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,
6 * Copyright (c) 1982, 1986, 1991, 1993
7 * The Regents of the University of California. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * $DragonFly: src/sys/kern/kern_device.c,v 1.27 2007/07/23 18:59:50 dillon Exp $
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/sysctl.h>
36 #include <sys/systm.h>
37 #include <sys/module.h>
38 #include <sys/malloc.h>
42 #include <sys/vnode.h>
43 #include <sys/queue.h>
44 #include <sys/device.h>
46 #include <sys/syslink_rpc.h>
48 #include <machine/stdarg.h>
49 #include <sys/thread2.h>
50 #include <sys/devfs.h>
53 * system link descriptors identify the command in the
54 * arguments structure.
56 #define DDESCNAME(name) __CONCAT(__CONCAT(dev_,name),_desc)
58 #define DEVOP_DESC_INIT(name) \
59 struct syslink_desc DDESCNAME(name) = { \
60 __offsetof(struct dev_ops, __CONCAT(d_, name)), \
63 DEVOP_DESC_INIT(default);
64 DEVOP_DESC_INIT(open
);
65 DEVOP_DESC_INIT(close
);
66 DEVOP_DESC_INIT(read
);
67 DEVOP_DESC_INIT(write
);
68 DEVOP_DESC_INIT(ioctl
);
69 DEVOP_DESC_INIT(dump
);
70 DEVOP_DESC_INIT(psize
);
71 DEVOP_DESC_INIT(poll
);
72 DEVOP_DESC_INIT(mmap
);
73 DEVOP_DESC_INIT(strategy
);
74 DEVOP_DESC_INIT(kqfilter
);
75 DEVOP_DESC_INIT(revoke
);
76 DEVOP_DESC_INIT(clone
);
81 struct dev_ops dead_dev_ops
;
83 struct dev_ops default_dev_ops
= {
85 .d_default
= NULL
, /* must be NULL */
93 .d_strategy
= nostrategy
,
96 .d_kqfilter
= nokqfilter
,
101 /************************************************************************
102 * GENERAL DEVICE API FUNCTIONS *
103 ************************************************************************/
106 dev_dopen(cdev_t dev
, int oflags
, int devtype
, struct ucred
*cred
)
108 struct dev_open_args ap
;
110 ap
.a_head
.a_desc
= &dev_open_desc
;
111 ap
.a_head
.a_dev
= dev
;
112 ap
.a_oflags
= oflags
;
113 ap
.a_devtype
= devtype
;
115 return(dev
->si_ops
->d_open(&ap
));
119 dev_dclose(cdev_t dev
, int fflag
, int devtype
)
121 struct dev_close_args ap
;
123 ap
.a_head
.a_desc
= &dev_close_desc
;
124 ap
.a_head
.a_dev
= dev
;
126 ap
.a_devtype
= devtype
;
127 return(dev
->si_ops
->d_close(&ap
));
131 dev_dread(cdev_t dev
, struct uio
*uio
, int ioflag
)
133 struct dev_read_args ap
;
136 ap
.a_head
.a_desc
= &dev_read_desc
;
137 ap
.a_head
.a_dev
= dev
;
139 ap
.a_ioflag
= ioflag
;
140 error
= dev
->si_ops
->d_read(&ap
);
142 dev
->si_lastread
= time_second
;
147 dev_dwrite(cdev_t dev
, struct uio
*uio
, int ioflag
)
149 struct dev_write_args ap
;
152 dev
->si_lastwrite
= time_second
;
153 ap
.a_head
.a_desc
= &dev_write_desc
;
154 ap
.a_head
.a_dev
= dev
;
156 ap
.a_ioflag
= ioflag
;
157 error
= dev
->si_ops
->d_write(&ap
);
162 dev_dioctl(cdev_t dev
, u_long cmd
, caddr_t data
, int fflag
, struct ucred
*cred
,
165 struct dev_ioctl_args ap
;
167 ap
.a_head
.a_desc
= &dev_ioctl_desc
;
168 ap
.a_head
.a_dev
= dev
;
174 return(dev
->si_ops
->d_ioctl(&ap
));
178 dev_dpoll(cdev_t dev
, int events
)
180 struct dev_poll_args ap
;
183 ap
.a_head
.a_desc
= &dev_poll_desc
;
184 ap
.a_head
.a_dev
= dev
;
185 ap
.a_events
= events
;
186 error
= dev
->si_ops
->d_poll(&ap
);
189 return (seltrue(dev
, events
));
193 dev_dmmap(cdev_t dev
, vm_offset_t offset
, int nprot
)
195 struct dev_mmap_args ap
;
198 ap
.a_head
.a_desc
= &dev_mmap_desc
;
199 ap
.a_head
.a_dev
= dev
;
200 ap
.a_offset
= offset
;
202 error
= dev
->si_ops
->d_mmap(&ap
);
209 dev_dclone(cdev_t dev
)
211 struct dev_clone_args ap
;
213 ap
.a_head
.a_desc
= &dev_clone_desc
;
214 ap
.a_head
.a_dev
= dev
;
215 return (dev
->si_ops
->d_clone(&ap
));
219 dev_drevoke(cdev_t dev
)
221 struct dev_revoke_args ap
;
223 ap
.a_head
.a_desc
= &dev_revoke_desc
;
224 ap
.a_head
.a_dev
= dev
;
225 return (dev
->si_ops
->d_revoke(&ap
));
229 * Core device strategy call, used to issue I/O on a device. There are
230 * two versions, a non-chained version and a chained version. The chained
231 * version reuses a BIO set up by vn_strategy(). The only difference is
232 * that, for now, we do not push a new tracking structure when chaining
233 * from vn_strategy. XXX this will ultimately have to change.
