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   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;
 422
 423         if (imajor(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
 424                 return -ENODEV;
 425         lock_kernel();
 426         minor = iminor(filp->f_path.dentry->d_inode);
 427         /* Check for minor 0 multiplexer. */
 428         if (minor == 0) {
 429                 struct tty_struct *tty;
 430                 mutex_lock(&tty_mutex);
 431                 tty = get_current_tty();
 432                 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
 433                         mutex_unlock(&tty_mutex);
 434                         rc = -ENODEV;
 435                         goto out;
 436                 }
 437                 minor = tty->index + RAW3270_FIRSTMINOR;
 438                 mutex_unlock(&tty_mutex);
 439         }
 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         if (rc) {
 458                 fs3270_free_view(&fp->view);
 459                 goto out;
 460         }
 461
 462         /* Allocate idal-buffer. */
 463         ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
 464         if (IS_ERR(ib)) {
 465                 raw3270_put_view(&fp->view);
 466                 raw3270_del_view(&fp->view);
 467                 rc = PTR_ERR(fp);
 468                 goto out;
 469         }
 470         fp->rdbuf = ib;
 471
 472         rc = raw3270_activate_view(&fp->view);
 473         if (rc) {
 474                 raw3270_put_view(&fp->view);
 475                 raw3270_del_view(&fp->view);
 476                 goto out;
 477         }
 478         filp->private_data = fp;
 479 out:
 480         unlock_kernel();
 481         return 0;
 482 }
 483
 484 /*
 485  * This routine is called when the 3270 tty is closed. We wait
 486  * for the remaining request to be completed. Then we clean up.
 487  */
 488 static int
 489 fs3270_close(struct inode *inode, struct file *filp)
 490 {
 491         struct fs3270 *fp;
 492
 493         fp = filp->private_data;
 494         filp->private_data = NULL;
 495         if (fp) {
 496                 put_pid(fp->fs_pid);
 497                 fp->fs_pid = NULL;
 498                 raw3270_reset(&fp->view);
 499                 raw3270_put_view(&fp->view);
 500                 raw3270_del_view(&fp->view);
 501         }
 502         return 0;
 503 }
 504
 505 static const struct file_operations fs3270_fops = {
 506         .owner           = THIS_MODULE,         /* owner */
 507         .read            = fs3270_read,         /* read */
 508         .write           = fs3270_write,        /* write */
 509         .unlocked_ioctl  = fs3270_ioctl,        /* ioctl */
 510         .compat_ioctl    = fs3270_ioctl,        /* ioctl */
 511         .open           = fs3270_open,          /* open */
 512         .release        = fs3270_close,         /* release */
 513 };
 514
 515 /*
 516  * 3270 fullscreen driver initialization.
 517  */
 518 static int __init
 519 fs3270_init(void)
 520 {
 521         int rc;
 522
 523         rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
 524         if (rc)
 525                 return rc;
 526         return 0;
 527 }
 528
 529 static void __exit
 530 fs3270_exit(void)
 531 {
 532         unregister_chrdev(IBM_FS3270_MAJOR, "fs3270");
 533 }
 534
 535 MODULE_LICENSE("GPL");
 536 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
 537
 538 module_init(fs3270_init);
 539 module_exit(fs3270_exit);