2 * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.h>
34 #include <sys/devctl.h>
36 #include <sys/mutex.h>
37 #include <sys/module.h>
38 #include <sys/malloc.h>
40 #include <sys/vnode.h>
41 #include <sys/queue.h>
44 #include <sys/ctype.h>
45 #include <sys/ucred.h>
46 #include <sys/taskqueue.h>
47 #include <machine/stdarg.h>
49 #include <fs/devfs/devfs_int.h>
52 static MALLOC_DEFINE(M_DEVT, "cdev", "cdev storage");
55 static void destroy_devl(struct cdev *dev);
56 static int destroy_dev_sched_cbl(struct cdev *dev,
57 void (*cb)(void *), void *arg);
58 static void destroy_dev_tq(void *ctx, int pending);
59 static void destroy_dev_tq_giant(void *ctx, int pending);
60 static int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw,
61 int unit, struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
64 static struct cdev_priv_list cdevp_free_list =
65 TAILQ_HEAD_INITIALIZER(cdevp_free_list);
66 static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
67 SLIST_HEAD_INITIALIZER(cdevsw_gt_post_list);
77 * Free all the memory collected while the cdev mutex was
78 * locked. Since devmtx is after the system map mutex, free() cannot
79 * be called immediately and is postponed until cdev mutex can be
83 dev_unlock_and_free(void)
85 struct cdev_priv_list cdp_free;
86 struct free_cdevsw csw_free;
87 struct cdev_priv *cdp;
90 dev_lock_assert_locked();
93 * Make the local copy of the list heads while the dev_mtx is
94 * held. Free it later.
96 TAILQ_INIT(&cdp_free);
97 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list);
98 csw_free = cdevsw_gt_post_list;
99 SLIST_INIT(&cdevsw_gt_post_list);
103 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
104 TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
105 devfs_free(&cdp->cdp_c);
107 while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
108 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
114 dev_free_devlocked(struct cdev *cdev)
116 struct cdev_priv *cdp;
118 dev_lock_assert_locked();
119 cdp = cdev2priv(cdev);
120 KASSERT((cdp->cdp_flags & CDP_UNREF_DTR) == 0,
121 ("destroy_dev() was not called after delist_dev(%p)", cdev));
122 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
126 cdevsw_free_devlocked(struct cdevsw *csw)
129 dev_lock_assert_locked();
130 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
141 dev_ref(struct cdev *dev)
144 dev_lock_assert_unlocked();
151 dev_refl(struct cdev *dev)
154 dev_lock_assert_locked();
159 dev_rel(struct cdev *dev)
163 dev_lock_assert_unlocked();
166 KASSERT(dev->si_refcount >= 0,
167 ("dev_rel(%s) gave negative count", devtoname(dev)));
168 if (dev->si_devsw == NULL && dev->si_refcount == 0) {
169 LIST_REMOVE(dev, si_list);
178 dev_refthread(struct cdev *dev, int *ref)
181 struct cdev_priv *cdp;
183 dev_lock_assert_unlocked();
184 if ((dev->si_flags & SI_ETERNAL) != 0) {
186 return (dev->si_devsw);
188 cdp = cdev2priv(dev);
189 mtx_lock(&cdp->cdp_threadlock);
192 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
193 atomic_add_long(&dev->si_threadcount, 1);
197 mtx_unlock(&cdp->cdp_threadlock);
204 devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
207 struct cdev_priv *cdp;
210 dev_lock_assert_unlocked();
211 if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
215 KASSERT((dev->si_flags & SI_ETERNAL) != 0,
216 ("Not eternal cdev"));
219 KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
231 cdp = cdev2priv(dev);
232 mtx_lock(&cdp->cdp_threadlock);
233 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
236 atomic_add_long(&dev->si_threadcount, 1);
238 mtx_unlock(&cdp->cdp_threadlock);
248 dev_relthread(struct cdev *dev, int ref)
251 dev_lock_assert_unlocked();
254 KASSERT(dev->si_threadcount > 0,
255 ("%s threadcount is wrong", dev->si_name));
256 atomic_subtract_rel_long(&dev->si_threadcount, 1);
285 /* Define a dead_cdevsw for use when devices leave unexpectedly. */
287 #define dead_open (d_open_t *)enxio
