xref: /dragonfly/sys/sys/param.h (revision 2983445f)
1 /*-
2  * Copyright (c) 1982, 1986, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
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. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)param.h	8.3 (Berkeley) 4/4/95
39  * $FreeBSD: src/sys/sys/param.h,v 1.61.2.38 2003/05/22 17:12:01 fjoe Exp $
40  * $DragonFly: src/sys/sys/param.h,v 1.53 2008/11/11 00:55:49 pavalos Exp $
41  */
42 
43 #ifndef _SYS_PARAM_H_
44 #define _SYS_PARAM_H_
45 
46 #define BSD	200708		/* XXX kern.osrevision */
47 #define BSD4_3	1		/* XXX obsolete */
48 #define BSD4_4	1		/* XXX obsolete */
49 
50 /*
51  * __DragonFly_version number.  The number doesn't really meaningfully
52  * translate to a version number.
53  *
54  * 170000 - base development version after 1.6 branch
55  * 170001 - base development version before 1.8 branch
56  * 190000 - base development version after 1.8 branch
57  * 195000 - base development version after 1.10 branch
58  * 197500 - base development version before 1.12 branch
59  * 197600 - 1.12 branch
60  * 197700 - base development version after 1.12 branch
61  * 199900 - base development version before 2.0 branch
62  * 200000 - 2.0 branch
63  * 200100 - base development version after 2.0 branch
64  * 200101 - lchflags syscall
65  * 200200 - 2.2 branch
66  * 200201 - base development version after 2.2 branch
67  * 200202 - major changes to libc
68  * 200203 - introduce PCI domain
69  * 200204 - suser() & suser_cred() removal
70  * 200205 - devfs import
71  * 200206 - *sleep() renames
72  * 200400 - 2.4 release
73  * 200500 - 2.5 master
74  * 200600 - 2.6 release
75  * 200700 - 2.7 master
76  * 200800 - 2.8 release			October 2010
77  * 200900 - 2.9 master
78  * 200901 - prototype changes for alphasort(3) and scandir(3)
79  * 200902 - Xerox NS protocol removal
80  */
81 #undef __DragonFly_version
82 #define __DragonFly_version 200902	/* propagated to newvers */
83 
84 #include <sys/_null.h>
85 
86 #ifndef LOCORE
87 #include <sys/types.h>
88 #endif
89 
90 /*
91  * Machine-independent constants (some used in following include files).
92  * Redefined constants are from POSIX 1003.1 limits file.
93  *
94  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
95  * MAXLOGNAME should be == UT_NAMESIZE+1 (see <utmp.h>)
96  */
97 #include <sys/syslimits.h>
98 
99 #define MAXCOMLEN	16		/* max command name remembered */
100 #define MAXINTERP	32		/* max interpreter file name length */
101 #define MAXLOGNAME	17		/* max login name length (incl. NUL) */
102 #define MAXUPRC		CHILD_MAX	/* max simultaneous processes */
103 #define NCARGS		ARG_MAX		/* max bytes for an exec function */
104 #define NGROUPS		NGROUPS_MAX	/* max number groups */
105 #define NOFILE		OPEN_MAX	/* max open files per process */
106 #define NOGROUP		65535		/* marker for empty group set member */
107 #define MAXHOSTNAMELEN	256		/* max hostname size */
108 
109 /* More types and definitions used throughout the kernel. */
110 #ifdef _KERNEL
111 #include <sys/cdefs.h>
112 #include <sys/errno.h>
113 #include <sys/time.h>
114 
115 #define FALSE	0
116 #define TRUE	1
117 #endif
118 
119 #ifndef _KERNEL
120 /* Signals. */
121 #include <sys/select.h>
122 #include <sys/signal.h>
123 #endif
124 
125 /* Machine type dependent parameters. */
126 #include <machine/param.h>
127 #ifndef _KERNEL
128 #include <machine/limits.h>
129 #endif
130 
131 #define PCATCH		0x00000100	/* tsleep checks signals */
132 #define PUSRFLAG1	0x00000200	/* Subsystem specific flag */
133 #define PINTERLOCKED	0x00000400	/* Interlocked tsleep */
134 #define PWAKEUP_CPUMASK	0x00003FFF	/* start cpu for chained wakeups */
