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 __user *) 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 __user *) arg))
 123                         rc = -EFAULT;
 124                 break;
 125         case TIOCSCLPSECHO:
 126                 /* enable/disable echo of input */
 127                 if (get_user(sclp_ioctls.echo, (unsigned char __user *) arg))
 128                         rc = -EFAULT;
 129                 break;
 130         case TIOCSCLPGECHO:
 131                 /* Is echo of input enabled ?  */
 132                 if (put_user(sclp_ioctls.echo, (unsigned char __user *) 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 __user *) 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 __user *) 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 __user *) 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 __user *) 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 __user *) 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 __user *) 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 __user *) 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 __user *) 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 __user *) 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 __user *) 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 __user *) 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                 tty_wakeup(sclp_tty);
 281         }
 282 }
 283
 284 static inline void
 285 __sclp_ttybuf_emit(struct sclp_buffer *buffer)
 286 {
 287         unsigned long flags;
 288         int count;
 289
 290         spin_lock_irqsave(&sclp_tty_lock, flags);
 291         list_add_tail(&buffer->list, &sclp_tty_outqueue);
 292         count = sclp_tty_buffer_count++;
 293         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 294
 295         if (count == 0)
 296                 sclp_emit_buffer(buffer, sclp_ttybuf_callback);
 297 }
 298
 299 /*
 300  * When this routine is called from the timer then we flush the
 301  * temporary write buffer.
 302  */
 303 static void
 304 sclp_tty_timeout(unsigned long data)
 305 {
 306         unsigned long flags;
 307         struct sclp_buffer *buf;
 308
 309         spin_lock_irqsave(&sclp_tty_lock, flags);
 310         buf = sclp_ttybuf;
 311         sclp_ttybuf = NULL;
 312         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 313
 314         if (buf != NULL) {
 315                 __sclp_ttybuf_emit(buf);
 316         }
 317 }
 318
 319 /*
 320  * Write a string to the sclp tty.
 321  */
 322 static void
 323 sclp_tty_write_string(const unsigned char *str, int count)
 324 {
 325         unsigned long flags;
 326         void *page;
 327         int written;
 328         struct sclp_buffer *buf;
 329
 330         if (count <= 0)
 331                 return;
 332         spin_lock_irqsave(&sclp_tty_lock, flags);
 333         do {
 334                 /* Create a sclp output buffer if none exists yet */
 335                 if (sclp_ttybuf == NULL) {
 336                         while (list_empty(&sclp_tty_pages)) {
 337                                 spin_unlock_irqrestore(&sclp_tty_lock, flags);
 338                                 if (in_interrupt())
 339                                         sclp_sync_wait();
 340                                 else
 341                                         wait_event(sclp_tty_waitq,
 342                                                 !list_empty(&sclp_tty_pages));
 343                                 spin_lock_irqsave(&sclp_tty_lock, flags);
 344                         }
 345                         page = sclp_tty_pages.next;
 346                         list_del((struct list_head *) page);
 347                         sclp_ttybuf = sclp_make_buffer(page,
 348                                                        sclp_ioctls.columns,
 349                                                        sclp_ioctls.htab);
 350                 }
 351                 /* try to write the string to the current output buffer */
 352                 written = sclp_write(sclp_ttybuf, str, count);
 353                 if (written == count)
 354                         break;
 355                 /*
 356                  * Not all characters could be written to the current
 357                  * output buffer. Emit the buffer, create a new buffer
 358                  * and then output the rest of the string.
