xref: /openbmc/linux/drivers/s390/char/con3270.c (revision a44e4f3a)
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/types.h>
17 #include <linux/slab.h>
18 #include <linux/err.h>
19 #include <linux/reboot.h>
20 
21 #include <asm/ccwdev.h>
22 #include <asm/cio.h>
23 #include <asm/cpcmd.h>
24 #include <asm/ebcdic.h>
25 
26 #include "raw3270.h"
27 #include "tty3270.h"
28 #include "ctrlchar.h"
29 
30 #define CON3270_OUTPUT_BUFFER_SIZE 1024
31 #define CON3270_STRING_PAGES 4
32 
33 static struct raw3270_fn con3270_fn;
34 
35 static bool auto_update = true;
36 module_param(auto_update, bool, 0);
37 
38 /*
39  * Main 3270 console view data structure.
40  */
41 struct con3270 {
42 	struct raw3270_view view;
43 	struct list_head freemem;	/* list of free memory for strings. */
44 
45 	/* Output stuff. */
46 	struct list_head lines;		/* list of lines. */
47 	struct list_head update;	/* list of lines to update. */
48 	int line_nr;			/* line number for next update. */
49 	int nr_lines;			/* # lines in list. */
50 	int nr_up;			/* # lines up in history. */
51 	unsigned long update_flags;	/* Update indication bits. */
52 	struct string *cline;		/* current output line. */
53 	struct string *status;		/* last line of display. */
54 	struct raw3270_request *write;	/* single write request. */
55 	struct timer_list timer;
56 
57 	/* Input stuff. */
58 	struct string *input;		/* input string for read request. */
59 	struct raw3270_request *read;	/* single read request. */
60 	struct raw3270_request *kreset;	/* single keyboard reset request. */
61 	struct tasklet_struct readlet;	/* tasklet to issue read request. */
62 };
63 
64 static struct con3270 *condev;
65 
66 /* con3270->update_flags. See con3270_update for details. */
67 #define CON_UPDATE_ERASE	1	/* Use EWRITEA instead of WRITE. */
68 #define CON_UPDATE_LIST		2	/* Update lines in tty3270->update. */
69 #define CON_UPDATE_STATUS	4	/* Update status line. */
70 #define CON_UPDATE_ALL		8	/* Recreate screen. */
71 
72 static void con3270_update(struct timer_list *);
73 
74 /*
75  * Setup timeout for a device. On timeout trigger an update.
76  */
77 static void con3270_set_timer(struct con3270 *cp, int expires)
78 {
79 	if (expires == 0)
80 		del_timer(&cp->timer);
81 	else
82 		mod_timer(&cp->timer, jiffies + expires);
83 }
84 
85 /*
86  * The status line is the last line of the screen. It shows the string
87  * "console view" in the lower left corner and "Running"/"More..."/"Holding"
88  * in the lower right corner of the screen.
89  */
90 static void
91 con3270_update_status(struct con3270 *cp)
92 {
93 	char *str;
94 
95 	str = (cp->nr_up != 0) ? "History" : "Running";
96 	memcpy(cp->status->string + 24, str, 7);
97 	codepage_convert(cp->view.ascebc, cp->status->string + 24, 7);
98 	cp->update_flags |= CON_UPDATE_STATUS;
99 }
100 
101 static void
102 con3270_create_status(struct con3270 *cp)
103 {
104 	static const unsigned char blueprint[] =
105 		{ TO_SBA, 0, 0, TO_SF,TF_LOG,TO_SA,TAT_COLOR, TAC_GREEN,
106 		  'c','o','n','s','o','l','e',' ','v','i','e','w',
107 		  TO_RA,0,0,0,'R','u','n','n','i','n','g',TO_SF,TF_LOG };
108 
109 	cp->status = alloc_string(&cp->freemem, sizeof(blueprint));
110 	/* Copy blueprint to status line */
111 	memcpy(cp->status->string, blueprint, sizeof(blueprint));
112 	/* Set TO_RA addresses. */
113 	raw3270_buffer_address(cp->view.dev, cp->status->string + 1,
114 			       cp->view.cols * (cp->view.rows - 1));
115 	raw3270_buffer_address(cp->view.dev, cp->status->string + 21,
116 			       cp->view.cols * cp->view.rows - 8);
117 	/* Convert strings to ebcdic. */
118 	codepage_convert(cp->view.ascebc, cp->status->string + 8, 12);
119 	codepage_convert(cp->view.ascebc, cp->status->string + 24, 7);
120 }
121 
122 /*
123  * Set output offsets to 3270 datastream fragment of a console string.
