#include "mm.h" #include "mm-types.h" #include "mmio.h" #include "slab.h" #include #include #include #include #include #include #include uint64_t mm_Total_Memory = 0; uint64_t mm_total_2M_pages = 0; struct mm_struct initial_mm = {0}; struct memory_desc memory_management_struct = {{0}, 0}; /** * @brief 从页表中获取pdt页表项的内容 * * @param proc_page_table_addr 页表的地址 * @param is_phys 页表地址是否为物理地址 * @param virt_addr_start 要清除的虚拟地址的起始地址 * @param length 要清除的区域的长度 * @param clear 是否清除标志位 */ uint64_t mm_get_PDE(ul proc_page_table_addr, bool is_phys, ul virt_addr, bool clear); /** * @brief 检查页表是否存在不为0的页表项 * * @param ptr 页表基指针 * @return int8_t 存在 -> 1 * 不存在 -> 0 */ int8_t mm_check_page_table(uint64_t *ptr) { for (int i = 0; i < 512; ++i, ++ptr) { if (*ptr != 0) return 1; } return 0; } void mm_init() { kinfo("Initializing memory management unit..."); // 设置内核程序不同部分的起止地址 memory_management_struct.kernel_code_start = (ul)&_text; memory_management_struct.kernel_code_end = (ul)&_etext; memory_management_struct.kernel_data_end = (ul)&_edata; memory_management_struct.rodata_end = (ul)&_erodata; memory_management_struct.start_brk = (ul)&_end; struct multiboot_mmap_entry_t mb2_mem_info[512]; int count; multiboot2_iter(multiboot2_get_memory, mb2_mem_info, &count); io_mfence(); for (int i = 0; i < count; ++i) { io_mfence(); // 可用的内存 if (mb2_mem_info->type == 1) mm_Total_Memory += mb2_mem_info->len; // kdebug("[i=%d] mb2_mem_info[i].type=%d, mb2_mem_info[i].addr=%#018lx", i, mb2_mem_info[i].type, mb2_mem_info[i].addr); // 保存信息到mms memory_management_struct.e820[i].BaseAddr = mb2_mem_info[i].addr; memory_management_struct.e820[i].Length = mb2_mem_info[i].len; memory_management_struct.e820[i].type = mb2_mem_info[i].type; memory_management_struct.len_e820 = i; // 脏数据 if (mb2_mem_info[i].type > 4 || mb2_mem_info[i].len == 0 || mb2_mem_info[i].type < 1) break; } printk("[ INFO ] Total amounts of RAM : %ld bytes\n", mm_Total_Memory); // 计算有效内存页数 io_mfence(); for (int i = 0; i < memory_management_struct.len_e820; ++i) { if (memory_management_struct.e820[i].type != 1) continue; io_mfence(); // 将内存段的起始物理地址按照2M进行对齐 ul addr_start = PAGE_2M_ALIGN(memory_management_struct.e820[i].BaseAddr); // 将内存段的终止物理地址的低2M区域清空，以实现对齐 ul addr_end = ((memory_management_struct.e820[i].BaseAddr + memory_management_struct.e820[i].Length) & PAGE_2M_MASK); // 内存段不可用 if (addr_end <= addr_start) continue; io_mfence(); mm_total_2M_pages += ((addr_end - addr_start) >> PAGE_2M_SHIFT); } kinfo("Total amounts of 2M pages : %ld.", mm_total_2M_pages); // 物理地址空间的最大地址（包含了物理内存、内存空洞、ROM等） ul max_addr = memory_management_struct.e820[memory_management_struct.len_e820].BaseAddr + memory_management_struct.e820[memory_management_struct.len_e820].Length; // 初始化mms的bitmap // bmp的指针指向截止位置的4k对齐的上边界（防止修改了别的数据） io_mfence(); memory_management_struct.bmp = (unsigned long *)((memory_management_struct.start_brk + PAGE_4K_SIZE - 1) & PAGE_4K_MASK); memory_management_struct.bits_size = max_addr >> PAGE_2M_SHIFT; // 物理地址空间的最大页面数 memory_management_struct.bmp_len = (((unsigned long)(max_addr >> PAGE_2M_SHIFT) + sizeof(unsigned long) * 8 - 1) / 8) & (~(sizeof(unsigned long) - 1)); // bmp由多少个unsigned long变量组成 io_mfence(); // 初始化bitmap， 先将整个bmp空间全部置位。