xref: /illumos-gate/usr/src/uts/sun/io/zs_hdlc.c (revision 915894ef19890baaed00080f85f6b69e225cda98)
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 	{ 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 	int n = ZSH_MAX_RSTANDBY; \
296 	while (--n >= 0) { \
297 	    if (zss->sl_rstandby[n] == NULL) { \
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 	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 	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 	mblk_t *tmp; \
370 	for (;;) { \
371 		ZSH_GETQ(tmp); \
372 		if (tmp == NULL) \
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 	int	unit;
390 	char	name[3] = { '\0', '\0', '\0' };
391 
392 	/*
393 	 * Since zsh is a child of the "pseudo" nexus, we can expect the
394 	 * attach routine to be called only once.  We need to create all
395 	 * necessary devices in one shot.  There is never more than one
396 	 * SCC chip that supports zsh devices.
397 	 */
398 
399 	if (cmd != DDI_ATTACH)
400 		return (DDI_FAILURE);
401 	if (zscom == NULL)
402 		return (DDI_FAILURE);	/* zsattach not done */
403 	unit = 2 * ddi_get_instance(dev);
404 	if (unit > 1)
405 		return (DDI_FAILURE);	/* only use cpu ports */
406 
407 	if (ddi_create_minor_node(dev, "zsh", S_IFCHR,
408 	    0, DDI_PSEUDO, CLONE_DEV) == DDI_FAILURE) {
409 		ddi_remove_minor_node(dev, NULL);
410 		cmn_err(CE_WARN, "zsh clone device creation failed.");
411 		return (DDI_FAILURE);
412 	}
413 
414 	for (; unit < maxzsh / 2; unit++) {
415 		zscom[unit].zs_hdlc_dip = dev;
416 
417 		(void) sprintf(name, "%d", unit);
418 		if (ddi_create_minor_node(dev, name, S_IFCHR,
419 		    2 * unit, DDI_PSEUDO, 0) == DDI_FAILURE) {
420 			ddi_remove_minor_node(dev, NULL);
421 			return (DDI_FAILURE);
422 		}
423 		unit++;
424 		(void) sprintf(name, "%d", unit);
425 		if (ddi_create_minor_node(dev, name, S_IFCHR,
426 		    2 * (unit - 1) + 1, DDI_PSEUDO, 0) == DDI_FAILURE) {
427 			ddi_remove_minor_node(dev, NULL);
428 			return (DDI_FAILURE);
429 		}
430 	}
431 
432 	return (DDI_SUCCESS);
433 }
434 
435 /* ARGSUSED */
436 int
437 zsh_info(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
438     void **result)
439 {
440 	dev_t dev = (dev_t)arg;
441 	int unit, error;
442 	struct zscom *zs;
443 
444 	if ((unit = UNIT(dev)) >= nzs)
445 		return (DDI_FAILURE);
446 
447 	switch (infocmd) {
448 	case DDI_INFO_DEVT2DEVINFO:
449 		if (zscom == NULL) {
450 			error = DDI_FAILURE;
451 		} else {
452 			zs = &zscom[unit];
453 			*result = zs->zs_hdlc_dip;
454 			error = DDI_SUCCESS;
455 		}
456 		break;
457 	case DDI_INFO_DEVT2INSTANCE:
458 		*result = (void *)(uintptr_t)(unit / 2);
459 		error = DDI_SUCCESS;
460 		break;
461 	default:
462 		error = DDI_FAILURE;
463 	}
464 	return (error);
465 }
466 
467 static int
468 zsh_detach(dev_info_t *dev, ddi_detach_cmd_t cmd)
469 {
470 	if (cmd != DDI_DETACH)
471 		return (DDI_FAILURE);
472 
473 	ddi_remove_minor_node(dev, NULL);
474 
475 	return (DDI_SUCCESS);
476 }
477 
478 static void
479 zsh_init_port(struct zscom *zs, struct syncline *zss)
480 {
481 	uchar_t s0;
482 
483 	SCC_WRITE(3, (ZSWR3_RX_ENABLE | ZSWR3_RXCRC_ENABLE | ZSWR3_RX_8));
484 	SCC_WRITE(5, (ZSWR5_TX_8 | ZSWR5_DTR | ZSWR5_TXCRC_ENABLE));
485 	zss->sl_rr0 = SCC_READ0();
486 	if (zss->sl_flags & SF_FDXPTP) {
487 		SCC_BIS(5, ZSWR5_TX_ENABLE);
488 		SCC_BIS(5, ZSWR5_RTS);
489 		s0 = SCC_READ0();
490 		if ((s0 & ZSRR0_CTS) ||
491 		    !(zss->sl_mode.sm_config & (CONN_SIGNAL | CONN_IBM))) {
492 			/*
493 			 * send msg that CTS is up
494 			 */
495 			zss->sl_rr0 |= ZSRR0_CTS;
496 			zss->sl_txstate = TX_IDLE;
497 		} else {
498 			zss->sl_flags |= SF_XMT_INPROG;
499 			zss->sl_txstate = TX_RTS;
500 			zss->sl_rr0 &= ~ZSRR0_CTS;
501 			zss->sl_wd_count = zsh_timer_count;
502 			if (zss->sl_wd_id == NULL)
503 				zss->sl_wd_id = timeout(zsh_watchdog,
504 				    zs, SIO_WATCHDOG_TICK);
505 		}
506 	} else {
507 		SCC_BIC(15, ZSR15_CTS);
508 		SCC_BIC(5, ZSWR5_TX_ENABLE);
509 		SCC_BIC(5, ZSWR5_RTS);
510 		zss->sl_flags &= ~SF_FLUSH_WQ;
511 	}
512 }
513 
514 /*
515  * Open routine.
516  */
517 
518 /*ARGSUSED*/
519 static int
520 zsh_open(queue_t *rq, dev_t *dev, int flag, int sflag, cred_t *cr)
521 {
522 	struct zscom *zs;
523 	struct syncline *zss;
524 	struct ser_str *stp;
525 	int	unit;
526 	int	tmp;
527 
528 	if (sflag != CLONEOPEN) {
529 		if (rq->q_ptr)
530 			return (EBUSY);  /* We got a stream that is in use */
531 
532 		unit = UNIT(*dev);
533 		if (unit >= maxzsh)
534 			return (ENXIO);  /* unit not configured */
535 
536 		if (zscom == NULL)
537 			return (ENXIO);  /* device not found by autoconfig */
538 		zs = &zscom[unit];
539 
540 		if (zs->zs_ops == NULL) {
541 			return (ENXIO);  /* device not found by autoconfig */
542 		}
543 
544 		TRACE_1(TR_ZSH, TR_ZSH_OPEN, "zsh_open:unit = %d", unit);
545 
546 		mutex_enter(zs->zs_excl);
547 		if ((zs->zs_ops != &zsops_null) &&
548 		    (zs->zs_ops != &zsops_hdlc)) {
549 			mutex_exit(zs->zs_excl);
550 			return (EBUSY);	 /* another protocol got here first */
551 		}
552 
553 		/* Mark device as busy (for power management) */
554 		(void) pm_busy_component(zs->zs_dip, unit%2+1);
555 		(void) ddi_dev_is_needed(zs->zs_dip, unit%2+1, 1);
556 
557 		zsopinit(zs, &zsops_hdlc);
558 
559 		zss = (struct syncline *)&zscom[unit].zs_priv_str;
560 		stp = &zss->sl_stream;
561 		stp->str_state = 0;
562 		stp->str_com = (caddr_t)zs;
563 
564 		zss->sl_xhead = NULL;
565 		zss->sl_xactb = NULL;
566 		zs->zs_wr_cur = NULL;
567 		zs->zs_wr_lim = NULL;
568 		zs->zs_wr_cur = NULL;
569 		zs->zs_wr_lim = NULL;
570 		zss->sl_rhead = NULL;
571 		zss->sl_ractb = NULL;
572 		zs->zs_rd_cur = NULL;
573 		zs->zs_rd_lim = NULL;
574 		zss->sl_mstat = NULL;
575 		zss->sl_xstandby = NULL;
576 		zss->sl_wd_id = 0;
577 		zss->sl_soft_active = 0;
578 		zss->sl_stream.str_rq = NULL;
579 
580 		zs->zs_priv = (caddr_t)zss;
581 
582 		zss->sl_mru = zsh_default_mru;
583 		tmp = ZSH_MAX_RSTANDBY;
584 		ZSH_GETBLOCK(zs, tmp);
585 		if (zss->sl_rstandby[0] == NULL) {
586 			cmn_err(CE_WARN, "zsh_open: can't alloc message block");
587 			mutex_exit(zs->zs_excl);
588 			return (ENOSR);
589 		}
590 		mutex_enter(zs->zs_excl_hi);
591 		ZSH_ALLOCB(zss->sl_ractb);
592 		zss->sl_txstate = TX_OFF;
593 		zss->sl_rr0 = SCC_READ0();
594 		zss->sl_flags &= (SF_INITIALIZED | SF_FDXPTP);
595 		if (zss->sl_flags & SF_INITIALIZED)
596 			zsh_init_port(zs, zss);
597 		mutex_exit(zs->zs_excl_hi);
598 		mutex_exit(zs->zs_excl);
599 	} else {   /* CLONEOPEN */
600 		mutex_enter(&zs_curr_lock);
601 		for (unit = maxzsh; unit < MAXZSHCLONES; unit++)
602 			if (zsh_usedminor[unit] == '\0') {
603 				zsh_usedminor[unit] = (unsigned char)unit;
604 				break;
605 			}
606 		mutex_exit(&zs_curr_lock);
607 		if (unit >= MAXZSHCLONES)	/* no slots available */
608 			return (ENODEV);
609 		*dev = makedevice(getmajor(*dev), unit);
610 
611 		stp = kmem_zalloc(sizeof (struct ser_str), KM_NOSLEEP);
612 		if (stp == NULL) {
613 			cmn_err(CE_WARN,
614 			    "zsh clone open failed, no memory, rq=%p\n",
615 			    (void *)rq);
616 			return (ENOMEM);
617 		}
618 		stp->str_state = STR_CLONE;
619 		stp->str_com = NULL;	/* can't determine without ppa */
620 	}
621 	stp->str_rq = rq;
622 	stp->str_inst = unit;
623 
624 	rq->q_ptr = WR(rq)->q_ptr = (caddr_t)stp;
625 	qprocson(rq);
626 	return (0);
627 }
628 
629 /*
630  * Close routine.
