2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1999-2002 Poul-Henning Kamp
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/kernel.h>
34 #include <sys/systm.h>
38 #include <sys/mutex.h>
39 #include <sys/module.h>
40 #include <sys/malloc.h>
42 #include <sys/vnode.h>
43 #include <sys/queue.h>
46 #include <sys/ctype.h>
47 #include <sys/ucred.h>
48 #include <sys/taskqueue.h>
49 #include <machine/stdarg.h>
51 #include <fs/devfs/devfs_int.h>
54 static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
57 static void destroy_devl(struct cdev *dev);
58 static int destroy_dev_sched_cbl(struct cdev *dev,
59 void (*cb)(void *), void *arg);
60 static void destroy_dev_tq(void *ctx, int pending);
61 static int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw,
62 int unit, struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
65 static struct cdev_priv_list cdevp_free_list =
66 TAILQ_HEAD_INITIALIZER(cdevp_free_list);
67 static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
68 SLIST_HEAD_INITIALIZER(cdevsw_gt_post_list);
78 * Free all the memory collected while the cdev mutex was
79 * locked. Since devmtx is after the system map mutex, free() cannot
80 * be called immediately and is postponed until cdev mutex can be
84 dev_unlock_and_free(void)
86 struct cdev_priv_list cdp_free;
87 struct free_cdevsw csw_free;
88 struct cdev_priv *cdp;
91 mtx_assert(&devmtx, MA_OWNED);
94 * Make the local copy of the list heads while the dev_mtx is
95 * held. Free it later.
97 TAILQ_INIT(&cdp_free);
98 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list);
99 csw_free = cdevsw_gt_post_list;
100 SLIST_INIT(&cdevsw_gt_post_list);
104 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
105 TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
106 devfs_free(&cdp->cdp_c);
108 while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
109 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
115 dev_free_devlocked(struct cdev *cdev)
117 struct cdev_priv *cdp;
119 mtx_assert(&devmtx, MA_OWNED);
120 cdp = cdev2priv(cdev);
121 KASSERT((cdp->cdp_flags & CDP_UNREF_DTR) == 0,
122 ("destroy_dev() was not called after delist_dev(%p)", cdev));
123 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
127 cdevsw_free_devlocked(struct cdevsw *csw)
130 mtx_assert(&devmtx, MA_OWNED);
131 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
142 dev_ref(struct cdev *dev)
145 mtx_assert(&devmtx, MA_NOTOWNED);
152 dev_refl(struct cdev *dev)
155 mtx_assert(&devmtx, MA_OWNED);
160 dev_rel(struct cdev *dev)
164 mtx_assert(&devmtx, MA_NOTOWNED);
167 KASSERT(dev->si_refcount >= 0,
168 ("dev_rel(%s) gave negative count", devtoname(dev)));
170 if (dev->si_usecount == 0 &&
171 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED))
175 if (dev->si_devsw == NULL && dev->si_refcount == 0) {
176 LIST_REMOVE(dev, si_list);
185 dev_refthread(struct cdev *dev, int *ref)
188 struct cdev_priv *cdp;
190 mtx_assert(&devmtx, MA_NOTOWNED);
191 if ((dev->si_flags & SI_ETERNAL) != 0) {
193 return (dev->si_devsw);
198 cdp = cdev2priv(dev);
199 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
200 atomic_add_long(&dev->si_threadcount, 1);
210 devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
213 struct cdev_priv *cdp;
216 mtx_assert(&devmtx, MA_NOTOWNED);
217 if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
221 KASSERT((dev->si_flags & SI_ETERNAL) != 0,
222 ("Not eternal cdev"));
225 KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
237 cdp = cdev2priv(dev);
238 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
241 atomic_add_long(&dev->si_threadcount, 1);
252 dev_relthread(struct cdev *dev, int ref)
255 mtx_assert(&devmtx, MA_NOTOWNED);
