drivers/s390/char/sclp_tty.c

   1 /*
   2  *  drivers/s390/char/sclp_tty.c
   3  *    SCLP line mode terminal driver.
   4  *
   5  *  S390 version
   6  *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
   7  *    Author(s): Martin Peschke <mpeschke@de.ibm.com>
   8  *               Martin Schwidefsky <schwidefsky@de.ibm.com>
   9  */
  10
  11 #include <linux/config.h>
  12 #include <linux/module.h>
  13 #include <linux/kmod.h>
  14 #include <linux/tty.h>
  15 #include <linux/tty_driver.h>
  16 #include <linux/sched.h>
  17 #include <linux/wait.h>
  18 #include <linux/slab.h>
  19 #include <linux/err.h>
  20 #include <linux/init.h>
  21 #include <linux/interrupt.h>
  22 #include <asm/uaccess.h>
  23
  24 #include "ctrlchar.h"
  25 #include "sclp.h"
  26 #include "sclp_rw.h"
  27 #include "sclp_tty.h"
  28
  29 #define SCLP_TTY_PRINT_HEADER "sclp tty driver: "
  30
  31 /*
  32  * size of a buffer that collects single characters coming in
  33  * via sclp_tty_put_char()
  34  */
  35 #define SCLP_TTY_BUF_SIZE 512
  36
  37 /*
  38  * There is exactly one SCLP terminal, so we can keep things simple
  39  * and allocate all variables statically.
  40  */
  41
  42 /* Lock to guard over changes to global variables. */
  43 static spinlock_t sclp_tty_lock;
  44 /* List of free pages that can be used for console output buffering. */
  45 static struct list_head sclp_tty_pages;
  46 /* List of full struct sclp_buffer structures ready for output. */
  47 static struct list_head sclp_tty_outqueue;
  48 /* Counter how many buffers are emitted. */
  49 static int sclp_tty_buffer_count;
  50 /* Pointer to current console buffer. */
  51 static struct sclp_buffer *sclp_ttybuf;
  52 /* Timer for delayed output of console messages. */
  53 static struct timer_list sclp_tty_timer;
  54 /* Waitqueue to wait for buffers to get empty. */
  55 static wait_queue_head_t sclp_tty_waitq;
  56
  57 static struct tty_struct *sclp_tty;
  58 static unsigned char sclp_tty_chars[SCLP_TTY_BUF_SIZE];
  59 static unsigned short int sclp_tty_chars_count;
  60
  61 struct tty_driver *sclp_tty_driver;
  62
  63 extern struct termios  tty_std_termios;
  64
  65 static struct sclp_ioctls sclp_ioctls;
  66 static struct sclp_ioctls sclp_ioctls_init =
  67 {
  68         8,                      /* 1 hor. tab. = 8 spaces */
  69         0,                      /* no echo of input by this driver */
  70         80,                     /* 80 characters/line */
  71         1,                      /* write after 1/10 s without final new line */
  72         MAX_KMEM_PAGES,         /* quick fix: avoid __alloc_pages */
  73         MAX_KMEM_PAGES,         /* take 32/64 pages from kernel memory, */
  74         0,                      /* do not convert to lower case */
  75         0x6c                    /* to seprate upper and lower case */
  76                                 /* ('%' in EBCDIC) */
  77 };
  78
  79 /* This routine is called whenever we try to open a SCLP terminal. */
  80 static int
  81 sclp_tty_open(struct tty_struct *tty, struct file *filp)
  82 {
  83         sclp_tty = tty;
  84         tty->driver_data = NULL;
  85         tty->low_latency = 0;
  86         return 0;
  87 }
  88
  89 /* This routine is called when the SCLP terminal is closed. */
  90 static void
  91 sclp_tty_close(struct tty_struct *tty, struct file *filp)
  92 {
  93         if (tty->count > 1)
  94                 return;
  95         sclp_tty = NULL;
  96 }
  97
  98 /* execute commands to control the i/o behaviour of the SCLP tty at runtime */
  99 static int
 100 sclp_tty_ioctl(struct tty_struct *tty, struct file * file,
 101                unsigned int cmd, unsigned long arg)
 102 {
 103         unsigned long flags;
 104         unsigned int obuf;
 105         int check;
 106         int rc;
 107
 108         if (tty->flags & (1 << TTY_IO_ERROR))
 109                 return -EIO;
 110         rc = 0;
 111         check = 0;
 112         switch (cmd) {
 113         case TIOCSCLPSHTAB:
 114                 /* set width of horizontal tab  */
 115                 if (get_user(sclp_ioctls.htab, (unsigned short *) arg))
