xref: /illumos-gate/usr/src/uts/sun/io/zs_hdlc.c (revision 9c2acf00e275b6b2125a306f33cdddcc58393220)
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  * Copyright (c) 2011 Bayard G. Bell. All rights reserved.
25  * Copyright (c) 2019 Peter Tribble.
26  */
27 
28 
29 /*
30  *	HDLC protocol handler for Z8530 SCC.
31  */
32 
33 #include	<sys/param.h>
34 #include	<sys/systm.h>
35 #include	<sys/types.h>
36 #include	<sys/sysmacros.h>
37 #include	<sys/kmem.h>
38 #include	<sys/stropts.h>
39 #include	<sys/stream.h>
40 #include	<sys/strsun.h>
41 #include	<sys/stat.h>
42 #include	<sys/cred.h>
43 #include	<sys/user.h>
44 #include	<sys/proc.h>
45 #include	<sys/file.h>
46 #include	<sys/uio.h>
47 #include	<sys/buf.h>
48 #include	<sys/mkdev.h>
49 #include	<sys/cmn_err.h>
50 #include	<sys/errno.h>
51 #include	<sys/fcntl.h>
52 
53 #include	<sys/zsdev.h>
54 #include	<sys/ser_sync.h>
55 #include	<sys/conf.h>
56 #include	<sys/ddi.h>
57 #include	<sys/sunddi.h>
58 #include	<sys/dlpi.h>
59 
60 #define	ZSH_TRACING
61 #ifdef	ZSH_TRACING
62 #include	<sys/vtrace.h>
63 
64 /*
65  * Temp tracepoint definitions
66  */
67 #define	TR_ZSH		50
68 
69 #define	TR_ZSH_TXINT	1
70 #define	TR_ZSH_XSINT	2
71 #define	TR_ZSH_RXINT	3
72 #define	TR_ZSH_SRINT	4
73 
74 #define	TR_ZSH_WPUT_START		5
75 #define	TR_ZSH_WPUT_END			6
76 #define	TR_ZSH_START_START		7
77 #define	TR_ZSH_START_END		8
78 #define	TR_ZSH_SOFT_START		9
79 #define	TR_ZSH_SOFT_END			10
80 
81 #define	TR_ZSH_OPEN	 11
82 #define	TR_ZSH_CLOSE	12
83 
84 #endif	/* ZSH_TRACING */
85 
86 /*
87  * Logging definitions
88  */
89 
90 /*
91  * #define	ZSH_DEBUG
92  */
93 #ifdef ZSH_DEBUG
94 
95 #ifdef ZS_DEBUG_ALL
96 extern	char	zs_h_log[];
97 extern	int	zs_h_log_n;
98 #define	zsh_h_log_add(c) \
99 	{ \
100 		if (zs_h_log_n >= ZS_H_LOG_MAX) \
101 			zs_h_log_n = 0; \
102 		zs_h_log[zs_h_log_n++] = 'A' + zs->zs_unit; \
103 		zs_h_log[zs_h_log_n++] = c; \
104 		zs_h_log[zs_h_log_n] = '\0'; \
105 	}
106 #define	zsh_h_log_clear
107 #else
108 #define	ZSH_H_LOG_MAX   0x8000
109 char zsh_h_log[2][ZSH_H_LOG_MAX +10];
110 int zsh_h_log_n[2];
111 #define	zsh_h_log_add(c) \
112 	{ \
113 		if (zsh_h_log_n[zs->zs_unit] >= ZSH_H_LOG_MAX) \
114 			zsh_h_log_n[zs->zs_unit] = 0; \
115 		zsh_h_log[zs->zs_unit][zsh_h_log_n[zs->zs_unit]++] = c; \
116 		zsh_h_log[zs->zs_unit][zsh_h_log_n[zs->zs_unit]] = '\0'; \
117 	}
118 
119 #define	zsh_h_log_clear \
120 	{ register char *p; \
121 	for (p = &zsh_h_log[zs->zs_unit][ZSH_H_LOG_MAX]; \
122 		p >= &zsh_h_log[zs->zs_unit][0]; p--) \
123 		*p = '\0'; \
124 	zsh_h_log_n[zs->zs_unit] = 0; \
125 	}
126 #endif
127 
128 #define	ZSH_R0_LOG(r0)  { \
129 	if (r0 & ZSRR0_RX_READY) zsh_h_log_add('R'); \
130 	if (r0 & ZSRR0_TIMER) zsh_h_log_add('Z'); \
131 	if (r0 & ZSRR0_TX_READY) zsh_h_log_add('T'); \
132 	if (r0 & ZSRR0_CD) zsh_h_log_add('D'); \
133 	if (r0 & ZSRR0_SYNC) zsh_h_log_add('S'); \
134 	if (r0 & ZSRR0_CTS) zsh_h_log_add('C'); \
135 	if (r0 & ZSRR0_TXUNDER) zsh_h_log_add('U'); \
136 	if (r0 & ZSRR0_BREAK) zsh_h_log_add('B'); \
137 	}
138 #endif
139 
140 #ifndef	MAXZSH
141 #define	MAXZSH	2
142 #define	MAXZSHCLONES	(80)	/* three clone opens per instance */
143 #endif	/* MAXZSH */
144 
145 int maxzsh = MAXZSH;
146 
147 int zsh_timer_count = 10;
148 int zsh_default_mru = 1024;
149 
150 struct ser_str *zsh_str = NULL;
151 unsigned char zsh_usedminor[MAXZSHCLONES];
152 
153 
154 /*
155  * The HDLC protocol
156  */
157 int zsh_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg, void **result);
158 static int  zsh_probe(dev_info_t *dev);
159 static int  zsh_attach(dev_info_t *dev, ddi_attach_cmd_t cmd);
160 static int  zsh_detach(dev_info_t *dev, ddi_detach_cmd_t cmd);
161 static int  zsh_open(queue_t *rq, dev_t *dev, int flag, int sflag, cred_t *cr);
162 static int  zsh_close(queue_t *rq, int flag, cred_t *cr);
163 static void zsh_wput(queue_t *wq, mblk_t *mp);
164 static int zsh_start(struct zscom *zs, struct syncline *zss);
165 static void zsh_ioctl(queue_t *wq, mblk_t *mp);
166 
167 static struct module_info hdlc_minfo = {
168 	0x5a48,		/* module ID number: "ZH" */
169 	"zsh",		/* module name */
170 	0,		/* minimum packet size accepted */
171 	INFPSZ,		/* maximum packet size accepted */
172 	12*1024,	/* queue high water mark (bytes) */
173 	4*1024		/* queue low water mark (bytes) */
174 };
175 
176 static struct qinit hdlc_rinit = {
177 	putq,		/* input put procedure */
178 	NULL,		/* input service procedure */
179 	zsh_open,	/* open procedure */
180 	zsh_close,	/* close procedure */
181 	NULL,		/* reserved */
182 	&hdlc_minfo,	/* module info */
183 	NULL		/* reserved */
184 };
185 
186 static struct qinit hdlc_winit = {
187 	(int (*)())zsh_wput,	/* output put procedure */
188 	NULL,		/* output service procedure */
189 	NULL,		/* open procedure */
190 	NULL,		/* close procedure */
191 	NULL,		/* reserved */
192 	&hdlc_minfo,	/* module info */
193 	NULL		/* reserved */
194 };
195 
196 struct streamtab hdlctab = {
197 	&hdlc_rinit,	/* initialize read queue */
198 	&hdlc_winit,	/* initialize write queue */
199 	NULL,		/* mux read qinit */
200 	NULL		/* mux write qinit */
201 };
202 
203 DDI_DEFINE_STREAM_OPS(zsh_ops, nulldev, zsh_probe, zsh_attach,
204     zsh_detach, nodev, zsh_info, D_MP, &hdlctab, ddi_quiesce_not_supported);
205 
206 /*
207  * This is the loadable module wrapper.
208  */
209 
210 #include	<sys/errno.h>
211 #include	<sys/modctl.h>
212 
213 /*
214  * Module linkage information for the kernel.
215  */
216 
217 static struct modldrv modldrv = {
218 	&mod_driverops, /* Type of module.  This one is a driver */
219 	"Z8530 serial HDLC drv",
220 	&zsh_ops,	/* our own ops for this module */
221 };
222 
223 static struct modlinkage modlinkage = {
224 	MODREV_1,
225 	(void *)&modldrv,
226 	NULL
227 };
228 
229 int
230 _init(void)
231 {
232 	return (mod_install(&modlinkage));
233 }
234 
235 int
236 _fini(void)
237 {
238 	return (mod_remove(&modlinkage));
239 }
240 
241 int
242 _info(struct modinfo *modinfop)
243 {
244 	return (mod_info(&modlinkage, modinfop));
245 }
246 
247 
248 /*
249  * The HDLC interrupt entry points.
250  */
251 static void	zsh_txint(struct zscom *zs);
252 static void	zsh_xsint(struct zscom *zs);
253 static void	zsh_rxint(struct zscom *zs);
254 static void	zsh_srint(struct zscom *zs);
255 static int	zsh_softint(struct zscom *zs);
256 
257 struct zsops zsops_hdlc = {
258 	zsh_txint,
259 	zsh_xsint,
260 	zsh_rxint,
261 	zsh_srint,
262 	zsh_softint,
263 	NULL,
264 	NULL
265 };
266 
267 static int	zsh_program(struct zscom *zs, struct scc_mode *sm);
268 static void	zsh_setmstat(struct zscom *zs, int event);
269 static void	zsh_rxbad(struct zscom *zs, struct syncline *zss);
270 static void	zsh_txbad(struct zscom *zs, struct syncline *zss);
271 static void	zsh_watchdog(void *);
272 static void	zsh_callback(void *);
273 static int	zsh_hdp_ok_or_rts_state(struct zscom *zs, struct syncline *zss);
274 static void	zsh_init_port(struct zscom *zs, struct syncline *zss);
275 static int	zsh_setmode(struct zscom *zs, struct syncline *zss,
276 			struct scc_mode *sm);
277 
278 
279 /*
280  * The HDLC Driver.
281  */
282 
283 
284 /*
285  * Special macros to handle STREAMS operations.
286  * These are required to address memory leakage problems.
287  * WARNING : the macro do NOT call ZSSETSOFT
288  */
289 
290 /*
291  * Should be called holding only the adaptive (zs_excl) mutex.
292  */
293 #define	ZSH_GETBLOCK(zs, allocbcount) \
294 { \
295 	register int n = ZSH_MAX_RSTANDBY; \
296 	while (--n >= 0) { \
297 	    if (!zss->sl_rstandby[n]) { \
298 		if ((zss->sl_rstandby[n] = \
299 		    allocb(zss->sl_mru, BPRI_MED)) == NULL) { \
300 		    if (zss->sl_bufcid == 0) { \
301 			mutex_enter(zs->zs_excl_hi); \
302 			if (zss->sl_txstate != TX_OFF) { \
303 			    mutex_exit(zs->zs_excl_hi); \
304 			    zss->sl_bufcid = bufcall(zss->sl_mru, \
305 				    BPRI_MED, zsh_callback, zs); \
306 			    break; \
307 			} else \
308 				mutex_exit(zs->zs_excl_hi); \
309 		    } \
310 		} \
311 		allocbcount--; \
312 	    } \
313 	} \
314 }
315 
316 /*
317  * Should be called holding the spin (zs_excl_hi) mutex.
