drivers/char/rio/riointr.c

   1 /*
   2 ** -----------------------------------------------------------------------------
   3 **
   4 **  Perle Specialix driver for Linux
   5 **  Ported from existing RIO Driver for SCO sources.
   6  *
   7  *  (C) 1990 - 2000 Specialix International Ltd., Byfleet, Surrey, UK.
   8  *
   9  *      This program is free software; you can redistribute it and/or modify
  10  *      it under the terms of the GNU General Public License as published by
  11  *      the Free Software Foundation; either version 2 of the License, or
  12  *      (at your option) any later version.
  13  *
  14  *      This program is distributed in the hope that it will be useful,
  15  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *      GNU General Public License for more details.
  18  *
  19  *      You should have received a copy of the GNU General Public License
  20  *      along with this program; if not, write to the Free Software
  21  *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 **
  23 **      Module          : riointr.c
  24 **      SID             : 1.2
  25 **      Last Modified   : 11/6/98 10:33:44
  26 **      Retrieved       : 11/6/98 10:33:49
  27 **
  28 **  ident @(#)riointr.c 1.2
  29 **
  30 ** -----------------------------------------------------------------------------
  31 */
  32 #ifdef SCCS_LABELS
  33 static char *_riointr_c_sccs_ = "@(#)riointr.c  1.2";
  34 #endif
  35
  36
  37 #include <linux/module.h>
  38 #include <linux/slab.h>
  39 #include <linux/errno.h>
  40 #include <linux/tty.h>
  41 #include <linux/tty_flip.h>
  42 #include <asm/io.h>
  43 #include <asm/system.h>
  44 #include <asm/string.h>
  45 #include <asm/semaphore.h>
  46 #include <asm/uaccess.h>
  47
  48 #include <linux/termios.h>
  49 #include <linux/serial.h>
  50
  51 #include <linux/generic_serial.h>
  52
  53 #include <linux/delay.h>
  54
  55 #include "linux_compat.h"
  56 #include "rio_linux.h"
  57 #include "pkt.h"
  58 #include "daemon.h"
  59 #include "rio.h"
  60 #include "riospace.h"
  61 #include "cmdpkt.h"
  62 #include "map.h"
  63 #include "rup.h"
  64 #include "port.h"
  65 #include "riodrvr.h"
  66 #include "rioinfo.h"
  67 #include "func.h"
  68 #include "errors.h"
  69 #include "pci.h"
  70
  71 #include "parmmap.h"
  72 #include "unixrup.h"
  73 #include "board.h"
  74 #include "host.h"
  75 #include "phb.h"
  76 #include "link.h"
  77 #include "cmdblk.h"
  78 #include "route.h"
  79 #include "cirrus.h"
  80 #include "rioioctl.h"
  81
  82
  83 static void RIOReceive(struct rio_info *, struct Port *);
  84
  85
  86 static char *firstchars(char *p, int nch)
  87 {
  88         static char buf[2][128];
  89         static int t = 0;
  90         t = !t;
  91         memcpy(buf[t], p, nch);
  92         buf[t][nch] = 0;
  93         return buf[t];
  94 }
  95
  96
  97 #define INCR( P, I )    ((P) = (((P)+(I)) & p->RIOBufferMask))
  98 /* Enable and start the transmission of packets */
  99 void RIOTxEnable(char *en)
 100 {
 101         struct Port *PortP;
 102         struct rio_info *p;
 103         struct tty_struct *tty;
 104         int c;
 105         struct PKT __iomem *PacketP;
 106         unsigned long flags;
 107
 108         PortP = (struct Port *) en;
 109         p = (struct rio_info *) PortP->p;
 110         tty = PortP->gs.tty;
 111
 112
 113         rio_dprintk(RIO_DEBUG_INTR, "tx port %d: %d chars queued.\n", PortP->PortNum, PortP->gs.xmit_cnt);
 114
 115         if (!PortP->gs.xmit_cnt)
 116                 return;
 117
 118
 119         /* This routine is an order of magnitude simpler than the specialix
 120            version. One of the disadvantages is that this version will send
 121            an incomplete packet (usually 64 bytes instead of 72) once for
 122            every 4k worth of data. Let's just say that this won't influence
 123            performance significantly..... */
 124
 125         rio_spin_lock_irqsave(&PortP->portSem, flags);
 126
 127         while (can_add_transmit(&PacketP, PortP)) {
 128                 c = PortP->gs.xmit_cnt;
 129                 if (c > PKT_MAX_DATA_LEN)
 130                         c = PKT_MAX_DATA_LEN;
