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/slab.h>
  16 #include <linux/types.h>
  17 #include <linux/smp_lock.h>
  18
  19 #include <asm/compat.h>
  20 #include <asm/ccwdev.h>
  21 #include <asm/cio.h>
  22 #include <asm/ebcdic.h>
  23 #include <asm/idals.h>
  24
  25 #include "raw3270.h"
  26 #include "ctrlchar.h"
  27
  28 static struct raw3270_fn fs3270_fn;
  29
  30 struct fs3270 {
  31         struct raw3270_view view;
  32         struct pid *fs_pid;             /* Pid of controlling program. */
  33         int read_command;               /* ccw command to use for reads. */
  34         int write_command;              /* ccw command to use for writes. */
  35         int attention;                  /* Got attention. */
  36         int active;                     /* Fullscreen view is active. */
  37         struct raw3270_request *init;   /* single init request. */
  38         wait_queue_head_t wait;         /* Init & attention wait queue. */
  39         struct idal_buffer *rdbuf;      /* full-screen-deactivate buffer */
  40         size_t rdbuf_size;              /* size of data returned by RDBUF */
  41 };
  42
  43 static DEFINE_MUTEX(fs3270_mutex);
  44
  45 static void
  46 fs3270_wake_up(struct raw3270_request *rq, void *data)
  47 {
  48         wake_up((wait_queue_head_t *) data);
  49 }
  50
  51 static inline int
  52 fs3270_working(struct fs3270 *fp)
  53 {
  54         /*
  55          * The fullscreen view is in working order if the view
  56          * has been activated AND the initial request is finished.
  57          */
  58         return fp->active && raw3270_request_final(fp->init);
  59 }
  60
  61 static int
  62 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
  92 fs3270_reset_callback(struct raw3270_request *rq, void *data)
  93 {
  94         struct fs3270 *fp;
  95
  96         fp = (struct fs3270 *) rq->view;
  97         raw3270_request_reset(rq);
  98         wake_up(&fp->wait);
  99 }
 100
 101 static void
 102 fs3270_restore_callback(struct raw3270_request *rq, void *data)
 103 {
 104         struct fs3270 *fp;
 105
 106         fp = (struct fs3270 *) rq->view;
 107         if (rq->rc != 0 || rq->rescnt != 0) {
 108                 if (fp->fs_pid)
 109                         kill_pid(fp->fs_pid, SIGHUP, 1);
 110         }
 111         fp->rdbuf_size = 0;
 112         raw3270_request_reset(rq);
 113         wake_up(&fp->wait);
 114 }
 115
 116 static int
 117 fs3270_activate(struct raw3270_view *view)
 118 {
 119         struct fs3270 *fp;
 120         char *cp;
 121         int rc;
 122
 123         fp = (struct fs3270 *) view;
 124
 125         /* If an old init command is still running just return. */
 126         if (!raw3270_request_final(fp->init))
 127                 return 0;
 128
 129         if (fp->rdbuf_size == 0) {
 130                 /* No saved buffer. Just clear the screen. */
 131                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 132                 fp->init->callback = fs3270_reset_callback;
 133         } else {
 134                 /* Restore fullscreen buffer saved by fs3270_deactivate. */
 135                 raw3270_request_set_cmd(fp->init, TC_EWRITEA);
 136                 raw3270_request_set_idal(fp->init, fp->rdbuf);
 137                 fp->init->ccw.count = fp->rdbuf_size;
 138                 cp = fp->rdbuf->data[0];
 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                 fp->init->rescnt = 0;
 148                 fp->init->callback = fs3270_restore_callback;
 149         }
 150         rc = fp->init->rc = raw3270_start_locked(view, fp->init);
 151         if (rc)
 152                 fp->init->callback(fp->init, NULL);
 153         else
 154                 fp->active = 1;
 155         return rc;
 156 }
 157
 158 /*
 159  * Shutdown fullscreen view.
 160  */
 161 static void
 162 fs3270_save_callback(struct raw3270_request *rq, void *data)
 163 {
 164         struct fs3270 *fp;
 165
 166         fp = (struct fs3270 *) rq->view;
 167
 168         /* Correct idal buffer element 0 address. */
 169         fp->rdbuf->data[0] -= 5;
 170         fp->rdbuf->size += 5;
 171
 172         /*
 173          * If the rdbuf command failed or the idal buffer is
 174          * to small for the amount of data returned by the
 175          * rdbuf command, then we have no choice but to send
 176          * a SIGHUP to the application.
