1/* $NetBSD: param.h,v 1.738.2.9 2026/07/30 15:23:12 martin Exp $ */
2
3/*-
4 * Copyright (c) 1982, 1986, 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)param.h 8.3 (Berkeley) 4/4/95
37 */
38
39#ifndef _SYS_PARAM_H_
40#define _SYS_PARAM_H_
41
42#ifdef _KERNEL_OPT
43#include "opt_param.h"
44#endif
45
46/*
47 * Historic BSD #defines -- probably will remain untouched for all time.
48 */
49#define BSD 199506 /* System version (year & month). */
50#define BSD4_3 1
51#define BSD4_4 1
52
53/*
54 * #define __NetBSD_Version__ MMmmrrpp00
55 *
56 * M = major version
57 * m = minor version; a minor number of 99 indicates current.
58 * r = 0 (*) or patchlevel in 9.99
59 * p = patchlevel
60 *
61 * When new releases are made, src/gnu/usr.bin/groff/tmac/mdoc.local
62 * needs to be updated and the changes sent back to the groff maintainers.
63 *
64 * (*) Up to 2.0I "release" used to be "",A-Z,Z[A-Z] but numeric
65 * e.g. NetBSD-1.2D = 102040000 ('D' == 4)
66 * NetBSD-2.0H (200080000) was changed on 20041001 to:
67 * 2.99.9 (299000900)
68 */
69
70/* zig patch: __NetBSD_Version__ is defined by the compiler */
71
72#define __NetBSD_Prereq__(M,m,p) (((((M) * 100000000) + \
73 (m) * 1000000) + (p) * 100) <= __NetBSD_Version__)
74
75/*
76 * Historical NetBSD #define
77 *
78 * NetBSD 1.4 was the last release for which this value was incremented.
79 * The value is now permanently fixed at 199905. It will never be
80 * changed again.
81 *
82 * New code must use __NetBSD_Version__ instead, and should not even
83 * count on NetBSD being defined.
84 *
85 */
86
87#define NetBSD 199905 /* NetBSD version (year & month). */
88
89/*
90 * These macros determine if we are running in protected mode or not.
91 * _HARDKERNEL: code uses kernel namespace and runs in hw privileged mode
92 * _SOFTKERNEL: code uses kernel namespace but runs without hw privileges
93 */
94#if defined(_KERNEL) && !defined(_RUMPKERNEL)
95#define _HARDKERNEL
96#endif
97#if defined(_KERNEL) && defined(_RUMPKERNEL)
98#define _SOFTKERNEL
99#endif
100
101#include <sys/null.h>
102
103#ifndef __ASSEMBLER__
104#include <sys/inttypes.h>
105#include <sys/types.h>
106
107/*
108 * Machine-independent constants (some used in following include files).
109 * Redefined constants are from POSIX 1003.1 limits file.
110 *
111 * MAXCOMLEN should be >= sizeof(ac_comm) (see <acct.h>)
112 * MAXHOSTNAMELEN should be >= (_POSIX_HOST_NAME_MAX + 1) (see <limits.h>)
113 * MAXLOGNAME should be >= UT_NAMESIZE (see <utmp.h>)
114 */
115#include <sys/syslimits.h>
116
117#define MAXCOMLEN 16 /* max command name remembered */
118#define MAXINTERP PATH_MAX /* max interpreter file name length */
119/* DEPRECATED: use LOGIN_NAME_MAX instead. */
120#define MAXLOGNAME (LOGIN_NAME_MAX - 1) /* max login name length */
121#define NCARGS ARG_MAX /* max bytes for an exec function */
122#define NGROUPS NGROUPS_MAX /* max number groups */
123#define NOGROUP 65535 /* marker for empty group set member */
124#define MAXHOSTNAMELEN 256 /* max hostname size */
125
126#ifndef NOFILE
127#define NOFILE OPEN_MAX /* max open files per process */
128#endif
129#ifndef MAXUPRC /* max simultaneous processes */
130#define MAXUPRC CHILD_MAX /* POSIX 1003.1-compliant default */
131#else
132#if (MAXUPRC - 0) < CHILD_MAX
133#error MAXUPRC less than CHILD_MAX. See options(4) for details.
134#endif /* (MAXUPRC - 0) < CHILD_MAX */
135#endif /* !defined(MAXUPRC) */
136
137/* Macros for min/max. */
138#define MIN(a,b) ((/*CONSTCOND*/(a)<(b))?(a):(b))
139#define MAX(a,b) ((/*CONSTCOND*/(a)>(b))?(a):(b))
140
141/* Machine type dependent parameters. */
142#include <machine/param.h>
143#include <machine/limits.h>
144
145/*
146 * Coherency unit: assumed cache line size. See also MIN_LWP_ALIGNMENT.