 131
 132                 /* Don't copy past the end of the source buffer */
 133                 if (c > SERIAL_XMIT_SIZE - PortP->gs.xmit_tail)
 134                         c = SERIAL_XMIT_SIZE - PortP->gs.xmit_tail;
 135
 136                 {
 137                         int t;
 138                         t = (c > 10) ? 10 : c;
 139
 140                         rio_dprintk(RIO_DEBUG_INTR, "rio: tx port %d: copying %d chars: %s - %s\n", PortP->PortNum, c, firstchars(PortP->gs.xmit_buf + PortP->gs.xmit_tail, t), firstchars(PortP->gs.xmit_buf + PortP->gs.xmit_tail + c - t, t));
 141                 }
 142                 /* If for one reason or another, we can't copy more data,
 143                    we're done! */
 144                 if (c == 0)
 145                         break;
 146
 147                 rio_memcpy_toio(PortP->HostP->Caddr, PacketP->data, PortP->gs.xmit_buf + PortP->gs.xmit_tail, c);
 148                 /*    udelay (1); */
 149
 150                 writeb(c, &(PacketP->len));
 151                 if (!(PortP->State & RIO_DELETED)) {
 152                         add_transmit(PortP);
 153                         /*
 154                          ** Count chars tx'd for port statistics reporting
 155                          */
 156                         if (PortP->statsGather)
 157                                 PortP->txchars += c;
 158                 }
 159                 PortP->gs.xmit_tail = (PortP->gs.xmit_tail + c) & (SERIAL_XMIT_SIZE - 1);
 160                 PortP->gs.xmit_cnt -= c;
 161         }
 162
 163         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 164
 165         if (PortP->gs.xmit_cnt <= (PortP->gs.wakeup_chars + 2 * PKT_MAX_DATA_LEN)) {
 166                 rio_dprintk(RIO_DEBUG_INTR, "Waking up.... ldisc:%d (%d/%d)....", (int) (PortP->gs.tty->flags & (1 << TTY_DO_WRITE_WAKEUP)), PortP->gs.wakeup_chars, PortP->gs.xmit_cnt);
 167                 if ((PortP->gs.tty->flags & (1 << TTY_DO_WRITE_WAKEUP)) && PortP->gs.tty->ldisc.write_wakeup)
 168                         (PortP->gs.tty->ldisc.write_wakeup) (PortP->gs.tty);
 169                 rio_dprintk(RIO_DEBUG_INTR, "(%d/%d)\n", PortP->gs.wakeup_chars, PortP->gs.xmit_cnt);
 170                 wake_up_interruptible(&PortP->gs.tty->write_wait);
 171         }
 172
 173 }
 174
 175
 176 /*
 177 ** RIO Host Service routine. Does all the work traditionally associated with an
 178 ** interrupt.
 179 */
 180 static int RupIntr;
 181 static int RxIntr;
 182 static int TxIntr;
 183
 184 void RIOServiceHost(struct rio_info *p, struct Host *HostP)
 185 {
 186         rio_spin_lock(&HostP->HostLock);
 187         if ((HostP->Flags & RUN_STATE) != RC_RUNNING) {
 188                 static int t = 0;
 189                 rio_spin_unlock(&HostP->HostLock);
 190                 if ((t++ % 200) == 0)
 191                         rio_dprintk(RIO_DEBUG_INTR, "Interrupt but host not running. flags=%x.\n", (int) HostP->Flags);
 192                 return;
 193         }
 194         rio_spin_unlock(&HostP->HostLock);
 195
 196         if (readw(&HostP->ParmMapP->rup_intr)) {
 197                 writew(0, &HostP->ParmMapP->rup_intr);
 198                 p->RIORupCount++;
 199                 RupIntr++;
 200                 rio_dprintk(RIO_DEBUG_INTR, "rio: RUP interrupt on host %Zd\n", HostP - p->RIOHosts);
 201                 RIOPollHostCommands(p, HostP);
 202         }
 203
 204         if (readw(&HostP->ParmMapP->rx_intr)) {
 205                 int port;
 206
 207                 writew(0, &HostP->ParmMapP->rx_intr);
 208                 p->RIORxCount++;
 209                 RxIntr++;
 210
 211                 rio_dprintk(RIO_DEBUG_INTR, "rio: RX interrupt on host %Zd\n", HostP - p->RIOHosts);
 212                 /*
 213                  ** Loop through every port. If the port is mapped into
 214                  ** the system ( i.e. has /dev/ttyXXXX associated ) then it is
 215                  ** worth checking. If the port isn't open, grab any packets
 216                  ** hanging on its receive queue and stuff them on the free
 217                  ** list; check for commands on the way.
