1 pub mod barrier; 2 pub mod bump; 3 4 use alloc::vec::Vec; 5 use hashbrown::HashSet; 6 use x86::time::rdtsc; 7 use x86_64::registers::model_specific::EferFlags; 8 9 use crate::driver::serial::serial8250::send_to_default_serial8250_port; 10 use crate::include::bindings::bindings::{ 11 multiboot2_get_load_base, multiboot2_get_memory, multiboot2_iter, multiboot_mmap_entry_t, 12 multiboot_tag_load_base_addr_t, 13 }; 14 use crate::libs::align::page_align_up; 15 use crate::libs::lib_ui::screen_manager::scm_disable_put_to_window; 16 use crate::libs::spinlock::SpinLock; 17 18 use crate::mm::allocator::page_frame::{FrameAllocator, PageFrameCount, PageFrameUsage}; 19 use crate::mm::memblock::mem_block_manager; 20 use crate::{ 21 arch::MMArch, 22 mm::allocator::{buddy::BuddyAllocator, bump::BumpAllocator}, 23 }; 24 25 use crate::mm::kernel_mapper::KernelMapper; 26 use crate::mm::page::{PageEntry, PageFlags, PAGE_1G_SHIFT}; 27 use crate::mm::{MemoryManagementArch, PageTableKind, PhysAddr, VirtAddr}; 28 use crate::{kdebug, kinfo, kwarn}; 29 use system_error::SystemError; 30 31 use core::arch::asm; 32 use core::ffi::c_void; 33 use core::fmt::Debug; 34 use core::mem::{self}; 35 36 use core::sync::atomic::{compiler_fence, AtomicBool, Ordering}; 37 38 use super::kvm::vmx::vmcs::VmcsFields; 39 use super::kvm::vmx::vmx_asm_wrapper::vmx_vmread; 40 41 pub type PageMapper = 42 crate::mm::page::PageMapper<crate::arch::x86_64::mm::X86_64MMArch, LockedFrameAllocator>; 43 44 /// 初始的CR3寄存器的值，用于内存管理初始化时，创建的第一个内核页表的位置 45 static mut INITIAL_CR3_VALUE: PhysAddr = PhysAddr::new(0); 46 47 /// 内核的第一个页表在pml4中的索引 48 /// 顶级页表的[256, 512)项是内核的页表 49 static KERNEL_PML4E_NO: usize = (X86_64MMArch::PHYS_OFFSET & ((1 << 48) - 1)) >> 39; 50 51 static INNER_ALLOCATOR: SpinLock<Option<BuddyAllocator<MMArch>>> = SpinLock::new(None); 52 53 #[derive(Clone, Copy, Debug)] 54 pub struct X86_64MMBootstrapInfo { 55 kernel_load_base_paddr: usize, 56 kernel_code_start: usize, 57 kernel_code_end: usize, 58 kernel_data_end: usize, 59 kernel_rodata_end: usize, 60 start_brk: usize, 61 } 62 63 pub(super) static mut BOOTSTRAP_MM_INFO: Option<X86_64MMBootstrapInfo> = None; 64 65 /// @brief X86_64的内存管理架构结构体 66 #[derive(Debug, Clone, Copy, Hash)] 67 pub struct X86_64MMArch; 68 69 /// XD标志位是否被保留 70 static XD_RESERVED: AtomicBool = AtomicBool::new(false); 71 72 impl MemoryManagementArch for X86_64MMArch { 73 /// 4K页 74 const PAGE_SHIFT: usize = 12; 75 76 /// 每个页表项占8字节，总共有512个页表项 77 const PAGE_ENTRY_SHIFT: usize = 9; 78 79 /// 四级页表（PML4T、PDPT、PDT、PT） 80 const PAGE_LEVELS: usize = 4; 81 82 /// 页表项的有效位的index。在x86_64中，页表项的第[0, 47]位表示地址和flag， 83 /// 第[48, 51]位表示保留。因此，有效位的index为52。 84 /// 请注意，第63位是XD位，表示是否允许执行。 