axmm/
lib.rs

1//! [ArceOS](https://github.com/arceos-org/arceos) memory management module.
2
3#![no_std]
4
5#[macro_use]
6extern crate log;
7extern crate alloc;
8
9mod aspace;
10mod backend;
11
12pub use self::aspace::AddrSpace;
13pub use self::backend::Backend;
14
15use axerrno::{AxError, AxResult};
16use axhal::mem::{MemRegionFlags, phys_to_virt};
17use axhal::paging::MappingFlags;
18use kspin::SpinNoIrq;
19use lazyinit::LazyInit;
20use memory_addr::{MemoryAddr, PhysAddr, VirtAddr, va};
21use memory_set::MappingError;
22
23static KERNEL_ASPACE: LazyInit<SpinNoIrq<AddrSpace>> = LazyInit::new();
24
25fn mapping_err_to_ax_err(err: MappingError) -> AxError {
26    if !matches!(err, MappingError::AlreadyExists) {
27        warn!("Mapping error: {err:?}");
28    }
29    match err {
30        MappingError::InvalidParam => AxError::InvalidInput,
31        MappingError::AlreadyExists => AxError::AlreadyExists,
32        MappingError::BadState => AxError::BadState,
33    }
34}
35
36fn reg_flag_to_map_flag(f: MemRegionFlags) -> MappingFlags {
37    let mut ret = MappingFlags::empty();
38    if f.contains(MemRegionFlags::READ) {
39        ret |= MappingFlags::READ;
40    }
41    if f.contains(MemRegionFlags::WRITE) {
42        ret |= MappingFlags::WRITE;
43    }
44    if f.contains(MemRegionFlags::EXECUTE) {
45        ret |= MappingFlags::EXECUTE;
46    }
47    if f.contains(MemRegionFlags::DEVICE) {
48        ret |= MappingFlags::DEVICE;
49    }
50    if f.contains(MemRegionFlags::UNCACHED) {
51        ret |= MappingFlags::UNCACHED;
52    }
53    ret
54}
55
56/// Creates a new address space for kernel itself.
57pub fn new_kernel_aspace() -> AxResult<AddrSpace> {
58    let mut aspace = AddrSpace::new_empty(
59        va!(axconfig::plat::KERNEL_ASPACE_BASE),
60        axconfig::plat::KERNEL_ASPACE_SIZE,
61    )?;
62    for r in axhal::mem::memory_regions() {
63        // mapped range should contain the whole region if it is not aligned.
64        let start = r.paddr.align_down_4k();
65        let end = (r.paddr + r.size).align_up_4k();
66        aspace.map_linear(
67            phys_to_virt(start),
68            start,
69            end - start,
70            reg_flag_to_map_flag(r.flags),
71        )?;
72    }
73    Ok(aspace)
74}
75
76/// Creates a new address space for user processes.
77pub fn new_user_aspace(base: VirtAddr, size: usize) -> AxResult<AddrSpace> {
78    let mut aspace = AddrSpace::new_empty(base, size)?;
79    if !cfg!(target_arch = "aarch64") && !cfg!(target_arch = "loongarch64") {
80        // ARMv8 (aarch64) and LoongArch64 use separate page tables for user space
81        // (aarch64: TTBR0_EL1, LoongArch64: PGDL), so there is no need to copy the
82        // kernel portion to the user page table.
83        aspace.copy_mappings_from(&kernel_aspace().lock())?;
84    }
85    Ok(aspace)
86}
87
88/// Returns the globally unique kernel address space.
89pub fn kernel_aspace() -> &'static SpinNoIrq<AddrSpace> {
90    &KERNEL_ASPACE
91}
92
93/// Returns the root physical address of the kernel page table.
94pub fn kernel_page_table_root() -> PhysAddr {
95    KERNEL_ASPACE.lock().page_table_root()
96}
97
98/// Initializes virtual memory management.
99///
100/// It mainly sets up the kernel virtual memory address space and recreate a
101/// fine-grained kernel page table.
102pub fn init_memory_management() {
103    info!("Initialize virtual memory management...");
104
105    let kernel_aspace = new_kernel_aspace().expect("failed to initialize kernel address space");
106    debug!("kernel address space init OK: {:#x?}", kernel_aspace);
107    KERNEL_ASPACE.init_once(SpinNoIrq::new(kernel_aspace));
108    unsafe { axhal::asm::write_kernel_page_table(kernel_page_table_root()) };
109}
110
111/// Initializes kernel paging for secondary CPUs.
112pub fn init_memory_management_secondary() {
113    unsafe { axhal::asm::write_kernel_page_table(kernel_page_table_root()) };
114}
axmm/lib.rs

axmm/
lib.rs
