xref: /DragonOS/kernel/src/arch/riscv64/mm/mod.rs (revision 731bc2b32d7b37298883d7a15b6dca659b436ee4)
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     /// 使远程cpu的TLB中,指定地址范围的页失效
46     pub fn remote_invalidate_page(
47         cpu: ProcessorId,
48         address: VirtAddr,
49         size: usize,
50     ) -> Result<(), SbiRet> {
51         let r = sbi_rt::remote_sfence_vma(Into::into(cpu), address.data(), size);
52         if r.is_ok() {
53             return Ok(());
54         } else {
55             return Err(r);
56         }
57     }
58 
59     /// 使指定远程cpu的TLB中,所有范围的页失效
60     pub fn remote_invalidate_all(cpu: ProcessorId) -> Result<(), SbiRet> {
61         let r = Self::remote_invalidate_page(
62             cpu,
63             VirtAddr::new(0),
64             1 << RiscV64MMArch::ENTRY_ADDRESS_SHIFT,
65         );
66 
67         return r;
68     }
69 
70     pub fn remote_invalidate_all_with_mask(mask: HartMask) -> Result<(), SbiRet> {
71         let r = sbi_rt::remote_sfence_vma(mask, 0, 1 << RiscV64MMArch::ENTRY_ADDRESS_SHIFT);
72         if r.is_ok() {
73             return Ok(());
74         } else {
75             return Err(r);
76         }
77     }
78 }
79 
80 /// 内核空间起始地址在顶层页表中的索引
81 const KERNEL_TOP_PAGE_ENTRY_NO: usize = (RiscV64MMArch::PHYS_OFFSET
82     & ((1 << RiscV64MMArch::ENTRY_ADDRESS_SHIFT) - 1))
83     >> (RiscV64MMArch::ENTRY_ADDRESS_SHIFT - RiscV64MMArch::PAGE_ENTRY_SHIFT);
84 
85 impl MemoryManagementArch for RiscV64MMArch {
86     /// riscv64暂不支持缺页中断
87     const PAGE_FAULT_ENABLED: bool = false;
88 
89     const PAGE_SHIFT: usize = 12;
90 
91     const PAGE_ENTRY_SHIFT: usize = 9;
92 
93     /// sv39分页只有三级
94     const PAGE_LEVELS: usize = 3;
95 
96     const ENTRY_ADDRESS_SHIFT: usize = 39;
97 
98     const ENTRY_FLAG_DEFAULT_PAGE: usize = Self::ENTRY_FLAG_PRESENT
99         | Self::ENTRY_FLAG_READWRITE
100         | Self::ENTRY_FLAG_DIRTY
101         | Self::ENTRY_FLAG_ACCESSED
102         | Self::ENTRY_FLAG_GLOBAL;
103 
104     const ENTRY_FLAG_DEFAULT_TABLE: usize = Self::ENTRY_FLAG_PRESENT;
105 
106     const ENTRY_FLAG_PRESENT: usize = 1 << 0;
107 
108     const ENTRY_FLAG_READONLY: usize = 0;
109 
110     const ENTRY_FLAG_READWRITE: usize = (1 << 2) | (1 << 1);
111 
112     const ENTRY_FLAG_USER: usize = (1 << 4);
113     const ENTRY_ADDRESS_MASK: usize = Self::ENTRY_ADDRESS_SIZE - (1 << 10);
114     const ENTRY_FLAG_WRITE_THROUGH: usize = (2 << 61);
115 
116     const ENTRY_FLAG_CACHE_DISABLE: usize = (2 << 61);
117 
118     const ENTRY_FLAG_NO_EXEC: usize = 0;
119 
120     const ENTRY_FLAG_EXEC: usize = (1 << 3);
121     const ENTRY_FLAG_ACCESSED: usize = (1 << 6);
122     const ENTRY_FLAG_DIRTY: usize = (1 << 7);
123     const ENTRY_FLAG_GLOBAL: usize = (1 << 5);
124 
125     const PHYS_OFFSET: usize = 0xffff_ffc0_0000_0000;
126     const KERNEL_LINK_OFFSET: usize = 0x1000000;
127 
128     const USER_END_VADDR: crate::mm::VirtAddr = VirtAddr::new(0x0000_003f_ffff_ffff);
129 
130     const USER_BRK_START: crate::mm::VirtAddr = VirtAddr::new(0x0000_001f_ffff_ffff);
131 
132     const USER_STACK_START: crate::mm::VirtAddr = VirtAddr::new(0x0000_001f_ffa0_0000);
133 
134     /// 在距离sv39的顶端还有64M的位置,设置为FIXMAP的起始地址
135     const FIXMAP_START_VADDR: VirtAddr = VirtAddr::new(0xffff_ffff_fc00_0000);
136     /// 设置1MB的fixmap空间
137     const FIXMAP_SIZE: usize = 256 * 4096;
138 
139     /// 在距离sv39的顶端还有2G的位置,设置为MMIO空间的起始地址
140     const MMIO_BASE: VirtAddr = VirtAddr::new(0xffff_ffff_8000_0000);
141     /// 设置1g的MMIO空间
142     const MMIO_SIZE: usize = 1 << PAGE_1G_SHIFT;
143 
144     const ENTRY_FLAG_HUGE_PAGE: usize = Self::ENTRY_FLAG_PRESENT | Self::ENTRY_FLAG_READWRITE;
145 
146     #[inline(never)]
147     unsafe fn init() {
148         riscv_mm_init().expect("init kernel memory management architecture failed");
149     }
150 
151     unsafe fn arch_post_init() {
152         // 映射fdt
153         open_firmware_fdt_driver()
154             .map_fdt()
155             .expect("openfirmware map fdt failed");
156     }
157 
158     unsafe fn invalidate_page(address: VirtAddr) {
159         riscv::asm::sfence_vma(0, address.data());
160     }
161 
162     unsafe fn invalidate_all() {
163         riscv::asm::sfence_vma_all();
164     }
165 
166     unsafe fn table(_table_kind: PageTableKind) -> PhysAddr {
167         // phys page number
168         let ppn = riscv::register::satp::read().ppn();
169 
170         let paddr = PhysPageFrame::from_ppn(ppn).phys_address();
171 
172         return paddr;
173     }
174 
175     unsafe fn set_table(_table_kind: PageTableKind, table: PhysAddr) {
176         let ppn = PhysPageFrame::new(table).ppn();
177         riscv::asm::sfence_vma_all();
178         satp::set(satp::Mode::Sv39, 0, ppn);
179     }
180 
181     fn virt_is_valid(virt: VirtAddr) -> bool {
182         virt.is_canonical()
183     }
184 
185     fn initial_page_table() -> PhysAddr {
186         todo!()
187     }
188 
189     fn setup_new_usermapper() -> Result<UserMapper, SystemError> {
190         let new_umapper: crate::mm::page::PageMapper<MMArch, LockedFrameAllocator> = unsafe {
191             PageMapper::create(PageTableKind::User, LockedFrameAllocator)
192                 .ok_or(SystemError::ENOMEM)?
