xref: /titanic_41/usr/src/uts/sun/io/ttymux/ttymux.c (revision 179184d3e9bc6ab146407a62a8461338687b1908)
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 2006 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  * DESCRIPTION
30  *
31  * ttymux - Multiplexer driver for multiplexing termio compliant streams onto
32  * a single upper stream.
33  *
34  * ADD2FRONT macro can be used to specify the order in which a console
35  * device is put in the queue of multiplexed physical serial devices,
36  * during the association and disassociation of a console interface.
37  * When this macro is defined, the device is placed in front of the queue,
38  * otherwise by default it is placed at the end.
39  * Console I/O happens to each of the physical devices in the order of
40  * their position in this queue.
41  */
42 
43 #include <sys/types.h>
44 #include <sys/file.h>
45 #include <sys/stream.h>
46 #include <sys/strsubr.h>
47 #include <sys/strlog.h>
48 #include <sys/strsun.h>
49 #include <sys/modctl.h>
50 #include <sys/debug.h>
51 #include <sys/kbio.h>
52 #include <sys/devops.h>
53 #include <sys/errno.h>
54 #include <sys/stat.h>
55 #include <sys/kmem.h>
56 #include <sys/ddi.h>
57 #include <sys/consdev.h>
58 #include <sys/tty.h>
59 #include <sys/ptyvar.h>
60 #include <sys/termio.h>
61 #include <sys/fcntl.h>
62 #include <sys/mkdev.h>
63 #include <sys/ser_sync.h>
64 #include <sys/esunddi.h>
65 #include <sys/policy.h>
66 
67 #include <sys/ttymux.h>
68 #include "ttymux_impl.h"
69 
70 /*
71  * Extern declarations
72  */
73 extern mblk_t *mkiocb(uint_t);
74 extern int nulldev();
75 extern uintptr_t space_fetch(char *key);
76 
77 extern int sm_ioctl_cmd(sm_uqi_t *, mblk_t *);
78 extern int ttymux_abort_ioctl(mblk_t *);
79 extern int ttymux_device_fini(sm_lqi_t *);
80 extern int ttymux_device_init(sm_lqi_t *);
81 
82 /*
83  * Exported interfaces
84  */
85 int sm_disassociate(int, sm_lqi_t *, ulong_t);
86 int sm_associate(int, sm_lqi_t *, ulong_t, uint_t, char *);
87 
88 /*
89  * Variables defined here and visible only internally
90  */
91 sm_ss_t		*sm_ssp = 0;
92 static int	sm_instance = 0;
93 static int	smctlunit;
94 
95 static uint_t	sm_default_trflag = 0;
96 uint_t		sm_max_units = 6;
97 uint_t		sm_minor_cnt = 0;
98 static uint_t	sm_refuse_opens = 0;
99 
100 /*
101  * Local definitions.
102  */
103 
104 /* force these flags to be unset on console devices */
105 static ulong_t	sm_cmask = (ulong_t)(CRTSXOFF|CRTSCTS);
106 
107 /*
108  * SECTION
109  * Implementation Section:
110  */
111 void
112 sm_debug(char *msg, ...)
113 {
114 	va_list	args;
115 	char	buf[256];
116 	int	sz;
117 
118 	va_start(args, msg);
119 	sz = vsnprintf(buf, sizeof (buf), msg, args);
120 	va_end(args);
121 
122 	if (sz < 0)
123 		(void) strlog(ddi_driver_major(sm_ssp->sm_dip), sm_instance, 1,
124 		    SL_TRACE, "vsnprintf parse error\n");
125 	else if (sz > sizeof (buf)) {
126 		char *b;
127 		size_t	len = sz + 1;
128 
129 		b = kmem_alloc(len, KM_SLEEP);
130 		va_start(args, msg);
131 		sz = vsnprintf(b, len, msg, args);
132 		va_end(args);
133 		if (sz > 0)
134 			(void) strlog(ddi_driver_major(sm_ssp->sm_dip),
135 			    sm_instance, 1, SL_TRACE, b);
136 		kmem_free(b, len);
137 	} else {
138 
139 		(void) strlog(ddi_driver_major(sm_ssp->sm_dip), sm_instance,
140 		    1, SL_TRACE, buf);
141 	}
142 }
143 
144 void
145 sm_log(char *msg, ...)
146 {
147 	va_list	args;
148 	char	buf[128];
149 	int	sz;
150 
151 	va_start(args, msg);
152 	sz = vsnprintf(buf, sizeof (buf), msg, args);
153 	va_end(args);
154 
155 	if (sz < 0)
156 		(void) strlog(ddi_driver_major(sm_ssp->sm_dip), sm_instance, 1,
157 		    SL_TRACE, "vsnprintf parse error\n");
158 	else if (sz > sizeof (buf)) {
159 		char *b;
160 		size_t	len = sz + 1;
161 
162 		b = kmem_alloc(len, KM_SLEEP);
163 		va_start(args, msg);
164 		sz = vsnprintf(b, len, msg, args);
165 		va_end(args);
166 		if (sz > 0)
167 			(void) strlog(ddi_driver_major(sm_ssp->sm_dip),
168 			    sm_instance, 1, SL_NOTE, b);
169 		kmem_free(b, len);
170 	} else {
171 
172 		(void) strlog(ddi_driver_major(sm_ssp->sm_dip), sm_instance,
173 		    1, SL_NOTE, buf);
174 	}
175 }
176 
177 /*
178  * Should only be called if the caller can guarantee that the vnode
179  * and/or the stream won't disappear while finding the dip.
180  * This routine is only called during an I_PLINK request so it's safe.
181  * The routine obtains the dev_t for a linked se stream.
182  */
183 static void
184 sm_setdip(queue_t *q, sm_lqi_t *lqi)
185 {
186 	lqi->sm_dev = q && STREAM(q) ? STREAM(q)->sd_vnode->v_rdev : NODEV;
187 }
188 
189 /*
190  * Called from driver close, state change reports and I_PUNLINK ioctl.
191  * A lower stream has been unlinked - clean up the state associated with it.
192  */
193 void
194 sm_lqifree(sm_lqi_t *lqi)
195 {
196 	int mu_owned;
197 	sm_lqi_t **pplqi;
198 
199 	ASSERT(mutex_owned(lqi->sm_umutex));
200 	ASSERT(SM_RQ(lqi) != 0);
201 
202 	/*
203 	 * Clear all state associated with this lower queue except
204 	 * the identity of the queues themselves and the link id which
205 	 * can only be cleared by issuing a streams I_PUNLINK ioctl.
206 	 *
207 	 * The association of a lower queue is a two step process:
208 	 * 1. initialise the lower q data structure on I_PLINK
209 	 * 2. associate an upper q with the lower q on SM_CMD_ASSOCIATE.
210 	 *
211 	 * If step 2 has ocurred then
212 	 * remove this lower queue info from the logical unit.
213 	 */
214 	if (lqi->sm_uqi) {
215 		sm_dbg('Y', ("lqifree unit %d, ", lqi->sm_uqi->sm_lunit));
216 		if ((mu_owned = mutex_owned(lqi->sm_uqi->sm_umutex)) == 0)
217 			LOCK_UNIT(lqi->sm_uqi);
218 
219 		pplqi = &lqi->sm_uqi->sm_lqs;
220 		while (*pplqi != lqi) {
221 			ASSERT(*pplqi);
222 			pplqi = &((*pplqi)->sm_nlqi);
223 		}
224 		*pplqi = lqi->sm_nlqi;
225 		lqi->sm_uqi->sm_nlqs--;
226 
227 		if (mu_owned == 0)
228 			UNLOCK_UNIT(lqi->sm_uqi);
229 
230 		lqi->sm_uqi = 0;
231 	}
232 }
233 
234 /*
235  * Given a q return the associated lower queue data structure or NULL.
236  * Return the data locked.
237  */
238 static sm_lqi_t *
239 get_lqi_byq(queue_t *q)
240 {
241 	int i;
242 	sm_lqi_t *lqi, *flqi = 0;
243 
244 	for (i = 0; i < MAX_LQS; i++) {
245 		lqi = &sm_ssp->sm_lqs[i];
246 		LOCK_UNIT(lqi);
247 		if (flqi == 0 && lqi->sm_linkid == 0) /* assumes muxids != 0 */
248 			flqi = lqi;
249 		else if (SM_RQ(lqi) == q || SM_WQ(lqi) == q) {
250 			if (flqi)
251 				UNLOCK_UNIT(flqi);
252 			return (lqi);
253 		}
254 		else
255 			UNLOCK_UNIT(lqi);
256 	}
257 	return (flqi);
258 }
259 
260 /*
261  * Given a streams link identifier return the associated lower queue data
262  * structure or NULL.
263  */
264 sm_lqi_t *
265 get_lqi_byid(int linkid)
266 {
267 	int i;
268 	sm_lqi_t *lqi;
269 
270 	if (linkid == 0)
271 		return (NULL);
272 	for (i = 0; i < MAX_LQS; i++) {
273 		lqi = &sm_ssp->sm_lqs[i];
274 		if (lqi->sm_linkid == linkid)
275 			return (lqi);
276 	}
277 	return (NULL);
278 }
279 
280 /*
281  * Given a dev_t for a lower stream return the associated lower queue data
282  * structure or NULL.
283  */
284 sm_lqi_t *
285 get_lqi_bydevt(dev_t dev)
286 {
287 	int i;
288 	sm_lqi_t *lqi;
289 
290 	if (dev == NODEV)
291 		return (NULL);
292 
293 	for (i = 0; i < MAX_LQS; i++) {
294 		lqi = &sm_ssp->sm_lqs[i];
295 		if (lqi->sm_dev == dev)
296 			return (lqi);
297 	}
298 	return (NULL);
299 }
300 
301 /*
302  * Determine whether the input flag is set on at least
303  * howmany queues.
304  */
305 static int
306 sm_is_flag_set(sm_uqi_t *uqi, uint_t flag, uint_t howmany)
307 {
308 	sm_lqi_t *lqi;
309 
310 	if (howmany == 0)
311 		return (0);
312 
313 	for (lqi = uqi->sm_lqs; lqi; lqi = lqi->sm_nlqi) {
314 		if (lqi->sm_flags & flag)
315 			if (--howmany == 0)
316 				return (1);
317 	}
318 	return (0);
319 }
320 
321 /*
322  * How many usable queues are associated with a given upper stream
323  */
324 static int
325 sm_uwq_error(sm_uqi_t *uqi)
326 {
327 	return (sm_is_flag_set(uqi, (WERROR_MODE|HANGUP_MODE), uqi->sm_nlqs));
328 }
329 
330 /*
331  * How many of the queues associated with a given upper stream
332  * - do not - have the given flags set.
333  */
334 static int
335 sm_q_count(sm_uqi_t *uqi, uint_t flag)
336 {
337 	sm_lqi_t *lqi;
338 	int count = 0;
339 
340 	for (lqi = uqi->sm_lqs; lqi; lqi = lqi->sm_nlqi) {
341 		if ((lqi->sm_flags & flag) == 0)
342 			count++;
343 	}
344 	return (count);
345 }
346 
347 /*
348  * How many of the queues associated with a given upper stream
349  * - do not - have the given flags set.
350  */
351 static int
352 sm_qs_without(sm_uqi_t *uqi, uint_t flag, uint_t ioflag)
353 {
354 	sm_lqi_t *lqi;
355 	int count = 0;
356 
357 	for (lqi = uqi->sm_lqs; lqi; lqi = lqi->sm_nlqi) {
358 		if ((lqi->sm_flags & flag) == 0 &&
359 			(lqi->sm_ioflag & ioflag) == 0)
360 			count++;
361 	}
362 	return (count);
363 }
364 
365 /*
366  * How many usable queues are associated with a given upper stream
367  */
368 static int
369 sm_good_qs(sm_uqi_t *uqi)
370 {
371 	return (sm_q_count(uqi, (WERROR_MODE|HANGUP_MODE)));
372 }
373 
374 static int
375 sm_cnt_oqs(sm_uqi_t *uqi)
376 {
377 	return (sm_qs_without(uqi, (WERROR_MODE|HANGUP_MODE),
378 		(uint_t)FOROUTPUT));
379 }
380 
381 /*
382  * Send an ioctl downstream and remember that it was sent so that
383  * its response can be caught on the way back up.
