Loading...
1/*
2 * drivers/s390/char/sclp_tty.c
3 * SCLP line mode terminal driver.
4 *
5 * S390 version
6 * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
7 * Author(s): Martin Peschke <mpeschke@de.ibm.com>
8 * Martin Schwidefsky <schwidefsky@de.ibm.com>
9 */
10
11#include <linux/module.h>
12#include <linux/kmod.h>
13#include <linux/tty.h>
14#include <linux/tty_driver.h>
15#include <linux/tty_flip.h>
16#include <linux/err.h>
17#include <linux/init.h>
18#include <linux/interrupt.h>
19#include <linux/gfp.h>
20#include <asm/uaccess.h>
21
22#include "ctrlchar.h"
23#include "sclp.h"
24#include "sclp_rw.h"
25#include "sclp_tty.h"
26
27/*
28 * size of a buffer that collects single characters coming in
29 * via sclp_tty_put_char()
30 */
31#define SCLP_TTY_BUF_SIZE 512
32
33/*
34 * There is exactly one SCLP terminal, so we can keep things simple
35 * and allocate all variables statically.
36 */
37
38/* Lock to guard over changes to global variables. */
39static spinlock_t sclp_tty_lock;
40/* List of free pages that can be used for console output buffering. */
41static struct list_head sclp_tty_pages;
42/* List of full struct sclp_buffer structures ready for output. */
43static struct list_head sclp_tty_outqueue;
44/* Counter how many buffers are emitted. */
45static int sclp_tty_buffer_count;
46/* Pointer to current console buffer. */
47static struct sclp_buffer *sclp_ttybuf;
48/* Timer for delayed output of console messages. */
49static struct timer_list sclp_tty_timer;
50
51static struct tty_struct *sclp_tty;
52static unsigned char sclp_tty_chars[SCLP_TTY_BUF_SIZE];
53static unsigned short int sclp_tty_chars_count;
54
55struct tty_driver *sclp_tty_driver;
56
57static int sclp_tty_tolower;
58static int sclp_tty_columns = 80;
59
60#define SPACES_PER_TAB 8
61#define CASE_DELIMITER 0x6c /* to separate upper and lower case (% in EBCDIC) */
62
63/* This routine is called whenever we try to open a SCLP terminal. */
64static int
65sclp_tty_open(struct tty_struct *tty, struct file *filp)
66{
67 sclp_tty = tty;
68 tty->driver_data = NULL;
69 tty->low_latency = 0;
70 return 0;
71}
72
73/* This routine is called when the SCLP terminal is closed. */
74static void
75sclp_tty_close(struct tty_struct *tty, struct file *filp)
76{
77 if (tty->count > 1)
78 return;
79 sclp_tty = NULL;
80}
81
82/*
83 * This routine returns the numbers of characters the tty driver
84 * will accept for queuing to be written. This number is subject
85 * to change as output buffers get emptied, or if the output flow
86 * control is acted. This is not an exact number because not every
87 * character needs the same space in the sccb. The worst case is
88 * a string of newlines. Every newlines creates a new mto which
89 * needs 8 bytes.
90 */
91static int
92sclp_tty_write_room (struct tty_struct *tty)
93{
94 unsigned long flags;
95 struct list_head *l;
96 int count;
97
98 spin_lock_irqsave(&sclp_tty_lock, flags);
99 count = 0;
100 if (sclp_ttybuf != NULL)
101 count = sclp_buffer_space(sclp_ttybuf) / sizeof(struct mto);
102 list_for_each(l, &sclp_tty_pages)
103 count += NR_EMPTY_MTO_PER_SCCB;
104 spin_unlock_irqrestore(&sclp_tty_lock, flags);
105 return count;
106}
107
108static void
109sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
110{
111 unsigned long flags;
112 void *page;
113
114 do {
115 page = sclp_unmake_buffer(buffer);
116 spin_lock_irqsave(&sclp_tty_lock, flags);
117 /* Remove buffer from outqueue */
118 list_del(&buffer->list);
119 sclp_tty_buffer_count--;
120 list_add_tail((struct list_head *) page, &sclp_tty_pages);
121 /* Check if there is a pending buffer on the out queue. */
122 buffer = NULL;
123 if (!list_empty(&sclp_tty_outqueue))
124 buffer = list_entry(sclp_tty_outqueue.next,
125 struct sclp_buffer, list);
126 spin_unlock_irqrestore(&sclp_tty_lock, flags);
127 } while (buffer && sclp_emit_buffer(buffer, sclp_ttybuf_callback));
128 /* check if the tty needs a wake up call */
129 if (sclp_tty != NULL) {
130 tty_wakeup(sclp_tty);
131 }
132}
133
134static inline void
135__sclp_ttybuf_emit(struct sclp_buffer *buffer)
136{
137 unsigned long flags;
138 int count;
139 int rc;
140
141 spin_lock_irqsave(&sclp_tty_lock, flags);
142 list_add_tail(&buffer->list, &sclp_tty_outqueue);
143 count = sclp_tty_buffer_count++;
144 spin_unlock_irqrestore(&sclp_tty_lock, flags);
145 if (count)
146 return;
147 rc = sclp_emit_buffer(buffer, sclp_ttybuf_callback);
148 if (rc)
149 sclp_ttybuf_callback(buffer, rc);
150}
151
152/*
153 * When this routine is called from the timer then we flush the
154 * temporary write buffer.