318  */
319 #define	ZSH_ALLOCB(mp) \
320 { \
321 	register int n = ZSH_MAX_RSTANDBY; \
322 	mp = NULL; \
323 	while (--n >= 0)  { \
324 		if ((mp = zss->sl_rstandby[n]) != NULL) { \
325 			zss->sl_rstandby[n] = NULL; \
326 			break; \
327 		} \
328 	} \
329 }
330 
331 #define	ZSH_PUTQ(mp) \
332 { \
333 	register int wptr, rptr;  \
334 	wptr = zss->sl_rdone_wptr; \
335 	rptr = zss->sl_rdone_rptr; \
336 	zss->sl_rdone[wptr] = mp; \
337 	if ((wptr) + 1 == ZSH_RDONE_MAX) \
338 		zss->sl_rdone_wptr = wptr = 0; \
339 	else \
340 		zss->sl_rdone_wptr = ++wptr; \
341 	if (wptr == rptr) {  /* Should never occur */ \
342 		SCC_BIC(1, ZSWR1_INIT); \
343 		zss->sl_m_error = ENOSR; \
344 		ZSSETSOFT(zs); \
345 	} \
346 }
347 
348 #define	ZSH_FREEMSG(mp) \
349 { \
350 	ZSH_PUTQ(mp); \
351 }
352 
353 
354 /*
355  * Should be called holding only the adaptive (zs_excl) mutex.
356  */
357 #define	ZSH_GETQ(mp) \
358 { \
359 	if (zss->sl_rdone_rptr != zss->sl_rdone_wptr) { \
360 		mp = zss->sl_rdone[zss->sl_rdone_rptr++]; \
361 		if (zss->sl_rdone_rptr == ZSH_RDONE_MAX) \
362 				zss->sl_rdone_rptr = 0; \
363 	} else \
364 		mp = NULL; \
365 }
366 
367 #define	ZSH_FLUSHQ \
368 { \
369 	register mblk_t *tmp; \
370 	for (;;) { \
371 		ZSH_GETQ(tmp); \
372 		if (!(tmp)) \
373 			break; \
374 		freemsg(tmp); \
375 	} \
376 }
377 
378 /*ARGSUSED*/
379 static int
380 zsh_probe(dev_info_t *dev)
381 {
382 	return (DDI_PROBE_DONTCARE);
383 }
384 
385 /*ARGSUSED*/
386 static int
387 zsh_attach(dev_info_t *dev, ddi_attach_cmd_t cmd)
388 {
389 	register int	unit;
390 	char		name[3] = {
391 		'\0', '\0', '\0' 	};
392 
393 	/*
394 	 * Since zsh is a child of the "pseudo" nexus, we can expect the
395 	 * attach routine to be called only once.  We need to create all
396 	 * necessary devices in one shot.  There is never more than one
397 	 * SCC chip that supports zsh devices.
398 	 */
399 
400 	if (cmd != DDI_ATTACH)
401 		return (DDI_FAILURE);
402 	if (zscom == NULL)
403 		return (DDI_FAILURE);	/* zsattach not done */
404 	unit = 2 * ddi_get_instance(dev);
405 	if (unit > 1)
406 		return (DDI_FAILURE);	/* only use cpu ports */
407 
408 	if (ddi_create_minor_node(dev, "zsh", S_IFCHR,
409 	    NULL, DDI_PSEUDO, CLONE_DEV) == DDI_FAILURE) {
410 		ddi_remove_minor_node(dev, NULL);
411 		cmn_err(CE_WARN, "zsh clone device creation failed.");
412 		return (DDI_FAILURE);
413 	}
414 
415 	for (; unit < maxzsh/2; unit++) {
416 		zscom[unit].zs_hdlc_dip = dev;
417 
418 		(void) sprintf(name, "%d", unit);
419 		if (ddi_create_minor_node(dev, name, S_IFCHR,
420 		    2*unit, DDI_PSEUDO, NULL) == DDI_FAILURE) {
421 			ddi_remove_minor_node(dev, NULL);
422 			return (DDI_FAILURE);
423 		}
424 		unit++;
425 		(void) sprintf(name, "%d", unit);
426 		if (ddi_create_minor_node(dev, name, S_IFCHR,
427 		    2*(unit-1)+1, DDI_PSEUDO, NULL) == DDI_FAILURE) {
428 			ddi_remove_minor_node(dev, NULL);
429 			return (DDI_FAILURE);
430 		}
431 	}
432 
433 	return (DDI_SUCCESS);
434 }
435 
436 /* ARGSUSED */
437 int
438 zsh_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
439 void **result)
440 {
441 	register dev_t dev = (dev_t)arg;
442 	register int unit, error;
443 	register struct zscom *zs;
444 
445 	if ((unit = UNIT(dev)) >= nzs)
446 		return (DDI_FAILURE);
447 
448 	switch (infocmd) {
449 	case DDI_INFO_DEVT2DEVINFO:
450 		if (zscom == NULL) {
451 			error = DDI_FAILURE;
452 		} else {
453 			zs = &zscom[unit];
454 			*result = zs->zs_hdlc_dip;
455 			error = DDI_SUCCESS;
456 		}
457 		break;
458 	case DDI_INFO_DEVT2INSTANCE:
459 		*result = (void *)(uintptr_t)(unit / 2);
460 		error = DDI_SUCCESS;
461 		break;
462 	default:
463 		error = DDI_FAILURE;
464 	}
465 	return (error);
466 }
467 
468 static int
469 zsh_detach(dev_info_t *dev, ddi_detach_cmd_t cmd)
470 {
471 	if (cmd != DDI_DETACH)
472 		return (DDI_FAILURE);
473 
474 	ddi_remove_minor_node(dev, NULL);
475 
476 	return (DDI_SUCCESS);
477 }
478 
479 static void
480 zsh_init_port(struct zscom *zs, struct syncline *zss)
481 {
482 	register uchar_t s0;
483 
484 	SCC_WRITE(3, (ZSWR3_RX_ENABLE | ZSWR3_RXCRC_ENABLE | ZSWR3_RX_8));
485 	SCC_WRITE(5, (ZSWR5_TX_8 | ZSWR5_DTR | ZSWR5_TXCRC_ENABLE));
486 	zss->sl_rr0 = SCC_READ0();
487 	if (zss->sl_flags & SF_FDXPTP) {
488 		SCC_BIS(5, ZSWR5_TX_ENABLE);
489 		SCC_BIS(5, ZSWR5_RTS);
490 		s0 = SCC_READ0();
491 		if ((s0 & ZSRR0_CTS) ||
492 		    !(zss->sl_mode.sm_config & (CONN_SIGNAL | CONN_IBM))) {
493 			/*
494 			 * send msg that CTS is up
495 			 */
496 			zss->sl_rr0 |= ZSRR0_CTS;
497 			zss->sl_txstate = TX_IDLE;
498 		} else {
499 			zss->sl_flags |= SF_XMT_INPROG;
500 			zss->sl_txstate = TX_RTS;
501 			zss->sl_rr0 &= ~ZSRR0_CTS;
502 			zss->sl_wd_count = zsh_timer_count;
503 			if (!zss->sl_wd_id)
504 				zss->sl_wd_id = timeout(zsh_watchdog,
505 				    zs, SIO_WATCHDOG_TICK);
506 		}
507 	} else {
508 		SCC_BIC(15, ZSR15_CTS);
509 		SCC_BIC(5, ZSWR5_TX_ENABLE);
510 		SCC_BIC(5, ZSWR5_RTS);
511 		zss->sl_flags &= ~SF_FLUSH_WQ;
512 	}
513 }
514 
515 /*
516  * Open routine.
517  */
518 
519 /*ARGSUSED*/
520 static int
521 zsh_open(queue_t *rq, dev_t *dev, int flag, int sflag, cred_t *cr)
522 {
523 	register struct zscom *zs;
524 	register struct syncline *zss;
525 	register struct ser_str *stp;
526 	register int	unit;
527 	register int 	tmp;
528 
529 	if (sflag != CLONEOPEN) {
530 		if (rq->q_ptr)
531 			return (EBUSY);  /* We got a stream that is in use */
532 
533 		unit = UNIT(*dev);
534 		if (unit >= maxzsh)
535 			return (ENXIO);  /* unit not configured */
536 
537 		if (zscom == NULL)
538 			return (ENXIO);  /* device not found by autoconfig */
539 		zs = &zscom[unit];
540 
541 		if (zs->zs_ops == NULL) {
542 			return (ENXIO);  /* device not found by autoconfig */
543 		}
544 
545 		TRACE_1(TR_ZSH, TR_ZSH_OPEN, "zsh_open:unit = %d", unit);
546 
547 		mutex_enter(zs->zs_excl);
548 		if ((zs->zs_ops != &zsops_null) &&
549 		    (zs->zs_ops != &zsops_hdlc)) {
550 			mutex_exit(zs->zs_excl);
551 			return (EBUSY);	 /* another protocol got here first */
552 		}
553 
554 		/* Mark device as busy (for power management) */
555 		(void) pm_busy_component(zs->zs_dip, unit%2+1);
556 		(void) ddi_dev_is_needed(zs->zs_dip, unit%2+1, 1);
557 
558 		zsopinit(zs, &zsops_hdlc);
559 
560 		zss = (struct syncline *)&zscom[unit].zs_priv_str;
561 		stp = &zss->sl_stream;
562 		stp->str_state = NULL;
563 		stp->str_com = (caddr_t)zs;
564 
565 		zss->sl_xhead = NULL;
566 		zss->sl_xactb = NULL;
567 		zs->zs_wr_cur = NULL;
568 		zs->zs_wr_lim = NULL;
569 		zs->zs_wr_cur = NULL;
570 		zs->zs_wr_lim = NULL;
571 		zss->sl_rhead = NULL;
572 		zss->sl_ractb = NULL;
573 		zs->zs_rd_cur = NULL;
574 		zs->zs_rd_lim = NULL;
575 		zss->sl_mstat = NULL;
576 		zss->sl_xstandby = NULL;
577 		zss->sl_wd_id = 0;
578 		zss->sl_soft_active = 0;
579 		zss->sl_stream.str_rq = NULL;
580 
581 		zs->zs_priv = (caddr_t)zss;
582 
583 		zss->sl_mru = zsh_default_mru;
584 		tmp = ZSH_MAX_RSTANDBY;
585 		ZSH_GETBLOCK(zs, tmp);
586 		if (zss->sl_rstandby[0] == NULL) {
587 			cmn_err(CE_WARN, "zsh_open: can't alloc message block");
588 			mutex_exit(zs->zs_excl);
589 			return (ENOSR);
590 		}
591 		mutex_enter(zs->zs_excl_hi);
592 		ZSH_ALLOCB(zss->sl_ractb);
593 		zss->sl_txstate = TX_OFF;
594 		zss->sl_rr0 = SCC_READ0();
595 		zss->sl_flags &= (SF_INITIALIZED | SF_FDXPTP);
596 		if (zss->sl_flags & SF_INITIALIZED)
597 			zsh_init_port(zs, zss);
598 		mutex_exit(zs->zs_excl_hi);
599 		mutex_exit(zs->zs_excl);
600 	} else {   /* CLONEOPEN */
601 		mutex_enter(&zs_curr_lock);
602 		for (unit = maxzsh; unit < MAXZSHCLONES; unit++)
603 			if (!zsh_usedminor[unit]) {
604 				zsh_usedminor[unit] = (unsigned char)unit;
605 				break;
606 			}
607 		mutex_exit(&zs_curr_lock);
608 		if (unit >= MAXZSHCLONES)	/* no slots available */
609 			return (ENODEV);
610 		*dev = makedevice(getmajor(*dev), unit);
611 
612 		stp = kmem_zalloc(sizeof (struct ser_str), KM_NOSLEEP);
613 		if (stp == NULL) {
614 			cmn_err(CE_WARN,
615 			    "zsh clone open failed, no memory, rq=%p\n",
616 			    (void *)rq);
617 			return (ENOMEM);
618 		}
619 		stp->str_state = STR_CLONE;
620 		stp->str_com = NULL;	/* can't determine without ppa */
621 	}
622 	stp->str_rq = rq;
623 	stp->str_inst = unit;
624 
625 	rq->q_ptr = WR(rq)->q_ptr = (caddr_t)stp;
626 	qprocson(rq);
627 	return (0);
628 }
629 
630 /*
631  * Close routine.
