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/list.h>
  15 #include <linux/slab.h>
  16 #include <linux/types.h>
  17
  18 #include <asm/compat.h>
  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 DEFINE_MUTEX(fs3270_mutex);
  43
  44 static void
  45 fs3270_wake_up(struct raw3270_request *rq, void *data)
  46 {
  47         wake_up((wait_queue_head_t *) data);
  48 }
  49
  50 static inline int
  51 fs3270_working(struct fs3270 *fp)
  52 {
  53         /*
  54          * The fullscreen view is in working order if the view
  55          * has been activated AND the initial request is finished.
  56          */
  57         return fp->active && raw3270_request_final(fp->init);
  58 }
  59
  60 static int
  61 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  */
  90 static void
  91 fs3270_reset_callback(struct raw3270_request *rq, void *data)
  92 {
  93         struct fs3270 *fp;
  94
  95         fp = (struct fs3270 *) rq->view;
  96         raw3270_request_reset(rq);
  97         wake_up(&fp->wait);
  98 }
  99
 100 static void
 101 fs3270_restore_callback(struct raw3270_request *rq, void *data)
 102 {
 103         struct fs3270 *fp;
 104
 105         fp = (struct fs3270 *) rq->view;
 106         if (rq->rc != 0 || rq->rescnt != 0) {
 107                 if (fp->fs_pid)
 108                         kill_pid(fp->fs_pid, SIGHUP, 1);
 109         }
 110         fp->rdbuf_size = 0;
 111         raw3270_request_reset(rq);
 112         wake_up(&fp->wait);
 113 }
 114
 115 static int
 116 fs3270_activate(struct raw3270_view *view)
 117 {
 118         struct fs3270 *fp;
 119         char *cp;
 120         int rc;
 121
 122         fp = (struct fs3270 *) view;
 123
 124         /* If an old init command is still running just return. */
 125         if (!raw3270_request_final(fp->init))
 126                 return 0;
 127
 128         if (fp->rdbuf_size == 0) {
 129                 /* No saved buffer. Just clear the screen. */
 130                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 131                 fp->init->callback = fs3270_reset_callback;
 132         } else {
 133                 /* Restore fullscreen buffer saved by fs3270_deactivate. */
 134                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 135                 raw3270_request_set_idal(fp->init, fp->rdbuf);
 136                 fp->init->ccw.count = fp->rdbuf_size;
 137                 cp = fp->rdbuf->data[0];
 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                 fp->init->rescnt = 0;
 147                 fp->init->callback = fs3270_restore_callback;
 148         }
 149         rc = fp->init->rc = raw3270_start_locked(view, fp->init);
 150         if (rc)
 151                 fp->init->callback(fp->init, NULL);
 152         else
 153                 fp->active = 1;
 154         return rc;
 155 }
 156
 157 /*
 158  * Shutdown fullscreen view.
 159  */
 160 static void
 161 fs3270_save_callback(struct raw3270_request *rq, void *data)
 162 {
 163         struct fs3270 *fp;
 164
 165         fp = (struct fs3270 *) rq->view;
 166
 167         /* Correct idal buffer element 0 address. */
 168         fp->rdbuf->data[0] -= 5;
 169         fp->rdbuf->size += 5;
 170
 171         /*
 172          * If the rdbuf command failed or the idal buffer is
 173          * to small for the amount of data returned by the
 174          * rdbuf command, then we have no choice but to send
 175          * a SIGHUP to the application.
 176          */
 177         if (rq->rc != 0 || rq->rescnt == 0) {
 178                 if (fp->fs_pid)
 179                         kill_pid(fp->fs_pid, SIGHUP, 1);
 180                 fp->rdbuf_size = 0;
 181         } else
 182                 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
 183         raw3270_request_reset(rq);
 184         wake_up(&fp->wait);
 185 }
 186
 187 static void
 188 fs3270_deactivate(struct raw3270_view *view)
 189 {
 190         struct fs3270 *fp;
 191
 192         fp = (struct fs3270 *) view;
 193         fp->active = 0;
 194
 195         /* If an old init command is still running just return. */
 196         if (!raw3270_request_final(fp->init))
 197                 return;
 198
 199         /* Prepare read-buffer request. */
 200         raw3270_request_set_cmd(fp->init, TC_RDBUF);
 201         /*
 202          * Hackish: skip first 5 bytes of the idal buffer to make
 203          * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
 204          * in the activation command.
