xref: /linux/drivers/s390/char/con3270.c (revision afca12e35e711ae8f97e835a3704cc305592eac9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *    IBM/3270 Driver - tty functions.
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
9  */
10 
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/kdev_t.h>
14 #include <linux/tty.h>
15 #include <linux/vt_kern.h>
16 #include <linux/init.h>
17 #include <linux/console.h>
18 #include <linux/interrupt.h>
19 #include <linux/workqueue.h>
20 #include <linux/panic_notifier.h>
21 #include <linux/reboot.h>
22 #include <linux/slab.h>
23 #include <linux/memblock.h>
24 #include <linux/compat.h>
25 
26 #include <asm/ccwdev.h>
27 #include <asm/cio.h>
28 #include <asm/ebcdic.h>
29 #include <asm/cpcmd.h>
30 #include <linux/uaccess.h>
31 
32 #include "raw3270.h"
33 #include "keyboard.h"
34 
35 #define TTY3270_CHAR_BUF_SIZE 256
36 #define TTY3270_OUTPUT_BUFFER_SIZE 4096
37 #define TTY3270_SCREEN_PAGES 8 /* has to be power-of-two */
38 #define TTY3270_RECALL_SIZE 16 /* has to be power-of-two */
39 #define TTY3270_STATUS_AREA_SIZE 40
40 
41 static struct tty_driver *tty3270_driver;
42 static int tty3270_max_index;
43 static struct raw3270_fn tty3270_fn;
44 
45 #define TTY3270_HIGHLIGHT_BLINK		1
46 #define TTY3270_HIGHLIGHT_REVERSE	2
47 #define TTY3270_HIGHLIGHT_UNDERSCORE	4
48 
49 struct tty3270_attribute {
50 	unsigned char alternate_charset:1;	/* Graphics charset */
51 	unsigned char highlight:3;		/* Blink/reverse/underscore */
52 	unsigned char f_color:4;		/* Foreground color */
53 	unsigned char b_color:4;		/* Background color */
54 };
55 
56 struct tty3270_cell {
57 	unsigned char character;
58 	struct tty3270_attribute attributes;
59 };
60 
61 struct tty3270_line {
62 	struct tty3270_cell *cells;
63 	int len;
64 	int dirty;
65 };
66 
67 static const unsigned char sfq_read_partition[] = {
68 	0x00, 0x07, 0x01, 0xff, 0x03, 0x00, 0x81
69 };
70 
71 #define ESCAPE_NPAR 8
72 
73 /*
74  * The main tty view data structure.
75  * FIXME:
76  * 1) describe line orientation & lines list concept against screen
77  * 2) describe conversion of screen to lines
78  * 3) describe line format.
79  */
80 struct tty3270 {
81 	struct raw3270_view view;
82 	struct tty_port port;
83 
84 	/* Output stuff. */
85 	unsigned char wcc;		/* Write control character. */
86 	int nr_up;			/* # lines up in history. */
87 	unsigned long update_flags;	/* Update indication bits. */
88 	struct raw3270_request *write;	/* Single write request. */
89 	struct timer_list timer;	/* Output delay timer. */
90 	char *converted_line;		/* RAW 3270 data stream */
91 	unsigned int line_view_start;	/* Start of visible area */
92 	unsigned int line_write_start;	/* current write position */
93 	unsigned int oops_line;		/* line counter used when print oops */
94 
95 	/* Current tty screen. */
96 	unsigned int cx, cy;		/* Current output position. */
97 	struct tty3270_attribute attributes;
98 	struct tty3270_attribute saved_attributes;
99 	int allocated_lines;
100 	struct tty3270_line *screen;
101 
102 	/* Input stuff. */
103 	char *prompt;			/* Output string for input area. */
104 	char *input;			/* Input string for read request. */
105 	struct raw3270_request *read;	/* Single read request. */
106 	struct raw3270_request *kreset;	/* Single keyboard reset request. */
107 	struct raw3270_request *readpartreq;
108 	unsigned char inattr;		/* Visible/invisible input. */
109 	int throttle, attn;		/* tty throttle/unthrottle. */
110 	struct tasklet_struct readlet;	/* Tasklet to issue read request. */
111 	struct tasklet_struct hanglet;	/* Tasklet to hang up the tty. */
112 	struct kbd_data *kbd;		/* key_maps stuff. */
113 
114 	/* Escape sequence parsing. */
115 	int esc_state, esc_ques, esc_npar;
116 	int esc_par[ESCAPE_NPAR];
117 	unsigned int saved_cx, saved_cy;
118 
119 	/* Command recalling. */
120 	char **rcl_lines;		/* Array of recallable lines */
121 	int rcl_write_index;		/* Write index of recallable items */
122 	int rcl_read_index;		/* Read index of recallable items */
123 
124 	/* Character array for put_char/flush_chars. */
125 	unsigned int char_count;
126 	char char_buf[TTY3270_CHAR_BUF_SIZE];
127 };
128 
129 /* tty3270->update_flags. See tty3270_update for details. */
130 #define TTY_UPDATE_INPUT	0x1	/* Update input line. */
131 #define TTY_UPDATE_STATUS	0x2	/* Update status line. */
132 #define TTY_UPDATE_LINES	0x4	/* Update visible screen lines */
133 #define TTY_UPDATE_ALL		0x7	/* Recreate screen. */
134 
135 #define TTY3270_INPUT_AREA_ROWS 2
136 
137 /*
138  * Setup timeout for a device. On timeout trigger an update.
139  */
140 static void tty3270_set_timer(struct tty3270 *tp, int expires)
141 {
142 	mod_timer(&tp->timer, jiffies + expires);
143 }
144 
145 static int tty3270_tty_rows(struct tty3270 *tp)
146 {
147 	return tp->view.rows - TTY3270_INPUT_AREA_ROWS;
148 }
149 
150 static char *tty3270_add_ba(struct tty3270 *tp, char *cp, char order, int x, int y)
151 {
152 	*cp++ = order;
153 	raw3270_buffer_address(tp->view.dev, cp, x, y);
154 	return cp + 2;
155 }
156 
157 static char *tty3270_add_ra(struct tty3270 *tp, char *cp, int x, int y, char c)
158 {
159 	cp = tty3270_add_ba(tp, cp, TO_RA, x, y);
160 	*cp++ = c;
161 	return cp;
162 }
163 
164 static char *tty3270_add_sa(struct tty3270 *tp, char *cp, char attr, char value)
165 {
166 	*cp++ = TO_SA;
167 	*cp++ = attr;
168 	*cp++ = value;
169 	return cp;
170 }
171 
172 static char *tty3270_add_ge(struct tty3270 *tp, char *cp, char c)
173 {
174 	*cp++ = TO_GE;
175 	*cp++ = c;
176 	return cp;
177 }
178 
179 static char *tty3270_add_sf(struct tty3270 *tp, char *cp, char type)
180 {
181 	*cp++ = TO_SF;
182 	*cp++ = type;
183 	return cp;
184 }
185 
186 static int tty3270_line_increment(struct tty3270 *tp, unsigned int line, unsigned int incr)
187 {
188 	return (line + incr) & (tp->allocated_lines - 1);
189 }
190 
191 static struct tty3270_line *tty3270_get_write_line(struct tty3270 *tp, unsigned int num)
192 {
193 	return tp->screen + tty3270_line_increment(tp, tp->line_write_start, num);
194 }
195 
196 static struct tty3270_line *tty3270_get_view_line(struct tty3270 *tp, unsigned int num)
197 {
198 	return tp->screen + tty3270_line_increment(tp, tp->line_view_start, num - tp->nr_up);
199 }
200 
201 static int tty3270_input_size(int cols)
202 {
203 	return cols * 2 - 11;
204 }
205 
206 static void tty3270_update_prompt(struct tty3270 *tp, char *input)
207 {
208 	strcpy(tp->prompt, input);
209 	tp->update_flags |= TTY_UPDATE_INPUT;
210 	tty3270_set_timer(tp, 1);
211 }
212 
213 /*
214  * The input line are the two last lines of the screen.
215  */
216 static int tty3270_add_prompt(struct tty3270 *tp)
217 {
218 	int count = 0;
219 	char *cp;
220 
221 	cp = tp->converted_line;
222 	cp = tty3270_add_ba(tp, cp, TO_SBA, 0, -2);
223 	*cp++ = tp->view.ascebc['>'];
224 
225 	if (*tp->prompt) {
226 		cp = tty3270_add_sf(tp, cp, TF_INMDT);
227 		count = min_t(int, strlen(tp->prompt),
228 			      tp->view.cols * 2 - TTY3270_STATUS_AREA_SIZE - 2);
229 		memcpy(cp, tp->prompt, count);
230 		cp += count;
231 	} else {
232 		cp = tty3270_add_sf(tp, cp, tp->inattr);
233 	}
234 	*cp++ = TO_IC;
235 	/* Clear to end of input line. */
236 	if (count < tp->view.cols * 2 - 11)
237 		cp = tty3270_add_ra(tp, cp, -TTY3270_STATUS_AREA_SIZE, -1, 0);
238 	return cp - tp->converted_line;
239 }
240 
241 static char *tty3270_ebcdic_convert(struct tty3270 *tp, char *d, char *s)
242 {
243 	while (*s)
244 		*d++ = tp->view.ascebc[(int)*s++];
245 	return d;
246 }
247 
248 /*
249  * The status line is the last line of the screen. It shows the string
250  * "Running"/"History X" in the lower right corner of the screen.
