xref: /freebsd/sys/dev/dcons/dcons.c (revision 138fbf67) 
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  * $FreeBSD$
36  */
37 
38 #include <sys/param.h>
39 #include <sys/kernel.h>
40 #include <sys/module.h>
41 #include <sys/systm.h>
42 #include <sys/types.h>
43 #include <sys/conf.h>
44 #include <sys/cons.h>
45 #include <sys/consio.h>
46 #include <sys/tty.h>
47 #include <sys/malloc.h>
48 #include <sys/proc.h>
49 #include <sys/ucred.h>
50 
51 #include <machine/bus.h>
52 
53 #include <dev/dcons/dcons.h>
54 
55 #include <ddb/ddb.h>
56 #include <sys/reboot.h>
57 
58 #include <sys/sysctl.h>
59 
60 #include "opt_ddb.h"
61 #include "opt_comconsole.h"
62 #include "opt_dcons.h"
63 
64 #ifndef DCONS_POLL_HZ
65 #define DCONS_POLL_HZ	100
66 #endif
67 
68 #ifndef DCONS_BUF_SIZE
69 #define DCONS_BUF_SIZE (16*1024)
70 #endif
71 
72 #ifndef DCONS_FORCE_CONSOLE
73 #define DCONS_FORCE_CONSOLE	0	/* mostly for FreeBSD-4 */
74 #endif
75 
76 #ifndef DCONS_FORCE_GDB
77 #define DCONS_FORCE_GDB	1
78 #endif
79 
80 #if __FreeBSD_version >= 500101
81 #define CONS_NODEV	1	/* for latest current */
82 static struct consdev gdbconsdev;
83 #endif
84 
85 
86 static d_open_t		dcons_open;
87 static d_close_t	dcons_close;
88 
89 static struct cdevsw dcons_cdevsw = {
90 #if __FreeBSD_version >= 500104
91 	.d_version =	D_VERSION,
92 	.d_open =	dcons_open,
93 	.d_close =	dcons_close,
94 	.d_name =	"dcons",
95 	.d_flags =	D_TTY | D_NEEDGIANT,
96 #else
97 	/* open */	dcons_open,
98 	/* close */	dcons_close,
99 	/* read */	ttyread,
100 	/* write */	ttywrite,
101 	/* ioctl */	dcons_ioctl,
102 	/* poll */	ttypoll,
103 	/* mmap */	nommap,
104 	/* strategy */	nostrategy,
105 	/* name */	"dcons",
106 	/* major */	CDEV_MAJOR,
107 	/* dump */	nodump,
108 	/* psize */	nopsize,
109 	/* flags */	0,
110 #endif
111 };
112 
113 #ifndef KLD_MODULE
114 static char bssbuf[DCONS_BUF_SIZE];	/* buf in bss */
115 #endif
116 
117 /* global data */
118 static struct dcons_global dg;
119 struct dcons_global *dcons_conf;
120 static int poll_hz = DCONS_POLL_HZ;
121 
122 SYSCTL_NODE(_kern, OID_AUTO, dcons, CTLFLAG_RD, 0, "Dumb Console");
123 SYSCTL_INT(_kern_dcons, OID_AUTO, poll_hz, CTLFLAG_RW, &poll_hz, 0,
124 				"dcons polling rate");
125 
126 static int drv_init = 0;
127 static struct callout dcons_callout;
128 struct dcons_buf *dcons_buf;		/* for local dconschat */
129 
130 /* per device data */
131 static struct dcons_softc {
132 	dev_t dev;
133 	struct dcons_ch	o, i;
134 	int brk_state;
135 #define DC_GDB	1
136 	int flags;
137 } sc[DCONS_NPORT];
138 static void	dcons_tty_start(struct tty *);
139 static int	dcons_tty_param(struct tty *, struct termios *);
