usr/src/sys/vm/device_pager.h

/*
 * Copyright (c) 1990 University of Utah.
 * Copyright (c) 1991 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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, 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.
 *
 *      @(#)device_pager.h      7.1 (Berkeley) 12/5/90
 */

#ifndef _DEVICE_PAGER_
#define _DEVICE_PAGER_  1

/*
 * Device pager private data.
 */
struct devpager {
        queue_head_t    devp_list;      /* list of managed devices */
        dev_t           devp_dev;       /* devno of device */
        vm_page_t       devp_pages;     /* page structs for device */
        int             devp_npages;    /* size of device in pages */
        int             devp_count;     /* reference count */
        vm_object_t     devp_object;    /* object representing this device */
};
typedef struct devpager *dev_pager_t;

#define DEV_PAGER_NULL  ((dev_pager_t)0)

#ifdef KERNEL

void            dev_pager_init();
vm_pager_t      dev_pager_alloc();
void            dev_pager_dealloc();
boolean_t       dev_pager_getpage(), dev_pager_putpage();
boolean_t       dev_pager_haspage();

struct pagerops devicepagerops = {
        dev_pager_init,
        dev_pager_alloc,
        dev_pager_dealloc,
        dev_pager_getpage,
        dev_pager_putpage,
        dev_pager_haspage
};

#endif

#endif  /* _DEVICE_PAGER_ */