631  */
632 int zsh_tx_enable_in_close = 0;
633 
634 /*ARGSUSED*/
635 static int
636 zsh_close(queue_t *rq, int flag, cred_t *cr __unused)
637 {
638 	struct ser_str *stp;
639 	struct zscom *zs;
640 	struct syncline *zss;
641 	mblk_t	*mp;
642 	int i;
643 	timeout_id_t sl_wd_id;
644 	bufcall_id_t sl_bufcid;
645 
646 	/*
647 	 * Note that a close is only called on the last close of a
648 	 * particular stream.  Assume that we need to do it all.
649 	 */
650 	qprocsoff(rq);				/* no new business after this */
651 
652 	stp = (struct ser_str *)rq->q_ptr;
653 	if (stp == NULL)
654 		return (0);			/* already been closed once */
655 
656 	if (stp->str_state == STR_CLONE) {
657 		zsh_usedminor[stp->str_inst] = 0;
658 	} else {
659 		zs = (struct zscom *)stp->str_com;
660 		if (zs == NULL)
661 			goto out;
662 
663 		TRACE_1(TR_ZSH, TR_ZSH_CLOSE, "zs = %p", zs);
664 
665 		zss = (struct syncline *)zs->zs_priv;
666 		mutex_enter(zs->zs_excl);
667 		flushq(WR(rq), FLUSHALL);
668 		mutex_enter(zs->zs_excl_hi);
669 		if (zss->sl_xstandby) {
670 			zss->sl_xstandby->b_wptr = zss->sl_xstandby->b_rptr;
671 			ZSH_FREEMSG(zss->sl_xstandby);
672 			zss->sl_xstandby = NULL;
673 		}
674 		mutex_exit(zs->zs_excl_hi);
675 
676 		ZSH_FLUSHQ;
677 
678 		/*
679 		 * Stop the Watchdog Timer.
680 		 */
681 		if ((sl_wd_id = zss->sl_wd_id) != 0)
682 			zss->sl_wd_id = 0;
683 
684 		/*
685 		 * Cancel outstanding "bufcall" request.
686 		 */
687 		if ((sl_bufcid = zss->sl_bufcid) != 0)
688 			zss->sl_bufcid = 0;
689 
690 		mutex_enter(zs->zs_excl_hi);
691 		if (zs->zs_wr_cur) {
692 			zs->zs_wr_cur = NULL;
693 			zs->zs_wr_lim = NULL;
694 			SCC_WRITE0(ZSWR0_SEND_ABORT);
695 			ZSDELAY();
696 			ZSDELAY();
697 		}
698 		zss->sl_txstate = TX_OFF;	/* so it can't rearm in close */
699 
700 		zs->zs_wr_cur = NULL;
701 		zs->zs_wr_lim = NULL;
702 		SCC_BIC(15,
703 		    (ZSR15_TX_UNDER | ZSR15_BREAK | ZSR15_SYNC | ZSR15_CTS));
704 		SCC_WRITE(3, 0);		/* Quiesce receiver */
705 		if (zsh_tx_enable_in_close && !(zss->sl_flags & SF_FDXPTP)) {
706 			SCC_BIS(5, ZSWR5_TX_ENABLE);
707 		} else
708 			SCC_BIC(5, ZSWR5_TX_ENABLE);
709 
710 		SCC_BIC(5,  (ZSWR5_DTR | ZSWR5_RTS | ZSWR5_TXCRC_ENABLE));
711 		SCC_WRITE0(ZSWR0_RESET_TXINT);		/* reset TX */
712 		SCC_WRITE0(ZSWR0_RESET_STATUS);		/* reset XS */
713 		SCC_WRITE0(ZSWR0_RESET_ERRORS);
714 		(void) SCC_READDATA();			/* reset RX */
715 		ZSDELAY();
716 		(void) SCC_READDATA();
717 		ZSDELAY();
718 		(void) SCC_READDATA();
719 		ZSDELAY();
720 
721 
722 		/*
723 		 * Free up everything we ever allocated.
724 		 */
725 		if ((mp = zss->sl_rhead) != NULL) {
726 			zss->sl_ractb = NULL;	/* already freed */
727 			zs->zs_rd_cur = NULL;
728 			zs->zs_rd_lim = NULL;
729 			zss->sl_rhead = NULL;
730 		}
731 		mutex_exit(zs->zs_excl_hi);
732 		if (mp)
733 			freemsg(mp);
734 
735 		mutex_enter(zs->zs_excl_hi);
736 		if ((mp = zss->sl_ractb) != NULL) {
737 			zs->zs_rd_cur = NULL;
738 			zs->zs_rd_lim = NULL;
739 			zss->sl_ractb = NULL;
740 		}
741 		mutex_exit(zs->zs_excl_hi);
742 		if (mp)
743 			freemsg(mp);
744 
745 		for (i = 0; i < ZSH_MAX_RSTANDBY; i++) {
746 			mutex_enter(zs->zs_excl_hi);
747 			mp = zss->sl_rstandby[i];
748 			zss->sl_rstandby[i] = NULL;
749 			mutex_exit(zs->zs_excl_hi);
750 			if (mp)
751 				freemsg(mp);
752 		}
753 
754 		mutex_enter(zs->zs_excl_hi);
755 		if ((mp = zss->sl_xhead) != NULL) {
756 			zss->sl_xhead = NULL;
757 			zss->sl_xactb = NULL;
758 		}
759 		mutex_exit(zs->zs_excl_hi);
760 		if (mp)
761 			freemsg(mp);
762 
763 		ZSH_FLUSHQ;
764 
765 		mutex_enter(zs->zs_excl_hi);
766 		if ((mp = zss->sl_xstandby) != NULL)
767 			zss->sl_xstandby = NULL;
768 		mutex_exit(zs->zs_excl_hi);
769 		if (mp)
770 			freemsg(mp);
771 
772 		mutex_enter(zs->zs_excl_hi);
773 		if ((mp = zss->sl_mstat) != NULL)
774 			zss->sl_mstat = NULL;
775 		zss->sl_txstate = TX_OFF;	/* so it can't rearm in close */
776 		mutex_exit(zs->zs_excl_hi);
777 		if (mp)
778 			freemsg(mp);
779 
780 		zss->sl_stream.str_rq = NULL;
781 		zsopinit(zs, &zsops_null);
782 		mutex_exit(zs->zs_excl);
783 		if (sl_wd_id)
784 			(void) untimeout(sl_wd_id);
785 		if (sl_bufcid)
786 			unbufcall(sl_bufcid);
787 		while (zss->sl_soft_active)
788 			drv_usecwait(1);
789 
790 		/* Mark device as available for power management */
791 		(void) pm_idle_component(zs->zs_dip, zs->zs_unit%2+1);
792 	}
793 
794 	if (stp->str_state == STR_CLONE)
795 		kmem_free(stp, sizeof (struct ser_str));
796 
797 out:
798 	rq->q_ptr = WR(rq)->q_ptr = NULL;
799 
800 	return (0);
801 }
802 
803 static int
804 zsh_hdp_ok_or_rts_state(struct zscom *zs, struct syncline *zss)
805 {
806 	uchar_t s0;
807 
808 	SCC_BIS(15, ZSR15_CTS);
809 	SCC_BIS(5, ZSWR5_RTS);
810 	s0 = SCC_READ0();
811 	if (s0 & ZSRR0_CTS) {
812 		SCC_BIS(5, ZSWR5_TX_ENABLE);
813 		zss->sl_rr0 |= ZSRR0_CTS;
814 		return (1);
815 	}
816 	zss->sl_flags |= SF_XMT_INPROG;
817 	zss->sl_txstate = TX_RTS;
818 	zss->sl_rr0 &= ~ZSRR0_CTS;
819 	zss->sl_wd_count = zsh_timer_count;
820 	return (0);
821 }
822 
823 /*
824  * Put procedure for write queue.
825  */
826 static void
827 zsh_wput(queue_t *wq, mblk_t *mp)
828 {
829 	struct ser_str *stp = (struct ser_str *)wq->q_ptr;
830 	struct zscom *zs;
831 	struct syncline *zss = NULL;
832 	ulong_t prim, error = 0;
833 	union DL_primitives *dlp;
834 	int	ppa;
835 	mblk_t *tmp;
836 	struct copyresp	*resp;
837 
838 	/*
839 	 * stp->str_com supplied by open or DLPI attach.
