xref: /linux/drivers/s390/char/fs3270.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 /*
2  * IBM/3270 Driver - fullscreen driver.
3  *
4  * Author(s):
5  *   Original 3270 Code for 2.4 written by Richard Hitt (UTS Global)
6  *   Rewritten for 2.5/2.6 by Martin Schwidefsky <schwidefsky@de.ibm.com>
7  *     Copyright IBM Corp. 2003, 2009
8  */
9 
10 #include <linux/bootmem.h>
11 #include <linux/console.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/compat.h>
15 #include <linux/module.h>
16 #include <linux/list.h>
17 #include <linux/slab.h>
18 #include <linux/types.h>
19 
20 #include <asm/compat.h>
21 #include <asm/ccwdev.h>
22 #include <asm/cio.h>
23 #include <asm/ebcdic.h>
24 #include <asm/idals.h>
25 
26 #include "raw3270.h"
27 #include "ctrlchar.h"
28 
29 static struct raw3270_fn fs3270_fn;
30 
31 struct fs3270 {
32 	struct raw3270_view view;
33 	struct pid *fs_pid;		/* Pid of controlling program. */
34 	int read_command;		/* ccw command to use for reads. */
35 	int write_command;		/* ccw command to use for writes. */
36 	int attention;			/* Got attention. */
37 	int active;			/* Fullscreen view is active. */
38 	struct raw3270_request *init;	/* single init request. */
39 	wait_queue_head_t wait;		/* Init & attention wait queue. */
40 	struct idal_buffer *rdbuf;	/* full-screen-deactivate buffer */
41 	size_t rdbuf_size;		/* size of data returned by RDBUF */
42 };
43 
44 static DEFINE_MUTEX(fs3270_mutex);
45 
46 static void
47 fs3270_wake_up(struct raw3270_request *rq, void *data)
48 {
49 	wake_up((wait_queue_head_t *) data);
50 }
51 
52 static inline int
53 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
63 fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
64 {
65 	struct fs3270 *fp;
66 	int rc;
67 
68 	fp = (struct fs3270 *) view;
69 	rq->callback = fs3270_wake_up;
70 	rq->callback_data = &fp->wait;
71 
72 	do {
73 		if (!fs3270_working(fp)) {
74 			/* Fullscreen view isn't ready yet. */
75 			rc = wait_event_interruptible(fp->wait,
76 						      fs3270_working(fp));
77 			if (rc != 0)
78 				break;
79 		}
80 		rc = raw3270_start(view, rq);
81 		if (rc == 0) {
82 			/* Started successfully. Now wait for completion. */
83 			wait_event(fp->wait, raw3270_request_final(rq));
84 		}
85 	} while (rc == -EACCES);
86 	return rc;
87 }
88 
89 /*
90  * Switch to the fullscreen view.
91  */
92 static void
93 fs3270_reset_callback(struct raw3270_request *rq, void *data)
94 {
95 	struct fs3270 *fp;
96 
97 	fp = (struct fs3270 *) rq->view;
98 	raw3270_request_reset(rq);
99 	wake_up(&fp->wait);
100 }
101 
102 static void
103 fs3270_restore_callback(struct raw3270_request *rq, void *data)
104 {
105 	struct fs3270 *fp;
106 
107 	fp = (struct fs3270 *) rq->view;
108 	if (rq->rc != 0 || rq->rescnt != 0) {
109 		if (fp->fs_pid)
110 			kill_pid(fp->fs_pid, SIGHUP, 1);
111 	}
112 	fp->rdbuf_size = 0;
113 	raw3270_request_reset(rq);
114 	wake_up(&fp->wait);
115 }
116 
117 static int
118 fs3270_activate(struct raw3270_view *view)
119 {
120 	struct fs3270 *fp;
121 	char *cp;
122 	int rc;
123 
124 	fp = (struct fs3270 *) view;
125 
126 	/* If an old init command is still running just return. */
127 	if (!raw3270_request_final(fp->init))
128 		return 0;
129 
130 	if (fp->rdbuf_size == 0) {
131 		/* No saved buffer. Just clear the screen. */
132 		raw3270_request_set_cmd(fp->init, TC_EWRITEA);
133 		fp->init->callback = fs3270_reset_callback;
134 	} else {
135 		/* Restore fullscreen buffer saved by fs3270_deactivate. */
136 		raw3270_request_set_cmd(fp->init, TC_EWRITEA);
137 		raw3270_request_set_idal(fp->init, fp->rdbuf);
138 		fp->init->ccw.count = fp->rdbuf_size;
139 		cp = fp->rdbuf->data[0];
140 		cp[0] = TW_KR;
141 		cp[1] = TO_SBA;
142 		cp[2] = cp[6];
143 		cp[3] = cp[7];
144 		cp[4] = TO_IC;
145 		cp[5] = TO_SBA;
146 		cp[6] = 0x40;
147 		cp[7] = 0x40;
148 		fp->init->rescnt = 0;
149 		fp->init->callback = fs3270_restore_callback;
150 	}
151 	rc = fp->init->rc = raw3270_start_locked(view, fp->init);
152 	if (rc)
153 		fp->init->callback(fp->init, NULL);
154 	else
155 		fp->active = 1;
156 	return rc;
157 }
158 
159 /*
160  * Shutdown fullscreen view.
