fs3270.c

  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/sched/signal.h>
 16#include <linux/module.h>
 17#include <linux/list.h>
 18#include <linux/slab.h>
 19#include <linux/types.h>
 20
 21#include <uapi/asm/fs3270.h>
 22#include <asm/ccwdev.h>
 23#include <asm/cio.h>
 24#include <asm/ebcdic.h>
 25#include <asm/idals.h>
 26
 27#include "raw3270.h"
 28#include "ctrlchar.h"
 29
 30static struct raw3270_fn fs3270_fn;
 31
 32struct fs3270 {
 33	struct raw3270_view view;
 34	struct pid *fs_pid;		/* Pid of controlling program. */
 35	int read_command;		/* ccw command to use for reads. */
 36	int write_command;		/* ccw command to use for writes. */
 37	int attention;			/* Got attention. */
 38	int active;			/* Fullscreen view is active. */
 39	struct raw3270_request *init;	/* single init request. */
 40	wait_queue_head_t wait;		/* Init & attention wait queue. */
 41	struct idal_buffer *rdbuf;	/* full-screen-deactivate buffer */
 42	size_t rdbuf_size;		/* size of data returned by RDBUF */
 43};
 44
 45static DEFINE_MUTEX(fs3270_mutex);
 46
 47static void fs3270_wake_up(struct raw3270_request *rq, void *data)
 48{
 49	wake_up((wait_queue_head_t *)data);
 50}
 51
 52static inline int fs3270_working(struct fs3270 *fp)
 53{
 54	/*
 55	 * The fullscreen view is in working order if the view
 56	 * has been activated AND the initial request is finished.
 57	 */
 58	return fp->active && raw3270_request_final(fp->init);
 59}
 60
 61static int fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
 62{
 63	struct fs3270 *fp;
 64	int rc;
 65
 66	fp = (struct fs3270 *)view;
 67	rq->callback = fs3270_wake_up;
 68	rq->callback_data = &fp->wait;
 69
 70	do {
 71		if (!fs3270_working(fp)) {
 72			/* Fullscreen view isn't ready yet. */
 73			rc = wait_event_interruptible(fp->wait,
 74						      fs3270_working(fp));
 75			if (rc != 0)
 76				break;
 77		}
 78		rc = raw3270_start(view, rq);
 79		if (rc == 0) {
 80			/* Started successfully. Now wait for completion. */
 81			wait_event(fp->wait, raw3270_request_final(rq));
 82		}
 83	} while (rc == -EACCES);
 84	return rc;
 85}
 86
 87/*
 88 * Switch to the fullscreen view.
 89 */
 90static void fs3270_reset_callback(struct raw3270_request *rq, void *data)
 91{
 92	struct fs3270 *fp;
 93
 94	fp = (struct fs3270 *)rq->view;
 95	raw3270_request_reset(rq);
 96	wake_up(&fp->wait);
 97}
 98
 99static void fs3270_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 fs3270_activate(struct raw3270_view *view)
114{
115	struct fs3270 *fp;
116	char *cp;
117	int rc;
118
119	fp = (struct fs3270 *)view;
120
121	/* If an old init command is still running just return. */
122	if (!raw3270_request_final(fp->init))
123		return 0;
124
125	raw3270_request_set_cmd(fp->init, TC_EWRITEA);
126	raw3270_request_set_idal(fp->init, fp->rdbuf);
127	fp->init->rescnt = 0;
128	cp = dma64_to_virt(fp->rdbuf->data[0]);
129	if (fp->rdbuf_size == 0) {
130		/* No saved buffer. Just clear the screen. */
131		fp->init->ccw.count = 1;
132		fp->init->callback = fs3270_reset_callback;
133		cp[0] = 0;
134	} else {
135		/* Restore fullscreen buffer saved by fs3270_deactivate. */
136		fp->init->ccw.count = fp->rdbuf_size;
137		fp->init->callback = fs3270_restore_callback;
138		cp[0] = TW_KR;
139		cp[1] = TO_SBA;
140		cp[2] = cp[6];
141		cp[3] = cp[7];
142		cp[4] = TO_IC;
143		cp[5] = TO_SBA;
144		cp[6] = 0x40;
145		cp[7] = 0x40;
146	}
147	rc = raw3270_start_locked(view, fp->init);
148	fp->init->rc = rc;
149	if (rc)
150		fp->init->callback(fp->init, NULL);
151	else
152		fp->active = 1;
153	return rc;
154}
155
156/*
157 * Shutdown fullscreen view.
