1// SPDX-License-Identifier: GPL-2.0
2/*
3 * 3215 line mode terminal driver.
4 *
5 * Copyright IBM Corp. 1999, 2009
6 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7 *
8 * Updated:
9 * Aug-2000: Added tab support
10 * Dan Morrison, IBM Corporation <dmorriso@cse.buffalo.edu>
11 */
12
13#include <linux/types.h>
14#include <linux/kdev_t.h>
15#include <linux/tty.h>
16#include <linux/tty_flip.h>
17#include <linux/vt_kern.h>
18#include <linux/init.h>
19#include <linux/console.h>
20#include <linux/interrupt.h>
21#include <linux/err.h>
22#include <linux/panic_notifier.h>
23#include <linux/reboot.h>
24#include <linux/serial.h> /* ASYNC_* flags */
25#include <linux/slab.h>
26#include <asm/ccwdev.h>
27#include <asm/cio.h>
28#include <linux/io.h>
29#include <asm/ebcdic.h>
30#include <linux/uaccess.h>
31#include <asm/delay.h>
32#include <asm/cpcmd.h>
33#include <asm/setup.h>
34
35#include "ctrlchar.h"
36
37#define NR_3215 1
38#define NR_3215_REQ (4*NR_3215)
39#define RAW3215_BUFFER_SIZE 65536 /* output buffer size */
40#define RAW3215_INBUF_SIZE 256 /* input buffer size */
41#define RAW3215_MIN_SPACE 128 /* minimum free space for wakeup */
42#define RAW3215_MIN_WRITE 1024 /* min. length for immediate output */
43#define RAW3215_MAX_BYTES 3968 /* max. bytes to write with one ssch */
44#define RAW3215_MAX_NEWLINE 50 /* max. lines to write with one ssch */
45#define RAW3215_NR_CCWS 3
46#define RAW3215_TIMEOUT HZ/10 /* time for delayed output */
47
48#define RAW3215_FIXED 1 /* 3215 console device is not be freed */
49#define RAW3215_WORKING 4 /* set if a request is being worked on */
50#define RAW3215_THROTTLED 8 /* set if reading is disabled */
51#define RAW3215_STOPPED 16 /* set if writing is disabled */
52#define RAW3215_TIMER_RUNS 64 /* set if the output delay timer is on */
53#define RAW3215_FLUSHING 128 /* set to flush buffer (no delay) */
54
55#define TAB_STOP_SIZE 8 /* tab stop size */
56
57/*
58 * Request types for a 3215 device
59 */
60enum raw3215_type {
61 RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
62};
63
64/*
65 * Request structure for a 3215 device
66 */
67struct raw3215_req {
68 enum raw3215_type type; /* type of the request */
69 int start, len; /* start index & len in output buffer */
70 int delayable; /* indication to wait for more data */
71 int residual; /* residual count for read request */
72 struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */
73 struct raw3215_info *info; /* pointer to main structure */
74 struct raw3215_req *next; /* pointer to next request */
75} __attribute__ ((aligned(8)));
76
77struct raw3215_info {
78 struct tty_port port;
79 struct ccw_device *cdev; /* device for tty driver */
80 spinlock_t *lock; /* pointer to irq lock */
81 int flags; /* state flags */
82 u8 *buffer; /* pointer to output buffer */
83 u8 *inbuf; /* pointer to input buffer */
84 int head; /* first free byte in output buffer */
85 int count; /* number of bytes in output buffer */
86 int written; /* number of bytes in write requests */
87 struct raw3215_req *queued_read; /* pointer to queued read requests */
88 struct raw3215_req *queued_write;/* pointer to queued write requests */
89 wait_queue_head_t empty_wait; /* wait queue for flushing */
90 struct timer_list timer; /* timer for delayed output */
91 int line_pos; /* position on the line (for tabs) */
92};
93
94/* array of 3215 devices structures */
95static struct raw3215_info *raw3215[NR_3215];
96/* spinlock to protect the raw3215 array */
97static DEFINE_SPINLOCK(raw3215_device_lock);
98/* list of free request structures */
99static struct raw3215_req *raw3215_freelist;
100/* spinlock to protect free list */
101static DEFINE_SPINLOCK(raw3215_freelist_lock);
102
103static struct tty_driver *tty3215_driver;
104static bool con3215_drop = true;
105
106/*
107 * Get a request structure from the free list
108 */
109static inline struct raw3215_req *raw3215_alloc_req(void)
110{
111 struct raw3215_req *req;
112 unsigned long flags;
113
114 spin_lock_irqsave(&raw3215_freelist_lock, flags);
115 req = raw3215_freelist;
116 raw3215_freelist = req->next;
117 spin_unlock_irqrestore(lock: &raw3215_freelist_lock, flags);
118 return req;
119}
120
121/*
122 * Put a request structure back to the free list
123 */
124static inline void raw3215_free_req(struct raw3215_req *req)
125{
126 unsigned long flags;
127
128 if (req->type == RAW3215_FREE)
129 return; /* don't free a free request */
130 req->type = RAW3215_FREE;
131 spin_lock_irqsave(&raw3215_freelist_lock, flags);
132 req->next = raw3215_freelist;
133 raw3215_freelist = req;
134 spin_unlock_irqrestore(lock: &raw3215_freelist_lock, flags);
135}
136
137/*
138 * Set up a read request that reads up to 160 byte from the 3215 device.