251  */
252 static int tty3270_add_status(struct tty3270 *tp)
253 {
254 	char *cp = tp->converted_line;
255 	int len;
256 
257 	cp = tty3270_add_ba(tp, cp, TO_SBA, -TTY3270_STATUS_AREA_SIZE, -1);
258 	cp = tty3270_add_sf(tp, cp, TF_LOG);
259 	cp = tty3270_add_sa(tp, cp, TAT_FGCOLOR, TAC_GREEN);
260 	cp = tty3270_ebcdic_convert(tp, cp, " 7");
261 	cp = tty3270_add_sa(tp, cp, TAT_EXTHI, TAX_REVER);
262 	cp = tty3270_ebcdic_convert(tp, cp, "PrevPg");
263 	cp = tty3270_add_sa(tp, cp, TAT_EXTHI, TAX_RESET);
264 	cp = tty3270_ebcdic_convert(tp, cp, " 8");
265 	cp = tty3270_add_sa(tp, cp, TAT_EXTHI, TAX_REVER);
266 	cp = tty3270_ebcdic_convert(tp, cp, "NextPg");
267 	cp = tty3270_add_sa(tp, cp, TAT_EXTHI, TAX_RESET);
268 	cp = tty3270_ebcdic_convert(tp, cp, " 12");
269 	cp = tty3270_add_sa(tp, cp, TAT_EXTHI, TAX_REVER);
270 	cp = tty3270_ebcdic_convert(tp, cp, "Recall");
271 	cp = tty3270_add_sa(tp, cp, TAT_EXTHI, TAX_RESET);
272 	cp = tty3270_ebcdic_convert(tp, cp, "  ");
273 	if (tp->nr_up) {
274 		len = sprintf(cp, "History %d", -tp->nr_up);
275 		codepage_convert(tp->view.ascebc, cp, len);
276 		cp += len;
277 	} else {
278 		cp = tty3270_ebcdic_convert(tp, cp, oops_in_progress ? "Crashed" : "Running");
279 	}
280 	cp = tty3270_add_sf(tp, cp, TF_LOG);
281 	cp = tty3270_add_sa(tp, cp, TAT_FGCOLOR, TAC_RESET);
282 	return cp - (char *)tp->converted_line;
283 }
284 
285 static void tty3270_blank_screen(struct tty3270 *tp)
286 {
287 	struct tty3270_line *line;
288 	int i;
289 
290 	for (i = 0; i < tty3270_tty_rows(tp); i++) {
291 		line = tty3270_get_write_line(tp, i);
292 		line->len = 0;
293 		line->dirty = 1;
294 	}
295 	tp->nr_up = 0;
296 }
297 
298 /*
299  * Write request completion callback.
300  */
301 static void tty3270_write_callback(struct raw3270_request *rq, void *data)
302 {
303 	struct tty3270 *tp = container_of(rq->view, struct tty3270, view);
304 
305 	if (rq->rc != 0) {
306 		/* Write wasn't successful. Refresh all. */
307 		tp->update_flags = TTY_UPDATE_ALL;
308 		tty3270_set_timer(tp, 1);
309 	}
310 	raw3270_request_reset(rq);
311 	xchg(&tp->write, rq);
312 }
313 
314 static int tty3270_required_length(struct tty3270 *tp, struct tty3270_line *line)
315 {
316 	unsigned char f_color, b_color, highlight;
317 	struct tty3270_cell *cell;
318 	int i, flen = 3;		/* Prefix (TO_SBA). */
319 
320 	flen += line->len;
321 	highlight = 0;
322 	f_color = TAC_RESET;
323 	b_color = TAC_RESET;
324 
325 	for (i = 0, cell = line->cells; i < line->len; i++, cell++) {
326 		if (cell->attributes.highlight != highlight) {
327 			flen += 3;	/* TO_SA to switch highlight. */
328 			highlight = cell->attributes.highlight;
329 		}
330 		if (cell->attributes.f_color != f_color) {
331 			flen += 3;	/* TO_SA to switch color. */
332 			f_color = cell->attributes.f_color;
333 		}
334 		if (cell->attributes.b_color != b_color) {
335 			flen += 3;	/* TO_SA to switch color. */
336 			b_color = cell->attributes.b_color;
337 		}
338 		if (cell->attributes.alternate_charset)
339 			flen += 1;	/* TO_GE to switch to graphics extensions */
340 	}
341 	if (highlight)
342 		flen += 3;	/* TO_SA to reset hightlight. */
343 	if (f_color != TAC_RESET)
344 		flen += 3;	/* TO_SA to reset color. */
345 	if (b_color != TAC_RESET)
346 		flen += 3;	/* TO_SA to reset color. */
347 	if (line->len < tp->view.cols)
348 		flen += 4;	/* Postfix (TO_RA). */
349 
350 	return flen;
351 }
352 
353 static char *tty3270_add_reset_attributes(struct tty3270 *tp, struct tty3270_line *line,
354 					  char *cp, struct tty3270_attribute *attr, int lineno)
355 {
356 	if (attr->highlight)
357 		cp = tty3270_add_sa(tp, cp, TAT_EXTHI, TAX_RESET);
358 	if (attr->f_color != TAC_RESET)
359 		cp = tty3270_add_sa(tp, cp, TAT_FGCOLOR, TAX_RESET);
360 	if (attr->b_color != TAC_RESET)
361 		cp = tty3270_add_sa(tp, cp, TAT_BGCOLOR, TAX_RESET);
362 	if (line->len < tp->view.cols)
363 		cp = tty3270_add_ra(tp, cp, 0, lineno + 1, 0);
364 	return cp;
365 }
366 
367 static char tty3270_graphics_translate(struct tty3270 *tp, char ch)
368 {
369 	switch (ch) {
370 	case 'q': /* - */
371 		return 0xa2;
372 	case 'x': /* '|' */
373 		return 0x85;
374 	case 'l': /* |- */
375 		return 0xc5;
376 	case 't': /* |_ */
377 		return 0xc6;
378 	case 'u': /* _| */
379 		return 0xd6;
380 	case 'k': /* -| */
381 		return 0xd5;
382 	case 'j':
383 		return 0xd4;
384 	case 'm':
385 		return 0xc4;
386 	case 'n': /* + */
387 		return 0xd3;
388 	case 'v':
389 		return 0xc7;
390 	case 'w':
391 		return 0xd7;
392 	default:
393 		return ch;
394 	}
395 }
396 
397 static char *tty3270_add_attributes(struct tty3270 *tp, struct tty3270_line *line,
398 				    struct tty3270_attribute *attr, char *cp, int lineno)
399 {
400 	const unsigned char colors[16] = {
401 		[0] = TAC_DEFAULT,
402 		[1] = TAC_RED,
403 		[2] = TAC_GREEN,
404 		[3] = TAC_YELLOW,
405 		[4] = TAC_BLUE,
406 		[5] = TAC_PINK,
407 		[6] = TAC_TURQ,
408 		[7] = TAC_WHITE,
409 		[9] = TAC_DEFAULT
410 	};
411 
412 	const unsigned char highlights[8] = {
413 		[TTY3270_HIGHLIGHT_BLINK] = TAX_BLINK,
414 		[TTY3270_HIGHLIGHT_REVERSE] = TAX_REVER,
415 		[TTY3270_HIGHLIGHT_UNDERSCORE] = TAX_UNDER,
416 	};
417 
418 	struct tty3270_cell *cell;
419 	int c, i;
420 
421 	cp = tty3270_add_ba(tp, cp, TO_SBA, 0, lineno);
422 
423 	for (i = 0, cell = line->cells; i < line->len; i++, cell++) {
424 		if (cell->attributes.highlight != attr->highlight) {
425 			attr->highlight = cell->attributes.highlight;
426 			cp = tty3270_add_sa(tp, cp, TAT_EXTHI, highlights[attr->highlight]);
427 		}
428 		if (cell->attributes.f_color != attr->f_color) {
429 			attr->f_color = cell->attributes.f_color;
430 			cp = tty3270_add_sa(tp, cp, TAT_FGCOLOR, colors[attr->f_color]);
431 		}
432 		if (cell->attributes.b_color != attr->b_color) {
433 			attr->b_color = cell->attributes.b_color;
434 			cp = tty3270_add_sa(tp, cp, TAT_BGCOLOR, colors[attr->b_color]);
435 		}
436 		c = cell->character;
437 		if (cell->attributes.alternate_charset)
438 			cp = tty3270_add_ge(tp, cp, tty3270_graphics_translate(tp, c));
439 		else
440 			*cp++ = tp->view.ascebc[c];
441 	}
442 	return cp;
443 }
444 
445 static void tty3270_reset_attributes(struct tty3270_attribute *attr)
446 {
447 	attr->highlight = TAX_RESET;
448 	attr->f_color = TAC_RESET;
449 	attr->b_color = TAC_RESET;
450 }
451 
452 /*
453  * Convert a tty3270_line to a 3270 data fragment usable for output.
454  */
455 static unsigned int tty3270_convert_line(struct tty3270 *tp, struct tty3270_line *line, int lineno)
456 {
457 	struct tty3270_attribute attr;
458 	int flen;
459 	char *cp;
460 
461 	/* Determine how long the fragment will be. */
462 	flen = tty3270_required_length(tp, line);
463 	if (flen > PAGE_SIZE)
464 		return 0;
465 	/* Write 3270 data fragment. */
466 	tty3270_reset_attributes(&attr);
467 	cp = tty3270_add_attributes(tp, line, &attr, tp->converted_line, lineno);
468 	cp = tty3270_add_reset_attributes(tp, line, cp, &attr, lineno);
469 	return cp - (char *)tp->converted_line;
470 }
471 
472 static void tty3270_update_lines_visible(struct tty3270 *tp, struct raw3270_request *rq)
473 {
474 	struct tty3270_line *line;
475 	int len, i;
476 
477 	for (i = 0; i < tty3270_tty_rows(tp); i++) {
478 		line = tty3270_get_view_line(tp, i);
479 		if (!line->dirty)
480 			continue;
481 		len = tty3270_convert_line(tp, line, i);
482 		if (raw3270_request_add_data(rq, tp->converted_line, len))
483 			break;
484 		line->dirty = 0;
485 	}
486 	if (i == tty3270_tty_rows(tp)) {
487 		for (i = 0; i < tp->allocated_lines; i++)
488 			tp->screen[i].dirty = 0;
489 		tp->update_flags &= ~TTY_UPDATE_LINES;
490 	}
491 }
492 
493 static void tty3270_update_lines_all(struct tty3270 *tp, struct raw3270_request *rq)
494 {
495 	struct tty3270_line *line;
496 	char buf[4];
497 	int len, i;
498 
499 	for (i = 0; i < tp->allocated_lines; i++) {
500 		line = tty3270_get_write_line(tp, i + tp->cy + 1);
501 		if (!line->dirty)
502 			continue;
503 		len = tty3270_convert_line(tp, line, tp->oops_line);
504 		if (raw3270_request_add_data(rq, tp->converted_line, len))
505 			break;
506 		line->dirty = 0;
507 		if (++tp->oops_line >= tty3270_tty_rows(tp))
508 			tp->oops_line = 0;
509 	}
510 
511 	if (i == tp->allocated_lines) {
512 		if (tp->oops_line < tty3270_tty_rows(tp)) {
513 			tty3270_add_ra(tp, buf, 0, tty3270_tty_rows(tp), 0);
514 			if (raw3270_request_add_data(rq, buf, sizeof(buf)))
515 				return;
516 		}
517 		tp->update_flags &= ~TTY_UPDATE_LINES;
518 	}
519 }
520 
521 /*
522  * Update 3270 display.