236 dev_dstrategy(cdev_t dev
, struct bio
*bio
)
238 struct dev_strategy_args ap
;
239 struct bio_track
*track
;
241 ap
.a_head
.a_desc
= &dev_strategy_desc
;
242 ap
.a_head
.a_dev
= dev
;
245 KKASSERT(bio
->bio_track
== NULL
);
246 KKASSERT(bio
->bio_buf
->b_cmd
!= BUF_CMD_DONE
);
247 if (bio
->bio_buf
->b_cmd
== BUF_CMD_READ
)
248 track
= &dev
->si_track_read
;
250 track
= &dev
->si_track_write
;
251 bio_track_ref(track
);
252 bio
->bio_track
= track
;
253 KKASSERT((bio
->bio_flags
& BIO_DONE
) == 0);
254 (void)dev
->si_ops
->d_strategy(&ap
);
258 dev_dstrategy_chain(cdev_t dev
, struct bio
*bio
)
260 struct dev_strategy_args ap
;
262 ap
.a_head
.a_desc
= &dev_strategy_desc
;
263 ap
.a_head
.a_dev
= dev
;
266 KKASSERT(bio
->bio_track
!= NULL
);
267 KKASSERT((bio
->bio_flags
& BIO_DONE
) == 0);
268 (void)dev
->si_ops
->d_strategy(&ap
);
272 * note: the disk layer is expected to set count, blkno, and secsize before
273 * forwarding the message.
276 dev_ddump(cdev_t dev
)
278 struct dev_dump_args ap
;
280 ap
.a_head
.a_desc
= &dev_dump_desc
;
281 ap
.a_head
.a_dev
= dev
;
285 return(dev
->si_ops
->d_dump(&ap
));
289 dev_dpsize(cdev_t dev
)
291 struct dev_psize_args ap
;
294 ap
.a_head
.a_desc
= &dev_psize_desc
;
295 ap
.a_head
.a_dev
= dev
;
296 error
= dev
->si_ops
->d_psize(&ap
);
298 return (ap
.a_result
);
303 dev_dkqfilter(cdev_t dev
, struct knote
*kn
)
305 struct dev_kqfilter_args ap
;
308 ap
.a_head
.a_desc
= &dev_kqfilter_desc
;
309 ap
.a_head
.a_dev
= dev
;
311 error
= dev
->si_ops
->d_kqfilter(&ap
);
317 /************************************************************************
318 * DEVICE HELPER FUNCTIONS *
319 ************************************************************************/
325 dev_drefs(cdev_t dev
)
327 return(dev
->si_sysref
.refcnt
);
334 dev_dname(cdev_t dev
)
336 return(dev
->si_ops
->head
.name
);
343 dev_dflags(cdev_t dev
)
345 return(dev
->si_ops
->head
.flags
);
354 return(dev
->si_ops
->head
.maj
);
358 * Used when forwarding a request through layers. The caller adjusts
359 * ap->a_head.a_dev and then calls this function.
362 dev_doperate(struct dev_generic_args
*ap
)
364 int (*func
)(struct dev_generic_args
*);
366 func
= *(void **)((char *)ap
->a_dev
->si_ops
+ ap
->a_desc
->sd_offset
);
371 * Used by the console intercept code only. Issue an operation through
372 * a foreign ops structure allowing the ops structure associated
373 * with the device to remain intact.