85 const ENTRY_ADDRESS_SHIFT: usize = 52; 86 87 const ENTRY_FLAG_DEFAULT_PAGE: usize = Self::ENTRY_FLAG_PRESENT; 88 89 const ENTRY_FLAG_DEFAULT_TABLE: usize = Self::ENTRY_FLAG_PRESENT; 90 91 const ENTRY_FLAG_PRESENT: usize = 1 << 0; 92 93 const ENTRY_FLAG_READONLY: usize = 0; 94 95 const ENTRY_FLAG_READWRITE: usize = 1 << 1; 96 97 const ENTRY_FLAG_USER: usize = 1 << 2; 98 99 const ENTRY_FLAG_WRITE_THROUGH: usize = 1 << 3; 100 101 const ENTRY_FLAG_CACHE_DISABLE: usize = 1 << 4; 102 103 const ENTRY_FLAG_NO_EXEC: usize = 1 << 63; 104 /// x86_64不存在EXEC标志位，只有NO_EXEC（XD）标志位 105 const ENTRY_FLAG_EXEC: usize = 0; 106 107 const ENTRY_FLAG_ACCESSED: usize = 0; 108 const ENTRY_FLAG_DIRTY: usize = 0; 109 110 /// 物理地址与虚拟地址的偏移量 111 /// 0xffff_8000_0000_0000 112 const PHYS_OFFSET: usize = Self::PAGE_NEGATIVE_MASK + (Self::PAGE_ADDRESS_SIZE >> 1); 113 const KERNEL_LINK_OFFSET: usize = 0x100000; 114 115 // 参考 https://code.dragonos.org.cn/xref/linux-6.1.9/arch/x86/include/asm/page_64_types.h#75 116 const USER_END_VADDR: VirtAddr = 117 VirtAddr::new((Self::PAGE_ADDRESS_SIZE >> 1) - Self::PAGE_SIZE); 118 const USER_BRK_START: VirtAddr = VirtAddr::new(0x700000000000); 119 const USER_STACK_START: VirtAddr = VirtAddr::new(0x6ffff0a00000); 120 121 const FIXMAP_START_VADDR: VirtAddr = VirtAddr::new(0xffffb00000000000); 122 /// 设置FIXMAP区域大小为1M 123 const FIXMAP_SIZE: usize = 256 * 4096; 124 125 const MMIO_BASE: VirtAddr = VirtAddr::new(0xffffa10000000000); 126 const MMIO_SIZE: usize = 1 << PAGE_1G_SHIFT; 127 128 /// @brief 获取物理内存区域 129 unsafe fn init() { 130 extern "C" { 131 fn _text(); 132 fn _etext(); 133 fn _edata(); 134 fn _erodata(); 135 fn _end(); 136 } 137 138 Self::init_xd_rsvd(); 139 let load_base_paddr = Self::get_load_base_paddr(); 140 141 let bootstrap_info = X86_64MMBootstrapInfo { 142 kernel_load_base_paddr: load_base_paddr.data(), 143 kernel_code_start: _text as usize, 144 kernel_code_end: _etext as usize, 145 kernel_data_end: _edata as usize, 146 kernel_rodata_end: _erodata as usize, 147 start_brk: _end as usize, 148 }; 149 150 unsafe { 151 BOOTSTRAP_MM_INFO = Some(bootstrap_info); 152 } 153 154 // 初始化物理内存区域(从multiboot2中获取) 155 Self::init_memory_area_from_multiboot2().expect("init memory area failed"); 156 157 kdebug!("bootstrap info: {:?}", unsafe { BOOTSTRAP_MM_INFO }); 158 kdebug!("phys[0]=virt[0x{:x}]", unsafe { 159 MMArch::phys_2_virt(PhysAddr::new(0)).unwrap().data() 160 }); 161 162 // 初始化内存管理器 163 unsafe { allocator_init() }; 164 165 send_to_default_serial8250_port("x86 64 init done\n\0".as_bytes()); 166 } 167 168 /// @brief 刷新TLB中，关于指定虚拟地址的条目 169 unsafe fn invalidate_page(address: VirtAddr) { 170 compiler_fence(Ordering::SeqCst); 171 asm!