drivers/char/rio/rioroute.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          : rioroute.c
  24 **      SID             : 1.3
  25 **      Last Modified   : 11/6/98 10:33:46
  26 **      Retrieved       : 11/6/98 10:33:50
  27 **
  28 **  ident @(#)rioroute.c        1.3
  29 **
  30 ** -----------------------------------------------------------------------------
  31 */
  32 #ifdef SCCS_LABELS
  33 static char *_rioroute_c_sccs_ = "@(#)rioroute.c        1.3";
  34 #endif
  35
  36 #include <linux/module.h>
  37 #include <linux/slab.h>
  38 #include <linux/errno.h>
  39 #include <asm/io.h>
  40 #include <asm/system.h>
  41 #include <asm/string.h>
  42 #include <asm/semaphore.h>
  43 #include <asm/uaccess.h>
  44
  45 #include <linux/termios.h>
  46 #include <linux/serial.h>
  47
  48 #include <linux/generic_serial.h>
  49
  50
  51 #include "linux_compat.h"
  52 #include "rio_linux.h"
  53 #include "pkt.h"
  54 #include "daemon.h"
  55 #include "rio.h"
  56 #include "riospace.h"
  57 #include "cmdpkt.h"
  58 #include "map.h"
  59 #include "rup.h"
  60 #include "port.h"
  61 #include "riodrvr.h"
  62 #include "rioinfo.h"
  63 #include "func.h"
  64 #include "errors.h"
  65 #include "pci.h"
  66
  67 #include "parmmap.h"
  68 #include "unixrup.h"
  69 #include "board.h"
  70 #include "host.h"
  71 #include "phb.h"
  72 #include "link.h"
  73 #include "cmdblk.h"
  74 #include "route.h"
  75 #include "cirrus.h"
  76 #include "rioioctl.h"
  77 #include "param.h"
  78
  79 static int RIOCheckIsolated(struct rio_info *, struct Host *, unsigned int);
  80 static int RIOIsolate(struct rio_info *, struct Host *, unsigned int);
  81 static int RIOCheck(struct Host *, unsigned int);
  82 static void RIOConCon(struct rio_info *, struct Host *, unsigned int, unsigned int, unsigned int, unsigned int, int);
  83
  84
  85 /*
  86 ** Incoming on the ROUTE_RUP
  87 ** I wrote this while I was tired. Forgive me.
  88 */
  89 int RIORouteRup(struct rio_info *p, unsigned int Rup, struct Host *HostP, struct PKT __iomem * PacketP)
  90 {
  91         struct PktCmd __iomem *PktCmdP = (struct PktCmd __iomem *) PacketP->data;
  92         struct PktCmd_M *PktReplyP;
  93         struct CmdBlk *CmdBlkP;
  94         struct Port *PortP;
  95         struct Map *MapP;
  96         struct Top *TopP;
  97         int ThisLink, ThisLinkMin, ThisLinkMax;
  98         int port;
  99         int Mod, Mod1, Mod2;
 100         unsigned short RtaType;
 101         unsigned int RtaUniq;
 102         unsigned int ThisUnit, ThisUnit2;       /* 2 ids to accommodate 16 port RTA */
 103         unsigned int OldUnit, NewUnit, OldLink, NewLink;
 104         char *MyType, *MyName;
 105         int Lies;
 106         unsigned long flags;
 107
 108         /*
 109          ** Is this unit telling us it's current link topology?
 110          */
 111         if (readb(&PktCmdP->Command) == ROUTE_TOPOLOGY) {
 112                 MapP = HostP->Mapping;
 113
 114                 /*
 115                  ** The packet can be sent either by the host or by an RTA.
 116                  ** If it comes from the host, then we need to fill in the
 117                  ** Topology array in the host structure. If it came in
 118                  ** from an RTA then we need to fill in the Mapping structure's
 119                  ** Topology array for the unit.
 120                  */
 121                 if (Rup >= (unsigned short) MAX_RUP) {
 122                         ThisUnit = HOST_ID;
 123                         TopP = HostP->Topology;
 124                         MyType = "Host";
 125                         MyName = HostP->Name;
 126                         ThisLinkMin = ThisLinkMax = Rup - MAX_RUP;
 127                 } else {
 128                         ThisUnit = Rup + 1;
 129                         TopP = HostP->Mapping[Rup].Topology;
 130                         MyType = "RTA";
 131                         MyName = HostP->Mapping[Rup].Name;
 132                         ThisLinkMin = 0;
 133                         ThisLinkMax = LINKS_PER_UNIT - 1;
 134                 }
 135
 136                 /*
 137                  ** Lies will not be tolerated.
 138                  ** If any pair of links claim to be connected to the same
 139                  ** place, then ignore this packet completely.
 140                  */
 141                 Lies = 0;
 142                 for (ThisLink = ThisLinkMin + 1; ThisLink <= ThisLinkMax; ThisLink++) {
 143                         /*
 144                          ** it won't lie about network interconnect, total disconnects
 145                          ** and no-IDs. (or at least, it doesn't *matter* if it does)
 146                          */
 147                         if (readb(&PktCmdP->RouteTopology[ThisLink].Unit) > (unsigned short) MAX_RUP)
 148                                 continue;
 149
 150                         for (NewLink = ThisLinkMin; NewLink < ThisLink; NewLink++) {
 151                                 if ((readb(&PktCmdP->RouteTopology[ThisLink].Unit) == readb(&PktCmdP->RouteTopology[NewLink].Unit)) && (readb(&PktCmdP->RouteTopology[ThisLink].Link) == readb(&PktCmdP->RouteTopology[NewLink].Link))) {
 152                                         Lies++;
 153                                 }
 154                         }
 155                 }
 156
 157                 if (Lies) {
 158                         rio_dprintk(RIO_DEBUG_ROUTE, "LIES! DAMN LIES! %d LIES!\n", Lies);
 159                         rio_dprintk(RIO_DEBUG_ROUTE, "%d:%c %d:%c %d:%c %d:%c\n",
 160                                     readb(&PktCmdP->RouteTopology[0].Unit),
 161                                     'A' + readb(&PktCmdP->RouteTopology[0].Link),
 162                                     readb(&PktCmdP->RouteTopology[1].Unit),
 163                                     'A' + readb(&PktCmdP->RouteTopology[1].Link), readb(&PktCmdP->RouteTopology[2].Unit), 'A' + readb(&PktCmdP->RouteTopology[2].Link), readb(&PktCmdP->RouteTopology[3].Unit), 'A' + readb(&PktCmdP->RouteTopology[3].Link));
 164                         return 1;
 165                 }
 166
 167                 /*
 168                  ** now, process each link.
