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/ccwdev.h>
  23 #include <asm/cio.h>
  24 #include <asm/ebcdic.h>
  25 #include <asm/idals.h>
  26
  27 #include "raw3270.h"
  28 #include "ctrlchar.h"
  29
  30 static struct raw3270_fn fs3270_fn;
  31
  32 struct fs3270 {
  33         struct raw3270_view view;
  34         struct pid *fs_pid;             /* Pid of controlling program. */
  35         int read_command;               /* ccw command to use for reads. */
  36         int write_command;              /* ccw command to use for writes. */
  37         int attention;                  /* Got attention. */
  38         int active;                     /* Fullscreen view is active. */
  39         struct raw3270_request *init;   /* single init request. */
  40         wait_queue_head_t wait;         /* Init & attention wait queue. */
  41         struct idal_buffer *rdbuf;      /* full-screen-deactivate buffer */
  42         size_t rdbuf_size;              /* size of data returned by RDBUF */
  43 };
  44
  45 static DEFINE_MUTEX(fs3270_mutex);
  46
  47 static void
  48 fs3270_wake_up(struct raw3270_request *rq, void *data)
  49 {
  50         wake_up((wait_queue_head_t *) data);
  51 }
  52
  53 static inline int
  54 fs3270_working(struct fs3270 *fp)
  55 {
  56         /*
  57          * The fullscreen view is in working order if the view
  58          * has been activated AND the initial request is finished.
  59          */
  60         return fp->active && raw3270_request_final(fp->init);
  61 }
  62
  63 static int
  64 fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
  65 {
  66         struct fs3270 *fp;
  67         int rc;
  68
  69         fp = (struct fs3270 *) view;
  70         rq->callback = fs3270_wake_up;
  71         rq->callback_data = &fp->wait;
  72
  73         do {
  74                 if (!fs3270_working(fp)) {
  75                         /* Fullscreen view isn't ready yet. */
  76                         rc = wait_event_interruptible(fp->wait,
  77                                                       fs3270_working(fp));
  78                         if (rc != 0)
  79                                 break;
  80                 }
  81                 rc = raw3270_start(view, rq);
  82                 if (rc == 0) {
  83                         /* Started successfully. Now wait for completion. */
  84                         wait_event(fp->wait, raw3270_request_final(rq));
  85                 }
  86         } while (rc == -EACCES);
  87         return rc;
  88 }
  89
  90 /*
  91  * Switch to the fullscreen view.
  92  */
  93 static void
  94 fs3270_reset_callback(struct raw3270_request *rq, void *data)
  95 {
  96         struct fs3270 *fp;
  97
  98         fp = (struct fs3270 *) rq->view;
  99         raw3270_request_reset(rq);
 100         wake_up(&fp->wait);
 101 }
 102
 103 static void
 104 fs3270_restore_callback(struct raw3270_request *rq, void *data)
 105 {
 106         struct fs3270 *fp;
 107
 108         fp = (struct fs3270 *) rq->view;
 109         if (rq->rc != 0 || rq->rescnt != 0) {
 110                 if (fp->fs_pid)
 111                         kill_pid(fp->fs_pid, SIGHUP, 1);
 112         }
 113         fp->rdbuf_size = 0;
 114         raw3270_request_reset(rq);
 115         wake_up(&fp->wait);
 116 }
 117
 118 static int
 119 fs3270_activate(struct raw3270_view *view)
 120 {
 121         struct fs3270 *fp;
 122         char *cp;
 123         int rc;
 124
 125         fp = (struct fs3270 *) view;
 126
 127         /* If an old init command is still running just return. */
 128         if (!raw3270_request_final(fp->init))
 129                 return 0;
 130
 131         if (fp->rdbuf_size == 0) {
 132                 /* No saved buffer. Just clear the screen. */
 133                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 134                 fp->init->callback = fs3270_reset_callback;
 135         } else {
 136                 /* Restore fullscreen buffer saved by fs3270_deactivate. */
 137                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 138                 raw3270_request_set_idal(fp->init, fp->rdbuf);
 139                 fp->init->ccw.count = fp->rdbuf_size;
 140                 cp = fp->rdbuf->data[0];
 141                 cp[0] = TW_KR;
 142                 cp[1] = TO_SBA;
 143                 cp[2] = cp[6];
 144                 cp[3] = cp[7];
 145                 cp[4] = TO_IC;
 146                 cp[5] = TO_SBA;
 147                 cp[6] = 0x40;
 148                 cp[7] = 0x40;
 149                 fp->init->rescnt = 0;
 150                 fp->init->callback = fs3270_restore_callback;
 151         }
 152         rc = fp->init->rc = raw3270_start_locked(view, fp->init);
 153         if (rc)
 154                 fp->init->callback(fp->init, NULL);
 155         else
 156                 fp->active = 1;
 157         return rc;
 158 }
 159
 160 /*
 161  * Shutdown fullscreen view.
