xref: /netbsd-src/sys/arch/i386/include/param.h (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /*	$NetBSD: param.h,v 1.87 2020/03/05 15:18:54 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 /*
41  * Machine dependent constants for Intel 386.
42  */
43 
44 /*
45  * MAXCPUS must be defined before cpu.h inclusion.  Note: i386 might
46  * support more CPUs, but due to the limited KVA space available on
47  * i386, such support would be inefficient.  Use amd64 instead.
48  */
49 #define	MAXCPUS		32
50 
51 #ifdef _KERNEL
52 #include <machine/cpu.h>
53 #endif
54 
55 #define	_MACHINE	i386
56 #define	MACHINE		"i386"
57 #define	_MACHINE_ARCH	i386
58 #define	MACHINE_ARCH	"i386"
59 #define	MID_MACHINE	MID_I386
60 
61 #define ALIGNED_POINTER(p,t)		1
62 #define ALIGNED_POINTER_LOAD(q,p,t)	memcpy((q), (p), sizeof(t))
63 
64 #define	PGSHIFT		12		/* LOG2(NBPG) */
65 #define	NBPG		(1 << PGSHIFT)	/* bytes/page */
66 #define	PGOFSET		(NBPG-1)	/* byte offset into page */
67 #define	NPTEPG		(NBPG/(sizeof (pt_entry_t)))
68 
69 #define	MAXIOMEM	0xffffffff
70 
71 /*
72  * Maximum physical memory supported by the implementation.
73  */
74 #ifdef PAE
75 #define MAXPHYSMEM	0x1000000000ULL /* 64GB */
76 #else
77 #define MAXPHYSMEM	0x100000000ULL	/* 4GB */
78 #endif
79 
80 #if defined(_KERNEL_OPT)
81 #include "opt_kernbase.h"
82 #endif /* defined(_KERNEL_OPT) */
83 
84 #ifndef	KERNBASE
85 #define	KERNBASE	0xc0000000UL	/* start of kernel virtual space */
86 #endif
87 
88 #define	KERNTEXTOFF	(KERNBASE + 0x100000) /* start of kernel text */
89 #define	BTOPKERNBASE	(KERNBASE >> PGSHIFT)
90 
91 #define	SSIZE		1		/* initial stack size/NBPG */
92 #define	SINCR		1		/* increment of stack/NBPG */
93 
94 #ifndef UPAGES
95 # ifdef DIAGNOSTIC
96 #  define	UPAGES		3	/* 2 + 1 page for redzone */
97 # else
98 #  define	UPAGES		2	/* normal pages of u-area */
99 # endif /* DIAGNOSTIC */
100 #endif /* !defined(UPAGES) */
101 #define	USPACE		(UPAGES * NBPG)	/* total size of u-area */
102 #define	INTRSTACKSIZE	8192
103 
104 #ifndef MSGBUFSIZE
105 #define MSGBUFSIZE	(16*NBPG)	/* default message buffer size */
106 #endif
107 
108 /*
109  * Constants related to network buffer management.
110  * MCLBYTES must be no larger than NBPG (the software page size), and,
111  * on machines that exchange pages of input or output buffers with mbuf
112  * clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
113  * of the hardware page size.
114  */
115 #define	MSIZE		256		/* size of an mbuf */
116 
117 #ifndef MCLSHIFT
118 #define	MCLSHIFT	11		/* convert bytes to m_buf clusters */
119 					/* 2K cluster can hold Ether frame */
120 #endif	/* MCLSHIFT */
121 
122 #define	MCLBYTES	(1 << MCLSHIFT)	/* size of a m_buf cluster */
123 
124 #ifndef NMBCLUSTERS_MAX
125 #define	NMBCLUSTERS_MAX	(0x4000000 / MCLBYTES)	/* Limit to 64MB for clusters */
126 #endif
127 
128 #ifndef NFS_RSIZE
129 #define NFS_RSIZE	32768
130 #endif
131 #ifndef NFS_WSIZE
132 #define NFS_WSIZE	32768
133 #endif
134 
135 /*
136  * Minimum and maximum sizes of the kernel malloc arena in PAGE_SIZE-sized
137  * logical pages.
138  */
139 #define	NKMEMPAGES_MIN_DEFAULT	((16 * 1024 * 1024) >> PAGE_SHIFT)
140 #define	NKMEMPAGES_MAX_DEFAULT	((360 * 1024 * 1024) >> PAGE_SHIFT)
141 
142 /*
143  * Mach derived conversion macros
144  */
145 #define	x86_round_pdr(x) \
146 	((((unsigned long)(x)) + (NBPD_L2 - 1)) & ~(NBPD_L2 - 1))
147 #define	x86_trunc_pdr(x)	((unsigned long)(x) & ~(NBPD_L2 - 1))
148 #define	x86_btod(x)		((unsigned long)(x) >> L2_SHIFT)
149 #define	x86_dtob(x)		((unsigned long)(x) << L2_SHIFT)
150 #define	x86_round_page(x)	((((paddr_t)(x)) + PGOFSET) & ~PGOFSET)
151 #define	x86_trunc_page(x)	((paddr_t)(x) & ~PGOFSET)
152 #define	x86_btop(x)		((paddr_t)(x) >> PGSHIFT)
153 #define	x86_ptob(x)		((paddr_t)(x) << PGSHIFT)
154 
155 #endif /* _I386_PARAM_H_ */
156