 205          */
 206         fp->rdbuf->data[0] += 5;
 207         fp->rdbuf->size -= 5;
 208         raw3270_request_set_idal(fp->init, fp->rdbuf);
 209         fp->init->rescnt = 0;
 210         fp->init->callback = fs3270_save_callback;
 211
 212         /* Start I/O to read in the 3270 buffer. */
 213         fp->init->rc = raw3270_start_locked(view, fp->init);
 214         if (fp->init->rc)
 215                 fp->init->callback(fp->init, NULL);
 216 }
 217
 218 static int
 219 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
 220 {
 221         /* Handle ATTN. Set indication and wake waiters for attention. */
 222         if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
 223                 fp->attention = 1;
 224                 wake_up(&fp->wait);
 225         }
 226
 227         if (rq) {
 228                 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
 229                         rq->rc = -EIO;
 230                 else
 231                         /* Normal end. Copy residual count. */
 232                         rq->rescnt = irb->scsw.cmd.count;
 233         }
 234         return RAW3270_IO_DONE;
 235 }
 236
 237 /*
 238  * Process reads from fullscreen 3270.
 239  */
 240 static ssize_t
 241 fs3270_read(struct file *filp, char __user *data, size_t count, loff_t *off)
 242 {
 243         struct fs3270 *fp;
 244         struct raw3270_request *rq;
 245         struct idal_buffer *ib;
 246         ssize_t rc;
 247
 248         if (count == 0 || count > 65535)
 249                 return -EINVAL;
 250         fp = filp->private_data;
 251         if (!fp)
 252                 return -ENODEV;
 253         ib = idal_buffer_alloc(count, 0);
 254         if (IS_ERR(ib))
 255                 return -ENOMEM;
 256         rq = raw3270_request_alloc(0);
 257         if (!IS_ERR(rq)) {
 258                 if (fp->read_command == 0 && fp->write_command != 0)
 259                         fp->read_command = 6;
 260                 raw3270_request_set_cmd(rq, fp->read_command ? : 2);
 261                 raw3270_request_set_idal(rq, ib);
 262                 rc = wait_event_interruptible(fp->wait, fp->attention);
 263                 fp->attention = 0;
 264                 if (rc == 0) {
 265                         rc = fs3270_do_io(&fp->view, rq);
 266                         if (rc == 0) {
 267                                 count -= rq->rescnt;
 268                                 if (idal_buffer_to_user(ib, data, count) != 0)
 269                                         rc = -EFAULT;
 270                                 else
 271                                         rc = count;
 272
 273                         }
 274                 }
 275                 raw3270_request_free(rq);
 276         } else
 277                 rc = PTR_ERR(rq);
 278         idal_buffer_free(ib);
 279         return rc;
 280 }
 281
 282 /*
 283  * Process writes to fullscreen 3270.
