los_vm_map.h

/*
 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of
 *    conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
 *    of conditions and the following disclaimer in the documentation and/or other materials
 *    provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
 *    to endorse or promote products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @defgroup los_vm_map vm mapping management
 * @ingroup kernel
 */

#ifndef __LOS_VM_MAP_H__
#define __LOS_VM_MAP_H__

#include "los_typedef.h"
#include "los_arch_mmu.h"
#include "los_rbtree.h"
#include "los_vm_syscall.h"
#include "los_vm_zone.h"
#include "los_vm_common.h"

#ifdef __cplusplus
#if __cplusplus
extern "C" {
#endif /* __cplusplus */
#endif /* __cplusplus */
#if 0 // @note_#if0
file结构体来自 ..\third_party\NuttX\include\nuttx\fs\fs.h
struct file //打开文件的基本表示形式
{
  unsigned int         f_magicnum;  /* file magic number */
  int                  f_oflags;    /* Open mode flags */
  FAR struct inode     *f_inode;    /* Driver interface */
  loff_t               f_pos;       /* File position */
  unsigned long        f_refcount;  /* reference count */
  char                 *f_path;     /* File fullpath */
  void                 *f_priv;     /* Per file driver private data */
  const char           *f_relpath;  /* realpath */
  struct page_mapping  *f_mapping;  /* mapping file to memory */
  void                 *f_dir;      /* DIR struct for iterate the directory if open a directory */
};

struct page_mapping {
  LOS_DL_LIST                           page_list;    /* all pages */
  SPIN_LOCK_S                           list_lock;    /* lock protecting it */
  LosMux                                mux_lock;     /* mutex lock */
  unsigned long                         nrpages;      /* number of total pages */
  unsigned long                         flags;
  Atomic                                ref;          /* reference counting */
  struct file                           *host;        /* owner of this mapping */
};
#endif
/* If the kernel malloc size is less than 16k, use heap, otherwise use physical pages */
#define KMALLOC_LARGE_SIZE    (PAGE_SIZE << 2)
typedef struct VmMapRange {
    VADDR_T             base;           /**< vm region base addr */ //线性区基地址
    UINT32              size;           /**< vm region size */		//线性区大小
} LosVmMapRange;

struct VmMapRegion;
typedef struct VmMapRegion LosVmMapRegion;
struct VmFileOps;
typedef struct VmFileOps LosVmFileOps;
struct VmSpace;
typedef struct VmSpace LosVmSpace;
//缺页结构信息体 
typedef struct VmFault {
    UINT32          flags;              /* FAULT_FLAG_xxx flags */	//缺页标识
    unsigned long   pgoff;              /* Logical page offset based on region */	//基于线性区的逻辑页偏移量
    VADDR_T         vaddr;              /* Faulting virtual address */ //产生缺页的虚拟地址
    VADDR_T         *pageKVaddr;        /* KVaddr of pagefault's vm page's paddr */ //page cache中的虚拟地址
} LosVmPgFault;
//虚拟内存文件操作函数指针,上层开发可理解为 class 里的方法，注意是对线性区的操作
struct VmFileOps {// 文件操作 见于g_commVmOps
    void (*open)(struct VmMapRegion *region); //打开
    void (*close)(struct VmMapRegion *region);//关闭
    int  (*fault)(struct VmMapRegion *region, LosVmPgFault *pageFault);//缺页,OsVmmFileFault
    void (*remove)(struct VmMapRegion *region, LosArchMmu *archMmu, VM_OFFSET_T offset);//删除 OsVmmFileRemove
};

