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_ */