288 #define dead_close (d_close_t *)enxio
289 #define dead_read (d_read_t *)enxio
290 #define dead_write (d_write_t *)enxio
291 #define dead_ioctl (d_ioctl_t *)enxio
292 #define dead_poll (d_poll_t *)enodev
293 #define dead_mmap (d_mmap_t *)enodev
296 dead_strategy(struct bio *bp)
299 biofinish(bp, NULL, ENXIO);
302 #define dead_kqfilter (d_kqfilter_t *)enxio
303 #define dead_mmap_single (d_mmap_single_t *)enodev
305 static struct cdevsw dead_cdevsw = {
306 .d_version = D_VERSION,
308 .d_close = dead_close,
310 .d_write = dead_write,
311 .d_ioctl = dead_ioctl,
314 .d_strategy = dead_strategy,
316 .d_kqfilter = dead_kqfilter,
317 .d_mmap_single = dead_mmap_single
320 /* Default methods if driver does not specify method */
322 #define null_open (d_open_t *)nullop
323 #define null_close (d_close_t *)nullop
324 #define no_read (d_read_t *)enodev
325 #define no_write (d_write_t *)enodev
326 #define no_ioctl (d_ioctl_t *)enodev
327 #define no_mmap (d_mmap_t *)enodev
328 #define no_kqfilter (d_kqfilter_t *)enodev
329 #define no_mmap_single (d_mmap_single_t *)enodev
332 no_strategy(struct bio *bp)
335 biofinish(bp, NULL, ENODEV);
339 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
342 return (poll_no_poll(events));
346 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
351 dsw = dev_refthread(dev, &ref);
355 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
357 dev_relthread(dev, ref);
362 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
367 dsw = dev_refthread(dev, &ref);
371 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
373 dev_relthread(dev, ref);
378 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
383 dsw = dev_refthread(dev, &ref);
387 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
389 dev_relthread(dev, ref);
394 giant_strategy(struct bio *bp)
401 dsw = dev_refthread(dev, &ref);
403 biofinish(bp, NULL, ENXIO);
407 dsw->d_gianttrick->d_strategy(bp);
409 dev_relthread(dev, ref);
413 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
418 dsw = dev_refthread(dev, &ref);
422 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
424 dev_relthread(dev, ref);
429 giant_read(struct cdev *dev, struct uio *uio, int ioflag)
434 dsw = dev_refthread(dev, &ref);
438 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
440 dev_relthread(dev, ref);
445 giant_write(struct cdev *dev, struct uio *uio, int ioflag)
450 dsw = dev_refthread(dev, &ref);
454 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
456 dev_relthread(dev, ref);
461 giant_poll(struct cdev *dev, int events, struct thread *td)
466 dsw = dev_refthread(dev, &ref);
470 retval = dsw->d_gianttrick->d_poll(dev, events, td);
472 dev_relthread(dev, ref);
477 giant_kqfilter(struct cdev *dev, struct knote *kn)
482 dsw = dev_refthread(dev, &ref);
486 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
488 dev_relthread(dev, ref);
493 giant_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int nprot,
494 vm_memattr_t *memattr)
499 dsw = dev_refthread(dev, &ref);
503 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot,
506 dev_relthread(dev, ref);
511 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
512 vm_object_t *object, int nprot)
517 dsw = dev_refthread(dev, &ref);
521 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
524 dev_relthread(dev, ref);
529 notify(struct cdev *dev, const char *ev, int flags)
531 static const char prefix[] = "cdev=";
537 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
538 namelen = strlen(dev->si_name);
539 data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
542 memcpy(data, prefix, sizeof(prefix) - 1);
543 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
544 devctl_notify("DEVFS", "CDEV", ev, data);
549 notify_create(struct cdev *dev, int flags)
552 notify(dev, "CREATE", flags);
556 notify_destroy(struct cdev *dev)
559 notify(dev, "DESTROY", MAKEDEV_WAITOK);
563 newdev(struct make_dev_args *args, struct cdev *si)