158 */
159static void fs3270_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] = dma64_add(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	}
182	raw3270_request_reset(rq);
183	wake_up(&fp->wait);
184}
185
186static void fs3270_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] = dma64_add(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 void fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq,
217		       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}
233
234/*
235 * Process reads from fullscreen 3270.
236 */
237static ssize_t fs3270_read(struct file *filp, char __user *data,
238			   size_t count, loff_t *off)
239{
240	struct fs3270 *fp;
241	struct raw3270_request *rq;
242	struct idal_buffer *ib;
243	ssize_t rc;
244
245	if (count == 0 || count > 65535)
246		return -EINVAL;
247	fp = filp->private_data;
248	if (!fp)
249		return -ENODEV;
250	ib = idal_buffer_alloc(count, 0);
251	if (IS_ERR(ib))
252		return -ENOMEM;
253	rq = raw3270_request_alloc(0);
254	if (!IS_ERR(rq)) {
255		if (fp->read_command == 0 && fp->write_command != 0)
256			fp->read_command = 6;
257		raw3270_request_set_cmd(rq, fp->read_command ? : 2);
258		raw3270_request_set_idal(rq, ib);
259		rc = wait_event_interruptible(fp->wait, fp->attention);
260		fp->attention = 0;
261		if (rc == 0) {
262			rc = fs3270_do_io(&fp->view, rq);
263			if (rc == 0) {
264				count -= rq->rescnt;
265				if (idal_buffer_to_user(ib, data, count) != 0)
266					rc = -EFAULT;
267				else
268					rc = count;
269			}
270		}
271		raw3270_request_free(rq);
272	} else {
273		rc = PTR_ERR(rq);
274	}
275	idal_buffer_free(ib);
276	return rc;
277}
278
279/*
280 * Process writes to fullscreen 3270.
281 */
282static ssize_t fs3270_write(struct file *filp, const char __user *data,
283			    size_t count, loff_t *off)
284{
285	struct fs3270 *fp;
286	struct raw3270_request *rq;
287	struct idal_buffer *ib;
288	int write_command;
289	ssize_t rc;
290
291	fp = filp->private_data;
292	if (!fp)
293		return -ENODEV;
294	ib = idal_buffer_alloc(count, 0);
295	if (IS_ERR(ib))
296		return -ENOMEM;
297	rq = raw3270_request_alloc(0);
298	if (!IS_ERR(rq)) {
299		if (idal_buffer_from_user(ib, data, count) == 0) {
300			write_command = fp->write_command ? : 1;
301			if (write_command == 5)
302				write_command = 13;
303			raw3270_request_set_cmd(rq, write_command);
304			raw3270_request_set_idal(rq, ib);
305			rc = fs3270_do_io(&fp->view, rq);
306			if (rc == 0)
307				rc = count - rq->rescnt;
308		} else {
309			rc = -EFAULT;
310		}
311		raw3270_request_free(rq);
312	} else {
313		rc = PTR_ERR(rq);
314	}
315	idal_buffer_free(ib);
316	return rc;
317}
318
319/*
320 * process ioctl commands for the tube driver
321 */
322static long fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
323{
324	char __user *argp;
325	struct fs3270 *fp;
326	struct raw3270_iocb iocb;
327	int rc;
328
329	fp = filp->private_data;
330	if (!fp)
331		return -ENODEV;
332	argp = (char __user *)arg;
333	rc = 0;
334	mutex_lock(&fs3270_mutex);
335	switch (cmd) {
336	case TUBICMD:
337		fp->read_command = arg;
338		break;
339	case TUBOCMD:
340		fp->write_command = arg;
341		break;
342	case TUBGETI:
343		rc = put_user(fp->read_command, argp);
344		break;
345	case TUBGETO:
346		rc = put_user(fp->write_command, argp);
347		break;
348	case TUBGETMOD:
349		iocb.model = fp->view.model;
350		iocb.line_cnt = fp->view.rows;
351		iocb.col_cnt = fp->view.cols;
352		iocb.pf_cnt = 24;
353		iocb.re_cnt = 20;
354		iocb.map = 0;
355		if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
356			rc = -EFAULT;
357		break;
358	}
359	mutex_unlock(&fs3270_mutex);
360	return rc;
361}
362
363/*
364 * Allocate fs3270 structure.
