xref: /titanic_44/usr/src/uts/common/xen/io/xencons.c (revision f6e214c7418f43af38bd8c3a557e3d0a1d311cfa)
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 (c) 1990, 1991 UNIX System Laboratories, Inc.	*/
23 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989, 1990 AT&T	*/
24 /*	  All Rights Reserved					*/
25 
26 /*
27  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
28  * Use is subject to license terms.
29  */
30 
31 
32 /*
33  *
34  * Copyright (c) 2004 Christian Limpach.
35  * All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. This section intentionally left blank.
46  * 4. The name of the author may not be used to endorse or promote products
47  *    derived from this software without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
50  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
51  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
52  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
53  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
54  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
55  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
56  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
57  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
58  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
59  */
60 /*
61  * Section 3 of the above license was updated in response to bug 6379571.
62  */
63 
64 /*
65  * Hypervisor virtual console driver
66  */
67 
68 #include <sys/param.h>
69 #include <sys/types.h>
70 #include <sys/signal.h>
71 #include <sys/stream.h>
72 #include <sys/termio.h>
73 #include <sys/errno.h>
74 #include <sys/file.h>
75 #include <sys/cmn_err.h>
76 #include <sys/stropts.h>
77 #include <sys/strsubr.h>
78 #include <sys/strtty.h>
79 #include <sys/debug.h>
80 #include <sys/kbio.h>
81 #include <sys/cred.h>
82 #include <sys/stat.h>
83 #include <sys/consdev.h>
84 #include <sys/mkdev.h>
85 #include <sys/kmem.h>
86 #include <sys/cred.h>
87 #include <sys/strsun.h>
88 #ifdef DEBUG
89 #include <sys/promif.h>
90 #endif
91 #include <sys/modctl.h>
92 #include <sys/ddi.h>
93 #include <sys/sunddi.h>
94 #include <sys/sunndi.h>
95 #include <sys/policy.h>
96 #include <sys/atomic.h>
97 #include <sys/psm.h>
98 #include <xen/public/io/console.h>
99 
100 #include "xencons.h"
101 
102 #include <sys/hypervisor.h>
103 #include <sys/evtchn_impl.h>
104 #include <xen/sys/xenbus_impl.h>
105 #include <xen/sys/xendev.h>
106 
107 #ifdef DEBUG
108 #define	XENCONS_DEBUG_INIT	0x0001	/* msgs during driver initialization. */
109 #define	XENCONS_DEBUG_INPUT	0x0002	/* characters received during int. */
110 #define	XENCONS_DEBUG_EOT	0x0004	/* msgs when wait for xmit to finish. */
111 #define	XENCONS_DEBUG_CLOSE	0x0008	/* msgs when driver open/close called */
112 #define	XENCONS_DEBUG_PROCS	0x0020	/* each proc name as it is entered. */
113 #define	XENCONS_DEBUG_OUT	0x0100	/* msgs about output events. */
114 #define	XENCONS_DEBUG_BUSY	0x0200	/* msgs when xmit is enabled/disabled */
115 #define	XENCONS_DEBUG_MODEM	0x0400	/* msgs about modem status & control. */
116 #define	XENCONS_DEBUG_MODM2	0x0800	/* msgs about modem status & control. */
117 #define	XENCONS_DEBUG_IOCTL	0x1000	/* Output msgs about ioctl messages. */
118 #define	XENCONS_DEBUG_CHIP	0x2000	/* msgs about chip identification. */
119 #define	XENCONS_DEBUG_SFLOW	0x4000	/* msgs when S/W flowcontrol active */
120 #define	XENCONS_DEBUG(x) (debug & (x))
121 static int debug  = 0;
122 #else
123 #define	XENCONS_DEBUG(x) B_FALSE
124 #endif
125 
126 #define	XENCONS_WBUFSIZE	4096
127 
128 static boolean_t abort_charseq_recognize(uchar_t);
129 
130 /* The async interrupt entry points */
131 static void	xcasync_ioctl(struct asyncline *, queue_t *, mblk_t *);
132 static void	xcasync_reioctl(void *);
133 static void	xcasync_start(struct asyncline *);
134 static void	xenconsputchar(cons_polledio_arg_t, uchar_t);
135 static int	xenconsgetchar(cons_polledio_arg_t);
136 static boolean_t	xenconsischar(cons_polledio_arg_t);
137 
138 static uint_t	xenconsintr(caddr_t);
139 static uint_t	xenconsintr_priv(caddr_t);
140 /*PRINTFLIKE2*/
141 static void	xenconserror(int, const char *, ...) __KPRINTFLIKE(2);
142 static void	xencons_soft_state_free(struct xencons *);
143 static boolean_t
144 xcasync_flowcontrol_sw_input(struct xencons *, async_flowc_action, int);
145 static void
146 xcasync_flowcontrol_sw_output(struct xencons *, async_flowc_action);
147 
148 void		*xencons_soft_state;
149 char		*xencons_wbuf;
150 struct xencons	*xencons_console;
151 
152 static void
153 xenconssetup_avintr(struct xencons *xcp, int attach)
154 {
155 	/*
156 	 * On xen, CPU 0 always exists and can't be taken offline,
157 	 * so binding this thread to it should always succeed.
158 	 */
159 	mutex_enter(&cpu_lock);
160 	thread_affinity_set(curthread, 0);
161 	mutex_exit(&cpu_lock);
162 
163 	if (attach) {
164 		/* Setup our interrupt binding. */
165 		(void) add_avintr(NULL, IPL_CONS, (avfunc)xenconsintr_priv,
166 		    "xencons", xcp->console_irq, (caddr_t)xcp, NULL, NULL,
167 		    xcp->dip);
168 	} else {
169 		/*
170 		 * Cleanup interrupt configuration.  Note that the framework
171 		 * _should_ ensure that when rem_avintr() returns the interrupt
172 		 * service routine is not currently executing and that it won't
173 		 * be invoked again.
174 		 */
175 		(void) rem_avintr(NULL, IPL_CONS, (avfunc)xenconsintr_priv,
176 		    xcp->console_irq);
177 	}
178 
179 	/* Notify our caller that we're done. */
180 	mutex_enter(&xcp->excl);
181 	cv_signal(&xcp->excl_cv);
182 	mutex_exit(&xcp->excl);
183 
184 	/* Clear our binding to CPU 0 */
185 	thread_affinity_clear(curthread);
186 
187 }
188 
189 static void
190 xenconssetup_add_avintr(struct xencons *xcp)
191 {
192 	xenconssetup_avintr(xcp, B_TRUE);
193 }
194 
195 static void
196 xenconssetup_rem_avintr(struct xencons *xcp)
197 {
198 	xenconssetup_avintr(xcp, B_FALSE);
199 }
200 
201 static int
202 xenconsdetach(dev_info_t *devi, ddi_detach_cmd_t cmd)
203 {
204 	int instance;
205 	struct xencons *xcp;
206 
207 	if (cmd != DDI_DETACH && cmd != DDI_SUSPEND)
208 		return (DDI_FAILURE);
209 
210 	if (cmd == DDI_SUSPEND) {
211 		ddi_remove_intr(devi, 0, NULL);
212 		return (DDI_SUCCESS);
213 	}
214 
215 	/*
216 	 * We should never try to detach the console driver on a domU
217 	 * because it should always be held open
218 	 */
219 	ASSERT(DOMAIN_IS_INITDOMAIN(xen_info));
220 	if (!DOMAIN_IS_INITDOMAIN(xen_info))
221 		return (DDI_FAILURE);
222 
223 	instance = ddi_get_instance(devi);	/* find out which unit */
224 
225 	xcp = ddi_get_soft_state(xencons_soft_state, instance);
226 	if (xcp == NULL)
227 		return (DDI_FAILURE);
228 
229 	/*
230 	 * Cleanup our interrupt bindings.  For more info on why we
231 	 * do this in a seperate thread, see the comments for when we
232 	 * setup the interrupt bindings.