632  */
633 int zsh_tx_enable_in_close = 0;
634 
635 /*ARGSUSED*/
636 static int
637 zsh_close(queue_t *rq, int flag, cred_t *cr __unused)
638 {
639 	struct ser_str *stp;
640 	struct zscom *zs;
641 	struct syncline *zss;
642 	mblk_t	*mp;
643 	int i;
644 	timeout_id_t sl_wd_id;
645 	bufcall_id_t sl_bufcid;
646 
647 	/*
648 	 * Note that a close is only called on the last close of a
649 	 * particular stream.  Assume that we need to do it all.
650 	 */
651 	qprocsoff(rq);				/* no new business after this */
652 
653 	stp = (struct ser_str *)rq->q_ptr;
654 	if (stp == NULL)
655 		return (0);			/* already been closed once */
656 
657 	if (stp->str_state == STR_CLONE) {
658 		zsh_usedminor[stp->str_inst] = 0;
659 	} else {
660 		zs = (struct zscom *)stp->str_com;
661 		if (zs == NULL)
662 			goto out;
663 
664 		TRACE_1(TR_ZSH, TR_ZSH_CLOSE, "zs = %p", zs);
665 
666 		zss = (struct syncline *)zs->zs_priv;
667 		mutex_enter(zs->zs_excl);
668 		flushq(WR(rq), FLUSHALL);
669 		mutex_enter(zs->zs_excl_hi);
670 		if (zss->sl_xstandby) {
671 			zss->sl_xstandby->b_wptr = zss->sl_xstandby->b_rptr;
672 			ZSH_FREEMSG(zss->sl_xstandby);
673 			zss->sl_xstandby = NULL;
674 		}
675 		mutex_exit(zs->zs_excl_hi);
676 
677 		ZSH_FLUSHQ;
678 
679 		/*
680 		 * Stop the Watchdog Timer.
681 		 */
682 		if ((sl_wd_id = zss->sl_wd_id) != 0)
683 			zss->sl_wd_id = 0;
684 
685 		/*
686 		 * Cancel outstanding "bufcall" request.
687 		 */
688 		if ((sl_bufcid = zss->sl_bufcid) != 0)
689 			zss->sl_bufcid = 0;
690 
691 		mutex_enter(zs->zs_excl_hi);
692 		if (zs->zs_wr_cur) {
693 			zs->zs_wr_cur = NULL;
694 			zs->zs_wr_lim = NULL;
695 			SCC_WRITE0(ZSWR0_SEND_ABORT);
696 			ZSDELAY();
697 			ZSDELAY();
698 		}
699 		zss->sl_txstate = TX_OFF;	/* so it can't rearm in close */
700 
701 		zs->zs_wr_cur = NULL;
702 		zs->zs_wr_lim = NULL;
703 		SCC_BIC(15,
704 		    (ZSR15_TX_UNDER | ZSR15_BREAK | ZSR15_SYNC | ZSR15_CTS));
705 		SCC_WRITE(3, 0);		/* Quiesce receiver */
706 		if (zsh_tx_enable_in_close && !(zss->sl_flags & SF_FDXPTP)) {
707 			SCC_BIS(5, ZSWR5_TX_ENABLE);
708 		} else
709 			SCC_BIC(5, ZSWR5_TX_ENABLE);
710 
711 		SCC_BIC(5,  (ZSWR5_DTR | ZSWR5_RTS | ZSWR5_TXCRC_ENABLE));
712 		SCC_WRITE0(ZSWR0_RESET_TXINT);		/* reset TX */
713 		SCC_WRITE0(ZSWR0_RESET_STATUS);		/* reset XS */
714 		SCC_WRITE0(ZSWR0_RESET_ERRORS);
715 		(void) SCC_READDATA();			/* reset RX */
716 		ZSDELAY();
717 		(void) SCC_READDATA();
718 		ZSDELAY();
719 		(void) SCC_READDATA();
720 		ZSDELAY();
721 
722 
723 		/*
724 		 * Free up everything we ever allocated.
725 		 */
726 		if ((mp = zss->sl_rhead) != NULL) {
727 			zss->sl_ractb = NULL;	/* already freed */
728 			zs->zs_rd_cur = NULL;
729 			zs->zs_rd_lim = NULL;
730 			zss->sl_rhead = NULL;
731 		}
732 		mutex_exit(zs->zs_excl_hi);
733 		if (mp)
734 			freemsg(mp);
735 
736 		mutex_enter(zs->zs_excl_hi);
737 		if ((mp = zss->sl_ractb) != NULL) {
738 			zs->zs_rd_cur = NULL;
739 			zs->zs_rd_lim = NULL;
740 			zss->sl_ractb = NULL;
741 		}
742 		mutex_exit(zs->zs_excl_hi);
743 		if (mp)
744 			freemsg(mp);
745 
746 		for (i = 0; i < ZSH_MAX_RSTANDBY; i++) {
747 			mutex_enter(zs->zs_excl_hi);
748 			mp = zss->sl_rstandby[i];
749 			zss->sl_rstandby[i] = NULL;
750 			mutex_exit(zs->zs_excl_hi);
751 			if (mp)
752 				freemsg(mp);
753 		}
754 
755 		mutex_enter(zs->zs_excl_hi);
756 		if ((mp = zss->sl_xhead) != NULL) {
757 			zss->sl_xhead = NULL;
758 			zss->sl_xactb = NULL;
759 		}
760 		mutex_exit(zs->zs_excl_hi);
761 		if (mp)
762 			freemsg(mp);
763 
764 		ZSH_FLUSHQ;
765 
766 		mutex_enter(zs->zs_excl_hi);
767 		if ((mp = zss->sl_xstandby) != NULL)
768 			zss->sl_xstandby = NULL;
769 		mutex_exit(zs->zs_excl_hi);
770 		if (mp)
771 			freemsg(mp);
772 
773 		mutex_enter(zs->zs_excl_hi);
774 		if ((mp = zss->sl_mstat) != NULL)
775 			zss->sl_mstat = NULL;
776 		zss->sl_txstate = TX_OFF;	/* so it can't rearm in close */
777 		mutex_exit(zs->zs_excl_hi);
778 		if (mp)
779 			freemsg(mp);
780 
781 		zss->sl_stream.str_rq = NULL;
782 		zsopinit(zs, &zsops_null);
783 		mutex_exit(zs->zs_excl);
784 		if (sl_wd_id)
785 			(void) untimeout(sl_wd_id);
786 		if (sl_bufcid)
787 			unbufcall(sl_bufcid);
788 		while (zss->sl_soft_active)
789 			drv_usecwait(1);
790 
791 		/* Mark device as available for power management */
792 		(void) pm_idle_component(zs->zs_dip, zs->zs_unit%2+1);
793 	}
794 
795 	if (stp->str_state == STR_CLONE)
796 		kmem_free(stp, sizeof (struct ser_str));
797 
798 out:
799 	rq->q_ptr = WR(rq)->q_ptr = NULL;
800 
801 	return (0);
802 }
803 
804 static int
805 zsh_hdp_ok_or_rts_state(struct zscom *zs, struct syncline *zss)
806 {
807 	register uchar_t s0;
808 
809 	SCC_BIS(15, ZSR15_CTS);
810 	SCC_BIS(5, ZSWR5_RTS);
811 	s0 = SCC_READ0();
812 	if (s0 & ZSRR0_CTS) {
813 		SCC_BIS(5, ZSWR5_TX_ENABLE);
814 		zss->sl_rr0 |= ZSRR0_CTS;
815 		return (1);
816 	}
817 	zss->sl_flags |= SF_XMT_INPROG;
818 	zss->sl_txstate = TX_RTS;
819 	zss->sl_rr0 &= ~ZSRR0_CTS;
820 	zss->sl_wd_count = zsh_timer_count;
821 	return (0);
822 }
823 
824 /*
825  * Put procedure for write queue.
826  */
827 static void
828 zsh_wput(queue_t *wq, mblk_t *mp)
829 {
830 	register struct ser_str *stp = (struct ser_str *)wq->q_ptr;
831 	register struct zscom *zs;
832 	register struct syncline *zss = NULL;
833 	register ulong_t prim, error = 0;
834 	register union DL_primitives *dlp;
835 	register int	ppa;
836 	register mblk_t *tmp;
837 	register struct copyresp	*resp;
838 
839 	/*
840 	 * stp->str_com supplied by open or DLPI attach.
841 	 */
842 	if (stp == NULL) {
843 		freemsg(mp);
844 		return;
845 	}
846 	zs = (struct zscom *)stp->str_com;
847 
848 	TRACE_0(TR_ZSH, TR_ZSH_WPUT_START, "zsh_wput start");
849 
850 	if ((mp->b_datap->db_type == M_FLUSH) &&
851 	    (stp->str_state == STR_CLONE)) {
852 		if (*mp->b_rptr & FLUSHW) {
853 			flushq(wq, FLUSHDATA);
854 			*mp->b_rptr &= ~FLUSHW;
855 		}
856 		if (*mp->b_rptr & FLUSHR)
857 			qreply(wq, mp);  /* let the read queues have at it */
858 		else
859 			freemsg(mp);
860 		return;
861 	}
862 
863 	if ((zs == NULL) && (mp->b_datap->db_type != M_PROTO)) {
864 		freemsg(mp);
865 		cmn_err(CE_WARN,
866 		    "zsh: clone device %d must be attached before use!",
867 		    stp->str_inst);
868 		(void) putnextctl1(RD(wq), M_ERROR, EPROTO);
869 		return;
870 	}
871 
872 	if (stp->str_state == STR_CLONE) {	/* Clone opened, limited. */
873 		if ((mp->b_datap->db_type != M_PROTO) &&
874 		    (mp->b_datap->db_type != M_IOCTL) &&
875 		    (mp->b_datap->db_type != M_IOCDATA)) {
876 			freemsg(mp);
877 			cmn_err(CE_WARN,
878 			    "zsh%x: invalid operation for clone dev.\n",
879 			    stp->str_inst);
880 			(void) putnextctl1(RD(wq), M_ERROR, EPROTO);
881 			return;
882 		}
883 	} else {
884 		zss = (struct syncline *)zs->zs_priv;
885 	}
886 
887 	switch (mp->b_datap->db_type) {
888 
889 	case M_DATA:
890 		/*
891 		 * Queue the message up to be transmitted.
892 		 * Set "in progress" flag and call the start routine.
