*: convert stream-like files from nonseekable_open -> stream_open
[sfrench/cifs-2.6.git] / drivers / s390 / char / 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/compat.h>
16 #include <linux/sched/signal.h>
17 #include <linux/module.h>
18 #include <linux/list.h>
19 #include <linux/slab.h>
20 #include <linux/types.h>
21
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
30 static struct raw3270_fn fs3270_fn;
31
32 struct 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
45 static DEFINE_MUTEX(fs3270_mutex);
46
47 static void
48 fs3270_wake_up(struct raw3270_request *rq, void *data)
49 {
50         wake_up((wait_queue_head_t *) data);
51 }
52
53 static inline int
54 fs3270_working(struct fs3270 *fp)
55 {
56         /*
57          * The fullscreen view is in working order if the view
58          * has been activated AND the initial request is finished.
59          */
60         return fp->active && raw3270_request_final(fp->init);
61 }
62
63 static int
64 fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
65 {
66         struct fs3270 *fp;
67         int rc;
68
69         fp = (struct fs3270 *) view;
70         rq->callback = fs3270_wake_up;
71         rq->callback_data = &fp->wait;
72
73         do {
74                 if (!fs3270_working(fp)) {
75                         /* Fullscreen view isn't ready yet. */
76                         rc = wait_event_interruptible(fp->wait,
77                                                       fs3270_working(fp));
78                         if (rc != 0)
79                                 break;
80                 }
81                 rc = raw3270_start(view, rq);
82                 if (rc == 0) {
83                         /* Started successfully. Now wait for completion. */
84                         wait_event(fp->wait, raw3270_request_final(rq));
85                 }
86         } while (rc == -EACCES);
87         return rc;
88 }
89
90 /*
91  * Switch to the fullscreen view.
92  */
93 static void
94 fs3270_reset_callback(struct raw3270_request *rq, void *data)
95 {
96         struct fs3270 *fp;
97
98         fp = (struct fs3270 *) rq->view;
99         raw3270_request_reset(rq);
100         wake_up(&fp->wait);
101 }
102
103 static void
104 fs3270_restore_callback(struct raw3270_request *rq, void *data)
105 {
106         struct fs3270 *fp;
107
108         fp = (struct fs3270 *) rq->view;
109         if (rq->rc != 0 || rq->rescnt != 0) {
110                 if (fp->fs_pid)
111                         kill_pid(fp->fs_pid, SIGHUP, 1);
112         }
113         fp->rdbuf_size = 0;
114         raw3270_request_reset(rq);
115         wake_up(&fp->wait);
116 }
117
118 static int
119 fs3270_activate(struct raw3270_view *view)
120 {
121         struct fs3270 *fp;
122         char *cp;
123         int rc;
124
125         fp = (struct fs3270 *) view;
126
127         /* If an old init command is still running just return. */
128         if (!raw3270_request_final(fp->init))
129                 return 0;
130
131         if (fp->rdbuf_size == 0) {
132                 /* No saved buffer. Just clear the screen. */
133                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
134                 fp->init->callback = fs3270_reset_callback;
135         } else {
136                 /* Restore fullscreen buffer saved by fs3270_deactivate. */
137                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
138                 raw3270_request_set_idal(fp->init, fp->rdbuf);
139                 fp->init->ccw.count = fp->rdbuf_size;
140                 cp = fp->rdbuf->data[0];
141                 cp[0] = TW_KR;
142                 cp[1] = TO_SBA;
143                 cp[2] = cp[6];
144                 cp[3] = cp[7];
145                 cp[4] = TO_IC;
146                 cp[5] = TO_SBA;
147                 cp[6] = 0x40;
148                 cp[7] = 0x40;
149                 fp->init->rescnt = 0;
150                 fp->init->callback = fs3270_restore_callback;
151         }
152         rc = fp->init->rc = raw3270_start_locked(view, fp->init);
153         if (rc)
154                 fp->init->callback(fp->init, NULL);
155         else
156                 fp->active = 1;
157         return rc;
158 }
159
160 /*
161  * Shutdown fullscreen view.
162  */
163 static void
164 fs3270_save_callback(struct raw3270_request *rq, void *data)
165 {
166         struct fs3270 *fp;
167
168         fp = (struct fs3270 *) rq->view;
169
170         /* Correct idal buffer element 0 address. */
171         fp->rdbuf->data[0] -= 5;
172         fp->rdbuf->size += 5;
173
174         /*
175          * If the rdbuf command failed or the idal buffer is
176          * to small for the amount of data returned by the
177          * rdbuf command, then we have no choice but to send
178          * a SIGHUP to the application.