 359                  */
 360                 buf = sclp_ttybuf;
 361                 sclp_ttybuf = NULL;
 362                 spin_unlock_irqrestore(&sclp_tty_lock, flags);
 363                 __sclp_ttybuf_emit(buf);
 364                 spin_lock_irqsave(&sclp_tty_lock, flags);
 365                 str += written;
 366                 count -= written;
 367         } while (count > 0);
 368         /* Setup timer to output current console buffer after 1/10 second */
 369         if (sclp_ioctls.final_nl) {
 370                 if (sclp_ttybuf != NULL &&
 371                     sclp_chars_in_buffer(sclp_ttybuf) != 0 &&
 372                     !timer_pending(&sclp_tty_timer)) {
 373                         init_timer(&sclp_tty_timer);
 374                         sclp_tty_timer.function = sclp_tty_timeout;
 375                         sclp_tty_timer.data = 0UL;
 376                         sclp_tty_timer.expires = jiffies + HZ/10;
 377                         add_timer(&sclp_tty_timer);
 378                 }
 379         } else {
 380                 if (sclp_ttybuf != NULL &&
 381                     sclp_chars_in_buffer(sclp_ttybuf) != 0) {
 382                         buf = sclp_ttybuf;
 383                         sclp_ttybuf = NULL;
 384                         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 385                         __sclp_ttybuf_emit(buf);
 386                         spin_lock_irqsave(&sclp_tty_lock, flags);
 387                 }
 388         }
 389         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 390 }
 391
 392 /*
 393  * This routine is called by the kernel to write a series of characters to the
 394  * tty device. The characters may come from user space or kernel space. This
 395  * routine will return the number of characters actually accepted for writing.
 396  */
 397 static int
 398 sclp_tty_write(struct tty_struct *tty, int from_user,
 399                const unsigned char *buf, int count)
 400 {
 401         int length, ret;
 402
 403         if (sclp_tty_chars_count > 0) {
 404                 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
 405                 sclp_tty_chars_count = 0;
 406         }
 407         if (!from_user) {
 408                 sclp_tty_write_string(buf, count);
 409                 return count;
 410         }
 411         ret = 0;
 412         while (count > 0) {
 413                 length = count < SCLP_TTY_BUF_SIZE ?
 414                         count : SCLP_TTY_BUF_SIZE;
 415                 length -= copy_from_user(sclp_tty_chars,
 416                                 (const unsigned char __user *)buf, length);
 417                 if (length == 0) {
 418                         if (!ret)
 419                                 ret = -EFAULT;
 420                         break;
 421                 }
 422                 sclp_tty_write_string(sclp_tty_chars, length);
 423                 buf += length;
 424                 count -= length;
 425                 ret += length;
 426         }
 427         return ret;
 428 }
 429
 430 /*
 431  * This routine is called by the kernel to write a single character to the tty
 432  * device. If the kernel uses this routine, it must call the flush_chars()
 433  * routine (if defined) when it is done stuffing characters into the driver.
 434  *
 435  * Characters provided to sclp_tty_put_char() are buffered by the SCLP driver.
 436  * If the given character is a '\n' the contents of the SCLP write buffer
 437  * - including previous characters from sclp_tty_put_char() and strings from
 438  * sclp_write() without final '\n' - will be written.
 439  */
 440 static void
 441 sclp_tty_put_char(struct tty_struct *tty, unsigned char ch)
 442 {
 443         sclp_tty_chars[sclp_tty_chars_count++] = ch;
 444         if (ch == '\n' || sclp_tty_chars_count >= SCLP_TTY_BUF_SIZE) {
 445                 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
 446                 sclp_tty_chars_count = 0;
 447         }
 448 }
 449
 450 /*
 451  * This routine is called by the kernel after it has written a series of
 452  * characters to the tty device using put_char().
 453  */
 454 static void
 455 sclp_tty_flush_chars(struct tty_struct *tty)
 456 {
 457         if (sclp_tty_chars_count > 0) {
 458                 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
 459                 sclp_tty_chars_count = 0;
 460         }
 461 }
 462
 463 /*
 464  * This routine returns the number of characters in the write buffer of the
 465  * SCLP driver. The provided number includes all characters that are stored
 466  * in the SCCB (will be written next time the SCLP is not busy) as well as
 467  * characters in the write buffer (will not be written as long as there is a
 468  * final line feed missing).
 469  */
 470 static int
 471 sclp_tty_chars_in_buffer(struct tty_struct *tty)
 472 {
 473         unsigned long flags;
 474         struct list_head *l;
 475         struct sclp_buffer *t;
 476         int count;
 477
 478         spin_lock_irqsave(&sclp_tty_lock, flags);
 479         count = 0;
 480         if (sclp_ttybuf != NULL)
 481                 count = sclp_chars_in_buffer(sclp_ttybuf);
 482         list_for_each(l, &sclp_tty_outqueue) {
 483                 t = list_entry(l, struct sclp_buffer, list);
 484                 count += sclp_chars_in_buffer(t);
 485         }
 486         spin_unlock_irqrestore(&sclp_tty_lock, flags);
 487         return count;
 488 }
 489
 490 /*
 491  * removes all content from buffers of low level driver
 492  */
 493 static void
 494 sclp_tty_flush_buffer(struct tty_struct *tty)
 495 {
 496         if (sclp_tty_chars_count > 0) {
 497                 sclp_tty_write_string(sclp_tty_chars, sclp_tty_chars_count);
 498                 sclp_tty_chars_count = 0;
 499         }
 500 }
 501
 502 /*
 503  * push input to tty
 504  */
 505 static void
 506 sclp_tty_input(unsigned char* buf, unsigned int count)
 507 {
 508         unsigned int cchar;
 509
 510         /*
 511          * If this tty driver is currently closed
 512          * then throw the received input away.
