xref: /openbmc/linux/drivers/s390/char/con3270.c (revision ccc319dc) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * IBM/3270 Driver - console view.
4  *
5  * Author(s):
6  *   Original 3270 Code for 2.4 written by Richard Hitt (UTS Global)
7  *   Rewritten for 2.5 by Martin Schwidefsky <schwidefsky@de.ibm.com>
8  *     Copyright IBM Corp. 2003, 2009
9  */
10 
11 #include <linux/module.h>
12 #include <linux/console.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/list.h>
16 #include <linux/panic_notifier.h>
17 #include <linux/types.h>
18 #include <linux/slab.h>
19 #include <linux/err.h>
20 #include <linux/reboot.h>
21 
22 #include <asm/ccwdev.h>
23 #include <asm/cio.h>
24 #include <asm/cpcmd.h>
25 #include <asm/ebcdic.h>
26 
27 #include "raw3270.h"
28 #include "tty3270.h"
29 #include "ctrlchar.h"
30 
31 #define CON3270_OUTPUT_BUFFER_SIZE 1024
32 #define CON3270_STRING_PAGES 4
33 
34 static struct raw3270_fn con3270_fn;
35 
36 static bool auto_update = true;
37 module_param(auto_update, bool, 0);
38 
39 /*
40  * Main 3270 console view data structure.
41  */
42 struct con3270 {
43 	struct raw3270_view view;
44 	struct list_head freemem;	/* list of free memory for strings. */
45 
46 	/* Output stuff. */
47 	struct list_head lines;		/* list of lines. */
48 	struct list_head update;	/* list of lines to update. */
49 	int line_nr;			/* line number for next update. */
50 	int nr_lines;			/* # lines in list. */
51 	int nr_up;			/* # lines up in history. */
52 	unsigned long update_flags;	/* Update indication bits. */
53 	struct string *cline;		/* current output line. */
54 	struct string *status;		/* last line of display. */
55 	struct raw3270_request *write;	/* single write request. */
56 	struct timer_list timer;
57 
58 	/* Input stuff. */
59 	struct string *input;		/* input string for read request. */
60 	struct raw3270_request *read;	/* single read request. */
61 	struct raw3270_request *kreset;	/* single keyboard reset request. */
62 	struct tasklet_struct readlet;	/* tasklet to issue read request. */
63 };
64 
65 static struct con3270 *condev;
66 
67 /* con3270->update_flags. See con3270_update for details. */
68 #define CON_UPDATE_ERASE	1	/* Use EWRITEA instead of WRITE. */
69 #define CON_UPDATE_LIST		2	/* Update lines in tty3270->update. */
70 #define CON_UPDATE_STATUS	4	/* Update status line. */
71 #define CON_UPDATE_ALL		8	/* Recreate screen. */
72 
73 static void con3270_update(struct timer_list *);
74 
75 /*
76  * Setup timeout for a device. On timeout trigger an update.
77  */
78 static void con3270_set_timer(struct con3270 *cp, int expires)
79 {
80 	if (expires == 0)
81 		del_timer(&cp->timer);
82 	else
83 		mod_timer(&cp->timer, jiffies + expires);
84 }
85 
86 /*
87  * The status line is the last line of the screen. It shows the string
88  * "console view" in the lower left corner and "Running"/"More..."/"Holding"
89  * in the lower right corner of the screen.
