1/*
2 * IBM/3270 Driver - console view.
3 *
4 * Author(s):
5 *   Original 3270 Code for 2.4 written by Richard Hitt (UTS Global)
6 *   Rewritten for 2.5 by Martin Schwidefsky <schwidefsky@de.ibm.com>
7 *     Copyright IBM Corp. 2003, 2009
8 */
9
10#include <linux/console.h>
11#include <linux/init.h>
12#include <linux/interrupt.h>
13#include <linux/list.h>
14#include <linux/types.h>
15#include <linux/slab.h>
16#include <linux/err.h>
17#include <linux/reboot.h>
18
19#include <asm/ccwdev.h>
20#include <asm/cio.h>
21#include <asm/cpcmd.h>
22#include <asm/ebcdic.h>
23
24#include "raw3270.h"
25#include "tty3270.h"
26#include "ctrlchar.h"
27
28#define CON3270_OUTPUT_BUFFER_SIZE 1024
29#define CON3270_STRING_PAGES 4
30
31static struct raw3270_fn con3270_fn;
32
33/*
34 * Main 3270 console view data structure.
35 */
36struct con3270 {
37	struct raw3270_view view;
38	spinlock_t lock;
39	struct list_head freemem;	/* list of free memory for strings. */
40
41	/* Output stuff. */
42	struct list_head lines;		/* list of lines. */
43	struct list_head update;	/* list of lines to update. */
44	int line_nr;			/* line number for next update. */
45	int nr_lines;			/* # lines in list. */
46	int nr_up;			/* # lines up in history. */
47	unsigned long update_flags;	/* Update indication bits. */
48	struct string *cline;		/* current output line. */
49	struct string *status;		/* last line of display. */
50	struct raw3270_request *write;	/* single write request. */
51	struct timer_list timer;
52
53	/* Input stuff. */
54	struct string *input;		/* input string for read request. */
55	struct raw3270_request *read;	/* single read request. */
56	struct raw3270_request *kreset;	/* single keyboard reset request. */
57	struct tasklet_struct readlet;	/* tasklet to issue read request. */
58};
59
60static struct con3270 *condev;
61
62/* con3270->update_flags. See con3270_update for details. */
63#define CON_UPDATE_ERASE	1	/* Use EWRITEA instead of WRITE. */
64#define CON_UPDATE_LIST		2	/* Update lines in tty3270->update. */
65#define CON_UPDATE_STATUS	4	/* Update status line. */
66#define CON_UPDATE_ALL		8	/* Recreate screen. */
67
68static void con3270_update(struct con3270 *);
69
70/*
71 * Setup timeout for a device. On timeout trigger an update.
72 */
73static void con3270_set_timer(struct con3270 *cp, int expires)
74{
75	if (expires == 0)
76		del_timer(&cp->timer);
77	else
78		mod_timer(&cp->timer, jiffies + expires);
79}
80
81/*
82 * The status line is the last line of the screen. It shows the string
83 * "console view" in the lower left corner and "Running"/"More..."/"Holding"
84 * in the lower right corner of the screen.
85 */
86static void
87con3270_update_status(struct con3270 *cp)
88{
89	char *str;
90
91	str = (cp->nr_up != 0) ? "History" : "Running";
92	memcpy(cp->status->string + 24, str, 7);
93	codepage_convert(cp->view.ascebc, cp->status->string + 24, 7);
94	cp->update_flags |= CON_UPDATE_STATUS;
95}
96
97static void
98con3270_create_status(struct con3270 *cp)
99{
100	static const unsigned char blueprint[] =
101		{ TO_SBA, 0, 0, TO_SF,TF_LOG,TO_SA,TAT_COLOR, TAC_GREEN,
102		  'c','o','n','s','o','l','e',' ','v','i','e','w',
103		  TO_RA,0,0,0,'R','u','n','n','i','n','g',TO_SF,TF_LOG };
104
105	cp->status = alloc_string(&cp->freemem, sizeof(blueprint));
106	/* Copy blueprint to status line */
107	memcpy(cp->status->string, blueprint, sizeof(blueprint));
108	/* Set TO_RA addresses. */
109	raw3270_buffer_address(cp->view.dev, cp->status->string + 1,
110			       cp->view.cols * (cp->view.rows - 1));
111	raw3270_buffer_address(cp->view.dev, cp->status->string + 21,
112			       cp->view.cols * cp->view.rows - 8);
113	/* Convert strings to ebcdic. */
114	codepage_convert(cp->view.ascebc, cp->status->string + 8, 12);
115	codepage_convert(cp->view.ascebc, cp->status->string + 24, 7);
116}
117
118/*
119 * Set output offsets to 3270 datastream fragment of a console string.