258 KASSERT(dev->si_threadcount > 0,
259 ("%s threadcount is wrong", dev->si_name));
260 atomic_subtract_rel_long(&dev->si_threadcount, 1);
289 /* Define a dead_cdevsw for use when devices leave unexpectedly. */
291 #define dead_open (d_open_t *)enxio
292 #define dead_close (d_close_t *)enxio
293 #define dead_read (d_read_t *)enxio
294 #define dead_write (d_write_t *)enxio
295 #define dead_ioctl (d_ioctl_t *)enxio
296 #define dead_poll (d_poll_t *)enodev
297 #define dead_mmap (d_mmap_t *)enodev
300 dead_strategy(struct bio *bp)
303 biofinish(bp, NULL, ENXIO);
306 #define dead_dump (dumper_t *)enxio
307 #define dead_kqfilter (d_kqfilter_t *)enxio
308 #define dead_mmap_single (d_mmap_single_t *)enodev
310 static struct cdevsw dead_cdevsw = {
311 .d_version = D_VERSION,
313 .d_close = dead_close,
315 .d_write = dead_write,
316 .d_ioctl = dead_ioctl,
319 .d_strategy = dead_strategy,
322 .d_kqfilter = dead_kqfilter,
323 .d_mmap_single = dead_mmap_single
326 /* Default methods if driver does not specify method */
328 #define null_open (d_open_t *)nullop
329 #define null_close (d_close_t *)nullop
330 #define no_read (d_read_t *)enodev
331 #define no_write (d_write_t *)enodev
332 #define no_ioctl (d_ioctl_t *)enodev
333 #define no_mmap (d_mmap_t *)enodev
334 #define no_kqfilter (d_kqfilter_t *)enodev
335 #define no_mmap_single (d_mmap_single_t *)enodev
338 no_strategy(struct bio *bp)
341 biofinish(bp, NULL, ENODEV);
345 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
348 return (poll_no_poll(events));
351 #define no_dump (dumper_t *)enodev
354 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
359 dsw = dev_refthread(dev, &ref);
363 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
365 dev_relthread(dev, ref);
370 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
375 dsw = dev_refthread(dev, &ref);
379 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
381 dev_relthread(dev, ref);
386 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
391 dsw = dev_refthread(dev, &ref);
395 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
397 dev_relthread(dev, ref);
402 giant_strategy(struct bio *bp)
409 dsw = dev_refthread(dev, &ref);
411 biofinish(bp, NULL, ENXIO);
415 dsw->d_gianttrick->d_strategy(bp);
417 dev_relthread(dev, ref);
421 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
426 dsw = dev_refthread(dev, &ref);
430 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
432 dev_relthread(dev, ref);
437 giant_read(struct cdev *dev, struct uio *uio, int ioflag)
442 dsw = dev_refthread(dev, &ref);
446 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
448 dev_relthread(dev, ref);
453 giant_write(struct cdev *dev, struct uio *uio, int ioflag)
458 dsw = dev_refthread(dev, &ref);
462 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
464 dev_relthread(dev, ref);
469 giant_poll(struct cdev *dev, int events, struct thread *td)
474 dsw = dev_refthread(dev, &ref);
478 retval = dsw->d_gianttrick->d_poll(dev, events, td);
480 dev_relthread(dev, ref);
485 giant_kqfilter(struct cdev *dev, struct knote *kn)
490 dsw = dev_refthread(dev, &ref);
494 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
496 dev_relthread(dev, ref);
501 giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot,
502 vm_memattr_t *memattr)
507 dsw = dev_refthread(dev, &ref);
511 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot,
514 dev_relthread(dev, ref);
519 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
520 vm_object_t *object, int nprot)
525 dsw = dev_refthread(dev, &ref);
529 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
532 dev_relthread(dev, ref);
537 notify(struct cdev *dev, const char *ev, int flags)
