Full support for Ginger Console

[linux-ginger.git] / drivers / char / rio / rioroute.c

/*
** -----------------------------------------------------------------------------
**
**  Perle Specialix driver for Linux
**  Ported from existing RIO Driver for SCO sources.
 *
 *  (C) 1990 - 2000 Specialix International Ltd., Byfleet, Surrey, UK.
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *
 *      This program is distributed in the hope that it will be useful,
 *      but WITHOUT ANY WARRANTY; without even the implied warranty of
 *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *      GNU General Public License for more details.
 *
 *      You should have received a copy of the GNU General Public License
 *      along with this program; if not, write to the Free Software
 *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
**      Module          : rioroute.c
**      SID             : 1.3
**      Last Modified   : 11/6/98 10:33:46
**      Retrieved       : 11/6/98 10:33:50
**
**  ident @(#)rioroute.c        1.3
**
** -----------------------------------------------------------------------------
*/

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/string.h>
#include <asm/uaccess.h>

#include <linux/termios.h>
#include <linux/serial.h>

#include <linux/generic_serial.h>


#include "linux_compat.h"
#include "rio_linux.h"
#include "pkt.h"
#include "daemon.h"
#include "rio.h"
#include "riospace.h"
#include "cmdpkt.h"
#include "map.h"
#include "rup.h"
#include "port.h"
#include "riodrvr.h"
#include "rioinfo.h"
#include "func.h"
#include "errors.h"
#include "pci.h"

#include "parmmap.h"
#include "unixrup.h"
#include "board.h"
#include "host.h"
#include "phb.h"
#include "link.h"
#include "cmdblk.h"
#include "route.h"
#include "cirrus.h"
#include "rioioctl.h"
#include "param.h"

static int RIOCheckIsolated(struct rio_info *, struct Host *, unsigned int);
static int RIOIsolate(struct rio_info *, struct Host *, unsigned int);
static int RIOCheck(struct Host *, unsigned int);
static void RIOConCon(struct rio_info *, struct Host *, unsigned int, unsigned int, unsigned int, unsigned int, int);


/*
** Incoming on the ROUTE_RUP
** I wrote this while I was tired. Forgive me.
*/
int RIORouteRup(struct rio_info *p, unsigned int Rup, struct Host *HostP, struct PKT __iomem * PacketP)
{
        struct PktCmd __iomem *PktCmdP = (struct PktCmd __iomem *) PacketP->data;
        struct PktCmd_M *PktReplyP;
        struct CmdBlk *CmdBlkP;
        struct Port *PortP;
        struct Map *MapP;
        struct Top *TopP;
        int ThisLink, ThisLinkMin, ThisLinkMax;
        int port;
        int Mod, Mod1, Mod2;
        unsigned short RtaType;
        unsigned int RtaUniq;
        unsigned int ThisUnit, ThisUnit2;       /* 2 ids to accommodate 16 port RTA */
        unsigned int OldUnit, NewUnit, OldLink, NewLink;
        char *MyType, *MyName;
        int Lies;
        unsigned long flags;

        /*
         ** Is this unit telling us it's current link topology?
         */
        if (readb(&PktCmdP->Command) == ROUTE_TOPOLOGY) {
                MapP = HostP->Mapping;

                /*
                 ** The packet can be sent either by the host or by an RTA.
                 ** If it comes from the host, then we need to fill in the
                 ** Topology array in the host structure. If it came in
                 ** from an RTA then we need to fill in the Mapping structure's
                 ** Topology array for the unit.
                 */
                if (Rup >= (unsigned short) MAX_RUP) {
                        ThisUnit = HOST_ID;
                        TopP = HostP->Topology;
                        MyType = "Host";
                        MyName = HostP->Name;
                        ThisLinkMin = ThisLinkMax = Rup - MAX_RUP;
                } else {
                        ThisUnit = Rup + 1;
                        TopP = HostP->Mapping[Rup].Topology;
                        MyType = "RTA";
                        MyName = HostP->Mapping[Rup].Name;
                        ThisLinkMin = 0;
                        ThisLinkMax = LINKS_PER_UNIT - 1;
                }

                /*
                 ** Lies will not be tolerated.
                 ** If any pair of links claim to be connected to the same
                 ** place, then ignore this packet completely.
                 */
                Lies = 0;
                for (ThisLink = ThisLinkMin + 1; ThisLink <= ThisLinkMax; ThisLink++) {
                        /*
                         ** it won't lie about network interconnect, total disconnects
                         ** and no-IDs. (or at least, it doesn't *matter* if it does)
                         */
                        if (readb(&PktCmdP->RouteTopology[ThisLink].Unit) > (unsigned short) MAX_RUP)
                                continue;

                        for (NewLink = ThisLinkMin; NewLink < ThisLink; NewLink++) {
                                if ((readb(&PktCmdP->RouteTopology[ThisLink].Unit) == readb(&PktCmdP->RouteTopology[NewLink].Unit)) && (readb(&PktCmdP->RouteTopology[ThisLink].Link) == readb(&PktCmdP->RouteTopology[NewLink].Link))) {
                                        Lies++;
                                }
                        }
                }

                if (Lies) {
                        rio_dprintk(RIO_DEBUG_ROUTE, "LIES! DAMN LIES! %d LIES!\n", Lies);
                        rio_dprintk(RIO_DEBUG_ROUTE, "%d:%c %d:%c %d:%c %d:%c\n",
                                    readb(&PktCmdP->RouteTopology[0].Unit),
                                    'A' + readb(&PktCmdP->RouteTopology[0].Link),
                                    readb(&PktCmdP->RouteTopology[1].Unit),
                                    '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));
                        return 1;
                }