840 	 */
841 	if (stp == NULL) {
842 		freemsg(mp);
843 		return;
844 	}
845 	zs = (struct zscom *)stp->str_com;
846 
847 	TRACE_0(TR_ZSH, TR_ZSH_WPUT_START, "zsh_wput start");
848 
849 	if ((mp->b_datap->db_type == M_FLUSH) &&
850 	    (stp->str_state == STR_CLONE)) {
851 		if (*mp->b_rptr & FLUSHW) {
852 			flushq(wq, FLUSHDATA);
853 			*mp->b_rptr &= ~FLUSHW;
854 		}
855 		if (*mp->b_rptr & FLUSHR)
856 			qreply(wq, mp);  /* let the read queues have at it */
857 		else
858 			freemsg(mp);
859 		return;
860 	}
861 
862 	if ((zs == NULL) && (mp->b_datap->db_type != M_PROTO)) {
863 		freemsg(mp);
864 		cmn_err(CE_WARN,
865 		    "zsh: clone device %d must be attached before use!",
866 		    stp->str_inst);
867 		(void) putnextctl1(RD(wq), M_ERROR, EPROTO);
868 		return;
869 	}
870 
871 	if (stp->str_state == STR_CLONE) {	/* Clone opened, limited. */
872 		if ((mp->b_datap->db_type != M_PROTO) &&
873 		    (mp->b_datap->db_type != M_IOCTL) &&
874 		    (mp->b_datap->db_type != M_IOCDATA)) {
875 			freemsg(mp);
876 			cmn_err(CE_WARN,
877 			    "zsh%x: invalid operation for clone dev.\n",
878 			    stp->str_inst);
879 			(void) putnextctl1(RD(wq), M_ERROR, EPROTO);
880 			return;
881 		}
882 	} else {
883 		zss = (struct syncline *)zs->zs_priv;
884 	}
885 
886 	switch (mp->b_datap->db_type) {
887 
888 	case M_DATA:
889 		/*
890 		 * Queue the message up to be transmitted.
891 		 * Set "in progress" flag and call the start routine.
892 		 */
893 		mutex_enter(zs->zs_excl_hi);
894 		if (!(zss->sl_flags & SF_INITIALIZED)) {
895 			mutex_exit(zs->zs_excl_hi);
896 			cmn_err(CE_WARN,
897 			    "zsh%x not initialized, can't send message",
898 			    zs->zs_unit);
899 			freemsg(mp);
900 			(void) putnextctl1(RD(wq), M_ERROR, ECOMM);
901 			return;
902 		}
903 		mutex_exit(zs->zs_excl_hi);
904 		if (zs->zs_flags & ZS_NEEDSOFT) {
905 			zs->zs_flags &= ~ZS_NEEDSOFT;
906 			(void) zsh_softint(zs);
907 		}
908 		while (mp->b_wptr == mp->b_rptr) {
909 			mblk_t *mp1;
910 			mp1 = unlinkb(mp);
911 			freemsg(mp);
912 			mp = mp1;
913 			if (mp == NULL)
914 				return;
915 		}
916 		mutex_enter(zs->zs_excl);
917 		(void) putq(wq, mp);
918 		mutex_enter(zs->zs_excl_hi);
919 		if (zss->sl_flags & SF_FLUSH_WQ) {
920 			mutex_exit(zs->zs_excl_hi);
921 			flushq(wq, FLUSHDATA);
922 			mutex_exit(zs->zs_excl);
923 
924 			TRACE_1(TR_ZSH, TR_ZSH_WPUT_END,
925 			    "zsh_wput end: zs = %p", zs);
926 
927 			return;
928 		}
929 		tmp = NULL;
930 again:
931 		if (zss->sl_xstandby == NULL) {
932 			if (tmp)
933 				zss->sl_xstandby = tmp;
934 			else {
935 				mutex_exit(zs->zs_excl_hi);
936 				tmp = getq(wq);
937 				mutex_enter(zs->zs_excl_hi);
938 				if (tmp)
939 					goto again;
940 			}
941 		} else if (tmp) {
942 			mutex_exit(zs->zs_excl_hi);
943 			(void) putbq(wq, tmp);
944 			mutex_enter(zs->zs_excl_hi);
945 		}
946 
947 		if (zss->sl_flags & SF_XMT_INPROG) {
948 			mutex_exit(zs->zs_excl_hi);
949 			mutex_exit(zs->zs_excl);
950 
951 			TRACE_1(TR_ZSH, TR_ZSH_WPUT_END,
952 			    "zsh_wput end: zs = %p", zs);
953 
954 			return;
955 		}
956 
957 		if (zss->sl_wd_id == NULL) {
958 			zss->sl_wd_count = zsh_timer_count;
959 			zss->sl_txstate = TX_IDLE;
960 			mutex_exit(zs->zs_excl_hi);
961 			zss->sl_wd_id = timeout(zsh_watchdog, zs,
962 			    SIO_WATCHDOG_TICK);
963 			mutex_enter(zs->zs_excl_hi);
964 		}
965 
966 		zss->sl_flags |= SF_XMT_INPROG;
967 		if ((zss->sl_flags & SF_FDXPTP) ||
968 		    zsh_hdp_ok_or_rts_state(zs, zss))
969 			(void) zsh_start(zs, zss);
970 		mutex_exit(zs->zs_excl_hi);
971 		mutex_exit(zs->zs_excl);
972 		break;
973 
974 	case M_PROTO:
975 		/*
976 		 * Here is where a clone device finds out about the
977 		 * hardware it is going to attach to.  The request is
978 		 * validated and a ppa is extracted from it and validated.
979 		 * This number is used to index the hardware data structure
980 		 * and the protocol data structure, in case the latter
981 		 * was not provided by a data-path open before this.
982 		 */
983 		if (stp->str_state != STR_CLONE) {
984 			freemsg(mp);
985 			return;
986 		}
987 
988 		if (MBLKL(mp) < DL_ATTACH_REQ_SIZE) {
989 			prim = DL_ATTACH_REQ;
990 			error = DL_BADPRIM;
991 			goto end_proto;
992 		}
993 		dlp = (union DL_primitives *)mp->b_rptr;
994 		prim = dlp->dl_primitive;
995 		if (prim != DL_ATTACH_REQ) {
996 			error = DL_BADPRIM;
997 			goto end_proto;
998 		}
999 		ppa = dlp->attach_req.dl_ppa;
1000 		ppa = (ppa%2) ? ((ppa-1)*2 +1) : (ppa*2);
1001 		if (ppa >= maxzsh) {
1002 			error = DL_BADPPA;
1003 			goto end_proto;
1004 		}
1005 		zs = &zscom[ppa];
1006 		if (zs->zs_ops == NULL) {
1007 			error = ENXIO;
1008 			goto end_proto;
1009 		}
1010 		mutex_enter(zs->zs_excl);
1011 		if ((zs->zs_ops != &zsops_null) &&
1012 		    (zs->zs_ops != &zsops_hdlc)) {
1013 			/*
1014 			 * another protocol got here first
1015 			 */
1016 			error = (EBUSY);
1017 			mutex_exit(zs->zs_excl);
1018 			goto end_proto;
1019 
1020 		}
1021 
1022 		stp->str_com = (caddr_t)zs;
1023 		mutex_exit(zs->zs_excl);
1024 end_proto:
1025 		if (error)
1026 			dlerrorack(wq, mp, prim, error, 0);
1027 		else
1028 			dlokack(wq, mp, DL_ATTACH_REQ);
1029 		break;
1030 
1031 	case M_IOCTL:
1032 		zsh_ioctl(wq, mp);
1033 		break;
1034 
1035 	case M_IOCDATA:
1036 		resp = (struct copyresp *)mp->b_rptr;
1037 		if (resp->cp_rval) {
1038 			/*
1039 			 * Just free message on failure.
1040 			 */
1041 			freemsg(mp);
1042 			break;
1043 		}
1044 
1045 		switch (resp->cp_cmd) {
1046 
1047 		case S_IOCGETMODE:
1048 		case S_IOCGETSTATS:
1049 		case S_IOCGETSPEED:
1050 		case S_IOCGETMCTL:
1051 		case S_IOCGETMRU:
1052 			mioc2ack(mp, NULL, 0, 0);
1053 			qreply(wq, mp);
1054 			break;
1055 
1056 		case S_IOCSETMODE:
1057 			zss  = (struct syncline *)&zs->zs_priv_str;
1058 			mutex_enter(zs->zs_excl);
1059 			error = zsh_setmode(zs, zss,
1060 			    (struct scc_mode *)mp->b_cont->b_rptr);
1061 			if (error) {
1062 				struct iocblk  *iocp =
1063 				    (struct iocblk *)mp->b_rptr;
1064 				mp->b_datap->db_type = M_IOCNAK;
1065 				iocp->ioc_error = error;
1066 			} else
1067 				mioc2ack(mp, NULL, 0, 0);
1068 			mutex_exit(zs->zs_excl);
1069 			qreply(wq, mp);
1070 			break;
1071 
1072 		case S_IOCSETMRU:
1073 			zss  = (struct syncline *)&zs->zs_priv_str;
1074 			mutex_enter(zs->zs_excl);
1075 			zss->sl_mru = *(int *)mp->b_cont->b_rptr;
1076 			mutex_exit(zs->zs_excl);
1077 			mioc2ack(mp, NULL, 0, 0);
1078 			qreply(wq, mp);
1079 			break;
1080 		default:
1081 			freemsg(mp);
1082 		}
1083 		break;
1084 
1085 		/*
1086 		 * We're at the bottom of the food chain, so we flush our
1087 		 * write queue, clear the FLUSHW bit so it doesn't go round
1088 		 * and round forever, then flush our read queue (since there's
1089 		 * no read put procedure down here) and pass it up for any
1090 		 * higher modules to deal with in their own way.
1091 		 */
1092 	case M_FLUSH:
1093 		if (*mp->b_rptr & FLUSHW) {
1094 			mutex_enter(zs->zs_excl);
1095 			flushq(wq, FLUSHDATA);
1096 			mutex_enter(zs->zs_excl_hi);
1097 			tmp = zss->sl_xstandby;
1098 			zss->sl_xstandby = NULL;
1099 			mutex_exit(zs->zs_excl_hi);
1100 			if (tmp)
1101 				freemsg(tmp);
1102 			mutex_exit(zs->zs_excl);
1103 			*mp->b_rptr &= ~FLUSHW;
1104 		}
1105 
1106 		if (*mp->b_rptr & FLUSHR) {
1107 			mutex_enter(zs->zs_excl);
1108 			ZSH_FLUSHQ;
1109 			mutex_exit(zs->zs_excl);
1110 			qreply(wq, mp);  /* let the read queues have at it */
1111 		} else
1112 			freemsg(mp);
1113 		break;
1114 
1115 	default:
1116 		/*
1117 		 * "No, I don't want a subscription to Chain Store Age,
1118 		 * thank you anyway."