124  */
125 static void
126 con3270_update_string(struct con3270 *cp, struct string *s, int nr)
127 {
128 	if (s->len < 4) {
129 		/* This indicates a bug, but printing a warning would
130 		 * cause a deadlock. */
131 		return;
132 	}
133 	if (s->string[s->len - 4] != TO_RA)
134 		return;
135 	raw3270_buffer_address(cp->view.dev, s->string + s->len - 3,
136 			       cp->view.cols * (nr + 1));
137 }
138 
139 /*
140  * Rebuild update list to print all lines.
141  */
142 static void
143 con3270_rebuild_update(struct con3270 *cp)
144 {
145 	struct string *s, *n;
146 	int nr;
147 
148 	/*
149 	 * Throw away update list and create a new one,
150 	 * containing all lines that will fit on the screen.
151 	 */
152 	list_for_each_entry_safe(s, n, &cp->update, update)
153 		list_del_init(&s->update);
154 	nr = cp->view.rows - 2 + cp->nr_up;
155 	list_for_each_entry_reverse(s, &cp->lines, list) {
156 		if (nr < cp->view.rows - 1)
157 			list_add(&s->update, &cp->update);
158 		if (--nr < 0)
159 			break;
160 	}
161 	cp->line_nr = 0;
162 	cp->update_flags |= CON_UPDATE_LIST;
163 }
164 
165 /*
166  * Alloc string for size bytes. Free strings from history if necessary.
167  */
168 static struct string *
169 con3270_alloc_string(struct con3270 *cp, size_t size)
170 {
171 	struct string *s, *n;
172 
173 	s = alloc_string(&cp->freemem, size);
174 	if (s)
175 		return s;
176 	list_for_each_entry_safe(s, n, &cp->lines, list) {
177 		list_del(&s->list);
178 		if (!list_empty(&s->update))
179 			list_del(&s->update);
180 		cp->nr_lines--;
181 		if (free_string(&cp->freemem, s) >= size)
182 			break;
183 	}
184 	s = alloc_string(&cp->freemem, size);
185 	BUG_ON(!s);
186 	if (cp->nr_up != 0 && cp->nr_up + cp->view.rows > cp->nr_lines) {
187 		cp->nr_up = cp->nr_lines - cp->view.rows + 1;
188 		con3270_rebuild_update(cp);
189 		con3270_update_status(cp);
190 	}
191 	return s;
192 }
193 
194 /*
195  * Write completion callback.
196  */
197 static void
198 con3270_write_callback(struct raw3270_request *rq, void *data)
199 {
200 	raw3270_request_reset(rq);
201 	xchg(&((struct con3270 *) rq->view)->write, rq);
202 }
203 
204 /*
205  * Update console display.