179          */
180         if (rq->rc != 0 || rq->rescnt == 0) {
181                 if (fp->fs_pid)
182                         kill_pid(fp->fs_pid, SIGHUP, 1);
183                 fp->rdbuf_size = 0;
184         } else
185                 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
186         raw3270_request_reset(rq);
187         wake_up(&fp->wait);
188 }
189
190 static void
191 fs3270_deactivate(struct raw3270_view *view)
192 {
193         struct fs3270 *fp;
194
195         fp = (struct fs3270 *) view;
196         fp->active = 0;
197
198         /* If an old init command is still running just return. */
199         if (!raw3270_request_final(fp->init))
200                 return;
201
202         /* Prepare read-buffer request. */
203         raw3270_request_set_cmd(fp->init, TC_RDBUF);
204         /*
205          * Hackish: skip first 5 bytes of the idal buffer to make
206          * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
207          * in the activation command.
208          */
209         fp->rdbuf->data[0] += 5;
210         fp->rdbuf->size -= 5;
211         raw3270_request_set_idal(fp->init, fp->rdbuf);
212         fp->init->rescnt = 0;
213         fp->init->callback = fs3270_save_callback;
214
215         /* Start I/O to read in the 3270 buffer. */
216         fp->init->rc = raw3270_start_locked(view, fp->init);
217         if (fp->init->rc)
218                 fp->init->callback(fp->init, NULL);
219 }
220
221 static void
222 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
223 {
224         /* Handle ATTN. Set indication and wake waiters for attention. */
225         if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
226                 fp->attention = 1;
227                 wake_up(&fp->wait);
228         }
229
230         if (rq) {
231                 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
232                         rq->rc = -EIO;
233                 else
234                         /* Normal end. Copy residual count. */
235                         rq->rescnt = irb->scsw.cmd.count;
236         }
237 }
238
239 /*
240  * Process reads from fullscreen 3270.
241  */
242 static ssize_t
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
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
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 *
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
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
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
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(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                               RAW3270_VIEW_LOCK_BH);
468         if (rc) {
469                 fs3270_free_view(&fp->view);
470                 goto out;
471         }
472
473         /* Allocate idal-buffer. */
474         ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
475         if (IS_ERR(ib)) {
476                 raw3270_put_view(&fp->view);
477                 raw3270_del_view(&fp->view);
478                 rc = PTR_ERR(ib);
479                 goto out;
480         }
481         fp->rdbuf = ib;
482
483         rc = raw3270_activate_view(&fp->view);
484         if (rc) {
485                 raw3270_put_view(&fp->view);
486                 raw3270_del_view(&fp->view);
487                 goto out;
488         }
489         stream_open(inode, filp);
490         filp->private_data = fp;
491 out:
492         mutex_unlock(&fs3270_mutex);
493         return rc;
494 }
495
496 /*
497  * This routine is called when the 3270 tty is closed. We wait
498  * for the remaining request to be completed. Then we clean up.
499  */
500 static int
501 fs3270_close(struct inode *inode, struct file *filp)
502 {
503         struct fs3270 *fp;
504
505         fp = filp->private_data;
506         filp->private_data = NULL;
507         if (fp) {
508                 put_pid(fp->fs_pid);
509                 fp->fs_pid = NULL;
510                 raw3270_reset(&fp->view);
511                 raw3270_put_view(&fp->view);
512                 raw3270_del_view(&fp->view);
513         }
514         return 0;
515 }
516
517 static const struct file_operations fs3270_fops = {
518         .owner           = THIS_MODULE,         /* owner */
519         .read            = fs3270_read,         /* read */
520         .write           = fs3270_write,        /* write */
521         .unlocked_ioctl  = fs3270_ioctl,        /* ioctl */
522         .compat_ioctl    = fs3270_ioctl,        /* ioctl */
523         .open            = fs3270_open,         /* open */
524         .release         = fs3270_close,        /* release */
525         .llseek         = no_llseek,
526 };
527
528 static void fs3270_create_cb(int minor)
529 {
530         __register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops);
531         device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
532                       NULL, "3270/tub%d", minor);
533 }
534
535 static void fs3270_destroy_cb(int minor)
536 {
537         device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, minor));
538         __unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub");
539 }
540
541 static struct raw3270_notifier fs3270_notifier =
542 {
543         .create = fs3270_create_cb,
544         .destroy = fs3270_destroy_cb,
545 };
546
547 /*
548  * 3270 fullscreen driver initialization.
549  */
550 static int __init
551 fs3270_init(void)
552 {
553         int rc;
554
555         rc = __register_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270", &fs3270_fops);
556         if (rc)
557                 return rc;
558         device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0),
559                       NULL, "3270/tub");
560         raw3270_register_notifier(&fs3270_notifier);
561         return 0;
562 }
563
564 static void __exit
565 fs3270_exit(void)
566 {
567         raw3270_unregister_notifier(&fs3270_notifier);
568         device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, 0));
569         __unregister_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270");
570 }
571
572 MODULE_LICENSE("GPL");
573 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
574
575 module_init(fs3270_init);
576 module_exit(fs3270_exit);