diff options
Diffstat (limited to 'sys/kern/kern_conf.c')
| -rw-r--r-- | sys/kern/kern_conf.c | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/sys/kern/kern_conf.c b/sys/kern/kern_conf.c new file mode 100644 index 0000000..acdf85e --- /dev/null +++ b/sys/kern/kern_conf.c @@ -0,0 +1,509 @@ +/*- + * Copyright (c) 1999-2002 Poul-Henning Kamp + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/kernel.h> +#include <sys/systm.h> +#include <sys/bio.h> +#include <sys/lock.h> +#include <sys/mutex.h> +#include <sys/sysctl.h> +#include <sys/module.h> +#include <sys/malloc.h> +#include <sys/conf.h> +#include <sys/vnode.h> +#include <sys/queue.h> +#include <sys/ctype.h> +#include <machine/stdarg.h> + +static MALLOC_DEFINE(M_DEVT, "dev_t", "dev_t storage"); + +/* Built at compile time from sys/conf/majors */ +extern unsigned char reserved_majors[256]; + +/* + * 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 cdev devt_stash[DEVT_STASH]; + +static LIST_HEAD(, cdev) dev_hash[DEVT_HASH]; + +static LIST_HEAD(, cdev) dev_free; + +static int ready_for_devs; + +static int free_devt; +SYSCTL_INT(_debug, OID_AUTO, free_devt, CTLFLAG_RW, &free_devt, 0, ""); + +/* Define a dead_cdevsw for use when devices leave unexpectedly. */ + +static int +enxio(void) +{ + return (ENXIO); +} + +#define dead_open (d_open_t *)enxio +#define dead_close (d_close_t *)enxio +#define dead_read (d_read_t *)enxio +#define dead_write (d_write_t *)enxio +#define dead_ioctl (d_ioctl_t *)enxio +#define dead_poll nopoll +#define dead_mmap nommap + +static void +dead_strategy(struct bio *bp) +{ + + biofinish(bp, NULL, ENXIO); +} + +#define dead_dump (dumper_t *)enxio + +#define dead_kqfilter (d_kqfilter_t *)enxio + +static struct cdevsw dead_cdevsw = { + .d_open = dead_open, + .d_close = dead_close, + .d_read = dead_read, + .d_write = dead_write, + .d_ioctl = dead_ioctl, + .d_poll = dead_poll, + .d_mmap = dead_mmap, + .d_strategy = dead_strategy, + .d_name = "dead", + .d_maj = 255, + .d_dump = dead_dump, + .d_kqfilter = dead_kqfilter +}; + + +struct cdevsw * +devsw(dev_t dev) +{ + if (dev->si_devsw) + return (dev->si_devsw); + return (&dead_cdevsw); +} + +/* + * 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 +dev2unit(dev_t x) +{ + int i; + + if (x == NODEV) + return NOUDEV; + i = minor(x); + return ((i & 0xff) | (i >> 8)); +} + +int +unit2minor(int unit) +{ + + KASSERT(unit <= 0xffffff, ("Invalid unit (%d) in unit2minor", unit)); + return ((unit & 0xff) | ((unit << 8) & ~0xffff)); +} + +static dev_t +allocdev(void) +{ + static int stashed; + struct cdev *si; + + if (LIST_FIRST(&dev_free)) { + si = LIST_FIRST(&dev_free); + LIST_REMOVE(si, si_hash); + } else if (stashed >= DEVT_STASH) { + MALLOC(si, struct cdev *, sizeof(*si), M_DEVT, + M_USE_RESERVE | M_ZERO | M_WAITOK); + } else { + si = devt_stash + stashed++; + bzero(si, sizeof *si); + si->si_flags |= SI_STASHED; + } + si->__si_namebuf[0] = '\0'; + si->si_name = si->__si_namebuf; + LIST_INIT(&si->si_children); + TAILQ_INIT(&si->si_snapshots); + return (si); +} + +dev_t +makedev(int x, int y) +{ + struct cdev *si; + udev_t udev; + int hash; + + if (x == umajor(NOUDEV) && y == uminor(NOUDEV)) + panic("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); + } + si = allocdev(); + si->si_udev = udev; + LIST_INSERT_HEAD(&dev_hash[hash], si, si_hash); + return (si); +} + +void +freedev(dev_t dev) +{ + + if (!free_devt) + return; + if (SLIST_FIRST(&dev->si_hlist)) + return; + if (dev->si_devsw || dev->si_drv1 || dev->si_drv2) + return; + LIST_REMOVE(dev, si_hash); + if (dev->si_flags & SI_STASHED) { + bzero(dev, sizeof(*dev)); + dev->si_flags |= SI_STASHED; + 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 (NODEV); + 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; + + KASSERT((minor & ~0xffff00ff) == 0, + ("Invalid minor (0x%x) in make_dev", minor)); + + 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_kqfilter == NULL) devsw->d_kqfilter = nokqfilter; + + if (devsw->d_maj == MAJOR_AUTO) { + for (i = NUMCDEVSW - 1; i > 0; i--) + if (reserved_majors[i] != i) + break; + KASSERT(i > 0, ("Out of major numbers (%s)", devsw->d_name)); + devsw->d_maj = i; + reserved_majors[i] = i; + } else { + if (devsw->d_maj == 256) /* XXX: tty_cons.c is magic */ + devsw->d_maj = 0; + KASSERT(devsw->d_maj >= 0 && devsw->d_maj < 256, + ("Invalid major (%d) in make_dev", devsw->d_maj)); + if (reserved_majors[devsw->d_maj] != devsw->d_maj) { + printf("WARNING: driver \"%s\" used %s %d\n", + devsw->d_name, "unreserved major device number", + devsw->d_maj); + reserved_majors[devsw->d_maj] = devsw->d_maj; + } + } + + if (!ready_for_devs) { + printf("WARNING: Driver mistake: make_dev(%s) called before SI_SUB_DRIVERS\n", + fmt); + /* XXX panic here once drivers are cleaned up */ + } + + dev = makedev(devsw->d_maj, minor); + if (dev->si_flags & SI_NAMED) { + printf( "WARNING: Driver mistake: repeat make_dev(\"%s\")\n", + dev->si_name); + panic("don't do that"); + } + va_start(ap, fmt); + i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); + if (i > (sizeof dev->__si_namebuf - 1)) { + printf("WARNING: Device name truncated! (%s)", + dev->__si_namebuf); + } + va_end(ap); + dev->si_devsw = devsw; + dev->si_uid = uid; + dev->si_gid = gid; + dev->si_mode = perms; + dev->si_flags |= SI_NAMED; + + devfs_create(dev); + return (dev); +} + +int +dev_named(dev_t pdev, const char *name) +{ + dev_t cdev; + + if (strcmp(devtoname(pdev), name) == 0) + return (1); + LIST_FOREACH(cdev, &pdev->si_children, si_siblings) + if (strcmp(devtoname(cdev), name) == 0) + return (1); + return (0); +} + +void +dev_depends(dev_t pdev, dev_t cdev) +{ + + cdev->si_parent = pdev; + cdev->si_flags |= SI_CHILD; + LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings); +} + +dev_t +make_dev_alias(dev_t pdev, const char *fmt, ...) +{ + dev_t dev; + va_list ap; + int i; + + dev = allocdev(); + dev->si_flags |= SI_ALIAS; + dev->si_flags |= SI_NAMED; + dev_depends(pdev, dev); + va_start(ap, fmt); + i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap); + if (i > (sizeof dev->__si_namebuf - 1)) { + printf("WARNING: Device name truncated! (%s)", + dev->__si_namebuf); + } + va_end(ap); + + devfs_create(dev); + return (dev); +} + +void +revoke_and_destroy_dev(dev_t dev) +{ + struct vnode *vp; + + GIANT_REQUIRED; + + vp = SLIST_FIRST(&dev->si_hlist); + if (vp != NULL) + VOP_REVOKE(vp, REVOKEALL); + destroy_dev(dev); +} + +void +destroy_dev(dev_t dev) +{ + + if (!(dev->si_flags & SI_NAMED)) { + printf( "WARNING: Driver mistake: destroy_dev on %d/%d\n", + major(dev), minor(dev)); + panic("don't do that"); + } + + devfs_destroy(dev); + if (dev->si_flags & SI_CHILD) { + LIST_REMOVE(dev, si_siblings); + dev->si_flags &= ~SI_CHILD; + } + while (!LIST_EMPTY(&dev->si_children)) + destroy_dev(LIST_FIRST(&dev->si_children)); + dev->si_drv1 = 0; + dev->si_drv2 = 0; + dev->si_devsw = 0; + bzero(&dev->__si_u, sizeof(dev->__si_u)); + dev->si_flags &= ~SI_NAMED; + dev->si_flags &= ~SI_ALIAS; + 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); +} + +int +dev_stdclone(char *name, char **namep, const char *stem, int *unit) +{ + int u, i; + + i = strlen(stem); + if (bcmp(stem, name, i) != 0) + return (0); + if (!isdigit(name[i])) + return (0); + u = 0; + if (name[i] == '0' && isdigit(name[i+1])) + return (0); + while (isdigit(name[i])) { + u *= 10; + u += name[i++] - '0'; + } + if (u > 0xffffff) + return (0); + *unit = u; + if (namep) + *namep = &name[i]; + if (name[i]) + return (2); + return (1); +} + +/* + * Helper sysctl for devname(3). We're given a {u}dev_t and return + * the name, if any, registered by the device driver. + */ +static int +sysctl_devname(SYSCTL_HANDLER_ARGS) +{ + int error; + udev_t ud; + dev_t dev; + + error = SYSCTL_IN(req, &ud, sizeof (ud)); + if (error) + return (error); + if (ud == NOUDEV) + return(EINVAL); + dev = makedev(umajor(ud), uminor(ud)); + if (dev->si_name[0] == '\0') + error = ENOENT; + else + error = SYSCTL_OUT(req, dev->si_name, strlen(dev->si_name) + 1); + freedev(dev); + return (error); +} + +SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY, + NULL, 0, sysctl_devname, "", "devname(3) handler"); + +/* + * Set ready_for_devs; prior to this point, device creation is not allowed. + */ +static void +dev_set_ready(void *junk) +{ + ready_for_devs = 1; +} + +SYSINIT(dev_ready, SI_SUB_DEVFS, SI_ORDER_FIRST, dev_set_ready, NULL); |
