network.c

RTEMS (Real-Time Executive for Multiprocessor Systems) is a free open source real-time operating sys

        rtems_bsdnet_event_receive (INTERRUPT_EVENT,
                                    RTEMS_WAIT|RTEMS_EVENT_ANY,
                                    RTEMS_NO_TIMEOUT,
                                    &events);

/*        printk( "Rxd " ); */
      }
    }
    
    /*
     * Check that packet is valid
     */
    if ((status & (M8260_BD_LAST |
                   M8260_BD_FIRST_IN_FRAME |
    		   M8260_BD_LONG |
                   M8260_BD_NONALIGNED |
                   M8260_BD_ABORT |
                   M8260_BD_CRC_ERROR |
                   M8260_BD_OVERRUN /*|
                   M8260_BD_CARRIER_LOST*/)) ==
                   (M8260_BD_LAST |
                   M8260_BD_FIRST_IN_FRAME ) ) {

/*      printk( "RxV " ); */

/*
 * Invalidate the buffer for this descriptor
 */

      rtems_cache_invalidate_multiple_data_lines((void *)rxBd->buffer, rxBd->length);

      m = sc->rxMbuf[rxBdIndex];

      /* strip off HDLC CRC */
      m->m_len = m->m_pkthdr.len = rxBd->length - sizeof(rtems_unsigned16);

      hdlc_input( ifp, m );

      /*
       * Allocate a new mbuf
       */
      MGETHDR (m, M_WAIT, MT_DATA);
      MCLGET (m, M_WAIT);
      m->m_pkthdr.rcvif = ifp;
      sc->rxMbuf[rxBdIndex] = m;
      rxBd->buffer = mtod (m, void *);
    }
    else {
      printk( "RxErr[%04X,%d]", status, rxBd->length );
      /*
       * Something went wrong with the reception
       */
      if (!(status & M8260_BD_LAST))
        sc->rxNotLast++;
      if (!(status & M8260_BD_FIRST_IN_FRAME))
        sc->rxNotFirst++;

      if (status & M8260_BD_LONG)
        sc->rxGiant++;
      if (status & M8260_BD_NONALIGNED)
        sc->rxNonOctet++;
      if (status & M8260_BD_ABORT)
        sc->rxAbort++;
      if (status & M8260_BD_CRC_ERROR)
        sc->rxBadCRC++;
      if (status & M8260_BD_OVERRUN)
        sc->rxOverrun++;
      if (status & M8260_BD_CARRIER_LOST)
        sc->rxLostCarrier++;
    }
    
    /*
     * Reenable the buffer descriptor
     */
    rxBd->status = (status & (M8260_BD_WRAP | M8260_BD_INTERRUPT)) |
                    M8260_BD_EMPTY;
    
    /*
     * Move to next buffer descriptor
     */
    if (++rxBdIndex == sc->rxBdCount)
      rxBdIndex = 0;
  }
}


static void
scc_sendpacket (struct ifnet *ifp, struct mbuf *m)
{
  struct m8260_hdlc_struct *sc = ifp->if_softc;
  volatile m8260BufferDescriptor_t *firstTxBd, *txBd;
  struct mbuf *l = NULL;
  rtems_unsigned16 status;
  int nAdded;
  
  /*
   * Free up buffer descriptors
   */
  m8260Enet_retire_tx_bd (sc);
  
  /*
   * Set up the transmit buffer descriptors.
   * No need to pad out short packets since the
   * hardware takes care of that automatically.
   * No need to copy the packet to a contiguous buffer
   * since the hardware is capable of scatter/gather DMA.
   */
  nAdded = 0;
  txBd = firstTxBd = sc->txBdBase + sc->txBdHead;

/*
  m8260.scc3.sccm |= (M8260_SCCE_TX | M8260_SCCE_TXE);
*/

  for (;;) {
    /*
     * Wait for buffer descriptor to become available.
     */
    if ((sc->txBdActiveCount + nAdded) == sc->txBdCount) {
      /*
       * Clear old events
       */
      m8260.scc3.scce = M8260_SCCE_TX | M8260_SCCE_TXE;
      
      /*
       * Wait for buffer descriptor to become available.
       * Note that the buffer descriptors are checked
       * *before* * entering the wait loop -- this catches
       * the possibility that a buffer descriptor became
       * available between the `if' above, and the clearing
       * of the event register.
       * This is to catch the case where the transmitter
       * stops in the middle of a frame -- and only the
       * last buffer descriptor in a frame can generate
       * an interrupt.
       */
      m8260Enet_retire_tx_bd (sc);
      while ((sc->txBdActiveCount + nAdded) == sc->txBdCount) {
        rtems_event_set events;
        
        /*
         * Unmask TX (buffer transmitted) event
         */
        m8260.scc3.sccm |= (M8260_SCCE_TX | M8260_SCCE_TXE);

        rtems_bsdnet_event_receive (INTERRUPT_EVENT,
                                    RTEMS_WAIT|RTEMS_EVENT_ANY,
                                    RTEMS_NO_TIMEOUT,
                                    &events);
        m8260Enet_retire_tx_bd (sc);
      }
    }
    