523  */
524 static void tty3270_update(struct timer_list *t)
525 {
526 	struct tty3270 *tp = from_timer(tp, t, timer);
527 	struct raw3270_request *wrq;
528 	u8 cmd = TC_WRITE;
529 	int rc, len;
530 
531 	wrq = xchg(&tp->write, 0);
532 	if (!wrq) {
533 		tty3270_set_timer(tp, 1);
534 		return;
535 	}
536 
537 	spin_lock_irq(&tp->view.lock);
538 	if (tp->update_flags == TTY_UPDATE_ALL)
539 		cmd = TC_EWRITEA;
540 
541 	raw3270_request_set_cmd(wrq, cmd);
542 	raw3270_request_add_data(wrq, &tp->wcc, 1);
543 	tp->wcc = TW_NONE;
544 
545 	/*
546 	 * Update status line.
547 	 */
548 	if (tp->update_flags & TTY_UPDATE_STATUS) {
549 		len = tty3270_add_status(tp);
550 		if (raw3270_request_add_data(wrq, tp->converted_line, len) == 0)
551 			tp->update_flags &= ~TTY_UPDATE_STATUS;
552 	}
553 
554 	/*
555 	 * Write input line.
556 	 */
557 	if (tp->update_flags & TTY_UPDATE_INPUT) {
558 		len = tty3270_add_prompt(tp);
559 		if (raw3270_request_add_data(wrq, tp->converted_line, len) == 0)
560 			tp->update_flags &= ~TTY_UPDATE_INPUT;
561 	}
562 
563 	if (tp->update_flags & TTY_UPDATE_LINES) {
564 		if (oops_in_progress)
565 			tty3270_update_lines_all(tp, wrq);
566 		else
567 			tty3270_update_lines_visible(tp, wrq);
568 	}
569 
570 	wrq->callback = tty3270_write_callback;
571 	rc = raw3270_start(&tp->view, wrq);
572 	if (rc == 0) {
573 		if (tp->update_flags)
574 			tty3270_set_timer(tp, 1);
575 	} else {
576 		raw3270_request_reset(wrq);
577 		xchg(&tp->write, wrq);
578 	}
579 	spin_unlock_irq(&tp->view.lock);
580 }
581 
582 /*
583  * Command recalling.
584  */
585 static void tty3270_rcl_add(struct tty3270 *tp, char *input, int len)
586 {
587 	char *p;
588 
589 	if (len <= 0)
590 		return;
591 	p = tp->rcl_lines[tp->rcl_write_index++];
592 	tp->rcl_write_index &= TTY3270_RECALL_SIZE - 1;
593 	memcpy(p, input, len);
594 	p[len] = '\0';
595 	tp->rcl_read_index = tp->rcl_write_index;
596 }
597 
598 static void tty3270_rcl_backward(struct kbd_data *kbd)
599 {
600 	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
601 	int i = 0;
602 
603 	spin_lock_irq(&tp->view.lock);
604 	if (tp->inattr == TF_INPUT) {
605 		do {
606 			tp->rcl_read_index--;
607 			tp->rcl_read_index &= TTY3270_RECALL_SIZE - 1;
608 		} while (!*tp->rcl_lines[tp->rcl_read_index] &&
609 			 i++ < TTY3270_RECALL_SIZE - 1);
610 		tty3270_update_prompt(tp, tp->rcl_lines[tp->rcl_read_index]);
611 	}
612 	spin_unlock_irq(&tp->view.lock);
613 }
614 
615 /*
616  * Deactivate tty view.
617  */
618 static void tty3270_exit_tty(struct kbd_data *kbd)
619 {
620 	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
621 
622 	raw3270_deactivate_view(&tp->view);
623 }
624 
625 static void tty3270_redraw(struct tty3270 *tp)
626 {
627 	int i;
628 
629 	for (i = 0; i < tty3270_tty_rows(tp); i++)
630 		tty3270_get_view_line(tp, i)->dirty = 1;
631 	tp->update_flags = TTY_UPDATE_ALL;
632 	tty3270_set_timer(tp, 1);
633 }
634 
635 /*
636  * Scroll forward in history.
637  */
638 static void tty3270_scroll_forward(struct kbd_data *kbd)
639 {
640 	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
641 
642 	spin_lock_irq(&tp->view.lock);
643 
644 	if (tp->nr_up >= tty3270_tty_rows(tp))
645 		tp->nr_up -= tty3270_tty_rows(tp) / 2;
646 	else
647 		tp->nr_up = 0;
648 	tty3270_redraw(tp);
649 	spin_unlock_irq(&tp->view.lock);
650 }
651 
652 /*
653  * Scroll backward in history.
654  */
655 static void tty3270_scroll_backward(struct kbd_data *kbd)
656 {
657 	struct tty3270 *tp = container_of(kbd->port, struct tty3270, port);
658 
659 	spin_lock_irq(&tp->view.lock);
660 	tp->nr_up += tty3270_tty_rows(tp) / 2;
661 	if (tp->nr_up > tp->allocated_lines - tty3270_tty_rows(tp))
662 		tp->nr_up = tp->allocated_lines - tty3270_tty_rows(tp);
663 	tty3270_redraw(tp);
664 	spin_unlock_irq(&tp->view.lock);
665 }
666 
667 /*
668  * Pass input line to tty.
669  */
670 static void tty3270_read_tasklet(unsigned long data)
671 {
672 	struct raw3270_request *rrq = (struct raw3270_request *)data;
673 	static char kreset_data = TW_KR;
674 	struct tty3270 *tp = container_of(rrq->view, struct tty3270, view);
675 	char *input;
676 	int len;
677 
678 	spin_lock_irq(&tp->view.lock);
679 	/*
680 	 * Two AID keys are special: For 0x7d (enter) the input line
681 	 * has to be emitted to the tty and for 0x6d the screen
682 	 * needs to be redrawn.
683 	 */
684 	input = NULL;
685 	len = 0;
686 	switch (tp->input[0]) {
687 	case AID_ENTER:
688 		/* Enter: write input to tty. */
689 		input = tp->input + 6;
690 		len = tty3270_input_size(tp->view.cols) - 6 - rrq->rescnt;
691 		if (tp->inattr != TF_INPUTN)
692 			tty3270_rcl_add(tp, input, len);
693 		if (tp->nr_up > 0)
694 			tp->nr_up = 0;
695 		/* Clear input area. */
696 		tty3270_update_prompt(tp, "");
697 		tty3270_set_timer(tp, 1);
698 		break;
699 	case AID_CLEAR:
700 		/* Display has been cleared. Redraw. */
701 		tp->update_flags = TTY_UPDATE_ALL;
702 		tty3270_set_timer(tp, 1);
703 		if (!list_empty(&tp->readpartreq->list))
704 			break;
705 		raw3270_start_request(&tp->view, tp->readpartreq, TC_WRITESF,
706 				      (char *)sfq_read_partition, sizeof(sfq_read_partition));
707 		break;
708 	case AID_READ_PARTITION:
709 		raw3270_read_modified_cb(tp->readpartreq, tp->input);
710 		break;
711 	default:
712 		break;
713 	}
714 	spin_unlock_irq(&tp->view.lock);
715 
716 	/* Start keyboard reset command. */
717 	raw3270_start_request(&tp->view, tp->kreset, TC_WRITE, &kreset_data, 1);
718 
719 	while (len-- > 0)
720 		kbd_keycode(tp->kbd, *input++);
721 	/* Emit keycode for AID byte. */
722 	kbd_keycode(tp->kbd, 256 + tp->input[0]);
723 
724 	raw3270_request_reset(rrq);
725 	xchg(&tp->read, rrq);
726 	raw3270_put_view(&tp->view);
727 }
728 
729 /*
730  * Read request completion callback.
731  */
732 static void tty3270_read_callback(struct raw3270_request *rq, void *data)
733 {
734 	struct tty3270 *tp = container_of(rq->view, struct tty3270, view);
735 
736 	raw3270_get_view(rq->view);
737 	/* Schedule tasklet to pass input to tty. */
738 	tasklet_schedule(&tp->readlet);
739 }
740 
741 /*
742  * Issue a read request. Call with device lock.
743  */
744 static void tty3270_issue_read(struct tty3270 *tp, int lock)
745 {
746 	struct raw3270_request *rrq;
747 	int rc;
748 
749 	rrq = xchg(&tp->read, 0);
750 	if (!rrq)
751 		/* Read already scheduled. */
752 		return;
753 	rrq->callback = tty3270_read_callback;
754 	rrq->callback_data = tp;
755 	raw3270_request_set_cmd(rrq, TC_READMOD);
756 	raw3270_request_set_data(rrq, tp->input, tty3270_input_size(tp->view.cols));
757 	/* Issue the read modified request. */
758 	if (lock)
759 		rc = raw3270_start(&tp->view, rrq);
760 	else
761 		rc = raw3270_start_irq(&tp->view, rrq);
762 	if (rc) {
763 		raw3270_request_reset(rrq);
764 		xchg(&tp->read, rrq);
765 	}
766 }
767 
768 /*
769  * Hang up the tty
770  */
771 static void tty3270_hangup_tasklet(unsigned long data)
772 {
773 	struct tty3270 *tp = (struct tty3270 *)data;
774 
775 	tty_port_tty_hangup(&tp->port, true);
776 	raw3270_put_view(&tp->view);
777 }
778 
779 /*
780  * Switch to the tty view.