893 		 */
894 		mutex_enter(zs->zs_excl_hi);
895 		if (!(zss->sl_flags & SF_INITIALIZED)) {
896 			mutex_exit(zs->zs_excl_hi);
897 			cmn_err(CE_WARN,
898 			    "zsh%x not initialized, can't send message",
899 			    zs->zs_unit);
900 			freemsg(mp);
901 			(void) putnextctl1(RD(wq), M_ERROR, ECOMM);
902 			return;
903 		}
904 		mutex_exit(zs->zs_excl_hi);
905 		if (zs->zs_flags & ZS_NEEDSOFT) {
906 			zs->zs_flags &= ~ZS_NEEDSOFT;
907 			(void) zsh_softint(zs);
908 		}
909 		while (mp->b_wptr == mp->b_rptr) {
910 			register mblk_t *mp1;
911 			mp1 = unlinkb(mp);
912 			freemsg(mp);
913 			mp = mp1;
914 			if (mp == NULL)
915 				return;
916 		}
917 		mutex_enter(zs->zs_excl);
918 		(void) putq(wq, mp);
919 		mutex_enter(zs->zs_excl_hi);
920 		if (zss->sl_flags & SF_FLUSH_WQ) {
921 			mutex_exit(zs->zs_excl_hi);
922 			flushq(wq, FLUSHDATA);
923 			mutex_exit(zs->zs_excl);
924 
925 			TRACE_1(TR_ZSH, TR_ZSH_WPUT_END,
926 			    "zsh_wput end: zs = %p", zs);
927 
928 			return;
929 		}
930 		tmp = NULL;
931 again:
932 		if (!zss->sl_xstandby) {
933 			if (tmp)
934 				zss->sl_xstandby = tmp;
935 			else {
936 				mutex_exit(zs->zs_excl_hi);
937 				tmp = getq(wq);
938 				mutex_enter(zs->zs_excl_hi);
939 				if (tmp)
940 					goto again;
941 			}
942 		} else if (tmp) {
943 			mutex_exit(zs->zs_excl_hi);
944 			(void) putbq(wq, tmp);
945 			mutex_enter(zs->zs_excl_hi);
946 		}
947 
948 		if (zss->sl_flags & SF_XMT_INPROG) {
949 			mutex_exit(zs->zs_excl_hi);
950 			mutex_exit(zs->zs_excl);
951 
952 			TRACE_1(TR_ZSH, TR_ZSH_WPUT_END,
953 			    "zsh_wput end: zs = %p", zs);
954 
955 			return;
956 		}
957 
958 		if (!zss->sl_wd_id) {
959 			zss->sl_wd_count = zsh_timer_count;
960 			zss->sl_txstate = TX_IDLE;
961 			mutex_exit(zs->zs_excl_hi);
962 			zss->sl_wd_id = timeout(zsh_watchdog, zs,
963 			    SIO_WATCHDOG_TICK);
964 			mutex_enter(zs->zs_excl_hi);
965 		}
966 
967 		zss->sl_flags |= SF_XMT_INPROG;
968 		if ((zss->sl_flags & SF_FDXPTP) ||
969 		    zsh_hdp_ok_or_rts_state(zs, zss))
970 			(void) zsh_start(zs, zss);
971 		mutex_exit(zs->zs_excl_hi);
972 		mutex_exit(zs->zs_excl);
973 		break;
974 
975 	case M_PROTO:
976 		/*
977 		 * Here is where a clone device finds out about the
978 		 * hardware it is going to attach to.  The request is
979 		 * validated and a ppa is extracted from it and validated.
980 		 * This number is used to index the hardware data structure
981 		 * and the protocol data structure, in case the latter
982 		 * was not provided by a data-path open before this.
983 		 */
984 		if (stp->str_state != STR_CLONE) {
985 			freemsg(mp);
986 			return;
987 		}
988 
989 		if (MBLKL(mp) < DL_ATTACH_REQ_SIZE) {
990 			prim = DL_ATTACH_REQ;
991 			error = DL_BADPRIM;
992 			goto end_proto;
993 		}
994 		dlp = (union DL_primitives *)mp->b_rptr;
995 		prim = dlp->dl_primitive;
996 		if (prim != DL_ATTACH_REQ) {
997 			error = DL_BADPRIM;
998 			goto end_proto;
999 		}
1000 		ppa = dlp->attach_req.dl_ppa;
1001 		ppa = (ppa%2) ? ((ppa-1)*2 +1) : (ppa*2);
1002 		if (ppa >= maxzsh) {
1003 			error = DL_BADPPA;
1004 			goto end_proto;
1005 		}
1006 		zs = &zscom[ppa];
1007 		if (zs->zs_ops == NULL) {
1008 			error = ENXIO;
1009 			goto end_proto;
1010 		}
1011 		mutex_enter(zs->zs_excl);
1012 		if ((zs->zs_ops != &zsops_null) &&
1013 		    (zs->zs_ops != &zsops_hdlc)) {
1014 			/*
1015 			 * another protocol got here first
1016 			 */
1017 			error = (EBUSY);
1018 			mutex_exit(zs->zs_excl);
1019 			goto end_proto;
1020 
1021 		}
1022 
1023 		stp->str_com = (caddr_t)zs;
1024 		mutex_exit(zs->zs_excl);
1025 end_proto:
1026 		if (error)
1027 			dlerrorack(wq, mp, prim, error, 0);
1028 		else
1029 			dlokack(wq, mp, DL_ATTACH_REQ);
1030 		break;
1031 
1032 	case M_IOCTL:
1033 		zsh_ioctl(wq, mp);
1034 		break;
1035 
1036 	case M_IOCDATA:
1037 		resp = (struct copyresp *)mp->b_rptr;
1038 		if (resp->cp_rval) {
1039 			/*
1040 			 * Just free message on failure.
1041 			 */
1042 			freemsg(mp);
1043 			break;
1044 		}
1045 
1046 		switch (resp->cp_cmd) {
1047 
1048 		case S_IOCGETMODE:
1049 		case S_IOCGETSTATS:
1050 		case S_IOCGETSPEED:
1051 		case S_IOCGETMCTL:
1052 		case S_IOCGETMRU:
1053 			mioc2ack(mp, NULL, 0, 0);
1054 			qreply(wq, mp);
1055 			break;
1056 
1057 		case S_IOCSETMODE:
1058 			zss  = (struct syncline *)&zs->zs_priv_str;
1059 			mutex_enter(zs->zs_excl);
1060 			error = zsh_setmode(zs, zss,
1061 			    (struct scc_mode *)mp->b_cont->b_rptr);
1062 			if (error) {
1063 				register struct iocblk  *iocp =
1064 				    (struct iocblk *)mp->b_rptr;
1065 				mp->b_datap->db_type = M_IOCNAK;
1066 				iocp->ioc_error = error;
1067 			} else
1068 				mioc2ack(mp, NULL, 0, 0);
1069 			mutex_exit(zs->zs_excl);
1070 			qreply(wq, mp);
1071 			break;
1072 
1073 		case S_IOCSETMRU:
1074 			zss  = (struct syncline *)&zs->zs_priv_str;
1075 			mutex_enter(zs->zs_excl);
1076 			zss->sl_mru = *(int *)mp->b_cont->b_rptr;
1077 			mutex_exit(zs->zs_excl);
1078 			mioc2ack(mp, NULL, 0, 0);
1079 			qreply(wq, mp);
1080 			break;
1081 		default:
1082 			freemsg(mp);
1083 		}
1084 		break;
1085 
1086 		/*
1087 		 * We're at the bottom of the food chain, so we flush our
1088 		 * write queue, clear the FLUSHW bit so it doesn't go round
1089 		 * and round forever, then flush our read queue (since there's
1090 		 * no read put procedure down here) and pass it up for any
1091 		 * higher modules to deal with in their own way.
1092 		 */
1093 	case M_FLUSH:
1094 		if (*mp->b_rptr & FLUSHW) {
1095 			mutex_enter(zs->zs_excl);
1096 			flushq(wq, FLUSHDATA);
1097 			mutex_enter(zs->zs_excl_hi);
1098 			tmp = zss->sl_xstandby;
1099 			zss->sl_xstandby = NULL;
1100 			mutex_exit(zs->zs_excl_hi);
1101 			if (tmp)
1102 				freemsg(tmp);
1103 			mutex_exit(zs->zs_excl);
1104 			*mp->b_rptr &= ~FLUSHW;
1105 		}
1106 
1107 		if (*mp->b_rptr & FLUSHR) {
1108 			mutex_enter(zs->zs_excl);
1109 			ZSH_FLUSHQ;
1110 			mutex_exit(zs->zs_excl);
1111 			qreply(wq, mp);  /* let the read queues have at it */
1112 		} else
1113 			freemsg(mp);
1114 		break;
1115 
1116 	default:
1117 		/*
1118 		 * "No, I don't want a subscription to Chain Store Age,
1119 		 * thank you anyway."
1120 		 */
1121 		freemsg(mp);
1122 		break;
1123 	}
1124 
1125 	TRACE_1(TR_ZSH, TR_ZSH_WPUT_END, "zsh_wput end: zs = %p", zs);
1126 }
1127 
1128 /*
1129  * Get the next message from the write queue, set up the necessary pointers,
1130  * state info, etc., and start the transmit "engine" by sending the first
1131  * character.  We'll then rotate through txint until done, then get an xsint.
1132  */
1133 static int
1134 zsh_start(struct zscom *zs, struct syncline *zss)
1135 {
1136 	register mblk_t *mp;
1137 	register uchar_t *wptr;
1138 	register uchar_t *rptr;
1139 	register uchar_t sl_flags = zss->sl_flags;
1140 
1141 	/*
1142 	 * Attempt to grab the next M_DATA message off the queue (that's
1143 	 * all that will be left after wput) and begin transmission.
1144 	 * This routine is normally called after completion of a previous
1145 	 * frame, or when zsh_wput gets a new message.  If we are in a
1146 	 * mode that put us in the TX_RTS state, waiting for CTS, and CTS
1147 	 * is not up yet, we have no business here.  Ditto if we're in
1148 	 * either the TX_ACTIVE or TX_CRC states.  In these cases we
1149 	 * don't clear SF_CALLSTART, so we don't forget there's work to do.