365 */
366static struct fs3270 *fs3270_alloc_view(void)
367{
368	struct fs3270 *fp;
369
370	fp = kzalloc(sizeof(*fp), 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 fs3270_free_view(struct raw3270_view *view)
385{
386	struct fs3270 *fp;
387
388	fp = (struct fs3270 *)view;
389	if (fp->rdbuf)
390		idal_buffer_free(fp->rdbuf);
391	raw3270_request_free(((struct fs3270 *)view)->init);
392	kfree(view);
393}
394
395/*
396 * Unlink fs3270 data structure from filp.
397 */
398static void fs3270_release(struct raw3270_view *view)
399{
400	struct fs3270 *fp;
401
402	fp = (struct fs3270 *)view;
403	if (fp->fs_pid)
404		kill_pid(fp->fs_pid, SIGHUP, 1);
405}
406
407/* View to a 3270 device. Can be console, tty or fullscreen. */
408static struct raw3270_fn fs3270_fn = {
409	.activate = fs3270_activate,
410	.deactivate = fs3270_deactivate,
411	.intv = (void *)fs3270_irq,
412	.release = fs3270_release,
413	.free = fs3270_free_view
414};
415
416/*
417 * This routine is called whenever a 3270 fullscreen device is opened.
418 */
419static int fs3270_open(struct inode *inode, struct file *filp)
420{
421	struct fs3270 *fp;
422	struct idal_buffer *ib;
423	int minor, rc = 0;
424
425	if (imajor(file_inode(filp)) != IBM_FS3270_MAJOR)
426		return -ENODEV;
427	minor = iminor(file_inode(filp));
428	/* Check for minor 0 multiplexer. */
429	if (minor == 0) {
430		struct tty_struct *tty = get_current_tty();
431
432		if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
433			tty_kref_put(tty);
434			return -ENODEV;
435		}
436		minor = tty->index;
437		tty_kref_put(tty);
438	}
439	mutex_lock(&fs3270_mutex);
440	/* Check if some other program is already using fullscreen mode. */
441	fp = (struct fs3270 *)raw3270_find_view(&fs3270_fn, minor);
442	if (!IS_ERR(fp)) {
443		raw3270_put_view(&fp->view);
444		rc = -EBUSY;
445		goto out;
446	}
447	/* Allocate fullscreen view structure. */
448	fp = fs3270_alloc_view();
449	if (IS_ERR(fp)) {
450		rc = PTR_ERR(fp);
451		goto out;
452	}
453
454	init_waitqueue_head(&fp->wait);
455	fp->fs_pid = get_pid(task_pid(current));
456	rc = raw3270_add_view(&fp->view, &fs3270_fn, minor,
457			      RAW3270_VIEW_LOCK_BH);
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(ib);
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	stream_open(inode, filp);
480	filp->private_data = fp;
481out:
482	mutex_unlock(&fs3270_mutex);
483	return rc;
484}
485
486/*
487 * This routine is called when the 3270 tty is closed. We wait
488 * for the remaining request to be completed. Then we clean up.
489 */
490static int fs3270_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	.open		 = fs3270_open,		/* open */
512	.release	 = fs3270_close,	/* release */
513};
514
515static void fs3270_create_cb(int minor)
516{
517	__register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops);
518	device_create(&class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
519		      NULL, "3270/tub%d", minor);
520}
521
522static void fs3270_destroy_cb(int minor)
523{
524	device_destroy(&class3270, MKDEV(IBM_FS3270_MAJOR, minor));
525	__unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub");
526}
527
528static struct raw3270_notifier fs3270_notifier = {
529	.create = fs3270_create_cb,
530	.destroy = fs3270_destroy_cb,
531};
532
533/*
534 * 3270 fullscreen driver initialization.
535 */
536static int __init fs3270_init(void)
537{
538	int rc;
539
540	rc = __register_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270", &fs3270_fops);
541	if (rc)
542		return rc;
543	device_create(&class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0),
544		      NULL, "3270/tub");
545	raw3270_register_notifier(&fs3270_notifier);
546	return 0;
547}
548
549static void __exit fs3270_exit(void)
550{
551	raw3270_unregister_notifier(&fs3270_notifier);
552	device_destroy(&class3270, MKDEV(IBM_FS3270_MAJOR, 0));
553	__unregister_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270");
554}
555
556MODULE_DESCRIPTION("IBM/3270 Driver - fullscreen driver");
557MODULE_LICENSE("GPL");
558MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
559
560module_init(fs3270_init);
561module_exit(fs3270_exit);