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/memblock.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 <uapi/asm/fs3270.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 fs3270_wake_up(struct raw3270_request *rq, void *data)
  49 {
  50         wake_up((wait_queue_head_t *)data);
  51 }
  52
  53 static inline int fs3270_working(struct fs3270 *fp)
  54 {
  55         /*
  56          * The fullscreen view is in working order if the view
  57          * has been activated AND the initial request is finished.
  58          */
  59         return fp->active && raw3270_request_final(fp->init);
  60 }
  61
  62 static int fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
  63 {
  64         struct fs3270 *fp;
  65         int rc;
  66
  67         fp = (struct fs3270 *)view;
  68         rq->callback = fs3270_wake_up;
  69         rq->callback_data = &fp->wait;
  70
  71         do {
  72                 if (!fs3270_working(fp)) {
  73                         /* Fullscreen view isn't ready yet. */
  74                         rc = wait_event_interruptible(fp->wait,
  75                                                       fs3270_working(fp));
  76                         if (rc != 0)
  77                                 break;
  78                 }
  79                 rc = raw3270_start(view, rq);
  80                 if (rc == 0) {
  81                         /* Started successfully. Now wait for completion. */
  82                         wait_event(fp->wait, raw3270_request_final(rq));
  83                 }
  84         } while (rc == -EACCES);
  85         return rc;
  86 }
  87
  88 /*
  89  * Switch to the fullscreen view.
  90  */
  91 static void 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 fs3270_restore_callback(struct raw3270_request *rq, void *data)
 101 {
 102         struct fs3270 *fp;
 103
 104         fp = (struct fs3270 *)rq->view;
 105         if (rq->rc != 0 || rq->rescnt != 0) {
 106                 if (fp->fs_pid)
 107                         kill_pid(fp->fs_pid, SIGHUP, 1);
 108         }
 109         fp->rdbuf_size = 0;
 110         raw3270_request_reset(rq);
 111         wake_up(&fp->wait);
 112 }
 113
 114 static int 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         raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 127         raw3270_request_set_idal(fp->init, fp->rdbuf);
 128         fp->init->rescnt = 0;
 129         cp = fp->rdbuf->data[0];
 130         if (fp->rdbuf_size == 0) {
 131                 /* No saved buffer. Just clear the screen. */
 132                 fp->init->ccw.count = 1;
 133                 fp->init->callback = fs3270_reset_callback;
 134                 cp[0] = 0;
 135         } else {
 136                 /* Restore fullscreen buffer saved by fs3270_deactivate. */
 137                 fp->init->ccw.count = fp->rdbuf_size;
 138                 fp->init->callback = fs3270_restore_callback;
 139                 cp[0] = TW_KR;
 140                 cp[1] = TO_SBA;
 141                 cp[2] = cp[6];
 142                 cp[3] = cp[7];
 143                 cp[4] = TO_IC;
 144                 cp[5] = TO_SBA;
 145                 cp[6] = 0x40;
 146                 cp[7] = 0x40;
 147         }
 148         rc = raw3270_start_locked(view, fp->init);
 149         fp->init->rc = rc;
 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 fs3270_save_callback(struct raw3270_request *rq, void *data)
 161 {
 162         struct fs3270 *fp;
 163
 164         fp = (struct fs3270 *)rq->view;
 165
 166         /* Correct idal buffer element 0 address. */
 167         fp->rdbuf->data[0] -= 5;
 168         fp->rdbuf->size += 5;
 169
 170         /*
 171          * If the rdbuf command failed or the idal buffer is
 172          * to small for the amount of data returned by the
 173          * rdbuf command, then we have no choice but to send
 174          * a SIGHUP to the application.
 175          */
 176         if (rq->rc != 0 || rq->rescnt == 0) {
 177                 if (fp->fs_pid)
 178                         kill_pid(fp->fs_pid, SIGHUP, 1);
 179                 fp->rdbuf_size = 0;
 180         } else {
 181                 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
 182         }
 183         raw3270_request_reset(rq);
 184         wake_up(&fp->wait);
 185 }
 186
 187 static void fs3270_deactivate(struct raw3270_view *view)
 188 {
 189         struct fs3270 *fp;
 190
 191         fp = (struct fs3270 *)view;
 192         fp->active = 0;
 193
 194         /* If an old init command is still running just return. */
 195         if (!raw3270_request_final(fp->init))
 196                 return;
 197
 198         /* Prepare read-buffer request. */
 199         raw3270_request_set_cmd(fp->init, TC_RDBUF);
 200         /*
 201          * Hackish: skip first 5 bytes of the idal buffer to make
 202          * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
 203          * in the activation command.