384  */
385 static void
386 sm_issue_ioctl(void *arg)
387 {
388 	sm_lqi_t *lqi = arg;
389 	uint_t cmdflag = 0;
390 	queue_t *q = SM_WQ(lqi);
391 	int iocmd, size;
392 
393 	LOCK_UNIT(lqi);
394 
395 	lqi->sm_bid = 0;
396 	if ((lqi->sm_flags & (WERROR_MODE|HANGUP_MODE)) == 0 &&
397 		(lqi->sm_flags & (WANT_CDSTAT|WANT_TCSET))) {
398 		mblk_t *pioc;
399 
400 		if (lqi->sm_flags & WANT_TCSET) {
401 			lqi->sm_flags &= ~WANT_TCSET;
402 			iocmd = TCSETS;
403 			cmdflag = WANT_TCSET;
404 		} else if (lqi->sm_flags & WANT_SC) {
405 			lqi->sm_flags &= ~WANT_SC;
406 			iocmd = TIOCGSOFTCAR;
407 			cmdflag = WANT_SC;
408 		} else if (lqi->sm_flags & WANT_CD) {
409 			lqi->sm_flags &= ~WANT_CD;
410 			iocmd = TIOCMGET;
411 		} else if (lqi->sm_flags & WANT_CL) {
412 			lqi->sm_flags &= ~WANT_CL;
413 			iocmd = TCGETS;
414 			cmdflag = WANT_CL;
415 		} else {
416 			UNLOCK_UNIT(lqi);
417 			return;
418 		}
419 
420 		if (pioc = mkiocb(iocmd)) {
421 			if (cmdflag == WANT_TCSET) {
422 				pioc->b_cont =
423 				    sm_allocb(sizeof (struct termios),
424 				    BPRI_MED);
425 				if (pioc->b_cont == 0) {
426 					freemsg(pioc);
427 					pioc = 0;
428 				} else {
429 					struct termios *tc = (struct termios *)
430 					    pioc->b_cont->b_wptr;
431 
432 					bzero((caddr_t)tc,
433 					    sizeof (struct termios));
434 					tc->c_cflag = lqi->sm_ttycommon->
435 							t_cflag;
436 					pioc->b_cont->b_rptr =
437 					    pioc->b_cont->b_wptr;
438 					pioc->b_cont->b_wptr +=
439 					    sizeof (struct termios);
440 				}
441 				size = sizeof (struct iocblk) +
442 				    sizeof (struct termios);
443 			}
444 			else
445 				size = sizeof (struct iocblk);
446 		}
447 		else
448 			size = sizeof (struct iocblk);
449 
450 		if (pioc != 0) {
451 
452 			lqi->sm_piocid = ((struct iocblk *)pioc->b_rptr)->
453 						ioc_id;
454 			lqi->sm_flags |= SM_IOCPENDING;
455 
456 			/* lqi->sm_flags |= cmdflag; */
457 			UNLOCK_UNIT(lqi);
458 			(void) putq(q, pioc);
459 		} else {
460 			UNLOCK_UNIT(lqi);
461 			lqi->sm_bid = qbufcall(WR(q), size, BPRI_MED,
462 				sm_issue_ioctl, lqi);
463 		}
464 	}
465 	else
466 		UNLOCK_UNIT(lqi);
467 }
468 
469 /*
470  * Associate one of the drivers minor nodes with a serial device.
471  */
472 int
473 sm_associate(int unit, sm_lqi_t *plqi, ulong_t tag, uint_t ioflag, char *dp)
474 {
475 	sm_uqi_t *uqi;
476 	int rval = 0;
477 
478 	sm_dbg('Y', ("sm_associate(%d, %d, %d): ",
479 		(plqi) ? plqi->sm_linkid : 0, unit, ioflag));
480 	/*
481 	 * Check the data is valid.
482 	 * Associate a lower queue with a logical unit.
483 	 */
484 
485 	if (unit < 0 || unit >= NLUNITS || plqi == 0 ||
486 	    (uqi = get_uqi(sm_ssp, unit)) == 0) {
487 		sm_dbg('@', (" invalid: lqi=0x%p lui=0x%p:", plqi, uqi));
488 		rval = EINVAL;
489 	} else {
490 		if ((ioflag & FORIO) == 0)
491 			ioflag = FORIO;
492 
493 		LOCK_UNIT(plqi);
494 
495 		if (plqi->sm_uqi) {
496 			if (plqi->sm_uqi->sm_lunit == unit) {
497 				if ((ioflag & (uint_t)FORIO) != 0)
498 					plqi->sm_ioflag =
499 					    (ioflag & (uint_t)FORIO);
500 				rval = 0;
501 			} else {
502 				sm_dbg('@', ("already associated with unit %d:",
503 				    plqi->sm_uqi->sm_lunit));
504 				rval = EINVAL;
505 			}
506 		} else {
507 
508 			LOCK_UNIT(uqi);
509 
510 			if ((ioflag & (uint_t)FORIO) != 0)
511 				plqi->sm_ioflag = (ioflag & (uint_t)FORIO);
512 
513 			plqi->sm_ttycommon->t_cflag = uqi->sm_ttycommon->
514 							t_cflag;
515 			plqi->sm_ttycommon->t_flags = uqi->sm_ttycommon->
516 							t_flags;
517 			plqi->sm_uqi = uqi;
518 			plqi->sm_mbits = 0;
519 			plqi->sm_tag = tag;
520 
521 			if (*dp == '/')
522 				(void) strncpy(plqi->sm_path, dp, MAXPATHLEN);
523 			else
524 				*(plqi->sm_path) = '\0';
525 
526 			plqi->sm_flags |= WANT_TCSET;
527 #ifdef ADD2FRONT
528 			plqi->sm_nlqi = uqi->sm_lqs;
529 			uqi->sm_lqs = plqi;
530 #else
531 			plqi->sm_nlqi = 0;
532 			if (uqi->sm_lqs) {
533 				sm_lqi_t *lq;
534 				for (lq = uqi->sm_lqs; lq->sm_nlqi;
535 						lq = lq->sm_nlqi) {
536 				}
537 				lq->sm_nlqi = plqi;
538 			} else
539 				uqi->sm_lqs = plqi;
540 #endif
541 			uqi->sm_nlqs++;
542 
543 			(void) ttymux_device_init(plqi);
544 
545 			UNLOCK_UNIT(uqi);
546 			rval = 0;
547 			/*
548 			 * Everything looks good so it's now ok to enable lower
549 			 * queue processing.
550 			 * Note the lower queue should be enabled as soon as
551 			 * I_PLINK returns (used in sm_get_ttymodes etc).
552 			 * Schedule ioctls to obtain the terminal settings.
553 			 */
554 
555 			if ((uqi->sm_flags & FULLY_OPEN) || uqi->sm_waitq)
556 				plqi->sm_uqflags |= SM_UQVALID;
557 
558 			qenable(SM_RQ(plqi));
559 			if (plqi->sm_flags & (WANT_CDSTAT|WANT_TCSET)) {
560 				/*
561 				 * Bypass the lower half of the driver (hence
562 				 * no qwriter) and apply the current termio
563 				 * settings on the lower stream.
564 				 */
565 				UNLOCK_UNIT(plqi);
566 				if (plqi->sm_bid) {
567 					qunbufcall(SM_WQ(plqi), plqi->sm_bid);
568 					plqi->sm_bid = 0;
569 				}
570 				/*
571 				 * Only set cflags on the lower q if we know
572 				 * the settings on any other lower queue.
573 				 */
574 				sm_issue_ioctl(plqi);
575 				LOCK_UNIT(plqi);
576 
577 			}
578 		}
579 
580 		UNLOCK_UNIT(plqi);
581 	}
582 	sm_dbg('Y', ("sm_associate: rval=%d.\n", rval));
583 	return (rval);
584 }
585 
586 /*
587  * Break an association between one of the driver's minor nodes and
588  * a serial device.
589  */
590 int
591 sm_disassociate(int unit, sm_lqi_t *plqi, ulong_t tag)
592 {
593 	sm_uqi_t *uqi;
594 	int rval = 0;
595 
596 	sm_dbg('Y', ("sm_disassociate: link %d, unit %d: ",
597 	    (plqi) ? plqi->sm_linkid : 0, unit));
598 	/*
599 	 * Check the data is valid.
600 	 * Disassociate a lower queue with a logical unit.
601 	 */
602 	if (unit < 0 || unit >= NLUNITS || plqi == 0 ||
603 	    (uqi = get_uqi(sm_ssp, unit)) == 0) {
604 		sm_dbg('@', ("invalid: lqi=0x%p lui=0x%p", plqi, uqi));
605 		rval = EINVAL;
606 	} else {
607 		LOCK_UNIT(plqi);
608 
609 		if (plqi->sm_uqi == NULL) {
610 			sm_dbg('@', ("unit not associated"));
611 			rval = EINVAL;
612 		} else if (plqi->sm_uqi->sm_lunit != unit) {
613 			sm_dbg('@', ("unit and linkid not related",
614 			    plqi->sm_uqi->sm_lunit));
615 			rval = EINVAL;
616 		} else if (plqi->sm_tag != tag) {
617 			sm_dbg('@',
618 			    ("Invalid tag for TTYMUX_DISASSOC ioctl\n"));
619 			rval = EPERM;
620 		} else {
621 			sm_dbg('Y', ("disassociating "));
622 
623 			(void) ttymux_device_fini(plqi);
624 
625 			/*
626 			 * Indicate that carrier status is no
627 			 * longer required and that the upper
628 			 * queue should not be used by plqi
629 			 */
630 			plqi->sm_flags &= ~(WANT_CDSTAT|WANT_TCSET);
631 			plqi->sm_uqflags &= ~(SM_UQVALID|SM_OBPCNDEV);
632 			plqi->sm_ioflag = 0u;
633 
634 			sm_lqifree(plqi);
635 			rval = 0;
636 		}
637 		UNLOCK_UNIT(plqi);
638 	}
639 	sm_dbg('Y', (" rval=%d.\n", rval));
640 	return (rval);
641 
642 }
643 
644 /*
645  * Streams helper routines;
646  */
647 
648 /*
649  * Schedule a qbufcall for an upper queue.
650  * Must be called within the perimiter of the parameter q.
651  * fn must reenable the q.
652  * Called:
653  *	 whenever a message must be placed on multiple queues and allocb fails;
654  */
655 static void
656 sm_sched_uqcb(queue_t *q, int memreq, int pri, void (*fn)())
657 {
658 	sm_uqi_t	*uqi = q->q_ptr;
659 
660 	if (uqi->sm_ttybid != 0)
661 		qunbufcall(q, uqi->sm_ttybid);
662 
663 	noenable(q);
664 
665 	uqi->sm_ttybid = qbufcall(q, memreq, pri, fn, uqi);
666 }
667 
668 /*
669  * qbufcall routine to restart the queues when memory is available.
670  */
671 static void
672 sm_reenable_q(sm_uqi_t *uqi)
673 {
674 	queue_t *wq = SM_WQ(uqi);
675 
676 	if ((uqi->sm_flags & SM_STOPPED) == 0) {
677 		enableok(wq);
678 		qenable(wq);
679 	}
680 }
681 
682 /*
683  * Place a message on the write queue of each stream associated with
684  * the given upper stream.
685  */
686 static void
687 sm_senddown(sm_uqi_t *uqi)
688 {
689 	sm_lqi_t *lqi;
690 
691 	for (lqi = uqi->sm_lqs; lqi != 0; lqi = lqi->sm_nlqi) {
692 		if (lqi->sm_mp != 0) {
693 			putnext(SM_WQ(lqi), lqi->sm_mp);
694 			lqi->sm_mp = 0;
695 		}
696 	}
697 }
698 
699 /*
700  * For each lower device that should receive a write message duplicate
701  * the message block.
702  */
703 static int
704 sm_dupmsg(sm_uqi_t *uqi, mblk_t *mp)
705 {
706 	sm_lqi_t	*lqi;
707 	mblk_t	*origmp = mp;
708 
709 	for (lqi = uqi->sm_lqs; lqi != 0; lqi = lqi->sm_nlqi) {
710 		lqi->sm_mp = 0;
711 		if (lqi->sm_flags & WERROR_MODE) {
712 			continue;
713 		}
714 		if ((lqi->sm_ioflag & (uint_t)FOROUTPUT) == 0) {
715 			if (DB_TYPE(mp) == M_DATA)
716 				continue;
717 		}
718 		if (lqi->sm_nlqi == 0) {
719 			lqi->sm_mp = mp;
720 			origmp = NULL;
721 		} else if ((lqi->sm_mp = sm_copymsg(mp)) == 0) {
722 			sm_lqi_t *flqi;
723 
724 			for (flqi = uqi->sm_lqs; flqi != lqi;
725 					flqi = flqi->sm_nlqi) {
726 				if (lqi->sm_mp) {
727 				/* must have been sm_copymsg */
728 					sm_freemsg(lqi->sm_mp);
729 					lqi->sm_mp = 0;
730 				}
731 			}
732 			return (sm_cnt_oqs(uqi) * msgdsize(mp));
733 		}
734 	}
735 	if (origmp != NULL)
736 		freemsg(origmp);
737 	return (0);
738 }
739 
740 /*
741  * Return 1 if all associated lower devices have room for another message
742  * otherwise return 0.
743  */
744 static int
745 sm_cansenddown(sm_uqi_t *uqi)
746 {
747 
748 	register sm_lqi_t	*lqi;
749 
750 	if (uqi->sm_lqs == 0)
751 		return (0);
752 
753 	for (lqi = uqi->sm_lqs; lqi != 0; lqi = lqi->sm_nlqi) {
754 		if ((lqi->sm_flags & WERROR_MODE) == 0 &&
755 		    canputnext(SM_WQ(lqi)) == 0)
756 			return (0);
757 	}
758 	return (1);
759 }
760 
761 /*
762  * Put a message down all associated lower queues.
763  * Return 1 if the q function was called.
764  */
765 static int
766 sm_putqs(queue_t *q, mblk_t *mp, int (*qfn)())
767 {
768 	register sm_uqi_t *uqi = (sm_uqi_t *)q->q_ptr;
769 	register int memreq;
770 	int pri = (DB_TYPE(mp) < QPCTL) ? BPRI_MED : BPRI_HI;
771 	int rval = 0;
772 
773 	if (uqi->sm_lqs == 0 || (uqi->sm_flags & WERROR_MODE)) {
774 
775 		sm_dbg('Q', ("sm_putqs: freeing (0x%p 0x%p).\n", uqi->sm_lqs,
776 					uqi->sm_flags));
777 		freemsg(mp);
778 	} else if (pri != BPRI_HI && sm_cansenddown(uqi) == 0) {
779 		/* a lower q is flow controlled */
780 		(void) qfn(q, mp);
781 		rval = 1;
782 	} else if ((memreq = sm_dupmsg(uqi, mp)) == 0) {
783 
784 		sm_senddown(uqi);
785 
786 	} else {
787 		sm_log("sm_putqs: msg 0x%x - can't alloc %d bytes (pri %d).\n",
788 				DB_TYPE(mp), memreq, pri);
789 		sm_sched_uqcb(q, memreq, pri, sm_reenable_q);
790 
791 		(void) qfn(q, mp);
792 		rval = 1;
793 
794 	}
795 
796 	return (rval);
797 }
798 
799 /*
800  * Service a streams link and unlink requests.
