drivers/s390/char/fs3270.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   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 IBM Corp. 2003, 2009
   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/compat.h>
  16 #include <linux/sched/signal.h>
  17 #include <linux/module.h>
  18 #include <linux/list.h>
  19 #include <linux/slab.h>
  20 #include <linux/types.h>
  21
  22 #include <asm/compat.h>
  23 #include <asm/ccwdev.h>
  24 #include <asm/cio.h>
  25 #include <asm/ebcdic.h>
  26 #include <asm/idals.h>
  27
  28 #include "raw3270.h"
  29 #include "ctrlchar.h"
  30
  31 static struct raw3270_fn fs3270_fn;
  32
  33 struct fs3270 {
  34         struct raw3270_view view;
  35         struct pid *fs_pid;             /* Pid of controlling program. */
  36         int read_command;               /* ccw command to use for reads. */
  37         int write_command;              /* ccw command to use for writes. */
  38         int attention;                  /* Got attention. */
  39         int active;                     /* Fullscreen view is active. */
  40         struct raw3270_request *init;   /* single init request. */
  41         wait_queue_head_t wait;         /* Init & attention wait queue. */
  42         struct idal_buffer *rdbuf;      /* full-screen-deactivate buffer */
  43         size_t rdbuf_size;              /* size of data returned by RDBUF */
  44 };
  45
  46 static DEFINE_MUTEX(fs3270_mutex);
  47
  48 static void
  49 fs3270_wake_up(struct raw3270_request *rq, void *data)
  50 {
  51         wake_up((wait_queue_head_t *) data);
  52 }
  53
  54 static inline int
  55 fs3270_working(struct fs3270 *fp)
  56 {
  57         /*
  58          * The fullscreen view is in working order if the view
  59          * has been activated AND the initial request is finished.
  60          */
  61         return fp->active && raw3270_request_final(fp->init);
  62 }
  63
  64 static int
  65 fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
  66 {
  67         struct fs3270 *fp;
  68         int rc;
  69
  70         fp = (struct fs3270 *) view;
  71         rq->callback = fs3270_wake_up;
  72         rq->callback_data = &fp->wait;
  73
  74         do {
  75                 if (!fs3270_working(fp)) {
  76                         /* Fullscreen view isn't ready yet. */
  77                         rc = wait_event_interruptible(fp->wait,
  78                                                       fs3270_working(fp));
  79                         if (rc != 0)
  80                                 break;
  81                 }
  82                 rc = raw3270_start(view, rq);
  83                 if (rc == 0) {
  84                         /* Started successfully. Now wait for completion. */
  85                         wait_event(fp->wait, raw3270_request_final(rq));
  86                 }
  87         } while (rc == -EACCES);
  88         return rc;
  89 }
  90
  91 /*
  92  * Switch to the fullscreen view.
  93  */
  94 static void
  95 fs3270_reset_callback(struct raw3270_request *rq, void *data)
  96 {
  97         struct fs3270 *fp;
  98
  99         fp = (struct fs3270 *) rq->view;
 100         raw3270_request_reset(rq);
 101         wake_up(&fp->wait);
 102 }
 103
 104 static void
 105 fs3270_restore_callback(struct raw3270_request *rq, void *data)
 106 {
 107         struct fs3270 *fp;
 108
 109         fp = (struct fs3270 *) rq->view;
 110         if (rq->rc != 0 || rq->rescnt != 0) {
 111                 if (fp->fs_pid)
 112                         kill_pid(fp->fs_pid, SIGHUP, 1);
 113         }
 114         fp->rdbuf_size = 0;
 115         raw3270_request_reset(rq);
 116         wake_up(&fp->wait);
 117 }
 118
 119 static int
 120 fs3270_activate(struct raw3270_view *view)
 121 {
 122         struct fs3270 *fp;
 123         char *cp;
 124         int rc;
 125
 126         fp = (struct fs3270 *) view;
 127
 128         /* If an old init command is still running just return. */
 129         if (!raw3270_request_final(fp->init))
 130                 return 0;
 131
 132         if (fp->rdbuf_size == 0) {
 133                 /* No saved buffer. Just clear the screen. */
 134                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 135                 fp->init->callback = fs3270_reset_callback;
 136         } else {
 137                 /* Restore fullscreen buffer saved by fs3270_deactivate. */
 138                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 139                 raw3270_request_set_idal(fp->init, fp->rdbuf);
 140                 fp->init->ccw.count = fp->rdbuf_size;
 141                 cp = fp->rdbuf->data[0];
 142                 cp[0] = TW_KR;
 143                 cp[1] = TO_SBA;
 144                 cp[2] = cp[6];
 145                 cp[3] = cp[7];
 146                 cp[4] = TO_IC;
 147                 cp[5] = TO_SBA;
 148                 cp[6] = 0x40;
 149                 cp[7] = 0x40;
 150                 fp->init->rescnt = 0;
 151                 fp->init->callback = fs3270_restore_callback;
 152         }
 153         rc = fp->init->rc = raw3270_start_locked(view, fp->init);
 154         if (rc)
 155                 fp->init->callback(fp->init, NULL);
 156         else
 157                 fp->active = 1;
 158         return rc;
 159 }
 160
 161 /*
 162  * Shutdown fullscreen view.