 204          */
 205         fp->rdbuf->data[0] += 5;
 206         fp->rdbuf->size -= 5;
 207         raw3270_request_set_idal(fp->init, fp->rdbuf);
 208         fp->init->rescnt = 0;
 209         fp->init->callback = fs3270_save_callback;
 210
 211         /* Start I/O to read in the 3270 buffer. */
 212         fp->init->rc = raw3270_start_locked(view, fp->init);
 213         if (fp->init->rc)
 214                 fp->init->callback(fp->init, NULL);
 215 }
 216
 217 static void fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq,
 218                        struct irb *irb)
 219 {
 220         /* Handle ATTN. Set indication and wake waiters for attention. */
 221         if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
 222                 fp->attention = 1;
 223                 wake_up(&fp->wait);
 224         }
 225
 226         if (rq) {
 227                 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
 228                         rq->rc = -EIO;
 229                 else
 230                         /* Normal end. Copy residual count. */
 231                         rq->rescnt = irb->scsw.cmd.count;
 232         }
 233 }
 234
 235 /*
 236  * Process reads from fullscreen 3270.
 237  */
 238 static ssize_t fs3270_read(struct file *filp, char __user *data,
 239                            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                 raw3270_request_free(rq);
 273         } else {
 274                 rc = PTR_ERR(rq);
 275         }
 276         idal_buffer_free(ib);
 277         return rc;
 278 }
 279
 280 /*
 281  * Process writes to fullscreen 3270.
 282  */
 283 static ssize_t fs3270_write(struct file *filp, const char __user *data,
 284                             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                 }
 312                 raw3270_request_free(rq);
 313         } else {
 314                 rc = PTR_ERR(rq);
 315         }
 316         idal_buffer_free(ib);
 317         return rc;
 318 }
 319
 320 /*
 321  * process ioctl commands for the tube driver
 322  */
 323 static long fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 324 {
 325         char __user *argp;
 326         struct fs3270 *fp;
 327         struct raw3270_iocb iocb;
 328         int rc;
 329
 330         fp = filp->private_data;
 331         if (!fp)
 332                 return -ENODEV;
 333         if (is_compat_task())
 334                 argp = compat_ptr(arg);
 335         else
 336                 argp = (char __user *)arg;
 337         rc = 0;
 338         mutex_lock(&fs3270_mutex);
 339         switch (cmd) {
 340         case TUBICMD:
 341                 fp->read_command = arg;
 342                 break;
 343         case TUBOCMD:
 344                 fp->write_command = arg;
 345                 break;
 346         case TUBGETI:
 347                 rc = put_user(fp->read_command, argp);
 348                 break;
 349         case TUBGETO:
 350                 rc = put_user(fp->write_command, argp);
 351                 break;
 352         case TUBGETMOD:
 353                 iocb.model = fp->view.model;
 354                 iocb.line_cnt = fp->view.rows;
 355                 iocb.col_cnt = fp->view.cols;
 356                 iocb.pf_cnt = 24;
 357                 iocb.re_cnt = 20;
 358                 iocb.map = 0;
 359                 if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
 360                         rc = -EFAULT;
 361                 break;
 362         }
 363         mutex_unlock(&fs3270_mutex);
 364         return rc;
 365 }
 366
 367 /*
 368  * Allocate fs3270 structure.
 369  */
 370 static struct fs3270 *fs3270_alloc_view(void)
 371 {
 372         struct fs3270 *fp;
 373
 374         fp = kzalloc(sizeof(*fp), GFP_KERNEL);
 375         if (!fp)
 376                 return ERR_PTR(-ENOMEM);
 377         fp->init = raw3270_request_alloc(0);
 378         if (IS_ERR(fp->init)) {
 379                 kfree(fp);
 380                 return ERR_PTR(-ENOMEM);
 381         }
 382         return fp;
 383 }
 384
 385 /*
 386  * Free fs3270 structure.
 387  */
 388 static void fs3270_free_view(struct raw3270_view *view)
 389 {
 390         struct fs3270 *fp;
 391
 392         fp = (struct fs3270 *)view;
 393         if (fp->rdbuf)
 394                 idal_buffer_free(fp->rdbuf);
 395         raw3270_request_free(((struct fs3270 *)view)->init);
 396         kfree(view);
 397 }
 398
 399 /*
 400  * Unlink fs3270 data structure from filp.
 401  */
 402 static void fs3270_release(struct raw3270_view *view)
 403 {
 404         struct fs3270 *fp;
 405
 406         fp = (struct fs3270 *)view;
 407         if (fp->fs_pid)
 408                 kill_pid(fp->fs_pid, SIGHUP, 1);
 409 }
 410
 411 /* View to a 3270 device. Can be console, tty or fullscreen. */
 412 static struct raw3270_fn fs3270_fn = {
 413         .activate = fs3270_activate,
 414         .deactivate = fs3270_deactivate,
 415         .intv = (void *)fs3270_irq,
 416         .release = fs3270_release,
 417         .free = fs3270_free_view
 418 };
 419
 420 /*
 421  * This routine is called whenever a 3270 fullscreen device is opened.