801  */
802 static void
803 sm_link_req(queue_t *wq, mblk_t *mp)
804 {
805 	struct linkblk *linkp;
806 	int rval;
807 	int cmd;
808 	sm_lqi_t *plqi;
809 
810 	ASSERT(DB_TYPE(mp) == M_IOCTL);
811 
812 	cmd = ((struct iocblk *)mp->b_rptr)->ioc_cmd;
813 	switch (cmd) {
814 
815 	case I_LINK:
816 	case I_PLINK:
817 		sm_dbg('G', ("sm_link_req: M_IOCTL %x (I_PLINK).\n", cmd));
818 
819 		linkp = (struct linkblk *)mp->b_cont->b_rptr;
820 
821 		/*
822 		 * 1.	Sanity check the link block.
823 		 * 2.	Validate that the queue is not already linked
824 		 *		(and resources available).
825 		 * 3.	Validate that the lower queue is not associated with
826 		 *		a logical unit.
827 		 * 4.	Remember that this lower queue is linked to the driver.
828 		 */
829 		if ((linkp == NULL) || (MBLKL(mp) < sizeof (*linkp)) ||
830 			linkp->l_qbot == NULL) {
831 			sm_dbg('I', ("sm_link_req: invalid link block.\n"));
832 			rval = EINVAL;
833 		} else if ((plqi = get_lqi_byq(linkp->l_qbot)) == 0) {
834 			sm_dbg('I', ("sm_link_req: out of resources.\n"));
835 			rval = EBUSY; /* out of resources */
836 		} else if (plqi->sm_uqi) {
837 			UNLOCK_UNIT(plqi); /* was aquired by get_lqi_byq */
838 			sm_dbg('I', ("sm_link_req: already associated.\n"));
839 			rval = EBUSY; /* already linked */
840 		} else {
841 			SM_WQ(plqi) = linkp->l_qbot;
842 			SM_RQ(plqi)	= OTHERQ(linkp->l_qbot);
843 
844 			linkp->l_qbot->q_ptr =
845 				OTHERQ(linkp->l_qbot)->q_ptr = plqi;
846 			plqi->sm_linkid = linkp->l_index;
847 			UNLOCK_UNIT(plqi); /* was aquired by get_lqi_byq */
848 
849 			sm_dbg('H', ("sm_link_req: linkid = %d.\n",
850 				linkp->l_index));
851 
852 			sm_setdip(linkp->l_qbot, plqi);
853 			plqi->sm_ttycommon->t_flags = 0;
854 			plqi->sm_ttycommon->t_cflag = 0;
855 			plqi->sm_mbits = 0;
856 			(void) ttymux_device_init(plqi);
857 			rval = 0;
858 		}
859 
860 		break;
861 
862 	case I_UNLINK:
863 	case I_PUNLINK:
864 		sm_dbg('G', ("sm_link_req: M_IOCTL (I_PUNLINK).\n"));
865 
866 		linkp = (struct linkblk *)mp->b_cont->b_rptr;
867 
868 		if ((linkp == NULL) ||
869 			(MBLKL(mp) < sizeof (*linkp)) ||
870 			linkp->l_qbot == NULL) {
871 			rval = EINVAL;
872 		} else if ((plqi = get_lqi_byid(linkp->l_index)) == 0) {
873 			rval = EINVAL;
874 		} else {
875 			sm_uqi_t *uqi;
876 			int werrmode;
877 
878 			/*
879 			 * Mark the lower q as invalid.
880 			 */
881 			sm_dbg('G', ("I_PUNLINK: freeing link %d\n",
882 					linkp->l_index));
883 
884 			if (plqi->sm_bid) {
885 				qunbufcall(SM_RQ(plqi), plqi->sm_bid);
886 				plqi->sm_bid = 0;
887 			}
888 			if (plqi->sm_ttybid) {
889 				qunbufcall(SM_RQ(plqi), plqi->sm_ttybid);
890 				plqi->sm_ttybid = 0;
891 			}
892 
893 			uqi = plqi->sm_uqi;
894 
895 
896 			(void) ttymux_device_fini(plqi);
897 
898 			if (uqi)
899 				(void) sm_disassociate(uqi->sm_lunit,
900 					plqi, plqi->sm_tag);
901 
902 			LOCK_UNIT(plqi);
903 
904 			plqi->sm_piocid = 0;
905 
906 			werrmode = (plqi->sm_flags & (WERROR_MODE|HANGUP_MODE))
907 			    ? 1 : 0;
908 
909 			plqi->sm_mbits = 0;
910 			plqi->sm_flags = 0;
911 
912 			ttycommon_close(plqi->sm_ttycommon);
913 			/* SM_RQ(plqi) = SM_WQ(plqi) = 0; */
914 			plqi->sm_ttycommon->t_flags = 0;
915 			plqi->sm_ttycommon->t_cflag = 0;
916 			plqi->sm_ttycommon->t_iflag = 0;
917 			plqi->sm_linkid = 0;
918 			plqi->sm_dev = NODEV;
919 			plqi->sm_hadkadbchar = 0;
920 			plqi->sm_nachar = sm_ssp->sm_abs;
921 
922 			UNLOCK_UNIT(plqi);
923 			if (uqi &&
924 			    werrmode &&
925 			    (uqi->sm_flags & FULLY_OPEN) &&
926 			    sm_uwq_error(uqi) &&
927 			    putnextctl(SM_RQ(uqi), M_HANGUP) == 0) {
928 				sm_log("sm_link_req: putnextctl(M_HANGUP)"
929 					" failed.\n");
930 			}
931 
932 			rval = 0;
933 		}
934 
935 		break;
936 	default:
937 		rval = EINVAL;
938 	}
939 	if (rval != 0)
940 		miocnak(wq, mp, 0, rval);
941 	else
942 		miocack(wq, mp, 0, 0);
943 }
944 
945 static int
946 sm_getiocinfo(mblk_t *mp, struct sm_iocinfo *info)
947 {
948 	switch (DB_TYPE(mp)) {
949 	case M_COPYOUT:
950 		info->sm_id = ((struct copyreq *)mp->b_rptr)->cq_id;
951 		info->sm_cmd = ((struct copyreq *)mp->b_rptr)->cq_cmd;
952 		info->sm_data = (((struct copyreq *)mp->b_rptr)->cq_size &&
953 		    mp->b_cont) ? (void *)mp->b_cont->b_rptr : 0;
954 		break;
955 	case M_COPYIN:
956 		info->sm_id = ((struct copyresp *)mp->b_rptr)->cp_id;
957 		info->sm_cmd = ((struct copyresp *)mp->b_rptr)->cp_cmd;
958 		info->sm_data = 0;
959 		break;
960 	case M_IOCACK:
961 		info->sm_id = ((struct iocblk *)mp->b_rptr)->ioc_id;
962 		info->sm_cmd = ((struct iocblk *)mp->b_rptr)->ioc_cmd;
963 		/* the se driver has bug so we cannot use ioc_count */
964 		info->sm_data = (((struct iocblk *)mp->b_rptr)->
965 					ioc_error == 0 && mp->b_cont) ?
966 					(void *)mp->b_cont->b_rptr : 0;
967 		break;
968 	case M_IOCNAK:
969 		info->sm_id = ((struct iocblk *)mp->b_rptr)->ioc_id;
970 		info->sm_cmd = ((struct iocblk *)mp->b_rptr)->ioc_cmd;
971 		info->sm_data = 0;
972 		break;
973 	case M_IOCDATA:
974 		info->sm_id = ((struct copyresp *)mp->b_rptr)->cp_id;
975 		info->sm_cmd = ((struct copyresp *)mp->b_rptr)->cp_cmd;
976 		info->sm_data = (((struct copyresp *)mp->b_rptr)->
977 					cp_rval == 0 && mp->b_cont) ?
978 					(void *)mp->b_cont->b_rptr : 0;
979 		break;
980 	case M_IOCTL:
981 		info->sm_id = ((struct iocblk *)mp->b_rptr)->ioc_id;
982 		info->sm_cmd = ((struct iocblk *)mp->b_rptr)->ioc_cmd;
983 		info->sm_data = 0;
984 		break;
985 	default:
986 		return (EINVAL);
987 	}
988 	return (0);
989 }
990 
991 /*
992  * Record the termio settings that have been set on the upper stream
993  */
994 static int
995 sm_update_ttyinfo(mblk_t *mp, sm_uqi_t *uqi)
996 {
997 	int err;
998 	struct sm_iocinfo info;
999 
1000 	if ((err = sm_getiocinfo(mp, &info)) != 0)
1001 		return (err);
1002 
1003 	switch (info.sm_cmd) {
1004 	case TIOCSPPS:
1005 	case TIOCGPPS:
1006 	case TIOCGPPSEV:
1007 		return (ENOTSUP);
1008 	case TIOCGWINSZ:
1009 	case TIOCSWINSZ:
1010 		break;
1011 	case TCSBRK:
1012 	case TIOCSBRK:
1013 	case TIOCCBRK:
1014 		break;
1015 	case TCSETSF:
1016 		uqi->sm_flags |= FLUSHR_PEND;
1017 		sm_dbg('I', ("TCSETSF: FLUSH is pending\n"));
1018 		/*FALLTHROUGH*/
1019 	case TCSETSW:
1020 	case TCSETS:
1021 	case TCGETS:
1022 		if (info.sm_data != 0) {
1023 			((struct termios *)info.sm_data)->c_cflag &=
1024 			    (tcflag_t)(~uqi->sm_cmask);
1025 			uqi->sm_ttycommon->t_cflag =
1026 			    ((struct termios *)info.sm_data)->c_cflag;
1027 		}
1028 		break;
1029 	case TCSETAF:
1030 		sm_dbg('I', ("TCSETAF: FLUSH is pending\n"));
1031 		uqi->sm_flags |= FLUSHR_PEND;
1032 		/*FALLTHROUGH*/
1033 	case TCSETAW:
1034 	case TCSETA:
1035 	case TCGETA:
1036 		if (info.sm_data != 0) {
1037 			((struct termio *)info.sm_data)->c_cflag &=
1038 			    (tcflag_t)(~uqi->sm_cmask);
1039 			uqi->sm_ttycommon->t_cflag =
1040 			    (tcflag_t)((struct termio *)info.sm_data)->c_cflag;
1041 		}
1042 		break;
1043 	case TIOCSSOFTCAR:
1044 	case TIOCGSOFTCAR:
1045 		if (info.sm_data != 0) {
1046 			if (*(int *)info.sm_data == 1)
1047 				uqi->sm_ttycommon->t_flags |= TS_SOFTCAR;
1048 			else
1049 				uqi->sm_ttycommon->t_flags &= ~TS_SOFTCAR;
1050 		}
1051 		break;
1052 	case TIOCMSET:
1053 	case TIOCMGET:
1054 		if (info.sm_data != 0)
1055 			uqi->sm_mbits = *(int *)info.sm_data;
1056 		break;
1057 	case TIOCMBIS:
1058 		if (info.sm_data != 0)
1059 			uqi->sm_mbits |= *(int *)info.sm_data;
1060 		break;
1061 	case TIOCMBIC:
1062 		if (info.sm_data != 0)
1063 			uqi->sm_mbits &= ~(*(int *)info.sm_data);
1064 		break;
1065 	default:
1066 		return (EINVAL);
1067 		/* NOTREACHED */
1068 	} /* end switch cmd */
1069 
1070 	if ((uqi->sm_mbits & TIOCM_CD) ||
1071 		(uqi->sm_ttycommon->t_flags & TS_SOFTCAR) ||
1072 		(uqi->sm_ttycommon->t_cflag & CLOCAL))
1073 		uqi->sm_flags |= SM_CARON;
1074 	else
1075 		uqi->sm_flags &= ~SM_CARON;
1076 
1077 	return (0);
1078 }
1079 
1080 /*
1081  * SECTION
1082  * STREAM's interface to the OS.
1083  * Routines directly callable from the OS.
1084  */
1085 
1086 /*
1087  * Processes high priority messages comming from modules above the
1088  * multiplexor.
1089  * Return 1 if the queue was disabled.
1090  */
1091 static int
1092 sm_hp_uwput(queue_t *wq, mblk_t *mp)
1093 {
1094 	sm_uqi_t	*uqi = (sm_uqi_t *)(wq->q_ptr);
1095 	int	rval = 0;
1096 	sm_lqi_t	*plqi;
1097 	int	msgtype = DB_TYPE(mp);
1098 
1099 	switch (msgtype) {
1100 
1101 	case M_FLUSH:
1102 		/*
1103 		 * How to flush the bottom half:
1104 		 * putctl1(SM_WQ(plqi), *mp->b_rptr)
1105 		 * will work on the bottom half but if FLUSHR is set
1106 		 * when is the right time to flush the upper read queue.
1107 		 *
1108 		 * Could set uqi->sm_flags & WANT_FLUSH but then what happens
1109 		 * if FLUSHR is set and the driver sends up a FLUSHR
1110 		 * before it handles the current FLUSHR request
1111 		 * (if only there was an id for the message that could
1112 		 * be matched when it returns back from the drivers.
1113 		 *
1114 		 * Thus I'm going by the book - the bottom half acts like
1115 		 * a stream head and turns around FLUSHW back down to
1116 		 * the driver (see lrput). The upper half acts like a
1117 		 * driver and turns around FLUSHR:
1118 		 */
1119 
1120 		sm_dbg('I', ("sm_hp_uwput: FLUSH request 0x%x\n", *mp->b_rptr));
1121 		/* flush the upper write queue */
1122 		if (*mp->b_rptr & FLUSHW)
1123 			flushq(wq, FLUSHDATA);
1124 
1125 		/*
1126 		 * flush each associated lower write queue
1127 		 * and pass down the driver (ignore the FLUSHR and deal with
1128 		 * it when it comes back up the read side.
