new: 初步完成了mmio地址空间自动分配（未测试）

bugfix: mmio虚拟地址分配的bug

kernel/mm/mmap.c

@@ -326,7 +326,6 @@ int mm_create_vma(struct mm_struct *mm, uint64_t vaddr, uint64_t length, vm_flag
     vma->vm_flags = vm_flags;
     vma->vm_start = vaddr;
     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
@@ -335,7 +334,8 @@ int mm_create_vma(struct mm_struct *mm, uint64_t vaddr, uint64_t length, vm_flag
         kfree(vma);
         return -EEXIST;
     }
-    *res_vma = vma;
+    if (res_vma != NULL)
+        *res_vma = vma;
     return 0;
 }
 
@@ -350,7 +350,12 @@ int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr)
 {
     int retval = 0;
     // 获取物理地址对应的页面
-    struct Page *pg = Phy_to_2M_Page(paddr);
+    struct Page *pg;
+    if (vma->vm_flags & VM_IO) // 对于mmio的内存，创建新的page结构体
+        pg = __create_mmio_page_struct(paddr);
+    else
+        pg = Phy_to_2M_Page(paddr);
+
     if (unlikely(pg->anon_vma == NULL)) // 若页面不存在anon_vma，则为页面创建anon_vma
     {
         spin_lock(&pg->op_lock);
@@ -400,8 +405,13 @@ int mm_map_vma(struct vm_area_struct *vma, uint64_t paddr)
         if (unlikely(retval != 0))
             goto failed;
     }
-    // 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);
+
+    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:;
@@ -409,6 +419,46 @@ failed:;
     return retval;
 }
 
+/**
+ * @brief 在页表中映射物理地址到指定的虚拟地址（需要页表中已存在对应的vma）
+ *
+ * @param mm 内存管理结构体
+ * @param vaddr 虚拟地址
+ * @param length 长度（字节）
+ * @param paddr 物理地址
+ * @return int 返回码
+ */
+int mm_map(struct mm_struct *mm, uint64_t vaddr, uint64_t length, uint64_t paddr)
+{
+    int retval = 0;
+    for (uint64_t mapped = 0; mapped < length;)
+    {
+
+        struct vm_area_struct *vma = vma_find(mm, vaddr + mapped);
+        if (unlikely(vma == NULL))
+        {
+            kerror("Map addr failed: vma not found. At address: %#018lx, pid=%ld", vaddr + mapped, current_pcb->pid);
+            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);
+        if (unlikely(retval != 0))
+            goto failed;
+
+        mapped += vma->vm_end - vma->vm_start;
+    }
+    return 0;
+failed:;
+    kerror("Map addr failed.");
+    return retval;
+}
+
 /**
  * @brief 在页表中取消指定的vma的映射
  *
@@ -417,15 +467,70 @@ failed:;
  * @param paddr 返回的被取消映射的起始物理地址
  * @return int 返回码
  */
-int mm_umap_vma(struct mm_struct *mm, struct vm_area_struct *vma, uint64_t *paddr)
+int mm_unmap_vma(struct mm_struct *mm, struct vm_area_struct *vma, uint64_t *paddr)
 {
     // 确保vma对应的mm与指定的mm相一致
     if (unlikely(vma->vm_mm != mm))
         return -EINVAL;
-
+    struct anon_vma_t *anon = vma->anon_vma;
     if (paddr != NULL)
         *paddr = __mm_get_paddr(mm, vma->vm_start);
+    if (anon == NULL)
+        kwarn("anon is NULL");
+    semaphore_down(&anon->sem);
 
     mm_unmap_proc_table((uint64_t)mm->pgd, true, vma->vm_start, vma->vm_end - vma->vm_start);
+    __anon_vma_del(vma);
+    /** todo: 这里应该会存在bug，应修复。
+     * 若anon_vma的等待队列上有其他的进程，由于anon_vma被释放
+     * 这些在等待队列上的进程将无法被唤醒。
+     */
+    list_init(&vma->anon_vma_list);
+
+    semaphore_up(&anon->sem);
+
     return 0;
-}
+}
+
+/**
+ * @brief 解除一段虚拟地址的映射（这些地址必须在vma中存在）
+ *
+ * @param mm 内存空间结构体
+ * @param vaddr 起始地址
+ * @param length 结束地址
+ * @param destroy 是否释放vma结构体
+ * @return int 错误码
+ */
+int mm_unmap(struct mm_struct *mm, uint64_t vaddr, uint64_t length, bool destroy)
+{
+    int retval = 0;
+    for (uint64_t unmapped = 0; unmapped < length;)
+    {
+        struct vm_area_struct *vma = vma_find(mm, vaddr + unmapped);
+        if (unlikely(vma == NULL))
+        {
+            kerror("Unmap addr failed: vma not found. At address: %#018lx, pid=%ld", vaddr + unmapped, current_pcb->pid);
+            return -EINVAL;
+        }
+
+        if (unlikely(vma->vm_start != (vaddr + unmapped)))
+        {
+            kerror("Unmap addr failed: addr_start is not equal to current: %#018lx.", vaddr + unmapped);
+            return -EINVAL;
+        }
+        if (vma->anon_vma != NULL)
+            mm_unmap_vma(mm, vma, NULL);
+
+        unmapped += vma->vm_end - vma->vm_start;
+        // 释放vma结构体
+        if (destroy)
+        {
+            vm_area_del(vma);
+            vm_area_free(vma);
+        }
+    }
+    return 0;
+failed:;
+    kerror("Unmap addr failed.");
+    return retval;
+}