120 */
121static void
122con3270_update_string(struct con3270 *cp, struct string *s, int nr)
123{
124	if (s->len >= cp->view.cols - 5)
125		return;
126	raw3270_buffer_address(cp->view.dev, s->string + s->len - 3,
127			       cp->view.cols * (nr + 1));
128}
129
130/*
131 * Rebuild update list to print all lines.
132 */
133static void
134con3270_rebuild_update(struct con3270 *cp)
135{
136	struct string *s, *n;
137	int nr;
138
139	/*
140	 * Throw away update list and create a new one,
141	 * containing all lines that will fit on the screen.
142	 */
143	list_for_each_entry_safe(s, n, &cp->update, update)
144		list_del_init(&s->update);
145	nr = cp->view.rows - 2 + cp->nr_up;
146	list_for_each_entry_reverse(s, &cp->lines, list) {
147		if (nr < cp->view.rows - 1)
148			list_add(&s->update, &cp->update);
149		if (--nr < 0)
150			break;
151	}
152	cp->line_nr = 0;
153	cp->update_flags |= CON_UPDATE_LIST;
154}
155
156/*
157 * Alloc string for size bytes. Free strings from history if necessary.
158 */
159static struct string *
160con3270_alloc_string(struct con3270 *cp, size_t size)
161{
162	struct string *s, *n;
163
164	s = alloc_string(&cp->freemem, size);
165	if (s)
166		return s;
167	list_for_each_entry_safe(s, n, &cp->lines, list) {
168		list_del(&s->list);
169		if (!list_empty(&s->update))
170			list_del(&s->update);
171		cp->nr_lines--;
172		if (free_string(&cp->freemem, s) >= size)
173			break;
174	}
175	s = alloc_string(&cp->freemem, size);
176	BUG_ON(!s);
177	if (cp->nr_up != 0 && cp->nr_up + cp->view.rows > cp->nr_lines) {
178		cp->nr_up = cp->nr_lines - cp->view.rows + 1;
179		con3270_rebuild_update(cp);
180		con3270_update_status(cp);
181	}
182	return s;
183}
184
185/*
186 * Write completion callback.
187 */
188static void
189con3270_write_callback(struct raw3270_request *rq, void *data)
190{
191	raw3270_request_reset(rq);
192	xchg(&((struct con3270 *) rq->view)->write, rq);
193}
194
195/*
196 * Update console display.
197 */
198static void
199con3270_update(struct con3270 *cp)
200{
201	struct raw3270_request *wrq;
202	char wcc, prolog[6];
203	unsigned long flags;
204	unsigned long updated;
205	struct string *s, *n;
206	int rc;
207
208	if (cp->view.dev)
209		raw3270_activate_view(&cp->view);
210
211	wrq = xchg(&cp->write, 0);
212	if (!wrq) {
213		con3270_set_timer(cp, 1);
214		return;
215	}
216
217	spin_lock_irqsave(&cp->view.lock, flags);
218	updated = 0;
219	if (cp->update_flags & CON_UPDATE_ALL) {
220		con3270_rebuild_update(cp);
221		con3270_update_status(cp);
222		cp->update_flags = CON_UPDATE_ERASE | CON_UPDATE_LIST |
223			CON_UPDATE_STATUS;
224	}
225	if (cp->update_flags & CON_UPDATE_ERASE) {
226		/* Use erase write alternate to initialize display. */
227		raw3270_request_set_cmd(wrq, TC_EWRITEA);
228		updated |= CON_UPDATE_ERASE;
229	} else
230		raw3270_request_set_cmd(wrq, TC_WRITE);
231
232	wcc = TW_NONE;
233	raw3270_request_add_data(wrq, &wcc, 1);
234
235	/*
236	 * Update status line.