1129 		 */
1130 		for (plqi = uqi->sm_lqs; plqi != 0; plqi = plqi->sm_nlqi) {
1131 			if ((plqi->sm_flags & WERROR_MODE) == 0 &&
1132 						SM_WQ(plqi)) {
1133 				sm_dbg('I', ("flush lq 0x%p\n", SM_WQ(plqi)));
1134 				if (*mp->b_rptr & FLUSHW)
1135 					flushq(SM_WQ(plqi), FLUSHDATA);
1136 				(void) putnextctl1(SM_WQ(plqi), M_FLUSH,
1137 				    *mp->b_rptr);
1138 			}
1139 		}
1140 		break;
1141 
1142 	case M_STARTI:
1143 		for (plqi = uqi->sm_lqs; plqi != 0; plqi = plqi->sm_nlqi) {
1144 			plqi->sm_flags &= ~SM_ISTOPPED;
1145 			if ((plqi->sm_flags & WERROR_MODE) == 0)
1146 				(void) putnextctl(SM_WQ(plqi), msgtype);
1147 		}
1148 		break;
1149 
1150 	case M_STOPI:
1151 		for (plqi = uqi->sm_lqs; plqi != 0; plqi = plqi->sm_nlqi) {
1152 			plqi->sm_flags |= SM_ISTOPPED;
1153 			if ((plqi->sm_flags & WERROR_MODE) == 0)
1154 				(void) putnextctl(SM_WQ(plqi), msgtype);
1155 		}
1156 		break;
1157 
1158 	case M_STOP:	/* must never be queued */
1159 		uqi->sm_flags |= SM_STOPPED;
1160 		noenable(wq);
1161 		for (plqi = uqi->sm_lqs; plqi != 0; plqi = plqi->sm_nlqi)
1162 			if ((plqi->sm_flags & WERROR_MODE) == 0)
1163 				(void) putnextctl(SM_WQ(plqi), msgtype);
1164 
1165 		rval = 1;
1166 		break;
1167 
1168 	case M_START:	/* never be queued */
1169 		uqi->sm_flags &= ~SM_STOPPED;
1170 		enableok(wq);
1171 		qenable(wq);
1172 		for (plqi = uqi->sm_lqs; plqi != 0; plqi = plqi->sm_nlqi)
1173 			if ((plqi->sm_flags & WERROR_MODE) == 0)
1174 				(void) putnextctl(SM_WQ(plqi), msgtype);
1175 
1176 		break;
1177 
1178 	case M_PCSIG:
1179 	case M_COPYOUT:
1180 	case M_COPYIN:
1181 	case M_IOCACK:
1182 	case M_IOCNAK:
1183 		/* Wrong direction for message */
1184 		break;
1185 	case M_READ:
1186 		break;
1187 	case M_PCPROTO:
1188 	case M_PCRSE:
1189 	default:
1190 		sm_dbg('I', ("sm_hp_uwput: default case %d.\n", msgtype));
1191 		break;
1192 	} /* end switch on high pri message type */
1193 
1194 	freemsg(mp);
1195 	return (rval);
1196 }
1197 
1198 static int
1199 sm_default_uwioctl(queue_t *wq, mblk_t *mp, int (*qfn)())
1200 {
1201 	int	err;
1202 	struct iocblk	*iobp;
1203 	sm_uqi_t	*uqi;
1204 
1205 	uqi = (sm_uqi_t *)(wq->q_ptr);
1206 	iobp = (struct iocblk *)mp->b_rptr;
1207 
1208 	switch (iobp->ioc_cmd) {
1209 	case TIOCEXCL:
1210 	case TIOCNXCL:
1211 	case TIOCSTI:
1212 		/*
1213 		 * The three ioctl types we support do not require any
1214 		 * additional allocation and should not return a pending
1215 		 * ioctl state. For this reason it is safe for us to ignore
1216 		 * the return value from ttycommon_ioctl().
1217 		 * Additionally, we translate any error response from
1218 		 * ttycommon_ioctl() into EINVAL.
1219 		 */
1220 		(void) ttycommon_ioctl(uqi->sm_ttycommon, wq, mp, &err);
1221 		if (err < 0)
1222 			miocnak(wq, mp, 0, EINVAL);
1223 		else
1224 			miocack(wq, mp, 0, 0);
1225 		return (0);
1226 	default:
1227 		break;
1228 	}
1229 	if ((err = sm_update_ttyinfo(mp, uqi)) != 0) {
1230 		miocnak(wq, mp, 0, err);
1231 		return (0);
1232 	}
1233 
1234 	/*
1235 	 * If uqi->sm_siocdata.sm_iocid just overwrite it since the stream
1236 	 * head will have timed it out
1237 	 */
1238 	uqi->sm_siocdata.sm_iocid = iobp->ioc_id;
1239 	uqi->sm_siocdata.sm_acked = 0;
1240 	uqi->sm_siocdata.sm_nacks = sm_good_qs(uqi);
1241 	uqi->sm_siocdata.sm_acnt = 0;
1242 	uqi->sm_siocdata.sm_policy = uqi->sm_policy;
1243 	uqi->sm_siocdata.sm_flags = 0;
1244 	sm_dbg('Z', (" want %d acks for id %d.\n",
1245 	    uqi->sm_siocdata.sm_nacks, iobp->ioc_id));
1246 
1247 	return (sm_putqs(wq, mp, qfn));
1248 }
1249 
1250 /*
1251  *
1252  * sm_uwput - put function for an upper STREAM write.
1253  */
1254 static int
1255 sm_uwput(queue_t *wq, mblk_t *mp)
1256 {
1257 	sm_uqi_t		*uqi;
1258 	uchar_t		msgtype;
1259 	int		cmd;
1260 	struct iocblk	*iobp;
1261 
1262 	uqi = (sm_uqi_t *)(wq->q_ptr);
1263 	msgtype = DB_TYPE(mp);
1264 
1265 	ASSERT(uqi != 0 && sm_ssp != 0);
1266 
1267 	if (msgtype >= QPCTL && msgtype != M_IOCDATA) {
1268 		(void) sm_hp_uwput(wq, mp);
1269 		return (0);
1270 	}
1271 
1272 	switch (DB_TYPE(mp)) {
1273 	case M_DATA:
1274 	case M_DELAY:
1275 	case M_BREAK:
1276 	default:
1277 		(void) sm_putqs(wq, mp, putq);
1278 		break;
1279 
1280 	case M_CTL:
1281 		if (((struct iocblk *)mp->b_rptr)->ioc_cmd == MC_CANONQUERY) {
1282 			(void) putnextctl1(OTHERQ(wq), M_CTL, MC_NOCANON);
1283 		}
1284 		freemsg(mp);
1285 		break;
1286 	case M_IOCDATA: /* not handled as high pri because may need to putbq */
1287 		sm_dbg('M', ("sm_uwput(M_IOCDATA)\n"));
1288 		/*FALLTHROUGH*/
1289 	case M_IOCTL:
1290 		cmd = (msgtype == M_IOCDATA) ?
1291 		    ((struct copyresp *)mp->b_rptr)->cp_cmd :
1292 		    ((struct iocblk *)mp->b_rptr)->ioc_cmd;
1293 
1294 		iobp = (struct iocblk *)mp->b_rptr;
1295 		iobp->ioc_rval = 0;
1296 
1297 		sm_dbg('M', ("sm_uwput(M_IOCTL:%d)\n", cmd));
1298 
1299 		switch (cmd) {
1300 
1301 		case CONSGETABORTENABLE:
1302 			iobp->ioc_error = ttymux_abort_ioctl(mp);
1303 			DB_TYPE(mp) = iobp->ioc_error ? M_IOCNAK : M_IOCACK;
1304 			qreply(wq, mp);
1305 			break;
1306 		case CONSSETABORTENABLE:
1307 			iobp->ioc_error =
1308 			    secpolicy_sys_config(iobp->ioc_cr, B_FALSE) != 0 ?
1309 				EPERM : ttymux_abort_ioctl(mp);
1310 			DB_TYPE(mp) = iobp->ioc_error ? M_IOCNAK : M_IOCACK;
1311 			qreply(wq, mp);
1312 			break;
1313 		case TTYMUX_SETABORT:
1314 			if (secpolicy_sys_config(iobp->ioc_cr, B_FALSE) != 0) {
1315 				iobp->ioc_error = EPERM;
1316 				DB_TYPE(mp) = M_IOCNAK;
1317 				qreply(wq, mp);
1318 				break;
1319 			}
1320 			/*FALLTHROUGH*/
1321 		case TTYMUX_GETABORT:
1322 		case TTYMUX_GETABORTSTR:
1323 		case TTYMUX_ASSOC:
1324 		case TTYMUX_DISASSOC:
1325 		case TTYMUX_SETCTL:
1326 		case TTYMUX_GETLINK:
1327 		case TTYMUX_CONSDEV:
1328 		case TTYMUX_GETCTL:
1329 		case TTYMUX_LIST:
1330 			(void) sm_ioctl_cmd(uqi, mp);
1331 			qreply(wq, mp);
1332 			break;
1333 		case I_LINK:
1334 		case I_PLINK:
1335 		case I_UNLINK:
1336 		case I_PUNLINK:
1337 			qwriter(wq, mp, sm_link_req, PERIM_OUTER);
1338 			break;
1339 		case TCSETSW:
1340 		case TCSETSF:
1341 		case TCSETAW:
1342 		case TCSETAF:
1343 		case TCSBRK:
1344 			if (wq->q_first) {
1345 				sm_dbg('A', ("sm_uwput: TCSET-> on srv q.\n"));
1346 				/* keep message order intact */
1347 				(void) putq(wq, mp);
1348 				break;
1349 			}
1350 			/*FALLTHROUGH*/
1351 		default:
1352 			(void) sm_default_uwioctl(wq, mp, putq);
1353 			break;
1354 		}
1355 
1356 		break; /* M_IOCTL */
1357 
1358 	} /* end switch on message type */
1359 
1360 	return (0);
1361 }
1362 
1363 /*
1364  * sm_uwsrv - service function for an upper STREAM write.
1365  * 'sm_uwsrv' takes a q parameter.	The q parameter specifies the queue
1366  * which is to be serviced.	This function reads the messages which are on
1367  * this service queue and passes them to the appropriate lower driver queue.
1368  */
1369 static int
1370 sm_uwsrv(queue_t *q)
1371 {
1372 	mblk_t	*mp;
1373 	sm_uqi_t	*uqi = (sm_uqi_t *)(q->q_ptr);
1374 	int		msgtype;
1375 
1376 	ASSERT(q == SM_WQ(uqi));
1377 
1378 	/*
1379 	 * Empty the queue unless explicitly stopped.
1380 	 */
1381 	while (mp = getq(q)) {
1382 		msgtype = DB_TYPE(mp);
1383 
1384 		if (msgtype >= QPCTL && msgtype != M_IOCDATA)
1385 			if (sm_hp_uwput(q, mp)) {
1386 				sm_dbg('T', ("sm_uwsrv: flowcontrolled.\n"));
1387 				break; /* indicates that the is disabled */
1388 			}
1389 			else
1390 				continue;
1391 
1392 		if (uqi->sm_flags & SM_STOPPED) {
1393 			(void) putbq(q, mp);
1394 			sm_dbg('T', ("sm_uwsrv: SM_STOPPED.\n"));
1395 			break;
1396 		}
1397 
1398 		/*
1399 		 * Read any ttycommon data that may
1400 		 * change (TS_SOFTCAR, CREAD, etc.).
1401 		 */
1402 		switch (DB_TYPE(mp)) {
1403 		case M_IOCTL:
1404 		case M_IOCDATA:
1405 			if (sm_default_uwioctl(q, mp, putbq))
1406 				return (0);
1407 			break;
1408 
1409 		default:
1410 			if (sm_putqs(q, mp, putbq))
1411 				return (0);
1412 		}
1413 	}
1414 	return (0);
1415 }
1416 
1417 /*
1418  * Lower write side service routine used for backenabling upstream
1419  * flow control.
1420  */
1421 static int
1422 sm_lwsrv(queue_t *q)
1423 {
1424 	sm_lqi_t *lqi = (sm_lqi_t *)q->q_ptr;
1425 	queue_t *uwq;
1426 
1427 	LOCK_UNIT(lqi);
1428 	if (lqi->sm_uqflags & SM_UQVALID) {
1429 		/*
1430 		 * It's safe to lock uqi since lwsrv runs asynchronously
1431 		 * with the upper write routines so this cannot be an
1432 		 * upper half thread. While holding the lqi lock and
1433 		 * if SM_UQVALID is set we are guaranteed that
1434 		 * lqi->sm_uqi will be valid.
1435 		 */
1436 		sm_dbg('I', ("sm_lwsrv: re-enabling upper queue.\n"));
1437 
1438 		uwq = SM_WQ(lqi->sm_uqi);
1439 		UNLOCK_UNIT(lqi);
1440 		qenable(uwq);
1441 	} else  {
1442 		UNLOCK_UNIT(lqi);
1443 	}
1444 	return (0);
1445 }
1446 
1447 /*
1448  * Upper read queue ioctl response handler for messages
1449  * passed from the lower half of the driver.
1450  */
1451 static int
1452 sm_uriocack(queue_t *rq, mblk_t *mp)
1453 {
1454 	sm_uqi_t		*uqi = (sm_uqi_t *)rq->q_ptr;
1455 	int		err, flag;
1456 	sm_iocdata_t	*iodp;
1457 	struct sm_iocinfo	info;
1458 
1459 	if ((err = sm_getiocinfo(mp, &info)) != 0) {
1460 		sm_dbg('I', ("Unknown ioctl response\n"));
1461 		return (err);
1462 	}
1463 
1464 	if (info.sm_id == uqi->sm_piocdata.sm_iocid) {
1465 		iodp = &uqi->sm_piocdata;
1466 	} else if (info.sm_id == uqi->sm_siocdata.sm_iocid) {
1467 		iodp = &uqi->sm_siocdata;
1468 	} else {
1469 		sm_log("Unexpected ioctl response\n");
1470 		sm_dbg('I', ("Unexpected ioctl response (id %d)\n",
1471 				info.sm_id));
1472 
1473 		/*
1474 		 * If the response is sent up it will result in
1475 		 * duplicate ioctl responses. The ioctl has probably been
1476 		 * timed out by the stream head so dispose of the response
1477 		 * (since it has arrived too late.