                /*
                 ** now, process each link.
                 */
                for (ThisLink = ThisLinkMin; ThisLink <= ThisLinkMax; ThisLink++) {
                        /*
                         ** this is what it was connected to
                         */
                        OldUnit = TopP[ThisLink].Unit;
                        OldLink = TopP[ThisLink].Link;

                        /*
                         ** this is what it is now connected to
                         */
                        NewUnit = readb(&PktCmdP->RouteTopology[ThisLink].Unit);
                        NewLink = readb(&PktCmdP->RouteTopology[ThisLink].Link);

                        if (OldUnit != NewUnit || OldLink != NewLink) {
                                /*
                                 ** something has changed!
                                 */

                                if (NewUnit > MAX_RUP && NewUnit != ROUTE_DISCONNECT && NewUnit != ROUTE_NO_ID && NewUnit != ROUTE_INTERCONNECT) {
                                        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);
                                } else {
                                        /*
                                         ** put the new values in
                                         */
                                        TopP[ThisLink].Unit = NewUnit;
                                        TopP[ThisLink].Link = NewLink;

                                        RIOSetChange(p);

                                        if (OldUnit <= MAX_RUP) {
                                                /*
                                                 ** If something has become bust, then re-enable them messages
                                                 */
                                                if (!p->RIONoMessage)
                                                        RIOConCon(p, HostP, ThisUnit, ThisLink, OldUnit, OldLink, DISCONNECT);
                                        }

                                        if ((NewUnit <= MAX_RUP) && !p->RIONoMessage)
                                                RIOConCon(p, HostP, ThisUnit, ThisLink, NewUnit, NewLink, CONNECT);

                                        if (NewUnit == ROUTE_NO_ID)
                                                rio_dprintk(RIO_DEBUG_ROUTE, "%s %s (%c) is connected to an unconfigured unit.\n", MyType, MyName, 'A' + ThisLink);

                                        if (NewUnit == ROUTE_INTERCONNECT) {
                                                if (!p->RIONoMessage)
                                                        printk(KERN_DEBUG "rio: %s '%s' (%c) is connected to another network.\n", MyType, MyName, 'A' + ThisLink);
                                        }

                                        /*
                                         ** perform an update for 'the other end', so that these messages
                                         ** only appears once. Only disconnect the other end if it is pointing
                                         ** at us!
                                         */
                                        if (OldUnit == HOST_ID) {
                                                if (HostP->Topology[OldLink].Unit == ThisUnit && HostP->Topology[OldLink].Link == ThisLink) {
                                                        rio_dprintk(RIO_DEBUG_ROUTE, "SETTING HOST (%c) TO DISCONNECTED!\n", OldLink + 'A');
                                                        HostP->Topology[OldLink].Unit = ROUTE_DISCONNECT;
                                                        HostP->Topology[OldLink].Link = NO_LINK;
                                                } else {
                                                        rio_dprintk(RIO_DEBUG_ROUTE, "HOST(%c) WAS NOT CONNECTED TO %s (%c)!\n", OldLink + 'A', HostP->Mapping[ThisUnit - 1].Name, ThisLink + 'A');
                                                }
                                        } else if (OldUnit <= MAX_RUP) {
                                                if (HostP->Mapping[OldUnit - 1].Topology[OldLink].Unit == ThisUnit && HostP->Mapping[OldUnit - 1].Topology[OldLink].Link == ThisLink) {
                                                        rio_dprintk(RIO_DEBUG_ROUTE, "SETTING RTA %s (%c) TO DISCONNECTED!\n", HostP->Mapping[OldUnit - 1].Name, OldLink + 'A');
                                                        HostP->Mapping[OldUnit - 1].Topology[OldLink].Unit = ROUTE_DISCONNECT;
                                                        HostP->Mapping[OldUnit - 1].Topology[OldLink].Link = NO_LINK;
                                                } else {
                                                        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');
                                                }
                                        }
                                        if (NewUnit == HOST_ID) {
                                                rio_dprintk(RIO_DEBUG_ROUTE, "MARKING HOST (%c) CONNECTED TO %s (%c)\n", NewLink + 'A', MyName, ThisLink + 'A');
                                                HostP->Topology[NewLink].Unit = ThisUnit;
                                                HostP->Topology[NewLink].Link = ThisLink;
                                        } else if (NewUnit <= MAX_RUP) {
                                                rio_dprintk(RIO_DEBUG_ROUTE, "MARKING RTA %s (%c) CONNECTED TO %s (%c)\n", HostP->Mapping[NewUnit - 1].Name, NewLink + 'A', MyName, ThisLink + 'A');
                                                HostP->Mapping[NewUnit - 1].Topology[NewLink].Unit = ThisUnit;
                                                HostP->Mapping[NewUnit - 1].Topology[NewLink].Link = ThisLink;
                                        }
                                }
                                RIOSetChange(p);
                                RIOCheckIsolated(p, HostP, OldUnit);
                        }
                }
                return 1;
        }

        /*
         ** The only other command we recognise is a route_request command
         */
        if (readb(&PktCmdP->Command) != ROUTE_REQUEST) {
                rio_dprintk(RIO_DEBUG_ROUTE, "Unknown command %d received on rup %d host %p ROUTE_RUP\n", readb(&PktCmdP->Command), Rup, HostP);
                return 1;
        }