781  */
782 static int tty3270_activate(struct raw3270_view *view)
783 {
784 	struct tty3270 *tp = container_of(view, struct tty3270, view);
785 
786 	tp->update_flags = TTY_UPDATE_ALL;
787 	tty3270_set_timer(tp, 1);
788 	return 0;
789 }
790 
791 static void tty3270_deactivate(struct raw3270_view *view)
792 {
793 	struct tty3270 *tp = container_of(view, struct tty3270, view);
794 
795 	del_timer(&tp->timer);
796 }
797 
798 static void tty3270_irq(struct tty3270 *tp, struct raw3270_request *rq, struct irb *irb)
799 {
800 	/* Handle ATTN. Schedule tasklet to read aid. */
801 	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
802 		if (!tp->throttle)
803 			tty3270_issue_read(tp, 0);
804 		else
805 			tp->attn = 1;
806 	}
807 
808 	if (rq) {
809 		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK) {
810 			rq->rc = -EIO;
811 			raw3270_get_view(&tp->view);
812 			tasklet_schedule(&tp->hanglet);
813 		} else {
814 			/* Normal end. Copy residual count. */
815 			rq->rescnt = irb->scsw.cmd.count;
816 		}
817 	} else if (irb->scsw.cmd.dstat & DEV_STAT_DEV_END) {
818 		/* Interrupt without an outstanding request -> update all */
819 		tp->update_flags = TTY_UPDATE_ALL;
820 		tty3270_set_timer(tp, 1);
821 	}
822 }
823 
824 /*
825  * Allocate tty3270 structure.
826  */
827 static struct tty3270 *tty3270_alloc_view(void)
828 {
829 	struct tty3270 *tp;
830 
831 	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
832 	if (!tp)
833 		goto out_err;
834 
835 	tp->write = raw3270_request_alloc(TTY3270_OUTPUT_BUFFER_SIZE);
836 	if (IS_ERR(tp->write))
837 		goto out_tp;
838 	tp->read = raw3270_request_alloc(0);
839 	if (IS_ERR(tp->read))
840 		goto out_write;
841 	tp->kreset = raw3270_request_alloc(1);
842 	if (IS_ERR(tp->kreset))
843 		goto out_read;
844 	tp->readpartreq = raw3270_request_alloc(sizeof(sfq_read_partition));
845 	if (IS_ERR(tp->readpartreq))
846 		goto out_reset;
847 	tp->kbd = kbd_alloc();
848 	if (!tp->kbd)
849 		goto out_readpartreq;
850 
851 	tty_port_init(&tp->port);
852 	timer_setup(&tp->timer, tty3270_update, 0);
853 	tasklet_init(&tp->readlet, tty3270_read_tasklet,
854 		     (unsigned long)tp->read);
855 	tasklet_init(&tp->hanglet, tty3270_hangup_tasklet,
856 		     (unsigned long)tp);
857 	return tp;
858 
859 out_readpartreq:
860 	raw3270_request_free(tp->readpartreq);
861 out_reset:
862 	raw3270_request_free(tp->kreset);
863 out_read:
864 	raw3270_request_free(tp->read);
865 out_write:
866 	raw3270_request_free(tp->write);
867 out_tp:
868 	kfree(tp);
869 out_err:
870 	return ERR_PTR(-ENOMEM);
871 }
872 
873 /*
874  * Free tty3270 structure.
875  */
876 static void tty3270_free_view(struct tty3270 *tp)
877 {
878 	kbd_free(tp->kbd);
879 	raw3270_request_free(tp->kreset);
880 	raw3270_request_free(tp->read);
881 	raw3270_request_free(tp->write);
882 	free_page((unsigned long)tp->converted_line);
883 	tty_port_destroy(&tp->port);
884 	kfree(tp);
885 }
886 
887 /*
888  * Allocate tty3270 screen.
889  */
890 static struct tty3270_line *tty3270_alloc_screen(struct tty3270 *tp, unsigned int rows,
891 						 unsigned int cols, int *allocated_out)
892 {
893 	struct tty3270_line *screen;
894 	int allocated, lines;
895 
896 	allocated = __roundup_pow_of_two(rows) * TTY3270_SCREEN_PAGES;
897 	screen = kcalloc(allocated, sizeof(struct tty3270_line), GFP_KERNEL);
898 	if (!screen)
899 		goto out_err;
900 	for (lines = 0; lines < allocated; lines++) {
901 		screen[lines].cells = kcalloc(cols, sizeof(struct tty3270_cell), GFP_KERNEL);
902 		if (!screen[lines].cells)
903 			goto out_screen;
904 	}
905 	*allocated_out = allocated;
906 	return screen;
907 out_screen:
908 	while (lines--)
909 		kfree(screen[lines].cells);
910 	kfree(screen);
911 out_err:
912 	return ERR_PTR(-ENOMEM);
913 }
914 
915 static char **tty3270_alloc_recall(int cols)
916 {
917 	char **lines;
918 	int i;
919 
920 	lines = kmalloc_array(TTY3270_RECALL_SIZE, sizeof(char *), GFP_KERNEL);
921 	if (!lines)
922 		return NULL;
923 	for (i = 0; i < TTY3270_RECALL_SIZE; i++) {
924 		lines[i] = kcalloc(1, tty3270_input_size(cols) + 1, GFP_KERNEL);
925 		if (!lines[i])
926 			break;
927 	}
928 
929 	if (i == TTY3270_RECALL_SIZE)
930 		return lines;
931 
932 	while (i--)
933 		kfree(lines[i]);
934 	kfree(lines);
935 	return NULL;
936 }
937 
938 static void tty3270_free_recall(char **lines)
939 {
940 	int i;
941 
942 	for (i = 0; i < TTY3270_RECALL_SIZE; i++)
943 		kfree(lines[i]);
944 	kfree(lines);
945 }
946 
947 /*
948  * Free tty3270 screen.
949  */
950 static void tty3270_free_screen(struct tty3270_line *screen, int old_lines)
951 {
952 	int lines;
953 
954 	for (lines = 0; lines < old_lines; lines++)
955 		kfree(screen[lines].cells);
956 	kfree(screen);
957 }
958 
959 /*
960  * Resize tty3270 screen
961  */
962 static void tty3270_resize(struct raw3270_view *view,
963 			   int new_model, int new_rows, int new_cols,
964 			   int old_model, int old_rows, int old_cols)
965 {
966 	struct tty3270 *tp = container_of(view, struct tty3270, view);
967 	struct tty3270_line *screen, *oscreen;
968 	char **old_rcl_lines, **new_rcl_lines;
969 	char *old_prompt, *new_prompt;
970 	char *old_input, *new_input;
971 	struct tty_struct *tty;
972 	struct winsize ws;
973 	int new_allocated, old_allocated = tp->allocated_lines;
974 
975 	if (old_model == new_model &&
976 	    old_cols == new_cols &&
977 	    old_rows == new_rows) {
978 		spin_lock_irq(&tp->view.lock);
979 		tty3270_redraw(tp);
980 		spin_unlock_irq(&tp->view.lock);
981 		return;
982 	}
983 
984 	new_input = kzalloc(tty3270_input_size(new_cols), GFP_KERNEL | GFP_DMA);
985 	if (!new_input)
986 		return;
987 	new_prompt = kzalloc(tty3270_input_size(new_cols), GFP_KERNEL);
988 	if (!new_prompt)
989 		goto out_input;
990 	screen = tty3270_alloc_screen(tp, new_rows, new_cols, &new_allocated);
991 	if (IS_ERR(screen))
992 		goto out_prompt;
993 	new_rcl_lines = tty3270_alloc_recall(new_cols);
994 	if (!new_rcl_lines)
995 		goto out_screen;
996 
997 	/* Switch to new output size */
998 	spin_lock_irq(&tp->view.lock);
999 	tty3270_blank_screen(tp);
1000 	oscreen = tp->screen;
1001 	tp->screen = screen;
1002 	tp->allocated_lines = new_allocated;
1003 	tp->view.rows = new_rows;
1004 	tp->view.cols = new_cols;
1005 	tp->view.model = new_model;
1006 	tp->update_flags = TTY_UPDATE_ALL;
1007 	old_input = tp->input;
1008 	old_prompt = tp->prompt;
1009 	old_rcl_lines = tp->rcl_lines;
1010 	tp->input = new_input;
1011 	tp->prompt = new_prompt;
1012 	tp->rcl_lines = new_rcl_lines;
1013 	tp->rcl_read_index = 0;
1014 	tp->rcl_write_index = 0;
1015 	spin_unlock_irq(&tp->view.lock);
1016 	tty3270_free_screen(oscreen, old_allocated);
1017 	kfree(old_input);
1018 	kfree(old_prompt);
1019 	tty3270_free_recall(old_rcl_lines);
1020 	tty3270_set_timer(tp, 1);
1021 	/* Informat tty layer about new size */
1022 	tty = tty_port_tty_get(&tp->port);
1023 	if (!tty)
1024 		return;
1025 	ws.ws_row = tty3270_tty_rows(tp);
1026 	ws.ws_col = tp->view.cols;
1027 	tty_do_resize(tty, &ws);
1028 	tty_kref_put(tty);
1029 	return;
1030 out_screen:
1031 	tty3270_free_screen(screen, new_rows);
1032 out_prompt:
1033 	kfree(new_prompt);
1034 out_input:
1035 	kfree(new_input);
1036 }
1037 
1038 /*
1039  * Unlink tty3270 data structure from tty.
1040  */
1041 static void tty3270_release(struct raw3270_view *view)
1042 {
1043 	struct tty3270 *tp = container_of(view, struct tty3270, view);
1044 	struct tty_struct *tty = tty_port_tty_get(&tp->port);
1045 
1046 	if (tty) {
1047 		tty->driver_data = NULL;
1048 		tty_port_tty_set(&tp->port, NULL);
1049 		tty_hangup(tty);
1050 		raw3270_put_view(&tp->view);
1051 		tty_kref_put(tty);
1052 	}
1053 }
1054 
1055 /*
1056  * Free tty3270 data structure
1057  */
1058 static void tty3270_free(struct raw3270_view *view)
1059 {
1060 	struct tty3270 *tp = container_of(view, struct tty3270, view);
1061 
1062 	del_timer_sync(&tp->timer);
1063 	tty3270_free_screen(tp->screen, tp->allocated_lines);
1064 	free_page((unsigned long)tp->converted_line);
1065 	kfree(tp->input);
1066 	kfree(tp->prompt);
1067 	tty3270_free_view(tp);
1068 }
1069 
1070 /*
1071  * Delayed freeing of tty3270 views.
