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 DEFINE_MUTEX(fs3270_mutex);
  42
  43 static void
  44 fs3270_wake_up(struct raw3270_request *rq, void *data)
  45 {
  46         wake_up((wait_queue_head_t *) data);
  47 }
  48
  49 static inline int
  50 fs3270_working(struct fs3270 *fp)
  51 {
  52         /*
  53          * The fullscreen view is in working order if the view
  54          * has been activated AND the initial request is finished.
  55          */
  56         return fp->active && raw3270_request_final(fp->init);
  57 }
  58
  59 static int
  60 fs3270_do_io(struct raw3270_view *view, struct raw3270_request *rq)
  61 {
  62         struct fs3270 *fp;
  63         int rc;
  64
  65         fp = (struct fs3270 *) view;
  66         rq->callback = fs3270_wake_up;
  67         rq->callback_data = &fp->wait;
  68
  69         do {
  70                 if (!fs3270_working(fp)) {
  71                         /* Fullscreen view isn't ready yet. */
  72                         rc = wait_event_interruptible(fp->wait,
  73                                                       fs3270_working(fp));
  74                         if (rc != 0)
  75                                 break;
  76                 }
  77                 rc = raw3270_start(view, rq);
  78                 if (rc == 0) {
  79                         /* Started successfully. Now wait for completion. */
  80                         wait_event(fp->wait, raw3270_request_final(rq));
  81                 }
  82         } while (rc == -EACCES);
  83         return rc;
  84 }
  85
  86 /*
  87  * Switch to the fullscreen view.
  88  */
  89 static void
  90 fs3270_reset_callback(struct raw3270_request *rq, void *data)
  91 {
  92         struct fs3270 *fp;
  93
  94         fp = (struct fs3270 *) rq->view;
  95         raw3270_request_reset(rq);
  96         wake_up(&fp->wait);
  97 }
  98
  99 static void
 100 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
 115 fs3270_activate(struct raw3270_view *view)
 116 {
 117         struct fs3270 *fp;
 118         char *cp;
 119         int rc;
 120
 121         fp = (struct fs3270 *) view;
 122
 123         /* If an old init command is still running just return. */
 124         if (!raw3270_request_final(fp->init))
 125                 return 0;
 126
 127         if (fp->rdbuf_size == 0) {
 128                 /* No saved buffer. Just clear the screen. */
 129                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 130                 fp->init->callback = fs3270_reset_callback;
 131         } else {
 132                 /* Restore fullscreen buffer saved by fs3270_deactivate. */
 133                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 134                 raw3270_request_set_idal(fp->init, fp->rdbuf);
 135                 fp->init->ccw.count = fp->rdbuf_size;
 136                 cp = fp->rdbuf->data[0];
 137                 cp[0] = TW_KR;
 138                 cp[1] = TO_SBA;
 139                 cp[2] = cp[6];
 140                 cp[3] = cp[7];
 141                 cp[4] = TO_IC;
 142                 cp[5] = TO_SBA;
 143                 cp[6] = 0x40;
 144                 cp[7] = 0x40;
 145                 fp->init->rescnt = 0;
 146                 fp->init->callback = fs3270_restore_callback;
 147         }
 148         rc = fp->init->rc = raw3270_start_locked(view, fp->init);
 149         if (rc)
 150                 fp->init->callback(fp->init, NULL);
 151         else
 152                 fp->active = 1;
 153         return rc;
 154 }
 155
 156 /*
 157  * Shutdown fullscreen view.
 158  */
 159 static void
 160 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         raw3270_request_reset(rq);
 183         wake_up(&fp->wait);
 184 }
 185
 186 static void
 187 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 int
 218 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, 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         return RAW3270_IO_DONE;
 234 }
 235
 236 /*
 237  * Process reads from fullscreen 3270.
 238  */
 239 static ssize_t
 240 fs3270_read(struct file *filp, char __user *data, size_t count, loff_t *off)
 241 {
 242         struct fs3270 *fp;
 243         struct raw3270_request *rq;
 244         struct idal_buffer *ib;
 245         ssize_t rc;
 246
 247         if (count == 0 || count > 65535)
 248                 return -EINVAL;
 249         fp = filp->private_data;
 250         if (!fp)
 251                 return -ENODEV;
 252         ib = idal_buffer_alloc(count, 0);
 253         if (IS_ERR(ib))
 254                 return -ENOMEM;
 255         rq = raw3270_request_alloc(0);
 256         if (!IS_ERR(rq)) {
 257                 if (fp->read_command == 0 && fp->write_command != 0)
 258                         fp->read_command = 6;
 259                 raw3270_request_set_cmd(rq, fp->read_command ? : 2);
 260                 raw3270_request_set_idal(rq, ib);
 261                 rc = wait_event_interruptible(fp->wait, fp->attention);
 262                 fp->attention = 0;
 263                 if (rc == 0) {
 264                         rc = fs3270_do_io(&fp->view, rq);
 265                         if (rc == 0) {
 266                                 count -= rq->rescnt;
 267                                 if (idal_buffer_to_user(ib, data, count) != 0)
 268                                         rc = -EFAULT;
 269                                 else
 270                                         rc = count;
 271
 272                         }
 273                 }
 274                 raw3270_request_free(rq);
 275         } else
 276                 rc = PTR_ERR(rq);
 277         idal_buffer_free(ib);
 278         return rc;
 279 }
 280
 281 /*
 282  * Process writes to fullscreen 3270.
