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 #define __NO_VERSION__
37 #include <linux/module.h>
38 #include <linux/slab.h>
39 #include <linux/errno.h>
40 #include <asm/io.h>
41 #include <asm/system.h>
42 #include <asm/string.h>
43 #include <asm/semaphore.h>
44 #include <asm/uaccess.h>
45
46 #include <linux/termios.h>
47 #include <linux/serial.h>
48
49 #include <linux/compatmac.h>
50 #include <linux/generic_serial.h>
51
52
53 #include "linux_compat.h"
54 #include "rio_linux.h"
55 #include "typdef.h"
56 #include "pkt.h"
57 #include "daemon.h"
58 #include "rio.h"
59 #include "riospace.h"
60 #include "top.h"
61 #include "cmdpkt.h"
62 #include "map.h"
63 #include "riotypes.h"
64 #include "rup.h"
65 #include "port.h"
66 #include "riodrvr.h"
67 #include "rioinfo.h"
68 #include "func.h"
69 #include "errors.h"
70 #include "pci.h"
71
72 #include "parmmap.h"
73 #include "unixrup.h"
74 #include "board.h"
75 #include "host.h"
76 #include "error.h"
77 #include "phb.h"
78 #include "link.h"
79 #include "cmdblk.h"
80 #include "route.h"
81 #include "control.h"
82 #include "cirrus.h"
83 #include "rioioctl.h"
84 #include "param.h"
85 #include "list.h"
86 #include "sam.h"
87
88 /*
89 ** Incoming on the ROUTE_RUP
90 ** I wrote this while I was tired. Forgive me.
91 */
RIORouteRup(struct rio_info * p,uint Rup,struct Host * HostP,PKT * PacketP)92 int RIORouteRup( struct rio_info *p, uint Rup, struct Host *HostP, PKT *PacketP )
93 {
94 struct PktCmd *PktCmdP = (struct PktCmd *)PacketP->data;
95 struct PktCmd_M *PktReplyP;
96 struct CmdBlk *CmdBlkP;
97 struct Port *PortP;
98 struct Map *MapP;
99 struct Top *TopP;
100 int ThisLink, ThisLinkMin, ThisLinkMax;
101 int port;
102 int Mod, Mod1, Mod2;
103 ushort RtaType;
104 uint RtaUniq;
105 uint ThisUnit, ThisUnit2; /* 2 ids to accommodate 16 port RTA */
106 uint OldUnit, NewUnit, OldLink, NewLink;
107 char *MyType, *MyName;
108 int Lies;
109 unsigned long flags;
110
111 #ifdef STACK
112 RIOStackCheck("RIORouteRup");
113 #endif
114 #ifdef CHECK
115 CheckPacketP(PacketP);
116 CheckHostP(HostP);
117 CheckRup(Rup);
118 CheckHost(Host);
119 #endif
120 /*
121 ** Is this unit telling us it's current link topology?
122 */
123 if ( RBYTE(PktCmdP->Command) == ROUTE_TOPOLOGY )
124 {
125 MapP = HostP->Mapping;
126
127 /*
128 ** The packet can be sent either by the host or by an RTA.
129 ** If it comes from the host, then we need to fill in the
130 ** Topology array in the host structure. If it came in
131 ** from an RTA then we need to fill in the Mapping structure's
132 ** Topology array for the unit.
133 */
134 if ( Rup >= (ushort)MAX_RUP )
135 {
136 ThisUnit = HOST_ID;
137 TopP = HostP->Topology;
138 MyType = "Host";
139 MyName = HostP->Name;
140 ThisLinkMin = ThisLinkMax = Rup - MAX_RUP;
141 }
142 else
143 {
144 ThisUnit = Rup+1;
145 TopP = HostP->Mapping[Rup].Topology;
146 MyType = "RTA";
147 MyName = HostP->Mapping[Rup].Name;
148 ThisLinkMin = 0;
149 ThisLinkMax = LINKS_PER_UNIT - 1;
150 }
151
152 /*
153 ** Lies will not be tolerated.
154 ** If any pair of links claim to be connected to the same
155 ** place, then ignore this packet completely.
156 */
157 Lies = 0;
158 for ( ThisLink=ThisLinkMin + 1; ThisLink <= ThisLinkMax; ThisLink++)
159 {
160 /*
161 ** it won't lie about network interconnect, total disconnects
162 ** and no-IDs. (or at least, it doesn't *matter* if it does)
163 */
164 if ( RBYTE(PktCmdP->RouteTopology[ThisLink].Unit) > (ushort)MAX_RUP )
165 continue;
166
167 for ( NewLink=ThisLinkMin; NewLink < ThisLink; NewLink++ )
168 {
169 if ( (RBYTE(PktCmdP->RouteTopology[ThisLink].Unit) ==
170 RBYTE(PktCmdP->RouteTopology[NewLink].Unit)) &&
171 (RBYTE(PktCmdP->RouteTopology[ThisLink].Link) ==
172 RBYTE(PktCmdP->RouteTopology[NewLink].Link)) )
173 {
174 Lies++;
175 }
176 }
177 }
178
179 if ( Lies )
180 {
181 rio_dprintk (RIO_DEBUG_ROUTE, "LIES! DAMN LIES! %d LIES!\n",Lies);
182 rio_dprintk (RIO_DEBUG_ROUTE, "%d:%c %d:%c %d:%c %d:%c\n",
183 RBYTE(PktCmdP->RouteTopology[0].Unit),
184 'A'+RBYTE(PktCmdP->RouteTopology[0].Link),
185 RBYTE(PktCmdP->RouteTopology[1].Unit),
186 'A'+RBYTE(PktCmdP->RouteTopology[1].Link),
187 RBYTE(PktCmdP->RouteTopology[2].Unit),
188 'A'+RBYTE(PktCmdP->RouteTopology[2].Link),
189 RBYTE(PktCmdP->RouteTopology[3].Unit),
190 'A'+RBYTE(PktCmdP->RouteTopology[3].Link));
191 return TRUE;
192 }
193
194 /*
195 ** now, process each link.
