111 lines
3.4 KiB
C
111 lines
3.4 KiB
C
/* $NetBSD: uvm_anon.h,v 1.32 2020/03/20 19:08:54 ad Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1997 Charles D. Cranor and Washington University.
|
|
* 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.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#ifndef _UVM_UVM_ANON_H_
|
|
#define _UVM_UVM_ANON_H_
|
|
|
|
/*
|
|
* uvm_anon.h
|
|
*/
|
|
|
|
#if defined(_KERNEL_OPT)
|
|
#include "opt_vmswap.h"
|
|
#endif
|
|
|
|
/*
|
|
* anonymous memory management
|
|
*
|
|
* anonymous virtual memory is short term virtual memory that goes away
|
|
* when the processes referencing it go away. an anonymous page of
|
|
* virtual memory is described by the following data structure:
|
|
*/
|
|
|
|
struct vm_anon {
|
|
krwlock_t *an_lock; /* Lock for an_ref */
|
|
uintptr_t an_ref; /* Reference count [an_lock] */
|
|
struct vm_page *an_page; /* If in RAM [an_lock] */
|
|
#if defined(VMSWAP) || 1 /* XXX libkvm */
|
|
/*
|
|
* Drum swap slot # (if != 0) [an_lock. also, it is ok to read
|
|
* an_swslot if we hold an_page PG_BUSY].
|
|
*/
|
|
int an_swslot;
|
|
#endif
|
|
};
|
|
|
|
/*
|
|
* for active vm_anon's the data can be in one of the following state:
|
|
* [1] in a vm_page with no backing store allocated yet, [2] in a vm_page
|
|
* with backing store allocated, or [3] paged out to backing store
|
|
* (no vm_page).
|
|
*
|
|
* for pageout in case [2]: if the page has been modified then we must
|
|
* flush it out to backing store, otherwise we can just dump the
|
|
* vm_page.
|
|
*/
|
|
|
|
/*
|
|
* anons are grouped together in anonymous memory maps, or amaps.
|
|
* amaps are defined in uvm_amap.h.
|
|
*/
|
|
|
|
/*
|
|
* processes reference anonymous virtual memory maps with an anonymous
|
|
* reference structure:
|
|
*/
|
|
|
|
struct vm_aref {
|
|
int ar_pageoff; /* page offset into amap we start */
|
|
struct vm_amap *ar_amap; /* pointer to amap */
|
|
};
|
|
|
|
/*
|
|
* the offset field indicates which part of the amap we are referencing.
|
|
* locked by vm_map lock.
|
|
*/
|
|
|
|
#ifdef _KERNEL
|
|
|
|
/*
|
|
* prototypes
|
|
*/
|
|
|
|
struct vm_anon *uvm_analloc(void);
|
|
void uvm_anfree(struct vm_anon *);
|
|
void uvm_anon_init(void);
|
|
struct vm_page *uvm_anon_lockloanpg(struct vm_anon *);
|
|
#if defined(VMSWAP)
|
|
void uvm_anon_dropswap(struct vm_anon *);
|
|
#else /* defined(VMSWAP) */
|
|
#define uvm_anon_dropswap(a) /* nothing */
|
|
#endif /* defined(VMSWAP) */
|
|
void uvm_anon_release(struct vm_anon *);
|
|
bool uvm_anon_pagein(struct vm_amap *, struct vm_anon *);
|
|
#endif /* _KERNEL */
|
|
|
|
#endif /* _UVM_UVM_ANON_H_ */
|