kern_conf.c revision 116182
133965Sjdp/*- 233965Sjdp * Copyright (c) 1999-2002 Poul-Henning Kamp 333965Sjdp * All rights reserved. 433965Sjdp * 533965Sjdp * Redistribution and use in source and binary forms, with or without 633965Sjdp * modification, are permitted provided that the following conditions 733965Sjdp * are met: 833965Sjdp * 1. Redistributions of source code must retain the above copyright 933965Sjdp * notice, this list of conditions and the following disclaimer. 1060522Sobrien * 2. Redistributions in binary form must reproduce the above copyright 1160522Sobrien * notice, this list of conditions and the following disclaimer in the 12218822Sdim * documentation and/or other materials provided with the distribution. 13218822Sdim * 14218822Sdim * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15218822Sdim * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16130570Sobrien * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17130570Sobrien * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1833965Sjdp * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1933965Sjdp * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20218822Sdim * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2160522Sobrien * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22218822Sdim * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23218822Sdim * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2433965Sjdp * SUCH DAMAGE. 25218822Sdim */ 26218822Sdim 27218822Sdim#include <sys/cdefs.h> 28218822Sdim__FBSDID("$FreeBSD: head/sys/kern/kern_conf.c 116182 2003-06-11 00:56:59Z obrien $"); 2933965Sjdp 30218822Sdim#include <sys/param.h> 31218822Sdim#include <sys/kernel.h> 32218822Sdim#include <sys/systm.h> 33218822Sdim#include <sys/bio.h> 34218822Sdim#include <sys/lock.h> 35218822Sdim#include <sys/mutex.h> 36218822Sdim#include <sys/sysctl.h> 37218822Sdim#include <sys/module.h> 38218822Sdim#include <sys/malloc.h> 39218822Sdim#include <sys/conf.h> 40218822Sdim#include <sys/vnode.h> 41218822Sdim#include <sys/queue.h> 42218822Sdim#include <sys/ctype.h> 43218822Sdim#include <machine/stdarg.h> 44218822Sdim 45218822Sdimstatic MALLOC_DEFINE(M_DEVT, "dev_t", "dev_t storage"); 46218822Sdim 47218822Sdim/* Built at compile time from sys/conf/majors */ 48218822Sdimextern unsigned char reserved_majors[256]; 49218822Sdim 50218822Sdim/* 51218822Sdim * This is the number of hash-buckets. Experiements with 'real-life' 52218822Sdim * udev_t's show that a prime halfway between two powers of two works 53218822Sdim * best. 54218822Sdim */ 55218822Sdim#define DEVT_HASH 83 56218822Sdim 57218822Sdim/* The number of dev_t's we can create before malloc(9) kick in. */ 58218822Sdim#define DEVT_STASH 50 59218822Sdim 60218822Sdimstatic struct cdev devt_stash[DEVT_STASH]; 61218822Sdim 62218822Sdimstatic LIST_HEAD(, cdev) dev_hash[DEVT_HASH]; 63218822Sdim 64218822Sdimstatic LIST_HEAD(, cdev) dev_free; 65218822Sdim 66218822Sdimstatic int ready_for_devs; 67218822Sdim 68218822Sdimstatic int free_devt; 69218822SdimSYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, ""); 70218822Sdim 71218822Sdim/* Define a dead_cdevsw for use when devices leave unexpectedly. */ 72218822Sdim 73218822Sdimstatic int 74218822Sdimenxio(void) 75218822Sdim{ 76218822Sdim return (ENXIO); 77218822Sdim} 78218822Sdim 79218822Sdim#define dead_open (d_open_t *)enxio 80218822Sdim#define dead_close (d_close_t *)enxio 81218822Sdim#define dead_read (d_read_t *)enxio 82218822Sdim#define dead_write (d_write_t *)enxio 83218822Sdim#define