1 pub mod barrier; 2 pub mod bump; 3 mod c_adapter; 4 5 use alloc::vec::Vec; 6 use hashbrown::HashSet; 7 use x86::time::rdtsc; 8 use x86_64::registers::model_specific::EferFlags; 9 10 use crate::driver::serial::serial8250::send_to_default_serial8250_port; 11 use crate::include::bindings::bindings::{ 12 multiboot2_get_load_base, multiboot2_get_memory, multiboot2_iter, multiboot_mmap_entry_t, 13 multiboot_tag_load_base_addr_t, 14 }; 15 use crate::libs::align::page_align_up; 16 use crate::libs::lib_ui::screen_manager::scm_disable_put_to_window; 17 use crate::libs::spinlock::SpinLock; 18 19 use crate::mm::allocator::page_frame::{FrameAllocator, PageFrameCount, PageFrameUsage}; 20 use crate::mm::memblock::mem_block_manager; 21 use crate::{ 22 arch::MMArch, 23 mm::allocator::{buddy::BuddyAllocator, bump::BumpAllocator}, 24 }; 25 26 use crate::mm::kernel_mapper::KernelMapper; 27 use crate::mm::page::{PageEntry, PageFlags}; 28 use crate::mm::{MemoryManagementArch, PageTableKind, PhysAddr, VirtAddr}; 29 use crate::{kdebug, kinfo, kwarn}; 30 use system_error::SystemError; 31 32 use core::arch::asm; 33 use core::ffi::c_void; 34 use core::fmt::Debug; 35 use core::mem::{self}; 36 37 use core::sync::atomic::{compiler_fence, AtomicBool, Ordering}; 38 39 use super::kvm::vmx::vmcs::VmcsFields; 40 use super::kvm::vmx::vmx_asm_wrapper::vmx_vmread; 41 42 pub type PageMapper = 43 crate::mm::page::PageMapper<crate::arch::x86_64::mm::X86_64MMArch, LockedFrameAllocator>; 44 45 /// 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 46 static mut INITIAL_CR3_VALUE: PhysAddr = PhysAddr::new(0); 47 48 /// 内核的第一个页表在pml4中的索引 49 /// 顶级页表的[256, 512)项是内核的页表 50 static KERNEL_PML4E_NO: usize = (X86_64MMArch::PHYS_OFFSET & ((1 << 48) - 1)) >> 39; 51 52 static INNER_ALLOCATOR: SpinLock<Option<BuddyAllocator<MMArch>>> = SpinLock::new(None); 53 54 #[derive(Clone, Copy, Debug)] 55 pub struct X86_64MMBootstrapInfo { 56 kernel_load_base_paddr: usize, 57 kernel_code_start: usize, 58 kernel_code_end: usize, 59 kernel_data_end: usize, 60 kernel_rodata_end: usize, 61 start_brk: usize, 62 } 63 64 pub(super) static mut BOOTSTRAP_MM_INFO: Option<X86_64MMBootstrapInfo> = None; 65 66 /// @brief X86_64的内存管理架构结构体 67 #[derive(Debug, Clone, Copy, Hash)] 68 pub struct X86_64MMArch; 69 70 /// XD标志位是否被保留 71 static XD_RESERVED: AtomicBool = AtomicBool::new(false); 72 73 impl MemoryManagementArch for X86_64MMArch { 74 /// 4K页 75 const PAGE_SHIFT: usize = 12; 76 77 /// 每个页表项占8字节，总共有512个页表项 78 const PAGE_ENTRY_SHIFT: usize = 9; 79 80 /// 四级页表（PML4T、PDPT、PDT、PT） 81 const PAGE_LEVELS: usize = 4; 82 83 /// 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， 84 /// 第[48, 51]位表示保留。因此，有效位的index为52。 85 /// 请注意，第63位是XD位，表示是否允许执行。 