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/types.h>
  16 #include <linux/smp_lock.h>
  17
  18 #include <asm/ccwdev.h>
  19 #include <asm/cio.h>
  20 #include <asm/ebcdic.h>
  21 #include <asm/idals.h>
  22
  23 #include "raw3270.h"
  24 #include "ctrlchar.h"
  25
  26 static struct raw3270_fn fs3270_fn;
  27
  28 struct fs3270 {
  29         struct raw3270_view view;
  30         struct pid *fs_pid;             /* Pid of controlling program. */
  31         int read_command;               /* ccw command to use for reads. */
  32         int write_command;              /* ccw command to use for writes. */
  33         int attention;                  /* Got attention. */
  34         int active;                     /* Fullscreen view is active. */
  35         struct raw3270_request *init;   /* single init request. */
  36         wait_queue_head_t wait;         /* Init & attention wait queue. */
  37         struct idal_buffer *rdbuf;      /* full-screen-deactivate buffer */
  38         size_t rdbuf_size;              /* size of data returned by RDBUF */
  39 };
  40
  41 static void
  42 fs3270_wake_up(struct raw3270_request *rq, void *data)
  43 {
  44         wake_up((wait_queue_head_t *) data);
  45 }
  46
  47 static inline int
  48 fs3270_working(struct fs3270 *fp)
  49 {
  50         /*
  51          * The fullscreen view is in working order if the view
  52          * has been activated AND the initial request is finished.
  53          */
  54         return fp->active && raw3270_request_final(fp->init);
  55 }
  56
  57 static int
  58 fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
  59 {
  60         struct fs3270 *fp;
  61         int rc;
  62
  63         fp = (struct fs3270 *) view;
  64         rq->callback = fs3270_wake_up;
  65         rq->callback_data = &fp->wait;
  66
  67         do {
  68                 if (!fs3270_working(fp)) {
  69                         /* Fullscreen view isn't ready yet. */
  70                         rc = wait_event_interruptible(fp->wait,
  71                                                       fs3270_working(fp));
  72                         if (rc != 0)
  73                                 break;
  74                 }
  75                 rc = raw3270_start(view, rq);
  76                 if (rc == 0) {
  77                         /* Started sucessfully. Now wait for completion. */
  78                         wait_event(fp->wait, raw3270_request_final(rq));
  79                 }
  80         } while (rc == -EACCES);
  81         return rc;
  82 }
  83
  84 /*
  85  * Switch to the fullscreen view.
  86  */
  87 static void
  88 fs3270_reset_callback(struct raw3270_request *rq, void *data)
  89 {
  90         struct fs3270 *fp;
  91
  92         fp = (struct fs3270 *) rq->view;
  93         raw3270_request_reset(rq);
  94         wake_up(&fp->wait);
  95 }
  96
  97 static void
  98 fs3270_restore_callback(struct raw3270_request *rq, void *data)
  99 {
 100         struct fs3270 *fp;
 101
 102         fp = (struct fs3270 *) rq->view;
 103         if (rq->rc != 0 || rq->rescnt != 0) {
 104                 if (fp->fs_pid)
 105                         kill_pid(fp->fs_pid, SIGHUP, 1);
 106         }
 107         fp->rdbuf_size = 0;
 108         raw3270_request_reset(rq);
 109         wake_up(&fp->wait);
 110 }
 111
 112 static int
 113 fs3270_activate(struct raw3270_view *view)
 114 {
 115         struct fs3270 *fp;
 116         char *cp;
 117         int rc;
 118
 119         fp = (struct fs3270 *) view;
 120
 121         /* If an old init command is still running just return. */
 122         if (!raw3270_request_final(fp->init))
 123                 return 0;
 124
 125         if (fp->rdbuf_size == 0) {
 126                 /* No saved buffer. Just clear the screen. */
 127                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 128                 fp->init->callback = fs3270_reset_callback;
 129         } else {
 130                 /* Restore fullscreen buffer saved by fs3270_deactivate. */
 131                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 132                 raw3270_request_set_idal(fp->init, fp->rdbuf);
 133                 fp->init->ccw.count = fp->rdbuf_size;
 134                 cp = fp->rdbuf->data[0];
 135                 cp[0] = TW_KR;
 136                 cp[1] = TO_SBA;
 137                 cp[2] = cp[6];
 138                 cp[3] = cp[7];
 139                 cp[4] = TO_IC;
 140                 cp[5] = TO_SBA;
 141                 cp[6] = 0x40;
 142                 cp[7] = 0x40;
 143                 fp->init->rescnt = 0;
 144                 fp->init->callback = fs3270_restore_callback;
 145         }
 146         rc = fp->init->rc = raw3270_start_locked(view, fp->init);
 147         if (rc)
 148                 fp->init->callback(fp->init, NULL);
 149         else
 150                 fp->active = 1;
 151         return rc;
 152 }
 153
 154 /*
 155  * Shutdown fullscreen view.
