rioroute.c

linux-2.6.15.6

		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)
*/

uint
GetUnitType(Uniq)
uint 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(p)
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(p, HostP, FromId, FromLink, ToId, ToLink, Change)
struct rio_info *	p;
struct Host *HostP;
uint FromId;
uint FromLink;
uint ToId;
uint 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");
    cprintf("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)
	{
	    bzero((caddr_t)&p->RIOSavedTable[entry], 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);
	bzero((caddr_t)&HostP->Mapping[nOther], 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, uint *pID1, uint *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.
		*/
		bzero(&HostP->Mapping[unit], 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.
		*/
		bzero(&HostP->Mapping[unit], 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.
*/