193         };
194 
195         let current_ktable: KernelMapper = KernelMapper::lock();
196         let copy_mapping = |pml4_entry_no| unsafe {
197             let entry: PageEntry<RiscV64MMArch> = current_ktable
198                 .table()
199                 .entry(pml4_entry_no)
200                 .unwrap_or_else(|| panic!("entry {} not found", pml4_entry_no));
201             new_umapper.table().set_entry(pml4_entry_no, entry)
202         };
203 
204         // 复制内核的映射
205         for pml4_entry_no in KERNEL_TOP_PAGE_ENTRY_NO..512 {
206             copy_mapping(pml4_entry_no);
207         }
208 
209         return Ok(crate::mm::ucontext::UserMapper::new(new_umapper));
210     }
211 
212     unsafe fn phys_2_virt(phys: PhysAddr) -> Option<VirtAddr> {
213         // 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
214         // 因此这里需要特殊处理
215         if phys >= KERNEL_BEGIN_PA && phys < KERNEL_END_PA {
216             let r = KERNEL_BEGIN_VA + (phys - KERNEL_BEGIN_PA);
217             return Some(r);
218         }
219 
220         if let Some(vaddr) = phys.data().checked_add(Self::PHYS_OFFSET) {
221             return Some(VirtAddr::new(vaddr));
222         } else {
223             return None;
224         }
225     }
226 
227     unsafe fn virt_2_phys(virt: VirtAddr) -> Option<PhysAddr> {
228         if virt >= KERNEL_BEGIN_VA && virt < KERNEL_END_VA {
229             let r = KERNEL_BEGIN_PA + (virt - KERNEL_BEGIN_VA);
230             return Some(r);
231         }
232 
233         if let Some(paddr) = virt.data().checked_sub(Self::PHYS_OFFSET) {
234             let r = PhysAddr::new(paddr);
235             return Some(r);
236         } else {
237             return None;
238         }
239     }
240 
241     fn make_entry(paddr: PhysAddr, page_flags: usize) -> usize {
242         let ppn = PhysPageFrame::new(paddr).ppn();
243         let r = ((ppn & ((1 << 54) - 1)) << 10) | page_flags;
244         return r;
245     }
246 
247     fn vma_access_permitted(
248         _vma: alloc::sync::Arc<crate::mm::ucontext::LockedVMA>,
249         _write: bool,
250         _execute: bool,
251         _foreign: bool,
252     ) -> bool {
253         true
254     }
255 }
256 
257 impl VirtAddr {
258     /// 判断虚拟地址是否合法
259     #[inline(always)]
260     pub fn is_canonical(self) -> bool {
261         let x = self.data() & RiscV64MMArch::PHYS_OFFSET;
262         // 如果x为0,说明虚拟地址的高位为0,是合法的用户地址
263         // 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
264         return x == 0 || x == RiscV64MMArch::PHYS_OFFSET;
265     }
266 }
267 
268 /// 获取内核地址默认的页面标志
269 pub unsafe fn kernel_page_flags<A: MemoryManagementArch>(_virt: VirtAddr) -> PageFlags<A> {
270     PageFlags::from_data(RiscV64MMArch::ENTRY_FLAG_DEFAULT_PAGE)
271         .set_user(false)
272         .set_execute(true)
273 }
274 
275 /// 全局的页帧分配器
276 #[derive(Debug, Clone, Copy, Hash)]
277 pub struct LockedFrameAllocator;
278 
279 impl FrameAllocator for LockedFrameAllocator {
280     unsafe fn allocate(&mut self, count: PageFrameCount) -> Option<(PhysAddr, PageFrameCount)> {
281         if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() {
282             return allocator.allocate(count);
283         } else {
284             return None;
285         }
286     }
287 
288     unsafe fn free(&mut self, address: crate::mm::PhysAddr, count: PageFrameCount) {
289         assert!(count.data().is_power_of_two());
290         if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() {
291             return allocator.free(address, count);
292         }
293     }
294 
295     unsafe fn usage(&self) -> PageFrameUsage {
296         if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() {
297             return allocator.usage();
298         } else {
299             panic!("usage error");
300         }
301     }
302 }
303