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
fs3270_wake_up(struct raw3270_request * rq,void * data)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
fs3270_working(struct fs3270 * fp)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
fs3270_do_io(struct raw3270_view * view,struct raw3270_request * rq)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
fs3270_reset_callback(struct raw3270_request * rq,void * data)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
fs3270_restore_callback(struct raw3270_request * rq,void * data)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
fs3270_activate(struct raw3270_view * view)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
fs3270_save_callback(struct raw3270_request * rq,void * data)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
fs3270_deactivate(struct raw3270_view * view)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 int
fs3270_irq(struct fs3270 * fp,struct raw3270_request * rq,struct irb * irb)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 	return RAW3270_IO_DONE;
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(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
437 		return -ENODEV;
438 	minor = iminor(filp->f_path.dentry->d_inode);
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 + RAW3270_FIRSTMINOR;
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 	if (rc) {
468 		fs3270_free_view(&fp->view);
469 		goto out;
470 	}
471 
472 	/* Allocate idal-buffer. */
473 	ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
474 	if (IS_ERR(ib)) {
475 		raw3270_put_view(&fp->view);
476 		raw3270_del_view(&fp->view);
477 		rc = PTR_ERR(ib);
478 		goto out;
479 	}
480 	fp->rdbuf = ib;
481 
482 	rc = raw3270_activate_view(&fp->view);
483 	if (rc) {
484 		raw3270_put_view(&fp->view);
485 		raw3270_del_view(&fp->view);
486 		goto out;
487 	}
488 	nonseekable_open(inode, filp);
489 	filp->private_data = fp;
490 out:
491 	mutex_unlock(&fs3270_mutex);
492 	return rc;
493 }
494 
495 /*
496  * This routine is called when the 3270 tty is closed. We wait
497  * for the remaining request to be completed. Then we clean up.
498  */
499 static int
fs3270_close(struct inode * inode,struct file * filp)500 fs3270_close(struct inode *inode, struct file *filp)
501 {
502 	struct fs3270 *fp;
503 
504 	fp = filp->private_data;
505 	filp->private_data = NULL;
506 	if (fp) {
507 		put_pid(fp->fs_pid);
508 		fp->fs_pid = NULL;
509 		raw3270_reset(&fp->view);
510 		raw3270_put_view(&fp->view);
511 		raw3270_del_view(&fp->view);
512 	}
513 	return 0;
514 }
515 
516 static const struct file_operations fs3270_fops = {
517 	.owner		 = THIS_MODULE,		/* owner */
518 	.read		 = fs3270_read,		/* read */
519 	.write		 = fs3270_write,	/* write */
520 	.unlocked_ioctl	 = fs3270_ioctl,	/* ioctl */
521 	.compat_ioctl	 = fs3270_ioctl,	/* ioctl */
522 	.open		 = fs3270_open,		/* open */
523 	.release	 = fs3270_close,	/* release */
524 	.llseek		= no_llseek,
525 };
526 
527 /*
528  * 3270 fullscreen driver initialization.
529  */
530 static int __init
fs3270_init(void)531 fs3270_init(void)
532 {
533 	int rc;
534 
535 	rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
536 	if (rc)
537 		return rc;
538 	return 0;
539 }
540 
541 static void __exit
fs3270_exit(void)542 fs3270_exit(void)
543 {
544 	unregister_chrdev(IBM_FS3270_MAJOR, "fs3270");
545 }
546 
547 MODULE_LICENSE("GPL");
548 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
549 
550 module_init(fs3270_init);
551 module_exit(fs3270_exit);
552