xref: /illumos-gate/usr/src/uts/common/io/vuidmice/vuidmice.c (revision bfed486ad8de8b8ebc6345a8e10accae08bf2f45)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 
29 /*
30  * VUIDMICE module:  put mouse events into vuid format
31  */
32 
33 #include <sys/param.h>
34 #include <sys/stream.h>
35 #include <sys/stropts.h>
36 #include <sys/strsun.h>
37 #include <sys/errno.h>
38 #include <sys/debug.h>
39 #include <sys/cmn_err.h>
40 #include <sys/sad.h>
41 #include <sys/vuid_event.h>
42 #include <sys/vuidmice.h>
43 #include <sys/vuid_wheel.h>
44 #include <sys/msio.h>
45 
46 #include <sys/conf.h>
47 #include <sys/modctl.h>
48 
49 #include <sys/kmem.h>
50 #include <sys/ddi.h>
51 #include <sys/sunddi.h>
52 
53 static int vuidmice_open(queue_t *const, const dev_t *const,
54 	const int, const int, const cred_t *const);
55 static int vuidmice_close(queue_t *const, const int, const cred_t *const);
56 static int vuidmice_rput(queue_t *const, mblk_t *);
57 static int vuidmice_rsrv(queue_t *const);
58 static int vuidmice_wput(queue_t *const, mblk_t *);
59 static void vuidmice_miocdata(queue_t *const, mblk_t *);
60 static int vuidmice_handle_wheel_resolution_ioctl(queue_t *const,
61 	mblk_t *, int);
62 
63 static int vuidmice_service_wheel_info(mblk_t *);
64 static int vuidmice_service_wheel_state(queue_t *, mblk_t *, uint_t);
65 
66 void VUID_QUEUE(queue_t *const, mblk_t *);
67 int VUID_OPEN(queue_t *const);
68 void VUID_CLOSE(queue_t *const);
69 
70 static kmutex_t vuidmice_lock;
71 
72 static struct module_info vuidmice_iinfo = {
73 	0,
74 	VUID_NAME,
75 	0,
76 	INFPSZ,
77 	1000,
78 	100
79 };
80 
81 static struct qinit vuidmice_rinit = {
82 	vuidmice_rput,
83 	vuidmice_rsrv,
84 	vuidmice_open,
85 	vuidmice_close,
86 	NULL,
87 	&vuidmice_iinfo,
88 	NULL
89 };
90 
91 static struct module_info vuidmice_oinfo = {
92 	0,
93 	VUID_NAME,
94 	0,
95 	INFPSZ,
96 	1000,
97 	100
98 };
99 
100 static struct qinit vuidmice_winit = {
101 	vuidmice_wput,
102 	NULL,
103 	NULL,
104 	NULL,
105 	NULL,
106 	&vuidmice_oinfo,
107 	NULL
108 };
109 
110 struct streamtab vuidmice_info = {
111 	&vuidmice_rinit,
112 	&vuidmice_winit,
113 	NULL,
114 	NULL
115 };
116 
117 /*
118  * This is the loadable module wrapper.
119  */
120 
121 /*
122  * D_MTQPAIR effectively makes the module single threaded.
123  * There can be only one thread active in the module at any time.
124  * It may be a read or write thread.
125  */
126 #define	VUIDMICE_CONF_FLAG	(D_MP | D_MTQPAIR)
127 
128 static struct fmodsw fsw = {
129 	VUID_NAME,
130 	&vuidmice_info,
131 	VUIDMICE_CONF_FLAG
132 };
133 
134 static struct modlstrmod modlstrmod = {
135 	&mod_strmodops,
136 	"mouse events to vuid events",
137 	&fsw
138 };
139 
140 /*
141  * Module linkage information for the kernel.