86 const ENTRY_ADDRESS_SHIFT: usize = 52; 87 88 const ENTRY_FLAG_DEFAULT_PAGE: usize = Self::ENTRY_FLAG_PRESENT; 89 90 const ENTRY_FLAG_DEFAULT_TABLE: usize = Self::ENTRY_FLAG_PRESENT; 91 92 const ENTRY_FLAG_PRESENT: usize = 1 << 0; 93 94 const ENTRY_FLAG_READONLY: usize = 0; 95 96 const ENTRY_FLAG_READWRITE: usize = 1 << 1; 97 98 const ENTRY_FLAG_USER: usize = 1 << 2; 99 100 const ENTRY_FLAG_WRITE_THROUGH: usize = 1 << 3; 101 102 const ENTRY_FLAG_CACHE_DISABLE: usize = 1 << 4; 103 104 const ENTRY_FLAG_NO_EXEC: usize = 1 << 63; 105 /// x86_64不存在EXEC标志位，只有NO_EXEC（XD）标志位 106 const ENTRY_FLAG_EXEC: usize = 0; 107 108 const ENTRY_FLAG_ACCESSED: usize = 0; 109 const ENTRY_FLAG_DIRTY: usize = 0; 110 111 /// 物理地址与虚拟地址的偏移量 112 /// 0xffff_8000_0000_0000 113 const PHYS_OFFSET: usize = Self::PAGE_NEGATIVE_MASK + (Self::PAGE_ADDRESS_SIZE >> 1); 114 const KERNEL_LINK_OFFSET: usize = 0x100000; 115 116 // 参考 https://code.dragonos.org.cn/xref/linux-6.1.9/arch/x86/include/asm/page_64_types.h#75 117 const USER_END_VADDR: VirtAddr = 118 VirtAddr::new((Self::PAGE_ADDRESS_SIZE >> 1) - Self::PAGE_SIZE); 119 const USER_BRK_START: VirtAddr = VirtAddr::new(0x700000000000); 120 const USER_STACK_START: VirtAddr = VirtAddr::new(0x6ffff0a00000); 121 122 const FIXMAP_START_VADDR: VirtAddr = VirtAddr::new(0xffffb00000000000); 123 /// 设置FIXMAP区域大小为1M 124 const FIXMAP_SIZE: usize = 256 * 4096; 125 126 /// @brief 获取物理内存区域 127 unsafe fn init() { 128 extern "C" { 129 fn _text(); 130 fn _etext(); 131 fn _edata(); 132 fn _erodata(); 133 fn _end(); 134 } 135 136 Self::init_xd_rsvd(); 137 let load_base_paddr = Self::get_load_base_paddr(); 138 139 let bootstrap_info = X86_64MMBootstrapInfo { 140 kernel_load_base_paddr: load_base_paddr.data(), 141 kernel_code_start: _text as usize, 142 kernel_code_end: _etext as usize, 143 kernel_data_end: _edata as usize, 144 kernel_rodata_end: _erodata as usize, 145 start_brk: _end as usize, 146 }; 147 148 unsafe { 149 BOOTSTRAP_MM_INFO = Some(bootstrap_info); 150 } 151 152 // 初始化物理内存区域(从multiboot2中获取) 153 Self::init_memory_area_from_multiboot2().expect("init memory area failed"); 154 155 kdebug!("bootstrap info: {:?}", unsafe { BOOTSTRAP_MM_INFO }); 156 kdebug!("phys[0]=virt[0x{:x}]", unsafe { 157 MMArch::phys_2_virt(PhysAddr::new(0)).unwrap().data() 158 }); 159 160 // 初始化内存管理器 161 unsafe { allocator_init() }; 162 send_to_default_serial8250_port("x86 64 init done\n\0".as_bytes()); 163 } 164 165 /// @brief 刷新TLB中，关于指定虚拟地址的条目 166 unsafe fn invalidate_page(address: VirtAddr) { 167 compiler_fence(Ordering::SeqCst); 168 asm!("invlpg [{0}]", in(reg) address.data(), options(nostack, preserves_flags)); 169 compiler_fence(Ordering::SeqCst); 170 } 171 172 /// @brief 刷新TLB中，所有的条目 173 unsafe fn invalidate_all() { 174 compiler_fence(Ordering::SeqCst); 175 // 通过设置cr3寄存器，来刷新整个TLB 176 Self::set_table(PageTableKind::User, Self::table(PageTableKind::User)); 177 compiler_fence(Ordering::SeqCst); 178 } 179 180 /// @brief 获取顶级页表的物理地址 181 unsafe fn table(table_kind: PageTableKind) -> PhysAddr { 182 match table_kind { 183 PageTableKind::Kernel | PageTableKind::User => { 184 let paddr: usize; 185 compiler_fence(Ordering::SeqCst); 186 asm!("mov {}, cr3", out(reg) paddr, options(nomem, nostack, preserves_flags)); 187 compiler_fence(Ordering::SeqCst); 188 return PhysAddr::new(paddr); 189 } 190 PageTableKind::EPT => { 191 let eptp = 192 vmx_vmread(VmcsFields::CTRL_EPTP_PTR as u32).expect("Failed to read eptp"); 193 return PhysAddr::new(eptp as usize); 194 } 195 } 196 } 197 198 /// @brief 设置顶级页表的物理地址到处理器中 199 unsafe fn set_table(_table_kind: PageTableKind, table: PhysAddr) { 200 compiler_fence(Ordering::SeqCst); 201 asm!