xref: /freebsd/sys/i386/include/vmparam.h (revision ce6a89e27cd190313be39bb479880aeda4778436)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1990 The Regents of the University of California.
5  * All rights reserved.
6  * Copyright (c) 1994 John S. Dyson
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * William Jolitz.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. 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  * $FreeBSD$
38  */
39 
40 
41 #ifndef _MACHINE_VMPARAM_H_
42 #define _MACHINE_VMPARAM_H_ 1
43 
44 /*
45  * Machine dependent constants for 386.
46  */
47 
48 /*
49  * Virtual memory related constants, all in bytes
50  */
51 #define	MAXTSIZ		(128UL*1024*1024)	/* max text size */
52 #ifndef DFLDSIZ
53 #define	DFLDSIZ		(128UL*1024*1024)	/* initial data size limit */
54 #endif
55 #ifndef MAXDSIZ
56 #define	MAXDSIZ		(512UL*1024*1024)	/* max data size */
57 #endif
58 #ifndef	DFLSSIZ
59 #define	DFLSSIZ		(8UL*1024*1024)		/* initial stack size limit */
60 #endif
61 #ifndef	MAXSSIZ
62 #define	MAXSSIZ		(64UL*1024*1024)	/* max stack size */
63 #endif
64 #ifndef SGROWSIZ
65 #define SGROWSIZ	(128UL*1024)		/* amount to grow stack */
66 #endif
67 
68 /*
69  * Choose between DENSE and SPARSE based on whether lower execution time or
70  * lower kernel address space consumption is desired.  Under PAE, kernel
71  * address space is often in short supply.
72  */
73 #ifdef PAE
74 #define	VM_PHYSSEG_SPARSE
75 #else
76 #define	VM_PHYSSEG_DENSE
77 #endif
78 
79 /*
80  * The number of PHYSSEG entries must be one greater than the number
81  * of phys_avail entries because the phys_avail entry that spans the
82  * largest physical address that is accessible by ISA DMA is split
83  * into two PHYSSEG entries.
84  */
85 #define	VM_PHYSSEG_MAX		17
86 
87 /*
88  * Create one free page pool.  Since the i386 kernel virtual address
89  * space does not include a mapping onto the machine's entire physical
90  * memory, VM_FREEPOOL_DIRECT is defined as an alias for the default
91  * pool, VM_FREEPOOL_DEFAULT.
92  */
93 #define	VM_NFREEPOOL		1
94 #define	VM_FREEPOOL_DEFAULT	0
95 #define	VM_FREEPOOL_DIRECT	0
96 
97 /*
98  * Create up to three free page lists: VM_FREELIST_DMA32 is for physical pages
99  * that have physical addresses below 4G but are not accessible by ISA DMA,
100  * and VM_FREELIST_ISADMA is for physical pages that are accessible by ISA
101  * DMA.
102  */
103 #define	VM_NFREELIST		3
104 #define	VM_FREELIST_DEFAULT	0
105 #define	VM_FREELIST_DMA32	1
106 #define	VM_FREELIST_LOWMEM	2
107 
108 #define VM_LOWMEM_BOUNDARY	(16 << 20)	/* 16MB ISA DMA limit */
109 
110 /*
111  * Always create DMA32 freelist if there is any memory above 4G.
112  * Bounce dma is extremely fragile and simultaneously intensively
113  * used.
114  */
115 #define	VM_DMA32_NPAGES_THRESHOLD	1
116 
117 /*
118  * The largest allocation size is 2MB under PAE and 4MB otherwise.
119  */
120 #define	VM_NFREEORDER_PAE		10
121 #define	VM_NFREEORDER_NOPAE		11
122 #define	VM_NFREEORDER_MAX		VM_NFREEORDER_NOPAE
123 #define	VM_NFREEORDER			i386_pmap_VM_NFREEORDER
124 
125 /*
126  * Enable superpage reservations: 1 level.
127  */
128 #ifndef	VM_NRESERVLEVEL
129 #define	VM_NRESERVLEVEL		1
130 #endif
131 
132 /*
133  * Level 0 reservations consist of 512 pages when PAE pagetables are
134  * used, and 1024 pages otherwise.
135  */
136 #ifndef	VM_LEVEL_0_ORDER
137 #define	VM_LEVEL_0_ORDER_PAE	9
138 #define	VM_LEVEL_0_ORDER_NOPAE	10
139 #define	VM_LEVEL_0_ORDER_MAX	VM_LEVEL_0_ORDER_NOPAE
140 #define	VM_LEVEL_0_ORDER	i386_pmap_VM_LEVEL_0_ORDER
141 #else
142 #define	VM_LEVEL_0_ORDER_MAX	VM_LEVEL_0_ORDER
143 #endif
144 
145 /*
146  * Kernel physical load address.