    /*
     * Don't set the READY flag till the
     * whole packet has been readied.
     */
    status = nAdded ? M8260_BD_READY : 0;
    
    /*
     *  FIXME: Why not deal with empty mbufs at at higher level?
     * The IP fragmentation routine in ip_output
     * can produce packet fragments with zero length.
     * I think that ip_output should be changed to get
     * rid of these zero-length mbufs, but for now,
     * I'll deal with them here.
     */
    if (m->m_len) {
      /*
       * Fill in the buffer descriptor
       */

      txBd->buffer = mtod (m, void *);
      txBd->length = m->m_len;


      /*
       * Flush the buffer for this descriptor
       */

      rtems_cache_flush_multiple_data_lines((void *)txBd->buffer, txBd->length);


/* throw off the header for Ethernet Emulation mode */
/*
      txBd->buffer = mtod (m, void *);
      txBd->buffer += sizeof( struct ether_header ) + 2;
      txBd->length = m->m_len - sizeof( struct ether_header ) - 2;
*/
      sc->txMbuf[sc->txBdHead] = m;
      nAdded++;
      if (++sc->txBdHead == sc->txBdCount) {
        status |= M8260_BD_WRAP;
        sc->txBdHead = 0;
      }
      l = m;
      m = m->m_next;
    }
    else {
      /*
       * Just toss empty mbufs
       */
      struct mbuf *n;
      MFREE (m, n);
      m = n;
      if (l != NULL)
        l->m_next = m;
    }
    
    /*
     * Set the transmit buffer status.
     * Break out of the loop if this mbuf is the last in the frame.
     */
    if (m == NULL) {
      if (nAdded) {
        status |= M8260_BD_LAST | M8260_BD_TX_CRC | M8260_BD_INTERRUPT;
        txBd->status = status;
        firstTxBd->status |= M8260_BD_READY;
        sc->txBdActiveCount += nAdded;
      }
      break;
    }
    txBd->status = status;
    txBd = sc->txBdBase + sc->txBdHead;
  }
}


/*
 * Driver transmit daemon
 */
void
scc_txDaemon (void *arg)
{
  struct m8260_hdlc_struct *sc = (struct m8260_hdlc_struct *)arg;
  struct ifnet *ifp = &sc->ac_if;
  struct mbuf *m;
  rtems_event_set events;
  
  for (;;) {
    /*
     * Wait for packet
     */
    rtems_bsdnet_event_receive (START_TRANSMIT_EVENT, RTEMS_EVENT_ANY | RTEMS_WAIT, RTEMS_NO_TIMEOUT, &events);
    
    /*
     * Send packets till queue is empty
     */
    for (;;) {
      /*
       * Get the next mbuf chain to transmit.
       */
      IF_DEQUEUE(&ifp->if_snd, m);
      if (!m)
        break;


      scc_sendpacket (ifp, m);


    }
    ifp->if_flags &= ~IFF_OACTIVE;
  }
}


/*
 * Send packet (caller provides header).
 */
static void
m8260_hdlc_start (struct ifnet *ifp)
{
  struct m8260_hdlc_struct *sc = ifp->if_softc;
  
  rtems_event_send (sc->txDaemonTid, START_TRANSMIT_EVENT);
  ifp->if_flags |= IFF_OACTIVE;
}

/*
 * Initialize and start the device
 */
static void
scc_init (void *arg)
{
  struct m8260_hdlc_struct *sc = arg;
  struct ifnet *ifp = &sc->ac_if;
  
  if (sc->txDaemonTid == 0) {
    
    /*
     * Set up SCC hardware
     */
    m8260_scc_initialize_hardware (sc);
    
    /*
     * Start driver tasks
     */
    sc->txDaemonTid = rtems_bsdnet_newproc ("SCtx", 4096, scc_txDaemon, sc);
    sc->rxDaemonTid = rtems_bsdnet_newproc ("SCrx", 4096, scc_rxDaemon, sc);
    
  }
  
#if 0
  /*
   * Set flags appropriately
   */
  if (ifp->if_flags & IFF_PROMISC)
    m8260.scc3.psmr |= 0x200;
  else
    m8260.scc3.psmr &= ~0x200;
#endif

  /*
   * Tell the world that we're running.
   */
  ifp->if_flags |= IFF_RUNNING;
  
  /*
   * Enable receiver and transmitter
   */
  m8260.scc3.gsmr_l |= 0x30;
}



/*
 * Stop the device
 */
static void
scc_stop (struct m8260_hdlc_struct *sc)
{
  struct ifnet *ifp = &sc->ac_if;
  
  ifp->if_flags &= ~IFF_RUNNING;
  