稍后再将可用物理内存页复位。 memset(memory_management_struct.bmp, 0xff, memory_management_struct.bmp_len); io_mfence(); // 初始化内存页结构 // 将页结构映射于bmp之后 memory_management_struct.pages_struct = (struct Page *)(((unsigned long)memory_management_struct.bmp + memory_management_struct.bmp_len + PAGE_4K_SIZE - 1) & PAGE_4K_MASK); memory_management_struct.count_pages = max_addr >> PAGE_2M_SHIFT; memory_management_struct.pages_struct_len = ((max_addr >> PAGE_2M_SHIFT) * sizeof(struct Page) + sizeof(long) - 1) & (~(sizeof(long) - 1)); // 将pages_struct全部清空，以备后续初始化 memset(memory_management_struct.pages_struct, 0x00, memory_management_struct.pages_struct_len); // init pages memory io_mfence(); // 初始化内存区域 memory_management_struct.zones_struct = (struct Zone *)(((ul)memory_management_struct.pages_struct + memory_management_struct.pages_struct_len + PAGE_4K_SIZE - 1) & PAGE_4K_MASK); io_mfence(); // 由于暂时无法计算zone结构体的数量，因此先将其设为0 memory_management_struct.count_zones = 0; io_mfence(); // zones-struct 成员变量暂时按照5个来计算 memory_management_struct.zones_struct_len = (10 * sizeof(struct Zone) + sizeof(ul) - 1) & (~(sizeof(ul) - 1)); io_mfence(); memset(memory_management_struct.zones_struct, 0x00, memory_management_struct.zones_struct_len); // ==== 遍历e820数组，完成成员变量初始化工作 === for (int i = 0; i < memory_management_struct.len_e820; ++i) { io_mfence(); if (memory_management_struct.e820[i].type != 1) // 不是操作系统可以使用的物理内存 continue; ul addr_start = PAGE_2M_ALIGN(memory_management_struct.e820[i].BaseAddr); ul addr_end = (memory_management_struct.e820[i].BaseAddr + memory_management_struct.e820[i].Length) & PAGE_2M_MASK; if (addr_end <= addr_start) continue; // zone init struct Zone *z = memory_management_struct.zones_struct + memory_management_struct.count_zones; ++memory_management_struct.count_zones; z->zone_addr_start = addr_start; z->zone_addr_end = addr_end; z->zone_length = addr_end - addr_start; z->count_pages_using = 0; z->count_pages_free = (addr_end - addr_start) >> PAGE_2M_SHIFT; z->total_pages_link = 0; z->attr = 0; z->gmd_struct = &memory_management_struct; z->count_pages = (addr_end - addr_start) >> PAGE_2M_SHIFT; z->pages_group = (struct Page *)(memory_management_struct.pages_struct + (addr_start >> PAGE_2M_SHIFT)); // 初始化页 struct Page *p = z->pages_group; for (int j = 0; j < z->count_pages; ++j, ++p) { p->zone = z; p->addr_phys = addr_start + PAGE_2M_SIZE * j; p->attr = 0; p->ref_counts = 0; p->age = 0; // 将bmp中对应的位 复位 *(memory_management_struct.bmp + ((p->addr_phys >> PAGE_2M_SHIFT) >> 6)) ^= (1UL << ((p->addr_phys >> PAGE_2M_SHIFT) % 64)); } } // 初始化0~2MB的物理页 // 由于这个区间的内存由多个内存段组成，因此不会被以上代码初始化，需要我们手动配置page[0]。 