dead_ioctl (d_ioctl_t *)enxio 84218822Sdim#define dead_poll nopoll 85218822Sdim#define dead_mmap nommap 86218822Sdim 87218822Sdimstatic void 88218822Sdimdead_strategy(struct bio *bp) 89218822Sdim{ 90218822Sdim 91218822Sdim biofinish(bp, NULL, ENXIO); 92218822Sdim} 93218822Sdim 94218822Sdim#define dead_dump (dumper_t *)enxio 95218822Sdim 96218822Sdim#define dead_kqfilter (d_kqfilter_t *)enxio 97218822Sdim 98218822Sdimstatic struct cdevsw dead_cdevsw = { 99218822Sdim .d_open = dead_open, 100218822Sdim .d_close = dead_close, 101218822Sdim .d_read = dead_read, 102218822Sdim .d_write = dead_write, 10360522Sobrien .d_ioctl = dead_ioctl, 104218822Sdim .d_poll = dead_poll, 10560522Sobrien .d_mmap = dead_mmap, 106218822Sdim .d_strategy = dead_strategy, 107218822Sdim .d_name = "dead", 108218822Sdim .d_maj = 255, 109130570Sobrien .d_dump = dead_dump, 110218822Sdim .d_kqfilter = dead_kqfilter 111218822Sdim}; 112218822Sdim 113218822Sdim 114218822Sdimstruct cdevsw * 115218822Sdimdevsw(dev_t dev) 116218822Sdim{ 117218822Sdim if (dev->si_devsw) 118218822Sdim return (dev->si_devsw); 119218822Sdim return (&dead_cdevsw); 120218822Sdim} 121218822Sdim 122218822Sdim/* 123218822Sdim * dev_t and u_dev_t primitives 124218822Sdim */ 125218822Sdim 126218822Sdimint 12777316Sobrienmajor(dev_t x) 12877316Sobrien{ 12977316Sobrien if (x == NODEV) 130218822Sdim return NOUDEV; 131218822Sdim return((x->si_udev >> 8) & 0xff); 132218822Sdim} 13377316Sobrien 134218822Sdimint 135218822Sdimminor(dev_t x) 136218822Sdim{ 137218822Sdim if (x == NODEV) 13833965Sjdp return NOUDEV; 13960522Sobrien return(x->si_udev & 0xffff00ff); 14060522Sobrien} 141218822Sdim 14277316Sobrienint 143218822Sdimdev2unit(dev_t x) 14433965Sjdp{ 145218822Sdim int i; 146218822Sdim 14738891Sjdp if (x == NODEV) 148218822Sdim return NOUDEV; 149218822Sdim i = minor(x); 15033965Sjdp return ((i & 0xff) | (i >> 8)); 151218822Sdim} 152218822Sdim 153218822Sdimint 154218822Sdimunit2minor(int unit) 155218822Sdim{ 156218822Sdim 157218822Sdim KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit)); 158218822Sdim return ((unit & 0xff) | ((unit << 8) & ~0xffff)); 15989871Sobrien} 160218822Sdim 161218822Sdimstatic dev_t 162218822Sdimallocdev(void) 163218822Sdim{ 164218822Sdim static int stashed; 165218822Sdim struct cdev *si; 166218822Sdim 16760522Sobrien if (LIST_FIRST(&dev_free)) { 168218822Sdim si = LIST_FIRST(&dev_free); 16960522Sobrien LIST_REMOVE(si, si_hash); 170130570Sobrien } else if (stashed >= DEVT_STASH) { 171130570Sobrien MALLOC(si, struct cdev *, sizeof(*si), M_DEVT, 172130570Sobrien M_USE_RESERVE | M_ZERO | M_WAITOK); 173130570Sobrien } else { 174130570Sobrien si = devt_stash + stashed++; 175130570Sobrien bzero(si, sizeof *si); 176130570Sobrien si->si_flags |= SI_STASHED; 177130570Sobrien } 178130570Sobrien si->__si_namebuf[0] = '\0'; 179130570Sobrien si->si_name = si->__si_namebuf; 180130570Sobrien LIST_INIT(&si->si_children); 181218822Sdim TAILQ_INIT(&si->si_snapshots); 182130570Sobrien return (si); 183130570Sobrien} 184130570Sobrien 185130570Sobriendev_t 186130570Sobrienmakedev(int x, int y) 18733965Sjdp{ 188218822Sdim struct cdev *si; 189130570Sobrien udev_t udev; 190218822Sdim int hash; 19133965Sjdp 192218822Sdim if (x == umajor(NOUDEV) && y == uminor(NOUDEV)) 193218822Sdim panic("makedev of NOUDEV"); 194218822Sdim udev = (x << 8) | y; 195218822Sdim hash = udev % DEVT_HASH; 19677316Sobrien LIST_FOREACH(si, &dev_hash[hash], si_hash) { 19792833Sobrien if (si->si_udev == udev) 19892833Sobrien return (si); 