1072  */
1073 static void tty3270_del_views(void)
1074 {
1075 	int i;
1076 
1077 	for (i = RAW3270_FIRSTMINOR; i <= tty3270_max_index; i++) {
1078 		struct raw3270_view *view = raw3270_find_view(&tty3270_fn, i);
1079 
1080 		if (!IS_ERR(view))
1081 			raw3270_del_view(view);
1082 	}
1083 }
1084 
1085 static struct raw3270_fn tty3270_fn = {
1086 	.activate = tty3270_activate,
1087 	.deactivate = tty3270_deactivate,
1088 	.intv = (void *)tty3270_irq,
1089 	.release = tty3270_release,
1090 	.free = tty3270_free,
1091 	.resize = tty3270_resize
1092 };
1093 
1094 static int
1095 tty3270_create_view(int index, struct tty3270 **newtp)
1096 {
1097 	struct tty3270 *tp;
1098 	int rc;
1099 
1100 	if (tty3270_max_index < index + 1)
1101 		tty3270_max_index = index + 1;
1102 
1103 	/* Allocate tty3270 structure on first open. */
1104 	tp = tty3270_alloc_view();
1105 	if (IS_ERR(tp))
1106 		return PTR_ERR(tp);
1107 
1108 	rc = raw3270_add_view(&tp->view, &tty3270_fn,
1109 			      index + RAW3270_FIRSTMINOR,
1110 			      RAW3270_VIEW_LOCK_IRQ);
1111 	if (rc)
1112 		goto out_free_view;
1113 
1114 	tp->screen = tty3270_alloc_screen(tp, tp->view.rows, tp->view.cols,
1115 					  &tp->allocated_lines);
1116 	if (IS_ERR(tp->screen)) {
1117 		rc = PTR_ERR(tp->screen);
1118 		goto out_put_view;
1119 	}
1120 
1121 	tp->converted_line = (void *)__get_free_page(GFP_KERNEL);
1122 	if (!tp->converted_line) {
1123 		rc = -ENOMEM;
1124 		goto out_free_screen;
1125 	}
1126 
1127 	tp->input = kzalloc(tty3270_input_size(tp->view.cols), GFP_KERNEL | GFP_DMA);
1128 	if (!tp->input) {
1129 		rc = -ENOMEM;
1130 		goto out_free_converted_line;
1131 	}
1132 
1133 	tp->prompt = kzalloc(tty3270_input_size(tp->view.cols), GFP_KERNEL);
1134 	if (!tp->prompt) {
1135 		rc = -ENOMEM;
1136 		goto out_free_input;
1137 	}
1138 
1139 	tp->rcl_lines = tty3270_alloc_recall(tp->view.cols);
1140 	if (!tp->rcl_lines) {
1141 		rc = -ENOMEM;
1142 		goto out_free_prompt;
1143 	}
1144 
1145 	/* Create blank line for every line in the tty output area. */
1146 	tty3270_blank_screen(tp);
1147 
1148 	tp->kbd->port = &tp->port;
1149 	tp->kbd->fn_handler[KVAL(K_INCRCONSOLE)] = tty3270_exit_tty;
1150 	tp->kbd->fn_handler[KVAL(K_SCROLLBACK)] = tty3270_scroll_backward;
1151 	tp->kbd->fn_handler[KVAL(K_SCROLLFORW)] = tty3270_scroll_forward;
1152 	tp->kbd->fn_handler[KVAL(K_CONS)] = tty3270_rcl_backward;
1153 	kbd_ascebc(tp->kbd, tp->view.ascebc);
1154 
1155 	raw3270_activate_view(&tp->view);
1156 	raw3270_put_view(&tp->view);
1157 	*newtp = tp;
1158 	return 0;
1159 
1160 out_free_prompt:
1161 	kfree(tp->prompt);
1162 out_free_input:
1163 	kfree(tp->input);
1164 out_free_converted_line:
1165 	free_page((unsigned long)tp->converted_line);
1166 out_free_screen:
1167 	tty3270_free_screen(tp->screen, tp->view.rows);
1168 out_put_view:
1169 	raw3270_put_view(&tp->view);
1170 	raw3270_del_view(&tp->view);
1171 out_free_view:
1172 	tty3270_free_view(tp);
1173 	return rc;
1174 }
1175 
1176 /*
1177  * This routine is called whenever a 3270 tty is opened first time.
1178  */
1179 static int
1180 tty3270_install(struct tty_driver *driver, struct tty_struct *tty)
1181 {
1182 	struct raw3270_view *view;
1183 	struct tty3270 *tp;
1184 	int rc;
1185 
1186 	/* Check if the tty3270 is already there. */
1187 	view = raw3270_find_view(&tty3270_fn, tty->index + RAW3270_FIRSTMINOR);
1188 	if (IS_ERR(view)) {
1189 		rc = tty3270_create_view(tty->index, &tp);
1190 		if (rc)
1191 			return rc;
1192 	} else {
1193 		tp = container_of(view, struct tty3270, view);
1194 		tty->driver_data = tp;
1195 		tp->inattr = TF_INPUT;
1196 	}
1197 
1198 	tty->winsize.ws_row = tty3270_tty_rows(tp);
1199 	tty->winsize.ws_col = tp->view.cols;
1200 	rc = tty_port_install(&tp->port, driver, tty);
1201 	if (rc) {
1202 		raw3270_put_view(&tp->view);
1203 		return rc;
1204 	}
1205 	tty->driver_data = tp;
1206 	return 0;
1207 }
1208 
1209 /*
1210  * This routine is called whenever a 3270 tty is opened.
1211  */
1212 static int tty3270_open(struct tty_struct *tty, struct file *filp)
1213 {
1214 	struct tty3270 *tp = tty->driver_data;
1215 	struct tty_port *port = &tp->port;
1216 
1217 	port->count++;
1218 	tty_port_tty_set(port, tty);
1219 	return 0;
1220 }
1221 
1222 /*
1223  * This routine is called when the 3270 tty is closed. We wait
1224  * for the remaining request to be completed. Then we clean up.
1225  */
1226 static void tty3270_close(struct tty_struct *tty, struct file *filp)
1227 {
1228 	struct tty3270 *tp = tty->driver_data;
1229 
1230 	if (tty->count > 1)
1231 		return;
1232 	if (tp)
1233 		tty_port_tty_set(&tp->port, NULL);
1234 }
1235 
1236 static void tty3270_cleanup(struct tty_struct *tty)
1237 {
1238 	struct tty3270 *tp = tty->driver_data;
1239 
1240 	if (tp) {
1241 		tty->driver_data = NULL;
1242 		raw3270_put_view(&tp->view);
1243 	}
1244 }
1245 
1246 /*
1247  * We always have room.
1248  */
1249 static unsigned int tty3270_write_room(struct tty_struct *tty)
1250 {
1251 	return INT_MAX;
1252 }
1253 
1254 /*
1255  * Insert character into the screen at the current position with the
1256  * current color and highlight. This function does NOT do cursor movement.
1257  */
1258 static void tty3270_put_character(struct tty3270 *tp, char ch)
1259 {
1260 	struct tty3270_line *line;
1261 	struct tty3270_cell *cell;
1262 
1263 	line = tty3270_get_write_line(tp, tp->cy);
1264 	if (line->len <= tp->cx) {
1265 		while (line->len < tp->cx) {
1266 			cell = line->cells + line->len;
1267 			cell->character = ' ';
1268 			cell->attributes = tp->attributes;
1269 			line->len++;
1270 		}
1271 		line->len++;
1272 	}
1273 	cell = line->cells + tp->cx;
1274 	cell->character = ch;
1275 	cell->attributes = tp->attributes;
1276 	line->dirty = 1;
1277 }
1278 
1279 /*
1280  * Do carriage return.
1281  */
1282 static void tty3270_cr(struct tty3270 *tp)
1283 {
1284 	tp->cx = 0;
1285 }
1286 
1287 /*
1288  * Do line feed.
1289  */
1290 static void tty3270_lf(struct tty3270 *tp)
1291 {
1292 	struct tty3270_line *line;
1293 	int i;
1294 
1295 	if (tp->cy < tty3270_tty_rows(tp) - 1) {
1296 		tp->cy++;
1297 	} else {
1298 		tp->line_view_start = tty3270_line_increment(tp, tp->line_view_start, 1);
1299 		tp->line_write_start = tty3270_line_increment(tp, tp->line_write_start, 1);
1300 		for (i = 0; i < tty3270_tty_rows(tp); i++)
1301 			tty3270_get_view_line(tp, i)->dirty = 1;
1302 	}
1303 
1304 	line = tty3270_get_write_line(tp, tp->cy);
1305 	line->len = 0;
1306 	line->dirty = 1;
1307 }
1308 
1309 static void tty3270_ri(struct tty3270 *tp)
1310 {
1311 	if (tp->cy > 0)
1312 		tp->cy--;
1313 }
1314 
1315 static void tty3270_reset_cell(struct tty3270 *tp, struct tty3270_cell *cell)
1316 {
1317 	cell->character = ' ';
1318 	tty3270_reset_attributes(&cell->attributes);
1319 }
1320 
1321 /*
1322  * Insert characters at current position.
1323  */
1324 static void tty3270_insert_characters(struct tty3270 *tp, int n)
1325 {
1326 	struct tty3270_line *line;
1327 	int k;
1328 
1329 	line = tty3270_get_write_line(tp, tp->cy);
1330 	while (line->len < tp->cx)
1331 		tty3270_reset_cell(tp, &line->cells[line->len++]);
1332 	if (n > tp->view.cols - tp->cx)
1333 		n = tp->view.cols - tp->cx;
1334 	k = min_t(int, line->len - tp->cx, tp->view.cols - tp->cx - n);
1335 	while (k--)
1336 		line->cells[tp->cx + n + k] = line->cells[tp->cx + k];
1337 	line->len += n;
1338 	if (line->len > tp->view.cols)
1339 		line->len = tp->view.cols;
1340 	while (n-- > 0) {
1341 		line->cells[tp->cx + n].character = ' ';
1342 		line->cells[tp->cx + n].attributes = tp->attributes;
1343 	}
1344 }
1345 
1346 /*
1347  * Delete characters at current position.
1348  */
1349 static void tty3270_delete_characters(struct tty3270 *tp, int n)
1350 {
1351 	struct tty3270_line *line;
1352 	int i;
1353 
1354 	line = tty3270_get_write_line(tp, tp->cy);
1355 	if (line->len <= tp->cx)
1356 		return;
1357 	if (line->len - tp->cx <= n) {
1358 		line->len = tp->cx;
1359 		return;
1360 	}
1361 	for (i = tp->cx; i + n < line->len; i++)
1362 		line->cells[i] = line->cells[i + n];
1363 	line->len -= n;
1364 }
1365 
1366 /*
1367  * Erase characters at current position.