("invlpg [{0}]", in(reg) address.data(), options(nostack, preserves_flags)); 172 compiler_fence(Ordering::SeqCst); 173 } 174 175 /// @brief 刷新TLB中，所有的条目 176 unsafe fn invalidate_all() { 177 compiler_fence(Ordering::SeqCst); 178 // 通过设置cr3寄存器，来刷新整个TLB 179 Self::set_table(PageTableKind::User, Self::table(PageTableKind::User)); 180 compiler_fence(Ordering::SeqCst); 181 } 182 183 /// @brief 获取顶级页表的物理地址 184 unsafe fn table(table_kind: PageTableKind) -> PhysAddr { 185 match table_kind { 186 PageTableKind::Kernel | PageTableKind::User => { 187 compiler_fence(Ordering::SeqCst); 188 let cr3 = x86::controlregs::cr3() as usize; 189 compiler_fence(Ordering::SeqCst); 190 return PhysAddr::new(cr3); 191 } 192 PageTableKind::EPT => { 193 let eptp = 194 vmx_vmread(VmcsFields::CTRL_EPTP_PTR as u32).expect("Failed to read eptp"); 195 return PhysAddr::new(eptp as usize); 196 } 197 } 198 } 199 200 /// @brief 设置顶级页表的物理地址到处理器中 201 unsafe fn set_table(_table_kind: PageTableKind, table: PhysAddr) { 202 compiler_fence(Ordering::SeqCst); 203 asm!("mov cr3, {}", in(reg) table.data(), options(nostack, preserves_flags)); 204 compiler_fence(Ordering::SeqCst); 205 } 206 207 /// @brief 判断虚拟地址是否合法 208 fn virt_is_valid(virt: VirtAddr) -> bool { 209 return virt.is_canonical(); 210 } 211 212 /// 获取内存管理初始化时，创建的第一个内核页表的地址 213 fn initial_page_table() -> PhysAddr { 214 unsafe { 215 return INITIAL_CR3_VALUE; 216 } 217 } 218 219 /// @brief 创建新的顶层页表 220 /// 221 /// 该函数会创建页表并复制内核的映射到新的页表中 222 /// 223 /// @return 新的页表 224 fn setup_new_usermapper() -> Result<crate::mm::ucontext::UserMapper, SystemError> { 225 let new_umapper: crate::mm::page::PageMapper<X86_64MMArch, LockedFrameAllocator> = unsafe { 226 PageMapper::create(PageTableKind::User, LockedFrameAllocator) 227 .ok_or(SystemError::ENOMEM)? 228 }; 229 230 let current_ktable: KernelMapper = KernelMapper::lock(); 231 let copy_mapping = |pml4_entry_no| unsafe { 232 let entry: PageEntry<X86_64MMArch> = current_ktable 233 .table() 234 .entry(pml4_entry_no) 235 .unwrap_or_else(|| panic!("entry {} not found", pml4_entry_no)); 236 new_umapper.table().set_entry(pml4_entry_no, entry) 237 }; 238 239 // 复制内核的映射 240 for pml4_entry_no in KERNEL_PML4E_NO..512 { 241 copy_mapping(pml4_entry_no); 242 } 243 244 return Ok(crate::mm::ucontext::UserMapper::new(new_umapper)); 245 } 246 247 const PAGE_SIZE: usize = 1 << Self::PAGE_SHIFT; 248 249 const PAGE_OFFSET_MASK: usize = Self::PAGE_SIZE - 1; 250 251 const PAGE_MASK: usize = !(Self::PAGE_OFFSET_MASK); 252 253 const PAGE_ADDRESS_SHIFT: usize = Self::PAGE_LEVELS * Self::PAGE_ENTRY_SHIFT + Self::PAGE_SHIFT; 254 255 const PAGE_ADDRESS_SIZE: usize = 1 << Self::PAGE_ADDRESS_SHIFT; 256 257 const PAGE_ADDRESS_MASK: usize = Self::PAGE_ADDRESS_SIZE - Self::PAGE_SIZE; 258 259 const PAGE_ENTRY_SIZE: usize = 1 << (Self::PAGE_SHIFT - Self::PAGE_ENTRY_SHIFT); 260 261 const PAGE_ENTRY_NUM: usize = 1 << Self::PAGE_ENTRY_SHIFT; 262 263 const PAGE_ENTRY_MASK: usize = Self::PAGE_ENTRY_NUM - 1; 264 265 const PAGE_NEGATIVE_MASK: usize = !