1150 	 */
1151 
1152 	TRACE_1(TR_ZSH, TR_ZSH_START_START,
1153 	    "zsh_start start: zs = %p", zs);
1154 
1155 	if (sl_flags & SF_PHONY) {
1156 		sl_flags &= ~SF_PHONY;
1157 		SCC_BIC(15, ZSR15_CTS);
1158 		SCC_BIC(5, ZSWR5_RTS);
1159 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1160 		SCC_BIC(5, ZSWR5_TX_ENABLE);
1161 		zss->sl_rr0 &= ~ZSRR0_CTS;
1162 		zss->sl_txstate = TX_IDLE;
1163 		/*
1164 		 * if we get another msg by chance zsh_watchog will start
1165 		 */
1166 		sl_flags &= ~SF_XMT_INPROG;
1167 		zss->sl_flags = sl_flags;
1168 
1169 		TRACE_1(TR_ZSH, TR_ZSH_START_END,
1170 		    "zsh_start end: zs = %d", zs);
1171 
1172 		return (0);
1173 	}
1174 	mp = zss->sl_xstandby;
1175 	if (mp == NULL) {
1176 		if (!(sl_flags & SF_FDXPTP)) {
1177 			sl_flags |= SF_PHONY;
1178 			ZSH_ALLOCB(mp);
1179 			if (!mp)
1180 				return (0);
1181 			mp->b_datap->db_type = M_RSE;
1182 			mp->b_wptr = mp->b_rptr + 1;
1183 			goto transmit;
1184 		}
1185 		sl_flags &= ~SF_XMT_INPROG;
1186 		zss->sl_flags = sl_flags;
1187 
1188 		TRACE_1(TR_ZSH, TR_ZSH_START_END,
1189 		    "zsh_start end: zs = %p", zs);
1190 
1191 		return (0);
1192 	}
1193 
1194 transmit:
1195 	zss->sl_xstandby = NULL;
1196 	rptr = mp->b_rptr;
1197 	wptr = mp->b_wptr;
1198 	ZSSETSOFT(zs);
1199 
1200 #ifdef ZSH_DEBUG
1201 	if (zss->sl_xhead || zss->sl_xactb) {
1202 		debug_enter("xhead1");
1203 	}
1204 #endif
1205 
1206 	zss->sl_xhead = mp;
1207 	zss->sl_xactb = mp;
1208 	zss->sl_wd_count = zsh_timer_count;
1209 	zss->sl_txstate = TX_ACTIVE;
1210 	zss->sl_ocnt = 0;
1211 	SCC_BIS(10, ZSWR10_UNDERRUN_ABORT);	/* abort on underrun */
1212 	SCC_WRITE0(ZSWR0_RESET_TXCRC);		/* reset transmit CRC */
1213 	zss->sl_ocnt = wptr - rptr;
1214 	mp->b_wptr = rptr; /* to tell soft to free this msg */
1215 	SCC_WRITEDATA(*rptr++);    /* resets TXINT */
1216 	zs->zs_wr_cur = rptr;
1217 	zs->zs_wr_lim = wptr;
1218 
1219 	SCC_WRITE0(ZSWR0_RESET_EOM);
1220 
1221 	TRACE_1(TR_ZSH, TR_ZSH_START_END,
1222 	    "zsh_start end: zs = %p", zs);
1223 
1224 	zss->sl_flags = sl_flags;
1225 	return (1);
1226 }
1227 
1228 
1229 /*
1230  * Process an "ioctl" message sent down to us.
1231  */
1232 static void
1233 zsh_ioctl(queue_t *wq, mblk_t *mp)
1234 {
1235 	register struct ser_str *stp = (struct ser_str *)wq->q_ptr;
1236 	register struct zscom *zs = (struct zscom *)stp->str_com;
1237 	register struct syncline *zss  = (struct syncline *)&zs->zs_priv_str;
1238 	register struct iocblk   *iocp = (struct iocblk *)mp->b_rptr;
1239 	register struct scc_mode *sm;
1240 	register struct sl_stats *st;
1241 	register uchar_t	 *msignals;
1242 	register mblk_t		 *tmp;
1243 	register int		 error = 0;
1244 
1245 	mutex_enter(zs->zs_excl);
1246 	if ((zs->zs_ops != &zsops_null) &&
1247 	    (zs->zs_ops != &zsops_hdlc)) {
1248 		/*
1249 		 * another protocol got here first
1250 		 */
1251 		error = (EBUSY);
1252 		goto end_zsh_ioctl;
1253 	}
1254 
1255 
1256 	switch (iocp->ioc_cmd) {
1257 
1258 	case S_IOCGETMODE:
1259 		tmp = allocb(sizeof (struct scc_mode), BPRI_MED);
1260 		if (tmp == NULL) {
1261 			error = EAGAIN;
1262 			break;
1263 		}
1264 		if (iocp->ioc_count != TRANSPARENT)
1265 			mioc2ack(mp, tmp, sizeof (struct scc_mode), 0);
1266 		else
1267 			mcopyout(mp, NULL, sizeof (struct scc_mode), NULL, tmp);
1268 		sm = (struct scc_mode *)mp->b_cont->b_rptr;
1269 		bcopy(&zss->sl_mode, sm, sizeof (struct scc_mode));
1270 		break;
1271 
1272 	case S_IOCGETSTATS:
1273 		tmp = allocb(sizeof (struct sl_stats), BPRI_MED);
1274 		if (tmp == NULL) {
1275 			error = EAGAIN;
1276 			break;
1277 		}
1278 		if (iocp->ioc_count != TRANSPARENT)
1279 			mioc2ack(mp, tmp, sizeof (struct sl_stats), 0);
1280 		else
1281 			mcopyout(mp, NULL, sizeof (struct sl_stats), NULL, tmp);
1282 		st = (struct sl_stats *)mp->b_cont->b_rptr;
1283 		bcopy(&zss->sl_st, st, sizeof (struct sl_stats));
1284 		break;
1285 
1286 	case S_IOCGETSPEED:
1287 		tmp = allocb(sizeof (int), BPRI_MED);
1288 		if (tmp == NULL) {
1289 			error = EAGAIN;
1290 			break;
1291 		}
1292 		if (iocp->ioc_count != TRANSPARENT)
1293 			mioc2ack(mp, tmp, sizeof (int), 0);
1294 		else
1295 			mcopyout(mp, NULL, sizeof (int), NULL, tmp);
1296 		*(int *)mp->b_cont->b_rptr = zss->sl_mode.sm_baudrate;
1297 		break;
1298 
1299 	case S_IOCGETMCTL:
1300 		tmp = allocb(sizeof (char), BPRI_MED);
1301 		if (tmp == NULL) {
1302 			error = EAGAIN;
1303 			break;
1304 		}
1305 		if (iocp->ioc_count != TRANSPARENT)
1306 			mioc2ack(mp, tmp, sizeof (char), 0);
1307 		else
1308 			mcopyout(mp, NULL, sizeof (char), NULL, tmp);
1309 		msignals = (uchar_t *)mp->b_cont->b_rptr;
1310 		*msignals = zss->sl_rr0 & (ZSRR0_CD | ZSRR0_CTS);
1311 		break;
1312 
1313 	case S_IOCGETMRU:
1314 		tmp = allocb(sizeof (int), BPRI_MED);
1315 		if (tmp == NULL) {
1316 			error = EAGAIN;
1317 			break;
1318 		}
1319 		if (iocp->ioc_count != TRANSPARENT)
1320 			mioc2ack(mp, tmp, sizeof (int), 0);
1321 		else
1322 			mcopyout(mp, NULL, sizeof (int), NULL, tmp);
1323 		*(int *)mp->b_cont->b_rptr = zss->sl_mru;
1324 		break;
1325 
1326 	case S_IOCSETMODE:
1327 		if (iocp->ioc_count != TRANSPARENT) {
1328 			error = miocpullup(mp, sizeof (struct scc_mode));
1329 			if (error != 0)
1330 				break;
1331 			error = zsh_setmode(zs, zss,
1332 			    (struct scc_mode *)mp->b_cont->b_rptr);
1333 			if (error == 0)
1334 				mioc2ack(mp, NULL, 0, 0);
1335 		} else
1336 			mcopyin(mp, NULL, sizeof (struct scc_mode), NULL);
1337 		break;
1338 
1339 	case S_IOCCLRSTATS:
1340 		mutex_enter(zs->zs_excl_hi);
1341 		bzero(&zss->sl_st, sizeof (struct sl_stats));
1342 		mutex_exit(zs->zs_excl_hi);
1343 		mioc2ack(mp, NULL, 0, 0);
1344 		break;
1345 
1346 	case S_IOCSETMRU:
1347 		if (iocp->ioc_count != TRANSPARENT) {
1348 			error = miocpullup(mp, sizeof (int));
1349 			if (error != 0)
1350 				break;
1351 			zss->sl_mru = *(int *)mp->b_cont->b_rptr;
1352 			mioc2ack(mp, NULL, 0, 0);
1353 		} else
1354 			mcopyin(mp, NULL, sizeof (int), NULL);
1355 		break;
1356 
1357 	case S_IOCSETDTR:
1358 		/*
1359 		 * The first integer of the M_DATA block that should
1360 		 * follow indicate if DTR must be set or reset
1361 		 */
1362 		error = miocpullup(mp, sizeof (int));
1363 		if (error != 0)
1364 			break;
1365 
1366 		mutex_enter(zs->zs_excl_hi);
1367 		if (*(int *)mp->b_cont->b_rptr != 0)
1368 			(void) zsmctl(zs, ZSWR5_DTR, DMBIS);
1369 		else
1370 			(void) zsmctl(zs, ZSWR5_DTR, DMBIC);
1371 		mutex_exit(zs->zs_excl_hi);
1372 		break;
1373 
1374 	default:
1375 		error = EINVAL;
1376 
1377 	}
1378 end_zsh_ioctl:
1379 	iocp->ioc_error = error;
1380 	mp->b_datap->db_type = (error) ? M_IOCNAK : M_IOCACK;
1381 	mutex_exit(zs->zs_excl);
1382 	qreply(wq, mp);
1383 }
1384 
1385 /*
1386  * Set the mode of the zsh port
1387  */
1388 
1389 int
1390 zsh_setmode(struct zscom *zs, struct syncline *zss, struct scc_mode *sm)
1391 {
1392 	register int error = 0;
1393 	register mblk_t *mp;
1394 
1395 	mutex_enter(zs->zs_excl_hi);
1396 	if (sm->sm_rxclock == RXC_IS_PLL) {
1397 		zss->sl_mode.sm_retval = SMERR_RXC;
1398 		mutex_exit(zs->zs_excl_hi);
1399 		return (EINVAL);		/* not supported */
1400 	} else {
1401 		if (((zss->sl_mode.sm_config ^ sm->sm_config) &
1402 		    CONN_SIGNAL) != 0) { /* Changing, going... */
1403 			if (sm->sm_config & CONN_SIGNAL) { /* ...up. */
1404 				if (zss->sl_mstat == NULL) {
1405 					mutex_exit(zs->zs_excl_hi);
1406 					mp = allocb(
1407 					    sizeof (struct sl_status),
1408 					    BPRI_MED);
1409 					mutex_enter(zs->zs_excl_hi);
1410 					zss->sl_mstat = mp;
1411 				}
1412 			} else {			/* ...down. */
1413 				if ((mp = zss->sl_mstat) != NULL)
1414 					zss->sl_mstat = NULL;
1415 				mutex_exit(zs->zs_excl_hi);
1416 				if (mp)
1417 					freemsg(mp);
1418 				mutex_enter(zs->zs_excl_hi);
1419 			}
1420 		}
1421 		if (!(sm->sm_config & CONN_IBM)) {
1422 			if (sm->sm_config & CONN_HDX) {
1423 				zss->sl_mode.sm_retval = SMERR_HDX;
1424 				mutex_exit(zs->zs_excl_hi);
1425 				return (EINVAL);
1426 			}
1427 			if (sm->sm_config & CONN_MPT) {
1428 				zss->sl_mode.sm_retval = SMERR_MPT;
1429 				mutex_exit(zs->zs_excl_hi);
1430 				return (EINVAL);
1431 			}
1432 		}
1433 		zss->sl_flags &= ~SF_FDXPTP;		/* "conmode" */
1434 		if ((sm->sm_config & (CONN_HDX | CONN_MPT)) == 0)
1435 			zss->sl_flags |= SF_FDXPTP;
1436 
1437 		error = zsh_program(zs, sm);
1438 		if (!error && (zs->zs_ops != &zsops_null))
1439 			zsh_init_port(zs, zss);
1440 	}
1441 	mutex_exit(zs->zs_excl_hi);
1442 
1443 	return (error);
1444 }
1445 
1446 /*
1447  * Transmit interrupt service procedure
1448  */
1449 
1450 static void
1451 zsh_txint(struct zscom *zs)
1452 {
1453 	register struct syncline *zss;
1454 	register mblk_t *mp;
1455 	register int tmp;
1456 	register uchar_t *wr_cur;
1457 
1458 	TRACE_1(TR_ZSH, TR_ZSH_TXINT, "zsh_txint: zs = %p", zs);
1459 
1460 	if ((wr_cur =  zs->zs_wr_cur) != NULL && (wr_cur <  zs->zs_wr_lim)) {
1461 		SCC_WRITEDATA(*wr_cur++);
1462 		zs->zs_wr_cur = wr_cur;
1463 		return;
1464 	}
1465 
1466 
1467 	zss = (struct syncline *)&zs->zs_priv_str;
1468 
1469 	switch (zss->sl_txstate) {
1470 
1471 	/*
1472 	 * we here because end of message block lim = cur
1473 	 */
1474 	case TX_ACTIVE:
1475 
1476 		mp = zss->sl_xactb;
1477 
1478 again_txint:
1479 		mp = mp->b_cont;
1480 		if (mp) {
1481 			zss->sl_xactb = mp;
1482 			zss->sl_ocnt += tmp = mp->b_wptr - mp->b_rptr;
1483 			if (!tmp)
1484 				goto again_txint;
1485 			zs->zs_wr_cur = mp->b_rptr;
1486 			zs->zs_wr_lim = mp->b_wptr;
1487 			SCC_WRITEDATA(*zs->zs_wr_cur++);
1488 			return;
1489 		}
1490 
1491 		/*
1492 		 * This is where the fun starts.  At this point the
1493 		 * last character in the frame has been sent.  We
1494 		 * issue a RESET_TXINT so we won't get another txint
1495 		 * until the CRC has been completely sent.  Also we
1496 		 * reset the Abort-On-Underrun bit so that CRC is
1497 		 * sent at EOM, rather than an Abort.
