xref: /openbmc/linux/drivers/s390/char/fs3270.c (revision 0c6dfa75) 
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 
48 static void 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 {
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 
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  */
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 
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 
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  */
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 
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 
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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  */
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 
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 
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  */
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 
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