dcons.c revision 125862 
1/*
2 * Copyright (C) 2003
3 * 	Hidetoshi Shimokawa. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *
16 *	This product includes software developed by Hidetoshi Shimokawa.
17 *
18 * 4. Neither the name of the author nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * $Id: dcons.c,v 1.65 2003/10/24 03:24:55 simokawa Exp $
35 * $FreeBSD: head/sys/dev/dcons/dcons.c 125862 2004-02-16 07:25:46Z simokawa $
36 */
37
38#include <sys/param.h>
39#include <sys/kernel.h>
40#include <sys/systm.h>
41#include <sys/types.h>
42#include <sys/conf.h>
43#include <sys/cons.h>
44#include <sys/consio.h>
45#include <sys/tty.h>
46#include <sys/malloc.h>
47#include <sys/proc.h>
48#include <sys/ucred.h>
49
50#include <machine/bus.h>
51
52#include <dev/dcons/dcons.h>
53
54#include <ddb/ddb.h>
55#include <sys/reboot.h>
56
57#include <sys/sysctl.h>
58
59#include "opt_ddb.h"
60#include "opt_comconsole.h"
61#include "opt_dcons.h"
62
63#ifndef DCONS_POLL_HZ
64#define DCONS_POLL_HZ	100
65#endif
66
67#ifndef DCONS_BUF_SIZE
68#define DCONS_BUF_SIZE (16*1024)
69#endif
70
71#ifndef DCONS_FORCE_CONSOLE
72#define DCONS_FORCE_CONSOLE	0	/* mostly for FreeBSD-4 */
73#endif
74
75#ifndef DCONS_FORCE_GDB
76#define DCONS_FORCE_GDB	1
77#endif
78
79#if __FreeBSD_version >= 500101
80#define CONS_NODEV	1	/* for latest current */
81static struct consdev gdbconsdev;
82#endif
83
84#define	CDEV_MAJOR	184
85
86static d_open_t		dcons_open;
87static d_close_t	dcons_close;
88static d_ioctl_t	dcons_ioctl;
89
90static struct cdevsw dcons_cdevsw = {
91#if __FreeBSD_version >= 500104
92	.d_open =	dcons_open,
93	.d_close =	dcons_close,
94	.d_read =	ttyread,
95	.d_write =	ttywrite,
96	.d_ioctl =	dcons_ioctl,
97	.d_poll =	ttypoll,
98	.d_name =	"dcons",
99	.d_maj =	CDEV_MAJOR,
100#else
101	/* open */	dcons_open,
102	/* close */	dcons_close,
103	/* read */	ttyread,
104	/* write */	ttywrite,
105	/* ioctl */	dcons_ioctl,
106	/* poll */	ttypoll,
107	/* mmap */	nommap,
108	/* strategy */	nostrategy,
109	/* name */	"dcons",
110	/* major */	CDEV_MAJOR,
111	/* dump */	nodump,
112	/* psize */	nopsize,
113	/* flags */	0,
114#endif
115};
116
117#ifndef KLD_MODULE
118static char bssbuf[DCONS_BUF_SIZE];	/* buf in bss */
119#endif
120
121/* global data */
122static struct dcons_global dg;
123struct dcons_global *dcons_conf;
124static int poll_hz = DCONS_POLL_HZ;
125
126SYSCTL_NODE(_kern, OID_AUTO, dcons, CTLFLAG_RD, 0, "Dumb Console");
127SYSCTL_INT(_kern_dcons, OID_AUTO, poll_hz, CTLFLAG_RW, &poll_hz, 0,
128				"dcons polling rate");
129
130static int drv_init = 0;
131static struct callout dcons_callout;
132struct dcons_buf *dcons_buf;		/* for local dconschat */
133
134/* per device data */
135static struct dcons_softc {
136	dev_t dev;