 163  */
 164 static void
 165 fs3270_save_callback(struct raw3270_request *rq, void *data)
 166 {
 167         struct fs3270 *fp;
 168
 169         fp = (struct fs3270 *) rq->view;
 170
 171         /* Correct idal buffer element 0 address. */
 172         fp->rdbuf->data[0] -= 5;
 173         fp->rdbuf->size += 5;
 174
 175         /*
 176          * If the rdbuf command failed or the idal buffer is
 177          * to small for the amount of data returned by the
 178          * rdbuf command, then we have no choice but to send
 179          * a SIGHUP to the application.
 180          */
 181         if (rq->rc != 0 || rq->rescnt == 0) {
 182                 if (fp->fs_pid)
 183                         kill_pid(fp->fs_pid, SIGHUP, 1);
 184                 fp->rdbuf_size = 0;
 185         } else
 186                 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
 187         raw3270_request_reset(rq);
 188         wake_up(&fp->wait);
 189 }
 190
 191 static void
 192 fs3270_deactivate(struct raw3270_view *view)
 193 {
 194         struct fs3270 *fp;
 195
 196         fp = (struct fs3270 *) view;
 197         fp->active = 0;
 198
 199         /* If an old init command is still running just return. */
 200         if (!raw3270_request_final(fp->init))
 201                 return;
 202
 203         /* Prepare read-buffer request. */
 204         raw3270_request_set_cmd(fp->init, TC_RDBUF);
 205         /*
 206          * Hackish: skip first 5 bytes of the idal buffer to make
 207          * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
 208          * in the activation command.
 209          */
 210         fp->rdbuf->data[0] += 5;
 211         fp->rdbuf->size -= 5;
 212         raw3270_request_set_idal(fp->init, fp->rdbuf);
 213         fp->init->rescnt = 0;
 214         fp->init->callback = fs3270_save_callback;
 215
 216         /* Start I/O to read in the 3270 buffer. */
 217         fp->init->rc = raw3270_start_locked(view, fp->init);
 218         if (fp->init->rc)
 219                 fp->init->callback(fp->init, NULL);
 220 }
 221
 222 static void
 223 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
 224 {
 225         /* Handle ATTN. Set indication and wake waiters for attention. */
 226         if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
 227                 fp->attention = 1;
 228                 wake_up(&fp->wait);
 229         }
 230
 231         if (rq) {
 232                 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
 233                         rq->rc = -EIO;
 234                 else
 235                         /* Normal end. Copy residual count. */
 236                         rq->rescnt = irb->scsw.cmd.count;
 237         }
 238 }
 239
 240 /*
 241  * Process reads from fullscreen 3270.
 242  */
 243 static ssize_t
 244 fs3270_read(struct file *filp, char __user *data, size_t count, loff_t *off)
 245 {
 246         struct fs3270 *fp;
 247         struct raw3270_request *rq;
 248         struct idal_buffer *ib;
 249         ssize_t rc;
 250
 251         if (count == 0 || count > 65535)
 252                 return -EINVAL;
 253         fp = filp->private_data;
 254         if (!fp)
 255                 return -ENODEV;
 256         ib = idal_buffer_alloc(count, 0);
 257         if (IS_ERR(ib))
 258                 return -ENOMEM;
 259         rq = raw3270_request_alloc(0);
 260         if (!IS_ERR(rq)) {
 261                 if (fp->read_command == 0 && fp->write_command != 0)
 262                         fp->read_command = 6;
 263                 raw3270_request_set_cmd(rq, fp->read_command ? : 2);
 264                 raw3270_request_set_idal(rq, ib);
 265                 rc = wait_event_interruptible(fp->wait, fp->attention);
 266                 fp->attention = 0;
 267                 if (rc == 0) {
 268                         rc = fs3270_do_io(&fp->view, rq);
 269                         if (rc == 0) {
 270                                 count -= rq->rescnt;
 271                                 if (idal_buffer_to_user(ib, data, count) != 0)
 272                                         rc = -EFAULT;
 273                                 else
 274                                         rc = count;
 275
 276                         }
 277                 }
 278                 raw3270_request_free(rq);
 279         } else
 280                 rc = PTR_ERR(rq);
 281         idal_buffer_free(ib);
 282         return rc;
 283 }
 284
 285 /*
 286  * Process writes to fullscreen 3270.