io_mfence(); memory_management_struct.pages_struct->zone = memory_management_struct.zones_struct; memory_management_struct.pages_struct->addr_phys = 0UL; set_page_attr(memory_management_struct.pages_struct, PAGE_PGT_MAPPED | PAGE_KERNEL_INIT | PAGE_KERNEL); memory_management_struct.pages_struct->ref_counts = 1; memory_management_struct.pages_struct->age = 0; // 将第0页的标志位给置上 //*(memory_management_struct.bmp) |= 1UL; // 计算zone结构体的总长度（按照64位对齐） memory_management_struct.zones_struct_len = (memory_management_struct.count_zones * sizeof(struct Zone) + sizeof(ul) - 1) & (~(sizeof(ul) - 1)); ZONE_DMA_INDEX = 0; ZONE_NORMAL_INDEX = memory_management_struct.count_zones ; ZONE_UNMAPPED_INDEX = 0; // kdebug("ZONE_DMA_INDEX=%d\tZONE_NORMAL_INDEX=%d\tZONE_UNMAPPED_INDEX=%d", ZONE_DMA_INDEX, ZONE_NORMAL_INDEX, ZONE_UNMAPPED_INDEX); // 设置内存页管理结构的地址，预留了一段空间，防止内存越界。 memory_management_struct.end_of_struct = (ul)((ul)memory_management_struct.zones_struct + memory_management_struct.zones_struct_len + sizeof(long) * 32) & (~(sizeof(long) - 1)); // 初始化内存管理单元结构所占的物理页的结构体 ul mms_max_page = (virt_2_phys(memory_management_struct.end_of_struct) >> PAGE_2M_SHIFT); // 内存管理单元所占据的序号最大的物理页 // kdebug("mms_max_page=%ld", mms_max_page); struct Page *tmp_page = NULL; ul page_num; // 第0个page已经在上方配置 for (ul j = 1; j <= mms_max_page; ++j) { barrier(); tmp_page = memory_management_struct.pages_struct + j; page_init(tmp_page, PAGE_PGT_MAPPED | PAGE_KERNEL | PAGE_KERNEL_INIT); barrier(); page_num = tmp_page->addr_phys >> PAGE_2M_SHIFT; *(memory_management_struct.bmp + (page_num >> 6)) |= (1UL << (page_num % 64)); ++tmp_page->zone->count_pages_using; --tmp_page->zone->count_pages_free; } kinfo("Memory management unit initialize complete!"); flush_tlb(); // todo: 在这里增加代码，暂时停止视频输出，否则可能会导致图像数据写入slab的区域，从而造成异常 // 初始化slab内存池 slab_init(); page_table_init(); initial_mm.pgd = (pml4t_t *)get_CR3(); initial_mm.code_addr_start = memory_management_struct.kernel_code_start; initial_mm.code_addr_end = memory_management_struct.kernel_code_end; initial_mm.data_addr_start = (ul)&_data; initial_mm.data_addr_end = memory_management_struct.kernel_data_end; initial_mm.rodata_addr_start = (ul)&_rodata; initial_mm.rodata_addr_end = (ul)&_erodata; initial_mm.bss_start = (uint64_t)&_bss; initial_mm.bss_end = (uint64_t)&_ebss; initial_mm.brk_start = memory_management_struct.start_brk; initial_mm.brk_end = current_pcb->addr_limit; initial_mm.stack_start = _stack_start; initial_mm.vmas = NULL; mmio_init(); } /** * @brief 初始化内存页 * * @param page 内存页结构体 * @param flags 标志位 * 本函数只负责初始化内存页，允许对同一页面进行多次初始化 * 而维护计数器及置位bmp标志位的功能，应当在分配页面的时候手动完成 * @return unsigned long */ unsigned long page_init(struct Page *page, ul flags) { page->attr |= flags; // 若页面的引用计数为0或是共享页，增加引用计数 if ((!page->ref_counts) || (page->attr & PAGE_SHARED)) { ++page->ref_counts; barrier(); if (page->zone) ++page->zone->total_pages_link; } page->anon_vma = NULL; spin_init(&(page->op_lock)); return 0; } /** * @brief 从已初始化的页结构中搜索符合申请条件的、连续num个struct page * * @param zone_select 选择内存区域, 可选项：dma, mapped in pgt(normal), unmapped in pgt * @param num 需要申请的连续内存页的数量 num<64 * @param flags 将页面属性设置成flag * @return struct Page* */ struct Page *alloc_pages(unsigned int zone_select, int num, ul flags) { ul zone_start = 0, zone_end = 0; if (num >= 64 && num <= 0) { kerror("alloc_pages(): num is invalid."); return NULL; } ul attr = flags; switch (zone_select) { case ZONE_DMA: // DMA区域 zone_start = 0; zone_end = ZONE_DMA_INDEX; attr |= PAGE_PGT_MAPPED; break; case ZONE_NORMAL: zone_start = ZONE_DMA_INDEX; zone_end = ZONE_NORMAL_INDEX; attr |= PAGE_PGT_MAPPED; break; case ZONE_UNMAPPED_IN_PGT: zone_start = ZONE_NORMAL_INDEX; zone_end = ZONE_UNMAPPED_INDEX; attr = 0; break; default: kerror("In alloc_pages: param: zone_select incorrect."); // 返回空 return NULL; break; } for (int i = zone_start; i < zone_end; ++i) { if ((memory_management_struct.zones_struct + i)->count_pages_free < num) continue; struct Zone *z = memory_management_struct.zones_struct + i; // 区域对应的起止页号 ul page_start = (z->zone_addr_start >> PAGE_2M_SHIFT); ul page_end = (z->zone_addr_end >> PAGE_2M_SHIFT); ul tmp = 64 - page_start % 64; for (ul j = page_start; j < page_end; j += ((j % 64) ? tmp : 64)) { // 按照bmp中的每一个元素进行查找 // 先将p定位到bmp的起始元素 ul *p = memory_management_struct.bmp + (j >> 6); ul shift = j % 64; ul tmp_num = ((1UL << num) - 1); for (ul k = shift; k < 64; ++k) { // 寻找连续num个空页 if (!((k ? ((*p >> k) | (*(p + 1) << (64 - k))) : *p) & tmp_num)) { ul start_page_num = j + k - shift; // 计算得到要开始获取的内存页的页号 for (ul l = 0; l < num; ++l) { struct Page *x = memory_management_struct.pages_struct + start_page_num + l; // 分配页面，手动配置属性及计数器 // 置位bmp *(memory_management_struct.bmp + ((x->addr_phys >> PAGE_2M_SHIFT) >> 6)) |= (1UL << (x->addr_phys >> PAGE_2M_SHIFT) % 64); ++(z->count_pages_using); --(z->count_pages_free); page_init(x, attr); } // 成功分配了页面，返回第一个页面的指针 // kwarn("start page num=%d\n", start_page_num); return (struct Page *)(memory_management_struct.pages_struct + start_page_num); } } } } kBUG("Cannot alloc page, ZONE=%d\tnums=%d, mm_total_2M_pages=%d", zone_select, num, mm_total_2M_pages); return NULL; } /** * @brief 清除页面的引用计数， 计数为0时清空除页表已映射以外的所有属性 * * @param p 物理页结构体 * @return unsigned long */ unsigned long page_clean(struct Page *p) { --p->ref_counts; --p->zone->total_pages_link; // 若引用计数为空，则清空除PAGE_PGT_MAPPED以外的所有属性 if (!p->ref_counts) { p->attr &= PAGE_PGT_MAPPED; } return 0; } /** * @brief Get the page's attr * * @param page 内存页结构体 * @return ul 属性 */ ul get_page_attr(struct Page *page) { if (page == NULL) { kBUG("get_page_attr(): page == NULL"); return EPAGE_NULL; } else return