        RtaUniq = (readb(&PktCmdP->UniqNum[0])) + (readb(&PktCmdP->UniqNum[1]) << 8) + (readb(&PktCmdP->UniqNum[2]) << 16) + (readb(&PktCmdP->UniqNum[3]) << 24);

        /*
         ** Determine if 8 or 16 port RTA
         */
        RtaType = GetUnitType(RtaUniq);

        rio_dprintk(RIO_DEBUG_ROUTE, "Received a request for an ID for serial number %x\n", RtaUniq);

        Mod = readb(&PktCmdP->ModuleTypes);
        Mod1 = LONYBLE(Mod);
        if (RtaType == TYPE_RTA16) {
                /*
                 ** Only one ident is set for a 16 port RTA. To make compatible
                 ** with 8 port, set 2nd ident in Mod2 to the same as Mod1.
                 */
                Mod2 = Mod1;
                rio_dprintk(RIO_DEBUG_ROUTE, "Backplane type is %s (all ports)\n", p->RIOModuleTypes[Mod1].Name);
        } else {
                Mod2 = HINYBLE(Mod);
                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);
        }

        /*
         ** try to unhook a command block from the command free list.
         */
        if (!(CmdBlkP = RIOGetCmdBlk())) {
                rio_dprintk(RIO_DEBUG_ROUTE, "No command blocks to route RTA! come back later.\n");
                return 0;
        }

        /*
         ** Fill in the default info on the command block
         */
        CmdBlkP->Packet.dest_unit = Rup;
        CmdBlkP->Packet.dest_port = ROUTE_RUP;
        CmdBlkP->Packet.src_unit = HOST_ID;
        CmdBlkP->Packet.src_port = ROUTE_RUP;
        CmdBlkP->Packet.len = PKT_CMD_BIT | 1;
        CmdBlkP->PreFuncP = CmdBlkP->PostFuncP = NULL;
        PktReplyP = (struct PktCmd_M *) CmdBlkP->Packet.data;

        if (!RIOBootOk(p, HostP, RtaUniq)) {
                rio_dprintk(RIO_DEBUG_ROUTE, "RTA %x tried to get an ID, but does not belong - FOAD it!\n", RtaUniq);
                PktReplyP->Command = ROUTE_FOAD;
                memcpy(PktReplyP->CommandText, "RT_FOAD", 7);
                RIOQueueCmdBlk(HostP, Rup, CmdBlkP);
                return 1;
        }

        /*
         ** Check to see if the RTA is configured for this host
         */
        for (ThisUnit = 0; ThisUnit < MAX_RUP; ThisUnit++) {
                rio_dprintk(RIO_DEBUG_ROUTE, "Entry %d Flags=%s %s UniqueNum=0x%x\n",
                            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);

                /*
                 ** We have an entry for it.
                 */
                if ((HostP->Mapping[ThisUnit].Flags & (SLOT_IN_USE | SLOT_TENTATIVE)) && (HostP->Mapping[ThisUnit].RtaUniqueNum == RtaUniq)) {
                        if (RtaType == TYPE_RTA16) {
                                ThisUnit2 = HostP->Mapping[ThisUnit].ID2 - 1;
                                rio_dprintk(RIO_DEBUG_ROUTE, "Found unit 0x%x at slots %d+%d\n", RtaUniq, ThisUnit, ThisUnit2);
                        } else
                                rio_dprintk(RIO_DEBUG_ROUTE, "Found unit 0x%x at slot %d\n", RtaUniq, ThisUnit);
                        /*
                         ** If we have no knowledge of booting it, then the host has
                         ** been re-booted, and so we must kill the RTA, so that it
                         ** will be booted again (potentially with new bins)
                         ** and it will then re-ask for an ID, which we will service.
                         */
                        if ((HostP->Mapping[ThisUnit].Flags & SLOT_IN_USE) && !(HostP->Mapping[ThisUnit].Flags & RTA_BOOTED)) {
                                if (!(HostP->Mapping[ThisUnit].Flags & MSG_DONE)) {
                                        if (!p->RIONoMessage)
                                                printk(KERN_DEBUG "rio: RTA '%s' is being updated.\n", HostP->Mapping[ThisUnit].Name);
                                        HostP->Mapping[ThisUnit].Flags |= MSG_DONE;
                                }
                                PktReplyP->Command = ROUTE_FOAD;
                                memcpy(PktReplyP->CommandText, "RT_FOAD", 7);
                                RIOQueueCmdBlk(HostP, Rup, CmdBlkP);
                                return 1;
                        }

                        /*
                         ** Send the ID (entry) to this RTA. The ID number is implicit as
                         ** the offset into the table. It is worth noting at this stage
                         ** that offset zero in the table contains the entries for the
                         ** RTA with ID 1!!!!
                         */
                        PktReplyP->Command = ROUTE_ALLOCATE;
                        PktReplyP->IDNum = ThisUnit + 1;
                        if (RtaType == TYPE_RTA16) {
                                if (HostP->Mapping[ThisUnit].Flags & SLOT_IN_USE)
                                        /*
                                         ** Adjust the phb and tx pkt dest_units for 2nd block of 8
                                         ** only if the RTA has ports associated (SLOT_IN_USE)
                                         */
                                        RIOFixPhbs(p, HostP, ThisUnit2);
                                PktReplyP->IDNum2 = ThisUnit2 + 1;
                                rio_dprintk(RIO_DEBUG_ROUTE, "RTA '%s' has been allocated IDs %d+%d\n", HostP->Mapping[ThisUnit].Name, PktReplyP->IDNum, PktReplyP->IDNum2);
                        } else {
                                PktReplyP->IDNum2 = ROUTE_NO_ID;
                                rio_dprintk(RIO_DEBUG_ROUTE, "RTA '%s' has been allocated ID %d\n", HostP->Mapping[ThisUnit].Name, PktReplyP->IDNum);
                        }
                        memcpy(PktReplyP->CommandText, "RT_ALLOCAT", 10);

