xref: /freebsd/sys/i386/include/vmparam.h (revision 0a44b8a5)
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 
37 #ifndef _MACHINE_VMPARAM_H_
38 #define _MACHINE_VMPARAM_H_ 1
39 
40 /*
41  * Machine dependent constants for 386.
42  */
43 
44 /*
45  * Virtual memory related constants, all in bytes
46  */
47 #define	MAXTSIZ		(128UL*1024*1024)	/* max text size */
48 #ifndef DFLDSIZ
49 #define	DFLDSIZ		(128UL*1024*1024)	/* initial data size limit */
50 #endif
51 #ifndef MAXDSIZ
52 #define	MAXDSIZ		(512UL*1024*1024)	/* max data size */
53 #endif
54 #ifndef	DFLSSIZ
55 #define	DFLSSIZ		(8UL*1024*1024)		/* initial stack size limit */
56 #endif
57 #ifndef	MAXSSIZ
58 #define	MAXSSIZ		(64UL*1024*1024)	/* max stack size */
59 #endif
60 #ifndef SGROWSIZ
61 #define SGROWSIZ	(128UL*1024)		/* amount to grow stack */
62 #endif
63 
64 /*
65  * Choose between DENSE and SPARSE based on whether lower execution time or
66  * lower kernel address space consumption is desired.  Under PAE, kernel
67  * address space is often in short supply.
68  */
69 #ifdef PAE
70 #define	VM_PHYSSEG_SPARSE
71 #else
72 #define	VM_PHYSSEG_DENSE
73 #endif
74 
75 /*
76  * The number of PHYSSEG entries must be one greater than the number
77  * of phys_avail entries because the phys_avail entry that spans the
78  * largest physical address that is accessible by ISA DMA is split
79  * into two PHYSSEG entries.
80  */
81 #define	VM_PHYSSEG_MAX		17
82 
83 /*
84  * Create one free page pool.  Since the i386 kernel virtual address
85  * space does not include a mapping onto the machine's entire physical
86  * memory, VM_FREEPOOL_DIRECT is defined as an alias for the default
87  * pool, VM_FREEPOOL_DEFAULT.
88  */
89 #define	VM_NFREEPOOL		1
90 #define	VM_FREEPOOL_DEFAULT	0
91 #define	VM_FREEPOOL_DIRECT	0
92 
93 /*
94  * Create up to three free page lists: VM_FREELIST_DMA32 is for physical pages
95  * that have physical addresses below 4G but are not accessible by ISA DMA,
96  * and VM_FREELIST_ISADMA is for physical pages that are accessible by ISA
97  * DMA.
98  */
99 #define	VM_NFREELIST		3
100 #define	VM_FREELIST_DEFAULT	0
101 #define	VM_FREELIST_DMA32	1
102 #define	VM_FREELIST_LOWMEM	2
103 
104 #define VM_LOWMEM_BOUNDARY	(16 << 20)	/* 16MB ISA DMA limit */
105 
106 /*
107  * Always create DMA32 freelist if there is any memory above 4G.
108  * Bounce dma is extremely fragile and simultaneously intensively
109  * used.
110  */
111 #define	VM_DMA32_NPAGES_THRESHOLD	1
112 
113 /*
114  * The largest allocation size is 2MB under PAE and 4MB otherwise.
115  */
116 #define	VM_NFREEORDER_PAE		10
117 #define	VM_NFREEORDER_NOPAE		11
118 #define	VM_NFREEORDER_MAX		VM_NFREEORDER_NOPAE
119 #define	VM_NFREEORDER			i386_pmap_VM_NFREEORDER
120 
121 /*
122  * Enable superpage reservations: 1 level.
123  */
124 #ifndef	VM_NRESERVLEVEL
125 #define	VM_NRESERVLEVEL		1
126 #endif
127 
128 /*
129  * Level 0 reservations consist of 512 pages when PAE pagetables are
130  * used, and 1024 pages otherwise.
131  */
132 #ifndef	VM_LEVEL_0_ORDER
133 #define	VM_LEVEL_0_ORDER_PAE	9
134 #define	VM_LEVEL_0_ORDER_NOPAE	10
135 #define	VM_LEVEL_0_ORDER_MAX	VM_LEVEL_0_ORDER_NOPAE
136 #define	VM_LEVEL_0_ORDER	i386_pmap_VM_LEVEL_0_ORDER
137 #else
138 #define	VM_LEVEL_0_ORDER_MAX	VM_LEVEL_0_ORDER
139 #endif
140 
141 /*
142  * Kernel physical load address.
143  */
144 #ifndef KERNLOAD
145 #define	KERNLOAD		(8 * 1024 * 1024)
146 #endif /* !defined(KERNLOAD) */
147 
148 /*
149  * Virtual addresses of things.  Derived from the page directory and
150  * page table indexes from pmap.h for precision.
