2 * Copyright (c) 1999-2002 Poul-Henning Kamp
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.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 int make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw,
59 int unit, struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
62 static struct cdev_priv_list cdevp_free_list =
63 TAILQ_HEAD_INITIALIZER(cdevp_free_list);
64 static SLIST_HEAD(free_cdevsw, cdevsw) cdevsw_gt_post_list =
65 SLIST_HEAD_INITIALIZER(cdevsw_gt_post_list);
75 * Free all the memory collected while the cdev mutex was
76 * locked. Since devmtx is after the system map mutex, free() cannot
77 * be called immediately and is postponed until cdev mutex can be
81 dev_unlock_and_free(void)
83 struct cdev_priv_list cdp_free;
84 struct free_cdevsw csw_free;
85 struct cdev_priv *cdp;
88 mtx_assert(&devmtx, MA_OWNED);
91 * Make the local copy of the list heads while the dev_mtx is
92 * held. Free it later.
94 TAILQ_INIT(&cdp_free);
95 TAILQ_CONCAT(&cdp_free, &cdevp_free_list, cdp_list);
96 csw_free = cdevsw_gt_post_list;
97 SLIST_INIT(&cdevsw_gt_post_list);
101 while ((cdp = TAILQ_FIRST(&cdp_free)) != NULL) {
102 TAILQ_REMOVE(&cdp_free, cdp, cdp_list);
103 devfs_free(&cdp->cdp_c);
105 while ((csw = SLIST_FIRST(&csw_free)) != NULL) {
106 SLIST_REMOVE_HEAD(&csw_free, d_postfree_list);
112 dev_free_devlocked(struct cdev *cdev)
114 struct cdev_priv *cdp;
116 mtx_assert(&devmtx, MA_OWNED);
117 cdp = cdev2priv(cdev);
118 KASSERT((cdp->cdp_flags & CDP_UNREF_DTR) == 0,
119 ("destroy_dev() was not called after delist_dev(%p)", cdev));
120 TAILQ_INSERT_HEAD(&cdevp_free_list, cdp, cdp_list);
124 cdevsw_free_devlocked(struct cdevsw *csw)
127 mtx_assert(&devmtx, MA_OWNED);
128 SLIST_INSERT_HEAD(&cdevsw_gt_post_list, csw, d_postfree_list);
139 dev_ref(struct cdev *dev)
142 mtx_assert(&devmtx, MA_NOTOWNED);
149 dev_refl(struct cdev *dev)
152 mtx_assert(&devmtx, MA_OWNED);
157 dev_rel(struct cdev *dev)
161 mtx_assert(&devmtx, MA_NOTOWNED);
164 KASSERT(dev->si_refcount >= 0,
165 ("dev_rel(%s) gave negative count", devtoname(dev)));
167 if (dev->si_usecount == 0 &&
168 (dev->si_flags & SI_CHEAPCLONE) && (dev->si_flags & SI_NAMED))
172 if (dev->si_devsw == NULL && dev->si_refcount == 0) {
173 LIST_REMOVE(dev, si_list);
182 dev_refthread(struct cdev *dev, int *ref)
185 struct cdev_priv *cdp;
187 mtx_assert(&devmtx, MA_NOTOWNED);
188 if ((dev->si_flags & SI_ETERNAL) != 0) {
190 return (dev->si_devsw);
195 cdp = cdev2priv(dev);
196 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0)
197 dev->si_threadcount++;
207 devvn_refthread(struct vnode *vp, struct cdev **devp, int *ref)
210 struct cdev_priv *cdp;
213 mtx_assert(&devmtx, MA_NOTOWNED);
214 if ((vp->v_vflag & VV_ETERNALDEV) != 0) {
218 KASSERT((dev->si_flags & SI_ETERNAL) != 0,
219 ("Not eternal cdev"));
222 KASSERT(csw != NULL, ("Eternal cdev is destroyed"));
234 cdp = cdev2priv(dev);
235 if ((cdp->cdp_flags & CDP_SCHED_DTR) == 0) {
238 dev->si_threadcount++;
249 dev_relthread(struct cdev *dev, int ref)
252 mtx_assert(&devmtx, MA_NOTOWNED);
256 KASSERT(dev->si_threadcount > 0,
257 ("%s threadcount is wrong", dev->si_name));
258 dev->si_threadcount--;
288 /* Define a dead_cdevsw for use when devices leave unexpectedly. */
290 #define dead_open (d_open_t *)enxio
291 #define dead_close (d_close_t *)enxio
292 #define dead_read (d_read_t *)enxio
293 #define dead_write (d_write_t *)enxio
294 #define dead_ioctl (d_ioctl_t *)enxio
295 #define dead_poll (d_poll_t *)enodev
296 #define dead_mmap (d_mmap_t *)enodev
299 dead_strategy(struct bio *bp)
302 biofinish(bp, NULL, ENXIO);
305 #define dead_dump (dumper_t *)enxio
306 #define dead_kqfilter (d_kqfilter_t *)enxio
307 #define dead_mmap_single (d_mmap_single_t *)enodev
309 static struct cdevsw dead_cdevsw = {
310 .d_version = D_VERSION,
312 .d_close = dead_close,
314 .d_write = dead_write,
315 .d_ioctl = dead_ioctl,
318 .d_strategy = dead_strategy,
321 .d_kqfilter = dead_kqfilter,
322 .d_mmap_single = dead_mmap_single
325 /* Default methods if driver does not specify method */
327 #define null_open (d_open_t *)nullop
328 #define null_close (d_close_t *)nullop
329 #define no_read (d_read_t *)enodev
330 #define no_write (d_write_t *)enodev
331 #define no_ioctl (d_ioctl_t *)enodev
332 #define no_mmap (d_mmap2_t *)enodev
333 #define no_kqfilter (d_kqfilter_t *)enodev
334 #define no_mmap_single (d_mmap_single_t *)enodev
337 no_strategy(struct bio *bp)
340 biofinish(bp, NULL, ENODEV);
344 no_poll(struct cdev *dev __unused, int events, struct thread *td __unused)
347 return (poll_no_poll(events));
350 #define no_dump (dumper_t *)enodev
353 giant_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
358 dsw = dev_refthread(dev, &ref);
362 retval = dsw->d_gianttrick->d_open(dev, oflags, devtype, td);
364 dev_relthread(dev, ref);
369 giant_fdopen(struct cdev *dev, int oflags, struct thread *td, struct file *fp)
374 dsw = dev_refthread(dev, &ref);
378 retval = dsw->d_gianttrick->d_fdopen(dev, oflags, td, fp);
380 dev_relthread(dev, ref);
385 giant_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
390 dsw = dev_refthread(dev, &ref);
394 retval = dsw->d_gianttrick->d_close(dev, fflag, devtype, td);
396 dev_relthread(dev, ref);
401 giant_strategy(struct bio *bp)
408 dsw = dev_refthread(dev, &ref);
410 biofinish(bp, NULL, ENXIO);
414 dsw->d_gianttrick->d_strategy(bp);
416 dev_relthread(dev, ref);
420 giant_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
425 dsw = dev_refthread(dev, &ref);
429 retval = dsw->d_gianttrick->d_ioctl(dev, cmd, data, fflag, td);
431 dev_relthread(dev, ref);
436 giant_read(struct cdev *dev, struct uio *uio, int ioflag)
441 dsw = dev_refthread(dev, &ref);
445 retval = dsw->d_gianttrick->d_read(dev, uio, ioflag);
447 dev_relthread(dev, ref);
452 giant_write(struct cdev *dev, struct uio *uio, int ioflag)
457 dsw = dev_refthread(dev, &ref);
461 retval = dsw->d_gianttrick->d_write(dev, uio, ioflag);
463 dev_relthread(dev, ref);
468 giant_poll(struct cdev *dev, int events, struct thread *td)
473 dsw = dev_refthread(dev, &ref);
477 retval = dsw->d_gianttrick->d_poll(dev, events, td);
479 dev_relthread(dev, ref);
484 giant_kqfilter(struct cdev *dev, struct knote *kn)
489 dsw = dev_refthread(dev, &ref);
493 retval = dsw->d_gianttrick->d_kqfilter(dev, kn);
495 dev_relthread(dev, ref);
500 giant_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot,
501 vm_memattr_t *memattr)
506 dsw = dev_refthread(dev, &ref);
510 if (dsw->d_gianttrick->d_flags & D_MMAP2)
511 retval = dsw->d_gianttrick->d_mmap2(dev, offset, paddr, nprot,
514 retval = dsw->d_gianttrick->d_mmap(dev, offset, paddr, nprot);
516 dev_relthread(dev, ref);
521 giant_mmap_single(struct cdev *dev, vm_ooffset_t *offset, vm_size_t size,
522 vm_object_t *object, int nprot)
527 dsw = dev_refthread(dev, &ref);
531 retval = dsw->d_gianttrick->d_mmap_single(dev, offset, size, object,
534 dev_relthread(dev, ref);
539 notify(struct cdev *dev, const char *ev, int flags)
541 static const char prefix[] = "cdev=";
547 mflags = (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK;
548 namelen = strlen(dev->si_name);
549 data = malloc(namelen + sizeof(prefix), M_TEMP, mflags);
552 memcpy(data, prefix, sizeof(prefix) - 1);
553 memcpy(data + sizeof(prefix) - 1, dev->si_name, namelen + 1);
554 devctl_notify_f("DEVFS", "CDEV", ev, data, mflags);
559 notify_create(struct cdev *dev, int flags)
562 notify(dev, "CREATE", flags);
566 notify_destroy(struct cdev *dev)
569 notify(dev, "DESTROY", MAKEDEV_WAITOK);
573 newdev(struct cdevsw *csw, int unit, struct cdev *si)
577 mtx_assert(&devmtx, MA_OWNED);
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) == unit) {
582 dev_free_devlocked(si);
589 LIST_INSERT_HEAD(&csw->d_devs, si, si_list);
594 fini_cdevsw(struct cdevsw *devsw)
598 if (devsw->d_gianttrick != NULL) {
599 gt = devsw->d_gianttrick;
600 memcpy(devsw, gt, sizeof *devsw);
601 cdevsw_free_devlocked(gt);
602 devsw->d_gianttrick = NULL;
604 devsw->d_flags &= ~D_INIT;
608 prep_cdevsw(struct cdevsw *devsw, int flags)
612 mtx_assert(&devmtx, MA_OWNED);
613 if (devsw->d_flags & D_INIT)
615 if (devsw->d_flags & D_NEEDGIANT) {
617 dsw2 = malloc(sizeof *dsw2, M_DEVT,
618 (flags & MAKEDEV_NOWAIT) ? M_NOWAIT : M_WAITOK);
620 if (dsw2 == NULL && !(devsw->d_flags & D_INIT))
624 if (devsw->d_flags & D_INIT) {
626 cdevsw_free_devlocked(dsw2);
630 if (devsw->d_version != D_VERSION_01 &&
631 devsw->d_version != D_VERSION_02) {
633 "WARNING: Device driver \"%s\" has wrong version %s\n",
634 devsw->d_name == NULL ? "???" : devsw->d_name,
635 "and is disabled. Recompile KLD module.");
636 devsw->d_open = dead_open;
637 devsw->d_close = dead_close;
638 devsw->d_read = dead_read;
639 devsw->d_write = dead_write;
640 devsw->d_ioctl = dead_ioctl;
641 devsw->d_poll = dead_poll;
642 devsw->d_mmap = dead_mmap;
643 devsw->d_strategy = dead_strategy;
644 devsw->d_dump = dead_dump;
645 devsw->d_kqfilter = dead_kqfilter;
647 if (devsw->d_version == D_VERSION_01)
648 devsw->d_mmap_single = NULL;
650 if (devsw->d_flags & D_NEEDGIANT) {
651 if (devsw->d_gianttrick == NULL) {
652 memcpy(dsw2, devsw, sizeof *dsw2);
653 devsw->d_gianttrick = dsw2;
654 devsw->d_flags |= D_MMAP2;
659 #define FIXUP(member, noop, giant) \
661 if (devsw->member == NULL) { \
662 devsw->member = noop; \
663 } else if (devsw->d_flags & D_NEEDGIANT) \
664 devsw->member = giant; \
668 FIXUP(d_open, null_open, giant_open);
669 FIXUP(d_fdopen, NULL, giant_fdopen);
670 FIXUP(d_close, null_close, giant_close);
671 FIXUP(d_read, no_read, giant_read);
672 FIXUP(d_write, no_write, giant_write);
673 FIXUP(d_ioctl, no_ioctl, giant_ioctl);
674 FIXUP(d_poll, no_poll, giant_poll);
675 FIXUP(d_mmap2, no_mmap, giant_mmap);
676 FIXUP(d_strategy, no_strategy, giant_strategy);
677 FIXUP(d_kqfilter, no_kqfilter, giant_kqfilter);
678 FIXUP(d_mmap_single, no_mmap_single, giant_mmap_single);
680 if (devsw->d_dump == NULL) devsw->d_dump = no_dump;
682 LIST_INIT(&devsw->d_devs);
684 devsw->d_flags |= D_INIT;
687 cdevsw_free_devlocked(dsw2);
692 make_dev_credv(int flags, struct cdev **dres, struct cdevsw *devsw, int unit,
693 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt,
699 KASSERT((flags & MAKEDEV_WAITOK) == 0 || (flags & MAKEDEV_NOWAIT) == 0,
700 ("make_dev_credv: both WAITOK and NOWAIT specified"));
701 dev = devfs_alloc(flags);
705 res = prep_cdevsw(devsw, flags);
711 dev = newdev(devsw, unit, dev);
712 if (flags & MAKEDEV_REF)
714 if (flags & MAKEDEV_ETERNAL)
715 dev->si_flags |= SI_ETERNAL;
716 if (dev->si_flags & SI_CHEAPCLONE &&
717 dev->si_flags & SI_NAMED) {
719 * This is allowed as it removes races and generally
720 * simplifies cloning devices.
723 dev_unlock_and_free();
727 KASSERT(!(dev->si_flags & SI_NAMED),
728 ("make_dev() by driver %s on pre-existing device (min=%x, name=%s)",
729 devsw->d_name, dev2unit(dev), devtoname(dev)));
731 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
732 if (i > (sizeof dev->__si_namebuf - 1)) {
733 printf("WARNING: Device name truncated! (%s)\n",
737 dev->si_flags |= SI_NAMED;
739 dev->si_cred = crhold(cr);
745 clean_unrhdrl(devfs_inos);
746 dev_unlock_and_free();
748 notify_create(dev, flags);
755 make_dev(struct cdevsw *devsw, int unit, uid_t uid, gid_t gid, int mode,
756 const char *fmt, ...)
763 res = make_dev_credv(0, &dev, devsw, unit, NULL, uid, gid, mode, fmt,
766 KASSERT(res == 0 && dev != NULL, ("make_dev: failed make_dev_credv"));
771 make_dev_cred(struct cdevsw *devsw, int unit, struct ucred *cr, uid_t uid,
772 gid_t gid, int mode, const char *fmt, ...)
779 res = make_dev_credv(0, &dev, devsw, unit, cr, uid, gid, mode, fmt, ap);
782 KASSERT(res == 0 && dev != NULL,
783 ("make_dev_cred: failed make_dev_credv"));
788 make_dev_credf(int flags, struct cdevsw *devsw, int unit, struct ucred *cr,
789 uid_t uid, gid_t gid, int mode, const char *fmt, ...)
796 res = make_dev_credv(flags, &dev, devsw, unit, cr, uid, gid, mode,
800 KASSERT((flags & MAKEDEV_NOWAIT) != 0 || res == 0,
801 ("make_dev_credf: failed make_dev_credv"));
802 return (res == 0 ? dev : NULL);
806 make_dev_p(int flags, struct cdev **cdev, struct cdevsw *devsw,
807 struct ucred *cr, uid_t uid, gid_t gid, int mode, const char *fmt, ...)
813 res = make_dev_credv(flags, cdev, devsw, 0, cr, uid, gid, mode,
817 KASSERT((flags & MAKEDEV_NOWAIT) != 0 || res == 0,
818 ("make_dev_p: failed make_dev_credv"));
823 dev_dependsl(struct cdev *pdev, struct cdev *cdev)
826 cdev->si_parent = pdev;
827 cdev->si_flags |= SI_CHILD;
828 LIST_INSERT_HEAD(&pdev->si_children, cdev, si_siblings);
833 dev_depends(struct cdev *pdev, struct cdev *cdev)
837 dev_dependsl(pdev, cdev);
842 make_dev_alias(struct cdev *pdev, const char *fmt, ...)
848 KASSERT(pdev != NULL, ("NULL pdev"));
849 dev = devfs_alloc(MAKEDEV_WAITOK);
851 dev->si_flags |= SI_ALIAS;
852 dev->si_flags |= SI_NAMED;
854 i = vsnrprintf(dev->__si_namebuf, sizeof dev->__si_namebuf, 32, fmt, ap);
855 if (i > (sizeof dev->__si_namebuf - 1)) {
856 printf("WARNING: Device name truncated! (%s)\n",
862 dev_dependsl(pdev, dev);
863 clean_unrhdrl(devfs_inos);
866 notify_create(dev, MAKEDEV_WAITOK);
872 destroy_devl(struct cdev *dev)
875 struct cdev_privdata *p;
876 struct cdev_priv *cdp;
878 mtx_assert(&devmtx, MA_OWNED);
879 KASSERT(dev->si_flags & SI_NAMED,
880 ("WARNING: Driver mistake: destroy_dev on %d\n", dev2unit(dev)));
881 KASSERT((dev->si_flags & SI_ETERNAL) == 0,
882 ("WARNING: Driver mistake: destroy_dev on eternal %d\n",
885 cdp = cdev2priv(dev);
886 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
888 * Avoid race with dev_rel(), e.g. from the populate
889 * loop. If CDP_UNREF_DTR flag is set, the reference
890 * to be dropped at the end of destroy_devl() was
891 * already taken by delist_dev_locked().
898 /* Remove name marking */
899 dev->si_flags &= ~SI_NAMED;
901 /* If we are a child, remove us from the parents list */
902 if (dev->si_flags & SI_CHILD) {
903 LIST_REMOVE(dev, si_siblings);
904 dev->si_flags &= ~SI_CHILD;
907 /* Kill our children */
908 while (!LIST_EMPTY(&dev->si_children))
909 destroy_devl(LIST_FIRST(&dev->si_children));
911 /* Remove from clone list */
912 if (dev->si_flags & SI_CLONELIST) {
913 LIST_REMOVE(dev, si_clone);
914 dev->si_flags &= ~SI_CLONELIST;
918 dev->si_devsw = NULL; /* already NULL for SI_ALIAS */
919 while (csw != NULL && csw->d_purge != NULL && dev->si_threadcount) {
921 msleep(csw, &devmtx, PRIBIO, "devprg", hz/10);
922 if (dev->si_threadcount)
923 printf("Still %lu threads in %s\n",
924 dev->si_threadcount, devtoname(dev));
926 while (dev->si_threadcount != 0) {
927 /* Use unique dummy wait ident */
928 msleep(&csw, &devmtx, PRIBIO, "devdrn", hz / 10);
932 if ((cdp->cdp_flags & CDP_UNREF_DTR) == 0) {
933 /* avoid out of order notify events */
936 mtx_lock(&cdevpriv_mtx);
937 while ((p = LIST_FIRST(&cdp->cdp_fdpriv)) != NULL) {
938 devfs_destroy_cdevpriv(p);
939 mtx_lock(&cdevpriv_mtx);
941 mtx_unlock(&cdevpriv_mtx);
946 bzero(&dev->__si_u, sizeof(dev->__si_u));
948 if (!(dev->si_flags & SI_ALIAS)) {
949 /* Remove from cdevsw list */
950 LIST_REMOVE(dev, si_list);
952 /* If cdevsw has no more struct cdev *'s, clean it */
953 if (LIST_EMPTY(&csw->d_devs)) {
955 wakeup(&csw->d_devs);
958 dev->si_flags &= ~SI_ALIAS;
959 cdp->cdp_flags &= ~CDP_UNREF_DTR;
962 if (dev->si_refcount > 0)
963 LIST_INSERT_HEAD(&dead_cdevsw.d_devs, dev, si_list);
965 dev_free_devlocked(dev);
969 delist_dev_locked(struct cdev *dev)
971 struct cdev_priv *cdp;
974 mtx_assert(&devmtx, MA_OWNED);
975 cdp = cdev2priv(dev);
976 if ((cdp->cdp_flags & CDP_UNREF_DTR) != 0)
978 cdp->cdp_flags |= CDP_UNREF_DTR;
981 LIST_FOREACH(child, &dev->si_children, si_siblings)
982 delist_dev_locked(child);
984 /* ensure the destroy event is queued in order */
990 * This function will delist a character device and its children from
991 * the directory listing and create a destroy event without waiting
992 * for all character device references to go away. At some later point
993 * destroy_dev() must be called to complete the character device
994 * destruction. After calling this function the character device name
995 * can instantly be re-used.
998 delist_dev(struct cdev *dev)
1001 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "delist_dev");
1003 delist_dev_locked(dev);
1008 destroy_dev(struct cdev *dev)
1011 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "destroy_dev");
1014 dev_unlock_and_free();
1018 devtoname(struct cdev *dev)
1021 return (dev->si_name);
1025 dev_stdclone(char *name, char **namep, const char *stem, int *unit)
1030 if (bcmp(stem, name, i) != 0)
1032 if (!isdigit(name[i]))
1035 if (name[i] == '0' && isdigit(name[i+1]))
1037 while (isdigit(name[i])) {
1039 u += name[i++] - '0';
1052 * Helper functions for cloning device drivers.
1054 * The objective here is to make it unnecessary for the device drivers to
1055 * use rman or similar to manage their unit number space. Due to the way
1056 * we do "on-demand" devices, using rman or other "private" methods
1057 * will be very tricky to lock down properly once we lock down this file.
1059 * Instead we give the drivers these routines which puts the struct cdev *'s
1060 * that are to be managed on their own list, and gives the driver the ability
1061 * to ask for the first free unit number or a given specified unit number.
1063 * In addition these routines support paired devices (pty, nmdm and similar)
1064 * by respecting a number of "flag" bits in the minor number.
1069 LIST_HEAD(,cdev) head;
1073 clone_setup(struct clonedevs **cdp)
1076 *cdp = malloc(sizeof **cdp, M_DEVBUF, M_WAITOK | M_ZERO);
1077 LIST_INIT(&(*cdp)->head);
1081 clone_create(struct clonedevs **cdp, struct cdevsw *csw, int *up,
1082 struct cdev **dp, int extra)
1084 struct clonedevs *cd;
1085 struct cdev *dev, *ndev, *dl, *de;
1088 KASSERT(*cdp != NULL,
1089 ("clone_setup() not called in driver \"%s\"", csw->d_name));
1090 KASSERT(!(extra & CLONE_UNITMASK),
1091 ("Illegal extra bits (0x%x) in clone_create", extra));
1092 KASSERT(*up <= CLONE_UNITMASK,
1093 ("Too high unit (0x%x) in clone_create", *up));
1094 KASSERT(csw->d_flags & D_NEEDMINOR,
1095 ("clone_create() on cdevsw without minor numbers"));
1099 * Search the list for a lot of things in one go:
1100 * A preexisting match is returned immediately.
1101 * The lowest free unit number if we are passed -1, and the place
1102 * in the list where we should insert that new element.
1103 * The place to insert a specified unit number, if applicable
1104 * the end of the list.
1107 ndev = devfs_alloc(MAKEDEV_WAITOK);
1109 prep_cdevsw(csw, MAKEDEV_WAITOK);
1113 LIST_FOREACH(dev, &cd->head, si_clone) {
1114 KASSERT(dev->si_flags & SI_CLONELIST,
1115 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1117 if (u == (unit | extra)) {
1123 if (unit == -1 && u == low) {
1127 } else if (u < (unit | extra)) {
1130 } else if (u > (unit | extra)) {
1136 unit = low & CLONE_UNITMASK;
1137 dev = newdev(csw, unit | extra, ndev);
1138 if (dev->si_flags & SI_CLONELIST) {
1139 printf("dev %p (%s) is on clonelist\n", dev, dev->si_name);
1140 printf("unit=%d, low=%d, extra=0x%x\n", unit, low, extra);
1141 LIST_FOREACH(dev, &cd->head, si_clone) {
1142 printf("\t%p %s\n", dev, dev->si_name);
1146 KASSERT(!(dev->si_flags & SI_CLONELIST),
1147 ("Dev %p(%s) should not be on clonelist", dev, dev->si_name));
1149 LIST_INSERT_BEFORE(dl, dev, si_clone);
1150 else if (de != NULL)
1151 LIST_INSERT_AFTER(de, dev, si_clone);
1153 LIST_INSERT_HEAD(&cd->head, dev, si_clone);
1154 dev->si_flags |= SI_CLONELIST;
1156 dev_unlock_and_free();
1161 * Kill everything still on the list. The driver should already have
1162 * disposed of any softc hung of the struct cdev *'s at this time.
1165 clone_cleanup(struct clonedevs **cdp)
1168 struct cdev_priv *cp;
1169 struct clonedevs *cd;
1175 while (!LIST_EMPTY(&cd->head)) {
1176 dev = LIST_FIRST(&cd->head);
1177 LIST_REMOVE(dev, si_clone);
1178 KASSERT(dev->si_flags & SI_CLONELIST,
1179 ("Dev %p(%s) should be on clonelist", dev, dev->si_name));
1180 dev->si_flags &= ~SI_CLONELIST;
1181 cp = cdev2priv(dev);
1182 if (!(cp->cdp_flags & CDP_SCHED_DTR)) {
1183 cp->cdp_flags |= CDP_SCHED_DTR;
1184 KASSERT(dev->si_flags & SI_NAMED,
1185 ("Driver has goofed in cloning underways udev %x unit %x", dev2udev(dev), dev2unit(dev)));
1189 dev_unlock_and_free();
1194 static TAILQ_HEAD(, cdev_priv) dev_ddtr =
1195 TAILQ_HEAD_INITIALIZER(dev_ddtr);
1196 static struct task dev_dtr_task;
1199 destroy_dev_tq(void *ctx, int pending)
1201 struct cdev_priv *cp;
1207 while (!TAILQ_EMPTY(&dev_ddtr)) {
1208 cp = TAILQ_FIRST(&dev_ddtr);
1210 KASSERT(cp->cdp_flags & CDP_SCHED_DTR,
1211 ("cdev %p in dev_destroy_tq without CDP_SCHED_DTR", cp));
1212 TAILQ_REMOVE(&dev_ddtr, cp, cdp_dtr_list);
1213 cb = cp->cdp_dtr_cb;
1214 cb_arg = cp->cdp_dtr_cb_arg;
1216 dev_unlock_and_free();
1226 * devmtx shall be locked on entry. devmtx will be unlocked after
1230 destroy_dev_sched_cbl(struct cdev *dev, void (*cb)(void *), void *arg)
1232 struct cdev_priv *cp;
1234 mtx_assert(&devmtx, MA_OWNED);
1235 cp = cdev2priv(dev);
1236 if (cp->cdp_flags & CDP_SCHED_DTR) {
1241 cp->cdp_flags |= CDP_SCHED_DTR;
1242 cp->cdp_dtr_cb = cb;
1243 cp->cdp_dtr_cb_arg = arg;
1244 TAILQ_INSERT_TAIL(&dev_ddtr, cp, cdp_dtr_list);
1246 taskqueue_enqueue(taskqueue_swi_giant, &dev_dtr_task);
1251 destroy_dev_sched_cb(struct cdev *dev, void (*cb)(void *), void *arg)
1255 return (destroy_dev_sched_cbl(dev, cb, arg));
1259 destroy_dev_sched(struct cdev *dev)
1262 return (destroy_dev_sched_cb(dev, NULL, NULL));
1266 destroy_dev_drain(struct cdevsw *csw)
1270 while (!LIST_EMPTY(&csw->d_devs)) {
1271 msleep(&csw->d_devs, &devmtx, PRIBIO, "devscd", hz/10);
1277 drain_dev_clone_events(void)
1280 sx_xlock(&clone_drain_lock);
1281 sx_xunlock(&clone_drain_lock);
1285 devdtr_init(void *dummy __unused)
1288 TASK_INIT(&dev_dtr_task, 0, destroy_dev_tq, NULL);
1291 SYSINIT(devdtr, SI_SUB_DEVFS, SI_ORDER_SECOND, devdtr_init, NULL);
1293 #include "opt_ddb.h"
1295 #include <sys/kernel.h>
1297 #include <ddb/ddb.h>
1299 DB_SHOW_COMMAND(cdev, db_show_cdev)
1301 struct cdev_priv *cdp;
1307 TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
1309 db_printf("%s %p\n", dev->si_name, dev);
1316 dev = (struct cdev *)addr;
1317 cdp = cdev2priv(dev);
1318 db_printf("dev %s ref %d use %ld thr %ld inuse %u fdpriv %p\n",
1319 dev->si_name, dev->si_refcount, dev->si_usecount,
1320 dev->si_threadcount, cdp->cdp_inuse, cdp->cdp_fdpriv.lh_first);
1321 db_printf("devsw %p si_drv0 %d si_drv1 %p si_drv2 %p\n",
1322 dev->si_devsw, dev->si_drv0, dev->si_drv1, dev->si_drv2);
1323 flags = dev->si_flags;
1324 #define SI_FLAG(flag) do { \
1325 if (flags & (flag)) { \
1326 if (buf[0] != '\0') \
1327 strlcat(buf, ", ", sizeof(buf)); \
1328 strlcat(buf, (#flag) + 3, sizeof(buf)); \
1333 SI_FLAG(SI_ETERNAL);
1336 SI_FLAG(SI_CHEAPCLONE);
1338 SI_FLAG(SI_DEVOPEN);
1339 SI_FLAG(SI_CONSOPEN);
1340 SI_FLAG(SI_DUMPDEV);
1341 SI_FLAG(SI_CANDELETE);
1342 SI_FLAG(SI_CLONELIST);
1343 db_printf("si_flags %s\n", buf);
1345 flags = cdp->cdp_flags;
1346 #define CDP_FLAG(flag) do { \
1347 if (flags & (flag)) { \
1348 if (buf[0] != '\0') \
1349 strlcat(buf, ", ", sizeof(buf)); \
1350 strlcat(buf, (#flag) + 4, sizeof(buf)); \
1355 CDP_FLAG(CDP_ACTIVE);
1356 CDP_FLAG(CDP_SCHED_DTR);
1357 db_printf("cdp_flags %s\n", buf);