kern_conf.c revision 53896
1154133Sharti/*- 2154133Sharti * Parts Copyright (c) 1995 Terrence R. Lambert 3154133Sharti * Copyright (c) 1995 Julian R. Elischer 4154133Sharti * All rights reserved. 5154133Sharti * 6154133Sharti * Redistribution and use in source and binary forms, with or without 7154133Sharti * modification, are permitted provided that the following conditions 8154133Sharti * are met: 9154133Sharti * 1. Redistributions of source code must retain the above copyright 10154133Sharti * notice, this list of conditions and the following disclaimer. 11154133Sharti * 2. Redistributions in binary form must reproduce the above copyright 12154133Sharti * notice, this list of conditions and the following disclaimer in the 13154133Sharti * documentation and/or other materials provided with the distribution. 14154133Sharti * 3. All advertising materials mentioning features or use of this software 15154133Sharti * must display the following acknowledgement: 16154133Sharti * This product includes software developed by Terrence R. Lambert. 17154133Sharti * 4. The name Terrence R. Lambert may not be used to endorse or promote 18154133Sharti * products derived from this software without specific prior written 19154133Sharti * permission. 20154133Sharti * 21154133Sharti * THIS SOFTWARE IS PROVIDED BY Julian R. Elischer ``AS IS'' AND ANY 22154133Sharti * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23154133Sharti * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24154133Sharti * ARE DISCLAIMED. IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE 25154133Sharti * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26154133Sharti * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27154133Sharti * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28154133Sharti * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29154133Sharti * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30154133Sharti * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31154133Sharti * SUCH DAMAGE. 32154133Sharti * 33154133Sharti * $FreeBSD: head/sys/kern/kern_conf.c 53896 1999-11-29 20:50:58Z phk $ 34154133Sharti */ 35160341Sharti 36154133Sharti#include <sys/param.h> 37154133Sharti#include <sys/kernel.h> 38154133Sharti#include <sys/sysctl.h> 39154133Sharti#include <sys/systm.h> 40154133Sharti#include <sys/module.h> 41154133Sharti#include <sys/malloc.h> 42154133Sharti#include <sys/conf.h> 43154133Sharti#include <sys/vnode.h> 44154133Sharti#include <sys/queue.h> 45154133Sharti#include <machine/stdarg.h> 46154133Sharti 47154133Sharti#define cdevsw_ALLOCSTART (NUMCDEVSW/2) 48154133Sharti 49154133Shartistruct cdevsw *cdevsw[NUMCDEVSW]; 50154133Sharti 51154133Shartistatic int bmaj2cmaj[NUMCDEVSW]; 52154133Sharti 53154133ShartiMALLOC_DEFINE(M_DEVT, "dev_t", "dev_t storage"); 54160341Sharti 55154133Sharti/* 56154133Sharti * This is the number of hash-buckets. Experiements with 'real-life' 57154133Sharti * udev_t's show that a prime halfway between two powers of two works 58154133Sharti * best. 59154133Sharti */ 60160341Sharti#define DEVT_HASH 83 61160341Sharti 62160341Sharti/* The number of dev_t's we can create before malloc(9) kick in. */ 63160341Sharti#define DEVT_STASH 50 64160341Sharti 65160341Shartistatic struct specinfo devt_stash[DEVT_STASH]; 66154133Sharti 67154133Shartistatic LIST_HEAD(, specinfo) dev_hash[DEVT_HASH]; 68154133Sharti 69154133Shartistatic LIST_HEAD(, specinfo) dev_free; 70154133Sharti 71154133Shartidevfs_create_t *devfs_create_hook; 72154133Shartidevfs_remove_t *devfs_remove_hook; 73154133Sharti 74154133Shartistatic int free_devt; 75154133ShartiSYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, ""); 76154133Sharti 77154133Shartistruct cdevsw * 78154133Shartidevsw(dev_t dev) 79154133Sharti{ 80154133Sharti if (dev->si_devsw) 81154133Sharti return (dev->si_devsw); 82154133Sharti return(cdevsw[major(dev)]); 83154133Sharti} 84154133Sharti 85154133Sharti/* 86154133Sharti * Add a cdevsw entry 87154133Sharti */ 88295435Skib 89154133Shartiint 