140 static void	dcons_timeout(void *);
141 static int	dcons_drv_init(int);
142 static int	dcons_getc(struct dcons_softc *);
143 static int	dcons_checkc(struct dcons_softc *);
144 static void	dcons_putc(struct dcons_softc *, int);
145 
146 static cn_probe_t	dcons_cnprobe;
147 static cn_init_t	dcons_cninit;
148 static cn_getc_t	dcons_cngetc;
149 static cn_checkc_t 	dcons_cncheckc;
150 static cn_putc_t	dcons_cnputc;
151 
152 CONS_DRIVER(dcons, dcons_cnprobe, dcons_cninit, NULL, dcons_cngetc,
153     dcons_cncheckc, dcons_cnputc, NULL);
154 
155 #if __FreeBSD_version < 500000
156 #define THREAD	proc
157 #else
158 #define THREAD	thread
159 #endif
160 
161 static int
162 dcons_open(dev_t dev, int flag, int mode, struct THREAD *td)
163 {
164 	struct tty *tp;
165 	int unit, error, s;
166 
167 	unit = minor(dev);
168 	if (unit != 0)
169 		return (ENXIO);
170 
171 	tp = dev->si_tty = ttymalloc(dev->si_tty);
172 	tp->t_oproc = dcons_tty_start;
173 	tp->t_param = dcons_tty_param;
174 	tp->t_stop = nottystop;
175 	tp->t_dev = dev;
176 
177 	error = 0;
178 
179 	s = spltty();
180 	if ((tp->t_state & TS_ISOPEN) == 0) {
181 		tp->t_state |= TS_CARR_ON;
182 		ttychars(tp);
183 		tp->t_iflag = TTYDEF_IFLAG;
184 		tp->t_oflag = TTYDEF_OFLAG;
185 		tp->t_cflag = TTYDEF_CFLAG|CLOCAL;
186 		tp->t_lflag = TTYDEF_LFLAG;
187 		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
188 		ttsetwater(tp);
189 	} else if ((tp->t_state & TS_XCLUDE) && suser(td)) {
190 		splx(s);
191 		return (EBUSY);
192 	}
193 	splx(s);
194 
195 	error = (*linesw[tp->t_line].l_open)(dev, tp);
196 
197 	return (error);
198 }
199 
200 static int
201 dcons_close(dev_t dev, int flag, int mode, struct THREAD *td)
202 {
203 	int	unit;
204 	struct	tty *tp;
205 
206 	unit = minor(dev);
207 	if (unit != 0)
208 		return (ENXIO);
209 
210 	tp = dev->si_tty;
211 	if (tp->t_state & TS_ISOPEN) {
212 		(*linesw[tp->t_line].l_close)(tp, flag);
213 		ttyclose(tp);
214 	}
215 
216 	return (0);
217 }
218 
219 static int
220 dcons_tty_param(struct tty *tp, struct termios *t)
221 {
222 	tp->t_ispeed = t->c_ispeed;
223 	tp->t_ospeed = t->c_ospeed;
224 	tp->t_cflag = t->c_cflag;
225 	return 0;
226 }
227 
228 static void
229 dcons_tty_start(struct tty *tp)
230 {
231 	struct dcons_softc *dc;
232 	int s;
233 
234 	dc = (struct dcons_softc *)tp->t_dev->si_drv1;
235 	s = spltty();
236 	if (tp->t_state & (TS_TIMEOUT | TS_TTSTOP)) {
237 		ttwwakeup(tp);
238 		return;
239 	}
240 
241 	tp->t_state |= TS_BUSY;
242 	while (tp->t_outq.c_cc != 0)
243 		dcons_putc(dc, getc(&tp->t_outq));
244 	tp->t_state &= ~TS_BUSY;
245 
246 	ttwwakeup(tp);
247 	splx(s);