 162  */
 163 static void
 164 fs3270_save_callback(struct raw3270_request *rq, void *data)
 165 {
 166         struct fs3270 *fp;
 167
 168         fp = (struct fs3270 *) rq->view;
 169
 170         /* Correct idal buffer element 0 address. */
 171         fp->rdbuf->data[0] -= 5;
 172         fp->rdbuf->size += 5;
 173
 174         /*
 175          * If the rdbuf command failed or the idal buffer is
 176          * to small for the amount of data returned by the
 177          * rdbuf command, then we have no choice but to send
 178          * a SIGHUP to the application.
 179          */
 180         if (rq->rc != 0 || rq->rescnt == 0) {
 181                 if (fp->fs_pid)
 182                         kill_pid(fp->fs_pid, SIGHUP, 1);
 183                 fp->rdbuf_size = 0;
 184         } else
 185                 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
 186         raw3270_request_reset(rq);
 187         wake_up(&fp->wait);
 188 }
 189
 190 static void
 191 fs3270_deactivate(struct raw3270_view *view)
 192 {
 193         struct fs3270 *fp;
 194
 195         fp = (struct fs3270 *) view;
 196         fp->active = 0;
 197
 198         /* If an old init command is still running just return. */
 199         if (!raw3270_request_final(fp->init))
 200                 return;
 201
 202         /* Prepare read-buffer request. */
 203         raw3270_request_set_cmd(fp->init, TC_RDBUF);
 204         /*
 205          * Hackish: skip first 5 bytes of the idal buffer to make
 206          * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
 207          * in the activation command.
 208          */
 209         fp->rdbuf->data[0] += 5;
 210         fp->rdbuf->size -= 5;
 211         raw3270_request_set_idal(fp->init, fp->rdbuf);
 212         fp->init->rescnt = 0;
 213         fp->init->callback = fs3270_save_callback;
 214
 215         /* Start I/O to read in the 3270 buffer. */
 216         fp->init->rc = raw3270_start_locked(view, fp->init);
 217         if (fp->init->rc)
 218                 fp->init->callback(fp->init, NULL);
 219 }
 220
 221 static void
 222 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
 223 {
 224         /* Handle ATTN. Set indication and wake waiters for attention. */
 225         if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
 226                 fp->attention = 1;
 227                 wake_up(&fp->wait);
 228         }
 229
 230         if (rq) {
 231                 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
 232                         rq->rc = -EIO;
 233                 else
 234                         /* Normal end. Copy residual count. */
 235                         rq->rescnt = irb->scsw.cmd.count;
 236         }
 237 }
 238
 239 /*
 240  * Process reads from fullscreen 3270.