 513          */
 514         if (sclp_tty == NULL)
 515                 return;
 516         cchar = ctrlchar_handle(buf, count, sclp_tty);
 517         switch (cchar & CTRLCHAR_MASK) {
 518         case CTRLCHAR_SYSRQ:
 519                 break;
 520         case CTRLCHAR_CTRL:
 521                 sclp_tty->flip.count++;
 522                 *sclp_tty->flip.flag_buf_ptr++ = TTY_NORMAL;
 523                 *sclp_tty->flip.char_buf_ptr++ = cchar;
 524                 tty_flip_buffer_push(sclp_tty);
 525                 break;
 526         case CTRLCHAR_NONE:
 527                 /* send (normal) input to line discipline */
 528                 memcpy(sclp_tty->flip.char_buf_ptr, buf, count);
 529                 if (count < 2 ||
 530                     (strncmp ((const char *) buf + count - 2, "^n", 2) &&
 531                      strncmp ((const char *) buf + count - 2, "\0252n", 2))) {
 532                         sclp_tty->flip.char_buf_ptr[count] = '\n';
 533                         count++;
 534                 } else
 535                         count -= 2;
 536                 memset(sclp_tty->flip.flag_buf_ptr, TTY_NORMAL, count);
 537                 sclp_tty->flip.char_buf_ptr += count;
 538                 sclp_tty->flip.flag_buf_ptr += count;
 539                 sclp_tty->flip.count += count;
 540                 tty_flip_buffer_push(sclp_tty);
 541                 break;
 542         }
 543 }
 544
 545 /*
 546  * get a EBCDIC string in upper/lower case,
 547  * find out characters in lower/upper case separated by a special character,
 548  * modifiy original string,
 549  * returns length of resulting string
 550  */
 551 static int
 552 sclp_switch_cases(unsigned char *buf, int count,
 553                   unsigned char delim, int tolower)
 554 {
 555         unsigned char *ip, *op;
 556         int toggle;
 557
 558         /* initially changing case is off */
 559         toggle = 0;
 560         ip = op = buf;
 561         while (count-- > 0) {
 562                 /* compare with special character */
 563                 if (*ip == delim) {
 564                         /* followed by another special character? */
 565                         if (count && ip[1] == delim) {
 566                                 /*
 567                                  * ... then put a single copy of the special
 568                                  * character to the output string
 569                                  */
 570                                 *op++ = *ip++;
 571                                 count--;
 572                         } else
 573                                 /*
 574                                  * ... special character follower by a normal
 575                                  * character toggles the case change behaviour
 576                                  */
 577                                 toggle = ~toggle;
 578                         /* skip special character */
 579                         ip++;
 580                 } else
 581                         /* not the special character */
 582                         if (toggle)
 583                                 /* but case switching is on */
 584                                 if (tolower)
 585                                         /* switch to uppercase */
 586                                         *op++ = _ebc_toupper[(int) *ip++];
 587                                 else
 588                                         /* switch to lowercase */
 589                                         *op++ = _ebc_tolower[(int) *ip++];
 590                         else
 591                                 /* no case switching, copy the character */
 592                                 *op++ = *ip++;
 593         }
 594         /* return length of reformatted string. */
 595         return op - buf;
 596 }
 597
 598 static void
 599 sclp_get_input(unsigned char *start, unsigned char *end)
 600 {
 601         int count;
 602
 603         count = end - start;
 604         /*
 605          * if set in ioctl convert EBCDIC to lower case
 606          * (modify original input in SCCB)
 607          */