539 static const char prefix[] = "cdev=";
545 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
546 namelen = strlen(dev->si_name);
547 data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
550 memcpy(data, prefix, sizeof(prefix) - 1);
551 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
552 devctl_notify_f("DEVFS", "CDEV", ev, data, mflags);
557 notify_create(struct cdev *dev, int flags)
560 notify(dev, "CREATE", flags);
564 notify_destroy(struct cdev *dev)
567 notify(dev, "DESTROY", MAKEDEV_WAITOK);
571 newdev(struct make_dev_args *args, struct cdev *si)
576 mtx_assert(&devmtx, MA_OWNED);
577 csw = args->mda_devsw;
578 if (csw->d_flags & D_NEEDMINOR) {
579 /* We may want to return an existing device */
580 LIST_FOREACH(si2, &csw->d_devs, si_list) {
581 if (dev2unit(si2) == args->mda_unit) {
582 dev_free_devlocked(si);
587 si->si_drv0 = args->mda_unit;
589 si->si_drv1 = args->mda_si_drv1;
590 si->si_drv2 = args->mda_si_drv2;
591 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
596 fini_cdevsw(struct cdevsw *devsw)
600 if (devsw->d_gianttrick != NULL) {
601 gt = devsw->d_gianttrick;
602 memcpy(devsw, gt, sizeof *devsw);
603 cdevsw_free_devlocked(gt);
604 devsw->d_gianttrick = NULL;
606 devsw->d_flags &= ~D_INIT;
610 prep_cdevsw(struct cdevsw *devsw, int flags)
614 mtx_assert(&devmtx, MA_OWNED);
615 if (devsw->d_flags & D_INIT)
617 if (devsw->d_flags & D_NEEDGIANT) {
619 dsw2 = malloc(sizeof *dsw2, M_DEVT,
620 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
622 if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
626 if (devsw->d_flags & D_INIT) {
628 cdevsw_free_devlocked(dsw2);
632 if (devsw->d_version != D_VERSION_03) {
634 "WARNING: Device driver \"%s\" has wrong version %s\n",
635 devsw->d_name == NULL ? "???" : devsw->d_name,
636 "and is disabled. Recompile KLD module.");
637 devsw->d_open = dead_open;
638 devsw->d_close = dead_close;
639 devsw->d_read = dead_read;
640 devsw->d_write = dead_write;
641 devsw->d_ioctl = dead_ioctl;
642 devsw->d_poll = dead_poll;
643 devsw->d_mmap = dead_mmap;
644 devsw->d_mmap_single = dead_mmap_single;
645 devsw->d_strategy = dead_strategy;
646 devsw->d_dump = dead_dump;
647 devsw->d_kqfilter = dead_kqfilter;
650 if (devsw->d_flags & D_NEEDGIANT) {
651 if (devsw->d_gianttrick == NULL) {
652 memcpy(dsw2, devsw, sizeof *dsw2);
653 devsw->d_gianttrick = dsw2;
658 #define FIXUP(member, noop, giant) \
660 if (devsw->member == NULL) { \
661 devsw->member = noop; \
662 } else if (devsw->d_flags & D_NEEDGIANT) \
663 devsw->member = giant; \
667 FIXUP(d_open, null_open, giant_open);
668 FIXUP(d_fdopen, NULL, giant_fdopen);
669 FIXUP(d_close, null_close, giant_close);
670 FIXUP(d_read, no_read, giant_read);
671 FIXUP(d_write, no_write, giant_write);
672 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
673 FIXUP(d_poll, no_poll, giant_poll);
674 FIXUP(d_mmap, no_mmap, giant_mmap);
675 FIXUP(d_strategy, no_strategy, giant_strategy);
676 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
677 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
679 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
681 LIST_INIT(&devsw->d_devs);
683 devsw->d_flags |= D_INIT;
686 cdevsw_free_devlocked(dsw2);
691 prep_devname(struct cdev *dev, const char *fmt, va_list ap)
694 char *from, *q, *s, *to;
696 mtx_assert(&devmtx, MA_OWNED);
698 len = vsnrprintf(dev->si_name, sizeof(dev->si_name), 32, fmt, ap);
699 if (len > sizeof(dev->si_name) - 1)
700 return (ENAMETOOLONG);
702 /* Strip leading slashes. */
703 for (from = dev->si_name; *from == '/'; from++)
706 for (to = dev->si_name; *from != '\0'; from++, to++) {
708 * Spaces and double quotation marks cause
709 * problems for the devctl(4) protocol.