90  */
91 static void
92 con3270_update_status(struct con3270 *cp)
93 {
94 	char *str;
95 
96 	str = (cp->nr_up != 0) ? "History" : "Running";
97 	memcpy(cp->status->string + 24, str, 7);
98 	codepage_convert(cp->view.ascebc, cp->status->string + 24, 7);
99 	cp->update_flags |= CON_UPDATE_STATUS;
100 }
101 
102 static void
103 con3270_create_status(struct con3270 *cp)
104 {
105 	static const unsigned char blueprint[] =
106 		{ TO_SBA, 0, 0, TO_SF,TF_LOG,TO_SA,TAT_COLOR, TAC_GREEN,
107 		  'c','o','n','s','o','l','e',' ','v','i','e','w',
108 		  TO_RA,0,0,0,'R','u','n','n','i','n','g',TO_SF,TF_LOG };
109 
110 	cp->status = alloc_string(&cp->freemem, sizeof(blueprint));
111 	/* Copy blueprint to status line */
112 	memcpy(cp->status->string, blueprint, sizeof(blueprint));
113 	/* Set TO_RA addresses. */
114 	raw3270_buffer_address(cp->view.dev, cp->status->string + 1,
115 			       cp->view.cols * (cp->view.rows - 1));
116 	raw3270_buffer_address(cp->view.dev, cp->status->string + 21,
117 			       cp->view.cols * cp->view.rows - 8);
118 	/* Convert strings to ebcdic. */
119 	codepage_convert(cp->view.ascebc, cp->status->string + 8, 12);
120 	codepage_convert(cp->view.ascebc, cp->status->string + 24, 7);
121 }
122 
123 /*
124  * Set output offsets to 3270 datastream fragment of a console string.
125  */
126 static void
127 con3270_update_string(struct con3270 *cp, struct string *s, int nr)
128 {
129 	if (s->len < 4) {
130 		/* This indicates a bug, but printing a warning would
131 		 * cause a deadlock. */
132 		return;
133 	}
134 	if (s->string[s->len - 4] != TO_RA)
135 		return;
136 	raw3270_buffer_address(cp->view.dev, s->string + s->len - 3,
137 			       cp->view.cols * (nr + 1));
138 }
139 
140 /*
141  * Rebuild update list to print all lines.
142  */
143 static void
144 con3270_rebuild_update(struct con3270 *cp)
145 {
146 	struct string *s, *n;
147 	int nr;
148 
149 	/*
150 	 * Throw away update list and create a new one,
151 	 * containing all lines that will fit on the screen.
152 	 */
153 	list_for_each_entry_safe(s, n, &cp->update, update)
154 		list_del_init(&s->update);
155 	nr = cp->view.rows - 2 + cp->nr_up;
156 	list_for_each_entry_reverse(s, &cp->lines, list) {
157 		if (nr < cp->view.rows - 1)
158 			list_add(&s->update, &cp->update);
159 		if (--nr < 0)
160 			break;
161 	}
162 	cp->line_nr = 0;
163 	cp->update_flags |= CON_UPDATE_LIST;
164 }
165 
166 /*
167  * Alloc string for size bytes. Free strings from history if necessary.
168  */
169 static struct string *
170 con3270_alloc_string(struct con3270 *cp, size_t size)
171 {
172 	struct string *s, *n;
173 
174 	s = alloc_string(&cp->freemem, size);
175 	if (s)
176 		return s;
177 	list_for_each_entry_safe(s, n, &cp->lines, list) {
178 		list_del(&s->list);
179 		if (!list_empty(&s->update))
180 			list_del(&s->update);
181 		cp->nr_lines--;
182 		if (free_string(&cp->freemem, s) >= size)
183 			break;
184 	}
185 	s = alloc_string(&cp->freemem, size);
186 	BUG_ON(!s);
187 	if (cp->nr_up != 0 && cp->nr_up + cp->view.rows > cp->nr_lines) {
188 		cp->nr_up = cp->nr_lines - cp->view.rows + 1;
189 		con3270_rebuild_update(cp);
190 		con3270_update_status(cp);
191 	}
192 	return s;
193 }
194 
195 /*
196  * Write completion callback.
197  */
198 static void
199 con3270_write_callback(struct raw3270_request *rq, void *data)
200 {
201 	raw3270_request_reset(rq);
202 	xchg(&((struct con3270 *) rq->view)->write, rq);
203 }
204 
205 /*
206  * Update console display.