137	struct dcons_ch	o, i;
138	int brk_state;
139#define DC_GDB	1
140	int flags;
141} sc[DCONS_NPORT];
142static void	dcons_tty_start(struct tty *);
143static int	dcons_tty_param(struct tty *, struct termios *);
144static void	dcons_timeout(void *);
145static int	dcons_drv_init(int);
146static int	dcons_getc(struct dcons_softc *);
147static int	dcons_checkc(struct dcons_softc *);
148static void	dcons_putc(struct dcons_softc *, int);
149
150static cn_probe_t	dcons_cnprobe;
151static cn_init_t	dcons_cninit;
152static cn_getc_t	dcons_cngetc;
153static cn_checkc_t 	dcons_cncheckc;
154static cn_putc_t	dcons_cnputc;
155
156CONS_DRIVER(dcons, dcons_cnprobe, dcons_cninit, NULL, dcons_cngetc,
157    dcons_cncheckc, dcons_cnputc, NULL);
158
159#if __FreeBSD_version < 500000
160#define THREAD	proc
161#else
162#define THREAD	thread
163#endif
164
165static int
166dcons_open(dev_t dev, int flag, int mode, struct THREAD *td)
167{
168	struct tty *tp;
169	int unit, error, s;
170
171	unit = minor(dev);
172	if (unit != 0)
173		return (ENXIO);
174
175	tp = dev->si_tty = ttymalloc(dev->si_tty);
176	tp->t_oproc = dcons_tty_start;
177	tp->t_param = dcons_tty_param;
178	tp->t_stop = nottystop;
179	tp->t_dev = dev;
180
181	error = 0;
182
183	s = spltty();
184	if ((tp->t_state & TS_ISOPEN) == 0) {
185		tp->t_state |= TS_CARR_ON;
186		ttychars(tp);
187		tp->t_iflag = TTYDEF_IFLAG;
188		tp->t_oflag = TTYDEF_OFLAG;
189		tp->t_cflag = TTYDEF_CFLAG|CLOCAL;
190		tp->t_lflag = TTYDEF_LFLAG;
191		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
192		ttsetwater(tp);
193	} else if ((tp->t_state & TS_XCLUDE) && suser(td)) {
194		splx(s);
195		return (EBUSY);
196	}
197	splx(s);
198
199	error = (*linesw[tp->t_line].l_open)(dev, tp);
200
201	return (error);
202}
203
204static int
205dcons_close(dev_t dev, int flag, int mode, struct THREAD *td)
206{
207	int	unit;
208	struct	tty *tp;
209
210	unit = minor(dev);
211	if (unit != 0)
212		return (ENXIO);
213
214	tp = dev->si_tty;
215	if (tp->t_state & TS_ISOPEN) {
216		(*linesw[tp->t_line].l_close)(tp, flag);
217		ttyclose(tp);
218	}
219
220	return (0);
221}
222
223static int
224dcons_ioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct THREAD *td)
225{
226	int	unit;
227	struct	tty *tp;
228	int	error;
229
230	unit = minor(dev);
231	if (unit != 0)
232		return (ENXIO);
233
234	tp = dev->si_tty;
235	error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, td);
236	if (error != ENOIOCTL)
237		return (error);
238
239	error = ttioctl(tp, cmd, data, flag);
240	if (error != ENOIOCTL)
241		return (error);
242
243	return (ENOTTY);
244}
245
246static int
247dcons_tty_param(struct tty *tp, struct termios *t)
248{
249	tp->t_ispeed = t->c_ispeed;
250	tp->t_ospeed = t->c_ospeed;
251	tp->t_cflag = t->c_cflag;
