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/* ethernet.c -- Simulation of Ethernet MAC
 
   Copyright (C) 2001 by Erez Volk, erez@opencores.org
                         Ivan Guzvinec, ivang@opencores.org
   Copyright (C) 2008, 2001 Embecosm Limited
   Copyright (C) 2010 ORSoC
 
   Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>
   Contributor Julius Baxter <julius@orsoc.se>
 
   This file is part of Or1ksim, the OpenRISC 1000 Architectural Simulator.
 
   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 3 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, see <http://www.gnu.org/licenses/>.  */
 
/* This program is commented throughout in a fashion suitable for processing
   with Doxygen. */
 
 
/* Autoconf and/or portability configuration */
#include "config.h"
#include "port.h"
 
/* System includes */
#include <stdlib.h>
#include <stdio.h>
 
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
 
#include <sys/poll.h>
#include <unistd.h>
#include <errno.h>
 
#include <linux/if.h>
#include <linux/if_tun.h>
 
/* Package includes */
#include "arch.h"
#include "config.h"
#include "abstract.h"
#include "eth.h"
#include "dma.h"
#include "sim-config.h"
#include "fields.h"
#include "crc32.h"
#include "vapi.h"
#include "pic.h"
#include "sched.h"
#include "toplevel-support.h"
#include "sim-cmd.h"
 
 
/* Control debug messages */
#define ETH_DEBUG 0
#ifndef ETH_DEBUG
# define ETH_DEBUG  1
#endif
 
/*! Period (clock cycles) for rescheduling Rx and Tx controllers.
    Experimenting with FTP on one machine suggests that a value of 500-2000 is
    optimal. It's a trade off between prompt response and extra computational
    load for Or1ksim. */
#define  RTX_RESCHED_PERIOD  2000
 
/*! MAC address that is always accepted. */
static const unsigned char mac_broadcast[ETHER_ADDR_LEN] =
  { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 
/* -------------------------------------------------------------------------- */
/*!Structure describing the Ethernet device                                   */
/* -------------------------------------------------------------------------- */
struct eth_device
{
  /* Basic stuff about the device */
  int                enabled;           /* Is peripheral enabled */
  oraddr_t           baseaddr;          /* Base address in memory */
  unsigned long int  base_vapi_id;      /* Start of VAPI ID block */
 
  /* DMA controller this MAC is connected to, and associated channels */
  unsigned dma;
  unsigned tx_channel;
  unsigned rx_channel;
 
  /* Details of the hardware */
  unsigned char      mac_address[ETHER_ADDR_LEN];  /* Ext HW address */
  unsigned long int  phy_addr;          /* Int HW address */
  unsigned long int  mac_int;           /* interrupt line number */
  int                dummy_crc;         /* Flag indicating if we add CRC */
  int                int_line_stat;     /* interrupt line status */
 
  /* External interface deatils */
  int rtx_type;                         /* Type of external i/f: FILE or TAP */
 
  /* RX and TX file names and handles for FILE type connection. */
  char  *rxfile;                        /* Rx filename */
  char  *txfile;                        /* Tx filename */
  int    txfd;                          /* Rx file handle */
  int    rxfd;                          /* Tx file handle */
 
  /* Info for TAP type connections */
  char *tap_dev;                        /* The TAP device */
  int   rtx_fd;                         /* TAP device handle */
 
  /* Indices into the buffer descriptors. */
  unsigned long int  tx_bd_index;
  unsigned long int  rx_bd_index;
 
  /* Visible registers */
  struct
  {
    unsigned long int  moder;
    unsigned long int  int_source;
    unsigned long int  int_mask;
    unsigned long int  ipgt;
    unsigned long int  ipgr1;
    unsigned long int  ipgr2;
    unsigned long int  packetlen;
    unsigned long int  collconf;
    unsigned long int  tx_bd_num;
    unsigned long int  controlmoder;
    unsigned long int  miimoder;
    unsigned long int  miicommand;
    unsigned long int  miiaddress;
    unsigned long int  miitx_data;
    unsigned long int  miirx_data;
    unsigned long int  miistatus;
    unsigned long int  hash0;
    unsigned long int  hash1;
 
    /* Buffer descriptors */
    unsigned long int  bd_ram[ETH_BD_SPACE / 4];
  } regs;
};
 
 
/* -------------------------------------------------------------------------- */
/*!Write an Ethernet packet to a FILE interface.
 
   This writes a single Ethernet packet to a FILE interface. The format is to
   write the length, then the data.
 
