1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * IBM/3270 Driver - fullscreen driver.
4 *
5 * Author(s):
6 * Original 3270 Code for 2.4 written by Richard Hitt (UTS Global)
7 * Rewritten for 2.5/2.6 by Martin Schwidefsky <schwidefsky@de.ibm.com>
8 * Copyright IBM Corp. 2003, 2009
9 */
10
11 #include <linux/memblock.h>
12 #include <linux/console.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/compat.h>
16 #include <linux/sched/signal.h>
17 #include <linux/module.h>
18 #include <linux/list.h>
19 #include <linux/slab.h>
20 #include <linux/types.h>
21
22 #include <asm/ccwdev.h>
23 #include <asm/cio.h>
24 #include <asm/ebcdic.h>
25 #include <asm/idals.h>
26
27 #include "raw3270.h"
28 #include "ctrlchar.h"
29
30 static struct raw3270_fn fs3270_fn;
31
32 struct fs3270 {
33 struct raw3270_view view;
34 struct pid *fs_pid; /* Pid of controlling program. */
35 int read_command; /* ccw command to use for reads. */
36 int write_command; /* ccw command to use for writes. */
37 int attention; /* Got attention. */
38 int active; /* Fullscreen view is active. */
39 struct raw3270_request *init; /* single init request. */
40 wait_queue_head_t wait; /* Init & attention wait queue. */
41 struct idal_buffer *rdbuf; /* full-screen-deactivate buffer */
42 size_t rdbuf_size; /* size of data returned by RDBUF */
43 };
44
45 static DEFINE_MUTEX(fs3270_mutex);
46
47 static void
fs3270_wake_up(struct raw3270_request * rq,void * data)48 fs3270_wake_up(struct raw3270_request *rq, void *data)
49 {
50 wake_up((wait_queue_head_t *) data);
51 }
52
53 static inline int
fs3270_working(struct fs3270 * fp)54 fs3270_working(struct fs3270 *fp)
55 {
56 /*
57 * The fullscreen view is in working order if the view
58 * has been activated AND the initial request is finished.
59 */
60 return fp->active && raw3270_request_final(fp->init);
61 }
62
63 static int
fs3270_do_io(struct raw3270_view * view,struct raw3270_request * rq)64 fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
65 {
66 struct fs3270 *fp;
67 int rc;
68
69 fp = (struct fs3270 *) view;
70 rq->callback = fs3270_wake_up;
71 rq->callback_data = &fp->wait;
72
73 do {
74 if (!fs3270_working(fp)) {
75 /* Fullscreen view isn't ready yet. */
76 rc = wait_event_interruptible(fp->wait,
77 fs3270_working(fp));
78 if (rc != 0)
79 break;
80 }
81 rc = raw3270_start(view, rq);
82 if (rc == 0) {
83 /* Started successfully. Now wait for completion. */
84 wait_event(fp->wait, raw3270_request_final(rq));
85 }
86 } while (rc == -EACCES);
87 return rc;
88 }
89
90 /*
91 * Switch to the fullscreen view.
92 */
93 static void
fs3270_reset_callback(struct raw3270_request * rq,void * data)94 fs3270_reset_callback(struct raw3270_request *rq, void *data)
95 {
96 struct fs3270 *fp;
97
98 fp = (struct fs3270 *) rq->view;
99 raw3270_request_reset(rq);
100 wake_up(&fp->wait);
101 }
102
103 static void
fs3270_restore_callback(struct raw3270_request * rq,void * data)104 fs3270_restore_callback(struct raw3270_request *rq, void *data)
105 {
106 struct fs3270 *fp;
107
108 fp = (struct fs3270 *) rq->view;
109 if (rq->rc != 0 || rq->rescnt != 0) {
110 if (fp->fs_pid)
111 kill_pid(fp->fs_pid, SIGHUP, 1);
112 }
113 fp->rdbuf_size = 0;
114 raw3270_request_reset(rq);
115 wake_up(&fp->wait);
116 }
117
118 static int
fs3270_activate(struct raw3270_view * view)119 fs3270_activate(struct raw3270_view *view)
120 {
121 struct fs3270 *fp;
122 char *cp;
123 int rc;
124
125 fp = (struct fs3270 *) view;
126
127 /* If an old init command is still running just return. */
128 if (!raw3270_request_final(fp->init))
129 return 0;
130
131 if (fp->rdbuf_size == 0) {
132 /* No saved buffer. Just clear the screen. */
133 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
134 fp->init->callback = fs3270_reset_callback;
135 } else {
136 /* Restore fullscreen buffer saved by fs3270_deactivate. */
137 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
138 raw3270_request_set_idal(fp->init, fp->rdbuf);
139 fp->init->ccw.count = fp->rdbuf_size;
140 cp = fp->rdbuf->data[0];
141 cp[0] = TW_KR;
142 cp[1] = TO_SBA;
143 cp[2] = cp[6];
144 cp[3] = cp[7];
145 cp[4] = TO_IC;
146 cp[5] = TO_SBA;
147 cp[6] = 0x40;
148 cp[7] = 0x40;
149 fp->init->rescnt = 0;
150 fp->init->callback = fs3270_restore_callback;
151 }
152 rc = fp->init->rc = raw3270_start_locked(view, fp->init);
153 if (rc)
154 fp->init->callback(fp->init, NULL);
155 else
156 fp->active = 1;
157 return rc;
158 }
159
160 /*
161 * Shutdown fullscreen view.
