xref: /netbsd-src/sys/arch/sun3/include/vmparam.h (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: vmparam.h,v 1.19 1997/07/12 16:20:14 perry Exp $	*/
2 
3 /*
4  * Copyright (c) 1994 Gordon W. Ross
5  * Copyright (c) 1993 Adam Glass
6  * Copyright (c) 1988 University of Utah.
7  * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
8  * All rights reserved.
9  *
10  * This code is derived from software contributed to Berkeley by
11  * the Systems Programming Group of the University of Utah Computer
12  * Science Department.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. All advertising materials mentioning features or use of this software
23  *    must display the following acknowledgement:
24  *	This product includes software developed by the University of
25  *	California, Berkeley and its contributors.
26  * 4. Neither the name of the University nor the names of its contributors
27  *    may be used to endorse or promote products derived from this software
28  *    without specific prior written permission.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40  * SUCH DAMAGE.
41  *
42  *	from: Utah $Hdr: vmparam.h 1.16 91/01/18$
43  *	from: @(#)vmparam.h	7.3 (Berkeley) 5/7/91
44  *	vmparam.h,v 1.2 1993/05/22 07:58:38 cgd Exp
45  */
46 
47 /*
48  * Machine dependent constants for Sun3
49  *
50  * The Sun3 has limited total kernel virtual space (32MB) and
51  * can not use main memory for page tables.  (All active PTEs
52  * must be installed in special translation RAM in the MMU).
53  * Therefore, parameters that would normally configure the
54  * size of various page tables are irrelevant.  Only things
55  * that consume portions of kernel virtual (KV) space matter,
56  * and those things should be chosen to conserve KV space.
57  */
58 
59 /*
60  * USRTEXT is the start of the user text/data space, while
61  * USRSTACK is the top (end) of the user stack.
62  */
63 #define	USRTEXT 	NBPG		/* Start of user text */
64 #define	USRSTACK	KERNBASE	/* High end of user stack */
65 
66 /*
67  * Virtual memory related constants, all in bytes
68  */
69 #ifndef MAXTSIZ
70 #define	MAXTSIZ		(8*1024*1024)		/* max text size */
71 #endif
72 #ifndef DFLDSIZ
73 #define	DFLDSIZ		(16*1024*1024)		/* initial data size limit */
74 #endif
75 #ifndef MAXDSIZ
76 #define	MAXDSIZ		(32*1024*1024)		/* max data size */
77 #endif
78 #ifndef	DFLSSIZ
79 #define	DFLSSIZ		(512*1024)		/* initial stack size limit */
80 #endif
81 #ifndef	MAXSSIZ
82 #define	MAXSSIZ		MAXDSIZ			/* max stack size */
83 #endif
84 
85 /*
86  * PTEs for mapping user space into the kernel for phyio operations.
87  * The actual limitation for physio requests will be the DVMA space,
88  * and that is fixed by hardware design at 1MB.  We could make the
89  * physio map larger than that, but it would not buy us much.
90  */
91 #ifndef USRIOSIZE
92 #define USRIOSIZE	128		/* 1 MB */
93 #endif
94 
95 /*
96  * PTEs for system V style shared memory.
97  * This is basically slop for kmempt which we actually allocate (malloc) from.
98  */
99 #ifndef SHMMAXPGS
100 #define SHMMAXPGS	512 	/* 4 MB */
101 #endif
102 
103 /*
104  * The time for a process to be blocked before being very swappable.
105  * This is a number of seconds which the system takes as being a non-trivial
106  * amount of real time.  You probably shouldn't change this;
107  * it is used in subtle ways (fractions and multiples of it are, that is, like
108  * half of a ``long time'', almost a long time, etc.)
109  * It is related to human patience and other factors which don't really
110  * change over time.
111  */
112 #define	MAXSLP 		20
113 
114 /*
115  * A swapped in process is given a small amount of core without being bothered
116  * by the page replacement algorithm.  Basically this says that if you are
117  * swapped in you deserve some resources.  We protect the last SAFERSS
118  * pages against paging and will just swap you out rather than paging you.
119  * Note that each process has at least UPAGES+CLSIZE pages which are not
120  * paged anyways (this is currently 8+2=10 pages or 5k bytes), so this
121  * number just means a swapped in process is given around 25k bytes.
122  * Just for fun: current memory prices are 4600$ a megabyte on VAX (4/22/81),
123  * so we loan each swapped in process memory worth 100$, or just admit
124  * that we don't consider it worthwhile and swap it out to disk which costs
125  * $30/mb or about $0.75.
126  * Update: memory prices have changed recently (9/96). At the current
127  * value of $6 per megabyte, we lend each swapped in process memory worth
128  * $0.15, or just admit that we don't consider it worthwhile and swap it out
129  * to disk which costs $0.20/MB, or just under half a cent.
130  */
131 #define	SAFERSS		4		/* nominal ``small'' resident set size
132 					   protected against replacement */
133 
134 /*
135  * Mach-derived constants, virtual memory map:
136  *
137  * 0000.0000  user space
138  * 0E00.0000  kernel space
139  * 0FE0.0000  monitor map (devices)
140  * 0FF0.0000  DVMA space
141  * 0FFE.0000  monitor RAM seg.
142  * 0FFF.E000  monitor RAM page
143  */
144 
145 /* user/kernel map constants */
146 #define VM_MIN_ADDRESS		((vm_offset_t)0)
147 #define VM_MAX_ADDRESS		((vm_offset_t)KERNBASE)
148 #define VM_MAXUSER_ADDRESS	((vm_offset_t)KERNBASE)
149 #define VM_MIN_KERNEL_ADDRESS	((vm_offset_t)KERNBASE)
150 #define VM_MAX_KERNEL_ADDRESS	((vm_offset_t)KERN_END)
151 
152 /* virtual sizes (bytes) for various kernel submaps */
153 #define VM_MBUF_SIZE		(NMBCLUSTERS*MCLBYTES)
154 #define VM_KMEM_SIZE		(NKMEMCLUSTERS*CLBYTES)
155 #define VM_PHYS_SIZE		(USRIOSIZE*CLBYTES)
156 
157 #define MACHINE_NONCONTIG	/* VM <=> pmap interface modifier */
158