237	 */
238	if (cp->update_flags & CON_UPDATE_STATUS)
239		if (raw3270_request_add_data(wrq, cp->status->string,
240					     cp->status->len) == 0)
241			updated |= CON_UPDATE_STATUS;
242
243	if (cp->update_flags & CON_UPDATE_LIST) {
244		prolog[0] = TO_SBA;
245		prolog[3] = TO_SA;
246		prolog[4] = TAT_COLOR;
247		prolog[5] = TAC_TURQ;
248		raw3270_buffer_address(cp->view.dev, prolog + 1,
249				       cp->view.cols * cp->line_nr);
250		raw3270_request_add_data(wrq, prolog, 6);
251		/* Write strings in the update list to the screen. */
252		list_for_each_entry_safe(s, n, &cp->update, update) {
253			if (s != cp->cline)
254				con3270_update_string(cp, s, cp->line_nr);
255			if (raw3270_request_add_data(wrq, s->string,
256						     s->len) != 0)
257				break;
258			list_del_init(&s->update);
259			if (s != cp->cline)
260				cp->line_nr++;
261		}
262		if (list_empty(&cp->update))
263			updated |= CON_UPDATE_LIST;
264	}
265	wrq->callback = con3270_write_callback;
266	rc = raw3270_start(&cp->view, wrq);
267	if (rc == 0) {
268		cp->update_flags &= ~updated;
269		if (cp->update_flags)
270			con3270_set_timer(cp, 1);
271	} else {
272		raw3270_request_reset(wrq);
273		xchg(&cp->write, wrq);
274	}
275	spin_unlock_irqrestore(&cp->view.lock, flags);
276}
277
278/*
279 * Read tasklet.
280 */
281static void
282con3270_read_tasklet(struct raw3270_request *rrq)
283{
284	static char kreset_data = TW_KR;
285	struct con3270 *cp;
286	unsigned long flags;
287	int nr_up, deactivate;
288
289	cp = (struct con3270 *) rrq->view;
290	spin_lock_irqsave(&cp->view.lock, flags);
291	nr_up = cp->nr_up;
292	deactivate = 0;
293	/* Check aid byte. */
294	switch (cp->input->string[0]) {
295	case 0x7d:	/* enter: jump to bottom. */
296		nr_up = 0;
297		break;
298	case 0xf3:	/* PF3: deactivate the console view. */
299		deactivate = 1;
300		break;
301	case 0x6d:	/* clear: start from scratch. */
302		cp->update_flags = CON_UPDATE_ALL;
303		con3270_set_timer(cp, 1);
304		break;
305	case 0xf7:	/* PF7: do a page up in the console log. */
306		nr_up += cp->view.rows - 2;
307		if (nr_up + cp->view.rows - 1 > cp->nr_lines) {
308			nr_up = cp->nr_lines - cp->view.rows + 1;
309			if (nr_up < 0)
310				nr_up = 0;
311		}
312		break;
313	case 0xf8:	/* PF8: do a page down in the console log. */
314		nr_up -= cp->view.rows - 2;
315		if (nr_up < 0)
316			nr_up = 0;
317		break;
318	}
319	if (nr_up != cp->nr_up) {
320		cp->nr_up = nr_up;
321		con3270_rebuild_update(cp);
322		con3270_update_status(cp);
323		con3270_set_timer(cp, 1);
324	}
325	spin_unlock_irqrestore(&cp->view.lock, flags);
326
327	/* Start keyboard reset command. */
328	raw3270_request_reset(cp->kreset);
329	raw3270_request_set_cmd(cp->kreset, TC_WRITE);
330	raw3270_request_add_data(cp->kreset, &kreset_data, 1);
331	raw3270_start(&cp->view, cp->kreset);
332
333	if (deactivate)
334		raw3270_deactivate_view(&cp->view);
335
336	raw3270_request_reset(rrq);
337	xchg(&cp->read, rrq);
338	raw3270_put_view(&cp->view);
339}
340
341/*
342 * Read request completion callback.
343 */
344static void
345con3270_read_callback(struct raw3270_request *rq, void *data)
346{
347	raw3270_get_view(rq->view);
348	/* Schedule tasklet to pass input to tty. */
349	tasklet_schedule(&((struct con3270 *) rq->view)->readlet);
350}
351
352/*
353 * Issue a read request. Called only from interrupt function.