 218                  */
 219                 for (port = p->RIOFirstPortsBooted; port < p->RIOLastPortsBooted + PORTS_PER_RTA; port++) {
 220                         struct Port *PortP = p->RIOPortp[port];
 221                         struct tty_struct *ttyP;
 222                         struct PKT __iomem *PacketP;
 223
 224                         /*
 225                          ** not mapped in - most of the RIOPortp[] information
 226                          ** has not been set up!
 227                          ** Optimise: ports come in bundles of eight.
 228                          */
 229                         if (!PortP->Mapped) {
 230                                 port += 7;
 231                                 continue;       /* with the next port */
 232                         }
 233
 234                         /*
 235                          ** If the host board isn't THIS host board, check the next one.
 236                          ** optimise: ports come in bundles of eight.
 237                          */
 238                         if (PortP->HostP != HostP) {
 239                                 port += 7;
 240                                 continue;
 241                         }
 242
 243                         /*
 244                          ** Let us see - is the port open? If not, then don't service it.
 245                          */
 246                         if (!(PortP->PortState & PORT_ISOPEN)) {
 247                                 continue;
 248                         }
 249
 250                         /*
 251                          ** find corresponding tty structure. The process of mapping
 252                          ** the ports puts these here.
 253                          */
 254                         ttyP = PortP->gs.tty;
 255
 256                         /*
 257                          ** Lock the port before we begin working on it.
 258                          */
 259                         rio_spin_lock(&PortP->portSem);
 260
 261                         /*
 262                          ** Process received data if there is any.
 263                          */
 264                         if (can_remove_receive(&PacketP, PortP))
 265                                 RIOReceive(p, PortP);
 266
 267                         /*
 268                          ** If there is no data left to be read from the port, and
 269                          ** it's handshake bit is set, then we must clear the handshake,
 270                          ** so that that downstream RTA is re-enabled.
 271                          */
 272                         if (!can_remove_receive(&PacketP, PortP) && (readw(&PortP->PhbP->handshake) == PHB_HANDSHAKE_SET)) {
 273                                 /*
 274                                  ** MAGIC! ( Basically, handshake the RX buffer, so that
 275                                  ** the RTAs upstream can be re-enabled. )
 276                                  */
 277                                 rio_dprintk(RIO_DEBUG_INTR, "Set RX handshake bit\n");
 278                                 writew(PHB_HANDSHAKE_SET | PHB_HANDSHAKE_RESET, &PortP->PhbP->handshake);
 279                         }
 280                         rio_spin_unlock(&PortP->portSem);
 281                 }
 282         }
 283
 284         if (readw(&HostP->ParmMapP->tx_intr)) {
 285                 int port;
 286
 287                 writew(0, &HostP->ParmMapP->tx_intr);
 288
 289                 p->RIOTxCount++;
 290                 TxIntr++;
 291                 rio_dprintk(RIO_DEBUG_INTR, "rio: TX interrupt on host %Zd\n", HostP - p->RIOHosts);
 292
 293                 /*
 294                  ** Loop through every port.
 295                  ** If the port is mapped into the system ( i.e. has /dev/ttyXXXX
 296                  ** associated ) then it is worth checking.
