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Code Issues Releases Wiki Activity

🆕 回收堆内存给操作系统

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This commit is contained in:
fslongjin
2022-05-11 20:42:53 +08:00
parent edb21695ae
commit 1cc3db5e88
6 changed files with 311 additions and 88 deletions
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235
kernel/mm/mm.c
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@ -8,6 +8,18 @@
ul Total_Memory = 0;
ul total_2M_pages = 0;
static ul root_page_table_phys_addr = 0; // 内核层根页表的物理地址
/**
* @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);
void mm_init()
{
kinfo("Initializing memory management unit...");
@ -444,36 +456,6 @@ void page_table_init()
for (int j = 0; j < z->count_pages; ++j)
{
mm_map_phys_addr((ul)phys_2_virt(p->addr_phys), p->addr_phys, PAGE_2M_SIZE, PAGE_KERNEL_PAGE);
/*
// 计算出PML4页表中的页表项的地址
tmp_addr = (ul *)((ul)pml4_addr + ((((ul)phys_2_virt(p->addr_phys)) >> PAGE_GDT_SHIFT) & 0x1ff) * 8);
// 说明该页还没有分配pdpt页表，使用kmalloc分配一个
if (*tmp_addr = 0)
{
ul *virt_addr = kmalloc(PAGE_4K_SIZE, 0);
set_pml4t(tmp_addr, mk_pml4t(virt_2_phys(virt_addr), PAGE_KERNEL_PGT));
}
// 计算出pdpt页表的页表项的地址
tmp_addr = (ul *)((ul)(phys_2_virt(*tmp_addr & (~0xfffUL))) + ((((ul)phys_2_virt(p->addr_phys)) >> PAGE_1G_SHIFT) & 0x1ff) * 8);
// 说明该页还没有分配pd页表，使用kmalloc分配一个
if (*tmp_addr = 0)
{
ul *virt_addr = kmalloc(PAGE_4K_SIZE, 0);
set_pdpt(tmp_addr, mk_pdpt(virt_2_phys(virt_addr), PAGE_KERNEL_DIR));
}
// 计算出pd页表的页表项的地址
tmp_addr = (ul *)((ul)(phys_2_virt(*tmp_addr & (~0xfffUL))) + ((((ul)phys_2_virt(p->addr_phys)) >> PAGE_2M_SHIFT) & 0x1ff) * 8);
// 填入pd页表的页表项，映射2MB物理页
set_pdt(tmp_addr, mk_pdt(virt_2_phys(p->addr_phys), PAGE_KERNEL_PAGE));
*/
// 测试
if (j % 50 == 0)
kdebug("pd_addr=%#018lx, *pd_addr=%#018lx", tmp_addr, *tmp_addr);
}
}
@ -631,19 +613,14 @@ void mm_map_proc_page_table(ul proc_page_table_addr, bool is_phys, ul virt_addr_
else
tmp = (ul *)((ul)proc_page_table_addr & (~0xfffUL)) + ((virt_addr_start >> PAGE_GDT_SHIFT) & 0x1ff);
// kdebug("tmp = %#018lx", tmp);
if (*tmp == 0)
{
ul *virt_addr = kmalloc(PAGE_4K_SIZE, 0);
memset(virt_addr, 0, PAGE_4K_SIZE);
set_pml4t(tmp, mk_pml4t(virt_2_phys(virt_addr), (user ? PAGE_USER_PGT : PAGE_KERNEL_PGT)));
}
// kdebug("*tmp = %#018lx", *tmp);
if (is_phys)
tmp = phys_2_virt((ul *)(*tmp & (~0xfffUL)) + ((virt_addr_start >> PAGE_1G_SHIFT) & 0x1ff));
else
tmp = (ul *)(*tmp & (~0xfffUL)) + ((virt_addr_start >> PAGE_1G_SHIFT) & 0x1ff);
tmp = phys_2_virt((ul *)(*tmp & (~0xfffUL)) + ((virt_addr_start >> PAGE_1G_SHIFT) & 0x1ff));
if (*tmp == 0)
{
