xref: /DragonOS/kernel/src/arch/riscv64/mm/mod.rs (revision 418ad41fd84c15ed7e132e56970150ac38fc24a9)
1 use riscv::register::satp;
2 use sbi_rt::{HartMask, SbiRet};
3 use system_error::SystemError;
4 
5 use crate::{
6     arch::MMArch,
7     driver::open_firmware::fdt::open_firmware_fdt_driver,
8     libs::spinlock::SpinLock,
9     mm::{
10         allocator::{
11             buddy::BuddyAllocator,
12             page_frame::{FrameAllocator, PageFrameCount, PageFrameUsage, PhysPageFrame},
13         },
14         kernel_mapper::KernelMapper,
15         page::{PageEntry, PageFlags, PAGE_1G_SHIFT},
16         ucontext::UserMapper,
17         MemoryManagementArch, PageTableKind, PhysAddr, VirtAddr,
18     },
19     smp::cpu::ProcessorId,
20 };
21 
22 use self::init::riscv_mm_init;
23 
24 pub mod bump;
25 pub(super) mod init;
26 
27 pub type PageMapper = crate::mm::page::PageMapper<RiscV64MMArch, LockedFrameAllocator>;
28 
29 /// 内核起始物理地址
30 pub(self) static mut KERNEL_BEGIN_PA: PhysAddr = PhysAddr::new(0);
31 /// 内核结束的物理地址
32 pub(self) static mut KERNEL_END_PA: PhysAddr = PhysAddr::new(0);
33 /// 内核起始虚拟地址
34 pub(self) static mut KERNEL_BEGIN_VA: VirtAddr = VirtAddr::new(0);
35 /// 内核结束虚拟地址
36 pub(self) static mut KERNEL_END_VA: VirtAddr = VirtAddr::new(0);
37 
38 pub(self) static INNER_ALLOCATOR: SpinLock<Option<BuddyAllocator<MMArch>>> = SpinLock::new(None);
39 
40 /// RiscV64的内存管理架构结构体(sv39)
41 #[derive(Debug, Clone, Copy, Hash)]
42 pub struct RiscV64MMArch;
43 
44 impl RiscV64MMArch {
45     pub const ENTRY_FLAG_GLOBAL: usize = 1 << 5;
46 
47     /// 使远程cpu的TLB中,指定地址范围的页失效
48     pub fn remote_invalidate_page(
49         cpu: ProcessorId,
50         address: VirtAddr,
51         size: usize,
52     ) -> Result<(), SbiRet> {
53         let r = sbi_rt::remote_sfence_vma(Into::into(cpu), address.data(), size);
54         if r.is_ok() {
55             return Ok(());
56         } else {
57             return Err(r);
58         }
59     }
60 
61     /// 使指定远程cpu的TLB中,所有范围的页失效
62     pub fn remote_invalidate_all(cpu: ProcessorId) -> Result<(), SbiRet> {
63         let r = Self::remote_invalidate_page(
64             cpu,
65             VirtAddr::new(0),
66             1 << RiscV64MMArch::ENTRY_ADDRESS_SHIFT,
67         );
68 
69         return r;
70     }
71 
72     pub fn remote_invalidate_all_with_mask(mask: HartMask) -> Result<(), SbiRet> {
73         let r = sbi_rt::remote_sfence_vma(mask, 0, 1 << RiscV64MMArch::ENTRY_ADDRESS_SHIFT);
74         if r.is_ok() {
75             return Ok(());
76         } else {
77             return Err(r);
78         }
79     }
80 }
81 
82 /// 内核空间起始地址在顶层页表中的索引
83 const KERNEL_TOP_PAGE_ENTRY_NO: usize = (RiscV64MMArch::PHYS_OFFSET
84     & ((1 << RiscV64MMArch::ENTRY_ADDRESS_SHIFT) - 1))
85     >> (RiscV64MMArch::ENTRY_ADDRESS_SHIFT - RiscV64MMArch::PAGE_ENTRY_SHIFT);
86 
87 impl MemoryManagementArch for RiscV64MMArch {
88     const PAGE_SHIFT: usize = 12;
89 
90     const PAGE_ENTRY_SHIFT: usize = 9;
91 
92     /// sv39分页只有三级
93     const PAGE_LEVELS: usize = 3;
94 
95     const ENTRY_ADDRESS_SHIFT: usize = 39;
96 
97     const ENTRY_FLAG_DEFAULT_PAGE: usize = Self::ENTRY_FLAG_PRESENT
