/*- * Parts Copyright (c) 1995 Terrence R. Lambert * Copyright (c) 1995 Julian R. Elischer * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Terrence R. Lambert. * 4. The name Terrence R. Lambert may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED BY Julian R. Elischer ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD: src/sys/kern/kern_conf.c,v 1.73.2.3 2003/03/10 02:18:25 imp Exp $ * $DragonFly: src/sys/kern/kern_conf.c,v 1.2 2003/06/17 04:28:41 dillon Exp $ */ #include #include #include #include #include #include #include #include #include #include #define cdevsw_ALLOCSTART (NUMCDEVSW/2) struct cdevsw *cdevsw[NUMCDEVSW]; static int bmaj2cmaj[NUMCDEVSW]; MALLOC_DEFINE(M_DEVT, "dev_t", "dev_t storage"); /* * This is the number of hash-buckets. Experiements with 'real-life' * udev_t's show that a prime halfway between two powers of two works * best. */ #define DEVT_HASH 83 /* The number of dev_t's we can create before malloc(9) kick in. */ #define DEVT_STASH 50 static struct specinfo devt_stash[DEVT_STASH]; static LIST_HEAD(, specinfo) dev_hash[DEVT_HASH]; static LIST_HEAD(, specinfo) dev_free; static int free_devt; SYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, ""); struct cdevsw * devsw(dev_t dev) { if (dev->si_devsw) return (dev->si_devsw); return(cdevsw[major(dev)]); } static void compile_devsw(struct cdevsw *devsw) { if (devsw->d_open == NULL) devsw->d_open = noopen; if (devsw->d_close == NULL) devsw->d_close = noclose; if (devsw->d_read == NULL) devsw->d_read = noread; if (devsw->d_write == NULL) devsw->d_write = nowrite; if (devsw->d_ioctl == NULL) devsw->d_ioctl = noioctl; if (devsw->d_poll == NULL) devsw->d_poll = nopoll; if (devsw->d_mmap == NULL) devsw->d_mmap = nommap; if (devsw->d_strategy == NULL) devsw->d_strategy = nostrategy; if (devsw->d_dump == NULL) devsw->d_dump = nodump; if (devsw->d_psize == NULL) devsw->d_psize = nopsize; if (devsw->d_kqfilter == NULL) devsw->d_kqfilter = nokqfilter; } /* * Add a cdevsw entry */ int cdevsw_add(struct cdevsw *newentry) { int i; static int setup; if (!setup) { for (i = 0; i < NUMCDEVSW; i++) if (!bmaj2cmaj[i]) bmaj2cmaj[i] = 254; setup++; } compile_devsw(newentry); if (newentry->d_maj < 0 || newentry->d_maj >= NUMCDEVSW) { printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n", newentry->d_name, newentry->d_maj); return (EINVAL); } if (newentry->d_bmaj >= NUMCDEVSW) { printf("%s: ERROR: driver has bogus cdevsw->d_bmaj = %d\n", newentry->d_name, newentry->d_bmaj); return (EINVAL); } if (newentry->d_bmaj >= 0 && (newentry->d_flags & D_DISK) == 0) { printf("ERROR: \"%s\" bmaj but is not a disk\n", newentry->d_name); return (EINVAL); } if (cdevsw[newentry->d_maj]) { printf("WARNING: \"%s\" is usurping \"%s\"'s cdevsw[]\n", newentry->d_name, cdevsw[newentry->d_maj]->d_name); } cdevsw[newentry->d_maj] = newentry; if (newentry->d_bmaj < 0) return (0); if (bmaj2cmaj[newentry->d_bmaj] != 254) { printf("WARNING: \"%s\" is usurping \"%s\"'s bmaj\n", newentry->d_name, cdevsw[bmaj2cmaj[newentry->d_bmaj]]->d_name); } bmaj2cmaj[newentry->d_bmaj] = newentry->d_maj; return (0); } /* * Remove a cdevsw entry */ int