   @param[in] eth     Pointer to the relevant Ethernet data structure.
   @param[in] buf     Where to get the data.
   @param[in] length  Length of data to write.
 
   @return  The length if successful, a negative value otherwise.             */
/* -------------------------------------------------------------------------- */
static ssize_t
eth_write_file_packet (struct eth_device *eth,
                       unsigned char     *buf,
                       unsigned long int  length)
{
  ssize_t  nwritten;
 
  /* Write length to file. */
  nwritten = write (eth->txfd, &(length), sizeof (length));
  if (nwritten != sizeof (length))
    {
      fprintf (stderr, "ERROR: Failed to write Ethernet packet length: %s.\n",
               strerror (errno));
      return  -1;
    }
 
  /* write data to file */
  nwritten = write (eth->txfd, buf, length);
  if (nwritten != length)
    {
      fprintf (stderr, "ERROR: Failed to write Ethernet packet data: %s.\n",
               strerror (errno));
      return  -1;
    }
 
  return  nwritten;
 
}       /* eth_write_file_packet () */
 
 
/* -------------------------------------------------------------------------- */
/*!Write an Ethernet packet to a TAP interface.
 
   This writes a single Ethernet packet to a TAP interface.
 
   @param[in] eth     Pointer to the relevant Ethernet data structure.
   @param[in] buf     Where to get the data.
   @param[in] length  Length of data to write.
 
   @return  The length if successful, a negative value otherwise.             */
/* -------------------------------------------------------------------------- */
static ssize_t
eth_write_tap_packet (struct eth_device *eth,
                      unsigned char     *buf,
                      unsigned long int  length)
{
  ssize_t  nwritten;
 
#if ETH_DEBUG
  int  j;
 
  printf ("Writing TAP\n");
  printf ("  packet %d bytes:", (int) length);
 
  for (j = 0; j < length; j++)
    {
      if (0 == (j % 16))
        {
          printf ("\n");
        }
      else if (0 == (j % 8))
        {
          printf (" ");
        }
 
      printf ("%.2x ", buf[j]);
    }
 
  printf("\nend packet:\n");
#endif    
 
  /* Write the data to the TAP */
  nwritten = write (eth->rtx_fd, buf, length);
  if (nwritten != length)
    {
      fprintf (stderr, "ERROR: Failed to write Ethernet packet data: %s.\n",
               strerror (errno));
      return  -1;
    }
 
  return  nwritten;
 
}       /* eth_write_tap_packet () */
 
 
/* -------------------------------------------------------------------------- */
/*!Write an Ethernet packet.
 
   This writes a single Ethernet packet to the outside world from the supplied
   buffer. It deals with the different types of external interface.
 
   @param[in] eth     Pointer to the relevant Ethernet data structure.
   @param[in] buf     Where to get the data.
   @param[in] length  Length of data to write.
 
   @return  The length if successful, zero if no packet was available,
            a negative value otherwise.                                       */
/* -------------------------------------------------------------------------- */
static ssize_t
eth_write_packet (struct eth_device *eth,
                  unsigned char     *buf,
                  ssize_t            length)
{
  /* Send packet according to interface type. */
  switch (eth->rtx_type)
    {
    case ETH_RTX_FILE: return  eth_write_file_packet (eth, buf, length);
    case ETH_RTX_TAP:  return  eth_write_tap_packet (eth, buf, length);
 
    default:
      fprintf (stderr, "Unknown Ethernet write interface: ignored.\n");
      return  (ssize_t) -1;
    }
}       /* eth_write_packet () */
 
 
/* -------------------------------------------------------------------------- */
/*!Flush a Tx buffer descriptor to the outside world.
 
   We know the buffer descriptor is full, so write it to the appropriate
   outside interface.
 
   @param[in] eth  The Ethernet data structure.                               */
/* -------------------------------------------------------------------------- */
static void
eth_flush_bd (struct eth_device *eth)
{
  /* First word of BD is flags and length, second is pointer to buffer */
  unsigned long int  bd_info = eth->regs.bd_ram[eth->tx_bd_index];
  unsigned long int  bd_addr = eth->regs.bd_ram[eth->tx_bd_index + 1];
  unsigned char      buf[ETH_MAXPL];
  long int           packet_length;
  long int           bytes_sent;
  int                ok_to_int_p;
 
  /* Get the packet length */
  packet_length = GET_FIELD (bd_info, ETH_TX_BD, LENGTH);
 