 297                  */
 298                 for (port = p->RIOFirstPortsBooted; port < p->RIOLastPortsBooted + PORTS_PER_RTA; port++) {
 299                         struct Port *PortP = p->RIOPortp[port];
 300                         struct tty_struct *ttyP;
 301                         struct PKT __iomem *PacketP;
 302
 303                         /*
 304                          ** not mapped in - most of the RIOPortp[] information
 305                          ** has not been set up!
 306                          */
 307                         if (!PortP->Mapped) {
 308                                 port += 7;
 309                                 continue;       /* with the next port */
 310                         }
 311
 312                         /*
 313                          ** If the host board isn't running, then its data structures
 314                          ** are no use to us - continue quietly.
 315                          */
 316                         if (PortP->HostP != HostP) {
 317                                 port += 7;
 318                                 continue;       /* with the next port */
 319                         }
 320
 321                         /*
 322                          ** Let us see - is the port open? If not, then don't service it.
 323                          */
 324                         if (!(PortP->PortState & PORT_ISOPEN)) {
 325                                 continue;
 326                         }
 327
 328                         rio_dprintk(RIO_DEBUG_INTR, "rio: Looking into port %d.\n", port);
 329                         /*
 330                          ** Lock the port before we begin working on it.
 331                          */
 332                         rio_spin_lock(&PortP->portSem);
 333
 334                         /*
 335                          ** If we can't add anything to the transmit queue, then
 336                          ** we need do none of this processing.
 337                          */
 338                         if (!can_add_transmit(&PacketP, PortP)) {
 339                                 rio_dprintk(RIO_DEBUG_INTR, "Can't add to port, so skipping.\n");
 340                                 rio_spin_unlock(&PortP->portSem);
 341                                 continue;
 342                         }
 343
 344                         /*
 345                          ** find corresponding tty structure. The process of mapping
 346                          ** the ports puts these here.
 347                          */
 348                         ttyP = PortP->gs.tty;
 349                         /* If ttyP is NULL, the port is getting closed. Forget about it. */
 350                         if (!ttyP) {
 351                                 rio_dprintk(RIO_DEBUG_INTR, "no tty, so skipping.\n");
 352                                 rio_spin_unlock(&PortP->portSem);
 353                                 continue;
 354                         }
 355                         /*
 356                          ** If there is more room available we start up the transmit
 357                          ** data process again. This can be direct I/O, if the cookmode
 358                          ** is set to COOK_RAW or COOK_MEDIUM, or will be a call to the
 359                          ** riotproc( T_OUTPUT ) if we are in COOK_WELL mode, to fetch
 360                          ** characters via the line discipline. We must always call
 361                          ** the line discipline,
 362                          ** so that user input characters can be echoed correctly.
 363                          **
 364                          ** ++++ Update +++++
 365                          ** With the advent of double buffering, we now see if
 366                          ** TxBufferOut-In is non-zero. If so, then we copy a packet
 367                          ** to the output place, and set it going. If this empties
 368                          ** the buffer, then we must issue a wakeup( ) on OUT.
 369                          ** If it frees space in the buffer then we must issue
 370                          ** a wakeup( ) on IN.
 371                          **
 372                          ** ++++ Extra! Extra! If PortP->WflushFlag is set, then we
 373                          ** have to send a WFLUSH command down the PHB, to mark the
 374                          ** end point of a WFLUSH. We also need to clear out any
 375                          ** data from the double buffer! ( note that WflushFlag is a
 376                          ** *count* of the number of WFLUSH commands outstanding! )
 377                          **
 378                          ** ++++ And there's more!
 379                          ** If an RTA is powered off, then on again, and rebooted,
 380                          ** whilst it has ports open, then we need to re-open the ports.
 381                          ** ( reasonable enough ). We can't do this when we spot the
 382                          ** re-boot, in interrupt time, because the queue is probably
 383                          ** full. So, when we come in here, we need to test if any
 384                          ** ports are in this condition, and re-open the port before
 385                          ** we try to send any more data to it. Now, the re-booted
 386                          ** RTA will be discarding packets from the PHB until it
 387                          ** receives this open packet, but don't worry tooo much
 388                          ** about that. The one thing that is interesting is the
 389                          ** combination of this effect and the WFLUSH effect!