199218822Sdim } 200130570Sobrien si = allocdev(); 201130570Sobrien si->si_udev = udev; 202218822Sdim LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); 203218822Sdim return (si); 20489871Sobrien} 205130570Sobrien 206130570Sobrienvoid 20789871Sobrienfreedev(dev_t dev) 208218822Sdim{ 20989871Sobrien 210130570Sobrien if (!free_devt) 211130570Sobrien return; 212130570Sobrien if (SLIST_FIRST(&dev->si_hlist)) 213130570Sobrien return; 214218822Sdim if (dev->si_devsw || dev->si_drv1 || dev->si_drv2) 215130570Sobrien return; 216218822Sdim LIST_REMOVE(dev, si_hash); 217130570Sobrien if (dev->si_flags & SI_STASHED) { 218218822Sdim bzero(dev, sizeof(*dev)); 21989871Sobrien dev->si_flags |= SI_STASHED; 22089871Sobrien LIST_INSERT_HEAD(&dev_free, dev, si_hash); 22189871Sobrien } else { 22289871Sobrien FREE(dev, M_DEVT); 22389871Sobrien } 224218822Sdim} 225218822Sdim 226218822Sdimudev_t 227218822Sdimdev2udev(dev_t x) 228130570Sobrien{ 229130570Sobrien if (x == NODEV) 230218822Sdim return NOUDEV; 231218822Sdim return (x->si_udev); 232218822Sdim} 233130570Sobrien 234130570Sobriendev_t 23560522Sobrienudev2dev(udev_t x, int b) 236130570Sobrien{ 237130570Sobrien 23891054Sobrien if (x == NOUDEV) 239130570Sobrien return (NODEV); 240130570Sobrien switch (b) { 24191054Sobrien case 0: 242218822Sdim return makedev(umajor(x), uminor(x)); 243218822Sdim case 1: 244218822Sdim return (NODEV); 24591054Sobrien default: 246218822Sdim Debugger("udev2dev(...,X)"); 247130570Sobrien return NODEV; 248130570Sobrien } 249130570Sobrien} 250130570Sobrien 251130570Sobrienint 252130570Sobrienuminor(udev_t dev) 253130570Sobrien{ 25460522Sobrien return(dev & 0xffff00ff); 255130570Sobrien} 25660522Sobrien 257130570Sobrienint 258130570Sobrienumajor(udev_t dev) 259130570Sobrien{ 260130570Sobrien return((dev & 0xff00) >> 8); 26160522Sobrien} 262218822Sdim 263218822Sdimudev_t 264130570Sobrienmakeudev(int x, int y) 26560522Sobrien{ 266130570Sobrien return ((x << 8) | y); 267130570Sobrien} 268218822Sdim 269218822Sdimdev_t 27033965Sjdpmake_dev(struct cdevsw *devsw, int minor, uid_t uid, gid_t gid, int perms, const char *fmt, ...) 271218822Sdim{ 272218822Sdim dev_t dev; 273218822Sdim va_list ap; 27489871Sobrien int i; 275218822Sdim 276218822Sdim KASSERT((minor & ~0xffff00ff) == 0, 277218822Sdim ("Invalid minor (0x%x) in make_dev", minor)); 278218822Sdim 279218822Sdim if (devsw->d_open == NULL) devsw->d_open = noopen; 280218822Sdim if (devsw->d_close == NULL) devsw->d_close = noclose; 281218822Sdim if (devsw->d_read == NULL) devsw->d_read = noread; 28233965Sjdp if (devsw->d_write == NULL) devsw->d_write = nowrite; 283218822Sdim if (devsw->d_ioctl == NULL) devsw->d_ioctl = noioctl; 284218822Sdim if (devsw->d_poll == NULL) devsw->d_poll = nopoll; 285218822Sdim if (devsw->d_mmap == NULL) devsw->d_mmap = nommap; 286218822Sdim if (devsw->d_strategy == NULL) devsw->d_strategy = nostrategy; 287218822Sdim if (devsw->d_dump == NULL) devsw->d_dump = nodump; 288218822Sdim if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = nokqfilter; 289218822Sdim 29089871Sobrien if (devsw->d_maj == MAJOR_AUTO) { 291218822Sdim for (i = NUMCDEVSW - 1; i > 0; i--) 292130570Sobrien if (reserved_majors[i] != i) 293218822Sdim break; 294130570Sobrien KASSERT(i > 0, ("Out of major numbers (%s)", devsw->d_name)); 295218822Sdim devsw->d_maj = i; 29677316Sobrien reserved_majors[i] = i; 297218822Sdim } else { 298218822Sdim if (devsw->d_maj == 256) /* XXX: tty_cons.c is magic */ 299218822Sdim devsw->d_maj = 0; 300218822Sdim KASSERT(devsw->d_maj >= 