142  */
143 static struct modlinkage modlinkage = {
144 	MODREV_1,
145 	&modlstrmod,
146 	NULL
147 };
148 
149 static int module_open = 0;	/* allow only one open of this module */
150 
151 int
152 _init(void)
153 {
154 	register int rc;
155 
156 	mutex_init(&vuidmice_lock, NULL, MUTEX_DEFAULT, NULL);
157 	if ((rc = mod_install(&modlinkage)) != 0) {
158 		mutex_destroy(&vuidmice_lock);
159 	}
160 	return (rc);
161 }
162 
163 int
164 _fini(void)
165 {
166 	register int rc;
167 
168 	if ((rc = mod_remove(&modlinkage)) == 0)
169 		mutex_destroy(&vuidmice_lock);
170 	return (rc);
171 }
172 
173 int
174 _info(struct modinfo *modinfop)
175 {
176 	return (mod_info(&modlinkage, modinfop));
177 }
178 
179 
180 /* ARGSUSED1 */
181 static int
182 vuidmice_open(queue_t *const qp, const dev_t *const devp,
183 	const int oflag, const int sflag, const cred_t *const crp)
184 {
185 	if (qp->q_ptr != NULL)
186 		return (0);	 /* reopen */
187 
188 	mutex_enter(&vuidmice_lock);
189 
190 	/* Allow only 1 open of this module */
191 	if (module_open) {
192 		mutex_exit(&vuidmice_lock);
193 		return (EBUSY);
194 	}
195 
196 	module_open++;
197 	mutex_exit(&vuidmice_lock);
198 
199 	/*
200 	 * Both the read and write queues share the same state structures.
201 	 */
202 	qp->q_ptr = kmem_zalloc(sizeof (struct MouseStateInfo), KM_SLEEP);
203 	WR(qp)->q_ptr = qp->q_ptr;
204 
205 	/* initialize state */
206 	STATEP->format = VUID_NATIVE;
207 
208 	qprocson(qp);
209 
210 #ifdef	VUID_OPEN
211 	if (VUID_OPEN(qp) != 0) {
212 		qprocsoff(qp);
213 
214 		mutex_enter(&vuidmice_lock);
215 		module_open--;
216 		mutex_exit(&vuidmice_lock);
217 		kmem_free(qp->q_ptr, sizeof (struct MouseStateInfo));
218 		qp->q_ptr = NULL;
219 		return (ENXIO);
220 	}
221 #endif
222 
223 	return (0);
224 }
225 
226 /* ARGSUSED1 */
227 static int
228 vuidmice_close(queue_t *const qp, const int flag, const cred_t *const crp)
229 {
230 	ASSERT(qp != NULL);
231 
232 	qprocsoff(qp);
233 	flushq(qp, FLUSHALL);
234 	flushq(OTHERQ(qp), FLUSHALL);
235 
236 #ifdef	VUID_CLOSE
237 	VUID_CLOSE(qp);
238 #endif
239 	mutex_enter(&vuidmice_lock);
240 	module_open--;
241 	mutex_exit(&vuidmice_lock);
242 	kmem_free(qp->q_ptr, sizeof (struct MouseStateInfo));
243 	qp->q_ptr = NULL;
244 
245 	return (0);
246 }
247 
248 /*
249  * Put procedure for input from driver end of stream (read queue).
250  */
251 static int
252 vuidmice_rput(queue_t *const qp, mblk_t *mp)
253 {
254 	ASSERT(qp != NULL);
255 	ASSERT(mp != NULL);
256 
257 	/*
258 	 * Handle all the related high priority messages here, hence
259 	 * should spend the least amount of time here.