 241  */
 242 static ssize_t
 243 fs3270_read(struct file *filp, char __user *data, size_t count, loff_t *off)
 244 {
 245         struct fs3270 *fp;
 246         struct raw3270_request *rq;
 247         struct idal_buffer *ib;
 248         ssize_t rc;
 249
 250         if (count == 0 || count > 65535)
 251                 return -EINVAL;
 252         fp = filp->private_data;
 253         if (!fp)
 254                 return -ENODEV;
 255         ib = idal_buffer_alloc(count, 0);
 256         if (IS_ERR(ib))
 257                 return -ENOMEM;
 258         rq = raw3270_request_alloc(0);
 259         if (!IS_ERR(rq)) {
 260                 if (fp->read_command == 0 && fp->write_command != 0)
 261                         fp->read_command = 6;
 262                 raw3270_request_set_cmd(rq, fp->read_command ? : 2);
 263                 raw3270_request_set_idal(rq, ib);
 264                 rc = wait_event_interruptible(fp->wait, fp->attention);
 265                 fp->attention = 0;
 266                 if (rc == 0) {
 267                         rc = fs3270_do_io(&fp->view, rq);
 268                         if (rc == 0) {
 269                                 count -= rq->rescnt;
 270                                 if (idal_buffer_to_user(ib, data, count) != 0)
 271                                         rc = -EFAULT;
 272                                 else
 273                                         rc = count;
 274
 275                         }
 276                 }
 277                 raw3270_request_free(rq);
 278         } else
 279                 rc = PTR_ERR(rq);
 280         idal_buffer_free(ib);
 281         return rc;
 282 }
 283
 284 /*
 285  * Process writes to fullscreen 3270.
 286  */
 287 static ssize_t
 288 fs3270_write(struct file *filp, const char __user *data, size_t count, loff_t *off)
 289 {
 290         struct fs3270 *fp;
 291         struct raw3270_request *rq;
 292         struct idal_buffer *ib;
 293         int write_command;
 294         ssize_t rc;
 295
 296         fp = filp->private_data;
 297         if (!fp)
 298                 return -ENODEV;
 299         ib = idal_buffer_alloc(count, 0);
 300         if (IS_ERR(ib))
 301                 return -ENOMEM;
 302         rq = raw3270_request_alloc(0);
 303         if (!IS_ERR(rq)) {
 304                 if (idal_buffer_from_user(ib, data, count) == 0) {
 305                         write_command = fp->write_command ? : 1;
 306                         if (write_command == 5)
 307                                 write_command = 13;
 308                         raw3270_request_set_cmd(rq, write_command);
 309                         raw3270_request_set_idal(rq, ib);
 310                         rc = fs3270_do_io(&fp->view, rq);
 311                         if (rc == 0)
 312                                 rc = count - rq->rescnt;
 313                 } else
 314                         rc = -EFAULT;
 315                 raw3270_request_free(rq);
 316         } else
 317                 rc = PTR_ERR(rq);
 318         idal_buffer_free(ib);
 319         return rc;
 320 }
 321
 322 /*
 323  * process ioctl commands for the tube driver
 324  */
 325 static long
 326 fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 327 {
 328         char __user *argp;
 329         struct fs3270 *fp;
 330         struct raw3270_iocb iocb;
 331         int rc;
 332
 333         fp = filp->private_data;
 334         if (!fp)
 335                 return -ENODEV;
 336         if (is_compat_task())
 337                 argp = compat_ptr(arg);
 338         else
 339                 argp = (char __user *)arg;
 340         rc = 0;
 341         mutex_lock(&fs3270_mutex);
 342         switch (cmd) {
 343         case TUBICMD:
 344                 fp->read_command = arg;
 345                 break;
 346         case TUBOCMD:
 347                 fp->write_command = arg;
 348                 break;
 349         case TUBGETI:
 350                 rc = put_user(fp->read_command, argp);
 351                 break;
 352         case TUBGETO:
 353                 rc = put_user(fp->write_command, argp);
 354                 break;
 355         case TUBGETMOD:
 356                 iocb.model = fp->view.model;
 357                 iocb.line_cnt = fp->view.rows;
 358                 iocb.col_cnt = fp->view.cols;
 359                 iocb.pf_cnt = 24;
 360                 iocb.re_cnt = 20;
 361                 iocb.map = 0;
 362                 if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
 363                         rc = -EFAULT;
 364                 break;
 365         }
 366         mutex_unlock(&fs3270_mutex);
 367         return rc;
 368 }
 369
 370 /*
 371  * Allocate fs3270 structure.