 177          */
 178         if (rq->rc != 0 || rq->rescnt == 0) {
 179                 if (fp->fs_pid)
 180                         kill_pid(fp->fs_pid, SIGHUP, 1);
 181                 fp->rdbuf_size = 0;
 182         } else
 183                 fp->rdbuf_size = fp->rdbuf->size - rq->rescnt;
 184         raw3270_request_reset(rq);
 185         wake_up(&fp->wait);
 186 }
 187
 188 static void
 189 fs3270_deactivate(struct raw3270_view *view)
 190 {
 191         struct fs3270 *fp;
 192
 193         fp = (struct fs3270 *) view;
 194         fp->active = 0;
 195
 196         /* If an old init command is still running just return. */
 197         if (!raw3270_request_final(fp->init))
 198                 return;
 199
 200         /* Prepare read-buffer request. */
 201         raw3270_request_set_cmd(fp->init, TC_RDBUF);
 202         /*
 203          * Hackish: skip first 5 bytes of the idal buffer to make
 204          * room for the TW_KR/TO_SBA/<address>/<address>/TO_IC sequence
 205          * in the activation command.
 206          */
 207         fp->rdbuf->data[0] += 5;
 208         fp->rdbuf->size -= 5;
 209         raw3270_request_set_idal(fp->init, fp->rdbuf);
 210         fp->init->rescnt = 0;
 211         fp->init->callback = fs3270_save_callback;
 212
 213         /* Start I/O to read in the 3270 buffer. */
 214         fp->init->rc = raw3270_start_locked(view, fp->init);
 215         if (fp->init->rc)
 216                 fp->init->callback(fp->init, NULL);
 217 }
 218
 219 static int
 220 fs3270_irq(struct fs3270 *fp, struct raw3270_request *rq, struct irb *irb)
 221 {
 222         /* Handle ATTN. Set indication and wake waiters for attention. */
 223         if (irb->scsw.cmd.dstat & DEV_STAT_ATTENTION) {
 224                 fp->attention = 1;
 225                 wake_up(&fp->wait);
 226         }
 227
 228         if (rq) {
 229                 if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
 230                         rq->rc = -EIO;
 231                 else
 232                         /* Normal end. Copy residual count. */
 233                         rq->rescnt = irb->scsw.cmd.count;
 234         }
 235         return RAW3270_IO_DONE;
 236 }
 237
 238 /*
 239  * Process reads from fullscreen 3270.
 240  */
 241 static ssize_t
 242 fs3270_read(struct file *filp, char __user *data, size_t count, loff_t *off)
 243 {
 244         struct fs3270 *fp;
 245         struct raw3270_request *rq;
 246         struct idal_buffer *ib;
 247         ssize_t rc;
 248
 249         if (count == 0 || count > 65535)
 250                 return -EINVAL;
 251         fp = filp->private_data;
 252         if (!fp)
 253                 return -ENODEV;
 254         ib = idal_buffer_alloc(count, 0);
 255         if (IS_ERR(ib))
 256                 return -ENOMEM;
 257         rq = raw3270_request_alloc(0);
 258         if (!IS_ERR(rq)) {
 259                 if (fp->read_command == 0 && fp->write_command != 0)
 260                         fp->read_command = 6;
 261                 raw3270_request_set_cmd(rq, fp->read_command ? : 2);
 262                 raw3270_request_set_idal(rq, ib);
 263                 rc = wait_event_interruptible(fp->wait, fp->attention);
 264                 fp->attention = 0;
 265                 if (rc == 0) {
 266                         rc = fs3270_do_io(&fp->view, rq);
 267                         if (rc == 0) {
 268                                 count -= rq->rescnt;
 269                                 if (idal_buffer_to_user(ib, data, count) != 0)
 270                                         rc = -EFAULT;
 271                                 else
 272                                         rc = count;
 273
 274                         }
 275                 }
 276                 raw3270_request_free(rq);
 277         } else
 278                 rc = PTR_ERR(rq);
 279         idal_buffer_free(ib);
 280         return rc;
 281 }
 282
 283 /*
 284  * Process writes to fullscreen 3270.
