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/machine.h>
27#include <asm/ccwdev.h>
28#include <asm/cio.h>
29#include <linux/io.h>
30#include <asm/ebcdic.h>
31#include <linux/uaccess.h>
32#include <asm/delay.h>
33#include <asm/cpcmd.h>
34#include <asm/setup.h>
35
36#include "ctrlchar.h"
37
38#define NR_3215 1
39#define NR_3215_REQ (4*NR_3215)
40#define RAW3215_BUFFER_SIZE 65536 /* output buffer size */
41#define RAW3215_INBUF_SIZE 256 /* input buffer size */
42#define RAW3215_MIN_SPACE 128 /* minimum free space for wakeup */
43#define RAW3215_MIN_WRITE 1024 /* min. length for immediate output */
44#define RAW3215_MAX_BYTES 3968 /* max. bytes to write with one ssch */
45#define RAW3215_MAX_NEWLINE 50 /* max. lines to write with one ssch */
46#define RAW3215_NR_CCWS 3
47#define RAW3215_TIMEOUT HZ/10 /* time for delayed output */
48
49#define RAW3215_FIXED 1 /* 3215 console device is not be freed */
50#define RAW3215_WORKING 4 /* set if a request is being worked on */
51#define RAW3215_THROTTLED 8 /* set if reading is disabled */
52#define RAW3215_STOPPED 16 /* set if writing is disabled */
53#define RAW3215_TIMER_RUNS 64 /* set if the output delay timer is on */
54#define RAW3215_FLUSHING 128 /* set to flush buffer (no delay) */
55
56#define TAB_STOP_SIZE 8 /* tab stop size */
57
58/*
59 * Request types for a 3215 device
60 */
61enum raw3215_type {
62 RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
63};
64
65/*
66 * Request structure for a 3215 device
67 */
68struct raw3215_req {
69 enum raw3215_type type; /* type of the request */
70 int start, len; /* start index & len in output buffer */
71 int delayable; /* indication to wait for more data */
72 int residual; /* residual count for read request */
73 struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */
74 struct raw3215_info *info; /* pointer to main structure */
75 struct raw3215_req *next; /* pointer to next request */
76} __attribute__ ((aligned(8)));
77
78struct raw3215_info {
79 struct tty_port port;
80 struct ccw_device *cdev; /* device for tty driver */
81 spinlock_t *lock; /* pointer to irq lock */
82 int flags; /* state flags */
83 u8 *buffer; /* pointer to output buffer */
84 u8 *inbuf; /* pointer to input buffer */
85 int head; /* first free byte in output buffer */
86 int count; /* number of bytes in output buffer */
87 int written; /* number of bytes in write requests */
88 struct raw3215_req *queued_read; /* pointer to queued read requests */
89 struct raw3215_req *queued_write;/* pointer to queued write requests */
90 wait_queue_head_t empty_wait; /* wait queue for flushing */
91 struct timer_list timer; /* timer for delayed output */
92 int line_pos; /* position on the line (for tabs) */
93};
94
95/* array of 3215 devices structures */
96static struct raw3215_info *raw3215[NR_3215];
97/* spinlock to protect the raw3215 array */
98static DEFINE_SPINLOCK(raw3215_device_lock);
99/* list of free request structures */
100static struct raw3215_req *raw3215_freelist;
101/* spinlock to protect free list */
102static DEFINE_SPINLOCK(raw3215_freelist_lock);
103
104static struct tty_driver *tty3215_driver;
105static bool con3215_drop = true;
106
107/*
108 * Get a request structure from the free list
109 */
110static inline struct raw3215_req *raw3215_alloc_req(void)
111{
112 struct raw3215_req *req;
113 unsigned long flags;
114
115 spin_lock_irqsave(&raw3215_freelist_lock, flags);
116 req = raw3215_freelist;
117 raw3215_freelist = req->next;
118 spin_unlock_irqrestore(lock: &raw3215_freelist_lock, flags);
119 return req;
120}
121
122/*
123 * Put a request structure back to the free list
124 */
125static inline void raw3215_free_req(struct raw3215_req *req)
126{
127 unsigned long flags;
128
129 if (req->type == RAW3215_FREE)
130 return; /* don't free a free request */
131 req->type = RAW3215_FREE;
132 spin_lock_irqsave(&raw3215_freelist_lock, flags);
133 req->next = raw3215_freelist;
134 raw3215_freelist = req;
135 spin_unlock_irqrestore(lock: &raw3215_freelist_lock, flags);
136}
137
138/*
139 * Set up a read request that reads up to 160 byte from the 3215 device.