1368  */
1369 static void tty3270_erase_characters(struct tty3270 *tp, int n)
1370 {
1371 	struct tty3270_line *line;
1372 	struct tty3270_cell *cell;
1373 
1374 	line = tty3270_get_write_line(tp, tp->cy);
1375 	while (line->len > tp->cx && n-- > 0) {
1376 		cell = line->cells + tp->cx++;
1377 		tty3270_reset_cell(tp, cell);
1378 	}
1379 	tp->cx += n;
1380 	tp->cx = min_t(int, tp->cx, tp->view.cols - 1);
1381 }
1382 
1383 /*
1384  * Erase line, 3 different cases:
1385  *  Esc [ 0 K	Erase from current position to end of line inclusive
1386  *  Esc [ 1 K	Erase from beginning of line to current position inclusive
1387  *  Esc [ 2 K	Erase entire line (without moving cursor)
1388  */
1389 static void tty3270_erase_line(struct tty3270 *tp, int mode)
1390 {
1391 	struct tty3270_line *line;
1392 	struct tty3270_cell *cell;
1393 	int i, start, end;
1394 
1395 	line = tty3270_get_write_line(tp, tp->cy);
1396 
1397 	switch (mode) {
1398 	case 0:
1399 		start = tp->cx;
1400 		end = tp->view.cols;
1401 		break;
1402 	case 1:
1403 		start = 0;
1404 		end = tp->cx;
1405 		break;
1406 	case 2:
1407 		start = 0;
1408 		end = tp->view.cols;
1409 		break;
1410 	default:
1411 		return;
1412 	}
1413 
1414 	for (i = start; i < end; i++) {
1415 		cell = line->cells + i;
1416 		tty3270_reset_cell(tp, cell);
1417 		cell->attributes.b_color = tp->attributes.b_color;
1418 	}
1419 
1420 	if (line->len <= end)
1421 		line->len = end;
1422 }
1423 
1424 /*
1425  * Erase display, 3 different cases:
1426  *  Esc [ 0 J	Erase from current position to bottom of screen inclusive
1427  *  Esc [ 1 J	Erase from top of screen to current position inclusive
1428  *  Esc [ 2 J	Erase entire screen (without moving the cursor)
1429  */
1430 static void tty3270_erase_display(struct tty3270 *tp, int mode)
1431 {
1432 	struct tty3270_line *line;
1433 	int i, start, end;
1434 
1435 	switch (mode) {
1436 	case 0:
1437 		tty3270_erase_line(tp, 0);
1438 		start = tp->cy + 1;
1439 		end = tty3270_tty_rows(tp);
1440 		break;
1441 	case 1:
1442 		start = 0;
1443 		end = tp->cy;
1444 		tty3270_erase_line(tp, 1);
1445 		break;
1446 	case 2:
1447 		start = 0;
1448 		end = tty3270_tty_rows(tp);
1449 		break;
1450 	default:
1451 		return;
1452 	}
1453 	for (i = start; i < end; i++) {
1454 		line = tty3270_get_write_line(tp, i);
1455 		line->len = 0;
1456 		line->dirty = 1;
1457 	}
1458 }
1459 
1460 /*
1461  * Set attributes found in an escape sequence.
1462  *  Esc [ <attr> ; <attr> ; ... m
1463  */
1464 static void tty3270_set_attributes(struct tty3270 *tp)
1465 {
1466 	int i, attr;
1467 
1468 	for (i = 0; i <= tp->esc_npar; i++) {
1469 		attr = tp->esc_par[i];
1470 		switch (attr) {
1471 		case 0:		/* Reset */
1472 			tty3270_reset_attributes(&tp->attributes);
1473 			break;
1474 		/* Highlight. */
1475 		case 4:		/* Start underlining. */
1476 			tp->attributes.highlight = TTY3270_HIGHLIGHT_UNDERSCORE;
1477 			break;
1478 		case 5:		/* Start blink. */
1479 			tp->attributes.highlight = TTY3270_HIGHLIGHT_BLINK;
1480 			break;
1481 		case 7:		/* Start reverse. */
1482 			tp->attributes.highlight = TTY3270_HIGHLIGHT_REVERSE;
1483 			break;
1484 		case 24:	/* End underlining */
1485 			tp->attributes.highlight &= ~TTY3270_HIGHLIGHT_UNDERSCORE;
1486 			break;
1487 		case 25:	/* End blink. */
1488 			tp->attributes.highlight &= ~TTY3270_HIGHLIGHT_BLINK;
1489 			break;
1490 		case 27:	/* End reverse. */
1491 			tp->attributes.highlight &= ~TTY3270_HIGHLIGHT_REVERSE;
1492 			break;
1493 		/* Foreground color. */
1494 		case 30:	/* Black */
1495 		case 31:	/* Red */
1496 		case 32:	/* Green */
1497 		case 33:	/* Yellow */
1498 		case 34:	/* Blue */
1499 		case 35:	/* Magenta */
1500 		case 36:	/* Cyan */
1501 		case 37:	/* White */
1502 		case 39:	/* Black */
1503 			tp->attributes.f_color = attr - 30;
1504 			break;
1505 		/* Background color. */
1506 		case 40:	/* Black */
1507 		case 41:	/* Red */
1508 		case 42:	/* Green */
1509 		case 43:	/* Yellow */
1510 		case 44:	/* Blue */
1511 		case 45:	/* Magenta */
1512 		case 46:	/* Cyan */
1513 		case 47:	/* White */
1514 		case 49:	/* Black */
1515 			tp->attributes.b_color = attr - 40;
1516 			break;
1517 		}
1518 	}
1519 }
1520 
1521 static inline int tty3270_getpar(struct tty3270 *tp, int ix)
1522 {
1523 	return (tp->esc_par[ix] > 0) ? tp->esc_par[ix] : 1;
1524 }
1525 
1526 static void tty3270_goto_xy(struct tty3270 *tp, int cx, int cy)
1527 {
1528 	struct tty3270_line *line;
1529 	struct tty3270_cell *cell;
1530 	int max_cx = max(0, cx);
1531 	int max_cy = max(0, cy);
1532 
1533 	tp->cx = min_t(int, tp->view.cols - 1, max_cx);
1534 	line = tty3270_get_write_line(tp, tp->cy);
1535 	while (line->len < tp->cx) {
1536 		cell = line->cells + line->len;
1537 		cell->character = ' ';
1538 		cell->attributes = tp->attributes;
1539 		line->len++;
1540 	}
1541 	tp->cy = min_t(int, tty3270_tty_rows(tp) - 1, max_cy);
1542 }
1543 
1544 /*
1545  * Process escape sequences. Known sequences:
1546  *  Esc 7			Save Cursor Position
1547  *  Esc 8			Restore Cursor Position
1548  *  Esc [ Pn ; Pn ; .. m	Set attributes
1549  *  Esc [ Pn ; Pn H		Cursor Position
1550  *  Esc [ Pn ; Pn f		Cursor Position
1551  *  Esc [ Pn A			Cursor Up
1552  *  Esc [ Pn B			Cursor Down
1553  *  Esc [ Pn C			Cursor Forward
1554  *  Esc [ Pn D			Cursor Backward
1555  *  Esc [ Pn G			Cursor Horizontal Absolute
1556  *  Esc [ Pn X			Erase Characters
1557  *  Esc [ Ps J			Erase in Display
1558  *  Esc [ Ps K			Erase in Line
1559  * // FIXME: add all the new ones.
1560  *
1561  *  Pn is a numeric parameter, a string of zero or more decimal digits.
1562  *  Ps is a selective parameter.