 284  */
 285 static ssize_t
 286 fs3270_write(struct file *filp, const char __user *data, size_t count, loff_t *off)
 287 {
 288         struct fs3270 *fp;
 289         struct raw3270_request *rq;
 290         struct idal_buffer *ib;
 291         int write_command;
 292         ssize_t rc;
 293
 294         fp = filp->private_data;
 295         if (!fp)
 296                 return -ENODEV;
 297         ib = idal_buffer_alloc(count, 0);
 298         if (IS_ERR(ib))
 299                 return -ENOMEM;
 300         rq = raw3270_request_alloc(0);
 301         if (!IS_ERR(rq)) {
 302                 if (idal_buffer_from_user(ib, data, count) == 0) {
 303                         write_command = fp->write_command ? : 1;
 304                         if (write_command == 5)
 305                                 write_command = 13;
 306                         raw3270_request_set_cmd(rq, write_command);
 307                         raw3270_request_set_idal(rq, ib);
 308                         rc = fs3270_do_io(&fp->view, rq);
 309                         if (rc == 0)
 310                                 rc = count - rq->rescnt;
 311                 } else
 312                         rc = -EFAULT;
 313                 raw3270_request_free(rq);
 314         } else
 315                 rc = PTR_ERR(rq);
 316         idal_buffer_free(ib);
 317         return rc;
 318 }
 319
 320 /*
 321  * process ioctl commands for the tube driver
 322  */
 323 static long
 324 fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 325 {
 326         char __user *argp;
 327         struct fs3270 *fp;
 328         struct raw3270_iocb iocb;
 329         int rc;
 330
 331         fp = filp->private_data;
 332         if (!fp)
 333                 return -ENODEV;
 334         if (is_compat_task())
 335                 argp = compat_ptr(arg);
 336         else
 337                 argp = (char __user *)arg;
 338         rc = 0;
 339         mutex_lock(&fs3270_mutex);
 340         switch (cmd) {
 341         case TUBICMD:
 342                 fp->read_command = arg;
 343                 break;
 344         case TUBOCMD:
 345                 fp->write_command = arg;
 346                 break;
 347         case TUBGETI:
 348                 rc = put_user(fp->read_command, argp);
 349                 break;
 350         case TUBGETO:
 351                 rc = put_user(fp->write_command, argp);
 352                 break;
 353         case TUBGETMOD:
 354                 iocb.model = fp->view.model;
 355                 iocb.line_cnt = fp->view.rows;
 356                 iocb.col_cnt = fp->view.cols;
 357                 iocb.pf_cnt = 24;
 358                 iocb.re_cnt = 20;
 359                 iocb.map = 0;
 360                 if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
 361                         rc = -EFAULT;
 362                 break;
 363         }
 364         mutex_unlock(&fs3270_mutex);
 365         return rc;
 366 }
 367
 368 /*
 369  * Allocate fs3270 structure.
 370  */
 371 static struct fs3270 *
 372 fs3270_alloc_view(void)
 373 {
 374         struct fs3270 *fp;
 375
 376         fp = kzalloc(sizeof(struct fs3270),GFP_KERNEL);
 377         if (!fp)
 378                 return ERR_PTR(-ENOMEM);
 379         fp->init = raw3270_request_alloc(0);
 380         if (IS_ERR(fp->init)) {
 381                 kfree(fp);
 382                 return ERR_PTR(-ENOMEM);
 383         }
 384         return fp;
 385 }
 386
 387 /*
 388  * Free fs3270 structure.
 389  */
 390 static void
 391 fs3270_free_view(struct raw3270_view *view)
 392 {
 393         struct fs3270 *fp;
 394
 395         fp = (struct fs3270 *) view;
 396         if (fp->rdbuf)
 397                 idal_buffer_free(fp->rdbuf);
 398         raw3270_request_free(((struct fs3270 *) view)->init);
 399         kfree(view);
 400 }
 401
 402 /*
 403  * Unlink fs3270 data structure from filp.
 404  */
 405 static void
 406 fs3270_release(struct raw3270_view *view)
 407 {
 408         struct fs3270 *fp;
 409
 410         fp = (struct fs3270 *) view;
 411         if (fp->fs_pid)
 412                 kill_pid(fp->fs_pid, SIGHUP, 1);
 413 }
 414
 415 /* View to a 3270 device. Can be console, tty or fullscreen. */
 416 static struct raw3270_fn fs3270_fn = {
 417         .activate = fs3270_activate,
 418         .deactivate = fs3270_deactivate,
 419         .intv = (void *) fs3270_irq,
 420         .release = fs3270_release,
 421         .free = fs3270_free_view
 422 };
 423
 424 /*
 425  * This routine is called whenever a 3270 fullscreen device is opened.
