xref: /DragonOS/kernel/src/mm/mm.h (revision 2b7818e80e00fcfe4d03533f587cc125ea5e4bec)

#pragma once

#include <common/glib.h>
#include <process/process.h>

#define PAGE_4K_SHIFT 12
#define PAGE_2M_SHIFT 21
#define PAGE_1G_SHIFT 30
#define PAGE_GDT_SHIFT 39

// 不同大小的页的容量
#define PAGE_4K_SIZE (1UL << PAGE_4K_SHIFT)
#define PAGE_2M_SIZE (1UL << PAGE_2M_SHIFT)
#define PAGE_1G_SIZE (1UL << PAGE_1G_SHIFT)

// 屏蔽低于x的数值
#define PAGE_4K_MASK (~(PAGE_4K_SIZE - 1))
#define PAGE_2M_MASK (~(PAGE_2M_SIZE - 1))

// 将addr按照x的上边界对齐
#define PAGE_4K_ALIGN(addr)                                                    \
  (((unsigned long)(addr) + PAGE_4K_SIZE - 1) & PAGE_4K_MASK)
#define PAGE_2M_ALIGN(addr)                                                    \
  (((unsigned long)(addr) + PAGE_2M_SIZE - 1) & PAGE_2M_MASK)

// 虚拟地址与物理地址转换
#define virt_2_phys(addr) ((unsigned long)(addr)-PAGE_OFFSET)
#define phys_2_virt(addr)                                                      \
  ((unsigned long *)((unsigned long)(addr) + PAGE_OFFSET))

// ===== 页面属性 =====
// 页面在页表中已被映射 mapped=1 unmapped=0
#define PAGE_PGT_MAPPED (1 << 0)

// 内核初始化所占用的页 init-code=1 normal-code/data=0
#define PAGE_KERNEL_INIT (1 << 1)

// 1=设备MMIO映射的内存 0=物理内存
#define PAGE_DEVICE (1 << 2)

// 内核层页 kernel=1 memory=0
#define PAGE_KERNEL (1 << 3)

// 共享的页 shared=1 single-use=0
#define PAGE_SHARED (1 << 4)

// =========== 页表项权限 ========

//	bit 63	Execution Disable:
#define PAGE_XD (1UL << 63)

//	bit 12	Page Attribute Table
#define PAGE_PAT (1UL << 12)
// 对于PTE而言，第7位是PAT
#define PAGE_4K_PAT (1UL << 7)

//	bit 8	Global Page:1,global;0,part
#define PAGE_GLOBAL (1UL << 8)

//	bit 7	Page Size:1,big page;0,small page;
#define PAGE_PS (1UL << 7)

//	bit 6	Dirty:1,dirty;0,clean;
#define PAGE_DIRTY (1UL << 6)

//	bit 5	Accessed:1,visited;0,unvisited;
#define PAGE_ACCESSED (1UL << 5)

//	bit 4	Page Level Cache Disable
#define PAGE_PCD (1UL << 4)

//	bit 3	Page Level Write Through
#define PAGE_PWT (1UL << 3)

//	bit 2	User Supervisor:1,user and supervisor;0,supervisor;
#define PAGE_U_S (1UL << 2)

//	bit 1	Read Write:1,read and write;0,read;
#define PAGE_R_W (1UL << 1)

//	bit 0	Present:1,present;0,no present;
#define PAGE_PRESENT (1UL << 0)

// 1,0
#define PAGE_KERNEL_PGT (PAGE_R_W | PAGE_PRESENT)

// 1,0
#define PAGE_KERNEL_DIR (PAGE_R_W | PAGE_PRESENT)

// 1,0 (4级页表在3级页表中的页表项的属性)
#define PAGE_KERNEL_PDE (PAGE_R_W | PAGE_PRESENT)

// 7,1,0
#define PAGE_KERNEL_PAGE (PAGE_PS | PAGE_R_W | PAGE_PRESENT)

#define PAGE_KERNEL_4K_PAGE (PAGE_R_W | PAGE_PRESENT)

#define PAGE_USER_PGT (PAGE_U_S | PAGE_R_W | PAGE_PRESENT)

// 2,1,0
#define PAGE_USER_DIR (PAGE_U_S | PAGE_R_W | PAGE_PRESENT)

// 1,0 (4级页表在3级页表中的页表项的属性)
#define PAGE_USER_PDE (PAGE_U_S | PAGE_R_W | PAGE_PRESENT)
// 7,2,1,0
#define PAGE_USER_PAGE (PAGE_PS | PAGE_U_S | PAGE_R_W | PAGE_PRESENT)

#define PAGE_USER_4K_PAGE (PAGE_U_S | PAGE_R_W | PAGE_PRESENT)

// 导出内核程序的几个段的起止地址
extern char _text;
extern char _etext;
extern char _data;
extern char _edata;
extern char _rodata;
extern char _erodata;
extern char _bss;
extern char _ebss;
extern char _end;

/*
 *  vm_area_struct中的vm_flags的可选值
 * 对应的结构体请见mm-types.h
 */
#define VM_NONE 0
#define VM_READ (1 << 0)
#define VM_WRITE (1 << 1)
#define VM_EXEC (1 << 2)
#define VM_SHARED (1 << 3)
#define VM_IO (1 << 4) // MMIO的内存区域
#define VM_SOFTDIRTY (1 << 5)
#define VM_MAYSHARE (1 << 6) // 该vma可被共享
#define VM_USER (1 << 7)     // 该vma可被用户态访问
#define VM_DONTCOPY (1 << 8) // 当fork的时候不拷贝该虚拟内存区域

/* VMA basic access permission flags */
#define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC)