2 * Copyright (c) 2003 Matthew Dillon <dillon@backplane.com> All rights reserved.
3 * cdevsw from kern/kern_conf.c Copyright (c) 1995 Terrence R. Lambert
4 * cdevsw from kern/kern_conf.c Copyright (c) 1995 Julian R. Elishcer,
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
28 * $DragonFly: src/sys/kern/kern_device.c,v 1.13 2004/09/15 03:21:03 dillon Exp $
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/sysctl.h>
33 #include <sys/systm.h>
34 #include <sys/module.h>
35 #include <sys/malloc.h>
37 #include <sys/vnode.h>
38 #include <sys/queue.h>
39 #include <sys/msgport.h>
40 #include <sys/device.h>
41 #include <machine/stdarg.h>
43 #include <sys/thread2.h>
44 #include <sys/msgport2.h>
46 static struct cdevlink *cdevbase[NUMCDEVSW];
48 static int cdevsw_putport(lwkt_port_t port, lwkt_msg_t msg);
50 struct cdevsw dead_cdevsw;
53 * Initialize a message port to serve as the default message-handling port
54 * for device operations. This message port provides compatibility with
55 * traditional cdevsw dispatch functions by running them synchronously.
57 * YYY NOTE: ms_cmd can now hold a function pointer, should this code be
58 * converted from an integer op to a function pointer with a flag to
59 * indicate legacy operation?
62 init_default_cdevsw_port(lwkt_port_t port)
64 lwkt_initport(port, NULL);
65 port->mp_putport = cdevsw_putport;
70 cdevsw_putport(lwkt_port_t port, lwkt_msg_t lmsg)
72 cdevallmsg_t msg = (cdevallmsg_t)lmsg;
73 struct cdevsw *devsw = msg->am_msg.dev->si_devsw;
77 * Run the device switch function synchronously in the context of the
78 * caller and return a synchronous error code (anything not EASYNC).
80 switch(msg->am_lmsg.ms_cmd.cm_op) {
82 error = devsw->old_open(
89 error = devsw->old_close(
90 msg->am_close.msg.dev,
92 msg->am_close.devtype,
95 case CDEV_CMD_STRATEGY:
96 devsw->old_strategy(msg->am_strategy.bp);
100 error = devsw->old_ioctl(
101 msg->am_ioctl.msg.dev,
108 error = devsw->old_dump(
109 msg->am_dump.msg.dev,
112 msg->am_dump.secsize);
115 msg->am_psize.result = devsw->old_psize(msg->am_psize.msg.dev);
119 error = devsw->old_read(
120 msg->am_read.msg.dev,
122 msg->am_read.ioflag);
125 error = devsw->old_write(
126 msg->am_read.msg.dev,
128 msg->am_read.ioflag);
131 msg->am_poll.events = devsw->old_poll(
132 msg->am_poll.msg.dev,
137 case CDEV_CMD_KQFILTER:
138 msg->am_kqfilter.result = devsw->old_kqfilter(
139 msg->am_kqfilter.msg.dev,
140 msg->am_kqfilter.kn);
144 msg->am_mmap.result = devsw->old_mmap(
145 msg->am_mmap.msg.dev,
154 KKASSERT(error != EASYNC);
160 _init_cdevmsg(dev_t dev, cdevmsg_t msg, int cmd)
162 lwkt_initmsg_simple(&msg->msg, cmd);
164 return(dev->si_port);
168 dev_dopen(dev_t dev, int oflags, int devtype, thread_t td)
170 struct cdevmsg_open msg;
173 port = _init_cdevmsg(dev, &msg.msg, CDEV_CMD_OPEN);
177 msg.devtype = devtype;
179 return(lwkt_domsg(port, &msg.msg.msg));
183 dev_dclose(dev_t dev, int fflag, int devtype, thread_t td)
185 struct cdevmsg_close msg;
188 port = _init_cdevmsg(dev, &msg.msg, CDEV_CMD_CLOSE);
192 msg.devtype = devtype;
194 return(lwkt_domsg(port, &msg.msg.msg));
198 dev_dstrategy(dev_t dev, struct buf *bp)
200 struct cdevmsg_strategy msg;
203 port = _init_cdevmsg(dev, &msg.msg, CDEV_CMD_STRATEGY);
204 KKASSERT(port); /* 'nostrategy' function is NULL YYY */
206 lwkt_domsg(port, &msg.msg.msg);
210 dev_dioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, thread_t td)
212 struct cdevmsg_ioctl msg;
215 port = _init_cdevmsg(dev, &msg.msg, CDEV_CMD_IOCTL);
222 return(lwkt_domsg(port, &msg.msg.msg));
226 * note: the disk layer is expected to set count, blkno, and secsize before
227 * forwarding the message.
232 struct cdevmsg_dump msg;
235 port = _init_cdevmsg(dev, &msg.msg, CDEV_CMD_DUMP);
241 return(lwkt_domsg(port, &msg.msg.msg));
245 dev_dpsize(dev_t dev)
247 struct cdevmsg_psize msg;
251 port = _init_cdevmsg(dev, &msg.msg, CDEV_CMD_PSIZE);
254 error = lwkt_domsg(port, &msg.msg.msg);
261 dev_dread(dev_t dev, struct uio *uio, int ioflag)
263 struct cdevmsg_read msg;
266 port = _init_cdevmsg(dev, &msg.msg, CDEV_CMD_READ);
271 return(lwkt_domsg(port, &msg.msg.msg));
275 dev_dwrite(dev_t dev, struct uio *uio, int ioflag)
277 struct cdevmsg_write msg;
280 port = _init_cdevmsg(dev, &msg.msg, CDEV_CMD_WRITE);
285 return(lwkt_domsg(port, &msg.msg.msg));
289 dev_dpoll(dev_t dev, int events, thread_t td)
291 struct cdevmsg_poll msg;
295 port = _init_cdevmsg(dev, &msg.msg, CDEV_CMD_POLL);
300 error = lwkt_domsg(port, &msg.msg.msg);
303 return(seltrue(dev, msg.events, td));
307 dev_dkqfilter(dev_t dev, struct knote *kn)
309 struct cdevmsg_kqfilter msg;
313 port = _init_cdevmsg(dev, &msg.msg, CDEV_CMD_KQFILTER);
317 error = lwkt_domsg(port, &msg.msg.msg);
324 dev_dmmap(dev_t dev, vm_offset_t offset, int nprot)
326 struct cdevmsg_mmap msg;
330 port = _init_cdevmsg(dev, &msg.msg, CDEV_CMD_MMAP);
335 error = lwkt_domsg(port, &msg.msg.msg);
344 return(dev->si_devsw->d_name);
348 dev_dflags(dev_t dev)
350 return(dev->si_devsw->d_flags);
356 return(dev->si_devsw->d_maj);
362 return(dev->si_port);
366 * Convert a cdevsw template into the real thing, filling in fields the
367 * device left empty with appropriate defaults.
370 compile_devsw(struct cdevsw *devsw)
372 static lwkt_port devsw_compat_port;
374 if (devsw_compat_port.mp_putport == NULL)
375 init_default_cdevsw_port(&devsw_compat_port);
377 if (devsw->old_open == NULL)
378 devsw->old_open = noopen;
379 if (devsw->old_close == NULL)
380 devsw->old_close = noclose;
381 if (devsw->old_read == NULL)
382 devsw->old_read = noread;
383 if (devsw->old_write == NULL)
384 devsw->old_write = nowrite;
385 if (devsw->old_ioctl == NULL)
386 devsw->old_ioctl = noioctl;
387 if (devsw->old_poll == NULL)
388 devsw->old_poll = nopoll;
389 if (devsw->old_mmap == NULL)
390 devsw->old_mmap = nommap;
391 if (devsw->old_strategy == NULL)
392 devsw->old_strategy = nostrategy;
393 if (devsw->old_dump == NULL)
394 devsw->old_dump = nodump;
395 if (devsw->old_psize == NULL)
396 devsw->old_psize = nopsize;
397 if (devsw->old_kqfilter == NULL)
398 devsw->old_kqfilter = nokqfilter;
400 if (devsw->d_port == NULL)
401 devsw->d_port = &devsw_compat_port;
402 if (devsw->d_clone == NULL)
403 devsw->d_clone = noclone;
407 * This makes a cdevsw entry visible to userland (e.g /dev/<blah>).