155 */
156static void
157sclp_tty_timeout(unsigned long data)
158{
159 unsigned long flags;
160 struct sclp_buffer *buf;
161
162 spin_lock_irqsave(&sclp_tty_lock, flags);
163 buf = sclp_ttybuf;
164 sclp_ttybuf = NULL;
165 spin_unlock_irqrestore(&sclp_tty_lock, flags);
166
167 if (buf != NULL) {
168 __sclp_ttybuf_emit(buf);
169 }
170}
171
172/*
173 * Write a string to the sclp tty.
174 */
175static int sclp_tty_write_string(const unsigned char *str, int count, int may_fail)
176{
177 unsigned long flags;
178 void *page;
179 int written;
180 int overall_written;
181 struct sclp_buffer *buf;
182
183 if (count <= 0)
184 return 0;
185 overall_written = 0;
186 spin_lock_irqsave(&sclp_tty_lock, flags);
187 do {
188 /* Create a sclp output buffer if none exists yet */
189 if (sclp_ttybuf == NULL) {
190 while (list_empty(&sclp_tty_pages)) {
191 spin_unlock_irqrestore(&sclp_tty_lock, flags);
192 if (may_fail)
193 goto out;
194 else
195 sclp_sync_wait();
196 spin_lock_irqsave(&sclp_tty_lock, flags);
197 }
198 page = sclp_tty_pages.next;
199 list_del((struct list_head *) page);
200 sclp_ttybuf = sclp_make_buffer(page, sclp_tty_columns,
201 SPACES_PER_TAB);
202 }
203 /* try to write the string to the current output buffer */
204 written = sclp_write(sclp_ttybuf, str, count);
205 overall_written += written;
206 if (written == count)
207 break;
208 /*
209 * Not all characters could be written to the current
210 * output buffer. Emit the buffer, create a new buffer
211 * and then output the rest of the string.
212 */
213 buf = sclp_ttybuf;
214 sclp_ttybuf = NULL;
215 spin_unlock_irqrestore(&sclp_tty_lock, flags);
216 __sclp_ttybuf_emit(buf);
217 spin_lock_irqsave(&sclp_tty_lock, flags);
218 str += written;
219 count -= written;
220 } while (count > 0);
221 /* Setup timer to output current console buffer after 1/10 second */
222 if (sclp_ttybuf && sclp_chars_in_buffer(sclp_ttybuf) &&
223 !timer_pending(&sclp_tty_timer)) {
224 init_timer(&sclp_tty_timer);
225 sclp_tty_timer.function = sclp_tty_timeout;
226 sclp_tty_timer.data = 0UL;
227 sclp_tty_timer.expires = jiffies + HZ/10;
228 add_timer(&sclp_tty_timer);
229 }
230 spin_unlock_irqrestore(&sclp_tty_lock, flags);
231out:
232 return overall_written;
233}
234
235/*
236 * This routine is called by the kernel to write a series of characters to the
237 * tty device. The characters may come from user space or kernel space. This
238 * routine will return the number of characters actually accepted for writing.
239 */
240static int
241sclp_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
242{
243 if (sclp_tty_chars_count > 0) {
244 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
245 sclp_tty_chars_count = 0;
246 }
247 return sclp_tty_write_string(buf, count, 1);
248}
249
250/*
251 * This routine is called by the kernel to write a single character to the tty
252 * device. If the kernel uses this routine, it must call the flush_chars()
253 * routine (if defined) when it is done stuffing characters into the driver.
254 *
255 * Characters provided to sclp_tty_put_char() are buffered by the SCLP driver.
256 * If the given character is a '\n' the contents of the SCLP write buffer
257 * - including previous characters from sclp_tty_put_char() and strings from
258 * sclp_write() without final '\n' - will be written.
259 */
260static int
261sclp_tty_put_char(struct tty_struct *tty, unsigned char ch)
262{
263 sclp_tty_chars[sclp_tty_chars_count++] = ch;
264 if (ch == '\n' || sclp_tty_chars_count >= SCLP_TTY_BUF_SIZE) {
265 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
266 sclp_tty_chars_count = 0;
267 }
268 return 1;
269}
270
271/*
272 * This routine is called by the kernel after it has written a series of
273 * characters to the tty device using put_char().
