xref: /freebsd/sys/i386/include/vmparam.h (revision 5b81b6b301437eb9a6df491c829475bd29ae5d6c)
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  *	@(#)vmparam.h	5.9 (Berkeley) 5/12/91
37  */
38 
39 
40 /*
41  * Machine dependent constants for 386.
42  */
43 
44 /*
45  * Virtual address space arrangement. On 386, both user and kernel
46  * share the address space, not unlike the vax.
47  * USRTEXT is the start of the user text/data space, while USRSTACK
48  * is the top (end) of the user stack. Immediately above the user stack
49  * resides the user structure, which is UPAGES long and contains the
50  * kernel stack.
51  *
52  * Immediately after the user structure is the page table map, and then
53  * kernal address space.
54  */
55 #define	USRTEXT		0
56 #define	USRSTACK	0xFDBFE000
57 #define	BTOPUSRSTACK	(0xFDC00-(UPAGES))	/* btop(USRSTACK) */
58 #define	LOWPAGES	0
59 #define HIGHPAGES	UPAGES
60 
61 /*
62  * Virtual memory related constants, all in bytes
63  */
64 #define	MAXTSIZ		(6*1024*1024)		/* max text size */
65 #ifndef DFLDSIZ
66 #define	DFLDSIZ		(6*1024*1024)		/* initial data size limit */
67 #endif
68 #ifndef MAXDSIZ
69 #define	MAXDSIZ		(32*1024*1024)		/* max data size */
70 #endif
71 #ifndef	DFLSSIZ
72 #define	DFLSSIZ		(512*1024)		/* initial stack size limit */
73 #endif
74 #ifndef	MAXSSIZ
75 #define	MAXSSIZ		MAXDSIZ			/* max stack size */
76 #endif
77 
78 /*
79  * Default sizes of swap allocation chunks (see dmap.h).
80  * The actual values may be changed in vminit() based on MAXDSIZ.
81  * With MAXDSIZ of 16Mb and NDMAP of 38, dmmax will be 1024.
82  */
83 #define	DMMIN	32			/* smallest swap allocation */
84 #define	DMMAX	4096			/* largest potential swap allocation */
85 #define	DMTEXT	1024			/* swap allocation for text */
86 
87 /*
88  * Sizes of the system and user portions of the system page table.
89  */
90 #define	SYSPTSIZE 	(2*NPTEPG)
91 #define	USRPTSIZE 	(2*NPTEPG)
92 
93 /*
94  * Size of User Raw I/O map
95  */
96 #define	USRIOSIZE 	300
97 
98 /*
99  * The size of the clock loop.
100  */
101 #define	LOOPPAGES	(maxfree - firstfree)
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  * { wfj 6/16/89: Retail AT memory expansion $800/megabyte, loan of $17
127  *   on disk costing $7/mb or $0.18 (in memory still 100:1 in cost!) }
128  */
129 #define	SAFERSS		8		/* nominal ``small'' resident set size
130 					   protected against replacement */
131 
132 /*
133  * DISKRPM is used to estimate the number of paging i/o operations
134  * which one can expect from a single disk controller.
135  */
136 #define	DISKRPM		60
137 
138 /*
139  * Klustering constants.  Klustering is the gathering
140  * of pages together for pagein/pageout, while clustering
141  * is the treatment of hardware page size as though it were
142  * larger than it really is.
143  *
144  * KLMAX gives maximum cluster size in CLSIZE page (cluster-page)
145  * units.  Note that KLMAX*CLSIZE must be <= DMMIN in dmap.h.
146  */
147 
148 #define	KLMAX	(4/CLSIZE)
149 #define	KLSEQL	(2/CLSIZE)		/* in klust if vadvise(VA_SEQL) */
150 #define	KLIN	(4/CLSIZE)		/* default data/stack in klust */
151 #define	KLTXT	(4/CLSIZE)		/* default text in klust */
152 #define	KLOUT	(4/CLSIZE)
153 
154 /*
155  * KLSDIST is the advance or retard of the fifo reclaim for sequential
156  * processes data space.
157  */
158 #define	KLSDIST	3		/* klusters advance/retard for seq. fifo */
159 
160 /*
161  * Paging thresholds (see vm_sched.c).