("mov cr3, {}", in(reg) table.data(), options(nostack, preserves_flags)); 202 compiler_fence(Ordering::SeqCst); 203 } 204 205 /// @brief 判断虚拟地址是否合法 206 fn virt_is_valid(virt: VirtAddr) -> bool { 207 return virt.is_canonical(); 208 } 209 210 /// 获取内存管理初始化时，创建的第一个内核页表的地址 211 fn initial_page_table() -> PhysAddr { 212 unsafe { 213 return INITIAL_CR3_VALUE; 214 } 215 } 216 217 /// @brief 创建新的顶层页表 218 /// 219 /// 该函数会创建页表并复制内核的映射到新的页表中 220 /// 221 /// @return 新的页表 222 fn setup_new_usermapper() -> Result<crate::mm::ucontext::UserMapper, SystemError> { 223 let new_umapper: crate::mm::page::PageMapper<X86_64MMArch, LockedFrameAllocator> = unsafe { 224 PageMapper::create(PageTableKind::User, LockedFrameAllocator) 225 .ok_or(SystemError::ENOMEM)? 226 }; 227 228 let current_ktable: KernelMapper = KernelMapper::lock(); 229 let copy_mapping = |pml4_entry_no| unsafe { 230 let entry: PageEntry<X86_64MMArch> = current_ktable 231 .table() 232 .entry(pml4_entry_no) 233 .unwrap_or_else(|| panic!("entry {} not found", pml4_entry_no)); 234 new_umapper.table().set_entry(pml4_entry_no, entry) 235 }; 236 237 // 复制内核的映射 238 for pml4_entry_no in KERNEL_PML4E_NO..512 { 239 copy_mapping(pml4_entry_no); 240 } 241 242 return Ok(crate::mm::ucontext::UserMapper::new(new_umapper)); 243 } 244 245 const PAGE_SIZE: usize = 1 << Self::PAGE_SHIFT; 246 247 const PAGE_OFFSET_MASK: usize = Self::PAGE_SIZE - 1; 248 249 const PAGE_MASK: usize = !(Self::PAGE_OFFSET_MASK); 250 251 const PAGE_ADDRESS_SHIFT: usize = Self::PAGE_LEVELS * Self::PAGE_ENTRY_SHIFT + Self::PAGE_SHIFT; 252 253 const PAGE_ADDRESS_SIZE: usize = 1 << Self::PAGE_ADDRESS_SHIFT; 254 255 const PAGE_ADDRESS_MASK: usize = Self::PAGE_ADDRESS_SIZE - Self::PAGE_SIZE; 256 257 const PAGE_ENTRY_SIZE: usize = 1 << (Self::PAGE_SHIFT - Self::PAGE_ENTRY_SHIFT); 258 259 const PAGE_ENTRY_NUM: usize = 1 << Self::PAGE_ENTRY_SHIFT; 260 261 const PAGE_ENTRY_MASK: usize = Self::PAGE_ENTRY_NUM - 1; 262 263 const PAGE_NEGATIVE_MASK: usize = !((Self::PAGE_ADDRESS_SIZE) - 1); 264 265 const ENTRY_ADDRESS_SIZE: usize = 1 << Self::ENTRY_ADDRESS_SHIFT; 266 267 const ENTRY_ADDRESS_MASK: usize = Self::ENTRY_ADDRESS_SIZE - Self::PAGE_SIZE; 268 269 const ENTRY_FLAGS_MASK: usize = !Self::ENTRY_ADDRESS_MASK; 270 271 unsafe fn read<T>(address: VirtAddr) -> T { 272 return core::ptr::read(address.data() as *const T); 273 } 274 275 unsafe fn write<T>(address: VirtAddr, value: T) { 276 core::ptr::write(address.data() as *mut T, value); 277 } 278 279 unsafe fn write_bytes(address: VirtAddr, value: u8, count: usize) { 280 core::ptr::write_bytes(address.data() as *mut u8, value, count); 281 } 282 283 unsafe fn phys_2_virt(phys: PhysAddr) -> Option<VirtAddr> { 284 if let Some(vaddr) = phys.data().checked_add(Self::PHYS_OFFSET) { 285 return Some(VirtAddr::new(vaddr)); 286 } else { 287 return None; 288 } 289 } 290 291 unsafe fn virt_2_phys(virt: VirtAddr) -> Option<PhysAddr> { 292 if let Some(paddr) = virt.data().checked_sub(Self::PHYS_OFFSET) { 293 return Some(PhysAddr::new(paddr)); 294 } else { 295 return None; 296 } 297 } 298 299 #[inline(always)] 300 fn make_entry(paddr: PhysAddr, page_flags: usize) -> usize { 301 return paddr.data() | page_flags; 302 } 303 } 304 305 impl X86_64MMArch { 306 unsafe fn get_load_base_paddr() -> PhysAddr { 307 let mut mb2_lb_info: [multiboot_tag_load_base_addr_t; 512] = mem::zeroed(); 308 send_to_default_serial8250_port("get_load_base_paddr begin\n\0".as_bytes()); 309 310 let mut mb2_count: u32 = 0; 311 multiboot2_iter( 312 Some(multiboot2_get_load_base), 313 &mut mb2_lb_info as *mut [multiboot_tag_load_base_addr_t; 512] as usize as *mut c_void, 314 &mut mb2_count, 315 ); 316 317 if mb2_count == 0 { 318 send_to_default_serial8250_port( 319 "get_load_base_paddr mb2_count == 0, default to 1MB\n\0".as_bytes(), 320 ); 321 return PhysAddr::new(0x100000); 322 } 323 324 let phys = mb2_lb_info[0].load_base_addr as usize; 325 326 return PhysAddr::new(phys); 327 } 328 unsafe fn init_memory_area_from_multiboot2() -> Result<usize, SystemError> { 329 // 这个数组用来存放内存区域的信息（从C获取） 330 let mut mb2_mem_info: [multiboot_mmap_entry_t; 512] = mem::zeroed(); 331 send_to_default_serial8250_port("init_memory_area_from_multiboot2 begin\n\0".as_bytes()); 332 333 let mut mb2_count: u32 = 0; 334 multiboot2_iter( 335 Some(multiboot2_get_memory), 336 &mut mb2_mem_info as *mut [multiboot_mmap_entry_t; 512] as usize as *mut c_void, 337 &mut mb2_count, 338 ); 339 send_to_default_serial8250_port("init_memory_area_from_multiboot2 2\n\0".as_bytes()); 340 341 let mb2_count = mb2_count as usize; 342 let mut areas_count = 0usize; 343 let mut total_mem_size = 0usize; 344 for i in 0..mb2_count { 345 // Only use the memory area if its type is 1 (RAM) 346 if mb2_mem_info[i].type_ == 1 { 347 // Skip the memory area if its len is 0 348 if mb2_mem_info[i].len == 0 { 349 continue; 350 } 351 352 total_mem_size += mb2_mem_info[i].len as usize; 353 354 mem_block_manager() 355 .add_block( 356 PhysAddr::new(mb2_mem_info[i].addr as usize), 357 mb2_mem_info[i].len as usize, 358 ) 359 .unwrap_or_else(|e| { 360 kwarn!( 361 "Failed to add memory block: base={:#x}, size={:#x}, error={:?}", 362 mb2_mem_info[i].addr, 363 mb2_mem_info[i].len, 364 e 365 ); 366 }); 367 areas_count += 1; 368 } 369 } 370 send_to_default_serial8250_port("init_memory_area_from_multiboot2 end\n\0".as_bytes()); 371 kinfo!("Total memory size: {} MB, total areas from multiboot2: {mb2_count}, valid areas: {areas_count}", total_mem_size / 1024 / 1024); 372 return Ok(areas_count); 373 } 374 375 fn init_xd_rsvd() { 376 // 读取ia32-EFER寄存器的值 377 let efer: EferFlags = x86_64::registers::model_specific::Efer::read(); 378 if !efer.contains(EferFlags::NO_EXECUTE_ENABLE) { 379 // NO_EXECUTE_ENABLE是false，那么就设置xd_reserved为true 380 kdebug!("NO_EXECUTE_ENABLE is false, set XD_RESERVED to true"); 381 XD_RESERVED.store(true, Ordering::Relaxed); 382 } 383 compiler_fence(Ordering::SeqCst); 384 } 385 386 /// 判断XD标志位是否被保留 387 pub fn is_xd_reserved() -> bool { 388 // return XD_RESERVED.load(Ordering::Relaxed); 389 390 // 由于暂时不支持execute disable，因此直接返回true 391 // 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 392 return true; 393 } 394 } 395 396 impl VirtAddr { 397 /// @brief 判断虚拟地址是否合法 398 #[inline(always)] 399 pub fn is_canonical(self) -> bool { 400 let