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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 con3270 *);
73 
74 /*
75  * Setup timeout for a device. On timeout trigger an update.
76  */
con3270_set_timer(struct con3270 * cp,int expires)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
con3270_update_status(struct con3270 * cp)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
con3270_create_status(struct con3270 * cp)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
con3270_update_string(struct con3270 * cp,struct string * s,int nr)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
con3270_rebuild_update(struct con3270 * cp)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 *
con3270_alloc_string(struct con3270 * cp,size_t size)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
con3270_write_callback(struct raw3270_request * rq,void * data)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
con3270_update(struct con3270 * cp)208 con3270_update(struct con3270 *cp)
209 {
210 	struct raw3270_request *wrq;
211 	char wcc, prolog[6];
212 	unsigned long flags;
213 	unsigned long updated;
214 	struct string *s, *n;
215 	int rc;
216 
217 	if (!auto_update && !raw3270_view_active(&cp->view))
218 		return;
219 	if (cp->view.dev)
220 		raw3270_activate_view(&cp->view);
221 
222 	wrq = xchg(&cp->write, 0);
223 	if (!wrq) {
224 		con3270_set_timer(cp, 1);
225 		return;
226 	}
227 
228 	spin_lock_irqsave(&cp->view.lock, flags);
229 	updated = 0;
230 	if (cp->update_flags & CON_UPDATE_ALL) {
231 		con3270_rebuild_update(cp);
232 		con3270_update_status(cp);
233 		cp->update_flags = CON_UPDATE_ERASE | CON_UPDATE_LIST |
234 			CON_UPDATE_STATUS;
235 	}
236 	if (cp->update_flags & CON_UPDATE_ERASE) {
237 		/* Use erase write alternate to initialize display. */
238 		raw3270_request_set_cmd(wrq, TC_EWRITEA);
239 		updated |= CON_UPDATE_ERASE;
240 	} else
241 		raw3270_request_set_cmd(wrq, TC_WRITE);
242 
243 	wcc = TW_NONE;
244 	raw3270_request_add_data(wrq, &wcc, 1);
245 
246 	/*
247 	 * Update status line.
248 	 */
249 	if (cp->update_flags & CON_UPDATE_STATUS)
250 		if (raw3270_request_add_data(wrq, cp->status->string,
251 					     cp->status->len) == 0)
252 			updated |= CON_UPDATE_STATUS;
253 
254 	if (cp->update_flags & CON_UPDATE_LIST) {
255 		prolog[0] = TO_SBA;
256 		prolog[3] = TO_SA;
257 		prolog[4] = TAT_COLOR;
258 		prolog[5] = TAC_TURQ;
259 		raw3270_buffer_address(cp->view.dev, prolog + 1,
260 				       cp->view.cols * cp->line_nr);
261 		raw3270_request_add_data(wrq, prolog, 6);
262 		/* Write strings in the update list to the screen. */
263 		list_for_each_entry_safe(s, n, &cp->update, update) {
264 			if (s != cp->cline)
265 				con3270_update_string(cp, s, cp->line_nr);
266 			if (raw3270_request_add_data(wrq, s->string,
267 						     s->len) != 0)
268 				break;
269 			list_del_init(&s->update);
270 			if (s != cp->cline)
271 				cp->line_nr++;
272 		}
273 		if (list_empty(&cp->update))
274 			updated |= CON_UPDATE_LIST;
275 	}
276 	wrq->callback = con3270_write_callback;
277 	rc = raw3270_start(&cp->view, wrq);
278 	if (rc == 0) {
279 		cp->update_flags &= ~updated;
280 		if (cp->update_flags)
281 			con3270_set_timer(cp, 1);
282 	} else {
283 		raw3270_request_reset(wrq);
284 		xchg(&cp->write, wrq);
285 	}
286 	spin_unlock_irqrestore(&cp->view.lock, flags);
287 }
288 
289 /*
290  * Read tasklet.