568 dev_lock_assert_locked();
569 csw = args->mda_devsw;
571 if (csw->d_flags & D_NEEDMINOR) {
572 /* We may want to return an existing device */
573 LIST_FOREACH(si2, &csw->d_devs, si_list) {
574 if (dev2unit(si2) == args->mda_unit) {
575 dev_free_devlocked(si);
582 * If we're returning an existing device, we should make sure
583 * it isn't already initialized. This would have been caught
584 * in consumers anyways, but it's good to catch such a case
585 * early. We still need to complete initialization of the
586 * device, and we'll use whatever make_dev_args were passed in
589 KASSERT(si2 == NULL || (si2->si_flags & SI_NAMED) == 0,
590 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
591 args->mda_devsw->d_name, dev2unit(si2), devtoname(si2)));
593 si->si_drv0 = args->mda_unit;
594 si->si_drv1 = args->mda_si_drv1;
595 si->si_drv2 = args->mda_si_drv2;
596 /* Only push to csw->d_devs if it's not a cloned device. */
599 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
601 KASSERT(si->si_devsw == csw,
602 ("%s: inconsistent devsw between clone_create() and make_dev()",
609 fini_cdevsw(struct cdevsw *devsw)
613 if (devsw->d_gianttrick != NULL) {
614 gt = devsw->d_gianttrick;
615 memcpy(devsw, gt, sizeof *devsw);
616 cdevsw_free_devlocked(gt);
617 devsw->d_gianttrick = NULL;
619 devsw->d_flags &= ~D_INIT;
623 prep_cdevsw(struct cdevsw *devsw, int flags)
627 dev_lock_assert_locked();
628 if (devsw->d_flags & D_INIT)
630 if (devsw->d_flags & D_NEEDGIANT) {
632 dsw2 = malloc(sizeof *dsw2, M_DEVT,
633 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
635 if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
639 if (devsw->d_flags & D_INIT) {
641 cdevsw_free_devlocked(dsw2);
645 if (devsw->d_version != D_VERSION_04) {
647 "WARNING: Device driver \"%s\" has wrong version %s\n",
648 devsw->d_name == NULL ? "???" : devsw->d_name,
649 "and is disabled. Recompile KLD module.");
650 devsw->d_open = dead_open;
651 devsw->d_close = dead_close;
652 devsw->d_read = dead_read;
653 devsw->d_write = dead_write;
654 devsw->d_ioctl = dead_ioctl;
655 devsw->d_poll = dead_poll;
656 devsw->d_mmap = dead_mmap;
657 devsw->d_mmap_single = dead_mmap_single;
658 devsw->d_strategy = dead_strategy;
659 devsw->d_kqfilter = dead_kqfilter;
662 if ((devsw->d_flags & D_NEEDGIANT) != 0) {
663 if ((devsw->d_flags & D_GIANTOK) == 0) {
665 "WARNING: Device \"%s\" is Giant locked and may be "
666 "deleted before FreeBSD 14.0.\n",
667 devsw->d_name == NULL ? "???" : devsw->d_name);
669 if (devsw->d_gianttrick == NULL) {
670 memcpy(dsw2, devsw, sizeof *dsw2);
671 devsw->d_gianttrick = dsw2;
676 #define FIXUP(member, noop, giant) \
678 if (devsw->member == NULL) { \
679 devsw->member = noop; \
680 } else if (devsw->d_flags & D_NEEDGIANT) \
681 devsw->member = giant; \
685 FIXUP(d_open, null_open, giant_open);
686 FIXUP(d_fdopen, NULL, giant_fdopen);
687 FIXUP(d_close, null_close, giant_close);
688 FIXUP(d_read, no_read, giant_read);
689 FIXUP(d_write, no_write, giant_write);
690 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
691 FIXUP(d_poll, no_poll, giant_poll);
692 FIXUP(d_mmap, no_mmap, giant_mmap);
693 FIXUP(d_strategy, no_strategy, giant_strategy);
694 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
695 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
697 LIST_INIT(&devsw->d_devs);
699 devsw->d_flags |= D_INIT;
702 cdevsw_free_devlocked(dsw2);
707 prep_devname(struct cdev *dev, const char *fmt, va_list ap)
710 char *from, *q, *s, *to;
712 dev_lock_assert_locked();
714 len = vsnrprintf(dev->si_name, sizeof(dev->si_name), 32, fmt, ap);
715 if (len > sizeof(dev->si_name) - 1)
716 return (ENAMETOOLONG);
718 /* Strip leading slashes. */
719 for (from = dev->si_name; *from == '/'; from++)
722 for (to = dev->si_name; *from != '\0'; from++, to++) {
724 * Spaces and double quotation marks cause
725 * problems for the devctl(4) protocol.