162 */
163 static void
fs3270_save_callback(struct raw3270_request * rq,void * data)164 fs3270_save_callback(struct raw3270_request *rq, void *data)
165 {
166 struct fs3270 *fp;
167
168 fp = (struct fs3270 *) rq->view;
169
170 /* Correct idal buffer element 0 address. */
171 fp->rdbuf->data[0] -= 5;
172 fp->rdbuf->size += 5;
173
174 /*
175 * If the rdbuf command failed or the idal buffer is
176 * to small for the amount of data returned by the
177 * rdbuf command, then we have no choice but to send
178 * a SIGHUP to the application.
179 */
180 if (rq->rc != 0 || rq->rescnt == 0) {
181 if (fp->fs_pid)
182 kill_pid(fp->fs_pid, SIGHUP, 1);
183 fp->rdbuf_size = 0;
184 } else
185 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
186 raw3270_request_reset(rq);
187 wake_up(&fp->wait);
188 }
189
190 static void
fs3270_deactivate(struct raw3270_view * view)191 fs3270_deactivate(struct raw3270_view *view)
192 {
193 struct fs3270 *fp;
194
195 fp = (struct fs3270 *) view;
196 fp->active = 0;
197
198 /* If an old init command is still running just return. */
199 if (!raw3270_request_final(fp->init))
200 return;
201
202 /* Prepare read-buffer request. */
203 raw3270_request_set_cmd(fp->init, TC_RDBUF);
204 /*
205 * Hackish: skip first 5 bytes of the idal buffer to make
206 * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
207 * in the activation command.
208 */
209 fp->rdbuf->data[0] += 5;
210 fp->rdbuf->size -= 5;
211 raw3270_request_set_idal(fp->init, fp->rdbuf);
212 fp->init->rescnt = 0;
213 fp->init->callback = fs3270_save_callback;
214
215 /* Start I/O to read in the 3270 buffer. */
216 fp->init->rc = raw3270_start_locked(view, fp->init);
217 if (fp->init->rc)
218 fp->init->callback(fp->init, NULL);
219 }
220
221 static void
fs3270_irq(struct fs3270 * fp,struct raw3270_request * rq,struct irb * irb)222 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
223 {
224 /* Handle ATTN. Set indication and wake waiters for attention. */
225 if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
226 fp->attention = 1;
227 wake_up(&fp->wait);
228 }
229
230 if (rq) {
231 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
232 rq->rc = -EIO;
233 else
234 /* Normal end. Copy residual count. */
235 rq->rescnt = irb->scsw.cmd.count;
236 }
237 }
238
239 /*
240 * Process reads from fullscreen 3270.
241 */
242 static ssize_t
fs3270_read(struct file * filp,char __user * data,size_t count,loff_t * off)243 fs3270_read(struct file *filp, char __user *data, size_t count, loff_t *off)
244 {
245 struct fs3270 *fp;
246 struct raw3270_request *rq;
247 struct idal_buffer *ib;
248 ssize_t rc;
249
250 if (count == 0 || count > 65535)
251 return -EINVAL;
252 fp = filp->private_data;
253 if (!fp)
254 return -ENODEV;
255 ib = idal_buffer_alloc(count, 0);
256 if (IS_ERR(ib))
257 return -ENOMEM;
258 rq = raw3270_request_alloc(0);
259 if (!IS_ERR(rq)) {
260 if (fp->read_command == 0 && fp->write_command != 0)
261 fp->read_command = 6;
262 raw3270_request_set_cmd(rq, fp->read_command ? : 2);
263 raw3270_request_set_idal(rq, ib);
264 rc = wait_event_interruptible(fp->wait, fp->attention);
265 fp->attention = 0;
266 if (rc == 0) {
267 rc = fs3270_do_io(&fp->view, rq);
268 if (rc == 0) {
269 count -= rq->rescnt;
270 if (idal_buffer_to_user(ib, data, count) != 0)
271 rc = -EFAULT;
272 else
273 rc = count;
274
275 }
276 }
277 raw3270_request_free(rq);
278 } else
279 rc = PTR_ERR(rq);
280 idal_buffer_free(ib);
281 return rc;
282 }
283
284 /*
285 * Process writes to fullscreen 3270.