                        RIOQueueCmdBlk(HostP, Rup, CmdBlkP);

                        /*
                         ** If this is a freshly booted RTA, then we need to re-open
                         ** the ports, if any where open, so that data may once more
                         ** flow around the system!
                         */
                        if ((HostP->Mapping[ThisUnit].Flags & RTA_NEWBOOT) && (HostP->Mapping[ThisUnit].SysPort != NO_PORT)) {
                                /*
                                 ** look at the ports associated with this beast and
                                 ** see if any where open. If they was, then re-open
                                 ** them, using the info from the tty flags.
                                 */
                                for (port = 0; port < PORTS_PER_RTA; port++) {
                                        PortP = p->RIOPortp[port + HostP->Mapping[ThisUnit].SysPort];
                                        if (PortP->State & (RIO_MOPEN | RIO_LOPEN)) {
                                                rio_dprintk(RIO_DEBUG_ROUTE, "Re-opened this port\n");
                                                rio_spin_lock_irqsave(&PortP->portSem, flags);
                                                PortP->MagicFlags |= MAGIC_REBOOT;
                                                rio_spin_unlock_irqrestore(&PortP->portSem, flags);
                                        }
                                }
                                if (RtaType == TYPE_RTA16) {
                                        for (port = 0; port < PORTS_PER_RTA; port++) {
                                                PortP = p->RIOPortp[port + HostP->Mapping[ThisUnit2].SysPort];
                                                if (PortP->State & (RIO_MOPEN | RIO_LOPEN)) {
                                                        rio_dprintk(RIO_DEBUG_ROUTE, "Re-opened this port\n");
                                                        rio_spin_lock_irqsave(&PortP->portSem, flags);
                                                        PortP->MagicFlags |= MAGIC_REBOOT;
                                                        rio_spin_unlock_irqrestore(&PortP->portSem, flags);
                                                }
                                        }
                                }
                        }

                        /*
                         ** keep a copy of the module types!
                         */
                        HostP->UnixRups[ThisUnit].ModTypes = Mod;
                        if (RtaType == TYPE_RTA16)
                                HostP->UnixRups[ThisUnit2].ModTypes = Mod;

                        /*
                         ** If either of the modules on this unit is read-only or write-only
                         ** or none-xprint, then we need to transfer that info over to the
                         ** relevant ports.
                         */
                        if (HostP->Mapping[ThisUnit].SysPort != NO_PORT) {
                                for (port = 0; port < PORTS_PER_MODULE; port++) {
                                        p->RIOPortp[port + HostP->Mapping[ThisUnit].SysPort]->Config &= ~RIO_NOMASK;
                                        p->RIOPortp[port + HostP->Mapping[ThisUnit].SysPort]->Config |= p->RIOModuleTypes[Mod1].Flags[port];
                                        p->RIOPortp[port + PORTS_PER_MODULE + HostP->Mapping[ThisUnit].SysPort]->Config &= ~RIO_NOMASK;
                                        p->RIOPortp[port + PORTS_PER_MODULE + HostP->Mapping[ThisUnit].SysPort]->Config |= p->RIOModuleTypes[Mod2].Flags[port];
                                }
                                if (RtaType == TYPE_RTA16) {
                                        for (port = 0; port < PORTS_PER_MODULE; port++) {
                                                p->RIOPortp[port + HostP->Mapping[ThisUnit2].SysPort]->Config &= ~RIO_NOMASK;
                                                p->RIOPortp[port + HostP->Mapping[ThisUnit2].SysPort]->Config |= p->RIOModuleTypes[Mod1].Flags[port];
                                                p->RIOPortp[port + PORTS_PER_MODULE + HostP->Mapping[ThisUnit2].SysPort]->Config &= ~RIO_NOMASK;
                                                p->RIOPortp[port + PORTS_PER_MODULE + HostP->Mapping[ThisUnit2].SysPort]->Config |= p->RIOModuleTypes[Mod2].Flags[port];
                                        }
                                }
                        }

                        /*
                         ** Job done, get on with the interrupts!
                         */
                        return 1;
                }
        }
        /*
         ** There is no table entry for this RTA at all.
         **
         ** Lets check to see if we actually booted this unit - if not,
         ** then we reset it and it will go round the loop of being booted
         ** we can then worry about trying to fit it into the table.
         */
        for (ThisUnit = 0; ThisUnit < HostP->NumExtraBooted; ThisUnit++)
                if (HostP->ExtraUnits[ThisUnit] == RtaUniq)
                        break;
        if (ThisUnit == HostP->NumExtraBooted && ThisUnit != MAX_EXTRA_UNITS) {
                /*
                 ** if the unit wasn't in the table, and the table wasn't full, then
                 ** we reset the unit, because we didn't boot it.
                 ** However, if the table is full, it could be that we did boot
                 ** this unit, and so we won't reboot it, because it isn't really
                 ** all that disasterous to keep the old bins in most cases. This
                 ** is a rather tacky feature, but we are on the edge of reallity
                 ** here, because the implication is that someone has connected
                 ** 16+MAX_EXTRA_UNITS onto one host.
                 */
                static int UnknownMesgDone = 0;

                if (!UnknownMesgDone) {
                        if (!p->RIONoMessage)
                                printk(KERN_DEBUG "rio: One or more unknown RTAs are being updated.\n");
                        UnknownMesgDone = 1;
                }