 156  */
 157 static void
 158 fs3270_save_callback(struct raw3270_request *rq, void *data)
 159 {
 160         struct fs3270 *fp;
 161
 162         fp = (struct fs3270 *) rq->view;
 163
 164         /* Correct idal buffer element 0 address. */
 165         fp->rdbuf->data[0] -= 5;
 166         fp->rdbuf->size += 5;
 167
 168         /*
 169          * If the rdbuf command failed or the idal buffer is
 170          * to small for the amount of data returned by the
 171          * rdbuf command, then we have no choice but to send
 172          * a SIGHUP to the application.
 173          */
 174         if (rq->rc != 0 || rq->rescnt == 0) {
 175                 if (fp->fs_pid)
 176                         kill_pid(fp->fs_pid, SIGHUP, 1);
 177                 fp->rdbuf_size = 0;
 178         } else
 179                 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
 180         raw3270_request_reset(rq);
 181         wake_up(&fp->wait);
 182 }
 183
 184 static void
 185 fs3270_deactivate(struct raw3270_view *view)
 186 {
 187         struct fs3270 *fp;
 188
 189         fp = (struct fs3270 *) view;
 190         fp->active = 0;
 191
 192         /* If an old init command is still running just return. */
 193         if (!raw3270_request_final(fp->init))
 194                 return;
 195
 196         /* Prepare read-buffer request. */
 197         raw3270_request_set_cmd(fp->init, TC_RDBUF);
 198         /*
 199          * Hackish: skip first 5 bytes of the idal buffer to make
 200          * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
 201          * in the activation command.
 202          */
 203         fp->rdbuf->data[0] += 5;
 204         fp->rdbuf->size -= 5;
 205         raw3270_request_set_idal(fp->init, fp->rdbuf);
 206         fp->init->rescnt = 0;
 207         fp->init->callback = fs3270_save_callback;
 208
 209         /* Start I/O to read in the 3270 buffer. */
 210         fp->init->rc = raw3270_start_locked(view, fp->init);
 211         if (fp->init->rc)
 212                 fp->init->callback(fp->init, NULL);
 213 }
 214
 215 static int
 216 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
 217 {
 218         /* Handle ATTN. Set indication and wake waiters for attention. */
 219         if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
 220                 fp->attention = 1;
 221                 wake_up(&fp->wait);
 222         }
 223
 224         if (rq) {
 225                 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
 226                         rq->rc = -EIO;
 227                 else
 228                         /* Normal end. Copy residual count. */
 229                         rq->rescnt = irb->scsw.cmd.count;
 230         }
 231         return RAW3270_IO_DONE;
 232 }
 233
 234 /*
 235  * Process reads from fullscreen 3270.
 236  */
 237 static ssize_t
 238 fs3270_read(struct file *filp, char __user *data, size_t count, loff_t *off)
 239 {
 240         struct fs3270 *fp;
 241         struct raw3270_request *rq;
 242         struct idal_buffer *ib;
 243         ssize_t rc;
 244
 245         if (count == 0 || count > 65535)
 246                 return -EINVAL;
 247         fp = filp->private_data;
 248         if (!fp)
 249                 return -ENODEV;
 250         ib = idal_buffer_alloc(count, 0);
 251         if (IS_ERR(ib))
 252                 return -ENOMEM;
 253         rq = raw3270_request_alloc(0);
 254         if (!IS_ERR(rq)) {
 255                 if (fp->read_command == 0 && fp->write_command != 0)
 256                         fp->read_command = 6;
 257                 raw3270_request_set_cmd(rq, fp->read_command ? : 2);
 258                 raw3270_request_set_idal(rq, ib);
 259                 rc = wait_event_interruptible(fp->wait, fp->attention);
 260                 fp->attention = 0;
 261                 if (rc == 0) {
 262                         rc = fs3270_do_io(&fp->view, rq);
 263                         if (rc == 0) {
 264                                 count -= rq->rescnt;
 265                                 if (idal_buffer_to_user(ib, data, count) != 0)
 266                                         rc = -EFAULT;
 267                                 else
 268                                         rc = count;
 269
 270                         }
 271                 }
 272                 raw3270_request_free(rq);
 273         } else
 274                 rc = PTR_ERR(rq);
 275         idal_buffer_free(ib);
 276         return rc;
 277 }
 278
 279 /*
 280  * Process writes to fullscreen 3270.