 283  */
 284 static ssize_t
 285 fs3270_write(struct file *filp, const char __user *data, size_t count, loff_t *off)
 286 {
 287         struct fs3270 *fp;
 288         struct raw3270_request *rq;
 289         struct idal_buffer *ib;
 290         int write_command;
 291         ssize_t rc;
 292
 293         fp = filp->private_data;
 294         if (!fp)
 295                 return -ENODEV;
 296         ib = idal_buffer_alloc(count, 0);
 297         if (IS_ERR(ib))
 298                 return -ENOMEM;
 299         rq = raw3270_request_alloc(0);
 300         if (!IS_ERR(rq)) {
 301                 if (idal_buffer_from_user(ib, data, count) == 0) {
 302                         write_command = fp->write_command ? : 1;
 303                         if (write_command == 5)
 304                                 write_command = 13;
 305                         raw3270_request_set_cmd(rq, write_command);
 306                         raw3270_request_set_idal(rq, ib);
 307                         rc = fs3270_do_io(&fp->view, rq);
 308                         if (rc == 0)
 309                                 rc = count - rq->rescnt;
 310                 } else
 311                         rc = -EFAULT;
 312                 raw3270_request_free(rq);
 313         } else
 314                 rc = PTR_ERR(rq);
 315         idal_buffer_free(ib);
 316         return rc;
 317 }
 318
 319 /*
 320  * process ioctl commands for the tube driver
 321  */
 322 static long
 323 fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 324 {
 325         struct fs3270 *fp;
 326         struct raw3270_iocb iocb;
 327         int rc;
 328
 329         fp = filp->private_data;
 330         if (!fp)
 331                 return -ENODEV;
 332         rc = 0;
 333         mutex_lock(&fs3270_mutex);
 334         switch (cmd) {
 335         case TUBICMD:
 336                 fp->read_command = arg;
 337                 break;
 338         case TUBOCMD:
 339                 fp->write_command = arg;
 340                 break;
 341         case TUBGETI:
 342                 rc = put_user(fp->read_command, (char __user *) arg);
 343                 break;
 344         case TUBGETO:
 345                 rc = put_user(fp->write_command,(char __user *) arg);
 346                 break;
 347         case TUBGETMOD:
 348                 iocb.model = fp->view.model;
 349                 iocb.line_cnt = fp->view.rows;
 350                 iocb.col_cnt = fp->view.cols;
 351                 iocb.pf_cnt = 24;
 352                 iocb.re_cnt = 20;
 353                 iocb.map = 0;
 354                 if (copy_to_user((char __user *) arg, &iocb,
 355                                  sizeof(struct raw3270_iocb)))
 356                         rc = -EFAULT;
 357                 break;
 358         }
 359         mutex_unlock(&fs3270_mutex);
 360         return rc;
 361 }
 362
 363 /*
 364  * Allocate fs3270 structure.
 365  */
 366 static struct fs3270 *
 367 fs3270_alloc_view(void)
 368 {
 369         struct fs3270 *fp;
 370
 371         fp = kzalloc(sizeof(struct fs3270),GFP_KERNEL);
 372         if (!fp)
 373                 return ERR_PTR(-ENOMEM);
 374         fp->init = raw3270_request_alloc(0);
 375         if (IS_ERR(fp->init)) {
 376                 kfree(fp);
 377                 return ERR_PTR(-ENOMEM);
 378         }
 379         return fp;
 380 }
 381
 382 /*
 383  * Free fs3270 structure.
 384  */
 385 static void
 386 fs3270_free_view(struct raw3270_view *view)
 387 {
 388         struct fs3270 *fp;
 389
 390         fp = (struct fs3270 *) view;
 391         if (fp->rdbuf)
 392                 idal_buffer_free(fp->rdbuf);
 393         raw3270_request_free(((struct fs3270 *) view)->init);
 394         kfree(view);
 395 }
 396
 397 /*
 398  * Unlink fs3270 data structure from filp.