274 */
275static void
276sclp_tty_flush_chars(struct tty_struct *tty)
277{
278 if (sclp_tty_chars_count > 0) {
279 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
280 sclp_tty_chars_count = 0;
281 }
282}
283
284/*
285 * This routine returns the number of characters in the write buffer of the
286 * SCLP driver. The provided number includes all characters that are stored
287 * in the SCCB (will be written next time the SCLP is not busy) as well as
288 * characters in the write buffer (will not be written as long as there is a
289 * final line feed missing).
290 */
291static int
292sclp_tty_chars_in_buffer(struct tty_struct *tty)
293{
294 unsigned long flags;
295 struct list_head *l;
296 struct sclp_buffer *t;
297 int count;
298
299 spin_lock_irqsave(&sclp_tty_lock, flags);
300 count = 0;
301 if (sclp_ttybuf != NULL)
302 count = sclp_chars_in_buffer(sclp_ttybuf);
303 list_for_each(l, &sclp_tty_outqueue) {
304 t = list_entry(l, struct sclp_buffer, list);
305 count += sclp_chars_in_buffer(t);
306 }
307 spin_unlock_irqrestore(&sclp_tty_lock, flags);
308 return count;
309}
310
311/*
312 * removes all content from buffers of low level driver
313 */
314static void
315sclp_tty_flush_buffer(struct tty_struct *tty)
316{
317 if (sclp_tty_chars_count > 0) {
318 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
319 sclp_tty_chars_count = 0;
320 }
321}
322
323/*
324 * push input to tty
325 */
326static void
327sclp_tty_input(unsigned char* buf, unsigned int count)
328{
329 unsigned int cchar;
330
331 /*
332 * If this tty driver is currently closed
333 * then throw the received input away.
334 */
335 if (sclp_tty == NULL)
336 return;
337 cchar = ctrlchar_handle(buf, count, sclp_tty);
338 switch (cchar & CTRLCHAR_MASK) {
339 case CTRLCHAR_SYSRQ:
340 break;
341 case CTRLCHAR_CTRL:
342 tty_insert_flip_char(sclp_tty, cchar, TTY_NORMAL);
343 tty_flip_buffer_push(sclp_tty);
344 break;
345 case CTRLCHAR_NONE:
346 /* send (normal) input to line discipline */
347 if (count < 2 ||
348 (strncmp((const char *) buf + count - 2, "^n", 2) &&
349 strncmp((const char *) buf + count - 2, "\252n", 2))) {
350 /* add the auto \n */
351 tty_insert_flip_string(sclp_tty, buf, count);
352 tty_insert_flip_char(sclp_tty, '\n', TTY_NORMAL);
353 } else
354 tty_insert_flip_string(sclp_tty, buf, count - 2);
355 tty_flip_buffer_push(sclp_tty);
356 break;
357 }
358}
359
360/*
361 * get a EBCDIC string in upper/lower case,
362 * find out characters in lower/upper case separated by a special character,
363 * modifiy original string,
364 * returns length of resulting string
365 */
366static int sclp_switch_cases(unsigned char *buf, int count)
367{
368 unsigned char *ip, *op;
369 int toggle;
370
371 /* initially changing case is off */
372 toggle = 0;
373 ip = op = buf;
374 while (count-- > 0) {
375 /* compare with special character */
376 if (*ip == CASE_DELIMITER) {
377 /* followed by another special character? */
378 if (count && ip[1] == CASE_DELIMITER) {
379 /*
380 * ... then put a single copy of the special
381 * character to the output string
382 */
383 *op++ = *ip++;
384 count--;
385 } else
386 /*
387 * ... special character follower by a normal
388 * character toggles the case change behaviour
389 */
390 toggle = ~toggle;
391 /* skip special character */
392 ip++;
393 } else
394 /* not the special character */
395 if (toggle)
396 /* but case switching is on */
397 if (sclp_tty_tolower)
398 /* switch to uppercase */
399 *op++ = _ebc_toupper[(int) *ip++];
400 else
401 /* switch to lowercase */
402 *op++ = _ebc_tolower[(int) *ip++];
403 else
404 /* no case switching, copy the character */
405 *op++ = *ip++;
406 }
407 /* return length of reformatted string. */
408 return op - buf;
409}
410
411static void sclp_get_input(struct gds_subvector *sv)
412{
413 unsigned char *str;
414 int count;
415
416 str = (unsigned char *) (sv + 1);
417 count = sv->length - sizeof(*sv);
418 if (sclp_tty_tolower)
419 EBC_TOLOWER(str, count);
420 count = sclp_switch_cases(str, count);
421 /* convert EBCDIC to ASCII (modify original input in SCCB) */
