1 /*
2 * SCLP VT220 terminal driver.
3 *
4 * Copyright IBM Corp. 2003, 2009
5 *
6 * Author(s): Peter Oberparleiter <Peter.Oberparleiter@de.ibm.com>
7 */
8
9 #include <linux/module.h>
10 #include <linux/spinlock.h>
11 #include <linux/list.h>
12 #include <linux/wait.h>
13 #include <linux/timer.h>
14 #include <linux/kernel.h>
15 #include <linux/tty.h>
16 #include <linux/tty_driver.h>
17 #include <linux/tty_flip.h>
18 #include <linux/errno.h>
19 #include <linux/mm.h>
20 #include <linux/major.h>
21 #include <linux/console.h>
22 #include <linux/kdev_t.h>
23 #include <linux/interrupt.h>
24 #include <linux/init.h>
25 #include <linux/reboot.h>
26 #include <linux/slab.h>
27
28 #include <asm/uaccess.h>
29 #include "sclp.h"
30
31 #define SCLP_VT220_MAJOR TTY_MAJOR
32 #define SCLP_VT220_MINOR 65
33 #define SCLP_VT220_DRIVER_NAME "sclp_vt220"
34 #define SCLP_VT220_DEVICE_NAME "ttysclp"
35 #define SCLP_VT220_CONSOLE_NAME "ttyS"
36 #define SCLP_VT220_CONSOLE_INDEX 1 /* console=ttyS1 */
37 #define SCLP_VT220_BUF_SIZE 80
38
39 /* Representation of a single write request */
40 struct sclp_vt220_request {
41 struct list_head list;
42 struct sclp_req sclp_req;
43 int retry_count;
44 };
45
46 /* VT220 SCCB */
47 struct sclp_vt220_sccb {
48 struct sccb_header header;
49 struct evbuf_header evbuf;
50 };
51
52 #define SCLP_VT220_MAX_CHARS_PER_BUFFER (PAGE_SIZE - \
53 sizeof(struct sclp_vt220_request) - \
54 sizeof(struct sclp_vt220_sccb))
55
56 /* Structures and data needed to register tty driver */
57 static struct tty_driver *sclp_vt220_driver;
58
59 /* The tty_struct that the kernel associated with us */
60 static struct tty_struct *sclp_vt220_tty;
61
62 /* Lock to protect internal data from concurrent access */
63 static spinlock_t sclp_vt220_lock;
64
65 /* List of empty pages to be used as write request buffers */
66 static struct list_head sclp_vt220_empty;
67
68 /* List of pending requests */
69 static struct list_head sclp_vt220_outqueue;
70
71 /* Suspend mode flag */
72 static int sclp_vt220_suspended;
73
74 /* Flag that output queue is currently running */
75 static int sclp_vt220_queue_running;
76
77 /* Timer used for delaying write requests to merge subsequent messages into
78 * a single buffer */
79 static struct timer_list sclp_vt220_timer;
80
81 /* Pointer to current request buffer which has been partially filled but not
82 * yet sent */
83 static struct sclp_vt220_request *sclp_vt220_current_request;
84
85 /* Number of characters in current request buffer */
86 static int sclp_vt220_buffered_chars;
87
88 /* Counter controlling core driver initialization. */
89 static int __initdata sclp_vt220_init_count;
90
91 /* Flag indicating that sclp_vt220_current_request should really
92 * have been already queued but wasn't because the SCLP was processing
93 * another buffer */
94 static int sclp_vt220_flush_later;
95
96 static void sclp_vt220_receiver_fn(struct evbuf_header *evbuf);
97 static void sclp_vt220_pm_event_fn(struct sclp_register *reg,
98 enum sclp_pm_event sclp_pm_event);
99 static int __sclp_vt220_emit(struct sclp_vt220_request *request);
100 static void sclp_vt220_emit_current(void);
101
102 /* Registration structure for our interest in SCLP event buffers */
103 static struct sclp_register sclp_vt220_register = {
104 .send_mask = EVTYP_VT220MSG_MASK,
105 .receive_mask = EVTYP_VT220MSG_MASK,
106 .state_change_fn = NULL,
107 .receiver_fn = sclp_vt220_receiver_fn,
108 .pm_event_fn = sclp_vt220_pm_event_fn,
109 };
110
111
112 /*
113 * Put provided request buffer back into queue and check emit pending
114 * buffers if necessary.