354 */
355static void
356con3270_issue_read(struct con3270 *cp)
357{
358	struct raw3270_request *rrq;
359	int rc;
360
361	rrq = xchg(&cp->read, 0);
362	if (!rrq)
363		/* Read already scheduled. */
364		return;
365	rrq->callback = con3270_read_callback;
366	rrq->callback_data = cp;
367	raw3270_request_set_cmd(rrq, TC_READMOD);
368	raw3270_request_set_data(rrq, cp->input->string, cp->input->len);
369	/* Issue the read modified request. */
370	rc = raw3270_start_irq(&cp->view, rrq);
371	if (rc)
372		raw3270_request_reset(rrq);
373}
374
375/*
376 * Switch to the console view.
377 */
378static int
379con3270_activate(struct raw3270_view *view)
380{
381	struct con3270 *cp;
382
383	cp = (struct con3270 *) view;
384	cp->update_flags = CON_UPDATE_ALL;
385	con3270_set_timer(cp, 1);
386	return 0;
387}
388
389static void
390con3270_deactivate(struct raw3270_view *view)
391{
392	struct con3270 *cp;
393
394	cp = (struct con3270 *) view;
395	del_timer(&cp->timer);
396}
397
398static int
399con3270_irq(struct con3270 *cp, struct raw3270_request *rq, struct irb *irb)
400{
401	/* Handle ATTN. Schedule tasklet to read aid. */
402	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION)
403		con3270_issue_read(cp);
404
405	if (rq) {
406		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
407			rq->rc = -EIO;
408		else
409			/* Normal end. Copy residual count. */
410			rq->rescnt = irb->scsw.cmd.count;
411	}
412	return RAW3270_IO_DONE;
413}
414
415/* Console view to a 3270 device. */
416static struct raw3270_fn con3270_fn = {
417	.activate = con3270_activate,
418	.deactivate = con3270_deactivate,
419	.intv = (void *) con3270_irq
420};
421
422static inline void
423con3270_cline_add(struct con3270 *cp)
424{
425	if (!list_empty(&cp->cline->list))
426		/* Already added. */
427		return;
428	list_add_tail(&cp->cline->list, &cp->lines);
429	cp->nr_lines++;
430	con3270_rebuild_update(cp);
431}
432
433static inline void
434con3270_cline_insert(struct con3270 *cp, unsigned char c)
435{
436	cp->cline->string[cp->cline->len++] =
437		cp->view.ascebc[(c < ' ') ? ' ' : c];
438	if (list_empty(&cp->cline->update)) {
439		list_add_tail(&cp->cline->update, &cp->update);
440		cp->update_flags |= CON_UPDATE_LIST;
441	}
442}
443
444static inline void
445con3270_cline_end(struct con3270 *cp)
446{
447	struct string *s;
448	unsigned int size;
449
450	/* Copy cline. */
451	size = (cp->cline->len < cp->view.cols - 5) ?
452		cp->cline->len + 4 : cp->view.cols;
453	s = con3270_alloc_string(cp, size);
454	memcpy(s->string, cp->cline->string, cp->cline->len);
455	if (s->len < cp->view.cols - 5) {
456		s->string[s->len - 4] = TO_RA;
457		s->string[s->len - 1] = 0;
458	} else {
459		while (--size > cp->cline->len)
460			s->string[size] = cp->view.ascebc[' '];
461	}
462	/* Replace cline with allocated line s and reset cline. */
463	list_add(&s->list, &cp->cline->list);
464	list_del_init(&cp->cline->list);
465	if (!list_empty(&cp->cline->update)) {
466		list_add(&s->update, &cp->cline->update);
467		list_del_init(&cp->cline->update);
468	}
469	cp->cline->len = 0;
470}
471
472/*
473 * Write a string to the 3270 console
474 */
475static void
476con3270_write(struct console *co, const char *str, unsigned int count)
477{
478	struct con3270 *cp;
479	unsigned long flags;
480	unsigned char c;
481
482	cp = condev;
483	spin_lock_irqsave(&cp->view.lock, flags);
484	while (count-- > 0) {
485		c = *str++;
486		if (cp->cline->len == 0)
487			con3270_cline_add(cp);
488		if (c != '\n')
489			con3270_cline_insert(cp, c);
490		if (c == '\n' || cp->cline->len >= cp->view.cols)
491			con3270_cline_end(cp);
492	}
493	/* Setup timer to output current console buffer after 1/10 second */
494	cp->nr_up = 0;
495	if (cp->view.dev && !timer_pending(&cp->timer))
496		con3270_set_timer(cp, HZ/10);
497	spin_unlock_irqrestore(&cp->view.lock,flags);
498}
499
500static struct tty_driver *
501con3270_device(struct console *c, int *index)
502{
503	*index = c->index;
504	return tty3270_driver;
505}
506
507/*
508 * Wait for end of write request.