 608         if (sclp_ioctls.tolower)
 609                 EBC_TOLOWER(start, count);
 610
 611         /*
 612          * if set in ioctl find out characters in lower or upper case
 613          * (depends on current case) separated by a special character,
 614          * works on EBCDIC
 615          */
 616         if (sclp_ioctls.delim)
 617                 count = sclp_switch_cases(start, count,
 618                                           sclp_ioctls.delim,
 619                                           sclp_ioctls.tolower);
 620
 621         /* convert EBCDIC to ASCII (modify original input in SCCB) */
 622         sclp_ebcasc_str(start, count);
 623
 624         /* if set in ioctl write operators input to console  */
 625         if (sclp_ioctls.echo)
 626                 sclp_tty_write(sclp_tty, 0, start, count);
 627
 628         /* transfer input to high level driver */
 629         sclp_tty_input(start, count);
 630 }
 631
 632 static inline struct gds_vector *
 633 find_gds_vector(struct gds_vector *start, struct gds_vector *end, u16 id)
 634 {
 635         struct gds_vector *vec;
 636
 637         for (vec = start; vec < end; vec = (void *) vec + vec->length)
 638                 if (vec->gds_id == id)
 639                         return vec;
 640         return NULL;
 641 }
 642
 643 static inline struct gds_subvector *
 644 find_gds_subvector(struct gds_subvector *start,
 645                    struct gds_subvector *end, u8 key)
 646 {
 647         struct gds_subvector *subvec;
 648
 649         for (subvec = start; subvec < end;
 650              subvec = (void *) subvec + subvec->length)
 651                 if (subvec->key == key)
 652                         return subvec;
 653         return NULL;
 654 }
 655
 656 static inline void
 657 sclp_eval_selfdeftextmsg(struct gds_subvector *start,
 658                          struct gds_subvector *end)
 659 {
 660         struct gds_subvector *subvec;
 661
 662         subvec = start;
 663         while (subvec < end) {
 664                 subvec = find_gds_subvector(subvec, end, 0x30);
 665                 if (!subvec)
 666                         break;
 667                 sclp_get_input((unsigned char *)(subvec + 1),
 668                                (unsigned char *) subvec + subvec->length);
 669                 subvec = (void *) subvec + subvec->length;
 670         }
 671 }
 672
 673 static inline void
 674 sclp_eval_textcmd(struct gds_subvector *start,
 675                   struct gds_subvector *end)
 676 {
 677         struct gds_subvector *subvec;
 678
 679         subvec = start;
 680         while (subvec < end) {
 681                 subvec = find_gds_subvector(subvec, end,
 682                                             GDS_KEY_SelfDefTextMsg);
 683                 if (!subvec)
 684                         break;
 685                 sclp_eval_selfdeftextmsg((struct gds_subvector *)(subvec + 1),
 686                                          (void *)subvec + subvec->length);
 687                 subvec = (void *) subvec + subvec->length;
 688         }
 689 }
 690
 691 static inline void
 692 sclp_eval_cpmsu(struct gds_vector *start, struct gds_vector *end)
 693 {
 694         struct gds_vector *vec;
 695
 696         vec = start;
 697         while (vec < end) {
 698                 vec = find_gds_vector(vec, end, GDS_ID_TextCmd);
 699                 if (!vec)
 700                         break;
 701                 sclp_eval_textcmd((struct gds_subvector *)(vec + 1),
 702                                   (void *) vec + vec->length);
 703                 vec = (void *) vec + vec->length;
 704         }
 705 }
 706
 707
 708 static inline void
 709 sclp_eval_mdsmu(struct gds_vector *start, void *end)
 710 {
 711         struct gds_vector *vec;
 712
 713         vec = find_gds_vector(start, end, GDS_ID_CPMSU);
 714         if (vec)
 715                 sclp_eval_cpmsu(vec + 1, (void *) vec + vec->length);
 716 }
 717
 718 static void
 719 sclp_tty_receiver(struct evbuf_header *evbuf)
 720 {
 721         struct gds_vector *start, *end, *vec;
 722
 723         start = (struct gds_vector *)(evbuf + 1);
