FreeBSD/Linux Kernel Cross Reference
sys/sys/param.h
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 */
41
42 #ifndef _SYS_PARAM_H_
43 #define _SYS_PARAM_H_
44
45 #define BSD 200708 /* XXX kern.osrevision */
46 #define BSD4_3 1 /* XXX obsolete */
47 #define BSD4_4 1 /* XXX obsolete */
48
49 /*
50 * __DragonFly_version number. The number doesn't really meaningfully
51 * translate to a version number.
52 *
53 * 170000 - base development version after 1.6 branch
54 * 170001 - base development version before 1.8 branch
55 * 190000 - base development version after 1.8 branch
56 * 195000 - base development version after 1.10 branch
57 * 197500 - base development version before 1.12 branch
58 * 197600 - 1.12 branch
59 * 197700 - base development version after 1.12 branch
60 * 199900 - base development version before 2.0 branch
61 * 200000 - 2.0 branch
62 * 200100 - base development version after 2.0 branch
63 * 200101 - lchflags syscall
64 * 200200 - 2.2 branch
65 * 200201 - base development version after 2.2 branch
66 * 200202 - major changes to libc
67 * 200203 - introduce PCI domain
68 * 200204 - suser() & suser_cred() removal
69 * 200205 - devfs import
70 * 200206 - *sleep() renames
71 * 200400 - 2.4 release
72 * 200500 - 2.5 master
73 * 200600 - 2.6 release
74 * 200700 - 2.7 master
75 * 200800 - 2.8 release October 2010
76 * 200900 - 2.9 master
77 * 200901 - prototype changes for alphasort(3) and scandir(3)
78 * 200902 - Xerox NS protocol removal
79 * 201000 - 2.10 release
80 * 201100 - 2.11 master
81 * 201200 - 2.12 release
82 * 201300 - 2.13 master
83 * 201301 - header rename: <vfs/gnu/ext2fs/...> -> <gnu/vfs/ext2fs/...>
84 * 201302 - header <crypt.h> is gone
85 * 201303 - <netatalk/...> and <netproto/atalk/...> are gone
86 * 201304 - Added wcscasecmp, wcsncasecmp to libc
87 * 201305 - Sync libm with NetBSD-current libm (new functions added)
88 * 201306 - Sync libm with FreeBSD-current libm (~50 new functions)
89 * 300000 - 3.0 release
90 * 300100 - 3.1 master
91 * 300101 - i4b (ISDN) removal
92 * 300102 - <sys/ata.h> is now just a link of <sys/nata.h>
93 * 300103 - if SIG_IGN is set on SIGCHLD, do not keep zombie children
94 * 300200 - 3.2 release
95 * 300300 - 3.3 master
96 * 300301 - Add eaccess syscall
97 * 300302 - fpsave changes - ucontext_t, mcontext_t, sigcontext, sigframe
98 * 300303 - Demarcation of old m4/flex with new m4/flex
99 * 300304 - Update to dialog-1.2-20121230
100 * 300400 - 3.4 release
101 * 300500 - 3.5 master
102 * 300501 - Convert libm to FreeBSD's version
103 * 300502 - GEM and i915 KMS support in kernel
104 * 300503 - Upgrade libiconv, locales, and associated libc functions
105 * 300600 - 3.6 release
106 * 300700 - 3.7 master
107 */
108 #undef __DragonFly_version
109 #define __DragonFly_version 300700 /* propagated to newvers */
110
111 #include <sys/_null.h>
112
113 #ifndef LOCORE
114 #include <sys/types.h>
115 #endif
116
117 /*
118 * Machine-independent constants (some used in following include files).
119 * Redefined constants are from POSIX 1003.1 limits file.