286 */
287 static ssize_t
fs3270_write(struct file * filp,const char __user * data,size_t count,loff_t * off)288 fs3270_write(struct file *filp, const char __user *data, size_t count, loff_t *off)
289 {
290 struct fs3270 *fp;
291 struct raw3270_request *rq;
292 struct idal_buffer *ib;
293 int write_command;
294 ssize_t rc;
295
296 fp = filp->private_data;
297 if (!fp)
298 return -ENODEV;
299 ib = idal_buffer_alloc(count, 0);
300 if (IS_ERR(ib))
301 return -ENOMEM;
302 rq = raw3270_request_alloc(0);
303 if (!IS_ERR(rq)) {
304 if (idal_buffer_from_user(ib, data, count) == 0) {
305 write_command = fp->write_command ? : 1;
306 if (write_command == 5)
307 write_command = 13;
308 raw3270_request_set_cmd(rq, write_command);
309 raw3270_request_set_idal(rq, ib);
310 rc = fs3270_do_io(&fp->view, rq);
311 if (rc == 0)
312 rc = count - rq->rescnt;
313 } else
314 rc = -EFAULT;
315 raw3270_request_free(rq);
316 } else
317 rc = PTR_ERR(rq);
318 idal_buffer_free(ib);
319 return rc;
320 }
321
322 /*
323 * process ioctl commands for the tube driver
324 */
325 static long
fs3270_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)326 fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
327 {
328 char __user *argp;
329 struct fs3270 *fp;
330 struct raw3270_iocb iocb;
331 int rc;
332
333 fp = filp->private_data;
334 if (!fp)
335 return -ENODEV;
336 if (is_compat_task())
337 argp = compat_ptr(arg);
338 else
339 argp = (char __user *)arg;
340 rc = 0;
341 mutex_lock(&fs3270_mutex);
342 switch (cmd) {
343 case TUBICMD:
344 fp->read_command = arg;
345 break;
346 case TUBOCMD:
347 fp->write_command = arg;
348 break;
349 case TUBGETI:
350 rc = put_user(fp->read_command, argp);
351 break;
352 case TUBGETO:
353 rc = put_user(fp->write_command, argp);
354 break;
355 case TUBGETMOD:
356 iocb.model = fp->view.model;
357 iocb.line_cnt = fp->view.rows;
358 iocb.col_cnt = fp->view.cols;
359 iocb.pf_cnt = 24;
360 iocb.re_cnt = 20;
361 iocb.map = 0;
362 if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
363 rc = -EFAULT;
364 break;
365 }
366 mutex_unlock(&fs3270_mutex);
367 return rc;
368 }
369
370 /*
371 * Allocate fs3270 structure.
372 */
373 static struct fs3270 *
fs3270_alloc_view(void)374 fs3270_alloc_view(void)
375 {
376 struct fs3270 *fp;
377
378 fp = kzalloc(sizeof(struct fs3270),GFP_KERNEL);
379 if (!fp)
380 return ERR_PTR(-ENOMEM);
381 fp->init = raw3270_request_alloc(0);
382 if (IS_ERR(fp->init)) {
383 kfree(fp);
384 return ERR_PTR(-ENOMEM);
385 }
386 return fp;
387 }
388
389 /*
390 * Free fs3270 structure.
391 */
392 static void
fs3270_free_view(struct raw3270_view * view)393 fs3270_free_view(struct raw3270_view *view)
394 {
395 struct fs3270 *fp;
396
397 fp = (struct fs3270 *) view;
398 if (fp->rdbuf)
399 idal_buffer_free(fp->rdbuf);
400 raw3270_request_free(((struct fs3270 *) view)->init);
401 kfree(view);
402 }
403
404 /*
405 * Unlink fs3270 data structure from filp.
406 */
407 static void
fs3270_release(struct raw3270_view * view)408 fs3270_release(struct raw3270_view *view)
409 {
410 struct fs3270 *fp;
411
412 fp = (struct fs3270 *) view;
413 if (fp->fs_pid)
414 kill_pid(fp->fs_pid, SIGHUP, 1);
415 }
416
417 /* View to a 3270 device. Can be console, tty or fullscreen. */
418 static struct raw3270_fn fs3270_fn = {
419 .activate = fs3270_activate,
420 .deactivate = fs3270_deactivate,
421 .intv = (void *) fs3270_irq,
422 .release = fs3270_release,
423 .free = fs3270_free_view
424 };
425
426 /*
427 * This routine is called whenever a 3270 fullscreen device is opened.