struct VmMapRegion {//线性区描述符,内核通过线性区管理虚拟地址,而线性地址就是虚拟地址
    LosRbNode           rbNode;         /**< region red-black tree node */	//红黑树节点,通过它将本线性区挂在VmSpace.regionRbTree
    LosVmSpace          *space;			//所属虚拟空间,虚拟空间由多个线性区组成
    LOS_DL_LIST         node;           /**< region dl list */				//链表节点,通过它将本线性区挂在VmSpace.regions上
    LosVmMapRange       range;          /**< region address range */		//记录线性区的范围
    VM_OFFSET_T         pgOff;          /**< region page offset to file */	//以文件开始处的偏移量, 必须是分页大小的整数倍, 通常为0, 表示从文件头开始映射。
    UINT32              regionFlags;   /**< region flags: cow, user_wired *///线性区标签
    UINT32              shmid;          /**< shmid about shared region */	//shmid为共享线性区id,id背后就是共享线性区
    UINT8               forkFlags;      /**< vm space fork flags: COPY, ZERO, */	//fork的方式
    UINT8               regionType;     /**< vm region type: ANON, FILE, DEV */	//映射类型是匿名,文件,还是设备,所谓匿名可理解为内存映射
    union {
        struct VmRegionFile {//
            unsigned int fileMagic;//具有特殊文件格式的文件,魔法数字.例如 stack top 的魔法数字为 0xCCCCCCCC
            struct file *file;		//文件指针
            const LosVmFileOps *vmFOps;//文件处理各操作接口
        } rf;
        struct VmRegionAnon {//匿名映射可理解为就是物理内存
            LOS_DL_LIST  node;          /**< region LosVmPage list */ 	//线性区虚拟页链表
        } ra;
        struct VmRegionDev {
            LOS_DL_LIST  node;          /**< region LosVmPage list */	//线性区虚拟页链表
            const LosVmFileOps *vmFOps; //设备也是一种文件
        } rd;
    } unTypeData;
};

typedef struct VmSpace {
    LOS_DL_LIST         node;           /**< vm space dl list */	//节点,通过它挂到全局虚拟空间 g_vmSpaceList 链表上
    LOS_DL_LIST         regions;        /**< region dl list */		//双循环链表方式管理本空间各个线性区
    LosRbTree           regionRbTree;   /**< region red-black tree root */	//采用红黑树方式管理本空间各个线性区
    LosMux              regionMux;      /**< region list mutex lock */	//虚拟空间的互斥锁
    VADDR_T             base;           /**< vm space base addr */		//虚拟空间的基地址,常用于判断地址是否在内核还是用户空间
    UINT32              size;           /**< vm space size */			//虚拟空间大小
    VADDR_T             heapBase;       /**< vm space heap base address */	//用户进程专用，堆区基地址，表堆区范围起点
    VADDR_T             heapNow;        /**< vm space heap base now */		//用户进程专用，堆区结束地址，表堆区范围终点，do_brk()直接修改堆的大小返回新的堆区结束地址， heapNow >= heapBase
    LosVmMapRegion      *heap;          /**< heap region */					//堆区是个特殊的线性区，用于满足进程的动态内存需求，大家熟知的malloc,realloc,free其实就是在操作这个区
    VADDR_T             mapBase;        /**< vm space mapping area base */	//虚拟空间映射区基地址,L1，L2表存放在这个区
    UINT32              mapSize;        /**< vm space mapping area size */	//虚拟空间映射区大小，映射区是个很大的区。
    LosArchMmu          archMmu;        /**< vm mapping physical memory */	//MMU记录<虚拟地址,物理地址>的映射情况
#ifdef LOSCFG_DRIVERS_TZDRIVER
    VADDR_T             codeStart;      /**< user process code area start */
    VADDR_T             codeEnd;        /**< user process code area end */
#endif
} LosVmSpace;

#define     VM_MAP_REGION_TYPE_NONE                 (0x0)//初始化使用
#define     VM_MAP_REGION_TYPE_ANON                 (0x1)//匿名映射线性区
#define     VM_MAP_REGION_TYPE_FILE                 (0x2)//文件映射线性区
#define     VM_MAP_REGION_TYPE_DEV                  (0x4)//设备映射线性区
#define     VM_MAP_REGION_TYPE_MASK                 (0x7)//映射线性区掩码