115 */
116 static void
sclp_vt220_process_queue(struct sclp_vt220_request * request)117 sclp_vt220_process_queue(struct sclp_vt220_request *request)
118 {
119 unsigned long flags;
120 void *page;
121
122 do {
123 /* Put buffer back to list of empty buffers */
124 page = request->sclp_req.sccb;
125 spin_lock_irqsave(&sclp_vt220_lock, flags);
126 /* Move request from outqueue to empty queue */
127 list_del(&request->list);
128 list_add_tail((struct list_head *) page, &sclp_vt220_empty);
129 /* Check if there is a pending buffer on the out queue. */
130 request = NULL;
131 if (!list_empty(&sclp_vt220_outqueue))
132 request = list_entry(sclp_vt220_outqueue.next,
133 struct sclp_vt220_request, list);
134 if (!request || sclp_vt220_suspended) {
135 sclp_vt220_queue_running = 0;
136 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
137 break;
138 }
139 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
140 } while (__sclp_vt220_emit(request));
141 if (request == NULL && sclp_vt220_flush_later)
142 sclp_vt220_emit_current();
143 /* Check if the tty needs a wake up call */
144 if (sclp_vt220_tty != NULL) {
145 tty_wakeup(sclp_vt220_tty);
146 }
147 }
148
149 #define SCLP_BUFFER_MAX_RETRY 1
150
151 /*
152 * Callback through which the result of a write request is reported by the
153 * SCLP.
154 */
155 static void
sclp_vt220_callback(struct sclp_req * request,void * data)156 sclp_vt220_callback(struct sclp_req *request, void *data)
157 {
158 struct sclp_vt220_request *vt220_request;
159 struct sclp_vt220_sccb *sccb;
160
161 vt220_request = (struct sclp_vt220_request *) data;
162 if (request->status == SCLP_REQ_FAILED) {
163 sclp_vt220_process_queue(vt220_request);
164 return;
165 }
166 sccb = (struct sclp_vt220_sccb *) vt220_request->sclp_req.sccb;
167
168 /* Check SCLP response code and choose suitable action */
169 switch (sccb->header.response_code) {
170 case 0x0020 :
171 break;
172
173 case 0x05f0: /* Target resource in improper state */
174 break;
175
176 case 0x0340: /* Contained SCLP equipment check */
177 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY)
178 break;
179 /* Remove processed buffers and requeue rest */
180 if (sclp_remove_processed((struct sccb_header *) sccb) > 0) {
181 /* Not all buffers were processed */
182 sccb->header.response_code = 0x0000;
183 vt220_request->sclp_req.status = SCLP_REQ_FILLED;
184 if (sclp_add_request(request) == 0)
185 return;
186 }
187 break;
188
189 case 0x0040: /* SCLP equipment check */
190 if (++vt220_request->retry_count > SCLP_BUFFER_MAX_RETRY)
191 break;
192 sccb->header.response_code = 0x0000;
193 vt220_request->sclp_req.status = SCLP_REQ_FILLED;
194 if (sclp_add_request(request) == 0)
195 return;
196 break;
197
198 default:
199 break;
200 }
201 sclp_vt220_process_queue(vt220_request);
202 }
203
204 /*
205 * Emit vt220 request buffer to SCLP. Return zero on success, non-zero
206 * otherwise.
207 */
208 static int
__sclp_vt220_emit(struct sclp_vt220_request * request)209 __sclp_vt220_emit(struct sclp_vt220_request *request)
210 {
211 if (!(sclp_vt220_register.sclp_receive_mask & EVTYP_VT220MSG_MASK)) {
212 request->sclp_req.status = SCLP_REQ_FAILED;
213 return -EIO;
214 }
215 request->sclp_req.command = SCLP_CMDW_WRITE_EVENT_DATA;
216 request->sclp_req.status = SCLP_REQ_FILLED;
217 request->sclp_req.callback = sclp_vt220_callback;
218 request->sclp_req.callback_data = (void *) request;
219
220 return sclp_add_request(&request->sclp_req);
221 }
222
223 /*
224 * Queue and emit current request.