x = self.data() & X86_64MMArch::PHYS_OFFSET; 401 // 如果x为0，说明虚拟地址的高位为0，是合法的用户地址 402 // 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 403 return x == 0 || x == X86_64MMArch::PHYS_OFFSET; 404 } 405 } 406 407 unsafe fn allocator_init() { 408 let virt_offset = BOOTSTRAP_MM_INFO.unwrap().start_brk; 409 let phy_offset = 410 unsafe { MMArch::virt_2_phys(VirtAddr::new(page_align_up(virt_offset))) }.unwrap(); 411 412 let mut bump_allocator = BumpAllocator::<X86_64MMArch>::new(phy_offset.data()); 413 kdebug!( 414 "BumpAllocator created, offset={:?}", 415 bump_allocator.offset() 416 ); 417 418 // 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！ 419 // 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， 420 // 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） 421 let _old_page_table = MMArch::table(PageTableKind::Kernel); 422 423 let new_page_table: PhysAddr; 424 // 使用bump分配器，把所有的内存页都映射到页表 425 { 426 // 用bump allocator创建新的页表 427 let mut mapper: crate::mm::page::PageMapper<MMArch, &mut BumpAllocator<MMArch>> = 428 crate::mm::page::PageMapper::<MMArch, _>::create( 429 PageTableKind::Kernel, 430 &mut bump_allocator, 431 ) 432 .expect("Failed to create page mapper"); 433 new_page_table = mapper.table().phys(); 434 kdebug!("PageMapper created"); 435 436 // 取消最开始时候，在head.S中指定的映射(暂时不刷新TLB) 437 { 438 let table = mapper.table(); 439 let empty_entry = PageEntry::<MMArch>::from_usize(0); 440 for i in 0..MMArch::PAGE_ENTRY_NUM { 441 table 442 .set_entry(i, empty_entry) 443 .expect("Failed to empty page table entry"); 444 } 445 } 446 kdebug!("Successfully emptied page table"); 447 448 let total_num = mem_block_manager().total_initial_memory_regions(); 449 for i in 0..total_num { 450 let area = mem_block_manager().get_initial_memory_region(i).unwrap(); 451 // kdebug!("area: base={:?}, size={:#x}, end={:?}", area.base, area.size, area.base + area.size); 452 for i in 0..((area.size + MMArch::PAGE_SIZE - 1) / MMArch::PAGE_SIZE) { 453 let paddr = area.base.add(i * MMArch::PAGE_SIZE); 454 let vaddr = unsafe { MMArch::phys_2_virt(paddr) }.unwrap(); 455 let flags = kernel_page_flags::<MMArch>(vaddr); 456 457 let flusher = mapper 458 .map_phys(vaddr, paddr, flags) 459 .expect("Failed to map frame"); 460 // 暂时不刷新TLB 461 flusher.ignore(); 462 } 463 } 464 465 // 添加低地址的映射（在smp完成初始化之前，需要使用低地址的映射.初始化之后需要取消这一段映射） 466 LowAddressRemapping::remap_at_low_address(&mut mapper); 467 } 468 469 unsafe { 470 INITIAL_CR3_VALUE = new_page_table; 471 } 472 kdebug!( 473 "After mapping all physical memory, DragonOS used: {} KB", 474 bump_allocator.offset() / 1024 475 ); 476 477 // 初始化buddy_allocator 478 let buddy_allocator = unsafe { BuddyAllocator::<X86_64MMArch>::new(bump_allocator).unwrap() }; 479 // 设置全局的页帧分配器 480 unsafe { set_inner_allocator(buddy_allocator) }; 481 kinfo!("Successfully initialized buddy allocator"); 482 // 关闭显示输出 483 scm_disable_put_to_window(); 484 485 // make the new page table current 486 { 487 let mut binding = INNER_ALLOCATOR.lock(); 488 let mut allocator_guard = binding.as_mut().unwrap(); 489 kdebug!