                PktReplyP->Command = ROUTE_FOAD;
                memcpy(PktReplyP->CommandText, "RT_FOAD", 7);
        } else {
                /*
                 ** we did boot it (as an extra), and there may now be a table
                 ** slot free (because of a delete), so we will try to make
                 ** a tentative entry for it, so that the configurator can see it
                 ** and fill in the details for us.
                 */
                if (RtaType == TYPE_RTA16) {
                        if (RIOFindFreeID(p, HostP, &ThisUnit, &ThisUnit2) == 0) {
                                RIODefaultName(p, HostP, ThisUnit);
                                rio_fill_host_slot(ThisUnit, ThisUnit2, RtaUniq, HostP);
                        }
                } else {
                        if (RIOFindFreeID(p, HostP, &ThisUnit, NULL) == 0) {
                                RIODefaultName(p, HostP, ThisUnit);
                                rio_fill_host_slot(ThisUnit, 0, RtaUniq, HostP);
                        }
                }
                PktReplyP->Command = ROUTE_USED;
                memcpy(PktReplyP->CommandText, "RT_USED", 7);
        }
        RIOQueueCmdBlk(HostP, Rup, CmdBlkP);
        return 1;
}


void RIOFixPhbs(struct rio_info *p, struct Host *HostP, unsigned int unit)
{
        unsigned short link, port;
        struct Port *PortP;
        unsigned long flags;
        int PortN = HostP->Mapping[unit].SysPort;

        rio_dprintk(RIO_DEBUG_ROUTE, "RIOFixPhbs unit %d sysport %d\n", unit, PortN);

        if (PortN != -1) {
                unsigned short dest_unit = HostP->Mapping[unit].ID2;

                /*
                 ** Get the link number used for the 1st 8 phbs on this unit.
                 */
                PortP = p->RIOPortp[HostP->Mapping[dest_unit - 1].SysPort];

                link = readw(&PortP->PhbP->link);

                for (port = 0; port < PORTS_PER_RTA; port++, PortN++) {
                        unsigned short dest_port = port + 8;
                        u16 __iomem *TxPktP;
                        struct PKT __iomem *Pkt;

                        PortP = p->RIOPortp[PortN];

                        rio_spin_lock_irqsave(&PortP->portSem, flags);
                        /*
                         ** If RTA is not powered on, the tx packets will be
                         ** unset, so go no further.
                         */
                        if (!PortP->TxStart) {
                                rio_dprintk(RIO_DEBUG_ROUTE, "Tx pkts not set up yet\n");
                                rio_spin_unlock_irqrestore(&PortP->portSem, flags);
                                break;
                        }

                        /*
                         ** For the second slot of a 16 port RTA, the driver needs to
                         ** sort out the phb to port mappings. The dest_unit for this
                         ** group of 8 phbs is set to the dest_unit of the accompanying
                         ** 8 port block. The dest_port of the second unit is set to
                         ** be in the range 8-15 (i.e. 8 is added). Thus, for a 16 port
                         ** RTA with IDs 5 and 6, traffic bound for port 6 of unit 6
                         ** (being the second map ID) will be sent to dest_unit 5, port
                         ** 14. When this RTA is deleted, dest_unit for ID 6 will be
                         ** restored, and the dest_port will be reduced by 8.
                         ** Transmit packets also have a destination field which needs
                         ** adjusting in the same manner.
                         ** Note that the unit/port bytes in 'dest' are swapped.
                         ** We also need to adjust the phb and rup link numbers for the
                         ** second block of 8 ttys.
                         */
                        for (TxPktP = PortP->TxStart; TxPktP <= PortP->TxEnd; TxPktP++) {
                                /*
                                 ** *TxPktP is the pointer to the transmit packet on the host
                                 ** card. This needs to be translated into a 32 bit pointer
                                 ** so it can be accessed from the driver.
                                 */
                                Pkt = (struct PKT __iomem *) RIO_PTR(HostP->Caddr, readw(TxPktP));

                                /*
                                 ** If the packet is used, reset it.
                                 */
                                Pkt = (struct PKT __iomem *) ((unsigned long) Pkt & ~PKT_IN_USE);
                                writeb(dest_unit, &Pkt->dest_unit);
                                writeb(dest_port, &Pkt->dest_port);
                        }
                        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);
                        writew(dest_unit + (dest_port << 8), &PortP->PhbP->destination);
                        writew(link, &PortP->PhbP->link);

                        rio_spin_unlock_irqrestore(&PortP->portSem, flags);
                }
                /*
                 ** Now make sure the range of ports to be serviced includes
                 ** the 2nd 8 on this 16 port RTA.
                 */
                if (link > 3)
                        return;
                if (((unit * 8) + 7) > readw(&HostP->LinkStrP[link].last_port)) {
                        rio_dprintk(RIO_DEBUG_ROUTE, "last port on host link %d: %d\n", link, (unit * 8) + 7);
                        writew((unit * 8) + 7, &HostP->LinkStrP[link].last_port);
                }
        }
}