422 sclp_ebcasc_str(str, count);
423
424 /* transfer input to high level driver */
425 sclp_tty_input(str, count);
426}
427
428static inline void sclp_eval_selfdeftextmsg(struct gds_subvector *sv)
429{
430 void *end;
431
432 end = (void *) sv + sv->length;
433 for (sv = sv + 1; (void *) sv < end; sv = (void *) sv + sv->length)
434 if (sv->key == 0x30)
435 sclp_get_input(sv);
436}
437
438static inline void sclp_eval_textcmd(struct gds_vector *v)
439{
440 struct gds_subvector *sv;
441 void *end;
442
443 end = (void *) v + v->length;
444 for (sv = (struct gds_subvector *) (v + 1);
445 (void *) sv < end; sv = (void *) sv + sv->length)
446 if (sv->key == GDS_KEY_SELFDEFTEXTMSG)
447 sclp_eval_selfdeftextmsg(sv);
448
449}
450
451static inline void sclp_eval_cpmsu(struct gds_vector *v)
452{
453 void *end;
454
455 end = (void *) v + v->length;
456 for (v = v + 1; (void *) v < end; v = (void *) v + v->length)
457 if (v->gds_id == GDS_ID_TEXTCMD)
458 sclp_eval_textcmd(v);
459}
460
461
462static inline void sclp_eval_mdsmu(struct gds_vector *v)
463{
464 v = sclp_find_gds_vector(v + 1, (void *) v + v->length, GDS_ID_CPMSU);
465 if (v)
466 sclp_eval_cpmsu(v);
467}
468
469static void sclp_tty_receiver(struct evbuf_header *evbuf)
470{
471 struct gds_vector *v;
472
473 v = sclp_find_gds_vector(evbuf + 1, (void *) evbuf + evbuf->length,
474 GDS_ID_MDSMU);
475 if (v)
476 sclp_eval_mdsmu(v);
477}
478
479static void
480sclp_tty_state_change(struct sclp_register *reg)
481{
482}
483
484static struct sclp_register sclp_input_event =
485{
486 .receive_mask = EVTYP_OPCMD_MASK | EVTYP_PMSGCMD_MASK,
487 .state_change_fn = sclp_tty_state_change,
488 .receiver_fn = sclp_tty_receiver
489};
490
491static const struct tty_operations sclp_ops = {
492 .open = sclp_tty_open,
493 .close = sclp_tty_close,
494 .write = sclp_tty_write,
495 .put_char = sclp_tty_put_char,
496 .flush_chars = sclp_tty_flush_chars,
497 .write_room = sclp_tty_write_room,
498 .chars_in_buffer = sclp_tty_chars_in_buffer,
499 .flush_buffer = sclp_tty_flush_buffer,
500};
501
502static int __init
503sclp_tty_init(void)
504{
505 struct tty_driver *driver;
506 void *page;
507 int i;
508 int rc;
509
510 if (!CONSOLE_IS_SCLP)
511 return 0;
512 driver = alloc_tty_driver(1);
513 if (!driver)
514 return -ENOMEM;
515
516 rc = sclp_rw_init();
517 if (rc) {
518 put_tty_driver(driver);
519 return rc;
520 }
521 /* Allocate pages for output buffering */
522 INIT_LIST_HEAD(&sclp_tty_pages);
523 for (i = 0; i < MAX_KMEM_PAGES; i++) {
524 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
525 if (page == NULL) {
526 put_tty_driver(driver);
527 return -ENOMEM;
528 }
529 list_add_tail((struct list_head *) page, &sclp_tty_pages);
530 }
531 INIT_LIST_HEAD(&sclp_tty_outqueue);
532 spin_lock_init(&sclp_tty_lock);
533 init_timer(&sclp_tty_timer);
534 sclp_ttybuf = NULL;
535 sclp_tty_buffer_count = 0;
536 if (MACHINE_IS_VM) {
537 /*
538 * save 4 characters for the CPU number
539 * written at start of each line by VM/CP
540 */
541 sclp_tty_columns = 76;
542 /* case input lines to lowercase */
543 sclp_tty_tolower = 1;
544 }
545 sclp_tty_chars_count = 0;
546 sclp_tty = NULL;
547
548 rc = sclp_register(&sclp_input_event);
549 if (rc) {
550 put_tty_driver(driver);
551 return rc;
552 }
553
554 driver->owner = THIS_MODULE;
555 driver->driver_name = "sclp_line";
556 driver->name = "sclp_line";
557 driver->major = TTY_MAJOR;
558 driver->minor_start = 64;
559 driver->type = TTY_DRIVER_TYPE_SYSTEM;
560 driver->subtype = SYSTEM_TYPE_TTY;
561 driver->init_termios = tty_std_termios;
562 driver->init_termios.c_iflag = IGNBRK | IGNPAR;
563 driver->init_termios.c_oflag = ONLCR | XTABS;
564 driver->init_termios.c_lflag = ISIG | ECHO;
565 driver->flags = TTY_DRIVER_REAL_RAW;
566 tty_set_operations(driver, &sclp_ops);
567 rc = tty_register_driver(driver);
568 if (rc) {
569 put_tty_driver(driver);
570 return rc;
571 }
572 sclp_tty_driver = driver;
573 return 0;
574}
575module_init(sclp_tty_init);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * SCLP line mode terminal driver.
