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
33static struct raw3270_fn con3270_fn;
34
35static bool auto_update = true;
36module_param(auto_update, bool, 0);
37
38/*
39 * Main 3270 console view data structure.
40 */
41struct 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
64static 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
72static void con3270_update(struct timer_list *);
73
74/*
75 * Setup timeout for a device. On timeout trigger an update.
76 */
77static 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 */
90static void
91con3270_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
101static void
102con3270_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 */
125static void
126con3270_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 */
142static void
143con3270_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 */
168static struct string *
169con3270_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 */
197static void
198con3270_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 */
207static void
208con3270_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 */
293static void
294con3270_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 */
356static void
357con3270_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 */
367static void
368con3270_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 */
390static int
391con3270_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
401static void
402con3270_deactivate(struct raw3270_view *view)
403{
404	struct con3270 *cp;
405
406	cp = (struct con3270 *) view;
407	del_timer(&cp->timer);
408}
409
410static void
411con3270_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. */
431static struct raw3270_fn con3270_fn = {
432	.activate = con3270_activate,
433	.deactivate = con3270_deactivate,
434	.intv = (void *) con3270_irq
435};
436
437static inline void
438con3270_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
448static inline void
449con3270_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
459static inline void
460con3270_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 */
490static void
491con3270_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
515static struct tty_driver *
516con3270_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 */
525static void
526con3270_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 */
538static void
539con3270_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
563static int con3270_notify(struct notifier_block *self,
564			  unsigned long event, void *data)
565{
566	con3270_flush();
567	return NOTIFY_OK;
568}
569
570static struct notifier_block on_panic_nb = {
571	.notifier_call = con3270_notify,
572	.priority = 0,
573};
574
575static 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 */
583static 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 */
593static int __init
594con3270_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
649console_initcall(con3270_init);
650