233 	 */
234 	xencons_console = NULL;
235 	mutex_enter(&xcp->excl);
236 	(void) taskq_dispatch(system_taskq,
237 	    (void (*)(void *))xenconssetup_rem_avintr, xcp, TQ_SLEEP);
238 	cv_wait(&xcp->excl_cv, &xcp->excl);
239 	mutex_exit(&xcp->excl);
240 
241 	/* remove all minor device node(s) for this device */
242 	ddi_remove_minor_node(devi, NULL);
243 
244 	/* free up state */
245 	xencons_soft_state_free(xcp);
246 	kmem_free(xencons_wbuf, XENCONS_WBUFSIZE);
247 
248 	DEBUGNOTE1(XENCONS_DEBUG_INIT, "xencons%d: shutdown complete",
249 	    instance);
250 	return (DDI_SUCCESS);
251 }
252 
253 static void
254 xenconssetup(struct xencons *xcp)
255 {
256 	xcp->ifp = (volatile struct xencons_interface *)HYPERVISOR_console_page;
257 
258 	if (DOMAIN_IS_INITDOMAIN(xen_info)) {
259 		xencons_wbuf = kmem_alloc(XENCONS_WBUFSIZE, KM_SLEEP);
260 
261 		/*
262 		 * Activate the xen console virq.  Note that xen requires
263 		 * that VIRQs be bound to CPU 0 when first created.
264 		 */
265 		xcp->console_irq = ec_bind_virq_to_irq(VIRQ_CONSOLE, 0);
266 
267 		/*
268 		 * Ok.  This is kinda ugly.  We want to register an
269 		 * interrupt handler for the xen console virq, but
270 		 * virq's are xen sepcific and currently the DDI doesn't
271 		 * support binding to them.  So instead we need to use
272 		 * add_avintr().  So to make things more complicated,
273 		 * we already had to bind the xen console VIRQ to CPU 0,
274 		 * and add_avintr() needs to be invoked on the same CPU
275 		 * where the VIRQ is bound, in this case on CPU 0.  We
276 		 * could just temporarily bind ourselves to CPU 0, but
277 		 * we don't want to do that since this attach thread
278 		 * could have been invoked in a user thread context,
279 		 * in which case this thread could already have some
280 		 * pre-existing cpu binding.  So to avoid changing our
281 		 * cpu binding we're going to use a taskq thread that
282 		 * will bind to CPU 0 and register our interrupts
283 		 * handler for us.
284 		 */
285 		mutex_enter(&xcp->excl);
286 		(void) taskq_dispatch(system_taskq,
287 		    (void (*)(void *))xenconssetup_add_avintr, xcp, TQ_SLEEP);
288 		cv_wait(&xcp->excl_cv, &xcp->excl);
289 		mutex_exit(&xcp->excl);
290 	} else {
291 		(void) xvdi_alloc_evtchn(xcp->dip);
292 		xcp->evtchn = xvdi_get_evtchn(xcp->dip);
293 		(void) ddi_add_intr(xcp->dip, 0, NULL, NULL, xenconsintr,
294 		    (caddr_t)xcp);
295 	}
296 }
297 
298 static int
299 xenconsattach(dev_info_t *devi, ddi_attach_cmd_t cmd)
300 {
301 	int instance = ddi_get_instance(devi);
302 	struct xencons *xcp;
303 	int ret;
304 
305 	/* There can be only one. */
306 	if (instance != 0)
307 		return (DDI_FAILURE);
308 
309 	switch (cmd) {
310 	case DDI_RESUME:
311 		xcp = xencons_console;
312 		xenconssetup(xcp);
313 		return (DDI_SUCCESS);
314 	case DDI_ATTACH:
315 		break;
316 	default:
317 		return (DDI_FAILURE);
318 	}
319 
320 	ret = ddi_soft_state_zalloc(xencons_soft_state, instance);
321 	if (ret != DDI_SUCCESS)
322 		return (DDI_FAILURE);
323 	xcp = ddi_get_soft_state(xencons_soft_state, instance);
324 	ASSERT(xcp != NULL);	/* can't fail - we only just allocated it */
325 
326 	/*
327 	 * Set up the other components of the xencons structure for this port.
328 	 */
329 	xcp->unit = instance;
330 	xcp->dip = devi;
331 
332 	/* Fill in the polled I/O structure. */
333 	xcp->polledio.cons_polledio_version = CONSPOLLEDIO_V0;
334 	xcp->polledio.cons_polledio_argument = (cons_polledio_arg_t)xcp;
335 	xcp->polledio.cons_polledio_putchar = xenconsputchar;
336 	xcp->polledio.cons_polledio_getchar = xenconsgetchar;
337 	xcp->polledio.cons_polledio_ischar = xenconsischar;
338 	xcp->polledio.cons_polledio_enter = NULL;
339 	xcp->polledio.cons_polledio_exit = NULL;
340 
341 	/*
342 	 * Initializes the asyncline structure which has TTY protocol-private
343 	 * data before enabling interrupts.
344 	 */
345 	xcp->priv = kmem_zalloc(sizeof (struct asyncline), KM_SLEEP);
346 	xcp->priv->async_common = xcp;
347 	cv_init(&xcp->priv->async_flags_cv, NULL, CV_DRIVER, NULL);
348 
349 	/* Initialize mutexes before accessing the interface. */
350 	mutex_init(&xcp->excl, NULL, MUTEX_DRIVER, NULL);
351 	cv_init(&xcp->excl_cv, NULL, CV_DEFAULT, NULL);
352 
353 	/* create minor device node for this device */
354 	ret = ddi_create_minor_node(devi, "xencons", S_IFCHR, instance,
355 	    DDI_NT_SERIAL, NULL);
356 	if (ret != DDI_SUCCESS) {
357 		ddi_remove_minor_node(devi, NULL);
358 		xencons_soft_state_free(xcp);
359 		return (DDI_FAILURE);
360 	}
361 
362 	ddi_report_dev(devi);
363 	xencons_console = xcp;
364 	xenconssetup(xcp);
365 	DEBUGCONT1(XENCONS_DEBUG_INIT, "xencons%dattach: done\n", instance);
366 	return (DDI_SUCCESS);
367 }
368 
369 /*ARGSUSED*/
370 static int
371 xenconsinfo(dev_info_t *dip, ddi_info_cmd_t infocmd, void *arg,
372 	void **result)
373 {
374 	dev_t dev = (dev_t)arg;
375 	int instance, error;
376 	struct xencons *xcp;
377 
378 	instance = getminor(dev);
379 	xcp = ddi_get_soft_state(xencons_soft_state, instance);
380 	if (xcp == NULL)
381 		return (DDI_FAILURE);
382 
383 	switch (infocmd) {
384 	case DDI_INFO_DEVT2DEVINFO:
385 		if (xcp->dip == NULL)
386 			error = DDI_FAILURE;
387 		else {
388 			*result = (void *) xcp->dip;
389 			error = DDI_SUCCESS;
390 		}
391 		break;
392 	case DDI_INFO_DEVT2INSTANCE:
393 		*result = (void *)(intptr_t)instance;
394 		error = DDI_SUCCESS;
395 		break;
396 	default:
397 		error = DDI_FAILURE;
398 	}
399 	return (error);
400 }
401 
402 /* xencons_soft_state_free - local wrapper for ddi_soft_state_free(9F) */
403 
404 static void
405 xencons_soft_state_free(struct xencons *xcp)
406 {
407 	mutex_destroy(&xcp->excl);
408 	cv_destroy(&xcp->excl_cv);
409 	kmem_free(xcp->priv, sizeof (struct asyncline));
410 	ddi_soft_state_free(xencons_soft_state, xcp->unit);
411 }
412 
413 /*ARGSUSED*/
414 static int
415 xenconsopen(queue_t *rq, dev_t *dev, int flag, int sflag, cred_t *cr)
416 {
417 	struct xencons	*xcp;
418 	struct asyncline *async;
419 	int		unit;
420 
421 	unit = getminor(*dev);
422 	DEBUGCONT1(XENCONS_DEBUG_CLOSE, "xencons%dopen\n", unit);
423 	xcp = ddi_get_soft_state(xencons_soft_state, unit);
424 	if (xcp == NULL)
425 		return (ENXIO);		/* unit not configured */
426 	async = xcp->priv;
427 	mutex_enter(&xcp->excl);
428 
429 again:
430 
431 	if ((async->async_flags & ASYNC_ISOPEN) == 0) {
432 		async->async_ttycommon.t_iflag = 0;
433 		async->async_ttycommon.t_iocpending = NULL;
434 		async->async_ttycommon.t_size.ws_row = 0;
435 		async->async_ttycommon.t_size.ws_col = 0;
436 		async->async_ttycommon.t_size.ws_xpixel = 0;
437 		async->async_ttycommon.t_size.ws_ypixel = 0;
438 		async->async_dev = *dev;
439 		async->async_wbufcid = 0;
440 
441 		async->async_startc = CSTART;
442 		async->async_stopc = CSTOP;
443 	} else if ((async->async_ttycommon.t_flags & TS_XCLUDE) &&
444 	    secpolicy_excl_open(cr) != 0) {
445 		mutex_exit(&xcp->excl);
446 		return (EBUSY);
447 	}
448 
449 	async->async_ttycommon.t_flags |= TS_SOFTCAR;
450 
451 	async->async_ttycommon.t_readq = rq;
452 	async->async_ttycommon.t_writeq = WR(rq);
453 	rq->q_ptr = WR(rq)->q_ptr = (caddr_t)async;
454 	mutex_exit(&xcp->excl);
455 	/*
456 	 * Caution here -- qprocson sets the pointers that are used by canput
457 	 * called by xencons_rxint.  ASYNC_ISOPEN must *not* be set until those
458 	 * pointers are valid.