 169                  */
 170                 for (ThisLink = ThisLinkMin; ThisLink <= ThisLinkMax; ThisLink++) {
 171                         /*
 172                          ** this is what it was connected to
 173                          */
 174                         OldUnit = TopP[ThisLink].Unit;
 175                         OldLink = TopP[ThisLink].Link;
 176
 177                         /*
 178                          ** this is what it is now connected to
 179                          */
 180                         NewUnit = readb(&PktCmdP->RouteTopology[ThisLink].Unit);
 181                         NewLink = readb(&PktCmdP->RouteTopology[ThisLink].Link);
 182
 183                         if (OldUnit != NewUnit || OldLink != NewLink) {
 184                                 /*
 185                                  ** something has changed!
 186                                  */
 187
 188                                 if (NewUnit > MAX_RUP && NewUnit != ROUTE_DISCONNECT && NewUnit != ROUTE_NO_ID && NewUnit != ROUTE_INTERCONNECT) {
 189                                         rio_dprintk(RIO_DEBUG_ROUTE, "I have a link from %s %s to unit %d:%d - I don't like it.\n", MyType, MyName, NewUnit, NewLink);
 190                                 } else {
 191                                         /*
 192                                          ** put the new values in
 193                                          */
 194                                         TopP[ThisLink].Unit = NewUnit;
 195                                         TopP[ThisLink].Link = NewLink;
 196
 197                                         RIOSetChange(p);
 198
 199                                         if (OldUnit <= MAX_RUP) {
 200                                                 /*
 201                                                  ** If something has become bust, then re-enable them messages
 202                                                  */
 203                                                 if (!p->RIONoMessage)
 204                                                         RIOConCon(p, HostP, ThisUnit, ThisLink, OldUnit, OldLink, DISCONNECT);
 205                                         }
 206
 207                                         if ((NewUnit <= MAX_RUP) && !p->RIONoMessage)
 208                                                 RIOConCon(p, HostP, ThisUnit, ThisLink, NewUnit, NewLink, CONNECT);
 209
 210                                         if (NewUnit == ROUTE_NO_ID)
 211                                                 rio_dprintk(RIO_DEBUG_ROUTE, "%s %s (%c) is connected to an unconfigured unit.\n", MyType, MyName, 'A' + ThisLink);
 212
 213                                         if (NewUnit == ROUTE_INTERCONNECT) {
 214                                                 if (!p->RIONoMessage)
 215                                                         printk(KERN_DEBUG "rio: %s '%s' (%c) is connected to another network.\n", MyType, MyName, 'A' + ThisLink);
 216                                         }
 217
 218                                         /*
 219                                          ** perform an update for 'the other end', so that these messages
 220                                          ** only appears once. Only disconnect the other end if it is pointing
 221                                          ** at us!
 222                                          */
 223                                         if (OldUnit == HOST_ID) {
 224                                                 if (HostP->Topology[OldLink].Unit == ThisUnit && HostP->Topology[OldLink].Link == ThisLink) {
 225                                                         rio_dprintk(RIO_DEBUG_ROUTE, "SETTING HOST (%c) TO DISCONNECTED!\n", OldLink + 'A');
 226                                                         HostP->Topology[OldLink].Unit = ROUTE_DISCONNECT;
 227                                                         HostP->Topology[OldLink].Link = NO_LINK;
 228                                                 } else {
 229                                                         rio_dprintk(RIO_DEBUG_ROUTE, "HOST(%c) WAS NOT CONNECTED TO %s (%c)!\n", OldLink + 'A', HostP->Mapping[ThisUnit - 1].Name, ThisLink + 'A');
 230                                                 }
 231                                         } else if (OldUnit <= MAX_RUP) {
 232                                                 if (HostP->Mapping[OldUnit - 1].Topology[OldLink].Unit == ThisUnit && HostP->Mapping[OldUnit - 1].Topology[OldLink].Link == ThisLink) {
 233                                                         rio_dprintk(RIO_DEBUG_ROUTE, "SETTING RTA %s (%c) TO DISCONNECTED!\n", HostP->Mapping[OldUnit - 1].Name, OldLink + 'A');
 234                                                         HostP->Mapping[OldUnit - 1].Topology[OldLink].Unit = ROUTE_DISCONNECT;
 235                                                         HostP->Mapping[OldUnit - 1].Topology[OldLink].Link = NO_LINK;
 236                                                 } else {
 237                                                         rio_dprintk(RIO_DEBUG_ROUTE, "RTA %s (%c) WAS NOT CONNECTED TO %s (%c)\n", HostP->Mapping[OldUnit - 1].Name, OldLink + 'A', HostP->Mapping[ThisUnit - 1].Name, ThisLink + 'A');
 238                                                 }
 239                                         }
 240                                         if (NewUnit == HOST_ID) {
 241                                                 rio_dprintk(RIO_DEBUG_ROUTE, "MARKING HOST (%c) CONNECTED TO %s (%c)\n", NewLink + 'A', MyName, ThisLink + 'A');
 242                                                 HostP->Topology[NewLink].Unit = ThisUnit;
 243                                                 HostP->Topology[NewLink].Link = ThisLink;
 244                                         } else if (NewUnit <= MAX_RUP) {
 245                                                 rio_dprintk(RIO_DEBUG_ROUTE, "MARKING RTA %s (%c) CONNECTED TO %s (%c)\n", HostP->Mapping[NewUnit - 1].Name, NewLink + 'A', MyName, ThisLink + 'A');
 246                                                 HostP->Mapping[NewUnit - 1].Topology[NewLink].Unit = ThisUnit;
 247                                                 HostP->Mapping[NewUnit - 1].Topology[NewLink].Link = ThisLink;
 248                                         }
 249                                 }
 250                                 RIOSetChange(p);
 251                                 RIOCheckIsolated(p, HostP, OldUnit);
 252                         }
 253                 }
 254                 return 1;
 255         }
 256
 257         /*
 258          ** The only other command we recognise is a route_request command
 259          */
 260         if (readb(&PktCmdP->Command) != ROUTE_REQUEST) {
 261                 rio_dprintk(RIO_DEBUG_ROUTE, "Unknown command %d received on rup %d host %p ROUTE_RUP\n", readb(&PktCmdP->Command), Rup, HostP);
 262                 return 1;
 263         }
 264
 265         RtaUniq = (readb(&PktCmdP->UniqNum[0])) + (readb(&PktCmdP->UniqNum[1]) << 8) + (readb(&PktCmdP->UniqNum[2]) << 16) + (readb(&PktCmdP->UniqNum[3]) << 24);
 266
 267         /*
 268          ** Determine if 8 or 16 port RTA
 269          */
 270         RtaType = GetUnitType(RtaUniq);
 271
 272         rio_dprintk(RIO_DEBUG_ROUTE, "Received a request for an ID for serial number %x\n", RtaUniq);
 273
 274         Mod = readb(&PktCmdP->ModuleTypes);
 275         Mod1 = LONYBLE(Mod);
 276         if (RtaType == TYPE_RTA16) {
 277                 /*
 278                  ** Only one ident is set for a 16 port RTA. To make compatible
 279                  ** with 8 port, set 2nd ident in Mod2 to the same as Mod1.