710 * Reject names containing those characters.
712 if (isspace(*from) || *from == '"')
714 /* Treat multiple sequential slashes as single. */
715 while (from[0] == '/' && from[1] == '/')
717 /* Trailing slash is considered invalid. */
718 if (from[0] == '/' && from[1] == '\0')
724 if (dev->si_name[0] == '\0')
727 /* Disallow "." and ".." components. */
728 for (s = dev->si_name;;) {
729 for (q = s; *q != '/' && *q != '\0'; q++)
731 if (q - s == 1 && s[0] == '.')
733 if (q - s == 2 && s[0] == '.' && s[1] == '.')
740 if (devfs_dev_exists(dev->si_name) != 0)
747 make_dev_args_init_impl(struct make_dev_args *args, size_t sz)
755 make_dev_sv(struct make_dev_args *args1, struct cdev **dres,
756 const char *fmt, va_list ap)
758 struct cdev *dev, *dev_new;
759 struct make_dev_args args;
762 bzero(&args, sizeof(args));
763 if (sizeof(args) < args1->mda_size)
765 bcopy(args1, &args, args1->mda_size);
766 KASSERT((args.mda_flags & MAKEDEV_WAITOK) == 0 ||
767 (args.mda_flags & MAKEDEV_NOWAIT) == 0,
768 ("make_dev_sv: both WAITOK and NOWAIT specified"));
769 dev_new = devfs_alloc(args.mda_flags);
773 res = prep_cdevsw(args.mda_devsw, args.mda_flags);
779 dev = newdev(&args, dev_new);
780 if ((dev->si_flags & SI_NAMED) == 0) {
781 res = prep_devname(dev, fmt, ap);
783 if ((args.mda_flags & MAKEDEV_CHECKNAME) == 0) {
785 "make_dev_sv: bad si_name (error=%d, si_name=%s)",
788 if (dev == dev_new) {
789 LIST_REMOVE(dev, si_list);
797 if ((args.mda_flags & MAKEDEV_REF) != 0)
799 if ((args.mda_flags & MAKEDEV_ETERNAL) != 0)
800 dev->si_flags |= SI_ETERNAL;
801 if (dev->si_flags & SI_CHEAPCLONE &&
802 dev->si_flags & SI_NAMED) {
804 * This is allowed as it removes races and generally
805 * simplifies cloning devices.
808 dev_unlock_and_free();
812 KASSERT(!(dev->si_flags & SI_NAMED),
813 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
814 args.mda_devsw->d_name, dev2unit(dev), devtoname(dev)));
815 dev->si_flags |= SI_NAMED;
816 if (args.mda_cr != NULL)
817 dev->si_cred = crhold(args.mda_cr);
818 dev->si_uid = args.mda_uid;
819 dev->si_gid = args.mda_gid;
820 dev->si_mode = args.mda_mode;
823 clean_unrhdrl(devfs_inos);
824 dev_unlock_and_free();
826 notify_create(dev, args.mda_flags);
833 make_dev_s(struct make_dev_args *args, struct cdev **dres,
834 const char *fmt, ...)
840 res = make_dev_sv(args, dres, fmt, ap);
846 make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
847 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
850 struct make_dev_args args;
852 make_dev_args_init(&args);
853 args.mda_flags = flags;
854 args.mda_devsw = devsw;
858 args.mda_mode = mode;
859 args.mda_unit = unit;
860 return (make_dev_sv(&args, dres, fmt, ap));
864 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
865 const char *fmt, ...)