1478 		 */
1479 		goto out;
1480 	}
1481 
1482 	flag = SM_COPYIN;
1483 
1484 	switch (DB_TYPE(mp)) {
1485 	case M_COPYOUT:
1486 		flag = SM_COPYOUT;
1487 		/*FALLTHRU*/
1488 	case M_COPYIN:
1489 		if (iodp->sm_flags & flag)
1490 			goto out;
1491 		iodp->sm_flags |= flag;
1492 
1493 		break;
1494 	case M_IOCACK:
1495 		iodp->sm_ackcnt += 1;
1496 		iodp->sm_acnt += 1;
1497 		if (iodp->sm_policy == FIRSTACK) {
1498 			if (iodp->sm_acnt == iodp->sm_nacks)
1499 				iodp->sm_iocid = 0;
1500 			if (iodp->sm_acnt == 1)
1501 				iodp->sm_acked = 1;
1502 			else
1503 				goto out;
1504 		} else {
1505 			if (iodp->sm_acnt == iodp->sm_nacks) {
1506 				iodp->sm_iocid = 0;
1507 				iodp->sm_acked = 1;
1508 			} else
1509 				goto out;
1510 		}
1511 		break;
1512 	case M_IOCNAK:
1513 		iodp->sm_nakcnt += 1;
1514 		iodp->sm_acnt += 1;
1515 		if (iodp->sm_acnt == iodp->sm_nacks) {
1516 			iodp->sm_iocid = 0;
1517 			if (iodp->sm_acked == 0) {
1518 				iodp->sm_acked = 1;
1519 				break;
1520 			}
1521 		}
1522 		goto out;
1523 	default:
1524 		goto out;
1525 	}
1526 
1527 	/*
1528 	 * Merge the tty settings each of the associated lower streams.
1529 	 */
1530 	if (info.sm_data)
1531 		(void) sm_update_ttyinfo(mp, uqi);
1532 
1533 	if (iodp == &uqi->sm_piocdata) {
1534 		if (iodp->sm_iocid == 0) {
1535 			uqi->sm_flags &= ~SM_IOCPENDING;
1536 		}
1537 	} else {
1538 		sm_dbg('I', ("sm_uriocack: forwarding response for %d.\n",
1539 		    info.sm_id));
1540 		putnext(rq, mp);
1541 		return (0);
1542 	}
1543 out:
1544 	sm_dbg('I', ("sm_uriocack: freeing response for %d.\n", info.sm_id));
1545 	freemsg(mp);
1546 	return (0);
1547 }
1548 
1549 /*
1550  * Transfer a message from the lower read side of the multiplexer onto
1551  * the associated upper stream.
1552  */
1553 static int
1554 sm_ursendup(queue_t *q, mblk_t *mp)
1555 {
1556 	sm_uqi_t	*uqi = (sm_uqi_t *)q->q_ptr;
1557 
1558 	if (!canputnext(q) && DB_TYPE(mp) < QPCTL) {
1559 		sm_dbg('I', ("sm_ursendup: flow controlled.\n"));
1560 		return (1);
1561 	}
1562 
1563 	switch (DB_TYPE(mp)) {
1564 	case M_COPYIN:
1565 	case M_COPYOUT:
1566 	case M_IOCACK:
1567 	case M_IOCNAK:
1568 		(void) sm_uriocack(q, mp);
1569 		break;
1570 	case M_HANGUP:
1571 		if (sm_uwq_error(uqi)) {
1572 			/* there are no usable lower q's */
1573 			uqi->sm_flags &= ~SM_CARON;
1574 			putnext(q, mp);
1575 		} else {
1576 			/* there are still usable q's - don't send up */
1577 			freemsg(mp);
1578 		}
1579 		break;
1580 	case M_ERROR:
1581 		if (sm_uwq_error(uqi)) {
1582 			/* there are no usable lower q's */
1583 			uqi->sm_flags &= ~SM_CARON;
1584 			putnext(q, mp);
1585 		} else if (*mp->b_rptr == NOERROR) {
1586 			/* the error has cleared */
1587 			uqi->sm_flags &= ~ERROR_MODE;
1588 			putnext(q, mp);
1589 		} else {
1590 			/* there are still usable q's - don't send up */
1591 			freemsg(mp);
1592 		}
1593 		break;
1594 	case M_FLUSH:
1595 		flushq(q, FLUSHDATA);
1596 		putnext(q, mp);	/* time to use FLUSHR_PEND flag */
1597 		break;
1598 	case M_CTL:
1599 		/* wrong direction - must have come from sm_close */
1600 		uqi->sm_flags |= SM_CLOSE;
1601 		sm_dbg('I', ("sm_ursrv: had SM_CLOSE.\n"));
1602 		freemsg(mp);
1603 		break;
1604 	case M_UNHANGUP:
1605 		/* just pass them all up - they're harmless */
1606 		uqi->sm_flags |= SM_CARON;
1607 		/* FALLTHROUGH */
1608 	default:
1609 		putnext(q, mp);
1610 		break;
1611 	}
1612 
1613 	return (0);
1614 }
1615 
1616 /*
1617  * sm_urput - put function for a lower STREAM read.
1618  */
1619 static int
1620 sm_urput(queue_t *q, mblk_t *mp)
1621 {
1622 	if (sm_ursendup(q, mp) != 0)
1623 		(void) putq(q, mp);
1624 
1625 	return (0);
1626 }
1627 
1628 /*
1629  * Upper read side service routine.
1630  * Read side needs to be fast so only check for duplicate M_IOCTL acks.
1631  */
1632 static int
1633 sm_ursrv(queue_t *q)
1634 {
1635 	sm_uqi_t	*uqi = (sm_uqi_t *)q->q_ptr;
1636 	mblk_t	*mp;
1637 	int	flags = uqi->sm_flags;
1638 
1639 	while ((mp = getq(q))) {
1640 		if (sm_ursendup(q, mp) != 0) {
1641 			sm_dbg('I', ("sm_ursrv: flow controlled.\n"));
1642 			(void) putbq(q, mp);
1643 			uqi->sm_flags |= WANT_RENB;
1644 			break;
1645 		}
1646 	}
1647 
1648 	/*
1649 	 * If the q service was called because it was no longer
1650 	 * flow controled then enable each of the driver queues.
1651 	 */
1652 	if ((flags & WANT_RENB) && !(uqi->sm_flags & WANT_RENB)) {
1653 		sm_lqi_t *lqi;
1654 		queue_t *drq; /* read q of linked driver */
1655 
1656 		uqi->sm_flags &= ~WANT_RENB;
1657 		for (lqi = uqi->sm_lqs; lqi != 0; lqi = lqi->sm_nlqi) {
1658 			drq = SM_RQ(lqi)->q_next;
1659 			if (drq && drq->q_first != 0)
1660 				qenable(drq);
1661 		}
1662 	}
1663 
1664 	return (0);
1665 }
1666 
1667 /*
1668  * Check a message sent from a linked device for abort requests and
1669  * for flow control.
1670  */
1671 static int
1672 sm_lrmsg_check(queue_t *q, mblk_t *mp)
1673 {
1674 	sm_lqi_t	*lqi	= (sm_lqi_t *)q->q_ptr;
1675 
1676 	switch (DB_TYPE(mp)) {
1677 	case M_DATA:
1678 		LOCK_UNIT(lqi);
1679 		/*
1680 		 * check for abort - only allow abort on I/O consoles
1681 		 * known to OBP -
1682 		 * fix it when we do polled io
1683 		 */
1684 		if ((lqi->sm_ioflag & (uint_t)FORINPUT) == 0) {
1685 			freemsg(mp);
1686 			UNLOCK_UNIT(lqi);
1687 			return (1);
1688 		}
1689 		if ((lqi->sm_uqflags & SM_OBPCNDEV) &&
1690 		    lqi->sm_ctrla_abort_on &&
1691 		    abort_enable == KIOCABORTALTERNATE) {
1692 
1693 			uchar_t		*rxc;
1694 			boolean_t	aborted = B_FALSE;
1695 
1696 			for (rxc = mp->b_rptr;
1697 			    rxc != mp->b_wptr;
1698 			    rxc++)
1699 
1700 				if (*rxc == *lqi->sm_nachar) {
1701 					lqi->sm_nachar++;
1702 					if (*lqi->sm_nachar == '\0') {
1703 						abort_sequence_enter(
1704 							(char *)NULL);
1705 						lqi->sm_nachar = sm_ssp->sm_abs;
1706 						aborted = B_TRUE;
1707 					}
1708 				} else
1709 					lqi->sm_nachar = (*rxc == *sm_ssp->
1710 								sm_abs) ?
1711 								sm_ssp->
1712 								sm_abs + 1 :
1713 								sm_ssp->sm_abs;
1714 
1715 			if (aborted) {
1716 				freemsg(mp);
1717 				UNLOCK_UNIT(lqi);
1718 				return (1);
1719 			}
1720 		}
1721 		UNLOCK_UNIT(lqi);
1722 		break;
1723 	case M_BREAK:	/* we'll eventually see this as a flush */
1724 		LOCK_UNIT(lqi);
1725 		/*
1726 		 * Only allow abort on OBP devices. When polled I/O is
1727 		 * supported allow abort on any console device.
1728 		 * Parity errors are reported upstream as breaks so
1729 		 * ensure that there is no data in the message before
1730 		 * deciding whether to abort.
1731 		 */
1732 		if ((lqi->sm_uqflags & SM_OBPCNDEV) && /* console stream */
1733 		    (mp->b_wptr - mp->b_rptr == 0 &&
1734 		    msgdsize(mp) == 0)) {	/* not due to parity */
1735 
1736 			if (lqi->sm_break_abort_on &&
1737 			    abort_enable != KIOCABORTALTERNATE)
1738 				abort_sequence_enter((char *)NULL);
1739 
1740 			freemsg(mp);
1741 			UNLOCK_UNIT(lqi);
1742 			return (1);
1743 		} else {
1744 			UNLOCK_UNIT(lqi);
1745 		}
1746 		break;
1747 	default:
1748 		break;
1749 	}
1750 
1751 	if (DB_TYPE(mp) >= QPCTL)
1752 		return (0);
1753 
1754 	LOCK_UNIT(lqi); /* lock out the upper half */
1755 	if ((lqi->sm_uqflags & SM_UQVALID) && SM_RQ(lqi->sm_uqi)) {
1756 		UNLOCK_UNIT(lqi);
1757 		if (!canput(SM_RQ(lqi->sm_uqi))) {
1758 			sm_dbg('I', ("sm_lrmsg_check: flow controlled.\n"));
1759 			(void) putq(q, mp);
1760 			return (1);
1761 		}
1762 	} else {
1763 		UNLOCK_UNIT(lqi);
1764 	}
1765 
1766 	return (0);
1767 }
1768 
1769 /*
1770  * sm_sendup - deliver a message to the upper read side of the multiplexer
1771  */
1772 static int
1773 sm_sendup(queue_t *q, mblk_t *mp)
1774 {
1775 	sm_lqi_t	*lqi	= (sm_lqi_t *)q->q_ptr;
1776 
1777 	if (sm_ssp == NULL) {
1778 		freemsg(mp);
1779 		return (0);
1780 	}
1781 
1782 	/*
1783 	 * Check for CD status change messages from driver.
1784 	 * (Remark: this is an se driver thread running at soft interupt
1785 	 * priority and the waiters are in user context).
1786 	 */
1787 	switch (DB_TYPE(mp)) {
1788 	case M_DATA:
1789 	case M_BREAK:	/* we'll eventually see this as a flush */
1790 		break;
1791 
1792 	/* high priority messages */
1793 	case M_IOCACK:
1794 	case M_IOCNAK:
1795 		if ((lqi->sm_flags & SM_IOCPENDING) && lqi->sm_piocid ==
1796 		    ((struct iocblk *)mp->b_rptr)->ioc_id) {
1797 			freemsg(mp);
1798 			lqi->sm_flags &= ~SM_IOCPENDING;
1799 			sm_issue_ioctl(lqi);
1800 			return (0);
1801 		}
1802 		break;
1803 	case M_UNHANGUP:
1804 		/*
1805 		 * If the driver can send an M_UNHANGUP it must be able to
1806 		 * accept messages from above (ie clear WERROR_MODE if set).
1807 		 */
1808 		sm_dbg('E', ("lrput: M_UNHANGUP\n"));
1809 		lqi->sm_mbits |= TIOCM_CD;
1810 		lqi->sm_flags &= ~(WERROR_MODE|HANGUP_MODE);
1811 
1812 		break;
1813 
1814 	case M_HANGUP:
1815 		sm_dbg('E', ("lrput: MHANGUP\n"));
1816 		lqi->sm_mbits &= ~TIOCM_CD;
1817 		lqi->sm_flags |= (WERROR_MODE|HANGUP_MODE);
1818 		break;
1819 
1820 	case M_ERROR:
1821 
1822 		sm_dbg('E', ("lrput: MERROR\n"));
1823 		/*
1824 		 * Tell the driver to flush rd/wr queue if its read/write error.
1825 		 * if its a read/write error flush rq/wq (type in first bytes).
