riointr.c

内核linux2.4.20,可跟rtlinux3.2打补丁 组成实时linux系统,编译内核

    WWORD( HostP->ParmMapP->rup_intr , 0 );
    p->RIORupCount++;
    RupIntr++;
    rio_dprintk (RIO_DEBUG_INTR, "rio: RUP interrupt on host %d\n", HostP-p->RIOHosts);
    RIOPollHostCommands(p, HostP );
  }

  if ( RWORD( HostP->ParmMapP->rx_intr ) ) {
    int port;

    WWORD( HostP->ParmMapP->rx_intr , 0 );
    p->RIORxCount++;
    RxIntr++;

    rio_dprintk (RIO_DEBUG_INTR, "rio: RX interrupt on host %d\n", HostP-p->RIOHosts);
    /*
    ** Loop through every port. If the port is mapped into
    ** the system ( i.e. has /dev/ttyXXXX associated ) then it is
    ** worth checking. If the port isn't open, grab any packets
    ** hanging on its receive queue and stuff them on the free
    ** list; check for commands on the way.
    */
    for ( port=p->RIOFirstPortsBooted; 
	  port<p->RIOLastPortsBooted+PORTS_PER_RTA; port++ ) {
      struct Port *PortP = p->RIOPortp[port];
      struct tty_struct *ttyP;
      struct PKT *PacketP;
		
      /*
      ** not mapped in - most of the RIOPortp[] information
      ** has not been set up!
      ** Optimise: ports come in bundles of eight.
      */
      if ( !PortP->Mapped ) {
	port += 7;
	continue; /* with the next port */
      }

      /*
      ** If the host board isn't THIS host board, check the next one.
      ** optimise: ports come in bundles of eight.
      */
      if ( PortP->HostP != HostP ) {
	port += 7;
	continue;
      }

      /*
      ** Let us see - is the port open? If not, then don't service it.
      */
      if ( !( PortP->PortState & PORT_ISOPEN ) ) {
	continue;
      }

      /*
      ** find corresponding tty structure. The process of mapping
      ** the ports puts these here.
      */
      ttyP = PortP->gs.tty;

      /*
      ** Lock the port before we begin working on it.
      */
      rio_spin_lock(&PortP->portSem);

      /*
      ** Process received data if there is any.
      */
      if ( can_remove_receive( &PacketP, PortP ) )
	RIOReceive(p, PortP);

      /*
      ** If there is no data left to be read from the port, and
      ** it's handshake bit is set, then we must clear the handshake,
      ** so that that downstream RTA is re-enabled.
      */
      if ( !can_remove_receive( &PacketP, PortP ) && 
	   ( RWORD( PortP->PhbP->handshake )==PHB_HANDSHAKE_SET ) ) {
				/*
				** MAGIC! ( Basically, handshake the RX buffer, so that
				** the RTAs upstream can be re-enabled. )
				*/
	rio_dprintk (RIO_DEBUG_INTR, "Set RX handshake bit\n");
	WWORD( PortP->PhbP->handshake, 
	       PHB_HANDSHAKE_SET|PHB_HANDSHAKE_RESET );
      }
      rio_spin_unlock(&PortP->portSem);
    }
  }

  if ( RWORD( HostP->ParmMapP->tx_intr ) ) {
    int port;

    WWORD( HostP->ParmMapP->tx_intr , 0);

    p->RIOTxCount++;
    TxIntr++;
    rio_dprintk (RIO_DEBUG_INTR, "rio: TX interrupt on host %d\n", HostP-p->RIOHosts);

    /*
    ** Loop through every port.
    ** If the port is mapped into the system ( i.e. has /dev/ttyXXXX
    ** associated ) then it is worth checking.
    */
    for ( port=p->RIOFirstPortsBooted; 
	  port<p->RIOLastPortsBooted+PORTS_PER_RTA; port++ ) {
      struct Port *PortP = p->RIOPortp[port];
      struct tty_struct *ttyP;
      struct PKT *PacketP;

      /*
      ** not mapped in - most of the RIOPortp[] information
      ** has not been set up!
      */
      if ( !PortP->Mapped ) {
	port += 7;
	continue; /* with the next port */
      }

      /*
      ** If the host board isn't running, then its data structures
      ** are no use to us - continue quietly.
      */
      if ( PortP->HostP != HostP ) {
	port += 7;
	continue; /* with the next port */
      }