 390                          */
 391                         /* For now don't handle RTA reboots. -- REW.
 392                            Reenabled. Otherwise RTA reboots didn't work. Duh. -- REW */
 393                         if (PortP->MagicFlags) {
 394                                 if (PortP->MagicFlags & MAGIC_REBOOT) {
 395                                         /*
 396                                          ** well, the RTA has been rebooted, and there is room
 397                                          ** on its queue to add the open packet that is required.
 398                                          **
 399                                          ** The messy part of this line is trying to decide if
 400                                          ** we need to call the Param function as a tty or as
 401                                          ** a modem.
 402                                          ** DONT USE CLOCAL AS A TEST FOR THIS!
 403                                          **
 404                                          ** If we can't param the port, then move on to the
 405                                          ** next port.
 406                                          */
 407                                         PortP->InUse = NOT_INUSE;
 408
 409                                         rio_spin_unlock(&PortP->portSem);
 410                                         if (RIOParam(PortP, OPEN, ((PortP->Cor2Copy & (COR2_RTSFLOW | COR2_CTSFLOW)) == (COR2_RTSFLOW | COR2_CTSFLOW)) ? 1 : 0, DONT_SLEEP) == RIO_FAIL) {
 411                                                 continue;       /* with next port */
 412                                         }
 413                                         rio_spin_lock(&PortP->portSem);
 414                                         PortP->MagicFlags &= ~MAGIC_REBOOT;
 415                                 }
 416
 417                                 /*
 418                                  ** As mentioned above, this is a tacky hack to cope
 419                                  ** with WFLUSH
 420                                  */
 421                                 if (PortP->WflushFlag) {
 422                                         rio_dprintk(RIO_DEBUG_INTR, "Want to WFLUSH mark this port\n");
 423
 424                                         if (PortP->InUse)
 425                                                 rio_dprintk(RIO_DEBUG_INTR, "FAILS - PORT IS IN USE\n");
 426                                 }
 427
 428                                 while (PortP->WflushFlag && can_add_transmit(&PacketP, PortP) && (PortP->InUse == NOT_INUSE)) {
 429                                         int p;
 430                                         struct PktCmd __iomem *PktCmdP;
 431
 432                                         rio_dprintk(RIO_DEBUG_INTR, "Add WFLUSH marker to data queue\n");
 433                                         /*
 434                                          ** make it look just like a WFLUSH command
 435                                          */
 436                                         PktCmdP = (struct PktCmd __iomem *) &PacketP->data[0];
 437
 438                                         writeb(WFLUSH, &PktCmdP->Command);
 439
 440                                         p = PortP->HostPort % (u16) PORTS_PER_RTA;
 441
 442                                         /*
 443                                          ** If second block of ports for 16 port RTA, add 8
 444                                          ** to index 8-15.
 445                                          */
 446                                         if (PortP->SecondBlock)
 447                                                 p += PORTS_PER_RTA;
 448
 449                                         writeb(p, &PktCmdP->PhbNum);
 450
 451                                         /*
 452                                          ** to make debuggery easier
 453                                          */
 454                                         writeb('W', &PacketP->data[2]);
 455                                         writeb('F', &PacketP->data[3]);
 456                                         writeb('L', &PacketP->data[4]);
 457                                         writeb('U', &PacketP->data[5]);
 458                                         writeb('S', &PacketP->data[6]);
 459                                         writeb('H', &PacketP->data[7]);
 460                                         writeb(' ', &PacketP->data[8]);
 461                                         writeb('0' + PortP->WflushFlag, &PacketP->data[9]);
 462                                         writeb(' ', &PacketP->data[10]);
 463                                         writeb(' ', &PacketP->data[11]);
 464                                         writeb('\0', &PacketP->data[12]);
 465
 466                                         /*
 467                                          ** its two bytes long!
 468                                          */
 469                                         writeb(PKT_CMD_BIT | 2, &PacketP->len);
 470
 471                                         /*
 472                                          ** queue it!