161  */
162 static void
163 fs3270_save_callback(struct raw3270_request *rq, void *data)
164 {
165 	struct fs3270 *fp;
166 
167 	fp = (struct fs3270 *) rq->view;
168 
169 	/* Correct idal buffer element 0 address. */
170 	fp->rdbuf->data[0] -= 5;
171 	fp->rdbuf->size += 5;
172 
173 	/*
174 	 * If the rdbuf command failed or the idal buffer is
175 	 * to small for the amount of data returned by the
176 	 * rdbuf command, then we have no choice but to send
177 	 * a SIGHUP to the application.
178 	 */
179 	if (rq->rc != 0 || rq->rescnt == 0) {
180 		if (fp->fs_pid)
181 			kill_pid(fp->fs_pid, SIGHUP, 1);
182 		fp->rdbuf_size = 0;
183 	} else
184 		fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
185 	raw3270_request_reset(rq);
186 	wake_up(&fp->wait);
187 }
188 
189 static void
190 fs3270_deactivate(struct raw3270_view *view)
191 {
192 	struct fs3270 *fp;
193 
194 	fp = (struct fs3270 *) view;
195 	fp->active = 0;
196 
197 	/* If an old init command is still running just return. */
198 	if (!raw3270_request_final(fp->init))
199 		return;
200 
201 	/* Prepare read-buffer request. */
202 	raw3270_request_set_cmd(fp->init, TC_RDBUF);
203 	/*
204 	 * Hackish: skip first 5 bytes of the idal buffer to make
205 	 * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
206 	 * in the activation command.
207 	 */
208 	fp->rdbuf->data[0] += 5;
209 	fp->rdbuf->size -= 5;
210 	raw3270_request_set_idal(fp->init, fp->rdbuf);
211 	fp->init->rescnt = 0;
212 	fp->init->callback = fs3270_save_callback;
213 
214 	/* Start I/O to read in the 3270 buffer. */
215 	fp->init->rc = raw3270_start_locked(view, fp->init);
216 	if (fp->init->rc)
217 		fp->init->callback(fp->init, NULL);
218 }
219 
220 static void
221 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
222 {
223 	/* Handle ATTN. Set indication and wake waiters for attention. */
224 	if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
225 		fp->attention = 1;
226 		wake_up(&fp->wait);
227 	}
228 
229 	if (rq) {
230 		if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
231 			rq->rc = -EIO;
232 		else
233 			/* Normal end. Copy residual count. */
234 			rq->rescnt = irb->scsw.cmd.count;
235 	}
236 }
237 
238 /*
239  * Process reads from fullscreen 3270.
240  */
241 static ssize_t
242 fs3270_read(struct file *filp, char __user *data, size_t count, loff_t *off)
243 {
244 	struct fs3270 *fp;
245 	struct raw3270_request *rq;
246 	struct idal_buffer *ib;
247 	ssize_t rc;
248 
249 	if (count == 0 || count > 65535)
250 		return -EINVAL;
251 	fp = filp->private_data;
252 	if (!fp)
253 		return -ENODEV;
254 	ib = idal_buffer_alloc(count, 0);
255 	if (IS_ERR(ib))
256 		return -ENOMEM;
257 	rq = raw3270_request_alloc(0);
258 	if (!IS_ERR(rq)) {
259 		if (fp->read_command == 0 && fp->write_command != 0)
260 			fp->read_command = 6;
261 		raw3270_request_set_cmd(rq, fp->read_command ? : 2);
262 		raw3270_request_set_idal(rq, ib);
263 		rc = wait_event_interruptible(fp->wait, fp->attention);
264 		fp->attention = 0;
265 		if (rc == 0) {
266 			rc = fs3270_do_io(&fp->view, rq);
267 			if (rc == 0) {
268 				count -= rq->rescnt;
269 				if (idal_buffer_to_user(ib, data, count) != 0)
270 					rc = -EFAULT;
271 				else
272 					rc = count;
273 
274 			}
275 		}
276 		raw3270_request_free(rq);
277 	} else
278 		rc = PTR_ERR(rq);
279 	idal_buffer_free(ib);
280 	return rc;
281 }
282 
283 /*
284  * Process writes to fullscreen 3270.
