Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm...
[linux-2.6.git] / drivers / s390 / char / sclp_tty.c
blob7ed7a59878165bf8ef265e3fae90ee4b10017827
1 /*
2 * SCLP line mode terminal driver.
4 * S390 version
5 * Copyright IBM Corp. 1999
6 * Author(s): Martin Peschke <mpeschke@de.ibm.com>
7 * Martin Schwidefsky <schwidefsky@de.ibm.com>
8 */
10 #include <linux/module.h>
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 <asm/uaccess.h>
21 #include "ctrlchar.h"
22 #include "sclp.h"
23 #include "sclp_rw.h"
24 #include "sclp_tty.h"
27 * size of a buffer that collects single characters coming in
28 * via sclp_tty_put_char()
30 #define SCLP_TTY_BUF_SIZE 512
33 * There is exactly one SCLP terminal, so we can keep things simple
34 * and allocate all variables statically.
37 /* Lock to guard over changes to global variables. */
38 static spinlock_t sclp_tty_lock;
39 /* List of free pages that can be used for console output buffering. */
40 static struct list_head sclp_tty_pages;
41 /* List of full struct sclp_buffer structures ready for output. */
42 static struct list_head sclp_tty_outqueue;
43 /* Counter how many buffers are emitted. */
44 static int sclp_tty_buffer_count;
45 /* Pointer to current console buffer. */
46 static struct sclp_buffer *sclp_ttybuf;
47 /* Timer for delayed output of console messages. */
48 static struct timer_list sclp_tty_timer;
50 static struct tty_port sclp_port;
51 static unsigned char sclp_tty_chars[SCLP_TTY_BUF_SIZE];
52 static unsigned short int sclp_tty_chars_count;
54 struct tty_driver *sclp_tty_driver;
56 static int sclp_tty_tolower;
57 static int sclp_tty_columns = 80;
59 #define SPACES_PER_TAB 8
60 #define CASE_DELIMITER 0x6c /* to separate upper and lower case (% in EBCDIC) */
62 /* This routine is called whenever we try to open a SCLP terminal. */
63 static int
64 sclp_tty_open(struct tty_struct *tty, struct file *filp)
66 tty_port_tty_set(&sclp_port, tty);
67 tty->driver_data = NULL;
68 sclp_port.low_latency = 0;
69 return 0;
72 /* This routine is called when the SCLP terminal is closed. */
73 static void
74 sclp_tty_close(struct tty_struct *tty, struct file *filp)
76 if (tty->count > 1)
77 return;
78 tty_port_tty_set(&sclp_port, NULL);
82 * This routine returns the numbers of characters the tty driver
83 * will accept for queuing to be written. This number is subject
84 * to change as output buffers get emptied, or if the output flow
85 * control is acted. This is not an exact number because not every
86 * character needs the same space in the sccb. The worst case is
87 * a string of newlines. Every newlines creates a new mto which
88 * needs 8 bytes.
90 static int
91 sclp_tty_write_room (struct tty_struct *tty)
93 unsigned long flags;
94 struct list_head *l;
95 int count;
97 spin_lock_irqsave(&sclp_tty_lock, flags);
98 count = 0;
99 if (sclp_ttybuf != NULL)
100 count = sclp_buffer_space(sclp_ttybuf) / sizeof(struct mto);
101 list_for_each(l, &sclp_tty_pages)
102 count += NR_EMPTY_MTO_PER_SCCB;
103 spin_unlock_irqrestore(&sclp_tty_lock, flags);
104 return count;
107 static void
108 sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
110 unsigned long flags;
111 void *page;
113 do {
114 page = sclp_unmake_buffer(buffer);
115 spin_lock_irqsave(&sclp_tty_lock, flags);
116 /* Remove buffer from outqueue */
117 list_del(&buffer->list);
118 sclp_tty_buffer_count--;
119 list_add_tail((struct list_head *) page, &sclp_tty_pages);
120 /* Check if there is a pending buffer on the out queue. */
121 buffer = NULL;
122 if (!list_empty(&sclp_tty_outqueue))
123 buffer = list_entry(sclp_tty_outqueue.next,
124 struct sclp_buffer, list);
125 spin_unlock_irqrestore(&sclp_tty_lock, flags);
126 } while (buffer && sclp_emit_buffer(buffer, sclp_ttybuf_callback));
128 tty_port_tty_wakeup(&sclp_port);
131 static inline void
132 __sclp_ttybuf_emit(struct sclp_buffer *buffer)
134 unsigned long flags;
135 int count;
136 int rc;
138 spin_lock_irqsave(&sclp_tty_lock, flags);
139 list_add_tail(&buffer->list, &sclp_tty_outqueue);
140 count = sclp_tty_buffer_count++;
141 spin_unlock_irqrestore(&sclp_tty_lock, flags);
142 if (count)
143 return;
144 rc = sclp_emit_buffer(buffer, sclp_ttybuf_callback);
145 if (rc)
146 sclp_ttybuf_callback(buffer, rc);
150 * When this routine is called from the timer then we flush the
151 * temporary write buffer.
