fs3270.c revision 452a00d2ee288f2cbc36f676edd06cb14d2878c1 
1/*
2 *  drivers/s390/char/fs3270.c
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 (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
9 */
10
11#include <linux/bootmem.h>
12#include <linux/console.h>
13#include <linux/init.h>
14#include <linux/interrupt.h>
15#include <linux/list.h>
16#include <linux/types.h>
17#include <linux/smp_lock.h>
18
19#include <asm/ccwdev.h>
20#include <asm/cio.h>
21#include <asm/ebcdic.h>
22#include <asm/idals.h>
23
24#include "raw3270.h"
25#include "ctrlchar.h"
26
27static struct raw3270_fn fs3270_fn;
28
29struct fs3270 {
30	struct raw3270_view view;
31	struct pid *fs_pid;		/* Pid of controlling program. */
32	int read_command;		/* ccw command to use for reads. */
33	int write_command;		/* ccw command to use for writes. */
34	int attention;			/* Got attention. */
35	int active;			/* Fullscreen view is active. */
36	struct raw3270_request *init;	/* single init request. */
37	wait_queue_head_t wait;		/* Init & attention wait queue. */
38	struct idal_buffer *rdbuf;	/* full-screen-deactivate buffer */
39	size_t rdbuf_size;		/* size of data returned by RDBUF */
40};
41
42static void
43fs3270_wake_up(struct raw3270_request *rq, void *data)
44{
45	wake_up((wait_queue_head_t *) data);
46}
47
48static inline int
49fs3270_working(struct fs3270 *fp)
50{
51	/*
52	 * The fullscreen view is in working order if the view
53	 * has been activated AND the initial request is finished.
54	 */
55	return fp->active && raw3270_request_final(fp->init);
56}
57
58static int
59fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
60{
61	struct fs3270 *fp;
62	int rc;
63
64	fp = (struct fs3270 *) view;
65	rq->callback = fs3270_wake_up;
66	rq->callback_data = &fp->wait;
67
68	do {
69		if (!fs3270_working(fp)) {
70			/* Fullscreen view isn't ready yet. */
71			rc = wait_event_interruptible(fp->wait,
72						      fs3270_working(fp));
73			if (rc != 0)
74				break;
75		}
76		rc = raw3270_start(view, rq);
77		if (rc == 0) {
78			/* Started sucessfully. Now wait for completion. */
79			wait_event(fp->wait, raw3270_request_final(rq));
80		}
81	} while (rc == -EACCES);
82	return rc;
83}
84
85/*
86 * Switch to the fullscreen view.
87 */
88static void
89fs3270_reset_callback(struct raw3270_request *rq, void *data)
90{
91	struct fs3270 *fp;
92
93	fp = (struct fs3270 *) rq->view;
94	raw3270_request_reset(rq);
95	wake_up(&fp->wait);
96}
97
98static void
99fs3270_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
113static int
114fs3270_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	if (fp->rdbuf_size == 0) {
127		/* No saved buffer. Just clear the screen. */
128		raw3270_request_set_cmd(fp->init, TC_EWRITEA);
129		fp->init->callback = fs3270_reset_callback;
130	} else {
131		/* Restore fullscreen buffer saved by fs3270_deactivate. */
132		raw3270_request_set_cmd(fp->init, TC_EWRITEA);
133		raw3270_request_set_idal(fp->init, fp->rdbuf);
134		fp->init->ccw.count = fp->rdbuf_size;
135		cp = fp->rdbuf->data[0];
136		cp[0] = TW_KR;
137		cp[1] = TO_SBA;
138		cp[2] = cp[6];
139		cp[3] = cp[7];
140		cp[4] = TO_IC;
141		cp[5] = TO_SBA;
142		cp[6] = 0x40;
143		cp[7] = 0x40;
144		fp->init->rescnt = 0;
145		fp->init->callback = fs3270_restore_callback;
146	}
147	rc = fp->init->rc = raw3270_start_locked(view, fp->init);
148	if (rc)
149		fp->init->callback(fp->init, NULL);
150	else
151		fp->active = 1;
152	return rc;
153}
154
155/*
156 * Shutdown fullscreen view.
157 */
158static void
159fs3270_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] -= 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	raw3270_request_reset(rq);
182	wake_up(&fp->wait);
183}
184
185static void
186fs3270_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] += 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
216static int
217fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, 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	return RAW3270_IO_DONE;
233}
234
235/*
236 * Process reads from fullscreen 3270.
237 */
238static ssize_t
239fs3270_read(struct file *filp, char __user *data, 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		}
273		raw3270_request_free(rq);
274	} else
275		rc = PTR_ERR(rq);
276	idal_buffer_free(ib);
277	return rc;
278}
279
280/*
281 * Process writes to fullscreen 3270.