 280                  */
 281                 Mod2 = Mod1;
 282                 rio_dprintk(RIO_DEBUG_ROUTE, "Backplane type is %s (all ports)\n", p->RIOModuleTypes[Mod1].Name);
 283         } else {
 284                 Mod2 = HINYBLE(Mod);
 285                 rio_dprintk(RIO_DEBUG_ROUTE, "Module types are %s (ports 0-3) and %s (ports 4-7)\n", p->RIOModuleTypes[Mod1].Name, p->RIOModuleTypes[Mod2].Name);
 286         }
 287
 288         /*
 289          ** try to unhook a command block from the command free list.
 290          */
 291         if (!(CmdBlkP = RIOGetCmdBlk())) {
 292                 rio_dprintk(RIO_DEBUG_ROUTE, "No command blocks to route RTA! come back later.\n");
 293                 return 0;
 294         }
 295
 296         /*
 297          ** Fill in the default info on the command block
 298          */
 299         CmdBlkP->Packet.dest_unit = Rup;
 300         CmdBlkP->Packet.dest_port = ROUTE_RUP;
 301         CmdBlkP->Packet.src_unit = HOST_ID;
 302         CmdBlkP->Packet.src_port = ROUTE_RUP;
 303         CmdBlkP->Packet.len = PKT_CMD_BIT | 1;
 304         CmdBlkP->PreFuncP = CmdBlkP->PostFuncP = NULL;
 305         PktReplyP = (struct PktCmd_M *) CmdBlkP->Packet.data;
 306
 307         if (!RIOBootOk(p, HostP, RtaUniq)) {
 308                 rio_dprintk(RIO_DEBUG_ROUTE, "RTA %x tried to get an ID, but does not belong - FOAD it!\n", RtaUniq);
 309                 PktReplyP->Command = ROUTE_FOAD;
 310                 memcpy(PktReplyP->CommandText, "RT_FOAD", 7);
 311                 RIOQueueCmdBlk(HostP, Rup, CmdBlkP);
 312                 return 1;
 313         }
 314
 315         /*
 316          ** Check to see if the RTA is configured for this host
 317          */
 318         for (ThisUnit = 0; ThisUnit < MAX_RUP; ThisUnit++) {
 319                 rio_dprintk(RIO_DEBUG_ROUTE, "Entry %d Flags=%s %s UniqueNum=0x%x\n",
 320                             ThisUnit, HostP->Mapping[ThisUnit].Flags & SLOT_IN_USE ? "Slot-In-Use" : "Not In Use", HostP->Mapping[ThisUnit].Flags & SLOT_TENTATIVE ? "Slot-Tentative" : "Not Tentative", HostP->Mapping[ThisUnit].RtaUniqueNum);
 321
 322                 /*
 323                  ** We have an entry for it.
 324                  */
 325                 if ((HostP->Mapping[ThisUnit].Flags & (SLOT_IN_USE | SLOT_TENTATIVE)) && (HostP->Mapping[ThisUnit].RtaUniqueNum == RtaUniq)) {
 326                         if (RtaType == TYPE_RTA16) {
 327                                 ThisUnit2 = HostP->Mapping[ThisUnit].ID2 - 1;
 328                                 rio_dprintk(RIO_DEBUG_ROUTE, "Found unit 0x%x at slots %d+%d\n", RtaUniq, ThisUnit, ThisUnit2);
 329                         } else
 330                                 rio_dprintk(RIO_DEBUG_ROUTE, "Found unit 0x%x at slot %d\n", RtaUniq, ThisUnit);
 331                         /*
 332                          ** If we have no knowledge of booting it, then the host has
 333                          ** been re-booted, and so we must kill the RTA, so that it
 334                          ** will be booted again (potentially with new bins)
 335                          ** and it will then re-ask for an ID, which we will service.
 336                          */
 337                         if ((HostP->Mapping[ThisUnit].Flags & SLOT_IN_USE) && !(HostP->Mapping[ThisUnit].Flags & RTA_BOOTED)) {
 338                                 if (!(HostP->Mapping[ThisUnit].Flags & MSG_DONE)) {
 339                                         if (!p->RIONoMessage)
 340                                                 printk(KERN_DEBUG "rio: RTA '%s' is being updated.\n", HostP->Mapping[ThisUnit].Name);
 341                                         HostP->Mapping[ThisUnit].Flags |= MSG_DONE;
 342                                 }
 343                                 PktReplyP->Command = ROUTE_FOAD;
 344                                 memcpy(PktReplyP->CommandText, "RT_FOAD", 7);
 345                                 RIOQueueCmdBlk(HostP, Rup, CmdBlkP);
 346                                 return 1;
 347                         }
 348
 349                         /*
 350                          ** Send the ID (entry) to this RTA. The ID number is implicit as
 351                          ** the offset into the table. It is worth noting at this stage
 352                          ** that offset zero in the table contains the entries for the
 353                          ** RTA with ID 1!!!!