459 	 */
460 	qprocson(rq);
461 	async->async_flags |= ASYNC_ISOPEN;
462 	DEBUGCONT1(XENCONS_DEBUG_INIT, "asy%dopen: done\n", unit);
463 	return (0);
464 }
465 
466 
467 /*
468  * Close routine.
469  */
470 /*ARGSUSED*/
471 static int
472 xenconsclose(queue_t *q, int flag, cred_t *credp)
473 {
474 	struct asyncline *async;
475 	struct xencons	 *xcp;
476 #ifdef DEBUG
477 	int instance;
478 #endif
479 
480 	async = (struct asyncline *)q->q_ptr;
481 	ASSERT(async != NULL);
482 	xcp = async->async_common;
483 #ifdef DEBUG
484 	instance = xcp->unit;
485 	DEBUGCONT1(XENCONS_DEBUG_CLOSE, "xencons%dclose\n", instance);
486 #endif
487 
488 	mutex_enter(&xcp->excl);
489 	async->async_flags |= ASYNC_CLOSING;
490 
491 	async->async_ocnt = 0;
492 	if (async->async_xmitblk != NULL)
493 		freeb(async->async_xmitblk);
494 	async->async_xmitblk = NULL;
495 
496 out:
497 	ttycommon_close(&async->async_ttycommon);
498 
499 	/*
500 	 * Cancel outstanding "bufcall" request.
501 	 */
502 	if (async->async_wbufcid != 0) {
503 		unbufcall(async->async_wbufcid);
504 		async->async_wbufcid = 0;
505 	}
506 
507 	/* Note that qprocsoff can't be done until after interrupts are off */
508 	qprocsoff(q);
509 	q->q_ptr = WR(q)->q_ptr = NULL;
510 	async->async_ttycommon.t_readq = NULL;
511 	async->async_ttycommon.t_writeq = NULL;
512 
513 	/*
514 	 * Clear out device state, except persistant device property flags.
515 	 */
516 	async->async_flags = 0;
517 	cv_broadcast(&async->async_flags_cv);
518 	mutex_exit(&xcp->excl);
519 
520 	DEBUGCONT1(XENCONS_DEBUG_CLOSE, "xencons%dclose: done\n", instance);
521 	return (0);
522 }
523 
524 #define	INBUF_IX(ix, ifp)	(DOMAIN_IS_INITDOMAIN(xen_info) ? \
525 	(ix) : MASK_XENCONS_IDX((ix), (ifp)->in))
526 
527 /*
528  * Handle a xen console rx interrupt.
529  */
530 /*ARGSUSED*/
531 static void
532 xencons_rxint(struct xencons *xcp)
533 {
534 	struct asyncline *async;
535 	short	cc;
536 	mblk_t	*bp;
537 	queue_t	*q;
538 	uchar_t	c, buf[16];
539 	uchar_t	*cp;
540 	tty_common_t	*tp;
541 	int instance;
542 	volatile struct xencons_interface *ifp;
543 	XENCONS_RING_IDX cons, prod;
544 
545 	DEBUGCONT0(XENCONS_DEBUG_PROCS, "xencons_rxint\n");
546 
547 loop:
548 	mutex_enter(&xcp->excl);
549 
550 	/* sanity check if we should bail */
551 	if (xencons_console == NULL) {
552 		mutex_exit(&xcp->excl);
553 		goto out;
554 	}
555 
556 	async = xcp->priv;
557 	instance = xcp->unit;
558 	ifp = xcp->ifp;
559 	tp = &async->async_ttycommon;
560 	q = tp->t_readq;
561 
562 	if (async->async_flags & ASYNC_OUT_FLW_RESUME) {
563 		xcasync_start(async);
564 		async->async_flags &= ~ASYNC_OUT_FLW_RESUME;
565 	}
566 
567 	/*
568 	 * If data is available, send it up the stream if there's
569 	 * somebody listening.
570 	 */
571 	if (!(async->async_flags & ASYNC_ISOPEN)) {
572 		mutex_exit(&xcp->excl);
573 		goto out;
574 	}
575 	if (DOMAIN_IS_INITDOMAIN(xen_info)) {
576 		cc = HYPERVISOR_console_io(CONSOLEIO_read, 16, (char *)buf);
577 		cp = buf;
578 		cons = 0;
579 	} else {
580 		cons = ifp->in_cons;
581 		prod = ifp->in_prod;
582 
583 		cc = prod - cons;
584 		cp = (uchar_t *)ifp->in;
585 	}
586 	if (cc <= 0) {
587 		mutex_exit(&xcp->excl);
588 		goto out;
589 	}
590 
591 	/*
592 	 * Check for character break sequence.
593 	 *
594 	 * Note that normally asy drivers only check for a character sequence
595 	 * if abort_enable == KIOCABORTALTERNATE and otherwise use a break
596 	 * sensed on the line to do an abort_sequence_enter.  Since the
597 	 * hypervisor does not use a real chip for the console we default to
598 	 * using the alternate sequence.
599 	 */
600 	if ((abort_enable == KIOCABORTENABLE) && (xcp->flags & ASY_CONSOLE)) {
601 		XENCONS_RING_IDX i;
602 
603 		for (i = 0; i < cc; i++) {
604 			c = cp[INBUF_IX(cons + i, ifp)];
605 			if (abort_charseq_recognize(c)) {
606 				/*
607 				 * Eat abort seg, it's not a valid debugger
608 				 * command.