196 */
197 for ( ThisLink=ThisLinkMin; ThisLink <= ThisLinkMax; ThisLink++)
198 {
199 /*
200 ** this is what it was connected to
201 */
202 OldUnit = TopP[ThisLink].Unit;
203 OldLink = TopP[ThisLink].Link;
204
205 /*
206 ** this is what it is now connected to
207 */
208 NewUnit = RBYTE(PktCmdP->RouteTopology[ThisLink].Unit);
209 NewLink = RBYTE(PktCmdP->RouteTopology[ThisLink].Link);
210
211 if ( OldUnit != NewUnit || OldLink != NewLink )
212 {
213 /*
214 ** something has changed!
215 */
216
217 if ( NewUnit > MAX_RUP &&
218 NewUnit != ROUTE_DISCONNECT &&
219 NewUnit != ROUTE_NO_ID &&
220 NewUnit != ROUTE_INTERCONNECT )
221 {
222 rio_dprintk (RIO_DEBUG_ROUTE, "I have a link from %s %s to unit %d:%d - I don't like it.\n",
223 MyType,
224 MyName,
225 NewUnit,
226 NewLink);
227 }
228 else
229 {
230 /*
231 ** put the new values in
232 */
233 TopP[ThisLink].Unit = NewUnit;
234 TopP[ThisLink].Link = NewLink;
235
236 RIOSetChange(p);
237
238 if ( OldUnit <= MAX_RUP )
239 {
240 /*
241 ** If something has become bust, then re-enable them messages
242 */
243 if (! p->RIONoMessage)
244 RIOConCon(p,HostP,ThisUnit,ThisLink,OldUnit,OldLink,DISCONNECT);
245 }
246
247 if ( ( NewUnit <= MAX_RUP ) && !p->RIONoMessage )
248 RIOConCon(p,HostP,ThisUnit,ThisLink,NewUnit,NewLink,CONNECT);
249
250 if ( NewUnit == ROUTE_NO_ID )
251 rio_dprintk (RIO_DEBUG_ROUTE, "%s %s (%c) is connected to an unconfigured unit.\n",
252 MyType,MyName,'A'+ThisLink);
253
254 if ( NewUnit == ROUTE_INTERCONNECT )
255 {
256 if (! p->RIONoMessage)
257 cprintf("%s '%s' (%c) is connected to another network.\n", MyType,MyName,'A'+ThisLink);
258 }
259
260 /*
261 ** perform an update for 'the other end', so that these messages
262 ** only appears once. Only disconnect the other end if it is pointing
263 ** at us!
264 */
265 if ( OldUnit == HOST_ID )
266 {
267 if ( HostP->Topology[OldLink].Unit == ThisUnit &&
268 HostP->Topology[OldLink].Link == ThisLink )
269 {
270 rio_dprintk (RIO_DEBUG_ROUTE, "SETTING HOST (%c) TO DISCONNECTED!\n", OldLink+'A');
271 HostP->Topology[OldLink].Unit = ROUTE_DISCONNECT;
272 HostP->Topology[OldLink].Link = NO_LINK;
273 }
274 else
275 {
276 rio_dprintk (RIO_DEBUG_ROUTE, "HOST(%c) WAS NOT CONNECTED TO %s (%c)!\n",
277 OldLink+'A',HostP->Mapping[ThisUnit-1].Name,ThisLink+'A');
278 }
279 }
280 else if ( OldUnit <= MAX_RUP )
281 {
282 if ( HostP->Mapping[OldUnit-1].Topology[OldLink].Unit == ThisUnit &&
283 HostP->Mapping[OldUnit-1].Topology[OldLink].Link == ThisLink )
284 {
285 rio_dprintk (RIO_DEBUG_ROUTE, "SETTING RTA %s (%c) TO DISCONNECTED!\n",
286 HostP->Mapping[OldUnit-1].Name,OldLink+'A');
287 HostP->Mapping[OldUnit-1].Topology[OldLink].Unit=ROUTE_DISCONNECT;
288 HostP->Mapping[OldUnit-1].Topology[OldLink].Link=NO_LINK;
289 }
290 else
291 {
292 rio_dprintk (RIO_DEBUG_ROUTE, "RTA %s (%c) WAS NOT CONNECTED TO %s (%c)\n",
293 HostP->Mapping[OldUnit-1].Name,OldLink+'A',
294 HostP->Mapping[ThisUnit-1].Name,ThisLink+'A');
295 }
296 }
297 if ( NewUnit == HOST_ID )
298 {
299 rio_dprintk (RIO_DEBUG_ROUTE, "MARKING HOST (%c) CONNECTED TO %s (%c)\n",
300 NewLink+'A',MyName,ThisLink+'A');
301 HostP->Topology[NewLink].Unit = ThisUnit;
302 HostP->Topology[NewLink].Link = ThisLink;
303 }
304 else if ( NewUnit <= MAX_RUP )
305 {
306 rio_dprintk (RIO_DEBUG_ROUTE, "MARKING RTA %s (%c) CONNECTED TO %s (%c)\n",
307 HostP->Mapping[NewUnit-1].Name,NewLink+'A',MyName,ThisLink+'A');
308 HostP->Mapping[NewUnit-1].Topology[NewLink].Unit=ThisUnit;
309 HostP->Mapping[NewUnit-1].Topology[NewLink].Link=ThisLink;
310 }
311 }
312 RIOSetChange(p);
313 RIOCheckIsolated(p, HostP, OldUnit );
314 }
315 }
316 return TRUE;
317 }
318
319 /*
320 ** The only other command we recognise is a route_request command
321 */
322 if ( RBYTE(PktCmdP->Command) != ROUTE_REQUEST )
323 {
324 rio_dprintk (RIO_DEBUG_ROUTE, "Unknown command %d received on rup %d host %d ROUTE_RUP\n",
325 RBYTE(PktCmdP->Command),Rup,(int)HostP);
326 return TRUE;
327 }
328
329 RtaUniq = (RBYTE(PktCmdP->UniqNum[0])) +
330 (RBYTE(PktCmdP->UniqNum[1]) << 8) +
331 (RBYTE(PktCmdP->UniqNum[2]) << 16) +
332 (RBYTE(PktCmdP->UniqNum[3]) << 24);
333
334 /*
335 ** Determine if 8 or 16 port RTA
336 */
337 RtaType = GetUnitType(RtaUniq);
338
339 rio_dprintk (RIO_DEBUG_ROUTE, "Received a request for an ID for serial number %x\n", RtaUniq);
340
341 Mod = RBYTE(PktCmdP->ModuleTypes);
342 Mod1 = LONYBLE(Mod);
343 if (RtaType == TYPE_RTA16)
344 {
345 /*
346 ** Only one ident is set for a 16 port RTA. To make compatible
347 ** with 8 port, set 2nd ident in Mod2 to the same as Mod1.