139 * If there is a queued read request it is used, but that shouldn't happen
140 * because a 3215 terminal won't accept a new read before the old one is
141 * completed.
142 */
143static void raw3215_mk_read_req(struct raw3215_info *raw)
144{
145 struct raw3215_req *req;
146 struct ccw1 *ccw;
147
148 /* there can only be ONE read request at a time */
149 req = raw->queued_read;
150 if (req == NULL) {
151 /* no queued read request, use new req structure */
152 req = raw3215_alloc_req();
153 req->type = RAW3215_READ;
154 req->info = raw;
155 raw->queued_read = req;
156 }
157
158 ccw = req->ccws;
159 ccw->cmd_code = 0x0A; /* read inquiry */
160 ccw->flags = 0x20; /* ignore incorrect length */
161 ccw->count = 160;
162 ccw->cda = virt_to_dma32(raw->inbuf);
163}
164
165/*
166 * Set up a write request with the information from the main structure.
167 * A ccw chain is created that writes as much as possible from the output
168 * buffer to the 3215 device. If a queued write exists it is replaced by
169 * the new, probably lengthened request.
170 */
171static void raw3215_mk_write_req(struct raw3215_info *raw)
172{
173 struct raw3215_req *req;
174 struct ccw1 *ccw;
175 int len, count, ix, lines;
176
177 if (raw->count <= raw->written)
178 return;
179 /* check if there is a queued write request */
180 req = raw->queued_write;
181 if (req == NULL) {
182 /* no queued write request, use new req structure */
183 req = raw3215_alloc_req();
184 req->type = RAW3215_WRITE;
185 req->info = raw;
186 raw->queued_write = req;
187 } else {
188 raw->written -= req->len;
189 }
190
191 ccw = req->ccws;
192 req->start = (raw->head - raw->count + raw->written) &
193 (RAW3215_BUFFER_SIZE - 1);
194 /*
195 * now we have to count newlines. We can at max accept
196 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
197 * a restriction in VM
198 */
199 lines = 0;
200 ix = req->start;
201 while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
202 if (raw->buffer[ix] == 0x15)
203 lines++;
204 ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
205 }
206 len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
207 if (len > RAW3215_MAX_BYTES)
208 len = RAW3215_MAX_BYTES;
209 req->len = len;
210 raw->written += len;
211
212 /* set the indication if we should try to enlarge this request */
213 req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
214
215 ix = req->start;
216 while (len > 0) {
217 if (ccw > req->ccws)
218 ccw[-1].flags |= 0x40; /* use command chaining */
219 ccw->cmd_code = 0x01; /* write, auto carrier return */
220 ccw->flags = 0x20; /* ignore incorrect length ind. */
221 ccw->cda = virt_to_dma32(raw->buffer + ix);
222 count = len;
223 if (ix + count > RAW3215_BUFFER_SIZE)
224 count = RAW3215_BUFFER_SIZE - ix;
225 ccw->count = count;
226 len -= count;
227 ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
228 ccw++;
229 }
230 /*
231 * Add a NOP to the channel program. 3215 devices are purely
232 * emulated and its much better to avoid the channel end
233 * interrupt in this case.