90154133Sharticdevsw_add(struct cdevsw *newentry) 91154133Sharti{ 92154133Sharti int i; 93154133Sharti static int setup; 94154133Sharti 95154133Sharti if (!setup) { 96160341Sharti for (i = 0; i < NUMCDEVSW; i++) 97154133Sharti if (!bmaj2cmaj[i]) 98160341Sharti bmaj2cmaj[i] = 254; 99154133Sharti setup++; 100160341Sharti } 101160341Sharti 102160341Sharti if (newentry->d_maj < 0 || newentry->d_maj >= NUMCDEVSW) { 103160341Sharti printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n", 104160341Sharti newentry->d_name, newentry->d_maj); 105160341Sharti return (EINVAL); 106160341Sharti } 107160341Sharti if (newentry->d_bmaj >= NUMCDEVSW) { 108160341Sharti printf("%s: ERROR: driver has bogus cdevsw->d_bmaj = %d\n", 109160341Sharti newentry->d_name, newentry->d_bmaj); 110160341Sharti return (EINVAL); 111160341Sharti } 112160341Sharti if (newentry->d_bmaj >= 0 && (newentry->d_flags & D_DISK) == 0) { 113160341Sharti printf("ERROR: \"%s\" bmaj but is not a disk\n", 114160341Sharti newentry->d_name); 115160341Sharti return (EINVAL); 116160341Sharti } 117160341Sharti 118154133Sharti if (cdevsw[newentry->d_maj]) { 119154133Sharti printf("WARNING: \"%s\" is usurping \"%s\"'s cdevsw[]\n", 120154133Sharti newentry->d_name, cdevsw[newentry->d_maj]->d_name); 121154133Sharti } 122154133Sharti 123160341Sharti cdevsw[newentry->d_maj] = newentry; 124160341Sharti 125160341Sharti if (newentry->d_bmaj < 0) 126160341Sharti return (0); 127154133Sharti 128154133Sharti if (bmaj2cmaj[newentry->d_bmaj] != 254) { 129160341Sharti printf("WARNING: \"%s\" is usurping \"%s\"'s bmaj\n", 130154133Sharti newentry->d_name, 131160341Sharti cdevsw[bmaj2cmaj[newentry->d_bmaj]]->d_name); 132154133Sharti } 133154133Sharti bmaj2cmaj[newentry->d_bmaj] = newentry->d_maj; 134154133Sharti return (0); 135160341Sharti} 136160341Sharti 137160341Sharti/* 138154133Sharti * Remove a cdevsw entry 139154133Sharti */ 140154133Sharti 141154133Shartiint 142154133Sharticdevsw_remove(struct cdevsw *oldentry) 143154133Sharti{ 144154133Sharti if (oldentry->d_maj < 0 || oldentry->d_maj >= NUMCDEVSW) { 145154133Sharti printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n", 146154133Sharti oldentry->d_name, oldentry->d_maj); 147154133Sharti return EINVAL; 148154133Sharti } 149154133Sharti 150154133Sharti cdevsw[oldentry->d_maj] = NULL; 151160341Sharti 152160341Sharti if (oldentry->d_bmaj >= 0 && oldentry->d_bmaj < NUMCDEVSW) 153154133Sharti bmaj2cmaj[oldentry->d_bmaj] = 254; 154154133Sharti 155154133Sharti return 0; 156154133Sharti} 157154133Sharti 158154133Sharti/* 159154133Sharti * dev_t and u_dev_t primitives 160154133Sharti */ 161154133Sharti 162154133Shartiint 163154133Shartimajor(dev_t x) 164154133Sharti{ 165154133Sharti if (x == NODEV) 166154133Sharti return NOUDEV; 167154133Sharti return((x->si_udev >> 8) & 0xff); 168154133Sharti} 169154133Sharti 170154133Shartiint 171154133Shartiminor(dev_t x) 172154133Sharti{ 173154133Sharti if (x == NODEV) 174154133Sharti return NOUDEV; 175154133Sharti return(x->si_udev & 0xffff00ff); 176154133Sharti} 177154133Sharti 178154133Shartiint 179154133Shartilminor(dev_t x) 180154133Sharti{ 181154133Sharti int i; 182154133Sharti 183154133Sharti if (x == NODEV) 184154133Sharti return NOUDEV; 185154133Sharti i = minor(x); 186154133Sharti return ((i & 0xff) | (i >> 8)); 187154133Sharti} 188154133Sharti 189154133Shartidev_t 190154133Shartimakebdev(int x, int y) 191154133Sharti{ 192154133Sharti return (makedev(bmaj2cmaj[x], y)); 193154133Sharti} 194154133Sharti 195154133Shartidev_t 196154133Shartimakedev(int x, int y) 197154133Sharti{ 198154133Sharti struct specinfo *si; 199154133Sharti udev_t udev; 200154133Sharti int hash; 201154133Sharti static int stashed; 202154133Sharti 203154133Sharti udev = (x << 8) | y; 204154133Sharti hash = udev % DEVT_HASH; 205154133Sharti LIST_FOREACH(si, &dev_hash[hash], si_hash) { 206154133Sharti if (si->si_udev == udev) 207154133Sharti return (si); 208154133Sharti } 209154133Sharti if (stashed >= DEVT_STASH) { 210154133Sharti