348 */
349 Mod2 = Mod1;
350 rio_dprintk (RIO_DEBUG_ROUTE, "Backplane type is %s (all ports)\n",
351 p->RIOModuleTypes[Mod1].Name);
352 }
353 else
354 {
355 Mod2 = HINYBLE(Mod);
356 rio_dprintk (RIO_DEBUG_ROUTE, "Module types are %s (ports 0-3) and %s (ports 4-7)\n",
357 p->RIOModuleTypes[Mod1].Name, p->RIOModuleTypes[Mod2].Name);
358 }
359
360 if ( RtaUniq == 0xffffffff )
361 {
362 ShowPacket( DBG_SPECIAL, PacketP );
363 }
364
365 /*
366 ** try to unhook a command block from the command free list.
367 */
368 if ( !(CmdBlkP = RIOGetCmdBlk()) )
369 {
370 rio_dprintk (RIO_DEBUG_ROUTE, "No command blocks to route RTA! come back later.\n");
371 return 0;
372 }
373
374 /*
375 ** Fill in the default info on the command block
376 */
377 CmdBlkP->Packet.dest_unit = Rup;
378 CmdBlkP->Packet.dest_port = ROUTE_RUP;
379 CmdBlkP->Packet.src_unit = HOST_ID;
380 CmdBlkP->Packet.src_port = ROUTE_RUP;
381 CmdBlkP->Packet.len = PKT_CMD_BIT | 1;
382 CmdBlkP->PreFuncP = CmdBlkP->PostFuncP = NULL;
383 PktReplyP = (struct PktCmd_M *)CmdBlkP->Packet.data;
384
385 if (! RIOBootOk(p, HostP, RtaUniq))
386 {
387 rio_dprintk (RIO_DEBUG_ROUTE, "RTA %x tried to get an ID, but does not belong - FOAD it!\n",
388 RtaUniq);
389 PktReplyP->Command = ROUTE_FOAD;
390 HostP->Copy("RT_FOAD", PktReplyP->CommandText, 7);
391 RIOQueueCmdBlk(HostP, Rup, CmdBlkP);
392 return TRUE;
393 }
394
395 /*
396 ** Check to see if the RTA is configured for this host
397 */
398 for ( ThisUnit=0; ThisUnit<MAX_RUP; ThisUnit++ )
399 {
400 rio_dprintk (RIO_DEBUG_ROUTE, "Entry %d Flags=%s %s UniqueNum=0x%x\n",
401 ThisUnit,
402 HostP->Mapping[ThisUnit].Flags & SLOT_IN_USE ?
403 "Slot-In-Use":"Not In Use",
404 HostP->Mapping[ThisUnit].Flags & SLOT_TENTATIVE ?
405 "Slot-Tentative":"Not Tentative",
406 HostP->Mapping[ThisUnit].RtaUniqueNum);
407
408 /*
409 ** We have an entry for it.
410 */
411 if ( (HostP->Mapping[ThisUnit].Flags & (SLOT_IN_USE | SLOT_TENTATIVE)) &&
412 (HostP->Mapping[ThisUnit].RtaUniqueNum == RtaUniq) )
413 {
414 if (RtaType == TYPE_RTA16)
415 {
416 ThisUnit2 = HostP->Mapping[ThisUnit].ID2 - 1;
417 rio_dprintk (RIO_DEBUG_ROUTE, "Found unit 0x%x at slots %d+%d\n",
418 RtaUniq,ThisUnit,ThisUnit2);
419 }
420 else
421 rio_dprintk (RIO_DEBUG_ROUTE, "Found unit 0x%x at slot %d\n",
422 RtaUniq,ThisUnit);
423 /*
424 ** If we have no knowledge of booting it, then the host has
425 ** been re-booted, and so we must kill the RTA, so that it
426 ** will be booted again (potentially with new bins)
427 ** and it will then re-ask for an ID, which we will service.
428 */
429 if ( (HostP->Mapping[ThisUnit].Flags & SLOT_IN_USE) &&
430 !(HostP->Mapping[ThisUnit].Flags & RTA_BOOTED) )
431 {
432 if ( !(HostP->Mapping[ThisUnit].Flags & MSG_DONE) )
433 {
434 if ( !p->RIONoMessage )
435 cprintf("RTA '%s' is being updated.\n",HostP->Mapping[ThisUnit].Name);
436 HostP->Mapping[ThisUnit].Flags |= MSG_DONE;
437 }
438 PktReplyP->Command = ROUTE_FOAD;
439 HostP->Copy("RT_FOAD",PktReplyP->CommandText,7);
440 RIOQueueCmdBlk(HostP, Rup, CmdBlkP);
441 return TRUE;
442 }
443
444 /*
445 ** Send the ID (entry) to this RTA. The ID number is implicit as
446 ** the offset into the table. It is worth noting at this stage
447 ** that offset zero in the table contains the entries for the
448 ** RTA with ID 1!!!!
449 */
450 PktReplyP->Command = ROUTE_ALLOCATE;
451 PktReplyP->IDNum = ThisUnit+1;
452 if (RtaType == TYPE_RTA16)
453 {
454 if (HostP->Mapping[ThisUnit].Flags & SLOT_IN_USE)
455 /*
456 ** Adjust the phb and tx pkt dest_units for 2nd block of 8
457 ** only if the RTA has ports associated (SLOT_IN_USE)
458 */
459 RIOFixPhbs(p, HostP, ThisUnit2);
460 PktReplyP->IDNum2 = ThisUnit2+1;
461 rio_dprintk (RIO_DEBUG_ROUTE, "RTA '%s' has been allocated IDs %d+%d\n",
462 HostP->Mapping[ThisUnit].Name, PktReplyP->IDNum, PktReplyP->IDNum2);
463 }
464 else
465 {
466 PktReplyP->IDNum2 = ROUTE_NO_ID;
467 rio_dprintk (RIO_DEBUG_ROUTE, "RTA '%s' has been allocated ID %d\n",
468 HostP->Mapping[ThisUnit].Name,PktReplyP->IDNum);
469 }
470 HostP->Copy("RT_ALLOCAT",PktReplyP->CommandText,10);
471
472 RIOQueueCmdBlk( HostP, Rup, CmdBlkP);
473
474 /*
475 ** If this is a freshly booted RTA, then we need to re-open
476 ** the ports, if any where open, so that data may once more
477 ** flow around the system!
