e71298158f9eaa83a0531269a7da5c83c0c1d14a
[linux-2.6.git] / drivers / s390 / char / fs3270.c
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/module.h>
15 #include <linux/list.h>
16 #include <linux/slab.h>
17 #include <linux/types.h>
18
19 #include <asm/compat.h>
20 #include <asm/ccwdev.h>
21 #include <asm/cio.h>
22 #include <asm/ebcdic.h>
23 #include <asm/idals.h>
24
25 #include "raw3270.h"
26 #include "ctrlchar.h"
27
28 static struct raw3270_fn fs3270_fn;
29
30 struct fs3270 {
31         struct raw3270_view view;
32         struct pid *fs_pid;             /* Pid of controlling program. */
33         int read_command;               /* ccw command to use for reads. */
34         int write_command;              /* ccw command to use for writes. */
35         int attention;                  /* Got attention. */
36         int active;                     /* Fullscreen view is active. */
37         struct raw3270_request *init;   /* single init request. */
38         wait_queue_head_t wait;         /* Init & attention wait queue. */
39         struct idal_buffer *rdbuf;      /* full-screen-deactivate buffer */
40         size_t rdbuf_size;              /* size of data returned by RDBUF */
41 };
42
43 static DEFINE_MUTEX(fs3270_mutex);
44
45 static void
46 fs3270_wake_up(struct raw3270_request *rq, void *data)
47 {
48         wake_up((wait_queue_head_t *) data);
49 }
50
51 static inline int
52 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
61 static int
62 fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
63 {
64         struct fs3270 *fp;
65         int rc;
66
67         fp = (struct fs3270 *) view;
68         rq->callback = fs3270_wake_up;
69         rq->callback_data = &fp->wait;
70
71         do {
72                 if (!fs3270_working(fp)) {
73                         /* Fullscreen view isn't ready yet. */
74                         rc = wait_event_interruptible(fp->wait,
75                                                       fs3270_working(fp));
76                         if (rc != 0)
77                                 break;
78                 }
79                 rc = raw3270_start(view, rq);
80                 if (rc == 0) {
81                         /* Started successfully. Now wait for completion. */
82                         wait_event(fp->wait, raw3270_request_final(rq));
83                 }
84         } while (rc == -EACCES);
85         return rc;
86 }
87
88 /*
89  * Switch to the fullscreen view.
90  */
91 static void
92 fs3270_reset_callback(struct raw3270_request *rq, void *data)
93 {
94         struct fs3270 *fp;
95
96         fp = (struct fs3270 *) rq->view;
97         raw3270_request_reset(rq);
98         wake_up(&fp->wait);
99 }
100
101 static void
102 fs3270_restore_callback(struct raw3270_request *rq, void *data)
103 {
104         struct fs3270 *fp;
105
106         fp = (struct fs3270 *) rq->view;
107         if (rq->rc != 0 || rq->rescnt != 0) {
108                 if (fp->fs_pid)
109                         kill_pid(fp->fs_pid, SIGHUP, 1);
110         }
111         fp->rdbuf_size = 0;
112         raw3270_request_reset(rq);
113         wake_up(&fp->wait);
114 }
115
116 static int
117 fs3270_activate(struct raw3270_view *view)
118 {
119         struct fs3270 *fp;
120         char *cp;
121         int rc;
122
123         fp = (struct fs3270 *) view;
124
125         /* If an old init command is still running just return. */
126         if (!raw3270_request_final(fp->init))
127                 return 0;
128
129         if (fp->rdbuf_size == 0) {
130                 /* No saved buffer. Just clear the screen. */
131                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
132                 fp->init->callback = fs3270_reset_callback;
133         } else {
134                 /* Restore fullscreen buffer saved by fs3270_deactivate. */
135                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
136                 raw3270_request_set_idal(fp->init, fp->rdbuf);
137                 fp->init->ccw.count = fp->rdbuf_size;
138                 cp = fp->rdbuf->data[0];
139                 cp[0] = TW_KR;
140                 cp[1] = TO_SBA;
141                 cp[2] = cp[6];
142                 cp[3] = cp[7];
143                 cp[4] = TO_IC;
144                 cp[5] = TO_SBA;
145                 cp[6] = 0x40;
146                 cp[7] = 0x40;
147                 fp->init->rescnt = 0;
148                 fp->init->callback = fs3270_restore_callback;
149         }
150         rc = fp->init->rc = raw3270_start_locked(view, fp->init);
151         if (rc)
152                 fp->init->callback(fp->init, NULL);
153         else
154                 fp->active = 1;
155         return rc;
156 }
157
158 /*
159  * Shutdown fullscreen view.