153 static void
154 sclp_tty_timeout(unsigned long data)
156 unsigned long flags;
157 struct sclp_buffer *buf;
159 spin_lock_irqsave(&sclp_tty_lock, flags);
160 buf = sclp_ttybuf;
161 sclp_ttybuf = NULL;
162 spin_unlock_irqrestore(&sclp_tty_lock, flags);
164 if (buf != NULL) {
165 __sclp_ttybuf_emit(buf);
170 * Write a string to the sclp tty.
172 static int sclp_tty_write_string(const unsigned char *str, int count, int may_fail)
174 unsigned long flags;
175 void *page;
176 int written;
177 int overall_written;
178 struct sclp_buffer *buf;
180 if (count <= 0)
181 return 0;
182 overall_written = 0;
183 spin_lock_irqsave(&sclp_tty_lock, flags);
184 do {
185 /* Create a sclp output buffer if none exists yet */
186 if (sclp_ttybuf == NULL) {
187 while (list_empty(&sclp_tty_pages)) {
188 spin_unlock_irqrestore(&sclp_tty_lock, flags);
189 if (may_fail)
190 goto out;
191 else
192 sclp_sync_wait();
193 spin_lock_irqsave(&sclp_tty_lock, flags);
195 page = sclp_tty_pages.next;
196 list_del((struct list_head *) page);
197 sclp_ttybuf = sclp_make_buffer(page, sclp_tty_columns,
198 SPACES_PER_TAB);
200 /* try to write the string to the current output buffer */
201 written = sclp_write(sclp_ttybuf, str, count);
202 overall_written += written;
203 if (written == count)
204 break;
206 * Not all characters could be written to the current
207 * output buffer. Emit the buffer, create a new buffer
208 * and then output the rest of the string.
210 buf = sclp_ttybuf;
211 sclp_ttybuf = NULL;
212 spin_unlock_irqrestore(&sclp_tty_lock, flags);
213 __sclp_ttybuf_emit(buf);
214 spin_lock_irqsave(&sclp_tty_lock, flags);
215 str += written;
216 count -= written;
217 } while (count > 0);
218 /* Setup timer to output current console buffer after 1/10 second */
219 if (sclp_ttybuf && sclp_chars_in_buffer(sclp_ttybuf) &&
220 !timer_pending(&sclp_tty_timer)) {
221 init_timer(&sclp_tty_timer);
222 sclp_tty_timer.function = sclp_tty_timeout;
223 sclp_tty_timer.data = 0UL;
224 sclp_tty_timer.expires = jiffies + HZ/10;
225 add_timer(&sclp_tty_timer);
227 spin_unlock_irqrestore(&sclp_tty_lock, flags);
228 out:
229 return overall_written;
233 * This routine is called by the kernel to write a series of characters to the
234 * tty device. The characters may come from user space or kernel space. This
235 * routine will return the number of characters actually accepted for writing.
237 static int
238 sclp_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
240 if (sclp_tty_chars_count > 0) {
241 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
242 sclp_tty_chars_count = 0;
244 return sclp_tty_write_string(buf, count, 1);
248 * This routine is called by the kernel to write a single character to the tty
249 * device. If the kernel uses this routine, it must call the flush_chars()
250 * routine (if defined) when it is done stuffing characters into the driver.
252 * Characters provided to sclp_tty_put_char() are buffered by the SCLP driver.
253 * If the given character is a '\n' the contents of the SCLP write buffer
254 * - including previous characters from sclp_tty_put_char() and strings from
255 * sclp_write() without final '\n' - will be written.
257 static int
258 sclp_tty_put_char(struct tty_struct *tty, unsigned char ch)
260 sclp_tty_chars[sclp_tty_chars_count++] = ch;
261 if (ch == '\n' || sclp_tty_chars_count >= SCLP_TTY_BUF_SIZE) {
262 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
263 sclp_tty_chars_count = 0;
265 return 1;
269 * This routine is called by the kernel after it has written a series of
270 * characters to the tty device using put_char().
272 static void
273 sclp_tty_flush_chars(struct tty_struct *tty)
275 if (sclp_tty_chars_count > 0) {
276 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
277 sclp_tty_chars_count = 0;
282 * This routine returns the number of characters in the write buffer of the
283 * SCLP driver. The provided number includes all characters that are stored
284 * in the SCCB (will be written next time the SCLP is not busy) as well as
285 * characters in the write buffer (will not be written as long as there is a
286 * final line feed missing).