478 */
479 if ( (HostP->Mapping[ThisUnit].Flags & RTA_NEWBOOT) &&
480 (HostP->Mapping[ThisUnit].SysPort != NO_PORT) )
481 {
482 /*
483 ** look at the ports associated with this beast and
484 ** see if any where open. If they was, then re-open
485 ** them, using the info from the tty flags.
486 */
487 for ( port=0; port<PORTS_PER_RTA; port++ )
488 {
489 PortP = p->RIOPortp[port+HostP->Mapping[ThisUnit].SysPort];
490 if ( PortP->State & (RIO_MOPEN|RIO_LOPEN) )
491 {
492 rio_dprintk (RIO_DEBUG_ROUTE, "Re-opened this port\n");
493 rio_spin_lock_irqsave(&PortP->portSem, flags);
494 PortP->MagicFlags |= MAGIC_REBOOT;
495 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
496 }
497 }
498 if (RtaType == TYPE_RTA16)
499 {
500 for ( port=0; port<PORTS_PER_RTA; port++ )
501 {
502 PortP = p->RIOPortp[port+HostP->Mapping[ThisUnit2].SysPort];
503 if ( PortP->State & (RIO_MOPEN|RIO_LOPEN) )
504 {
505 rio_dprintk (RIO_DEBUG_ROUTE, "Re-opened this port\n");
506 rio_spin_lock_irqsave(&PortP->portSem, flags);
507 PortP->MagicFlags |= MAGIC_REBOOT;
508 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
509 }
510 }
511 }
512 }
513
514 /*
515 ** keep a copy of the module types!
516 */
517 HostP->UnixRups[ThisUnit].ModTypes = Mod;
518 if (RtaType == TYPE_RTA16)
519 HostP->UnixRups[ThisUnit2].ModTypes = Mod;
520
521 /*
522 ** If either of the modules on this unit is read-only or write-only
523 ** or none-xprint, then we need to transfer that info over to the
524 ** relevent ports.
525 */
526 if ( HostP->Mapping[ThisUnit].SysPort != NO_PORT )
527 {
528 for ( port=0; port<PORTS_PER_MODULE; port++ )
529 {
530 p->RIOPortp[port+HostP->Mapping[ThisUnit].SysPort]->Config &= ~RIO_NOMASK;
531 p->RIOPortp[port+HostP->Mapping[ThisUnit].SysPort]->Config |=
532 p->RIOModuleTypes[Mod1].Flags[port];
533 p->RIOPortp[port+PORTS_PER_MODULE+HostP->Mapping[ThisUnit].SysPort]->Config &= ~RIO_NOMASK;
534 p->RIOPortp[port+PORTS_PER_MODULE+HostP->Mapping[ThisUnit].SysPort]->Config |= p->RIOModuleTypes[Mod2].Flags[port];
535 }
536 if (RtaType == TYPE_RTA16)
537 {
538 for ( port=0; port<PORTS_PER_MODULE; port++ )
539 {
540 p->RIOPortp[port+HostP->Mapping[ThisUnit2].SysPort]->Config &= ~RIO_NOMASK;
541 p->RIOPortp[port+HostP->Mapping[ThisUnit2].SysPort]->Config |= p->RIOModuleTypes[Mod1].Flags[port];
542 p->RIOPortp[port+PORTS_PER_MODULE+HostP->Mapping[ThisUnit2].SysPort]->Config &= ~RIO_NOMASK;
543 p->RIOPortp[port+PORTS_PER_MODULE+HostP->Mapping[ThisUnit2].SysPort]->Config |= p->RIOModuleTypes[Mod2].Flags[port];
544 }
545 }
546 }
547
548 /*
549 ** Job done, get on with the interrupts!
550 */
551 return TRUE;
552 }
553 }
554 /*
555 ** There is no table entry for this RTA at all.
556 **
557 ** Lets check to see if we actually booted this unit - if not,
558 ** then we reset it and it will go round the loop of being booted
559 ** we can then worry about trying to fit it into the table.
560 */
561 for ( ThisUnit=0; ThisUnit<HostP->NumExtraBooted; ThisUnit++ )
562 if ( HostP->ExtraUnits[ThisUnit] == RtaUniq )
563 break;
564 if ( ThisUnit == HostP->NumExtraBooted && ThisUnit != MAX_EXTRA_UNITS )
565 {
566 /*
567 ** if the unit wasn't in the table, and the table wasn't full, then
568 ** we reset the unit, because we didn't boot it.
569 ** However, if the table is full, it could be that we did boot
570 ** this unit, and so we won't reboot it, because it isn't really
571 ** all that disasterous to keep the old bins in most cases. This
572 ** is a rather tacky feature, but we are on the edge of reallity
573 ** here, because the implication is that someone has connected
574 ** 16+MAX_EXTRA_UNITS onto one host.
575 */
576 static int UnknownMesgDone = 0;
577
578 if ( !UnknownMesgDone )
579 {
580 if (! p->RIONoMessage)
581 cprintf("One or more unknown RTAs are being updated.\n");
582 UnknownMesgDone = 1;
583 }
584
585 PktReplyP->Command = ROUTE_FOAD;
586 HostP->Copy("RT_FOAD",PktReplyP->CommandText,7);
587 }
588 else
589 {
590 /*
591 ** we did boot it (as an extra), and there may now be a table
592 ** slot free (because of a delete), so we will try to make
593 ** a tentative entry for it, so that the configurator can see it
594 ** and fill in the details for us.