/* the high 8 bits(24~31) should reserved, shm will use it */
#define     VM_MAP_REGION_FLAG_CACHED               (0<<0)		//缓冲区
#define     VM_MAP_REGION_FLAG_UNCACHED             (1<<0)		//非缓冲区
#define     VM_MAP_REGION_FLAG_UNCACHED_DEVICE      (2<<0) /* only exists on some arches, otherwise UNCACHED */
#define     VM_MAP_REGION_FLAG_STRONGLY_ORDERED     (3<<0) /* only exists on some arches, otherwise UNCACHED */
#define     VM_MAP_REGION_FLAG_CACHE_MASK           (3<<0)		//缓冲区掩码
#define     VM_MAP_REGION_FLAG_PERM_USER            (1<<2)		//用户区
#define     VM_MAP_REGION_FLAG_PERM_READ            (1<<3)		//可读取区
#define     VM_MAP_REGION_FLAG_PERM_WRITE           (1<<4)		//可写入区
#define     VM_MAP_REGION_FLAG_PERM_EXECUTE         (1<<5)		//可被执行区
#define     VM_MAP_REGION_FLAG_PROT_MASK            (0xF<<2)	//访问权限掩码
#define     VM_MAP_REGION_FLAG_NS                   (1<<6) 		/* NON-SECURE */
#define     VM_MAP_REGION_FLAG_SHARED               (1<<7)		//MAP_SHARED：把对该内存段的修改保存到磁盘文件中 详见 OsCvtProtFlagsToRegionFlags ,要和 VM_MAP_REGION_FLAG_SHM区别理解
#define     VM_MAP_REGION_FLAG_PRIVATE              (1<<8)		//MAP_PRIVATE：内存段私有，对它的修改值仅对本进程有效,详见 OsCvtProtFlagsToRegionFlags。
#define     VM_MAP_REGION_FLAG_FLAG_MASK            (3<<7)		//掩码
#define     VM_MAP_REGION_FLAG_STACK                (1<<9)		//线性区的类型:栈区
#define     VM_MAP_REGION_FLAG_HEAP                 (1<<10)		//线性区的类型:堆区
#define     VM_MAP_REGION_FLAG_DATA                 (1<<11)		//data数据区 编译在ELF中
#define     VM_MAP_REGION_FLAG_TEXT                 (1<<12)		//代码区
#define     VM_MAP_REGION_FLAG_BSS                  (1<<13)		//bbs数据区 由运行时动态分配
#define     VM_MAP_REGION_FLAG_VDSO                 (1<<14)		//VDSO(Virtual Dynamically-lined Shared Object)由内核提供的虚拟.so文件，它不在磁盘上，而在内核里，内核将其映射到一个地址空间中，被所有程序共享，正文段大小为一个页面。
#define     VM_MAP_REGION_FLAG_MMAP                 (1<<15)		//映射区,虚拟空间内有专门用来存储<虚拟地址-物理地址>映射的区域
#define     VM_MAP_REGION_FLAG_SHM                  (1<<16) 	//共享内存区,和代码区同级概念,意思是整个线性区被贴上共享标签
#define     VM_MAP_REGION_FLAG_FIXED                (1<<17)
#define     VM_MAP_REGION_FLAG_FIXED_NOREPLACE      (1<<18)
#define     VM_MAP_REGION_FLAG_INVALID              (1<<19) /* indicates that flags are not specified */

STATIC INLINE UINT32 OsCvtProtFlagsToRegionFlags(unsigned long prot, unsigned long flags)
{
    UINT32 regionFlags = 0;

    regionFlags |= VM_MAP_REGION_FLAG_PERM_USER;								//必须是可用区
    regionFlags |= (prot & PROT_READ) ? VM_MAP_REGION_FLAG_PERM_READ : 0; 		//映射区可被读
    regionFlags |= (prot & PROT_WRITE) ? (VM_MAP_REGION_FLAG_PERM_READ | VM_MAP_REGION_FLAG_PERM_WRITE) : 0;
    regionFlags |= (prot & PROT_EXEC) ? (VM_MAP_REGION_FLAG_PERM_READ | VM_MAP_REGION_FLAG_PERM_EXECUTE) : 0;
    regionFlags |= (flags & MAP_SHARED) ? VM_MAP_REGION_FLAG_SHARED : 0;
    regionFlags |= (flags & MAP_PRIVATE) ? VM_MAP_REGION_FLAG_PRIVATE : 0;
    regionFlags |= (flags & MAP_FIXED) ? VM_MAP_REGION_FLAG_FIXED : 0;
    regionFlags |= (flags & MAP_FIXED_NOREPLACE) ? VM_MAP_REGION_FLAG_FIXED_NOREPLACE : 0;