609 				 */
610 				if (!DOMAIN_IS_INITDOMAIN(xen_info)) {
611 					membar_producer();
612 					ifp->in_cons = cons + i;
613 				} else {
614 					cons += i;
615 				}
616 				abort_sequence_enter((char *)NULL);
617 				/*
618 				 * Back from debugger, resume normal processing
619 				 */
620 				mutex_exit(&xcp->excl);
621 				goto loop;
622 			}
623 		}
624 	}
625 
626 	if (!canput(q)) {
627 		if (!(async->async_inflow_source & IN_FLOW_STREAMS)) {
628 			(void) xcasync_flowcontrol_sw_input(xcp, FLOW_STOP,
629 			    IN_FLOW_STREAMS);
630 		}
631 		mutex_exit(&xcp->excl);
632 		goto out;
633 	}
634 	if (async->async_inflow_source & IN_FLOW_STREAMS) {
635 		(void) xcasync_flowcontrol_sw_input(xcp, FLOW_START,
636 		    IN_FLOW_STREAMS);
637 	}
638 	DEBUGCONT2(XENCONS_DEBUG_INPUT,
639 	    "xencons%d_rxint: %d char(s) in queue.\n", instance, cc);
640 	if (!(bp = allocb(cc, BPRI_MED))) {
641 		mutex_exit(&xcp->excl);
642 		ttycommon_qfull(&async->async_ttycommon, q);
643 		goto out;
644 	}
645 	do {
646 		c = cp[INBUF_IX(cons++, ifp)];
647 		/*
648 		 * We handle XON/XOFF char if IXON is set,
649 		 * but if received char is _POSIX_VDISABLE,
650 		 * we left it to the up level module.
651 		 */
652 		if (tp->t_iflag & IXON) {
653 			if ((c == async->async_stopc) &&
654 			    (c != _POSIX_VDISABLE)) {
655 				xcasync_flowcontrol_sw_output(xcp, FLOW_STOP);
656 				continue;
657 			} else if ((c == async->async_startc) &&
658 			    (c != _POSIX_VDISABLE)) {
659 				xcasync_flowcontrol_sw_output(xcp, FLOW_START);
660 				continue;
661 			}
662 			if ((tp->t_iflag & IXANY) &&
663 			    (async->async_flags & ASYNC_SW_OUT_FLW)) {
664 				xcasync_flowcontrol_sw_output(xcp, FLOW_START);
665 			}
666 		}
667 		*bp->b_wptr++ = c;
668 	} while (--cc);
669 	membar_producer();
670 	if (!DOMAIN_IS_INITDOMAIN(xen_info))
671 		ifp->in_cons = cons;
672 	mutex_exit(&xcp->excl);
673 	if (bp->b_wptr > bp->b_rptr) {
674 		if (!canput(q)) {
675 			xenconserror(CE_NOTE, "xencons%d: local queue full",
676 			    instance);
677 			freemsg(bp);
678 		} else
679 			(void) putq(q, bp);
680 	} else
681 		freemsg(bp);
682 	if (DOMAIN_IS_INITDOMAIN(xen_info))
683 		goto loop;
684 out:
685 	DEBUGCONT1(XENCONS_DEBUG_PROCS, "xencons%d_rxint: done\n", instance);
686 	if (!DOMAIN_IS_INITDOMAIN(xen_info))
687 		ec_notify_via_evtchn(xcp->evtchn);
688 }
689 
690 
691 /*
692  * Handle a xen console tx interrupt.
693  */
694 /*ARGSUSED*/
695 static void
696 xencons_txint(struct xencons *xcp)
697 {
698 	struct asyncline *async;
699 
700 	DEBUGCONT0(XENCONS_DEBUG_PROCS, "xencons_txint\n");
701 
702 	/*
703 	 * prevent recursive entry
704 	 */
705 	if (mutex_owner(&xcp->excl) == curthread) {
706 		goto out;
707 	}
708 
709 	mutex_enter(&xcp->excl);
710 	if (xencons_console == NULL) {
711 		mutex_exit(&xcp->excl);
712 		goto out;
713 	}
714 
715 	/* make sure the device is open */
716 	async = xcp->priv;
717 	if ((async->async_flags & ASYNC_ISOPEN) != 0)
718 		xcasync_start(async);
719 
720 	mutex_exit(&xcp->excl);
721 out:
722 	DEBUGCONT0(XENCONS_DEBUG_PROCS, "xencons_txint: done\n");
723 }
724 
725 
726 /*
727  * Get an event when input ring becomes not empty or output ring becomes not
728  * full.
729  */
730 static uint_t
731 xenconsintr(caddr_t arg)
732 {
733 	struct xencons *xcp = (struct xencons *)arg;
734 	volatile struct xencons_interface *ifp = xcp->ifp;
735 
736 	if (ifp->in_prod != ifp->in_cons)
737 		xencons_rxint(xcp);
738 	if (ifp->out_prod - ifp->out_cons < sizeof (ifp->out))
739 		xencons_txint(xcp);
740 	return (DDI_INTR_CLAIMED);
741 }
742 
743 /*
744  * Console interrupt routine for priviliged domains
745  */
746 static uint_t
747 xenconsintr_priv(caddr_t arg)
748 {
749 	struct xencons *xcp = (struct xencons *)arg;
750 
751 	xencons_rxint(xcp);
752 	xencons_txint(xcp);
753 	return (DDI_INTR_CLAIMED);
754 }
755 
756 /*
757  * Start output on a line, unless it's busy, frozen, or otherwise.
758  */
759 /*ARGSUSED*/
760 static void
761 xcasync_start(struct asyncline *async)
762 {
763 	struct xencons *xcp = async->async_common;
764 	int cc;
765 	queue_t *q;
766 	mblk_t *bp;
767 	int	len, space, blen;
768 	mblk_t *nbp;
769 
770 #ifdef DEBUG
771 	int instance = xcp->unit;
772 
773 	DEBUGCONT1(XENCONS_DEBUG_PROCS, "async%d_nstart\n", instance);
774 #endif
775 	ASSERT(mutex_owned(&xcp->excl));
776 
777 	/*
778 	 * Check only pended sw input flow control.
779 	 */
780 domore:
781 	(void) xcasync_flowcontrol_sw_input(xcp, FLOW_CHECK, IN_FLOW_NULL);
782 
783 	if ((q = async->async_ttycommon.t_writeq) == NULL) {
784 		return;	/* not attached to a stream */
785 	}
786 
787 	for (;;) {
788 		if ((bp = getq(q)) == NULL)
789 			return;	/* no data to transmit */
790 
791 		/*
792 		 * We have a message block to work on.
793 		 * Check whether it's a break, a delay, or an ioctl (the latter
794 		 * occurs if the ioctl in question was waiting for the output
795 		 * to drain).  If it's one of those, process it immediately.
796 		 */
797 		switch (bp->b_datap->db_type) {
798 
799 		case M_IOCTL:
800 			/*
801 			 * This ioctl was waiting for the output ahead of
802 			 * it to drain; obviously, it has.  Do it, and
803 			 * then grab the next message after it.
804 			 */
805 			mutex_exit(&xcp->excl);
806 			xcasync_ioctl(async, q, bp);
807 			mutex_enter(&xcp->excl);
808 			continue;
809 		}
810 
811 		while (bp != NULL && (cc = bp->b_wptr - bp->b_rptr) == 0) {
812 			nbp = bp->b_cont;
813 			freeb(bp);
814 			bp = nbp;
815 		}
816 		if (bp != NULL)
817 			break;
818 	}
819 
820 	/*
821 	 * We have data to transmit.  If output is stopped, put
822 	 * it back and try again later.