225 */
226 static void
sclp_vt220_emit_current(void)227 sclp_vt220_emit_current(void)
228 {
229 unsigned long flags;
230 struct sclp_vt220_request *request;
231 struct sclp_vt220_sccb *sccb;
232
233 spin_lock_irqsave(&sclp_vt220_lock, flags);
234 if (sclp_vt220_current_request) {
235 sccb = (struct sclp_vt220_sccb *)
236 sclp_vt220_current_request->sclp_req.sccb;
237 /* Only emit buffers with content */
238 if (sccb->header.length != sizeof(struct sclp_vt220_sccb)) {
239 list_add_tail(&sclp_vt220_current_request->list,
240 &sclp_vt220_outqueue);
241 sclp_vt220_current_request = NULL;
242 if (timer_pending(&sclp_vt220_timer))
243 del_timer(&sclp_vt220_timer);
244 }
245 sclp_vt220_flush_later = 0;
246 }
247 if (sclp_vt220_queue_running || sclp_vt220_suspended)
248 goto out_unlock;
249 if (list_empty(&sclp_vt220_outqueue))
250 goto out_unlock;
251 request = list_first_entry(&sclp_vt220_outqueue,
252 struct sclp_vt220_request, list);
253 sclp_vt220_queue_running = 1;
254 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
255
256 if (__sclp_vt220_emit(request))
257 sclp_vt220_process_queue(request);
258 return;
259 out_unlock:
260 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
261 }
262
263 #define SCLP_NORMAL_WRITE 0x00
264
265 /*
266 * Helper function to initialize a page with the sclp request structure.
267 */
268 static struct sclp_vt220_request *
sclp_vt220_initialize_page(void * page)269 sclp_vt220_initialize_page(void *page)
270 {
271 struct sclp_vt220_request *request;
272 struct sclp_vt220_sccb *sccb;
273
274 /* Place request structure at end of page */
275 request = ((struct sclp_vt220_request *)
276 ((addr_t) page + PAGE_SIZE)) - 1;
277 request->retry_count = 0;
278 request->sclp_req.sccb = page;
279 /* SCCB goes at start of page */
280 sccb = (struct sclp_vt220_sccb *) page;
281 memset((void *) sccb, 0, sizeof(struct sclp_vt220_sccb));
282 sccb->header.length = sizeof(struct sclp_vt220_sccb);
283 sccb->header.function_code = SCLP_NORMAL_WRITE;
284 sccb->header.response_code = 0x0000;
285 sccb->evbuf.type = EVTYP_VT220MSG;
286 sccb->evbuf.length = sizeof(struct evbuf_header);
287
288 return request;
289 }
290
291 static inline unsigned int
sclp_vt220_space_left(struct sclp_vt220_request * request)292 sclp_vt220_space_left(struct sclp_vt220_request *request)
293 {
294 struct sclp_vt220_sccb *sccb;
295 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
296 return PAGE_SIZE - sizeof(struct sclp_vt220_request) -
297 sccb->header.length;
298 }
299
300 static inline unsigned int
sclp_vt220_chars_stored(struct sclp_vt220_request * request)301 sclp_vt220_chars_stored(struct sclp_vt220_request *request)
302 {
303 struct sclp_vt220_sccb *sccb;
304 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
305 return sccb->evbuf.length - sizeof(struct evbuf_header);
306 }
307
308 /*
309 * Add msg to buffer associated with request. Return the number of characters
310 * added.
311 */
312 static int
sclp_vt220_add_msg(struct sclp_vt220_request * request,const unsigned char * msg,int count,int convertlf)313 sclp_vt220_add_msg(struct sclp_vt220_request *request,
314 const unsigned char *msg, int count, int convertlf)
315 {
316 struct sclp_vt220_sccb *sccb;
317 void *buffer;
318 unsigned char c;
319 int from;
320 int to;
321
322 if (count > sclp_vt220_space_left(request))
323 count = sclp_vt220_space_left(request);
324 if (count <= 0)
325 return 0;
326
327 sccb = (struct sclp_vt220_sccb *) request->sclp_req.sccb;
328 buffer = (void *) ((addr_t) sccb + sccb->header.length);
329
330 if (convertlf) {
331 /* Perform Linefeed conversion (0x0a -> 0x0a 0x0d)*/
332 for (from=0, to=0;
333 (from < count) && (to < sclp_vt220_space_left(request));
334 from++) {
335 /* Retrieve character */
336 c = msg[from];
337 /* Perform conversion */
338 if (c == 0x0a) {
339 if (to + 1 < sclp_vt220_space_left(request)) {
340 ((unsigned char *) buffer)[to++] = c;
341 ((unsigned char *) buffer)[to++] = 0x0d;
342 } else
343 break;
344
345 } else
346 ((unsigned char *) buffer)[to++] = c;
347 }
348 sccb->header.length += to;
349 sccb->evbuf.length += to;
350 return from;
351 } else {
352 memcpy(buffer, (const void *) msg, count);
353 sccb->header.length += count;
354 sccb->evbuf.length += count;
355 return count;
356 }
357 }
358
359 /*
360 * Emit buffer after having waited long enough for more data to arrive.