  /* Clear error status bits and retry count. */
  CLEAR_FLAG (bd_info, ETH_TX_BD, DEFER);
  CLEAR_FLAG (bd_info, ETH_TX_BD, COLLISION);
  CLEAR_FLAG (bd_info, ETH_TX_BD, RETRANSMIT);
  CLEAR_FLAG (bd_info, ETH_TX_BD, UNDERRUN);
  CLEAR_FLAG (bd_info, ETH_TX_BD, NO_CARRIER);
 
  SET_FIELD (bd_info, ETH_TX_BD, RETRY, 0);
 
  /* Copy data from buffer descriptor address into our local buf. */
  for (bytes_sent = 0; bytes_sent < packet_length; bytes_sent +=4)
    {
      unsigned long int  read_word =
        eval_direct32 (bytes_sent + bd_addr, 0, 0);
 
      buf[bytes_sent]     = (unsigned char) (read_word >> 24);
      buf[bytes_sent + 1] = (unsigned char) (read_word >> 16);
      buf[bytes_sent + 2] = (unsigned char) (read_word >> 8);
      buf[bytes_sent + 3] = (unsigned char) (read_word);
    }
 
  /* Send packet according to interface type and set BD status. If we didn't
     write the whole packet, then we retry. */
  if (eth_write_packet (eth, buf, packet_length) == packet_length)
    {
      CLEAR_FLAG (bd_info, ETH_TX_BD, READY);
      SET_FLAG (eth->regs.int_source, ETH_INT_SOURCE, TXB);
      ok_to_int_p = TEST_FLAG (eth->regs.int_mask, ETH_INT_MASK, TXB_M);
    }
  else
    {
      /* Does this retry mechanism really work? */
      CLEAR_FLAG (bd_info, ETH_TX_BD, READY);
      CLEAR_FLAG (bd_info, ETH_TX_BD, COLLISION);
      SET_FLAG (eth->regs.int_source, ETH_INT_SOURCE, TXE);
      ok_to_int_p = TEST_FLAG (eth->regs.int_mask, ETH_INT_MASK, TXE_M);
#if ETH_DEBUG
      printf ("Transmit retry request.\n");
#endif
    }
 
  /* Update the flags in the buffer descriptor */
  eth->regs.bd_ram[eth->tx_bd_index] = bd_info;
 
  /* Generate interrupt to indicate transfer complete, under the
     following criteria all being met:
     - either INT_MASK flag for Tx (OK or error) is set
     - the buffer descriptor has its IRQ flag set
     - there is no interrupt in progress.
 
     @todo We ought to warn if we get here and fail to set an IRQ. */
  if (ok_to_int_p && TEST_FLAG (bd_info, ETH_TX_BD, IRQ))
    {
      if (eth->int_line_stat)
        {
          fprintf (stderr, "Warning: Interrupt active during Tx.\n");
        }
      else
        {
#if ETH_DEBUG
          printf ("TRANSMIT interrupt\n");
#endif
          report_interrupt (eth->mac_int);
          eth->int_line_stat = 1;
        }
    }
 
  /* Advance to next BD, wrapping around if appropriate. */
  if (TEST_FLAG (bd_info, ETH_TX_BD, WRAP) ||
      eth->tx_bd_index >= ((eth->regs.tx_bd_num - 1) * 2))
    {
      eth->tx_bd_index = 0;
    }
  else
    {
      eth->tx_bd_index += 2;
    }
}       /* eth_flush_bd () */
 
 
/* -------------------------------------------------------------------------- */
/*!Tx clock function.
 
   Responsible for starting and completing any TX actions.
 
   The original version had 4 states, which allowed modeling the transfer of
   data one byte per cycle.  For now we use only the one state for
   efficiency. When we find something in a buffer descriptor, we transmit
   it.
 
   We reschedule every cycle. There is no point in trying to do anything if
   there is an interrupt still being processed by the core.
 
   @todo We should eventually reinstate the one byte per cycle transfer.
 
   @param[in] dat  The Ethernet data structure, passed as a void pointer.    */
/* -------------------------------------------------------------------------- */
static void
eth_controller_tx_clock (void *dat)
{
  struct eth_device *eth = dat;
 
  /* Only do anything if there is not an interrupt outstanding. */
  if (!eth->int_line_stat)
    {
      /* First word of BD is flags. If we have a buffer ready, get it and
         transmit it. */
      if (TEST_FLAG (eth->regs.bd_ram[eth->tx_bd_index], ETH_TX_BD, READY))
        {
          eth_flush_bd (eth);
        }
    }
 
  /* Reschedule to wake up again. */
  SCHED_ADD (eth_controller_tx_clock, dat, RTX_RESCHED_PERIOD);
 
}       /* eth_controller_tx_clock () */
 
 
/* -------------------------------------------------------------------------- */
/*!Read an Ethernet packet from a FILE interface.
 