    return regionFlags;
}
//是否为内核空间
STATIC INLINE BOOL LOS_IsKernelAddress(VADDR_T vaddr)
{
    return ((vaddr >= (VADDR_T)KERNEL_ASPACE_BASE) &&
            (vaddr <= ((VADDR_T)KERNEL_ASPACE_BASE + ((VADDR_T)KERNEL_ASPACE_SIZE - 1))));
}
//给定范围是否在内核空间中
STATIC INLINE BOOL LOS_IsKernelAddressRange(VADDR_T vaddr, size_t len)
{
    return (vaddr + len > vaddr) && LOS_IsKernelAddress(vaddr) && (LOS_IsKernelAddress(vaddr + len - 1));
}
//获取区的结束地址
STATIC INLINE VADDR_T LOS_RegionEndAddr(LosVmMapRegion *region)
{
    return (region->range.base + region->range.size - 1);
}
//线性区大小
STATIC INLINE size_t LOS_RegionSize(VADDR_T start, VADDR_T end)
{
    return (end - start + 1);
}
//是否为文件映射区
STATIC INLINE BOOL LOS_IsRegionTypeFile(LosVmMapRegion* region)
{
    return region->regionType == VM_MAP_REGION_TYPE_FILE;
}
//permanent 用户进程常量区
STATIC INLINE BOOL LOS_IsRegionPermUserReadOnly(LosVmMapRegion* region)
{
    return ((region->regionFlags & VM_MAP_REGION_FLAG_PROT_MASK) ==
            (VM_MAP_REGION_FLAG_PERM_USER | VM_MAP_REGION_FLAG_PERM_READ));
}
//是否为私有线性区
STATIC INLINE BOOL LOS_IsRegionFlagPrivateOnly(LosVmMapRegion* region)
{
    return ((region->regionFlags & VM_MAP_REGION_FLAG_FLAG_MASK) == VM_MAP_REGION_FLAG_PRIVATE);
}
//设置线性区为文件映射
STATIC INLINE VOID LOS_SetRegionTypeFile(LosVmMapRegion* region)
{
    region->regionType = VM_MAP_REGION_TYPE_FILE;
}
//是否为设备映射线性区
STATIC INLINE BOOL LOS_IsRegionTypeDev(LosVmMapRegion* region)
{
    return region->regionType == VM_MAP_REGION_TYPE_DEV;
}
//设为设备映射线性区
STATIC INLINE VOID LOS_SetRegionTypeDev(LosVmMapRegion* region)
{
    region->regionType = VM_MAP_REGION_TYPE_DEV;
}
//是否为匿名swap映射线性区
STATIC INLINE BOOL LOS_IsRegionTypeAnon(LosVmMapRegion* region)
{
    return region->regionType == VM_MAP_REGION_TYPE_ANON;
}
//设为匿名swap映射线性区
STATIC INLINE VOID LOS_SetRegionTypeAnon(LosVmMapRegion* region)
{
    region->regionType = VM_MAP_REGION_TYPE_ANON;
}
//虚拟地址是否在用户空间
STATIC INLINE BOOL LOS_IsUserAddress(VADDR_T vaddr)
{
    return ((vaddr >= USER_ASPACE_BASE) &&
            (vaddr <= (USER_ASPACE_BASE + (USER_ASPACE_SIZE - 1))));
}
//虚拟地址[vaddr,vaddr + len]是否在用户空间
STATIC INLINE BOOL LOS_IsUserAddressRange(VADDR_T vaddr, size_t len)
{
    return (vaddr + len > vaddr) && LOS_IsUserAddress(vaddr) && (LOS_IsUserAddress(vaddr + len - 1));
}

//是否是一个动态分配的地址
STATIC INLINE BOOL LOS_IsVmallocAddress(VADDR_T vaddr)
{
    return ((vaddr >= VMALLOC_START) &&
            (vaddr <= (VMALLOC_START + (VMALLOC_SIZE - 1))));
}
//是否为一个空线性区
STATIC INLINE BOOL OsIsVmRegionEmpty(LosVmSpace *vmSpace)
{
    if (vmSpace->regionRbTree.ulNodes == 0) {
        return TRUE;
    }
    return FALSE;
}