162  * Strategy of 1/19/85:
163  *	lotsfree is 512k bytes, but at most 1/4 of memory
164  *	desfree is 200k bytes, but at most 1/8 of memory
165  *	minfree is 64k bytes, but at most 1/2 of desfree
166  */
167 #define	LOTSFREE	(512 * 1024)
168 #define	LOTSFREEFRACT	4
169 #define	DESFREE		(200 * 1024)
170 #define	DESFREEFRACT	8
171 #define	MINFREE		(64 * 1024)
172 #define	MINFREEFRACT	2
173 
174 /*
175  * There are two clock hands, initially separated by HANDSPREAD bytes
176  * (but at most all of user memory).  The amount of time to reclaim
177  * a page once the pageout process examines it increases with this
178  * distance and decreases as the scan rate rises.
179  */
180 #define	HANDSPREAD	(2 * 1024 * 1024)
181 
182 /*
183  * The number of times per second to recompute the desired paging rate
184  * and poke the pagedaemon.
185  */
186 #define	RATETOSCHEDPAGING	4
187 
188 /*
189  * Believed threshold (in megabytes) for which interleaved
190  * swapping area is desirable.
191  */
192 #define	LOTSOFMEM	2
193 
194 #define	mapin(pte, v, pfnum, prot) \
195 	{(*(int *)(pte) = ((pfnum)<<PGSHIFT) | (prot)) ; }
196 
197 /*
198  * Mach derived constants
199  */
200 
201 /* user/kernel map constants */
202 #define VM_MIN_ADDRESS		((vm_offset_t)0)
203 #define VM_MAXUSER_ADDRESS	((vm_offset_t)0xFDBFE000)
204 #define UPT_MIN_ADDRESS		((vm_offset_t)0xFDC00000)
205 #define UPT_MAX_ADDRESS		((vm_offset_t)0xFDFF7000)
206 #define VM_MAX_ADDRESS		UPT_MAX_ADDRESS
207 #define VM_MIN_KERNEL_ADDRESS	((vm_offset_t)0xFDFF7000)
208 #define UPDT			VM_MIN_KERNEL_ADDRESS
209 #define KPT_MIN_ADDRESS		((vm_offset_t)0xFDFF8000)
210 #define KPT_MAX_ADDRESS		((vm_offset_t)0xFDFFF000)
211 #define VM_MAX_KERNEL_ADDRESS	((vm_offset_t)0xFF7FF000)
212 
213 /* virtual sizes (bytes) for various kernel submaps */
214 #define VM_MBUF_SIZE		(NMBCLUSTERS*MCLBYTES)
215 #define VM_KMEM_SIZE		(NKMEMCLUSTERS*CLBYTES)
216 #define VM_PHYS_SIZE		(USRIOSIZE*CLBYTES)
217 
218 /* # of kernel PT pages (initial only, can grow dynamically) */
219 #define VM_KERNEL_PT_PAGES	((vm_size_t)2)		/* XXX: SYSPTSIZE */
220 
221 /* pcb base */
222 #define	pcbb(p)		((u_int)(p)->p_addr)
223 
224 /*
225  * Flush MMU TLB
226  */
227 
228 #ifndef I386_CR3PAT
229 #define	I386_CR3PAT	0x0
230 #endif
231 
232 #ifdef notyet
233 #define _cr3() ({u_long rtn; \
234 	asm (" movl %%cr3,%%eax; movl %%eax,%0 " \
235 		: "=g" (rtn) \
236 		: \
237 		: "ax"); \
238 	rtn; \
239 })
240 
241 #define load_cr3(s) ({ u_long val; \
242 	val = (s) | I386_CR3PAT; \
243 	asm ("movl %0,%%eax; movl %%eax,%%cr3" \
244 		:  \
245 		: "g" (val) \
246 		: "ax"); \
247 })
248 
249 #define tlbflush() ({ u_long val; \
250 	val = u.u_pcb.pcb_ptd | I386_CR3PAT; \
251 	asm ("movl %0,%%eax; movl %%eax,%%cr3" \
252 		:  \
253 		: "g" (val) \
254 		: "ax"); \
255 })
256 #endif
257