291  */
292 static void
con3270_read_tasklet(struct raw3270_request * rrq)293 con3270_read_tasklet(struct raw3270_request *rrq)
294 {
295 	static char kreset_data = TW_KR;
296 	struct con3270 *cp;
297 	unsigned long flags;
298 	int nr_up, deactivate;
299 
300 	cp = (struct con3270 *) rrq->view;
301 	spin_lock_irqsave(&cp->view.lock, flags);
302 	nr_up = cp->nr_up;
303 	deactivate = 0;
304 	/* Check aid byte. */
305 	switch (cp->input->string[0]) {
306 	case 0x7d:	/* enter: jump to bottom. */
307 		nr_up = 0;
308 		break;
309 	case 0xf3:	/* PF3: deactivate the console view. */
310 		deactivate = 1;
311 		break;
312 	case 0x6d:	/* clear: start from scratch. */
313 		cp->update_flags = CON_UPDATE_ALL;
314 		con3270_set_timer(cp, 1);
315 		break;
316 	case 0xf7:	/* PF7: do a page up in the console log. */
317 		nr_up += cp->view.rows - 2;
318 		if (nr_up + cp->view.rows - 1 > cp->nr_lines) {
319 			nr_up = cp->nr_lines - cp->view.rows + 1;
320 			if (nr_up < 0)
321 				nr_up = 0;
322 		}
323 		break;
324 	case 0xf8:	/* PF8: do a page down in the console log. */
325 		nr_up -= cp->view.rows - 2;
326 		if (nr_up < 0)
327 			nr_up = 0;
328 		break;
329 	}
330 	if (nr_up != cp->nr_up) {
331 		cp->nr_up = nr_up;
332 		con3270_rebuild_update(cp);
333 		con3270_update_status(cp);
334 		con3270_set_timer(cp, 1);
335 	}
336 	spin_unlock_irqrestore(&cp->view.lock, flags);
337 
338 	/* Start keyboard reset command. */
339 	raw3270_request_reset(cp->kreset);
340 	raw3270_request_set_cmd(cp->kreset, TC_WRITE);
341 	raw3270_request_add_data(cp->kreset, &kreset_data, 1);
342 	raw3270_start(&cp->view, cp->kreset);
343 
344 	if (deactivate)
345 		raw3270_deactivate_view(&cp->view);
346 
347 	raw3270_request_reset(rrq);
348 	xchg(&cp->read, rrq);
349 	raw3270_put_view(&cp->view);
350 }
351 
352 /*
353  * Read request completion callback.
354  */
355 static void
con3270_read_callback(struct raw3270_request * rq,void * data)356 con3270_read_callback(struct raw3270_request *rq, void *data)
357 {
358 	raw3270_get_view(rq->view);
359 	/* Schedule tasklet to pass input to tty. */
360 	tasklet_schedule(&((struct con3270 *) rq->view)->readlet);
361 }
362 
363 /*
364  * Issue a read request. Called only from interrupt function.
365  */
366 static void
con3270_issue_read(struct con3270 * cp)367 con3270_issue_read(struct con3270 *cp)
368 {
369 	struct raw3270_request *rrq;
370 	int rc;
371 
372 	rrq = xchg(&cp->read, 0);
373 	if (!rrq)
374 		/* Read already scheduled. */
375 		return;
376 	rrq->callback = con3270_read_callback;
377 	rrq->callback_data = cp;
378 	raw3270_request_set_cmd(rrq, TC_READMOD);
379 	raw3270_request_set_data(rrq, cp->input->string, cp->input->len);
380 	/* Issue the read modified request. */
381 	rc = raw3270_start_irq(&cp->view, rrq);
382 	if (rc)
383 		raw3270_request_reset(rrq);
384 }
385 
386 /*
387  * Switch to the console view.