147  */
148 #ifndef KERNLOAD
149 #define	KERNLOAD		(8 * 1024 * 1024)
150 #endif /* !defined(KERNLOAD) */
151 
152 /*
153  * Virtual addresses of things.  Derived from the page directory and
154  * page table indexes from pmap.h for precision.
155  * Because of the page that is both a PD and PT, it looks a little
156  * messy at times, but hey, we'll do anything to save a page :-)
157  */
158 
159 #define VM_MAX_KERNEL_ADDRESS	(0xffffffffU - 16 * 1024 * 1024 + 1)
160 
161 #define VM_MIN_KERNEL_ADDRESS	0
162 
163 #define	KERNBASE		KERNLOAD
164 
165 #define UPT_MAX_ADDRESS		VADDR(PTDPTDI, PTDPTDI)
166 #define UPT_MIN_ADDRESS		VADDR(PTDPTDI, 0)
167 
168 #define VM_MAXUSER_ADDRESS	(0xffffffff - 4 * 1024 * 1024 + 1)
169 
170 #define	SHAREDPAGE		(VM_MAXUSER_ADDRESS - PAGE_SIZE)
171 #define	USRSTACK		SHAREDPAGE
172 
173 #define VM_MAX_ADDRESS		VADDR(PTDPTDI, 0)
174 #define VM_MIN_ADDRESS		((vm_offset_t)0)
175 
176 #define	PMAP_TRM_MIN_ADDRESS	VM_MAXUSER_ADDRESS
177 #define	PMAP_TRM_MAX_ADDRESS	0xffffffff
178 
179 #define	PMAP_MAP_LOW		(4 * 1024 * 1024)
180 
181 /*
182  * KVA layout.  The unit of the system allocation is single PDE, which
183  * represents NBPDR bytes, aligned to NBPDR.  NBPDR is 4M for non-PAE
184  * page tables, and 2M for PAE, so PAE mode requires twice as many PTDs
185  * to create the same memory map as non-PAE.
186  *
187  * 0x00000000 - 0x003fffff	Transient identity map of low memory (0-4M),
188  *				normally disabled to catch NULL derefs.
189  * 0x00400000 - 0x007fffff	Fixed mapping of the low memory (4-8M).
190  * 0x00800000 - 0xffbfffff	KERNBASE (VA) == KERNLOAD (PA), kernel
191  *				text + data and all kernel maps.  Managed
192  *				by MI VM.
193  * 0xffc00000 - 0xffdfffff	Recursive kernel page table mapping, pointed
194  *				to by PTmap.  PTD[] recursively points
195  *				into PTmap.
196  * 0xffe00000 - 0xffffffff	Kernel/User mode shared PDE, contains GDT,
197  *				IDT, TSS, LDT, trampoline code and stacks.
198  *				Managed by pmap_trm_alloc().
199  */
200 
201 /*
202  * How many physical pages per kmem arena virtual page.
203  */
204 #ifndef VM_KMEM_SIZE_SCALE
205 #define	VM_KMEM_SIZE_SCALE	(1)
206 #endif
207 
208 /*
209  * Optional floor (in bytes) on the size of the kmem arena.
210  */
211 #ifndef VM_KMEM_SIZE_MIN
212 #define	VM_KMEM_SIZE_MIN	(12 * 1024 * 1024)
213 #endif
214 
215 /*
216  * Optional ceiling (in bytes) on the size of the kmem arena: 40% of the
217  * kernel map rounded to the nearest multiple of the superpage size.
218  */
219 #ifndef VM_KMEM_SIZE_MAX
220 #define	VM_KMEM_SIZE_MAX	(((((VM_MAX_KERNEL_ADDRESS - \
221     VM_MIN_KERNEL_ADDRESS) >> (PDRSHIFT - 2)) + 5) / 10) << PDRSHIFT)
222 #endif
223 
224 /* initial pagein size of beginning of executable file */
225 #ifndef VM_INITIAL_PAGEIN
226 #define	VM_INITIAL_PAGEIN	16
227 #endif
228 
229 #define	ZERO_REGION_SIZE	(64 * 1024)	/* 64KB */
230 
231 #ifndef VM_MAX_AUTOTUNE_MAXUSERS
232 #define VM_MAX_AUTOTUNE_MAXUSERS 384
233 #endif
234 
235 #define	SFBUF
236 #define	SFBUF_MAP
237 #define	SFBUF_CPUSET
238 #define	SFBUF_PROCESS_PAGE
239 
240 #define	PMAP_HAS_DMAP	0
241 #define	PHYS_TO_DMAP(x)	({ panic("No direct map exists"); 0; })
242 #define	DMAP_TO_PHYS(x)	({ panic("No direct map exists"); 0; })
243 
244 #endif /* _MACHINE_VMPARAM_H_ */
245