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Code Issues Releases Wiki Activity

Combine vma (#42)

Browse Source 
* 合并vma

* 调整vma映射，修复bug

* 删除注释

Co-authored-by: fslongjin <longjin@RinGoTek.cn>
Co-authored-by: houmkh <100781004+houmkh@users.noreply.github.com>
This commit is contained in:
houmkh
2022-09-22 00:31:17 +08:00
committed by GitHub
parent cbbf79b2cf
commit be9ac3d58b
7 changed files with 113 additions and 42 deletions
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93
kernel/mm/mmap.c
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@ -2,6 +2,7 @@
#include "slab.h"
#include "internal.h"
#include <common/compiler.h>
#include <debug/bug.h>
extern uint64_t mm_total_2M_pages;
@ -319,6 +320,10 @@ void mm_unmap_proc_table(ul proc_page_table_addr, bool is_phys, ul virt_addr_sta
int mm_create_vma(struct mm_struct *mm, uint64_t vaddr, uint64_t length, vm_flags_t vm_flags, struct vm_operations_t *vm_ops, struct vm_area_struct **res_vma)
{
int retval = 0;
// 输入的地址如果不是4K对齐，则报错
if (unlikely(vaddr & (PAGE_4K_SIZE - 1)))
return -EINVAL;
struct vm_area_struct *vma = vm_area_alloc(mm);
if (unlikely(vma == NULL))
return -ENOMEM;
@ -328,12 +333,16 @@ int mm_create_vma(struct mm_struct *mm, uint64_t vaddr, uint64_t length, vm_flag
vma->vm_end = vaddr + length;
// 将VMA加入mm的链表
retval = vma_insert(mm, vma);
if (retval == -EEXIST) // 之前已经存在了相同的vma，直接返回
if (retval == -EEXIST || retval == __VMA_MERGED) // 之前已经存在了相同的vma，直接返回
{
*res_vma = vma_find(mm, vma->vm_start);
kfree(vma);
return -EEXIST;
if (retval == -EEXIST)
return -EEXIST;
else
return 0;
}
if (res_vma != NULL)
*res_vma = vma;
return 0;
@ -344,11 +353,16 @@ int mm_create_vma(struct mm_struct *mm, uint64_t vaddr, uint64_t length, vm_flag
*
* @param vma 要进行映射的VMA结构体
* @param paddr 起始物理地址
* @param offset 要映射的起始位置在vma中的偏移量
* @param length 要映射的长度
* @return int 错误码
*/
int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr)
int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr, uint64_t offset, uint64_t length)
{
int retval = 0;
int retval = 0;
uint64_t mapped = 0;
BUG_ON((offset & (PAGE_4K_SIZE - 1)) != 0);
length = PAGE_4K_ALIGN(length); // 将length按照4K进行对齐
// 获取物理地址对应的页面
struct Page *pg;
uint64_t page_flags = 0;
@ -374,17 +388,39 @@ int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr)
// 将anon vma与vma进行绑定
__anon_vma_add(pg->anon_vma, vma);
barrier();
uint64_t length = vma->vm_end - vma->vm_start;
// ==== 将地址映射到页表 ====
uint64_t len_4k = length % PAGE_2M_SIZE;
uint64_t len_2m = length - len_4k;
// 长度超过界限
BUG_ON(vma->vm_start + offset + length > vma->vm_end);
/*
todo: 限制页面的读写权限
*/
// kdebug("len2m=%d", len_2m);
// 先映射2M页
// ==== 将地址映射到页表 ====
uint64_t len_4k, len_2m;
// 将地址使用4k页填补，使得地址按照2M对齐
len_4k = PAGE_2M_ALIGN(vma->vm_start + offset) - (vma->vm_start + offset);
if (len_4k > 0)
len_4k = (len_4k > length) ? length : len_4k;
if (len_4k)
{
if (vma->vm_flags & VM_USER)
page_flags |= PAGE_USER_4K_PAGE;
else
page_flags |= PAGE_KERNEL_4K_PAGE;
// 这里直接设置user标志位为false，因为该函数内部会对其进行自动校正
retval = mm_map_proc_page_table((uint64_t)vma->vm_mm->pgd, true, vma->vm_start + offset, paddr, len_4k, page_flags, false, false, true);
if (unlikely(retval != 0))
goto failed;
mapped += len_4k;
length -= len_4k;
}
len_4k = length % PAGE_2M_SIZE;
len_2m = length / PAGE_2M_SIZE;
// 映射连续的2M页
if (likely(len_2m > 0))
{
if (vma->vm_flags & VM_USER)
@ -392,31 +428,32 @@ int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr)
else
page_flags |= PAGE_KERNEL_PAGE;
// 这里直接设置user标志位为false，因为该函数内部会对其进行自动校正
retval = mm_map_proc_page_table((uint64_t)vma->vm_mm->pgd, true, vma->vm_start, paddr, len_2m, page_flags, false, false, false);
retval = mm_map_proc_page_table((uint64_t)vma->vm_mm->pgd, true, vma->vm_start + offset + mapped, paddr + mapped, len_2m, page_flags, false, false, false);
if (unlikely(retval != 0))
goto failed;
mapped += len_2m;
}
// 最后再使用4K页填补
if (likely(len_4k > 0))
{
len_4k = ALIGN(len_4k, PAGE_4K_SIZE);
if (vma->vm_flags & VM_USER)
page_flags |= PAGE_USER_4K_PAGE;
else
page_flags |= PAGE_KERNEL_4K_PAGE;
// 这里直接设置user标志位为false，因为该函数内部会对其进行自动校正
retval = mm_map_proc_page_table((uint64_t)vma->vm_mm->pgd, true, vma->vm_start + len_2m, paddr + len_2m, len_4k, page_flags, false, false, true);
retval = mm_map_proc_page_table((uint64_t)vma->vm_mm->pgd, true, vma->vm_start + offset + mapped, paddr + mapped, len_4k, page_flags, false, false, true);
if (unlikely(retval != 0))
goto failed;
mapped += len_4k;
}
if (vma->vm_flags & VM_IO)
vma->page_offset = 0;
else
{ // 计算当前vma的起始地址在对应的物理页中的偏移量
vma->page_offset = paddr - (paddr & PAGE_2M_MASK);
}
flush_tlb();
return 0;
failed:;
@ -436,6 +473,7 @@ failed:;
int mm_map(struct mm_struct *mm, uint64_t vaddr, uint64_t length, uint64_t paddr)
{
int retval = 0;
uint64_t offset = 0;
for (uint64_t mapped = 0; mapped < length;)
{
@ -446,17 +484,20 @@ int mm_map(struct mm_struct *mm, uint64_t vaddr, uint64_t length, uint64_t paddr
return -EINVAL;
}
if (unlikely(vma->vm_start != (vaddr + mapped)))
{
kerror("Map addr failed: addr_start is not equal to current: %#018lx.", vaddr + mapped);
return -EINVAL;
}
// if (unlikely(vma->vm_start != (vaddr + mapped)))
// {
// kerror("Map addr failed: addr_start is not equal to current: %#018lx.", vaddr + mapped);
// return -EINVAL;
// }
retval = mm_map_vma(vma, paddr + mapped);
offset = vaddr + mapped - vma->vm_start;
uint64_t m_len = vma->vm_end - vma->vm_start - offset;
// kdebug("start=%#018lx, offset=%ld", vma->vm_start, offset);
retval = mm_map_vma(vma, paddr + mapped, offset, m_len);
if (unlikely(retval != 0))
goto failed;
mapped += vma->vm_end - vma->vm_start;
mapped += m_len;
}
return 0;
failed:;