248 }
249 
250 static void
251 dcons_timeout(void *v)
252 {
253 	struct	tty *tp;
254 	struct dcons_softc *dc;
255 	int i, c, polltime;
256 
257 	for (i = 0; i < DCONS_NPORT; i ++) {
258 		dc = &sc[i];
259 		tp = dc->dev->si_tty;
260 		while ((c = dcons_checkc(dc)) != -1)
261 			if (tp->t_state & TS_ISOPEN)
262 				(*linesw[tp->t_line].l_rint)(c, tp);
263 	}
264 	polltime = hz / poll_hz;
265 	if (polltime < 1)
266 		polltime = 1;
267 	callout_reset(&dcons_callout, polltime, dcons_timeout, tp);
268 }
269 
270 static void
271 dcons_cnprobe(struct consdev *cp)
272 {
273 #if __FreeBSD_version >= 501109
274 	sprintf(cp->cn_name, "dcons");
275 #else
276 	cp->cn_dev = makedev(CDEV_MAJOR, DCONS_CON);
277 #endif
278 #if DCONS_FORCE_CONSOLE
279 	cp->cn_pri = CN_REMOTE;
280 #else
281 	cp->cn_pri = CN_NORMAL;
282 #endif
283 }
284 
285 static void
286 dcons_cninit(struct consdev *cp)
287 {
288 	dcons_drv_init(0);
289 #if CONS_NODEV
290 	cp->cn_arg
291 #else
292 	cp->cn_dev->si_drv1
293 #endif
294 		= (void *)&sc[DCONS_CON]; /* share port0 with unit0 */
295 }
296 
297 #if CONS_NODEV
298 static int
299 dcons_cngetc(struct consdev *cp)
300 {
301 	return(dcons_getc((struct dcons_softc *)cp->cn_arg));
302 }
303 static int
304 dcons_cncheckc(struct consdev *cp)
305 {
306 	return(dcons_checkc((struct dcons_softc *)cp->cn_arg));
307 }
308 static void
309 dcons_cnputc(struct consdev *cp, int c)
310 {
311 	dcons_putc((struct dcons_softc *)cp->cn_arg, c);
312 }
313 #else
314 static int
315 dcons_cngetc(dev_t dev)
316 {
317 	return(dcons_getc((struct dcons_softc *)dev->si_drv1));
318 }
319 static int
320 dcons_cncheckc(dev_t dev)
321 {
322 	return(dcons_checkc((struct dcons_softc *)dev->si_drv1));
323 }
324 static void
325 dcons_cnputc(dev_t dev, int c)
326 {
327 	dcons_putc((struct dcons_softc *)dev->si_drv1, c);
328 }
329 #endif
330 
331 static int
332 dcons_getc(struct dcons_softc *dc)
333 {
334 	int c;
335 
336 	while ((c = dcons_checkc(dc)) == -1);
337 
338 	return (c & 0xff);
339 }
340 
341 static int
342 dcons_checkc(struct dcons_softc *dc)
343 {
344 	unsigned char c;
345 	u_int32_t ptr, pos, gen, next_gen;
346 	struct dcons_ch *ch;
347 
348 	ch = &dc->i;
349 
350 	if (dg.dma_tag != NULL)
351 		bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_POSTREAD);
352 	ptr = ntohl(*ch->ptr);
353 	gen = ptr >> DCONS_GEN_SHIFT;
354 	pos = ptr & DCONS_POS_MASK;
355 	if (gen == ch->gen && pos == ch->pos)
356 		return (-1);
357 
358 	next_gen = DCONS_NEXT_GEN(ch->gen);
359 	/* XXX sanity check */
360 	if ((gen != ch->gen && gen != next_gen)
361 			|| (gen == ch->gen && pos < ch->pos)) {
362 		/* generation skipped !! */