 354                          */
 355                         PktReplyP->Command = ROUTE_ALLOCATE;
 356                         PktReplyP->IDNum = ThisUnit + 1;
 357                         if (RtaType == TYPE_RTA16) {
 358                                 if (HostP->Mapping[ThisUnit].Flags & SLOT_IN_USE)
 359                                         /*
 360                                          ** Adjust the phb and tx pkt dest_units for 2nd block of 8
 361                                          ** only if the RTA has ports associated (SLOT_IN_USE)
 362                                          */
 363                                         RIOFixPhbs(p, HostP, ThisUnit2);
 364                                 PktReplyP->IDNum2 = ThisUnit2 + 1;
 365                                 rio_dprintk(RIO_DEBUG_ROUTE, "RTA '%s' has been allocated IDs %d+%d\n", HostP->Mapping[ThisUnit].Name, PktReplyP->IDNum, PktReplyP->IDNum2);
 366                         } else {
 367                                 PktReplyP->IDNum2 = ROUTE_NO_ID;
 368                                 rio_dprintk(RIO_DEBUG_ROUTE, "RTA '%s' has been allocated ID %d\n", HostP->Mapping[ThisUnit].Name, PktReplyP->IDNum);
 369                         }
 370                         memcpy(PktReplyP->CommandText, "RT_ALLOCAT", 10);
 371
 372                         RIOQueueCmdBlk(HostP, Rup, CmdBlkP);
 373
 374                         /*
 375                          ** If this is a freshly booted RTA, then we need to re-open
 376                          ** the ports, if any where open, so that data may once more
 377                          ** flow around the system!
 378                          */
 379                         if ((HostP->Mapping[ThisUnit].Flags & RTA_NEWBOOT) && (HostP->Mapping[ThisUnit].SysPort != NO_PORT)) {
 380                                 /*
 381                                  ** look at the ports associated with this beast and
 382                                  ** see if any where open. If they was, then re-open
 383                                  ** them, using the info from the tty flags.
 384                                  */
 385                                 for (port = 0; port < PORTS_PER_RTA; port++) {
 386                                         PortP = p->RIOPortp[port + HostP->Mapping[ThisUnit].SysPort];
 387                                         if (PortP->State & (RIO_MOPEN | RIO_LOPEN)) {
 388                                                 rio_dprintk(RIO_DEBUG_ROUTE, "Re-opened this port\n");
 389                                                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 390                                                 PortP->MagicFlags |= MAGIC_REBOOT;
 391                                                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 392                                         }
 393                                 }
 394                                 if (RtaType == TYPE_RTA16) {
 395                                         for (port = 0; port < PORTS_PER_RTA; port++) {
 396                                                 PortP = p->RIOPortp[port + HostP->Mapping[ThisUnit2].SysPort];
 397                                                 if (PortP->State & (RIO_MOPEN | RIO_LOPEN)) {
 398                                                         rio_dprintk(RIO_DEBUG_ROUTE, "Re-opened this port\n");
 399                                                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 400                                                         PortP->MagicFlags |= MAGIC_REBOOT;
 401                                                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 402                                                 }
 403                                         }
 404                                 }
 405                         }
 406
 407                         /*
 408                          ** keep a copy of the module types!
 409                          */
 410                         HostP->UnixRups[ThisUnit].ModTypes = Mod;
 411                         if (RtaType == TYPE_RTA16)
 412                                 HostP->UnixRups[ThisUnit2].ModTypes = Mod;
 413
 414                         /*
 415                          ** If either of the modules on this unit is read-only or write-only
 416                          ** or none-xprint, then we need to transfer that info over to the
 417                          ** relevant ports.
 418                          */
 419                         if (HostP->Mapping[ThisUnit].SysPort != NO_PORT) {
 420                                 for (port = 0; port < PORTS_PER_MODULE; port++) {
 421                                         p->RIOPortp[port + HostP->Mapping[ThisUnit].SysPort]->Config &= ~RIO_NOMASK;
 422                                         p->RIOPortp[port + HostP->Mapping[ThisUnit].SysPort]->Config |= p->RIOModuleTypes[Mod1].Flags[port];
 423                                         p->RIOPortp[port + PORTS_PER_MODULE + HostP->Mapping[ThisUnit].SysPort]->Config &= ~RIO_NOMASK;
 424                                         p->RIOPortp[port + PORTS_PER_MODULE + HostP->Mapping[ThisUnit].SysPort]->Config |= p->RIOModuleTypes[Mod2].Flags[port];
 425                                 }
 426                                 if (RtaType == TYPE_RTA16) {
 427                                         for (port = 0; port < PORTS_PER_MODULE; port++) {
 428                                                 p->RIOPortp[port + HostP->Mapping[ThisUnit2].SysPort]->Config &= ~RIO_NOMASK;
 429                                                 p->RIOPortp[port + HostP->Mapping[ThisUnit2].SysPort]->Config |= p->RIOModuleTypes[Mod1].Flags[port];
 430                                                 p->RIOPortp[port + PORTS_PER_MODULE + HostP->Mapping[ThisUnit2].SysPort]->Config &= ~RIO_NOMASK;
 431                                                 p->RIOPortp[port + PORTS_PER_MODULE + HostP->Mapping[ThisUnit2].SysPort]->Config |= p->RIOModuleTypes[Mod2].Flags[port];
 432                                         }
 433                                 }
 434                         }
 435
 436                         /*
 437                          ** Job done, get on with the interrupts!
 438                          */
 439                         return 1;
 440                 }
 441         }
 442         /*
 443          ** There is no table entry for this RTA at all.
 444          **
 445          ** Lets check to see if we actually booted this unit - if not,
 446          ** then we reset it and it will go round the loop of being booted
 447          ** we can then worry about trying to fit it into the table.
 448          */
 449         for (ThisUnit = 0; ThisUnit < HostP->NumExtraBooted; ThisUnit++)
 450                 if (HostP->ExtraUnits[ThisUnit] == RtaUniq)
 451                         break;
 452         if (ThisUnit == HostP->NumExtraBooted && ThisUnit != MAX_EXTRA_UNITS) {
 453                 /*
 454                  ** if the unit wasn't in the table, and the table wasn't full, then
 455                  ** we reset the unit, because we didn't boot it.
 456                  ** However, if the table is full, it could be that we did boot
 457                  ** this unit, and so we won't reboot it, because it isn't really
 458                  ** all that disasterous to keep the old bins in most cases. This
 459                  ** is a rather tacky feature, but we are on the edge of reallity
 460                  ** here, because the implication is that someone has connected
 461                  ** 16+MAX_EXTRA_UNITS onto one host.