1563  */
1564 static void tty3270_escape_sequence(struct tty3270 *tp, char ch)
1565 {
1566 	enum { ES_NORMAL, ES_ESC, ES_SQUARE, ES_PAREN, ES_GETPARS };
1567 
1568 	if (tp->esc_state == ES_NORMAL) {
1569 		if (ch == 0x1b)
1570 			/* Starting new escape sequence. */
1571 			tp->esc_state = ES_ESC;
1572 		return;
1573 	}
1574 	if (tp->esc_state == ES_ESC) {
1575 		tp->esc_state = ES_NORMAL;
1576 		switch (ch) {
1577 		case '[':
1578 			tp->esc_state = ES_SQUARE;
1579 			break;
1580 		case '(':
1581 			tp->esc_state = ES_PAREN;
1582 			break;
1583 		case 'E':
1584 			tty3270_cr(tp);
1585 			tty3270_lf(tp);
1586 			break;
1587 		case 'M':
1588 			tty3270_ri(tp);
1589 			break;
1590 		case 'D':
1591 			tty3270_lf(tp);
1592 			break;
1593 		case 'Z':		/* Respond ID. */
1594 			kbd_puts_queue(&tp->port, "\033[?6c");
1595 			break;
1596 		case '7':		/* Save cursor position. */
1597 			tp->saved_cx = tp->cx;
1598 			tp->saved_cy = tp->cy;
1599 			tp->saved_attributes = tp->attributes;
1600 			break;
1601 		case '8':		/* Restore cursor position. */
1602 			tty3270_goto_xy(tp, tp->saved_cx, tp->saved_cy);
1603 			tp->attributes = tp->saved_attributes;
1604 			break;
1605 		case 'c':		/* Reset terminal. */
1606 			tp->cx = 0;
1607 			tp->cy = 0;
1608 			tp->saved_cx = 0;
1609 			tp->saved_cy = 0;
1610 			tty3270_reset_attributes(&tp->attributes);
1611 			tty3270_reset_attributes(&tp->saved_attributes);
1612 			tty3270_erase_display(tp, 2);
1613 			break;
1614 		}
1615 		return;
1616 	}
1617 
1618 	switch (tp->esc_state) {
1619 	case ES_PAREN:
1620 		tp->esc_state = ES_NORMAL;
1621 		switch (ch) {
1622 		case 'B':
1623 			tp->attributes.alternate_charset = 0;
1624 			break;
1625 		case '0':
1626 			tp->attributes.alternate_charset = 1;
1627 			break;
1628 		}
1629 		return;
1630 	case ES_SQUARE:
1631 		tp->esc_state = ES_GETPARS;
1632 		memset(tp->esc_par, 0, sizeof(tp->esc_par));
1633 		tp->esc_npar = 0;
1634 		tp->esc_ques = (ch == '?');
1635 		if (tp->esc_ques)
1636 			return;
1637 		fallthrough;
1638 	case ES_GETPARS:
1639 		if (ch == ';' && tp->esc_npar < ESCAPE_NPAR - 1) {
1640 			tp->esc_npar++;
1641 			return;
1642 		}
1643 		if (ch >= '0' && ch <= '9') {
1644 			tp->esc_par[tp->esc_npar] *= 10;
1645 			tp->esc_par[tp->esc_npar] += ch - '0';
1646 			return;
1647 		}
1648 		break;
1649 	default:
1650 		break;
1651 	}
1652 	tp->esc_state = ES_NORMAL;
1653 	if (ch == 'n' && !tp->esc_ques) {
1654 		if (tp->esc_par[0] == 5)		/* Status report. */
1655 			kbd_puts_queue(&tp->port, "\033[0n");
1656 		else if (tp->esc_par[0] == 6) {	/* Cursor report. */
1657 			char buf[40];
1658 
1659 			sprintf(buf, "\033[%d;%dR", tp->cy + 1, tp->cx + 1);
1660 			kbd_puts_queue(&tp->port, buf);
1661 		}
1662 		return;
1663 	}
1664 	if (tp->esc_ques)
1665 		return;
1666 	switch (ch) {
1667 	case 'm':
1668 		tty3270_set_attributes(tp);
1669 		break;
1670 	case 'H':	/* Set cursor position. */
1671 	case 'f':
1672 		tty3270_goto_xy(tp, tty3270_getpar(tp, 1) - 1,
1673 				tty3270_getpar(tp, 0) - 1);
1674 		break;
1675 	case 'd':	/* Set y position. */
1676 		tty3270_goto_xy(tp, tp->cx, tty3270_getpar(tp, 0) - 1);
1677 		break;
1678 	case 'A':	/* Cursor up. */
1679 	case 'F':
1680 		tty3270_goto_xy(tp, tp->cx, tp->cy - tty3270_getpar(tp, 0));
1681 		break;
1682 	case 'B':	/* Cursor down. */
1683 	case 'e':
1684 	case 'E':
1685 		tty3270_goto_xy(tp, tp->cx, tp->cy + tty3270_getpar(tp, 0));
1686 		break;
1687 	case 'C':	/* Cursor forward. */
1688 	case 'a':
1689 		tty3270_goto_xy(tp, tp->cx + tty3270_getpar(tp, 0), tp->cy);
1690 		break;
1691 	case 'D':	/* Cursor backward. */
1692 		tty3270_goto_xy(tp, tp->cx - tty3270_getpar(tp, 0), tp->cy);
1693 		break;
1694 	case 'G':	/* Set x position. */
1695 	case '`':
1696 		tty3270_goto_xy(tp, tty3270_getpar(tp, 0), tp->cy);
1697 		break;
1698 	case 'X':	/* Erase Characters. */
1699 		tty3270_erase_characters(tp, tty3270_getpar(tp, 0));
1700 		break;
1701 	case 'J':	/* Erase display. */
1702 		tty3270_erase_display(tp, tp->esc_par[0]);
1703 		break;
1704 	case 'K':	/* Erase line. */
1705 		tty3270_erase_line(tp, tp->esc_par[0]);
1706 		break;
1707 	case 'P':	/* Delete characters. */
1708 		tty3270_delete_characters(tp, tty3270_getpar(tp, 0));
1709 		break;
1710 	case '@':	/* Insert characters. */
1711 		tty3270_insert_characters(tp, tty3270_getpar(tp, 0));
1712 		break;
1713 	case 's':	/* Save cursor position. */
1714 		tp->saved_cx = tp->cx;
1715 		tp->saved_cy = tp->cy;
1716 		tp->saved_attributes = tp->attributes;
1717 		break;
1718 	case 'u':	/* Restore cursor position. */
1719 		tty3270_goto_xy(tp, tp->saved_cx, tp->saved_cy);
1720 		tp->attributes = tp->saved_attributes;
1721 		break;
1722 	}
1723 }
1724 
1725 /*
1726  * String write routine for 3270 ttys
1727  */
1728 static void tty3270_do_write(struct tty3270 *tp, struct tty_struct *tty,
1729 			     const unsigned char *buf, int count)
1730 {
1731 	int i_msg, i;
1732 
1733 	spin_lock_irq(&tp->view.lock);
1734 	for (i_msg = 0; !tty->flow.stopped && i_msg < count; i_msg++) {
1735 		if (tp->esc_state != 0) {
1736 			/* Continue escape sequence. */
1737 			tty3270_escape_sequence(tp, buf[i_msg]);
1738 			continue;
1739 		}
1740 
1741 		switch (buf[i_msg]) {
1742 		case 0x00:
1743 			break;
1744 		case 0x07:		/* '\a' -- Alarm */
1745 			tp->wcc |= TW_PLUSALARM;
1746 			break;
1747 		case 0x08:		/* Backspace. */
1748 			if (tp->cx > 0) {
1749 				tp->cx--;
1750 				tty3270_put_character(tp, ' ');
1751 			}
1752 			break;
1753 		case 0x09:		/* '\t' -- Tabulate */
1754 			for (i = tp->cx % 8; i < 8; i++) {
1755 				if (tp->cx >= tp->view.cols) {
1756 					tty3270_cr(tp);
1757 					tty3270_lf(tp);
1758 					break;
1759 				}
1760 				tty3270_put_character(tp, ' ');
1761 				tp->cx++;
1762 			}
1763 			break;
1764 		case 0x0a:		/* '\n' -- New Line */
1765 			tty3270_cr(tp);
1766 			tty3270_lf(tp);
1767 			break;
1768 		case 0x0c:		/* '\f' -- Form Feed */
1769 			tty3270_erase_display(tp, 2);
1770 			tp->cx = 0;
1771 			tp->cy = 0;
1772 			break;
1773 		case 0x0d:		/* '\r' -- Carriage Return */
1774 			tp->cx = 0;
1775 			break;
1776 		case 0x0e:
1777 			tp->attributes.alternate_charset = 1;
1778 			break;
1779 		case 0x0f:		/* SuSE "exit alternate mode" */
1780 			tp->attributes.alternate_charset = 0;
1781 			break;
1782 		case 0x1b:		/* Start escape sequence. */
1783 			tty3270_escape_sequence(tp, buf[i_msg]);
1784 			break;
1785 		default:		/* Insert normal character. */
1786 			if (tp->cx >= tp->view.cols) {
1787 				tty3270_cr(tp);
1788 				tty3270_lf(tp);
1789 			}
1790 			tty3270_put_character(tp, buf[i_msg]);
1791 			tp->cx++;
1792 			break;
1793 		}
1794 	}
1795 	/* Setup timer to update display after 1/10 second */
1796 	tp->update_flags |= TTY_UPDATE_LINES;
1797 	if (!timer_pending(&tp->timer))
1798 		tty3270_set_timer(tp, msecs_to_jiffies(100));
1799 
1800 	spin_unlock_irq(&tp->view.lock);
1801 }
1802 
1803 /*
1804  * String write routine for 3270 ttys
1805  */
1806 static ssize_t tty3270_write(struct tty_struct *tty, const u8 *buf,
1807 			     size_t count)
1808 {
1809 	struct tty3270 *tp;
1810 
1811 	tp = tty->driver_data;
1812 	if (!tp)
1813 		return 0;
1814 	if (tp->char_count > 0) {
1815 		tty3270_do_write(tp, tty, tp->char_buf, tp->char_count);
1816 		tp->char_count = 0;
1817 	}
1818 	tty3270_do_write(tp, tty, buf, count);
1819 	return count;
1820 }
1821 
1822 /*
1823  * Put single characters to the ttys character buffer
1824  */
1825 static int tty3270_put_char(struct tty_struct *tty, u8 ch)
1826 {
1827 	struct tty3270 *tp;
1828 
1829 	tp = tty->driver_data;
1830 	if (!tp || tp->char_count >= TTY3270_CHAR_BUF_SIZE)
1831 		return 0;
1832 	tp->char_buf[tp->char_count++] = ch;
1833 	return 1;
1834 }
1835 
1836 /*
1837  * Flush all characters from the ttys characeter buffer put there
1838  * by tty3270_put_char.
1839  */
1840 static void tty3270_flush_chars(struct tty_struct *tty)
1841 {
1842 	struct tty3270 *tp;
1843 
1844 	tp = tty->driver_data;
1845 	if (!tp)
1846 		return;
1847 	if (tp->char_count > 0) {
1848 		tty3270_do_write(tp, tty, tp->char_buf, tp->char_count);
1849 		tp->char_count = 0;
1850 	}
1851 }
1852 
1853 /*
1854  * Check for visible/invisible input switches
1855  */
1856 static void tty3270_set_termios(struct tty_struct *tty, const struct ktermios *old)
1857 {
1858 	struct tty3270 *tp;
1859 	int new;
1860 
1861 	tp = tty->driver_data;
1862 	if (!tp)
1863 		return;
1864 	spin_lock_irq(&tp->view.lock);
1865 	if (L_ICANON(tty)) {
1866 		new = L_ECHO(tty) ? TF_INPUT : TF_INPUTN;
1867 		if (new != tp->inattr) {
1868 			tp->inattr = new;
1869 			tty3270_update_prompt(tp, "");
1870 			tty3270_set_timer(tp, 1);
1871 		}
1872 	}
1873 	spin_unlock_irq(&tp->view.lock);
1874 }
1875 
1876 /*
1877  * Disable reading from a 3270 tty
1878  */
1879 static void tty3270_throttle(struct tty_struct *tty)
1880 {
1881 	struct tty3270 *tp;
1882 
1883 	tp = tty->driver_data;
1884 	if (!tp)
1885 		return;
1886 	tp->throttle = 1;
1887 }
1888 
1889 /*
1890  * Enable reading from a 3270 tty
1891  */
1892 static void tty3270_unthrottle(struct tty_struct *tty)
1893 {
1894 	struct tty3270 *tp;
1895 
1896 	tp = tty->driver_data;
1897 	if (!tp)
1898 		return;
1899 	tp->throttle = 0;
1900 	if (tp->attn)
1901 		tty3270_issue_read(tp, 1);
1902 }
1903 
1904 /*
1905  * Hang up the tty device.
