gems-kernel/source/THIRDPARTY/xnu/bsd/vm/vnode_pager.h
2024-06-03 11:29:39 -05:00

132 lines
4.7 KiB
C

/*
* Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* Mach Operating System
* Copyright (c) 1987 Carnegie-Mellon University
* All rights reserved. The CMU software License Agreement specifies
* the terms and conditions for use and redistribution.
*/
#ifndef _VNODE_PAGER_
#define _VNODE_PAGER_ 1
#include <mach/kern_return.h>
#include <sys/types.h>
#include <kern/queue.h>
#ifdef KERNEL
#include <mach/boolean.h>
#include <mach/memory_object_types.h>
#include <mach/vm_types.h>
#include <vm/vm_protos.h>
#include <vm/vm_pager.h>
/*
* Vstructs are the internal (to us) description of a unit of backing store.
* The are the link between memory objects and the backing store they represent.
* For the vnode pager, backing store comes in two flavors: normal files and
* swap files.
*
* For objects that page to and from normal files (e.g. objects that represent
* program text segments), we maintain some simple parameters that allow us to
* access the file's contents directly through the vnode interface.
*
* Data for objects without associated vnodes is maintained in the swap files.
* Each object that uses one of these as backing store has a vstruct indicating
* the swap file of preference (vs_pf) and a mapping between contiguous object
* offsets and swap file offsets (vs_pmap). Each entry in this mapping specifies
* the pager file to use, and the offset of the page in that pager file. These
* mapping entries are of type pfMapEntry.
*/
/*
* Pager file structure. One per swap file.
*/
typedef struct pager_file {
queue_chain_t pf_chain; /* link to other paging files */
struct vnode *pf_vp; /* vnode of paging file */
u_int pf_count; /* Number of vstruct using this file */
u_char *pf_bmap; /* Map of used blocks */
long pf_npgs; /* Size of file in pages */
long pf_pfree; /* Number of unused pages */
long pf_lowat; /* Low water page */
long pf_hipage; /* Highest page allocated */
long pf_hint; /* Lowest page unallocated */
char *pf_name; /* Filename of this file */
boolean_t pf_prefer;
int pf_index; /* index into the pager_file array */
void * pf_lock; /* Lock for alloc and dealloc */
} *pager_file_t;
#define PAGER_FILE_NULL (pager_file_t) 0
#define MAXPAGERFILES 16
#define MAX_BACKING_STORE 100
struct bs_map {
struct vnode *vp;
void *bs;
};
extern struct bs_map bs_port_table[];
/*
* Pager file data structures.
*/
#define INDEX_NULL 0
typedef struct {
unsigned int index:8; /* paging file this block is in */
unsigned int offset:24; /* page number where block resides */
} pf_entry;
typedef enum {
IS_INODE, /* Local disk */
IS_RNODE /* NFS */
} vpager_fstype;
/*
* Basic vnode pager structure. One per object, backing-store pair.
*/
typedef struct vstruct {
boolean_t is_device; /* Must be first - see vm_pager.h */
pager_file_t vs_pf; /* Pager file this uses */
pf_entry **vs_pmap; /* Map of pages into paging file */
unsigned int
/* boolean_t */ vs_swapfile:1; /* vnode is a swapfile */
short vs_count; /* use count */
int vs_size; /* size of this chunk in pages*/
struct vnode *vs_vp; /* vnode to page to */
} *vnode_pager_t;
#define VNODE_PAGER_NULL ((vnode_pager_t) 0)
#endif /* KERNEL */
#endif /* _VNODE_PAGER_ */