4 *
5 * S390 version
6 * Copyright IBM Corp. 1999
7 * Author(s): Martin Peschke <mpeschke@de.ibm.com>
8 * Martin Schwidefsky <schwidefsky@de.ibm.com>
9 */
10
11#include <linux/kmod.h>
12#include <linux/tty.h>
13#include <linux/tty_driver.h>
14#include <linux/tty_flip.h>
15#include <linux/err.h>
16#include <linux/init.h>
17#include <linux/interrupt.h>
18#include <linux/gfp.h>
19#include <linux/uaccess.h>
20
21#include "ctrlchar.h"
22#include "sclp.h"
23#include "sclp_rw.h"
24#include "sclp_tty.h"
25
26/*
27 * size of a buffer that collects single characters coming in
28 * via sclp_tty_put_char()
29 */
30#define SCLP_TTY_BUF_SIZE 512
31
32/*
33 * There is exactly one SCLP terminal, so we can keep things simple
34 * and allocate all variables statically.
35 */
36
37/* Lock to guard over changes to global variables. */
38static DEFINE_SPINLOCK(sclp_tty_lock);
39/* List of free pages that can be used for console output buffering. */
40static LIST_HEAD(sclp_tty_pages);
41/* List of full struct sclp_buffer structures ready for output. */
42static LIST_HEAD(sclp_tty_outqueue);
43/* Counter how many buffers are emitted. */
44static int sclp_tty_buffer_count;
45/* Pointer to current console buffer. */
46static struct sclp_buffer *sclp_ttybuf;
47/* Timer for delayed output of console messages. */
48static struct timer_list sclp_tty_timer;
49
50static struct tty_port sclp_port;
51static u8 sclp_tty_chars[SCLP_TTY_BUF_SIZE];
52static unsigned short int sclp_tty_chars_count;
53
54struct tty_driver *sclp_tty_driver;
55
56static int sclp_tty_tolower;
57
58#define SCLP_TTY_COLUMNS 320
59#define SPACES_PER_TAB 8
60#define CASE_DELIMITER 0x6c /* to separate upper and lower case (% in EBCDIC) */
61
62/* This routine is called whenever we try to open a SCLP terminal. */
63static int
64sclp_tty_open(struct tty_struct *tty, struct file *filp)
65{
66 tty_port_tty_set(&sclp_port, tty);
67 tty->driver_data = NULL;
68 return 0;
69}
70
71/* This routine is called when the SCLP terminal is closed. */
72static void
73sclp_tty_close(struct tty_struct *tty, struct file *filp)
74{
75 if (tty->count > 1)
76 return;
77 tty_port_tty_set(&sclp_port, NULL);
78}
79
80/*
81 * This routine returns the numbers of characters the tty driver
82 * will accept for queuing to be written. This number is subject
83 * to change as output buffers get emptied, or if the output flow
84 * control is acted. This is not an exact number because not every
85 * character needs the same space in the sccb. The worst case is
86 * a string of newlines. Every newline creates a new message which
87 * needs 82 bytes.
88 */
89static unsigned int
90sclp_tty_write_room (struct tty_struct *tty)
91{
92 unsigned long flags;
93 struct list_head *l;
94 unsigned int count;
95
96 spin_lock_irqsave(&sclp_tty_lock, flags);
97 count = 0;
98 if (sclp_ttybuf != NULL)
99 count = sclp_buffer_space(sclp_ttybuf) / sizeof(struct msg_buf);
100 list_for_each(l, &sclp_tty_pages)
101 count += NR_EMPTY_MSG_PER_SCCB;
102 spin_unlock_irqrestore(&sclp_tty_lock, flags);
103 return count;
104}
105
106static void
107sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
108{
109 unsigned long flags;
110 void *page;
111
112 do {
113 page = sclp_unmake_buffer(buffer);
114 spin_lock_irqsave(&sclp_tty_lock, flags);
115 /* Remove buffer from outqueue */
116 list_del(&buffer->list);
117 sclp_tty_buffer_count--;
118 list_add_tail((struct list_head *) page, &sclp_tty_pages);
119 /* Check if there is a pending buffer on the out queue. */
120 buffer = NULL;
121 if (!list_empty(&sclp_tty_outqueue))
122 buffer = list_entry(sclp_tty_outqueue.next,
123 struct sclp_buffer, list);
124 spin_unlock_irqrestore(&sclp_tty_lock, flags);
125 } while (buffer && sclp_emit_buffer(buffer, sclp_ttybuf_callback));
126
127 tty_port_tty_wakeup(&sclp_port);
128}
129
130static inline void
131__sclp_ttybuf_emit(struct sclp_buffer *buffer)
132{
133 unsigned long flags;
134 int count;
135 int rc;
136
137 spin_lock_irqsave(&sclp_tty_lock, flags);
138 list_add_tail(&buffer->list, &sclp_tty_outqueue);
139 count = sclp_tty_buffer_count++;
140 spin_unlock_irqrestore(&sclp_tty_lock, flags);
141 if (count)
142 return;
143 rc = sclp_emit_buffer(buffer, sclp_ttybuf_callback);
144 if (rc)
145 sclp_ttybuf_callback(buffer, rc);
146}
147
148/*
149 * When this routine is called from the timer then we flush the
150 * temporary write buffer.