206  */
207 static void
208 con3270_update(struct timer_list *t)
209 {
210 	struct con3270 *cp = from_timer(cp, t, timer);
211 	struct raw3270_request *wrq;
212 	char wcc, prolog[6];
213 	unsigned long flags;
214 	unsigned long updated;
215 	struct string *s, *n;
216 	int rc;
217 
218 	if (!auto_update && !raw3270_view_active(&cp->view))
219 		return;
220 	if (cp->view.dev)
221 		raw3270_activate_view(&cp->view);
222 
223 	wrq = xchg(&cp->write, 0);
224 	if (!wrq) {
225 		con3270_set_timer(cp, 1);
226 		return;
227 	}
228 
229 	spin_lock_irqsave(&cp->view.lock, flags);
230 	updated = 0;
231 	if (cp->update_flags & CON_UPDATE_ALL) {
232 		con3270_rebuild_update(cp);
233 		con3270_update_status(cp);
234 		cp->update_flags = CON_UPDATE_ERASE | CON_UPDATE_LIST |
235 			CON_UPDATE_STATUS;
236 	}
237 	if (cp->update_flags & CON_UPDATE_ERASE) {
238 		/* Use erase write alternate to initialize display. */
239 		raw3270_request_set_cmd(wrq, TC_EWRITEA);
240 		updated |= CON_UPDATE_ERASE;
241 	} else
242 		raw3270_request_set_cmd(wrq, TC_WRITE);
243 
244 	wcc = TW_NONE;
245 	raw3270_request_add_data(wrq, &wcc, 1);
246 
247 	/*
248 	 * Update status line.
249 	 */
250 	if (cp->update_flags & CON_UPDATE_STATUS)
251 		if (raw3270_request_add_data(wrq, cp->status->string,
252 					     cp->status->len) == 0)
253 			updated |= CON_UPDATE_STATUS;
254 
255 	if (cp->update_flags & CON_UPDATE_LIST) {
256 		prolog[0] = TO_SBA;
257 		prolog[3] = TO_SA;
258 		prolog[4] = TAT_COLOR;
259 		prolog[5] = TAC_TURQ;
260 		raw3270_buffer_address(cp->view.dev, prolog + 1,
261 				       cp->view.cols * cp->line_nr);
262 		raw3270_request_add_data(wrq, prolog, 6);
263 		/* Write strings in the update list to the screen. */
264 		list_for_each_entry_safe(s, n, &cp->update, update) {
265 			if (s != cp->cline)
266 				con3270_update_string(cp, s, cp->line_nr);
267 			if (raw3270_request_add_data(wrq, s->string,
268 						     s->len) != 0)
269 				break;
270 			list_del_init(&s->update);
271 			if (s != cp->cline)
272 				cp->line_nr++;
273 		}
274 		if (list_empty(&cp->update))
275 			updated |= CON_UPDATE_LIST;
276 	}
277 	wrq->callback = con3270_write_callback;
278 	rc = raw3270_start(&cp->view, wrq);
279 	if (rc == 0) {
280 		cp->update_flags &= ~updated;
281 		if (cp->update_flags)
282 			con3270_set_timer(cp, 1);
283 	} else {
284 		raw3270_request_reset(wrq);
285 		xchg(&cp->write, wrq);
286 	}
287 	spin_unlock_irqrestore(&cp->view.lock, flags);
288 }
289 
290 /*
291  * Read tasklet.