595 */
596 if (RtaType == TYPE_RTA16)
597 {
598 if (RIOFindFreeID(p, HostP, &ThisUnit, &ThisUnit2) == 0)
599 {
600 RIODefaultName(p, HostP, ThisUnit);
601 FillSlot(ThisUnit, ThisUnit2, RtaUniq, HostP);
602 }
603 }
604 else
605 {
606 if (RIOFindFreeID(p, HostP, &ThisUnit, NULL) == 0)
607 {
608 RIODefaultName(p, HostP, ThisUnit);
609 FillSlot(ThisUnit, 0, RtaUniq, HostP);
610 }
611 }
612 PktReplyP->Command = ROUTE_USED;
613 HostP->Copy("RT_USED",PktReplyP->CommandText,7);
614 }
615 RIOQueueCmdBlk( HostP, Rup, CmdBlkP);
616 return TRUE;
617 }
618
619
620 void
RIOFixPhbs(p,HostP,unit)621 RIOFixPhbs(p, HostP, unit)
622 struct rio_info *p;
623 struct Host *HostP;
624 uint unit;
625 {
626 ushort link, port;
627 struct Port *PortP;
628 unsigned long flags;
629 int PortN = HostP->Mapping[unit].SysPort;
630
631 rio_dprintk (RIO_DEBUG_ROUTE, "RIOFixPhbs unit %d sysport %d\n", unit, PortN);
632
633 if (PortN != -1) {
634 ushort dest_unit = HostP->Mapping[unit].ID2;
635
636 /*
637 ** Get the link number used for the 1st 8 phbs on this unit.
638 */
639 PortP = p->RIOPortp[HostP->Mapping[dest_unit - 1].SysPort];
640
641 link = RWORD(PortP->PhbP->link);
642
643 for (port = 0; port < PORTS_PER_RTA; port++, PortN++) {
644 ushort dest_port = port + 8;
645 #if 0
646 uint PktInt;
647 #endif
648 WORD *TxPktP;
649 PKT *Pkt;
650
651 PortP = p->RIOPortp[PortN];
652
653 rio_spin_lock_irqsave(&PortP->portSem, flags);
654 /*
655 ** If RTA is not powered on, the tx packets will be
656 ** unset, so go no further.
657 */
658 if (PortP->TxStart == 0) {
659 rio_dprintk (RIO_DEBUG_ROUTE, "Tx pkts not set up yet\n");
660 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
661 break;
662 }
663
664 /*
665 ** For the second slot of a 16 port RTA, the driver needs to
666 ** sort out the phb to port mappings. The dest_unit for this
667 ** group of 8 phbs is set to the dest_unit of the accompanying
668 ** 8 port block. The dest_port of the second unit is set to
669 ** be in the range 8-15 (i.e. 8 is added). Thus, for a 16 port
670 ** RTA with IDs 5 and 6, traffic bound for port 6 of unit 6
671 ** (being the second map ID) will be sent to dest_unit 5, port
672 ** 14. When this RTA is deleted, dest_unit for ID 6 will be
673 ** restored, and the dest_port will be reduced by 8.
674 ** Transmit packets also have a destination field which needs
675 ** adjusting in the same manner.
676 ** Note that the unit/port bytes in 'dest' are swapped.
677 ** We also need to adjust the phb and rup link numbers for the
678 ** second block of 8 ttys.
679 */
680 for (TxPktP = PortP->TxStart; TxPktP <= PortP->TxEnd; TxPktP++) {
681 /*
682 ** *TxPktP is the pointer to the transmit packet on the host
683 ** card. This needs to be translated into a 32 bit pointer
684 ** so it can be accessed from the driver.
685 */
686 Pkt = (PKT *) RIO_PTR(HostP->Caddr,RINDW(TxPktP));
687
688 /*
689 ** If the packet is used, reset it.
690 */
691 Pkt = (PKT *)((uint)Pkt & ~PKT_IN_USE);
692 WBYTE(Pkt->dest_unit, dest_unit);
693 WBYTE(Pkt->dest_port, dest_port);
694 }
695 rio_dprintk (RIO_DEBUG_ROUTE, "phb dest: Old %x:%x New %x:%x\n",
696 RWORD(PortP->PhbP->destination) & 0xff,
697 (RWORD(PortP->PhbP->destination) >> 8) & 0xff,
698 dest_unit, dest_port);
699 WWORD(PortP->PhbP->destination, dest_unit + (dest_port << 8));
700 WWORD(PortP->PhbP->link, link);
701
702 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
703 }
704 /*
705 ** Now make sure the range of ports to be serviced includes
706 ** the 2nd 8 on this 16 port RTA.
707 */
708 if (link > 3) return;
709 if (((unit * 8) + 7) > RWORD(HostP->LinkStrP[link].last_port)) {
710 rio_dprintk (RIO_DEBUG_ROUTE, "last port on host link %d: %d\n", link, (unit * 8) + 7);
711 WWORD(HostP->LinkStrP[link].last_port, (unit * 8) + 7);
712 }
713 }
714 }
715
716 /*
717 ** Check to see if the new disconnection has isolated this unit.
718 ** If it has, then invalidate all its link information, and tell
719 ** the world about it. This is done to ensure that the configurator
720 ** only gets up-to-date information about what is going on.
721 */
722 int
RIOCheckIsolated(p,HostP,UnitId)723 RIOCheckIsolated(p, HostP, UnitId)
724 struct rio_info * p;
725 struct Host *HostP;
726 uint UnitId;
727 {
728 unsigned long flags;
729 rio_spin_lock_irqsave(&HostP->HostLock, flags);
730
731 #ifdef CHECK
732 CheckHostP( HostP );
733 CheckUnitId( UnitId );
734 #endif
735 if ( RIOCheck( HostP, UnitId ) ) {
736 rio_dprintk (RIO_DEBUG_ROUTE, "Unit %d is NOT isolated\n", UnitId);
737 rio_spin_unlock_irqrestore(&HostP->HostLock, flags);
738 return(0);
739 }
740
741 RIOIsolate(p, HostP, UnitId );
742 RIOSetChange(p);
743 rio_spin_unlock_irqrestore(&HostP->HostLock, flags);
744 return 1;
745 }
746
747 /*
748 ** Invalidate all the link interconnectivity of this unit, and of
749 ** all the units attached to it. This will mean that the entire
750 ** subnet will re-introduce itself.