 116                         rc = -EFAULT;
 117                 else
 118                         check = 1;
 119                 break;
 120         case TIOCSCLPGHTAB:
 121                 /* get width of horizontal tab  */
 122                 if (put_user(sclp_ioctls.htab, (unsigned short *) arg))
 123                         rc = -EFAULT;
 124                 break;
 125         case TIOCSCLPSECHO:
 126                 /* enable/disable echo of input */
 127                 if (get_user(sclp_ioctls.echo, (unsigned char *) arg))
 128                         rc = -EFAULT;
 129                 break;
 130         case TIOCSCLPGECHO:
 131                 /* Is echo of input enabled ?  */
 132                 if (put_user(sclp_ioctls.echo, (unsigned char *) arg))
 133                         rc = -EFAULT;
 134                 break;
 135         case TIOCSCLPSCOLS:
 136                 /* set number of columns for output  */
 137                 if (get_user(sclp_ioctls.columns, (unsigned short *) arg))
 138                         rc = -EFAULT;
 139                 else
 140                         check = 1;
 141                 break;
 142         case TIOCSCLPGCOLS:
 143                 /* get number of columns for output  */
 144                 if (put_user(sclp_ioctls.columns, (unsigned short *) arg))
 145                         rc = -EFAULT;
 146                 break;
 147         case TIOCSCLPSNL:
 148                 /* enable/disable writing without final new line character  */
 149                 if (get_user(sclp_ioctls.final_nl, (signed char *) arg))
 150                         rc = -EFAULT;
 151                 break;
 152         case TIOCSCLPGNL:
 153                 /* Is writing without final new line character enabled ?  */
 154                 if (put_user(sclp_ioctls.final_nl, (signed char *) arg))
 155                         rc = -EFAULT;
 156                 break;
 157         case TIOCSCLPSOBUF:
 158                 /*
 159                  * set the maximum buffers size for output, will be rounded
 160                  * up to next 4kB boundary and stored as number of SCCBs
 161                  * (4kB Buffers) limitation: 256 x 4kB
 162                  */
 163                 if (get_user(obuf, (unsigned int *) arg) == 0) {
 164                         if (obuf & 0xFFF)
 165                                 sclp_ioctls.max_sccb = (obuf >> 12) + 1;
 166                         else
 167                                 sclp_ioctls.max_sccb = (obuf >> 12);
 168                 } else
 169                         rc = -EFAULT;
 170                 break;
 171         case TIOCSCLPGOBUF:
 172                 /* get the maximum buffers size for output  */
 173                 obuf = sclp_ioctls.max_sccb << 12;
 174                 if (put_user(obuf, (unsigned int *) arg))
 175                         rc = -EFAULT;
 176                 break;
 177         case TIOCSCLPGKBUF:
 178                 /* get the number of buffers got from kernel at startup */
 179                 if (put_user(sclp_ioctls.kmem_sccb, (unsigned short *) arg))
 180                         rc = -EFAULT;
 181                 break;
 182         case TIOCSCLPSCASE:
 183                 /* enable/disable conversion from upper to lower case */
 184                 if (get_user(sclp_ioctls.tolower, (unsigned char *) arg))
 185                         rc = -EFAULT;
 186                 break;
 187         case TIOCSCLPGCASE:
 188                 /* Is conversion from upper to lower case of input enabled? */
 189                 if (put_user(sclp_ioctls.tolower, (unsigned char *) arg))
 190                         rc = -EFAULT;
 191                 break;
 192         case TIOCSCLPSDELIM:
 193                 /*
 194                  * set special character used for separating upper and
 195                  * lower case, 0x00 disables this feature
 196                  */
 197                 if (get_user(sclp_ioctls.delim, (unsigned char *) arg))
 198                         rc = -EFAULT;
 199                 break;
 200         case TIOCSCLPGDELIM:
 201                 /*
 202                  * get special character used for separating upper and