428 */
429 static int
fs3270_open(struct inode * inode,struct file * filp)430 fs3270_open(struct inode *inode, struct file *filp)
431 {
432 struct fs3270 *fp;
433 struct idal_buffer *ib;
434 int minor, rc = 0;
435
436 if (imajor(file_inode(filp)) != IBM_FS3270_MAJOR)
437 return -ENODEV;
438 minor = iminor(file_inode(filp));
439 /* Check for minor 0 multiplexer. */
440 if (minor == 0) {
441 struct tty_struct *tty = get_current_tty();
442 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
443 tty_kref_put(tty);
444 return -ENODEV;
445 }
446 minor = tty->index;
447 tty_kref_put(tty);
448 }
449 mutex_lock(&fs3270_mutex);
450 /* Check if some other program is already using fullscreen mode. */
451 fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
452 if (!IS_ERR(fp)) {
453 raw3270_put_view(&fp->view);
454 rc = -EBUSY;
455 goto out;
456 }
457 /* Allocate fullscreen view structure. */
458 fp = fs3270_alloc_view();
459 if (IS_ERR(fp)) {
460 rc = PTR_ERR(fp);
461 goto out;
462 }
463
464 init_waitqueue_head(&fp->wait);
465 fp->fs_pid = get_pid(task_pid(current));
466 rc = raw3270_add_view(&fp->view, &fs3270_fn, minor,
467 RAW3270_VIEW_LOCK_BH);
468 if (rc) {
469 fs3270_free_view(&fp->view);
470 goto out;
471 }
472
473 /* Allocate idal-buffer. */
474 ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
475 if (IS_ERR(ib)) {
476 raw3270_put_view(&fp->view);
477 raw3270_del_view(&fp->view);
478 rc = PTR_ERR(ib);
479 goto out;
480 }
481 fp->rdbuf = ib;
482
483 rc = raw3270_activate_view(&fp->view);
484 if (rc) {
485 raw3270_put_view(&fp->view);
486 raw3270_del_view(&fp->view);
487 goto out;
488 }
489 stream_open(inode, filp);
490 filp->private_data = fp;
491 out:
492 mutex_unlock(&fs3270_mutex);
493 return rc;
494 }
495
496 /*
497 * This routine is called when the 3270 tty is closed. We wait
498 * for the remaining request to be completed. Then we clean up.
499 */
500 static int
fs3270_close(struct inode * inode,struct file * filp)501 fs3270_close(struct inode *inode, struct file *filp)
502 {
503 struct fs3270 *fp;
504
505 fp = filp->private_data;
506 filp->private_data = NULL;
507 if (fp) {
508 put_pid(fp->fs_pid);
509 fp->fs_pid = NULL;
510 raw3270_reset(&fp->view);
511 raw3270_put_view(&fp->view);
512 raw3270_del_view(&fp->view);
513 }
514 return 0;
515 }
516
517 static const struct file_operations fs3270_fops = {
518 .owner = THIS_MODULE, /* owner */
519 .read = fs3270_read, /* read */
520 .write = fs3270_write, /* write */
521 .unlocked_ioctl = fs3270_ioctl, /* ioctl */
522 .compat_ioctl = fs3270_ioctl, /* ioctl */
523 .open = fs3270_open, /* open */
524 .release = fs3270_close, /* release */
525 .llseek = no_llseek,
526 };
527
fs3270_create_cb(int minor)528 static void fs3270_create_cb(int minor)
529 {
530 __register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops);
531 device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
532 NULL, "3270/tub%d", minor);
533 }
534
fs3270_destroy_cb(int minor)535 static void fs3270_destroy_cb(int minor)
536 {
537 device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, minor));
538 __unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub");
539 }
540
541 static struct raw3270_notifier fs3270_notifier =
542 {
543 .create = fs3270_create_cb,
544 .destroy = fs3270_destroy_cb,
545 };
546
547 /*
548 * 3270 fullscreen driver initialization.
549 */
550 static int __init
fs3270_init(void)551 fs3270_init(void)
552 {
553 int rc;
554
555 rc = __register_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270", &fs3270_fops);
556 if (rc)
557 return rc;
558 device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0),
559 NULL, "3270/tub");
560 raw3270_register_notifier(&fs3270_notifier);
561 return 0;
562 }
563
564 static void __exit
fs3270_exit(void)565 fs3270_exit(void)
566 {
567 raw3270_unregister_notifier(&fs3270_notifier);
568 device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, 0));
569 __unregister_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270");
570 }
571
572 MODULE_LICENSE("GPL");
573 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
574
575 module_init(fs3270_init);
576 module_exit(fs3270_exit);
577