 281  */
 282 static ssize_t
 283 fs3270_write(struct file *filp, const char __user *data, size_t count, loff_t *off)
 284 {
 285         struct fs3270 *fp;
 286         struct raw3270_request *rq;
 287         struct idal_buffer *ib;
 288         int write_command;
 289         ssize_t rc;
 290
 291         fp = filp->private_data;
 292         if (!fp)
 293                 return -ENODEV;
 294         ib = idal_buffer_alloc(count, 0);
 295         if (IS_ERR(ib))
 296                 return -ENOMEM;
 297         rq = raw3270_request_alloc(0);
 298         if (!IS_ERR(rq)) {
 299                 if (idal_buffer_from_user(ib, data, count) == 0) {
 300                         write_command = fp->write_command ? : 1;
 301                         if (write_command == 5)
 302                                 write_command = 13;
 303                         raw3270_request_set_cmd(rq, write_command);
 304                         raw3270_request_set_idal(rq, ib);
 305                         rc = fs3270_do_io(&fp->view, rq);
 306                         if (rc == 0)
 307                                 rc = count - rq->rescnt;
 308                 } else
 309                         rc = -EFAULT;
 310                 raw3270_request_free(rq);
 311         } else
 312                 rc = PTR_ERR(rq);
 313         idal_buffer_free(ib);
 314         return rc;
 315 }
 316
 317 /*
 318  * process ioctl commands for the tube driver
 319  */
 320 static long
 321 fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 322 {
 323         struct fs3270 *fp;
 324         struct raw3270_iocb iocb;
 325         int rc;
 326
 327         fp = filp->private_data;
 328         if (!fp)
 329                 return -ENODEV;
 330         rc = 0;
 331         lock_kernel();
 332         switch (cmd) {
 333         case TUBICMD:
 334                 fp->read_command = arg;
 335                 break;
 336         case TUBOCMD:
 337                 fp->write_command = arg;
 338                 break;
 339         case TUBGETI:
 340                 rc = put_user(fp->read_command, (char __user *) arg);
 341                 break;
 342         case TUBGETO:
 343                 rc = put_user(fp->write_command,(char __user *) arg);
 344                 break;
 345         case TUBGETMOD:
 346                 iocb.model = fp->view.model;
 347                 iocb.line_cnt = fp->view.rows;
 348                 iocb.col_cnt = fp->view.cols;
 349                 iocb.pf_cnt = 24;
 350                 iocb.re_cnt = 20;
 351                 iocb.map = 0;
 352                 if (copy_to_user((char __user *) arg, &iocb,
 353                                  sizeof(struct raw3270_iocb)))
 354                         rc = -EFAULT;
 355                 break;
 356         }
 357         unlock_kernel();
 358         return rc;
 359 }
 360
 361 /*
 362  * Allocate fs3270 structure.
 363  */
 364 static struct fs3270 *
 365 fs3270_alloc_view(void)
 366 {
 367         struct fs3270 *fp;
 368
 369         fp = kzalloc(sizeof(struct fs3270),GFP_KERNEL);
 370         if (!fp)
 371                 return ERR_PTR(-ENOMEM);
 372         fp->init = raw3270_request_alloc(0);
 373         if (IS_ERR(fp->init)) {
 374                 kfree(fp);
 375                 return ERR_PTR(-ENOMEM);
 376         }
 377         return fp;
 378 }
 379
 380 /*
 381  * Free fs3270 structure.
 382  */
 383 static void
 384 fs3270_free_view(struct raw3270_view *view)
 385 {
 386         struct fs3270 *fp;
 387
 388         fp = (struct fs3270 *) view;
 389         if (fp->rdbuf)
 390                 idal_buffer_free(fp->rdbuf);
 391         raw3270_request_free(((struct fs3270 *) view)->init);
 392         kfree(view);
 393 }
 394
 395 /*
 396  * Unlink fs3270 data structure from filp.