292  */
293 static void
294 con3270_read_tasklet(struct raw3270_request *rrq)
295 {
296 	static char kreset_data = TW_KR;
297 	struct con3270 *cp;
298 	unsigned long flags;
299 	int nr_up, deactivate;
300 
301 	cp = (struct con3270 *) rrq->view;
302 	spin_lock_irqsave(&cp->view.lock, flags);
303 	nr_up = cp->nr_up;
304 	deactivate = 0;
305 	/* Check aid byte. */
306 	switch (cp->input->string[0]) {
307 	case 0x7d:	/* enter: jump to bottom. */
308 		nr_up = 0;
309 		break;
310 	case 0xf3:	/* PF3: deactivate the console view. */
311 		deactivate = 1;
312 		break;
313 	case 0x6d:	/* clear: start from scratch. */
314 		cp->update_flags = CON_UPDATE_ALL;
315 		con3270_set_timer(cp, 1);
316 		break;
317 	case 0xf7:	/* PF7: do a page up in the console log. */
318 		nr_up += cp->view.rows - 2;
319 		if (nr_up + cp->view.rows - 1 > cp->nr_lines) {
320 			nr_up = cp->nr_lines - cp->view.rows + 1;
321 			if (nr_up < 0)
322 				nr_up = 0;
323 		}
324 		break;
325 	case 0xf8:	/* PF8: do a page down in the console log. */
326 		nr_up -= cp->view.rows - 2;
327 		if (nr_up < 0)
328 			nr_up = 0;
329 		break;
330 	}
331 	if (nr_up != cp->nr_up) {
332 		cp->nr_up = nr_up;
333 		con3270_rebuild_update(cp);
334 		con3270_update_status(cp);
335 		con3270_set_timer(cp, 1);
336 	}
337 	spin_unlock_irqrestore(&cp->view.lock, flags);
338 
339 	/* Start keyboard reset command. */
340 	raw3270_request_reset(cp->kreset);
341 	raw3270_request_set_cmd(cp->kreset, TC_WRITE);
342 	raw3270_request_add_data(cp->kreset, &kreset_data, 1);
343 	raw3270_start(&cp->view, cp->kreset);
344 
345 	if (deactivate)
346 		raw3270_deactivate_view(&cp->view);
347 
348 	raw3270_request_reset(rrq);
349 	xchg(&cp->read, rrq);
350 	raw3270_put_view(&cp->view);
351 }
352 
353 /*
354  * Read request completion callback.
355  */
356 static void
357 con3270_read_callback(struct raw3270_request *rq, void *data)
358 {
359 	raw3270_get_view(rq->view);
360 	/* Schedule tasklet to pass input to tty. */
361 	tasklet_schedule(&((struct con3270 *) rq->view)->readlet);
362 }
363 
364 /*
365  * Issue a read request. Called only from interrupt function.
366  */
367 static void
368 con3270_issue_read(struct con3270 *cp)
369 {
370 	struct raw3270_request *rrq;
371 	int rc;
372 
373 	rrq = xchg(&cp->read, 0);
374 	if (!rrq)
375 		/* Read already scheduled. */
376 		return;
377 	rrq->callback = con3270_read_callback;
378 	rrq->callback_data = cp;
379 	raw3270_request_set_cmd(rrq, TC_READMOD);
380 	raw3270_request_set_data(rrq, cp->input->string, cp->input->len);
381 	/* Issue the read modified request. */
382 	rc = raw3270_start_irq(&cp->view, rrq);
383 	if (rc)
384 		raw3270_request_reset(rrq);
385 }
386 
387 /*
388  * Switch to the console view.
389  */
390 static int
391 con3270_activate(struct raw3270_view *view)
392 {
393 	struct con3270 *cp;
394 
395 	cp = (struct con3270 *) view;
396 	cp->update_flags = CON_UPDATE_ALL;
397 	con3270_set_timer(cp, 1);
398 	return 0;
399 }
400 
401 static void
402 con3270_deactivate(struct raw3270_view *view)
403 {
404 	struct con3270 *cp;
405 
406 	cp = (struct con3270 *) view;
407 	del_timer(&cp->timer);
408 }
409 
410 static void
411 con3270_irq(struct con3270 *cp, struct raw3270_request *rq, struct irb *irb)
412 {
413 	/* Handle ATTN. Schedule tasklet to read aid. */
414 	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION)
415 		con3270_issue_read(cp);
416 