260 	 */
261 
262 	if (DB_TYPE(mp) == M_DATA) {
263 		if ((int)STATEP->format ==  VUID_FIRM_EVENT)
264 			return (putq(qp, mp));   /* queue message & return */
265 	} else if (DB_TYPE(mp) == M_FLUSH) {
266 			if (*mp->b_rptr & FLUSHR)
267 				flushq(qp, FLUSHALL);
268 	}
269 
270 	putnext(qp, mp);	/* pass it on */
271 	return (0);
272 }
273 
274 static int
275 vuidmice_rsrv(queue_t *const qp)
276 {
277 	register mblk_t *mp;
278 
279 	ASSERT(qp != NULL);
280 
281 	while ((mp = getq(qp)) != NULL) {
282 		ASSERT(DB_TYPE(mp) == M_DATA);
283 
284 		if (!canputnext(qp))
285 			return (putbq(qp, mp)); /* read side is blocked */
286 
287 		switch (DB_TYPE(mp)) {
288 		case M_DATA:
289 			if ((int)STATEP->format == VUID_FIRM_EVENT)
290 				(void) VUID_QUEUE(qp, mp);
291 			else
292 				(void) putnext(qp, mp);
293 			break;
294 
295 		default:
296 			cmn_err(CE_WARN,
297 			    "vuidmice_rsrv: bad message type (0x%x)\n",
298 			    DB_TYPE(mp));
299 
300 			(void) putnext(qp, mp);
301 			break;
302 		}
303 	}
304 	return (0);
305 }
306 
307 /*
308  * Put procedure for write from user end of stream (write queue).
309  */
310 static int
311 vuidmice_wput(queue_t *const qp, mblk_t *mp)
312 {
313 	int	error = 0;
314 
315 	ASSERT(qp != NULL);
316 	ASSERT(mp != NULL);
317 
318 	/*
319 	 * Handle all the related high priority messages here, hence
320 	 * should spend the least amount of time here.
321 	 */
322 	switch (DB_TYPE(mp)) {	/* handle hi pri messages here */
323 	case M_FLUSH:
324 		if (*mp->b_rptr & FLUSHW)
325 			flushq(qp, FLUSHALL);
326 		putnext(qp, mp);			/* pass it on */
327 		return (0);
328 
329 	case M_IOCTL: {
330 		struct iocblk *iocbp = (void *)mp->b_rptr;
331 
332 		switch (iocbp->ioc_cmd) {
333 		case VUIDSFORMAT:
334 
335 			/*
336 			 * VUIDSFORMAT is known to the stream head and thus
337 			 * is guaranteed to be an I_STR ioctl.
338 			 */
339 			if (iocbp->ioc_count == TRANSPARENT) {
340 				miocnak(qp, mp, 0, EINVAL);
341 				return (0);
342 			} else {
343 				int format_type;
344 
345 				error = miocpullup(mp, sizeof (int));
346 				if (error != 0) {
347 					miocnak(qp, mp, 0, error);
348 					return (0);
349 				}
350 
351 				format_type =
352 				    *(int *)(void *)mp->b_cont->b_rptr;
353 				STATEP->format = (uchar_t)format_type;
354 				iocbp->ioc_rval = 0;
355 				iocbp->ioc_count = 0;
356 				iocbp->ioc_error = 0;
357 				mp->b_datap->db_type = M_IOCACK;
358 			}
359 
360 			/* return buffer to pool ASAP */
361 			if (mp->b_cont) {
362 				freemsg(mp->b_cont);
363 				mp->b_cont = NULL;
364 			}
365 
366 			qreply(qp, mp);
367 			return (0);
368 
369 		case VUIDGFORMAT:
370 
371 			/* return buffer to pool ASAP */
372 			if (mp->b_cont) {
373 				freemsg(mp->b_cont); /* over written below */
374 				mp->b_cont = NULL;
375 			}
376 
377 			/*
378 			 * VUIDGFORMAT is known to the stream head and thus
379 			 * is guaranteed to be an I_STR ioctl.