 372  */
 373 static struct fs3270 *
 374 fs3270_alloc_view(void)
 375 {
 376         struct fs3270 *fp;
 377
 378         fp = kzalloc(sizeof(struct fs3270),GFP_KERNEL);
 379         if (!fp)
 380                 return ERR_PTR(-ENOMEM);
 381         fp->init = raw3270_request_alloc(0);
 382         if (IS_ERR(fp->init)) {
 383                 kfree(fp);
 384                 return ERR_PTR(-ENOMEM);
 385         }
 386         return fp;
 387 }
 388
 389 /*
 390  * Free fs3270 structure.
 391  */
 392 static void
 393 fs3270_free_view(struct raw3270_view *view)
 394 {
 395         struct fs3270 *fp;
 396
 397         fp = (struct fs3270 *) view;
 398         if (fp->rdbuf)
 399                 idal_buffer_free(fp->rdbuf);
 400         raw3270_request_free(((struct fs3270 *) view)->init);
 401         kfree(view);
 402 }
 403
 404 /*
 405  * Unlink fs3270 data structure from filp.
 406  */
 407 static void
 408 fs3270_release(struct raw3270_view *view)
 409 {
 410         struct fs3270 *fp;
 411
 412         fp = (struct fs3270 *) view;
 413         if (fp->fs_pid)
 414                 kill_pid(fp->fs_pid, SIGHUP, 1);
 415 }
 416
 417 /* View to a 3270 device. Can be console, tty or fullscreen. */
 418 static struct raw3270_fn fs3270_fn = {
 419         .activate = fs3270_activate,
 420         .deactivate = fs3270_deactivate,
 421         .intv = (void *) fs3270_irq,
 422         .release = fs3270_release,
 423         .free = fs3270_free_view
 424 };
 425
 426 /*
 427  * This routine is called whenever a 3270 fullscreen device is opened.
 428  */
 429 static int
 430 fs3270_open(struct inode *inode, struct file *filp)
 431 {
 432         struct fs3270 *fp;
 433         struct idal_buffer *ib;
 434         int minor, rc = 0;
 435
 436         if (imajor(file_inode(filp)) != IBM_FS3270_MAJOR)
 437                 return -ENODEV;
 438         minor = iminor(file_inode(filp));
 439         /* Check for minor 0 multiplexer. */
 440         if (minor == 0) {
 441                 struct tty_struct *tty = get_current_tty();
 442                 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
 443                         tty_kref_put(tty);
 444                         return -ENODEV;
 445                 }
 446                 minor = tty->index;
 447                 tty_kref_put(tty);
 448         }
 449         mutex_lock(&fs3270_mutex);
 450         /* Check if some other program is already using fullscreen mode. */
 451         fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
 452         if (!IS_ERR(fp)) {
 453                 raw3270_put_view(&fp->view);
 454                 rc = -EBUSY;
 455                 goto out;
 456         }
 457         /* Allocate fullscreen view structure. */
 458         fp = fs3270_alloc_view();
 459         if (IS_ERR(fp)) {
 460                 rc = PTR_ERR(fp);
 461                 goto out;
 462         }
 463
 464         init_waitqueue_head(&fp->wait);
 465         fp->fs_pid = get_pid(task_pid(current));
 466         rc = raw3270_add_view(&fp->view, &fs3270_fn, minor,
 467                               RAW3270_VIEW_LOCK_BH);
 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);