((Self::PAGE_ADDRESS_SIZE) - 1); 266 267 const ENTRY_ADDRESS_SIZE: usize = 1 << Self::ENTRY_ADDRESS_SHIFT; 268 269 const ENTRY_ADDRESS_MASK: usize = Self::ENTRY_ADDRESS_SIZE - Self::PAGE_SIZE; 270 271 const ENTRY_FLAGS_MASK: usize = !Self::ENTRY_ADDRESS_MASK; 272 273 unsafe fn read<T>(address: VirtAddr) -> T { 274 return core::ptr::read(address.data() as *const T); 275 } 276 277 unsafe fn write<T>(address: VirtAddr, value: T) { 278 core::ptr::write(address.data() as *mut T, value); 279 } 280 281 unsafe fn write_bytes(address: VirtAddr, value: u8, count: usize) { 282 core::ptr::write_bytes(address.data() as *mut u8, value, count); 283 } 284 285 unsafe fn phys_2_virt(phys: PhysAddr) -> Option<VirtAddr> { 286 if let Some(vaddr) = phys.data().checked_add(Self::PHYS_OFFSET) { 287 return Some(VirtAddr::new(vaddr)); 288 } else { 289 return None; 290 } 291 } 292 293 unsafe fn virt_2_phys(virt: VirtAddr) -> Option<PhysAddr> { 294 if let Some(paddr) = virt.data().checked_sub(Self::PHYS_OFFSET) { 295 return Some(PhysAddr::new(paddr)); 296 } else { 297 return None; 298 } 299 } 300 301 #[inline(always)] 302 fn make_entry(paddr: PhysAddr, page_flags: usize) -> usize { 303 return paddr.data() | page_flags; 304 } 305 } 306 307 impl X86_64MMArch { 308 unsafe fn get_load_base_paddr() -> PhysAddr { 309 let mut mb2_lb_info: [multiboot_tag_load_base_addr_t; 512] = mem::zeroed(); 310 send_to_default_serial8250_port("get_load_base_paddr begin\n\0".as_bytes()); 311 312 let mut mb2_count: u32 = 0; 313 multiboot2_iter( 314 Some(multiboot2_get_load_base), 315 &mut mb2_lb_info as *mut [multiboot_tag_load_base_addr_t; 512] as usize as *mut c_void, 316 &mut mb2_count, 317 ); 318 319 if mb2_count == 0 { 320 send_to_default_serial8250_port( 321 "get_load_base_paddr mb2_count == 0, default to 1MB\n\0".as_bytes(), 322 ); 323 return PhysAddr::new(0x100000); 324 } 325 326 let phys = mb2_lb_info[0].load_base_addr as usize; 327 328 return PhysAddr::new(phys); 329 } 330 unsafe fn init_memory_area_from_multiboot2() -> Result<usize, SystemError> { 331 // 这个数组用来存放内存区域的信息（从C获取） 332 let mut mb2_mem_info: [multiboot_mmap_entry_t; 512] = mem::zeroed(); 333 send_to_default_serial8250_port("init_memory_area_from_multiboot2 begin\n\0".as_bytes()); 334 335 let mut mb2_count: u32 = 0; 336 multiboot2_iter( 337 Some(multiboot2_get_memory), 338 &mut mb2_mem_info as *mut [multiboot_mmap_entry_t; 512] as usize as *mut c_void, 339 &mut mb2_count, 340 ); 341 send_to_default_serial8250_port("init_memory_area_from_multiboot2 2\n\0".as_bytes()); 342 343 let mb2_count = mb2_count as usize; 344 let mut areas_count = 0usize; 345 let