xref: /netbsd-src/sys/arch/i386/include/vmparam.h (revision 4b30c543a0b21e3ba94f2c569e9a82b4fdb2075f)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * William Jolitz.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	from: @(#)vmparam.h	5.9 (Berkeley) 5/12/91
37  *	$Id: vmparam.h,v 1.6 1993/09/04 22:21:28 cgd Exp $
38  */
39 
40 
41 /*
42  * Machine dependent constants for 386.
43  */
44 
45 /*
46  * Virtual address space arrangement. On 386, both user and kernel
47  * share the address space, not unlike the vax.
48  * USRTEXT is the start of the user text/data space, while USRSTACK
49  * is the top (end) of the user stack. Immediately above the user stack
50  * resides the user structure, which is UPAGES long and contains the
51  * kernel stack.
52  *
53  * Immediately after the user structure is the page table map, and then
54  * kernal address space.
55  */
56 #define	USRTEXT		4096
57 #define	USRSTACK	0xFDBFE000
58 #define	BTOPUSRSTACK	(0xFDC00-(UPAGES))	/* btop(USRSTACK) */
59 #define	LOWPAGES	0
60 #define HIGHPAGES	UPAGES
61 
62 /*
63  * Virtual memory related constants, all in bytes
64  */
65 #define	MAXTSIZ		(6*1024*1024)		/* max text size */
66 #ifndef DFLDSIZ
67 #define	DFLDSIZ		(16*1024*1024)		/* initial data size limit */
68 #endif
69 #ifndef MAXDSIZ
70 #define	MAXDSIZ		(32*1024*1024)		/* max data size */
71 #endif
72 #ifndef	DFLSSIZ
73 #define	DFLSSIZ		(512*1024)		/* initial stack size limit */
74 #endif
75 #ifndef	MAXSSIZ
76 #define	MAXSSIZ		(8*1024*1024)		/* max stack size */
77 #endif
78 
79 /*
80  * Default sizes of swap allocation chunks (see dmap.h).
81  * The actual values may be changed in vminit() based on MAXDSIZ.
82  * With MAXDSIZ of 16Mb and NDMAP of 38, dmmax will be 1024.
83  */
84 #define	DMMIN	32			/* smallest swap allocation */
85 #define	DMMAX	4096			/* largest potential swap allocation */
86 #define	DMTEXT	1024			/* swap allocation for text */
87 
88 /*
89  * Sizes of the system and user portions of the system page table.
90  */
91 #define	SYSPTSIZE 	(2*NPTEPG)
92 #define	USRPTSIZE 	(2*NPTEPG)
93 
94 /*
95  * Size of User Raw I/O map
96  */
97 #define	USRIOSIZE 	300
98 
99 /*
100  * The size of the clock loop.
101  */
102 #define	LOOPPAGES	(maxfree - firstfree)
103 
104 /*
105  * The time for a process to be blocked before being very swappable.
106  * This is a number of seconds which the system takes as being a non-trivial
107  * amount of real time.  You probably shouldn't change this;
108  * it is used in subtle ways (fractions and multiples of it are, that is, like
109  * half of a ``long time'', almost a long time, etc.)
110  * It is related to human patience and other factors which don't really
111  * change over time.
112  */
113 #define	MAXSLP 		20
114 
115 /*
116  * A swapped in process is given a small amount of core without being bothered
117  * by the page replacement algorithm.  Basically this says that if you are
118  * swapped in you deserve some resources.  We protect the last SAFERSS
119  * pages against paging and will just swap you out rather than paging you.
120  * Note that each process has at least UPAGES+CLSIZE pages which are not
121  * paged anyways (this is currently 8+2=10 pages or 5k bytes), so this
122  * number just means a swapped in process is given around 25k bytes.
123  * Just for fun: current memory prices are 4600$ a megabyte on VAX (4/22/81),
124  * so we loan each swapped in process memory worth 100$, or just admit
125  * that we don't consider it worthwhile and swap it out to disk which costs
126  * $30/mb or about $0.75.
127  * { wfj 6/16/89: Retail AT memory expansion $800/megabyte, loan of $17
128  *   on disk costing $7/mb or $0.18 (in memory still 100:1 in cost!) }
129  */
130 #define	SAFERSS		8		/* nominal ``small'' resident set size
131 					   protected against replacement */
132 
133 /*
134  * DISKRPM is used to estimate the number of paging i/o operations
135  * which one can expect from a single disk controller.
136  */
137 #define	DISKRPM		60
138 
139 /*
140  * Klustering constants.  Klustering is the gathering
141  * of pages together for pagein/pageout, while clustering
142  * is the treatment of hardware page size as though it were
143  * larger than it really is.
144  *
145  * KLMAX gives maximum cluster size in CLSIZE page (cluster-page)
146  * units.  Note that KLMAX*CLSIZE must be <= DMMIN in dmap.h.
147  */
148 
149 #define	KLMAX	(4/CLSIZE)
150 #define	KLSEQL	(2/CLSIZE)		/* in klust if vadvise(VA_SEQL) */
151 #define	KLIN	(4/CLSIZE)		/* default data/stack in klust */
152 #define	KLTXT	(4/CLSIZE)		/* default text in klust */
153 #define	KLOUT	(4/CLSIZE)
154 
155 /*
156  * KLSDIST is the advance or retard of the fifo reclaim for sequential
157  * processes data space.
158  */
159 #define	KLSDIST	3		/* klusters advance/retard for seq. fifo */
160 
161 /*
162  * Paging thresholds (see vm_sched.c).
163  * Strategy of 1/19/85:
164  *	lotsfree is 512k bytes, but at most 1/4 of memory
165  *	desfree is 200k bytes, but at most 1/8 of memory
166  *	minfree is 64k bytes, but at most 1/2 of desfree
167  */
168 #define	LOTSFREE	(512 * 1024)
169 #define	LOTSFREEFRACT	4
170 #define	DESFREE		(200 * 1024)
171 #define	DESFREEFRACT	8
172 #define	MINFREE		(64 * 1024)
173 #define	MINFREEFRACT	2
174 
175 /*
176  * There are two clock hands, initially separated by HANDSPREAD bytes
177  * (but at most all of user memory).  The amount of time to reclaim
178  * a page once the pageout process examines it increases with this
179  * distance and decreases as the scan rate rises.
180  */
181 #define	HANDSPREAD	(2 * 1024 * 1024)
182 
183 /*
184  * The number of times per second to recompute the desired paging rate
185  * and poke the pagedaemon.
186  */
187 #define	RATETOSCHEDPAGING	4
188 
189 /*
190  * Believed threshold (in megabytes) for which interleaved
191  * swapping area is desirable.
192  */
193 #define	LOTSOFMEM	2
194 
195 #define	mapin(pte, v, pfnum, prot) \
196 	{(*(int *)(pte) = ((pfnum)<<PGSHIFT) | (prot)) ; }
197 
198 /*
199  * Mach derived constants
200  */
201 
202 /* user/kernel map constants */
203 #define VM_MIN_ADDRESS		((vm_offset_t)0)
204 #define VM_MAXUSER_ADDRESS	((vm_offset_t)0xFDBFE000)
205 #define UPT_MIN_ADDRESS		((vm_offset_t)0xFDC00000)
206 #define UPT_MAX_ADDRESS		((vm_offset_t)0xFDFF7000)
207 #define VM_MAX_ADDRESS		UPT_MAX_ADDRESS
208 #define VM_MIN_KERNEL_ADDRESS	((vm_offset_t)0xFDFF7000)
209 #define UPDT			VM_MIN_KERNEL_ADDRESS
210 #define KPT_MIN_ADDRESS		((vm_offset_t)0xFDFF8000)
211 #define KPT_MAX_ADDRESS		((vm_offset_t)0xFDFFF000)
212 #define VM_MAX_KERNEL_ADDRESS	((vm_offset_t)0xFF7FF000)
213 
214 /* virtual sizes (bytes) for various kernel submaps */
215 #define VM_MBUF_SIZE		(NMBCLUSTERS*MCLBYTES)
216 #define VM_KMEM_SIZE		(NKMEMCLUSTERS*CLBYTES)
217 #define VM_PHYS_SIZE		(USRIOSIZE*CLBYTES)
218 
219 /* # of kernel PT pages (initial only, can grow dynamically) */
220 #define VM_KERNEL_PT_PAGES	((vm_size_t)2)		/* XXX: SYSPTSIZE */
221 
222 /* pcb base */
223 #define	pcbb(p)		((u_int)(p)->p_addr)
224 
225 /*
226  * Flush MMU TLB
227  */
228 
229 #ifndef I386_CR3PAT
230 #define	I386_CR3PAT	0x0
231 #endif
232 
233 #ifdef notyet
234 #define _cr3() ({u_long rtn; \
235 	asm (" movl %%cr3,%%eax; movl %%eax,%0 " \
236 		: "=g" (rtn) \
237 		: \
238 		: "ax"); \
239 	rtn; \
240 })
241 
242 #define load_cr3(s) ({ u_long val; \
243 	val = (s) | I386_CR3PAT; \
244 	asm ("movl %0,%%eax; movl %%eax,%%cr3" \
245 		:  \
246 		: "g" (val) \
247 		: "ax"); \
248 })
249 
250 #define tlbflush() ({ u_long val; \
251 	val = u.u_pcb.pcb_ptd | I386_CR3PAT; \
252 	asm ("movl %0,%%eax; movl %%eax,%%cr3" \
253 		:  \
254 		: "g" (val) \
255 		: "ax"); \
256 })
257 #endif
258