207  */
208 static void
209 con3270_update(struct timer_list *t)
210 {
211 	struct con3270 *cp = from_timer(cp, t, timer);
212 	struct raw3270_request *wrq;
213 	char wcc, prolog[6];
214 	unsigned long flags;
215 	unsigned long updated;
216 	struct string *s, *n;
217 	int rc;
218 
219 	if (!auto_update && !raw3270_view_active(&cp->view))
220 		return;
221 	if (cp->view.dev)
222 		raw3270_activate_view(&cp->view);
223 
224 	wrq = xchg(&cp->write, 0);
225 	if (!wrq) {
226 		con3270_set_timer(cp, 1);
227 		return;
228 	}
229 
230 	spin_lock_irqsave(&cp->view.lock, flags);
231 	updated = 0;
232 	if (cp->update_flags & CON_UPDATE_ALL) {
233 		con3270_rebuild_update(cp);
234 		con3270_update_status(cp);
235 		cp->update_flags = CON_UPDATE_ERASE | CON_UPDATE_LIST |
236 			CON_UPDATE_STATUS;
237 	}
238 	if (cp->update_flags & CON_UPDATE_ERASE) {
239 		/* Use erase write alternate to initialize display. */
240 		raw3270_request_set_cmd(wrq, TC_EWRITEA);
241 		updated |= CON_UPDATE_ERASE;
242 	} else
243 		raw3270_request_set_cmd(wrq, TC_WRITE);
244 
245 	wcc = TW_NONE;
246 	raw3270_request_add_data(wrq, &wcc, 1);
247 
248 	/*
249 	 * Update status line.
250 	 */
251 	if (cp->update_flags & CON_UPDATE_STATUS)
252 		if (raw3270_request_add_data(wrq, cp->status->string,
253 					     cp->status->len) == 0)
254 			updated |= CON_UPDATE_STATUS;
255 
256 	if (cp->update_flags & CON_UPDATE_LIST) {
257 		prolog[0] = TO_SBA;
258 		prolog[3] = TO_SA;
259 		prolog[4] = TAT_COLOR;
260 		prolog[5] = TAC_TURQ;
261 		raw3270_buffer_address(cp->view.dev, prolog + 1,
262 				       cp->view.cols * cp->line_nr);
263 		raw3270_request_add_data(wrq, prolog, 6);
264 		/* Write strings in the update list to the screen. */
265 		list_for_each_entry_safe(s, n, &cp->update, update) {
266 			if (s != cp->cline)
267 				con3270_update_string(cp, s, cp->line_nr);
268 			if (raw3270_request_add_data(wrq, s->string,
269 						     s->len) != 0)
270 				break;
271 			list_del_init(&s->update);
272 			if (s != cp->cline)
273 				cp->line_nr++;
274 		}
275 		if (list_empty(&cp->update))
276 			updated |= CON_UPDATE_LIST;
277 	}
278 	wrq->callback = con3270_write_callback;
279 	rc = raw3270_start(&cp->view, wrq);
280 	if (rc == 0) {
281 		cp->update_flags &= ~updated;
282 		if (cp->update_flags)
283 			con3270_set_timer(cp, 1);
284 	} else {
285 		raw3270_request_reset(wrq);
286 		xchg(&cp->write, wrq);
287 	}
288 	spin_unlock_irqrestore(&cp->view.lock, flags);
289 }
290 
291 /*
292  * Read tasklet.