874 DBGSET(res, make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
877 KASSERT(res == 0 && dev != NULL,
878 ("make_dev: failed make_dev_credv (error=%d)", res));
883 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
884 gid_t gid, int mode, const char *fmt, ...)
893 DBGSET(res, make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap));
896 KASSERT(res == 0 && dev != NULL,
897 ("make_dev_cred: failed make_dev_credv (error=%d)", res));
902 make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
903 uid_t uid, gid_t gid, int mode, const char *fmt, ...)
910 res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
914 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
915 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
916 ("make_dev_credf: failed make_dev_credv (error=%d)", res));
917 return (res == 0 ? dev : NULL);
921 make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
922 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
928 res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
932 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
933 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
934 ("make_dev_p: failed make_dev_credv (error=%d)", res));
939 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
942 cdev->si_parent = pdev;
943 cdev->si_flags |= SI_CHILD;
944 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
949 dev_depends(struct cdev *pdev, struct cdev *cdev)
953 dev_dependsl(pdev, cdev);
958 make_dev_alias_v(int flags, struct cdev **cdev, struct cdev *pdev,
959 const char *fmt, va_list ap)
964 KASSERT(pdev != NULL, ("make_dev_alias_v: pdev is NULL"));
965 KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
966 ("make_dev_alias_v: both WAITOK and NOWAIT specified"));
967 KASSERT((flags & ~(MAKEDEV_WAITOK | MAKEDEV_NOWAIT |
968 MAKEDEV_CHECKNAME)) == 0,
969 ("make_dev_alias_v: invalid flags specified (flags=%02x)", flags));
971 dev = devfs_alloc(flags);
975 dev->si_flags |= SI_ALIAS;
976 error = prep_devname(dev, fmt, ap);
978 if ((flags & MAKEDEV_CHECKNAME) == 0) {
979 panic("make_dev_alias_v: bad si_name "
980 "(error=%d, si_name=%s)", error, dev->si_name);
986 dev->si_flags |= SI_NAMED;
988 dev_dependsl(pdev, dev);
989 clean_unrhdrl(devfs_inos);
992 notify_create(dev, flags);
999 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
1007 DBGSET(res, make_dev_alias_v(MAKEDEV_WAITOK, &dev, pdev, fmt, ap));
1010 KASSERT(res == 0 && dev != NULL,
1011 ("make_dev_alias: failed make_dev_alias_v (error=%d)", res));
1016 make_dev_alias_p(int flags, struct cdev **cdev, struct cdev *pdev,
1017 const char *fmt, ...)
1023 res = make_dev_alias_v(flags, cdev, pdev, fmt, ap);
1029 make_dev_physpath_alias(int flags, struct cdev **cdev, struct cdev *pdev,
1030 struct cdev *old_alias, const char *physpath)
1034 int max_parentpath_len;
1036 int devfspathbuf_len;
1042 physpath_len = strlen(physpath);
1044 if (physpath_len == 0)
1047 if (strncmp("id1,", physpath, 4) == 0) {
1050 if (physpath_len == 0)
1054 max_parentpath_len = SPECNAMELEN - physpath_len - /*/*/1;
1055 parentpath_len = strlen(pdev->si_name);
1056 if (max_parentpath_len < parentpath_len) {
1058 printf("WARNING: Unable to alias %s "
1059 "to %s/%s - path too long\n",
1060 pdev->si_name, physpath, pdev->si_name);
1065 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
1066 devfspathbuf_len = physpath_len + /*/*/1 + parentpath_len + /*NUL*/1;
1067 devfspath = malloc(devfspathbuf_len, M_DEVBUF, mflags);
1068 if (devfspath == NULL) {
1073 sprintf(devfspath, "%s/%s", physpath, pdev->si_name);
1074 if (old_alias != NULL && strcmp(old_alias->si_name, devfspath) == 0) {
1075 /* Retain the existing alias. */
1080 ret = make_dev_alias_p(flags, cdev, pdev, "%s", devfspath);
1083 if (old_alias != NULL)
1084 destroy_dev(old_alias);
1085 if (devfspath != NULL)
1086 free(devfspath, M_DEVBUF);
1091 destroy_devl(struct cdev *dev)
1094 struct cdev_privdata *p;
1095 struct cdev_priv *cdp;
1097 mtx_assert(&devmtx, MA_OWNED);
1098 KASSERT(dev->si_flags & SI_NAMED,
1099 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
1100 KASSERT((dev->si_flags & SI_ETERNAL) == 0,
1101 ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
1104 cdp = cdev2priv(dev);
1105 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1107 * Avoid race with dev_rel(), e.g. from the populate
1108 * loop. If CDP_UNREF_DTR flag is set, the reference
1109 * to be dropped at the end of destroy_devl() was
1110 * already taken by delist_dev_locked().