380 			 */
381 			if (iocbp->ioc_count == TRANSPARENT) {
382 				miocnak(qp, mp, 0, EINVAL);
383 				return (0);
384 			}
385 
386 			mp->b_cont = allocb(sizeof (int), BPRI_MED);
387 			if (mp->b_cont == NULL) {
388 				miocnak(qp, mp, 0, EAGAIN);
389 				return (0);
390 			}
391 
392 			*(int *)(void *)mp->b_cont->b_rptr =
393 			    (int)STATEP->format;
394 			mp->b_cont->b_wptr += sizeof (int);
395 
396 			iocbp->ioc_count = sizeof (int);
397 			mp->b_datap->db_type = M_IOCACK;
398 			qreply(qp, mp);
399 			return (0);
400 
401 		case VUID_NATIVE:
402 		case VUIDSADDR:
403 		case VUIDGADDR:
404 			miocnak(qp, mp, 0, ENOTTY);
405 			return (0);
406 
407 		case MSIOBUTTONS:
408 			/* return buffer to pool ASAP */
409 			if (mp->b_cont) {
410 				freemsg(mp->b_cont); /* over written below */
411 				mp->b_cont = NULL;
412 			}
413 
414 			/*
415 			 * MSIOBUTTONS is known to streamio.c and this
416 			 * is assume to be non-I_STR & non-TRANSPARENT ioctl
417 			 */
418 
419 			if (iocbp->ioc_count == TRANSPARENT) {
420 				miocnak(qp, mp, 0, EINVAL);
421 				return (0);
422 			}
423 
424 			if (STATEP->nbuttons == 0) {
425 				miocnak(qp, mp, 0, EINVAL);
426 				return (0);
427 			}
428 
429 			mp->b_cont = allocb(sizeof (int), BPRI_MED);
430 			if (mp->b_cont == NULL) {
431 				miocnak(qp, mp, 0, EAGAIN);
432 				return (0);
433 			}
434 
435 			*(int *)(void *)mp->b_cont->b_rptr =
436 			    (int)STATEP->nbuttons;
437 			mp->b_cont->b_wptr += sizeof (int);
438 
439 			iocbp->ioc_count = sizeof (int);
440 			mp->b_datap->db_type = M_IOCACK;
441 			qreply(qp, mp);
442 			return (0);
443 
444 		/*
445 		 * New IOCTL support. Since it's explicitly mentioned
446 		 * that you can't add more ioctls to stream head's
447 		 * hard coded list, we have to do the transparent
448 		 * ioctl processing which is not very exciting.
449 		 */
450 		case VUIDGWHEELCOUNT:
451 		case VUIDGWHEELINFO:
452 		case VUIDGWHEELSTATE:
453 		case VUIDSWHEELSTATE:
454 		case MSIOSRESOLUTION:
455 			error = vuidmice_handle_wheel_resolution_ioctl(qp,
456 			    mp, iocbp->ioc_cmd);
457 			if (!error) {
458 				return (0);
459 			} else {
460 				miocnak(qp, mp, 0, error);
461 				return (0);
462 			}
463 		default:
464 			putnext(qp, mp);	/* nothing to process here */
465 
466 			return (0);
467 		}
468 
469 	} /* End of case M_IOCTL */
470 
471 	case M_IOCDATA:
472 		vuidmice_miocdata(qp, mp);
473 
474 		return (0);
475 	default:
476 		putnext(qp, mp);		/* pass it on */
477 		return (0);
478 	}
479 	/*NOTREACHED*/
480 }
481 
482 void
483 VUID_PUTNEXT(queue_t *const qp, uchar_t event_id, uchar_t event_pair_type,
484 	uchar_t event_pair, int event_value)
485 {
486 	int strikes = 1;
487 	mblk_t *bp;
488 	Firm_event *fep;
489 
490 	/*
491 	 * Give this event 3 chances to allocate blocks,
492 	 * otherwise discard this mouse event.  3 Strikes and you're out.