151 */
152static void
153sclp_tty_timeout(struct timer_list *unused)
154{
155 unsigned long flags;
156 struct sclp_buffer *buf;
157
158 spin_lock_irqsave(&sclp_tty_lock, flags);
159 buf = sclp_ttybuf;
160 sclp_ttybuf = NULL;
161 spin_unlock_irqrestore(&sclp_tty_lock, flags);
162
163 if (buf != NULL) {
164 __sclp_ttybuf_emit(buf);
165 }
166}
167
168/*
169 * Write a string to the sclp tty.
170 */
171static int sclp_tty_write_string(const u8 *str, int count, int may_fail)
172{
173 unsigned long flags;
174 void *page;
175 int written;
176 int overall_written;
177 struct sclp_buffer *buf;
178
179 if (count <= 0)
180 return 0;
181 overall_written = 0;
182 spin_lock_irqsave(&sclp_tty_lock, flags);
183 do {
184 /* Create a sclp output buffer if none exists yet */
185 if (sclp_ttybuf == NULL) {
186 while (list_empty(&sclp_tty_pages)) {
187 spin_unlock_irqrestore(&sclp_tty_lock, flags);
188 if (may_fail)
189 goto out;
190 else
191 sclp_sync_wait();
192 spin_lock_irqsave(&sclp_tty_lock, flags);
193 }
194 page = sclp_tty_pages.next;
195 list_del((struct list_head *) page);
196 sclp_ttybuf = sclp_make_buffer(page, SCLP_TTY_COLUMNS,
197 SPACES_PER_TAB);
198 }
199 /* try to write the string to the current output buffer */
200 written = sclp_write(sclp_ttybuf, str, count);
201 overall_written += written;
202 if (written == count)
203 break;
204 /*
205 * Not all characters could be written to the current
206 * output buffer. Emit the buffer, create a new buffer
207 * and then output the rest of the string.
208 */
209 buf = sclp_ttybuf;
210 sclp_ttybuf = NULL;
211 spin_unlock_irqrestore(&sclp_tty_lock, flags);
212 __sclp_ttybuf_emit(buf);
213 spin_lock_irqsave(&sclp_tty_lock, flags);
214 str += written;
215 count -= written;
216 } while (count > 0);
217 /* Setup timer to output current console buffer after 1/10 second */
218 if (sclp_ttybuf && sclp_chars_in_buffer(sclp_ttybuf) &&
219 !timer_pending(&sclp_tty_timer)) {
220 mod_timer(&sclp_tty_timer, jiffies + HZ / 10);
221 }
222 spin_unlock_irqrestore(&sclp_tty_lock, flags);
223out:
224 return overall_written;
225}
226
227/*
228 * This routine is called by the kernel to write a series of characters to the
229 * tty device. The characters may come from user space or kernel space. This
230 * routine will return the number of characters actually accepted for writing.
231 */
232static ssize_t
233sclp_tty_write(struct tty_struct *tty, const u8 *buf, size_t count)
234{
235 if (sclp_tty_chars_count > 0) {
236 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
237 sclp_tty_chars_count = 0;
238 }
239 return sclp_tty_write_string(buf, count, 1);
240}
241
242/*
243 * This routine is called by the kernel to write a single character to the tty
244 * device. If the kernel uses this routine, it must call the flush_chars()
245 * routine (if defined) when it is done stuffing characters into the driver.
246 *
247 * Characters provided to sclp_tty_put_char() are buffered by the SCLP driver.
248 * If the given character is a '\n' the contents of the SCLP write buffer
249 * - including previous characters from sclp_tty_put_char() and strings from
250 * sclp_write() without final '\n' - will be written.
251 */
252static int
253sclp_tty_put_char(struct tty_struct *tty, u8 ch)
254{
255 sclp_tty_chars[sclp_tty_chars_count++] = ch;
256 if (ch == '\n' || sclp_tty_chars_count >= SCLP_TTY_BUF_SIZE) {
257 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
258 sclp_tty_chars_count = 0;
259 }
260 return 1;
261}
262
263/*
264 * This routine is called by the kernel after it has written a series of
265 * characters to the tty device using put_char().