1117 /* Remove name marking */
1118 dev->si_flags &= ~SI_NAMED;
1120 /* If we are a child, remove us from the parents list */
1121 if (dev->si_flags & SI_CHILD) {
1122 LIST_REMOVE(dev, si_siblings);
1123 dev->si_flags &= ~SI_CHILD;
1126 /* Kill our children */
1127 while (!LIST_EMPTY(&dev->si_children))
1128 destroy_devl(LIST_FIRST(&dev->si_children));
1130 /* Remove from clone list */
1131 if (dev->si_flags & SI_CLONELIST) {
1132 LIST_REMOVE(dev, si_clone);
1133 dev->si_flags &= ~SI_CLONELIST;
1136 csw = dev->si_devsw;
1137 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
1138 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
1140 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
1141 if (dev->si_threadcount)
1142 printf("Still %lu threads in %s\n",
1143 dev->si_threadcount, devtoname(dev));
1145 while (dev->si_threadcount != 0) {
1146 /* Use unique dummy wait ident */
1147 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
1151 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1152 /* avoid out of order notify events */
1153 notify_destroy(dev);
1155 mtx_lock(&cdevpriv_mtx);
1156 while ((p = LIST_FIRST(&cdp->cdp_fdpriv)) != NULL) {
1157 devfs_destroy_cdevpriv(p);
1158 mtx_lock(&cdevpriv_mtx);
1160 mtx_unlock(&cdevpriv_mtx);
1165 bzero(&dev->__si_u, sizeof(dev->__si_u));
1167 if (!(dev->si_flags & SI_ALIAS)) {
1168 /* Remove from cdevsw list */
1169 LIST_REMOVE(dev, si_list);
1171 /* If cdevsw has no more struct cdev *'s, clean it */
1172 if (LIST_EMPTY(&csw->d_devs)) {
1174 wakeup(&csw->d_devs);
1177 dev->si_flags &= ~SI_ALIAS;
1178 cdp->cdp_flags &= ~CDP_UNREF_DTR;
1181 if (dev->si_refcount > 0)
1182 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
1184 dev_free_devlocked(dev);
1188 delist_dev_locked(struct cdev *dev)
1190 struct cdev_priv *cdp;
1193 mtx_assert(&devmtx, MA_OWNED);
1194 cdp = cdev2priv(dev);
1195 if ((cdp->cdp_flags & CDP_UNREF_DTR) != 0)
1197 cdp->cdp_flags |= CDP_UNREF_DTR;
1200 LIST_FOREACH(child, &dev->si_children, si_siblings)
1201 delist_dev_locked(child);
1203 /* ensure the destroy event is queued in order */
1204 notify_destroy(dev);
1209 * This function will delist a character device and its children from
1210 * the directory listing and create a destroy event without waiting
1211 * for all character device references to go away. At some later point
1212 * destroy_dev() must be called to complete the character device
1213 * destruction. After calling this function the character device name
1214 * can instantly be re-used.
