NetBSD/sys/sys/map.h
1995-03-26 20:23:52 +00:00

84 lines
3.8 KiB
C

/* $NetBSD: map.h,v 1.8 1995/03/26 20:24:22 jtc Exp $ */
/*-
* Copyright (c) 1982, 1986, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* 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.
*
* @(#)map.h 8.3 (Berkeley) 1/26/94
*/
/*
* Resource allocation maps.
*
* Associated routines manage sub-allocation of an address space using
* an array of segment descriptors. The first element of this array
* is a map structure, describing the arrays extent and the name
* of the controlled object. Each additional structure represents
* a free segment of the address space.
*
* A call to rminit initializes a resource map. Later on, rmfree may be used
* to free some more address space for the map. Subsequent calls to rmalloc
* and rmfree allocate and free space in the resource map. If the resource
* map becomes too fragmented to be described in the available space,
* then some of the resource is discarded. This may lead to critical
* shortages, but is better than not checking (as the previous versions
* of these routines did) or giving up and calling panic(). The routines
* could use linked lists and call a memory allocator when they run
* out of space, but that would not solve the out of space problem when
* called at interrupt time.
*
* N.B.: The address 0 in the resource address space is not available
* as it is used internally by the resource map routines.
*/
struct map {
struct mapent *m_limit; /* first slot beyond map */
char *m_name; /* name of resource, for messages */
};
struct mapent {
long m_size; /* size of this segment of the map */
long m_addr; /* start of segment */
};
#ifdef _KERNEL
struct map *swapmap;
int nswapmap;
long rmalloc __P((struct map *, long));
void rmfree __P((struct map *, long, long));
void rminit __P((struct map *, long, long, char *, int));
#endif