xref: /xnu-11215/bsd/sys/param.h (revision bb611c8f)
1 /*
2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /* Copyright (c) 1995, 1997 Apple Computer, Inc. All Rights Reserved */
29 /*-
30  * Copyright (c) 1982, 1986, 1989, 1993
31  *	The Regents of the University of California.  All rights reserved.
32  * (c) UNIX System Laboratories, Inc.
33  * All or some portions of this file are derived from material licensed
34  * to the University of California by American Telephone and Telegraph
35  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
36  * the permission of UNIX System Laboratories, Inc.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. All advertising materials mentioning features or use of this software
47  *    must display the following acknowledgement:
48  *	This product includes software developed by the University of
49  *	California, Berkeley and its contributors.
50  * 4. Neither the name of the University nor the names of its contributors
51  *    may be used to endorse or promote products derived from this software
52  *    without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64  * SUCH DAMAGE.
65  *
66  *	@(#)param.h	8.3 (Berkeley) 4/4/95
67  */
68 
69 #ifndef _SYS_PARAM_H_
70 #define _SYS_PARAM_H_
71 
72 #define BSD     199506          /* System version (year & month). */
73 #define BSD4_3  1
74 #define BSD4_4  1
75 
76 #define NeXTBSD 1995064         /* NeXTBSD version (year, month, release) */
77 #define NeXTBSD4_0 0            /* NeXTBSD 4.0 */
78 
79 #include <sys/_types.h>
80 #include <sys/_types/_null.h>
81 
82 #ifndef LOCORE
83 #include <sys/types.h>
84 #endif
85 
86 /*
87  * Machine-independent constants (some used in following include files).
88  * Redefined constants are from POSIX 1003.1 limits file.
89  *
90  * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
91  * MAXLOGNAME should be >= UT_NAMESIZE (see <utmp.h>)
92  */
93 #include <sys/syslimits.h>
94 
95 #define MAXCOMLEN       16              /* max command name remembered */
96 #define MAXINTERP       64              /* max interpreter file name length */
97 #define MAXLOGNAME      255             /* max login name length */
98 #define MAXUPRC         CHILD_MAX       /* max simultaneous processes */
99 #define NCARGS          ARG_MAX         /* max bytes for an exec function */
100 #define NGROUPS         NGROUPS_MAX     /* max number groups */
101 #define NOFILE          256             /* default max open files per process */
102 #define NOGROUP         65535           /* marker for empty group set member */
103 #define MAXHOSTNAMELEN  256             /* max hostname size */
104 #define MAXDOMNAMELEN   256             /* maximum domain name length */
105 
106 /* Machine type dependent parameters. */
107 #include <machine/param.h>
108 
109 /* More types and definitions used throughout the kernel. */
110 #ifdef KERNEL
111 #include <machine/limits.h>
112 #include <sys/cdefs.h>
113 #include <sys/errno.h>
114 #include <sys/time.h>
115 #include <sys/resource.h>
116 #include <sys/ucred.h>
117 #include <sys/uio.h>
118 #else
119 #include <limits.h>
120 #endif
121 
122 /* Signals. */
123 #include <sys/signal.h>
124 
125 /*
126  * Priorities.  Note that with 32 run queues, differences less than 4 are
127  * insignificant.
128  */
129 #define PSWP    0
130 #define PVM     4
131 #define PINOD   8
132 #define PRIBIO  16
133 #define PVFS    20
134 #define PZERO   22              /* No longer magic, shouldn't be here.  XXX */
135 #define PSOCK   24
136 #define PWAIT   32
137 #define PLOCK   36
138 #define PPAUSE  40
139 #define PUSER   50
140 #define MAXPRI  127             /* Priorities range from 0 through MAXPRI. */
141 
142 #define PRIMASK 0x0ff
143 #define PCATCH  0x100           /* OR'd with pri for tsleep to check signals */
144 #define PTTYBLOCK 0x200         /* for tty SIGTTOU and SIGTTIN blocking */
145 #define PDROP   0x400           /* OR'd with pri to stop re-aquistion of mutex upon wakeup */
146 #define PSPIN   0x800           /* OR'd with pri to require mutex in spin mode upon wakeup */
147 
148 #define NBPW    sizeof(int)     /* number of bytes per word (integer) */
149 
150 #define CMASK   022             /* default file mask: S_IWGRP|S_IWOTH */
151 #define NODEV   (dev_t)(-1)     /* non-existent device */
152 
153 /*
154  * Clustering of hardware pages on machines with ridiculously small
155  * page sizes is done here.  The paging subsystem deals with units of
156  * CLSIZE pte's describing NBPG (from machine/param.h) pages each.