1119 		 */
1120 		freemsg(mp);
1121 		break;
1122 	}
1123 
1124 	TRACE_1(TR_ZSH, TR_ZSH_WPUT_END, "zsh_wput end: zs = %p", zs);
1125 }
1126 
1127 /*
1128  * Get the next message from the write queue, set up the necessary pointers,
1129  * state info, etc., and start the transmit "engine" by sending the first
1130  * character.  We'll then rotate through txint until done, then get an xsint.
1131  */
1132 static int
1133 zsh_start(struct zscom *zs, struct syncline *zss)
1134 {
1135 	mblk_t *mp;
1136 	uchar_t *wptr;
1137 	uchar_t *rptr;
1138 	uchar_t sl_flags = zss->sl_flags;
1139 
1140 	/*
1141 	 * Attempt to grab the next M_DATA message off the queue (that's
1142 	 * all that will be left after wput) and begin transmission.
1143 	 * This routine is normally called after completion of a previous
1144 	 * frame, or when zsh_wput gets a new message.  If we are in a
1145 	 * mode that put us in the TX_RTS state, waiting for CTS, and CTS
1146 	 * is not up yet, we have no business here.  Ditto if we're in
1147 	 * either the TX_ACTIVE or TX_CRC states.  In these cases we
1148 	 * don't clear SF_CALLSTART, so we don't forget there's work to do.
1149 	 */
1150 
1151 	TRACE_1(TR_ZSH, TR_ZSH_START_START,
1152 	    "zsh_start start: zs = %p", zs);
1153 
1154 	if (sl_flags & SF_PHONY) {
1155 		sl_flags &= ~SF_PHONY;
1156 		SCC_BIC(15, ZSR15_CTS);
1157 		SCC_BIC(5, ZSWR5_RTS);
1158 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1159 		SCC_BIC(5, ZSWR5_TX_ENABLE);
1160 		zss->sl_rr0 &= ~ZSRR0_CTS;
1161 		zss->sl_txstate = TX_IDLE;
1162 		/*
1163 		 * if we get another msg by chance zsh_watchog will start
1164 		 */
1165 		sl_flags &= ~SF_XMT_INPROG;
1166 		zss->sl_flags = sl_flags;
1167 
1168 		TRACE_1(TR_ZSH, TR_ZSH_START_END,
1169 		    "zsh_start end: zs = %d", zs);
1170 
1171 		return (0);
1172 	}
1173 	mp = zss->sl_xstandby;
1174 	if (mp == NULL) {
1175 		if (!(sl_flags & SF_FDXPTP)) {
1176 			sl_flags |= SF_PHONY;
1177 			ZSH_ALLOCB(mp);
1178 			if (mp == NULL)
1179 				return (0);
1180 			mp->b_datap->db_type = M_RSE;
1181 			mp->b_wptr = mp->b_rptr + 1;
1182 			goto transmit;
1183 		}
1184 		sl_flags &= ~SF_XMT_INPROG;
1185 		zss->sl_flags = sl_flags;
1186 
1187 		TRACE_1(TR_ZSH, TR_ZSH_START_END,
1188 		    "zsh_start end: zs = %p", zs);
1189 
1190 		return (0);
1191 	}
1192 
1193 transmit:
1194 	zss->sl_xstandby = NULL;
1195 	rptr = mp->b_rptr;
1196 	wptr = mp->b_wptr;
1197 	ZSSETSOFT(zs);
1198 
1199 #ifdef ZSH_DEBUG
1200 	if (zss->sl_xhead || zss->sl_xactb) {
1201 		debug_enter("xhead1");
1202 	}
1203 #endif
1204 
1205 	zss->sl_xhead = mp;
1206 	zss->sl_xactb = mp;
1207 	zss->sl_wd_count = zsh_timer_count;
1208 	zss->sl_txstate = TX_ACTIVE;
1209 	zss->sl_ocnt = 0;
1210 	SCC_BIS(10, ZSWR10_UNDERRUN_ABORT);	/* abort on underrun */
1211 	SCC_WRITE0(ZSWR0_RESET_TXCRC);		/* reset transmit CRC */
1212 	zss->sl_ocnt = wptr - rptr;
1213 	mp->b_wptr = rptr; /* to tell soft to free this msg */
1214 	SCC_WRITEDATA(*rptr++);    /* resets TXINT */
1215 	zs->zs_wr_cur = rptr;
1216 	zs->zs_wr_lim = wptr;
1217 
1218 	SCC_WRITE0(ZSWR0_RESET_EOM);
1219 
1220 	TRACE_1(TR_ZSH, TR_ZSH_START_END,
1221 	    "zsh_start end: zs = %p", zs);
1222 
1223 	zss->sl_flags = sl_flags;
1224 	return (1);
1225 }
1226 
1227 
1228 /*
1229  * Process an "ioctl" message sent down to us.
1230  */
1231 static void
1232 zsh_ioctl(queue_t *wq, mblk_t *mp)
1233 {
1234 	struct ser_str *stp = (struct ser_str *)wq->q_ptr;
1235 	struct zscom *zs = (struct zscom *)stp->str_com;
1236 	struct syncline *zss  = (struct syncline *)&zs->zs_priv_str;
1237 	struct iocblk   *iocp = (struct iocblk *)mp->b_rptr;
1238 	struct scc_mode *sm;
1239 	struct sl_stats *st;
1240 	uchar_t	 *msignals;
1241 	mblk_t		 *tmp;
1242 	int		 error = 0;
1243 
1244 	mutex_enter(zs->zs_excl);
1245 	if ((zs->zs_ops != &zsops_null) &&
1246 	    (zs->zs_ops != &zsops_hdlc)) {
1247 		/*
1248 		 * another protocol got here first
1249 		 */
1250 		error = (EBUSY);
1251 		goto end_zsh_ioctl;
1252 	}
1253 
1254 
1255 	switch (iocp->ioc_cmd) {
1256 
1257 	case S_IOCGETMODE:
1258 		tmp = allocb(sizeof (struct scc_mode), BPRI_MED);
1259 		if (tmp == NULL) {
1260 			error = EAGAIN;
1261 			break;
1262 		}
1263 		if (iocp->ioc_count != TRANSPARENT)
1264 			mioc2ack(mp, tmp, sizeof (struct scc_mode), 0);
1265 		else
1266 			mcopyout(mp, NULL, sizeof (struct scc_mode), NULL, tmp);
1267 		sm = (struct scc_mode *)mp->b_cont->b_rptr;
1268 		bcopy(&zss->sl_mode, sm, sizeof (struct scc_mode));
1269 		break;
1270 
1271 	case S_IOCGETSTATS:
1272 		tmp = allocb(sizeof (struct sl_stats), BPRI_MED);
1273 		if (tmp == NULL) {
1274 			error = EAGAIN;
1275 			break;
1276 		}
1277 		if (iocp->ioc_count != TRANSPARENT)
1278 			mioc2ack(mp, tmp, sizeof (struct sl_stats), 0);
1279 		else
1280 			mcopyout(mp, NULL, sizeof (struct sl_stats), NULL, tmp);
1281 		st = (struct sl_stats *)mp->b_cont->b_rptr;
1282 		bcopy(&zss->sl_st, st, sizeof (struct sl_stats));
1283 		break;
1284 
1285 	case S_IOCGETSPEED:
1286 		tmp = allocb(sizeof (int), BPRI_MED);
1287 		if (tmp == NULL) {
1288 			error = EAGAIN;
1289 			break;
1290 		}
1291 		if (iocp->ioc_count != TRANSPARENT)
1292 			mioc2ack(mp, tmp, sizeof (int), 0);
1293 		else
1294 			mcopyout(mp, NULL, sizeof (int), NULL, tmp);
1295 		*(int *)mp->b_cont->b_rptr = zss->sl_mode.sm_baudrate;
1296 		break;
1297 
1298 	case S_IOCGETMCTL:
1299 		tmp = allocb(sizeof (char), BPRI_MED);
1300 		if (tmp == NULL) {
1301 			error = EAGAIN;
1302 			break;
1303 		}
1304 		if (iocp->ioc_count != TRANSPARENT)
1305 			mioc2ack(mp, tmp, sizeof (char), 0);
1306 		else
1307 			mcopyout(mp, NULL, sizeof (char), NULL, tmp);
1308 		msignals = (uchar_t *)mp->b_cont->b_rptr;
1309 		*msignals = zss->sl_rr0 & (ZSRR0_CD | ZSRR0_CTS);
1310 		break;
1311 
1312 	case S_IOCGETMRU:
1313 		tmp = allocb(sizeof (int), BPRI_MED);
1314 		if (tmp == NULL) {
1315 			error = EAGAIN;
1316 			break;
1317 		}
1318 		if (iocp->ioc_count != TRANSPARENT)
1319 			mioc2ack(mp, tmp, sizeof (int), 0);
1320 		else
1321 			mcopyout(mp, NULL, sizeof (int), NULL, tmp);
1322 		*(int *)mp->b_cont->b_rptr = zss->sl_mru;
1323 		break;
1324 
1325 	case S_IOCSETMODE:
1326 		if (iocp->ioc_count != TRANSPARENT) {
1327 			error = miocpullup(mp, sizeof (struct scc_mode));
1328 			if (error != 0)
1329 				break;
1330 			error = zsh_setmode(zs, zss,
1331 			    (struct scc_mode *)mp->b_cont->b_rptr);
1332 			if (error == 0)
1333 				mioc2ack(mp, NULL, 0, 0);
1334 		} else
1335 			mcopyin(mp, NULL, sizeof (struct scc_mode), NULL);
1336 		break;
1337 
1338 	case S_IOCCLRSTATS:
1339 		mutex_enter(zs->zs_excl_hi);
1340 		bzero(&zss->sl_st, sizeof (struct sl_stats));
1341 		mutex_exit(zs->zs_excl_hi);
1342 		mioc2ack(mp, NULL, 0, 0);
1343 		break;
1344 
1345 	case S_IOCSETMRU:
1346 		if (iocp->ioc_count != TRANSPARENT) {
1347 			error = miocpullup(mp, sizeof (int));