388  */
389 static int
con3270_activate(struct raw3270_view * view)390 con3270_activate(struct raw3270_view *view)
391 {
392 	struct con3270 *cp;
393 
394 	cp = (struct con3270 *) view;
395 	cp->update_flags = CON_UPDATE_ALL;
396 	con3270_set_timer(cp, 1);
397 	return 0;
398 }
399 
400 static void
con3270_deactivate(struct raw3270_view * view)401 con3270_deactivate(struct raw3270_view *view)
402 {
403 	struct con3270 *cp;
404 
405 	cp = (struct con3270 *) view;
406 	del_timer(&cp->timer);
407 }
408 
409 static void
con3270_irq(struct con3270 * cp,struct raw3270_request * rq,struct irb * irb)410 con3270_irq(struct con3270 *cp, struct raw3270_request *rq, struct irb *irb)
411 {
412 	/* Handle ATTN. Schedule tasklet to read aid. */
413 	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION)
414 		con3270_issue_read(cp);
415 
416 	if (rq) {
417 		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
418 			rq->rc = -EIO;
419 		else
420 			/* Normal end. Copy residual count. */
421 			rq->rescnt = irb->scsw.cmd.count;
422 	} else if (irb->scsw.cmd.dstat & DEV_STAT_DEV_END) {
423 		/* Interrupt without an outstanding request -> update all */
424 		cp->update_flags = CON_UPDATE_ALL;
425 		con3270_set_timer(cp, 1);
426 	}
427 }
428 
429 /* Console view to a 3270 device. */
430 static struct raw3270_fn con3270_fn = {
431 	.activate = con3270_activate,
432 	.deactivate = con3270_deactivate,
433 	.intv = (void *) con3270_irq
434 };
435 
436 static inline void
con3270_cline_add(struct con3270 * cp)437 con3270_cline_add(struct con3270 *cp)
438 {
439 	if (!list_empty(&cp->cline->list))
440 		/* Already added. */
441 		return;
442 	list_add_tail(&cp->cline->list, &cp->lines);
443 	cp->nr_lines++;
444 	con3270_rebuild_update(cp);
445 }
446 
447 static inline void
con3270_cline_insert(struct con3270 * cp,unsigned char c)448 con3270_cline_insert(struct con3270 *cp, unsigned char c)
449 {
450 	cp->cline->string[cp->cline->len++] =
451 		cp->view.ascebc[(c < ' ') ? ' ' : c];
452 	if (list_empty(&cp->cline->update)) {
453 		list_add_tail(&cp->cline->update, &cp->update);
454 		cp->update_flags |= CON_UPDATE_LIST;
455 	}
456 }
457 
458 static inline void
con3270_cline_end(struct con3270 * cp)459 con3270_cline_end(struct con3270 *cp)
460 {
461 	struct string *s;
462 	unsigned int size;
463 
464 	/* Copy cline. */
465 	size = (cp->cline->len < cp->view.cols - 5) ?
466 		cp->cline->len + 4 : cp->view.cols;
467 	s = con3270_alloc_string(cp, size);
468 	memcpy(s->string, cp->cline->string, cp->cline->len);
469 	if (cp->cline->len < cp->view.cols - 5) {
470 		s->string[s->len - 4] = TO_RA;
471 		s->string[s->len - 1] = 0;
472 	} else {
473 		while (--size >= cp->cline->len)
474 			s->string[size] = cp->view.ascebc[' '];
475 	}
476 	/* Replace cline with allocated line s and reset cline. */
477 	list_add(&s->list, &cp->cline->list);
478 	list_del_init(&cp->cline->list);
479 	if (!list_empty(&cp->cline->update)) {
480 		list_add(&s->update, &cp->cline->update);
481 		list_del_init(&cp->cline->update);
482 	}
483 	cp->cline->len = 0;
484 }
485 
486 /*
487  * Write a string to the 3270 console
488  */
489 static void
con3270_write(struct console * co,const char * str,unsigned int count)490 con3270_write(struct console *co, const char *str, unsigned int count)
491 {
492 	struct con3270 *cp;
493 	unsigned long flags;
494 	unsigned char c;
495 
496 	cp = condev;
497 	spin_lock_irqsave(&cp->view.lock, flags);
498 	while (count-- > 0) {
499 		c = *str++;
500 		if (cp->cline->len == 0)
501 			con3270_cline_add(cp);
502 		if (c != '\n')
503 			con3270_cline_insert(cp, c);
504 		if (c == '\n' || cp->cline->len >= cp->view.cols)
505 			con3270_cline_end(cp);
506 	}
507 	/* Setup timer to output current console buffer after 1/10 second */
508 	cp->nr_up = 0;
509 	if (cp->view.dev && !timer_pending(&cp->timer))
510 		con3270_set_timer(cp, HZ/10);
511 	spin_unlock_irqrestore(&cp->view.lock,flags);
512 }
513 
514 static struct tty_driver *
con3270_device(struct console * c,int * index)515 con3270_device(struct console *c, int *index)
516 {
517 	*index = c->index;
518 	return tty3270_driver;
519 }
520 
521 /*
522  * Wait for end of write request.