361 */
362 static void
sclp_vt220_timeout(unsigned long data)363 sclp_vt220_timeout(unsigned long data)
364 {
365 sclp_vt220_emit_current();
366 }
367
368 #define BUFFER_MAX_DELAY HZ/20
369
370 /*
371 * Internal implementation of the write function. Write COUNT bytes of data
372 * from memory at BUF
373 * to the SCLP interface. In case that the data does not fit into the current
374 * write buffer, emit the current one and allocate a new one. If there are no
375 * more empty buffers available, wait until one gets emptied. If DO_SCHEDULE
376 * is non-zero, the buffer will be scheduled for emitting after a timeout -
377 * otherwise the user has to explicitly call the flush function.
378 * A non-zero CONVERTLF parameter indicates that 0x0a characters in the message
379 * buffer should be converted to 0x0a 0x0d. After completion, return the number
380 * of bytes written.
381 */
382 static int
__sclp_vt220_write(const unsigned char * buf,int count,int do_schedule,int convertlf,int may_fail)383 __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule,
384 int convertlf, int may_fail)
385 {
386 unsigned long flags;
387 void *page;
388 int written;
389 int overall_written;
390
391 if (count <= 0)
392 return 0;
393 overall_written = 0;
394 spin_lock_irqsave(&sclp_vt220_lock, flags);
395 do {
396 /* Create an sclp output buffer if none exists yet */
397 if (sclp_vt220_current_request == NULL) {
398 while (list_empty(&sclp_vt220_empty)) {
399 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
400 if (may_fail || sclp_vt220_suspended)
401 goto out;
402 else
403 sclp_sync_wait();
404 spin_lock_irqsave(&sclp_vt220_lock, flags);
405 }
406 page = (void *) sclp_vt220_empty.next;
407 list_del((struct list_head *) page);
408 sclp_vt220_current_request =
409 sclp_vt220_initialize_page(page);
410 }
411 /* Try to write the string to the current request buffer */
412 written = sclp_vt220_add_msg(sclp_vt220_current_request,
413 buf, count, convertlf);
414 overall_written += written;
415 if (written == count)
416 break;
417 /*
418 * Not all characters could be written to the current
419 * output buffer. Emit the buffer, create a new buffer
420 * and then output the rest of the string.
421 */
422 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
423 sclp_vt220_emit_current();
424 spin_lock_irqsave(&sclp_vt220_lock, flags);
425 buf += written;
426 count -= written;
427 } while (count > 0);
428 /* Setup timer to output current console buffer after some time */
429 if (sclp_vt220_current_request != NULL &&
430 !timer_pending(&sclp_vt220_timer) && do_schedule) {
431 sclp_vt220_timer.function = sclp_vt220_timeout;
432 sclp_vt220_timer.data = 0UL;
433 sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY;
434 add_timer(&sclp_vt220_timer);
435 }
436 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
437 out:
438 return overall_written;
439 }
440
441 /*
442 * This routine is called by the kernel to write a series of
443 * characters to the tty device. The characters may come from
444 * user space or kernel space. This routine will return the
445 * number of characters actually accepted for writing.
446 */
447 static int
sclp_vt220_write(struct tty_struct * tty,const unsigned char * buf,int count)448 sclp_vt220_write(struct tty_struct *tty, const unsigned char *buf, int count)
449 {
450 return __sclp_vt220_write(buf, count, 1, 0, 1);
451 }
452
453 #define SCLP_VT220_SESSION_ENDED 0x01
454 #define SCLP_VT220_SESSION_STARTED 0x80
455 #define SCLP_VT220_SESSION_DATA 0x00
456
457 /*
458 * Called by the SCLP to report incoming event buffers.