98         | Self::ENTRY_FLAG_READWRITE
99         | Self::ENTRY_FLAG_DIRTY
100         | Self::ENTRY_FLAG_ACCESSED
101         | Self::ENTRY_FLAG_GLOBAL;
102 
103     const ENTRY_FLAG_DEFAULT_TABLE: usize = Self::ENTRY_FLAG_PRESENT;
104 
105     const ENTRY_FLAG_PRESENT: usize = 1 << 0;
106 
107     const ENTRY_FLAG_READONLY: usize = 0;
108 
109     const ENTRY_FLAG_READWRITE: usize = (1 << 2) | (1 << 1);
110 
111     const ENTRY_FLAG_USER: usize = (1 << 4);
112 
113     const ENTRY_FLAG_WRITE_THROUGH: usize = (2 << 61);
114 
115     const ENTRY_FLAG_CACHE_DISABLE: usize = (2 << 61);
116 
117     const ENTRY_FLAG_NO_EXEC: usize = 0;
118 
119     const ENTRY_FLAG_EXEC: usize = (1 << 3);
120     const ENTRY_FLAG_ACCESSED: usize = (1 << 6);
121     const ENTRY_FLAG_DIRTY: usize = (1 << 7);
122 
123     const PHYS_OFFSET: usize = 0xffff_ffc0_0000_0000;
124     const KERNEL_LINK_OFFSET: usize = 0x1000000;
125 
126     const USER_END_VADDR: crate::mm::VirtAddr = VirtAddr::new(0x0000_003f_ffff_ffff);
127 
128     const USER_BRK_START: crate::mm::VirtAddr = VirtAddr::new(0x0000_001f_ffff_ffff);
129 
130     const USER_STACK_START: crate::mm::VirtAddr = VirtAddr::new(0x0000_001f_ffa0_0000);
131 
132     /// 在距离sv39的顶端还有64M的位置,设置为FIXMAP的起始地址
133     const FIXMAP_START_VADDR: VirtAddr = VirtAddr::new(0xffff_ffff_fc00_0000);
134     /// 设置1MB的fixmap空间
135     const FIXMAP_SIZE: usize = 256 * 4096;
136 
137     /// 在距离sv39的顶端还有2G的位置,设置为MMIO空间的起始地址
138     const MMIO_BASE: VirtAddr = VirtAddr::new(0xffff_ffff_8000_0000);
139     /// 设置1g的MMIO空间
140     const MMIO_SIZE: usize = 1 << PAGE_1G_SHIFT;
141 
142     #[inline(never)]
143     unsafe fn init() {
144         riscv_mm_init().expect("init kernel memory management architecture failed");
145     }
146 
147     unsafe fn arch_post_init() {
148         // 映射fdt
149         open_firmware_fdt_driver()
150             .map_fdt()
151             .expect("openfirmware map fdt failed");
152     }
153 
154     unsafe fn invalidate_page(address: VirtAddr) {
155         riscv::asm::sfence_vma(0, address.data());
156     }
157 
158     unsafe fn invalidate_all() {
159         riscv::asm::sfence_vma_all();
160     }
161 
162     unsafe fn table(_table_kind: PageTableKind) -> PhysAddr {
163         // phys page number
164         let ppn = riscv::register::satp::read().ppn();
165 
166         let paddr = PhysPageFrame::from_ppn(ppn).phys_address();
167 
168         return paddr;
169     }
170 
171     unsafe fn set_table(_table_kind: PageTableKind, table: PhysAddr) {
172         let ppn = PhysPageFrame::new(table).ppn();
173         riscv::asm::sfence_vma_all();
174         satp::set(satp::Mode::Sv39, 0, ppn);
175     }
176 
177     fn virt_is_valid(virt: VirtAddr) -> bool {
178         virt.is_canonical()
179     }
180 
181     fn initial_page_table() -> PhysAddr {
182         todo!()
183     }
184 
185     fn setup_new_usermapper() -> Result<UserMapper, SystemError> {
186         let new_umapper: crate::mm::page::PageMapper<MMArch, LockedFrameAllocator> = unsafe {
187             PageMapper::create(PageTableKind::User, LockedFrameAllocator)
188                 .ok_or(SystemError::ENOMEM)?