 287  */
 288 static ssize_t
 289 fs3270_write(struct file *filp, const char __user *data, size_t count, loff_t *off)
 290 {
 291         struct fs3270 *fp;
 292         struct raw3270_request *rq;
 293         struct idal_buffer *ib;
 294         int write_command;
 295         ssize_t rc;
 296
 297         fp = filp->private_data;
 298         if (!fp)
 299                 return -ENODEV;
 300         ib = idal_buffer_alloc(count, 0);
 301         if (IS_ERR(ib))
 302                 return -ENOMEM;
 303         rq = raw3270_request_alloc(0);
 304         if (!IS_ERR(rq)) {
 305                 if (idal_buffer_from_user(ib, data, count) == 0) {
 306                         write_command = fp->write_command ? : 1;
 307                         if (write_command == 5)
 308                                 write_command = 13;
 309                         raw3270_request_set_cmd(rq, write_command);
 310                         raw3270_request_set_idal(rq, ib);
 311                         rc = fs3270_do_io(&fp->view, rq);
 312                         if (rc == 0)
 313                                 rc = count - rq->rescnt;
 314                 } else
 315                         rc = -EFAULT;
 316                 raw3270_request_free(rq);
 317         } else
 318                 rc = PTR_ERR(rq);
 319         idal_buffer_free(ib);
 320         return rc;
 321 }
 322
 323 /*
 324  * process ioctl commands for the tube driver
 325  */
 326 static long
 327 fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 328 {
 329         char __user *argp;
 330         struct fs3270 *fp;
 331         struct raw3270_iocb iocb;
 332         int rc;
 333
 334         fp = filp->private_data;
 335         if (!fp)
 336                 return -ENODEV;
 337         if (is_compat_task())
 338                 argp = compat_ptr(arg);
 339         else
 340                 argp = (char __user *)arg;
 341         rc = 0;
 342         mutex_lock(&fs3270_mutex);
 343         switch (cmd) {
 344         case TUBICMD:
 345                 fp->read_command = arg;
 346                 break;
 347         case TUBOCMD:
 348                 fp->write_command = arg;
 349                 break;
 350         case TUBGETI:
 351                 rc = put_user(fp->read_command, argp);
 352                 break;
 353         case TUBGETO:
 354                 rc = put_user(fp->write_command, argp);
 355                 break;
 356         case TUBGETMOD:
 357                 iocb.model = fp->view.model;
 358                 iocb.line_cnt = fp->view.rows;
 359                 iocb.col_cnt = fp->view.cols;
 360                 iocb.pf_cnt = 24;
 361                 iocb.re_cnt = 20;
 362                 iocb.map = 0;
 363                 if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
 364                         rc = -EFAULT;
 365                 break;
 366         }
 367         mutex_unlock(&fs3270_mutex);
 368         return rc;
 369 }
 370
 371 /*
 372  * Allocate fs3270 structure.
 373  */
 374 static struct fs3270 *
 375 fs3270_alloc_view(void)
 376 {
 377         struct fs3270 *fp;
 378
 379         fp = kzalloc(sizeof(struct fs3270),GFP_KERNEL);
 380         if (!fp)
 381                 return ERR_PTR(-ENOMEM);
 382         fp->init = raw3270_request_alloc(0);
 383         if (IS_ERR(fp->init)) {
 384                 kfree(fp);
 385                 return ERR_PTR(-ENOMEM);
 386         }
 387         return fp;
 388 }
 389
 390 /*
 391  * Free fs3270 structure.
 392  */
 393 static void
 394 fs3270_free_view(struct raw3270_view *view)
 395 {
 396         struct fs3270 *fp;
 397
 398         fp = (struct fs3270 *) view;
 399         if (fp->rdbuf)
 400                 idal_buffer_free(fp->rdbuf);
 401         raw3270_request_free(((struct fs3270 *) view)->init);
 402         kfree(view);
 403 }
 404
 405 /*
 406  * Unlink fs3270 data structure from filp.
 407  */
 408 static void
 409 fs3270_release(struct raw3270_view *view)
 410 {
 411         struct fs3270 *fp;
 412
 413         fp = (struct fs3270 *) view;
 414         if (fp->fs_pid)
 415                 kill_pid(fp->fs_pid, SIGHUP, 1);
 416 }
 417
 418 /* View to a 3270 device. Can be console, tty or fullscreen. */
 419 static struct raw3270_fn fs3270_fn = {
 420         .activate = fs3270_activate,
 421         .deactivate = fs3270_deactivate,
 422         .intv = (void *) fs3270_irq,
 423         .release = fs3270_release,
 424         .free = fs3270_free_view
 425 };
 426
 427 /*
 428  * This routine is called whenever a 3270 fullscreen device is opened.