 203                  * lower case, 0x00 disables this feature
 204                  */
 205                 if (put_user(sclp_ioctls.delim, (unsigned char *) arg))
 206                         rc = -EFAULT;
 207                 break;
 208         case TIOCSCLPSINIT:
 209                 /* set initial (default) sclp ioctls  */
 210                 sclp_ioctls = sclp_ioctls_init;
 211                 check = 1;
 212                 break;
 213         default:
 214                 rc = -ENOIOCTLCMD;
 215                 break;
 216         }
 217         if (check) {
 218                 spin_lock_irqsave(&sclp_tty_lock, flags);
 219                 if (sclp_ttybuf != NULL) {
 220                         sclp_set_htab(sclp_ttybuf, sclp_ioctls.htab);
 221                         sclp_set_columns(sclp_ttybuf, sclp_ioctls.columns);
 222                 }
 223                 spin_unlock_irqrestore(&sclp_tty_lock, flags);
 224         }
 225         return rc;
 226 }
 227
 228 /*
 229  * This routine returns the numbers of characters the tty driver
 230  * will accept for queuing to be written.  This number is subject
 231  * to change as output buffers get emptied, or if the output flow
 232  * control is acted. This is not an exact number because not every
 233  * character needs the same space in the sccb. The worst case is
 234  * a string of newlines. Every newlines creates a new mto which
 235  * needs 8 bytes.
 236  */
 237 static int
 238 sclp_tty_write_room (struct tty_struct *tty)
 239 {
 240         unsigned long flags;
 241         struct list_head *l;
 242         int count;
 243
 244         spin_lock_irqsave(&sclp_tty_lock, flags);
 245         count = 0;
 246         if (sclp_ttybuf != NULL)
 247                 count = sclp_buffer_space(sclp_ttybuf) / sizeof(struct mto);
 248         list_for_each(l, &sclp_tty_pages)
 249                 count += NR_EMPTY_MTO_PER_SCCB;
 250         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 251         return count;
 252 }
 253
 254 static void
 255 sclp_ttybuf_callback(struct sclp_buffer *buffer, int rc)
 256 {
 257         unsigned long flags;
 258         struct sclp_buffer *next;
 259         void *page;
 260
 261         /* Ignore return code - because tty-writes aren't critical,
 262            we do without a sophisticated error recovery mechanism.  */
 263         page = sclp_unmake_buffer(buffer);
 264         spin_lock_irqsave(&sclp_tty_lock, flags);
 265         /* Remove buffer from outqueue */
 266         list_del(&buffer->list);
 267         sclp_tty_buffer_count--;
 268         list_add_tail((struct list_head *) page, &sclp_tty_pages);
 269         /* Check if there is a pending buffer on the out queue. */
 270         next = NULL;
 271         if (!list_empty(&sclp_tty_outqueue))
 272                 next = list_entry(sclp_tty_outqueue.next,
 273                                   struct sclp_buffer, list);
 274         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 275         if (next != NULL)
 276                 sclp_emit_buffer(next, sclp_ttybuf_callback);
 277         wake_up(&sclp_tty_waitq);
 278         /* check if the tty needs a wake up call */
 279         if (sclp_tty != NULL) {
 280                 if ((sclp_tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) &&
 281                     sclp_tty->ldisc.write_wakeup)
 282                         (sclp_tty->ldisc.write_wakeup)(sclp_tty);
 283                 wake_up_interruptible(&sclp_tty->write_wait);
 284         }
 285 }
 286
 287 static inline void
 288 __sclp_ttybuf_emit(struct sclp_buffer *buffer)
 289 {
 290         unsigned long flags;
 291         int count;
 292
 293         spin_lock_irqsave(&sclp_tty_lock, flags);
 294         list_add_tail(&buffer->list, &sclp_tty_outqueue);
 295         count = sclp_tty_buffer_count++;
 296         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 297
 298         if (count == 0)
 299                 sclp_emit_buffer(buffer, sclp_ttybuf_callback);
 300 }
 301
 302 /*
 303  * When this routine is called from the timer then we flush the
 304  * temporary write buffer.