234 */
235 if (ccw > req->ccws)
236 ccw[-1].flags |= 0x40; /* use command chaining */
237 ccw->cmd_code = 0x03; /* NOP */
238 ccw->flags = 0;
239 ccw->cda = 0;
240 ccw->count = 1;
241}
242
243/*
244 * Start a read or a write request
245 */
246static void raw3215_start_io(struct raw3215_info *raw)
247{
248 struct raw3215_req *req;
249 int res;
250
251 req = raw->queued_read;
252 if (req != NULL &&
253 !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
254 /* dequeue request */
255 raw->queued_read = NULL;
256 res = ccw_device_start(raw->cdev, req->ccws,
257 (unsigned long) req, 0, 0);
258 if (res != 0) {
259 /* do_IO failed, put request back to queue */
260 raw->queued_read = req;
261 } else {
262 raw->flags |= RAW3215_WORKING;
263 }
264 }
265 req = raw->queued_write;
266 if (req != NULL &&
267 !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
268 /* dequeue request */
269 raw->queued_write = NULL;
270 res = ccw_device_start(raw->cdev, req->ccws,
271 (unsigned long) req, 0, 0);
272 if (res != 0) {
273 /* do_IO failed, put request back to queue */
274 raw->queued_write = req;
275 } else {
276 raw->flags |= RAW3215_WORKING;
277 }
278 }
279}
280
281/*
282 * Function to start a delayed output after RAW3215_TIMEOUT seconds
283 */
284static void raw3215_timeout(struct timer_list *t)
285{
286 struct raw3215_info *raw = from_timer(raw, t, timer);
287 unsigned long flags;
288
289 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
290 raw->flags &= ~RAW3215_TIMER_RUNS;
291 raw3215_mk_write_req(raw);
292 raw3215_start_io(raw);
293 if ((raw->queued_read || raw->queued_write) &&
294 !(raw->flags & RAW3215_WORKING) &&
295 !(raw->flags & RAW3215_TIMER_RUNS)) {
296 raw->timer.expires = RAW3215_TIMEOUT + jiffies;
297 add_timer(timer: &raw->timer);
298 raw->flags |= RAW3215_TIMER_RUNS;
299 }
300 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
301}
302
303/*
304 * Function to conditionally start an IO. A read is started immediately,
305 * a write is only started immediately if the flush flag is on or the
306 * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
307 * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
308 */
309static inline void raw3215_try_io(struct raw3215_info *raw)
310{
311 if (!tty_port_initialized(port: &raw->port))
312 return;
313 if (raw->queued_read != NULL)
314 raw3215_start_io(raw);
315 else if (raw->queued_write != NULL) {
316 if ((raw->queued_write->delayable == 0) ||
317 (raw->flags & RAW3215_FLUSHING)) {
318 /* execute write requests bigger than minimum size */
319 raw3215_start_io(raw);
320 }
321 }
322 if ((raw->queued_read || raw->queued_write) &&
323 !(raw->flags & RAW3215_WORKING) &&
324 !(raw->flags & RAW3215_TIMER_RUNS)) {
325 raw->timer.expires = RAW3215_TIMEOUT + jiffies;
326 add_timer(timer: &raw->timer);
327 raw->flags |= RAW3215_TIMER_RUNS;
328 }
329}
330
331/*
332 * Try to start the next IO and wake up processes waiting on the tty.
333 */
334static void raw3215_next_io(struct raw3215_info *raw, struct tty_struct *tty)
335{
336 raw3215_mk_write_req(raw);
337 raw3215_try_io(raw);
338 if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
339 tty_wakeup(tty);
340}
341
342/*
343 * Interrupt routine, called from common io layer
344 */
345static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
346 struct irb *irb)
347{
348 struct raw3215_info *raw;
349 struct raw3215_req *req;
350 struct tty_struct *tty;
351 int cstat, dstat;
352 int count;
353
354 raw = dev_get_drvdata(dev: &cdev->dev);
355 req = (struct raw3215_req *) intparm;
356 tty = tty_port_tty_get(port: &raw->port);
357 cstat = irb->scsw.cmd.cstat;
358 dstat = irb->scsw.cmd.dstat;
359 if (cstat != 0)
360 raw3215_next_io(raw, tty);
361 if (dstat & 0x01) { /* we got a unit exception */
362 dstat &= ~0x01; /* we can ignore it */
363 }
364 switch (dstat) {
365 case 0x80:
366 if (cstat != 0)
367 break;
368 /* Attention interrupt, someone hit the enter key */
369 raw3215_mk_read_req(raw);
370 raw3215_next_io(raw, tty);
371 break;
372 case 0x08:
373 case 0x0C:
374 /* Channel end interrupt. */
375 if ((raw = req->info) == NULL)
376 goto put_tty; /* That shouldn't happen ... */
377 if (req->type == RAW3215_READ) {
378 /* store residual count, then wait for device end */
379 req->residual = irb->scsw.cmd.count;
380 }
381 if (dstat == 0x08)
382 break;
383 fallthrough;
384 case 0x04:
385 /* Device end interrupt. */
386 if ((raw = req->info) == NULL)
387 goto put_tty; /* That shouldn't happen ... */
388 if (req->type == RAW3215_READ && tty != NULL) {
389 unsigned int cchar;
390
391 count = 160 - req->residual;
392 EBCASC(raw->inbuf, count);
393 cchar = ctrlchar_handle(buf: raw->inbuf, len: count, tty);
394 switch (cchar & CTRLCHAR_MASK) {
395 case CTRLCHAR_SYSRQ:
396 break;
397
398 case CTRLCHAR_CTRL:
399 tty_insert_flip_char(port: &raw->port, ch: cchar,
400 TTY_NORMAL);
401 tty_flip_buffer_push(port: &raw->port);
402 break;
403
404 case CTRLCHAR_NONE:
405 if (count < 2 ||
406 (strncmp(raw->inbuf+count-2, "\252n", 2) &&
407 strncmp(raw->inbuf+count-2, "^n", 2)) ) {
408 /* add the auto \n */
409 raw->inbuf[count] = '\n';
410 count++;
411 } else
412 count -= 2;
413 tty_insert_flip_string(port: &raw->port, chars: raw->inbuf,
414 size: count);
415 tty_flip_buffer_push(port: &raw->port);
416 break;
417 }
418 } else if (req->type == RAW3215_WRITE) {
419 raw->count -= req->len;
420 raw->written -= req->len;
421 }
422 raw->flags &= ~RAW3215_WORKING;
423 raw3215_free_req(req);
424 /* check for empty wait */
425 if (waitqueue_active(wq_head: &raw->empty_wait) &&
426 raw->queued_write == NULL &&
427 raw->queued_read == NULL) {
428 wake_up_interruptible(&raw->empty_wait);
429 }
430 raw3215_next_io(raw, tty);
431 break;
432 default:
433 /* Strange interrupt, I'll do my best to clean up */
434 if (req != NULL && req->type != RAW3215_FREE) {
435 if (req->type == RAW3215_WRITE) {
436 raw->count -= req->len;
437 raw->written -= req->len;
438 }
439 raw->flags &= ~RAW3215_WORKING;
440 raw3215_free_req(req);
441 }
442 raw3215_next_io(raw, tty);
443 }
444put_tty:
445 tty_kref_put(tty);
446}
447
448/*
449 * Need to drop data to avoid blocking. Drop as much data as possible.