cdevsw_remove(struct cdevsw *oldentry) { if (oldentry->d_maj < 0 || oldentry->d_maj >= NUMCDEVSW) { printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n", oldentry->d_name, oldentry->d_maj); return EINVAL; } cdevsw[oldentry->d_maj] = NULL; if (oldentry->d_bmaj >= 0 && oldentry->d_bmaj < NUMCDEVSW) bmaj2cmaj[oldentry->d_bmaj] = 254; return 0; } /* * dev_t and u_dev_t primitives */ int major(dev_t x) { if (x == NODEV) return NOUDEV; return((x->si_udev >> 8) & 0xff); } int minor(dev_t x) { if (x == NODEV) return NOUDEV; return(x->si_udev & 0xffff00ff); } int lminor(dev_t x) { int i; if (x == NODEV) return NOUDEV; i = minor(x); return ((i & 0xff) | (i >> 8)); } dev_t makebdev(int x, int y) { if (x == umajor(NOUDEV) && y == uminor(NOUDEV)) Debugger("makebdev of NOUDEV"); return (makedev(bmaj2cmaj[x], y)); } dev_t makedev(int x, int y) { struct specinfo *si; udev_t udev; int hash; static int stashed; if (x == umajor(NOUDEV) && y == uminor(NOUDEV)) Debugger("makedev of NOUDEV"); udev = (x << 8) | y; hash = udev % DEVT_HASH; LIST_FOREACH(si, &dev_hash[hash], si_hash) { if (si->si_udev == udev) return (si); } if (stashed >= DEVT_STASH) { MALLOC(si, struct specinfo *, sizeof(*si), M_DEVT, M_USE_RESERVE); bzero(si, sizeof(*si)); } else if (LIST_FIRST(&dev_free)) { si = LIST_FIRST(&dev_free); LIST_REMOVE(si, si_hash); } else { si = devt_stash + stashed++; si->si_flags |= SI_STASHED; } si->si_udev = udev; LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); return (si); } void freedev(dev_t dev) { int hash; if (!free_devt) return; if (SLIST_FIRST(&dev->si_hlist)) return; if (dev->si_devsw || dev->si_drv1 || dev->si_drv2) return; hash = dev->si_udev % DEVT_HASH; LIST_REMOVE(dev, si_hash); if (dev->si_flags & SI_STASHED) { bzero(dev, sizeof(*dev)); LIST_INSERT_HEAD(&dev_free, dev, si_hash); } else { FREE(dev, M_DEVT); } } udev_t dev2udev(dev_t x) { if (x == NODEV) return NOUDEV; return (x->si_udev); } dev_t udev2dev(udev_t x, int b) { if (x == NOUDEV) return (NODEV); switch (b) { case 0: return makedev(umajor(x), uminor(x)); case 1: return makebdev(umajor(x), uminor(x)); default: Debugger("udev2dev(...,X)"); return NODEV; } } int uminor(udev_t dev) { return(dev & 0xffff00ff); } int umajor(udev_t dev) { return((dev & 0xff00) >> 8); } udev_t makeudev(int x, int y) { return ((x << 8) | y); } dev_t make_dev(struct cdevsw *devsw, int minor, uid_t uid, gid_t gid, int perms, const char *fmt, ...) { dev_t dev; va_list ap; int i; compile_devsw(devsw); dev = makedev(devsw->d_maj, minor); va_start(ap, fmt); i = kvprintf(fmt, NULL, dev->si_name, 32, ap); dev->si_name[i] = '\0'; va_end(ap); dev->si_devsw = devsw; return (dev); } void destroy_dev(dev_t dev) { dev->si_drv1 = 0; dev->si_drv2 = 0; dev->si_devsw = 0; freedev(dev); } const char * devtoname(dev_t dev) { char *p; int mynor; if (dev->si_name[0] == '#' || dev->si_name[0] == '\0') { p = dev->si_name; if (devsw(dev)) sprintf(p, "#%s/", devsw(dev)->d_name); else sprintf(p, "#%d/", major(dev)); p += strlen(p); mynor = minor(dev); if (mynor < 0 || mynor > 255) sprintf(p, "%#x", (u_int)mynor); else sprintf(p, "%d", mynor); } return (dev->si_name); }