0 && devsw->d_maj < 256, 30189871Sobrien ("Invalid major (%d) in make_dev", devsw->d_maj)); 302218822Sdim if (reserved_majors[devsw->d_maj] != devsw->d_maj) { 303218822Sdim printf("WARNING: driver \"%s\" used %s %d\n", 304218822Sdim devsw->d_name, "unreserved major device number", 305218822Sdim devsw->d_maj); 306218822Sdim reserved_majors[devsw->d_maj] = devsw->d_maj; 307218822Sdim } 308218822Sdim } 309218822Sdim 31033965Sjdp if (!ready_for_devs) { 31133965Sjdp printf("WARNING: Driver mistake: make_dev(%s) called before SI_SUB_DRIVERS\n", 31233965Sjdp fmt); 31333965Sjdp /* XXX panic here once drivers are cleaned up */ 31433965Sjdp } 31533965Sjdp 31633965Sjdp dev = makedev(devsw->d_maj, minor); 31733965Sjdp if (dev->si_flags & SI_NAMED) { 31833965Sjdp printf( "WARNING: Driver mistake: repeat make_dev(\"%s\")\n", 319218822Sdim dev->si_name); 320218822Sdim panic("don't do that"); 32133965Sjdp } 322218822Sdim va_start(ap, fmt); 323130570Sobrien i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 32460522Sobrien if (i > (sizeof dev->__si_namebuf - 1)) { 32589871Sobrien printf("WARNING: Device name truncated! (%s)", 32689871Sobrien dev->__si_namebuf); 32789871Sobrien } 32889871Sobrien va_end(ap); 32989871Sobrien dev->si_devsw = devsw; 33089871Sobrien dev->si_uid = uid; 33189871Sobrien dev->si_gid = gid; 33233965Sjdp dev->si_mode = perms; 33385824Sobrien dev->si_flags |= SI_NAMED; 334218822Sdim 335218822Sdim devfs_create(dev); 336218822Sdim return (dev); 337218822Sdim} 338218822Sdim 339218822Sdimint 340218822Sdimdev_named(dev_t pdev, const char *name) 341218822Sdim{ 342218822Sdim dev_t cdev; 343218822Sdim 344218822Sdim if (strcmp(devtoname(pdev), name) == 0) 34560522Sobrien return (1); 34660522Sobrien LIST_FOREACH(cdev, &pdev->si_children, si_siblings) 34733965Sjdp if (strcmp(devtoname(cdev), name) == 0) 34833965Sjdp return (1); 34960522Sobrien return (0); 35060522Sobrien} 35160522Sobrien 352218822Sdimvoid 35333965Sjdpdev_depends(dev_t pdev, dev_t cdev) 35433965Sjdp{ 35533965Sjdp 356218822Sdim cdev->si_parent = pdev; 357218822Sdim cdev->si_flags |= SI_CHILD; 35889871Sobrien LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); 359218822Sdim} 360218822Sdim 361218822Sdimdev_t 36233965Sjdpmake_dev_alias(dev_t pdev, const char *fmt, ...) 36333965Sjdp{ 36433965Sjdp dev_t dev; 36533965Sjdp va_list ap; 36633965Sjdp int i; 36733965Sjdp 36833965Sjdp dev = allocdev(); 369218822Sdim dev->si_flags |= SI_ALIAS; 370218822Sdim dev->si_flags |= SI_NAMED; 371218822Sdim dev_depends(pdev, dev); 372218822Sdim va_start(ap, fmt); 37333965Sjdp i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); 37433965Sjdp if (i > (sizeof dev->__si_namebuf - 1)) { 37533965Sjdp printf("WARNING: Device name truncated! (%s)", 376218822Sdim dev->__si_namebuf); 377218822Sdim } 378218822Sdim va_end(ap); 379218822Sdim 380130570Sobrien devfs_create(dev); 381218822Sdim return (dev); 382130570Sobrien} 383218822Sdim 384218822Sdimvoid 385130570Sobrienrevoke_and_destroy_dev(dev_t dev) 386218822Sdim{ 387218822Sdim struct vnode *vp; 388130570Sobrien 389218822Sdim GIANT_REQUIRED; 390218822Sdim 391130570Sobrien vp = SLIST_FIRST(&dev->si_hlist); 392218822Sdim if (vp != NULL) 393218822Sdim VOP_REVOKE(vp, REVOKEALL); 394218822Sdim destroy_dev(dev); 39533965Sjdp} 39689871Sobrien 39789871Sobrienvoid 39889871Sobriendestroy_dev(dev_t dev) 399218822Sdim{ 40033965Sjdp 401218822Sdim if (!