459 */
460 static void
sclp_vt220_receiver_fn(struct evbuf_header * evbuf)461 sclp_vt220_receiver_fn(struct evbuf_header *evbuf)
462 {
463 char *buffer;
464 unsigned int count;
465
466 /* Ignore input if device is not open */
467 if (sclp_vt220_tty == NULL)
468 return;
469
470 buffer = (char *) ((addr_t) evbuf + sizeof(struct evbuf_header));
471 count = evbuf->length - sizeof(struct evbuf_header);
472
473 switch (*buffer) {
474 case SCLP_VT220_SESSION_ENDED:
475 case SCLP_VT220_SESSION_STARTED:
476 break;
477 case SCLP_VT220_SESSION_DATA:
478 /* Send input to line discipline */
479 buffer++;
480 count--;
481 tty_insert_flip_string(sclp_vt220_tty, buffer, count);
482 tty_flip_buffer_push(sclp_vt220_tty);
483 break;
484 }
485 }
486
487 /*
488 * This routine is called when a particular tty device is opened.
489 */
490 static int
sclp_vt220_open(struct tty_struct * tty,struct file * filp)491 sclp_vt220_open(struct tty_struct *tty, struct file *filp)
492 {
493 if (tty->count == 1) {
494 sclp_vt220_tty = tty;
495 tty->driver_data = kmalloc(SCLP_VT220_BUF_SIZE, GFP_KERNEL);
496 if (tty->driver_data == NULL)
497 return -ENOMEM;
498 tty->low_latency = 0;
499 if (!tty->winsize.ws_row && !tty->winsize.ws_col) {
500 tty->winsize.ws_row = 24;
501 tty->winsize.ws_col = 80;
502 }
503 }
504 return 0;
505 }
506
507 /*
508 * This routine is called when a particular tty device is closed.
509 */
510 static void
sclp_vt220_close(struct tty_struct * tty,struct file * filp)511 sclp_vt220_close(struct tty_struct *tty, struct file *filp)
512 {
513 if (tty->count == 1) {
514 sclp_vt220_tty = NULL;
515 kfree(tty->driver_data);
516 tty->driver_data = NULL;
517 }
518 }
519
520 /*
521 * This routine is called by the kernel to write a single
522 * character to the tty device. If the kernel uses this routine,
523 * it must call the flush_chars() routine (if defined) when it is
524 * done stuffing characters into the driver.
525 */
526 static int
sclp_vt220_put_char(struct tty_struct * tty,unsigned char ch)527 sclp_vt220_put_char(struct tty_struct *tty, unsigned char ch)
528 {
529 return __sclp_vt220_write(&ch, 1, 0, 0, 1);
530 }
531
532 /*
533 * This routine is called by the kernel after it has written a
534 * series of characters to the tty device using put_char().
535 */
536 static void
sclp_vt220_flush_chars(struct tty_struct * tty)537 sclp_vt220_flush_chars(struct tty_struct *tty)
538 {
539 if (!sclp_vt220_queue_running)
540 sclp_vt220_emit_current();
541 else
542 sclp_vt220_flush_later = 1;
543 }
544
545 /*
546 * This routine returns the numbers of characters the tty driver
547 * will accept for queuing to be written. This number is subject
548 * to change as output buffers get emptied, or if the output flow
549 * control is acted.
550 */
551 static int
sclp_vt220_write_room(struct tty_struct * tty)552 sclp_vt220_write_room(struct tty_struct *tty)
553 {
554 unsigned long flags;
555 struct list_head *l;
556 int count;
557
558 spin_lock_irqsave(&sclp_vt220_lock, flags);
559 count = 0;
560 if (sclp_vt220_current_request != NULL)
561 count = sclp_vt220_space_left(sclp_vt220_current_request);
562 list_for_each(l, &sclp_vt220_empty)
563 count += SCLP_VT220_MAX_CHARS_PER_BUFFER;
564 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
565 return count;
566 }
567
568 /*
569 * Return number of buffered chars.
570 */
571 static int
sclp_vt220_chars_in_buffer(struct tty_struct * tty)572 sclp_vt220_chars_in_buffer(struct tty_struct *tty)
573 {
574 unsigned long flags;
575 struct list_head *l;
576 struct sclp_vt220_request *r;
577 int count;
578
579 spin_lock_irqsave(&sclp_vt220_lock, flags);
580 count = 0;
581 if (sclp_vt220_current_request != NULL)
582 count = sclp_vt220_chars_stored(sclp_vt220_current_request);
583 list_for_each(l, &sclp_vt220_outqueue) {
584 r = list_entry(l, struct sclp_vt220_request, list);
585 count += sclp_vt220_chars_stored(r);
586 }
587 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
588 return count;
589 }
590
591 /*
592 * Pass on all buffers to the hardware. Return only when there are no more
593 * buffers pending.
