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