450 * This is unqueued part in the buffer and the queued part in the request.
451 * Also adjust the head position to append new data and set count
452 * accordingly.
453 *
454 * Return number of bytes available in buffer.
455 */
456static unsigned int raw3215_drop(struct raw3215_info *raw)
457{
458 struct raw3215_req *req;
459
460 req = raw->queued_write;
461 if (req) {
462 /* Drop queued data and delete request */
463 raw->written -= req->len;
464 raw3215_free_req(req);
465 raw->queued_write = NULL;
466 }
467 raw->head = (raw->head - raw->count + raw->written) &
468 (RAW3215_BUFFER_SIZE - 1);
469 raw->count = raw->written;
470
471 return RAW3215_BUFFER_SIZE - raw->count;
472}
473
474/*
475 * Wait until length bytes are available int the output buffer.
476 * If drop mode is active and wait condition holds true, start dropping
477 * data.
478 * Has to be called with the s390irq lock held. Can be called
479 * disabled.
480 */
481static unsigned int raw3215_make_room(struct raw3215_info *raw,
482 unsigned int length, bool drop)
483{
484 while (RAW3215_BUFFER_SIZE - raw->count < length) {
485 if (drop)
486 return raw3215_drop(raw);
487
488 /* there might be a request pending */
489 raw->flags |= RAW3215_FLUSHING;
490 raw3215_mk_write_req(raw);
491 raw3215_try_io(raw);
492 raw->flags &= ~RAW3215_FLUSHING;
493#ifdef CONFIG_TN3215_CONSOLE
494 ccw_device_wait_idle(raw->cdev);
495#endif
496 /* Enough room freed up ? */
497 if (RAW3215_BUFFER_SIZE - raw->count >= length)
498 break;
499 /* there might be another cpu waiting for the lock */
500 spin_unlock(lock: get_ccwdev_lock(raw->cdev));
501 udelay(100);
502 spin_lock(lock: get_ccwdev_lock(raw->cdev));
503 }
504 return length;
505}
506
507#define RAW3215_COUNT 1
508#define RAW3215_STORE 2
509
510/*
511 * Add text to console buffer. Find tabs in input and calculate size
512 * including tab replacement.
513 * This function operates in 2 different modes, depending on parameter
514 * opmode:
515 * RAW3215_COUNT: Get the size needed for the input string with
516 * proper tab replacement calculation.
517 * Return value is the number of bytes required to store the
518 * input. However no data is actually stored.
519 * The parameter todrop is not used.
520 * RAW3215_STORE: Add data to the console buffer. The parameter todrop is
521 * valid and contains the number of bytes to be dropped from head of
522 * string without blocking.
523 * Return value is the number of bytes copied.
524 */
525static unsigned int raw3215_addtext(const u8 *str, size_t length,
526 struct raw3215_info *raw, int opmode,
527 unsigned int todrop)
528{
529 unsigned int i, blanks, expanded_size = 0;
530 unsigned int column = raw->line_pos;
531 size_t c;
532 u8 ch;
533
534 if (opmode == RAW3215_COUNT)
535 todrop = 0;
536
537 for (c = 0; c < length; ++c) {
538 blanks = 1;
539 ch = str[c];
540
541 switch (ch) {
542 case '\n':
543 expanded_size++;
544 column = 0;
545 break;
546 case '\t':
547 blanks = TAB_STOP_SIZE - (column % TAB_STOP_SIZE);
548 column += blanks;
549 expanded_size += blanks;
550 ch = ' ';
551 break;
552 default:
553 expanded_size++;
554 column++;
555 break;
556 }
557
558 if (opmode == RAW3215_COUNT)
559 continue;
560 if (todrop && expanded_size < todrop) /* Drop head data */
561 continue;
562 for (i = 0; i < blanks; i++) {
563 raw->buffer[raw->head] = _ascebc[ch];
564 raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
565 raw->count++;
566 }
567 raw->line_pos = column;
568 }
569 return expanded_size - todrop;
570}
571
572/*
573 * String write routine for 3215 devices
574 */
575static void raw3215_write(struct raw3215_info *raw, const u8 *str,
576 size_t length)
577{
578 unsigned int count, avail;
579 unsigned long flags;
580
581 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
582
583 count = raw3215_addtext(str, length, raw, RAW3215_COUNT, todrop: 0);
584
585 avail = raw3215_make_room(raw, length: count, drop: con3215_drop);
586 if (avail) {
587 raw3215_addtext(str, length, raw, RAW3215_STORE,
588 todrop: count - avail);
589 }
590 if (!(raw->flags & RAW3215_WORKING)) {
591 raw3215_mk_write_req(raw);
592 /* start or queue request */
593 raw3215_try_io(raw);
594 }
595 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
596}
597
598/*
599 * Put character routine for 3215 devices
600 */
601static void raw3215_putchar(struct raw3215_info *raw, u8 ch)
602{
603 raw3215_write(raw, str: &ch, length: 1);
604}
605
606/*
607 * Flush routine, it simply sets the flush flag and tries to start
608 * pending IO.
609 */
610static void raw3215_flush_buffer(struct raw3215_info *raw)
611{
612 unsigned long flags;
613
614 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
615 if (raw->count > 0) {
616 raw->flags |= RAW3215_FLUSHING;
617 raw3215_try_io(raw);
618 raw->flags &= ~RAW3215_FLUSHING;
619 }
620 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
621}
622
623/*
624 * Fire up a 3215 device.
625 */
626static int raw3215_startup(struct raw3215_info *raw)
627{
628 unsigned long flags;
629
630 if (tty_port_initialized(port: &raw->port))
631 return 0;
632 raw->line_pos = 0;
633 tty_port_set_initialized(port: &raw->port, val: true);
634 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
635 raw3215_try_io(raw);
636 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
637
638 return 0;
639}
640
641/*
642 * Shutdown a 3215 device.
643 */
644static void raw3215_shutdown(struct raw3215_info *raw)
645{
646 DECLARE_WAITQUEUE(wait, current);
647 unsigned long flags;
648
649 if (!tty_port_initialized(port: &raw->port) || (raw->flags & RAW3215_FIXED))
650 return;
651 /* Wait for outstanding requests, then free irq */
652 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
653 if ((raw->flags & RAW3215_WORKING) ||
654 raw->queued_write != NULL ||
655 raw->queued_read != NULL) {
656 add_wait_queue(wq_head: &raw->empty_wait, wq_entry: &wait);
657 set_current_state(TASK_INTERRUPTIBLE);
658 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
659 schedule();
660 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
661 remove_wait_queue(wq_head: &raw->empty_wait, wq_entry: &wait);
662 set_current_state(TASK_RUNNING);
663 tty_port_set_initialized(port: &raw->port, val: true);
664 }
665 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
666}
667
668static struct raw3215_info *raw3215_alloc_info(void)
669{
670 struct raw3215_info *info;
671
672 info = kzalloc(size: sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
673 if (!info)
674 return NULL;
675
676 info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
677 info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
678 if (!info->buffer || !info->inbuf) {
679 kfree(objp: info->inbuf);
680 kfree(objp: info->buffer);
681 kfree(objp: info);
682 return NULL;
683 }
684
685 timer_setup(&info->timer, raw3215_timeout, 0);
686 init_waitqueue_head(&info->empty_wait);
687 tty_port_init(port: &info->port);
688
689 return info;
690}
691
692static void raw3215_free_info(struct raw3215_info *raw)
693{
694 kfree(objp: raw->inbuf);
695 kfree(objp: raw->buffer);
696 tty_port_destroy(port: &raw->port);
697 kfree(objp: raw);
698}
699
700static int raw3215_probe(struct ccw_device *cdev)
701{
702 struct raw3215_info *raw;
703 int line;
704
705 /* Console is special. */