mut total_mem_size = 0usize; 346 for info_entry in mb2_mem_info.iter().take(mb2_count) { 347 // Only use the memory area if its type is 1 (RAM) 348 if info_entry.type_ == 1 { 349 // Skip the memory area if its len is 0 350 if info_entry.len == 0 { 351 continue; 352 } 353 354 total_mem_size += info_entry.len as usize; 355 356 mem_block_manager() 357 .add_block( 358 PhysAddr::new(info_entry.addr as usize), 359 info_entry.len as usize, 360 ) 361 .unwrap_or_else(|e| { 362 kwarn!( 363 "Failed to add memory block: base={:#x}, size={:#x}, error={:?}", 364 info_entry.addr, 365 info_entry.len, 366 e 367 ); 368 }); 369 areas_count += 1; 370 } 371 } 372 send_to_default_serial8250_port("init_memory_area_from_multiboot2 end\n\0".as_bytes()); 373 kinfo!("Total memory size: {} MB, total areas from multiboot2: {mb2_count}, valid areas: {areas_count}", total_mem_size / 1024 / 1024); 374 return Ok(areas_count); 375 } 376 377 fn init_xd_rsvd() { 378 // 读取ia32-EFER寄存器的值 379 let efer: EferFlags = x86_64::registers::model_specific::Efer::read(); 380 if !efer.contains(EferFlags::NO_EXECUTE_ENABLE) { 381 // NO_EXECUTE_ENABLE是false，那么就设置xd_reserved为true 382 kdebug!("NO_EXECUTE_ENABLE is false, set XD_RESERVED to true"); 383 XD_RESERVED.store(true, Ordering::Relaxed); 384 } 385 compiler_fence(Ordering::SeqCst); 386 } 387 388 /// 判断XD标志位是否被保留 389 pub fn is_xd_reserved() -> bool { 390 // return XD_RESERVED.load(Ordering::Relaxed); 391 392 // 由于暂时不支持execute disable，因此直接返回true 393 // 不支持的原因是，目前好像没有能正确的设置page-level的xd位，会触发page fault 394 return true; 395 } 396 } 397 398 impl VirtAddr { 399 /// @brief 判断虚拟地址是否合法 400 #[inline(always)] 401 pub fn is_canonical(self) -> bool { 402 let x = self.data() & X86_64MMArch::PHYS_OFFSET; 403 // 如果x为0，说明虚拟地址的高位为0，是合法的用户地址 404 // 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 405 return x == 0 || x == X86_64MMArch::PHYS_OFFSET; 406 } 407 } 408 409 unsafe fn allocator_init() { 410 let virt_offset = VirtAddr::new(page_align_up(BOOTSTRAP_MM_INFO.unwrap().start_brk)); 411 412 let phy_offset = unsafe { MMArch::virt_2_phys(virt_offset) }.unwrap(); 413 414 mem_block_manager() 415 .reserve_block(PhysAddr::new(0), phy_offset.data()) 416 .expect("Failed to reserve block"); 417 let mut bump_allocator = BumpAllocator::<X86_64MMArch>::new(phy_offset.data()); 418 kdebug!( 419 "BumpAllocator created, offset={:?}", 420 bump_allocator.offset() 421 ); 422 423 // 暂存初始在head.S中指定的页表的地址，后面再考虑是否需要把它加到buddy的可用空间里面！ 424 // 现在不加的原因是，我担心会有安全漏洞问题：这些初始的页表，位于内核的数据段。