751 */
752 int
RIOIsolate(p,HostP,UnitId)753 RIOIsolate(p, HostP, UnitId)
754 struct rio_info * p;
755 struct Host * HostP;
756 uint UnitId;
757 {
758 uint link, unit;
759
760 #ifdef CHECK
761 CheckHostP( HostP );
762 CheckUnitId( UnitId );
763 #endif
764 UnitId--; /* this trick relies on the Unit Id being UNSIGNED! */
765
766 if ( UnitId > MAX_RUP ) /* dontcha just lurv unsigned maths! */
767 return(0);
768
769 if ( HostP->Mapping[UnitId].Flags & BEEN_HERE )
770 return(0);
771
772 HostP->Mapping[UnitId].Flags |= BEEN_HERE;
773
774 if ( p->RIOPrintDisabled == DO_PRINT )
775 rio_dprintk (RIO_DEBUG_ROUTE, "RIOMesgIsolated %s", HostP->Mapping[UnitId].Name);
776
777 for ( link=0; link<LINKS_PER_UNIT; link++) {
778 unit = HostP->Mapping[UnitId].Topology[link].Unit;
779 HostP->Mapping[UnitId].Topology[link].Unit = ROUTE_DISCONNECT;
780 HostP->Mapping[UnitId].Topology[link].Link = NO_LINK;
781 RIOIsolate(p, HostP, unit );
782 }
783 HostP->Mapping[UnitId].Flags &= ~BEEN_HERE;
784 return 1;
785 }
786
787 int
RIOCheck(HostP,UnitId)788 RIOCheck(HostP, UnitId)
789 struct Host *HostP;
790 uint UnitId;
791 {
792 unsigned char link;
793
794 #ifdef CHECK
795 CheckHostP( HostP );
796 CheckUnitId( UnitId );
797 #endif
798 /* rio_dprint(RIO_DEBUG_ROUTE, ("Check to see if unit %d has a route to the host\n",UnitId)); */
799 rio_dprintk (RIO_DEBUG_ROUTE, "RIOCheck : UnitID = %d\n", UnitId);
800
801 if ( UnitId == HOST_ID ) {
802 /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d is NOT isolated - it IS the host!\n", UnitId)); */
803 return 1;
804 }
805
806 UnitId--;
807
808 if ( UnitId >= MAX_RUP ) {
809 /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d - ignored.\n", UnitId)); */
810 return 0;
811 }
812
813 for ( link=0; link<LINKS_PER_UNIT; link++ ) {
814 if ( HostP->Mapping[UnitId].Topology[link].Unit==HOST_ID ) {
815 /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d is connected directly to host via link (%c).\n",
816 UnitId, 'A'+link)); */
817 return 1;
818 }
819 }
820
821 if ( HostP->Mapping[UnitId].Flags & BEEN_HERE ) {
822 /* rio_dprint(RIO_DEBUG_ROUTE, ("Been to Unit %d before - ignoring\n", UnitId)); */
823 return 0;
824 }
825
826 HostP->Mapping[UnitId].Flags |= BEEN_HERE;
827
828 for ( link=0; link < LINKS_PER_UNIT; link++ ) {
829 /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d check link (%c)\n", UnitId,'A'+link)); */
830 if ( RIOCheck( HostP, HostP->Mapping[UnitId].Topology[link].Unit ) ) {
831 /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d is connected to something that knows the host via link (%c)\n", UnitId,link+'A')); */
832 HostP->Mapping[UnitId].Flags &= ~BEEN_HERE;
833 return 1;
834 }
835 }
836
837 HostP->Mapping[UnitId].Flags &= ~BEEN_HERE;
838
839 /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d DOESNT KNOW THE HOST!\n", UnitId)); */
840
841 return 0;
842 }
843
844 /*
845 ** Returns the type of unit (host, 16/8 port RTA)
846 */
847
848 uint
GetUnitType(Uniq)849 GetUnitType(Uniq)
850 uint Uniq;
851 {
852 switch ( (Uniq >> 28) & 0xf)
853 {
854 case RIO_AT:
855 case RIO_MCA:
856 case RIO_EISA:
857 case RIO_PCI:
858 rio_dprintk (RIO_DEBUG_ROUTE, "Unit type: Host\n");
859 return(TYPE_HOST);
860 case RIO_RTA_16:
861 rio_dprintk (RIO_DEBUG_ROUTE, "Unit type: 16 port RTA\n");
862 return(TYPE_RTA16);
863 case RIO_RTA:
864 rio_dprintk (RIO_DEBUG_ROUTE, "Unit type: 8 port RTA\n");
865 return(TYPE_RTA8);
866 default :
867 rio_dprintk (RIO_DEBUG_ROUTE, "Unit type: Unrecognised\n");
868 return(99);
869 }
870 }
871
872 int
RIOSetChange(p)873 RIOSetChange(p)
874 struct rio_info * p;
875 {
876 if ( p->RIOQuickCheck != NOT_CHANGED )
877 return(0);
878 p->RIOQuickCheck = CHANGED;
879 if ( p->RIOSignalProcess ) {
880 rio_dprintk (RIO_DEBUG_ROUTE, "Send SIG-HUP");
881 /*
882 psignal( RIOSignalProcess, SIGHUP );
883 */
884 }
885 return(0);
886 }
887
888 void
RIOConCon(p,HostP,FromId,FromLink,ToId,ToLink,Change)889 RIOConCon(p, HostP, FromId, FromLink, ToId, ToLink, Change)
890 struct rio_info * p;
891 struct Host *HostP;
892 uint FromId;
893 uint FromLink;
894 uint ToId;
895 uint ToLink;
896 int Change;
897 {
898 char *FromName;
899 char *FromType;
900 char *ToName;
901 char *ToType;
902 unsigned int tp;
903
904 /*
905 ** 15.10.1998 ARG - ESIL 0759
906 ** (Part) fix for port being trashed when opened whilst RTA "disconnected"
907 **
908 ** What's this doing in here anyway ?
909 ** It was causing the port to be 'unmapped' if opened whilst RTA "disconnected"
910 **
911 ** 09.12.1998 ARG - ESIL 0776 - part fix
912 ** Okay, We've found out what this was all about now !