   This reads a single Ethernet packet from the outside world via a FILE
   interface.
 
   The format is 4 bytes of packet length, followed by the packet data.
 
   @param[in]  eth  Pointer to the relevant Ethernet data structure
   @param[out] buf  Where to put the data
 
   @return  The length if successful, zero if no packet was available
            (i.e. EOF), a negative value otherwise.                           */
/* -------------------------------------------------------------------------- */
static ssize_t
eth_read_file_packet (struct eth_device *eth,
                      unsigned char     *buf)
{
  ssize_t  packet_length;
  ssize_t  nread;
 
  /* Read packet length. We may be at EOF. */
  nread = read (eth->rxfd, &(packet_length), sizeof (packet_length));
 
  if (0 == nread)
    {
      return  0;                 /* No more packets */
    }
  else if (nread < sizeof (packet_length))
    {
      fprintf (stderr, "ERROR: Failed to read length from file.\n");
      return  -1;
    }
 
  /* Packet must be big enough to hold a header */
  if (packet_length < ETHER_HDR_LEN)
    {
      fprintf (stderr, "Warning: Ethernet packet length %zd too small.\n",
               packet_length);
      return  -1;
    }
 
  /* Read the packet proper. */
  nread = read (eth->rxfd, buf, packet_length);
 
  if (nread != packet_length)
    {
      fprintf (stderr, "ERROR: Failed to read packet from file.\n");
      return  -1;
    }
 
  return  packet_length;
 
}       /* eth_read_file_packet () */
 
 
/* -------------------------------------------------------------------------- */
/*!Read an Ethernet packet from a FILE interface.
 
   This reads a single Ethernet packet from the outside world via a TAP
   interface.
 
   A complete packet is always read, so its length (minus CRC) is the amount
   read.
 
   @param[in]  eth  Pointer to the relevant Ethernet data structure
   @param[out] buf  Where to put the data
 
   @return  The length if successful, zero if no packet was available,
            a negative value otherwise.                                       */
/* -------------------------------------------------------------------------- */
static ssize_t
eth_read_tap_packet (struct eth_device *eth,
                     unsigned char     *buf)
{
  struct pollfd  fds[1];
  int            n;
  ssize_t        packet_length;
 
  /* Poll to see if there is data to read */
  fds[0].fd     = eth->rtx_fd;
  fds[0].events = POLLIN;
 
  n = poll (fds, 1, 0);
  if (n < 0)
    {
      fprintf (stderr, "Warning: Poll for TAP receive failed %s: ignored.\n",
               strerror (errno));
      return  -1;
    }
  else if ((n > 0) && ((fds[0].revents & POLLIN) == POLLIN))
    {
      /* Data to be read from TAP */
      packet_length = read (eth->rtx_fd, buf, ETH_MAXPL);
#if ETH_DEBUG
      printf ("%d bytes read from TAP.\n", (int) packet_length);
#endif
      if (packet_length < 0)
        {
          fprintf (stderr, "Warning: Read of RXTATE_RECV failed: %s.\n",
                   strerror (errno));
          SET_FLAG (eth->regs.int_source, ETH_INT_SOURCE, RXE);
 
          /* Signal interrupt if enabled, and no interrupt currently in
             progress. */
          if (TEST_FLAG (eth->regs.int_mask, ETH_INT_MASK, RXE_M) &&
              !eth->int_line_stat)
            {
#if ETH_DEBUG
              printf ("Ethernet failed receive interrupt\n");
#endif
              report_interrupt (eth->mac_int);
              eth->int_line_stat = 1;
            }
        }
 
      return  packet_length;
    }
  else
    {
      return  0;                 /* No packet */
    }
}       /* eth_read_tap_packet () */
 
 
/* -------------------------------------------------------------------------- */
/*!Read an Ethernet packet.
 
   This reads a single Ethernet packet from the outside world into the
   supplied buffer. It deals with the different types of external interface.
 