 399  */
 400 static void
 401 fs3270_release(struct raw3270_view *view)
 402 {
 403         struct fs3270 *fp;
 404
 405         fp = (struct fs3270 *) view;
 406         if (fp->fs_pid)
 407                 kill_pid(fp->fs_pid, SIGHUP, 1);
 408 }
 409
 410 /* View to a 3270 device. Can be console, tty or fullscreen. */
 411 static struct raw3270_fn fs3270_fn = {
 412         .activate = fs3270_activate,
 413         .deactivate = fs3270_deactivate,
 414         .intv = (void *) fs3270_irq,
 415         .release = fs3270_release,
 416         .free = fs3270_free_view
 417 };
 418
 419 /*
 420  * This routine is called whenever a 3270 fullscreen device is opened.
 421  */
 422 static int
 423 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(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
 430                 return -ENODEV;
 431         minor = iminor(filp->f_path.dentry->d_inode);
 432         /* Check for minor 0 multiplexer. */
 433         if (minor == 0) {
 434                 struct tty_struct *tty = get_current_tty();
 435                 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
 436                         tty_kref_put(tty);
 437                         return -ENODEV;
 438                 }
 439                 minor = tty->index + RAW3270_FIRSTMINOR;
 440                 tty_kref_put(tty);
 441         }
 442         mutex_lock(&fs3270_mutex);
 443         /* Check if some other program is already using fullscreen mode. */
 444         fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
 445         if (!IS_ERR(fp)) {
 446                 raw3270_put_view(&fp->view);
 447                 rc = -EBUSY;
 448                 goto out;
 449         }
 450         /* Allocate fullscreen view structure. */
 451         fp = fs3270_alloc_view();
 452         if (IS_ERR(fp)) {
 453                 rc = PTR_ERR(fp);
 454                 goto out;
 455         }
 456
 457         init_waitqueue_head(&fp->wait);
 458         fp->fs_pid = get_pid(task_pid(current));
 459         rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
 460         if (rc) {
 461                 fs3270_free_view(&fp->view);
 462                 goto out;
 463         }
 464
 465         /* Allocate idal-buffer. */
 466         ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
 467         if (IS_ERR(ib)) {
 468                 raw3270_put_view(&fp->view);
 469                 raw3270_del_view(&fp->view);
 470                 rc = PTR_ERR(ib);
 471                 goto out;
 472         }
 473         fp->rdbuf = ib;
 474
 475         rc = raw3270_activate_view(&fp->view);
 476         if (rc) {
 477                 raw3270_put_view(&fp->view);
 478                 raw3270_del_view(&fp->view);
 479                 goto out;
 480         }
 481         filp->private_data = fp;
 482 out:
 483         mutex_unlock(&fs3270_mutex);
 484         return rc;
 485 }
 486
 487 /*
 488  * This routine is called when the 3270 tty is closed. We wait
 489  * for the remaining request to be completed. Then we clean up.
 490  */
 491 static int
 492 fs3270_close(struct inode *inode, struct file *filp)
 493 {
 494         struct fs3270 *fp;
 495
 496         fp = filp->private_data;
 497         filp->private_data = NULL;
 498         if (fp) {
 499                 put_pid(fp->fs_pid);
 500                 fp->fs_pid = NULL;
 501                 raw3270_reset(&fp->view);
 502                 raw3270_put_view(&fp->view);
 503                 raw3270_del_view(&fp->view);
 504         }
 505         return 0;
 506 }
 507
 508 static const struct file_operations fs3270_fops = {
 509         .owner           = THIS_MODULE,         /* owner */
 510         .read            = fs3270_read,         /* read */
 511         .write           = fs3270_write,        /* write */
 512         .unlocked_ioctl  = fs3270_ioctl,        /* ioctl */
 513         .compat_ioctl    = fs3270_ioctl,        /* ioctl */
 514         .open           = fs3270_open,          /* open */
 515         .release        = fs3270_close,         /* release */
 516 };
 517
 518 /*
 519  * 3270 fullscreen driver initialization.
 520  */
 521 static int __init
 522 fs3270_init(void)
 523 {
 524         int rc;
 525
 526         rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
 527         if (rc)
 528                 return rc;
 529         return 0;
 530 }
 531
 532 static void __exit
 533 fs3270_exit(void)
 534 {
 535         unregister_chrdev(IBM_FS3270_MAJOR, "fs3270");
 536 }
 537
 538 MODULE_LICENSE("GPL");
 539 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
 540
 541 module_init(fs3270_init);
 542 module_exit(fs3270_exit);