726 * Reject names containing those characters.
728 if (isspace(*from) || *from == '"')
730 /* Treat multiple sequential slashes as single. */
731 while (from[0] == '/' && from[1] == '/')
733 /* Trailing slash is considered invalid. */
734 if (from[0] == '/' && from[1] == '\0')
740 if (dev->si_name[0] == '\0')
743 /* Disallow "." and ".." components. */
744 for (s = dev->si_name;;) {
745 for (q = s; *q != '/' && *q != '\0'; q++)
747 if (q - s == 1 && s[0] == '.')
749 if (q - s == 2 && s[0] == '.' && s[1] == '.')
756 if (devfs_dev_exists(dev->si_name) != 0)
763 make_dev_args_init_impl(struct make_dev_args *args, size_t sz)
771 make_dev_sv(struct make_dev_args *args1, struct cdev **dres,
772 const char *fmt, va_list ap)
774 struct cdev *dev, *dev_new;
775 struct make_dev_args args;
778 bzero(&args, sizeof(args));
779 if (sizeof(args) < args1->mda_size)
781 bcopy(args1, &args, args1->mda_size);
782 KASSERT((args.mda_flags & MAKEDEV_WAITOK) == 0 ||
783 (args.mda_flags & MAKEDEV_NOWAIT) == 0,
784 ("make_dev_sv: both WAITOK and NOWAIT specified"));
785 dev_new = devfs_alloc(args.mda_flags);
789 res = prep_cdevsw(args.mda_devsw, args.mda_flags);
795 dev = newdev(&args, dev_new);
796 if ((dev->si_flags & SI_NAMED) == 0) {
797 res = prep_devname(dev, fmt, ap);
799 if ((args.mda_flags & MAKEDEV_CHECKNAME) == 0) {
801 "make_dev_sv: bad si_name (error=%d, si_name=%s)",
804 if (dev == dev_new) {
805 LIST_REMOVE(dev, si_list);
813 if ((args.mda_flags & MAKEDEV_REF) != 0)
815 if ((args.mda_flags & MAKEDEV_ETERNAL) != 0)
816 dev->si_flags |= SI_ETERNAL;
817 KASSERT(!(dev->si_flags & SI_NAMED),
818 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
819 args.mda_devsw->d_name, dev2unit(dev), devtoname(dev)));
820 dev->si_flags |= SI_NAMED;
821 if (args.mda_cr != NULL)
822 dev->si_cred = crhold(args.mda_cr);
823 dev->si_uid = args.mda_uid;
824 dev->si_gid = args.mda_gid;
825 dev->si_mode = args.mda_mode;
828 clean_unrhdrl(devfs_inos);
829 dev_unlock_and_free();
831 notify_create(dev, args.mda_flags);
838 make_dev_s(struct make_dev_args *args, struct cdev **dres,
839 const char *fmt, ...)
