xref: /netbsd-src/sys/arch/i386/include/param.h (revision b1b36fc1a10b1078c497878e46e52f63a262628f)
1 /*	$NetBSD: param.h,v 1.88 2021/05/31 14:38:55 simonb 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 #define	PGSHIFT		12		/* LOG2(NBPG) */
69 #define	NBPG		(1 << PGSHIFT)	/* bytes/page */
70 #define	PGOFSET		(NBPG-1)	/* byte offset into page */
71 #define	NPTEPG		(NBPG/(sizeof (pt_entry_t)))
72 
73 #define	MAXIOMEM	0xffffffff
74 
75 /*
76  * Maximum physical memory supported by the implementation.
77  */
78 #ifdef PAE
79 #define MAXPHYSMEM	0x1000000000ULL /* 64GB */
80 #else
81 #define MAXPHYSMEM	0x100000000ULL	/* 4GB */
82 #endif
83 
84 #if defined(_KERNEL_OPT)
85 #include "opt_kernbase.h"
86 #endif /* defined(_KERNEL_OPT) */
87 
88 #ifndef	KERNBASE
89 #define	KERNBASE	0xc0000000UL	/* start of kernel virtual space */
90 #endif
91 
92 #define	KERNTEXTOFF	(KERNBASE + 0x100000) /* start of kernel text */
93 #define	BTOPKERNBASE	(KERNBASE >> PGSHIFT)
94 
95 #define	SSIZE		1		/* initial stack size/NBPG */
96 #define	SINCR		1		/* increment of stack/NBPG */
97 
98 #ifndef UPAGES
99 # ifdef DIAGNOSTIC
100 #  define	UPAGES		3	/* 2 + 1 page for redzone */
101 # else
102 #  define	UPAGES		2	/* normal pages of u-area */
103 # endif /* DIAGNOSTIC */
104 #endif /* !defined(UPAGES) */
105 #define	USPACE		(UPAGES * NBPG)	/* total size of u-area */
106 #define	INTRSTACKSIZE	8192
107 
108 #ifndef MSGBUFSIZE
109 #define MSGBUFSIZE	(16*NBPG)	/* default message buffer size */
110 #endif
111 
112 /*
113  * Constants related to network buffer management.
114  * MCLBYTES must be no larger than NBPG (the software page size), and,
115  * on machines that exchange pages of input or output buffers with mbuf
116  * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
117  * of the hardware page size.
118  */
119 #define	MSIZE		256		/* size of an mbuf */
120 
121 #ifndef MCLSHIFT
122 #define	MCLSHIFT	11		/* convert bytes to m_buf clusters */
123 					/* 2K cluster can hold Ether frame */
124 #endif	/* MCLSHIFT */
125 
126 #define	MCLBYTES	(1 << MCLSHIFT)	/* size of a m_buf cluster */
127 
128 #ifndef NMBCLUSTERS_MAX
129 #define	NMBCLUSTERS_MAX	(0x4000000 / MCLBYTES)	/* Limit to 64MB for clusters */
130 #endif
131 
132 #ifndef NFS_RSIZE
133 #define NFS_RSIZE	32768
134 #endif
135 #ifndef NFS_WSIZE
136 #define NFS_WSIZE	32768
137 #endif
138 
139 /*
140  * Minimum and maximum sizes of the kernel malloc arena in PAGE_SIZE-sized
141  * logical pages.
142  */
143 #define	NKMEMPAGES_MIN_DEFAULT	((16 * 1024 * 1024) >> PAGE_SHIFT)
144 #define	NKMEMPAGES_MAX_DEFAULT	((360 * 1024 * 1024) >> PAGE_SHIFT)
145 
146 /*
147  * Mach derived conversion macros
148  */
149 #define	x86_round_pdr(x) \
150 	((((unsigned long)(x)) + (NBPD_L2 - 1)) & ~(NBPD_L2 - 1))
151 #define	x86_trunc_pdr(x)	((unsigned long)(x) & ~(NBPD_L2 - 1))
152 #define	x86_btod(x)		((unsigned long)(x) >> L2_SHIFT)
153 #define	x86_dtob(x)		((unsigned long)(x) << L2_SHIFT)
154 #define	x86_round_page(x)	((((paddr_t)(x)) + PGOFSET) & ~PGOFSET)
155 #define	x86_trunc_page(x)	((paddr_t)(x) & ~PGOFSET)
156 #define	x86_btop(x)		((paddr_t)(x) >> PGSHIFT)
157 #define	x86_ptob(x)		((paddr_t)(x) << PGSHIFT)
158 
159 #endif /* _I386_PARAM_H_ */
160