/*
** Check to see if the new disconnection has isolated this unit.
** If it has, then invalidate all its link information, and tell
** the world about it. This is done to ensure that the configurator
** only gets up-to-date information about what is going on.
*/
static int RIOCheckIsolated(struct rio_info *p, struct Host *HostP, unsigned int UnitId)
{
        unsigned long flags;
        rio_spin_lock_irqsave(&HostP->HostLock, flags);

        if (RIOCheck(HostP, UnitId)) {
                rio_dprintk(RIO_DEBUG_ROUTE, "Unit %d is NOT isolated\n", UnitId);
                rio_spin_unlock_irqrestore(&HostP->HostLock, flags);
                return (0);
        }

        RIOIsolate(p, HostP, UnitId);
        RIOSetChange(p);
        rio_spin_unlock_irqrestore(&HostP->HostLock, flags);
        return 1;
}

/*
** Invalidate all the link interconnectivity of this unit, and of
** all the units attached to it. This will mean that the entire
** subnet will re-introduce itself.
*/
static int RIOIsolate(struct rio_info *p, struct Host *HostP, unsigned int UnitId)
{
        unsigned int link, unit;

        UnitId--;               /* this trick relies on the Unit Id being UNSIGNED! */

        if (UnitId >= MAX_RUP)  /* dontcha just lurv unsigned maths! */
                return (0);

        if (HostP->Mapping[UnitId].Flags & BEEN_HERE)
                return (0);

        HostP->Mapping[UnitId].Flags |= BEEN_HERE;

        if (p->RIOPrintDisabled == DO_PRINT)
                rio_dprintk(RIO_DEBUG_ROUTE, "RIOMesgIsolated %s", HostP->Mapping[UnitId].Name);

        for (link = 0; link < LINKS_PER_UNIT; link++) {
                unit = HostP->Mapping[UnitId].Topology[link].Unit;
                HostP->Mapping[UnitId].Topology[link].Unit = ROUTE_DISCONNECT;
                HostP->Mapping[UnitId].Topology[link].Link = NO_LINK;
                RIOIsolate(p, HostP, unit);
        }
        HostP->Mapping[UnitId].Flags &= ~BEEN_HERE;
        return 1;
}

static int RIOCheck(struct Host *HostP, unsigned int UnitId)
{
        unsigned char link;

/*      rio_dprint(RIO_DEBUG_ROUTE, ("Check to see if unit %d has a route to the host\n",UnitId)); */
        rio_dprintk(RIO_DEBUG_ROUTE, "RIOCheck : UnitID = %d\n", UnitId);

        if (UnitId == HOST_ID) {
                /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d is NOT isolated - it IS the host!\n", UnitId)); */
                return 1;
        }

        UnitId--;

        if (UnitId >= MAX_RUP) {
                /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d - ignored.\n", UnitId)); */
                return 0;
        }

        for (link = 0; link < LINKS_PER_UNIT; link++) {
                if (HostP->Mapping[UnitId].Topology[link].Unit == HOST_ID) {
                        /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d is connected directly to host via link (%c).\n", 
                           UnitId, 'A'+link)); */
                        return 1;
                }
        }

        if (HostP->Mapping[UnitId].Flags & BEEN_HERE) {
                /* rio_dprint(RIO_DEBUG_ROUTE, ("Been to Unit %d before - ignoring\n", UnitId)); */
                return 0;
        }

        HostP->Mapping[UnitId].Flags |= BEEN_HERE;

        for (link = 0; link < LINKS_PER_UNIT; link++) {
                /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d check link (%c)\n", UnitId,'A'+link)); */
                if (RIOCheck(HostP, HostP->Mapping[UnitId].Topology[link].Unit)) {
                        /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d is connected to something that knows the host via link (%c)\n", UnitId,link+'A')); */
                        HostP->Mapping[UnitId].Flags &= ~BEEN_HERE;
                        return 1;
                }
        }

        HostP->Mapping[UnitId].Flags &= ~BEEN_HERE;

        /* rio_dprint(RIO_DEBUG_ROUTE, ("Unit %d DOESNT KNOW THE HOST!\n", UnitId)); */

        return 0;
}

/*
** Returns the type of unit (host, 16/8 port RTA)
*/

unsigned int GetUnitType(unsigned int Uniq)
{
        switch ((Uniq >> 28) & 0xf) {
        case RIO_AT:
        case RIO_MCA:
        case RIO_EISA:
        case RIO_PCI:
                rio_dprintk(RIO_DEBUG_ROUTE, "Unit type: Host\n");
                return (TYPE_HOST);
        case RIO_RTA_16:
                rio_dprintk(RIO_DEBUG_ROUTE, "Unit type: 16 port RTA\n");
                return (TYPE_RTA16);
        case RIO_RTA:
                rio_dprintk(RIO_DEBUG_ROUTE, "Unit type: 8 port RTA\n");
                return (TYPE_RTA8);
        default:
                rio_dprintk(RIO_DEBUG_ROUTE, "Unit type: Unrecognised\n");
                return (99);
        }
}

int RIOSetChange(struct rio_info *p)
{
        if (p->RIOQuickCheck != NOT_CHANGED)
                return (0);
        p->RIOQuickCheck = CHANGED;
        if (p->RIOSignalProcess) {
                rio_dprintk(RIO_DEBUG_ROUTE, "Send SIG-HUP");
                /*
                   psignal( RIOSignalProcess, SIGHUP );
                 */
        }
        return (0);
}

static void RIOConCon(struct rio_info *p,
                      struct Host *HostP,
                      unsigned int FromId,
                      unsigned int FromLink,
                      unsigned int ToId,
                      unsigned int ToLink,
                      int Change)
{
        char *FromName;
        char *FromType;
        char *ToName;
        char *ToType;
        unsigned int tp;