 724         end = (void *) evbuf + evbuf->length;
 725         vec = find_gds_vector(start, end, GDS_ID_MDSMU);
 726         if (vec)
 727                 sclp_eval_mdsmu(vec + 1, (void *) vec + vec->length);
 728 }
 729
 730 static void
 731 sclp_tty_state_change(struct sclp_register *reg)
 732 {
 733 }
 734
 735 static struct sclp_register sclp_input_event =
 736 {
 737         .receive_mask = EvTyp_OpCmd_Mask | EvTyp_PMsgCmd_Mask,
 738         .state_change_fn = sclp_tty_state_change,
 739         .receiver_fn = sclp_tty_receiver
 740 };
 741
 742 static struct tty_operations sclp_ops = {
 743         .open = sclp_tty_open,
 744         .close = sclp_tty_close,
 745         .write = sclp_tty_write,
 746         .put_char = sclp_tty_put_char,
 747         .flush_chars = sclp_tty_flush_chars,
 748         .write_room = sclp_tty_write_room,
 749         .chars_in_buffer = sclp_tty_chars_in_buffer,
 750         .flush_buffer = sclp_tty_flush_buffer,
 751         .ioctl = sclp_tty_ioctl,
 752 };
 753
 754 int __init
 755 sclp_tty_init(void)
 756 {
 757         struct tty_driver *driver;
 758         void *page;
 759         int i;
 760         int rc;
 761
 762         if (!CONSOLE_IS_SCLP)
 763                 return 0;
 764         driver = alloc_tty_driver(1);
 765         if (!driver)
 766                 return -ENOMEM;
 767
 768         rc = sclp_rw_init();
 769         if (rc) {
 770                 printk(KERN_ERR SCLP_TTY_PRINT_HEADER
 771                        "could not register tty - "
 772                        "sclp_rw_init returned %d\n", rc);
 773                 put_tty_driver(driver);
 774                 return rc;
 775         }
 776         /* Allocate pages for output buffering */
 777         INIT_LIST_HEAD(&sclp_tty_pages);
 778         for (i = 0; i < MAX_KMEM_PAGES; i++) {
 779                 page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
 780                 if (page == NULL) {
 781                         put_tty_driver(driver);
 782                         return -ENOMEM;
 783                 }
 784                 list_add_tail((struct list_head *) page, &sclp_tty_pages);
 785         }
 786         INIT_LIST_HEAD(&sclp_tty_outqueue);
 787         spin_lock_init(&sclp_tty_lock);
 788         init_waitqueue_head(&sclp_tty_waitq);
 789         init_timer(&sclp_tty_timer);
 790         sclp_ttybuf = NULL;
 791         sclp_tty_buffer_count = 0;
 792         if (MACHINE_IS_VM) {
 793                 /*
 794                  * save 4 characters for the CPU number
 795                  * written at start of each line by VM/CP
 796                  */
 797                 sclp_ioctls_init.columns = 76;
 798                 /* case input lines to lowercase */
 799                 sclp_ioctls_init.tolower = 1;
 800         }
 801         sclp_ioctls = sclp_ioctls_init;
 802         sclp_tty_chars_count = 0;
 803         sclp_tty = NULL;
 804
 805         rc = sclp_register(&sclp_input_event);
 806         if (rc) {
 807                 put_tty_driver(driver);
 808                 return rc;
 809         }
 810
 811         driver->owner = THIS_MODULE;
 812         driver->driver_name = "sclp_line";
 813         driver->name = "sclp_line";
 814         driver->major = TTY_MAJOR;
 815         driver->minor_start = 64;
 816         driver->type = TTY_DRIVER_TYPE_SYSTEM;
 817         driver->subtype = SYSTEM_TYPE_TTY;
 818         driver->init_termios = tty_std_termios;
 819         driver->init_termios.c_iflag = IGNBRK | IGNPAR;
 820         driver->init_termios.c_oflag = ONLCR | XTABS;
 821         driver->init_termios.c_lflag = ISIG | ECHO;
 822         driver->flags = TTY_DRIVER_REAL_RAW;
 823         tty_set_operations(driver, &sclp_ops);
 824         rc = tty_register_driver(driver);
 825         if (rc) {
 826                 printk(KERN_ERR SCLP_TTY_PRINT_HEADER
 827                        "could not register tty - "
 828                        "tty_register_driver returned %d\n", rc);
 829                 put_tty_driver(driver);
 830                 return rc;
 831         }
 832         sclp_tty_driver = driver;
 833         return 0;
 834 }
 835 module_init(sclp_tty_init);