120 *
121 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
122 * MAXLOGNAME should be == UT_NAMESIZE+1 (see <utmp.h>)
123 */
124 #include <sys/syslimits.h>
125
126 #define MAXCOMLEN 16 /* max command name remembered */
127 #define MAXINTERP 32 /* max interpreter file name length */
128 #define MAXLOGNAME 17 /* max login name length (incl. NUL) */
129 #define MAXUPRC CHILD_MAX /* max simultaneous processes */
130 #define NCARGS ARG_MAX /* max bytes for an exec function */
131 #define NGROUPS NGROUPS_MAX /* max number groups */
132 #define NOFILE OPEN_MAX /* max open files per process */
133 #define NOGROUP 65535 /* marker for empty group set member */
134 #define MAXHOSTNAMELEN 256 /* max hostname size */
135
136 /* More types and definitions used throughout the kernel. */
137 #ifdef _KERNEL
138 #include <sys/cdefs.h>
139 #include <sys/errno.h>
140 #include <sys/time.h>
141
142 #define FALSE 0
143 #define TRUE 1
144 #endif
145
146 #ifndef _KERNEL
147 /* Signals. */
148 #include <sys/select.h>
149 #include <sys/signal.h>
150 #endif
151
152 /* Machine type dependent parameters. */
153 #include <machine/param.h>
154 #ifndef _KERNEL
155 #include <machine/limits.h>
156 #endif
157
158 #define PCATCH 0x00000100 /* tsleep checks signals */
159 #define PUSRFLAG1 0x00000200 /* Subsystem specific flag */
160 #define PINTERLOCKED 0x00000400 /* Interlocked tsleep */
161 #define PWAKEUP_CPUMASK 0x00003FFF /* start cpu for chained wakeups */
162 #define PWAKEUP_MYCPU 0x00004000 /* wakeup on current cpu only */
163 #define PWAKEUP_ONE 0x00008000 /* argument to wakeup: only one */
164 #define PDOMAIN_MASK 0xFFFF0000 /* address domains for wakeup */
165 #define PDOMAIN_UMTX 0x00010000 /* independant domain for UMTX */
166 #define PDOMAIN_XLOCK 0x00020000 /* independant domain for fifo_lock */
167 #define PWAKEUP_ENCODE(domain, cpu) ((domain) | (cpu))
168 #define PWAKEUP_DECODE(domain) ((domain) & PWAKEUP_CPUMASK)
169
170 #define NZERO 0 /* default "nice" */
171
172 #define NBPW sizeof(int) /* number of bytes per word (integer) */
173
174 #define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
175 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
176 #define NOUDEV (udev_t)(-1) /* non-existent device */
177 #define NOMAJ 256 /* non-existent device */
178 #endif
179
180 #ifndef _KERNEL
181 #define NODEV (dev_t)(-1) /* non-existent device */
182 #endif
183
184 /*
185 * cpu_mi_feature bits
186 */
187 #define CPU_MI_BZERONT 0x00000001
188 #define CPU_MI_MONITOR 0x00000010
189
190 /*
191 * File system parameters and macros.
192 *
193 * MAXBSIZE - Filesystems are made out of blocks of at most MAXBSIZE bytes
194 * per block. MAXBSIZE may be made larger without effecting
195 * any existing filesystems as long as it does not exceed MAXPHYS,
196 * and may be made smaller at the risk of not being able to use
197 * filesystems which require a block size exceeding MAXBSIZE.
198 *
199 * BKVASIZE - Nominal buffer space per buffer, in bytes. BKVASIZE is the
200 * minimum KVM memory reservation the kernel is willing to make.
201 * Filesystems can of course request smaller chunks. Actual
202 * backing memory uses a chunk size of a page (PAGE_SIZE).
203 *
204 * If you make BKVASIZE too small you risk seriously fragmenting
205 * the buffer KVM map which may slow things down a bit. If you
206 * make it too big the kernel will not be able to optimally use
207 * the KVM memory reserved for the buffer cache and will wind
208 * up with too-few buffers.
209 *
210 * By default we now use maximally-sized reservations. But on
211 * 32-bit machines we reduce this 16KB. Maximally-sized
212 * reservations greatly reduces defragmentation and buffer_map
213 * messing around and is more SMP-friendly.
214 */
215 #define MAXBSIZE 65536 /* must be power of 2 */
216 #ifndef BKVASIZE
217 #define BKVASIZE MAXBSIZE /* must be power of 2 */
218 #endif
219
220 #define BKVAMASK (BKVASIZE-1)
221 #define MAXFRAG 8
222
223 /*
224 * MAXPATHLEN defines the longest permissible path length after expanding
225 * symbolic links. It is used to allocate a temporary buffer from the buffer
226 * pool in which to do the name expansion, hence should be a power of two,
227 * and must be less than or equal to MAXBSIZE. MAXSYMLINKS defines the
228 * maximum number of symbolic links that may be expanded in a path name.
229 * It should be set high enough to allow all legitimate uses, but halt
230 * infinite loops reasonably quickly.
231 */
232 #define MAXPATHLEN PATH_MAX
233 #define MAXSYMLINKS 32
234
235 /* Bit map related macros. */
236 #define setbit(a,i) ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
237 #define clrbit(a,i) ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
238 #define isset(a,i) ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
239 #define isclr(a,i) (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
240
241 /* Macros for counting and rounding. */
242 #ifndef howmany
243 #define howmany(x, y) (((x)+((y)-1))/(y))
244 #endif
245 #define rounddown(x, y) (((x)/(y))*(y))
246 #define rounddown2(x, y) ((x) & ~((y) - 1)) /* y power of two */
247 #define roundup(x, y) ((((x)+((y)-1))/(y))*(y)) /* to any y */
248 #define roundup2(x, y) (((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
249 #define powerof2(x) ((((x)-1)&(x))==0)
250
251 /*
252 * VM objects can be larger than the virtual address space, make sure
253 * we don't cut-off the mask.