252	return 0;
253}
254
255static void
256dcons_tty_start(struct tty *tp)
257{
258	struct dcons_softc *dc;
259	int s;
260
261	dc = (struct dcons_softc *)tp->t_dev->si_drv1;
262	s = spltty();
263	if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
264		ttwwakeup(tp);
265		return;
266	}
267
268	tp->t_state |= TS_BUSY;
269	while (tp->t_outq.c_cc != 0)
270		dcons_putc(dc, getc(&tp->t_outq));
271	tp->t_state &= ~TS_BUSY;
272
273	ttwwakeup(tp);
274	splx(s);
275}
276
277static void
278dcons_timeout(void *v)
279{
280	struct	tty *tp;
281	struct dcons_softc *dc;
282	int i, c, polltime;
283
284	for (i = 0; i < DCONS_NPORT; i ++) {
285		dc = &sc[i];
286		tp = dc->dev->si_tty;
287		while ((c = dcons_checkc(dc)) != -1)
288			if (tp->t_state & TS_ISOPEN)
289				(*linesw[tp->t_line].l_rint)(c, tp);
290	}
291	polltime = hz / poll_hz;
292	if (polltime < 1)
293		polltime = 1;
294	callout_reset(&dcons_callout, polltime, dcons_timeout, tp);
295}
296
297static void
298dcons_cnprobe(struct consdev *cp)
299{
300#if __FreeBSD_version >= 501109
301	sprintf(cp->cn_name, "dcons");
302#else
303	cp->cn_dev = makedev(CDEV_MAJOR, DCONS_CON);
304#endif
305#if DCONS_FORCE_CONSOLE
306	cp->cn_pri = CN_REMOTE;
307#else
308	cp->cn_pri = CN_NORMAL;
309#endif
310}
311
312static void
313dcons_cninit(struct consdev *cp)
314{
315	dcons_drv_init(0);
316#if CONS_NODEV
317	cp->cn_arg
318#else
319	cp->cn_dev->si_drv1
320#endif
321		= (void *)&sc[DCONS_CON]; /* share port0 with unit0 */
322}
323
324#if CONS_NODEV
325static int
326dcons_cngetc(struct consdev *cp)
327{
328	return(dcons_getc((struct dcons_softc *)cp->cn_arg));
329}
330static int
331dcons_cncheckc(struct consdev *cp)
332{
333	return(dcons_checkc((struct dcons_softc *)cp->cn_arg));
334}
335static void
336dcons_cnputc(struct consdev *cp, int c)
337{
338	dcons_putc((struct dcons_softc *)cp->cn_arg, c);
339}
340#else
341static int
342dcons_cngetc(dev_t dev)
343{
344	return(dcons_getc((struct dcons_softc *)dev->si_drv1));
345}
346static int
347dcons_cncheckc(dev_t dev)
348{
349	return(dcons_checkc((struct dcons_softc *)dev->si_drv1));
350}
351static void
352dcons_cnputc(dev_t dev, int c)
353{
354	dcons_putc((struct dcons_softc *)dev->si_drv1, c);
355}
356#endif
357
358static int
359dcons_getc(struct dcons_softc *dc)
360{
361	int c;
362
363	while ((c = dcons_checkc(dc)) == -1);
364
365	return (c & 0xff);
366}
367
368static int
369dcons_checkc(struct dcons_softc *dc)
370{
371	unsigned char c;
372	u_int32_t ptr, pos, gen, next_gen;
373	struct dcons_ch *ch;
374
375	ch = &dc->i;
376
377	if (dg.dma_tag != NULL)
378		bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_POSTREAD);
379	ptr = ntohl(*ch->ptr);
380	gen = ptr >> DCONS_GEN_SHIFT;
381	pos = ptr & DCONS_POS_MASK;
382	if (gen == ch->gen && pos == ch->pos)