845 res = make_dev_sv(args, dres, fmt, ap);
851 make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
852 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
855 struct make_dev_args args;
857 make_dev_args_init(&args);
858 args.mda_flags = flags;
859 args.mda_devsw = devsw;
863 args.mda_mode = mode;
864 args.mda_unit = unit;
865 return (make_dev_sv(&args, dres, fmt, ap));
869 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
870 const char *fmt, ...)
877 res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
880 KASSERT(res == 0 && dev != NULL,
881 ("make_dev: failed make_dev_credv (error=%d)", res));
886 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
887 gid_t gid, int mode, const char *fmt, ...)
894 res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
897 KASSERT(res == 0 && dev != NULL,
898 ("make_dev_cred: failed make_dev_credv (error=%d)", res));
903 make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
904 uid_t uid, gid_t gid, int mode, const char *fmt, ...)
911 res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
915 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
916 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
917 ("make_dev_credf: failed make_dev_credv (error=%d)", res));
918 return (res == 0 ? dev : NULL);
922 make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
923 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
929 res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
933 KASSERT(((flags & MAKEDEV_NOWAIT) != 0 && res == ENOMEM) ||
934 ((flags & MAKEDEV_CHECKNAME) != 0 && res != ENOMEM) || res == 0,
935 ("make_dev_p: failed make_dev_credv (error=%d)", res));
940 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
943 cdev->si_parent = pdev;
944 cdev->si_flags |= SI_CHILD;
945 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, ...)
1006 res = make_dev_alias_v(MAKEDEV_WAITOK, &dev, pdev, fmt, ap);
1009 KASSERT(res == 0 && dev != NULL,
1010 ("make_dev_alias: failed make_dev_alias_v (error=%d)", res));
1015 make_dev_alias_p(int flags, struct cdev **cdev, struct cdev *pdev,
1016 const char *fmt, ...)
1022 res = make_dev_alias_v(flags, cdev, pdev, fmt, ap);
1028 make_dev_physpath_alias(int flags, struct cdev **cdev, struct cdev *pdev,
1029 struct cdev *old_alias, const char *physpath)
1033 int max_parentpath_len;
1035 int devfspathbuf_len;
1041 physpath_len = strlen(physpath);
1043 if (physpath_len == 0)
1046 if (strncmp("id1,", physpath, 4) == 0) {
1049 if (physpath_len == 0)
1053 max_parentpath_len = SPECNAMELEN - physpath_len - /*/*/1;
1054 parentpath_len = strlen(pdev->si_name);
1055 if (max_parentpath_len < parentpath_len) {
1057 printf("WARNING: Unable to alias %s "
1058 "to %s/%s - path too long\n",
1059 pdev->si_name, physpath, pdev->si_name);
1064 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
1065 devfspathbuf_len = physpath_len + /*/*/1 + parentpath_len + /*NUL*/1;
1066 devfspath = malloc(devfspathbuf_len, M_DEVBUF, mflags);
1067 if (devfspath == NULL) {
1072 sprintf(devfspath, "%s/%s", physpath, pdev->si_name);
1073 if (old_alias != NULL && strcmp(old_alias->si_name, devfspath) == 0) {
1074 /* Retain the existing alias. */
1079 ret = make_dev_alias_p(flags, cdev, pdev, "%s", devfspath);
1082 if (old_alias != NULL)
1083 destroy_dev(old_alias);
1084 if (devfspath != NULL)
1085 free(devfspath, M_DEVBUF);
1090 destroy_devl(struct cdev *dev)
1093 struct cdev_privdata *p;
1094 struct cdev_priv *cdp;
1096 dev_lock_assert_locked();
1097 KASSERT(dev->si_flags & SI_NAMED,
1098 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
1099 KASSERT((dev->si_flags & SI_ETERNAL) == 0,
1100 ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
1103 cdp = cdev2priv(dev);
1104 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1106 * Avoid race with dev_rel(), e.g. from the populate
1107 * loop. If CDP_UNREF_DTR flag is set, the reference
1108 * to be dropped at the end of destroy_devl() was
1109 * already taken by delist_dev_locked().