1826 		 */
1827 		if ((mp->b_wptr - mp->b_rptr) == 2) {
1828 			uchar_t	rw = 0;
1829 
1830 			if (*mp->b_rptr == NOERROR) {
1831 				/* not in error anymore */
1832 				lqi->sm_flags &= ~ERROR_MODE;
1833 				lqi->sm_flags |= WANT_CD;
1834 			} else {
1835 				if (*mp->b_rptr != 0) {
1836 					/* read error */
1837 					rw |= FLUSHR;
1838 					lqi->sm_flags |= RERROR_MODE;
1839 				}
1840 				mp->b_rptr++;
1841 				if (*mp->b_rptr != 0) {
1842 					/* write error */
1843 					rw |= FLUSHW;
1844 					lqi->sm_flags |= WERROR_MODE;
1845 				}
1846 
1847 				mp->b_rptr--;
1848 				/* has next driver done qprocsoff */
1849 				if (rw && OTHERQ(q)->q_next != NULL) {
1850 					(void) putnextctl1(OTHERQ(q), M_FLUSH,
1851 						rw);
1852 				}
1853 			}
1854 		} else if (*mp->b_rptr != 0 && OTHERQ(q)->q_next != NULL) {
1855 			sm_dbg('E', ("lrput: old style MERROR (?)\n"));
1856 
1857 			lqi->sm_flags |= (RERROR_MODE | WERROR_MODE);
1858 			(void) putnextctl1(OTHERQ(q), M_FLUSH, FLUSHRW);
1859 		}
1860 		break;
1861 
1862 	case M_PCSIG:
1863 	case M_SIG:
1864 		break;
1865 	case M_COPYOUT:
1866 	case M_COPYIN:
1867 		break;
1868 	case M_FLUSH:
1869 		/* flush the read queue and pass on up */
1870 		flushq(q, FLUSHDATA);
1871 		break;
1872 	default:
1873 		break;
1874 	}
1875 
1876 	LOCK_UNIT(lqi); /* lock out the upper half */
1877 	if (lqi->sm_uqflags & SM_UQVALID && SM_RQ(lqi->sm_uqi)) {
1878 		UNLOCK_UNIT(lqi);
1879 		(void) putq(SM_RQ(lqi->sm_uqi), mp);
1880 		return (0);
1881 	} else {
1882 		sm_dbg('I', ("sm_sendup: uq not valid\n"));
1883 		freemsg(mp);
1884 	}
1885 	UNLOCK_UNIT(lqi);
1886 
1887 	return (0);
1888 }
1889 
1890 /*
1891  * sm_lrput - put function for a lower STREAM read.
1892  */
1893 static int
1894 sm_lrput(queue_t *q, mblk_t *mp)
1895 {
1896 	if (sm_lrmsg_check(q, mp) == 0)
1897 		(void) sm_sendup(q, mp);
1898 	return (0);
1899 }
1900 
1901 /*
1902  * sm_lrsrv - service function for the lower read STREAM.
1903  */
1904 static int
1905 sm_lrsrv(queue_t *q)
1906 {
1907 	mblk_t	*mp;
1908 
1909 	sm_dbg('I', ("sm_lrsrv: not controlled.\n"));
1910 	while (mp = getq(q))
1911 		(void) sm_sendup(q, mp);
1912 
1913 	return (0);
1914 }
1915 
1916 /*
1917  * Check whether a thread is allowed to open the requested device.
1918  */
1919 static int
1920 sm_ok_to_open(sm_uqi_t *uqi, int protocol, cred_t *credp, int *abort_waiters)
1921 {
1922 	int rval = 0;
1923 	int proto;
1924 
1925 	*abort_waiters = 0;
1926 
1927 	switch (protocol) {
1928 		case ASYNC_DEVICE: /* Standard async protocol */
1929 		if ((uqi->sm_protocol == NULL_PROTOCOL) ||
1930 			(uqi->sm_protocol == ASYN_PROTOCOL)) {
1931 			/*
1932 			 * Lock out other incompatible protocol requests.
1933 			 */
1934 			proto = ASYN_PROTOCOL;
1935 			rval = 0;
1936 		} else
1937 			rval = EBUSY;
1938 		break;
1939 
1940 		case OUTLINE:	/* Outdial protocol */
1941 		if ((uqi->sm_protocol == NULL_PROTOCOL) ||
1942 			(uqi->sm_protocol == OUTD_PROTOCOL)) {
1943 			proto = OUTD_PROTOCOL;
1944 			rval = 0;
1945 		} else if (uqi->sm_protocol == ASYN_PROTOCOL) {
1946 			/*
1947 			 * check for dialout request on a line that is already
1948 			 * open for dial in:
1949 			 * kick off any thread that is waiting to fully open
1950 			 */
1951 			if (uqi->sm_flags & FULLY_OPEN)
1952 				rval = EBUSY;
1953 			else {
1954 				proto = OUTD_PROTOCOL;
1955 				*abort_waiters = 1;
1956 			}
1957 		} else
1958 			rval = EBUSY;
1959 		break;
1960 		default:
1961 			rval = ENOTSUP;
1962 	}
1963 
1964 	if (rval == 0 &&
1965 		(uqi->sm_ttycommon->t_flags & TS_XCLUDE) &&
1966 		secpolicy_excl_open(credp) != 0) {
1967 
1968 		if (uqi->sm_flags & FULLY_OPEN) {
1969 			rval = EBUSY; /* exclusive device already open */
1970 		} else {
1971 			/* NB TS_XCLUDE cant be set during open so NOTREACHED */
1972 			/* force any waiters to yield TS_XCLUDE */
1973 			*abort_waiters = 1;
1974 		}
1975 	}
1976 
1977 	if (rval == 0)
1978 		uqi->sm_protocol = proto;
1979 
1980 	sm_dbg('A', ("ok_to_open (0x%p, %d) proto=%d rval %d (wabort=%d)",
1981 		uqi, protocol, uqi->sm_protocol, rval, *abort_waiters));
1982 
1983 	return (rval);
1984 }
1985 
1986 /* wait for memory to become available whilst performing a qwait */
1987 /*ARGSUSED*/
1988 static void dummy_callback(void *arg)
1989 {}
1990 
1991 /* ARGSUSED */
1992 static int
1993 sm_dump_msg(queue_t *q, mblk_t *mp)
1994 {
1995 	freemsg(mp);
1996 	return (0);
1997 }
1998 
1999 /*
2000  * Wait for a message to arrive - must be called with exclusive
2001  * access at the outer perimiter.
2002  */
2003 static int
2004 sm_qwait_sig(sm_uqi_t *uqi, queue_t *q)
2005 {
2006 	int err;
2007 
2008 	sm_dbg('C', ("sm_qwait_sig: waiting.\n"));
2009 
2010 	uqi->sm_waitq = q;
2011 	uqi->sm_nwaiters++;	/* required by the close routine */
2012 	err = qwait_sig(q);
2013 	if (--uqi->sm_nwaiters == 0)
2014 		uqi->sm_waitq = 0;
2015 
2016 	if (err == 0)
2017 		err = EINTR;
2018 	else if (q->q_ptr == 0) /* can happen if there are multiple waiters */
2019 		err = -1;
2020 	else if (uqi->sm_flags & SM_CLOSE) {
2021 		uqi->sm_flags &= ~SM_CLOSE;
2022 		err = 1;	/* a different protocol has closed its stream */
2023 	}
2024 	else
2025 		err = 0;	/* was worth waiting for */
2026 
2027 	sm_dbg('C', ("sm_qwait_sig: rval %d\n", err));
2028 	return (err);
2029 }
2030 
2031 /*
2032  * Defer the opening of one the drivers devices until the state of each
2033  * associated lower stream is known.
2034  */
2035 static int
2036 sm_defer_open(sm_uqi_t *uqi, queue_t *q)
2037 {
2038 	uint_t cmdflags = WANT_CDSTAT;
2039 	int err, nqs;
2040 
2041 	while ((nqs = sm_good_qs(uqi)) == 0) {
2042 		sm_dbg('C', ("sm_defer_open: no good qs\n"));
2043 		if (err = sm_qwait_sig(uqi, q))
2044 			return (err);
2045 	}
2046 
2047 	while ((uqi->sm_flags & SM_CARON) == 0) {
2048 		int iocmd;
2049 		mblk_t *pioc;
2050 
2051 		sm_dbg('C', ("sm_defer_open: flags 0x%x cmdflags 0x%x\n",
2052 					uqi->sm_flags, cmdflags));
2053 		if (cmdflags == 0) {
2054 			if (err = sm_qwait_sig(uqi, q))
2055 				return (err);
2056 			continue;	/* waiting for an M_UNHANGUP */
2057 		} else if (cmdflags & WANT_SC) {
2058 			cmdflags &= ~WANT_SC;
2059 			iocmd = TIOCGSOFTCAR;
2060 		} else if (cmdflags & WANT_CD) {
2061 			cmdflags &= ~WANT_CD;
2062 			iocmd = TIOCMGET;
2063 		} else if (cmdflags & WANT_CL) {
2064 			cmdflags &= ~WANT_CL;
2065 			iocmd = TCGETS;
2066 		}
2067 
2068 		if (uqi->sm_piocdata.sm_iocid == 0) {
2069 			while ((pioc = mkiocb(iocmd)) == 0) {
2070 				bufcall_id_t id =
2071 					qbufcall(q, sizeof (struct iocblk),
2072 					BPRI_MED, dummy_callback, 0);
2073 				if (err = sm_qwait_sig(uqi, q)) {
2074 					/* wait for the bufcall */
2075 					qunbufcall(q, id);
2076 					return (err);
2077 				}
2078 				qunbufcall(q, id);
2079 			}
2080 
2081 			uqi->sm_flags |= SM_IOCPENDING;
2082 
2083 			uqi->sm_piocdata.sm_iocid =
2084 			    ((struct iocblk *)pioc->b_rptr)->ioc_id;
2085 			uqi->sm_piocdata.sm_acked = 0;
2086 			uqi->sm_piocdata.sm_nacks = nqs;
2087 			uqi->sm_piocdata.sm_acnt = 0;
2088 			uqi->sm_piocdata.sm_ackcnt = uqi->
2089 					sm_piocdata.sm_nakcnt = 0;
2090 			uqi->sm_piocdata.sm_policy = uqi->sm_policy;
2091 			uqi->sm_piocdata.sm_flags = SM_INTERNALIOC;
2092 			if (sm_putqs(WR(q), pioc, sm_dump_msg) != 0) {
2093 				uqi->sm_piocdata.sm_iocid = 0;
2094 				sm_log("sm_defer_open: bad putqs\n");
2095 				return (-1);
2096 			}
2097 		}
2098 
2099 		sm_dbg('C', ("sm_defer_open: flags 0x%x\n", uqi->sm_flags));
2100 		while ((uqi->sm_flags & SM_CARON) == 0 &&
2101 		    (uqi->sm_flags & SM_IOCPENDING) != 0)
2102 			if (err = sm_qwait_sig(uqi, q))
2103 				return (err);
2104 
2105 		sm_dbg('C', ("defer_open: uq flags 0x%x.\n", uqi->sm_flags));
2106 	}
2107 	sm_dbg('C', ("defer_open: return 0.\n"));
2108 	return (0);
2109 }
2110 
2111 static int
2112 sm_open(queue_t *rq, dev_t *devp, int flag, int sflag, cred_t *credp)
2113 {
2114 	int		ftstat;
2115 	int		unit;
2116 	int		protocol;
2117 	sm_uqi_t		*uqi;
2118 	int		abort_waiters;
2119 
2120 	if (sm_ssp == NULL)
2121 		return (ENXIO);
2122 	/*
2123 	 * sflag = 0 => streams device.
2124 	 */
2125 	if (sflag != 0 || DEV_TO_UNIT(*devp) >= NLUNITS) {
2126 		sm_dbg('C', ("open: sflag=%d or bad dev_t.\n", sflag));
2127 		return (ENXIO);
2128 	}
2129 
2130 	unit = DEV_TO_UNIT(*devp);
2131 	protocol = DEV_TO_PROTOBITS(*devp);
2132 
2133 	uqi = get_uqi(sm_ssp, unit);
2134 
2135 	sm_dbg('C', ("open(0x%p, %d, 0x%x) :- unit=%d, proto=%d, uqi=0x%p\n",
2136 		rq, *devp, flag, unit, protocol, uqi));
2137 
2138 	if (uqi == 0)
2139 		return (ENXIO);
2140 
2141 	if (sm_refuse_opens && unit > smctlunit && uqi->sm_nlqs == 0)
2142 		return (ENXIO);
2143 
2144 	if (uqi->sm_flags & EXCL_OPEN && (flag & FEXCL)) {
2145 		return (EBUSY); /* device in use */
2146 	}
2147 
2148 	if ((flag & FEXCL)) {
2149 		if (secpolicy_excl_open(credp) != 0)
2150 			return (EPERM);
2151 
2152 		if ((uqi->sm_flags & FULLY_OPEN) || uqi->sm_nwaiters > 0)
2153 			return (EBUSY); /* device in use */
2154 
2155 		uqi->sm_flags |= EXCL_OPEN;
2156 	}
2157 
2158 	if (uqi->sm_protocol == NULL_PROTOCOL) {
2159 		struct termios *termiosp;
2160 		int len;
2161 
2162 		if (ddi_getlongprop(DDI_DEV_T_ANY, ddi_root_node(),
2163 		    DDI_PROP_NOTPROM, "ttymodes", (caddr_t)&termiosp, &len)
2164 		    == DDI_PROP_SUCCESS &&
2165 		    (len == sizeof (struct termios))) {
2166 
2167 			sm_dbg('C', ("open: c_cflag=0x%x\n",
2168 				termiosp->c_cflag));
2169 
2170 			uqi->sm_ttycommon->t_iflag = termiosp->c_iflag;
2171 			uqi->sm_ttycommon->t_cflag = termiosp->c_cflag;
2172 			uqi->sm_ttycommon->t_stopc = termiosp->c_cc[VSTOP];
2173 			uqi->sm_ttycommon->t_startc = termiosp->c_cc[VSTART];
2174 
2175 			/*
2176 			 * IGNBRK,BRKINT,INPCK,IXON,IXANY,IXOFF - drivers
2177 			 * PARMRK,IGNPAR,ISTRIP - how to report parity
2178 			 * INLCR,IGNCR,ICRNL,IUCLC - ldterm (sophisticated I/O)
2179 			 * IXON, IXANY, IXOFF - flow control input
2180 			 * CBAUD,CSIZE,CS5-8,CSTOPB,PARENB,PARODD,HUPCL,
2181 			 * RCV1EN,XMT1EN,LOBLK,XCLUDE,CRTSXOFF,CRTSCTS,
2182 			 * CIBAUD,PAREXT,CBAUDEXT,CIBAUDEXT,CREAD,CLOCAL
2183 			 */
2184 
2185 			kmem_free(termiosp, len);
2186 		}
2187 		else
2188 			bzero((caddr_t)uqi->sm_ttycommon,
2189 				sizeof (uqi->sm_ttycommon));
2190 
2191 		if (*devp == rconsdev) {
2192 			uqi->sm_cmask = sm_cmask;
2193 			uqi->sm_ttycommon->t_flags |= TS_SOFTCAR;
2194 		} else {
2195 			uqi->sm_ttycommon->t_flags &= ~TS_SOFTCAR;
2196 		}
2197 
2198 		/*
2199 		 * Clear the default CLOCAL and TS_SOFTCAR flags since
2200 		 * they must correspond to the settings on the real devices.
