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/compat.h>
  15 #include <linux/module.h>
  16 #include <linux/list.h>
  17 #include <linux/slab.h>
  18 #include <linux/types.h>
  19
  20 #include <asm/compat.h>
  21 #include <asm/ccwdev.h>
  22 #include <asm/cio.h>
  23 #include <asm/ebcdic.h>
  24 #include <asm/idals.h>
  25
  26 #include "raw3270.h"
  27 #include "ctrlchar.h"
  28
  29 static struct raw3270_fn fs3270_fn;
  30
  31 struct fs3270 {
  32         struct raw3270_view view;
  33         struct pid *fs_pid;             /* Pid of controlling program. */
  34         int read_command;               /* ccw command to use for reads. */
  35         int write_command;              /* ccw command to use for writes. */
  36         int attention;                  /* Got attention. */
  37         int active;                     /* Fullscreen view is active. */
  38         struct raw3270_request *init;   /* single init request. */
  39         wait_queue_head_t wait;         /* Init & attention wait queue. */
  40         struct idal_buffer *rdbuf;      /* full-screen-deactivate buffer */
  41         size_t rdbuf_size;              /* size of data returned by RDBUF */
  42 };
  43
  44 static DEFINE_MUTEX(fs3270_mutex);
  45
  46 static void
  47 fs3270_wake_up(struct raw3270_request *rq, void *data)
  48 {
  49         wake_up((wait_queue_head_t *) data);
  50 }
  51
  52 static inline int
  53 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
  63 fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
  64 {
  65         struct fs3270 *fp;
  66         int rc;
  67
  68         fp = (struct fs3270 *) view;
  69         rq->callback = fs3270_wake_up;
  70         rq->callback_data = &fp->wait;
  71
  72         do {
  73                 if (!fs3270_working(fp)) {
  74                         /* Fullscreen view isn't ready yet. */
  75                         rc = wait_event_interruptible(fp->wait,
  76                                                       fs3270_working(fp));
  77                         if (rc != 0)
  78                                 break;
  79                 }
  80                 rc = raw3270_start(view, rq);
  81                 if (rc == 0) {
  82                         /* Started successfully. Now wait for completion. */
  83                         wait_event(fp->wait, raw3270_request_final(rq));
  84                 }
  85         } while (rc == -EACCES);
  86         return rc;
  87 }
  88
  89 /*
  90  * Switch to the fullscreen view.
  91  */
  92 static void
  93 fs3270_reset_callback(struct raw3270_request *rq, void *data)
  94 {
  95         struct fs3270 *fp;
  96
  97         fp = (struct fs3270 *) rq->view;
  98         raw3270_request_reset(rq);
  99         wake_up(&fp->wait);
 100 }
 101
 102 static void
 103 fs3270_restore_callback(struct raw3270_request *rq, void *data)
 104 {
 105         struct fs3270 *fp;
 106
 107         fp = (struct fs3270 *) rq->view;
 108         if (rq->rc != 0 || rq->rescnt != 0) {
 109                 if (fp->fs_pid)
 110                         kill_pid(fp->fs_pid, SIGHUP, 1);
 111         }
 112         fp->rdbuf_size = 0;
 113         raw3270_request_reset(rq);
 114         wake_up(&fp->wait);
 115 }
 116
 117 static int
 118 fs3270_activate(struct raw3270_view *view)
 119 {
 120         struct fs3270 *fp;
 121         char *cp;
 122         int rc;
 123
 124         fp = (struct fs3270 *) view;
 125
 126         /* If an old init command is still running just return. */
 127         if (!raw3270_request_final(fp->init))
 128                 return 0;
 129
 130         if (fp->rdbuf_size == 0) {
 131                 /* No saved buffer. Just clear the screen. */
 132                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 133                 fp->init->callback = fs3270_reset_callback;
 134         } else {
 135                 /* Restore fullscreen buffer saved by fs3270_deactivate. */
 136                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 137                 raw3270_request_set_idal(fp->init, fp->rdbuf);
 138                 fp->init->ccw.count = fp->rdbuf_size;
 139                 cp = fp->rdbuf->data[0];
 140                 cp[0] = TW_KR;
 141                 cp[1] = TO_SBA;
 142                 cp[2] = cp[6];
 143                 cp[3] = cp[7];
 144                 cp[4] = TO_IC;
 145                 cp[5] = TO_SBA;
 146                 cp[6] = 0x40;
 147                 cp[7] = 0x40;
 148                 fp->init->rescnt = 0;
 149                 fp->init->callback = fs3270_restore_callback;
 150         }
 151         rc = fp->init->rc = raw3270_start_locked(view, fp->init);
 152         if (rc)
 153                 fp->init->callback(fp->init, NULL);
 154         else
 155                 fp->active = 1;
 156         return rc;
 157 }
 158
 159 /*
 160  * Shutdown fullscreen view.