如果归还到buddy， 425 // 可能会产生一定的安全风险（有的代码可能根据虚拟地址来进行安全校验） 426 let _old_page_table = MMArch::table(PageTableKind::Kernel); 427 428 let new_page_table: PhysAddr; 429 // 使用bump分配器，把所有的内存页都映射到页表 430 { 431 // 用bump allocator创建新的页表 432 let mut mapper: crate::mm::page::PageMapper<MMArch, &mut BumpAllocator<MMArch>> = 433 crate::mm::page::PageMapper::<MMArch, _>::create( 434 PageTableKind::Kernel, 435 &mut bump_allocator, 436 ) 437 .expect("Failed to create page mapper"); 438 new_page_table = mapper.table().phys(); 439 kdebug!("PageMapper created"); 440 441 // 取消最开始时候，在head.S中指定的映射(暂时不刷新TLB) 442 { 443 let table = mapper.table(); 444 let empty_entry = PageEntry::<MMArch>::from_usize(0); 445 for i in 0..MMArch::PAGE_ENTRY_NUM { 446 table 447 .set_entry(i, empty_entry) 448 .expect("Failed to empty page table entry"); 449 } 450 } 451 kdebug!("Successfully emptied page table"); 452 453 let total_num = mem_block_manager().total_initial_memory_regions(); 454 for i in 0..total_num { 455 let area = mem_block_manager().get_initial_memory_region(i).unwrap(); 456 // kdebug!("area: base={:?}, size={:#x}, end={:?}", area.base, area.size, area.base + area.size); 457 for i in 0..((area.size + MMArch::PAGE_SIZE - 1) / MMArch::PAGE_SIZE) { 458 let paddr = area.base.add(i * MMArch::PAGE_SIZE); 459 let vaddr = unsafe { MMArch::phys_2_virt(paddr) }.unwrap(); 460 let flags = kernel_page_flags::<MMArch>(vaddr); 461 462 let flusher = mapper 463 .map_phys(vaddr, paddr, flags) 464 .expect("Failed to map frame"); 465 // 暂时不刷新TLB 466 flusher.ignore(); 467 } 468 } 469 } 470 471 unsafe { 472 INITIAL_CR3_VALUE = new_page_table; 473 } 474 kdebug!( 475 "After mapping all physical memory, DragonOS used: {} KB", 476 bump_allocator.offset() / 1024 477 ); 478 479 // 初始化buddy_allocator 480 let buddy_allocator = unsafe { BuddyAllocator::<X86_64MMArch>::new(bump_allocator).unwrap() }; 481 // 设置全局的页帧分配器 482 unsafe { set_inner_allocator(buddy_allocator) }; 483 kinfo!("Successfully initialized buddy allocator"); 484 // 关闭显示输出 485 scm_disable_put_to_window(); 486 487 // make the new page table current 488 { 489 let mut binding = INNER_ALLOCATOR.lock(); 490 let mut allocator_guard = binding.as_mut().unwrap(); 491 kdebug!("To enable new page table."); 492 compiler_fence(Ordering::SeqCst); 493 let mapper = crate::mm::page::PageMapper::<MMArch, _>::new( 494 PageTableKind::Kernel, 495 new_page_table, 496 &mut allocator_guard, 497 ); 498 compiler_fence(Ordering::SeqCst); 499 mapper.make_current(); 500 compiler_fence(Ordering::SeqCst); 501 kdebug!("New page table enabled"); 502 } 503 kdebug!("Successfully enabled new page table"); 504 } 505 506 #[no_mangle] 507 pub extern "C" fn rs_test_buddy() { 508 test_buddy(); 509 } 510 pub fn test_buddy() { 511 // 申请内存然后写入数据然后free掉 512 // 总共申请200MB内存 513 const TOTAL_SIZE: usize = 200 * 1024 * 1024; 514 515 for i in 0..10 { 516 kdebug!