1498 		 */
1499 		zs->zs_wr_cur = zs->zs_wr_lim = NULL;
1500 		zss->sl_txstate = TX_CRC;
1501 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1502 		if (!(zss->sl_flags & SF_PHONY)) {
1503 			SCC_BIC(10, ZSWR10_UNDERRUN_ABORT);
1504 			zss->sl_st.opack++;
1505 			zss->sl_st.ochar += zss->sl_ocnt;
1506 		}
1507 		zss->sl_ocnt = 0;
1508 		ZSH_FREEMSG(zss->sl_xhead);
1509 		zss->sl_xhead = zss->sl_xactb = NULL;
1510 		ZSSETSOFT(zs);
1511 		break;
1512 	/*
1513 	 * This txint means we have sent the CRC bytes at EOF.
1514 	 * The next txint will mean we are sending or have sent the
1515 	 * flag character at EOF, but we handle that differently, and
1516 	 * enter different states,depending on whether we're IBM or not.
1517 	 */
1518 	case TX_CRC:
1519 		if (!(zss->sl_flags & SF_FDXPTP)) {
1520 			zss->sl_txstate = TX_FLAG;	/* HDX path */
1521 		} else {	/* FDX path */
1522 			if (!zsh_start(zs, zss)) {
1523 				zss->sl_txstate = TX_IDLE;
1524 				SCC_WRITE0(ZSWR0_RESET_TXINT);
1525 			}
1526 		}
1527 		break;
1528 
1529 	/*
1530 	 * This txint means the closing flag byte is going out the door.
1531 	 * We use this state to allow this to complete before dropping RTS.
1532 	 */
1533 	case TX_FLAG:
1534 		zss->sl_txstate = TX_LAST;
1535 		(void) zsh_start(zs, zss);
1536 		break;
1537 
1538 	/*
1539 	 * Arriving here means the flag should be out and it's finally
1540 	 * time to close the barn door.
1541 	 */
1542 	case TX_LAST:
1543 		zss->sl_txstate = TX_IDLE;
1544 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1545 		break;
1546 
1547 	/*
1548 	 * If transmit was aborted, do nothing - watchdog will recover.
1549 	 */
1550 	case TX_ABORTED:
1551 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1552 		break;
1553 
1554 	default:
1555 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1556 		break;
1557 	}
1558 }
1559 
1560 /*
1561  * External Status Change interrupt service procedure
1562  */
1563 static void
1564 zsh_xsint(struct zscom *zs)
1565 {
1566 	register struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
1567 	register uchar_t s0, x0;
1568 
1569 	TRACE_1(TR_ZSH, TR_ZSH_XSINT, "zsh_xsint: zs = %p", zs);
1570 
1571 	s0 = SCC_READ0();
1572 	x0 = s0 ^ zss->sl_rr0;
1573 	zss->sl_rr0 = s0;
1574 	SCC_WRITE0(ZSWR0_RESET_STATUS);
1575 
1576 	if (s0 & ZSRR0_TXUNDER) {
1577 		switch (zss->sl_txstate) {
1578 		/*
1579 		 * A transmitter underrun has occurred.  If we are not
1580 		 * here as the result of an abort sent by the watchdog
1581 		 * timeout routine, we need to send an abort to flush
1582 		 * the transmitter.  Otherwise there is a danger of
1583 		 * trashing the next frame but still sending a good crc.
1584 		 * The TX_ABORTED flag is set so that the watchdog
1585 		 * routine can initiate recovery.
1586 		 */
1587 		case TX_ACTIVE:
1588 			SCC_WRITE0(ZSWR0_SEND_ABORT);
1589 			SCC_WRITE0(ZSWR0_RESET_TXINT);
1590 			zss->sl_st.underrun++;
1591 			zsh_txbad(zs, zss);
1592 
1593 			zss->sl_txstate = TX_ABORTED;
1594 			zss->sl_wd_count = 0;
1595 			break;
1596 
1597 		case TX_CRC:
1598 			break;
1599 
1600 		case TX_FLAG:
1601 			break;
1602 
1603 		case TX_ABORTED:
1604 			break;
1605 
1606 		case TX_OFF:
1607 			break;
1608 
1609 		case TX_LAST:
1610 			break;
1611 
1612 		default:
1613 			break;
1614 		}
1615 	}
1616 
1617 	if ((x0 & ZSRR0_BREAK) && (s0 & ZSRR0_BREAK) && zs->zs_rd_cur) {
1618 		zss->sl_st.abort++;
1619 		zsh_rxbad(zs, zss);
1620 	} else if ((s0 & ZSRR0_SYNC) && (zs->zs_rd_cur)) {
1621 		/*
1622 		 * Tricky code to avoid disaster in the case where
1623 		 * an abort was detected while receiving a packet,
1624 		 * but the abort did not last long enough to be
1625 		 * detected by zsh_xsint - this can happen since
1626 		 * the ZSRR0_BREAK is not latched.  Since an abort
1627 		 * will automatically cause the SCC to enter
1628 		 * hunt mode, hopefully, the sync/hunt bit will be
1629 		 * set in this case (although if the interrupt is
1630 		 * sufficiently delayed, the SCC may have sync'ed
1631 		 * in again if it has detected a flag).
1632 		 */
1633 		zss->sl_st.abort++;
1634 		zsh_rxbad(zs, zss);
1635 	}
1636 
1637 	if (x0 & s0 & ZSRR0_CTS) {
1638 		if (zss->sl_txstate == TX_RTS) {
1639 			if (!(zss->sl_flags & SF_FDXPTP)) {
1640 				SCC_BIS(5, ZSWR5_TX_ENABLE);
1641 			}
1642 			(void) zsh_start(zs, zss);
1643 		} else if ((zss->sl_mode.sm_config &
1644 		    (CONN_IBM | CONN_SIGNAL))) {
1645 			zss->sl_flags &= ~SF_FLUSH_WQ;
1646 			zsh_setmstat(zs, CS_CTS_UP);
1647 		}
1648 	}
1649 
1650 	/*
1651 	 * We don't care about CTS transitions unless we are in either
1652 	 * IBM or SIGNAL mode, or both.  So, if we see CTS drop, and we
1653 	 * care, and we are not idle, send up a report message.
1654 	 */
1655 	if ((x0 & ZSRR0_CTS) && ((s0 & ZSRR0_CTS) == 0) &&
1656 	    (zss->sl_txstate != TX_OFF) &&
1657 	    (zss->sl_mode.sm_config & (CONN_IBM | CONN_SIGNAL))) {
1658 		SCC_BIC(15, ZSR15_CTS);
1659 		zsh_setmstat(zs, CS_CTS_DOWN);
1660 		zss->sl_flags &= ~SF_XMT_INPROG;
1661 		zss->sl_flags |= SF_FLUSH_WQ;
1662 		zss->sl_st.cts++;
1663 		if (zss->sl_txstate != TX_IDLE)
1664 			SCC_WRITE0(ZSWR0_SEND_ABORT);
1665 		SCC_WRITE0(ZSWR0_RESET_ERRORS);
1666 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1667 		zss->sl_wd_count = 0;
1668 		zsh_txbad(zs, zss);
1669 	}
1670 }
1671 
1672 
1673 /*
1674  * Receive interrupt service procedure
1675  */
1676 static void
1677 zsh_rxint(struct zscom *zs)
1678 {
1679 	register struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
1680 	register mblk_t *bp = zss->sl_ractb;
1681 	unsigned char *rd_cur;
1682 
1683 	TRACE_1(TR_ZSH, TR_ZSH_RXINT, "zsh_rxint: zs = %p", zs);
1684 
1685 	if (((rd_cur = zs->zs_rd_cur) != NULL) && rd_cur < zs->zs_rd_lim) {
1686 		*rd_cur++ = SCC_READDATA();
1687 		zs->zs_rd_cur = rd_cur;
1688 		return;
1689 	}
1690 
1691 	if (!rd_cur) { /* Beginning of frame */
1692 		if (!bp) {
1693 			ZSH_ALLOCB(bp);
1694 			zss->sl_ractb = bp;
1695 		}
1696 		zss->sl_rhead = bp;
1697 	} else {	/* end of data block should be cur==lim */
1698 		bp->b_wptr = zs->zs_rd_cur;
1699 		ZSH_ALLOCB(bp->b_cont);
1700 		bp = zss->sl_ractb = bp->b_cont;
1701 	}
1702 	if (!bp) {
1703 		zss->sl_st.nobuffers++;
1704 		zsh_rxbad(zs, zss);
1705 		return;
1706 	}
1707 	zs->zs_rd_cur = bp->b_wptr;
1708 	zs->zs_rd_lim = bp->b_datap->db_lim;
1709 	*zs->zs_rd_cur++ = SCC_READDATA(); /* Also resets interrupt */
1710 }
1711 
1712 
1713 /*
1714  * Special Receive Condition Interrupt routine
1715  */
1716 static void
1717 zsh_srint(struct zscom *zs)
1718 {
1719 	register struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
1720 	register uchar_t s1;
1721 	register uchar_t *rd_cur;
1722 
1723 	TRACE_1(TR_ZSH, TR_ZSH_SRINT, "zsh_srint: zs = %p", zs);
1724 
1725 	SCC_READ(1, s1);
1726 
1727 	if (s1 & ZSRR1_RXEOF) {			/* end of frame */
1728 		(void) SCC_READDATA();
1729 		SCC_WRITE0(ZSWR0_RESET_ERRORS);
1730 		if (s1 & ZSRR1_FE) {		/* bad CRC */
1731 			zss->sl_st.crc++;
1732 			zsh_rxbad(zs, zss);
1733 			return;
1734 		}
1735 
1736 		if ((rd_cur = zs->zs_rd_cur) == NULL)
1737 			return;
1738 
1739 		/*
1740 		 * Drop one CRC byte from length because it came in
1741 		 * before the special interrupt got here.
