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https://github.com/DragonOS-Community/DragonOS.git
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119 lines
3.4 KiB
C
119 lines
3.4 KiB
C
#include "mmio.h"
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#include "mmio-buddy.h"
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#include <common/math.h>
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void mmio_init()
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{
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mmio_buddy_init();
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}
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/**
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* @brief 创建一块mmio区域,并将vma绑定到initial_mm
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*
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* @param size mmio区域的大小(字节)
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* @param vm_flags 要把vma设置成的标志
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* @param res_vaddr 返回值-分配得到的虚拟地址
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* @param res_length 返回值-分配的虚拟地址空间长度
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* @return int 错误码
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*/
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int mmio_create(uint32_t size, vm_flags_t vm_flags, uint64_t *res_vaddr, uint64_t *res_size)
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{
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int retval = 0;
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// 申请的内存超过允许的最大大小
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if (unlikely(size > PAGE_1G_SIZE || size == 0))
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return -EPERM;
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// 计算要从buddy中申请地址空间大小(按照2的n次幂来对齐)
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int size_exp = 31 - __clz(size);
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if (size_exp < PAGE_4K_SHIFT)
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{
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size_exp = PAGE_4K_SHIFT;
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size = PAGE_4K_SIZE;
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}
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else if (size & (~(1 << size_exp)))
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{
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++size_exp;
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size = 1 << size_exp;
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}
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// 申请内存
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struct __mmio_buddy_addr_region *buddy_region = mmio_buddy_query_addr_region(size_exp);
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if (buddy_region == NULL) // 没有空闲的mmio空间了
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return -ENOMEM;
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*res_vaddr = buddy_region->vaddr;
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*res_size = size;
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// 释放region
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__mmio_buddy_release_addr_region(buddy_region);
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// ====创建vma===
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// 设置vma flags
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vm_flags |= (VM_IO | VM_DONTCOPY);
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uint64_t len_4k = size % PAGE_2M_SIZE;
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uint64_t len_2m = size - len_4k;
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// 先创建2M的vma,然后创建4k的
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for (uint32_t i = 0; i < len_2m; i += PAGE_2M_SIZE)
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{
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retval = mm_create_vma(&initial_mm, buddy_region->vaddr + i, PAGE_2M_SIZE, vm_flags, NULL, NULL);
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if (unlikely(retval != 0))
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goto failed;
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}
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for (uint32_t i = len_2m; i < size; i += PAGE_4K_SIZE)
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{
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retval = mm_create_vma(&initial_mm, buddy_region->vaddr + i, PAGE_4K_SIZE, vm_flags, NULL, NULL);
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if (unlikely(retval != 0))
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goto failed;
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}
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return 0;
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failed:;
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kerror("failed to create mmio vma. pid=%d", current_pcb->pid);
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// todo: 当失败时,将已创建的vma删除
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return retval;
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}
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/**
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* @brief 取消mmio的映射并将地址空间归还到buddy中
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*
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* @param vaddr 起始的虚拟地址
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* @param length 要归还的地址空间的长度
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* @return int 错误码
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*/
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int mmio_release(uint64_t vaddr, uint64_t length)
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{
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int retval = 0;
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// 先将这些区域都unmap了
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mm_unmap(&initial_mm, vaddr, length, false);
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// 将这些区域加入buddy
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for (uint64_t i = 0; i < length;)
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{
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struct vm_area_struct *vma = vma_find(&initial_mm, vaddr + i);
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if (unlikely(vma == NULL))
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{
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kerror("mmio_release failed: vma not found. At address: %#018lx, pid=%ld", vaddr + i, current_pcb->pid);
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return -EINVAL;
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}
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if (unlikely(vma->vm_start != (vaddr + i)))
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{
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kerror("mmio_release failed: addr_start is not equal to current: %#018lx.", vaddr + i);
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return -EINVAL;
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}
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// 往buddy中插入内存块
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retval = __mmio_buddy_give_back(vma->vm_start, 31 - __clz(vma->vm_end - vma->vm_start));
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i += vma->vm_end - vma->vm_start;
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// 释放vma结构体
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vm_area_del(vma);
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vm_area_free(vma);
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if (unlikely(retval != 0))
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goto give_back_failed;
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}
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return 0;
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give_back_failed:;
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kerror("mmio_release give_back failed: ");
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return retval;
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}
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