("To enable new page table."); 490 compiler_fence(Ordering::SeqCst); 491 let mapper = crate::mm::page::PageMapper::<MMArch, _>::new( 492 PageTableKind::Kernel, 493 new_page_table, 494 &mut allocator_guard, 495 ); 496 compiler_fence(Ordering::SeqCst); 497 mapper.make_current(); 498 compiler_fence(Ordering::SeqCst); 499 kdebug!("New page table enabled"); 500 } 501 kdebug!("Successfully enabled new page table"); 502 } 503 504 #[no_mangle] 505 pub extern "C" fn rs_test_buddy() { 506 test_buddy(); 507 } 508 pub fn test_buddy() { 509 // 申请内存然后写入数据然后free掉 510 // 总共申请200MB内存 511 const TOTAL_SIZE: usize = 200 * 1024 * 1024; 512 513 for i in 0..10 { 514 kdebug!("Test buddy, round: {i}"); 515 // 存放申请的内存块 516 let mut v: Vec<(PhysAddr, PageFrameCount)> = Vec::with_capacity(60 * 1024); 517 // 存放已经申请的内存块的地址（用于检查重复） 518 let mut addr_set: HashSet<PhysAddr> = HashSet::new(); 519 520 let mut allocated = 0usize; 521 522 let mut free_count = 0usize; 523 524 while allocated < TOTAL_SIZE { 525 let mut random_size = 0u64; 526 unsafe { x86::random::rdrand64(&mut random_size) }; 527 // 一次最多申请4M 528 random_size = random_size % (1024 * 4096); 529 if random_size == 0 { 530 continue; 531 } 532 let random_size = 533 core::cmp::min(page_align_up(random_size as usize), TOTAL_SIZE - allocated); 534 let random_size = PageFrameCount::from_bytes(random_size.next_power_of_two()).unwrap(); 535 // 获取帧 536 let (paddr, allocated_frame_count) = 537 unsafe { LockedFrameAllocator.allocate(random_size).unwrap() }; 538 assert!(allocated_frame_count.data().is_power_of_two()); 539 assert!(paddr.data() % MMArch::PAGE_SIZE == 0); 540 unsafe { 541 assert!(MMArch::phys_2_virt(paddr) 542 .as_ref() 543 .unwrap() 544 .check_aligned(allocated_frame_count.data() * MMArch::PAGE_SIZE)); 545 } 546 allocated += allocated_frame_count.data() * MMArch::PAGE_SIZE; 547 v.push((paddr, allocated_frame_count)); 548 assert!(addr_set.insert(paddr), "duplicate address: {:?}", paddr); 549 550 // 写入数据 551 let vaddr = unsafe { MMArch::phys_2_virt(paddr).unwrap() }; 552 let slice = unsafe { 553 core::slice::from_raw_parts_mut( 554 vaddr.data() as *mut u8, 555 allocated_frame_count.data() * MMArch::PAGE_SIZE, 556 ) 557 }; 558 for i in 0..slice.len() { 559 slice[i] = ((i + unsafe { rdtsc() } as usize) % 256) as u8; 560 } 561 562 // 随机释放一个内存块 563 if v.len() > 0 { 564 let mut random_index = 0u64; 565 unsafe { x86::random::rdrand64(&mut random_index) }; 566 // 70%概率释放 567 if random_index % 10 > 7 { 568 continue; 569 } 570 random_index = random_index % v.len() as u64; 571 let random_index = random_index as usize; 572 let (paddr, allocated_frame_count) = v.remove(random_index); 573 assert!(addr_set.remove(&paddr)); 574 unsafe { LockedFrameAllocator.free(paddr, allocated_frame_count) }; 575 free_count += allocated_frame_count.data() * MMArch::PAGE_SIZE; 576 } 577 } 578 579 kdebug!( 580 "Allocated {} MB memory, release: {} MB, no release: {} bytes", 581 allocated / 1024 / 1024, 582 free_count / 1024 / 1024, 583 (allocated - free_count) 584 ); 585 586 kdebug!("Now, to release buddy memory"); 587 // 释放所有的内存 588 for (paddr, allocated_frame_count) in v { 589 unsafe { LockedFrameAllocator.free(paddr, allocated_frame_count) }; 590 assert!(addr_set.remove(&paddr)); 591 free_count += allocated_frame_count.data() * MMArch::PAGE_SIZE; 592 } 593 594 kdebug!