LosVmSpace *LOS_GetKVmSpace(VOID);
LOS_DL_LIST *LOS_GetVmSpaceList(VOID);
LosVmSpace *LOS_GetVmallocSpace(VOID);
VOID OsInitMappingStartUp(VOID);
VOID OsKSpaceInit(VOID);
BOOL LOS_IsRangeInSpace(const LosVmSpace *space, VADDR_T vaddr, size_t size);
STATUS_T LOS_VmSpaceReserve(LosVmSpace *space, size_t size, VADDR_T vaddr);
INT32 OsUserHeapFree(LosVmSpace *vmSpace, VADDR_T addr, size_t len);
VADDR_T OsAllocRange(LosVmSpace *vmSpace, size_t len);
VADDR_T OsAllocSpecificRange(LosVmSpace *vmSpace, VADDR_T vaddr, size_t len, UINT32 regionFlags);
LosVmMapRegion *OsCreateRegion(VADDR_T vaddr, size_t len, UINT32 regionFlags, unsigned long offset);
BOOL OsInsertRegion(LosRbTree *regionRbTree, LosVmMapRegion *region);
LosVmSpace *LOS_SpaceGet(VADDR_T vaddr);
LosVmSpace *LOS_CurrSpaceGet(VOID);
BOOL LOS_IsRegionFileValid(LosVmMapRegion *region);
LosVmMapRegion *LOS_RegionRangeFind(LosVmSpace *vmSpace, VADDR_T addr, size_t len);
LosVmMapRegion *LOS_RegionFind(LosVmSpace *vmSpace, VADDR_T addr);
PADDR_T LOS_PaddrQuery(VOID *vaddr);
LosVmMapRegion *LOS_RegionAlloc(LosVmSpace *vmSpace, VADDR_T vaddr, size_t len, UINT32 regionFlags, VM_OFFSET_T pgoff);
STATUS_T OsRegionsRemove(LosVmSpace *space, VADDR_T vaddr, size_t size);
STATUS_T OsVmRegionAdjust(LosVmSpace *space, VADDR_T vaddr, size_t size);
LosVmMapRegion *OsVmRegionDup(LosVmSpace *space, LosVmMapRegion *oldRegion, VADDR_T vaddr, size_t size);
STATUS_T OsIsRegionCanExpand(LosVmSpace *space, LosVmMapRegion *region, size_t size);
STATUS_T LOS_RegionFree(LosVmSpace *space, LosVmMapRegion *region);
STATUS_T LOS_VmSpaceFree(LosVmSpace *space);
STATUS_T LOS_VaddrToPaddrMmap(LosVmSpace *space, VADDR_T vaddr, PADDR_T paddr, size_t len, UINT32 flags);
BOOL OsUserVmSpaceInit(LosVmSpace *vmSpace, VADDR_T *virtTtb);
LosVmSpace *OsCreateUserVmSapce(VOID);
STATUS_T LOS_VmSpaceClone(LosVmSpace *oldVmSpace, LosVmSpace *newVmSpace);
STATUS_T LOS_UserSpaceVmAlloc(LosVmSpace *space, size_t size, VOID **ptr, UINT8 align_log2, UINT32 regionFlags);
LosMux *OsGVmSpaceMuxGet(VOID);
STATUS_T OsUnMMap(LosVmSpace *space, VADDR_T addr, size_t size);
/**
 * thread safety
 * it is used to malloc continuous virtual memory, no sure for continuous physical memory.
 */
VOID *LOS_VMalloc(size_t size);
VOID LOS_VFree(const VOID *addr);

/**
 * thread safety
 * these is used to malloc or free kernel memory.
 * when the size is large and close to multiples of pages,
 * will alloc pmm pages, otherwise alloc bestfit memory.
 */
VOID *LOS_KernelMalloc(UINT32 size);
VOID *LOS_KernelMallocAlign(UINT32 size, UINT32 boundary);
VOID *LOS_KernelRealloc(VOID *ptr, UINT32 size);
VOID LOS_KernelFree(VOID *ptr);

#ifdef __cplusplus
#if __cplusplus
}
#endif /* __cplusplus */
#endif /* __cplusplus */

#endif /* __LOS_VM_MAP_H__ */