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/sched/signal.h>
16 #include <linux/module.h>
17 #include <linux/list.h>
18 #include <linux/slab.h>
19 #include <linux/types.h>
20
21 #include <uapi/asm/fs3270.h>
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
fs3270_wake_up(struct raw3270_request * rq,void * data)47 static void fs3270_wake_up(struct raw3270_request *rq, void *data)
48 {
49 wake_up((wait_queue_head_t *)data);
50 }
51
fs3270_working(struct fs3270 * fp)52 static inline int fs3270_working(struct fs3270 *fp)
53 {
54 /*
55 * The fullscreen view is in working order if the view
56 * has been activated AND the initial request is finished.
57 */
58 return fp->active && raw3270_request_final(fp->init);
59 }
60
fs3270_do_io(struct raw3270_view * view,struct raw3270_request * rq)61 static int fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
62 {
63 struct fs3270 *fp;
64 int rc;
65
66 fp = (struct fs3270 *)view;
67 rq->callback = fs3270_wake_up;
68 rq->callback_data = &fp->wait;
69
70 do {
71 if (!fs3270_working(fp)) {
72 /* Fullscreen view isn't ready yet. */
73 rc = wait_event_interruptible(fp->wait,
74 fs3270_working(fp));
75 if (rc != 0)
76 break;
77 }
78 rc = raw3270_start(view, rq);
79 if (rc == 0) {
80 /* Started successfully. Now wait for completion. */
81 wait_event(fp->wait, raw3270_request_final(rq));
82 }
83 } while (rc == -EACCES);
84 return rc;
85 }
86
87 /*
88 * Switch to the fullscreen view.
89 */
fs3270_reset_callback(struct raw3270_request * rq,void * data)90 static void fs3270_reset_callback(struct raw3270_request *rq, void *data)
91 {
92 struct fs3270 *fp;
93
94 fp = (struct fs3270 *)rq->view;
95 raw3270_request_reset(rq);
96 wake_up(&fp->wait);
97 }
98
fs3270_restore_callback(struct raw3270_request * rq,void * data)99 static void fs3270_restore_callback(struct raw3270_request *rq, void *data)
100 {
101 struct fs3270 *fp;
102
103 fp = (struct fs3270 *)rq->view;
104 if (rq->rc != 0 || rq->rescnt != 0) {
105 if (fp->fs_pid)
106 kill_pid(fp->fs_pid, SIGHUP, 1);
107 }
108 fp->rdbuf_size = 0;
109 raw3270_request_reset(rq);
110 wake_up(&fp->wait);
111 }
112
fs3270_activate(struct raw3270_view * view)113 static int fs3270_activate(struct raw3270_view *view)
114 {
115 struct fs3270 *fp;
116 char *cp;
117 int rc;
118
119 fp = (struct fs3270 *)view;
120
121 /* If an old init command is still running just return. */
122 if (!raw3270_request_final(fp->init))
123 return 0;
124
125 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
126 raw3270_request_set_idal(fp->init, fp->rdbuf);
127 fp->init->rescnt = 0;
128 cp = dma64_to_virt(fp->rdbuf->data[0]);
129 if (fp->rdbuf_size == 0) {
130 /* No saved buffer. Just clear the screen. */
131 fp->init->ccw.count = 1;
132 fp->init->callback = fs3270_reset_callback;
133 cp[0] = 0;
134 } else {
135 /* Restore fullscreen buffer saved by fs3270_deactivate. */
136 fp->init->ccw.count = fp->rdbuf_size;
137 fp->init->callback = fs3270_restore_callback;
138 cp[0] = TW_KR;
139 cp[1] = TO_SBA;
140 cp[2] = cp[6];
141 cp[3] = cp[7];
142 cp[4] = TO_IC;
143 cp[5] = TO_SBA;
144 cp[6] = 0x40;
145 cp[7] = 0x40;
146 }
147 rc = raw3270_start_locked(view, fp->init);
148 fp->init->rc = rc;
149 if (rc)
150 fp->init->callback(fp->init, NULL);
151 else
152 fp->active = 1;
153 return rc;
154 }
155
156 /*
157 * Shutdown fullscreen view.
