1/* $NetBSD: param.h,v 1.89 2025/04/20 22:33:13 riastradh Exp $ */
2
3/*-
4 * Copyright (c) 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * William Jolitz.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)param.h 5.8 (Berkeley) 6/28/91
35 */
36
37#ifndef _I386_PARAM_H_
38#define _I386_PARAM_H_
39
40#ifdef _KERNEL_OPT
41#include "opt_param.h"
42#endif
43
44/*
45 * Machine dependent constants for Intel 386.
46 */
47
48/*
49 * MAXCPUS must be defined before cpu.h inclusion. Note: i386 might
50 * support more CPUs, but due to the limited KVA space available on
51 * i386, such support would be inefficient. Use amd64 instead.
52 */
53#define MAXCPUS 32
54
55#ifdef _KERNEL
56#include <machine/cpu.h>
57#endif
58
59#define _MACHINE i386
60#define MACHINE "i386"
61#define _MACHINE_ARCH i386
62#define MACHINE_ARCH "i386"
63#define MID_MACHINE MID_I386
64
65#define ALIGNED_POINTER(p,t) 1
66#define ALIGNED_POINTER_LOAD(q,p,t) memcpy((q), (p), sizeof(t))
67
68/*
69 * Stack alignment is 4-byte, following the traditional i386 SysV ABI
70 * published by SCO. Note: Parts of the Linux world have altered the
71 * ABI to guarantee 16-byte alignment, which is convenient for SSE2,
72 * but an incompatible ABI change which we do not follow.
73 */
74#define STACK_ALIGNBYTES (4 - 1)
75
76#define PGSHIFT 12 /* LOG2(NBPG) */
77#define NBPG (1 << PGSHIFT) /* bytes/page */
78#define PGOFSET (NBPG-1) /* byte offset into page */
79#define NPTEPG (NBPG/(sizeof (pt_entry_t)))
80
81#define MAXIOMEM 0xffffffff
82
83/*
84 * Maximum physical memory supported by the implementation.
85 */
86#ifdef PAE
87#define MAXPHYSMEM 0x1000000000ULL /* 64GB */
88#else
89#define MAXPHYSMEM 0x100000000ULL /* 4GB */
90#endif
91
92#if defined(_KERNEL_OPT)
93#include "opt_kernbase.h"
94#endif /* defined(_KERNEL_OPT) */
95
96#ifndef KERNBASE
97#define KERNBASE 0xc0000000UL /* start of kernel virtual space */
98#endif
99
100#define KERNTEXTOFF (KERNBASE + 0x100000) /* start of kernel text */
101#define BTOPKERNBASE (KERNBASE >> PGSHIFT)
102
103#define SSIZE 1 /* initial stack size/NBPG */
104#define SINCR 1 /* increment of stack/NBPG */
105
106#ifndef UPAGES
107# ifdef DIAGNOSTIC
108# define UPAGES 3 /* 2 + 1 page for redzone */
109# else
110# define UPAGES 2 /* normal pages of u-area */
111# endif /* DIAGNOSTIC */
112#endif /* !defined(UPAGES) */
113#define USPACE (UPAGES * NBPG) /* total size of u-area */
114#define INTRSTACKSIZE 8192
115
116#ifndef MSGBUFSIZE
117#define MSGBUFSIZE (16*NBPG) /* default message buffer size */
118#endif
119
120/*
121 * Constants related to network buffer management.
122 * MCLBYTES must be no larger than NBPG (the software page size), and,
123 * on machines that exchange pages of input or output buffers with mbuf
124 * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
125 * of the hardware page size.
126 */
127#define MSIZE 256 /* size of an mbuf */
128
129#ifndef MCLSHIFT
130#define MCLSHIFT 11 /* convert bytes to m_buf clusters */
131 /* 2K cluster can hold Ether frame */
132#endif /* MCLSHIFT */
133
134#define MCLBYTES (1 << MCLSHIFT) /* size of a m_buf cluster */
135
136#ifndef NMBCLUSTERS_MAX
137#define NMBCLUSTERS_MAX (0x4000000 / MCLBYTES) /* Limit to 64MB for clusters */
138#endif
139
140#ifndef NFS_RSIZE
141#define NFS_RSIZE 32768
142#endif
143#ifndef NFS_WSIZE
144#define NFS_WSIZE 32768
145#endif
146
147/*
148 * Minimum and maximum sizes of the kernel malloc arena in PAGE_SIZE-sized
149 * logical pages.
150 */
151#define NKMEMPAGES_MIN_DEFAULT ((16 * 1024 * 1024) >> PAGE_SHIFT)
152#define NKMEMPAGES_MAX_DEFAULT ((360 * 1024 * 1024) >> PAGE_SHIFT)
153
154/*
155 * Mach derived conversion macros
156 */
157#define x86_round_pdr(x) \
158 ((((unsigned long)(x)) + (NBPD_L2 - 1)) & ~(NBPD_L2 - 1))
159#define x86_trunc_pdr(x) ((unsigned long)(x) & ~(NBPD_L2 - 1))
160#define x86_btod(x) ((unsigned long)(x) >> L2_SHIFT)
161#define x86_dtob(x) ((unsigned long)(x) << L2_SHIFT)
162#define x86_round_page(x) ((((paddr_t)(x)) + PGOFSET) & ~PGOFSET)
163#define x86_trunc_page(x) ((paddr_t)(x) & ~PGOFSET)
164#define x86_btop(x) ((paddr_t)(x) >> PGSHIFT)
165#define x86_ptob(x) ((paddr_t)(x) << PGSHIFT)
166
167#endif /* _I386_PARAM_H_ */