1116 /* Remove name marking */
1117 dev->si_flags &= ~SI_NAMED;
1119 /* If we are a child, remove us from the parents list */
1120 if (dev->si_flags & SI_CHILD) {
1121 LIST_REMOVE(dev, si_siblings);
1122 dev->si_flags &= ~SI_CHILD;
1125 /* Kill our children */
1126 while (!LIST_EMPTY(&dev->si_children))
1127 destroy_devl(LIST_FIRST(&dev->si_children));
1129 /* Remove from clone list */
1130 if (dev->si_flags & SI_CLONELIST) {
1131 LIST_REMOVE(dev, si_clone);
1132 dev->si_flags &= ~SI_CLONELIST;
1135 mtx_lock(&cdp->cdp_threadlock);
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 mtx_unlock(&cdp->cdp_threadlock);
1141 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
1142 mtx_lock(&cdp->cdp_threadlock);
1143 if (dev->si_threadcount)
1144 printf("Still %lu threads in %s\n",
1145 dev->si_threadcount, devtoname(dev));
1147 while (dev->si_threadcount != 0) {
1148 /* Use unique dummy wait ident */
1149 mtx_unlock(&cdp->cdp_threadlock);
1150 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
1151 mtx_lock(&cdp->cdp_threadlock);
1154 mtx_unlock(&cdp->cdp_threadlock);
1156 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
1157 /* avoid out of order notify events */
1158 notify_destroy(dev);
1160 mtx_lock(&cdevpriv_mtx);
1161 while ((p = LIST_FIRST(&cdp->cdp_fdpriv)) != NULL) {
1162 devfs_destroy_cdevpriv(p);
1163 mtx_lock(&cdevpriv_mtx);
1165 mtx_unlock(&cdevpriv_mtx);
1171 if (!(dev->si_flags & SI_ALIAS)) {
1172 /* Remove from cdevsw list */
1173 LIST_REMOVE(dev, si_list);
1175 /* If cdevsw has no more struct cdev *'s, clean it */
1176 if (LIST_EMPTY(&csw->d_devs)) {
1178 wakeup(&csw->d_devs);
1181 dev->si_flags &= ~SI_ALIAS;
1182 cdp->cdp_flags &= ~CDP_UNREF_DTR;
1185 if (dev->si_refcount > 0)
1186 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
1188 dev_free_devlocked(dev);
1192 delist_dev_locked(struct cdev *dev)
1194 struct cdev_priv *cdp;
1197 dev_lock_assert_locked();
1198 cdp = cdev2priv(dev);
1199 if ((cdp->cdp_flags & CDP_UNREF_DTR) != 0)
1201 cdp->cdp_flags |= CDP_UNREF_DTR;
1204 LIST_FOREACH(child, &dev->si_children, si_siblings)
1205 delist_dev_locked(child);
1207 /* ensure the destroy event is queued in order */
1208 notify_destroy(dev);
1213 * This function will delist a character device and its children from
1214 * the directory listing and create a destroy event without waiting
1215 * for all character device references to go away. At some later point
1216 * destroy_dev() must be called to complete the character device
1217 * destruction. After calling this function the character device name
1218 * can instantly be re-used.
1221 delist_dev(struct cdev *dev)
1224 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "delist_dev");
1226 delist_dev_locked(dev);
1231 destroy_dev(struct cdev *dev)
1234 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
1237 dev_unlock_and_free();
1241 devtoname(struct cdev *dev)
1244 return (dev->si_name);
1248 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
1253 if (strncmp(stem, name, i) != 0)
1255 if (!isdigit(name[i]))
1258 if (name[i] == '0' && isdigit(name[i+1]))
1260 while (isdigit(name[i])) {
1262 u += name[i++] - '0';
1275 * Helper functions for cloning device drivers.