409 * The kernel can overload a major number with multiple cdevsw's but only
410 * the one installed in cdevbase[] is visible to userland. make_dev() does
411 * not automatically call cdevsw_add() (nor do we want it to, since
412 * partition-managed disk devices are overloaded on top of the raw device).
415 cdevsw_add(struct cdevsw *devsw, u_int mask, u_int match)
418 struct cdevlink *link;
420 compile_devsw(devsw);
422 if (maj < 0 || maj >= NUMCDEVSW) {
423 printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n",
427 for (link = cdevbase[maj]; link; link = link->next) {
429 * If we get an exact match we usurp the target, but we only print
430 * a warning message if a different device switch is installed.
432 if (link->mask == mask && link->match == match) {
433 if (link->devsw != devsw) {
434 printf("WARNING: \"%s\" (%p) is usurping \"%s\"'s (%p)"
436 devsw->d_name, devsw,
437 link->devsw->d_name, link->devsw);
444 * XXX add additional warnings for overlaps
448 link = malloc(sizeof(struct cdevlink), M_DEVBUF, M_INTWAIT|M_ZERO);
452 link->next = cdevbase[maj];
453 cdevbase[maj] = link;
459 * Should only be used by udev2dev().
461 * If the minor number is -1, we match the first cdevsw we find for this
464 * Note that this function will return NULL if the minor number is not within
465 * the bounds of the installed mask(s).
468 cdevsw_get(int x, int y)
470 struct cdevlink *link;
472 if (x < 0 || x >= NUMCDEVSW)
474 for (link = cdevbase[x]; link; link = link->next) {
475 if (y == -1 || (link->mask & y) == link->match)
482 * Use the passed cdevsw as a template to create our intercept cdevsw,
483 * and install and return ours.
486 cdevsw_add_override(dev_t backing_dev, u_int mask, u_int match)
488 struct cdevsw *devsw;
489 struct cdevsw *bsw = backing_dev->si_devsw;
491 devsw = malloc(sizeof(struct cdevsw), M_DEVBUF, M_INTWAIT|M_ZERO);
492 devsw->d_name = bsw->d_name;
493 devsw->d_maj = bsw->d_maj;
494 devsw->d_flags = bsw->d_flags;
495 compile_devsw(devsw);
496 cdevsw_add(devsw, mask, match);
502 * Override a device's port, returning the previously installed port. This
503 * is XXX very dangerous.
506 cdevsw_dev_override(dev_t dev, lwkt_port_t port)
510 oport = dev->si_port;
516 * Remove a cdevsw entry from the cdevbase[] major array so no new user opens
517 * can be performed, and destroy all devices installed in the hash table
518 * which are associated with this cdevsw. (see destroy_all_dev()).
521 cdevsw_remove(struct cdevsw *devsw, u_int mask, u_int match)
523 int maj = devsw->d_maj;
524 struct cdevlink *link;
525 struct cdevlink **plink;
527 if (maj < 0 || maj >= NUMCDEVSW) {
528 printf("%s: ERROR: driver has bogus cdevsw->d_maj = %d\n",
532 if (devsw != &dead_cdevsw)
533 destroy_all_dev(devsw, mask, match);
534 for (plink = &cdevbase[maj]; (link = *plink) != NULL; plink = &link->next) {
535 if (link->mask == mask && link->match == match) {
536 if (link->devsw == devsw)
538 printf("%s: ERROR: cannot remove from cdevsw[], its major"
539 " number %d was stolen by %s\n",
546 printf("%s(%d)[%08x/%08x]: WARNING: cdevsw removed multiple times!\n",
547 devsw->d_name, maj, mask, match);
550 --devsw->d_refs; /* XXX cdevsw_release() / record refs */
551 free(link, M_DEVBUF);
553 if (cdevbase[maj] == NULL && devsw->d_refs != 0) {
554 printf("%s(%d)[%08x/%08x]: Warning: cdevsw_remove() called while "
555 "%d device refs still exist!\n",
556 devsw->d_name, maj, mask, match, devsw->d_refs);
558 printf("%s: cdevsw removed\n", devsw->d_name);
564 * Release a cdevsw entry. When the ref count reaches zero, recurse
568 cdevsw_release(struct cdevsw *devsw)
571 if (devsw->d_refs == 0) {