1906  */
1907 static void tty3270_hangup(struct tty_struct *tty)
1908 {
1909 	struct tty3270 *tp;
1910 
1911 	tp = tty->driver_data;
1912 	if (!tp)
1913 		return;
1914 	spin_lock_irq(&tp->view.lock);
1915 	tp->cx = 0;
1916 	tp->cy = 0;
1917 	tp->saved_cx = 0;
1918 	tp->saved_cy = 0;
1919 	tty3270_reset_attributes(&tp->attributes);
1920 	tty3270_reset_attributes(&tp->saved_attributes);
1921 	tty3270_blank_screen(tp);
1922 	tp->update_flags = TTY_UPDATE_ALL;
1923 	spin_unlock_irq(&tp->view.lock);
1924 	tty3270_set_timer(tp, 1);
1925 }
1926 
1927 static void tty3270_wait_until_sent(struct tty_struct *tty, int timeout)
1928 {
1929 }
1930 
1931 static int tty3270_ioctl(struct tty_struct *tty, unsigned int cmd,
1932 			 unsigned long arg)
1933 {
1934 	struct tty3270 *tp;
1935 
1936 	tp = tty->driver_data;
1937 	if (!tp)
1938 		return -ENODEV;
1939 	if (tty_io_error(tty))
1940 		return -EIO;
1941 	return kbd_ioctl(tp->kbd, cmd, arg);
1942 }
1943 
1944 #ifdef CONFIG_COMPAT
1945 static long tty3270_compat_ioctl(struct tty_struct *tty,
1946 				 unsigned int cmd, unsigned long arg)
1947 {
1948 	struct tty3270 *tp;
1949 
1950 	tp = tty->driver_data;
1951 	if (!tp)
1952 		return -ENODEV;
1953 	if (tty_io_error(tty))
1954 		return -EIO;
1955 	return kbd_ioctl(tp->kbd, cmd, (unsigned long)compat_ptr(arg));
1956 }
1957 #endif
1958 
1959 static const struct tty_operations tty3270_ops = {
1960 	.install = tty3270_install,
1961 	.cleanup = tty3270_cleanup,
1962 	.open = tty3270_open,
1963 	.close = tty3270_close,
1964 	.write = tty3270_write,
1965 	.put_char = tty3270_put_char,
1966 	.flush_chars = tty3270_flush_chars,
1967 	.write_room = tty3270_write_room,
1968 	.throttle = tty3270_throttle,
1969 	.unthrottle = tty3270_unthrottle,
1970 	.hangup = tty3270_hangup,
1971 	.wait_until_sent = tty3270_wait_until_sent,
1972 	.ioctl = tty3270_ioctl,
1973 #ifdef CONFIG_COMPAT
1974 	.compat_ioctl = tty3270_compat_ioctl,
1975 #endif
1976 	.set_termios = tty3270_set_termios
1977 };
1978 
1979 static void tty3270_create_cb(int minor)
1980 {
1981 	tty_register_device(tty3270_driver, minor - RAW3270_FIRSTMINOR, NULL);
1982 }
1983 
1984 static void tty3270_destroy_cb(int minor)
1985 {
1986 	tty_unregister_device(tty3270_driver, minor - RAW3270_FIRSTMINOR);
1987 }
1988 
1989 static struct raw3270_notifier tty3270_notifier = {
1990 	.create = tty3270_create_cb,
1991 	.destroy = tty3270_destroy_cb,
1992 };
1993 
1994 /*
1995  * 3270 tty registration code called from tty_init().
1996  * Most kernel services (incl. kmalloc) are available at this poimt.
1997  */
1998 static int __init tty3270_init(void)
1999 {
2000 	struct tty_driver *driver;
2001 	int ret;
2002 
2003 	driver = tty_alloc_driver(RAW3270_MAXDEVS,
2004 				  TTY_DRIVER_REAL_RAW |
2005 				  TTY_DRIVER_DYNAMIC_DEV |
2006 				  TTY_DRIVER_RESET_TERMIOS);
2007 	if (IS_ERR(driver))
2008 		return PTR_ERR(driver);
2009 
2010 	/*
2011 	 * Initialize the tty_driver structure
2012 	 * Entries in tty3270_driver that are NOT initialized:
2013 	 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
2014 	 */
2015 	driver->driver_name = "tty3270";
2016 	driver->name = "3270/tty";
2017 	driver->major = IBM_TTY3270_MAJOR;
2018 	driver->minor_start = RAW3270_FIRSTMINOR;
2019 	driver->name_base = RAW3270_FIRSTMINOR;
2020 	driver->type = TTY_DRIVER_TYPE_SYSTEM;
2021 	driver->subtype = SYSTEM_TYPE_TTY;
2022 	driver->init_termios = tty_std_termios;
2023 	tty_set_operations(driver, &tty3270_ops);
2024 	ret = tty_register_driver(driver);
2025 	if (ret) {
2026 		tty_driver_kref_put(driver);
2027 		return ret;
2028 	}
2029 	tty3270_driver = driver;
2030 	raw3270_register_notifier(&tty3270_notifier);
2031 	return 0;
2032 }
2033 
2034 static void __exit tty3270_exit(void)
2035 {
2036 	struct tty_driver *driver;
2037 
2038 	raw3270_unregister_notifier(&tty3270_notifier);
2039 	driver = tty3270_driver;
2040 	tty3270_driver = NULL;
2041 	tty_unregister_driver(driver);
2042 	tty_driver_kref_put(driver);
2043 	tty3270_del_views();
2044 }
2045 
2046 #if IS_ENABLED(CONFIG_TN3270_CONSOLE)
2047 
2048 static struct tty3270 *condev;
2049 
2050 static void
2051 con3270_write(struct console *co, const char *str, unsigned int count)
2052 {
2053 	struct tty3270 *tp = co->data;
2054 	unsigned long flags;
2055 	char c;
2056 
2057 	spin_lock_irqsave(&tp->view.lock, flags);
2058 	while (count--) {
2059 		c = *str++;
2060 		if (c == 0x0a) {
2061 			tty3270_cr(tp);
2062 			tty3270_lf(tp);
2063 		} else {
2064 			if (tp->cx >= tp->view.cols) {
2065 				tty3270_cr(tp);
2066 				tty3270_lf(tp);
2067 			}
2068 			tty3270_put_character(tp, c);
2069 			tp->cx++;
2070 		}
2071 	}
2072 	spin_unlock_irqrestore(&tp->view.lock, flags);
2073 }
2074 
2075 static struct tty_driver *
2076 con3270_device(struct console *c, int *index)
2077 {
2078 	*index = c->index;
2079 	return tty3270_driver;
2080 }
2081 
2082 static void
2083 con3270_wait_write(struct tty3270 *tp)
2084 {
2085 	while (!tp->write) {
2086 		raw3270_wait_cons_dev(tp->view.dev);
2087 		barrier();
2088 	}
2089 }
2090 
2091 /*
2092  * The below function is called as a panic/reboot notifier before the
2093  * system enters a disabled, endless loop.
2094  *
2095  * Notice we must use the spin_trylock() alternative, to prevent lockups
2096  * in atomic context (panic routine runs with secondary CPUs, local IRQs
2097  * and preemption disabled).
2098  */
2099 static int con3270_notify(struct notifier_block *self,
2100 			  unsigned long event, void *data)
2101 {
2102 	struct tty3270 *tp;
2103 	unsigned long flags;
2104 	int rc;
2105 
2106 	tp = condev;
2107 	if (!tp->view.dev)
2108 		return NOTIFY_DONE;
2109 	if (!raw3270_view_lock_unavailable(&tp->view)) {
2110 		rc = raw3270_activate_view(&tp->view);
2111 		if (rc)
2112 			return NOTIFY_DONE;
2113 	}
2114 	if (!spin_trylock_irqsave(&tp->view.lock, flags))
2115 		return NOTIFY_DONE;
2116 	con3270_wait_write(tp);
2117 	tp->nr_up = 0;
2118 	tp->update_flags = TTY_UPDATE_ALL;
2119 	while (tp->update_flags != 0) {
2120 		spin_unlock_irqrestore(&tp->view.lock, flags);
2121 		tty3270_update(&tp->timer);
2122 		spin_lock_irqsave(&tp->view.lock, flags);
2123 		con3270_wait_write(tp);
2124 	}
2125 	spin_unlock_irqrestore(&tp->view.lock, flags);
2126 	return NOTIFY_DONE;
2127 }
2128 
2129 static struct notifier_block on_panic_nb = {
2130 	.notifier_call = con3270_notify,
2131 	.priority = INT_MIN + 1, /* run the callback late */
2132 };
2133 
2134 static struct notifier_block on_reboot_nb = {
2135 	.notifier_call = con3270_notify,
2136 	.priority = INT_MIN + 1, /* run the callback late */
2137 };
2138 
2139 static struct console con3270 = {
2140 	.name	 = "tty3270",
2141 	.write	 = con3270_write,
2142 	.device	 = con3270_device,
2143 	.flags	 = CON_PRINTBUFFER,
2144 };
2145 
2146 static int __init
2147 con3270_init(void)
2148 {
2149 	struct raw3270_view *view;
2150 	struct raw3270 *rp;
2151 	struct tty3270 *tp;
2152 	int rc;
2153 
2154 	/* Check if 3270 is to be the console */
2155 	if (!CONSOLE_IS_3270)
2156 		return -ENODEV;
2157 
2158 	/* Set the console mode for VM */
2159 	if (MACHINE_IS_VM) {
2160 		cpcmd("TERM CONMODE 3270", NULL, 0, NULL);
2161 		cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
2162 	}
2163 
2164 	rp = raw3270_setup_console();
2165 	if (IS_ERR(rp))
2166 		return PTR_ERR(rp);
2167 
2168 	/* Check if the tty3270 is already there. */
2169 	view = raw3270_find_view(&tty3270_fn, RAW3270_FIRSTMINOR);
2170 	if (IS_ERR(view)) {
2171 		rc = tty3270_create_view(0, &tp);
2172 		if (rc)
2173 			return rc;
2174 	} else {
2175 		tp = container_of(view, struct tty3270, view);
2176 		tp->inattr = TF_INPUT;
2177 	}
2178 	con3270.data = tp;
2179 	condev = tp;
2180 	atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
2181 	register_reboot_notifier(&on_reboot_nb);
2182 	register_console(&con3270);
2183 	return 0;
2184 }
2185 console_initcall(con3270_init);
2186 #endif
2187 
2188 MODULE_LICENSE("GPL");
2189 MODULE_ALIAS_CHARDEV_MAJOR(IBM_TTY3270_MAJOR);
2190 
2191 module_init(tty3270_init);
2192 module_exit(tty3270_exit);
2193