383		return (-1);
384
385	next_gen = DCONS_NEXT_GEN(ch->gen);
386	/* XXX sanity check */
387	if ((gen != ch->gen && gen != next_gen)
388			|| (gen == ch->gen && pos < ch->pos)) {
389		/* generation skipped !! */
390		/* XXX discard */
391		ch->gen = gen;
392		ch->pos = pos;
393		return (-1);
394	}
395
396	c = ch->buf[ch->pos];
397	ch->pos ++;
398	if (ch->pos >= ch->size) {
399		ch->gen = next_gen;
400		ch->pos = 0;
401	}
402
403#if DDB && ALT_BREAK_TO_DEBUGGER
404	switch (dc->brk_state) {
405	case STATE1:
406		if (c == KEY_TILDE)
407			dc->brk_state = STATE2;
408		else
409			dc->brk_state = STATE0;
410		break;
411	case STATE2:
412		dc->brk_state = STATE0;
413		if (c == KEY_CTRLB) {
414#if DCONS_FORCE_GDB
415			if (dc->flags & DC_GDB)
416				boothowto |= RB_GDB;
417#endif
418			breakpoint();
419		}
420	}
421	if (c == KEY_CR)
422		dc->brk_state = STATE1;
423#endif
424	return (c);
425}
426
427static void
428dcons_putc(struct dcons_softc *dc, int c)
429{
430	struct dcons_ch *ch;
431
432	ch = &dc->o;
433
434	ch->buf[ch->pos] = c;
435	ch->pos ++;
436	if (ch->pos >= ch->size) {
437		ch->gen = DCONS_NEXT_GEN(ch->gen);
438		ch->pos = 0;
439	}
440	*ch->ptr = DCONS_MAKE_PTR(ch);
441	if (dg.dma_tag != NULL)
442		bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_PREWRITE);
443}
444
445static int
446dcons_init_port(int port, int offset, int size)
447{
448	int osize;
449	struct dcons_softc *dc;
450
451	dc = &sc[port];
452
453	osize = size * 3 / 4;
454
455	dc->o.size = osize;
456	dc->i.size = size - osize;
457	dc->o.buf = (char *)dg.buf + offset;
458	dc->i.buf = dc->o.buf + osize;
459	dc->o.gen = dc->i.gen = 0;
460	dc->o.pos = dc->i.pos = 0;
461	dc->o.ptr = &dg.buf->optr[port];
462	dc->i.ptr = &dg.buf->iptr[port];
463	dc->brk_state = STATE0;
464	dg.buf->osize[port] = htonl(osize);
465	dg.buf->isize[port] = htonl(size - osize);
466	dg.buf->ooffset[port] = htonl(offset);
467	dg.buf->ioffset[port] = htonl(offset + osize);
468	dg.buf->optr[port] = DCONS_MAKE_PTR(&dc->o);
469	dg.buf->iptr[port] = DCONS_MAKE_PTR(&dc->i);
470
471	return(0);
472}
473
474static int
475dcons_drv_init(int stage)
476{
477	int size, size0, offset;
478
479	if (drv_init)
480		return(drv_init);
481
482	drv_init = -1;
483
484	bzero(&dg, sizeof(dg));
485	dcons_conf = &dg;
486	dg.cdev = &dcons_consdev;
487	dg.size = DCONS_BUF_SIZE;
488
489#ifndef KLD_MODULE
490	if (stage == 0) /* XXX or cold */
491		/*
492		 * DCONS_FORCE_CONSOLE == 1 and statically linked.
493		 * called from cninit(). can't use contigmalloc yet .
494		 */
495		dg.buf = (struct dcons_buf *) bssbuf;
496	else
497#endif
498		/*
499		 * DCONS_FORCE_CONSOLE == 0 or kernel module case.
500		 * if the module is loaded after boot,
501		 * bssbuf could be non-continuous.