147 * The MD code depends on the current values of these constants. Don't
148 * change them without coordinating.
149 */
150#ifndef COHERENCY_UNIT
151#define COHERENCY_UNIT 64
152#endif
153#ifndef CACHE_LINE_SIZE
154#define CACHE_LINE_SIZE 64
155#endif
156
157/* More types and definitions used throughout the kernel. */
158#ifdef _KERNEL
159#include <sys/cdefs.h>
160#include <sys/errno.h>
161#include <sys/time.h>
162#include <sys/resource.h>
163#include <sys/ucred.h>
164#include <sys/uio.h>
165#include <uvm/uvm_param.h>
166#ifndef NPROC
167#define NPROC (20 + 16 * MAXUSERS)
168#endif
169#ifndef MAXFILES
170#define MAXFILES (3 * (NPROC + MAXUSERS) + 80)
171#define MAXFILES_IMPLICIT
172#endif
173#ifndef NTEXT
174#define NTEXT (80 + NPROC / 8) /* actually the object cache */
175#endif
176#ifndef NVNODE
177#define NVNODE (NPROC + NTEXT + 100)
178#define NVNODE_IMPLICIT
179#endif
180#ifndef VNODE_KMEM_MAXPCT
181#define VNODE_KMEM_MAXPCT 60
182#endif
183#ifndef BUFCACHE_VA_MAXPCT
184#define BUFCACHE_VA_MAXPCT 20
185#endif
186#define VNODE_COST 2048 /* assumed space in bytes */
187#endif /* _KERNEL */
188
189/* Signals. */
190#include <sys/signal.h>
191
192#define DEV_BSHIFT 9 /* log2(DEV_BSIZE) */
193#define DEV_BSIZE (1 << DEV_BSHIFT) /* 512 */
194
195#ifndef BLKDEV_IOSIZE
196#define BLKDEV_IOSIZE 2048
197#endif
198
199#ifndef MAXPHYS
200#define MAXPHYS (64 * 1024) /* max raw I/O transfer size */
201#endif
202
203/* pages ("clicks") to disk blocks */
204#define ctod(x) ((x) << (PGSHIFT - DEV_BSHIFT))
205#define dtoc(x) ((x) >> (PGSHIFT - DEV_BSHIFT))
206
207/* bytes to pages */
208#define ctob(x) ((x) << PGSHIFT)
209#define btoc(x) (((x) + PGOFSET) >> PGSHIFT)
210
211/* bytes to disk blocks */
212#define dbtob(x) ((x) << DEV_BSHIFT)
213#define btodb(x) ((x) >> DEV_BSHIFT)
214
215#ifndef MAXCPUS
216#define MAXCPUS 32
217#endif
218#ifndef MAX_LWP_PER_PROC
219#define MAX_LWP_PER_PROC 8000
220#endif
221
222/*
223 * Stack macros. On most architectures, the stack grows down,
224 * towards lower addresses; it is the rare architecture where
225 * it grows up, towards higher addresses.
226 *
227 * STACK_GROW and STACK_SHRINK adjust a stack pointer by some
228 * size, no questions asked. STACK_ALIGN aligns a stack pointer.
229 *
230 * STACK_ALLOC returns a pointer to allocated stack space of
231 * some size; given such a pointer and a size, STACK_MAX gives
232 * the maximum (in the "maxsaddr" sense) stack address of the
233 * allocated memory.
234 */
235#if defined(_KERNEL) || defined(__EXPOSE_STACK)
236
237#ifndef STACK_ALIGNBYTES
238#define STACK_ALIGNBYTES __ALIGNBYTES
239#endif
240
241#ifdef __MACHINE_STACK_GROWS_UP
242#define STACK_GROW(sp, _size) (((char *)(void *)(sp)) + (_size))
243#define STACK_SHRINK(sp, _size) (((char *)(void *)(sp)) - (_size))
244#define STACK_ALIGN(sp, bytes) \
245 ((char *)((((unsigned long)(sp)) + (bytes)) & ~(bytes)))
246#define STACK_ALLOC(sp, _size) ((char *)(void *)(sp))
247#define STACK_MAX(p, _size) (((char *)(void *)(p)) + (_size))
248#else
249#define STACK_GROW(sp, _size) (((char *)(void *)(sp)) - (_size))
250#define STACK_SHRINK(sp, _size) (((char *)(void *)(sp)) + (_size))
251#define STACK_ALIGN(sp, bytes) \
252 ((char *)(((unsigned long)(sp)) & ~(bytes)))
253#define STACK_ALLOC(sp, _size) (((char *)(void *)(sp)) - (_size))
254#define STACK_MAX(p, _size) ((char *)(void *)(p))
255#endif
256#define STACK_LEN_ALIGN(len, bytes) (((len) + (bytes)) & ~(bytes))
257
258#endif /* defined(_KERNEL) || defined(__EXPOSE_STACK) */
259
260/*
261 * Round p (pointer or byte index) up to a correctly-aligned value for all
262 * data types (int, long, ...). The result is uintptr_t and must be cast to
263 * any desired pointer type.