417 	if (rq) {
418 		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
419 			rq->rc = -EIO;
420 		else
421 			/* Normal end. Copy residual count. */
422 			rq->rescnt = irb->scsw.cmd.count;
423 	} else if (irb->scsw.cmd.dstat & DEV_STAT_DEV_END) {
424 		/* Interrupt without an outstanding request -> update all */
425 		cp->update_flags = CON_UPDATE_ALL;
426 		con3270_set_timer(cp, 1);
427 	}
428 }
429 
430 /* Console view to a 3270 device. */
431 static struct raw3270_fn con3270_fn = {
432 	.activate = con3270_activate,
433 	.deactivate = con3270_deactivate,
434 	.intv = (void *) con3270_irq
435 };
436 
437 static inline void
438 con3270_cline_add(struct con3270 *cp)
439 {
440 	if (!list_empty(&cp->cline->list))
441 		/* Already added. */
442 		return;
443 	list_add_tail(&cp->cline->list, &cp->lines);
444 	cp->nr_lines++;
445 	con3270_rebuild_update(cp);
446 }
447 
448 static inline void
449 con3270_cline_insert(struct con3270 *cp, unsigned char c)
450 {
451 	cp->cline->string[cp->cline->len++] =
452 		cp->view.ascebc[(c < ' ') ? ' ' : c];
453 	if (list_empty(&cp->cline->update)) {
454 		list_add_tail(&cp->cline->update, &cp->update);
455 		cp->update_flags |= CON_UPDATE_LIST;
456 	}
457 }
458 
459 static inline void
460 con3270_cline_end(struct con3270 *cp)
461 {
462 	struct string *s;
463 	unsigned int size;
464 
465 	/* Copy cline. */
466 	size = (cp->cline->len < cp->view.cols - 5) ?
467 		cp->cline->len + 4 : cp->view.cols;
468 	s = con3270_alloc_string(cp, size);
469 	memcpy(s->string, cp->cline->string, cp->cline->len);
470 	if (cp->cline->len < cp->view.cols - 5) {
471 		s->string[s->len - 4] = TO_RA;
472 		s->string[s->len - 1] = 0;
473 	} else {
474 		while (--size >= cp->cline->len)
475 			s->string[size] = cp->view.ascebc[' '];
476 	}
477 	/* Replace cline with allocated line s and reset cline. */
478 	list_add(&s->list, &cp->cline->list);
479 	list_del_init(&cp->cline->list);
480 	if (!list_empty(&cp->cline->update)) {
481 		list_add(&s->update, &cp->cline->update);
482 		list_del_init(&cp->cline->update);
483 	}
484 	cp->cline->len = 0;
485 }
486 
487 /*
488  * Write a string to the 3270 console
489  */
490 static void
491 con3270_write(struct console *co, const char *str, unsigned int count)
492 {
493 	struct con3270 *cp;
494 	unsigned long flags;
495 	unsigned char c;
496 
497 	cp = condev;
498 	spin_lock_irqsave(&cp->view.lock, flags);
499 	while (count-- > 0) {
500 		c = *str++;
501 		if (cp->cline->len == 0)
502 			con3270_cline_add(cp);
503 		if (c != '\n')
504 			con3270_cline_insert(cp, c);
505 		if (c == '\n' || cp->cline->len >= cp->view.cols)
506 			con3270_cline_end(cp);
507 	}
508 	/* Setup timer to output current console buffer after 1/10 second */
509 	cp->nr_up = 0;
510 	if (cp->view.dev && !timer_pending(&cp->timer))
511 		con3270_set_timer(cp, HZ/10);
512 	spin_unlock_irqrestore(&cp->view.lock,flags);
513 }
514 
515 static struct tty_driver *
516 con3270_device(struct console *c, int *index)
517 {
518 	*index = c->index;
519 	return tty3270_driver;
520 }
521 
522 /*
523  * Wait for end of write request.
524  */
525 static void
526 con3270_wait_write(struct con3270 *cp)
527 {
528 	while (!cp->write) {
529 		raw3270_wait_cons_dev(cp->view.dev);
530 		barrier();
531 	}
532 }
533 
534 /*
535  * panic() calls con3270_flush through a panic_notifier
536  * before the system enters a disabled, endless loop.