/*
** 15.10.1998 ARG - ESIL 0759
** (Part) fix for port being trashed when opened whilst RTA "disconnected"
**
** What's this doing in here anyway ?
** It was causing the port to be 'unmapped' if opened whilst RTA "disconnected"
**
** 09.12.1998 ARG - ESIL 0776 - part fix
** Okay, We've found out what this was all about now !
** Someone had botched this to use RIOHalted to indicated the number of RTAs
** 'disconnected'. The value in RIOHalted was then being used in the
** 'RIO_QUICK_CHECK' ioctl. A none zero value indicating that a least one RTA
** is 'disconnected'. The change was put in to satisfy a customer's needs.
** Having taken this bit of code out 'RIO_QUICK_CHECK' now no longer works for
** the customer.
**
    if (Change == CONNECT) {
                if (p->RIOHalted) p->RIOHalted --;
         }
         else {
                p->RIOHalted ++;
         }
**
** So - we need to implement it slightly differently - a new member of the
** rio_info struct - RIORtaDisCons (RIO RTA connections) keeps track of RTA
** connections and disconnections. 
*/
        if (Change == CONNECT) {
                if (p->RIORtaDisCons)
                        p->RIORtaDisCons--;
        } else {
                p->RIORtaDisCons++;
        }

        if (p->RIOPrintDisabled == DONT_PRINT)
                return;

        if (FromId > ToId) {
                tp = FromId;
                FromId = ToId;
                ToId = tp;
                tp = FromLink;
                FromLink = ToLink;
                ToLink = tp;
        }

        FromName = FromId ? HostP->Mapping[FromId - 1].Name : HostP->Name;
        FromType = FromId ? "RTA" : "HOST";
        ToName = ToId ? HostP->Mapping[ToId - 1].Name : HostP->Name;
        ToType = ToId ? "RTA" : "HOST";

        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");
        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");
}

/*
** RIORemoveFromSavedTable :
**
** Delete and RTA entry from the saved table given to us
** by the configuration program.
*/
static int RIORemoveFromSavedTable(struct rio_info *p, struct Map *pMap)
{
        int entry;

        /*
         ** We loop for all entries even after finding an entry and
         ** zeroing it because we may have two entries to delete if
         ** it's a 16 port RTA.
         */
        for (entry = 0; entry < TOTAL_MAP_ENTRIES; entry++) {
                if (p->RIOSavedTable[entry].RtaUniqueNum == pMap->RtaUniqueNum) {
                        memset(&p->RIOSavedTable[entry], 0, sizeof(struct Map));
                }
        }
        return 0;
}


/*
** RIOCheckDisconnected :
**
** Scan the unit links to and return zero if the unit is completely
** disconnected.
*/
static int RIOFreeDisconnected(struct rio_info *p, struct Host *HostP, int unit)
{
        int link;


        rio_dprintk(RIO_DEBUG_ROUTE, "RIOFreeDisconnect unit %d\n", unit);
        /*
         ** If the slot is tentative and does not belong to the
         ** second half of a 16 port RTA then scan to see if
         ** is disconnected.
         */
        for (link = 0; link < LINKS_PER_UNIT; link++) {
                if (HostP->Mapping[unit].Topology[link].Unit != ROUTE_DISCONNECT)
                        break;
        }

        /*
         ** If not all links are disconnected then we can forget about it.
         */
        if (link < LINKS_PER_UNIT)
                return 1;

#ifdef NEED_TO_FIX_THIS
        /* Ok so all the links are disconnected. But we may have only just
         ** made this slot tentative and not yet received a topology update.
         ** Lets check how long ago we made it tentative.
         */
        rio_dprintk(RIO_DEBUG_ROUTE, "Just about to check LBOLT on entry %d\n", unit);
        if (drv_getparm(LBOLT, (ulong_t *) & current_time))
                rio_dprintk(RIO_DEBUG_ROUTE, "drv_getparm(LBOLT,....) Failed.\n");

        elapse_time = current_time - TentTime[unit];
        rio_dprintk(RIO_DEBUG_ROUTE, "elapse %d = current %d - tent %d (%d usec)\n", elapse_time, current_time, TentTime[unit], drv_hztousec(elapse_time));
        if (drv_hztousec(elapse_time) < WAIT_TO_FINISH) {
                rio_dprintk(RIO_DEBUG_ROUTE, "Skipping slot %d, not timed out yet %d\n", unit, drv_hztousec(elapse_time));
                return 1;
        }
#endif

        /*
         ** We have found an usable slot.
         ** If it is half of a 16 port RTA then delete the other half.
         */
        if (HostP->Mapping[unit].ID2 != 0) {
                int nOther = (HostP->Mapping[unit].ID2) - 1;

                rio_dprintk(RIO_DEBUG_ROUTE, "RioFreedis second slot %d.\n", nOther);
                memset(&HostP->Mapping[nOther], 0, sizeof(struct Map));
        }
        RIORemoveFromSavedTable(p, &HostP->Mapping[unit]);

        return 0;
}


/*
** RIOFindFreeID :
**
** This function scans the given host table for either one
** or two free unit ID's.
*/

int RIOFindFreeID(struct rio_info *p, struct Host *HostP, unsigned int * pID1, unsigned int * pID2)
{
        int unit, tempID;