285  */
286 static ssize_t
287 fs3270_write(struct file *filp, const char __user *data, size_t count, loff_t *off)
288 {
289 	struct fs3270 *fp;
290 	struct raw3270_request *rq;
291 	struct idal_buffer *ib;
292 	int write_command;
293 	ssize_t rc;
294 
295 	fp = filp->private_data;
296 	if (!fp)
297 		return -ENODEV;
298 	ib = idal_buffer_alloc(count, 0);
299 	if (IS_ERR(ib))
300 		return -ENOMEM;
301 	rq = raw3270_request_alloc(0);
302 	if (!IS_ERR(rq)) {
303 		if (idal_buffer_from_user(ib, data, count) == 0) {
304 			write_command = fp->write_command ? : 1;
305 			if (write_command == 5)
306 				write_command = 13;
307 			raw3270_request_set_cmd(rq, write_command);
308 			raw3270_request_set_idal(rq, ib);
309 			rc = fs3270_do_io(&fp->view, rq);
310 			if (rc == 0)
311 				rc = count - rq->rescnt;
312 		} else
313 			rc = -EFAULT;
314 		raw3270_request_free(rq);
315 	} else
316 		rc = PTR_ERR(rq);
317 	idal_buffer_free(ib);
318 	return rc;
319 }
320 
321 /*
322  * process ioctl commands for the tube driver
323  */
324 static long
325 fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
326 {
327 	char __user *argp;
328 	struct fs3270 *fp;
329 	struct raw3270_iocb iocb;
330 	int rc;
331 
332 	fp = filp->private_data;
333 	if (!fp)
334 		return -ENODEV;
335 	if (is_compat_task())
336 		argp = compat_ptr(arg);
337 	else
338 		argp = (char __user *)arg;
339 	rc = 0;
340 	mutex_lock(&fs3270_mutex);
341 	switch (cmd) {
342 	case TUBICMD:
343 		fp->read_command = arg;
344 		break;
345 	case TUBOCMD:
346 		fp->write_command = arg;
347 		break;
348 	case TUBGETI:
349 		rc = put_user(fp->read_command, argp);
350 		break;
351 	case TUBGETO:
352 		rc = put_user(fp->write_command, argp);
353 		break;
354 	case TUBGETMOD:
355 		iocb.model = fp->view.model;
356 		iocb.line_cnt = fp->view.rows;
357 		iocb.col_cnt = fp->view.cols;
358 		iocb.pf_cnt = 24;
359 		iocb.re_cnt = 20;
360 		iocb.map = 0;
361 		if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
362 			rc = -EFAULT;
363 		break;
364 	}
365 	mutex_unlock(&fs3270_mutex);
366 	return rc;
367 }
368 
369 /*
370  * Allocate fs3270 structure.
371  */
372 static struct fs3270 *
373 fs3270_alloc_view(void)
374 {
375 	struct fs3270 *fp;
376 
377 	fp = kzalloc(sizeof(struct fs3270),GFP_KERNEL);
378 	if (!fp)
379 		return ERR_PTR(-ENOMEM);
380 	fp->init = raw3270_request_alloc(0);
381 	if (IS_ERR(fp->init)) {
382 		kfree(fp);
383 		return ERR_PTR(-ENOMEM);
384 	}
385 	return fp;
386 }
387 
388 /*
389  * Free fs3270 structure.
390  */
391 static void
392 fs3270_free_view(struct raw3270_view *view)
393 {
394 	struct fs3270 *fp;
395 
396 	fp = (struct fs3270 *) view;
397 	if (fp->rdbuf)
398 		idal_buffer_free(fp->rdbuf);
399 	raw3270_request_free(((struct fs3270 *) view)->init);
400 	kfree(view);
401 }
402 
403 /*
404  * Unlink fs3270 data structure from filp.
405  */
406 static void
407 fs3270_release(struct raw3270_view *view)
408 {
409 	struct fs3270 *fp;
410 
411 	fp = (struct fs3270 *) view;
412 	if (fp->fs_pid)
413 		kill_pid(fp->fs_pid, SIGHUP, 1);
414 }
415 
416 /* View to a 3270 device. Can be console, tty or fullscreen. */
417 static struct raw3270_fn fs3270_fn = {
418 	.activate = fs3270_activate,
419 	.deactivate = fs3270_deactivate,
420 	.intv = (void *) fs3270_irq,
421 	.release = fs3270_release,
422 	.free = fs3270_free_view
423 };
424 
425 /*
426  * This routine is called whenever a 3270 fullscreen device is opened.