537  */
538 static void
539 con3270_flush(void)
540 {
541 	struct con3270 *cp;
542 	unsigned long flags;
543 
544 	cp = condev;
545 	if (!cp->view.dev)
546 		return;
547 	raw3270_pm_unfreeze(&cp->view);
548 	raw3270_activate_view(&cp->view);
549 	spin_lock_irqsave(&cp->view.lock, flags);
550 	con3270_wait_write(cp);
551 	cp->nr_up = 0;
552 	con3270_rebuild_update(cp);
553 	con3270_update_status(cp);
554 	while (cp->update_flags != 0) {
555 		spin_unlock_irqrestore(&cp->view.lock, flags);
556 		con3270_update(&cp->timer);
557 		spin_lock_irqsave(&cp->view.lock, flags);
558 		con3270_wait_write(cp);
559 	}
560 	spin_unlock_irqrestore(&cp->view.lock, flags);
561 }
562 
563 static int con3270_notify(struct notifier_block *self,
564 			  unsigned long event, void *data)
565 {
566 	con3270_flush();
567 	return NOTIFY_OK;
568 }
569 
570 static struct notifier_block on_panic_nb = {
571 	.notifier_call = con3270_notify,
572 	.priority = 0,
573 };
574 
575 static struct notifier_block on_reboot_nb = {
576 	.notifier_call = con3270_notify,
577 	.priority = 0,
578 };
579 
580 /*
581  *  The console structure for the 3270 console
582  */
583 static struct console con3270 = {
584 	.name	 = "tty3270",
585 	.write	 = con3270_write,
586 	.device	 = con3270_device,
587 	.flags	 = CON_PRINTBUFFER,
588 };
589 
590 /*
591  * 3270 console initialization code called from console_init().
592  */
593 static int __init
594 con3270_init(void)
595 {
596 	struct raw3270 *rp;
597 	void *cbuf;
598 	int i;
599 
600 	/* Check if 3270 is to be the console */
601 	if (!CONSOLE_IS_3270)
602 		return -ENODEV;
603 
604 	/* Set the console mode for VM */
605 	if (MACHINE_IS_VM) {
606 		cpcmd("TERM CONMODE 3270", NULL, 0, NULL);
607 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
608 	}
609 
610 	rp = raw3270_setup_console();
611 	if (IS_ERR(rp))
612 		return PTR_ERR(rp);
613 
614 	condev = kzalloc(sizeof(struct con3270), GFP_KERNEL | GFP_DMA);
615 	if (!condev)
616 		return -ENOMEM;
617 	condev->view.dev = rp;
618 
619 	condev->read = raw3270_request_alloc(0);
620 	condev->read->callback = con3270_read_callback;
621 	condev->read->callback_data = condev;
622 	condev->write = raw3270_request_alloc(CON3270_OUTPUT_BUFFER_SIZE);
623 	condev->kreset = raw3270_request_alloc(1);
624 
625 	INIT_LIST_HEAD(&condev->lines);
626 	INIT_LIST_HEAD(&condev->update);
627 	timer_setup(&condev->timer, con3270_update, 0);
628 	tasklet_init(&condev->readlet,
629 		     (void (*)(unsigned long)) con3270_read_tasklet,
630 		     (unsigned long) condev->read);
631 
632 	raw3270_add_view(&condev->view, &con3270_fn, 1, RAW3270_VIEW_LOCK_IRQ);
633 
634 	INIT_LIST_HEAD(&condev->freemem);
635 	for (i = 0; i < CON3270_STRING_PAGES; i++) {
636 		cbuf = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
637 		add_string_memory(&condev->freemem, cbuf, PAGE_SIZE);
638 	}
639 	condev->cline = alloc_string(&condev->freemem, condev->view.cols);
640 	condev->cline->len = 0;
641 	con3270_create_status(condev);
642 	condev->input = alloc_string(&condev->freemem, 80);
643 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
644 	register_reboot_notifier(&on_reboot_nb);
645 	register_console(&con3270);
646 	return 0;
647 }
648 
649 console_initcall(con3270_init);
650