282 */
283static ssize_t
284fs3270_write(struct file *filp, const char __user *data, 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		raw3270_request_free(rq);
312	} else
313		rc = PTR_ERR(rq);
314	idal_buffer_free(ib);
315	return rc;
316}
317
318/*
319 * process ioctl commands for the tube driver
320 */
321static long
322fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
323{
324	struct fs3270 *fp;
325	struct raw3270_iocb iocb;
326	int rc;
327
328	fp = filp->private_data;
329	if (!fp)
330		return -ENODEV;
331	rc = 0;
332	lock_kernel();
333	switch (cmd) {
334	case TUBICMD:
335		fp->read_command = arg;
336		break;
337	case TUBOCMD:
338		fp->write_command = arg;
339		break;
340	case TUBGETI:
341		rc = put_user(fp->read_command, (char __user *) arg);
342		break;
343	case TUBGETO:
344		rc = put_user(fp->write_command,(char __user *) arg);
345		break;
346	case TUBGETMOD:
347		iocb.model = fp->view.model;
348		iocb.line_cnt = fp->view.rows;
349		iocb.col_cnt = fp->view.cols;
350		iocb.pf_cnt = 24;
351		iocb.re_cnt = 20;
352		iocb.map = 0;
353		if (copy_to_user((char __user *) arg, &iocb,
354				 sizeof(struct raw3270_iocb)))
355			rc = -EFAULT;
356		break;
357	}
358	unlock_kernel();
359	return rc;
360}
361
362/*
363 * Allocate fs3270 structure.
364 */
365static struct fs3270 *
366fs3270_alloc_view(void)
367{
368	struct fs3270 *fp;
369
370	fp = kzalloc(sizeof(struct fs3270),GFP_KERNEL);
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 */
384static void
385fs3270_free_view(struct raw3270_view *view)
386{
387	struct fs3270 *fp;
388
389	fp = (struct fs3270 *) view;
390	if (fp->rdbuf)
391		idal_buffer_free(fp->rdbuf);
392	raw3270_request_free(((struct fs3270 *) view)->init);
393	kfree(view);
394}
395
396/*
397 * Unlink fs3270 data structure from filp.
398 */
399static void
400fs3270_release(struct raw3270_view *view)
401{
402}
403
404/* View to a 3270 device. Can be console, tty or fullscreen. */
405static struct raw3270_fn fs3270_fn = {
406	.activate = fs3270_activate,
407	.deactivate = fs3270_deactivate,
408	.intv = (void *) fs3270_irq,
409	.release = fs3270_release,
410	.free = fs3270_free_view
411};
412
413/*
414 * This routine is called whenever a 3270 fullscreen device is opened.
415 */
416static int
417fs3270_open(struct inode *inode, struct file *filp)
418{
419	struct fs3270 *fp;
420	struct idal_buffer *ib;
421	int minor, rc;
422
423	if (imajor(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
424		return -ENODEV;
425	lock_kernel();
426	minor = iminor(filp->f_path.dentry->d_inode);
427	/* Check for minor 0 multiplexer. */
428	if (minor == 0) {
429		struct tty_struct *tty;
430		mutex_lock(&tty_mutex);
431		tty = get_current_tty();
432		if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
433			tty_kref_put(tty);
434			rc = -ENODEV;
435			goto out;
436		}
437		minor = tty->index + RAW3270_FIRSTMINOR;
438		tty_kref_put(tty);
439		mutex_unlock(&tty_mutex);
440	}
441	/* Check if some other program is already using fullscreen mode. */
442	fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
443	if (!IS_ERR(fp)) {
444		raw3270_put_view(&fp->view);
445		rc = -EBUSY;
446		goto out;
447	}
448	/* Allocate fullscreen view structure. */
449	fp = fs3270_alloc_view();
450	if (IS_ERR(fp)) {
451		rc = PTR_ERR(fp);
452		goto out;
453	}
454
455	init_waitqueue_head(&fp->wait);
456	fp->fs_pid = get_pid(task_pid(current));
457	rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
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(fp);
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	filp->private_data = fp;
480out:
481	unlock_kernel();
482	return 0;
483}
484
485/*
486 * This routine is called when the 3270 tty is closed. We wait
487 * for the remaining request to be completed. Then we clean up.
488 */
489static int
490fs3270_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
506static 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	.compat_ioctl	 = fs3270_ioctl,	/* ioctl */
512	.open	 	= fs3270_open,		/* open */
513	.release 	= fs3270_close,		/* release */
514};
515
516/*
517 * 3270 fullscreen driver initialization.
518 */
519static int __init
520fs3270_init(void)
521{
522	int rc;
523
524	rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
525	if (rc)
526		return rc;
527	return 0;
528}
529
530static void __exit
531fs3270_exit(void)
532{
533	unregister_chrdev(IBM_FS3270_MAJOR, "fs3270");
534}
535
536MODULE_LICENSE("GPL");
537MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
538
539module_init(fs3270_init);
540module_exit(fs3270_exit);
541