2201 		 */
2202 
2203 		uqi->sm_ttycommon->t_cflag &= ~(uqi->sm_cmask|CLOCAL);
2204 		uqi->sm_mbits = 0;
2205 		uqi->sm_policy = FIRSTACK;
2206 		if (unit == 0 && sm_ssp->sm_ms == 0)
2207 			sm_ssp->sm_ms = (sm_mux_state_t *)
2208 						space_fetch(TTYMUXPTR);
2209 		if (sm_ssp->sm_ms) {
2210 			if (sm_ssp->sm_ms->sm_cons_stdin.sm_dev == *devp ||
2211 			    sm_ssp->sm_ms->sm_cons_stdout.sm_dev == *devp)
2212 				sm_ssp->sm_lconsole = uqi;
2213 		}
2214 	}
2215 
2216 	/*
2217 	 * Does this thread need to wait?
2218 	 */
2219 
2220 	sm_dbg('C', ("sm_open: %d %d 0x%p 0x%x\n",
2221 	    !(flag & (FNDELAY|FNONBLOCK)), !(protocol == OUTLINE), uqi->sm_lqs,
2222 	    uqi->sm_flags));
2223 
2224 tryopen:
2225 
2226 	abort_waiters = 0;
2227 	if (ftstat = sm_ok_to_open(uqi, protocol, credp, &abort_waiters)) {
2228 		sm_dbg('C', ("open failed stat=%d.\n", ftstat));
2229 
2230 		if ((uqi->sm_flags & FULLY_OPEN) == 0 && uqi->sm_nwaiters == 0)
2231 			uqi->sm_protocol = NULL_PROTOCOL;
2232 		if (flag & FEXCL)
2233 			uqi->sm_flags &= ~EXCL_OPEN;
2234 		return (ftstat);
2235 	}
2236 
2237 	if (abort_waiters) {
2238 		uqi->sm_dev = *devp;
2239 		/* different device wants to use the unit */
2240 		SM_RQ(uqi) = rq;
2241 		SM_WQ(uqi) = WR(rq);
2242 	}
2243 	if (rq->q_ptr == 0) {
2244 		sm_lqi_t *lqi;
2245 
2246 		uqi->sm_dev = *devp;
2247 		rq->q_ptr = WR(rq)->q_ptr = uqi;
2248 		SM_RQ(uqi) = rq;
2249 		SM_WQ(uqi) = WR(rq);
2250 		qprocson(rq);
2251 		for (lqi = uqi->sm_lqs; lqi != 0; lqi = lqi->sm_nlqi) {
2252 			LOCK_UNIT(lqi);
2253 			lqi->sm_uqflags |= SM_UQVALID;
2254 			UNLOCK_UNIT(lqi);
2255 		}
2256 
2257 		sm_dbg('C', ("sm_open: SM_UQVALID set on lqs.\n"));
2258 	}
2259 
2260 	if (*devp != rconsdev && BLOCKING(uqi, protocol, flag)) {
2261 
2262 		uqi->sm_flags |= WANT_CDSTAT;
2263 
2264 		do {
2265 			/*
2266 			 * Wait for notifications of changes in the CLOCAL
2267 			 * and TS_SOFTCAR flags and a TIOCM_CD flag of a
2268 			 * TIOCMGET request (come in on the write side queue).
2269 			 */
2270 
2271 			if ((ftstat = sm_defer_open(uqi, rq)) != EINTR) {
2272 				if (ftstat) {
2273 					goto tryopen;
2274 				} else {
2275 					continue;
2276 				}
2277 			}
2278 
2279 			if (uqi->sm_nwaiters == 0) {	/* clean up */
2280 				/*
2281 				 * only opens on an asynchronous
2282 				 * protocols reach here so checking
2283 				 * nwaiters == 0 is sufficient to
2284 				 * ensure that no other thread
2285 				 * is waiting on this logical unit
2286 				 */
2287 				if ((uqi->sm_flags & FULLY_OPEN) == 0) {
2288 
2289 					sm_lqi_t *lqi;
2290 
2291 					uqi->sm_dev = NODEV;
2292 					sm_dbg('C', ("sm_open FULLY_OPEN=0\n"));
2293 					for (lqi = uqi->sm_lqs; lqi != 0;
2294 					    lqi = lqi->sm_nlqi) {
2295 						LOCK_UNIT(lqi);
2296 						lqi->sm_uqflags &= ~SM_UQVALID;
2297 						UNLOCK_UNIT(lqi);
2298 					}
2299 
2300 					qprocsoff(rq);
2301 					rq->q_ptr = WR(rq)->q_ptr = 0;
2302 					SM_RQ(uqi) = 0;
2303 					SM_WQ(uqi) = 0;
2304 				}
2305 			}
2306 			if ((uqi->sm_flags & FULLY_OPEN) == 0 &&
2307 			    uqi->sm_nwaiters == 0)
2308 				uqi->sm_protocol = NULL_PROTOCOL;
2309 			if (flag & FEXCL)
2310 				uqi->sm_flags &= ~EXCL_OPEN;
2311 			sm_dbg('C', ("sm_open: done (ret %d).\n", ftstat));
2312 			return (ftstat);
2313 		} while (BLOCKING(uqi, protocol, flag));
2314 	}
2315 
2316 	uqi->sm_flags |= FULLY_OPEN;
2317 
2318 	sm_dbg('C', ("sm_open done (ret %d).\n", ftstat));
2319 	return (ftstat);
2320 }
2321 
2322 /*
2323  * Multiplexer device close routine.
2324  */
2325 /*ARGSUSED*/
2326 static int
2327 sm_close(queue_t *rq, int flag, cred_t *credp)
2328 {
2329 	sm_uqi_t *uqi = (sm_uqi_t *)rq->q_ptr;
2330 	sm_lqi_t *lqi;
2331 
2332 	if (sm_ssp == NULL)
2333 		return (ENXIO);
2334 
2335 	if (uqi == NULL) {
2336 		sm_dbg('C', ("close: WARN:- q 0x%p already closed.\n", rq));
2337 		return (ENXIO);
2338 	}
2339 
2340 	sm_dbg('C', ("close: uqi=0x%p unit=%d q=0x%p)\n", uqi, uqi->sm_lunit,
2341 			rq));
2342 
2343 	if (SM_RQ(uqi) != rq)
2344 		sm_dbg('C', ("sm_close: rq != current uqi queue\n"));
2345 
2346 	if (uqi->sm_ttybid) {
2347 		qunbufcall(SM_RQ(uqi), uqi->sm_ttybid);
2348 		uqi->sm_ttybid = 0;
2349 	}
2350 
2351 	/*
2352 	 * Tell all the linked queues that the upper queue has gone
2353 	 * Note close will never get called on a stream while there is a
2354 	 * thread blocked trying to open the same stream.
2355 	 * If there is a blocked open on a different stream but on
2356 	 * the same logical unit it will reset the lower queue flags.
2357 	 */
2358 	for (lqi = uqi->sm_lqs; lqi != 0; lqi = lqi->sm_nlqi) {
2359 		LOCK_UNIT(lqi);
2360 		lqi->sm_uqflags &= ~SM_UQVALID;
2361 		UNLOCK_UNIT(lqi);
2362 	}
2363 
2364 	/*
2365 	 * Turn off the STREAMs queue processing for this queue.
2366 	 */
2367 	qprocsoff(rq);
2368 
2369 	/*
2370 	 * Similarly we will never get here if there is thread trying to
2371 	 * open ths stream.
2372 	 */
2373 	LOCK_UNIT(uqi);
2374 	if (uqi->sm_waitq == 0)
2375 		uqi->sm_flags = (uqi->sm_flags & SM_OBPCNDEV) ? SM_OBPCNDEV :
2376 									0U;
2377 
2378 	uqi->sm_dev = NODEV;
2379 	uqi->sm_protocol = NULL_PROTOCOL;
2380 	ttycommon_close(uqi->sm_ttycommon);
2381 	/* it just frees any pending ioctl */
2382 
2383 	uqi->sm_ttycommon->t_cflag = 0;
2384 	uqi->sm_ttycommon->t_flags = 0;
2385 
2386 	/*
2387 	 * Reset the queue pointers to NULL.
2388 	 * If a thread is qwaiting in the open routine it will recheck
2389 	 * the q_ptr.
2390 	 */
2391 	rq->q_ptr = NULL;
2392 	WR(rq)->q_ptr = NULL;
2393 	UNLOCK_UNIT(uqi);
2394 
2395 	if (sm_ssp->sm_lconsole == uqi) {
2396 		/* this will never be the outdial device closing */
2397 		sm_ssp->sm_lconsole = 0;
2398 	}
2399 	/*
2400 	 * If there is another thread waiting for this close then unblock
2401 	 * the thread by putting a message on its read queue.
2402 	 */
2403 	if (uqi->sm_waitq) {
2404 		sm_dbg('C', ("close(0x%p): doing putctl on 0x%p\n",
2405 			rq, uqi->sm_waitq));
2406 		if (rq == uqi->sm_waitq)
2407 			sm_log("close: waitq and closeq are same q\n");
2408 		(void) putctl(uqi->sm_waitq, M_CTL);
2409 	}
2410 
2411 	uqi->sm_flags &= ~(EXCL_OPEN | FULLY_OPEN);
2412 	sm_dbg('C', ("close: returning ok.\n"));
2413 	return (0);
2414 }
2415 
2416 /*
2417  * Initialise the software abort sequence for use when one of the
2418  * driver's nodes provides the system console.
2419  */
2420 static void
2421 sm_set_abort()
2422 {
2423 	char ds[3] = { '\r', '~', CNTRL('b') };
2424 	char as[SM_MAX_ABSLEN];
2425 	int len = SM_MAX_ABSLEN;
2426 
2427 	if (ddi_prop_op(DDI_DEV_T_ANY, sm_ssp->sm_dip, PROP_LEN_AND_VAL_BUF, 0,
2428 		"abort-str", as, &len) != DDI_PROP_SUCCESS ||
2429 		(len = strlen(as)) < SM_MIN_ABSLEN) {
2430 		(void) strcpy(as, ds);
2431 		len = strlen(as);
2432 	} else {
2433 		char *s;
2434 		int i;
2435 
2436 		for (s = as, i = 0; i < len-1; i++, s++) {
2437 			if (as[i] == '^' && as[i+1] >= 'a' && as[i+1] <= 'z') {
2438 				*s = as[i+1] - 'a' + 1;
2439 				i++;
2440 			} else {
2441 				*s = as[i];
2442 			}
2443 		}
2444 		*s++ = as[i];
2445 		*s = '\0';
2446 		len = strlen(as);
2447 	}
2448 
2449 	if (len < SM_MIN_ABSLEN)
2450 		(void) strcpy(sm_ssp->sm_abs, ds);
2451 	else
2452 		(void) strcpy(sm_ssp->sm_abs, as);
2453 }
2454 
2455 /*
2456  *
2457  * sm_attach - initialisation routine per driver instance.
2458  */
2459 static int
2460 sm_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
2461 {
2462 	int unit;
2463 	char name[32];
2464 	sm_uqi_t *uqi;
2465 	sm_lqi_t *lqip;
2466 
2467 	/*
2468 	 * Is this an attach?
2469 	 */
2470 	if (cmd != DDI_ATTACH) {
2471 		return (DDI_FAILURE);
2472 	}
2473 
2474 	/*
2475 	 * Validate the instance number (sm is a single instance driver).
2476 	 */
2477 	if (sm_ssp) {	/* only one instance allowed */
2478 		return (DDI_FAILURE);
2479 	}
2480 
2481 	sm_instance = ddi_get_instance(dip);
2482 
2483 	/*
2484 	 * Create the default minor node which will become the console.
2485 	 * (create it with three different names).:
2486 	 *	con which appears in the /dev filesystem;
2487 	 *	input which matches the prom /multiplexer:input node;
2488 	 *	output which matches the prom /multiplexer:input node
2489 	 * Create a minor node for control operations.
2490 	 */
2491 	if (ddi_create_minor_node(dip, "con", S_IFCHR, 0,
2492 	    DDI_PSEUDO, 0) != DDI_SUCCESS ||
2493 	    ddi_create_minor_node(dip, "input", S_IFCHR, 0,
2494 	    DDI_PSEUDO, 0) != DDI_SUCCESS ||
2495 	    ddi_create_minor_node(dip, "output", S_IFCHR, 0,
2496 	    DDI_PSEUDO, 0) != DDI_SUCCESS ||
2497 	    ddi_create_minor_node(dip, "ctl", S_IFCHR, 1,
2498 	    DDI_PSEUDO, 0) != DDI_SUCCESS) {
2499 
2500 		cmn_err(CE_WARN, "sm_attach: create minors failed.\n");
2501 		ddi_remove_minor_node(dip, NULL);
2502 		return (DDI_FAILURE);
2503 	}
2504 
2505 	smctlunit = 1;
2506 
2507 	/*
2508 	 * Allocate private state for this instance.