(dev->si_flags & SI_NAMED)) { 402218822Sdim printf( "WARNING: Driver mistake: destroy_dev on %d/%d\n", 403218822Sdim major(dev), minor(dev)); 404218822Sdim panic("don't do that"); 405130570Sobrien } 406218822Sdim 40777316Sobrien devfs_destroy(dev); 408218822Sdim if (dev->si_flags & SI_CHILD) { 409218822Sdim LIST_REMOVE(dev, si_siblings); 41033965Sjdp dev->si_flags &= ~SI_CHILD; 41189871Sobrien } 41291054Sobrien while (!LIST_EMPTY(&dev->si_children)) 41391054Sobrien destroy_dev(LIST_FIRST(&dev->si_children)); 414218822Sdim dev->si_drv1 = 0; 415218822Sdim dev->si_drv2 = 0; 416218822Sdim dev->si_devsw = 0; 417218822Sdim bzero(&dev->__si_u, sizeof(dev->__si_u)); 41889871Sobrien dev->si_flags &= ~SI_NAMED; 419218822Sdim dev->si_flags &= ~SI_ALIAS; 420218822Sdim freedev(dev); 421130570Sobrien} 422130570Sobrien 42391054Sobrienconst char * 42477316Sobriendevtoname(dev_t dev) 425218822Sdim{ 426218822Sdim char *p; 427218822Sdim int mynor; 428218822Sdim 429218822Sdim if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 430218822Sdim p = dev->si_name; 431218822Sdim if (devsw(dev)) 432218822Sdim sprintf(p, "#%s/", devsw(dev)->d_name); 433218822Sdim else 434218822Sdim sprintf(p, "#%d/", major(dev)); 435218822Sdim p += strlen(p); 436218822Sdim mynor = minor(dev); 437218822Sdim if (mynor < 0 || mynor > 255) 438218822Sdim sprintf(p, "%#x", (u_int)mynor); 439218822Sdim else 440218822Sdim sprintf(p, "%d", mynor); 44189871Sobrien } 44289871Sobrien return (dev->si_name); 443218822Sdim} 444218822Sdim 445218822Sdimint 446218822Sdimdev_stdclone(char *name, char **namep, const char *stem, int *unit) 447218822Sdim{ 448218822Sdim int u, i; 449218822Sdim 450218822Sdim i = strlen(stem); 451218822Sdim if (bcmp(stem, name, i) != 0) 45289871Sobrien return (0); 453218822Sdim if (!isdigit(name[i])) 454218822Sdim return (0); 455218822Sdim u = 0; 456218822Sdim if (name[i] == '0' && isdigit(name[i+1])) 457218822Sdim return (0); 458218822Sdim while (isdigit(name[i])) { 459218822Sdim u *= 10; 460218822Sdim u += name[i++] - '0'; 461218822Sdim } 462218822Sdim if (u > 0xffffff) 463218822Sdim return (0); 464218822Sdim *unit = u; 465218822Sdim if (namep) 466218822Sdim *namep = &name[i]; 467130570Sobrien if (name[i]) 468130570Sobrien return (2); 46933965Sjdp return (1); 47033965Sjdp} 47133965Sjdp 47233965Sjdp/* 47333965Sjdp * Helper sysctl for devname(3). We're given a {u}dev_t and return 47478840Sobrien * the name, if any, registered by the device driver. 475104845Sobrien */ 47633965Sjdpstatic int 47733965Sjdpsysctl_devname(SYSCTL_HANDLER_ARGS) 478104845Sobrien{ 479218822Sdim int error; 480104845Sobrien udev_t ud; 481218822Sdim dev_t dev; 482218822Sdim 483218822Sdim error = SYSCTL_IN(req, &ud, sizeof (ud)); 484218822Sdim if (error) 485218822Sdim return (error); 486218822Sdim if (ud == NOUDEV) 487218822Sdim return(EINVAL); 488218822Sdim dev = makedev(umajor(ud), uminor(ud)); 489218822Sdim if (dev->si_name[0] == '\0') 490218822Sdim error = ENOENT; 491218822Sdim else 492218822Sdim error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1); 493218822Sdim freedev(dev); 494218822Sdim return (error); 495218822Sdim} 496218822Sdim 497218822SdimSYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY, 498218822Sdim NULL, 0, sysctl_devname, "", "devname(3) handler"); 499218822Sdim 500218822Sdim/* 501218822Sdim * Set ready_for_devs; prior to this point, device creation is not allowed. 502218822Sdim */ 503218822Sdimstatic void 504218822Sdimdev_set_ready(void *junk) 505218822Sdim{ 506218822Sdim ready_for_devs = 1; 507218822Sdim} 508218822Sdim 509218822SdimSYSINIT(dev_ready, SI_SUB_DEVFS, SI_ORDER_FIRST, dev_set_ready, NULL); 510218822Sdim