 397  */
 398 static void
 399 fs3270_release(struct raw3270_view *view)
 400 {
 401         struct fs3270 *fp;
 402
 403         fp = (struct fs3270 *) view;
 404         if (fp->fs_pid)
 405                 kill_pid(fp->fs_pid, SIGHUP, 1);
 406 }
 407
 408 /* View to a 3270 device. Can be console, tty or fullscreen. */
 409 static struct raw3270_fn fs3270_fn = {
 410         .activate = fs3270_activate,
 411         .deactivate = fs3270_deactivate,
 412         .intv = (void *) fs3270_irq,
 413         .release = fs3270_release,
 414         .free = fs3270_free_view
 415 };
 416
 417 /*
 418  * This routine is called whenever a 3270 fullscreen device is opened.
 419  */
 420 static int
 421 fs3270_open(struct inode *inode, struct file *filp)
 422 {
 423         struct fs3270 *fp;
 424         struct idal_buffer *ib;
 425         int minor, rc = 0;
 426
 427         if (imajor(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
 428                 return -ENODEV;
 429         minor = iminor(filp->f_path.dentry->d_inode);
 430         /* Check for minor 0 multiplexer. */
 431         if (minor == 0) {
 432                 struct tty_struct *tty = get_current_tty();
 433                 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
 434                         tty_kref_put(tty);
 435                         return -ENODEV;
 436                 }
 437                 minor = tty->index + RAW3270_FIRSTMINOR;
 438                 tty_kref_put(tty);
 439         }
 440         lock_kernel();
 441         /* Check if some other program is already using fullscreen mode. */
 442         fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
 443         if (!IS_ERR(fp)) {
 444                 raw3270_put_view(&fp->view);
 445                 rc = -EBUSY;
 446                 goto out;
 447         }
 448         /* Allocate fullscreen view structure. */
 449         fp = fs3270_alloc_view();
 450         if (IS_ERR(fp)) {
 451                 rc = PTR_ERR(fp);
 452                 goto out;
 453         }
 454
 455         init_waitqueue_head(&fp->wait);
 456         fp->fs_pid = get_pid(task_pid(current));
 457         rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
 458         if (rc) {
 459                 fs3270_free_view(&fp->view);
 460                 goto out;
 461         }
 462
 463         /* Allocate idal-buffer. */
 464         ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
 465         if (IS_ERR(ib)) {
 466                 raw3270_put_view(&fp->view);
 467                 raw3270_del_view(&fp->view);
 468                 rc = PTR_ERR(fp);
 469                 goto out;
 470         }
 471         fp->rdbuf = ib;
 472
 473         rc = raw3270_activate_view(&fp->view);
 474         if (rc) {
 475                 raw3270_put_view(&fp->view);
 476                 raw3270_del_view(&fp->view);
 477                 goto out;
 478         }
 479         filp->private_data = fp;
 480 out:
 481         unlock_kernel();
 482         return rc;
 483 }
 484
 485 /*
 486  * This routine is called when the 3270 tty is closed. We wait
 487  * for the remaining request to be completed. Then we clean up.
 488  */
 489 static int
 490 fs3270_close(struct inode *inode, struct file *filp)
 491 {
 492         struct fs3270 *fp;
 493
 494         fp = filp->private_data;
 495         filp->private_data = NULL;
 496         if (fp) {
 497                 put_pid(fp->fs_pid);
 498                 fp->fs_pid = NULL;
 499                 raw3270_reset(&fp->view);
 500                 raw3270_put_view(&fp->view);
 501                 raw3270_del_view(&fp->view);
 502         }
 503         return 0;
 504 }
 505
 506 static const struct file_operations fs3270_fops = {
 507         .owner           = THIS_MODULE,         /* owner */
 508         .read            = fs3270_read,         /* read */
 509         .write           = fs3270_write,        /* write */
 510         .unlocked_ioctl  = fs3270_ioctl,        /* ioctl */
 511         .compat_ioctl    = fs3270_ioctl,        /* ioctl */
 512         .open           = fs3270_open,          /* open */
 513         .release        = fs3270_close,         /* release */
 514 };
 515
 516 /*
 517  * 3270 fullscreen driver initialization.
 518  */
 519 static int __init
 520 fs3270_init(void)
 521 {
 522         int rc;
 523
 524         rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
 525         if (rc)
 526                 return rc;
 527         return 0;
 528 }
 529
 530 static void __exit
 531 fs3270_exit(void)
 532 {
 533         unregister_chrdev(IBM_FS3270_MAJOR, "fs3270");
 534 }
 535
 536 MODULE_LICENSE("GPL");
 537 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
 538
 539 module_init(fs3270_init);
 540 module_exit(fs3270_exit);