594 */
595 static void
sclp_vt220_flush_buffer(struct tty_struct * tty)596 sclp_vt220_flush_buffer(struct tty_struct *tty)
597 {
598 sclp_vt220_emit_current();
599 }
600
601 /* Release allocated pages. */
__sclp_vt220_free_pages(void)602 static void __init __sclp_vt220_free_pages(void)
603 {
604 struct list_head *page, *p;
605
606 list_for_each_safe(page, p, &sclp_vt220_empty) {
607 list_del(page);
608 free_page((unsigned long) page);
609 }
610 }
611
612 /* Release memory and unregister from sclp core. Controlled by init counting -
613 * only the last invoker will actually perform these actions. */
__sclp_vt220_cleanup(void)614 static void __init __sclp_vt220_cleanup(void)
615 {
616 sclp_vt220_init_count--;
617 if (sclp_vt220_init_count != 0)
618 return;
619 sclp_unregister(&sclp_vt220_register);
620 __sclp_vt220_free_pages();
621 }
622
623 /* Allocate buffer pages and register with sclp core. Controlled by init
624 * counting - only the first invoker will actually perform these actions. */
__sclp_vt220_init(int num_pages)625 static int __init __sclp_vt220_init(int num_pages)
626 {
627 void *page;
628 int i;
629 int rc;
630
631 sclp_vt220_init_count++;
632 if (sclp_vt220_init_count != 1)
633 return 0;
634 spin_lock_init(&sclp_vt220_lock);
635 INIT_LIST_HEAD(&sclp_vt220_empty);
636 INIT_LIST_HEAD(&sclp_vt220_outqueue);
637 init_timer(&sclp_vt220_timer);
638 sclp_vt220_current_request = NULL;
639 sclp_vt220_buffered_chars = 0;
640 sclp_vt220_tty = NULL;
641 sclp_vt220_flush_later = 0;
642
643 /* Allocate pages for output buffering */
644 rc = -ENOMEM;
645 for (i = 0; i < num_pages; i++) {
646 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
647 if (!page)
648 goto out;
649 list_add_tail(page, &sclp_vt220_empty);
650 }
651 rc = sclp_register(&sclp_vt220_register);
652 out:
653 if (rc) {
654 __sclp_vt220_free_pages();
655 sclp_vt220_init_count--;
656 }
657 return rc;
658 }
659
660 static const struct tty_operations sclp_vt220_ops = {
661 .open = sclp_vt220_open,
662 .close = sclp_vt220_close,
663 .write = sclp_vt220_write,
664 .put_char = sclp_vt220_put_char,
665 .flush_chars = sclp_vt220_flush_chars,
666 .write_room = sclp_vt220_write_room,
667 .chars_in_buffer = sclp_vt220_chars_in_buffer,
668 .flush_buffer = sclp_vt220_flush_buffer,
669 };
670
671 /*
672 * Register driver with SCLP and Linux and initialize internal tty structures.
673 */
sclp_vt220_tty_init(void)674 static int __init sclp_vt220_tty_init(void)
675 {
676 struct tty_driver *driver;
677 int rc;
678
679 /* Note: we're not testing for CONSOLE_IS_SCLP here to preserve
680 * symmetry between VM and LPAR systems regarding ttyS1. */
681 driver = alloc_tty_driver(1);
682 if (!driver)
683 return -ENOMEM;
684 rc = __sclp_vt220_init(MAX_KMEM_PAGES);
685 if (rc)
686 goto out_driver;
687
688 driver->owner = THIS_MODULE;
689 driver->driver_name = SCLP_VT220_DRIVER_NAME;
690 driver->name = SCLP_VT220_DEVICE_NAME;
691 driver->major = SCLP_VT220_MAJOR;
692 driver->minor_start = SCLP_VT220_MINOR;
693 driver->type = TTY_DRIVER_TYPE_SYSTEM;
694 driver->subtype = SYSTEM_TYPE_TTY;
695 driver->init_termios = tty_std_termios;
696 driver->flags = TTY_DRIVER_REAL_RAW;
697 tty_set_operations(driver, &sclp_vt220_ops);
698
699 rc = tty_register_driver(driver);
700 if (rc)
701 goto out_init;
702 sclp_vt220_driver = driver;
703 return 0;
704
705 out_init:
706 __sclp_vt220_cleanup();
707 out_driver:
708 put_tty_driver(driver);
709 return rc;
710 }
711 __initcall(sclp_vt220_tty_init);
712
__sclp_vt220_flush_buffer(void)713 static void __sclp_vt220_flush_buffer(void)
714 {
715 unsigned long flags;
716
717 sclp_vt220_emit_current();
718 spin_lock_irqsave(&sclp_vt220_lock, flags);
719 if (timer_pending(&sclp_vt220_timer))
720 del_timer(&sclp_vt220_timer);
721 while (sclp_vt220_queue_running) {
722 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
723 sclp_sync_wait();
724 spin_lock_irqsave(&sclp_vt220_lock, flags);
725 }
726 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
727 }
728
729 /*
730 * Resume console: If there are cached messages, emit them.