 473                                          */
 474                                         if (!(PortP->State & RIO_DELETED)) {
 475                                                 add_transmit(PortP);
 476                                                 /*
 477                                                  ** Count chars tx'd for port statistics reporting
 478                                                  */
 479                                                 if (PortP->statsGather)
 480                                                         PortP->txchars += 2;
 481                                         }
 482
 483                                         if (--(PortP->WflushFlag) == 0) {
 484                                                 PortP->MagicFlags &= ~MAGIC_FLUSH;
 485                                         }
 486
 487                                         rio_dprintk(RIO_DEBUG_INTR, "Wflush count now stands at %d\n", PortP->WflushFlag);
 488                                 }
 489                                 if (PortP->MagicFlags & MORE_OUTPUT_EYGOR) {
 490                                         if (PortP->MagicFlags & MAGIC_FLUSH) {
 491                                                 PortP->MagicFlags |= MORE_OUTPUT_EYGOR;
 492                                         } else {
 493                                                 if (!can_add_transmit(&PacketP, PortP)) {
 494                                                         rio_spin_unlock(&PortP->portSem);
 495                                                         continue;
 496                                                 }
 497                                                 rio_spin_unlock(&PortP->portSem);
 498                                                 RIOTxEnable((char *) PortP);
 499                                                 rio_spin_lock(&PortP->portSem);
 500                                                 PortP->MagicFlags &= ~MORE_OUTPUT_EYGOR;
 501                                         }
 502                                 }
 503                         }
 504
 505
 506                         /*
 507                          ** If we can't add anything to the transmit queue, then
 508                          ** we need do none of the remaining processing.
 509                          */
 510                         if (!can_add_transmit(&PacketP, PortP)) {
 511                                 rio_spin_unlock(&PortP->portSem);
 512                                 continue;
 513                         }
 514
 515                         rio_spin_unlock(&PortP->portSem);
 516                         RIOTxEnable((char *) PortP);
 517                 }
 518         }
 519 }
 520
 521 /*
 522 ** Routine for handling received data for tty drivers
 523 */
 524 static void RIOReceive(struct rio_info *p, struct Port *PortP)
 525 {
 526         struct tty_struct *TtyP;
 527         unsigned short transCount;
 528         struct PKT __iomem *PacketP;
 529         register unsigned int DataCnt;
 530         unsigned char __iomem *ptr;
 531         unsigned char *buf;
 532         int copied = 0;
 533
 534         static int intCount, RxIntCnt;
 535
 536         /*
 537          ** The receive data process is to remove packets from the
 538          ** PHB until there aren't any more or the current cblock
 539          ** is full. When this occurs, there will be some left over
 540          ** data in the packet, that we must do something with.
 541          ** As we haven't unhooked the packet from the read list
 542          ** yet, we can just leave the packet there, having first
 543          ** made a note of how far we got. This means that we need
 544          ** a pointer per port saying where we start taking the
 545          ** data from - this will normally be zero, but when we
 546          ** run out of space it will be set to the offset of the
 547          ** next byte to copy from the packet data area. The packet
 548          ** length field is decremented by the number of bytes that
 549          ** we successfully removed from the packet. When this reaches
 550          ** zero, we reset the offset pointer to be zero, and free
 551          ** the packet from the front of the queue.
 552          */
 553
 554         intCount++;
 555
 556         TtyP = PortP->gs.tty;
 557         if (!TtyP) {
 558                 rio_dprintk(RIO_DEBUG_INTR, "RIOReceive: tty is null. \n");
 559                 return;
 560         }
 561
 562         if (PortP->State & RIO_THROTTLE_RX) {
 563                 rio_dprintk(RIO_DEBUG_INTR, "RIOReceive: Throttled. Can't handle more input.\n");
 564                 return;
 565         }
 566
 567         if (PortP->State & RIO_DELETED) {
 568                 while (can_remove_receive(&PacketP, PortP)) {
 569                         remove_receive(PortP);
 570                         put_free_end(PortP->HostP, PacketP);
 571                 }
 572         } else {
 573                 /*
 574                  ** loop, just so long as:
 575                  **   i ) there's some data ( i.e. can_remove_receive )
 576                  **  ii ) we haven't been blocked
 577                  ** iii ) there's somewhere to put the data
 578                  **  iv ) we haven't outstayed our welcome
 579                  */
 580                 transCount = 1;
 581                 while (can_remove_receive(&PacketP, PortP)
 582                        && transCount) {
 583                         RxIntCnt++;
 584
 585                         /*
 586                          ** check that it is not a command!