 462                  */
 463                 static int UnknownMesgDone = 0;
 464
 465                 if (!UnknownMesgDone) {
 466                         if (!p->RIONoMessage)
 467                                 printk(KERN_DEBUG "rio: One or more unknown RTAs are being updated.\n");
 468                         UnknownMesgDone = 1;
 469                 }
 470
 471                 PktReplyP->Command = ROUTE_FOAD;
 472                 memcpy(PktReplyP->CommandText, "RT_FOAD", 7);
 473         } else {
 474                 /*
 475                  ** we did boot it (as an extra), and there may now be a table
 476                  ** slot free (because of a delete), so we will try to make
 477                  ** a tentative entry for it, so that the configurator can see it
 478                  ** and fill in the details for us.
 479                  */
 480                 if (RtaType == TYPE_RTA16) {
 481                         if (RIOFindFreeID(p, HostP, &ThisUnit, &ThisUnit2) == 0) {
 482                                 RIODefaultName(p, HostP, ThisUnit);
 483                                 rio_fill_host_slot(ThisUnit, ThisUnit2, RtaUniq, HostP);
 484                         }
 485                 } else {
 486                         if (RIOFindFreeID(p, HostP, &ThisUnit, NULL) == 0) {
 487                                 RIODefaultName(p, HostP, ThisUnit);
 488                                 rio_fill_host_slot(ThisUnit, 0, RtaUniq, HostP);
 489                         }
 490                 }
 491                 PktReplyP->Command = ROUTE_USED;
 492                 memcpy(PktReplyP->CommandText, "RT_USED", 7);
 493         }
 494         RIOQueueCmdBlk(HostP, Rup, CmdBlkP);
 495         return 1;
 496 }
 497
 498
 499 void RIOFixPhbs(struct rio_info *p, struct Host *HostP, unsigned int unit)
 500 {
 501         unsigned short link, port;
 502         struct Port *PortP;
 503         unsigned long flags;
 504         int PortN = HostP->Mapping[unit].SysPort;
 505
 506         rio_dprintk(RIO_DEBUG_ROUTE, "RIOFixPhbs unit %d sysport %d\n", unit, PortN);
 507
 508         if (PortN != -1) {
 509                 unsigned short dest_unit = HostP->Mapping[unit].ID2;
 510
 511                 /*
 512                  ** Get the link number used for the 1st 8 phbs on this unit.
 513                  */
 514                 PortP = p->RIOPortp[HostP->Mapping[dest_unit - 1].SysPort];
 515
 516                 link = readw(&PortP->PhbP->link);
 517
 518                 for (port = 0; port < PORTS_PER_RTA; port++, PortN++) {
 519                         unsigned short dest_port = port + 8;
 520                         u16 __iomem *TxPktP;
 521                         struct PKT __iomem *Pkt;
 522
 523                         PortP = p->RIOPortp[PortN];
 524
 525                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 526                         /*
 527                          ** If RTA is not powered on, the tx packets will be
 528                          ** unset, so go no further.
 529                          */
 530                         if (PortP->TxStart == 0) {
 531                                 rio_dprintk(RIO_DEBUG_ROUTE, "Tx pkts not set up yet\n");
 532                                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 533                                 break;
 534                         }
 535
 536                         /*
 537                          ** For the second slot of a 16 port RTA, the driver needs to
 538                          ** sort out the phb to port mappings. The dest_unit for this
 539                          ** group of 8 phbs is set to the dest_unit of the accompanying
 540                          ** 8 port block. The dest_port of the second unit is set to
 541                          ** be in the range 8-15 (i.e. 8 is added). Thus, for a 16 port
 542                          ** RTA with IDs 5 and 6, traffic bound for port 6 of unit 6
 543                          ** (being the second map ID) will be sent to dest_unit 5, port
 544                          ** 14. When this RTA is deleted, dest_unit for ID 6 will be
 545                          ** restored, and the dest_port will be reduced by 8.
 546                          ** Transmit packets also have a destination field which needs
 547                          ** adjusting in the same manner.
 548                          ** Note that the unit/port bytes in 'dest' are swapped.
 549                          ** We also need to adjust the phb and rup link numbers for the
 550                          ** second block of 8 ttys.
 551                          */
 552                         for (TxPktP = PortP->TxStart; TxPktP <= PortP->TxEnd; TxPktP++) {
 553                                 /*
 554                                  ** *TxPktP is the pointer to the transmit packet on the host
 555                                  ** card. This needs to be translated into a 32 bit pointer
 556                                  ** so it can be accessed from the driver.
 557                                  */
 558                                 Pkt = (struct PKT __iomem *) RIO_PTR(HostP->Caddr, readw(TxPktP));
 559
 560                                 /*
 561                                  ** If the packet is used, reset it.
 562                                  */
 563                                 Pkt = (struct PKT __iomem *) ((unsigned long) Pkt & ~PKT_IN_USE);
 564                                 writeb(dest_unit, &Pkt->dest_unit);
 565                                 writeb(dest_port, &Pkt->dest_port);
 566                         }
 567                         rio_dprintk(RIO_DEBUG_ROUTE, "phb dest: Old %x:%x New %x:%x\n", readw(&PortP->PhbP->destination) & 0xff, (readw(&PortP->PhbP->destination) >> 8) & 0xff, dest_unit, dest_port);
 568                         writew(dest_unit + (dest_port << 8), &PortP->PhbP->destination);
 569                         writew(link, &PortP->PhbP->link);
 570
 571                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 572                 }
 573                 /*
 574                  ** Now make sure the range of ports to be serviced includes
 575                  ** the 2nd 8 on this 16 port RTA.
 576                  */
 577                 if (link > 3)
 578                         return;
 579                 if (((unit * 8) + 7) > readw(&HostP->LinkStrP[link].last_port)) {
 580                         rio_dprintk(RIO_DEBUG_ROUTE, "last port on host link %d: %d\n", link, (unit * 8) + 7);
 581                         writew((unit * 8) + 7, &HostP->LinkStrP[link].last_port);
 582                 }
 583         }
 584 }
 585
 586 /*
 587 ** Check to see if the new disconnection has isolated this unit.
 588 ** If it has, then invalidate all its link information, and tell
 589 ** the world about it. This is done to ensure that the configurator
 590 ** only gets up-to-date information about what is going on.