 305  */
 306 static void
 307 sclp_tty_timeout(unsigned long data)
 308 {
 309         unsigned long flags;
 310         struct sclp_buffer *buf;
 311
 312         spin_lock_irqsave(&sclp_tty_lock, flags);
 313         buf = sclp_ttybuf;
 314         sclp_ttybuf = NULL;
 315         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 316
 317         if (buf != NULL) {
 318                 __sclp_ttybuf_emit(buf);
 319         }
 320 }
 321
 322 /*
 323  * Write a string to the sclp tty.
 324  */
 325 static void
 326 sclp_tty_write_string(const unsigned char *str, int count)
 327 {
 328         unsigned long flags;
 329         void *page;
 330         int written;
 331         struct sclp_buffer *buf;
 332
 333         if (count <= 0)
 334                 return;
 335         spin_lock_irqsave(&sclp_tty_lock, flags);
 336         do {
 337                 /* Create a sclp output buffer if none exists yet */
 338                 if (sclp_ttybuf == NULL) {
 339                         while (list_empty(&sclp_tty_pages)) {
 340                                 spin_unlock_irqrestore(&sclp_tty_lock, flags);
 341                                 if (in_interrupt())
 342                                         sclp_sync_wait();
 343                                 else
 344                                         wait_event(sclp_tty_waitq,
 345                                                 !list_empty(&sclp_tty_pages));
 346                                 spin_lock_irqsave(&sclp_tty_lock, flags);
 347                         }
 348                         page = sclp_tty_pages.next;
 349                         list_del((struct list_head *) page);
 350                         sclp_ttybuf = sclp_make_buffer(page,
 351                                                        sclp_ioctls.columns,
 352                                                        sclp_ioctls.htab);
 353                 }
 354                 /* try to write the string to the current output buffer */
 355                 written = sclp_write(sclp_ttybuf, str, count);
 356                 if (written == count)
 357                         break;
 358                 /*
 359                  * Not all characters could be written to the current
 360                  * output buffer. Emit the buffer, create a new buffer
 361                  * and then output the rest of the string.
 362                  */
 363                 buf = sclp_ttybuf;
 364                 sclp_ttybuf = NULL;
 365                 spin_unlock_irqrestore(&sclp_tty_lock, flags);
 366                 __sclp_ttybuf_emit(buf);
 367                 spin_lock_irqsave(&sclp_tty_lock, flags);
 368                 str += written;
 369                 count -= written;
 370         } while (count > 0);
 371         /* Setup timer to output current console buffer after 1/10 second */
 372         if (sclp_ioctls.final_nl) {
 373                 if (sclp_ttybuf != NULL &&
 374                     sclp_chars_in_buffer(sclp_ttybuf) != 0 &&
 375                     !timer_pending(&sclp_tty_timer)) {
 376                         init_timer(&sclp_tty_timer);
 377                         sclp_tty_timer.function = sclp_tty_timeout;
 378                         sclp_tty_timer.data = 0UL;
 379                         sclp_tty_timer.expires = jiffies + HZ/10;
 380                         add_timer(&sclp_tty_timer);
 381                 }
 382         } else {
 383                 if (sclp_ttybuf != NULL &&
 384                     sclp_chars_in_buffer(sclp_ttybuf) != 0) {
 385                         buf = sclp_ttybuf;
 386                         sclp_ttybuf = NULL;
 387                         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 388                         __sclp_ttybuf_emit(buf);
 389                         spin_lock_irqsave(&sclp_tty_lock, flags);
 390                 }
 391         }
 392         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 393 }
 394
 395 /*
 396  * This routine is called by the kernel to write a series of characters to the
 397  * tty device. The characters may come from user space or kernel space. This
 398  * routine will return the number of characters actually accepted for writing.