151  * Because of the page that is both a PD and PT, it looks a little
152  * messy at times, but hey, we'll do anything to save a page :-)
153  */
154 
155 #define VM_MAX_KERNEL_ADDRESS	(0xffffffffU - 16 * 1024 * 1024 + 1)
156 
157 #define VM_MIN_KERNEL_ADDRESS	0
158 
159 #define	KERNBASE		KERNLOAD
160 
161 #define UPT_MAX_ADDRESS		VADDR(PTDPTDI, PTDPTDI)
162 #define UPT_MIN_ADDRESS		VADDR(PTDPTDI, 0)
163 
164 #define VM_MAXUSER_ADDRESS	(0xffffffff - 4 * 1024 * 1024 + 1)
165 
166 #define	SHAREDPAGE		(VM_MAXUSER_ADDRESS - PAGE_SIZE)
167 #define	USRSTACK		SHAREDPAGE
168 
169 #define VM_MAX_ADDRESS		VADDR(PTDPTDI, 0)
170 #define VM_MIN_ADDRESS		((vm_offset_t)0)
171 
172 #define	PMAP_TRM_MIN_ADDRESS	VM_MAXUSER_ADDRESS
173 #define	PMAP_TRM_MAX_ADDRESS	0xffffffff
174 
175 #define	PMAP_MAP_LOW		(4 * 1024 * 1024)
176 
177 /*
178  * KVA layout.  The unit of the system allocation is single PDE, which
179  * represents NBPDR bytes, aligned to NBPDR.  NBPDR is 4M for non-PAE
180  * page tables, and 2M for PAE, so PAE mode requires twice as many PTDs
181  * to create the same memory map as non-PAE.
182  *
183  * 0x00000000 - 0x003fffff	Transient identity map of low memory (0-4M),
184  *				normally disabled to catch NULL derefs.
185  * 0x00400000 - 0x007fffff	Fixed mapping of the low memory (4-8M).
186  * 0x00800000 - 0xffbfffff	KERNBASE (VA) == KERNLOAD (PA), kernel
187  *				text + data and all kernel maps.  Managed
188  *				by MI VM.
189  * 0xffc00000 - 0xffdfffff	Recursive kernel page table mapping, pointed
190  *				to by PTmap.  PTD[] recursively points
191  *				into PTmap.
192  * 0xffe00000 - 0xffffffff	Kernel/User mode shared PDE, contains GDT,
193  *				IDT, TSS, LDT, trampoline code and stacks.
194  *				Managed by pmap_trm_alloc().
195  */
196 
197 /*
198  * How many physical pages per kmem arena virtual page.
199  */
200 #ifndef VM_KMEM_SIZE_SCALE
201 #define	VM_KMEM_SIZE_SCALE	(1)
202 #endif
203 
204 /*
205  * Optional floor (in bytes) on the size of the kmem arena.
206  */
207 #ifndef VM_KMEM_SIZE_MIN
208 #define	VM_KMEM_SIZE_MIN	(12 * 1024 * 1024)
209 #endif
210 
211 /*
212  * Optional ceiling (in bytes) on the size of the kmem arena: 40% of the
213  * kernel map rounded to the nearest multiple of the superpage size.
214  */
215 #ifndef VM_KMEM_SIZE_MAX
216 #define	VM_KMEM_SIZE_MAX	(((((VM_MAX_KERNEL_ADDRESS - \
217     VM_MIN_KERNEL_ADDRESS) >> (PDRSHIFT - 2)) + 5) / 10) << PDRSHIFT)
218 #endif
219 
220 /* initial pagein size of beginning of executable file */
221 #ifndef VM_INITIAL_PAGEIN
222 #define	VM_INITIAL_PAGEIN	16
223 #endif
224 
225 #define	ZERO_REGION_SIZE	(64 * 1024)	/* 64KB */
226 
227 #ifndef VM_MAX_AUTOTUNE_MAXUSERS
228 #define VM_MAX_AUTOTUNE_MAXUSERS 384
229 #endif
230 
231 #define	SFBUF
232 #define	SFBUF_MAP
233 #define	SFBUF_CPUSET
234 #define	SFBUF_PROCESS_PAGE
235 
236 #define	PMAP_HAS_DMAP	0
237 #define	PHYS_TO_DMAP(x)	({ panic("No direct map exists"); 0; })
238 #define	DMAP_TO_PHYS(x)	({ panic("No direct map exists"); 0; })
239 
240 /*
241  * No non-transparent large page support in the pmap.
242  */
243 #define	PMAP_HAS_LARGEPAGES	0
244 
245 /*
246  * Need a page dump array for minidump.
247  */
248 #define MINIDUMP_PAGE_TRACKING	1
249 #define MINIDUMP_STARTUP_PAGE_TRACKING 0
250 
251 #endif /* _MACHINE_VMPARAM_H_ */
252