("Test buddy, round: {i}"); 517 // 存放申请的内存块 518 let mut v: Vec<(PhysAddr, PageFrameCount)> = Vec::with_capacity(60 * 1024); 519 // 存放已经申请的内存块的地址（用于检查重复） 520 let mut addr_set: HashSet<PhysAddr> = HashSet::new(); 521 522 let mut allocated = 0usize; 523 524 let mut free_count = 0usize; 525 526 while allocated < TOTAL_SIZE { 527 let mut random_size = 0u64; 528 unsafe { x86::random::rdrand64(&mut random_size) }; 529 // 一次最多申请4M 530 random_size %= 1024 * 4096; 531 if random_size == 0 { 532 continue; 533 } 534 let random_size = 535 core::cmp::min(page_align_up(random_size as usize), TOTAL_SIZE - allocated); 536 let random_size = PageFrameCount::from_bytes(random_size.next_power_of_two()).unwrap(); 537 // 获取帧 538 let (paddr, allocated_frame_count) = 539 unsafe { LockedFrameAllocator.allocate(random_size).unwrap() }; 540 assert!(allocated_frame_count.data().is_power_of_two()); 541 assert!(paddr.data() % MMArch::PAGE_SIZE == 0); 542 unsafe { 543 assert!(MMArch::phys_2_virt(paddr) 544 .as_ref() 545 .unwrap() 546 .check_aligned(allocated_frame_count.data() * MMArch::PAGE_SIZE)); 547 } 548 allocated += allocated_frame_count.data() * MMArch::PAGE_SIZE; 549 v.push((paddr, allocated_frame_count)); 550 assert!(addr_set.insert(paddr), "duplicate address: {:?}", paddr); 551 552 // 写入数据 553 let vaddr = unsafe { MMArch::phys_2_virt(paddr).unwrap() }; 554 let slice = unsafe { 555 core::slice::from_raw_parts_mut( 556 vaddr.data() as *mut u8, 557 allocated_frame_count.data() * MMArch::PAGE_SIZE, 558 ) 559 }; 560 for (i, item) in slice.iter_mut().enumerate() { 561 *item = ((i + unsafe { rdtsc() } as usize) % 256) as u8; 562 } 563 564 // 随机释放一个内存块 565 if !v.is_empty() { 566 let mut random_index = 0u64; 567 unsafe { x86::random::rdrand64(&mut random_index) }; 568 // 70%概率释放 569 if random_index % 10 > 7 { 570 continue; 571 } 572 random_index %= v.len() as u64; 573 let random_index = random_index as usize; 574 let (paddr, allocated_frame_count) = v.remove(random_index); 575 assert!(addr_set.remove(&paddr)); 576 unsafe { LockedFrameAllocator.free(paddr, allocated_frame_count) }; 577 free_count += allocated_frame_count.data() * MMArch::PAGE_SIZE; 578 } 579 } 580 581 kdebug!( 582 "Allocated {} MB memory, release: {} MB, no release: {} bytes", 583 allocated / 1024 / 1024, 584 free_count / 1024 / 1024, 585 (allocated - free_count) 586 ); 587 588 kdebug!("Now, to release buddy memory"); 589 // 释放所有的内存 590 for (paddr, allocated_frame_count) in v { 591 unsafe { LockedFrameAllocator.free(paddr, allocated_frame_count) }; 592 assert!(addr_set.remove(&paddr)); 593 free_count += allocated_frame_count.data() * MMArch::PAGE_SIZE; 594 } 595 596 kdebug!