 399  */
 400 static int
 401 sclp_tty_write(struct tty_struct *tty, int from_user,
 402                const unsigned char *buf, int count)
 403 {
 404         int length, ret;
 405
 406         if (sclp_tty_chars_count > 0) {
 407                 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
 408                 sclp_tty_chars_count = 0;
 409         }
 410         if (!from_user) {
 411                 sclp_tty_write_string(buf, count);
 412                 return count;
 413         }
 414         ret = 0;
 415         while (count > 0) {
 416                 length = count < SCLP_TTY_BUF_SIZE ?
 417                         count : SCLP_TTY_BUF_SIZE;
 418                 length -= copy_from_user(sclp_tty_chars, buf, length);
 419                 if (length == 0) {
 420                         if (!ret)
 421                                 ret = -EFAULT;
 422                         break;
 423                 }
 424                 sclp_tty_write_string(sclp_tty_chars, length);
 425                 buf += length;
 426                 count -= length;
 427                 ret += length;
 428         }
 429         return ret;
 430 }
 431
 432 /*
 433  * This routine is called by the kernel to write a single character to the tty
 434  * device. If the kernel uses this routine, it must call the flush_chars()
 435  * routine (if defined) when it is done stuffing characters into the driver.
 436  *
 437  * Characters provided to sclp_tty_put_char() are buffered by the SCLP driver.
 438  * If the given character is a '\n' the contents of the SCLP write buffer
 439  * - including previous characters from sclp_tty_put_char() and strings from
 440  * sclp_write() without final '\n' - will be written.
 441  */
 442 static void
 443 sclp_tty_put_char(struct tty_struct *tty, unsigned char ch)
 444 {
 445         sclp_tty_chars[sclp_tty_chars_count++] = ch;
 446         if (ch == '\n' || sclp_tty_chars_count >= SCLP_TTY_BUF_SIZE) {
 447                 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
 448                 sclp_tty_chars_count = 0;
 449         }
 450 }
 451
 452 /*
 453  * This routine is called by the kernel after it has written a series of
 454  * characters to the tty device using put_char().
 455  */
 456 static void
 457 sclp_tty_flush_chars(struct tty_struct *tty)
 458 {
 459         if (sclp_tty_chars_count > 0) {
 460                 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
 461                 sclp_tty_chars_count = 0;
 462         }
 463 }
 464
 465 /*
 466  * This routine returns the number of characters in the write buffer of the
 467  * SCLP driver. The provided number includes all characters that are stored
 468  * in the SCCB (will be written next time the SCLP is not busy) as well as
 469  * characters in the write buffer (will not be written as long as there is a
 470  * final line feed missing).
 471  */
 472 static int
 473 sclp_tty_chars_in_buffer(struct tty_struct *tty)
 474 {
 475         unsigned long flags;
 476         struct list_head *l;
 477         struct sclp_buffer *t;
 478         int count;
 479
 480         spin_lock_irqsave(&sclp_tty_lock, flags);
 481         count = 0;
 482         if (sclp_ttybuf != NULL)
 483                 count = sclp_chars_in_buffer(sclp_ttybuf);
 484         list_for_each(l, &sclp_tty_outqueue) {
 485                 t = list_entry(l, struct sclp_buffer, list);
 486                 count += sclp_chars_in_buffer(t);
 487         }
 488         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 489         return count;
 490 }
 491
 492 /*
 493  * removes all content from buffers of low level driver
 494  */
 495 static void
 496 sclp_tty_flush_buffer(struct tty_struct *tty)
 497 {
 498         if (sclp_tty_chars_count > 0) {
 499                 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
 500                 sclp_tty_chars_count = 0;
 501         }
 502 }
 503
 504 /*
 505  * push input to tty
 506  */
 507 static void
 508 sclp_tty_input(unsigned char* buf, unsigned int count)
 509 {
 510         unsigned int cchar;
 511
 512         /*
 513          * If this tty driver is currently closed
 514          * then throw the received input away.