140 * If there is a queued read request it is used, but that shouldn't happen
141 * because a 3215 terminal won't accept a new read before the old one is
142 * completed.
143 */
144static void raw3215_mk_read_req(struct raw3215_info *raw)
145{
146 struct raw3215_req *req;
147 struct ccw1 *ccw;
148
149 /* there can only be ONE read request at a time */
150 req = raw->queued_read;
151 if (req == NULL) {
152 /* no queued read request, use new req structure */
153 req = raw3215_alloc_req();
154 req->type = RAW3215_READ;
155 req->info = raw;
156 raw->queued_read = req;
157 }
158
159 ccw = req->ccws;
160 ccw->cmd_code = 0x0A; /* read inquiry */
161 ccw->flags = 0x20; /* ignore incorrect length */
162 ccw->count = 160;
163 ccw->cda = virt_to_dma32(raw->inbuf);
164}
165
166/*
167 * Set up a write request with the information from the main structure.
168 * A ccw chain is created that writes as much as possible from the output
169 * buffer to the 3215 device. If a queued write exists it is replaced by
170 * the new, probably lengthened request.
171 */
172static void raw3215_mk_write_req(struct raw3215_info *raw)
173{
174 struct raw3215_req *req;
175 struct ccw1 *ccw;
176 int len, count, ix, lines;
177
178 if (raw->count <= raw->written)
179 return;
180 /* check if there is a queued write request */
181 req = raw->queued_write;
182 if (req == NULL) {
183 /* no queued write request, use new req structure */
184 req = raw3215_alloc_req();
185 req->type = RAW3215_WRITE;
186 req->info = raw;
187 raw->queued_write = req;
188 } else {
189 raw->written -= req->len;
190 }
191
192 ccw = req->ccws;
193 req->start = (raw->head - raw->count + raw->written) &
194 (RAW3215_BUFFER_SIZE - 1);
195 /*
196 * now we have to count newlines. We can at max accept
197 * RAW3215_MAX_NEWLINE newlines in a single ssch due to
198 * a restriction in VM
199 */
200 lines = 0;
201 ix = req->start;
202 while (lines < RAW3215_MAX_NEWLINE && ix != raw->head) {
203 if (raw->buffer[ix] == 0x15)
204 lines++;
205 ix = (ix + 1) & (RAW3215_BUFFER_SIZE - 1);
206 }
207 len = ((ix - 1 - req->start) & (RAW3215_BUFFER_SIZE - 1)) + 1;
208 if (len > RAW3215_MAX_BYTES)
209 len = RAW3215_MAX_BYTES;
210 req->len = len;
211 raw->written += len;
212
213 /* set the indication if we should try to enlarge this request */
214 req->delayable = (ix == raw->head) && (len < RAW3215_MIN_WRITE);
215
216 ix = req->start;
217 while (len > 0) {
218 if (ccw > req->ccws)
219 ccw[-1].flags |= 0x40; /* use command chaining */
220 ccw->cmd_code = 0x01; /* write, auto carrier return */
221 ccw->flags = 0x20; /* ignore incorrect length ind. */
222 ccw->cda = virt_to_dma32(raw->buffer + ix);
223 count = len;
224 if (ix + count > RAW3215_BUFFER_SIZE)
225 count = RAW3215_BUFFER_SIZE - ix;
226 ccw->count = count;
227 len -= count;
228 ix = (ix + count) & (RAW3215_BUFFER_SIZE - 1);
229 ccw++;
230 }
231 /*
232 * Add a NOP to the channel program. 3215 devices are purely
233 * emulated and its much better to avoid the channel end
234 * interrupt in this case.