502		 */
503		dg.buf = (struct dcons_buf *) contigmalloc(dg.size,
504			M_DEVBUF, 0, 0x10000, 0xffffffff, PAGE_SIZE, 0ul);
505
506	dcons_buf = dg.buf;
507	offset = DCONS_HEADER_SIZE;
508	size = (dg.size - offset);
509	size0 = size * 3 / 4;
510
511	dcons_init_port(0, offset, size0);
512	offset += size0;
513	dcons_init_port(1, offset, size - size0);
514	dg.buf->version = htonl(DCONS_VERSION);
515	dg.buf->magic = ntohl(DCONS_MAGIC);
516
517#if DDB && DCONS_FORCE_GDB
518#if CONS_NODEV
519	gdbconsdev.cn_arg = (void *)&sc[DCONS_GDB];
520#if __FreeBSD_version >= 501109
521	sprintf(gdbconsdev.cn_name, "dgdb");
522#endif
523	gdb_arg = &gdbconsdev;
524#else
525	gdbdev = makedev(CDEV_MAJOR, DCONS_GDB);
526#endif
527	gdb_getc = dcons_cngetc;
528	gdb_putc = dcons_cnputc;
529#endif
530	drv_init = 1;
531
532	return 0;
533}
534
535
536static int
537dcons_attach_port(int port, char *name, int flags)
538{
539	struct dcons_softc *dc;
540	struct tty *tp;
541
542	dc = &sc[port];
543	dc->flags = flags;
544	dc->dev = make_dev(&dcons_cdevsw, port,
545			UID_ROOT, GID_WHEEL, 0600, name);
546	tp = ttymalloc(NULL);
547
548	dc->dev->si_drv1 = (void *)dc;
549	dc->dev->si_tty = tp;
550
551	tp->t_oproc = dcons_tty_start;
552	tp->t_param = dcons_tty_param;
553	tp->t_stop = nottystop;
554	tp->t_dev = dc->dev;
555
556	return(0);
557}
558
559static int
560dcons_attach(void)
561{
562	int polltime;
563
564	dcons_attach_port(DCONS_CON, "dcons", 0);
565	dcons_attach_port(DCONS_GDB, "dgdb", DC_GDB);
566#if __FreeBSD_version < 500000
567	callout_init(&dcons_callout);
568#else
569	callout_init(&dcons_callout, 0);
570#endif
571	polltime = hz / poll_hz;
572	if (polltime < 1)
573		polltime = 1;
574	callout_reset(&dcons_callout, polltime, dcons_timeout, NULL);
575	return(0);
576}
577
578static int
579dcons_detach(int port)
580{
581	struct	tty *tp;
582	struct dcons_softc *dc;
583
584	dc = &sc[port];
585
586	tp = dc->dev->si_tty;
587
588	if (tp->t_state & TS_ISOPEN) {
589		printf("dcons: still opened\n");
590		(*linesw[tp->t_line].l_close)(tp, 0);
591		tp->t_gen++;
592		ttyclose(tp);
593		ttwakeup(tp);
594		ttwwakeup(tp);
595	}
596	/* XXX
597	 * must wait until all device are closed.
598	 */
599	tsleep((void *)dc, PWAIT, "dcodtc", hz/4);
600	destroy_dev(dc->dev);
601
602	return(0);
603}
604
605
606/* cnXXX works only for FreeBSD-5 */
607static int
608dcons_modevent(module_t mode, int type, void *data)
609{
610	int err = 0, ret;
611
612	switch (type) {
613	case MOD_LOAD:
614		ret = dcons_drv_init(1);
615		dcons_attach();
616#if __FreeBSD_version >= 500000
617		if (ret == 0) {
618			dcons_cnprobe(&dcons_consdev);
619			dcons_cninit(&dcons_consdev);
620			cnadd(&dcons_consdev);
621		}
622#endif
623		break;
624	case MOD_UNLOAD:
625		printf("dcons: unload\n");
626		callout_stop(&dcons_callout);
627#if DDB && DCONS_FORCE_GDB
628#if CONS_NODEV
629		gdb_arg = NULL;
630#else
631		gdbdev = NODEV;
632#endif
633#endif
634#if __FreeBSD_version >= 500000
635		cnremove(&dcons_consdev);
636#endif
637		dcons_detach(DCONS_CON);
638		dcons_detach(DCONS_GDB);
639		dg.buf->magic = 0;
640
641		contigfree(dg.buf, DCONS_BUF_SIZE, M_DEVBUF);
642
643		break;
644	case MOD_SHUTDOWN:
645		break;
646	}
647	return(err);
648}
649
650DEV_MODULE(dcons, dcons_modevent, NULL);
651MODULE_VERSION(dcons, DCONS_VERSION);
652