135 #define PWAKEUP_MYCPU	0x00004000	/* wakeup on current cpu only */
136 #define PWAKEUP_ONE	0x00008000	/* argument to wakeup: only one */
137 #define PDOMAIN_MASK	0xFFFF0000	/* address domains for wakeup */
138 #define PDOMAIN_UMTX	0x00010000	/* independant domain for UMTX */
139 #define PWAKEUP_ENCODE(domain, cpu)	((domain) | (cpu))
140 #define PWAKEUP_DECODE(domain)		((domain) & PWAKEUP_CPUMASK)
141 
142 #define NZERO	0		/* default "nice" */
143 
144 #define NBPW	sizeof(int)	/* number of bytes per word (integer) */
145 
146 #define CMASK	022		/* default file mask: S_IWGRP|S_IWOTH */
147 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
148 #define NOUDEV	(udev_t)(-1)	/* non-existent device */
149 #define NOMAJ	256		/* non-existent device */
150 #endif
151 
152 #ifndef _KERNEL
153 #define NODEV	(dev_t)(-1)	/* non-existent device */
154 #endif
155 
156 /*
157  * cpu_mi_feature bits
158  */
159 #define CPU_MI_BZERONT	0x00000001
160 #define CPU_MI_MONITOR	0x00000010
161 
162 /*
163  * File system parameters and macros.
164  *
165  * MAXBSIZE -	Filesystems are made out of blocks of at most MAXBSIZE bytes
166  *		per block.  MAXBSIZE may be made larger without effecting
167  *		any existing filesystems as long as it does not exceed MAXPHYS,
168  *		and may be made smaller at the risk of not being able to use
169  *		filesystems which require a block size exceeding MAXBSIZE.
170  *
171  * BKVASIZE -	Nominal buffer space per buffer, in bytes.  BKVASIZE is the
172  *		minimum KVM memory reservation the kernel is willing to make.
173  *		Filesystems can of course request smaller chunks.  Actual
174  *		backing memory uses a chunk size of a page (PAGE_SIZE).
175  *
176  *		If you make BKVASIZE too small you risk seriously fragmenting
177  *		the buffer KVM map which may slow things down a bit.  If you
178  *		make it too big the kernel will not be able to optimally use
179  *		the KVM memory reserved for the buffer cache and will wind
180  *		up with too-few buffers.
181  *
182  *		The default is 16384, roughly 2x the block size used by a
183  *		normal UFS filesystem.
184  */
185 #define MAXBSIZE	65536	/* must be power of 2 */
186 #define BKVASIZE	16384	/* must be power of 2 */
187 #define BKVAMASK	(BKVASIZE-1)
188 #define MAXFRAG 	8
189 
190 /*
191  * MAXPATHLEN defines the longest permissible path length after expanding
192  * symbolic links. It is used to allocate a temporary buffer from the buffer
193  * pool in which to do the name expansion, hence should be a power of two,
194  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
195  * maximum number of symbolic links that may be expanded in a path name.
196  * It should be set high enough to allow all legitimate uses, but halt
197  * infinite loops reasonably quickly.
198  */
199 #define MAXPATHLEN	PATH_MAX
200 #define MAXSYMLINKS	32
201 
202 /* Bit map related macros. */
203 #define setbit(a,i)	((a)[(i)/NBBY] |= 1<<((i)%NBBY))
204 #define clrbit(a,i)	((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
205 #define isset(a,i)	((a)[(i)/NBBY] & (1<<((i)%NBBY)))
206 #define isclr(a,i)	(((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
207 
208 /* Macros for counting and rounding. */
209 #ifndef howmany
210 #define howmany(x, y)	(((x)+((y)-1))/(y))
211 #endif
212 #define rounddown(x, y)	(((x)/(y))*(y))
213 #define rounddown2(x, y) ((x) & ~((y) - 1))	   /* y power of two */
214 #define roundup(x, y)	((((x)+((y)-1))/(y))*(y))  /* to any y */
215 #define roundup2(x, y)	(((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
216 #define powerof2(x)	((((x)-1)&(x))==0)
217 
218 /*
219  * VM objects can be larger than the virtual address space, make sure
220  * we don't cut-off the mask.