235 */
236 if (ccw > req->ccws)
237 ccw[-1].flags |= 0x40; /* use command chaining */
238 ccw->cmd_code = 0x03; /* NOP */
239 ccw->flags = 0;
240 ccw->cda = 0;
241 ccw->count = 1;
242}
243
244/*
245 * Start a read or a write request
246 */
247static void raw3215_start_io(struct raw3215_info *raw)
248{
249 struct raw3215_req *req;
250 int res;
251
252 req = raw->queued_read;
253 if (req != NULL &&
254 !(raw->flags & (RAW3215_WORKING | RAW3215_THROTTLED))) {
255 /* dequeue request */
256 raw->queued_read = NULL;
257 res = ccw_device_start(raw->cdev, req->ccws,
258 (unsigned long) req, 0, 0);
259 if (res != 0) {
260 /* do_IO failed, put request back to queue */
261 raw->queued_read = req;
262 } else {
263 raw->flags |= RAW3215_WORKING;
264 }
265 }
266 req = raw->queued_write;
267 if (req != NULL &&
268 !(raw->flags & (RAW3215_WORKING | RAW3215_STOPPED))) {
269 /* dequeue request */
270 raw->queued_write = NULL;
271 res = ccw_device_start(raw->cdev, req->ccws,
272 (unsigned long) req, 0, 0);
273 if (res != 0) {
274 /* do_IO failed, put request back to queue */
275 raw->queued_write = req;
276 } else {
277 raw->flags |= RAW3215_WORKING;
278 }
279 }
280}
281
282/*
283 * Function to start a delayed output after RAW3215_TIMEOUT seconds
284 */
285static void raw3215_timeout(struct timer_list *t)
286{
287 struct raw3215_info *raw = timer_container_of(raw, t, timer);
288 unsigned long flags;
289
290 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
291 raw->flags &= ~RAW3215_TIMER_RUNS;
292 raw3215_mk_write_req(raw);
293 raw3215_start_io(raw);
294 if ((raw->queued_read || raw->queued_write) &&
295 !(raw->flags & RAW3215_WORKING) &&
296 !(raw->flags & RAW3215_TIMER_RUNS)) {
297 raw->timer.expires = RAW3215_TIMEOUT + jiffies;
298 add_timer(timer: &raw->timer);
299 raw->flags |= RAW3215_TIMER_RUNS;
300 }
301 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
302}
303
304/*
305 * Function to conditionally start an IO. A read is started immediately,
306 * a write is only started immediately if the flush flag is on or the
307 * amount of data is bigger than RAW3215_MIN_WRITE. If a write is not
308 * done immediately a timer is started with a delay of RAW3215_TIMEOUT.
309 */
310static inline void raw3215_try_io(struct raw3215_info *raw)
311{
312 if (!tty_port_initialized(port: &raw->port))
313 return;
314 if (raw->queued_read != NULL)
315 raw3215_start_io(raw);
316 else if (raw->queued_write != NULL) {
317 if ((raw->queued_write->delayable == 0) ||
318 (raw->flags & RAW3215_FLUSHING)) {
319 /* execute write requests bigger than minimum size */
320 raw3215_start_io(raw);
321 }
322 }
323 if ((raw->queued_read || raw->queued_write) &&
324 !(raw->flags & RAW3215_WORKING) &&
325 !(raw->flags & RAW3215_TIMER_RUNS)) {
326 raw->timer.expires = RAW3215_TIMEOUT + jiffies;
327 add_timer(timer: &raw->timer);
328 raw->flags |= RAW3215_TIMER_RUNS;
329 }
330}
331
332/*
333 * Try to start the next IO and wake up processes waiting on the tty.