160  */
161 static void
162 fs3270_save_callback(struct raw3270_request *rq, void *data)
163 {
164         struct fs3270 *fp;
165
166         fp = (struct fs3270 *) rq->view;
167
168         /* Correct idal buffer element 0 address. */
169         fp->rdbuf->data[0] -= 5;
170         fp->rdbuf->size += 5;
171
172         /*
173          * If the rdbuf command failed or the idal buffer is
174          * to small for the amount of data returned by the
175          * rdbuf command, then we have no choice but to send
176          * a SIGHUP to the application.
177          */
178         if (rq->rc != 0 || rq->rescnt == 0) {
179                 if (fp->fs_pid)
180                         kill_pid(fp->fs_pid, SIGHUP, 1);
181                 fp->rdbuf_size = 0;
182         } else
183                 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
184         raw3270_request_reset(rq);
185         wake_up(&fp->wait);
186 }
187
188 static void
189 fs3270_deactivate(struct raw3270_view *view)
190 {
191         struct fs3270 *fp;
192
193         fp = (struct fs3270 *) view;
194         fp->active = 0;
195
196         /* If an old init command is still running just return. */
197         if (!raw3270_request_final(fp->init))
198                 return;
199
200         /* Prepare read-buffer request. */
201         raw3270_request_set_cmd(fp->init, TC_RDBUF);
202         /*
203          * Hackish: skip first 5 bytes of the idal buffer to make
204          * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
205          * in the activation command.
206          */
207         fp->rdbuf->data[0] += 5;
208         fp->rdbuf->size -= 5;
209         raw3270_request_set_idal(fp->init, fp->rdbuf);
210         fp->init->rescnt = 0;
211         fp->init->callback = fs3270_save_callback;
212
213         /* Start I/O to read in the 3270 buffer. */
214         fp->init->rc = raw3270_start_locked(view, fp->init);
215         if (fp->init->rc)
216                 fp->init->callback(fp->init, NULL);
217 }
218
219 static int
220 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
221 {
222         /* Handle ATTN. Set indication and wake waiters for attention. */
223         if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
224                 fp->attention = 1;
225                 wake_up(&fp->wait);
226         }
227
228         if (rq) {
229                 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
230                         rq->rc = -EIO;
231                 else
232                         /* Normal end. Copy residual count. */
233                         rq->rescnt = irb->scsw.cmd.count;
234         }
235         return RAW3270_IO_DONE;
236 }
237
238 /*
239  * Process reads from fullscreen 3270.
240  */
241 static ssize_t
242 fs3270_read(struct file *filp, char __user *data, size_t count, loff_t *off)
243 {
244         struct fs3270 *fp;
245         struct raw3270_request *rq;
246         struct idal_buffer *ib;
247         ssize_t rc;
248         
249         if (count == 0 || count > 65535)
250                 return -EINVAL;
251         fp = filp->private_data;
252         if (!fp)
253                 return -ENODEV;
254         ib = idal_buffer_alloc(count, 0);
255         if (IS_ERR(ib))
256                 return -ENOMEM;
257         rq = raw3270_request_alloc(0);
258         if (!IS_ERR(rq)) {
259                 if (fp->read_command == 0 && fp->write_command != 0)
260                         fp->read_command = 6;
261                 raw3270_request_set_cmd(rq, fp->read_command ? : 2);
262                 raw3270_request_set_idal(rq, ib);
263                 rc = wait_event_interruptible(fp->wait, fp->attention);
264                 fp->attention = 0;
265                 if (rc == 0) {
266                         rc = fs3270_do_io(&fp->view, rq);
267                         if (rc == 0) {
268                                 count -= rq->rescnt;
269                                 if (idal_buffer_to_user(ib, data, count) != 0)
270                                         rc = -EFAULT;
271                                 else
272                                         rc = count;
273
274                         }
275                 }
276                 raw3270_request_free(rq);
277         } else
278                 rc = PTR_ERR(rq);
279         idal_buffer_free(ib);
280         return rc;
281 }
282
283 /*
284  * Process writes to fullscreen 3270.