288 static int
289 sclp_tty_chars_in_buffer(struct tty_struct *tty)
291 unsigned long flags;
292 struct list_head *l;
293 struct sclp_buffer *t;
294 int count;
296 spin_lock_irqsave(&sclp_tty_lock, flags);
297 count = 0;
298 if (sclp_ttybuf != NULL)
299 count = sclp_chars_in_buffer(sclp_ttybuf);
300 list_for_each(l, &sclp_tty_outqueue) {
301 t = list_entry(l, struct sclp_buffer, list);
302 count += sclp_chars_in_buffer(t);
304 spin_unlock_irqrestore(&sclp_tty_lock, flags);
305 return count;
309 * removes all content from buffers of low level driver
311 static void
312 sclp_tty_flush_buffer(struct tty_struct *tty)
314 if (sclp_tty_chars_count > 0) {
315 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count, 0);
316 sclp_tty_chars_count = 0;
321 * push input to tty
323 static void
324 sclp_tty_input(unsigned char* buf, unsigned int count)
326 struct tty_struct *tty = tty_port_tty_get(&sclp_port);
327 unsigned int cchar;
330 * If this tty driver is currently closed
331 * then throw the received input away.
333 if (tty == NULL)
334 return;
335 cchar = ctrlchar_handle(buf, count, tty);
336 switch (cchar & CTRLCHAR_MASK) {
337 case CTRLCHAR_SYSRQ:
338 break;
339 case CTRLCHAR_CTRL:
340 tty_insert_flip_char(&sclp_port, cchar, TTY_NORMAL);
341 tty_flip_buffer_push(&sclp_port);
342 break;
343 case CTRLCHAR_NONE:
344 /* send (normal) input to line discipline */
345 if (count < 2 ||
346 (strncmp((const char *) buf + count - 2, "^n", 2) &&
347 strncmp((const char *) buf + count - 2, "\252n", 2))) {
348 /* add the auto \n */
349 tty_insert_flip_string(&sclp_port, buf, count);
350 tty_insert_flip_char(&sclp_port, '\n', TTY_NORMAL);
351 } else
352 tty_insert_flip_string(&sclp_port, buf, count - 2);
353 tty_flip_buffer_push(&sclp_port);
354 break;
356 tty_kref_put(tty);
360 * get a EBCDIC string in upper/lower case,
361 * find out characters in lower/upper case separated by a special character,
362 * modifiy original string,
363 * returns length of resulting string
365 static int sclp_switch_cases(unsigned char *buf, int count)
367 unsigned char *ip, *op;
368 int toggle;
370 /* initially changing case is off */
371 toggle = 0;
372 ip = op = buf;
373 while (count-- > 0) {
374 /* compare with special character */
375 if (*ip == CASE_DELIMITER) {
376 /* followed by another special character? */
377 if (count && ip[1] == CASE_DELIMITER) {
379 * ... then put a single copy of the special
380 * character to the output string
382 *op++ = *ip++;
383 count--;
384 } else
386 * ... special character follower by a normal
387 * character toggles the case change behaviour
389 toggle = ~toggle;
390 /* skip special character */
391 ip++;
392 } else
393 /* not the special character */
394 if (toggle)
395 /* but case switching is on */
396 if (sclp_tty_tolower)
397 /* switch to uppercase */
398 *op++ = _ebc_toupper[(int) *ip++];
399 else
400 /* switch to lowercase */
401 *op++ = _ebc_tolower[(int) *ip++];
402 else
403 /* no case switching, copy the character */
404 *op++ = *ip++;
406 /* return length of reformatted string. */
407 return op - buf;
410 static void sclp_get_input(struct gds_subvector *sv)
412 unsigned char *str;
413 int count;
415 str = (unsigned char *) (sv + 1);
416 count = sv->length - sizeof(*sv);
417 if (sclp_tty_tolower)
418 EBC_TOLOWER(str, count);
419 count = sclp_switch_cases(str, count);
420 /* convert EBCDIC to ASCII (modify original input in SCCB) */
421 sclp_ebcasc_str(str, count);
423 /* transfer input to high level driver */
424 sclp_tty_input(str, count);
427 static inline void sclp_eval_selfdeftextmsg(struct gds_subvector *sv)
429 void *end;