 422  */
 423 static int fs3270_open(struct inode *inode, struct file *filp)
 424 {
 425         struct fs3270 *fp;
 426         struct idal_buffer *ib;
 427         int minor, rc = 0;
 428
 429         if (imajor(file_inode(filp)) != IBM_FS3270_MAJOR)
 430                 return -ENODEV;
 431         minor = iminor(file_inode(filp));
 432         /* Check for minor 0 multiplexer. */
 433         if (minor == 0) {
 434                 struct tty_struct *tty = get_current_tty();
 435
 436                 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
 437                         tty_kref_put(tty);
 438                         return -ENODEV;
 439                 }
 440                 minor = tty->index;
 441                 tty_kref_put(tty);
 442         }
 443         mutex_lock(&fs3270_mutex);
 444         /* Check if some other program is already using fullscreen mode. */
 445         fp = (struct fs3270 *)raw3270_find_view(&fs3270_fn, minor);
 446         if (!IS_ERR(fp)) {
 447                 raw3270_put_view(&fp->view);
 448                 rc = -EBUSY;
 449                 goto out;
 450         }
 451         /* Allocate fullscreen view structure. */
 452         fp = fs3270_alloc_view();
 453         if (IS_ERR(fp)) {
 454                 rc = PTR_ERR(fp);
 455                 goto out;
 456         }
 457
 458         init_waitqueue_head(&fp->wait);
 459         fp->fs_pid = get_pid(task_pid(current));
 460         rc = raw3270_add_view(&fp->view, &fs3270_fn, minor,
 461                               RAW3270_VIEW_LOCK_BH);
 462         if (rc) {
 463                 fs3270_free_view(&fp->view);
 464                 goto out;
 465         }
 466
 467         /* Allocate idal-buffer. */
 468         ib = idal_buffer_alloc(2 * fp->view.rows * fp->view.cols + 5, 0);
 469         if (IS_ERR(ib)) {
 470                 raw3270_put_view(&fp->view);
 471                 raw3270_del_view(&fp->view);
 472                 rc = PTR_ERR(ib);
 473                 goto out;
 474         }
 475         fp->rdbuf = ib;
 476
 477         rc = raw3270_activate_view(&fp->view);
 478         if (rc) {
 479                 raw3270_put_view(&fp->view);
 480                 raw3270_del_view(&fp->view);
 481                 goto out;
 482         }
 483         stream_open(inode, filp);
 484         filp->private_data = fp;
 485 out:
 486         mutex_unlock(&fs3270_mutex);
 487         return rc;
 488 }
 489
 490 /*
 491  * This routine is called when the 3270 tty is closed. We wait
 492  * for the remaining request to be completed. Then we clean up.
 493  */
 494 static int fs3270_close(struct inode *inode, struct file *filp)
 495 {
 496         struct fs3270 *fp;
 497
 498         fp = filp->private_data;
 499         filp->private_data = NULL;
 500         if (fp) {
 501                 put_pid(fp->fs_pid);
 502                 fp->fs_pid = NULL;
 503                 raw3270_reset(&fp->view);
 504                 raw3270_put_view(&fp->view);
 505                 raw3270_del_view(&fp->view);
 506         }
 507         return 0;
 508 }
 509
 510 static const struct file_operations fs3270_fops = {
 511         .owner           = THIS_MODULE,         /* owner */
 512         .read            = fs3270_read,         /* read */
 513         .write           = fs3270_write,        /* write */
 514         .unlocked_ioctl  = fs3270_ioctl,        /* ioctl */
 515         .compat_ioctl    = fs3270_ioctl,        /* ioctl */
 516         .open            = fs3270_open,         /* open */
 517         .release         = fs3270_close,        /* release */
 518         .llseek         = no_llseek,
 519 };
 520
 521 static void fs3270_create_cb(int minor)
 522 {
 523         __register_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub", &fs3270_fops);
 524         device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, minor),
 525                       NULL, "3270/tub%d", minor);
 526 }
 527
 528 static void fs3270_destroy_cb(int minor)
 529 {
 530         device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, minor));
 531         __unregister_chrdev(IBM_FS3270_MAJOR, minor, 1, "tub");
 532 }
 533
 534 static struct raw3270_notifier fs3270_notifier = {
 535         .create = fs3270_create_cb,
 536         .destroy = fs3270_destroy_cb,
 537 };
 538
 539 /*
 540  * 3270 fullscreen driver initialization.
 541  */
 542 static int __init fs3270_init(void)
 543 {
 544         int rc;
 545
 546         rc = __register_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270", &fs3270_fops);
 547         if (rc)
 548                 return rc;
 549         device_create(class3270, NULL, MKDEV(IBM_FS3270_MAJOR, 0),
 550                       NULL, "3270/tub");
 551         raw3270_register_notifier(&fs3270_notifier);
 552         return 0;
 553 }
 554
 555 static void __exit fs3270_exit(void)
 556 {
 557         raw3270_unregister_notifier(&fs3270_notifier);
 558         device_destroy(class3270, MKDEV(IBM_FS3270_MAJOR, 0));
 559         __unregister_chrdev(IBM_FS3270_MAJOR, 0, 1, "fs3270");
 560 }
 561
 562 MODULE_LICENSE("GPL");
 563 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
 564
 565 module_init(fs3270_init);
 566 module_exit(fs3270_exit);