264 *
265 * ALIGNED_POINTER is a boolean macro that checks whether an address
266 * is valid to fetch data elements of type t from on this architecture
267 * using ALIGNED_POINTER_LOAD. This does not reflect the optimal
268 * alignment, just the possibility (within reasonable limits).
269 *
270 * uint32_t x;
271 * unsigned char *p = ...;
272 *
273 * if (ALIGNED_POINTER(p, uint32_t)) {
274 * uint32_t t;
275 * ALIGNED_POINTER_LOAD(&t, p, uint32_t);
276 * x = t;
277 * } else {
278 * uint32_t t;
279 * memcpy(&t, p, sizeof(t));
280 * x = t;
281 * }
282 *
283 */
284#define ALIGNBYTES __ALIGNBYTES
285#ifndef ALIGN
286#define ALIGN(p) (((uintptr_t)(p) + ALIGNBYTES) & ~ALIGNBYTES)
287#endif
288#ifndef ALIGNED_POINTER
289#define ALIGNED_POINTER(p,t) ((((uintptr_t)(p)) & (__alignof(t) - 1)) == 0)
290#endif
291#ifndef ALIGNED_POINTER_LOAD
292#define ALIGNED_POINTER_LOAD(q,p,t) (*(q) = *((const t *)(p)))
293#endif
294
295/*
296 * Return if pointer p is accessible for type t. For primitive types
297 * this means that the pointer itself can be dereferenced; for structures
298 * and unions this means that any field can be dereferenced. On CPUs
299 * that allow unaligned pointer access, we always return that the pointer
300 * is accessible to prevent unnecessary copies, although this might not be
301 * necessarily faster.
302 */
303#ifdef __NO_STRICT_ALIGNMENT
304#define ACCESSIBLE_POINTER(p, t) 1
305#else
306#define ACCESSIBLE_POINTER(p, t) ALIGNED_POINTER(p, t)
307#endif
308
309/*
310 * Historic priority levels. These are meaningless and remain only
311 * for source compatibility. Do not use in new code.
312 */
313#define PSWP 0
314#define PVM 4
315#define PINOD 8
316#define PRIBIO 16
317#define PVFS 20
318#define PZERO 22
319#define PSOCK 24
320#define PWAIT 32
321#define PLOCK 36
322#define PPAUSE 40
323#define PUSER 50
324#define MAXPRI 127
325
326#define PCATCH 0x100 /* OR'd with pri for tsleep to check signals */
327#define PNORELOCK 0x200 /* OR'd with pri for tsleep to not relock */
328
329/*
330 * New priority levels.
331 */
332#define PRI_COUNT 224
333#define PRI_NONE (-1)
334
335#define PRI_KERNEL_RT 192
336#define NPRI_KERNEL_RT 32
337#define MAXPRI_KERNEL_RT (PRI_KERNEL_RT + NPRI_KERNEL_RT - 1)
338
339#define PRI_USER_RT 128
340#define NPRI_USER_RT 64
341#define MAXPRI_USER_RT (PRI_USER_RT + NPRI_USER_RT - 1)
342
343#define PRI_KTHREAD 96
344#define NPRI_KTHREAD 32
345#define MAXPRI_KTHREAD (PRI_KTHREAD + NPRI_KTHREAD - 1)
346
347#define PRI_KERNEL 64
348#define NPRI_KERNEL 32
349#define MAXPRI_KERNEL (PRI_KERNEL + NPRI_KERNEL - 1)
350
351#define PRI_USER 0
352#define NPRI_USER 64
353#define MAXPRI_USER (PRI_USER + NPRI_USER - 1)
354
355/* Priority range used by POSIX real-time features */
356#define SCHED_PRI_MIN 0
357#define SCHED_PRI_MAX 63
358
359/*
360 * Kernel thread priorities.