@ -657,10 +634,8 @@ void mm_map_proc_page_table(ul proc_page_table_addr, bool is_phys, ul virt_addr_
for (ul i = 0; i < (length); i += PAGE_2M_SIZE)
{
// 计算当前2M物理页对应的pdt的页表项的物理地址
if (is_phys)
tmp1 = phys_2_virt(((ul *)(*tmp & (~0xfffUL)) + (((ul)(virt_addr_start + i) >> PAGE_2M_SHIFT) & 0x1ff)));
else
tmp1 = ((ul *)(*tmp & (~0xfffUL)) + (((ul)(virt_addr_start + i) >> PAGE_2M_SHIFT) & 0x1ff));
tmp1 = phys_2_virt(((ul *)(*tmp & (~0xfffUL)) + (((ul)(virt_addr_start + i) >> PAGE_2M_SHIFT) & 0x1ff)));
// 页面写穿，禁止缓存
set_pdt(tmp1, mk_pdt((ul)phys_addr_start + i, flags | (user ? PAGE_USER_PAGE : PAGE_KERNEL_PAGE)));
@ -669,6 +644,148 @@ void mm_map_proc_page_table(ul proc_page_table_addr, bool is_phys, ul virt_addr_
flush_tlb();
}
/**
* @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 从页表中清除虚拟地址的映射
*
* @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
*/
void mm_unmap_proc_table(ul proc_page_table_addr, bool is_phys, ul virt_addr_start, ul length)
{
ul *tmp;
if (is_phys)
tmp = phys_2_virt((ul *)((ul)proc_page_table_addr & (~0xfffUL)) + ((virt_addr_start >> PAGE_GDT_SHIFT) & 0x1ff));
else
tmp = (ul *)((ul)proc_page_table_addr & (~0xfffUL)) + ((virt_addr_start >> PAGE_GDT_SHIFT) & 0x1ff);
// pml4页表项为0
if (*tmp == 0)
return;
tmp = phys_2_virt((ul *)(*tmp & (~0xfffUL)) + ((virt_addr_start >> PAGE_1G_SHIFT) & 0x1ff));
// pdpt页表项为0
if (*tmp == 0)
return;
ul *tmp1;
for (ul i = 0; i < (length); i += PAGE_2M_SIZE)
{
// 计算当前2M物理页对应的pdt的页表项的物理地址
tmp1 = phys_2_virt(((ul *)(*tmp & (~0xfffUL)) + (((ul)(virt_addr_start + i) >> PAGE_2M_SHIFT) & 0x1ff)));
// 清除映射
*tmp1 = 0;
}
flush_tlb();
}
/**
* @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）
*
@ -679,16 +796,38 @@ void mm_map_proc_page_table(ul proc_page_table_addr, bool is_phys, ul virt_addr_
*/
uint64_t mm_do_brk(uint64_t old_brk_end_addr, int64_t offset)
{
// 暂不支持缩小堆内存
if (offset < 0)
return old_brk_end_addr;
uint64_t end_addr = old_brk_end_addr + offset;
for (uint64_t i = old_brk_end_addr; i < end_addr; i += PAGE_2M_SIZE)
uint64_t end_addr = PAGE_2M_ALIGN(old_brk_end_addr + offset);
if (offset >= 0)
{
kdebug("map [%d]", i);
mm_map_proc_page_table((uint64_t)current_pcb->mm->pgd, true, i, alloc_pages(ZONE_NORMAL, 1, PAGE_PGT_MAPPED)->addr_phys, PAGE_2M_SIZE, PAGE_USER_PAGE, true);
for (uint64_t i = old_brk_end_addr; i < end_addr; i += PAGE_2M_SIZE)
{
kdebug("map [%#018lx]", i);
mm_map_proc_page_table((uint64_t)current_pcb->mm->pgd, true, i, alloc_pages(ZONE_NORMAL, 1, PAGE_PGT_MAPPED)->addr_phys, PAGE_2M_SIZE, PAGE_USER_PAGE, true);
}
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
}
current_pcb->mm->brk_end = end_addr;
return end_addr;
}