431 end = (void *) sv + sv->length;
432 for (sv = sv + 1; (void *) sv < end; sv = (void *) sv + sv->length)
433 if (sv->key == 0x30)
434 sclp_get_input(sv);
437 static inline void sclp_eval_textcmd(struct gds_vector *v)
439 struct gds_subvector *sv;
440 void *end;
442 end = (void *) v + v->length;
443 for (sv = (struct gds_subvector *) (v + 1);
444 (void *) sv < end; sv = (void *) sv + sv->length)
445 if (sv->key == GDS_KEY_SELFDEFTEXTMSG)
446 sclp_eval_selfdeftextmsg(sv);
450 static inline void sclp_eval_cpmsu(struct gds_vector *v)
452 void *end;
454 end = (void *) v + v->length;
455 for (v = v + 1; (void *) v < end; v = (void *) v + v->length)
456 if (v->gds_id == GDS_ID_TEXTCMD)
457 sclp_eval_textcmd(v);
461 static inline void sclp_eval_mdsmu(struct gds_vector *v)
463 v = sclp_find_gds_vector(v + 1, (void *) v + v->length, GDS_ID_CPMSU);
464 if (v)
465 sclp_eval_cpmsu(v);
468 static void sclp_tty_receiver(struct evbuf_header *evbuf)
470 struct gds_vector *v;
472 v = sclp_find_gds_vector(evbuf + 1, (void *) evbuf + evbuf->length,
473 GDS_ID_MDSMU);
474 if (v)
475 sclp_eval_mdsmu(v);
478 static void
479 sclp_tty_state_change(struct sclp_register *reg)
483 static struct sclp_register sclp_input_event =
485 .receive_mask = EVTYP_OPCMD_MASK | EVTYP_PMSGCMD_MASK,
486 .state_change_fn = sclp_tty_state_change,
487 .receiver_fn = sclp_tty_receiver
490 static const struct tty_operations sclp_ops = {
491 .open = sclp_tty_open,
492 .close = sclp_tty_close,
493 .write = sclp_tty_write,
494 .put_char = sclp_tty_put_char,
495 .flush_chars = sclp_tty_flush_chars,
496 .write_room = sclp_tty_write_room,
497 .chars_in_buffer = sclp_tty_chars_in_buffer,
498 .flush_buffer = sclp_tty_flush_buffer,
501 static int __init
502 sclp_tty_init(void)
504 struct tty_driver *driver;
505 void *page;
506 int i;
507 int rc;
509 if (!CONSOLE_IS_SCLP)
510 return 0;
511 driver = alloc_tty_driver(1);
512 if (!driver)
513 return -ENOMEM;
515 rc = sclp_rw_init();
516 if (rc) {
517 put_tty_driver(driver);
518 return rc;
520 /* Allocate pages for output buffering */
521 INIT_LIST_HEAD(&sclp_tty_pages);
522 for (i = 0; i < MAX_KMEM_PAGES; i++) {
523 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
524 if (page == NULL) {
525 put_tty_driver(driver);
526 return -ENOMEM;
528 list_add_tail((struct list_head *) page, &sclp_tty_pages);
530 INIT_LIST_HEAD(&sclp_tty_outqueue);
531 spin_lock_init(&sclp_tty_lock);
532 init_timer(&sclp_tty_timer);
533 sclp_ttybuf = NULL;
534 sclp_tty_buffer_count = 0;
535 if (MACHINE_IS_VM) {
537 * save 4 characters for the CPU number
538 * written at start of each line by VM/CP
540 sclp_tty_columns = 76;
541 /* case input lines to lowercase */
542 sclp_tty_tolower = 1;
544 sclp_tty_chars_count = 0;
546 rc = sclp_register(&sclp_input_event);
547 if (rc) {
548 put_tty_driver(driver);
549 return rc;
552 tty_port_init(&sclp_port);
554 driver->driver_name = "sclp_line";
555 driver->name = "sclp_line";
556 driver->major = TTY_MAJOR;
557 driver->minor_start = 64;
558 driver->type = TTY_DRIVER_TYPE_SYSTEM;
559 driver->subtype = SYSTEM_TYPE_TTY;
560 driver->init_termios = tty_std_termios;
561 driver->init_termios.c_iflag = IGNBRK | IGNPAR;
562 driver->init_termios.c_oflag = ONLCR | XTABS;
563 driver->init_termios.c_lflag = ISIG | ECHO;
564 driver->flags = TTY_DRIVER_REAL_RAW;
565 tty_set_operations(driver, &sclp_ops);
566 tty_port_link_device(&sclp_port, driver, 0);
567 rc = tty_register_driver(driver);
568 if (rc) {
569 put_tty_driver(driver);
570 tty_port_destroy(&sclp_port);
571 return rc;
573 sclp_tty_driver = driver;
574 return 0;
576 module_init(sclp_tty_init);