361 */
362#define PRI_SOFTSERIAL MAXPRI_KERNEL_RT
363#define PRI_SOFTNET (MAXPRI_KERNEL_RT - schedppq * 1)
364#define PRI_SOFTBIO (MAXPRI_KERNEL_RT - schedppq * 2)
365#define PRI_SOFTCLOCK (MAXPRI_KERNEL_RT - schedppq * 3)
366
367#define PRI_XCALL MAXPRI_KTHREAD
368#define PRI_PGDAEMON (MAXPRI_KTHREAD - schedppq * 1)
369#define PRI_VM (MAXPRI_KTHREAD - schedppq * 2)
370#define PRI_IOFLUSH (MAXPRI_KTHREAD - schedppq * 3)
371#define PRI_BIO (MAXPRI_KTHREAD - schedppq * 4)
372
373#define PRI_IDLE PRI_USER
374
375/*
376 * Miscellaneous.
377 */
378#define NBPW sizeof(int) /* number of bytes per word (integer) */
379
380#define CMASK 022 /* default file mask: S_IWGRP|S_IWOTH */
381#define NODEV (dev_t)(-1) /* non-existent device */
382
383/*
384 * File system parameters and macros.
385 *
386 * The file system is made out of blocks of at most MAXBSIZE units, with
387 * smaller units (fragments) only in the last direct block. MAXBSIZE
388 * primarily determines the size of buffers in the buffer pool. It may be
389 * made larger without any effect on existing file systems; however making
390 * it smaller may make some file systems unmountable.
391 */
392#ifndef MAXBSIZE /* XXX */
393#define MAXBSIZE MAXPHYS
394#endif
395#define MAXFRAG 8
396
397/*
398 * MAXPATHLEN defines the longest permissible path length after
399 * expanding symbolic links, including a trailing null terminator
400 * byte. It is used to allocate a temporary buffer from the buffer
401 * pool in which to do the name expansion, hence should be a power of
402 * two, and must be less than or equal to MAXBSIZE. It must be the
403 * same as PATH_MAX from <limits.h>.
404 *
405 * MAXSYMLINKS defines the maximum number of symbolic links that may
406 * be expanded in a path name. It should be set high enough to allow
407 * all legitimate uses, but halt infinite loops reasonably quickly.
408 *
409 * MAXSYMLINKS should be >= _POSIX_SYMLOOP_MAX (see <limits.h>)
410 */
411#define MAXPATHLEN PATH_MAX
412#define MAXSYMLINKS 32
413
414/*
415 * This is the maximum individual filename component length enforced by
416 * namei. Filesystems cannot exceed this limit. The upper bound for that
417 * limit is NAME_MAX. We don't bump it for now, for compatibility with
418 * old binaries during the time where MAXNAMLEN was 511 and NAME_MAX was
419 * 255
420 */
421#define KERNEL_NAME_MAX 255
422
423/* Bit map related macros. */
424#define setbit(a,i) ((a)[(i)/NBBY] |= 1<<((i)%NBBY))
425#define clrbit(a,i) ((a)[(i)/NBBY] &= ~(1<<((i)%NBBY)))
426#define isset(a,i) ((a)[(i)/NBBY] & (1<<((i)%NBBY)))
427#define isclr(a,i) (((a)[(i)/NBBY] & (1<<((i)%NBBY))) == 0)
428
429/* Macros for counting and rounding. */
430#ifndef howmany
431#define howmany(x, y) (((x)+((y)-1))/(y))
432#endif
433#define roundup(x, y) ((((x)+((y)-1))/(y))*(y))
434#define rounddown(x,y) (((x)/(y))*(y))
435
436/*
437 * Rounding to powers of two. The naive definitions of roundup2 and
438 * rounddown2,
439 *
440 * #define roundup2(x,m) (((x) + ((m) - 1)) & ~((m) - 1))
441 * #define rounddown2(x,m) ((x) & ~((m) - 1)),
442 *
443 * exhibit a quirk of integer arithmetic in C because the complement
444 * happens in the type of m, not in the type of x. So if unsigned int
445 * is 32-bit, and m is an unsigned int while x is a uint64_t, then
446 * roundup2 and rounddown2 would have the unintended effect of clearing
447 * the upper 32 bits of the result(!). These definitions avoid the
448 * pitfalls of C arithmetic depending on the types of x and m, and
449 * additionally avoid multiply evaluating their arguments.