MALLOC(si, struct specinfo *, sizeof(*si), M_DEVT, 211154133Sharti M_USE_RESERVE); 212154133Sharti bzero(si, sizeof(*si)); 213154133Sharti } else if (LIST_FIRST(&dev_free)) { 214154133Sharti si = LIST_FIRST(&dev_free); 215154133Sharti LIST_REMOVE(si, si_hash); 216154133Sharti } else { 217154133Sharti si = devt_stash + stashed++; 218154133Sharti si->si_flags |= SI_STASHED; 219154133Sharti } 220154133Sharti si->si_udev = udev; 221228990Suqs LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); 222154133Sharti return (si); 223154133Sharti} 224154133Sharti 225154133Shartivoid 226154133Shartifreedev(dev_t dev) 227154133Sharti{ 228154133Sharti int hash; 229154133Sharti 230154133Sharti if (!free_devt) 231154133Sharti return; 232154133Sharti if (SLIST_FIRST(&dev->si_hlist)) 233154133Sharti return; 234154133Sharti if (dev->si_devsw || dev->si_drv1 || dev->si_drv2) 235154133Sharti return; 236154133Sharti hash = dev->si_udev % DEVT_HASH; 237154133Sharti LIST_REMOVE(dev, si_hash); 238154133Sharti if (dev->si_flags & SI_STASHED) { 239154133Sharti bzero(dev, sizeof(*dev)); 240154133Sharti LIST_INSERT_HEAD(&dev_free, dev, si_hash); 241154133Sharti } else { 242154133Sharti FREE(dev, M_DEVT); 243154133Sharti } 244154133Sharti} 245154133Sharti 246154133Shartiudev_t 247154133Shartidev2udev(dev_t x) 248154133Sharti{ 249154133Sharti if (x == NODEV) 250154133Sharti return NOUDEV; 251154133Sharti return (x->si_udev); 252154133Sharti} 253154133Sharti 254154133Shartiudev_t 255160341Shartidev2budev(dev_t x) 256160341Sharti{ 257160341Sharti if (x == NODEV) 258154133Sharti return NOUDEV; 259154133Sharti else 260154133Sharti return makeudev(devsw(x)->d_bmaj, minor(x)); 261154133Sharti} 262154133Sharti 263154133Shartidev_t 264154133Shartiudev2dev(udev_t x, int b) 265154133Sharti{ 266154133Sharti switch (b) { 267154133Sharti case 0: 268154133Sharti return makedev(umajor(x), uminor(x)); 269154133Sharti case 1: 270154133Sharti return makebdev(umajor(x), uminor(x)); 271154133Sharti default: 272154133Sharti Debugger("udev2dev(...,X)"); 273154133Sharti return NODEV; 274154133Sharti } 275154133Sharti} 276154133Sharti 277154133Shartiint 278154133Shartiuminor(udev_t dev) 279154133Sharti{ 280154133Sharti return(dev & 0xffff00ff); 281154133Sharti} 282154133Sharti 283154133Shartiint 284154133Shartiumajor(udev_t dev) 285154133Sharti{ 286154133Sharti return((dev & 0xff00) >> 8); 287154133Sharti} 288154133Sharti 289154133Shartiudev_t 290154133Shartimakeudev(int x, int y) 291154133Sharti{ 292154133Sharti return ((x << 8) | y); 293154133Sharti} 294154133Sharti 295154133Shartidev_t 296154133Shartimake_dev(struct cdevsw *devsw, int minor, uid_t uid, gid_t gid, int perms, char *fmt, ...) 297154133Sharti{ 298154133Sharti dev_t dev; 299154133Sharti va_list ap; 300154133Sharti int i; 301154133Sharti 302154133Sharti dev = makedev(devsw->d_maj, minor); 303154133Sharti va_start(ap, fmt); 304154133Sharti i = kvprintf(fmt, NULL, dev->si_name, 32, ap); 305154133Sharti dev->si_name[i] = '\0'; 306154133Sharti va_end(ap); 307154133Sharti dev->si_devsw = devsw; 308154133Sharti 309154133Sharti if (devfs_create_hook) 310154133Sharti devfs_create_hook(dev, uid, gid, perms); 311154133Sharti return (dev); 312154133Sharti} 313154133Sharti 314154133Shartivoid 315154133Shartidestroy_dev(dev_t dev) 316154133Sharti{ 317154133Sharti if (devfs_remove_hook) 318154133Sharti devfs_remove_hook(dev); 319154133Sharti dev->si_drv1 = 0; 320154133Sharti dev->si_drv2 = 0; 321154133Sharti dev->si_devsw = 0; 322154133Sharti freedev(dev); 323154133Sharti} 324154133Sharti 325const char * 326devtoname(dev_t dev) 327{ 328 char *p; 329 int mynor; 330 331 if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { 332 p = dev->si_name; 333 if (devsw(dev)) 334 sprintf(p, "#%s/", devsw(dev)->d_name); 335 else 336 sprintf(p, "#%d/", major(dev)); 337 p += strlen(p); 338 mynor = minor(dev); 339 if (mynor < 0 || mynor > 255) 340 sprintf(p, "%#x", (u_int)mynor); 341 else 342 sprintf(p, "%d", mynor); 343 } 344 return (dev->si_name); 345} 346