157  */
158 #define CLBYTES         (CLSIZE*NBPG)
159 #define CLOFSET         (CLSIZE*NBPG-1) /* for clusters, like PGOFSET */
160 #define claligned(x)    ((((int)(x))&CLOFSET)==0)
161 #define CLOFF           CLOFSET
162 #define CLSHIFT         (PGSHIFT+CLSIZELOG2)
163 
164 #if CLSIZE == 1
165 #define clbase(i)       (i)
166 #define clrnd(i)        (i)
167 #else
168 /* Give the base virtual address (first of CLSIZE). */
169 #define clbase(i)       ((i) &~ (CLSIZE-1))
170 /* Round a number of clicks up to a whole cluster. */
171 #define clrnd(i)        (((i) + (CLSIZE-1)) &~ (CLSIZE-1))
172 #endif
173 
174 #define CBLOCK  64              /* Clist block size, must be a power of 2. */
175 #define CBQSIZE (CBLOCK/NBBY)   /* Quote bytes/cblock - can do better. */
176                                 /* Data chars/clist. */
177 #define CBSIZE  (CBLOCK - sizeof(struct cblock *) - CBQSIZE)
178 #define CROUND  (CBLOCK - 1)    /* Clist rounding. */
179 
180 /*
181  * File system parameters and macros.
182  *
183  * The file system is made out of blocks of at most MAXPHYS units, with
184  * smaller units (fragments) only in the last direct block.  MAXBSIZE
185  * primarily determines the size of buffers in the buffer pool.  It may be
186  * made larger than MAXPHYS without any effect on existing file systems;
187  * however making it smaller may make some file systems unmountable.
188  * We set this to track the value of MAX_UPL_TRANSFER_BYTES from
189  * osfmk/mach/memory_object_types.h to bound it at the maximum UPL size.
190  */
191 #define MAXBSIZE        (256 * 4096)
192 #define MAXPHYSIO       MAXPHYS
193 #define MAXFRAG         8
194 
195 #define MAXPHYSIO_WIRED (16 * 1024 * 1024)
196 
197 /*
198  * MAXPATHLEN defines the longest permissable path length after expanding
199  * symbolic links. It is used to allocate a temporary buffer from the buffer
200  * pool in which to do the name expansion, hence should be a power of two,
201  * and must be less than or equal to MAXBSIZE.  MAXSYMLINKS defines the
202  * maximum number of symbolic links that may be expanded in a path name.
203  * It should be set high enough to allow all legitimate uses, but halt
204  * infinite loops reasonably quickly.
205  */
206 #define MAXPATHLEN      PATH_MAX
207 #define MAXSYMLINKS     32
208 
209 /* Bit map related macros. */
210 #define setbit(a, i)     (((unsigned char *)(a))[(i)/NBBY] |= 1u<<((i)%NBBY))
211 #define clrbit(a, i)     (((unsigned char *)(a))[(i)/NBBY] &= ~(1u<<((i)%NBBY)))
212 #define isset(a, i)      (((unsigned char *)(a))[(i)/NBBY] & (1u<<((i)%NBBY)))
213 #define isclr(a, i)      ((((unsigned char *)(a))[(i)/NBBY] & (1u<<((i)%NBBY))) == 0)
214 
215 /* Macros for counting and rounding. */
216 #ifndef howmany
217 #define howmany(x, y)   ((((x) % (y)) == 0) ? ((x) / (y)) : (((x) / (y)) + 1))
218 #endif
219 #define roundup(x, y)   ((((x) % (y)) == 0) ? \
220 	                (x) : ((x) + ((y) - ((x) % (y)))))
221 #define powerof2(x)     ((((x)-1)&(x))==0)
222 
223 /* Macros for min/max. */
224 #ifndef MIN
225 #define MIN(a, b) (((a)<(b))?(a):(b))
226 #endif /* MIN */
227 #ifndef MAX
228 #define MAX(a, b) (((a)>(b))?(a):(b))
229 #endif  /* MAX */
230 
231 /*
232  * Scale factor for scaled integers used to count %cpu time and load avgs.
233  *
234  * The number of CPU `tick's that map to a unique `%age' can be expressed
235  * by the formula (1 / (2 ^ (FSHIFT - 11))).  The maximum load average that
236  * can be calculated (assuming 32 bits) can be closely approximated using
237  * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
238  *
239  * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
240  * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
241  */
242 #define FSHIFT  11              /* bits to right of fixed binary point */
243 #define FSCALE  (1<<FSHIFT)
244 
245 #endif  /* _SYS_PARAM_H_ */
246