 429  */
 430 static int
 431 fs3270_open(struct inode *inode, struct file *filp)
 432 {
 433         struct fs3270 *fp;
 434         struct idal_buffer *ib;
 435         int minor, rc = 0;
 436
 437         if (imajor(file_inode(filp)) != IBM_FS3270_MAJOR)
 438                 return -ENODEV;
 439         minor = iminor(file_inode(filp));
 440         /* Check for minor 0 multiplexer. */
 441         if (minor == 0) {
 442                 struct tty_struct *tty = get_current_tty();
 443                 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
 444                         tty_kref_put(tty);
 445                         return -ENODEV;
 446                 }
 447                 minor = tty->index;
 448                 tty_kref_put(tty);
 449         }
 450         mutex_lock(&fs3270_mutex);
 451         /* Check if some other program is already using fullscreen mode. */
 452         fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
 453         if (!IS_ERR(fp)) {
 454                 raw3270_put_view(&fp->view);
 455                 rc = -EBUSY;
 456                 goto out;
 457         }
 458         /* Allocate fullscreen view structure. */
 459         fp = fs3270_alloc_view();
 460         if (IS_ERR(fp)) {
 461                 rc = PTR_ERR(fp);
 462                 goto out;
 463         }
 464
 465         init_waitqueue_head(&fp->wait);
 466         fp->fs_pid = get_pid(task_pid(current));
 467         rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
 468         if (rc) {
 469                 fs3270_free_view(&fp->view);
 470                 goto out;
 471         }
 472
 473         /* Allocate idal-buffer. */
 474         ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
 475         if (IS_ERR(ib)) {
 476                 raw3270_put_view(&fp->view);
 477                 raw3270_del_view(&fp->view);
 478                 rc = PTR_ERR(ib);
 479                 goto out;
 480         }
 481         fp->rdbuf = ib;
 482
 483         rc = raw3270_activate_view(&fp->view);
 484         if (rc) {
 485                 raw3270_put_view(&fp->view);
 486                 raw3270_del_view(&fp->view);
 487                 goto out;
 488         }
 489         nonseekable_open(inode, filp);
 490         filp->private_data = fp;
 491 out:
 492         mutex_unlock(&fs3270_mutex);
 493         return rc;
 494 }
 495
 496 /*
 497  * This routine is called when the 3270 tty is closed. We wait
 498  * for the remaining request to be completed. Then we clean up.
 499  */
 500 static int
 501 fs3270_close(struct inode *inode, struct file *filp)
 502 {
 503         struct fs3270 *fp;
 504
 505         fp = filp->private_data;
 506         filp->private_data = NULL;
 507         if (fp) {
 508                 put_pid(fp->fs_pid);
 509                 fp->fs_pid = NULL;
 510                 raw3270_reset(&fp->view);
 511                 raw3270_put_view(&fp->view);
 512                 raw3270_del_view(&fp->view);
 513         }
 514         return 0;
 515 }
 516
 517 static const struct file_operations fs3270_fops = {
 518         .owner           = THIS_MODULE,         /* owner */
 519         .read            = fs3270_read,         /* read */
 520         .write           = fs3270_write,        /* write */
 521         .unlocked_ioctl  = fs3270_ioctl,        /* ioctl */
 522         .compat_ioctl    = fs3270_ioctl,        /* ioctl */
 523         .open            = fs3270_open,         /* open */
 524         .release         = fs3270_close,        /* release */
 525         .llseek         = no_llseek,
 526 };
 527
 528 static void fs3270_create_cb(int minor)
 529 {
 530         __register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops);
 531         device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
 532                       NULL, "3270/tub%d", minor);
 533 }
 534
 535 static void fs3270_destroy_cb(int minor)
 536 {
 537         device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, minor));
 538         __unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub");
 539 }
 540
 541 static struct raw3270_notifier fs3270_notifier =
 542 {
 543         .create = fs3270_create_cb,
 544         .destroy = fs3270_destroy_cb,
 545 };
 546
 547 /*
 548  * 3270 fullscreen driver initialization.
 549  */
 550 static int __init
 551 fs3270_init(void)
 552 {
 553         int rc;
 554
 555         rc = __register_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270", &fs3270_fops);
 556         if (rc)
 557                 return rc;
 558         device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0),
 559                       NULL, "3270/tub");
 560         raw3270_register_notifier(&fs3270_notifier);
 561         return 0;
 562 }
 563
 564 static void __exit
 565 fs3270_exit(void)
 566 {
 567         raw3270_unregister_notifier(&fs3270_notifier);
 568         device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, 0));
 569         __unregister_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270");
 570 }
 571
 572 MODULE_LICENSE("GPL");
 573 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
 574
 575 module_init(fs3270_init);
 576 module_exit(fs3270_exit);