334 */
335static void raw3215_next_io(struct raw3215_info *raw, struct tty_struct *tty)
336{
337 raw3215_mk_write_req(raw);
338 raw3215_try_io(raw);
339 if (tty && RAW3215_BUFFER_SIZE - raw->count >= RAW3215_MIN_SPACE)
340 tty_wakeup(tty);
341}
342
343/*
344 * Interrupt routine, called from common io layer
345 */
346static void raw3215_irq(struct ccw_device *cdev, unsigned long intparm,
347 struct irb *irb)
348{
349 struct raw3215_info *raw;
350 struct raw3215_req *req;
351 struct tty_struct *tty;
352 int cstat, dstat;
353 int count;
354
355 raw = dev_get_drvdata(dev: &cdev->dev);
356 req = (struct raw3215_req *) intparm;
357 tty = tty_port_tty_get(port: &raw->port);
358 cstat = irb->scsw.cmd.cstat;
359 dstat = irb->scsw.cmd.dstat;
360 if (cstat != 0)
361 raw3215_next_io(raw, tty);
362 if (dstat & 0x01) { /* we got a unit exception */
363 dstat &= ~0x01; /* we can ignore it */
364 }
365 switch (dstat) {
366 case 0x80:
367 if (cstat != 0)
368 break;
369 /* Attention interrupt, someone hit the enter key */
370 raw3215_mk_read_req(raw);
371 raw3215_next_io(raw, tty);
372 break;
373 case 0x08:
374 case 0x0C:
375 /* Channel end interrupt. */
376 if ((raw = req->info) == NULL)
377 goto put_tty; /* That shouldn't happen ... */
378 if (req->type == RAW3215_READ) {
379 /* store residual count, then wait for device end */
380 req->residual = irb->scsw.cmd.count;
381 }
382 if (dstat == 0x08)
383 break;
384 fallthrough;
385 case 0x04:
386 /* Device end interrupt. */
387 if ((raw = req->info) == NULL)
388 goto put_tty; /* That shouldn't happen ... */
389 if (req->type == RAW3215_READ && tty != NULL) {
390 unsigned int cchar;
391
392 count = 160 - req->residual;
393 EBCASC(raw->inbuf, count);
394 cchar = ctrlchar_handle(buf: raw->inbuf, len: count, tty);
395 switch (cchar & CTRLCHAR_MASK) {
396 case CTRLCHAR_SYSRQ:
397 break;
398
399 case CTRLCHAR_CTRL:
400 tty_insert_flip_char(port: &raw->port, ch: cchar,
401 TTY_NORMAL);
402 tty_flip_buffer_push(port: &raw->port);
403 break;
404
405 case CTRLCHAR_NONE:
406 if (count < 2 ||
407 (strncmp(raw->inbuf+count-2, "\252n", 2) &&
408 strncmp(raw->inbuf+count-2, "^n", 2)) ) {
409 /* add the auto \n */
410 raw->inbuf[count] = '\n';
411 count++;
412 } else
413 count -= 2;
414 tty_insert_flip_string(port: &raw->port, chars: raw->inbuf,
415 size: count);
416 tty_flip_buffer_push(port: &raw->port);
417 break;
418 }
419 } else if (req->type == RAW3215_WRITE) {
420 raw->count -= req->len;
421 raw->written -= req->len;
422 }
423 raw->flags &= ~RAW3215_WORKING;
424 raw3215_free_req(req);
425 /* check for empty wait */
426 if (waitqueue_active(wq_head: &raw->empty_wait) &&
427 raw->queued_write == NULL &&
428 raw->queued_read == NULL) {
429 wake_up_interruptible(&raw->empty_wait);
430 }
431 raw3215_next_io(raw, tty);
432 break;
433 default:
434 /* Strange interrupt, I'll do my best to clean up */
435 if (req != NULL && req->type != RAW3215_FREE) {
436 if (req->type == RAW3215_WRITE) {
437 raw->count -= req->len;
438 raw->written -= req->len;
439 }
440 raw->flags &= ~RAW3215_WORKING;
441 raw3215_free_req(req);
442 }
443 raw3215_next_io(raw, tty);
444 }
445put_tty:
446 tty_kref_put(tty);
447}
448
449/*
450 * Need to drop data to avoid blocking. Drop as much data as possible.
