vm.h

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#ifndef _MM_VM_H
#define _MM_VM_H
 
#include <core/system.h>
#include <core/printk.h>
 
struct vm_space;
struct vm_entry;
struct vm_object;
struct vm_page;
 
MALLOC_DECLARE(M_VM_ENTRY);
MALLOC_DECLARE(M_VM_OBJECT);
MALLOC_DECLARE(M_VM_ANON);
MALLOC_DECLARE(M_VM_AREF);
 
#include <ds/queue.h>
 
/*
 * Virtual memory: address spaces, their mappings, and where the mappings'
 * pages come from (anons and vm objects). See docs/kernel/memory.md.
 */

struct vm_space {
    struct pmap  *pmap;

    struct queue  vm_entries;
};
 
#include <fs/vfs.h>
#include <mm/mm.h>
#include <ds/hashmap.h>
 
/* A mapping's flags: its permissions, and more. */
#define VM_KR         0x0001         
#define VM_KW         0x0002         
#define VM_KX         0x0004         
#define VM_UR         0x0008         
#define VM_UW         0x0010         
#define VM_UX         0x0020         
#define VM_PERM       0x003F         
#define VM_NOCACHE    0x0040         
#define VM_SHARED     0x0080         
#define VM_COPY       0x0100         
 
#define VM_KRW  (VM_KR|VM_KW)        
#define VM_KRX  (VM_KR|VM_KX)        
#define VM_KWX  (VM_KW|VM_KX)        
#define VM_KRWX (VM_KR|VM_KW|VM_KX)  
#define VM_URW  (VM_UR|VM_UW)        
#define VM_URX  (VM_UR|VM_UX)        
#define VM_UWX  (VM_UW|VM_UX)        
#define VM_URWX (VM_UR|VM_UW|VM_UX)  
 
/* The kinds of vm objects. */
#define VMOBJ_ZERO    0x0000         
#define VMOBJ_FILE    0x0001         

struct vm_entry {
    paddr_t  paddr;

    vaddr_t base;

    size_t size;

    uint32_t flags;

    struct vm_anon *vm_anon;

    struct vm_object *vm_object;

    size_t off;

    struct qnode *qnode;
};

struct vm_pager {
    struct vm_page *(*in)(struct vm_object *vm_object, size_t off);

    int (*out)(struct vm_object *vm_object, size_t off);
};

struct vm_aref {
    struct vm_page *vm_page;

    size_t ref;

    uint32_t flags;
};

struct vm_anon {
    struct hashmap *arefs;

    size_t ref;

    int flags;
};

struct vm_object {
    struct hashmap *pages;

    int type;

    size_t ref;

    struct vm_pager *pager;

    void *p;
};

struct vm_page {
    paddr_t  paddr; 
 
    struct vm_object *vm_object; 
 
    size_t off; 
 
    size_t ref; 
};
 
/* The kernel's address space. */
extern struct vm_space kvm_space;
 
/* mm/kvmem.c: sets up kmalloc(); its self-checks */
void kvmem_setup(void);
void kvmem_selftest(void);
void kvmem_guardtest(void);
 
/* mm/vmm.c: maps and unmaps a map entry's range */
int  vm_map(struct vm_space *vm_space, struct vm_entry *vm_entry);
void vm_unmap_full(struct vm_space *vm_space, struct vm_entry *vm_entry);
 
/* mm/vm_space.c: address spaces */
int  vm_space_fork(struct vm_space *parent, struct vm_space *child);
void vm_space_destroy(struct vm_space *vm_space);
struct vm_entry *vm_space_find(struct vm_space *vm_space, vaddr_t vaddr);
int  vm_space_insert(struct vm_space *vm_space, struct vm_entry *vm_entry);
 
/* mm/vm_entry.c: map entries */
struct vm_entry *vm_entry_new(void);
void vm_entry_destroy(struct vm_entry *vm_entry);
 
/* mm/vm_anon.c: anons */
struct vm_anon *vm_anon_new(void);
struct vm_anon *vm_anon_copy(struct vm_anon *vm_anon);
void vm_anon_incref(struct vm_anon *vm_anon);
void vm_anon_decref(struct vm_anon *vm_anon);
void vm_anon_destroy(struct vm_anon *vm_anon);
 
/* fs/vm_object.c and mm/vm_object.c: vm objects, and a file's pages */
struct vm_object *vm_object_vnode(struct vnode *vnode);
void vnode_pages_update(struct vnode *vnode, off_t start, off_t end);
void vnode_pages_free(struct vnode *vnode);
int  vm_object_page_insert(struct vm_object *vm_object, struct vm_page *vm_page);
void vm_object_incref(struct vm_object *vm_object);
void vm_object_decref(struct vm_object *vm_object);
 
#endif  /* ! _MM_VM_H */