266 */
267static void
268sclp_tty_flush_chars(struct tty_struct *tty)
269{
270 if (sclp_tty_chars_count > 0) {
271 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
272 sclp_tty_chars_count = 0;
273 }
274}
275
276/*
277 * This routine returns the number of characters in the write buffer of the
278 * SCLP driver. The provided number includes all characters that are stored
279 * in the SCCB (will be written next time the SCLP is not busy) as well as
280 * characters in the write buffer (will not be written as long as there is a
281 * final line feed missing).
282 */
283static unsigned int
284sclp_tty_chars_in_buffer(struct tty_struct *tty)
285{
286 unsigned long flags;
287 struct sclp_buffer *t;
288 unsigned int count = 0;
289
290 spin_lock_irqsave(&sclp_tty_lock, flags);
291 if (sclp_ttybuf != NULL)
292 count = sclp_chars_in_buffer(sclp_ttybuf);
293 list_for_each_entry(t, &sclp_tty_outqueue, list) {
294 count += sclp_chars_in_buffer(t);
295 }
296 spin_unlock_irqrestore(&sclp_tty_lock, flags);
297 return count;
298}
299
300/*
301 * removes all content from buffers of low level driver
302 */
303static void
304sclp_tty_flush_buffer(struct tty_struct *tty)
305{
306 if (sclp_tty_chars_count > 0) {
307 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
308 sclp_tty_chars_count = 0;
309 }
310}
311
312/*
313 * push input to tty
314 */
315static void
316sclp_tty_input(unsigned char* buf, unsigned int count)
317{
318 struct tty_struct *tty = tty_port_tty_get(&sclp_port);
319 unsigned int cchar;
320
321 /*
322 * If this tty driver is currently closed
323 * then throw the received input away.
324 */
325 if (tty == NULL)
326 return;
327 cchar = ctrlchar_handle(buf, count, tty);
328 switch (cchar & CTRLCHAR_MASK) {
329 case CTRLCHAR_SYSRQ:
330 break;
331 case CTRLCHAR_CTRL:
332 tty_insert_flip_char(&sclp_port, cchar, TTY_NORMAL);
333 tty_flip_buffer_push(&sclp_port);
334 break;
335 case CTRLCHAR_NONE:
336 /* send (normal) input to line discipline */
337 if (count < 2 ||
338 (strncmp((const char *) buf + count - 2, "^n", 2) &&
339 strncmp((const char *) buf + count - 2, "\252n", 2))) {
340 /* add the auto \n */
341 tty_insert_flip_string(&sclp_port, buf, count);
342 tty_insert_flip_char(&sclp_port, '\n', TTY_NORMAL);
343 } else
344 tty_insert_flip_string(&sclp_port, buf, count - 2);
345 tty_flip_buffer_push(&sclp_port);
346 break;
347 }
348 tty_kref_put(tty);
349}
350
351/*
352 * get a EBCDIC string in upper/lower case,
353 * find out characters in lower/upper case separated by a special character,
354 * modifiy original string,
355 * returns length of resulting string
356 */
357static int sclp_switch_cases(unsigned char *buf, int count)
358{
359 unsigned char *ip, *op;
360 int toggle;
361
362 /* initially changing case is off */
363 toggle = 0;
364 ip = op = buf;
365 while (count-- > 0) {
366 /* compare with special character */
367 if (*ip == CASE_DELIMITER) {
368 /* followed by another special character? */
369 if (count && ip[1] == CASE_DELIMITER) {
370 /*
371 * ... then put a single copy of the special
372 * character to the output string
373 */
374 *op++ = *ip++;
375 count--;
376 } else
377 /*
378 * ... special character follower by a normal
379 * character toggles the case change behaviour
380 */
381 toggle = ~toggle;
382 /* skip special character */
383 ip++;
384 } else
385 /* not the special character */
386 if (toggle)
387 /* but case switching is on */
388 if (sclp_tty_tolower)
389 /* switch to uppercase */
390 *op++ = _ebc_toupper[(int) *ip++];
391 else
392 /* switch to lowercase */
393 *op++ = _ebc_tolower[(int) *ip++];
394 else
395 /* no case switching, copy the character */
396 *op++ = *ip++;
397 }
398 /* return length of reformatted string. */
399 return op - buf;
400}
401
402static void sclp_get_input(struct gds_subvector *sv)
403{
404 unsigned char *str;
405 int count;
406
407 str = (unsigned char *) (sv + 1);
408 count = sv->length - sizeof(*sv);
409 if (sclp_tty_tolower)
410 EBC_TOLOWER(str, count);
411 count = sclp_switch_cases(str, count);