 587                          */
 588                         if (readb(&PacketP->len) & PKT_CMD_BIT) {
 589                                 rio_dprintk(RIO_DEBUG_INTR, "RIO: unexpected command packet received on PHB\n");
 590                                 /*      rio_dprint(RIO_DEBUG_INTR, (" sysport   = %d\n", p->RIOPortp->PortNum)); */
 591                                 rio_dprintk(RIO_DEBUG_INTR, " dest_unit = %d\n", readb(&PacketP->dest_unit));
 592                                 rio_dprintk(RIO_DEBUG_INTR, " dest_port = %d\n", readb(&PacketP->dest_port));
 593                                 rio_dprintk(RIO_DEBUG_INTR, " src_unit  = %d\n", readb(&PacketP->src_unit));
 594                                 rio_dprintk(RIO_DEBUG_INTR, " src_port  = %d\n", readb(&PacketP->src_port));
 595                                 rio_dprintk(RIO_DEBUG_INTR, " len          = %d\n", readb(&PacketP->len));
 596                                 rio_dprintk(RIO_DEBUG_INTR, " control   = %d\n", readb(&PacketP->control));
 597                                 rio_dprintk(RIO_DEBUG_INTR, " csum         = %d\n", readw(&PacketP->csum));
 598                                 rio_dprintk(RIO_DEBUG_INTR, "    data bytes: ");
 599                                 for (DataCnt = 0; DataCnt < PKT_MAX_DATA_LEN; DataCnt++)
 600                                         rio_dprintk(RIO_DEBUG_INTR, "%d\n", readb(&PacketP->data[DataCnt]));
 601                                 remove_receive(PortP);
 602                                 put_free_end(PortP->HostP, PacketP);
 603                                 continue;       /* with next packet */
 604                         }
 605
 606                         /*
 607                          ** How many characters can we move 'upstream' ?
 608                          **
 609                          ** Determine the minimum of the amount of data
 610                          ** available and the amount of space in which to
 611                          ** put it.
 612                          **
 613                          ** 1.        Get the packet length by masking 'len'
 614                          **   for only the length bits.
 615                          ** 2.        Available space is [buffer size] - [space used]
 616                          **
 617                          ** Transfer count is the minimum of packet length
 618                          ** and available space.
 619                          */
 620
 621                         transCount = tty_buffer_request_room(TtyP, readb(&PacketP->len) & PKT_LEN_MASK);
 622                         rio_dprintk(RIO_DEBUG_REC, "port %d: Copy %d bytes\n", PortP->PortNum, transCount);
 623                         /*
 624                          ** To use the following 'kkprintfs' for debugging - change the '#undef'
 625                          ** to '#define', (this is the only place ___DEBUG_IT___ occurs in the
 626                          ** driver).
 627                          */
 628                         ptr = (unsigned char __iomem *) PacketP->data + PortP->RxDataStart;
 629
 630                         tty_prepare_flip_string(TtyP, &buf, transCount);
 631                         rio_memcpy_fromio(buf, ptr, transCount);
 632                         PortP->RxDataStart += transCount;
 633                         writeb(readb(&PacketP->len)-transCount, &PacketP->len);
 634                         copied += transCount;
 635
 636
 637
 638                         if (readb(&PacketP->len) == 0) {
 639                                 /*
 640                                  ** If we have emptied the packet, then we can
 641                                  ** free it, and reset the start pointer for
 642                                  ** the next packet.
 643                                  */
 644                                 remove_receive(PortP);
 645                                 put_free_end(PortP->HostP, PacketP);
 646                                 PortP->RxDataStart = 0;
 647                         }
 648                 }
 649         }
 650         if (copied) {
 651                 rio_dprintk(RIO_DEBUG_REC, "port %d: pushing tty flip buffer: %d total bytes copied.\n", PortP->PortNum, copied);
 652                 tty_flip_buffer_push(TtyP);
 653         }
 654
 655         return;
 656 }
 657