523  */
524 static void
con3270_wait_write(struct con3270 * cp)525 con3270_wait_write(struct con3270 *cp)
526 {
527 	while (!cp->write) {
528 		raw3270_wait_cons_dev(cp->view.dev);
529 		barrier();
530 	}
531 }
532 
533 /*
534  * panic() calls con3270_flush through a panic_notifier
535  * before the system enters a disabled, endless loop.
536  */
537 static void
con3270_flush(void)538 con3270_flush(void)
539 {
540 	struct con3270 *cp;
541 	unsigned long flags;
542 
543 	cp = condev;
544 	if (!cp->view.dev)
545 		return;
546 	raw3270_pm_unfreeze(&cp->view);
547 	raw3270_activate_view(&cp->view);
548 	spin_lock_irqsave(&cp->view.lock, flags);
549 	con3270_wait_write(cp);
550 	cp->nr_up = 0;
551 	con3270_rebuild_update(cp);
552 	con3270_update_status(cp);
553 	while (cp->update_flags != 0) {
554 		spin_unlock_irqrestore(&cp->view.lock, flags);
555 		con3270_update(cp);
556 		spin_lock_irqsave(&cp->view.lock, flags);
557 		con3270_wait_write(cp);
558 	}
559 	spin_unlock_irqrestore(&cp->view.lock, flags);
560 }
561 
con3270_notify(struct notifier_block * self,unsigned long event,void * data)562 static int con3270_notify(struct notifier_block *self,
563 			  unsigned long event, void *data)
564 {
565 	con3270_flush();
566 	return NOTIFY_OK;
567 }
568 
569 static struct notifier_block on_panic_nb = {
570 	.notifier_call = con3270_notify,
571 	.priority = 0,
572 };
573 
574 static struct notifier_block on_reboot_nb = {
575 	.notifier_call = con3270_notify,
576 	.priority = 0,
577 };
578 
579 /*
580  *  The console structure for the 3270 console
581  */
582 static struct console con3270 = {
583 	.name	 = "tty3270",
584 	.write	 = con3270_write,
585 	.device	 = con3270_device,
586 	.flags	 = CON_PRINTBUFFER,
587 };
588 
589 /*
590  * 3270 console initialization code called from console_init().
591  */
592 static int __init
con3270_init(void)593 con3270_init(void)
594 {
595 	struct raw3270 *rp;
596 	void *cbuf;
597 	int i;
598 
599 	/* Check if 3270 is to be the console */
600 	if (!CONSOLE_IS_3270)
601 		return -ENODEV;
602 
603 	/* Set the console mode for VM */
604 	if (MACHINE_IS_VM) {
605 		cpcmd("TERM CONMODE 3270", NULL, 0, NULL);
606 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
607 	}
608 
609 	rp = raw3270_setup_console();
610 	if (IS_ERR(rp))
611 		return PTR_ERR(rp);
612 
613 	condev = kzalloc(sizeof(struct con3270), GFP_KERNEL | GFP_DMA);
614 	if (!condev)
615 		return -ENOMEM;
616 	condev->view.dev = rp;
617 
618 	condev->read = raw3270_request_alloc(0);
619 	condev->read->callback = con3270_read_callback;
620 	condev->read->callback_data = condev;
621 	condev->write = raw3270_request_alloc(CON3270_OUTPUT_BUFFER_SIZE);
622 	condev->kreset = raw3270_request_alloc(1);
623 
624 	INIT_LIST_HEAD(&condev->lines);
625 	INIT_LIST_HEAD(&condev->update);
626 	setup_timer(&condev->timer, (void (*)(unsigned long)) con3270_update,
627 		    (unsigned long) condev);
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