451 * This is unqueued part in the buffer and the queued part in the request.
452 * Also adjust the head position to append new data and set count
453 * accordingly.
454 *
455 * Return number of bytes available in buffer.
456 */
457static unsigned int raw3215_drop(struct raw3215_info *raw)
458{
459 struct raw3215_req *req;
460
461 req = raw->queued_write;
462 if (req) {
463 /* Drop queued data and delete request */
464 raw->written -= req->len;
465 raw3215_free_req(req);
466 raw->queued_write = NULL;
467 }
468 raw->head = (raw->head - raw->count + raw->written) &
469 (RAW3215_BUFFER_SIZE - 1);
470 raw->count = raw->written;
471
472 return RAW3215_BUFFER_SIZE - raw->count;
473}
474
475/*
476 * Wait until length bytes are available int the output buffer.
477 * If drop mode is active and wait condition holds true, start dropping
478 * data.
479 * Has to be called with the s390irq lock held. Can be called
480 * disabled.
481 */
482static unsigned int raw3215_make_room(struct raw3215_info *raw,
483 unsigned int length, bool drop)
484{
485 while (RAW3215_BUFFER_SIZE - raw->count < length) {
486 if (drop)
487 return raw3215_drop(raw);
488
489 /* there might be a request pending */
490 raw->flags |= RAW3215_FLUSHING;
491 raw3215_mk_write_req(raw);
492 raw3215_try_io(raw);
493 raw->flags &= ~RAW3215_FLUSHING;
494#ifdef CONFIG_TN3215_CONSOLE
495 ccw_device_wait_idle(raw->cdev);
496#endif
497 /* Enough room freed up ? */
498 if (RAW3215_BUFFER_SIZE - raw->count >= length)
499 break;
500 /* there might be another cpu waiting for the lock */
501 spin_unlock(lock: get_ccwdev_lock(raw->cdev));
502 udelay(usec: 100);
503 spin_lock(lock: get_ccwdev_lock(raw->cdev));
504 }
505 return length;
506}
507
508#define RAW3215_COUNT 1
509#define RAW3215_STORE 2
510
511/*
512 * Add text to console buffer. Find tabs in input and calculate size
513 * including tab replacement.
514 * This function operates in 2 different modes, depending on parameter
515 * opmode:
516 * RAW3215_COUNT: Get the size needed for the input string with
517 * proper tab replacement calculation.
518 * Return value is the number of bytes required to store the
519 * input. However no data is actually stored.
520 * The parameter todrop is not used.
521 * RAW3215_STORE: Add data to the console buffer. The parameter todrop is
522 * valid and contains the number of bytes to be dropped from head of
523 * string without blocking.
524 * Return value is the number of bytes copied.