("release done!, allocated: {allocated}, free_count: {free_count}"); 595 } 596 } 597 598 /// 全局的页帧分配器 599 #[derive(Debug, Clone, Copy, Hash)] 600 pub struct LockedFrameAllocator; 601 602 impl FrameAllocator for LockedFrameAllocator { 603 unsafe fn allocate(&mut self, count: PageFrameCount) -> Option<(PhysAddr, PageFrameCount)> { 604 if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() { 605 return allocator.allocate(count); 606 } else { 607 return None; 608 } 609 } 610 611 unsafe fn free(&mut self, address: crate::mm::PhysAddr, count: PageFrameCount) { 612 assert!(count.data().is_power_of_two()); 613 if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() { 614 return allocator.free(address, count); 615 } 616 } 617 618 unsafe fn usage(&self) -> PageFrameUsage { 619 if let Some(ref mut allocator) = *INNER_ALLOCATOR.lock_irqsave() { 620 return allocator.usage(); 621 } else { 622 panic!("usage error"); 623 } 624 } 625 } 626 627 /// 获取内核地址默认的页面标志 628 pub unsafe fn kernel_page_flags<A: MemoryManagementArch>(virt: VirtAddr) -> PageFlags<A> { 629 let info: X86_64MMBootstrapInfo = BOOTSTRAP_MM_INFO.clone().unwrap(); 630 631 if virt.data() >= info.kernel_code_start && virt.data() < info.kernel_code_end { 632 // Remap kernel code execute 633 return PageFlags::new().set_execute(true).set_write(true); 634 } else if virt.data() >= info.kernel_data_end && virt.data() < info.kernel_rodata_end { 635 // Remap kernel rodata read only 636 return PageFlags::new().set_execute(true); 637 } else { 638 return PageFlags::new().set_write(true).set_execute(true); 639 } 640 } 641 642 unsafe fn set_inner_allocator(allocator: BuddyAllocator<MMArch>) { 643 static FLAG: AtomicBool = AtomicBool::new(false); 644 if FLAG 645 .compare_exchange(false, true, Ordering::SeqCst, Ordering::SeqCst) 646 .is_err() 647 { 648 panic!("Cannot set inner allocator twice!"); 649 } 650 *INNER_ALLOCATOR.lock() = Some(allocator); 651 } 652 653 /// 低地址重映射的管理器 654 /// 655 /// 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 656 pub struct LowAddressRemapping; 657 658 impl LowAddressRemapping { 659 // 映射64M 660 const REMAP_SIZE: usize = 64 * 1024 * 1024; 661 662 pub unsafe fn remap_at_low_address( 663 mapper: &mut crate::mm::page::PageMapper<MMArch, &mut BumpAllocator<MMArch>>, 664 ) { 665 for i in 0..(Self::REMAP_SIZE / MMArch::PAGE_SIZE) { 666 let paddr = PhysAddr::new(i * MMArch::PAGE_SIZE); 667 let vaddr = VirtAddr::new(i * MMArch::PAGE_SIZE); 668 let flags = kernel_page_flags::<MMArch>(vaddr); 669 670 let flusher = mapper 671 .map_phys(vaddr, paddr, flags) 672 .expect("Failed to map frame"); 673 // 暂时不刷新TLB 674 flusher.ignore(); 675 } 676 } 677 678 /// 取消低地址的映射 679 pub unsafe fn unmap_at_low_address(flush: bool) { 680 let mut mapper = KernelMapper::lock(); 681 assert!(mapper.as_mut().is_some()); 682 for i in 0..(Self::REMAP_SIZE / MMArch::PAGE_SIZE) { 683 let vaddr = VirtAddr::new(i * MMArch::PAGE_SIZE); 684 let (_, _, flusher) = mapper 685 .as_mut() 686 .unwrap() 687 .unmap_phys(vaddr, true) 688 .expect("Failed to unmap frame"); 689 if flush == false { 690 flusher.ignore(); 691 } 692 } 693 } 694 } 695