 591 */
 592 static int RIOCheckIsolated(struct rio_info *p, struct Host *HostP, unsigned int UnitId)
 593 {
 594         unsigned long flags;
 595         rio_spin_lock_irqsave(&HostP->HostLock, flags);
 596
 597         if (RIOCheck(HostP, UnitId)) {
 598                 rio_dprintk(RIO_DEBUG_ROUTE, "Unit %d is NOT isolated\n", UnitId);
 599                 rio_spin_unlock_irqrestore(&HostP->HostLock, flags);
 600                 return (0);
 601         }
 602
 603         RIOIsolate(p, HostP, UnitId);
 604         RIOSetChange(p);
 605         rio_spin_unlock_irqrestore(&HostP->HostLock, flags);
 606         return 1;
 607 }
 608
 609 /*
 610 ** Invalidate all the link interconnectivity of this unit, and of
 611 ** all the units attached to it. This will mean that the entire
 612 ** subnet will re-introduce itself.
 613 */
 614 static int RIOIsolate(struct rio_info *p, struct Host *HostP, unsigned int UnitId)
 615 {
 616         unsigned int link, unit;
 617
 618         UnitId--;               /* this trick relies on the Unit Id being UNSIGNED! */
 619
 620         if (UnitId >= MAX_RUP)  /* dontcha just lurv unsigned maths! */
 621                 return (0);
 622
 623         if (HostP->Mapping[UnitId].Flags & BEEN_HERE)
 624                 return (0);
 625
 626         HostP->Mapping[UnitId].Flags |= BEEN_HERE;
 627
 628         if (p->RIOPrintDisabled == DO_PRINT)
 629                 rio_dprintk(RIO_DEBUG_ROUTE, "RIOMesgIsolated %s", HostP->Mapping[UnitId].Name);
 630
 631         for (link = 0; link < LINKS_PER_UNIT; link++) {
 632                 unit = HostP->Mapping[UnitId].Topology[link].Unit;
 633                 HostP->Mapping[UnitId].Topology[link].Unit = ROUTE_DISCONNECT;
 634                 HostP->Mapping[UnitId].Topology[link].Link = NO_LINK;
 635                 RIOIsolate(p, HostP, unit);
 636         }
 637         HostP->Mapping[UnitId].Flags &= ~BEEN_HERE;
 638         return 1;
 639 }
 640
 641 static int RIOCheck(struct Host *HostP, unsigned int UnitId)
 642 {
 643         unsigned char link;
 644
 645 /*      rio_dprint(RIO_DEBUG_ROUTE, ("Check to see if unit %d has a route to the host\n",UnitId)); */
 646         rio_dprintk(RIO_DEBUG_ROUTE, "RIOCheck : UnitID = %d\n", UnitId);
 647
 648         if (UnitId == HOST_ID) {
 649                 /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d is NOT isolated - it IS the host!\n", UnitId)); */
 650                 return 1;
 651         }
 652
 653         UnitId--;
 654
 655         if (UnitId >= MAX_RUP) {
 656                 /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d - ignored.\n", UnitId)); */
 657                 return 0;
 658         }
 659
 660         for (link = 0; link < LINKS_PER_UNIT; link++) {
 661                 if (HostP->Mapping[UnitId].Topology[link].Unit == HOST_ID) {
 662                         /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d is connected directly to host via link (%c).\n",
 663                            UnitId, 'A'+link)); */
 664                         return 1;
 665                 }
 666         }
 667
 668         if (HostP->Mapping[UnitId].Flags & BEEN_HERE) {
 669                 /* rio_dprint(RIO_DEBUG_ROUTE, ("Been to Unit %d before - ignoring\n", UnitId)); */
 670                 return 0;
 671         }
 672
 673         HostP->Mapping[UnitId].Flags |= BEEN_HERE;
 674
 675         for (link = 0; link < LINKS_PER_UNIT; link++) {
 676                 /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d check link (%c)\n", UnitId,'A'+link)); */
 677                 if (RIOCheck(HostP, HostP->Mapping[UnitId].Topology[link].Unit)) {
 678                         /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d is connected to something that knows the host via link (%c)\n", UnitId,link+'A')); */
 679                         HostP->Mapping[UnitId].Flags &= ~BEEN_HERE;
 680                         return 1;
 681                 }
 682         }
 683
 684         HostP->Mapping[UnitId].Flags &= ~BEEN_HERE;
 685
 686         /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d DOESNT KNOW THE HOST!\n", UnitId)); */
 687
 688         return 0;
 689 }
 690
 691 /*
 692 ** Returns the type of unit (host, 16/8 port RTA)
 693 */
 694
 695 unsigned int GetUnitType(unsigned int Uniq)
 696 {
 697         switch ((Uniq >> 28) & 0xf) {
 698         case RIO_AT:
 699         case RIO_MCA:
 700         case RIO_EISA:
 701         case RIO_PCI:
 702                 rio_dprintk(RIO_DEBUG_ROUTE, "Unit type: Host\n");
 703                 return (TYPE_HOST);
 704         case RIO_RTA_16:
 705                 rio_dprintk(RIO_DEBUG_ROUTE, "Unit type: 16 port RTA\n");
 706                 return (TYPE_RTA16);
 707         case RIO_RTA:
 708                 rio_dprintk(RIO_DEBUG_ROUTE, "Unit type: 8 port RTA\n");
 709                 return (TYPE_RTA8);
 710         default:
 711                 rio_dprintk(RIO_DEBUG_ROUTE, "Unit type: Unrecognised\n");
 712                 return (99);
 713         }
 714 }
 715
 716 int RIOSetChange(struct rio_info *p)
 717 {
 718         if (p->RIOQuickCheck != NOT_CHANGED)
 719                 return (0);
 720         p->RIOQuickCheck = CHANGED;
 721         if (p->RIOSignalProcess) {
 722                 rio_dprintk(RIO_DEBUG_ROUTE, "Send SIG-HUP");
 723                 /*
 724                    psignal( RIOSignalProcess, SIGHUP );
 725                  */
 726         }
 727         return (0);
 728 }
 729
 730 static void RIOConCon(struct rio_info *p,
 731                       struct Host *HostP,
 732                       unsigned int FromId,
 733                       unsigned int FromLink,
 734                       unsigned int ToId,
 735                       unsigned int ToLink,
 736                       int Change)
 737 {
 738         char *FromName;
 739         char *FromType;
 740         char *ToName;
 741         char *ToType;
 742         unsigned int tp;
 743
 744 /*
 745 ** 15.10.1998 ARG - ESIL 0759
 746 ** (Part) fix for port being trashed when opened whilst RTA "disconnected"
 747 **
 748 ** What's this doing in here anyway ?