525 */
526static unsigned int raw3215_addtext(const u8 *str, size_t length,
527 struct raw3215_info *raw, int opmode,
528 unsigned int todrop)
529{
530 unsigned int i, blanks, expanded_size = 0;
531 unsigned int column = raw->line_pos;
532 size_t c;
533 u8 ch;
534
535 if (opmode == RAW3215_COUNT)
536 todrop = 0;
537
538 for (c = 0; c < length; ++c) {
539 blanks = 1;
540 ch = str[c];
541
542 switch (ch) {
543 case '\n':
544 expanded_size++;
545 column = 0;
546 break;
547 case '\t':
548 blanks = TAB_STOP_SIZE - (column % TAB_STOP_SIZE);
549 column += blanks;
550 expanded_size += blanks;
551 ch = ' ';
552 break;
553 default:
554 expanded_size++;
555 column++;
556 break;
557 }
558
559 if (opmode == RAW3215_COUNT)
560 continue;
561 if (todrop && expanded_size < todrop) /* Drop head data */
562 continue;
563 for (i = 0; i < blanks; i++) {
564 raw->buffer[raw->head] = _ascebc[ch];
565 raw->head = (raw->head + 1) & (RAW3215_BUFFER_SIZE - 1);
566 raw->count++;
567 }
568 raw->line_pos = column;
569 }
570 return expanded_size - todrop;
571}
572
573/*
574 * String write routine for 3215 devices
575 */
576static void raw3215_write(struct raw3215_info *raw, const u8 *str,
577 size_t length)
578{
579 unsigned int count, avail;
580 unsigned long flags;
581
582 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
583
584 count = raw3215_addtext(str, length, raw, RAW3215_COUNT, todrop: 0);
585
586 avail = raw3215_make_room(raw, length: count, drop: con3215_drop);
587 if (avail) {
588 raw3215_addtext(str, length, raw, RAW3215_STORE,
589 todrop: count - avail);
590 }
591 if (!(raw->flags & RAW3215_WORKING)) {
592 raw3215_mk_write_req(raw);
593 /* start or queue request */
594 raw3215_try_io(raw);
595 }
596 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
597}
598
599/*
600 * Put character routine for 3215 devices
601 */
602static void raw3215_putchar(struct raw3215_info *raw, u8 ch)
603{
604 raw3215_write(raw, str: &ch, length: 1);
605}
606
607/*
608 * Flush routine, it simply sets the flush flag and tries to start
609 * pending IO.
610 */
611static void raw3215_flush_buffer(struct raw3215_info *raw)
612{
613 unsigned long flags;
614
615 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
616 if (raw->count > 0) {
617 raw->flags |= RAW3215_FLUSHING;
618 raw3215_try_io(raw);
619 raw->flags &= ~RAW3215_FLUSHING;
620 }
621 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
622}
623
624/*
625 * Fire up a 3215 device.
626 */
627static int raw3215_startup(struct raw3215_info *raw)
628{
629 unsigned long flags;
630
631 if (tty_port_initialized(port: &raw->port))
632 return 0;
633 raw->line_pos = 0;
634 tty_port_set_initialized(port: &raw->port, val: true);
635 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
636 raw3215_try_io(raw);
637 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
638
639 return 0;
640}
641
642/*
643 * Shutdown a 3215 device.
644 */
645static void raw3215_shutdown(struct raw3215_info *raw)
646{
647 DECLARE_WAITQUEUE(wait, current);
648 unsigned long flags;
649
650 if (!tty_port_initialized(port: &raw->port) || (raw->flags & RAW3215_FIXED))
651 return;
652 /* Wait for outstanding requests, then free irq */
653 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
654 if ((raw->flags & RAW3215_WORKING) ||
655 raw->queued_write != NULL ||
656 raw->queued_read != NULL) {
657 add_wait_queue(wq_head: &raw->empty_wait, wq_entry: &wait);
658 set_current_state(TASK_INTERRUPTIBLE);
659 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
660 schedule();
661 spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);