1217 delist_dev(struct cdev *dev)
1220 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "delist_dev");
1222 delist_dev_locked(dev);
1227 destroy_dev(struct cdev *dev)
1230 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
1233 dev_unlock_and_free();
1237 devtoname(struct cdev *dev)
1240 return (dev->si_name);
1244 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
1249 if (bcmp(stem, name, i) != 0)
1251 if (!isdigit(name[i]))
1254 if (name[i] == '0' && isdigit(name[i+1]))
1256 while (isdigit(name[i])) {
1258 u += name[i++] - '0';
1271 * Helper functions for cloning device drivers.
1273 * The objective here is to make it unnecessary for the device drivers to
1274 * use rman or similar to manage their unit number space. Due to the way
1275 * we do "on-demand" devices, using rman or other "private" methods
1276 * will be very tricky to lock down properly once we lock down this file.
1278 * Instead we give the drivers these routines which puts the struct cdev *'s
1279 * that are to be managed on their own list, and gives the driver the ability
1280 * to ask for the first free unit number or a given specified unit number.
1282 * In addition these routines support paired devices (pty, nmdm and similar)
1283 * by respecting a number of "flag" bits in the minor number.
1288 LIST_HEAD(,cdev) head;
1292 clone_setup(struct clonedevs **cdp)
1295 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1296 LIST_INIT(&(*cdp)->head);
1300 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
1301 struct cdev **dp, int extra)
1303 struct clonedevs *cd;
1304 struct cdev *dev, *ndev, *dl, *de;
1305 struct make_dev_args args;
1308 KASSERT(*cdp != NULL,
1309 ("clone_setup() not called in driver \"%s\"", csw->d_name));
1310 KASSERT(!(extra & CLONE_UNITMASK),
1311 ("Illegal extra bits (0x%x) in clone_create", extra));
1312 KASSERT(*up <= CLONE_UNITMASK,
1313 ("Too high unit (0x%x) in clone_create", *up));
1314 KASSERT(csw->d_flags & D_NEEDMINOR,
1315 ("clone_create() on cdevsw without minor numbers"));
1319 * Search the list for a lot of things in one go:
1320 * A preexisting match is returned immediately.
1321 * The lowest free unit number if we are passed -1, and the place
1322 * in the list where we should insert that new element.
1323 * The place to insert a specified unit number, if applicable
1324 * the end of the list.
1327 ndev = devfs_alloc(MAKEDEV_WAITOK);
1329 prep_cdevsw(csw, MAKEDEV_WAITOK);
1333 LIST_FOREACH(dev, &cd->head, si_clone) {
1334 KASSERT(dev->si_flags & SI_CLONELIST,
1335 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1337 if (u == (unit | extra)) {
1343 if (unit == -1 && u == low) {
1347 } else if (u < (unit | extra)) {
1350 } else if (u > (unit | extra)) {
1356 unit = low & CLONE_UNITMASK;
1357 make_dev_args_init(&args);
1358 args.mda_unit = unit | extra;
1359 args.mda_devsw = csw;
1360 dev = newdev(&args, ndev);
1361 if (dev->si_flags & SI_CLONELIST) {
1362 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1363 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1364 LIST_FOREACH(dev, &cd->head, si_clone) {
1365 printf("\t%p %s\n", dev, dev->si_name);
1369 KASSERT(!(dev->si_flags & SI_CLONELIST),
1370 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1372 LIST_INSERT_BEFORE(dl, dev, si_clone);
1373 else if (de != NULL)
1374 LIST_INSERT_AFTER(de, dev, si_clone);
1376 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1377 dev->si_flags |= SI_CLONELIST;
1379 dev_unlock_and_free();
1384 * Kill everything still on the list. The driver should already have
1385 * disposed of any softc hung of the struct cdev *'s at this time.