363 		/* XXX discard */
364 		ch->gen = gen;
365 		ch->pos = pos;
366 		return (-1);
367 	}
368 
369 	c = ch->buf[ch->pos];
370 	ch->pos ++;
371 	if (ch->pos >= ch->size) {
372 		ch->gen = next_gen;
373 		ch->pos = 0;
374 	}
375 
376 #if DDB && ALT_BREAK_TO_DEBUGGER
377 	switch (dc->brk_state) {
378 	case STATE1:
379 		if (c == KEY_TILDE)
380 			dc->brk_state = STATE2;
381 		else
382 			dc->brk_state = STATE0;
383 		break;
384 	case STATE2:
385 		dc->brk_state = STATE0;
386 		if (c == KEY_CTRLB) {
387 #if DCONS_FORCE_GDB
388 			if (dc->flags & DC_GDB)
389 				boothowto |= RB_GDB;
390 #endif
391 			breakpoint();
392 		}
393 	}
394 	if (c == KEY_CR)
395 		dc->brk_state = STATE1;
396 #endif
397 	return (c);
398 }
399 
400 static void
401 dcons_putc(struct dcons_softc *dc, int c)
402 {
403 	struct dcons_ch *ch;
404 
405 	ch = &dc->o;
406 
407 	ch->buf[ch->pos] = c;
408 	ch->pos ++;
409 	if (ch->pos >= ch->size) {
410 		ch->gen = DCONS_NEXT_GEN(ch->gen);
411 		ch->pos = 0;
412 	}
413 	*ch->ptr = DCONS_MAKE_PTR(ch);
414 	if (dg.dma_tag != NULL)
415 		bus_dmamap_sync(dg.dma_tag, dg.dma_map, BUS_DMASYNC_PREWRITE);
416 }
417 
418 static int
419 dcons_init_port(int port, int offset, int size)
420 {
421 	int osize;
422 	struct dcons_softc *dc;
423 
424 	dc = &sc[port];
425 
426 	osize = size * 3 / 4;
427 
428 	dc->o.size = osize;
429 	dc->i.size = size - osize;
430 	dc->o.buf = (char *)dg.buf + offset;
431 	dc->i.buf = dc->o.buf + osize;
432 	dc->o.gen = dc->i.gen = 0;
433 	dc->o.pos = dc->i.pos = 0;
434 	dc->o.ptr = &dg.buf->optr[port];
435 	dc->i.ptr = &dg.buf->iptr[port];
436 	dc->brk_state = STATE0;
437 	dg.buf->osize[port] = htonl(osize);
438 	dg.buf->isize[port] = htonl(size - osize);
439 	dg.buf->ooffset[port] = htonl(offset);
440 	dg.buf->ioffset[port] = htonl(offset + osize);
441 	dg.buf->optr[port] = DCONS_MAKE_PTR(&dc->o);
442 	dg.buf->iptr[port] = DCONS_MAKE_PTR(&dc->i);
443 
444 	return(0);
445 }
446 
447 static int
448 dcons_drv_init(int stage)
449 {
450 	int size, size0, offset;
451 
452 	if (drv_init)
453 		return(drv_init);
454 
455 	drv_init = -1;
456 
457 	bzero(&dg, sizeof(dg));
458 	dcons_conf = &dg;
459 	dg.cdev = &dcons_consdev;
460 	dg.size = DCONS_BUF_SIZE;
461 
462 #ifndef KLD_MODULE
463 	if (stage == 0) /* XXX or cold */
464 		/*
465 		 * DCONS_FORCE_CONSOLE == 1 and statically linked.
466 		 * called from cninit(). can't use contigmalloc yet .
467 		 */
468 		dg.buf = (struct dcons_buf *) bssbuf;
469 	else
470 #endif
471 		/*
472 		 * DCONS_FORCE_CONSOLE == 0 or kernel module case.
473 		 * if the module is loaded after boot,
474 		 * bssbuf could be non-continuous.