493 	 */
494 	while ((bp = allocb((int)sizeof (Firm_event), BPRI_HI)) == NULL) {
495 		if (++strikes > 3)
496 			return;
497 		drv_usecwait(10);
498 	}
499 
500 	fep = (void *)bp->b_wptr;
501 	fep->id = vuid_id_addr(VKEY_FIRST) | vuid_id_offset(event_id);
502 
503 	fep->pair_type	= event_pair_type;
504 	fep->pair	= event_pair;
505 	fep->value	= event_value;
506 	uniqtime32(&fep->time);
507 	bp->b_wptr += sizeof (Firm_event);
508 
509 	if (canput(qp->q_next))
510 		putnext(qp, bp);
511 	else
512 		(void) putbq(qp, bp); /* read side is blocked */
513 }
514 
515 
516 /*
517  * vuidmice_miocdata
518  *	M_IOCDATA processing for IOCTL's: VUIDGWHEELCOUNT, VUIDGWHEELINFO,
519  *	VUIDGWHEELSTATE, VUIDSWHEELSTATE & MSIOSRESOLUTION.
520  */
521 static void
522 vuidmice_miocdata(queue_t *qp, mblk_t  *mp)
523 {
524 	struct copyresp		*copyresp;
525 	struct iocblk		*iocbp;
526 	mblk_t			*ioctmp;
527 	mblk_t			*datap;
528 	Mouse_iocstate_t	*Mouseioc;
529 	size_t			size;
530 	int			err = 0;
531 
532 
533 	copyresp = (void *)mp->b_rptr;
534 	iocbp = (void *)mp->b_rptr;
535 
536 	if (copyresp->cp_rval) {
537 		err = EAGAIN;
538 
539 		goto err;
540 	}
541 	switch (copyresp->cp_cmd) {
542 	case VUIDGWHEELCOUNT:
543 		mp->b_datap->db_type = M_IOCACK;
544 		mp->b_wptr = mp->b_rptr + sizeof (struct iocblk);
545 		iocbp->ioc_error = 0;
546 		iocbp->ioc_count = 0;
547 		iocbp->ioc_rval = 0;
548 		if (mp->b_cont != NULL) {
549 			freemsg(mp->b_cont);
550 			mp->b_cont = NULL;
551 		}
552 
553 		break;
554 	case VUIDGWHEELINFO:
555 	case VUIDGWHEELSTATE:
556 		ioctmp = copyresp->cp_private;
557 		Mouseioc = (void *)ioctmp->b_rptr;
558 		if (Mouseioc->ioc_state == GETSTRUCT) {
559 			if (mp->b_cont == NULL) {
560 				err = EINVAL;
561 
562 				break;
563 			}
564 			datap = mp->b_cont;
565 			if (copyresp->cp_cmd == VUIDGWHEELSTATE) {
566 				err = vuidmice_service_wheel_state(qp, datap,
567 				    VUIDGWHEELSTATE);
568 			} else {
569 				err = vuidmice_service_wheel_info(datap);
570 			}
571 			if (err) {
572 				break;
573 			}
574 
575 			if (copyresp->cp_cmd == VUIDGWHEELSTATE) {
576 				size = sizeof (wheel_state);
577 			} else {
578 				size = sizeof (wheel_info);
579 			}
580 
581 			Mouseioc->ioc_state = GETRESULT;
582 			ASSERT(Mouseioc->u_addr != NULL);
583 			mcopyout(mp, ioctmp, size, Mouseioc->u_addr, NULL);
584 		} else if (Mouseioc->ioc_state == GETRESULT) {
585 			freemsg(ioctmp);
586 			mp->b_datap->db_type = M_IOCACK;
587 			mp->b_wptr = mp->b_rptr + sizeof (struct iocblk);
588 			iocbp->ioc_error = 0;
589 			iocbp->ioc_count = 0;
590 			iocbp->ioc_rval = 0;
591 			if (mp->b_cont != NULL) {
592 				freemsg(mp->b_cont);
593 				mp->b_cont = NULL;
594 			}
595 		}
596 
597 		break;
598 	case VUIDSWHEELSTATE:
599 	case MSIOSRESOLUTION:
600 		ioctmp = copyresp->cp_private;
601 		Mouseioc = (void *)ioctmp->b_rptr;
602 		if (mp->b_cont == NULL) {
603 			err = EINVAL;
604 
605 			break;
606 		}
607 		datap = mp->b_cont;
608 
609 		if (copyresp->cp_cmd == VUIDSWHEELSTATE) {
610 			err = vuidmice_service_wheel_state(qp,
611 			    datap, VUIDSWHEELSTATE);
612 		}
613 
614 		if (err) {
615 			break;
616 		}
617 
618 		if (mp->b_cont) {
619 			freemsg(mp->b_cont);
620 			mp->b_cont = NULL;
621 		}
622 		freemsg(ioctmp);
623 		iocbp->ioc_count = 0;
624 		iocbp->ioc_error = 0;
625 		iocbp->ioc_rval = 0;
626 		mp->b_datap->db_type = M_IOCACK;
627 
628 		break;
629 	default:
630 		err = EINVAL;
631 
632 		break;
633 	}
634 
635 err:
636 	if (err) {
637 		mp->b_datap->db_type = M_IOCNAK;
638 		if (mp->b_cont) {
639 			freemsg(mp->b_cont);
640 			mp->b_cont = NULL;
641 		}
642 		if (copyresp->cp_private) {
643 			freemsg(copyresp->cp_private);
644 			copyresp->cp_private = NULL;
645 		}
646 		iocbp->ioc_count = 0;
647 		iocbp->ioc_error = err;
648 	}
649 	qreply(qp, mp);
650 }
651 
652 
653 /*
654  * vuidmice_handle_wheel_resolution_ioctl
655  *	Handle wheel mouse and MSIOSRESOLUTION ioctls.
656  *
657  * Here we also support non-transparent way of these ioctls
658  * just like usb mouse driver does, so the consms module is
659  * very simple to deal with these ioctls.
660  */
661 static int
662 vuidmice_handle_wheel_resolution_ioctl(queue_t *qp, mblk_t *mp, int cmd)
663 {
664 	int			err = 0;
665 	Mouse_iocstate_t	*Mouseioc;
666 	caddr_t			useraddr;
667 	size_t			size;
668 	mblk_t			*ioctmp;
669 	mblk_t			*datap;
670 
671 	struct iocblk *iocbp = (void *)mp->b_rptr;
672 
673 	if (iocbp->ioc_count == TRANSPARENT) {
674 		if (mp->b_cont == NULL)
675 			return (EINVAL);
676 		useraddr = *((caddr_t *)(void *)mp->b_cont->b_rptr);
677 		switch (cmd) {
678 		case VUIDGWHEELCOUNT:
679 			size = sizeof (int);
680 			if ((datap = allocb(sizeof (int), BPRI_HI)) == NULL)
681 				return (EAGAIN);
682 			*((int *)(void *)datap->b_wptr) =
683 			    STATEP->vuid_mouse_mode;
684 			mcopyout(mp, NULL, size, NULL, datap);
685 			qreply(qp, mp);
686 
687 			return (err);
688 		case VUIDGWHEELINFO:
689 			size = sizeof (wheel_info);
690 			break;
691 
692 		case VUIDSWHEELSTATE:
693 		case VUIDGWHEELSTATE:
694 			size = sizeof (wheel_state);
695 			break;
696 
697 		case MSIOSRESOLUTION:
698 			size = sizeof (Ms_screen_resolution);
699 			break;
700 		}
701 
702 		if ((ioctmp = allocb(sizeof (Mouse_iocstate_t),
703 		    BPRI_MED)) == NULL)
704 			return (EAGAIN);
705 		Mouseioc = (void *)ioctmp->b_rptr;
706 		Mouseioc->ioc_state = GETSTRUCT;
707 		Mouseioc->u_addr = useraddr;
708 		ioctmp->b_wptr = ioctmp->b_rptr + sizeof (Mouse_iocstate_t);
709 		mcopyin(mp, ioctmp, size, NULL);
710 		qreply(qp, mp);
711 