509 */
510static void
511con3270_wait_write(struct con3270 *cp)
512{
513	while (!cp->write) {
514		raw3270_wait_cons_dev(cp->view.dev);
515		barrier();
516	}
517}
518
519/*
520 * panic() calls con3270_flush through a panic_notifier
521 * before the system enters a disabled, endless loop.
522 */
523static void
524con3270_flush(void)
525{
526	struct con3270 *cp;
527	unsigned long flags;
528
529	cp = condev;
530	if (!cp->view.dev)
531		return;
532	raw3270_pm_unfreeze(&cp->view);
533	spin_lock_irqsave(&cp->view.lock, flags);
534	con3270_wait_write(cp);
535	cp->nr_up = 0;
536	con3270_rebuild_update(cp);
537	con3270_update_status(cp);
538	while (cp->update_flags != 0) {
539		spin_unlock_irqrestore(&cp->view.lock, flags);
540		con3270_update(cp);
541		spin_lock_irqsave(&cp->view.lock, flags);
542		con3270_wait_write(cp);
543	}
544	spin_unlock_irqrestore(&cp->view.lock, flags);
545}
546
547static int con3270_notify(struct notifier_block *self,
548			  unsigned long event, void *data)
549{
550	con3270_flush();
551	return NOTIFY_OK;
552}
553
554static struct notifier_block on_panic_nb = {
555	.notifier_call = con3270_notify,
556	.priority = 0,
557};
558
559static struct notifier_block on_reboot_nb = {
560	.notifier_call = con3270_notify,
561	.priority = 0,
562};
563
564/*
565 *  The console structure for the 3270 console
566 */
567static struct console con3270 = {
568	.name	 = "tty3270",
569	.write	 = con3270_write,
570	.device	 = con3270_device,
571	.flags	 = CON_PRINTBUFFER,
572};
573
574/*
575 * 3270 console initialization code called from console_init().
576 */
577static int __init
578con3270_init(void)
579{
580	struct ccw_device *cdev;
581	struct raw3270 *rp;
582	void *cbuf;
583	int i;
584
585	/* Check if 3270 is to be the console */
586	if (!CONSOLE_IS_3270)
587		return -ENODEV;
588
589	/* Set the console mode for VM */
590	if (MACHINE_IS_VM) {
591		cpcmd("TERM CONMODE 3270", NULL, 0, NULL);
592		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
593	}
594
595	cdev = ccw_device_probe_console();
596	if (IS_ERR(cdev))
597		return -ENODEV;
598	rp = raw3270_setup_console(cdev);
599	if (IS_ERR(rp))
600		return PTR_ERR(rp);
601
602	condev = kzalloc(sizeof(struct con3270), GFP_KERNEL | GFP_DMA);
603	condev->view.dev = rp;
604
605	condev->read = raw3270_request_alloc(0);
606	condev->read->callback = con3270_read_callback;
607	condev->read->callback_data = condev;
608	condev->write = raw3270_request_alloc(CON3270_OUTPUT_BUFFER_SIZE);
609	condev->kreset = raw3270_request_alloc(1);
610
611	INIT_LIST_HEAD(&condev->lines);
612	INIT_LIST_HEAD(&condev->update);
613	setup_timer(&condev->timer, (void (*)(unsigned long)) con3270_update,
614		    (unsigned long) condev);
615	tasklet_init(&condev->readlet,
616		     (void (*)(unsigned long)) con3270_read_tasklet,
617		     (unsigned long) condev->read);
618
619	raw3270_add_view(&condev->view, &con3270_fn, 1);
620
621	INIT_LIST_HEAD(&condev->freemem);
622	for (i = 0; i < CON3270_STRING_PAGES; i++) {
623		cbuf = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
624		add_string_memory(&condev->freemem, cbuf, PAGE_SIZE);
625	}
626	condev->cline = alloc_string(&condev->freemem, condev->view.cols);
627	condev->cline->len = 0;
628	con3270_create_status(condev);
629	condev->input = alloc_string(&condev->freemem, 80);
630	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
631	register_reboot_notifier(&on_reboot_nb);
632	register_console(&con3270);
633	return 0;
634}
635
636console_initcall(con3270_init);
637