376 dev_doperate_ops(struct dev_ops
*ops
, struct dev_generic_args
*ap
)
378 int (*func
)(struct dev_generic_args
*);
380 func
= *(void **)((char *)ops
+ ap
->a_desc
->sd_offset
);
385 * Convert a template dev_ops into the real thing by filling in
386 * uninitialized fields.
389 compile_dev_ops(struct dev_ops
*ops
)
393 for (offset
= offsetof(struct dev_ops
, dev_ops_first_field
);
394 offset
<= offsetof(struct dev_ops
, dev_ops_last_field
);
395 offset
+= sizeof(void *)
397 void **func_p
= (void **)((char *)ops
+ offset
);
398 void **def_p
= (void **)((char *)&default_dev_ops
+ offset
);
399 if (*func_p
== NULL
) {
401 *func_p
= ops
->d_default
;
408 /************************************************************************
409 * MAJOR/MINOR SPACE FUNCTION *
410 ************************************************************************/
413 * This makes a dev_ops entry visible to userland (e.g /dev/<blah>).
415 * Disk devices typically register their major, e.g. 'ad0', and then call
416 * into the disk label management code which overloads its own onto e.g. 'ad0'
417 * to support all the various slice and partition combinations.
419 * The mask/match supplied in this call are a full 32 bits and the same
420 * mask and match must be specified in a later dev_ops_remove() call to
421 * match this add. However, the match value for the minor number should never
422 * have any bits set in the major number's bit range (8-15). The mask value
423 * may be conveniently specified as -1 without creating any major number
429 rb_dev_ops_compare(struct dev_ops_maj
*a
, struct dev_ops_maj
*b
)
433 else if (a
->maj
> b
->maj
)
438 RB_GENERATE2(dev_ops_rb_tree
, dev_ops_maj
, rbnode
, rb_dev_ops_compare
, int, maj
);
440 struct dev_ops_rb_tree dev_ops_rbhead
= RB_INITIALIZER(dev_ops_rbhead
);
443 dev_ops_remove_all(struct dev_ops
*ops
)
445 return devfs_destroy_dev_by_ops(ops
, -1);
449 dev_ops_remove_minor(struct dev_ops
*ops
, int minor
)
451 return devfs_destroy_dev_by_ops(ops
, minor
);
455 dev_ops_intercept(cdev_t dev
, struct dev_ops
*iops
)
457 struct dev_ops
*oops
= dev
->si_ops
;
459 compile_dev_ops(iops
);
460 iops
->head
.maj
= oops
->head
.maj
;
461 iops
->head
.data
= oops
->head
.data
;
462 iops
->head
.flags
= oops
->head
.flags
;
464 dev
->si_flags
|= SI_INTERCEPTED
;
470 dev_ops_restore(cdev_t dev
, struct dev_ops
*oops
)
472 struct dev_ops
*iops
= dev
->si_ops
;
475 dev
->si_flags
&= ~SI_INTERCEPTED
;
477 iops
->head
.data
= NULL
;
478 iops
->head
.flags
= 0;
481 /************************************************************************
482 * DEFAULT DEV OPS FUNCTIONS *
483 ************************************************************************/
487 * Unsupported devswitch functions (e.g. for writing to read-only device).
488 * XXX may belong elsewhere.
491 norevoke(struct dev_revoke_args
*ap
)
498 noclone(struct dev_clone_args
*ap
)
501 return (0); /* allow the clone */
505 noopen(struct dev_open_args
*ap
)
511 noclose(struct dev_close_args
*ap
)
517 noread(struct dev_read_args
*ap
)
523 nowrite(struct dev_write_args
*ap
)
529 noioctl(struct dev_ioctl_args
*ap
)
535 nokqfilter(struct dev_kqfilter_args
*ap
)
541 nommap(struct dev_mmap_args
*ap
)
547 nopoll(struct dev_poll_args
*ap
)
554 nostrategy(struct dev_strategy_args
*ap
)
556 struct bio
*bio
= ap
->a_bio
;
558 bio
->bio_buf
->b_flags
|= B_ERROR
;
559 bio
->bio_buf
->b_error
= EOPNOTSUPP
;
565 nopsize(struct dev_psize_args
*ap
)
572 nodump(struct dev_dump_args
*ap
)
578 * XXX this is probably bogus. Any device that uses it isn't checking the
582 nullopen(struct dev_open_args
*ap
)
588 nullclose(struct dev_close_args
*ap
)