189         };
190 
191         let current_ktable: KernelMapper = KernelMapper::lock();
192         let copy_mapping = |pml4_entry_no| unsafe {
193             let entry: PageEntry<RiscV64MMArch> = current_ktable
194                 .table()
195                 .entry(pml4_entry_no)
196                 .unwrap_or_else(|| panic!("entry {} not found", pml4_entry_no));
197             new_umapper.table().set_entry(pml4_entry_no, entry)
198         };
199 
200         // 复制内核的映射
201         for pml4_entry_no in KERNEL_TOP_PAGE_ENTRY_NO..512 {
202             copy_mapping(pml4_entry_no);
203         }
204 
205         return Ok(crate::mm::ucontext::UserMapper::new(new_umapper));
206     }
207 
208     unsafe fn phys_2_virt(phys: PhysAddr) -> Option<VirtAddr> {
209         // riscv的内核文件所占用的空间,由于重定位而导致不满足线性偏移量的关系
210         // 因此这里需要特殊处理
211         if phys >= KERNEL_BEGIN_PA && phys < KERNEL_END_PA {
212             let r = KERNEL_BEGIN_VA + (phys - KERNEL_BEGIN_PA);
213             return Some(r);
214         }
215 
216         if let Some(vaddr) = phys.data().checked_add(Self::PHYS_OFFSET) {
217             return Some(VirtAddr::new(vaddr));
218         } else {
219             return None;
220         }
221     }
222 
223     unsafe fn virt_2_phys(virt: VirtAddr) -> Option<PhysAddr> {
224         if virt >= KERNEL_BEGIN_VA && virt < KERNEL_END_VA {
225             let r = KERNEL_BEGIN_PA + (virt - KERNEL_BEGIN_VA);
226             return Some(r);
227         }
228 
229         if let Some(paddr) = virt.data().checked_sub(Self::PHYS_OFFSET) {
230             let r = PhysAddr::new(paddr);
231             return Some(r);
232         } else {
233             return None;
234         }
235     }
236 
237     fn make_entry(paddr: PhysAddr, page_flags: usize) -> usize {
238         let ppn = PhysPageFrame::new(paddr).ppn();
239         let r = ((ppn & ((1 << 54) - 1)) << 10) | page_flags;
240         return r;
241     }
242 }
243 
244 impl VirtAddr {
245     /// 判断虚拟地址是否合法
246     #[inline(always)]
247     pub fn is_canonical(self) -> bool {
248         let x = self.data() & RiscV64MMArch::PHYS_OFFSET;
249         // 如果x为0,说明虚拟地址的高位为0,是合法的用户地址
250         // 如果x为PHYS_OFFSET,说明虚拟地址的高位全为1,是合法的内核地址
251         return x == 0 || x == RiscV64MMArch::PHYS_OFFSET;
252     }
253 }
254 
255 /// 获取内核地址默认的页面标志
256 pub unsafe fn kernel_page_flags<A: MemoryManagementArch>(_virt: VirtAddr) -> PageFlags<A> {
257     PageFlags::from_data(RiscV64MMArch::ENTRY_FLAG_DEFAULT_PAGE)
258         .set_user(false)
259         .set_execute(true)
260 }
261 
262 /// 全局的页帧分配器
263 #[derive(Debug, Clone, Copy, Hash)]
264 pub struct LockedFrameAllocator;
265 
266 impl FrameAllocator for LockedFrameAllocator {
267     unsafe fn allocate(&mut self, count: PageFrameCount) -> Option<(PhysAddr, PageFrameCount)> {
268         if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() {
269             return allocator.allocate(count);
270         } else {
271             return None;
272         }
273     }
274 
275     unsafe fn free(&mut self, address: crate::mm::PhysAddr, count: PageFrameCount) {
276         assert!(count.data().is_power_of_two());
277         if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() {
278             return allocator.free(address, count);
279         }
280     }
281 
282     unsafe fn usage(&self) -> PageFrameUsage {
283         if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() {
284             return allocator.usage();
285         } else {
286             panic!("usage error");
287         }
288     }
289 }
290