706 if (raw3215[0] && (raw3215[0] == dev_get_drvdata(dev: &cdev->dev)))
707 return 0;
708
709 raw = raw3215_alloc_info();
710 if (raw == NULL)
711 return -ENOMEM;
712
713 raw->cdev = cdev;
714 dev_set_drvdata(dev: &cdev->dev, data: raw);
715 cdev->handler = raw3215_irq;
716
717 spin_lock(lock: &raw3215_device_lock);
718 for (line = 0; line < NR_3215; line++) {
719 if (!raw3215[line]) {
720 raw3215[line] = raw;
721 break;
722 }
723 }
724 spin_unlock(lock: &raw3215_device_lock);
725 if (line == NR_3215) {
726 raw3215_free_info(raw);
727 return -ENODEV;
728 }
729
730 return 0;
731}
732
733static void raw3215_remove(struct ccw_device *cdev)
734{
735 struct raw3215_info *raw;
736 unsigned int line;
737
738 ccw_device_set_offline(cdev);
739 raw = dev_get_drvdata(dev: &cdev->dev);
740 if (raw) {
741 spin_lock(lock: &raw3215_device_lock);
742 for (line = 0; line < NR_3215; line++)
743 if (raw3215[line] == raw)
744 break;
745 raw3215[line] = NULL;
746 spin_unlock(lock: &raw3215_device_lock);
747 dev_set_drvdata(dev: &cdev->dev, NULL);
748 raw3215_free_info(raw);
749 }
750}
751
752static int raw3215_set_online(struct ccw_device *cdev)
753{
754 struct raw3215_info *raw;
755
756 raw = dev_get_drvdata(dev: &cdev->dev);
757 if (!raw)
758 return -ENODEV;
759
760 return raw3215_startup(raw);
761}
762
763static int raw3215_set_offline(struct ccw_device *cdev)
764{
765 struct raw3215_info *raw;
766
767 raw = dev_get_drvdata(dev: &cdev->dev);
768 if (!raw)
769 return -ENODEV;
770
771 raw3215_shutdown(raw);
772
773 return 0;
774}
775
776static struct ccw_device_id raw3215_id[] = {
777 { CCW_DEVICE(0x3215, 0) },
778 { /* end of list */ },
779};
780
781static ssize_t con_drop_store(struct device_driver *dev, const char *buf, size_t count)
782{
783 bool drop;
784 int rc;
785
786 rc = kstrtobool(s: buf, res: &drop);
787 if (!rc)
788 con3215_drop = drop;
789 return rc ?: count;
790}
791
792static ssize_t con_drop_show(struct device_driver *dev, char *buf)
793{
794 return sysfs_emit(buf, fmt: "%d\n", con3215_drop ? 1 : 0);
795}
796
797static DRIVER_ATTR_RW(con_drop);
798
799static struct attribute *con3215_drv_attrs[] = {
800 &driver_attr_con_drop.attr,
801 NULL,
802};
803
804static struct attribute_group con3215_drv_attr_group = {
805 .attrs = con3215_drv_attrs,
806 NULL,
807};
808
809static const struct attribute_group *con3215_drv_attr_groups[] = {
810 &con3215_drv_attr_group,
811 NULL,
812};
813
814static struct ccw_driver raw3215_ccw_driver = {
815 .driver = {
816 .name = "3215",
817 .groups = con3215_drv_attr_groups,
818 .owner = THIS_MODULE,
819 },
820 .ids = raw3215_id,
821 .probe = &raw3215_probe,
822 .remove = &raw3215_remove,
823 .set_online = &raw3215_set_online,
824 .set_offline = &raw3215_set_offline,
825 .int_class = IRQIO_C15,
826};
827
828static void handle_write(struct raw3215_info *raw, const u8 *str, size_t count)
829{
830 while (count > 0) {
831 size_t i = min_t(size_t, count, RAW3215_BUFFER_SIZE - 1);
832 raw3215_write(raw, str, length: i);
833 count -= i;
834 str += i;
835 }
836}
837
838#ifdef CONFIG_TN3215_CONSOLE
839/*
840 * Write a string to the 3215 console
841 */
842static void con3215_write(struct console *co, const char *str, unsigned int count)
843{
844 handle_write(raw3215[0], str, count);
845}
846
847static struct tty_driver *con3215_device(struct console *c, int *index)
848{
849 *index = c->index;
850 return tty3215_driver;
851}
852
853/*
854 * The below function is called as a panic/reboot notifier before the
855 * system enters a disabled, endless loop.
856 *
857 * Notice we must use the spin_trylock() alternative, to prevent lockups
858 * in atomic context (panic routine runs with secondary CPUs, local IRQs
859 * and preemption disabled).
860 */
861static int con3215_notify(struct notifier_block *self,
862 unsigned long event, void *data)
863{
864 struct raw3215_info *raw;
865 unsigned long flags;
866
867 raw = raw3215[0]; /* console 3215 is the first one */
868 if (!spin_trylock_irqsave(get_ccwdev_lock(raw->cdev), flags))
869 return NOTIFY_DONE;
870 raw3215_make_room(raw, RAW3215_BUFFER_SIZE, false);
871 spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
872
873 return NOTIFY_DONE;
874}
875
876static struct notifier_block on_panic_nb = {
877 .notifier_call = con3215_notify,
878 .priority = INT_MIN + 1, /* run the callback late */
879};
880
881static struct notifier_block on_reboot_nb = {
882 .notifier_call = con3215_notify,
883 .priority = INT_MIN + 1, /* run the callback late */
884};
885
886/*
887 * The console structure for the 3215 console
888 */
889static struct console con3215 = {
890 .name = "ttyS",
891 .write = con3215_write,
892 .device = con3215_device,
893 .flags = CON_PRINTBUFFER,
894};
895
896/*
897 * 3215 console initialization code called from console_init().
