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
29static struct raw3270_fn fs3270_fn;
30
31struct 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
44static DEFINE_MUTEX(fs3270_mutex);
45
46static void
47fs3270_wake_up(struct raw3270_request *rq, void *data)
48{
49	wake_up((wait_queue_head_t *) data);
50}
51
52static inline int
53fs3270_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
62static int
63fs3270_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 */
92static void
93fs3270_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
102static void
103fs3270_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
117static int
118fs3270_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 */
162static void
163fs3270_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
189static void
190fs3270_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
220static int
221fs3270_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 */
242static ssize_t
243fs3270_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 */
287static ssize_t
288fs3270_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 */
325static long
326fs3270_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 */
373static struct fs3270 *
374fs3270_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 */
392static void
393fs3270_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 */
407static void
408fs3270_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. */
418static 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 */
429static int
430fs3270_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(file_inode(filp)) != IBM_FS3270_MAJOR)
437		return -ENODEV;
438	minor = iminor(file_inode(filp));
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;
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;
490out:
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 */
499static int
500fs3270_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
516static 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
527static void fs3270_create_cb(int minor)
528{
529	__register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops);
530	device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
531		      NULL, "3270/tub%d", minor);
532}
533
534static void fs3270_destroy_cb(int minor)
535{
536	device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, minor));
537	__unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub");
538}
539
540static struct raw3270_notifier fs3270_notifier =
541{
542	.create = fs3270_create_cb,
543	.destroy = fs3270_destroy_cb,
544};
545
546/*
547 * 3270 fullscreen driver initialization.
548 */
549static int __init
550fs3270_init(void)
551{
552	int rc;
553
554	rc = __register_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270", &fs3270_fops);
555	if (rc)
556		return rc;
557	device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0),
558		      NULL, "3270/tub");
559	raw3270_register_notifier(&fs3270_notifier);
560	return 0;
561}
562
563static void __exit
564fs3270_exit(void)
565{
566	raw3270_unregister_notifier(&fs3270_notifier);
567	device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, 0));
568	__unregister_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270");
569}
570
571MODULE_LICENSE("GPL");
572MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
573
574module_init(fs3270_init);
575module_exit(fs3270_exit);
576