("release done!, allocated: {allocated}, free_count: {free_count}"); 597 } 598 } 599 600 /// 全局的页帧分配器 601 #[derive(Debug, Clone, Copy, Hash)] 602 pub struct LockedFrameAllocator; 603 604 impl FrameAllocator for LockedFrameAllocator { 605 unsafe fn allocate(&mut self, mut count: PageFrameCount) -> Option<(PhysAddr, PageFrameCount)> { 606 count = count.next_power_of_two(); 607 if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() { 608 return allocator.allocate(count); 609 } else { 610 return None; 611 } 612 } 613 614 unsafe fn free(&mut self, address: crate::mm::PhysAddr, count: PageFrameCount) { 615 assert!(count.data().is_power_of_two()); 616 if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() { 617 return allocator.free(address, count); 618 } 619 } 620 621 unsafe fn usage(&self) -> PageFrameUsage { 622 if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() { 623 return allocator.usage(); 624 } else { 625 panic!("usage error"); 626 } 627 } 628 } 629 630 /// 获取内核地址默认的页面标志 631 pub unsafe fn kernel_page_flags<A: MemoryManagementArch>(virt: VirtAddr) -> PageFlags<A> { 632 let info: X86_64MMBootstrapInfo = BOOTSTRAP_MM_INFO.unwrap(); 633 634 if virt.data() >= info.kernel_code_start && virt.data() < info.kernel_code_end { 635 // Remap kernel code execute 636 return PageFlags::new().set_execute(true).set_write(true); 637 } else if virt.data() >= info.kernel_data_end && virt.data() < info.kernel_rodata_end { 638 // Remap kernel rodata read only 639 return PageFlags::new().set_execute(true); 640 } else { 641 return PageFlags::new().set_write(true).set_execute(true); 642 } 643 } 644 645 unsafe fn set_inner_allocator(allocator: BuddyAllocator<MMArch>) { 646 static FLAG: AtomicBool = AtomicBool::new(false); 647 if FLAG 648 .compare_exchange(false, true, Ordering::SeqCst, Ordering::SeqCst) 649 .is_err() 650 { 651 panic!("Cannot set inner allocator twice!"); 652 } 653 *INNER_ALLOCATOR.lock() = Some(allocator); 654 } 655 656 /// 低地址重映射的管理器 657 /// 658 /// 低地址重映射的管理器，在smp初始化完成之前，需要使用低地址的映射，因此需要在smp初始化完成之后，取消这一段映射 659 pub struct LowAddressRemapping; 660 661 impl LowAddressRemapping { 662 // 映射64M 663 const REMAP_SIZE: usize = 64 * 1024 * 1024; 664 665 pub unsafe fn remap_at_low_address(mapper: &mut PageMapper) { 666 for i in 0..(Self::REMAP_SIZE / MMArch::PAGE_SIZE) { 667 let paddr = PhysAddr::new(i * MMArch::PAGE_SIZE); 668 let vaddr = VirtAddr::new(i * MMArch::PAGE_SIZE); 669 let flags = kernel_page_flags::<MMArch>(vaddr); 670 671 let flusher = mapper 672 .map_phys(vaddr, paddr, flags) 673 .expect("Failed to map frame"); 674 // 暂时不刷新TLB 675 flusher.ignore(); 676 } 677 } 678 679 /// 取消低地址的映射 680 pub unsafe fn unmap_at_low_address(mapper: &mut PageMapper, flush: bool) { 681 for i in 0..(Self::REMAP_SIZE / MMArch::PAGE_SIZE) { 682 let vaddr = VirtAddr::new(i * MMArch::PAGE_SIZE); 683 let (_, _, flusher) = mapper 684 .unmap_phys(vaddr, true) 685 .expect("Failed to unmap frame"); 686 if !flush { 687 flusher.ignore(); 688 } 689 } 690 } 691 } 692