898 */
899static int __init con3215_init(void)
900{
901 struct ccw_device *cdev;
902 struct raw3215_info *raw;
903 struct raw3215_req *req;
904 int i;
905
906 /* Check if 3215 is to be the console */
907 if (!CONSOLE_IS_3215)
908 return -ENODEV;
909
910 /* Set the console mode for VM */
911 if (MACHINE_IS_VM) {
912 cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
913 cpcmd("TERM AUTOCR OFF", NULL, 0, NULL);
914 }
915
916 /* allocate 3215 request structures */
917 raw3215_freelist = NULL;
918 for (i = 0; i < NR_3215_REQ; i++) {
919 req = kzalloc(sizeof(struct raw3215_req), GFP_KERNEL | GFP_DMA);
920 if (!req)
921 return -ENOMEM;
922 req->next = raw3215_freelist;
923 raw3215_freelist = req;
924 }
925
926 cdev = ccw_device_create_console(&raw3215_ccw_driver);
927 if (IS_ERR(cdev))
928 return -ENODEV;
929
930 raw3215[0] = raw = raw3215_alloc_info();
931 raw->cdev = cdev;
932 dev_set_drvdata(&cdev->dev, raw);
933 cdev->handler = raw3215_irq;
934
935 raw->flags |= RAW3215_FIXED;
936 if (ccw_device_enable_console(cdev)) {
937 ccw_device_destroy_console(cdev);
938 raw3215_free_info(raw);
939 raw3215[0] = NULL;
940 return -ENODEV;
941 }
942
943 /* Request the console irq */
944 if (raw3215_startup(raw) != 0) {
945 raw3215_free_info(raw);
946 raw3215[0] = NULL;
947 return -ENODEV;
948 }
949 atomic_notifier_chain_register(&panic_notifier_list, &on_panic_nb);
950 register_reboot_notifier(&on_reboot_nb);
951 register_console(&con3215);
952 return 0;
953}
954console_initcall(con3215_init);
955#endif
956
957static int tty3215_install(struct tty_driver *driver, struct tty_struct *tty)
958{
959 struct raw3215_info *raw;
960
961 raw = raw3215[tty->index];
962 if (raw == NULL)
963 return -ENODEV;
964
965 tty->driver_data = raw;
966
967 return tty_port_install(port: &raw->port, driver, tty);
968}
969
970/*
971 * tty3215_open
972 *
973 * This routine is called whenever a 3215 tty is opened.
974 */
975static int tty3215_open(struct tty_struct *tty, struct file * filp)
976{
977 struct raw3215_info *raw = tty->driver_data;
978
979 tty_port_tty_set(port: &raw->port, tty);
980
981 /*
982 * Start up 3215 device
983 */
984 return raw3215_startup(raw);
985}
986
987/*
988 * tty3215_close()
989 *
990 * This routine is called when the 3215 tty is closed. We wait
991 * for the remaining request to be completed. Then we clean up.
992 */
993static void tty3215_close(struct tty_struct *tty, struct file * filp)
994{
995 struct raw3215_info *raw = tty->driver_data;
996
997 if (raw == NULL || tty->count > 1)
998 return;
999 tty->closing = 1;
1000 /* Shutdown the terminal */
1001 raw3215_shutdown(raw);
1002 tty->closing = 0;
1003 tty_port_tty_set(port: &raw->port, NULL);
1004}
1005
1006/*
1007 * Returns the amount of free space in the output buffer.