 285  */
 286 static ssize_t
 287 fs3270_write(struct file *filp, const char __user *data, size_t count, loff_t *off)
 288 {
 289         struct fs3270 *fp;
 290         struct raw3270_request *rq;
 291         struct idal_buffer *ib;
 292         int write_command;
 293         ssize_t rc;
 294
 295         fp = filp->private_data;
 296         if (!fp)
 297                 return -ENODEV;
 298         ib = idal_buffer_alloc(count, 0);
 299         if (IS_ERR(ib))
 300                 return -ENOMEM;
 301         rq = raw3270_request_alloc(0);
 302         if (!IS_ERR(rq)) {
 303                 if (idal_buffer_from_user(ib, data, count) == 0) {
 304                         write_command = fp->write_command ? : 1;
 305                         if (write_command == 5)
 306                                 write_command = 13;
 307                         raw3270_request_set_cmd(rq, write_command);
 308                         raw3270_request_set_idal(rq, ib);
 309                         rc = fs3270_do_io(&fp->view, rq);
 310                         if (rc == 0)
 311                                 rc = count - rq->rescnt;
 312                 } else
 313                         rc = -EFAULT;
 314                 raw3270_request_free(rq);
 315         } else
 316                 rc = PTR_ERR(rq);
 317         idal_buffer_free(ib);
 318         return rc;
 319 }
 320
 321 /*
 322  * process ioctl commands for the tube driver
 323  */
 324 static long
 325 fs3270_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 326 {
 327         char __user *argp;
 328         struct fs3270 *fp;
 329         struct raw3270_iocb iocb;
 330         int rc;
 331
 332         fp = filp->private_data;
 333         if (!fp)
 334                 return -ENODEV;
 335         if (is_compat_task())
 336                 argp = compat_ptr(arg);
 337         else
 338                 argp = (char __user *)arg;
 339         rc = 0;
 340         mutex_lock(&fs3270_mutex);
 341         switch (cmd) {
 342         case TUBICMD:
 343                 fp->read_command = arg;
 344                 break;
 345         case TUBOCMD:
 346                 fp->write_command = arg;
 347                 break;
 348         case TUBGETI:
 349                 rc = put_user(fp->read_command, argp);
 350                 break;
 351         case TUBGETO:
 352                 rc = put_user(fp->write_command, argp);
 353                 break;
 354         case TUBGETMOD:
 355                 iocb.model = fp->view.model;
 356                 iocb.line_cnt = fp->view.rows;
 357                 iocb.col_cnt = fp->view.cols;
 358                 iocb.pf_cnt = 24;
 359                 iocb.re_cnt = 20;
 360                 iocb.map = 0;
 361                 if (copy_to_user(argp, &iocb, sizeof(struct raw3270_iocb)))
 362                         rc = -EFAULT;
 363                 break;
 364         }
 365         mutex_unlock(&fs3270_mutex);
 366         return rc;
 367 }
 368
 369 /*
 370  * Allocate fs3270 structure.
 371  */
 372 static struct fs3270 *
 373 fs3270_alloc_view(void)
 374 {
 375         struct fs3270 *fp;
 376
 377         fp = kzalloc(sizeof(struct fs3270),GFP_KERNEL);
 378         if (!fp)
 379                 return ERR_PTR(-ENOMEM);
 380         fp->init = raw3270_request_alloc(0);
 381         if (IS_ERR(fp->init)) {
 382                 kfree(fp);
 383                 return ERR_PTR(-ENOMEM);
 384         }
 385         return fp;
 386 }
 387
 388 /*
 389  * Free fs3270 structure.
 390  */
 391 static void
 392 fs3270_free_view(struct raw3270_view *view)
 393 {
 394         struct fs3270 *fp;
 395
 396         fp = (struct fs3270 *) view;
 397         if (fp->rdbuf)
 398                 idal_buffer_free(fp->rdbuf);
 399         raw3270_request_free(((struct fs3270 *) view)->init);
 400         kfree(view);
 401 }
 402
 403 /*
 404  * Unlink fs3270 data structure from filp.
 405  */
 406 static void
 407 fs3270_release(struct raw3270_view *view)
 408 {
 409         struct fs3270 *fp;
 410
 411         fp = (struct fs3270 *) view;
 412         if (fp->fs_pid)
 413                 kill_pid(fp->fs_pid, SIGHUP, 1);
 414 }
 415
 416 /* View to a 3270 device. Can be console, tty or fullscreen. */
 417 static struct raw3270_fn fs3270_fn = {
 418         .activate = fs3270_activate,
 419         .deactivate = fs3270_deactivate,
 420         .intv = (void *) fs3270_irq,
 421         .release = fs3270_release,
 422         .free = fs3270_free_view
 423 };
 424
 425 /*
 426  * This routine is called whenever a 3270 fullscreen device is opened.