731 */
sclp_vt220_resume(void)732 static void sclp_vt220_resume(void)
733 {
734 unsigned long flags;
735
736 spin_lock_irqsave(&sclp_vt220_lock, flags);
737 sclp_vt220_suspended = 0;
738 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
739 sclp_vt220_emit_current();
740 }
741
742 /*
743 * Suspend console: Set suspend flag and flush console
744 */
sclp_vt220_suspend(void)745 static void sclp_vt220_suspend(void)
746 {
747 unsigned long flags;
748
749 spin_lock_irqsave(&sclp_vt220_lock, flags);
750 sclp_vt220_suspended = 1;
751 spin_unlock_irqrestore(&sclp_vt220_lock, flags);
752 __sclp_vt220_flush_buffer();
753 }
754
sclp_vt220_pm_event_fn(struct sclp_register * reg,enum sclp_pm_event sclp_pm_event)755 static void sclp_vt220_pm_event_fn(struct sclp_register *reg,
756 enum sclp_pm_event sclp_pm_event)
757 {
758 switch (sclp_pm_event) {
759 case SCLP_PM_EVENT_FREEZE:
760 sclp_vt220_suspend();
761 break;
762 case SCLP_PM_EVENT_RESTORE:
763 case SCLP_PM_EVENT_THAW:
764 sclp_vt220_resume();
765 break;
766 }
767 }
768
769 #ifdef CONFIG_SCLP_VT220_CONSOLE
770
771 static void
sclp_vt220_con_write(struct console * con,const char * buf,unsigned int count)772 sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count)
773 {
774 __sclp_vt220_write((const unsigned char *) buf, count, 1, 1, 0);
775 }
776
777 static struct tty_driver *
sclp_vt220_con_device(struct console * c,int * index)778 sclp_vt220_con_device(struct console *c, int *index)
779 {
780 *index = 0;
781 return sclp_vt220_driver;
782 }
783
784 static int
sclp_vt220_notify(struct notifier_block * self,unsigned long event,void * data)785 sclp_vt220_notify(struct notifier_block *self,
786 unsigned long event, void *data)
787 {
788 __sclp_vt220_flush_buffer();
789 return NOTIFY_OK;
790 }
791
792 static struct notifier_block on_panic_nb = {
793 .notifier_call = sclp_vt220_notify,
794 .priority = 1,
795 };
796
797 static struct notifier_block on_reboot_nb = {
798 .notifier_call = sclp_vt220_notify,
799 .priority = 1,
800 };
801
802 /* Structure needed to register with printk */
803 static struct console sclp_vt220_console =
804 {
805 .name = SCLP_VT220_CONSOLE_NAME,
806 .write = sclp_vt220_con_write,
807 .device = sclp_vt220_con_device,
808 .flags = CON_PRINTBUFFER,
809 .index = SCLP_VT220_CONSOLE_INDEX
810 };
811
812 static int __init
sclp_vt220_con_init(void)813 sclp_vt220_con_init(void)
814 {
815 int rc;
816
817 if (!CONSOLE_IS_SCLP)
818 return 0;
819 rc = __sclp_vt220_init(MAX_CONSOLE_PAGES);
820 if (rc)
821 return rc;
822 /* Attach linux console */
823 atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
824 register_reboot_notifier(&on_reboot_nb);
825 register_console(&sclp_vt220_console);
826 return 0;
827 }
828
829 console_initcall(sclp_vt220_con_init);
830 #endif /* CONFIG_SCLP_VT220_CONSOLE */
831
832