch,
+    libs::{align::page_align_up, spinlock::SpinLock},
+    mm::no_init::{pseudo_map_phys, pseudo_unmap_phys},
+};
+
+use super::{allocator::page_frame::PageFrameCount, MemoryManagementArch, PhysAddr, VirtAddr};
+
+static SLOTS: SpinLock<[Slot; EarlyIoRemap::SLOT_CNT]> =
+    SpinLock::new([Slot::DEFAULT; EarlyIoRemap::SLOT_CNT]);
+
+/// 早期IO映射机制
+///
+/// 该机制在内存管理初始化之前，提供IO重映射的功能。
+///
+/// ## 注意
+///
+/// 该机制使用固定大小的slot来记录所有的映射，
+/// 而这些映射空间是有限的，由MMArch::FIXMAP_SIZE指定
+pub struct EarlyIoRemap;
+
+impl EarlyIoRemap {
+    const SLOT_CNT: usize = MMArch::FIXMAP_SIZE / MMArch::PAGE_SIZE;
+
+    /// 把物理内存映射到虚拟内存中
+    ///
+    /// ## 说明
+    ///
+    /// 虚拟内存由early io remap机制自动分配。
+    ///
+    /// ## 参数
+    ///
+    /// - phys: 物理内存地址（需要按页对齐）
+    /// - size: 映射的内存大小
+    ///
+    /// ## 返回值
+    ///
+    /// - 成功： (虚拟内存地址, 映射的内存大小)
+    /// - Err(SystemError::ENOMEM): 可用的slot不足
+    /// - Err(SystemError::EINVAL): 传入的物理地址没有对齐
+    #[allow(dead_code)]
+    pub fn map(phys: PhysAddr, size: usize) -> Result<(VirtAddr, usize), SystemError> {
+        if phys.check_aligned(MMArch::PAGE_SIZE) == false {
+            return Err(SystemError::EINVAL);
+        }
+
+        let mut slot_guard = SLOTS.lock();
+
+        let slot_count = PageFrameCount::from_bytes(page_align_up(size))
+            .unwrap()
+            .data();
+        // 寻找连续的slot
+        let mut start_slot = None;
+        for i in 0..(Self::SLOT_CNT - slot_count + 1) {
+            let mut is_continuous = true;
+
+            for j in 0..slot_count {
+                let slot_idx = i + j;
+                if slot_guard[slot_idx].start_idx.is_some() {
+                    is_continuous = false;
+                    break;
+                }
+            }
+
+            if is_continuous {
+                start_slot = Some(i);
+                break;
+            }
+        }
+
+        let start_slot = start_slot.ok_or(SystemError::ENOMEM)?;
+        let vaddr = Self::idx_to_virt(start_slot);
+        // 执行映射
+        unsafe { pseudo_map_phys(vaddr, phys, PageFrameCount::new(slot_count)) }
+
+        // 更新slot信息
+        let map_size = slot_count * MMArch::PAGE_SIZE;
+        for i in 0..slot_count {
+            let slot_idx = start_slot + i;
+            slot_guard[slot_idx].start_idx = Some(start_slot as u32);
+
+            if i == 0 {
+                slot_guard[slot_idx].size = map_size as u32;
+                slot_guard[slot_idx].phys = phys;
+            }
+        }
+
+        return Ok((vaddr, map_size));
+    }
+
+    /// 取消映射
+    ///
+    /// ## 参数
+    ///
+    /// - virt: 映射范围内的任意虚拟地址
+    ///
+    /// ## 返回值
+    ///
+    /// - Ok: 成功
+    /// - Err(SystemError::EINVAL): 传入的虚拟地址不在early io remap范围内,
+    ///     或者虚拟地址未映射
+    #[allow(dead_code)]
+    pub fn unmap(virt: VirtAddr) -> Result<(), SystemError> {
+        if virt < MMArch::FIXMAP_START_VADDR || virt >= MMArch::FIXMAP_END_VADDR {
+            return Err(SystemError::EINVAL);
+        }
+
+        let mut slot_guard = SLOTS.lock();
+        let mut idx = None;
+
+        // 寻找虚拟地址对应的区域的第一个slot
+        for slot_idx in 0..Self::SLOT_CNT {
+            let slot = &mut slot_guard[slot_idx];
+            if let Some(start_idx) = slot.start_idx {
+                if start_idx == slot_idx as u32 {
+                    let vaddr_start = Self::idx_to_virt(start_idx as usize);
+                    let vaddr_end = vaddr_start + slot.size as usize;
+                    if vaddr_start <= virt && virt < vaddr_end {
+                        // 找到区域了
+                        idx = Some(slot_idx);
+                        break;
+                    }
+                }
+            }
+        }
+
+        let idx = idx.ok_or(SystemError::EINVAL)?;
+
+        let vaddr = Self::idx_to_virt(idx as usize);
+        let count = PageFrameCount::from_bytes(slot_guard[idx].size as usize).unwrap();
+
+        // 取消映射
+
+        unsafe { pseudo_unmap_phys(vaddr, count) };
+
+        for i in 0..count.data() {
+            let slot_idx = idx + i;
+            let slot = &mut slot_guard[slot_idx];
+            *slot = Slot::DEFAULT;
+        }
+
+        todo!()
+    }
+
+    /// 把slot下标转换为这个slot对应的虚拟地址
+    fn idx_to_virt(idx: usize) -> VirtAddr {
+        MMArch::FIXMAP_START_VADDR + idx * MMArch::PAGE_SIZE
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+struct Slot {
+    /// 连续映射的起始槽位号
+    start_idx: Option<u32>,
+    /// 连续映射的区域大小（仅在起始槽位中设置）
+    size: u32,
+    /// 映射的起始物理地址
+    phys: PhysAddr,
+}
+
+impl Slot {
+    const DEFAULT: Self = Self {
+        start_idx: None,
+        size: 0,
+        phys: PhysAddr::new(0),
+    };
+}