1388 clone_cleanup(struct clonedevs **cdp)
1391 struct cdev_priv *cp;
1392 struct clonedevs *cd;
1398 while (!LIST_EMPTY(&cd->head)) {
1399 dev = LIST_FIRST(&cd->head);
1400 LIST_REMOVE(dev, si_clone);
1401 KASSERT(dev->si_flags & SI_CLONELIST,
1402 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1403 dev->si_flags &= ~SI_CLONELIST;
1404 cp = cdev2priv(dev);
1405 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1406 cp->cdp_flags |= CDP_SCHED_DTR;
1407 KASSERT(dev->si_flags & SI_NAMED,
1408 ("Driver has goofed in cloning underways udev %jx unit %x",
1409 (uintmax_t)dev2udev(dev), dev2unit(dev)));
1413 dev_unlock_and_free();
1418 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1419 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1420 static struct task dev_dtr_task = TASK_INITIALIZER(0, destroy_dev_tq, NULL);
1423 destroy_dev_tq(void *ctx, int pending)
1425 struct cdev_priv *cp;
1431 while (!TAILQ_EMPTY(&dev_ddtr)) {
1432 cp = TAILQ_FIRST(&dev_ddtr);
1434 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1435 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1436 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1437 cb = cp->cdp_dtr_cb;
1438 cb_arg = cp->cdp_dtr_cb_arg;
1440 dev_unlock_and_free();
1450 * devmtx shall be locked on entry. devmtx will be unlocked after
1454 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1456 struct cdev_priv *cp;
1458 mtx_assert(&devmtx, MA_OWNED);
1459 cp = cdev2priv(dev);
1460 if (cp->cdp_flags & CDP_SCHED_DTR) {
1465 cp->cdp_flags |= CDP_SCHED_DTR;
1466 cp->cdp_dtr_cb = cb;
1467 cp->cdp_dtr_cb_arg = arg;
1468 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1470 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1475 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1479 return (destroy_dev_sched_cbl(dev, cb, arg));
1483 destroy_dev_sched(struct cdev *dev)
1486 return (destroy_dev_sched_cb(dev, NULL, NULL));
1490 destroy_dev_drain(struct cdevsw *csw)
1494 while (!LIST_EMPTY(&csw->d_devs)) {
1495 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1501 drain_dev_clone_events(void)
1504 sx_xlock(&clone_drain_lock);
1505 sx_xunlock(&clone_drain_lock);
1508 #include "opt_ddb.h"
1510 #include <sys/kernel.h>
1512 #include <ddb/ddb.h>
1514 DB_SHOW_COMMAND(cdev, db_show_cdev)
1516 struct cdev_priv *cdp;
1522 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
1524 db_printf("%s %p\n", dev->si_name, dev);
1531 dev = (struct cdev *)addr;
1532 cdp = cdev2priv(dev);
1533 db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
1534 dev->si_name, dev->si_refcount, dev->si_usecount,
1535 dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
1536 db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
1537 dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
1538 flags = dev->si_flags;
1539 #define SI_FLAG(flag) do { \
1540 if (flags & (flag)) { \
1541 if (buf[0] != '\0') \
1542 strlcat(buf, ", ", sizeof(buf)); \
1543 strlcat(buf, (#flag) + 3, sizeof(buf)); \
1548 SI_FLAG(SI_ETERNAL);
1551 SI_FLAG(SI_CHEAPCLONE);
1553 SI_FLAG(SI_DUMPDEV);
1554 SI_FLAG(SI_CLONELIST);
1555 db_printf("si_flags %s\n", buf);
1557 flags = cdp->cdp_flags;
1558 #define CDP_FLAG(flag) do { \
1559 if (flags & (flag)) { \
1560 if (buf[0] != '\0') \
1561 strlcat(buf, ", ", sizeof(buf)); \
1562 strlcat(buf, (#flag) + 4, sizeof(buf)); \
1567 CDP_FLAG(CDP_ACTIVE);
1568 CDP_FLAG(CDP_SCHED_DTR);
1569 db_printf("cdp_flags %s\n", buf);