662 remove_wait_queue(wq_head: &raw->empty_wait, wq_entry: &wait);
663 set_current_state(TASK_RUNNING);
664 tty_port_set_initialized(port: &raw->port, val: true);
665 }
666 spin_unlock_irqrestore(lock: get_ccwdev_lock(raw->cdev), flags);
667}
668
669static struct raw3215_info *raw3215_alloc_info(void)
670{
671 struct raw3215_info *info;
672
673 info = kzalloc(sizeof(struct raw3215_info), GFP_KERNEL | GFP_DMA);
674 if (!info)
675 return NULL;
676
677 info->buffer = kzalloc(RAW3215_BUFFER_SIZE, GFP_KERNEL | GFP_DMA);
678 info->inbuf = kzalloc(RAW3215_INBUF_SIZE, GFP_KERNEL | GFP_DMA);
679 if (!info->buffer || !info->inbuf) {
680 kfree(objp: info->inbuf);
681 kfree(objp: info->buffer);
682 kfree(objp: info);
683 return NULL;
684 }
685
686 timer_setup(&info->timer, raw3215_timeout, 0);
687 init_waitqueue_head(&info->empty_wait);
688 tty_port_init(port: &info->port);
689
690 return info;
691}
692
693static void raw3215_free_info(struct raw3215_info *raw)
694{
695 kfree(objp: raw->inbuf);
696 kfree(objp: raw->buffer);
697 tty_port_destroy(port: &raw->port);
698 kfree(objp: raw);
699}
700
701static int raw3215_probe(struct ccw_device *cdev)
702{
703 struct raw3215_info *raw;
704 int line;
705
706 /* Console is special. */
707 if (raw3215[0] && (raw3215[0] == dev_get_drvdata(dev: &cdev->dev)))
708 return 0;
709
710 raw = raw3215_alloc_info();
711 if (raw == NULL)
712 return -ENOMEM;
713
714 raw->cdev = cdev;
715 dev_set_drvdata(dev: &cdev->dev, data: raw);
716 cdev->handler = raw3215_irq;
717
718 spin_lock(lock: &raw3215_device_lock);
719 for (line = 0; line < NR_3215; line++) {
720 if (!raw3215[line]) {
721 raw3215[line] = raw;
722 break;
723 }
724 }
725 spin_unlock(lock: &raw3215_device_lock);
726 if (line == NR_3215) {
727 raw3215_free_info(raw);
728 return -ENODEV;
729 }
730
731 return 0;
732}
733
734static void raw3215_remove(struct ccw_device *cdev)
735{
736 struct raw3215_info *raw;
737 unsigned int line;
738
739 ccw_device_set_offline(cdev);
740 raw = dev_get_drvdata(dev: &cdev->dev);
741 if (raw) {
742 spin_lock(lock: &raw3215_device_lock);
743 for (line = 0; line < NR_3215; line++)
744 if (raw3215[line] == raw)
745 break;
746 raw3215[line] = NULL;
747 spin_unlock(lock: &raw3215_device_lock);
748 dev_set_drvdata(dev: &cdev->dev, NULL);
749 raw3215_free_info(raw);
750 }
751}
752
753static int raw3215_set_online(struct ccw_device *cdev)
754{
755 struct raw3215_info *raw;
756
757 raw = dev_get_drvdata(dev: &cdev->dev);
758 if (!raw)
759 return -ENODEV;
760
761 return raw3215_startup(raw);
762}
763
764static int raw3215_set_offline(struct ccw_device *cdev)
765{
766 struct raw3215_info *raw;
767
768 raw = dev_get_drvdata(dev: &cdev->dev);
769 if (!raw)
770 return -ENODEV;
771
772 raw3215_shutdown(raw);
773
774 return 0;
775}
776
777static struct ccw_device_id raw3215_id[] = {
778 { CCW_DEVICE(0x3215, 0) },
779 { /* end of list */ },
780};
781
782static ssize_t con_drop_store(struct device_driver *dev, const char *buf, size_t count)
783{
784 bool drop;
785 int rc;
786
787 rc = kstrtobool(s: buf, res: &drop);
788 if (!rc)
789 con3215_drop = drop;
790 return rc ?: count;
791}
792
793static ssize_t con_drop_show(struct device_driver *dev, char *buf)
794{
795 return sysfs_emit(buf, fmt: "%d\n", con3215_drop ? 1 : 0);
796}
797
798static DRIVER_ATTR_RW(con_drop);
799
800static struct attribute *con3215_drv_attrs[] = {
801 &driver_attr_con_drop.attr,
802 NULL,
803};
804
805static struct attribute_group con3215_drv_attr_group = {
806 .attrs = con3215_drv_attrs,
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