1008 */
1009static unsigned int tty3215_write_room(struct tty_struct *tty)
1010{
1011 struct raw3215_info *raw = tty->driver_data;
1012
1013 /* Subtract TAB_STOP_SIZE to allow for a tab, 8 <<< 64K */
1014 if ((RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE) >= 0)
1015 return RAW3215_BUFFER_SIZE - raw->count - TAB_STOP_SIZE;
1016 else
1017 return 0;
1018}
1019
1020/*
1021 * String write routine for 3215 ttys
1022 */
1023static ssize_t tty3215_write(struct tty_struct *tty, const u8 *buf,
1024 size_t count)
1025{
1026 handle_write(raw: tty->driver_data, str: buf, count);
1027 return count;
1028}
1029
1030/*
1031 * Put character routine for 3215 ttys
1032 */
1033static int tty3215_put_char(struct tty_struct *tty, u8 ch)
1034{
1035 struct raw3215_info *raw = tty->driver_data;
1036
1037 raw3215_putchar(raw, ch);
1038
1039 return 1;
1040}
1041
1042static void tty3215_flush_chars(struct tty_struct *tty)
1043{
1044}
1045
1046/*
1047 * Returns the number of characters in the output buffer
1048 */
1049static unsigned int tty3215_chars_in_buffer(struct tty_struct *tty)
1050{
1051 struct raw3215_info *raw = tty->driver_data;
1052
1053 return raw->count;
1054}
1055
1056static void tty3215_flush_buffer(struct tty_struct *tty)
1057{
1058 struct raw3215_info *raw = tty->driver_data;
1059
1060 raw3215_flush_buffer(raw);
1061 tty_wakeup(tty);
1062}
1063
1064/*
1065 * Disable reading from a 3215 tty
1066 */
1067static void tty3215_throttle(struct tty_struct *tty)
1068{
1069 struct raw3215_info *raw = tty->driver_data;
1070
1071 raw->flags |= RAW3215_THROTTLED;
1072}
1073
1074/*
1075 * Enable reading from a 3215 tty
1076 */
1077static void tty3215_unthrottle(struct tty_struct *tty)
1078{
1079 struct raw3215_info *raw = tty->driver_data;
1080 unsigned long flags;
1081
1082 if (raw->flags & RAW3215_THROTTLED) {
1083 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1084 raw->flags &= ~RAW3215_THROTTLED;
1085 raw3215_try_io(raw);
1086 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
1087 }
1088}
1089
1090/*
1091 * Disable writing to a 3215 tty
1092 */
1093static void tty3215_stop(struct tty_struct *tty)
1094{
1095 struct raw3215_info *raw = tty->driver_data;
1096
1097 raw->flags |= RAW3215_STOPPED;
1098}
1099
1100/*
1101 * Enable writing to a 3215 tty
1102 */
1103static void tty3215_start(struct tty_struct *tty)
1104{
1105 struct raw3215_info *raw = tty->driver_data;
1106 unsigned long flags;
1107
1108 if (raw->flags & RAW3215_STOPPED) {
1109 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
1110 raw->flags &= ~RAW3215_STOPPED;
1111 raw3215_try_io(raw);
1112 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
1113 }
1114}
1115
1116static const struct tty_operations tty3215_ops = {
1117 .install = tty3215_install,
1118 .open = tty3215_open,
1119 .close = tty3215_close,
1120 .write = tty3215_write,
1121 .put_char = tty3215_put_char,
1122 .flush_chars = tty3215_flush_chars,
1123 .write_room = tty3215_write_room,
1124 .chars_in_buffer = tty3215_chars_in_buffer,
1125 .flush_buffer = tty3215_flush_buffer,
1126 .throttle = tty3215_throttle,
1127 .unthrottle = tty3215_unthrottle,
1128 .stop = tty3215_stop,
1129 .start = tty3215_start,
1130};
1131
1132static int __init con3215_setup_drop(char *str)
1133{
1134 bool drop;
1135 int rc;
1136
1137 rc = kstrtobool(s: str, res: &drop);
1138 if (!rc)
1139 con3215_drop = drop;
1140 return rc;
1141}
1142early_param("con3215_drop", con3215_setup_drop);
1143
1144/*
1145 * 3215 tty registration code called from tty_init().
1146 * Most kernel services (incl. kmalloc) are available at this poimt.
1147 */
1148static int __init tty3215_init(void)
1149{
1150 struct tty_driver *driver;
1151 int ret;
1152
1153 if (!CONSOLE_IS_3215)
1154 return 0;
1155
1156 driver = tty_alloc_driver(NR_3215, TTY_DRIVER_REAL_RAW);
1157 if (IS_ERR(ptr: driver))
1158 return PTR_ERR(ptr: driver);
1159
1160 ret = ccw_driver_register(&raw3215_ccw_driver);
1161 if (ret) {
1162 tty_driver_kref_put(driver);
1163 return ret;
1164 }
1165 /*
1166 * Initialize the tty_driver structure
1167 * Entries in tty3215_driver that are NOT initialized:
1168 * proc_entry, set_termios, flush_buffer, set_ldisc, write_proc
1169 */
1170
1171 driver->driver_name = "tty3215";
1172 driver->name = "ttyS";
1173 driver->major = TTY_MAJOR;
1174 driver->minor_start = 64;
1175 driver->type = TTY_DRIVER_TYPE_SYSTEM;
1176 driver->subtype = SYSTEM_TYPE_TTY;
1177 driver->init_termios = tty_std_termios;
1178 driver->init_termios.c_iflag = IGNBRK | IGNPAR;
1179 driver->init_termios.c_oflag = ONLCR;
1180 driver->init_termios.c_lflag = ISIG;
1181 tty_set_operations(driver, op: &tty3215_ops);
1182 ret = tty_register_driver(driver);
1183 if (ret) {
1184 tty_driver_kref_put(driver);
1185 return ret;
1186 }
1187 tty3215_driver = driver;
1188 return 0;
1189}
1190device_initcall(tty3215_init);
1191

source code of linux/drivers/s390/char/con3215.c