1348 			if (error != 0)
1349 				break;
1350 			zss->sl_mru = *(int *)mp->b_cont->b_rptr;
1351 			mioc2ack(mp, NULL, 0, 0);
1352 		} else
1353 			mcopyin(mp, NULL, sizeof (int), NULL);
1354 		break;
1355 
1356 	case S_IOCSETDTR:
1357 		/*
1358 		 * The first integer of the M_DATA block that should
1359 		 * follow indicate if DTR must be set or reset
1360 		 */
1361 		error = miocpullup(mp, sizeof (int));
1362 		if (error != 0)
1363 			break;
1364 
1365 		mutex_enter(zs->zs_excl_hi);
1366 		if (*(int *)mp->b_cont->b_rptr != 0)
1367 			(void) zsmctl(zs, ZSWR5_DTR, DMBIS);
1368 		else
1369 			(void) zsmctl(zs, ZSWR5_DTR, DMBIC);
1370 		mutex_exit(zs->zs_excl_hi);
1371 		break;
1372 
1373 	default:
1374 		error = EINVAL;
1375 
1376 	}
1377 end_zsh_ioctl:
1378 	iocp->ioc_error = error;
1379 	mp->b_datap->db_type = (error) ? M_IOCNAK : M_IOCACK;
1380 	mutex_exit(zs->zs_excl);
1381 	qreply(wq, mp);
1382 }
1383 
1384 /*
1385  * Set the mode of the zsh port
1386  */
1387 
1388 int
1389 zsh_setmode(struct zscom *zs, struct syncline *zss, struct scc_mode *sm)
1390 {
1391 	int error = 0;
1392 	mblk_t *mp;
1393 
1394 	mutex_enter(zs->zs_excl_hi);
1395 	if (sm->sm_rxclock == RXC_IS_PLL) {
1396 		zss->sl_mode.sm_retval = SMERR_RXC;
1397 		mutex_exit(zs->zs_excl_hi);
1398 		return (EINVAL);		/* not supported */
1399 	} else {
1400 		if (((zss->sl_mode.sm_config ^ sm->sm_config) &
1401 		    CONN_SIGNAL) != 0) { /* Changing, going... */
1402 			if (sm->sm_config & CONN_SIGNAL) { /* ...up. */
1403 				if (zss->sl_mstat == NULL) {
1404 					mutex_exit(zs->zs_excl_hi);
1405 					mp = allocb(
1406 					    sizeof (struct sl_status),
1407 					    BPRI_MED);
1408 					mutex_enter(zs->zs_excl_hi);
1409 					zss->sl_mstat = mp;
1410 				}
1411 			} else {			/* ...down. */
1412 				if ((mp = zss->sl_mstat) != NULL)
1413 					zss->sl_mstat = NULL;
1414 				mutex_exit(zs->zs_excl_hi);
1415 				if (mp)
1416 					freemsg(mp);
1417 				mutex_enter(zs->zs_excl_hi);
1418 			}
1419 		}
1420 		if (!(sm->sm_config & CONN_IBM)) {
1421 			if (sm->sm_config & CONN_HDX) {
1422 				zss->sl_mode.sm_retval = SMERR_HDX;
1423 				mutex_exit(zs->zs_excl_hi);
1424 				return (EINVAL);
1425 			}
1426 			if (sm->sm_config & CONN_MPT) {
1427 				zss->sl_mode.sm_retval = SMERR_MPT;
1428 				mutex_exit(zs->zs_excl_hi);
1429 				return (EINVAL);
1430 			}
1431 		}
1432 		zss->sl_flags &= ~SF_FDXPTP;		/* "conmode" */
1433 		if ((sm->sm_config & (CONN_HDX | CONN_MPT)) == 0)
1434 			zss->sl_flags |= SF_FDXPTP;
1435 
1436 		error = zsh_program(zs, sm);
1437 		if (!error && (zs->zs_ops != &zsops_null))
1438 			zsh_init_port(zs, zss);
1439 	}
1440 	mutex_exit(zs->zs_excl_hi);
1441 
1442 	return (error);
1443 }
1444 
1445 /*
1446  * Transmit interrupt service procedure
1447  */
1448 
1449 static void
1450 zsh_txint(struct zscom *zs)
1451 {
1452 	struct syncline *zss;
1453 	mblk_t *mp;
1454 	int tmp;
1455 	uchar_t *wr_cur;
1456 
1457 	TRACE_1(TR_ZSH, TR_ZSH_TXINT, "zsh_txint: zs = %p", zs);
1458 
1459 	if ((wr_cur =  zs->zs_wr_cur) != NULL && (wr_cur <  zs->zs_wr_lim)) {
1460 		SCC_WRITEDATA(*wr_cur++);
1461 		zs->zs_wr_cur = wr_cur;
1462 		return;
1463 	}
1464 
1465 
1466 	zss = (struct syncline *)&zs->zs_priv_str;
1467 
1468 	switch (zss->sl_txstate) {
1469 
1470 	/*
1471 	 * we here because end of message block lim = cur
1472 	 */
1473 	case TX_ACTIVE:
1474 
1475 		mp = zss->sl_xactb;
1476 
1477 again_txint:
1478 		mp = mp->b_cont;
1479 		if (mp) {
1480 			zss->sl_xactb = mp;
1481 			zss->sl_ocnt += tmp = mp->b_wptr - mp->b_rptr;
1482 			if (tmp == 0)
1483 				goto again_txint;
1484 			zs->zs_wr_cur = mp->b_rptr;
1485 			zs->zs_wr_lim = mp->b_wptr;
1486 			SCC_WRITEDATA(*zs->zs_wr_cur++);
1487 			return;
1488 		}
1489 
1490 		/*
1491 		 * This is where the fun starts.  At this point the
1492 		 * last character in the frame has been sent.  We
1493 		 * issue a RESET_TXINT so we won't get another txint
1494 		 * until the CRC has been completely sent.  Also we
1495 		 * reset the Abort-On-Underrun bit so that CRC is
1496 		 * sent at EOM, rather than an Abort.
1497 		 */
1498 		zs->zs_wr_cur = zs->zs_wr_lim = NULL;
1499 		zss->sl_txstate = TX_CRC;
1500 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1501 		if (!(zss->sl_flags & SF_PHONY)) {
1502 			SCC_BIC(10, ZSWR10_UNDERRUN_ABORT);
1503 			zss->sl_st.opack++;
1504 			zss->sl_st.ochar += zss->sl_ocnt;
1505 		}
1506 		zss->sl_ocnt = 0;
1507 		ZSH_FREEMSG(zss->sl_xhead);
1508 		zss->sl_xhead = zss->sl_xactb = NULL;
1509 		ZSSETSOFT(zs);
1510 		break;
1511 	/*
1512 	 * This txint means we have sent the CRC bytes at EOF.
1513 	 * The next txint will mean we are sending or have sent the
1514 	 * flag character at EOF, but we handle that differently, and
1515 	 * enter different states,depending on whether we're IBM or not.
1516 	 */
1517 	case TX_CRC:
1518 		if (!(zss->sl_flags & SF_FDXPTP)) {
1519 			zss->sl_txstate = TX_FLAG;	/* HDX path */
1520 		} else {	/* FDX path */
1521 			if (!zsh_start(zs, zss)) {
1522 				zss->sl_txstate = TX_IDLE;
1523 				SCC_WRITE0(ZSWR0_RESET_TXINT);
1524 			}
1525 		}
1526 		break;
1527 
1528 	/*
1529 	 * This txint means the closing flag byte is going out the door.
1530 	 * We use this state to allow this to complete before dropping RTS.
1531 	 */
1532 	case TX_FLAG:
1533 		zss->sl_txstate = TX_LAST;
1534 		(void) zsh_start(zs, zss);
1535 		break;
1536 
1537 	/*
1538 	 * Arriving here means the flag should be out and it's finally
1539 	 * time to close the barn door.
1540 	 */
1541 	case TX_LAST:
1542 		zss->sl_txstate = TX_IDLE;
1543 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1544 		break;
1545 
1546 	/*
1547 	 * If transmit was aborted, do nothing - watchdog will recover.
1548 	 */
1549 	case TX_ABORTED:
1550 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1551 		break;
1552 
1553 	default:
1554 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1555 		break;
1556 	}
1557 }
1558 
1559 /*
1560  * External Status Change interrupt service procedure
1561  */
1562 static void
1563 zsh_xsint(struct zscom *zs)
1564 {
1565 	struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
1566 	uchar_t s0, x0;
1567 
1568 	TRACE_1(TR_ZSH, TR_ZSH_XSINT, "zsh_xsint: zs = %p", zs);
1569 
1570 	s0 = SCC_READ0();
1571 	x0 = s0 ^ zss->sl_rr0;
1572 	zss->sl_rr0 = s0;
1573 	SCC_WRITE0(ZSWR0_RESET_STATUS);
1574 
1575 	if (s0 & ZSRR0_TXUNDER) {
1576 		switch (zss->sl_txstate) {
1577 		/*
1578 		 * A transmitter underrun has occurred.  If we are not
1579 		 * here as the result of an abort sent by the watchdog
1580 		 * timeout routine, we need to send an abort to flush
1581 		 * the transmitter.  Otherwise there is a danger of
1582 		 * trashing the next frame but still sending a good crc.
1583 		 * The TX_ABORTED flag is set so that the watchdog
1584 		 * routine can initiate recovery.