158 */
fs3270_save_callback(struct raw3270_request * rq,void * data)159 static void fs3270_save_callback(struct raw3270_request *rq, void *data)
160 {
161 struct fs3270 *fp;
162
163 fp = (struct fs3270 *)rq->view;
164
165 /* Correct idal buffer element 0 address. */
166 fp->rdbuf->data[0] = dma64_add(fp->rdbuf->data[0], -5);
167 fp->rdbuf->size += 5;
168
169 /*
170 * If the rdbuf command failed or the idal buffer is
171 * to small for the amount of data returned by the
172 * rdbuf command, then we have no choice but to send
173 * a SIGHUP to the application.
174 */
175 if (rq->rc != 0 || rq->rescnt == 0) {
176 if (fp->fs_pid)
177 kill_pid(fp->fs_pid, SIGHUP, 1);
178 fp->rdbuf_size = 0;
179 } else {
180 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
181 }
182 raw3270_request_reset(rq);
183 wake_up(&fp->wait);
184 }
185
fs3270_deactivate(struct raw3270_view * view)186 static void fs3270_deactivate(struct raw3270_view *view)
187 {
188 struct fs3270 *fp;
189
190 fp = (struct fs3270 *)view;
191 fp->active = 0;
192
193 /* If an old init command is still running just return. */
194 if (!raw3270_request_final(fp->init))
195 return;
196
197 /* Prepare read-buffer request. */
198 raw3270_request_set_cmd(fp->init, TC_RDBUF);
199 /*
200 * Hackish: skip first 5 bytes of the idal buffer to make
201 * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
202 * in the activation command.
203 */
204 fp->rdbuf->data[0] = dma64_add(fp->rdbuf->data[0], 5);
205 fp->rdbuf->size -= 5;
206 raw3270_request_set_idal(fp->init, fp->rdbuf);
207 fp->init->rescnt = 0;
208 fp->init->callback = fs3270_save_callback;
209
210 /* Start I/O to read in the 3270 buffer. */
211 fp->init->rc = raw3270_start_locked(view, fp->init);
212 if (fp->init->rc)
213 fp->init->callback(fp->init, NULL);
214 }
215
fs3270_irq(struct fs3270 * fp,struct raw3270_request * rq,struct irb * irb)216 static void fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq,
217 struct irb *irb)
218 {
219 /* Handle ATTN. Set indication and wake waiters for attention. */
220 if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
221 fp->attention = 1;
222 wake_up(&fp->wait);
223 }
224
225 if (rq) {
226 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
227 rq->rc = -EIO;
228 else
229 /* Normal end. Copy residual count. */
230 rq->rescnt = irb->scsw.cmd.count;
231 }
232 }
233
234 /*
235 * Process reads from fullscreen 3270.
236 */
fs3270_read(struct file * filp,char __user * data,size_t count,loff_t * off)237 static ssize_t fs3270_read(struct file *filp, char __user *data,
238 size_t count, loff_t *off)
239 {
240 struct fs3270 *fp;
241 struct raw3270_request *rq;
242 struct idal_buffer *ib;
243 ssize_t rc;
244
245 if (count == 0 || count > 65535)
246 return -EINVAL;
247 fp = filp->private_data;
248 if (!fp)
249 return -ENODEV;
250 ib = idal_buffer_alloc(count, 0);
251 if (IS_ERR(ib))
252 return -ENOMEM;
253 rq = raw3270_request_alloc(0);
254 if (!IS_ERR(rq)) {
255 if (fp->read_command == 0 && fp->write_command != 0)
256 fp->read_command = 6;
257 raw3270_request_set_cmd(rq, fp->read_command ? : 2);
258 raw3270_request_set_idal(rq, ib);
259 rc = wait_event_interruptible(fp->wait, fp->attention);
260 fp->attention = 0;
261 if (rc == 0) {
262 rc = fs3270_do_io(&fp->view, rq);
263 if (rc == 0) {
264 count -= rq->rescnt;
265 if (idal_buffer_to_user(ib, data, count) != 0)
266 rc = -EFAULT;
267 else
268 rc = count;
269 }
270 }
271 raw3270_request_free(rq);
272 } else {
273 rc = PTR_ERR(rq);
274 }
275 idal_buffer_free(ib);
276 return rc;
277 }
278
279 /*
280 * Process writes to fullscreen 3270.