427  */
428 static int
429 fs3270_open(struct inode *inode, struct file *filp)
430 {
431 	struct fs3270 *fp;
432 	struct idal_buffer *ib;
433 	int minor, rc = 0;
434 
435 	if (imajor(file_inode(filp)) != IBM_FS3270_MAJOR)
436 		return -ENODEV;
437 	minor = iminor(file_inode(filp));
438 	/* Check for minor 0 multiplexer. */
439 	if (minor == 0) {
440 		struct tty_struct *tty = get_current_tty();
441 		if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
442 			tty_kref_put(tty);
443 			return -ENODEV;
444 		}
445 		minor = tty->index;
446 		tty_kref_put(tty);
447 	}
448 	mutex_lock(&fs3270_mutex);
449 	/* Check if some other program is already using fullscreen mode. */
450 	fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
451 	if (!IS_ERR(fp)) {
452 		raw3270_put_view(&fp->view);
453 		rc = -EBUSY;
454 		goto out;
455 	}
456 	/* Allocate fullscreen view structure. */
457 	fp = fs3270_alloc_view();
458 	if (IS_ERR(fp)) {
459 		rc = PTR_ERR(fp);
460 		goto out;
461 	}
462 
463 	init_waitqueue_head(&fp->wait);
464 	fp->fs_pid = get_pid(task_pid(current));
465 	rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
466 	if (rc) {
467 		fs3270_free_view(&fp->view);
468 		goto out;
469 	}
470 
471 	/* Allocate idal-buffer. */
472 	ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
473 	if (IS_ERR(ib)) {
474 		raw3270_put_view(&fp->view);
475 		raw3270_del_view(&fp->view);
476 		rc = PTR_ERR(ib);
477 		goto out;
478 	}
479 	fp->rdbuf = ib;
480 
481 	rc = raw3270_activate_view(&fp->view);
482 	if (rc) {
483 		raw3270_put_view(&fp->view);
484 		raw3270_del_view(&fp->view);
485 		goto out;
486 	}
487 	nonseekable_open(inode, filp);
488 	filp->private_data = fp;
489 out:
490 	mutex_unlock(&fs3270_mutex);
491 	return rc;
492 }
493 
494 /*
495  * This routine is called when the 3270 tty is closed. We wait
496  * for the remaining request to be completed. Then we clean up.
497  */
498 static int
499 fs3270_close(struct inode *inode, struct file *filp)
500 {
501 	struct fs3270 *fp;
502 
503 	fp = filp->private_data;
504 	filp->private_data = NULL;
505 	if (fp) {
506 		put_pid(fp->fs_pid);
507 		fp->fs_pid = NULL;
508 		raw3270_reset(&fp->view);
509 		raw3270_put_view(&fp->view);
510 		raw3270_del_view(&fp->view);
511 	}
512 	return 0;
513 }
514 
515 static const struct file_operations fs3270_fops = {
516 	.owner		 = THIS_MODULE,		/* owner */
517 	.read		 = fs3270_read,		/* read */
518 	.write		 = fs3270_write,	/* write */
519 	.unlocked_ioctl	 = fs3270_ioctl,	/* ioctl */
520 	.compat_ioctl	 = fs3270_ioctl,	/* ioctl */
521 	.open		 = fs3270_open,		/* open */
522 	.release	 = fs3270_close,	/* release */
523 	.llseek		= no_llseek,
524 };
525 
526 static void fs3270_create_cb(int minor)
527 {
528 	__register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops);
529 	device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
530 		      NULL, "3270/tub%d", minor);
531 }
532 
533 static void fs3270_destroy_cb(int minor)
534 {
535 	device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, minor));
536 	__unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub");
537 }
538 
539 static struct raw3270_notifier fs3270_notifier =
540 {
541 	.create = fs3270_create_cb,
542 	.destroy = fs3270_destroy_cb,
543 };
544 
545 /*
546  * 3270 fullscreen driver initialization.
547  */
548 static int __init
549 fs3270_init(void)
550 {
551 	int rc;
552 
553 	rc = __register_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270", &fs3270_fops);
554 	if (rc)
555 		return rc;
556 	device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0),
557 		      NULL, "3270/tub");
558 	raw3270_register_notifier(&fs3270_notifier);
559 	return 0;
560 }
561 
562 static void __exit
563 fs3270_exit(void)
564 {
565 	raw3270_unregister_notifier(&fs3270_notifier);
566 	device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, 0));
567 	__unregister_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270");
568 }
569 
570 MODULE_LICENSE("GPL");
571 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
572 
573 module_init(fs3270_init);
574 module_exit(fs3270_exit);
575