 515          */
 516         if (sclp_tty == NULL)
 517                 return;
 518         cchar = ctrlchar_handle(buf, count, sclp_tty);
 519         switch (cchar & CTRLCHAR_MASK) {
 520         case CTRLCHAR_SYSRQ:
 521                 break;
 522         case CTRLCHAR_CTRL:
 523                 sclp_tty->flip.count++;
 524                 *sclp_tty->flip.flag_buf_ptr++ = TTY_NORMAL;
 525                 *sclp_tty->flip.char_buf_ptr++ = cchar;
 526                 tty_flip_buffer_push(sclp_tty);
 527                 break;
 528         case CTRLCHAR_NONE:
 529                 /* send (normal) input to line discipline */
 530                 memcpy(sclp_tty->flip.char_buf_ptr, buf, count);
 531                 if (count < 2 ||
 532                     (strncmp ((const char *) buf + count - 2, "^n", 2) &&
 533                      strncmp ((const char *) buf + count - 2, "\0252n", 2))) {
 534                         sclp_tty->flip.char_buf_ptr[count] = '\n';
 535                         count++;
 536                 } else
 537                         count -= 2;
 538                 memset(sclp_tty->flip.flag_buf_ptr, TTY_NORMAL, count);
 539                 sclp_tty->flip.char_buf_ptr += count;
 540                 sclp_tty->flip.flag_buf_ptr += count;
 541                 sclp_tty->flip.count += count;
 542                 tty_flip_buffer_push(sclp_tty);
 543                 break;
 544         }
 545 }
 546
 547 /*
 548  * get a EBCDIC string in upper/lower case,
 549  * find out characters in lower/upper case separated by a special character,
 550  * modifiy original string,
 551  * returns length of resulting string
 552  */
 553 static int
 554 sclp_switch_cases(unsigned char *buf, int count,
 555                   unsigned char delim, int tolower)
 556 {
 557         unsigned char *ip, *op;
 558         int toggle;
 559
 560         /* initially changing case is off */
 561         toggle = 0;
 562         ip = op = buf;
 563         while (count-- > 0) {
 564                 /* compare with special character */
 565                 if (*ip == delim) {
 566                         /* followed by another special character? */
 567                         if (count && ip[1] == delim) {
 568                                 /*
 569                                  * ... then put a single copy of the special
 570                                  * character to the output string
 571                                  */
 572                                 *op++ = *ip++;
 573                                 count--;
 574                         } else
 575                                 /*
 576                                  * ... special character follower by a normal
 577                                  * character toggles the case change behaviour
 578                                  */
 579                                 toggle = ~toggle;
 580                         /* skip special character */
 581                         ip++;
 582                 } else
 583                         /* not the special character */
 584                         if (toggle)
 585                                 /* but case switching is on */
 586                                 if (tolower)
 587                                         /* switch to uppercase */
 588                                         *op++ = _ebc_toupper[(int) *ip++];
 589                                 else
 590                                         /* switch to lowercase */
 591                                         *op++ = _ebc_tolower[(int) *ip++];
 592                         else
 593                                 /* no case switching, copy the character */
 594                                 *op++ = *ip++;
 595         }
 596         /* return length of reformatted string. */
 597         return op - buf;
 598 }
 599
 600 static void
 601 sclp_get_input(unsigned char *start, unsigned char *end)
 602 {
 603         int count;
 604
 605         count = end - start;
 606         /*
 607          * if set in ioctl convert EBCDIC to lower case
 608          * (modify original input in SCCB)
 609          */