 161  */
 162 static void
 163 fs3270_save_callback(struct raw3270_request *rq, void *data)
 164 {
 165         struct fs3270 *fp;
 166
 167         fp = (struct fs3270 *) rq->view;
 168
 169         /* Correct idal buffer element 0 address. */
 170         fp->rdbuf->data[0] -= 5;
 171         fp->rdbuf->size += 5;
 172
 173         /*
 174          * If the rdbuf command failed or the idal buffer is
 175          * to small for the amount of data returned by the
 176          * rdbuf command, then we have no choice but to send
 177          * a SIGHUP to the application.
 178          */
 179         if (rq->rc != 0 || rq->rescnt == 0) {
 180                 if (fp->fs_pid)
 181                         kill_pid(fp->fs_pid, SIGHUP, 1);
 182                 fp->rdbuf_size = 0;
 183         } else
 184                 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
 185         raw3270_request_reset(rq);
 186         wake_up(&fp->wait);
 187 }
 188
 189 static void
 190 fs3270_deactivate(struct raw3270_view *view)
 191 {
 192         struct fs3270 *fp;
 193
 194         fp = (struct fs3270 *) view;
 195         fp->active = 0;
 196
 197         /* If an old init command is still running just return. */
 198         if (!raw3270_request_final(fp->init))
 199                 return;
 200
 201         /* Prepare read-buffer request. */
 202         raw3270_request_set_cmd(fp->init, TC_RDBUF);
 203         /*
 204          * Hackish: skip first 5 bytes of the idal buffer to make
 205          * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
 206          * in the activation command.
 207          */
 208         fp->rdbuf->data[0] += 5;
 209         fp->rdbuf->size -= 5;
 210         raw3270_request_set_idal(fp->init, fp->rdbuf);
 211         fp->init->rescnt = 0;
 212         fp->init->callback = fs3270_save_callback;
 213
 214         /* Start I/O to read in the 3270 buffer. */
 215         fp->init->rc = raw3270_start_locked(view, fp->init);
 216         if (fp->init->rc)
 217                 fp->init->callback(fp->init, NULL);
 218 }
 219
 220 static int
 221 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
 222 {
 223         /* Handle ATTN. Set indication and wake waiters for attention. */
 224         if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
 225                 fp->attention = 1;
 226                 wake_up(&fp->wait);
 227         }
 228
 229         if (rq) {
 230                 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
 231                         rq->rc = -EIO;
 232                 else
 233                         /* Normal end. Copy residual count. */
 234                         rq->rescnt = irb->scsw.cmd.count;
 235         }
 236         return RAW3270_IO_DONE;
 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(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
 437                 return -ENODEV;
 438         minor = iminor(filp->f_path.dentry->d_inode);
 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 + RAW3270_FIRSTMINOR;
 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         if (rc) {
 468                 fs3270_free_view(&fp->view);
 469                 goto out;
 470         }
 471
 472         /* Allocate idal-buffer. */
 473         ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
 474         if (IS_ERR(ib)) {
 475                 raw3270_put_view(&fp->view);
 476                 raw3270_del_view(&fp->view);
 477                 rc = PTR_ERR(ib);
 478                 goto out;
 479         }
 480         fp->rdbuf = ib;
 481
 482         rc = raw3270_activate_view(&fp->view);
 483         if (rc) {
 484                 raw3270_put_view(&fp->view);
 485                 raw3270_del_view(&fp->view);
 486                 goto out;
 487         }
 488         nonseekable_open(inode, filp);
 489         filp->private_data = fp;
 490 out:
 491         mutex_unlock(&fs3270_mutex);
 492         return rc;
 493 }
 494
 495 /*
 496  * This routine is called when the 3270 tty is closed. We wait
 497  * for the remaining request to be completed. Then we clean up.
 498  */
 499 static int
 500 fs3270_close(struct inode *inode, struct file *filp)
 501 {
 502         struct fs3270 *fp;
 503
 504         fp = filp->private_data;
 505         filp->private_data = NULL;
 506         if (fp) {
 507                 put_pid(fp->fs_pid);
 508                 fp->fs_pid = NULL;
 509                 raw3270_reset(&fp->view);
 510                 raw3270_put_view(&fp->view);
 511                 raw3270_del_view(&fp->view);
 512         }
 513         return 0;
 514 }
 515
 516 static const struct file_operations fs3270_fops = {
 517         .owner           = THIS_MODULE,         /* owner */
 518         .read            = fs3270_read,         /* read */
 519         .write           = fs3270_write,        /* write */
 520         .unlocked_ioctl  = fs3270_ioctl,        /* ioctl */
 521         .compat_ioctl    = fs3270_ioctl,        /* ioctl */
 522         .open            = fs3270_open,         /* open */
 523         .release         = fs3270_close,        /* release */
 524         .llseek         = no_llseek,
 525 };
 526
 527 /*
 528  * 3270 fullscreen driver initialization.
 529  */
 530 static int __init
 531 fs3270_init(void)
 532 {
 533         int rc;
 534
 535         rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
 536         if (rc)
 537                 return rc;
 538         return 0;
 539 }
 540
 541 static void __exit
 542 fs3270_exit(void)
 543 {
 544         unregister_chrdev(IBM_FS3270_MAJOR, "fs3270");
 545 }
 546
 547 MODULE_LICENSE("GPL");
 548 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
 549
 550 module_init(fs3270_init);
 551 module_exit(fs3270_exit);