475 		 */
476 		dg.buf = (struct dcons_buf *) contigmalloc(dg.size,
477 			M_DEVBUF, 0, 0x10000, 0xffffffff, PAGE_SIZE, 0ul);
478 
479 	dcons_buf = dg.buf;
480 	offset = DCONS_HEADER_SIZE;
481 	size = (dg.size - offset);
482 	size0 = size * 3 / 4;
483 
484 	dcons_init_port(0, offset, size0);
485 	offset += size0;
486 	dcons_init_port(1, offset, size - size0);
487 	dg.buf->version = htonl(DCONS_VERSION);
488 	dg.buf->magic = ntohl(DCONS_MAGIC);
489 
490 #if DDB && DCONS_FORCE_GDB
491 #if CONS_NODEV
492 	gdbconsdev.cn_arg = (void *)&sc[DCONS_GDB];
493 #if __FreeBSD_version >= 501109
494 	sprintf(gdbconsdev.cn_name, "dgdb");
495 #endif
496 	gdb_arg = &gdbconsdev;
497 #else
498 	gdbdev = makedev(CDEV_MAJOR, DCONS_GDB);
499 #endif
500 	gdb_getc = dcons_cngetc;
501 	gdb_putc = dcons_cnputc;
502 #endif
503 	drv_init = 1;
504 
505 	return 0;
506 }
507 
508 
509 static int
510 dcons_attach_port(int port, char *name, int flags)
511 {
512 	struct dcons_softc *dc;
513 	struct tty *tp;
514 
515 	dc = &sc[port];
516 	dc->flags = flags;
517 	dc->dev = make_dev(&dcons_cdevsw, port,
518 			UID_ROOT, GID_WHEEL, 0600, name);
519 	tp = ttymalloc(NULL);
520 
521 	dc->dev->si_drv1 = (void *)dc;
522 	dc->dev->si_tty = tp;
523 
524 	tp->t_oproc = dcons_tty_start;
525 	tp->t_param = dcons_tty_param;
526 	tp->t_stop = nottystop;
527 	tp->t_dev = dc->dev;
528 
529 	return(0);
530 }
531 
532 static int
533 dcons_attach(void)
534 {
535 	int polltime;
536 
537 	dcons_attach_port(DCONS_CON, "dcons", 0);
538 	dcons_attach_port(DCONS_GDB, "dgdb", DC_GDB);
539 #if __FreeBSD_version < 500000
540 	callout_init(&dcons_callout);
541 #else
542 	callout_init(&dcons_callout, 0);
543 #endif
544 	polltime = hz / poll_hz;
545 	if (polltime < 1)
546 		polltime = 1;
547 	callout_reset(&dcons_callout, polltime, dcons_timeout, NULL);
548 	return(0);
549 }
550 
551 static int
552 dcons_detach(int port)
553 {
554 	struct	tty *tp;
555 	struct dcons_softc *dc;
556 
557 	dc = &sc[port];
558 
559 	tp = dc->dev->si_tty;
560 
561 	if (tp->t_state & TS_ISOPEN) {
562 		printf("dcons: still opened\n");
563 		(*linesw[tp->t_line].l_close)(tp, 0);
564 		ttyclose(tp);
565 	}
566 	/* XXX
567 	 * must wait until all device are closed.
568 	 */
569 	tsleep((void *)dc, PWAIT, "dcodtc", hz/4);
570 	destroy_dev(dc->dev);
571 
572 	return(0);
573 }
574 
575 
576 /* cnXXX works only for FreeBSD-5 */
577 static int
578 dcons_modevent(module_t mode, int type, void *data)
579 {
580 	int err = 0, ret;
581 
582 	switch (type) {
583 	case MOD_LOAD:
584 		ret = dcons_drv_init(1);
585 		dcons_attach();
586 #if __FreeBSD_version >= 500000
587 		if (ret == 0) {
588 			dcons_cnprobe(&dcons_consdev);
589 			dcons_cninit(&dcons_consdev);
590 			cnadd(&dcons_consdev);
591 		}
592 #endif
593 		break;
594 	case MOD_UNLOAD:
595 		printf("dcons: unload\n");
596 		callout_stop(&dcons_callout);
597 #if DDB && DCONS_FORCE_GDB
598 #if CONS_NODEV
599 		gdb_arg = NULL;
600 #else
601 		gdbdev = NODEV;
602 #endif
603 #endif
604 #if __FreeBSD_version >= 500000
605 		cnremove(&dcons_consdev);
606 #endif
607 		dcons_detach(DCONS_CON);
608 		dcons_detach(DCONS_GDB);
609 		dg.buf->magic = 0;
610 
611 		contigfree(dg.buf, DCONS_BUF_SIZE, M_DEVBUF);
612 
613 		break;
614 	case MOD_SHUTDOWN:
615 		break;
616 	}
617 	return(err);
618 }
619 
620 DEV_MODULE(dcons, dcons_modevent, NULL);
621 MODULE_VERSION(dcons, DCONS_VERSION);
622