293  */
294 static void
295 con3270_read_tasklet(unsigned long data)
296 {
297 	static char kreset_data = TW_KR;
298 	struct raw3270_request *rrq;
299 	struct con3270 *cp;
300 	unsigned long flags;
301 	int nr_up, deactivate;
302 
303 	rrq = (struct raw3270_request *)data;
304 	cp = (struct con3270 *) rrq->view;
305 	spin_lock_irqsave(&cp->view.lock, flags);
306 	nr_up = cp->nr_up;
307 	deactivate = 0;
308 	/* Check aid byte. */
309 	switch (cp->input->string[0]) {
310 	case 0x7d:	/* enter: jump to bottom. */
311 		nr_up = 0;
312 		break;
313 	case 0xf3:	/* PF3: deactivate the console view. */
314 		deactivate = 1;
315 		break;
316 	case 0x6d:	/* clear: start from scratch. */
317 		cp->update_flags = CON_UPDATE_ALL;
318 		con3270_set_timer(cp, 1);
319 		break;
320 	case 0xf7:	/* PF7: do a page up in the console log. */
321 		nr_up += cp->view.rows - 2;
322 		if (nr_up + cp->view.rows - 1 > cp->nr_lines) {
323 			nr_up = cp->nr_lines - cp->view.rows + 1;
324 			if (nr_up < 0)
325 				nr_up = 0;
326 		}
327 		break;
328 	case 0xf8:	/* PF8: do a page down in the console log. */
329 		nr_up -= cp->view.rows - 2;
330 		if (nr_up < 0)
331 			nr_up = 0;
332 		break;
333 	}
334 	if (nr_up != cp->nr_up) {
335 		cp->nr_up = nr_up;
336 		con3270_rebuild_update(cp);
337 		con3270_update_status(cp);
338 		con3270_set_timer(cp, 1);
339 	}
340 	spin_unlock_irqrestore(&cp->view.lock, flags);
341 
342 	/* Start keyboard reset command. */
343 	raw3270_request_reset(cp->kreset);
344 	raw3270_request_set_cmd(cp->kreset, TC_WRITE);
345 	raw3270_request_add_data(cp->kreset, &kreset_data, 1);
346 	raw3270_start(&cp->view, cp->kreset);
347 
348 	if (deactivate)
349 		raw3270_deactivate_view(&cp->view);
350 
351 	raw3270_request_reset(rrq);
352 	xchg(&cp->read, rrq);
353 	raw3270_put_view(&cp->view);
354 }
355 
356 /*
357  * Read request completion callback.
358  */
359 static void
360 con3270_read_callback(struct raw3270_request *rq, void *data)
361 {
362 	raw3270_get_view(rq->view);
363 	/* Schedule tasklet to pass input to tty. */
364 	tasklet_schedule(&((struct con3270 *) rq->view)->readlet);
365 }
366 
367 /*
368  * Issue a read request. Called only from interrupt function.
369  */
370 static void
371 con3270_issue_read(struct con3270 *cp)
372 {
373 	struct raw3270_request *rrq;
374 	int rc;
375 
376 	rrq = xchg(&cp->read, 0);
377 	if (!rrq)
378 		/* Read already scheduled. */
379 		return;
380 	rrq->callback = con3270_read_callback;
381 	rrq->callback_data = cp;
382 	raw3270_request_set_cmd(rrq, TC_READMOD);
383 	raw3270_request_set_data(rrq, cp->input->string, cp->input->len);
384 	/* Issue the read modified request. */
385 	rc = raw3270_start_irq(&cp->view, rrq);
386 	if (rc)
387 		raw3270_request_reset(rrq);
388 }
389 
390 /*
391  * Switch to the console view.
392  */
393 static int
394 con3270_activate(struct raw3270_view *view)
395 {
396 	struct con3270 *cp;
397 
398 	cp = (struct con3270 *) view;
399 	cp->update_flags = CON_UPDATE_ALL;
400 	con3270_set_timer(cp, 1);
401 	return 0;
402 }
403 
404 static void
405 con3270_deactivate(struct raw3270_view *view)
406 {
407 	struct con3270 *cp;
408 
409 	cp = (struct con3270 *) view;
410 	del_timer(&cp->timer);
411 }
412 
413 static void
414 con3270_irq(struct con3270 *cp, struct raw3270_request *rq, struct irb *irb)
415 {
416 	/* Handle ATTN. Schedule tasklet to read aid. */
417 	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION)
418 		con3270_issue_read(cp);
419 
420 	if (rq) {
421 		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