 426  */
 427 static int
 428 fs3270_open(struct inode *inode, struct file *filp)
 429 {
 430         struct fs3270 *fp;
 431         struct idal_buffer *ib;
 432         int minor, rc = 0;
 433
 434         if (imajor(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
 435                 return -ENODEV;
 436         minor = iminor(filp->f_path.dentry->d_inode);
 437         /* Check for minor 0 multiplexer. */
 438         if (minor == 0) {
 439                 struct tty_struct *tty = get_current_tty();
 440                 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
 441                         tty_kref_put(tty);
 442                         return -ENODEV;
 443                 }
 444                 minor = tty->index + RAW3270_FIRSTMINOR;
 445                 tty_kref_put(tty);
 446         }
 447         mutex_lock(&fs3270_mutex);
 448         /* Check if some other program is already using fullscreen mode. */
 449         fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
 450         if (!IS_ERR(fp)) {
 451                 raw3270_put_view(&fp->view);
 452                 rc = -EBUSY;
 453                 goto out;
 454         }
 455         /* Allocate fullscreen view structure. */
 456         fp = fs3270_alloc_view();
 457         if (IS_ERR(fp)) {
 458                 rc = PTR_ERR(fp);
 459                 goto out;
 460         }
 461
 462         init_waitqueue_head(&fp->wait);
 463         fp->fs_pid = get_pid(task_pid(current));
 464         rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
 465         if (rc) {
 466                 fs3270_free_view(&fp->view);
 467                 goto out;
 468         }
 469
 470         /* Allocate idal-buffer. */
 471         ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
 472         if (IS_ERR(ib)) {
 473                 raw3270_put_view(&fp->view);
 474                 raw3270_del_view(&fp->view);
 475                 rc = PTR_ERR(ib);
 476                 goto out;
 477         }
 478         fp->rdbuf = ib;
 479
 480         rc = raw3270_activate_view(&fp->view);
 481         if (rc) {
 482                 raw3270_put_view(&fp->view);
 483                 raw3270_del_view(&fp->view);
 484                 goto out;
 485         }
 486         nonseekable_open(inode, filp);
 487         filp->private_data = fp;
 488 out:
 489         mutex_unlock(&fs3270_mutex);
 490         return rc;
 491 }
 492
 493 /*
 494  * This routine is called when the 3270 tty is closed. We wait
 495  * for the remaining request to be completed. Then we clean up.
 496  */
 497 static int
 498 fs3270_close(struct inode *inode, struct file *filp)
 499 {
 500         struct fs3270 *fp;
 501
 502         fp = filp->private_data;
 503         filp->private_data = NULL;
 504         if (fp) {
 505                 put_pid(fp->fs_pid);
 506                 fp->fs_pid = NULL;
 507                 raw3270_reset(&fp->view);
 508                 raw3270_put_view(&fp->view);
 509                 raw3270_del_view(&fp->view);
 510         }
 511         return 0;
 512 }
 513
 514 static const struct file_operations fs3270_fops = {
 515         .owner           = THIS_MODULE,         /* owner */
 516         .read            = fs3270_read,         /* read */
 517         .write           = fs3270_write,        /* write */
 518         .unlocked_ioctl  = fs3270_ioctl,        /* ioctl */
 519         .compat_ioctl    = fs3270_ioctl,        /* ioctl */
 520         .open            = fs3270_open,         /* open */
 521         .release         = fs3270_close,        /* release */
 522         .llseek         = no_llseek,
 523 };
 524
 525 /*
 526  * 3270 fullscreen driver initialization.
 527  */
 528 static int __init
 529 fs3270_init(void)
 530 {
 531         int rc;
 532
 533         rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
 534         if (rc)
 535                 return rc;
 536         return 0;
 537 }
 538
 539 static void __exit
 540 fs3270_exit(void)
 541 {
 542         unregister_chrdev(IBM_FS3270_MAJOR, "fs3270");
 543 }
 544
 545 MODULE_LICENSE("GPL");
 546 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
 547
 548 module_init(fs3270_init);
 549 module_exit(fs3270_exit);