450 */
451#define roundup2(x,m) ((((x) - 1) | ((m) - 1)) + 1)
452#define rounddown2(x,m) ((x) & ~((__typeof__(x))((m) - 1)))
453
454#define powerof2(x) ((((x)-1)&(x))==0)
455
456/*
457 * Constants for setting the parameters of the kernel memory allocator.
458 *
459 * 2 ** MINBUCKET is the smallest unit of memory that will be
460 * allocated. It must be at least large enough to hold a pointer.
461 *
462 * Units of memory less or equal to MAXALLOCSAVE will permanently
463 * allocate physical memory; requests for these size pieces of
464 * memory are quite fast. Allocations greater than MAXALLOCSAVE must
465 * always allocate and free physical memory; requests for these
466 * size allocations should be done infrequently as they will be slow.
467 *
468 * Constraints: NBPG <= MAXALLOCSAVE <= 2 ** (MINBUCKET + 14), and
469 * MAXALLOCSAVE must be a power of two.
470 */
471#ifdef _LP64
472#define MINBUCKET 5 /* 5 => min allocation of 32 bytes */
473#else
474#define MINBUCKET 4 /* 4 => min allocation of 16 bytes */
475#endif
476#define MAXALLOCSAVE (2 * NBPG)
477
478/*
479 * Scale factor for scaled integers used to count %cpu time and load avgs.
480 *
481 * The number of CPU `tick's that map to a unique `%age' can be expressed
482 * by the formula (1 / (2 ^ (FSHIFT - 11))). The maximum load average that
483 * can be calculated (assuming 32 bits) can be closely approximated using
484 * the formula (2 ^ (2 * (16 - FSHIFT))) for (FSHIFT < 15).
485 *
486 * For the scheduler to maintain a 1:1 mapping of CPU `tick' to `%age',
487 * FSHIFT must be at least 11; this gives us a maximum load avg of ~1024.
488 */
489#define FSHIFT 11 /* bits to right of fixed binary point */
490#define FSCALE (1<<FSHIFT)
491
492/*
493 * The time for a process to be blocked before being very swappable.
494 * This is a number of seconds which the system takes as being a non-trivial
495 * amount of real time. You probably shouldn't change this;
496 * it is used in subtle ways (fractions and multiples of it are, that is, like
497 * half of a ``long time'', almost a long time, etc.)
498 * It is related to human patience and other factors which don't really
499 * change over time.
500 */
501#define MAXSLP 20
502
503/*
504 * Defaults for Unified Buffer Cache parameters.
505 * These may be overridden in <machine/param.h>.
506 */
507
508#ifndef UBC_WINSHIFT
509#define UBC_WINSHIFT 13
510#endif
511#ifndef UBC_NWINS
512#define UBC_NWINS 1024
513#endif
514
515#ifdef _KERNEL
516extern int hz;
517/*
518 * macro to convert from milliseconds to hz without integer overflow
519 * The 32 bit version uses only 32bit arithmetic; 0x20000 is safe for hz < 20000
520 * the 64 bit version does the computation directly.
521 */
522#ifndef mstohz
523# ifdef _LP64
524# define mstohz(ms) ((unsigned int)((ms + 0ul) * hz / 1000ul))
525# else
526static __inline unsigned int
527mstohz(unsigned int ms)
528{
529 return __predict_false(ms >= 0x20000u) ?
530 (ms / 1000u) * hz : (ms * hz) / 1000u;
531}
532# endif
533#endif
534
535#ifndef hztoms
536# ifdef _LP64
537# define hztoms(t) ((unsigned int)(((t) + 0ul) * 1000ul / hz))
538# else
539static __inline unsigned int
540hztoms(unsigned int t)
541{
542 return __predict_false(t >= 0x20000u) ?
543 (t / hz) * 1000u : (t * 1000u) / hz;
544}
545# endif
546#endif
547
548#define hz2bintime(t) (ms2bintime(hztoms(t)))
549
550extern const int schedppq;
551extern size_t coherency_unit;
552
553#endif /* _KERNEL */
554
555/*
556 * Minimum alignment of "struct lwp" needed by the architecture. This
557 * counts when packing a lock byte into a word alongside a pointer to an
558 * LWP. We need a minimum of 32, but go with the cache line size.
559 */
560#ifndef MIN_LWP_ALIGNMENT
561# if COHERENCY_UNIT > 32
562# define MIN_LWP_ALIGNMENT COHERENCY_UNIT
563# else
564# define MIN_LWP_ALIGNMENT 32
565# endif
566#endif
567#endif /* !__ASSEMBLER__ */
568
569#endif /* !_SYS_PARAM_H_ */