2509 	 */
2510 	sm_ssp = (sm_ss_t *)kmem_zalloc(sizeof (sm_ss_t), KM_SLEEP);
2511 
2512 	/*
2513 	 * Initialise per instance data.
2514 	 */
2515 	sm_ssp->sm_dip = dip;
2516 
2517 	/*
2518 	 * Get required debug level.
2519 	 */
2520 	sm_ssp->sm_trflag = ddi_prop_get_int(DDI_DEV_T_ANY, dip,
2521 		DDI_PROP_DONTPASS, "sm-trlv", sm_default_trflag);
2522 
2523 	sm_max_units = ddi_prop_get_int(DDI_DEV_T_ANY, dip,
2524 		DDI_PROP_DONTPASS, "sm-max-units", sm_max_units);
2525 	sm_minor_cnt = ddi_prop_get_int(DDI_DEV_T_ANY, dip,
2526 		DDI_PROP_DONTPASS, "sm-minor-cnt", 0);
2527 
2528 	sm_refuse_opens = ddi_prop_get_int(DDI_DEV_T_ANY, dip,
2529 		DDI_PROP_DONTPASS, "sm-refuse-opens", sm_refuse_opens);
2530 
2531 	sm_ssp->sm_ctrla_abort_on = ddi_prop_get_int(DDI_DEV_T_ANY, dip,
2532 		DDI_PROP_DONTPASS, "sm-ctrla-abort-on", 1);
2533 	sm_ssp->sm_break_abort_on = ddi_prop_get_int(DDI_DEV_T_ANY, dip,
2534 		DDI_PROP_DONTPASS, "sm-break-abort-on", 0);
2535 
2536 	sm_set_abort();
2537 
2538 	sm_ssp->sm_lqs = (sm_lqi_t *)kmem_zalloc(sizeof (sm_lqi_t) * MAX_LQS,
2539 							KM_SLEEP);
2540 	sm_ssp->sm_uqs = (sm_uqi_t *)kmem_zalloc(sizeof (sm_uqi_t) * NLUNITS,
2541 							KM_SLEEP);
2542 
2543 	for (unit = 2; unit < NLUNITS && unit < sm_minor_cnt + 2; unit++) {
2544 
2545 		if (snprintf(name, sizeof (name), "sm%c", 'a' + unit-2) >
2546 		    sizeof (name)) {
2547 			cmn_err(CE_WARN,
2548 			    "sm_attach: create device for unit %d failed.\n",
2549 			    unit);
2550 		} else if (ddi_create_minor_node(dip, name, S_IFCHR,
2551 		    unit, DDI_NT_SERIAL, NULL) != DDI_SUCCESS) {
2552 			ddi_remove_minor_node(dip, NULL);
2553 			return (DDI_FAILURE);
2554 		}
2555 
2556 		if (snprintf(name, sizeof (name), "sm%c,cu", 'a' + unit-2) >
2557 		    sizeof (name)) {
2558 			cmn_err(CE_WARN,
2559 			    "sm_attach: create cu device for unit %d failed.\n",
2560 			    unit);
2561 			continue;
2562 		} else if (ddi_create_minor_node(dip, name, S_IFCHR,
2563 		    unit|OUTLINE, DDI_NT_SERIAL_DO, NULL) != DDI_SUCCESS) {
2564 			ddi_remove_minor_node(dip, NULL);
2565 			return (DDI_FAILURE);
2566 		}
2567 	}
2568 
2569 	for (unit = 0; unit < NLUNITS; unit++) {
2570 
2571 		uqi = get_uqi(sm_ssp, unit);
2572 		uqi->sm_lqs = 0;
2573 		uqi->sm_dev = NODEV;
2574 		uqi->sm_nlqs = 0;
2575 		uqi->sm_lunit = unit;
2576 		uqi->sm_protocol = NULL_PROTOCOL;
2577 		mutex_init(uqi->sm_umutex, NULL, MUTEX_DRIVER, NULL);
2578 		cv_init(uqi->sm_ucv, NULL, CV_DRIVER, NULL);
2579 		mutex_init(&uqi->sm_ttycommon->t_excl, NULL,
2580 				MUTEX_DRIVER, NULL);
2581 	}
2582 
2583 	for (unit = 0; unit < MAX_LQS; unit++) {
2584 		lqip = get_lqi(sm_ssp, unit);
2585 		lqip->sm_unit = unit;
2586 		lqip->sm_hadkadbchar = 0;
2587 		lqip->sm_nachar = sm_ssp->sm_abs;
2588 		lqip->sm_ioflag = FORIO;
2589 		lqip->sm_ctrla_abort_on = sm_ssp->sm_ctrla_abort_on;
2590 		lqip->sm_break_abort_on = sm_ssp->sm_break_abort_on;
2591 		mutex_init(lqip->sm_umutex, NULL, MUTEX_DRIVER, NULL);
2592 		cv_init(lqip->sm_ucv, NULL, CV_DRIVER, NULL);
2593 		mutex_init(&lqip->sm_ttycommon->t_excl, NULL,
2594 				MUTEX_DRIVER, NULL);
2595 	}
2596 
2597 	return (DDI_SUCCESS);
2598 }
2599 
2600 /*
2601  *
2602  * sm_detach - detach routine per driver instance.
2603  */
2604 static int
2605 sm_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
2606 {
2607 	sm_uqi_t		*lu;
2608 	sm_lqi_t		*pu;
2609 	int		unit;
2610 
2611 	/*
2612 	 * Is this a detach request for instance 0 (single instance driver).
2613 	 */
2614 	if (cmd != DDI_DETACH)
2615 		return (DDI_FAILURE);
2616 
2617 	if (sm_ssp == NULL)
2618 		return (DDI_FAILURE);
2619 
2620 	sm_dbg('V', ("detach ..."));
2621 
2622 
2623 	/*
2624 	 * Check that all the upper and lower queues are closed.
2625 	 */
2626 
2627 	for (unit = 0; unit < NLUNITS; unit++) {
2628 		lu = &sm_ssp->sm_uqs[unit];
2629 		if (lu && lu->sm_protocol != NULL_PROTOCOL) {
2630 			sm_dbg('V', ("detach: upper unit still open.\n"));
2631 			return (DDI_FAILURE);
2632 		}
2633 	}
2634 	for (unit = 0; unit < MAX_LQS; unit++) {
2635 		pu = &sm_ssp->sm_lqs[unit];
2636 		if (pu && pu->sm_linkid != 0) {
2637 			sm_dbg('V', ("detach: lower unit still linked (%d)\n",
2638 			    pu->sm_linkid));
2639 			return (DDI_FAILURE);
2640 		}
2641 	}
2642 
2643 	for (unit = 0; unit < NLUNITS; unit++) {
2644 		lu = &sm_ssp->sm_uqs[unit];
2645 		mutex_destroy(lu->sm_umutex);
2646 		cv_destroy(lu->sm_ucv);
2647 		mutex_destroy(&lu->sm_ttycommon->t_excl);
2648 	}
2649 	for (unit = 0; unit < MAX_LQS; unit++) {
2650 		pu = &sm_ssp->sm_lqs[unit];
2651 		mutex_destroy(pu->sm_umutex);
2652 		cv_destroy(pu->sm_ucv);
2653 		mutex_destroy(&pu->sm_ttycommon->t_excl);
2654 	}
2655 
2656 	/*
2657 	 * Tidy up per instance state.
2658 	 */
2659 	kmem_free(sm_ssp->sm_lqs, sizeof (sm_lqi_t) * MAX_LQS);
2660 	kmem_free(sm_ssp->sm_uqs, sizeof (sm_uqi_t) * NLUNITS);
2661 	kmem_free(sm_ssp, sizeof (sm_ss_t));
2662 
2663 	sm_ssp = 0;
2664 
2665 	/*
2666 	 * Remove all of the devices created in attach.
2667 	 */
2668 	ddi_remove_minor_node(dip, NULL);
2669 
2670 	return (DDI_SUCCESS);
2671 }
2672 
2673 /*
2674  * SECTION
2675  * Driver interface to the OS.
2676  */
2677 
2678 /*
2679  * The driver is responsible for managing the mapping between the file system
2680  * device types (major/minor pairs) and the corresponding instance of the driver
2681  * or device information pointer (dip).
2682  * sm_info - return the instance or dip corresponding to the dev_t.
2683  */
2684 /*ARGSUSED*/
2685 static int
2686 sm_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result)
2687 {
2688 	int res = DDI_SUCCESS;
2689 
2690 	switch (infocmd) {
2691 	case DDI_INFO_DEVT2DEVINFO:
2692 		if (sm_ssp == NULL)
2693 			res = DDI_FAILURE;
2694 		else
2695 			*result = (void *)sm_ssp->sm_dip;
2696 		break;
2697 
2698 	case DDI_INFO_DEVT2INSTANCE:
2699 		*result = (void*)0;	/* single instance driver */
2700 		break;
2701 
2702 	default:
2703 		res = DDI_FAILURE;
2704 		break;
2705 	}
2706 
2707 	return (res);
2708 }
2709 
2710 /*
2711  * End of driver implementation
2712  */
2713 
2714 /*
2715  * Loadable module interface to the kernel
2716  */
2717 
2718 /*
2719  * Firstly the Streams specific interface
2720  */
2721 
2722 /*
2723  * Solaris driver/STREAM initialisation structures.
2724  */
2725 static struct module_info uinfo =
2726 {
2727 	SM_MOD_ID,
2728 	TTYMUX_DRVNAME,
2729 	0,		/* min packet size */
2730 	INFPSZ,		/* max packet size */
2731 	2048,		/* high water mark */
2732 	256,		/* low water mark */
2733 };
2734 
2735 /*
2736  * Use zero water marks becuase the lower queues are used only for flow control.
2737  */
2738 static struct module_info linfo =
2739 {
2740 	SM_MOD_ID,
2741 	TTYMUX_DRVNAME,
2742 	0,		/* min packet size */
2743 	INFPSZ,		/* max packet size */
2744 	0,		/* high water mark */
2745 	0		/* low water mark	*/
2746 };
2747 
2748 
2749 /*
2750  * Solaris upper read STREAM initialisation structure.
2751  */
2752 static struct qinit urinit =
2753 {
2754 	sm_urput,	/* put */
2755 	sm_ursrv,	/* service */
2756 	sm_open,	/* open */
2757 	sm_close,	/* close */
2758 	NULL,		/* admin */
2759 	&uinfo,		/* module info */
2760 	NULL		/* stats */
2761 };
2762 
2763 /*
2764  * Solaris upper write STREAM initialisation structure.
2765  */
2766 static struct qinit uwinit =
2767 {
2768 	sm_uwput,
2769 	sm_uwsrv,
2770 	NULL,
2771 	NULL,
2772 	NULL,
2773 	&uinfo,
2774 	NULL
2775 };
2776 
2777 /*
2778  * Solaris lower read STREAM initialisation structure.
2779  */
2780 static struct qinit lrinit =
2781 {
2782 	sm_lrput,
2783 	sm_lrsrv,
2784 	NULL,
2785 	NULL, NULL,
2786 	&linfo,
2787 	NULL
2788 };
2789 
2790 /*
2791  * Solaris lower write STREAM initialisation structure.
2792  */
2793 static struct qinit lwinit =
2794 {
2795 	putq,
2796 	sm_lwsrv,
2797 	NULL,
2798 	NULL,
2799 	NULL,
2800 	&linfo,
2801 	NULL
2802 };
2803 
2804 /*
2805  * Multiplexing STREAM structure.
2806  */
2807 struct streamtab sm_streamtab =
2808 {
2809 	&urinit,
2810 	&uwinit,
2811 	&lrinit,
2812 	&lwinit
2813 };
2814 
2815 /*
2816  * Driver operations structure (struct cb_ops) and
2817  * driver dynamic loading functions (struct dev_ops).
2818  */
2819 
2820 /*
2821  * Fold the Stream interface to the kernel into the driver interface
2822  * to the OS.
2823  */
2824 
2825 DDI_DEFINE_STREAM_OPS(sm_ops, \
2826 	nulldev, nulldev, \
2827 	sm_attach, sm_detach, nodev, \
2828 	sm_info, (D_NEW | D_MTQPAIR|D_MTOUTPERIM|D_MTOCEXCL | D_MP),
2829 	&sm_streamtab);
2830 
2831 /*
2832  * Driver module information.
2833  */
2834 extern struct mod_ops mod_driverops;
2835 static struct modldrv modldrv =
2836 {
2837 	&mod_driverops,
2838 	"serial mux driver %I%",
2839 	&sm_ops
2840 };
2841 
2842 static struct modlinkage modlinkage =
2843 {
2844 	MODREV_1,
2845 	&modldrv,
2846 	NULL
2847 };
2848 
2849 /*
2850  * Define the body of our interface to the OS.
2851  */
2852 
2853 /*
2854  * '_init' is called by Solaris to initialise any driver
2855  * specific state and to install the driver.
2856  */
2857 int
2858 _init(void)
2859 {
2860 	return (mod_install(&modlinkage));
2861 }
2862 
2863 /*
2864  * _info - return this drivers interface to the kernel.
2865  */
2866 int
2867 _info(struct modinfo *modinfop)
2868 {
2869 	return (mod_info(&modlinkage, modinfop));
2870 }
2871 
2872 /*
2873  * _fini - the OS is finished with the services provided by the driver.
2874  * remove ourself and then remove any footprint that remains.
2875  */
2876 int
2877 _fini(void)
2878 {
2879 	return (mod_remove(&modlinkage));
2880 }
2881