kernel/src/mm/mod.rs

@@ -20,6 +20,7 @@ use self::{
 
 pub mod allocator;
 pub mod c_adapter;
+pub mod early_ioremap;
 pub mod kernel_mapper;
 pub mod memblock;
 pub mod mmio_buddy;
@@ -92,7 +93,7 @@ impl PhysAddr {
 
     /// @brief 获取物理地址的值
     #[inline(always)]
-    pub fn data(&self) -> usize {
+    pub const fn data(&self) -> usize {
         self.0
     }
 
@@ -211,7 +212,7 @@ impl VirtAddr {
 
     /// @brief 获取虚拟地址的值
     #[inline(always)]
-    pub fn data(&self) -> usize {
+    pub const fn data(&self) -> usize {
         return self.0;
     }
 
@@ -429,6 +430,14 @@ pub trait MemoryManagementArch: Clone + Copy + Debug {
     /// 用户栈起始地址（向下生长，不包含该值）
     const USER_STACK_START: VirtAddr;
 
+    /// 内核的固定映射区的起始地址
+    const FIXMAP_START_VADDR: VirtAddr;
+    /// 内核的固定映射区的大小
+    const FIXMAP_SIZE: usize;
+    /// 内核的固定映射区的结束地址
+    const FIXMAP_END_VADDR: VirtAddr =
+        VirtAddr::new(Self::FIXMAP_START_VADDR.data() + Self::FIXMAP_SIZE);
+
     /// @brief 用于初始化内存管理模块与架构相关的信息。
     /// 该函数应调用其他模块的接口，把可用内存区域添加到memblock，提供给BumpAllocator使用
     unsafe fn init();

kernel/src/mm/no_init.rs

@@ -137,6 +137,7 @@ impl<MMA: MemoryManagementArch> FrameAllocator for PseudoAllocator<MMA> {
 /// 调用该函数时，必须保证内存管理器尚未初始化。否则将导致未定义的行为
 ///
 /// 并且，内核引导文件必须以4K页为粒度，填写了前100M的内存映射关系。（具体以本文件开头的注释为准）
+#[inline(never)]
 pub unsafe fn pseudo_map_phys(vaddr: VirtAddr, paddr: PhysAddr, count: PageFrameCount) {
     assert!(vaddr.check_aligned(MMArch::PAGE_SIZE));
     assert!(paddr.check_aligned(MMArch::PAGE_SIZE));
@@ -160,3 +161,31 @@ pub unsafe fn pseudo_map_phys(vaddr: VirtAddr, paddr: PhysAddr, count: PageFrame
 
     mapper.make_current();
 }
+
+/// Unmap physical memory from virtual memory.
+///
+/// ## 说明
+///
+/// 该函数在系统启动早期，内存管理尚未初始化的时候使用
+#[inline(never)]
+pub unsafe fn pseudo_unmap_phys(vaddr: VirtAddr, count: PageFrameCount) {
+    assert!(vaddr.check_aligned(MMArch::PAGE_SIZE));
+    assert!(count.data() == 1);
+
+    let mut pseudo_allocator = PseudoAllocator::<MMArch>::new();
+
+    let mut mapper = crate::mm::page::PageMapper::<MMArch, _>::new(
+        PageTableKind::Kernel,
+        MMArch::table(PageTableKind::Kernel),
+        &mut pseudo_allocator,
+    );
+
+    for i in 0..count.data() {
+        let vaddr = vaddr + i * MMArch::PAGE_SIZE;
+        mapper.unmap_phys(vaddr, true).map(|(_, _, flusher)| {
+            flusher.ignore();
+        });
+    }
+
+    mapper.make_current();
+}