      /*
      ** Let us see - is the port open? If not, then don't service it.
      */
      if ( !( PortP->PortState & PORT_ISOPEN ) ) {
	continue;
      }

      rio_dprintk (RIO_DEBUG_INTR, "rio: Looking into port %d.\n", port);
      /*
      ** Lock the port before we begin working on it.
      */
      rio_spin_lock(&PortP->portSem);

      /*
      ** If we can't add anything to the transmit queue, then
      ** we need do none of this processing.
      */
      if ( !can_add_transmit( &PacketP, PortP ) ) {
	rio_dprintk (RIO_DEBUG_INTR, "Can't add to port, so skipping.\n");
	rio_spin_unlock(&PortP->portSem);
	continue;
      }

      /*
      ** find corresponding tty structure. The process of mapping
      ** the ports puts these here.
      */
      ttyP = PortP->gs.tty;
      /* If ttyP is NULL, the port is getting closed. Forget about it. */
      if (!ttyP) {
	rio_dprintk (RIO_DEBUG_INTR, "no tty, so skipping.\n");
	rio_spin_unlock(&PortP->portSem);
	continue;
      }
      /*
      ** If there is more room available we start up the transmit
      ** data process again. This can be direct I/O, if the cookmode
      ** is set to COOK_RAW or COOK_MEDIUM, or will be a call to the
      ** riotproc( T_OUTPUT ) if we are in COOK_WELL mode, to fetch
      ** characters via the line discipline. We must always call
      ** the line discipline,
      ** so that user input characters can be echoed correctly.
      **
      ** ++++ Update +++++
      ** With the advent of double buffering, we now see if
      ** TxBufferOut-In is non-zero. If so, then we copy a packet
      ** to the output place, and set it going. If this empties
      ** the buffer, then we must issue a wakeup( ) on OUT.
      ** If it frees space in the buffer then we must issue
      ** a wakeup( ) on IN.
      **
      ** ++++ Extra! Extra! If PortP->WflushFlag is set, then we
      ** have to send a WFLUSH command down the PHB, to mark the
      ** end point of a WFLUSH. We also need to clear out any
      ** data from the double buffer! ( note that WflushFlag is a
      ** *count* of the number of WFLUSH commands outstanding! )
      **
      ** ++++ And there's more!
      ** If an RTA is powered off, then on again, and rebooted,
      ** whilst it has ports open, then we need to re-open the ports.
      ** ( reasonable enough ). We can't do this when we spot the
      ** re-boot, in interrupt time, because the queue is probably
      ** full. So, when we come in here, we need to test if any
      ** ports are in this condition, and re-open the port before
      ** we try to send any more data to it. Now, the re-booted
      ** RTA will be discarding packets from the PHB until it
      ** receives this open packet, but don't worry tooo much
      ** about that. The one thing that is interesting is the
      ** combination of this effect and the WFLUSH effect!
      */
      /* For now don't handle RTA reboots. -- REW. 
	 Reenabled. Otherwise RTA reboots didn't work. Duh. -- REW */
      if ( PortP->MagicFlags ) {
#if 1
	if ( PortP->MagicFlags & MAGIC_REBOOT ) {
	  /*
	  ** well, the RTA has been rebooted, and there is room
	  ** on its queue to add the open packet that is required.
	  **
	  ** The messy part of this line is trying to decide if
	  ** we need to call the Param function as a tty or as
	  ** a modem.
	  ** DONT USE CLOCAL AS A TEST FOR THIS!
	  **
	  ** If we can't param the port, then move on to the
	  ** next port.
	  */
	  PortP->InUse = NOT_INUSE;

	  rio_spin_unlock(&PortP->portSem);
	  if ( RIOParam(PortP, OPEN, ((PortP->Cor2Copy & 
				       (COR2_RTSFLOW|COR2_CTSFLOW ) )== 
				      (COR2_RTSFLOW|COR2_CTSFLOW ) ) ? 
			TRUE : FALSE, DONT_SLEEP ) == RIO_FAIL ) {
	    continue; /* with next port */
	  }
	  rio_spin_lock(&PortP->portSem);
	  PortP->MagicFlags &= ~MAGIC_REBOOT;
	}
#endif

	/*
	** As mentioned above, this is a tacky hack to cope
	** with WFLUSH
	*/
	if ( PortP->WflushFlag ) {
	  rio_dprintk (RIO_DEBUG_INTR, "Want to WFLUSH mark this port\n");

	  if ( PortP->InUse )
	    rio_dprintk (RIO_DEBUG_INTR, "FAILS - PORT IS IN USE\n");
	}
				
	while ( PortP->WflushFlag &&
		can_add_transmit( &PacketP, PortP ) && 
		( PortP->InUse == NOT_INUSE ) ) {
	  int p;
	  struct PktCmd *PktCmdP;

	  rio_dprintk (RIO_DEBUG_INTR, "Add WFLUSH marker to data queue\n");
	  /*
	  ** make it look just like a WFLUSH command
	  */
	  PktCmdP = ( struct PktCmd * )&PacketP->data[0];