        /*
         ** Initialise the ID's to MAX_RUP.
         ** We do this to make the loop for setting the ID's as simple as
         ** possible.
         */
        *pID1 = MAX_RUP;
        if (pID2 != NULL)
                *pID2 = MAX_RUP;

        /*
         ** Scan all entries of the host mapping table for free slots.
         ** We scan for free slots first and then if that is not successful
         ** we start all over again looking for tentative slots we can re-use.
         */
        for (unit = 0; unit < MAX_RUP; unit++) {
                rio_dprintk(RIO_DEBUG_ROUTE, "Scanning unit %d\n", unit);
                /*
                 ** If the flags are zero then the slot is empty.
                 */
                if (HostP->Mapping[unit].Flags == 0) {
                        rio_dprintk(RIO_DEBUG_ROUTE, "      This slot is empty.\n");
                        /*
                         ** If we haven't allocated the first ID then do it now.
                         */
                        if (*pID1 == MAX_RUP) {
                                rio_dprintk(RIO_DEBUG_ROUTE, "Make tentative entry for first unit %d\n", unit);
                                *pID1 = unit;

                                /*
                                 ** If the second ID is not needed then we can return
                                 ** now.
                                 */
                                if (pID2 == NULL)
                                        return 0;
                        } else {
                                /*
                                 ** Allocate the second slot and return.
                                 */
                                rio_dprintk(RIO_DEBUG_ROUTE, "Make tentative entry for second unit %d\n", unit);
                                *pID2 = unit;
                                return 0;
                        }
                }
        }

        /*
         ** If we manage to come out of the free slot loop then we
         ** need to start all over again looking for tentative slots
         ** that we can re-use.
         */
        rio_dprintk(RIO_DEBUG_ROUTE, "Starting to scan for tentative slots\n");
        for (unit = 0; unit < MAX_RUP; unit++) {
                if (((HostP->Mapping[unit].Flags & SLOT_TENTATIVE) || (HostP->Mapping[unit].Flags == 0)) && !(HostP->Mapping[unit].Flags & RTA16_SECOND_SLOT)) {
                        rio_dprintk(RIO_DEBUG_ROUTE, "    Slot %d looks promising.\n", unit);

                        if (unit == *pID1) {
                                rio_dprintk(RIO_DEBUG_ROUTE, "    No it isn't, its the 1st half\n");
                                continue;
                        }

                        /*
                         ** Slot is Tentative or Empty, but not a tentative second
                         ** slot of a 16 porter.
                         ** Attempt to free up this slot (and its parnter if
                         ** it is a 16 port slot. The second slot will become
                         ** empty after a call to RIOFreeDisconnected so thats why
                         ** we look for empty slots above  as well).
                         */
                        if (HostP->Mapping[unit].Flags != 0)
                                if (RIOFreeDisconnected(p, HostP, unit) != 0)
                                        continue;
                        /*
                         ** If we haven't allocated the first ID then do it now.
                         */
                        if (*pID1 == MAX_RUP) {
                                rio_dprintk(RIO_DEBUG_ROUTE, "Grab tentative entry for first unit %d\n", unit);
                                *pID1 = unit;

                                /*
                                 ** Clear out this slot now that we intend to use it.
                                 */
                                memset(&HostP->Mapping[unit], 0, sizeof(struct Map));

                                /*
                                 ** If the second ID is not needed then we can return
                                 ** now.
                                 */
                                if (pID2 == NULL)
                                        return 0;
                        } else {
                                /*
                                 ** Allocate the second slot and return.
                                 */
                                rio_dprintk(RIO_DEBUG_ROUTE, "Grab tentative/empty  entry for second unit %d\n", unit);
                                *pID2 = unit;

                                /*
                                 ** Clear out this slot now that we intend to use it.
                                 */
                                memset(&HostP->Mapping[unit], 0, sizeof(struct Map));

                                /* At this point under the right(wrong?) conditions
                                 ** we may have a first unit ID being higher than the
                                 ** second unit ID. This is a bad idea if we are about
                                 ** to fill the slots with a 16 port RTA.
                                 ** Better check and swap them over.
                                 */

                                if (*pID1 > *pID2) {
                                        rio_dprintk(RIO_DEBUG_ROUTE, "Swapping IDS %d %d\n", *pID1, *pID2);
                                        tempID = *pID1;
                                        *pID1 = *pID2;
                                        *pID2 = tempID;
                                }
                                return 0;
                        }
                }
        }

        /*
         ** If we manage to get to the end of the second loop then we
         ** can give up and return a failure.
         */
        return 1;
}


/*
** The link switch scenario.
**
** Rta Wun (A) is connected to Tuw (A).
** The tables are all up to date, and the system is OK.
**
** If Wun (A) is now moved to Wun (B) before Wun (A) can
** become disconnected, then the follow happens:
**
** Tuw (A) spots the change of unit:link at the other end
** of its link and Tuw sends a topology packet reflecting
** the change: Tuw (A) now disconnected from Wun (A), and
** this is closely followed by a packet indicating that 
** Tuw (A) is now connected to Wun (B).
**
** Wun (B) will spot that it has now become connected, and
** Wun will send a topology packet, which indicates that
** both Wun (A) and Wun (B) is connected to Tuw (A).
**
** Eventually Wun (A) realises that it is now disconnected
** and Wun will send out a topology packet indicating that
** Wun (A) is now disconnected.
*/