823 	 */
824 	if (async->async_flags & (ASYNC_SW_OUT_FLW | ASYNC_STOPPED)) {
825 		(void) putbq(q, bp);
826 		return;
827 	}
828 
829 
830 	if (DOMAIN_IS_INITDOMAIN(xen_info)) {
831 		len = 0;
832 		space = XENCONS_WBUFSIZE;
833 		while (bp != NULL && space) {
834 			blen = bp->b_wptr - bp->b_rptr;
835 			cc = min(blen, space);
836 			bcopy(bp->b_rptr, &xencons_wbuf[len], cc);
837 			bp->b_rptr += cc;
838 			if (cc == blen) {
839 				nbp = bp->b_cont;
840 				freeb(bp);
841 				bp = nbp;
842 			}
843 			space -= cc;
844 			len += cc;
845 		}
846 		mutex_exit(&xcp->excl);
847 		(void) HYPERVISOR_console_io(CONSOLEIO_write, len,
848 		    xencons_wbuf);
849 		mutex_enter(&xcp->excl);
850 		if (bp != NULL)
851 			(void) putbq(q, bp); /* not done with this msg yet */
852 		/*
853 		 * There are no completion interrupts when using the
854 		 * HYPERVISOR_console_io call to write console data
855 		 * so we loop here till we have sent all the data to the
856 		 * hypervisor.
857 		 */
858 		goto domore;
859 	} else {
860 		volatile struct xencons_interface *ifp = xcp->ifp;
861 		XENCONS_RING_IDX cons, prod;
862 
863 		cons = ifp->out_cons;
864 		prod = ifp->out_prod;
865 		membar_enter();
866 		while (bp != NULL && ((prod - cons) < sizeof (ifp->out))) {
867 			ifp->out[MASK_XENCONS_IDX(prod++, ifp->out)] =
868 			    *bp->b_rptr++;
869 			if (bp->b_rptr == bp->b_wptr) {
870 				nbp = bp->b_cont;
871 				freeb(bp);
872 				bp = nbp;
873 			}
874 		}
875 		membar_producer();
876 		ifp->out_prod = prod;
877 		ec_notify_via_evtchn(xcp->evtchn);
878 		if (bp != NULL)
879 			(void) putbq(q, bp); /* not done with this msg yet */
880 	}
881 }
882 
883 
884 /*
885  * Process an "ioctl" message sent down to us.
886  * Note that we don't need to get any locks until we are ready to access
887  * the hardware.  Nothing we access until then is going to be altered
888  * outside of the STREAMS framework, so we should be safe.
889  */
890 static void
891 xcasync_ioctl(struct asyncline *async, queue_t *wq, mblk_t *mp)
892 {
893 	struct xencons *xcp = async->async_common;
894 	tty_common_t  *tp = &async->async_ttycommon;
895 	struct iocblk *iocp;
896 	unsigned datasize;
897 	int error = 0;
898 
899 #ifdef DEBUG
900 	int instance = xcp->unit;
901 
902 	DEBUGCONT1(XENCONS_DEBUG_PROCS, "async%d_ioctl\n", instance);
903 #endif
904 
905 	if (tp->t_iocpending != NULL) {
906 		/*
907 		 * We were holding an "ioctl" response pending the
908 		 * availability of an "mblk" to hold data to be passed up;
909 		 * another "ioctl" came through, which means that "ioctl"
910 		 * must have timed out or been aborted.
911 		 */
912 		freemsg(async->async_ttycommon.t_iocpending);
913 		async->async_ttycommon.t_iocpending = NULL;
914 	}
915 
916 	iocp = (struct iocblk *)mp->b_rptr;
917 
918 	/*
919 	 * For TIOCMGET and the PPS ioctls, do NOT call ttycommon_ioctl()
920 	 * because this function frees up the message block (mp->b_cont) that
921 	 * contains the user location where we pass back the results.
922 	 *
923 	 * Similarly, CONSOPENPOLLEDIO needs ioc_count, which ttycommon_ioctl
924 	 * zaps.  We know that ttycommon_ioctl doesn't know any CONS*
925 	 * ioctls, so keep the others safe too.
926 	 */
927 	DEBUGCONT2(XENCONS_DEBUG_IOCTL, "async%d_ioctl: %s\n",
928 	    instance,
929 	    iocp->ioc_cmd == TIOCMGET ? "TIOCMGET" :
930 	    iocp->ioc_cmd == TIOCMSET ? "TIOCMSET" :
931 	    iocp->ioc_cmd == TIOCMBIS ? "TIOCMBIS" :
932 	    iocp->ioc_cmd == TIOCMBIC ? "TIOCMBIC" : "other");
933 
934 	switch (iocp->ioc_cmd) {
935 	case TIOCMGET:
936 	case TIOCGPPS:
937 	case TIOCSPPS:
938 	case TIOCGPPSEV:
939 	case CONSOPENPOLLEDIO:
940 	case CONSCLOSEPOLLEDIO:
941 	case CONSSETABORTENABLE:
942 	case CONSGETABORTENABLE:
943 		error = -1; /* Do Nothing */
944 		break;
945 	default:
946 
947 		/*
948 		 * The only way in which "ttycommon_ioctl" can fail is if the
949 		 * "ioctl" requires a response containing data to be returned
950 		 * to the user, and no mblk could be allocated for the data.
951 		 * No such "ioctl" alters our state.  Thus, we always go ahead
952 		 * and do any state-changes the "ioctl" calls for.  If we
953 		 * couldn't allocate the data, "ttycommon_ioctl" has stashed
954 		 * the "ioctl" away safely, so we just call "bufcall" to
955 		 * request that we be called back when we stand a better
956 		 * chance of allocating the data.
957 		 */
958 		if ((datasize = ttycommon_ioctl(tp, wq, mp, &error)) != 0) {
959 			if (async->async_wbufcid)
960 				unbufcall(async->async_wbufcid);
961 			async->async_wbufcid = bufcall(datasize, BPRI_HI,
962 			    (void (*)(void *)) xcasync_reioctl,
963 			    (void *)(intptr_t)async->async_common->unit);
964 			return;
965 		}
966 	}
967 
968 	mutex_enter(&xcp->excl);
969 
970 	if (error == 0) {
971 		/*
972 		 * "ttycommon_ioctl" did most of the work; we just use the
973 		 * data it set up.
974 		 */
975 		switch (iocp->ioc_cmd) {
976 
977 		case TCSETS:
978 		case TCSETSF:
979 		case TCSETSW:
980 		case TCSETA:
981 		case TCSETAW:
982 		case TCSETAF:
983 			break;
984 		}
985 	} else if (error < 0) {
986 		/*
987 		 * "ttycommon_ioctl" didn't do anything; we process it here.
988 		 */
989 		error = 0;
990 		switch (iocp->ioc_cmd) {
991 
992 		case TCSBRK:
993 			error = miocpullup(mp, sizeof (int));
994 			break;
995 
996 		case TIOCSBRK:
997 			mioc2ack(mp, NULL, 0, 0);
998 			break;
999 
1000 		case TIOCCBRK:
1001 			mioc2ack(mp, NULL, 0, 0);
1002 			break;
1003 
1004 		case CONSOPENPOLLEDIO:
1005 			error = miocpullup(mp, sizeof (cons_polledio_arg_t));
1006 			if (error != 0)
1007 				break;
1008 
1009 			*(cons_polledio_arg_t *)mp->b_cont->b_rptr =
1010 			    (cons_polledio_arg_t)&xcp->polledio;
1011 
1012 			mp->b_datap->db_type = M_IOCACK;
1013 			break;
1014 
1015 		case CONSCLOSEPOLLEDIO:
1016 			mp->b_datap->db_type = M_IOCACK;
1017 			iocp->ioc_error = 0;
1018 			iocp->ioc_rval = 0;
1019 			break;
1020 
1021 		case CONSSETABORTENABLE:
1022 			error = secpolicy_console(iocp->ioc_cr);
1023 			if (error != 0)
1024 				break;
1025 
1026 			if (iocp->ioc_count != TRANSPARENT) {
1027 				error = EINVAL;
1028 				break;
1029 			}
1030 
1031 			if (*(intptr_t *)mp->b_cont->b_rptr)
1032 				xcp->flags |= ASY_CONSOLE;
1033 			else
1034 				xcp->flags &= ~ASY_CONSOLE;
1035 
1036 			mp->b_datap->db_type = M_IOCACK;
1037 			iocp->ioc_error = 0;
1038 			iocp->ioc_rval = 0;
1039 			break;
1040 
1041 		case CONSGETABORTENABLE:
1042 			/*CONSTANTCONDITION*/
1043 			ASSERT(sizeof (boolean_t) <= sizeof (boolean_t *));
1044 			/*
1045 			 * Store the return value right in the payload
1046 			 * we were passed.  Crude.