913 ** Someone had botched this to use RIOHalted to indicated the number of RTAs
914 ** 'disconnected'. The value in RIOHalted was then being used in the
915 ** 'RIO_QUICK_CHECK' ioctl. A none zero value indicating that a least one RTA
916 ** is 'disconnected'. The change was put in to satisfy a customer's needs.
917 ** Having taken this bit of code out 'RIO_QUICK_CHECK' now no longer works for
918 ** the customer.
919 **
920 if (Change == CONNECT) {
921 if (p->RIOHalted) p->RIOHalted --;
922 }
923 else {
924 p->RIOHalted ++;
925 }
926 **
927 ** So - we need to implement it slightly differently - a new member of the
928 ** rio_info struct - RIORtaDisCons (RIO RTA connections) keeps track of RTA
929 ** connections and disconnections.
930 */
931 if (Change == CONNECT) {
932 if (p->RIORtaDisCons) p->RIORtaDisCons--;
933 }
934 else {
935 p->RIORtaDisCons++;
936 }
937
938 if ( p->RIOPrintDisabled == DONT_PRINT )
939 return;
940
941 if ( FromId > ToId ) {
942 tp = FromId;
943 FromId = ToId;
944 ToId = tp;
945 tp = FromLink;
946 FromLink = ToLink;
947 ToLink = tp;
948 }
949
950 FromName = FromId ? HostP->Mapping[FromId-1].Name : HostP->Name;
951 FromType = FromId ? "RTA" : "HOST";
952 ToName = ToId ? HostP->Mapping[ToId-1].Name : HostP->Name;
953 ToType = ToId ? "RTA" : "HOST";
954
955 rio_dprintk (RIO_DEBUG_ROUTE, "Link between %s '%s' (%c) and %s '%s' (%c) %s.\n",
956 FromType, FromName, 'A'+FromLink,
957 ToType, ToName, 'A'+ToLink,
958 (Change==CONNECT) ? "established" : "disconnected");
959 cprintf("Link between %s '%s' (%c) and %s '%s' (%c) %s.\n",
960 FromType, FromName, 'A'+FromLink,
961 ToType, ToName, 'A'+ToLink,
962 (Change==CONNECT) ? "established" : "disconnected");
963 }
964
965 /*
966 ** RIORemoveFromSavedTable :
967 **
968 ** Delete and RTA entry from the saved table given to us
969 ** by the configuration program.
970 */
971 int
RIORemoveFromSavedTable(struct rio_info * p,struct Map * pMap)972 RIORemoveFromSavedTable(struct rio_info *p, struct Map *pMap)
973 {
974 int entry;
975
976 /*
977 ** We loop for all entries even after finding an entry and
978 ** zeroing it because we may have two entries to delete if
979 ** its a 16 port RTA.
980 */
981 for (entry = 0; entry < TOTAL_MAP_ENTRIES; entry++)
982 {
983 if (p->RIOSavedTable[entry].RtaUniqueNum == pMap->RtaUniqueNum)
984 {
985 bzero((caddr_t)&p->RIOSavedTable[entry], sizeof(struct Map));
986 }
987 }
988 return 0;
989 }
990
991
992 /*
993 ** RIOCheckDisconnected :
994 **
995 ** Scan the unit links to and return zero if the unit is completely
996 ** disconnected.
997 */
998 int
RIOFreeDisconnected(struct rio_info * p,struct Host * HostP,int unit)999 RIOFreeDisconnected(struct rio_info *p, struct Host *HostP, int unit)
1000 {
1001 int link;
1002
1003
1004 rio_dprintk (RIO_DEBUG_ROUTE, "RIOFreeDisconnect unit %d\n", unit);
1005 /*
1006 ** If the slot is tentative and does not belong to the
1007 ** second half of a 16 port RTA then scan to see if
1008 ** is disconnected.
1009 */
1010 for (link = 0; link < LINKS_PER_UNIT; link++)
1011 {
1012 if (HostP->Mapping[unit].Topology[link].Unit != ROUTE_DISCONNECT)
1013 break;
1014 }
1015
1016 /*
1017 ** If not all links are disconnected then we can forget about it.
1018 */
1019 if (link < LINKS_PER_UNIT)
1020 return 1;
1021
1022 #if NEED_TO_FIX_THIS
1023 /* Ok so all the links are disconnected. But we may have only just
1024 ** made this slot tentative and not yet received a topology update.
1025 ** Lets check how long ago we made it tentative.
1026 */
1027 rio_dprintk (RIO_DEBUG_ROUTE, "Just about to check LBOLT on entry %d\n", unit);
1028 if (drv_getparm(LBOLT, (ulong_t *) ¤t_time))
1029 rio_dprintk (RIO_DEBUG_ROUTE, "drv_getparm(LBOLT,....) Failed.\n");
1030
1031 elapse_time = current_time - TentTime[unit];
1032 rio_dprintk (RIO_DEBUG_ROUTE, "elapse %d = current %d - tent %d (%d usec)\n",
1033 elapse_time, current_time, TentTime[unit], drv_hztousec(elapse_time));
1034 if (drv_hztousec(elapse_time) < WAIT_TO_FINISH)
1035 {
1036 rio_dprintk (RIO_DEBUG_ROUTE, "Skipping slot %d, not timed out yet %d\n",
1037 unit, drv_hztousec(elapse_time));
1038 return 1;
1039 }
1040 #endif
1041
1042 /*
1043 ** We have found an usable slot.
1044 ** If it is half of a 16 port RTA then delete the other half.
1045 */
1046 if (HostP->Mapping[unit].ID2 != 0)
1047 {
1048 int nOther = (HostP->Mapping[unit].ID2) -1;
1049
1050 rio_dprintk (RIO_DEBUG_ROUTE, "RioFreedis second slot %d.\n", nOther);
1051 bzero((caddr_t)&HostP->Mapping[nOther], sizeof(struct Map));
1052 }
1053 RIORemoveFromSavedTable(p, &HostP->Mapping[unit]);
1054
1055 return 0;
1056 }
1057
1058
1059 /*
1060 ** RIOFindFreeID :
1061 **
1062 ** This function scans the given host table for either one
1063 ** or two free unit ID's.