254 */
255 #define trunc_page64(x) ((x) & ~(int64_t)PAGE_MASK)
256 #define round_page64(x) (((x) + PAGE_MASK) & ~(int64_t)PAGE_MASK)
257
258 /* Macros for min/max. */
259 #define MIN(a,b) (((a)<(b))?(a):(b))
260 #define MAX(a,b) (((a)>(b))?(a):(b))
261
262 /* Macro for array size */
263 #define NELEM(ary) (sizeof(ary) / sizeof((ary)[0]))
264
265 /*
266 * Constants for setting the parameters of the kernel memory allocator.
267 *
268 * 2 ** MINBUCKET is the smallest unit of memory that will be
269 * allocated. It must be at least large enough to hold a pointer.
270 *
271 * Units of memory less or equal to MAXALLOCSAVE will permanently
272 * allocate physical memory; requests for these size pieces of
273 * memory are quite fast. Allocations greater than MAXALLOCSAVE must
274 * always allocate and free physical memory; requests for these
275 * size allocations should be done infrequently as they will be slow.
276 *
277 * Constraints: PAGE_SIZE <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
278 * MAXALLOCSIZE must be a power of two.
279 */
280 #define MINBUCKET 4 /* 4 => min allocation of 16 bytes */
281 #define MAXALLOCSAVE (2 * PAGE_SIZE)
282
283 /*
284 * Scale factor for scaled integers used to count %cpu time and load avgs.
285 *
286 * The number of CPU `tick's that map to a unique `%age' can be expressed
287 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
288 * can be calculated (assuming 32 bits) can be closely approximated using
289 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
290 *
291 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
292 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
293 */
294 #define FSHIFT 11 /* bits to right of fixed binary point */
295 #define FSCALE (1<<FSHIFT)
296
297 #define dbtoc(db) /* calculates devblks to pages */ \
298 ((db + (ctodb(1) - 1)) >> (PAGE_SHIFT - DEV_BSHIFT))
299
300 #define ctodb(db) /* calculates pages to devblks */ \
301 ((db) << (PAGE_SHIFT - DEV_BSHIFT))
302
303 #define MJUMPAGESIZE PAGE_SIZE /* jumbo cluster 4k */
304 #define MJUM9BYTES (9 * 1024) /* jumbo cluster 9k */
305 #define MJUM16BYTES (16 * 1024) /* jumbo cluster 16k */
306
307 /*
308 * MBUF Management.
309 *
310 * Because many drivers can't deal with multiple DMA segments all mbufs
311 * must avoid crossing a page boundary. While we can accomodate mbufs
312 * which are not a power-of-2 sized kmalloc() will only guarantee
313 * non-crossing alignment if we use a power-of-2. 256 is no longer large
314 * enough due to m_hdr and m_pkthdr bloat.
315 *
316 * MCLBYTES must be a power of 2 and is typically significantly larger
317 * than MSIZE, sufficient to hold a standard-mtu packet. 2K is considered
318 * reasonable.
319 */
320 #ifndef MSIZE
321 #define MSIZE 512 /* size of an mbuf */
322 #endif
323
324 #ifndef MCLSHIFT
325 #define MCLSHIFT 11 /* convert bytes to m_buf clusters */
326 #endif
327 #define MCLBYTES (1 << MCLSHIFT) /* size of an m_buf cluster */
328 #define MCLOFSET (MCLBYTES - 1) /* offset within an m_buf cluster */
329
330 /*
331 * Make this available for most of the kernel. There were too many
332 * things that included sys/systm.h just for panic().
333 */
334 #ifdef _KERNEL
335 void panic (const char *, ...) __dead2 __printflike(1, 2);
336 #endif
337
338 #ifndef htonl
339 #define htonl(x) __htonl(x)
340 #endif
341 #ifndef htons
342 #define htons(x) __htons(x)
343 #endif
344 #ifndef ntohl
345 #define ntohl(x) __ntohl(x)
346 #endif
347 #ifndef ntohs
348 #define ntohs(x) __ntohs(x)
349 #endif
350
351 /*
352 * Access a variable length array that has been declared as a fixed
353 * length array.
354 */
355 #define __PAST_END(array, offset) (((__typeof__(*(array)) *)(array))[offset])
356
357 #endif /* _SYS_PARAM_H_ */
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