281 */
fs3270_write(struct file * filp,const char __user * data,size_t count,loff_t * off)282 static ssize_t fs3270_write(struct file *filp, const char __user *data,
283 size_t count, loff_t *off)
284 {
285 struct fs3270 *fp;
286 struct raw3270_request *rq;
287 struct idal_buffer *ib;
288 int write_command;
289 ssize_t rc;
290
291 fp = filp->private_data;
292 if (!fp)
293 return -ENODEV;
294 ib = idal_buffer_alloc(count, 0);
295 if (IS_ERR(ib))
296 return -ENOMEM;
297 rq = raw3270_request_alloc(0);
298 if (!IS_ERR(rq)) {
299 if (idal_buffer_from_user(ib, data, count) == 0) {
300 write_command = fp->write_command ? : 1;
301 if (write_command == 5)
302 write_command = 13;
303 raw3270_request_set_cmd(rq, write_command);
304 raw3270_request_set_idal(rq, ib);
305 rc = fs3270_do_io(&fp->view, rq);
306 if (rc == 0)
307 rc = count - rq->rescnt;
308 } else {
309 rc = -EFAULT;
310 }
311 raw3270_request_free(rq);
312 } else {
313 rc = PTR_ERR(rq);
314 }
315 idal_buffer_free(ib);
316 return rc;
317 }
318
319 /*
320 * process ioctl commands for the tube driver
321 */
fs3270_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)322 static long fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
323 {
324 char __user *argp;
325 struct fs3270 *fp;
326 struct raw3270_iocb iocb;
327 int rc;
328
329 fp = filp->private_data;
330 if (!fp)
331 return -ENODEV;
332 argp = (char __user *)arg;
333 rc = 0;
334 mutex_lock(&fs3270_mutex);
335 switch (cmd) {
336 case TUBICMD:
337 fp->read_command = arg;
338 break;
339 case TUBOCMD:
340 fp->write_command = arg;
341 break;
342 case TUBGETI:
343 rc = put_user(fp->read_command, argp);
344 break;
345 case TUBGETO:
346 rc = put_user(fp->write_command, argp);
347 break;
348 case TUBGETMOD:
349 iocb.model = fp->view.model;
350 iocb.line_cnt = fp->view.rows;
351 iocb.col_cnt = fp->view.cols;
352 iocb.pf_cnt = 24;
353 iocb.re_cnt = 20;
354 iocb.map = 0;
355 if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
356 rc = -EFAULT;
357 break;
358 }
359 mutex_unlock(&fs3270_mutex);
360 return rc;
361 }
362
363 /*
364 * Allocate fs3270 structure.
365 */
fs3270_alloc_view(void)366 static struct fs3270 *fs3270_alloc_view(void)
367 {
368 struct fs3270 *fp;
369
370 fp = kzalloc_obj(*fp);
371 if (!fp)
372 return ERR_PTR(-ENOMEM);
373 fp->init = raw3270_request_alloc(0);
374 if (IS_ERR(fp->init)) {
375 kfree(fp);
376 return ERR_PTR(-ENOMEM);
377 }
378 return fp;
379 }
380
381 /*
382 * Free fs3270 structure.
383 */
fs3270_free_view(struct raw3270_view * view)384 static void fs3270_free_view(struct raw3270_view *view)
385 {
386 struct fs3270 *fp;
387
388 fp = (struct fs3270 *)view;
389 if (fp->rdbuf)
390 idal_buffer_free(fp->rdbuf);
391 raw3270_request_free(((struct fs3270 *)view)->init);
392 kfree(view);
393 }
394
395 /*
396 * Unlink fs3270 data structure from filp.
397 */
fs3270_release(struct raw3270_view * view)398 static void fs3270_release(struct raw3270_view *view)
399 {
400 struct fs3270 *fp;
401
402 fp = (struct fs3270 *)view;
403 if (fp->fs_pid)
404 kill_pid(fp->fs_pid, SIGHUP, 1);
405 }
406
407 /* View to a 3270 device. Can be console, tty or fullscreen. */
408 static struct raw3270_fn fs3270_fn = {
409 .activate = fs3270_activate,
410 .deactivate = fs3270_deactivate,
411 .intv = (void *)fs3270_irq,
412 .release = fs3270_release,
413 .free = fs3270_free_view
414 };
415
416 /*
417 * This routine is called whenever a 3270 fullscreen device is opened.