1585 		 */
1586 		case TX_ACTIVE:
1587 			SCC_WRITE0(ZSWR0_SEND_ABORT);
1588 			SCC_WRITE0(ZSWR0_RESET_TXINT);
1589 			zss->sl_st.underrun++;
1590 			zsh_txbad(zs, zss);
1591 
1592 			zss->sl_txstate = TX_ABORTED;
1593 			zss->sl_wd_count = 0;
1594 			break;
1595 
1596 		case TX_CRC:
1597 			break;
1598 
1599 		case TX_FLAG:
1600 			break;
1601 
1602 		case TX_ABORTED:
1603 			break;
1604 
1605 		case TX_OFF:
1606 			break;
1607 
1608 		case TX_LAST:
1609 			break;
1610 
1611 		default:
1612 			break;
1613 		}
1614 	}
1615 
1616 	if ((x0 & ZSRR0_BREAK) && (s0 & ZSRR0_BREAK) && zs->zs_rd_cur) {
1617 		zss->sl_st.abort++;
1618 		zsh_rxbad(zs, zss);
1619 	} else if ((s0 & ZSRR0_SYNC) && (zs->zs_rd_cur)) {
1620 		/*
1621 		 * Tricky code to avoid disaster in the case where
1622 		 * an abort was detected while receiving a packet,
1623 		 * but the abort did not last long enough to be
1624 		 * detected by zsh_xsint - this can happen since
1625 		 * the ZSRR0_BREAK is not latched.  Since an abort
1626 		 * will automatically cause the SCC to enter
1627 		 * hunt mode, hopefully, the sync/hunt bit will be
1628 		 * set in this case (although if the interrupt is
1629 		 * sufficiently delayed, the SCC may have sync'ed
1630 		 * in again if it has detected a flag).
1631 		 */
1632 		zss->sl_st.abort++;
1633 		zsh_rxbad(zs, zss);
1634 	}
1635 
1636 	if (x0 & s0 & ZSRR0_CTS) {
1637 		if (zss->sl_txstate == TX_RTS) {
1638 			if (!(zss->sl_flags & SF_FDXPTP)) {
1639 				SCC_BIS(5, ZSWR5_TX_ENABLE);
1640 			}
1641 			(void) zsh_start(zs, zss);
1642 		} else if ((zss->sl_mode.sm_config &
1643 		    (CONN_IBM | CONN_SIGNAL))) {
1644 			zss->sl_flags &= ~SF_FLUSH_WQ;
1645 			zsh_setmstat(zs, CS_CTS_UP);
1646 		}
1647 	}
1648 
1649 	/*
1650 	 * We don't care about CTS transitions unless we are in either
1651 	 * IBM or SIGNAL mode, or both.  So, if we see CTS drop, and we
1652 	 * care, and we are not idle, send up a report message.
1653 	 */
1654 	if ((x0 & ZSRR0_CTS) && ((s0 & ZSRR0_CTS) == 0) &&
1655 	    (zss->sl_txstate != TX_OFF) &&
1656 	    (zss->sl_mode.sm_config & (CONN_IBM | CONN_SIGNAL))) {
1657 		SCC_BIC(15, ZSR15_CTS);
1658 		zsh_setmstat(zs, CS_CTS_DOWN);
1659 		zss->sl_flags &= ~SF_XMT_INPROG;
1660 		zss->sl_flags |= SF_FLUSH_WQ;
1661 		zss->sl_st.cts++;
1662 		if (zss->sl_txstate != TX_IDLE)
1663 			SCC_WRITE0(ZSWR0_SEND_ABORT);
1664 		SCC_WRITE0(ZSWR0_RESET_ERRORS);
1665 		SCC_WRITE0(ZSWR0_RESET_TXINT);
1666 		zss->sl_wd_count = 0;
1667 		zsh_txbad(zs, zss);
1668 	}
1669 }
1670 
1671 
1672 /*
1673  * Receive interrupt service procedure
1674  */
1675 static void
1676 zsh_rxint(struct zscom *zs)
1677 {
1678 	struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
1679 	mblk_t *bp = zss->sl_ractb;
1680 	unsigned char *rd_cur;
1681 
1682 	TRACE_1(TR_ZSH, TR_ZSH_RXINT, "zsh_rxint: zs = %p", zs);
1683 
1684 	if (((rd_cur = zs->zs_rd_cur) != NULL) && rd_cur < zs->zs_rd_lim) {
1685 		*rd_cur++ = SCC_READDATA();
1686 		zs->zs_rd_cur = rd_cur;
1687 		return;
1688 	}
1689 
1690 	if (rd_cur == NULL) { /* Beginning of frame */
1691 		if (bp == NULL) {
1692 			ZSH_ALLOCB(bp);
1693 			zss->sl_ractb = bp;
1694 		}
1695 		zss->sl_rhead = bp;
1696 	} else {	/* end of data block should be cur==lim */
1697 		bp->b_wptr = zs->zs_rd_cur;
1698 		ZSH_ALLOCB(bp->b_cont);
1699 		bp = zss->sl_ractb = bp->b_cont;
1700 	}
1701 	if (bp == NULL) {
1702 		zss->sl_st.nobuffers++;
1703 		zsh_rxbad(zs, zss);
1704 		return;
1705 	}
1706 	zs->zs_rd_cur = bp->b_wptr;
1707 	zs->zs_rd_lim = bp->b_datap->db_lim;
1708 	*zs->zs_rd_cur++ = SCC_READDATA(); /* Also resets interrupt */
1709 }
1710 
1711 
1712 /*
1713  * Special Receive Condition Interrupt routine
1714  */
1715 static void
1716 zsh_srint(struct zscom *zs)
1717 {
1718 	struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
1719 	uchar_t s1;
1720 	uchar_t *rd_cur;
1721 
1722 	TRACE_1(TR_ZSH, TR_ZSH_SRINT, "zsh_srint: zs = %p", zs);
1723 
1724 	SCC_READ(1, s1);
1725 
1726 	if (s1 & ZSRR1_RXEOF) {			/* end of frame */
1727 		(void) SCC_READDATA();
1728 		SCC_WRITE0(ZSWR0_RESET_ERRORS);
1729 		if (s1 & ZSRR1_FE) {		/* bad CRC */
1730 			zss->sl_st.crc++;
1731 			zsh_rxbad(zs, zss);
1732 			return;
1733 		}
1734 
1735 		if ((rd_cur = zs->zs_rd_cur) == NULL)
1736 			return;
1737 
1738 		/*
1739 		 * Drop one CRC byte from length because it came in
1740 		 * before the special interrupt got here.
1741 		 */
1742 		zss->sl_ractb->b_wptr = rd_cur - 1;
1743 
1744 		/*
1745 		 * put on done queue
1746 		 */
1747 		ZSH_PUTQ(zss->sl_rhead);
1748 		zss->sl_rhead = NULL;
1749 		zss->sl_ractb = NULL;
1750 		zs->zs_rd_cur = NULL;
1751 		zs->zs_rd_lim = NULL;
1752 		ZSSETSOFT(zs);
1753 
1754 	} else if (s1 & ZSRR1_DO) {
1755 		(void) SCC_READDATA();
1756 		SCC_WRITE0(ZSWR0_RESET_ERRORS);
1757 		zss->sl_st.overrun++;
1758 		zsh_rxbad(zs, zss);
1759 	} else
1760 		SCC_WRITE0(ZSWR0_RESET_ERRORS);
1761 }
1762 
1763 /*
1764  * Handle a second stage interrupt.
1765  * Does mostly lower priority buffer management stuff.