  /*
   * Shut down receiver and transmitter
   */
  m8260.scc3.gsmr_l &= ~0x30;
}


/*
 * Show interface statistics
 */
static void
hdlc_stats (struct m8260_hdlc_struct *sc)
{
  printf ("      Rx Interrupts:%-8lu", sc->rxInterrupts);
  printf ("              Giant:%-8lu", sc->rxGiant);
  printf ("          Non-octet:%-8lu\n", sc->rxNonOctet);
  printf ("            Bad CRC:%-8lu", sc->rxBadCRC);
  printf ("            Overrun:%-8lu", sc->rxOverrun);
  printf ("         No Carrier:%-8lu\n", sc->rxLostCarrier);
  printf ("          Discarded:%-8lu\n", (unsigned long)m8260.scc3p.un.hdlc.disfc);
  
  printf ("      Tx Interrupts:%-8lu", sc->txInterrupts);
  printf ("         No Carrier:%-8lu", sc->txLostCarrier);
  printf ("           Underrun:%-8lu\n", sc->txUnderrun);
  printf ("    Raw output wait:%-8lu\n", sc->txRawWait);
}

/*
 * Driver ioctl handler
 */
static int
scc_ioctl (struct ifnet *ifp, int command, caddr_t data)
{
  struct m8260_hdlc_struct *sc = ifp->if_softc;
  int error = 0;
  
  switch (command) {
  case SIOCGIFADDR:
  case SIOCSIFADDR:
    hdlc_ioctl (ifp, command, data);
    break;
    
  case SIOCSIFFLAGS:
    switch (ifp->if_flags & (IFF_UP | IFF_RUNNING)) {
    case IFF_RUNNING:
      scc_stop (sc);
      break;
      
    case IFF_UP:
      scc_init (sc);
      break;
      
    case IFF_UP | IFF_RUNNING:
      scc_stop (sc);
      scc_init (sc);
      break;
      
    default:
      break;
    }
    break;
    
  case SIO_RTEMS_SHOW_STATS:
    hdlc_stats (sc);
    break;
    
    /*
     * FIXME: All sorts of multicast commands need to be added here!
     */
  default:
    error = EINVAL;
    break;
  }
  return error;
}



/*
 * Attach an SCC driver to the system
 */
int
rtems_scc3_driver_attach (struct rtems_bsdnet_ifconfig *config)
{
  struct m8260_hdlc_struct *sc;
  struct ifnet *ifp;
  int mtu;
  int i;
  
  /*
   * Find a free driver
   */
  for (i = 0 ; i < NIFACES ; i++) {
    sc = &hdlc_driver[i];
    ifp = &sc->ac_if;
    if (ifp->if_softc == NULL)
      break;
  }
  if (i >= NIFACES) {
    printf ("Too many SCC drivers.\n");
    return 0;
  }

#if 0
  /*
   * Process options
   */

  if (config->hardware_address) {
    memcpy (sc->arpcom.ac_enaddr, config->hardware_address, ETHER_ADDR_LEN);
  }
  else {
    sc->arpcom.ac_enaddr[0] = 0x44;
    sc->arpcom.ac_enaddr[1] = 0x22;
    sc->arpcom.ac_enaddr[2] = 0x33;
    sc->arpcom.ac_enaddr[3] = 0x33;
    sc->arpcom.ac_enaddr[4] = 0x22;
    sc->arpcom.ac_enaddr[5] = 0x44;
  }
#endif

  if (config->mtu)
    mtu = config->mtu;
  else
    mtu = ETHERMTU;
  if (config->rbuf_count)
    sc->rxBdCount = config->rbuf_count;
  else
    sc->rxBdCount = RX_BUF_COUNT;
  if (config->xbuf_count)
    sc->txBdCount = config->xbuf_count;
  else
    sc->txBdCount = TX_BUF_COUNT * TX_BD_PER_BUF;
  sc->acceptBroadcast = !config->ignore_broadcast;
  
  /*
   * Set up network interface values
   */
  ifp->if_softc = sc;
  ifp->if_unit = i + 1;
  ifp->if_name = "eth";
  ifp->if_mtu = mtu;
  ifp->if_init = scc_init;
  ifp->if_ioctl = scc_ioctl;
  ifp->if_start = m8260_hdlc_start;
  ifp->if_output = hdlc_output;
  ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | /*IFF_PROMISC |*/ IFF_NOARP;
  if (ifp->if_snd.ifq_maxlen == 0)
    ifp->if_snd.ifq_maxlen = ifqmaxlen;
  
  /*
   * Attach the interface
   */
  if_attach (ifp);
  hdlc_ifattach (ifp);
  return 1;
};


int
rtems_enet_driver_attach(struct rtems_bsdnet_ifconfig *config, int attaching)
{
  return rtems_scc3_driver_attach( config );

/*
  if ((m8260.fec.mii_data & 0xffff) == 0x2000) {
    return rtems_fec_driver_attach(config);
  }
  else {
    return rtems_scc1_driver_attach(config);
  }
*/
}