412 /* convert EBCDIC to ASCII (modify original input in SCCB) */
413 sclp_ebcasc_str(str, count);
414
415 /* transfer input to high level driver */
416 sclp_tty_input(str, count);
417}
418
419static inline void sclp_eval_selfdeftextmsg(struct gds_subvector *sv)
420{
421 void *end;
422
423 end = (void *) sv + sv->length;
424 for (sv = sv + 1; (void *) sv < end; sv = (void *) sv + sv->length)
425 if (sv->key == 0x30)
426 sclp_get_input(sv);
427}
428
429static inline void sclp_eval_textcmd(struct gds_vector *v)
430{
431 struct gds_subvector *sv;
432 void *end;
433
434 end = (void *) v + v->length;
435 for (sv = (struct gds_subvector *) (v + 1);
436 (void *) sv < end; sv = (void *) sv + sv->length)
437 if (sv->key == GDS_KEY_SELFDEFTEXTMSG)
438 sclp_eval_selfdeftextmsg(sv);
439
440}
441
442static inline void sclp_eval_cpmsu(struct gds_vector *v)
443{
444 void *end;
445
446 end = (void *) v + v->length;
447 for (v = v + 1; (void *) v < end; v = (void *) v + v->length)
448 if (v->gds_id == GDS_ID_TEXTCMD)
449 sclp_eval_textcmd(v);
450}
451
452
453static inline void sclp_eval_mdsmu(struct gds_vector *v)
454{
455 v = sclp_find_gds_vector(v + 1, (void *) v + v->length, GDS_ID_CPMSU);
456 if (v)
457 sclp_eval_cpmsu(v);
458}
459
460static void sclp_tty_receiver(struct evbuf_header *evbuf)
461{
462 struct gds_vector *v;
463
464 v = sclp_find_gds_vector(evbuf + 1, (void *) evbuf + evbuf->length,
465 GDS_ID_MDSMU);
466 if (v)
467 sclp_eval_mdsmu(v);
468}
469
470static void
471sclp_tty_state_change(struct sclp_register *reg)
472{
473}
474
475static struct sclp_register sclp_input_event =
476{
477 .receive_mask = EVTYP_OPCMD_MASK | EVTYP_PMSGCMD_MASK,
478 .state_change_fn = sclp_tty_state_change,
479 .receiver_fn = sclp_tty_receiver
480};
481
482static const struct tty_operations sclp_ops = {
483 .open = sclp_tty_open,
484 .close = sclp_tty_close,
485 .write = sclp_tty_write,
486 .put_char = sclp_tty_put_char,
487 .flush_chars = sclp_tty_flush_chars,
488 .write_room = sclp_tty_write_room,
489 .chars_in_buffer = sclp_tty_chars_in_buffer,
490 .flush_buffer = sclp_tty_flush_buffer,
491};
492
493static int __init
494sclp_tty_init(void)
495{
496 struct tty_driver *driver;
497 void *page;
498 int i;
499 int rc;
500
501 /* z/VM multiplexes the line mode output on the 32xx screen */
502 if (MACHINE_IS_VM && !CONSOLE_IS_SCLP)
503 return 0;
504 if (!sclp.has_linemode)
505 return 0;
506 driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW);
507 if (IS_ERR(driver))
508 return PTR_ERR(driver);
509
510 rc = sclp_rw_init();
511 if (rc) {
512 tty_driver_kref_put(driver);
513 return rc;
514 }
515 /* Allocate pages for output buffering */
516 for (i = 0; i < MAX_KMEM_PAGES; i++) {
517 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
518 if (page == NULL) {
519 tty_driver_kref_put(driver);
520 return -ENOMEM;
521 }
522 list_add_tail((struct list_head *) page, &sclp_tty_pages);
523 }
524 timer_setup(&sclp_tty_timer, sclp_tty_timeout, 0);
525 sclp_ttybuf = NULL;
526 sclp_tty_buffer_count = 0;
527 if (MACHINE_IS_VM) {
528 /* case input lines to lowercase */
529 sclp_tty_tolower = 1;
530 }
531 sclp_tty_chars_count = 0;
532
533 rc = sclp_register(&sclp_input_event);
534 if (rc) {
535 tty_driver_kref_put(driver);
536 return rc;
537 }
538
539 tty_port_init(&sclp_port);
540
541 driver->driver_name = "sclp_line";
542 driver->name = "sclp_line";
543 driver->major = TTY_MAJOR;
544 driver->minor_start = 64;
545 driver->type = TTY_DRIVER_TYPE_SYSTEM;
546 driver->subtype = SYSTEM_TYPE_TTY;
547 driver->init_termios = tty_std_termios;
548 driver->init_termios.c_iflag = IGNBRK | IGNPAR;
549 driver->init_termios.c_oflag = ONLCR;
550 driver->init_termios.c_lflag = ISIG | ECHO;
551 tty_set_operations(driver, &sclp_ops);
552 tty_port_link_device(&sclp_port, driver, 0);
553 rc = tty_register_driver(driver);
554 if (rc) {
555 tty_driver_kref_put(driver);
556 tty_port_destroy(&sclp_port);
557 return rc;
558 }
559 sclp_tty_driver = driver;
560 return 0;
561}
562device_initcall(sclp_tty_init);