1047 			 */
1048 			mcopyout(mp, NULL, sizeof (boolean_t), NULL, NULL);
1049 			*(boolean_t *)mp->b_cont->b_rptr =
1050 			    (xcp->flags & ASY_CONSOLE) != 0;
1051 			break;
1052 
1053 		default:
1054 			/*
1055 			 * If we don't understand it, it's an error.  NAK it.
1056 			 */
1057 			error = EINVAL;
1058 			break;
1059 		}
1060 	}
1061 	if (error != 0) {
1062 		iocp->ioc_error = error;
1063 		mp->b_datap->db_type = M_IOCNAK;
1064 	}
1065 	mutex_exit(&xcp->excl);
1066 	qreply(wq, mp);
1067 	DEBUGCONT1(XENCONS_DEBUG_PROCS, "async%d_ioctl: done\n", instance);
1068 }
1069 
1070 static int
1071 xenconsrsrv(queue_t *q)
1072 {
1073 	mblk_t *bp;
1074 
1075 	while (canputnext(q) && (bp = getq(q)))
1076 		putnext(q, bp);
1077 	return (0);
1078 }
1079 
1080 /*
1081  * Put procedure for write queue.
1082  * Respond to M_STOP, M_START, M_IOCTL, and M_FLUSH messages here;
1083  * set the flow control character for M_STOPI and M_STARTI messages;
1084  * queue up M_BREAK, M_DELAY, and M_DATA messages for processing
1085  * by the start routine, and then call the start routine; discard
1086  * everything else.  Note that this driver does not incorporate any
1087  * mechanism to negotiate to handle the canonicalization process.
1088  * It expects that these functions are handled in upper module(s),
1089  * as we do in ldterm.
1090  */
1091 static int
1092 xenconswput(queue_t *q, mblk_t *mp)
1093 {
1094 	struct asyncline *async;
1095 	struct xencons *xcp;
1096 
1097 	async = (struct asyncline *)q->q_ptr;
1098 	xcp = async->async_common;
1099 
1100 	switch (mp->b_datap->db_type) {
1101 
1102 	case M_STOP:
1103 		mutex_enter(&xcp->excl);
1104 		async->async_flags |= ASYNC_STOPPED;
1105 		mutex_exit(&xcp->excl);
1106 		freemsg(mp);
1107 		break;
1108 
1109 	case M_START:
1110 		mutex_enter(&xcp->excl);
1111 		if (async->async_flags & ASYNC_STOPPED) {
1112 			async->async_flags &= ~ASYNC_STOPPED;
1113 			xcasync_start(async);
1114 		}
1115 		mutex_exit(&xcp->excl);
1116 		freemsg(mp);
1117 		break;
1118 
1119 	case M_IOCTL:
1120 		switch (((struct iocblk *)mp->b_rptr)->ioc_cmd) {
1121 
1122 		case TCSETSW:
1123 		case TCSETSF:
1124 		case TCSETAW:
1125 		case TCSETAF:
1126 			/*
1127 			 * The changes do not take effect until all
1128 			 * output queued before them is drained.
1129 			 * Put this message on the queue, so that
1130 			 * "xcasync_start" will see it when it's done
1131 			 * with the output before it.  Poke the
1132 			 * start routine, just in case.
1133 			 */
1134 			(void) putq(q, mp);
1135 			mutex_enter(&xcp->excl);
1136 			xcasync_start(async);
1137 			mutex_exit(&xcp->excl);
1138 			break;
1139 
1140 		default:
1141 			/*
1142 			 * Do it now.
1143 			 */
1144 			xcasync_ioctl(async, q, mp);
1145 			break;
1146 		}
1147 		break;
1148 
1149 	case M_FLUSH:
1150 		if (*mp->b_rptr & FLUSHW) {
1151 			mutex_enter(&xcp->excl);
1152 			/*
1153 			 * Flush our write queue.
1154 			 */
1155 			flushq(q, FLUSHDATA);	/* XXX doesn't flush M_DELAY */
1156 			if (async->async_xmitblk != NULL) {
1157 				freeb(async->async_xmitblk);
1158 				async->async_xmitblk = NULL;
1159 			}
1160 			mutex_exit(&xcp->excl);
1161 			*mp->b_rptr &= ~FLUSHW;	/* it has been flushed */
1162 		}
1163 		if (*mp->b_rptr & FLUSHR) {
1164 			flushq(RD(q), FLUSHDATA);
1165 			qreply(q, mp);	/* give the read queues a crack at it */
1166 		} else {
1167 			freemsg(mp);
1168 		}
1169 
1170 		/*
1171 		 * We must make sure we process messages that survive the
1172 		 * write-side flush.
1173 		 */
1174 		mutex_enter(&xcp->excl);
1175 		xcasync_start(async);
1176 		mutex_exit(&xcp->excl);
1177 		break;
1178 
1179 	case M_BREAK:
1180 	case M_DELAY:
1181 	case M_DATA:
1182 		/*
1183 		 * Queue the message up to be transmitted,
1184 		 * and poke the start routine.
1185 		 */
1186 		(void) putq(q, mp);
1187 		mutex_enter(&xcp->excl);
1188 		xcasync_start(async);
1189 		mutex_exit(&xcp->excl);
1190 		break;
1191 
1192 	case M_STOPI:
1193 		mutex_enter(&xcp->excl);
1194 		mutex_enter(&xcp->excl);
1195 		if (!(async->async_inflow_source & IN_FLOW_USER)) {
1196 			(void) xcasync_flowcontrol_sw_input(xcp, FLOW_STOP,
1197 			    IN_FLOW_USER);
1198 		}
1199 		mutex_exit(&xcp->excl);
1200 		mutex_exit(&xcp->excl);
1201 		freemsg(mp);
1202 		break;
1203 
1204 	case M_STARTI:
1205 		mutex_enter(&xcp->excl);
1206 		mutex_enter(&xcp->excl);
1207 		if (async->async_inflow_source & IN_FLOW_USER) {
1208 			(void) xcasync_flowcontrol_sw_input(xcp, FLOW_START,
1209 			    IN_FLOW_USER);
1210 		}
1211 		mutex_exit(&xcp->excl);
1212 		mutex_exit(&xcp->excl);
1213 		freemsg(mp);
1214 		break;
1215 
1216 	case M_CTL:
1217 		if (MBLKL(mp) >= sizeof (struct iocblk) &&
1218 		    ((struct iocblk *)mp->b_rptr)->ioc_cmd == MC_POSIXQUERY) {
1219 			((struct iocblk *)mp->b_rptr)->ioc_cmd = MC_HAS_POSIX;
1220 			qreply(q, mp);
1221 		} else {
1222 			freemsg(mp);
1223 		}
1224 		break;
1225 
1226 	default:
1227 		freemsg(mp);
1228 		break;
1229 	}
1230 	return (0);
1231 }
1232 
1233 /*
1234  * Retry an "ioctl", now that "bufcall" claims we may be able to allocate
1235  * the buffer we need.