285  */
286 static ssize_t
287 fs3270_write(struct file *filp, const char __user *data, size_t count, loff_t *off)
288 {
289         struct fs3270 *fp;
290         struct raw3270_request *rq;
291         struct idal_buffer *ib;
292         int write_command;
293         ssize_t rc;
294
295         fp = filp->private_data;
296         if (!fp)
297                 return -ENODEV;
298         ib = idal_buffer_alloc(count, 0);
299         if (IS_ERR(ib))
300                 return -ENOMEM;
301         rq = raw3270_request_alloc(0);
302         if (!IS_ERR(rq)) {
303                 if (idal_buffer_from_user(ib, data, count) == 0) {
304                         write_command = fp->write_command ? : 1;
305                         if (write_command == 5)
306                                 write_command = 13;
307                         raw3270_request_set_cmd(rq, write_command);
308                         raw3270_request_set_idal(rq, ib);
309                         rc = fs3270_do_io(&fp->view, rq);
310                         if (rc == 0)
311                                 rc = count - rq->rescnt;
312                 } else
313                         rc = -EFAULT;
314                 raw3270_request_free(rq);
315         } else
316                 rc = PTR_ERR(rq);
317         idal_buffer_free(ib);
318         return rc;
319 }
320
321 /*
322  * process ioctl commands for the tube driver
323  */
324 static long
325 fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
326 {
327         char __user *argp;
328         struct fs3270 *fp;
329         struct raw3270_iocb iocb;
330         int rc;
331
332         fp = filp->private_data;
333         if (!fp)
334                 return -ENODEV;
335         if (is_compat_task())
336                 argp = compat_ptr(arg);
337         else
338                 argp = (char __user *)arg;
339         rc = 0;
340         mutex_lock(&fs3270_mutex);
341         switch (cmd) {
342         case TUBICMD:
343                 fp->read_command = arg;
344                 break;
345         case TUBOCMD:
346                 fp->write_command = arg;
347                 break;
348         case TUBGETI:
349                 rc = put_user(fp->read_command, argp);
350                 break;
351         case TUBGETO:
352                 rc = put_user(fp->write_command, argp);
353                 break;
354         case TUBGETMOD:
355                 iocb.model = fp->view.model;
356                 iocb.line_cnt = fp->view.rows;
357                 iocb.col_cnt = fp->view.cols;
358                 iocb.pf_cnt = 24;
359                 iocb.re_cnt = 20;
360                 iocb.map = 0;
361                 if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
362                         rc = -EFAULT;
363                 break;
364         }
365         mutex_unlock(&fs3270_mutex);
366         return rc;
367 }
368
369 /*
370  * Allocate fs3270 structure.
371  */
372 static struct fs3270 *
373 fs3270_alloc_view(void)
374 {
375         struct fs3270 *fp;
376
377         fp = kzalloc(sizeof(struct fs3270),GFP_KERNEL);
378         if (!fp)
379                 return ERR_PTR(-ENOMEM);
380         fp->init = raw3270_request_alloc(0);
381         if (IS_ERR(fp->init)) {
382                 kfree(fp);
383                 return ERR_PTR(-ENOMEM);
384         }
385         return fp;
386 }
387
388 /*
389  * Free fs3270 structure.
390  */
391 static void
392 fs3270_free_view(struct raw3270_view *view)
393 {
394         struct fs3270 *fp;
395
396         fp = (struct fs3270 *) view;
397         if (fp->rdbuf)
398                 idal_buffer_free(fp->rdbuf);
399         raw3270_request_free(((struct fs3270 *) view)->init);
400         kfree(view);
401 }
402
403 /*
404  * Unlink fs3270 data structure from filp.