 427  */
 428 static int
 429 fs3270_open(struct inode *inode, struct file *filp)
 430 {
 431         struct fs3270 *fp;
 432         struct idal_buffer *ib;
 433         int minor, rc = 0;
 434
 435         if (imajor(filp->f_path.dentry->d_inode) != IBM_FS3270_MAJOR)
 436                 return -ENODEV;
 437         minor = iminor(filp->f_path.dentry->d_inode);
 438         /* Check for minor 0 multiplexer. */
 439         if (minor == 0) {
 440                 struct tty_struct *tty = get_current_tty();
 441                 if (!tty || tty->driver->major != IBM_TTY3270_MAJOR) {
 442                         tty_kref_put(tty);
 443                         return -ENODEV;
 444                 }
 445                 minor = tty->index + RAW3270_FIRSTMINOR;
 446                 tty_kref_put(tty);
 447         }
 448         mutex_lock(&fs3270_mutex);
 449         /* Check if some other program is already using fullscreen mode. */
 450         fp = (struct fs3270 *) raw3270_find_view(&fs3270_fn, minor);
 451         if (!IS_ERR(fp)) {
 452                 raw3270_put_view(&fp->view);
 453                 rc = -EBUSY;
 454                 goto out;
 455         }
 456         /* Allocate fullscreen view structure. */
 457         fp = fs3270_alloc_view();
 458         if (IS_ERR(fp)) {
 459                 rc = PTR_ERR(fp);
 460                 goto out;
 461         }
 462
 463         init_waitqueue_head(&fp->wait);
 464         fp->fs_pid = get_pid(task_pid(current));
 465         rc = raw3270_add_view(&fp->view, &fs3270_fn, minor);
 466         if (rc) {
 467                 fs3270_free_view(&fp->view);
 468                 goto out;
 469         }
 470
 471         /* Allocate idal-buffer. */
 472         ib = idal_buffer_alloc(2*fp->view.rows*fp->view.cols + 5, 0);
 473         if (IS_ERR(ib)) {
 474                 raw3270_put_view(&fp->view);
 475                 raw3270_del_view(&fp->view);
 476                 rc = PTR_ERR(ib);
 477                 goto out;
 478         }
 479         fp->rdbuf = ib;
 480
 481         rc = raw3270_activate_view(&fp->view);
 482         if (rc) {
 483                 raw3270_put_view(&fp->view);
 484                 raw3270_del_view(&fp->view);
 485                 goto out;
 486         }
 487         nonseekable_open(inode, filp);
 488         filp->private_data = fp;
 489 out:
 490         mutex_unlock(&fs3270_mutex);
 491         return rc;
 492 }
 493
 494 /*
 495  * This routine is called when the 3270 tty is closed. We wait
 496  * for the remaining request to be completed. Then we clean up.
 497  */
 498 static int
 499 fs3270_close(struct inode *inode, struct file *filp)
 500 {
 501         struct fs3270 *fp;
 502
 503         fp = filp->private_data;
 504         filp->private_data = NULL;
 505         if (fp) {
 506                 put_pid(fp->fs_pid);
 507                 fp->fs_pid = NULL;
 508                 raw3270_reset(&fp->view);
 509                 raw3270_put_view(&fp->view);
 510                 raw3270_del_view(&fp->view);
 511         }
 512         return 0;
 513 }
 514
 515 static const struct file_operations fs3270_fops = {
 516         .owner           = THIS_MODULE,         /* owner */
 517         .read            = fs3270_read,         /* read */
 518         .write           = fs3270_write,        /* write */
 519         .unlocked_ioctl  = fs3270_ioctl,        /* ioctl */
 520         .compat_ioctl    = fs3270_ioctl,        /* ioctl */
 521         .open            = fs3270_open,         /* open */
 522         .release         = fs3270_close,        /* release */
 523 };
 524
 525 /*
 526  * 3270 fullscreen driver initialization.
 527  */
 528 static int __init
 529 fs3270_init(void)
 530 {
 531         int rc;
 532
 533         rc = register_chrdev(IBM_FS3270_MAJOR, "fs3270", &fs3270_fops);
 534         if (rc)
 535                 return rc;
 536         return 0;
 537 }
 538
 539 static void __exit
 540 fs3270_exit(void)
 541 {
 542         unregister_chrdev(IBM_FS3270_MAJOR, "fs3270");
 543 }
 544
 545 MODULE_LICENSE("GPL");
 546 MODULE_ALIAS_CHARDEV_MAJOR(IBM_FS3270_MAJOR);
 547
 548 module_init(fs3270_init);
 549 module_exit(fs3270_exit);