1236  */
1237 static void
1238 xcasync_reioctl(void *unit)
1239 {
1240 	int instance = (uintptr_t)unit;
1241 	struct asyncline *async;
1242 	struct xencons *xcp;
1243 	queue_t	*q;
1244 	mblk_t	*mp;
1245 
1246 	xcp = ddi_get_soft_state(xencons_soft_state, instance);
1247 	ASSERT(xcp != NULL);
1248 	async = xcp->priv;
1249 
1250 	/*
1251 	 * The bufcall is no longer pending.
1252 	 */
1253 	mutex_enter(&xcp->excl);
1254 	async->async_wbufcid = 0;
1255 	if ((q = async->async_ttycommon.t_writeq) == NULL) {
1256 		mutex_exit(&xcp->excl);
1257 		return;
1258 	}
1259 	if ((mp = async->async_ttycommon.t_iocpending) != NULL) {
1260 		/* not pending any more */
1261 		async->async_ttycommon.t_iocpending = NULL;
1262 		mutex_exit(&xcp->excl);
1263 		xcasync_ioctl(async, q, mp);
1264 	} else
1265 		mutex_exit(&xcp->excl);
1266 }
1267 
1268 
1269 /*
1270  * debugger/console support routines.
1271  */
1272 
1273 /*
1274  * put a character out
1275  * Do not use interrupts.  If char is LF, put out CR, LF.
1276  */
1277 /*ARGSUSED*/
1278 static void
1279 xenconsputchar(cons_polledio_arg_t arg, uchar_t c)
1280 {
1281 	struct xencons *xcp = xencons_console;
1282 	volatile struct xencons_interface *ifp = xcp->ifp;
1283 	XENCONS_RING_IDX prod;
1284 
1285 	if (c == '\n')
1286 		xenconsputchar(arg, '\r');
1287 
1288 	/*
1289 	 * domain 0 can use the console I/O...
1290 	 */
1291 	if (DOMAIN_IS_INITDOMAIN(xen_info)) {
1292 		char	buffer[1];
1293 
1294 		buffer[0] = c;
1295 		(void) HYPERVISOR_console_io(CONSOLEIO_write, 1, buffer);
1296 		return;
1297 	}
1298 
1299 	/*
1300 	 * domU has to go through dom0 virtual console.
1301 	 */
1302 	while (ifp->out_prod - ifp->out_cons == sizeof (ifp->out))
1303 		(void) HYPERVISOR_yield();
1304 
1305 	prod = ifp->out_prod;
1306 	ifp->out[MASK_XENCONS_IDX(prod++, ifp->out)] = c;
1307 	membar_producer();
1308 	ifp->out_prod = prod;
1309 	ec_notify_via_evtchn(xcp->evtchn);
1310 }
1311 
1312 /*
1313  * See if there's a character available. If no character is
1314  * available, return 0. Run in polled mode, no interrupts.
1315  */
1316 static boolean_t
1317 xenconsischar(cons_polledio_arg_t arg)
1318 {
1319 	struct xencons *xcp = (struct xencons *)arg;
1320 	volatile struct xencons_interface *ifp = xcp->ifp;
1321 
1322 	if (xcp->polldix < xcp->polllen)
1323 		return (B_TRUE);
1324 	/*
1325 	 * domain 0 can use the console I/O...
1326 	 */
1327 	xcp->polldix = 0;
1328 	xcp->polllen = 0;
1329 	if (DOMAIN_IS_INITDOMAIN(xen_info)) {
1330 		xcp->polllen = HYPERVISOR_console_io(CONSOLEIO_read, 1,
1331 		    (char *)xcp->pollbuf);
1332 		return (xcp->polllen != 0);
1333 	}
1334 
1335 	/*
1336 	 * domU has to go through virtual console device.
1337 	 */
1338 	if (ifp->in_prod != ifp->in_cons) {
1339 		XENCONS_RING_IDX cons;
1340 
1341 		cons = ifp->in_cons;
1342 		membar_enter();
1343 		xcp->pollbuf[0] = ifp->in[MASK_XENCONS_IDX(cons++, ifp->in)];
1344 		membar_producer();
1345 		ifp->in_cons = cons;
1346 		xcp->polllen = 1;
1347 	}
1348 	return (xcp->polllen != 0);
1349 }
1350 
1351 /*
1352  * Get a character. Run in polled mode, no interrupts.
1353  */
1354 static int
1355 xenconsgetchar(cons_polledio_arg_t arg)
1356 {
1357 	struct xencons *xcp = (struct xencons *)arg;
1358 
1359 	ec_wait_on_evtchn(xcp->evtchn, (int (*)(void *))xenconsischar, arg);
1360 
1361 	return (xcp->pollbuf[xcp->polldix++]);
1362 }
1363 
1364 static void
1365 xenconserror(int level, const char *fmt, ...)
1366 {
1367 	va_list adx;
1368 	static time_t	last;
1369 	static const char *lastfmt;
1370 	time_t now;
1371 
1372 	/*
1373 	 * Don't print the same error message too often.
1374 	 * Print the message only if we have not printed the
1375 	 * message within the last second.
1376 	 * Note: that fmt cannot be a pointer to a string
1377 	 * stored on the stack. The fmt pointer
1378 	 * must be in the data segment otherwise lastfmt would point
1379 	 * to non-sense.
1380 	 */
1381 	now = gethrestime_sec();
1382 	if (last == now && lastfmt == fmt)
1383 		return;
1384 
1385 	last = now;
1386 	lastfmt = fmt;
1387 
1388 	va_start(adx, fmt);
1389 	vcmn_err(level, fmt, adx);
1390 	va_end(adx);
1391 }
1392 
1393 
1394 /*
1395  * Check for abort character sequence
1396  */
1397 static boolean_t
1398 abort_charseq_recognize(uchar_t ch)
1399 {
1400 	static int state = 0;
1401 #define	CNTRL(c) ((c)&037)
1402 	static char sequence[] = { '\r', '~', CNTRL('b') };
1403 
1404 	if (ch == sequence[state]) {
1405 		if (++state >= sizeof (sequence)) {
1406 			state = 0;
1407 			return (B_TRUE);
1408 		}
1409 	} else {
1410 		state = (ch == sequence[0]) ? 1 : 0;
1411 	}
1412 	return (B_FALSE);
1413 }
1414 
1415 /*
1416  * Flow control functions
1417  */
1418 
1419 /*
1420  * Software output flow control
1421  * This function can be executed sucessfully at any situation.
1422  * It does not handle HW, and just change the SW output flow control flag.
1423  * INPUT VALUE of onoff:
1424  *                 FLOW_START means to clear SW output flow control flag,
1425  *			also set ASYNC_OUT_FLW_RESUME.
1426  *                 FLOW_STOP means to set SW output flow control flag,
1427  *			also clear ASYNC_OUT_FLW_RESUME.
1428  */
1429 static void
1430 xcasync_flowcontrol_sw_output(struct xencons *xcp, async_flowc_action onoff)
1431 {
1432 	struct asyncline *async = xcp->priv;
1433 	int instance = xcp->unit;
1434 
1435 	ASSERT(mutex_owned(&xcp->excl));
1436 
1437 	if (!(async->async_ttycommon.t_iflag & IXON))
1438 		return;
1439 
1440 	switch (onoff) {
1441 	case FLOW_STOP:
1442 		async->async_flags |= ASYNC_SW_OUT_FLW;
1443 		async->async_flags &= ~ASYNC_OUT_FLW_RESUME;
1444 		DEBUGCONT1(XENCONS_DEBUG_SFLOW,
1445 		    "xencons%d: output sflow stop\n", instance);
1446 		break;
1447 	case FLOW_START:
1448 		async->async_flags &= ~ASYNC_SW_OUT_FLW;
1449 		async->async_flags |= ASYNC_OUT_FLW_RESUME;
1450 		DEBUGCONT1(XENCONS_DEBUG_SFLOW,
1451 		    "xencons%d: output sflow start\n", instance);
1452 		break;
1453 	default:
1454 		break;
1455 	}
1456 }
1457 
1458 /*
1459  * Software input flow control
1460  * This function can execute software input flow control
1461  * INPUT VALUE of onoff:
1462  *               FLOW_START means to send out a XON char
1463  *                          and clear SW input flow control flag.