405  */
406 static void
407 fs3270_release(struct raw3270_view *view)
408 {
409         struct fs3270 *fp;
410
411         fp = (struct fs3270 *) view;
412         if (fp->fs_pid)
413                 kill_pid(fp->fs_pid, SIGHUP, 1);
414 }
415
416 /* View to a 3270 device. Can be console, tty or fullscreen. */
417 static struct raw3270_fn fs3270_fn = {
418         .activate = fs3270_activate,
419         .deactivate = fs3270_deactivate,
420         .intv = (void *) fs3270_irq,
421         .release = fs3270_release,
422         .free = fs3270_free_view
423 };
424
425 /*
426  * This routine is called whenever a 3270 fullscreen device is opened.
427  */
428 static int
429 fs3270_open(struct inode *inode, struct file *filp)
430 {
431         struct fs3270 *fp;
432         struct idal_buffer *ib;
433         int minor, rc = 0;
434
435         if (imajor(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
436                 return -ENODEV;
437         minor = iminor(filp->f_path.dentry->d_inode);
438         /* Check for minor 0 multiplexer. */
439         if (minor == 0) {
440                 struct tty_struct *tty = get_current_tty();
441                 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
442                         tty_kref_put(tty);
443                         return -ENODEV;
444                 }
445                 minor = tty->index + RAW3270_FIRSTMINOR;
446                 tty_kref_put(tty);
447         }
448         mutex_lock(&fs3270_mutex);
449         /* Check if some other program is already using fullscreen mode. */
450         fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
451         if (!IS_ERR(fp)) {
452                 raw3270_put_view(&fp->view);
453                 rc = -EBUSY;
454                 goto out;
455         }
456         /* Allocate fullscreen view structure. */
457         fp = fs3270_alloc_view();
458         if (IS_ERR(fp)) {
459                 rc = PTR_ERR(fp);
460                 goto out;
461         }
462
463         init_waitqueue_head(&fp->wait);
464         fp->fs_pid = get_pid(task_pid(current));
465         rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
466         if (rc) {
467                 fs3270_free_view(&fp->view);
468                 goto out;
469         }
470
471         /* Allocate idal-buffer. */
472         ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
473         if (IS_ERR(ib)) {
474                 raw3270_put_view(&fp->view);
475                 raw3270_del_view(&fp->view);
476                 rc = PTR_ERR(ib);
477                 goto out;
478         }
479         fp->rdbuf = ib;
480
481         rc = raw3270_activate_view(&fp->view);
482         if (rc) {
483                 raw3270_put_view(&fp->view);
484                 raw3270_del_view(&fp->view);
485                 goto out;
486         }
487         nonseekable_open(inode, filp);
488         filp->private_data = fp;
489 out:
490         mutex_unlock(&fs3270_mutex);
491         return rc;
492 }
493
494 /*
495  * This routine is called when the 3270 tty is closed. We wait
496  * for the remaining request to be completed. Then we clean up.
497  */
498 static int
499 fs3270_close(struct inode *inode, struct file *filp)
500 {
501         struct fs3270 *fp;
502
503         fp = filp->private_data;
504         filp->private_data = NULL;
505         if (fp) {
506                 put_pid(fp->fs_pid);
507                 fp->fs_pid = NULL;
508                 raw3270_reset(&fp->view);
509                 raw3270_put_view(&fp->view);
510                 raw3270_del_view(&fp->view);
511         }
512         return 0;
513 }
514
515 static const struct file_operations fs3270_fops = {
516         .owner           = THIS_MODULE,         /* owner */
517         .read            = fs3270_read,         /* read */
518         .write           = fs3270_write,        /* write */
519         .unlocked_ioctl  = fs3270_ioctl,        /* ioctl */
520         .compat_ioctl    = fs3270_ioctl,        /* ioctl */
521         .open            = fs3270_open,         /* open */
522         .release         = fs3270_close,        /* release */
523         .llseek         = no_llseek,
524 };
525
526 /*
527  * 3270 fullscreen driver initialization.
528  */
529 static int __init
530 fs3270_init(void)
531 {
532         int rc;
533
534         rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
535         if (rc)
536                 return rc;
537         return 0;
538 }
539
540 static void __exit
541 fs3270_exit(void)
542 {
543         unregister_chrdev(IBM_FS3270_MAJOR, "fs3270");
544 }
545
546 MODULE_LICENSE("GPL");
547 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
548
549 module_init(fs3270_init);
550 module_exit(fs3270_exit);