1742 		 */
1743 		zss->sl_ractb->b_wptr = rd_cur - 1;
1744 
1745 		/*
1746 		 * put on done queue
1747 		 */
1748 		ZSH_PUTQ(zss->sl_rhead);
1749 		zss->sl_rhead = NULL;
1750 		zss->sl_ractb = NULL;
1751 		zs->zs_rd_cur = NULL;
1752 		zs->zs_rd_lim = NULL;
1753 		ZSSETSOFT(zs);
1754 
1755 	} else if (s1 & ZSRR1_DO) {
1756 		(void) SCC_READDATA();
1757 		SCC_WRITE0(ZSWR0_RESET_ERRORS);
1758 		zss->sl_st.overrun++;
1759 		zsh_rxbad(zs, zss);
1760 	} else
1761 		SCC_WRITE0(ZSWR0_RESET_ERRORS);
1762 }
1763 
1764 /*
1765  * Handle a second stage interrupt.
1766  * Does mostly lower priority buffer management stuff.
1767  */
1768 static int
1769 zsh_softint(struct zscom *zs)
1770 {
1771 	register struct syncline *zss;
1772 	register queue_t *q;
1773 	register mblk_t *mp, *tmp;
1774 	register mblk_t *head = NULL, *tail = NULL;
1775 	register int allocbcount = 0;
1776 	int m_error;
1777 
1778 	TRACE_1(TR_ZSH, TR_ZSH_SOFT_START, "zsh_soft start: zs = %p", zs);
1779 
1780 	mutex_enter(zs->zs_excl);
1781 	zss = (struct syncline *)zs->zs_priv;
1782 	if (!zss || (q = zss->sl_stream.str_rq) == NULL) {
1783 		mutex_exit(zs->zs_excl);
1784 		return (0);
1785 	}
1786 	m_error = zss->sl_m_error;
1787 
1788 	zss->sl_m_error = 0;
1789 
1790 
1791 	if (!zss->sl_mstat)
1792 		zss->sl_mstat = allocb(sizeof (struct sl_status), BPRI_MED);
1793 
1794 	mutex_enter(zs->zs_excl_hi);
1795 	if (zss->sl_flags & SF_FLUSH_WQ) {
1796 		if (!(zss->sl_flags & SF_FDXPTP)) {
1797 			zss->sl_flags &= ~SF_FLUSH_WQ;
1798 		} else {
1799 			register uchar_t s0;
1800 
1801 			s0 = SCC_READ0();
1802 			if (s0 & ZSRR0_CTS) {
1803 				zss->sl_rr0 |= ZSRR0_CTS;
1804 				SCC_BIS(15, ZSR15_CTS);
1805 				zss->sl_flags &= ~SF_FLUSH_WQ;
1806 				zsh_setmstat(zs, CS_CTS_UP);
1807 			}
1808 			if (zss->sl_flags & SF_FLUSH_WQ) {
1809 				mutex_exit(zs->zs_excl_hi);
1810 				flushq(WR(q), FLUSHDATA);
1811 				goto next;
1812 			}
1813 		}
1814 	}
1815 	mutex_exit(zs->zs_excl_hi);
1816 
1817 next:
1818 	for (;;) {
1819 		ZSH_GETQ(mp);
1820 		if (!mp)
1821 			break;
1822 
1823 		if (mp->b_rptr == mp->b_wptr) {
1824 			if (mp->b_datap->db_type == M_RSE) {
1825 				allocbcount++;
1826 			}
1827 			freemsg(mp);
1828 			continue;
1829 		}
1830 		if (mp->b_datap->db_type == M_DATA) {
1831 			zss->sl_st.ichar += msgdsize(mp);
1832 			zss->sl_st.ipack++;
1833 			if (!(canputnext(q))) {
1834 				zss->sl_st.ierror++;
1835 				allocbcount++;
1836 				freemsg(mp);
1837 				continue;
1838 			}
1839 		} else if (mp->b_datap->db_type == M_PROTO) {
1840 			if (!(canputnext(q))) {
1841 				freemsg(mp);
1842 				continue;
1843 			}
1844 		}
1845 		if (!head) {
1846 			allocbcount++;
1847 			zss->sl_soft_active = 1;
1848 			head = mp;
1849 		} else {
1850 			if (!tail)
1851 				tail = head;
1852 			tail->b_next = mp;
1853 			tail = mp;
1854 		}
1855 	}
1856 	if (allocbcount)
1857 		ZSH_GETBLOCK(zs, allocbcount);
1858 
1859 	tmp = NULL;
1860 again:
1861 	mutex_enter(zs->zs_excl_hi);
1862 	if (!zss->sl_xstandby) {
1863 		if (tmp) {
1864 			zss->sl_xstandby = tmp;
1865 			mutex_exit(zs->zs_excl_hi);
1866 		} else {
1867 			mutex_exit(zs->zs_excl_hi);
1868 			if (tmp = getq(WR(q)))
1869 				goto again;
1870 		}
1871 	} else {
1872 		mutex_exit(zs->zs_excl_hi);
1873 		if (tmp)
1874 			(void) putbq(WR(q), tmp);
1875 	}
1876 
1877 	mutex_exit(zs->zs_excl);
1878 
1879 	while (head) {
1880 		if (!tail) {
1881 			putnext(q, head);
1882 			break;
1883 		}
1884 		mp = head;
1885 		head = head->b_next;
1886 		mp->b_next = NULL;
1887 		putnext(q, mp);
1888 
1889 	}
1890 
1891 	if (m_error)
1892 		(void) putnextctl1(q, M_ERROR, m_error);
1893 
1894 	zss->sl_soft_active = 0;
1895 
1896 	TRACE_1(TR_ZSH, TR_ZSH_SOFT_END, "zsh_soft end: zs = %p", zs);
1897 
1898 	return (0);
1899 }
1900 
1901 /*
1902  * Initialization routine.
1903  * Sets Clock sources, baud rate, modes and miscellaneous parameters.
1904  */
1905 static int
1906 zsh_program(struct zscom *zs, struct scc_mode *sm)
1907 {
1908 	register struct syncline *zss  = (struct syncline *)&zs->zs_priv_str;
1909 	register struct zs_prog *zspp;
1910 	register ushort_t	tconst = 0;
1911 	register int	wr11 = 0;
1912 	register int	baud = 0;
1913 	register int	pll = 0;
1914 	register int	speed = 0;
1915 	register int	flags = ZSP_SYNC;
1916 	int		err = 0;
1917 
1918 	ZSSETSOFT(zs); /* get our house in order */
1919 
1920 	switch (sm->sm_txclock) {
1921 	case TXC_IS_TXC:
1922 		wr11 |= ZSWR11_TXCLK_TRXC;
1923 		break;
1924 	case TXC_IS_RXC:
1925 		wr11 |= ZSWR11_TXCLK_RTXC;
1926 		break;
1927 	case TXC_IS_BAUD:
1928 		wr11 |= ZSWR11_TXCLK_BAUD;
1929 		wr11 |= ZSWR11_TRXC_OUT_ENA + ZSWR11_TRXC_XMIT;
1930 		baud++;
1931 		break;
1932 	case TXC_IS_PLL:
1933 		wr11 |= ZSWR11_TXCLK_DPLL;
1934 		pll++;
1935 		break;
1936 	default:
1937 		zss->sl_mode.sm_retval = SMERR_TXC;
1938 		err = EINVAL;
1939 		goto out;
1940 	}
1941 	switch (sm->sm_rxclock) {
1942 	case RXC_IS_RXC:
1943 		wr11 |= ZSWR11_RXCLK_RTXC;
1944 		break;
1945 	case RXC_IS_TXC:
1946 		wr11 |= ZSWR11_RXCLK_TRXC;
1947 		break;
1948 	case RXC_IS_BAUD:
1949 		wr11 |= ZSWR11_RXCLK_BAUD;
1950 		baud++;
1951 		break;
1952 	case RXC_IS_PLL:
1953 		wr11 |= ZSWR11_RXCLK_DPLL;
1954 		pll++;
1955 		break;
1956 	default:
1957 		zss->sl_mode.sm_retval = SMERR_RXC;
1958 		err = EINVAL;
1959 		goto out;
1960 	}
1961 	if (baud && pll) {
1962 		zss->sl_mode.sm_retval = SMERR_PLL;
1963 		err = EINVAL;
1964 		goto out;
1965 	}
1966 	if (pll && !(sm->sm_config & CONN_NRZI)) {
1967 		zss->sl_mode.sm_retval = SMERR_PLL;
1968 		err = EINVAL;
1969 		goto out;
1970 	}
1971 
1972 	/*
1973 	 * If we're going to use the BRG and the speed we want is != 0...
1974 	 */
1975 	if (baud && (speed = sm->sm_baudrate)) {
1976 		tconst = (PCLK + speed) / (2 * speed) - 2;
1977 		if (tconst == 0) {
1978 			zss->sl_mode.sm_retval = SMERR_BAUDRATE;
1979 			err = EINVAL;
1980 			goto out;
1981 		}
1982 		sm->sm_baudrate = PCLK / (2 * ((int)tconst + 2));
1983 	} else {
1984 		tconst = 0;	/* Stop BRG.  Also quiesces pin 24. */
1985 	}
1986 
1987 	if (pll) {
1988 		if ((speed  = sm->sm_baudrate * 32) != 0)
1989 			tconst = (PCLK + speed) / (2 * speed) - 2;
1990 		else
1991 			tconst = 0;
1992 		if (tconst == 0) {
1993 			zss->sl_mode.sm_retval = SMERR_BAUDRATE;
1994 			err = EINVAL;
1995 			goto out;
1996 		}
1997 		speed = PCLK / (2 * ((int)tconst + 2));
1998 		sm->sm_baudrate = speed / 32;
1999 		flags |= ZSP_PLL;
2000 	}
2001 
2002 	if ((sm->sm_config & (CONN_LPBK|CONN_ECHO)) == (CONN_LPBK|CONN_ECHO)) {
2003 		zss->sl_mode.sm_retval = SMERR_LPBKS;
2004 		err = EINVAL;
2005 		goto out;
2006 	}
2007 	if (sm->sm_config & CONN_LPBK)
2008 		flags |= ZSP_LOOP;
2009 	if (sm->sm_config & CONN_NRZI)
2010 		flags |= ZSP_NRZI;
2011 	if (sm->sm_config & CONN_ECHO)
2012 		flags |= ZSP_ECHO;
2013 
2014 	zspp = &zs_prog[zs->zs_unit];
2015 
2016 	zspp->zs = zs;
2017 	zspp->flags = (uchar_t)flags;
2018 	zspp->wr4 = ZSWR4_SDLC;
2019 	zspp->wr11 = (uchar_t)wr11;
2020 	zspp->wr12 = (uchar_t)(tconst & 0xff);
2021 	zspp->wr13 = (uchar_t)((tconst >> 8) & 0xff);
2022 	zspp->wr3 = (uchar_t)(ZSWR3_RX_ENABLE | ZSWR3_RXCRC_ENABLE |
2023 	    ZSWR3_RX_8);
2024 	zspp->wr5 = (uchar_t)(ZSWR5_TX_8 | ZSWR5_DTR | ZSWR5_TXCRC_ENABLE);
2025 
2026 	if (zss->sl_flags & SF_FDXPTP) {
2027 		zspp->wr5 |= ZSWR5_RTS;
2028 		zss->sl_rr0 |= ZSRR0_CTS;		/* Assume CTS is high */
2029 	}
2030 	if (sm->sm_config & CONN_IBM) {
2031 		zspp->wr15 = (uchar_t)
2032 		    (ZSR15_TX_UNDER | ZSR15_BREAK | ZSR15_SYNC | ZSR15_CTS);
2033 		if (!(zss->sl_flags & SF_FDXPTP))
2034 			zspp->wr15 &= ~ZSR15_CTS;
2035 	} else {
2036 		zspp->wr5 |= ZSWR5_TX_ENABLE;
2037 		zspp->wr15 = (uchar_t)
2038 		    (ZSR15_TX_UNDER | ZSR15_BREAK | ZSR15_SYNC);
2039 		if (sm->sm_config & CONN_SIGNAL)
2040 			zspp->wr15 |= ZSR15_CTS;
2041 	}
2042 
2043 	zs_program(zspp);
2044 	SCC_WRITE0(ZSWR0_RESET_STATUS);		/* reset XS */
2045 	SCC_WRITE0(ZSWR0_RESET_STATUS);		/* reset XS */
2046 	zss->sl_flags |= SF_INITIALIZED;
2047 	bzero(&zss->sl_st, sizeof (struct sl_stats));
2048 	bcopy(sm, &zss->sl_mode, sizeof (struct scc_mode));
2049 	zss->sl_mode.sm_retval = 0;	/* successful */
2050 out:
2051 	return (err);
2052 }
2053 
2054 /*
2055  * Function to store modem signal changes in sl_mstat field.