 749 ** It was causing the port to be 'unmapped' if opened whilst RTA "disconnected"
 750 **
 751 ** 09.12.1998 ARG - ESIL 0776 - part fix
 752 ** Okay, We've found out what this was all about now !
 753 ** Someone had botched this to use RIOHalted to indicated the number of RTAs
 754 ** 'disconnected'. The value in RIOHalted was then being used in the
 755 ** 'RIO_QUICK_CHECK' ioctl. A none zero value indicating that a least one RTA
 756 ** is 'disconnected'. The change was put in to satisfy a customer's needs.
 757 ** Having taken this bit of code out 'RIO_QUICK_CHECK' now no longer works for
 758 ** the customer.
 759 **
 760     if (Change == CONNECT) {
 761                 if (p->RIOHalted) p->RIOHalted --;
 762          }
 763          else {
 764                 p->RIOHalted ++;
 765          }
 766 **
 767 ** So - we need to implement it slightly differently - a new member of the
 768 ** rio_info struct - RIORtaDisCons (RIO RTA connections) keeps track of RTA
 769 ** connections and disconnections.
 770 */
 771         if (Change == CONNECT) {
 772                 if (p->RIORtaDisCons)
 773                         p->RIORtaDisCons--;
 774         } else {
 775                 p->RIORtaDisCons++;
 776         }
 777
 778         if (p->RIOPrintDisabled == DONT_PRINT)
 779                 return;
 780
 781         if (FromId > ToId) {
 782                 tp = FromId;
 783                 FromId = ToId;
 784                 ToId = tp;
 785                 tp = FromLink;
 786                 FromLink = ToLink;
 787                 ToLink = tp;
 788         }
 789
 790         FromName = FromId ? HostP->Mapping[FromId - 1].Name : HostP->Name;
 791         FromType = FromId ? "RTA" : "HOST";
 792         ToName = ToId ? HostP->Mapping[ToId - 1].Name : HostP->Name;
 793         ToType = ToId ? "RTA" : "HOST";
 794
 795         rio_dprintk(RIO_DEBUG_ROUTE, "Link between %s '%s' (%c) and %s '%s' (%c) %s.\n", FromType, FromName, 'A' + FromLink, ToType, ToName, 'A' + ToLink, (Change == CONNECT) ? "established" : "disconnected");
 796         printk(KERN_DEBUG "rio: Link between %s '%s' (%c) and %s '%s' (%c) %s.\n", FromType, FromName, 'A' + FromLink, ToType, ToName, 'A' + ToLink, (Change == CONNECT) ? "established" : "disconnected");
 797 }
 798
 799 /*
 800 ** RIORemoveFromSavedTable :
 801 **
 802 ** Delete and RTA entry from the saved table given to us
 803 ** by the configuration program.
 804 */
 805 static int RIORemoveFromSavedTable(struct rio_info *p, struct Map *pMap)
 806 {
 807         int entry;
 808
 809         /*
 810          ** We loop for all entries even after finding an entry and
 811          ** zeroing it because we may have two entries to delete if
 812          ** it's a 16 port RTA.
 813          */
 814         for (entry = 0; entry < TOTAL_MAP_ENTRIES; entry++) {
 815                 if (p->RIOSavedTable[entry].RtaUniqueNum == pMap->RtaUniqueNum) {
 816                         memset(&p->RIOSavedTable[entry], 0, sizeof(struct Map));
 817                 }
 818         }
 819         return 0;
 820 }
 821
 822
 823 /*
 824 ** RIOCheckDisconnected :
 825 **
 826 ** Scan the unit links to and return zero if the unit is completely
 827 ** disconnected.
 828 */
 829 static int RIOFreeDisconnected(struct rio_info *p, struct Host *HostP, int unit)
 830 {
 831         int link;
 832
 833
 834         rio_dprintk(RIO_DEBUG_ROUTE, "RIOFreeDisconnect unit %d\n", unit);
 835         /*
 836          ** If the slot is tentative and does not belong to the
 837          ** second half of a 16 port RTA then scan to see if
 838          ** is disconnected.
 839          */
 840         for (link = 0; link < LINKS_PER_UNIT; link++) {
 841                 if (HostP->Mapping[unit].Topology[link].Unit != ROUTE_DISCONNECT)
 842                         break;
 843         }
 844
 845         /*
 846          ** If not all links are disconnected then we can forget about it.
 847          */
 848         if (link < LINKS_PER_UNIT)
 849                 return 1;
 850
 851 #ifdef NEED_TO_FIX_THIS
 852         /* Ok so all the links are disconnected. But we may have only just
 853          ** made this slot tentative and not yet received a topology update.
 854          ** Lets check how long ago we made it tentative.
 855          */
 856         rio_dprintk(RIO_DEBUG_ROUTE, "Just about to check LBOLT on entry %d\n", unit);
 857         if (drv_getparm(LBOLT, (ulong_t *) & current_time))
 858                 rio_dprintk(RIO_DEBUG_ROUTE, "drv_getparm(LBOLT,....) Failed.\n");
 859
 860         elapse_time = current_time - TentTime[unit];
 861         rio_dprintk(RIO_DEBUG_ROUTE, "elapse %d = current %d - tent %d (%d usec)\n", elapse_time, current_time, TentTime[unit], drv_hztousec(elapse_time));
 862         if (drv_hztousec(elapse_time) < WAIT_TO_FINISH) {
 863                 rio_dprintk(RIO_DEBUG_ROUTE, "Skipping slot %d, not timed out yet %d\n", unit, drv_hztousec(elapse_time));
 864                 return 1;
 865         }
 866 #endif
 867
 868         /*
 869          ** We have found an usable slot.
 870          ** If it is half of a 16 port RTA then delete the other half.
 871          */
 872         if (HostP->Mapping[unit].ID2 != 0) {
 873                 int nOther = (HostP->Mapping[unit].ID2) - 1;
 874
 875                 rio_dprintk(RIO_DEBUG_ROUTE, "RioFreedis second slot %d.\n", nOther);
 876                 memset(&HostP->Mapping[nOther], 0, sizeof(struct Map));
 877         }
 878         RIORemoveFromSavedTable(p, &HostP->Mapping[unit]);
 879
 880         return 0;
 881 }
 882
 883
 884 /*
 885 ** RIOFindFreeID :
 886 **
 887 ** This function scans the given host table for either one
 888 ** or two free unit ID's.