418 */
fs3270_open(struct inode * inode,struct file * filp)419 static int fs3270_open(struct inode *inode, struct file *filp)
420 {
421 struct fs3270 *fp;
422 struct idal_buffer *ib;
423 int minor, rc = 0;
424
425 if (imajor(file_inode(filp)) != IBM_FS3270_MAJOR)
426 return -ENODEV;
427 minor = iminor(file_inode(filp));
428 /* Check for minor 0 multiplexer. */
429 if (minor == 0) {
430 struct tty_struct *tty = get_current_tty();
431
432 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
433 tty_kref_put(tty);
434 return -ENODEV;
435 }
436 minor = tty->index;
437 tty_kref_put(tty);
438 }
439 mutex_lock(&fs3270_mutex);
440 /* Check if some other program is already using fullscreen mode. */
441 fp = (struct fs3270 *)raw3270_find_view(&fs3270_fn, minor);
442 if (!IS_ERR(fp)) {
443 raw3270_put_view(&fp->view);
444 rc = -EBUSY;
445 goto out;
446 }
447 /* Allocate fullscreen view structure. */
448 fp = fs3270_alloc_view();
449 if (IS_ERR(fp)) {
450 rc = PTR_ERR(fp);
451 goto out;
452 }
453
454 init_waitqueue_head(&fp->wait);
455 fp->fs_pid = get_pid(task_pid(current));
456 rc = raw3270_add_view(&fp->view, &fs3270_fn, minor,
457 RAW3270_VIEW_LOCK_BH);
458 if (rc) {
459 fs3270_free_view(&fp->view);
460 goto out;
461 }
462
463 /* Allocate idal-buffer. */
464 ib = idal_buffer_alloc(2 * fp->view.rows * fp->view.cols + 5, 0);
465 if (IS_ERR(ib)) {
466 raw3270_put_view(&fp->view);
467 raw3270_del_view(&fp->view);
468 rc = PTR_ERR(ib);
469 goto out;
470 }
471 fp->rdbuf = ib;
472
473 rc = raw3270_activate_view(&fp->view);
474 if (rc) {
475 raw3270_put_view(&fp->view);
476 raw3270_del_view(&fp->view);
477 goto out;
478 }
479 stream_open(inode, filp);
480 filp->private_data = fp;
481 out:
482 mutex_unlock(&fs3270_mutex);
483 return rc;
484 }
485
486 /*
487 * This routine is called when the 3270 tty is closed. We wait
488 * for the remaining request to be completed. Then we clean up.
489 */
fs3270_close(struct inode * inode,struct file * filp)490 static int fs3270_close(struct inode *inode, struct file *filp)
491 {
492 struct fs3270 *fp;
493
494 fp = filp->private_data;
495 filp->private_data = NULL;
496 if (fp) {
497 put_pid(fp->fs_pid);
498 fp->fs_pid = NULL;
499 raw3270_reset(&fp->view);
500 raw3270_put_view(&fp->view);
501 raw3270_del_view(&fp->view);
502 }
503 return 0;
504 }
505
506 static const struct file_operations fs3270_fops = {
507 .owner = THIS_MODULE, /* owner */
508 .read = fs3270_read, /* read */
509 .write = fs3270_write, /* write */
510 .unlocked_ioctl = fs3270_ioctl, /* ioctl */
511 .open = fs3270_open, /* open */
512 .release = fs3270_close, /* release */
513 };
514
fs3270_create_cb(int minor)515 static void fs3270_create_cb(int minor)
516 {
517 __register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops);
518 device_create(&class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
519 NULL, "3270/tub%d", minor);
520 }
521
fs3270_destroy_cb(int minor)522 static void fs3270_destroy_cb(int minor)
523 {
524 device_destroy(&class3270, MKDEV(IBM_FS3270_MAJOR, minor));
525 __unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub");
526 }
527
528 static struct raw3270_notifier fs3270_notifier = {
529 .create = fs3270_create_cb,
530 .destroy = fs3270_destroy_cb,
531 };
532
533 /*
534 * 3270 fullscreen driver initialization.
535 */
fs3270_init(void)536 static int __init fs3270_init(void)
537 {
538 int rc;
539
540 rc = __register_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270", &fs3270_fops);
541 if (rc)
542 return rc;
543 device_create(&class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0),
544 NULL, "3270/tub");
545 raw3270_register_notifier(&fs3270_notifier);
546 return 0;
547 }
548
fs3270_exit(void)549 static void __exit fs3270_exit(void)
550 {
551 raw3270_unregister_notifier(&fs3270_notifier);
552 device_destroy(&class3270, MKDEV(IBM_FS3270_MAJOR, 0));
553 __unregister_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270");
554 }
555
556 MODULE_DESCRIPTION("IBM/3270 Driver - fullscreen driver");
557 MODULE_LICENSE("GPL");
558 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
559
560 module_init(fs3270_init);
561 module_exit(fs3270_exit);
562