2056  * Note that these events are supposed to be so far apart in time that
2057  * we should always be able to send up the event and allocate a message
2058  * block before another one happens.  If not, we'll overwrite this one.
2059  */
2060 static void
2061 zsh_setmstat(struct zscom *zs, int event)
2062 {
2063 	register struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
2064 	register struct sl_status *mstat;
2065 	register mblk_t *mp;
2066 
2067 	if (((mp = zss->sl_mstat) != NULL) &&
2068 	    (zss->sl_mode.sm_config & (CONN_SIGNAL))) {
2069 		mstat = (struct sl_status *)mp->b_wptr;
2070 		mstat->type = (zss->sl_mode.sm_config & CONN_IBM) ?
2071 		    SLS_LINKERR : SLS_MDMSTAT;
2072 		mstat->status = event;
2073 		gethrestime(&mstat->tstamp);
2074 		mp->b_wptr += sizeof (struct sl_status);
2075 		mp->b_datap->db_type = M_PROTO;
2076 		ZSH_PUTQ(mp);
2077 		zss->sl_mstat = NULL;
2078 		ZSSETSOFT(zs);
2079 	}
2080 }
2081 
2082 /*
2083  * Received Bad Frame procedure
2084  */
2085 static void
2086 zsh_rxbad(struct zscom *zs, struct syncline *zss)
2087 {
2088 	/*
2089 	 * swallow bad characters
2090 	 */
2091 	(void) SCC_READDATA();
2092 	(void) SCC_READDATA();
2093 	(void) SCC_READDATA();
2094 
2095 	SCC_BIS(3, ZSWR3_HUNT);	/* enter hunt mode - ignores rest of frame */
2096 
2097 	zss->sl_st.ierror++;
2098 
2099 	/*
2100 	 * Free active receive message.
2101 	 */
2102 	if (zss->sl_rhead) {
2103 		zss->sl_rhead->b_wptr = zss->sl_rhead->b_rptr;
2104 		zss->sl_rhead->b_datap->db_type = M_RSE;
2105 		ZSH_FREEMSG(zss->sl_rhead);
2106 		zss->sl_ractb = NULL;
2107 		zs->zs_rd_cur = NULL;
2108 		zs->zs_rd_lim = NULL;
2109 	}
2110 	if (zss->sl_rhead) {
2111 		zss->sl_rhead = NULL;
2112 		ZSH_ALLOCB(zss->sl_ractb);
2113 		zs->zs_rd_cur = NULL;
2114 		zs->zs_rd_lim = NULL;
2115 	}
2116 
2117 	ZSSETSOFT(zs);
2118 }
2119 
2120 /*
2121  * Transmit error procedure
2122  */
2123 static void
2124 zsh_txbad(struct zscom *zs, struct syncline *zss)
2125 {
2126 	if (zss->sl_xhead) {		/* free the message we were sending */
2127 		zss->sl_xhead->b_wptr = zss->sl_xhead->b_rptr;
2128 		ZSH_FREEMSG(zss->sl_xhead);
2129 		zss->sl_xactb = NULL;
2130 		zs->zs_wr_cur = NULL;
2131 		zs->zs_wr_lim = NULL;
2132 	}
2133 	zss->sl_xhead = NULL;
2134 
2135 	if (!(zss->sl_flags & SF_FDXPTP)) {
2136 		/*
2137 		 * drop RTS and our notion of CTS
2138 		 */
2139 		SCC_BIC(5, ZSWR5_RTS);
2140 		SCC_BIC(5, ZSWR5_TX_ENABLE);
2141 		zss->sl_rr0 &= ~ZSRR0_CTS;
2142 	}
2143 	zss->sl_txstate = TX_IDLE;
2144 	if (!(zss->sl_flags & SF_PHONY))
2145 		zss->sl_st.oerror++;
2146 }
2147 
2148 /*
2149  * Transmitter watchdog timeout routine
2150  */
2151 static void
2152 zsh_watchdog(void *arg)
2153 {
2154 	struct zscom *zs = arg;
2155 	struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
2156 	queue_t *wq;
2157 	mblk_t *mp;
2158 	int warning = 0;
2159 	uchar_t s0;
2160 	int do_flushwq = 0;
2161 
2162 	/*
2163 	 * The main reason for this routine is because, under some
2164 	 * circumstances, a transmit interrupt may get lost (ie., if
2165 	 * underrun occurs after the last character has been sent, and
2166 	 * the tx interrupt following the abort gets scheduled before
2167 	 * the current tx interrupt has been serviced).  Transmit can
2168 	 * also get hung if the cable is pulled out and the clock was
2169 	 * coming in from the modem.
2170 	 */
2171 
2172 	mutex_enter(zs->zs_excl);
2173 	if (zss->sl_stream.str_rq)
2174 		wq = WR(zss->sl_stream.str_rq);
2175 	else {
2176 		mutex_exit(zs->zs_excl);
2177 		return;		/* guard against close/callback race */
2178 	}
2179 
2180 	mutex_enter(zs->zs_excl_hi);
2181 	if (!(zss->sl_flags & SF_XMT_INPROG) && wq->q_first) {
2182 		zss->sl_flags |= SF_XMT_INPROG;
2183 		if ((zss->sl_flags & SF_FDXPTP) ||
2184 		    zsh_hdp_ok_or_rts_state(zs, zss))
2185 			(void) zsh_start(zs, zss);
2186 		goto end_watchdog;
2187 	}
2188 
2189 	if (zss->sl_wd_count-- > 0)
2190 		goto end_watchdog;
2191 
2192 	if (zss->sl_flags & SF_FLUSH_WQ) {
2193 		if (!(zss->sl_flags & SF_FDXPTP))
2194 			zss->sl_flags &= ~SF_FLUSH_WQ;
2195 		else {
2196 			s0 = SCC_READ0();
2197 			if (s0 & ZSRR0_CTS) {
2198 				zss->sl_rr0 |= ZSRR0_CTS;
2199 				SCC_BIS(15, ZSR15_CTS);
2200 				zss->sl_flags &= ~SF_FLUSH_WQ;
2201 				zsh_setmstat(zs, CS_CTS_UP);
2202 			}
2203 		}
2204 	}
2205 
2206 	switch (zss->sl_txstate) {
2207 
2208 	case TX_ABORTED:
2209 		/*
2210 		 * Transmitter was hung ... try restarting it.
2211 		 */
2212 		if (zss->sl_flags & SF_FDXPTP) {
2213 			zss->sl_flags |= SF_XMT_INPROG;
2214 			(void) zsh_start(zs, zss);
2215 		} else
2216 			do_flushwq = 1;
2217 		break;
2218 
2219 	case TX_ACTIVE:
2220 	case TX_CRC:
2221 		/*
2222 		 * Transmit is hung for some reason. Reset tx interrupt.
2223 		 * Flush transmit fifo by sending an abort command
2224 		 * which also sets the Underrun/EOM latch in WR0 and in
2225 		 * turn generates an External Status interrupt that
2226 		 * will reset the necessary message buffer pointers.
2227 		 * The watchdog timer will cycle again to allow the SCC
2228 		 * to settle down after the abort command.  The next
2229 		 * time through we'll see that the state is now TX_ABORTED
2230 		 * and call zsh_start to grab a new message.
2231 		 */
2232 		if (--zss->sl_wd_count <= 0) {
2233 			SCC_WRITE0(ZSWR0_SEND_ABORT);
2234 			SCC_WRITE0(ZSWR0_RESET_ERRORS);
2235 			SCC_WRITE0(ZSWR0_RESET_TXINT);
2236 			zsh_txbad(zs, zss);
2237 			zss->sl_txstate = TX_ABORTED; /* must be after txbad */
2238 			warning = 1;
2239 		}
2240 		break;
2241 
2242 	case TX_RTS:
2243 		/*
2244 		 * Timer expired after we raised RTS.  CTS never came up.
2245 		 */
2246 		zss->sl_st.cts++;
2247 
2248 		zsh_setmstat(zs, CS_CTS_TO);
2249 		zss->sl_flags &= ~SF_XMT_INPROG;
2250 		zss->sl_flags |= SF_FLUSH_WQ;
2251 		ZSSETSOFT(zs);
2252 		break;
2253 
2254 	default:
2255 		/*
2256 		 * If we time out in an inactive state we set a soft
2257 		 * interrupt.  This will call zsh_start which will
2258 		 * clear SF_XMT_INPROG if the queue is empty.
2259 		 */
2260 		break;
2261 	}
2262 end_watchdog:
2263 	if (zss->sl_txstate != TX_OFF) {
2264 		mutex_exit(zs->zs_excl_hi);
2265 		zss->sl_wd_id = timeout(zsh_watchdog, zs, SIO_WATCHDOG_TICK);
2266 	} else {
2267 		zss->sl_wd_id = 0;	/* safety */
2268 		mutex_exit(zs->zs_excl_hi);
2269 	}
2270 	if (warning || do_flushwq) {
2271 		flushq(wq, FLUSHDATA);
2272 		mutex_enter(zs->zs_excl_hi);
2273 		if ((mp = zss->sl_xstandby) != NULL)
2274 			zss->sl_xstandby = NULL;
2275 		mutex_exit(zs->zs_excl_hi);
2276 		if (mp)
2277 			freemsg(mp);
2278 	}
2279 	mutex_exit(zs->zs_excl);
2280 	if (warning)
2281 		cmn_err(CE_WARN, "zsh%x: transmit hung", zs->zs_unit);
2282 }
2283 
2284 static void
2285 zsh_callback(void *arg)
2286 {
2287 	struct zscom *zs = arg;
2288 	struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
2289 	int tmp = ZSH_MAX_RSTANDBY;
2290 
2291 	mutex_enter(zs->zs_excl);
2292 	if (zss->sl_bufcid) {
2293 		zss->sl_bufcid = 0;
2294 		ZSH_GETBLOCK(zs, tmp);
2295 	}
2296 	mutex_exit(zs->zs_excl);
2297 }
2298