1766  */
1767 static int
1768 zsh_softint(struct zscom *zs)
1769 {
1770 	struct syncline *zss;
1771 	queue_t *q;
1772 	mblk_t *mp, *tmp;
1773 	mblk_t *head = NULL, *tail = NULL;
1774 	int allocbcount = 0;
1775 	int m_error;
1776 
1777 	TRACE_1(TR_ZSH, TR_ZSH_SOFT_START, "zsh_soft start: zs = %p", zs);
1778 
1779 	mutex_enter(zs->zs_excl);
1780 	zss = (struct syncline *)zs->zs_priv;
1781 	if (zss == NULL || (q = zss->sl_stream.str_rq) == NULL) {
1782 		mutex_exit(zs->zs_excl);
1783 		return (0);
1784 	}
1785 	m_error = zss->sl_m_error;
1786 
1787 	zss->sl_m_error = 0;
1788 
1789 
1790 	if (zss->sl_mstat == NULL)
1791 		zss->sl_mstat = allocb(sizeof (struct sl_status), BPRI_MED);
1792 
1793 	mutex_enter(zs->zs_excl_hi);
1794 	if (zss->sl_flags & SF_FLUSH_WQ) {
1795 		if (!(zss->sl_flags & SF_FDXPTP)) {
1796 			zss->sl_flags &= ~SF_FLUSH_WQ;
1797 		} else {
1798 			uchar_t s0;
1799 
1800 			s0 = SCC_READ0();
1801 			if (s0 & ZSRR0_CTS) {
1802 				zss->sl_rr0 |= ZSRR0_CTS;
1803 				SCC_BIS(15, ZSR15_CTS);
1804 				zss->sl_flags &= ~SF_FLUSH_WQ;
1805 				zsh_setmstat(zs, CS_CTS_UP);
1806 			}
1807 			if (zss->sl_flags & SF_FLUSH_WQ) {
1808 				mutex_exit(zs->zs_excl_hi);
1809 				flushq(WR(q), FLUSHDATA);
1810 				goto next;
1811 			}
1812 		}
1813 	}
1814 	mutex_exit(zs->zs_excl_hi);
1815 
1816 next:
1817 	for (;;) {
1818 		ZSH_GETQ(mp);
1819 		if (mp == NULL)
1820 			break;
1821 
1822 		if (mp->b_rptr == mp->b_wptr) {
1823 			if (mp->b_datap->db_type == M_RSE) {
1824 				allocbcount++;
1825 			}
1826 			freemsg(mp);
1827 			continue;
1828 		}
1829 		if (mp->b_datap->db_type == M_DATA) {
1830 			zss->sl_st.ichar += msgdsize(mp);
1831 			zss->sl_st.ipack++;
1832 			if (!(canputnext(q))) {
1833 				zss->sl_st.ierror++;
1834 				allocbcount++;
1835 				freemsg(mp);
1836 				continue;
1837 			}
1838 		} else if (mp->b_datap->db_type == M_PROTO) {
1839 			if (!(canputnext(q))) {
1840 				freemsg(mp);
1841 				continue;
1842 			}
1843 		}
1844 		if (head == NULL) {
1845 			allocbcount++;
1846 			zss->sl_soft_active = 1;
1847 			head = mp;
1848 		} else {
1849 			if (tail == NULL)
1850 				tail = head;
1851 			tail->b_next = mp;
1852 			tail = mp;
1853 		}
1854 	}
1855 	if (allocbcount)
1856 		ZSH_GETBLOCK(zs, allocbcount);
1857 
1858 	tmp = NULL;
1859 again:
1860 	mutex_enter(zs->zs_excl_hi);
1861 	if (zss->sl_xstandby == NULL) {
1862 		if (tmp) {
1863 			zss->sl_xstandby = tmp;
1864 			mutex_exit(zs->zs_excl_hi);
1865 		} else {
1866 			mutex_exit(zs->zs_excl_hi);
1867 			if (tmp = getq(WR(q)))
1868 				goto again;
1869 		}
1870 	} else {
1871 		mutex_exit(zs->zs_excl_hi);
1872 		if (tmp)
1873 			(void) putbq(WR(q), tmp);
1874 	}
1875 
1876 	mutex_exit(zs->zs_excl);
1877 
1878 	while (head) {
1879 		if (tail == NULL) {
1880 			putnext(q, head);
1881 			break;
1882 		}
1883 		mp = head;
1884 		head = head->b_next;
1885 		mp->b_next = NULL;
1886 		putnext(q, mp);
1887 
1888 	}
1889 
1890 	if (m_error)
1891 		(void) putnextctl1(q, M_ERROR, m_error);
1892 
1893 	zss->sl_soft_active = 0;
1894 
1895 	TRACE_1(TR_ZSH, TR_ZSH_SOFT_END, "zsh_soft end: zs = %p", zs);
1896 
1897 	return (0);
1898 }
1899 
1900 /*
1901  * Initialization routine.
1902  * Sets Clock sources, baud rate, modes and miscellaneous parameters.
1903  */
1904 static int
1905 zsh_program(struct zscom *zs, struct scc_mode *sm)
1906 {
1907 	struct syncline *zss  = (struct syncline *)&zs->zs_priv_str;
1908 	struct zs_prog *zspp;
1909 	ushort_t	tconst = 0;
1910 	int	wr11 = 0;
1911 	int	baud = 0;
1912 	int	pll = 0;
1913 	int	speed = 0;
1914 	int	flags = ZSP_SYNC;
1915 	int		err = 0;
1916 
1917 	ZSSETSOFT(zs); /* get our house in order */
1918 
1919 	switch (sm->sm_txclock) {
1920 	case TXC_IS_TXC:
1921 		wr11 |= ZSWR11_TXCLK_TRXC;
1922 		break;
1923 	case TXC_IS_RXC:
1924 		wr11 |= ZSWR11_TXCLK_RTXC;
1925 		break;
1926 	case TXC_IS_BAUD:
1927 		wr11 |= ZSWR11_TXCLK_BAUD;
1928 		wr11 |= ZSWR11_TRXC_OUT_ENA + ZSWR11_TRXC_XMIT;
1929 		baud++;
1930 		break;
1931 	case TXC_IS_PLL:
1932 		wr11 |= ZSWR11_TXCLK_DPLL;
1933 		pll++;
1934 		break;
1935 	default:
1936 		zss->sl_mode.sm_retval = SMERR_TXC;
1937 		err = EINVAL;
1938 		goto out;
1939 	}
1940 	switch (sm->sm_rxclock) {
1941 	case RXC_IS_RXC:
1942 		wr11 |= ZSWR11_RXCLK_RTXC;
1943 		break;
1944 	case RXC_IS_TXC:
1945 		wr11 |= ZSWR11_RXCLK_TRXC;
1946 		break;
1947 	case RXC_IS_BAUD:
1948 		wr11 |= ZSWR11_RXCLK_BAUD;
1949 		baud++;
1950 		break;
1951 	case RXC_IS_PLL:
1952 		wr11 |= ZSWR11_RXCLK_DPLL;
1953 		pll++;
1954 		break;
1955 	default:
1956 		zss->sl_mode.sm_retval = SMERR_RXC;
1957 		err = EINVAL;
1958 		goto out;
1959 	}
1960 	if (baud && pll) {
1961 		zss->sl_mode.sm_retval = SMERR_PLL;
1962 		err = EINVAL;
1963 		goto out;
1964 	}
1965 	if (pll && !(sm->sm_config & CONN_NRZI)) {
1966 		zss->sl_mode.sm_retval = SMERR_PLL;
1967 		err = EINVAL;
1968 		goto out;
1969 	}
1970 
1971 	/*
1972 	 * If we're going to use the BRG and the speed we want is != 0...
1973 	 */
1974 	if (baud && (speed = sm->sm_baudrate)) {
1975 		tconst = (PCLK + speed) / (2 * speed) - 2;
1976 		if (tconst == 0) {
1977 			zss->sl_mode.sm_retval = SMERR_BAUDRATE;
1978 			err = EINVAL;
1979 			goto out;
1980 		}
1981 		sm->sm_baudrate = PCLK / (2 * ((int)tconst + 2));
1982 	} else {
1983 		tconst = 0;	/* Stop BRG.  Also quiesces pin 24. */
1984 	}
1985 
1986 	if (pll) {
1987 		if ((speed  = sm->sm_baudrate * 32) != 0)
1988 			tconst = (PCLK + speed) / (2 * speed) - 2;
1989 		else
1990 			tconst = 0;
1991 		if (tconst == 0) {
1992 			zss->sl_mode.sm_retval = SMERR_BAUDRATE;
1993 			err = EINVAL;
1994 			goto out;
1995 		}
1996 		speed = PCLK / (2 * ((int)tconst + 2));
1997 		sm->sm_baudrate = speed / 32;
1998 		flags |= ZSP_PLL;
1999 	}
2000 
2001 	if ((sm->sm_config & (CONN_LPBK|CONN_ECHO)) == (CONN_LPBK|CONN_ECHO)) {
2002 		zss->sl_mode.sm_retval = SMERR_LPBKS;
2003 		err = EINVAL;
2004 		goto out;
2005 	}
2006 	if (sm->sm_config & CONN_LPBK)
2007 		flags |= ZSP_LOOP;
2008 	if (sm->sm_config & CONN_NRZI)
2009 		flags |= ZSP_NRZI;
2010 	if (sm->sm_config & CONN_ECHO)
2011 		flags |= ZSP_ECHO;
2012 
2013 	zspp = &zs_prog[zs->zs_unit];
2014 
2015 	zspp->zs = zs;
2016 	zspp->flags = (uchar_t)flags;
2017 	zspp->wr4 = ZSWR4_SDLC;
2018 	zspp->wr11 = (uchar_t)wr11;
2019 	zspp->wr12 = (uchar_t)(tconst & 0xff);
2020 	zspp->wr13 = (uchar_t)((tconst >> 8) & 0xff);
2021 	zspp->wr3 = (uchar_t)(ZSWR3_RX_ENABLE | ZSWR3_RXCRC_ENABLE |
2022 	    ZSWR3_RX_8);
2023 	zspp->wr5 = (uchar_t)(ZSWR5_TX_8 | ZSWR5_DTR | ZSWR5_TXCRC_ENABLE);
2024 
2025 	if (zss->sl_flags & SF_FDXPTP) {
2026 		zspp->wr5 |= ZSWR5_RTS;
2027 		zss->sl_rr0 |= ZSRR0_CTS;		/* Assume CTS is high */
2028 	}
2029 	if (sm->sm_config & CONN_IBM) {
2030 		zspp->wr15 = (uchar_t)
2031 		    (ZSR15_TX_UNDER | ZSR15_BREAK | ZSR15_SYNC | ZSR15_CTS);
2032 		if (!(zss->sl_flags & SF_FDXPTP))
2033 			zspp->wr15 &= ~ZSR15_CTS;
2034 	} else {
2035 		zspp->wr5 |= ZSWR5_TX_ENABLE;
2036 		zspp->wr15 = (uchar_t)
2037 		    (ZSR15_TX_UNDER | ZSR15_BREAK | ZSR15_SYNC);
2038 		if (sm->sm_config & CONN_SIGNAL)
2039 			zspp->wr15 |= ZSR15_CTS;
2040 	}
2041 
2042 	zs_program(zspp);
2043 	SCC_WRITE0(ZSWR0_RESET_STATUS);		/* reset XS */
2044 	SCC_WRITE0(ZSWR0_RESET_STATUS);		/* reset XS */
2045 	zss->sl_flags |= SF_INITIALIZED;
2046 	bzero(&zss->sl_st, sizeof (struct sl_stats));
2047 	bcopy(sm, &zss->sl_mode, sizeof (struct scc_mode));
2048 	zss->sl_mode.sm_retval = 0;	/* successful */
2049 out:
2050 	return (err);
2051 }
2052 
2053 /*
2054  * Function to store modem signal changes in sl_mstat field.
2055  * Note that these events are supposed to be so far apart in time that
2056  * we should always be able to send up the event and allocate a message
2057  * block before another one happens.  If not, we'll overwrite this one.