1464  *               FLOW_STOP means to send out a XOFF char
1465  *                          and set SW input flow control flag.
1466  *               FLOW_CHECK means to check whether there is pending XON/XOFF
1467  *                          if it is true, send it out.
1468  * INPUT VALUE of type:
1469  *		 IN_FLOW_STREAMS means flow control is due to STREAMS
1470  *		 IN_FLOW_USER means flow control is due to user's commands
1471  * RETURN VALUE: B_FALSE means no flow control char is sent
1472  *               B_TRUE means one flow control char is sent
1473  */
1474 static boolean_t
1475 xcasync_flowcontrol_sw_input(struct xencons *xcp, async_flowc_action onoff,
1476     int type)
1477 {
1478 	struct asyncline *async = xcp->priv;
1479 	int instance = xcp->unit;
1480 	int rval = B_FALSE;
1481 
1482 	ASSERT(mutex_owned(&xcp->excl));
1483 
1484 	if (!(async->async_ttycommon.t_iflag & IXOFF))
1485 		return (rval);
1486 
1487 	/*
1488 	 * If we get this far, then we know IXOFF is set.
1489 	 */
1490 	switch (onoff) {
1491 	case FLOW_STOP:
1492 		async->async_inflow_source |= type;
1493 
1494 		/*
1495 		 * We'll send an XOFF character for each of up to
1496 		 * three different input flow control attempts to stop input.
1497 		 * If we already send out one XOFF, but FLOW_STOP comes again,
1498 		 * it seems that input flow control becomes more serious,
1499 		 * then send XOFF again.
1500 		 */
1501 		if (async->async_inflow_source & (IN_FLOW_STREAMS |
1502 		    IN_FLOW_USER))
1503 			async->async_flags |= ASYNC_SW_IN_FLOW |
1504 			    ASYNC_SW_IN_NEEDED;
1505 		DEBUGCONT2(XENCONS_DEBUG_SFLOW, "xencons%d: input sflow stop, "
1506 		    "type = %x\n", instance, async->async_inflow_source);
1507 		break;
1508 	case FLOW_START:
1509 		async->async_inflow_source &= ~type;
1510 		if (async->async_inflow_source == 0) {
1511 			async->async_flags = (async->async_flags &
1512 			    ~ASYNC_SW_IN_FLOW) | ASYNC_SW_IN_NEEDED;
1513 			DEBUGCONT1(XENCONS_DEBUG_SFLOW, "xencons%d: "
1514 			    "input sflow start\n", instance);
1515 		}
1516 		break;
1517 	default:
1518 		break;
1519 	}
1520 
1521 	if (async->async_flags & ASYNC_SW_IN_NEEDED) {
1522 		/*
1523 		 * If we get this far, then we know we need to send out
1524 		 * XON or XOFF char.
1525 		 */
1526 		char c;
1527 
1528 		rval = B_TRUE;
1529 		c = (async->async_flags & ASYNC_SW_IN_FLOW) ?
1530 		    async->async_stopc : async->async_startc;
1531 		if (DOMAIN_IS_INITDOMAIN(xen_info)) {
1532 			(void) HYPERVISOR_console_io(CONSOLEIO_write, 1, &c);
1533 			async->async_flags &= ~ASYNC_SW_IN_NEEDED;
1534 			return (rval);
1535 		} else {
1536 			xenconsputchar(NULL, c);
1537 		}
1538 	}
1539 	return (rval);
1540 }
1541 
1542 struct module_info xencons_info = {
1543 	0,
1544 	"xencons",
1545 	0,
1546 	INFPSZ,
1547 	4096,
1548 	128
1549 };
1550 
1551 static struct qinit xencons_rint = {
1552 	putq,
1553 	xenconsrsrv,
1554 	xenconsopen,
1555 	xenconsclose,
1556 	NULL,
1557 	&xencons_info,
1558 	NULL
1559 };
1560 
1561 static struct qinit xencons_wint = {
1562 	xenconswput,
1563 	NULL,
1564 	NULL,
1565 	NULL,
1566 	NULL,
1567 	&xencons_info,
1568 	NULL
1569 };
1570 
1571 struct streamtab xencons_str_info = {
1572 	&xencons_rint,
1573 	&xencons_wint,
1574 	NULL,
1575 	NULL
1576 };
1577 
1578 static struct cb_ops cb_xencons_ops = {
1579 	nodev,			/* cb_open */
1580 	nodev,			/* cb_close */
1581 	nodev,			/* cb_strategy */
1582 	nodev,			/* cb_print */
1583 	nodev,			/* cb_dump */
1584 	nodev,			/* cb_read */
1585 	nodev,			/* cb_write */
1586 	nodev,			/* cb_ioctl */
1587 	nodev,			/* cb_devmap */
1588 	nodev,			/* cb_mmap */
1589 	nodev,			/* cb_segmap */
1590 	nochpoll,		/* cb_chpoll */
1591 	ddi_prop_op,		/* cb_prop_op */
1592 	&xencons_str_info,		/* cb_stream */
1593 	D_MP			/* cb_flag */
1594 };
1595 
1596 struct dev_ops xencons_ops = {
1597 	DEVO_REV,		/* devo_rev */
1598 	0,			/* devo_refcnt */
1599 	xenconsinfo,		/* devo_getinfo */
1600 	nulldev,		/* devo_identify */
1601 	nulldev,		/* devo_probe */
1602 	xenconsattach,		/* devo_attach */
1603 	xenconsdetach,		/* devo_detach */
1604 	nodev,			/* devo_reset */
1605 	&cb_xencons_ops,	/* devo_cb_ops */
1606 	NULL,			/* devo_bus_ops */
1607 	NULL,			/* devo_power */
1608 	ddi_quiesce_not_needed,		/* devo_quiesce */
1609 };
1610 
1611 static struct modldrv modldrv = {
1612 	&mod_driverops, /* Type of module.  This one is a driver */
1613 	"virtual console driver",
1614 	&xencons_ops,	/* driver ops */
1615 };
1616 
1617 static struct modlinkage modlinkage = {
1618 	MODREV_1,
1619 	(void *)&modldrv,
1620 	NULL
1621 };
1622 
1623 int
1624 _init(void)
1625 {
1626 	int rv;
1627 
1628 	if ((rv = ddi_soft_state_init(&xencons_soft_state,
1629 	    sizeof (struct xencons), 1)) != 0)
1630 		return (rv);
1631 	if ((rv = mod_install(&modlinkage)) != 0) {
1632 		ddi_soft_state_fini(&xencons_soft_state);
1633 		return (rv);
1634 	}
1635 	DEBUGCONT2(XENCONS_DEBUG_INIT, "%s, debug = %x\n",
1636 	    modldrv.drv_linkinfo, debug);
1637 	return (0);
1638 }
1639 
1640 int
1641 _fini(void)
1642 {
1643 	int rv;
1644 
1645 	if ((rv = mod_remove(&modlinkage)) != 0)
1646 		return (rv);
1647 
1648 	ddi_soft_state_fini(&xencons_soft_state);
1649 	return (0);
1650 }
1651 
1652 int
1653 _info(struct modinfo *modinfop)
1654 {
1655 	return (mod_info(&modlinkage, modinfop));
1656 }
1657