 610         if (sclp_ioctls.tolower)
 611                 EBC_TOLOWER(start, count);
 612
 613         /*
 614          * if set in ioctl find out characters in lower or upper case
 615          * (depends on current case) separated by a special character,
 616          * works on EBCDIC
 617          */
 618         if (sclp_ioctls.delim)
 619                 count = sclp_switch_cases(start, count,
 620                                           sclp_ioctls.delim,
 621                                           sclp_ioctls.tolower);
 622
 623         /* convert EBCDIC to ASCII (modify original input in SCCB) */
 624         sclp_ebcasc_str(start, count);
 625
 626         /* if set in ioctl write operators input to console  */
 627         if (sclp_ioctls.echo)
 628                 sclp_tty_write(sclp_tty, 0, start, count);
 629
 630         /* transfer input to high level driver */
 631         sclp_tty_input(start, count);
 632 }
 633
 634 static inline struct gds_vector *
 635 find_gds_vector(struct gds_vector *start, struct gds_vector *end, u16 id)
 636 {
 637         struct gds_vector *vec;
 638
 639         for (vec = start; vec < end; vec = (void *) vec + vec->length)
 640                 if (vec->gds_id == id)
 641                         return vec;
 642         return NULL;
 643 }
 644
 645 static inline struct gds_subvector *
 646 find_gds_subvector(struct gds_subvector *start,
 647                    struct gds_subvector *end, u8 key)
 648 {
 649         struct gds_subvector *subvec;
 650
 651         for (subvec = start; subvec < end;
 652              subvec = (void *) subvec + subvec->length)
 653                 if (subvec->key == key)
 654                         return subvec;
 655         return NULL;
 656 }
 657
 658 static inline void
 659 sclp_eval_selfdeftextmsg(struct gds_subvector *start,
 660                          struct gds_subvector *end)
 661 {
 662         struct gds_subvector *subvec;
 663
 664         subvec = start;
 665         while (subvec < end) {
 666                 subvec = find_gds_subvector(subvec, end, 0x30);
 667                 if (!subvec)
 668                         break;
 669                 sclp_get_input((unsigned char *)(subvec + 1),
 670                                (unsigned char *) subvec + subvec->length);
 671                 subvec = (void *) subvec + subvec->length;
 672         }
 673 }
 674
 675 static inline void
 676 sclp_eval_textcmd(struct gds_subvector *start,
 677                   struct gds_subvector *end)
 678 {
 679         struct gds_subvector *subvec;
 680
 681         subvec = start;
 682         while (subvec < end) {
 683                 subvec = find_gds_subvector(subvec, end,
 684                                             GDS_KEY_SelfDefTextMsg);
 685                 if (!subvec)
 686                         break;
 687                 sclp_eval_selfdeftextmsg((struct gds_subvector *)(subvec + 1),
 688                                          (void *)subvec + subvec->length);
 689                 subvec = (void *) subvec + subvec->length;
 690         }
 691 }
 692
 693 static inline void
 694 sclp_eval_cpmsu(struct gds_vector *start, struct gds_vector *end)
 695 {
 696         struct gds_vector *vec;
 697
 698         vec = start;
 699         while (vec < end) {
 700                 vec = find_gds_vector(vec, end, GDS_ID_TextCmd);
 701                 if (!vec)
 702                         break;
 703                 sclp_eval_textcmd((struct gds_subvector *)(vec + 1),
 704                                   (void *) vec + vec->length);
 705                 vec = (void *) vec + vec->length;
 706         }
 707 }
 708
 709
 710 static inline void
 711 sclp_eval_mdsmu(struct gds_vector *start, void *end)
 712 {
 713         struct gds_vector *vec;
 714
 715         vec = find_gds_vector(start, end, GDS_ID_CPMSU);
 716         if (vec)
 717                 sclp_eval_cpmsu(vec + 1, (void *) vec + vec->length);
 718 }
 719
 720 static void
 721 sclp_tty_receiver(struct evbuf_header *evbuf)
 722 {
 723         struct gds_vector *start, *end, *vec;
 724
 725         start = (struct gds_vector *)(evbuf + 1);