422 			rq->rc = -EIO;
423 		else
424 			/* Normal end. Copy residual count. */
425 			rq->rescnt = irb->scsw.cmd.count;
426 	} else if (irb->scsw.cmd.dstat & DEV_STAT_DEV_END) {
427 		/* Interrupt without an outstanding request -> update all */
428 		cp->update_flags = CON_UPDATE_ALL;
429 		con3270_set_timer(cp, 1);
430 	}
431 }
432 
433 /* Console view to a 3270 device. */
434 static struct raw3270_fn con3270_fn = {
435 	.activate = con3270_activate,
436 	.deactivate = con3270_deactivate,
437 	.intv = (void *) con3270_irq
438 };
439 
440 static inline void
441 con3270_cline_add(struct con3270 *cp)
442 {
443 	if (!list_empty(&cp->cline->list))
444 		/* Already added. */
445 		return;
446 	list_add_tail(&cp->cline->list, &cp->lines);
447 	cp->nr_lines++;
448 	con3270_rebuild_update(cp);
449 }
450 
451 static inline void
452 con3270_cline_insert(struct con3270 *cp, unsigned char c)
453 {
454 	cp->cline->string[cp->cline->len++] =
455 		cp->view.ascebc[(c < ' ') ? ' ' : c];
456 	if (list_empty(&cp->cline->update)) {
457 		list_add_tail(&cp->cline->update, &cp->update);
458 		cp->update_flags |= CON_UPDATE_LIST;
459 	}
460 }
461 
462 static inline void
463 con3270_cline_end(struct con3270 *cp)
464 {
465 	struct string *s;
466 	unsigned int size;
467 
468 	/* Copy cline. */
469 	size = (cp->cline->len < cp->view.cols - 5) ?
470 		cp->cline->len + 4 : cp->view.cols;
471 	s = con3270_alloc_string(cp, size);
472 	memcpy(s->string, cp->cline->string, cp->cline->len);
473 	if (cp->cline->len < cp->view.cols - 5) {
474 		s->string[s->len - 4] = TO_RA;
475 		s->string[s->len - 1] = 0;
476 	} else {
477 		while (--size >= cp->cline->len)
478 			s->string[size] = cp->view.ascebc[' '];
479 	}
480 	/* Replace cline with allocated line s and reset cline. */
481 	list_add(&s->list, &cp->cline->list);
482 	list_del_init(&cp->cline->list);
483 	if (!list_empty(&cp->cline->update)) {
484 		list_add(&s->update, &cp->cline->update);
485 		list_del_init(&cp->cline->update);
486 	}
487 	cp->cline->len = 0;
488 }
489 
490 /*
491  * Write a string to the 3270 console
492  */
493 static void
494 con3270_write(struct console *co, const char *str, unsigned int count)
495 {
496 	struct con3270 *cp;
497 	unsigned long flags;
498 	unsigned char c;
499 
500 	cp = condev;
501 	spin_lock_irqsave(&cp->view.lock, flags);
502 	while (count-- > 0) {
503 		c = *str++;
504 		if (cp->cline->len == 0)
505 			con3270_cline_add(cp);
506 		if (c != '\n')
507 			con3270_cline_insert(cp, c);
508 		if (c == '\n' || cp->cline->len >= cp->view.cols)
509 			con3270_cline_end(cp);
510 	}
511 	/* Setup timer to output current console buffer after 1/10 second */
512 	cp->nr_up = 0;
513 	if (cp->view.dev && !timer_pending(&cp->timer))
514 		con3270_set_timer(cp, HZ/10);
515 	spin_unlock_irqrestore(&cp->view.lock,flags);
516 }
517 
518 static struct tty_driver *
519 con3270_device(struct console *c, int *index)
520 {
521 	*index = c->index;
522 	return tty3270_driver;
523 }
524 
525 /*
526  * Wait for end of write request.
527  */
528 static void
529 con3270_wait_write(struct con3270 *cp)
530 {
531 	while (!cp->write) {
532 		raw3270_wait_cons_dev(cp->view.dev);
533 		barrier();
534 	}
535 }
536 
537 /*
538  * The below function is called as a panic/reboot notifier before the
539  * system enters a disabled, endless loop.
540  *
541  * Notice we must use the spin_trylock() alternative, to prevent lockups
542  * in atomic context (panic routine runs with secondary CPUs, local IRQs
543  * and preemption disabled).