	  WBYTE( PktCmdP->Command , WFLUSH );

	  p =  PortP->HostPort % ( ushort )PORTS_PER_RTA;

	  /*
	  ** If second block of ports for 16 port RTA, add 8
	  ** to index 8-15.
	  */
	  if ( PortP->SecondBlock )
	    p += PORTS_PER_RTA;

	  WBYTE( PktCmdP->PhbNum, p );

	  /*
	  ** to make debuggery easier
	  */
	  WBYTE( PacketP->data[ 2], 'W'  );
	  WBYTE( PacketP->data[ 3], 'F'  );
	  WBYTE( PacketP->data[ 4], 'L'  );
	  WBYTE( PacketP->data[ 5], 'U'  );
	  WBYTE( PacketP->data[ 6], 'S'  );
	  WBYTE( PacketP->data[ 7], 'H'  );
	  WBYTE( PacketP->data[ 8], ' '  );
	  WBYTE( PacketP->data[ 9], '0'+PortP->WflushFlag );
	  WBYTE( PacketP->data[10], ' '  );
	  WBYTE( PacketP->data[11], ' '  );
	  WBYTE( PacketP->data[12], '\0' );

	  /*
	  ** its two bytes long!
	  */
	  WBYTE( PacketP->len , PKT_CMD_BIT | 2 );

	  /*
	  ** queue it!
	  */
	  if ( !( PortP->State & RIO_DELETED ) ) {
	    add_transmit( PortP );
	    /*
	    ** Count chars tx'd for port statistics reporting
	    */
	    if ( PortP->statsGather )
	      PortP->txchars += 2;
	  }

	  if ( --( PortP->WflushFlag ) == 0 ) {
	    PortP->MagicFlags &= ~MAGIC_FLUSH;
	  }

	  rio_dprintk (RIO_DEBUG_INTR, "Wflush count now stands at %d\n", 
		 PortP->WflushFlag);
	}
	if ( PortP->MagicFlags & MORE_OUTPUT_EYGOR ) {
	  if ( PortP->MagicFlags & MAGIC_FLUSH ) {
	    PortP->MagicFlags |= MORE_OUTPUT_EYGOR;
	  }
	  else {
	    if ( !can_add_transmit( &PacketP, PortP ) ) {
	      rio_spin_unlock(&PortP->portSem);
	      continue;
	    }
	    rio_spin_unlock(&PortP->portSem);
	    RIOTxEnable((char *)PortP);
	    rio_spin_lock(&PortP->portSem);
	    PortP->MagicFlags &= ~MORE_OUTPUT_EYGOR;
	  }
	}
      }


      /*
      ** If we can't add anything to the transmit queue, then
      ** we need do none of the remaining processing.
      */
      if (!can_add_transmit( &PacketP, PortP ) ) {
	rio_spin_unlock(&PortP->portSem);
	continue;
      }

      rio_spin_unlock(&PortP->portSem);
      RIOTxEnable((char *)PortP);
    }
  }
}

/*
** Routine for handling received data for clist drivers.
** NB: Called with the tty locked. The spl from the lockb( ) is passed.
** we return the ttySpl level that we re-locked at.
*/
void
RIOReceive(p, PortP)
struct rio_info *	p;
struct Port *		PortP;
{
  struct tty_struct *TtyP;
  register ushort transCount;
  struct PKT *PacketP;
  register uint	DataCnt;
  uchar *	ptr;
  int copied =0;

  static int intCount, RxIntCnt;

  /*
  ** The receive data process is to remove packets from the
  ** PHB until there aren't any more or the current cblock
  ** is full. When this occurs, there will be some left over
  ** data in the packet, that we must do something with.
  ** As we haven't unhooked the packet from the read list
  ** yet, we can just leave the packet there, having first
  ** made a note of how far we got. This means that we need
  ** a pointer per port saying where we start taking the
  ** data from - this will normally be zero, but when we
  ** run out of space it will be set to the offset of the
  ** next byte to copy from the packet data area. The packet
  ** length field is decremented by the number of bytes that
  ** we succesfully removed from the packet. When this reaches
  ** zero, we reset the offset pointer to be zero, and free
  ** the packet from the front of the queue.