 889 */
 890
 891 int RIOFindFreeID(struct rio_info *p, struct Host *HostP, unsigned int * pID1, unsigned int * pID2)
 892 {
 893         int unit, tempID;
 894
 895         /*
 896          ** Initialise the ID's to MAX_RUP.
 897          ** We do this to make the loop for setting the ID's as simple as
 898          ** possible.
 899          */
 900         *pID1 = MAX_RUP;
 901         if (pID2 != NULL)
 902                 *pID2 = MAX_RUP;
 903
 904         /*
 905          ** Scan all entries of the host mapping table for free slots.
 906          ** We scan for free slots first and then if that is not successful
 907          ** we start all over again looking for tentative slots we can re-use.
 908          */
 909         for (unit = 0; unit < MAX_RUP; unit++) {
 910                 rio_dprintk(RIO_DEBUG_ROUTE, "Scanning unit %d\n", unit);
 911                 /*
 912                  ** If the flags are zero then the slot is empty.
 913                  */
 914                 if (HostP->Mapping[unit].Flags == 0) {
 915                         rio_dprintk(RIO_DEBUG_ROUTE, "      This slot is empty.\n");
 916                         /*
 917                          ** If we haven't allocated the first ID then do it now.
 918                          */
 919                         if (*pID1 == MAX_RUP) {
 920                                 rio_dprintk(RIO_DEBUG_ROUTE, "Make tentative entry for first unit %d\n", unit);
 921                                 *pID1 = unit;
 922
 923                                 /*
 924                                  ** If the second ID is not needed then we can return
 925                                  ** now.
 926                                  */
 927                                 if (pID2 == NULL)
 928                                         return 0;
 929                         } else {
 930                                 /*
 931                                  ** Allocate the second slot and return.
 932                                  */
 933                                 rio_dprintk(RIO_DEBUG_ROUTE, "Make tentative entry for second unit %d\n", unit);
 934                                 *pID2 = unit;
 935                                 return 0;
 936                         }
 937                 }
 938         }
 939
 940         /*
 941          ** If we manage to come out of the free slot loop then we
 942          ** need to start all over again looking for tentative slots
 943          ** that we can re-use.
 944          */
 945         rio_dprintk(RIO_DEBUG_ROUTE, "Starting to scan for tentative slots\n");
 946         for (unit = 0; unit < MAX_RUP; unit++) {
 947                 if (((HostP->Mapping[unit].Flags & SLOT_TENTATIVE) || (HostP->Mapping[unit].Flags == 0)) && !(HostP->Mapping[unit].Flags & RTA16_SECOND_SLOT)) {
 948                         rio_dprintk(RIO_DEBUG_ROUTE, "    Slot %d looks promising.\n", unit);
 949
 950                         if (unit == *pID1) {
 951                                 rio_dprintk(RIO_DEBUG_ROUTE, "    No it isn't, its the 1st half\n");
 952                                 continue;
 953                         }
 954
 955                         /*
 956                          ** Slot is Tentative or Empty, but not a tentative second
 957                          ** slot of a 16 porter.
 958                          ** Attempt to free up this slot (and its parnter if
 959                          ** it is a 16 port slot. The second slot will become
 960                          ** empty after a call to RIOFreeDisconnected so thats why
 961                          ** we look for empty slots above  as well).
 962                          */
 963                         if (HostP->Mapping[unit].Flags != 0)
 964                                 if (RIOFreeDisconnected(p, HostP, unit) != 0)
 965                                         continue;
 966                         /*
 967                          ** If we haven't allocated the first ID then do it now.
 968                          */
 969                         if (*pID1 == MAX_RUP) {
 970                                 rio_dprintk(RIO_DEBUG_ROUTE, "Grab tentative entry for first unit %d\n", unit);
 971                                 *pID1 = unit;
 972
 973                                 /*
 974                                  ** Clear out this slot now that we intend to use it.
 975                                  */
 976                                 memset(&HostP->Mapping[unit], 0, sizeof(struct Map));
 977
 978                                 /*
 979                                  ** If the second ID is not needed then we can return
 980                                  ** now.
 981                                  */
 982                                 if (pID2 == NULL)
 983                                         return 0;
 984                         } else {
 985                                 /*
 986                                  ** Allocate the second slot and return.
 987                                  */
 988                                 rio_dprintk(RIO_DEBUG_ROUTE, "Grab tentative/empty  entry for second unit %d\n", unit);
 989                                 *pID2 = unit;
 990
 991                                 /*
 992                                  ** Clear out this slot now that we intend to use it.
 993                                  */
 994                                 memset(&HostP->Mapping[unit], 0, sizeof(struct Map));
 995
 996                                 /* At this point under the right(wrong?) conditions
 997                                  ** we may have a first unit ID being higher than the
 998                                  ** second unit ID. This is a bad idea if we are about
 999                                  ** to fill the slots with a 16 port RTA.
1000                                  ** Better check and swap them over.
1001                                  */
1002
1003                                 if (*pID1 > *pID2) {
1004                                         rio_dprintk(RIO_DEBUG_ROUTE, "Swapping IDS %d %d\n", *pID1, *pID2);
1005                                         tempID = *pID1;
1006                                         *pID1 = *pID2;
1007                                         *pID2 = tempID;
1008                                 }
1009                                 return 0;
1010                         }
1011                 }
1012         }
1013
1014         /*
1015          ** If we manage to get to the end of the second loop then we
1016          ** can give up and return a failure.
1017          */
1018         return 1;
1019 }
1020
1021
1022 /*
1023 ** The link switch scenario.
1024 **
1025 ** Rta Wun (A) is connected to Tuw (A).
1026 ** The tables are all up to date, and the system is OK.
1027 **
1028 ** If Wun (A) is now moved to Wun (B) before Wun (A) can
1029 ** become disconnected, then the follow happens:
1030 **
1031 ** Tuw (A) spots the change of unit:link at the other end
1032 ** of its link and Tuw sends a topology packet reflecting
1033 ** the change: Tuw (A) now disconnected from Wun (A), and
1034 ** this is closely followed by a packet indicating that
1035 ** Tuw (A) is now connected to Wun (B).
1036 **
1037 ** Wun (B) will spot that it has now become connected, and
1038 ** Wun will send a topology packet, which indicates that
1039 ** both Wun (A) and Wun (B) is connected to Tuw (A).
1040 **
1041 ** Eventually Wun (A) realises that it is now disconnected
1042 ** and Wun will send out a topology packet indicating that
1043 ** Wun (A) is now disconnected.
1044 */