544  */
545 static int con3270_notify(struct notifier_block *self,
546 			  unsigned long event, void *data)
547 {
548 	struct con3270 *cp;
549 	unsigned long flags;
550 
551 	cp = condev;
552 	if (!cp->view.dev)
553 		return NOTIFY_DONE;
554 	if (!raw3270_view_lock_unavailable(&cp->view))
555 		raw3270_activate_view(&cp->view);
556 	if (!spin_trylock_irqsave(&cp->view.lock, flags))
557 		return NOTIFY_DONE;
558 	con3270_wait_write(cp);
559 	cp->nr_up = 0;
560 	con3270_rebuild_update(cp);
561 	con3270_update_status(cp);
562 	while (cp->update_flags != 0) {
563 		spin_unlock_irqrestore(&cp->view.lock, flags);
564 		con3270_update(&cp->timer);
565 		spin_lock_irqsave(&cp->view.lock, flags);
566 		con3270_wait_write(cp);
567 	}
568 	spin_unlock_irqrestore(&cp->view.lock, flags);
569 
570 	return NOTIFY_DONE;
571 }
572 
573 static struct notifier_block on_panic_nb = {
574 	.notifier_call = con3270_notify,
575 	.priority = INT_MIN + 1, /* run the callback late */
576 };
577 
578 static struct notifier_block on_reboot_nb = {
579 	.notifier_call = con3270_notify,
580 	.priority = INT_MIN + 1, /* run the callback late */
581 };
582 
583 /*
584  *  The console structure for the 3270 console
585  */
586 static struct console con3270 = {
587 	.name	 = "tty3270",
588 	.write	 = con3270_write,
589 	.device	 = con3270_device,
590 	.flags	 = CON_PRINTBUFFER,
591 };
592 
593 /*
594  * 3270 console initialization code called from console_init().
595  */
596 static int __init
597 con3270_init(void)
598 {
599 	struct raw3270 *rp;
600 	void *cbuf;
601 	int i;
602 
603 	/* Check if 3270 is to be the console */
604 	if (!CONSOLE_IS_3270)
605 		return -ENODEV;
606 
607 	/* Set the console mode for VM */
608 	if (MACHINE_IS_VM) {
609 		cpcmd("TERM CONMODE 3270", NULL, 0, NULL);
610 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
611 	}
612 
613 	rp = raw3270_setup_console();
614 	if (IS_ERR(rp))
615 		return PTR_ERR(rp);
616 
617 	condev = kzalloc(sizeof(struct con3270), GFP_KERNEL | GFP_DMA);
618 	if (!condev)
619 		return -ENOMEM;
620 	condev->view.dev = rp;
621 
622 	condev->read = raw3270_request_alloc(0);
623 	condev->read->callback = con3270_read_callback;
624 	condev->read->callback_data = condev;
625 	condev->write = raw3270_request_alloc(CON3270_OUTPUT_BUFFER_SIZE);
626 	condev->kreset = raw3270_request_alloc(1);
627 
628 	INIT_LIST_HEAD(&condev->lines);
629 	INIT_LIST_HEAD(&condev->update);
630 	timer_setup(&condev->timer, con3270_update, 0);
631 	tasklet_init(&condev->readlet, con3270_read_tasklet,
632 		     (unsigned long) condev->read);
633 
634 	raw3270_add_view(&condev->view, &con3270_fn, 1, RAW3270_VIEW_LOCK_IRQ);
635 
636 	INIT_LIST_HEAD(&condev->freemem);
637 	for (i = 0; i < CON3270_STRING_PAGES; i++) {
638 		cbuf = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
639 		add_string_memory(&condev->freemem, cbuf, PAGE_SIZE);
640 	}
641 	condev->cline = alloc_string(&condev->freemem, condev->view.cols);
642 	condev->cline->len = 0;
643 	con3270_create_status(condev);
644 	condev->input = alloc_string(&condev->freemem, 80);
645 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
646 	register_reboot_notifier(&on_reboot_nb);
647 	register_console(&con3270);
648 	return 0;
649 }
650 
651 console_initcall(con3270_init);
652