1064 */
1065 int
RIOFindFreeID(struct rio_info * p,struct Host * HostP,uint * pID1,uint * pID2)1066 RIOFindFreeID(struct rio_info *p, struct Host *HostP, uint *pID1, uint *pID2)
1067 {
1068 int unit,tempID;
1069
1070 /*
1071 ** Initialise the ID's to MAX_RUP.
1072 ** We do this to make the loop for setting the ID's as simple as
1073 ** possible.
1074 */
1075 *pID1 = MAX_RUP;
1076 if (pID2 != NULL)
1077 *pID2 = MAX_RUP;
1078
1079 /*
1080 ** Scan all entries of the host mapping table for free slots.
1081 ** We scan for free slots first and then if that is not successful
1082 ** we start all over again looking for tentative slots we can re-use.
1083 */
1084 for (unit = 0; unit < MAX_RUP; unit++)
1085 {
1086 rio_dprintk (RIO_DEBUG_ROUTE, "Scanning unit %d\n",unit);
1087 /*
1088 ** If the flags are zero then the slot is empty.
1089 */
1090 if (HostP->Mapping[unit].Flags == 0)
1091 {
1092 rio_dprintk (RIO_DEBUG_ROUTE, " This slot is empty.\n");
1093 /*
1094 ** If we haven't allocated the first ID then do it now.
1095 */
1096 if (*pID1 == MAX_RUP)
1097 {
1098 rio_dprintk (RIO_DEBUG_ROUTE, "Make tentative entry for first unit %d\n", unit);
1099 *pID1 = unit;
1100
1101 /*
1102 ** If the second ID is not needed then we can return
1103 ** now.
1104 */
1105 if (pID2 == NULL)
1106 return 0;
1107 }
1108 else
1109 {
1110 /*
1111 ** Allocate the second slot and return.
1112 */
1113 rio_dprintk (RIO_DEBUG_ROUTE, "Make tentative entry for second unit %d\n", unit);
1114 *pID2 = unit;
1115 return 0;
1116 }
1117 }
1118 }
1119
1120 /*
1121 ** If we manage to come out of the free slot loop then we
1122 ** need to start all over again looking for tentative slots
1123 ** that we can re-use.
1124 */
1125 rio_dprintk (RIO_DEBUG_ROUTE, "Starting to scan for tentative slots\n");
1126 for (unit = 0; unit < MAX_RUP; unit++)
1127 {
1128 if (((HostP->Mapping[unit].Flags & SLOT_TENTATIVE) ||
1129 (HostP->Mapping[unit].Flags == 0)) && !
1130 (HostP->Mapping[unit].Flags & RTA16_SECOND_SLOT ))
1131 {
1132 rio_dprintk (RIO_DEBUG_ROUTE, " Slot %d looks promising.\n",unit);
1133
1134 if(unit == *pID1)
1135 {
1136 rio_dprintk (RIO_DEBUG_ROUTE, " No it isn't, its the 1st half\n");
1137 continue;
1138 }
1139
1140 /*
1141 ** Slot is Tentative or Empty, but not a tentative second
1142 ** slot of a 16 porter.
1143 ** Attempt to free up this slot (and its parnter if
1144 ** it is a 16 port slot. The second slot will become
1145 ** empty after a call to RIOFreeDisconnected so thats why
1146 ** we look for empty slots above as well).
1147 */
1148 if (HostP->Mapping[unit].Flags != 0)
1149 if (RIOFreeDisconnected(p, HostP, unit) != 0)
1150 continue;
1151 /*
1152 ** If we haven't allocated the first ID then do it now.
1153 */
1154 if (*pID1 == MAX_RUP)
1155 {
1156 rio_dprintk (RIO_DEBUG_ROUTE, "Grab tentative entry for first unit %d\n", unit);
1157 *pID1 = unit;
1158
1159 /*
1160 ** Clear out this slot now that we intend to use it.
1161 */
1162 bzero(&HostP->Mapping[unit], sizeof(struct Map));
1163
1164 /*
1165 ** If the second ID is not needed then we can return
1166 ** now.
1167 */
1168 if (pID2 == NULL)
1169 return 0;
1170 }
1171 else
1172 {
1173 /*
1174 ** Allocate the second slot and return.
1175 */
1176 rio_dprintk (RIO_DEBUG_ROUTE, "Grab tentative/empty entry for second unit %d\n",
1177 unit);
1178 *pID2 = unit;
1179
1180 /*
1181 ** Clear out this slot now that we intend to use it.
1182 */
1183 bzero(&HostP->Mapping[unit], sizeof(struct Map));
1184
1185 /* At this point under the right(wrong?) conditions
1186 ** we may have a first unit ID being higher than the
1187 ** second unit ID. This is a bad idea if we are about
1188 ** to fill the slots with a 16 port RTA.
1189 ** Better check and swap them over.
1190 */
1191
1192 if (*pID1 > *pID2)
1193 {
1194 rio_dprintk (RIO_DEBUG_ROUTE, "Swapping IDS %d %d\n", *pID1, *pID2);
1195 tempID = *pID1;
1196 *pID1 = *pID2;
1197 *pID2 = tempID;
1198 }
1199 return 0;
1200 }
1201 }
1202 }
1203
1204 /*
1205 ** If we manage to get to the end of the second loop then we
1206 ** can give up and return a failure.
1207 */
1208 return 1;
1209 }
1210
1211
1212 /*
1213 ** The link switch scenario.
1214 **
1215 ** Rta Wun (A) is connected to Tuw (A).
1216 ** The tables are all up to date, and the system is OK.
1217 **
1218 ** If Wun (A) is now moved to Wun (B) before Wun (A) can
1219 ** become disconnected, then the follow happens:
1220 **
1221 ** Tuw (A) spots the change of unit:link at the other end
1222 ** of its link and Tuw sends a topology packet reflecting
1223 ** the change: Tuw (A) now disconnected from Wun (A), and
1224 ** this is closely followed by a packet indicating that
1225 ** Tuw (A) is now connected to Wun (B).
1226 **
1227 ** Wun (B) will spot that it has now become connected, and
1228 ** Wun will send a topology packet, which indicates that
1229 ** both Wun (A) and Wun (B) is connected to Tuw (A).
1230 **
1231 ** Eventually Wun (A) realises that it is now disconnected
1232 ** and Wun will send out a topology packet indicating that
1233 ** Wun (A) is now disconnected.
1234 */
1235