 726         end = (void *) evbuf + evbuf->length;
 727         vec = find_gds_vector(start, end, GDS_ID_MDSMU);
 728         if (vec)
 729                 sclp_eval_mdsmu(vec + 1, (void *) vec + vec->length);
 730 }
 731
 732 static void
 733 sclp_tty_state_change(struct sclp_register *reg)
 734 {
 735 }
 736
 737 static struct sclp_register sclp_input_event =
 738 {
 739         .receive_mask = EvTyp_OpCmd_Mask | EvTyp_PMsgCmd_Mask,
 740         .state_change_fn = sclp_tty_state_change,
 741         .receiver_fn = sclp_tty_receiver
 742 };
 743
 744 static struct tty_operations sclp_ops = {
 745         .open = sclp_tty_open,
 746         .close = sclp_tty_close,
 747         .write = sclp_tty_write,
 748         .put_char = sclp_tty_put_char,
 749         .flush_chars = sclp_tty_flush_chars,
 750         .write_room = sclp_tty_write_room,
 751         .chars_in_buffer = sclp_tty_chars_in_buffer,
 752         .flush_buffer = sclp_tty_flush_buffer,
 753         .ioctl = sclp_tty_ioctl,
 754 };
 755
 756 int __init
 757 sclp_tty_init(void)
 758 {
 759         struct tty_driver *driver;
 760         void *page;
 761         int i;
 762         int rc;
 763
 764         if (!CONSOLE_IS_SCLP)
 765                 return 0;
 766         driver = alloc_tty_driver(1);
 767         if (!driver)
 768                 return -ENOMEM;
 769
 770         rc = sclp_rw_init();
 771         if (rc) {
 772                 printk(KERN_ERR SCLP_TTY_PRINT_HEADER
 773                        "could not register tty - "
 774                        "sclp_rw_init returned %d\n", rc);
 775                 put_tty_driver(driver);
 776                 return rc;
 777         }
 778         /* Allocate pages for output buffering */
 779         INIT_LIST_HEAD(&sclp_tty_pages);
 780         for (i = 0; i < MAX_KMEM_PAGES; i++) {
 781                 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 782                 if (page == NULL) {
 783                         put_tty_driver(driver);
 784                         return -ENOMEM;
 785                 }
 786                 list_add_tail((struct list_head *) page, &sclp_tty_pages);
 787         }
 788         INIT_LIST_HEAD(&sclp_tty_outqueue);
 789         spin_lock_init(&sclp_tty_lock);
 790         init_waitqueue_head(&sclp_tty_waitq);
 791         init_timer(&sclp_tty_timer);
 792         sclp_ttybuf = NULL;
 793         sclp_tty_buffer_count = 0;
 794         if (MACHINE_IS_VM) {
 795                 /*
 796                  * save 4 characters for the CPU number
 797                  * written at start of each line by VM/CP
 798                  */
 799                 sclp_ioctls_init.columns = 76;
 800                 /* case input lines to lowercase */
 801                 sclp_ioctls_init.tolower = 1;
 802         }
 803         sclp_ioctls = sclp_ioctls_init;
 804         sclp_tty_chars_count = 0;
 805         sclp_tty = NULL;
 806
 807         rc = sclp_register(&sclp_input_event);
 808         if (rc) {
 809                 put_tty_driver(driver);
 810                 return rc;
 811         }
 812
 813         driver->owner = THIS_MODULE;
 814         driver->driver_name = "sclp_line";
 815         driver->name = "sclp_line";
 816         driver->major = TTY_MAJOR;
 817         driver->minor_start = 64;
 818         driver->type = TTY_DRIVER_TYPE_SYSTEM;
 819         driver->subtype = SYSTEM_TYPE_TTY;
 820         driver->init_termios = tty_std_termios;
 821         driver->init_termios.c_iflag = IGNBRK | IGNPAR;
 822         driver->init_termios.c_oflag = ONLCR | XTABS;
 823         driver->init_termios.c_lflag = ISIG | ECHO;
 824         driver->flags = TTY_DRIVER_REAL_RAW;
 825         tty_set_operations(driver, &sclp_ops);
 826         rc = tty_register_driver(driver);
 827         if (rc) {
 828                 printk(KERN_ERR SCLP_TTY_PRINT_HEADER
 829                        "could not register tty - "
 830                        "tty_register_driver returned %d\n", rc);
 831                 put_tty_driver(driver);
 832                 return rc;
 833         }
 834         sclp_tty_driver = driver;
 835         return 0;
 836 }
 837 module_init(sclp_tty_init);