Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6] / drivers / s390 / char / fs3270.c
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
27 static struct raw3270_fn fs3270_fn;
28
29 struct 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
42 static void
43 fs3270_wake_up(struct raw3270_request *rq, void *data)
44 {
45         wake_up((wait_queue_head_t *) data);
46 }
47
48 static inline int
49 fs3270_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
58 static int
59 fs3270_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  */
88 static void
89 fs3270_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
98 static void
99 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
113 static int
114 fs3270_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  */
158 static void
159 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] -= 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
185 static void
186 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] += 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
216 static int
217 fs3270_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  */
238 static ssize_t
239 fs3270_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  */
283 static ssize_t
284 fs3270_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  */
321 static long
322 fs3270_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  */
365 static struct fs3270 *
366 fs3270_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  */
384 static void
385 fs3270_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  */
399 static void
400 fs3270_release(struct raw3270_view *view)
401 {
402 }
403
404 /* View to a 3270 device. Can be console, tty or fullscreen. */
405 static 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  */
416 static int
417 fs3270_open(struct inode *inode, struct file *filp)
418 {
419         struct fs3270 *fp;
420         struct idal_buffer *ib;
421         int minor, rc = 0;
422
423         if (imajor(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
424                 return -ENODEV;
425         minor = iminor(filp->f_path.dentry->d_inode);
426         /* Check for minor 0 multiplexer. */
427         if (minor == 0) {
428                 struct tty_struct *tty = get_current_tty();
429                 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
430                         tty_kref_put(tty);
431                         return -ENODEV;
432                 }
433                 minor = tty->index + RAW3270_FIRSTMINOR;
434                 tty_kref_put(tty);
435         }
436         lock_kernel();
437         /* Check if some other program is already using fullscreen mode. */
438         fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
439         if (!IS_ERR(fp)) {
440                 raw3270_put_view(&fp->view);
441                 rc = -EBUSY;
442                 goto out;
443         }
444         /* Allocate fullscreen view structure. */
445         fp = fs3270_alloc_view();
446         if (IS_ERR(fp)) {
447                 rc = PTR_ERR(fp);
448                 goto out;
449         }
450
451         init_waitqueue_head(&fp->wait);
452         fp->fs_pid = get_pid(task_pid(current));
453         rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
454         if (rc) {
455                 fs3270_free_view(&fp->view);
456                 goto out;
457         }
458
459         /* Allocate idal-buffer. */
460         ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
461         if (IS_ERR(ib)) {
462                 raw3270_put_view(&fp->view);
463                 raw3270_del_view(&fp->view);
464                 rc = PTR_ERR(fp);
465                 goto out;
466         }
467         fp->rdbuf = ib;
468
469         rc = raw3270_activate_view(&fp->view);
470         if (rc) {
471                 raw3270_put_view(&fp->view);
472                 raw3270_del_view(&fp->view);
473                 goto out;
474         }
475         filp->private_data = fp;
476 out:
477         unlock_kernel();
478         return rc;
479 }
480
481 /*
482  * This routine is called when the 3270 tty is closed. We wait
483  * for the remaining request to be completed. Then we clean up.
484  */
485 static int
486 fs3270_close(struct inode *inode, struct file *filp)
487 {
488         struct fs3270 *fp;
489
490         fp = filp->private_data;
491         filp->private_data = NULL;
492         if (fp) {
493                 put_pid(fp->fs_pid);
494                 fp->fs_pid = NULL;
495                 raw3270_reset(&fp->view);
496                 raw3270_put_view(&fp->view);
497                 raw3270_del_view(&fp->view);
498         }
499         return 0;
500 }
501
502 static const struct file_operations fs3270_fops = {
503         .owner           = THIS_MODULE,         /* owner */
504         .read            = fs3270_read,         /* read */
505         .write           = fs3270_write,        /* write */
506         .unlocked_ioctl  = fs3270_ioctl,        /* ioctl */
507         .compat_ioctl    = fs3270_ioctl,        /* ioctl */
508         .open           = fs3270_open,          /* open */
509         .release        = fs3270_close,         /* release */
510 };
511
512 /*
513  * 3270 fullscreen driver initialization.
514  */
515 static int __init
516 fs3270_init(void)
517 {
518         int rc;
519
520         rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
521         if (rc)
522                 return rc;
523         return 0;
524 }
525
526 static void __exit
527 fs3270_exit(void)
528 {
529         unregister_chrdev(IBM_FS3270_MAJOR, "fs3270");
530 }
531
532 MODULE_LICENSE("GPL");
533 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
534
535 module_init(fs3270_init);
536 module_exit(fs3270_exit);