1277 * The objective here is to make it unnecessary for the device drivers to
1278 * use rman or similar to manage their unit number space. Due to the way
1279 * we do "on-demand" devices, using rman or other "private" methods
1280 * will be very tricky to lock down properly once we lock down this file.
1282 * Instead we give the drivers these routines which puts the struct cdev *'s
1283 * that are to be managed on their own list, and gives the driver the ability
1284 * to ask for the first free unit number or a given specified unit number.
1286 * In addition these routines support paired devices (pty, nmdm and similar)
1287 * by respecting a number of "flag" bits in the minor number.
1292 LIST_HEAD(,cdev) head;
1296 clone_setup(struct clonedevs **cdp)
1299 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1300 LIST_INIT(&(*cdp)->head);
1304 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
1305 struct cdev **dp, int extra)
1307 struct clonedevs *cd;
1308 struct cdev *dev, *ndev, *dl, *de;
1309 struct make_dev_args args;
1312 KASSERT(*cdp != NULL,
1313 ("clone_setup() not called in driver \"%s\"", csw->d_name));
1314 KASSERT(!(extra & CLONE_UNITMASK),
1315 ("Illegal extra bits (0x%x) in clone_create", extra));
1316 KASSERT(*up <= CLONE_UNITMASK,
1317 ("Too high unit (0x%x) in clone_create", *up));
1318 KASSERT(csw->d_flags & D_NEEDMINOR,
1319 ("clone_create() on cdevsw without minor numbers"));
1322 * Search the list for a lot of things in one go:
1323 * A preexisting match is returned immediately.
1324 * The lowest free unit number if we are passed -1, and the place
1325 * in the list where we should insert that new element.
1326 * The place to insert a specified unit number, if applicable
1327 * the end of the list.
1330 ndev = devfs_alloc(MAKEDEV_WAITOK);
1332 prep_cdevsw(csw, MAKEDEV_WAITOK);
1336 LIST_FOREACH(dev, &cd->head, si_clone) {
1337 KASSERT(dev->si_flags & SI_CLONELIST,
1338 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1340 if (u == (unit | extra)) {
1346 if (unit == -1 && u == low) {
1350 } else if (u < (unit | extra)) {
1353 } else if (u > (unit | extra)) {
1359 unit = low & CLONE_UNITMASK;
1360 make_dev_args_init(&args);
1361 args.mda_unit = unit | extra;
1362 args.mda_devsw = csw;
1363 dev = newdev(&args, ndev);
1364 if (dev->si_flags & SI_CLONELIST) {
1365 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1366 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1367 LIST_FOREACH(dev, &cd->head, si_clone) {
1368 printf("\t%p %s\n", dev, dev->si_name);
1372 KASSERT(!(dev->si_flags & SI_CLONELIST),
1373 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1375 LIST_INSERT_BEFORE(dl, dev, si_clone);
1376 else if (de != NULL)
1377 LIST_INSERT_AFTER(de, dev, si_clone);
1379 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1380 dev->si_flags |= SI_CLONELIST;
1382 dev_unlock_and_free();
1387 * Kill everything still on the list. The driver should already have
1388 * disposed of any softc hung of the struct cdev *'s at this time.