page->attr; } /** * @brief Set the page's attr * * @param page 内存页结构体 * @param flags 属性 * @return ul 错误码 */ ul set_page_attr(struct Page *page, ul flags) { if (page == NULL) { kBUG("get_page_attr(): page == NULL"); return EPAGE_NULL; } else { page->attr = flags; return 0; } } /** * @brief 释放连续number个内存页 * * @param page 第一个要被释放的页面的结构体 * @param number 要释放的内存页数量 number<64 */ void free_pages(struct Page *page, int number) { if (page == NULL) { kerror("free_pages() page is invalid."); return; } if (number >= 64 || number <= 0) { kerror("free_pages(): number %d is invalid.", number); return; } ul page_num; for (int i = 0; i < number; ++i, ++page) { page_num = page->addr_phys >> PAGE_2M_SHIFT; // 复位bmp *(memory_management_struct.bmp + (page_num >> 6)) &= ~(1UL << (page_num % 64)); // 更新计数器 --page->zone->count_pages_using; ++page->zone->count_pages_free; page->attr = 0; } return; } /** * @brief 重新初始化页表的函数 * 将所有物理页映射到线性地址空间 */ void page_table_init() { kinfo("Re-Initializing page table..."); ul *global_CR3 = get_CR3(); int js = 0; ul *tmp_addr; for (int i = 0; i < memory_management_struct.count_zones; ++i) { struct Zone *z = memory_management_struct.zones_struct + i; struct Page *p = z->pages_group; if (i == ZONE_UNMAPPED_INDEX && ZONE_UNMAPPED_INDEX != 0) break; for (int j = 0; j < z->count_pages; ++j) { mm_map_proc_page_table((uint64_t)get_CR3(), true, (ul)phys_2_virt(p->addr_phys), p->addr_phys, PAGE_2M_SIZE, PAGE_KERNEL_PAGE, false, true, false); ++p; ++js; } } barrier(); // ========= 在IDLE进程的顶层页表中添加对内核地址空间的映射 ===================== // 由于IDLE进程的顶层页表的高地址部分会被后续进程所复制，为了使所有进程能够共享相同的内核空间， // 因此需要先在IDLE进程的顶层页表内映射二级页表 uint64_t *idle_pml4t_vaddr = (uint64_t *)phys_2_virt((uint64_t)get_CR3() & (~0xfffUL)); for (int i = 256; i < 512; ++i) { uint64_t *tmp = idle_pml4t_vaddr + i; barrier(); if (*tmp == 0) { void *pdpt = kmalloc(PAGE_4K_SIZE, 0); barrier(); memset(pdpt, 0, PAGE_4K_SIZE); barrier(); set_pml4t(tmp, mk_pml4t(virt_2_phys(pdpt), PAGE_KERNEL_PGT)); } } barrier(); flush_tlb(); kinfo("Page table Initialized. Affects:%d", js); } /** * @brief 从页表中获取pdt页表项的内容 * * @param proc_page_table_addr 页表的地址 * @param is_phys 页表地址是否为物理地址 * @param virt_addr_start 要清除的虚拟地址的起始地址 * @param length 要清除的区域的长度 * @param clear 是否清除标志位 */ uint64_t mm_get_PDE(ul proc_page_table_addr, bool is_phys, ul virt_addr, bool clear) { ul *tmp; if (is_phys) tmp = phys_2_virt((ul *)((ul)proc_page_table_addr & (~0xfffUL)) + ((virt_addr >> PAGE_GDT_SHIFT) & 0x1ff)); else tmp = (ul *)((ul)proc_page_table_addr & (~0xfffUL)) + ((virt_addr >> PAGE_GDT_SHIFT) & 0x1ff); // pml4页表项为0 if (*tmp == 0) return 0; tmp = phys_2_virt((ul *)(*tmp & (~0xfffUL)) + ((virt_addr >> PAGE_1G_SHIFT) & 0x1ff)); // pdpt页表项为0 if (*tmp == 0) return 0; // 读取pdt页表项 tmp = phys_2_virt(((ul *)(*tmp & (~0xfffUL)) + (((ul)(virt_addr) >> PAGE_2M_SHIFT) & 0x1ff))); if (clear) // 清除页表项的标志位 return *tmp & (~0x1fff); else return *tmp; } /** * @brief 从mms中寻找Page结构体 * * @param phys_addr * @return struct Page* */ static struct Page *mm_find_page(uint64_t phys_addr, uint32_t zone_select) { uint32_t zone_start, zone_end; switch (zone_select) { case ZONE_DMA: // DMA区域 zone_start = 0; zone_end = ZONE_DMA_INDEX; break; case ZONE_NORMAL: zone_start = ZONE_DMA_INDEX; zone_end = ZONE_NORMAL_INDEX; break; case ZONE_UNMAPPED_IN_PGT: zone_start = ZONE_NORMAL_INDEX; zone_end = ZONE_UNMAPPED_INDEX; break; default: kerror("In mm_find_page: param: zone_select incorrect."); // 返回空 return NULL; break; } for (int i = zone_start; i <= zone_end; ++i) { if ((memory_management_struct.zones_struct + i)->count_pages_using == 0) continue; struct Zone *z = memory_management_struct.zones_struct + i; // 区域对应的起止页号 ul page_start = (z->zone_addr_start >> PAGE_2M_SHIFT); ul page_end = (z->zone_addr_end >> PAGE_2M_SHIFT); ul tmp = 64 - page_start % 64; for (ul j = page_start; j < page_end; j += ((j % 64) ? tmp : 64)) { // 按照bmp中的每一个元素进行查找 // 先将p定位到bmp的起始元素 ul *p = memory_management_struct.bmp + (j >> 6); ul shift = j % 64; for (ul k = shift; k < 64; ++k) { if ((*p >> k) & 1) // 若当前页已分配 { uint64_t page_num = j + k - shift; struct Page *x = memory_management_struct.pages_struct + page_num; if (x->addr_phys == phys_addr) // 找到对应的页 return x; } } } } return NULL; } /** * @brief 调整堆区域的大小（暂时只能增加堆区域） * * @todo 缩小堆区域 * @param old_brk_end_addr 原本的堆内存区域的结束地址 * @param offset 新的地址相对于原地址的偏移量 * @return uint64_t */ uint64_t mm_do_brk(uint64_t old_brk_end_addr, int64_t offset) { uint64_t end_addr = PAGE_2M_ALIGN(old_brk_end_addr + offset); if (offset >= 0) { for (uint64_t i = old_brk_end_addr; i < end_addr; i += PAGE_2M_SIZE) { struct vm_area_struct *vma = NULL; mm_create_vma(current_pcb->mm, i, PAGE_2M_SIZE, VM_USER | VM_ACCESS_FLAGS, NULL, &vma); mm_map(current_pcb->mm, i, PAGE_2M_SIZE, alloc_pages(ZONE_NORMAL, 1, PAGE_PGT_MAPPED)->addr_phys); // mm_map_vma(vma, alloc_pages(ZONE_NORMAL, 1, PAGE_PGT_MAPPED)->addr_phys, 0, PAGE_2M_SIZE); } current_pcb->mm->brk_end = end_addr; } else { // 释放堆内存 for (uint64_t i = end_addr; i < old_brk_end_addr; i += PAGE_2M_SIZE) { uint64_t phys = mm_get_PDE((uint64_t)phys_2_virt((uint64_t)current_pcb->mm->pgd), false, i, true); // 找到对应的页 struct Page *p = mm_find_page(phys, ZONE_NORMAL); if (p == NULL) { kerror("cannot find page addr=%#018lx", phys); return end_addr; } free_pages(p, 1); } mm_unmap_proc_table((uint64_t)phys_2_virt((uint64_t)current_pcb->mm->pgd), false, end_addr, PAGE_2M_ALIGN(ABS(offset))); // 在页表中取消映射 } return end_addr; } /** * @brief 创建mmio对应的页结构体 * * @param paddr 物理地址 * @return struct Page* 创建成功的page */ struct Page *__create_mmio_page_struct(uint64_t paddr) { struct Page *p = (struct Page *)kzalloc(sizeof(struct Page), 0); if (p == NULL) return NULL; p->addr_phys = paddr; page_init(p, PAGE_DEVICE); return p; }