221  */
222 #define trunc_page64(x)           ((x) & ~(int64_t)PAGE_MASK)
223 #define round_page64(x)           (((x) + PAGE_MASK) & ~(int64_t)PAGE_MASK)
224 
225 /* Macros for min/max. */
226 #define MIN(a,b) (((a)<(b))?(a):(b))
227 #define MAX(a,b) (((a)>(b))?(a):(b))
228 
229 /* Macro for array size */
230 #define NELEM(ary) 	(sizeof(ary) / sizeof((ary))[0])
231 
232 /*
233  * Constants for setting the parameters of the kernel memory allocator.
234  *
235  * 2 ** MINBUCKET is the smallest unit of memory that will be
236  * allocated. It must be at least large enough to hold a pointer.
237  *
238  * Units of memory less or equal to MAXALLOCSAVE will permanently
239  * allocate physical memory; requests for these size pieces of
240  * memory are quite fast. Allocations greater than MAXALLOCSAVE must
241  * always allocate and free physical memory; requests for these
242  * size allocations should be done infrequently as they will be slow.
243  *
244  * Constraints: PAGE_SIZE <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
245  * MAXALLOCSIZE must be a power of two.
246  */
247 #define MINBUCKET	4		/* 4 => min allocation of 16 bytes */
248 #define MAXALLOCSAVE	(2 * PAGE_SIZE)
249 
250 /*
251  * Scale factor for scaled integers used to count %cpu time and load avgs.
252  *
253  * The number of CPU `tick's that map to a unique `%age' can be expressed
254  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
255  * can be calculated (assuming 32 bits) can be closely approximated using
256  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
257  *
258  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
259  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
260  */
261 #define FSHIFT	11		/* bits to right of fixed binary point */
262 #define FSCALE	(1<<FSHIFT)
263 
264 #define dbtoc(db)			/* calculates devblks to pages */ \
265 	((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
266 
267 #define ctodb(db)			/* calculates pages to devblks */ \
268 	((db) << (PAGE_SHIFT - DEV_BSHIFT))
269 
270 #define MJUMPAGESIZE	PAGE_SIZE	/* jumbo cluster 4k */
271 #define MJUM9BYTES	(9 * 1024)	/* jumbo cluster 9k */
272 #define MJUM16BYTES	(16 * 1024)	/* jumbo cluster 16k */
273 
274 /*
275  * MBUF Management.
276  *
277  * Because many drivers can't deal with multiple DMA segments all mbufs
278  * must avoid crossing a page boundary.  While we can accomodate mbufs
279  * which are not a power-of-2 sized kmalloc() will only guarantee
280  * non-crossing alignment if we use a power-of-2.  256 is no longer large
281  * enough due to m_hdr and m_pkthdr bloat.
282  *
283  * MCLBYTES must be a power of 2 and is typically significantly larger
284  * than MSIZE, sufficient to hold a standard-mtu packet.  2K is considered
285  * reasonable.
286  */
287 #ifndef MSIZE
288 #define MSIZE		512		/* size of an mbuf */
289 #endif
290 
291 #ifndef MCLSHIFT
292 #define MCLSHIFT        12              /* convert bytes to m_buf clusters */
293 #endif
294 #define MCLBYTES        (1 << MCLSHIFT) /* size of an m_buf cluster */
295 #define MCLOFSET        (MCLBYTES - 1)  /* offset within an m_buf cluster */
296 
297 /*
298  * Make this available for most of the kernel.  There were too many
299  * things that included sys/systm.h just for panic().
300  */
301 #ifdef _KERNEL
302 void	panic (const char *, ...) __dead2 __printflike(1, 2);
303 #endif
304 
305 #ifndef htonl
306 #define	htonl(x)	__htonl(x)
307 #endif
308 #ifndef htons
309 #define	htons(x)	__htons(x)
310 #endif
311 #ifndef ntohl
312 #define	ntohl(x)	__ntohl(x)
313 #endif
314 #ifndef ntohs
315 #define	ntohs(x)	__ntohs(x)
316 #endif
317 
318 #endif	/* _SYS_PARAM_H_ */
319