712 		return (err);
713 	} else {
714 		switch (cmd) {
715 		case VUIDGWHEELCOUNT:
716 			if (mp->b_cont) {
717 				freemsg(mp->b_cont);
718 				mp->b_cont = NULL;
719 			}
720 			if ((datap = allocb(sizeof (int), BPRI_HI)) == NULL) {
721 				err = EAGAIN;
722 				break;
723 			}
724 			*((int *)(void *)datap->b_wptr) =
725 			    STATEP->vuid_mouse_mode;
726 			datap->b_wptr +=  sizeof (int);
727 			mp->b_cont = datap;
728 			break;
729 
730 		case VUIDGWHEELINFO:
731 			if (mp->b_cont == NULL ||
732 			    iocbp->ioc_count != sizeof (wheel_info)) {
733 				err = EINVAL;
734 				break;
735 			}
736 			datap = mp->b_cont;
737 			err = vuidmice_service_wheel_info(datap);
738 			break;
739 
740 		case VUIDSWHEELSTATE:
741 		case VUIDGWHEELSTATE:
742 			if (mp->b_cont == NULL ||
743 			    iocbp->ioc_count != sizeof (wheel_state)) {
744 				err = EINVAL;
745 				break;
746 			}
747 			datap = mp->b_cont;
748 			err = vuidmice_service_wheel_state(qp, datap, cmd);
749 			break;
750 
751 		case MSIOSRESOLUTION:
752 			/*
753 			 * Now we just make Xserver and
754 			 * the virtual mouse happy. Of course,
755 			 * the screen resolution value may
756 			 * be used later for absolute PS/2 mouse.
757 			 */
758 			err = 0;
759 			break;
760 		}
761 
762 		if (!err) {
763 			mp->b_datap->db_type = M_IOCACK;
764 			iocbp->ioc_rval = 0;
765 			iocbp->ioc_error = 0;
766 			qreply(qp, mp);
767 		}
768 
769 		return (err);
770 	}
771 }
772 
773 static int
774 vuidmice_service_wheel_info(register mblk_t *datap)
775 {
776 	wheel_info		*wi;
777 	int			err = 0;
778 
779 	wi = (void *)datap->b_rptr;
780 	if (wi->vers != VUID_WHEEL_INFO_VERS) {
781 		err = EINVAL;
782 		return (err);
783 	}
784 
785 	if (wi->id > (VUIDMICE_NUM_WHEELS - 1)) {
786 		err = EINVAL;
787 		return (err);
788 	}
789 	wi->format = (wi->id == VUIDMICE_VERTICAL_WHEEL_ID) ?
790 	    VUID_WHEEL_FORMAT_VERTICAL : VUID_WHEEL_FORMAT_HORIZONTAL;
791 
792 	return (err);
793 }
794 
795 
796 static int
797 vuidmice_service_wheel_state(register queue_t	*qp,
798 			    register mblk_t	*datap,
799 			    register uint_t	cmd)
800 {
801 	wheel_state	*ws;
802 	uint_t		err = 0;
803 
804 	ws = (void *)datap->b_rptr;
805 	if (ws->vers != VUID_WHEEL_STATE_VERS) {
806 		err = EINVAL;
807 		return (err);
808 	}
809 
810 	if (ws->id > (VUIDMICE_NUM_WHEELS - 1)) {
811 		err = EINVAL;
812 		return (err);
813 	}
814 
815 	switch (cmd) {
816 	case	VUIDGWHEELSTATE:
817 		ws->stateflags =
818 		    (STATEP->wheel_state_bf >> ws->id) & 1;
819 
820 		break;
821 	case	VUIDSWHEELSTATE:
822 		STATEP->wheel_state_bf = (ws->stateflags << ws->id) |
823 		    (STATEP->wheel_state_bf & ~(1 << ws->id));
824 
825 		break;
826 	default:
827 		err = EINVAL;
828 
829 		return (err);
830 	}
831 
832 	return (err);
833 }
834