1391 clone_cleanup(struct clonedevs **cdp)
1394 struct cdev_priv *cp;
1395 struct clonedevs *cd;
1401 while (!LIST_EMPTY(&cd->head)) {
1402 dev = LIST_FIRST(&cd->head);
1403 LIST_REMOVE(dev, si_clone);
1404 KASSERT(dev->si_flags & SI_CLONELIST,
1405 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1406 dev->si_flags &= ~SI_CLONELIST;
1407 cp = cdev2priv(dev);
1408 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1409 cp->cdp_flags |= CDP_SCHED_DTR;
1410 KASSERT(dev->si_flags & SI_NAMED,
1411 ("Driver has goofed in cloning underways udev %jx unit %x",
1412 (uintmax_t)dev2udev(dev), dev2unit(dev)));
1416 dev_unlock_and_free();
1421 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1422 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1423 static TAILQ_HEAD(, cdev_priv) dev_ddtr_giant =
1424 TAILQ_HEAD_INITIALIZER(dev_ddtr_giant);
1425 static struct task dev_dtr_task = TASK_INITIALIZER(0, destroy_dev_tq, &dev_ddtr);
1426 static struct task dev_dtr_task_giant = TASK_INITIALIZER(0, destroy_dev_tq_giant,
1430 destroy_dev_tq(void *ctx, int pending)
1432 TAILQ_HEAD(, cdev_priv) *ddtr = ctx;
1433 struct cdev_priv *cp;
1439 while (!TAILQ_EMPTY(ddtr)) {
1440 cp = TAILQ_FIRST(ddtr);
1442 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1443 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1444 TAILQ_REMOVE(ddtr, cp, cdp_dtr_list);
1445 cb = cp->cdp_dtr_cb;
1446 cb_arg = cp->cdp_dtr_cb_arg;
1448 dev_unlock_and_free();
1458 destroy_dev_tq_giant(void *ctx, int pending)
1461 destroy_dev_tq(ctx, pending);
1466 * devmtx shall be locked on entry. devmtx will be unlocked after
1470 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1472 struct cdev_priv *cp;
1475 dev_lock_assert_locked();
1476 cp = cdev2priv(dev);
1477 if (cp->cdp_flags & CDP_SCHED_DTR) {
1482 cp->cdp_flags |= CDP_SCHED_DTR;
1483 cp->cdp_dtr_cb = cb;
1484 cp->cdp_dtr_cb_arg = arg;
1485 need_giant = (dev->si_devsw->d_flags & D_NEEDGIANT) != 0;
1487 TAILQ_INSERT_TAIL(&dev_ddtr_giant, cp, cdp_dtr_list);
1489 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1492 taskqueue_enqueue(taskqueue_thread, &dev_dtr_task_giant);
1494 taskqueue_enqueue(taskqueue_thread, &dev_dtr_task);
1499 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1503 return (destroy_dev_sched_cbl(dev, cb, arg));
1507 destroy_dev_sched(struct cdev *dev)
1510 return (destroy_dev_sched_cb(dev, NULL, NULL));
1514 destroy_dev_drain(struct cdevsw *csw)
1518 while (!LIST_EMPTY(&csw->d_devs)) {
1519 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1524 #include "opt_ddb.h"
1526 #include <sys/kernel.h>
1528 #include <ddb/ddb.h>
1530 DB_SHOW_COMMAND(cdev, db_show_cdev)
1532 struct cdev_priv *cdp;
1538 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
1540 db_printf("%s %p\n", dev->si_name, dev);
1547 dev = (struct cdev *)addr;
1548 cdp = cdev2priv(dev);
1549 db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
1550 dev->si_name, dev->si_refcount, dev->si_usecount,
1551 dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
1552 db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
1553 dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
1554 flags = dev->si_flags;
1555 #define SI_FLAG(flag) do { \
1556 if (flags & (flag)) { \
1557 if (buf[0] != '\0') \
1558 strlcat(buf, ", ", sizeof(buf)); \
1559 strlcat(buf, (#flag) + 3, sizeof(buf)); \
1564 SI_FLAG(SI_ETERNAL);
1568 SI_FLAG(SI_DUMPDEV);
1569 SI_FLAG(SI_CLONELIST);
1570 db_printf("si_flags %s\n", buf);
1572 flags = cdp->cdp_flags;
1573 #define CDP_FLAG(flag) do { \
1574 if (flags & (flag)) { \
1575 if (buf[0] != '\0') \
1576 strlcat(buf, ", ", sizeof(buf)); \
1577 strlcat(buf, (#flag) + 4, sizeof(buf)); \
1582 CDP_FLAG(CDP_ACTIVE);
1583 CDP_FLAG(CDP_SCHED_DTR);
1584 db_printf("cdp_flags %s\n", buf);