2058  */
2059 static void
2060 zsh_setmstat(struct zscom *zs, int event)
2061 {
2062 	struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
2063 	struct sl_status *mstat;
2064 	mblk_t *mp;
2065 
2066 	if (((mp = zss->sl_mstat) != NULL) &&
2067 	    (zss->sl_mode.sm_config & (CONN_SIGNAL))) {
2068 		mstat = (struct sl_status *)mp->b_wptr;
2069 		mstat->type = (zss->sl_mode.sm_config & CONN_IBM) ?
2070 		    SLS_LINKERR : SLS_MDMSTAT;
2071 		mstat->status = event;
2072 		gethrestime(&mstat->tstamp);
2073 		mp->b_wptr += sizeof (struct sl_status);
2074 		mp->b_datap->db_type = M_PROTO;
2075 		ZSH_PUTQ(mp);
2076 		zss->sl_mstat = NULL;
2077 		ZSSETSOFT(zs);
2078 	}
2079 }
2080 
2081 /*
2082  * Received Bad Frame procedure
2083  */
2084 static void
2085 zsh_rxbad(struct zscom *zs, struct syncline *zss)
2086 {
2087 	/*
2088 	 * swallow bad characters
2089 	 */
2090 	(void) SCC_READDATA();
2091 	(void) SCC_READDATA();
2092 	(void) SCC_READDATA();
2093 
2094 	SCC_BIS(3, ZSWR3_HUNT);	/* enter hunt mode - ignores rest of frame */
2095 
2096 	zss->sl_st.ierror++;
2097 
2098 	/*
2099 	 * Free active receive message.
2100 	 */
2101 	if (zss->sl_rhead) {
2102 		zss->sl_rhead->b_wptr = zss->sl_rhead->b_rptr;
2103 		zss->sl_rhead->b_datap->db_type = M_RSE;
2104 		ZSH_FREEMSG(zss->sl_rhead);
2105 		zss->sl_ractb = NULL;
2106 		zs->zs_rd_cur = NULL;
2107 		zs->zs_rd_lim = NULL;
2108 	}
2109 	if (zss->sl_rhead) {
2110 		zss->sl_rhead = NULL;
2111 		ZSH_ALLOCB(zss->sl_ractb);
2112 		zs->zs_rd_cur = NULL;
2113 		zs->zs_rd_lim = NULL;
2114 	}
2115 
2116 	ZSSETSOFT(zs);
2117 }
2118 
2119 /*
2120  * Transmit error procedure
2121  */
2122 static void
2123 zsh_txbad(struct zscom *zs, struct syncline *zss)
2124 {
2125 	if (zss->sl_xhead) {		/* free the message we were sending */
2126 		zss->sl_xhead->b_wptr = zss->sl_xhead->b_rptr;
2127 		ZSH_FREEMSG(zss->sl_xhead);
2128 		zss->sl_xactb = NULL;
2129 		zs->zs_wr_cur = NULL;
2130 		zs->zs_wr_lim = NULL;
2131 	}
2132 	zss->sl_xhead = NULL;
2133 
2134 	if (!(zss->sl_flags & SF_FDXPTP)) {
2135 		/*
2136 		 * drop RTS and our notion of CTS
2137 		 */
2138 		SCC_BIC(5, ZSWR5_RTS);
2139 		SCC_BIC(5, ZSWR5_TX_ENABLE);
2140 		zss->sl_rr0 &= ~ZSRR0_CTS;
2141 	}
2142 	zss->sl_txstate = TX_IDLE;
2143 	if (!(zss->sl_flags & SF_PHONY))
2144 		zss->sl_st.oerror++;
2145 }
2146 
2147 /*
2148  * Transmitter watchdog timeout routine
2149  */
2150 static void
2151 zsh_watchdog(void *arg)
2152 {
2153 	struct zscom *zs = arg;
2154 	struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
2155 	queue_t *wq;
2156 	mblk_t *mp;
2157 	int warning = 0;
2158 	uchar_t s0;
2159 	int do_flushwq = 0;
2160 
2161 	/*
2162 	 * The main reason for this routine is because, under some
2163 	 * circumstances, a transmit interrupt may get lost (ie., if
2164 	 * underrun occurs after the last character has been sent, and
2165 	 * the tx interrupt following the abort gets scheduled before
2166 	 * the current tx interrupt has been serviced).  Transmit can
2167 	 * also get hung if the cable is pulled out and the clock was
2168 	 * coming in from the modem.
2169 	 */
2170 
2171 	mutex_enter(zs->zs_excl);
2172 	if (zss->sl_stream.str_rq)
2173 		wq = WR(zss->sl_stream.str_rq);
2174 	else {
2175 		mutex_exit(zs->zs_excl);
2176 		return;		/* guard against close/callback race */
2177 	}
2178 
2179 	mutex_enter(zs->zs_excl_hi);
2180 	if (!(zss->sl_flags & SF_XMT_INPROG) && wq->q_first) {
2181 		zss->sl_flags |= SF_XMT_INPROG;
2182 		if ((zss->sl_flags & SF_FDXPTP) ||
2183 		    zsh_hdp_ok_or_rts_state(zs, zss))
2184 			(void) zsh_start(zs, zss);
2185 		goto end_watchdog;
2186 	}
2187 
2188 	if (zss->sl_wd_count-- > 0)
2189 		goto end_watchdog;
2190 
2191 	if (zss->sl_flags & SF_FLUSH_WQ) {
2192 		if (!(zss->sl_flags & SF_FDXPTP))
2193 			zss->sl_flags &= ~SF_FLUSH_WQ;
2194 		else {
2195 			s0 = SCC_READ0();
2196 			if (s0 & ZSRR0_CTS) {
2197 				zss->sl_rr0 |= ZSRR0_CTS;
2198 				SCC_BIS(15, ZSR15_CTS);
2199 				zss->sl_flags &= ~SF_FLUSH_WQ;
2200 				zsh_setmstat(zs, CS_CTS_UP);
2201 			}
2202 		}
2203 	}
2204 
2205 	switch (zss->sl_txstate) {
2206 
2207 	case TX_ABORTED:
2208 		/*
2209 		 * Transmitter was hung ... try restarting it.
2210 		 */
2211 		if (zss->sl_flags & SF_FDXPTP) {
2212 			zss->sl_flags |= SF_XMT_INPROG;
2213 			(void) zsh_start(zs, zss);
2214 		} else
2215 			do_flushwq = 1;
2216 		break;
2217 
2218 	case TX_ACTIVE:
2219 	case TX_CRC:
2220 		/*
2221 		 * Transmit is hung for some reason. Reset tx interrupt.
2222 		 * Flush transmit fifo by sending an abort command
2223 		 * which also sets the Underrun/EOM latch in WR0 and in
2224 		 * turn generates an External Status interrupt that
2225 		 * will reset the necessary message buffer pointers.
2226 		 * The watchdog timer will cycle again to allow the SCC
2227 		 * to settle down after the abort command.  The next
2228 		 * time through we'll see that the state is now TX_ABORTED
2229 		 * and call zsh_start to grab a new message.
2230 		 */
2231 		if (--zss->sl_wd_count <= 0) {
2232 			SCC_WRITE0(ZSWR0_SEND_ABORT);
2233 			SCC_WRITE0(ZSWR0_RESET_ERRORS);
2234 			SCC_WRITE0(ZSWR0_RESET_TXINT);
2235 			zsh_txbad(zs, zss);
2236 			zss->sl_txstate = TX_ABORTED; /* must be after txbad */
2237 			warning = 1;
2238 		}
2239 		break;
2240 
2241 	case TX_RTS:
2242 		/*
2243 		 * Timer expired after we raised RTS.  CTS never came up.
2244 		 */
2245 		zss->sl_st.cts++;
2246 
2247 		zsh_setmstat(zs, CS_CTS_TO);
2248 		zss->sl_flags &= ~SF_XMT_INPROG;
2249 		zss->sl_flags |= SF_FLUSH_WQ;
2250 		ZSSETSOFT(zs);
2251 		break;
2252 
2253 	default:
2254 		/*
2255 		 * If we time out in an inactive state we set a soft
2256 		 * interrupt.  This will call zsh_start which will
2257 		 * clear SF_XMT_INPROG if the queue is empty.
2258 		 */
2259 		break;
2260 	}
2261 end_watchdog:
2262 	if (zss->sl_txstate != TX_OFF) {
2263 		mutex_exit(zs->zs_excl_hi);
2264 		zss->sl_wd_id = timeout(zsh_watchdog, zs, SIO_WATCHDOG_TICK);
2265 	} else {
2266 		zss->sl_wd_id = 0;	/* safety */
2267 		mutex_exit(zs->zs_excl_hi);
2268 	}
2269 	if (warning || do_flushwq) {
2270 		flushq(wq, FLUSHDATA);
2271 		mutex_enter(zs->zs_excl_hi);
2272 		if ((mp = zss->sl_xstandby) != NULL)
2273 			zss->sl_xstandby = NULL;
2274 		mutex_exit(zs->zs_excl_hi);
2275 		if (mp)
2276 			freemsg(mp);
2277 	}
2278 	mutex_exit(zs->zs_excl);
2279 	if (warning)
2280 		cmn_err(CE_WARN, "zsh%x: transmit hung", zs->zs_unit);
2281 }
2282 
2283 static void
2284 zsh_callback(void *arg)
2285 {
2286 	struct zscom *zs = arg;
2287 	struct syncline *zss = (struct syncline *)&zs->zs_priv_str;
2288 	int tmp = ZSH_MAX_RSTANDBY;
2289 
2290 	mutex_enter(zs->zs_excl);
2291 	if (zss->sl_bufcid) {
2292 		zss->sl_bufcid = 0;
2293 		ZSH_GETBLOCK(zs, tmp);
2294 	}
2295 	mutex_exit(zs->zs_excl);
2296 }
2297