   @param[in]  eth  Pointer to the relevant Ethernet data structure
   @param[out] buf  Where to put the data
 
   @return  The length if successful, zero if no packet was available,
            a negative value otherwise.                                       */
/* -------------------------------------------------------------------------- */
static ssize_t
eth_read_packet (struct eth_device *eth,
                 unsigned char     *buf)
{
  switch (eth->rtx_type)
    {
    case ETH_RTX_FILE: return  eth_read_file_packet (eth, buf);
    case ETH_RTX_TAP:  return  eth_read_tap_packet (eth, buf);
 
    default:
      fprintf (stderr, "Unknown Ethernet read interface: ignored.\n");
      return  (ssize_t) -1;
    }
}       /* eth_read_packet () */
 
 
/* -------------------------------------------------------------------------- */
/*!Fill a buffer descriptor
 
   A buffer descriptor is empty. Attempt to fill it from the outside world.
 
   @param[in] eth  The Ethernet data structure, passed as a void pointer.    */
/* -------------------------------------------------------------------------- */
static void
eth_fill_bd (struct eth_device *eth)
{
 
  /* First word of BD is flags and length, second is pointer to buffer */
  unsigned long int  bd_info = eth->regs.bd_ram[eth->rx_bd_index];
  unsigned long int  bd_addr = eth->regs.bd_ram[eth->rx_bd_index + 1];
 
  long int           packet_length;
  long int           bytes_read;
  unsigned char      buf[ETH_MAXPL];
 
  /* Clear various status bits */
  CLEAR_FLAG (bd_info, ETH_RX_BD, MISS);
  CLEAR_FLAG (bd_info, ETH_RX_BD, INVALID);
  CLEAR_FLAG (bd_info, ETH_RX_BD, DRIBBLE);
  CLEAR_FLAG (bd_info, ETH_RX_BD, UVERRUN);
  CLEAR_FLAG (bd_info, ETH_RX_BD, COLLISION);
  CLEAR_FLAG (bd_info, ETH_RX_BD, TOOBIG);
  CLEAR_FLAG (bd_info, ETH_RX_BD, TOOSHORT);
 
  /* Loopback is permitted. We believe that Linux never uses it, so we'll
     note the attempt and ignore.
 
     @todo We should support this. */
  if (TEST_FLAG (eth->regs.moder, ETH_MODER, LOOPBCK))
    {
      PRINTF ("Ethernet loopback requested.\n");
      fprintf (stderr, "ERROR: Loopback not supported. Ignored.\n");
    }
 
  packet_length = eth_read_packet (eth, buf);
  if (packet_length <= 0)
    {
      /* Empty packet or error. No more to do here. */
      return;
    }
 
/* Got a packet successfully. If not promiscuous mode, check the destination
   address is meant for us. */
  if (!TEST_FLAG (eth->regs.moder, ETH_MODER, PRO))
    {
      if (TEST_FLAG (eth->regs.moder, ETH_MODER, IAM))
        {
          /* There is little documentation of how IAM is supposed to work. It
             seems that some mapping function (not defined) maps the address
             down to a number in the range 0-63. If that bit is set in
             HASH0/HASH1 registers, the packet is accepted. */
          fprintf (stderr, "Warning: Individual Address Mode ignored.\n");
        }
 
      /* Check for HW address match. */
      if ((0 != bcmp (eth->mac_address, buf, ETHER_ADDR_LEN)) &&
          (0 != bcmp (mac_broadcast,    buf, ETHER_ADDR_LEN)))
        {
#if ETH_DEBUG           
          printf ("packet for %.2x:%.2x:%.2x:%.2x:%.2x:%.2x ignored.\n",
                  buf[0], buf[1], buf[2], buf[3], buf[4], buf[5]);
#endif
          /* Not for us. No more to do here. */
          return;
        }
    }
 
  /* Transfer the buffer into the BD. */
#if ETH_DEBUG
  printf ("writing to Rx BD%d: %d bytes @ 0x%.8x\n",
          (int) eth->rx_bd_index / 2,  (int) packet_length,
          (unsigned int)bd_addr);
#endif
 
  for (bytes_read = 0; bytes_read < packet_length; bytes_read +=4)
    {
      unsigned long int  send_word =
        ((unsigned long) buf[bytes_read]     << 24) |
        ((unsigned long) buf[bytes_read + 1] << 16) |
        ((unsigned long) buf[bytes_read + 2] <<  8) |
        ((unsigned long) buf[bytes_read + 3]      );
      set_direct32 (bd_addr + bytes_read, send_word, 0, 0);
    }
 
#if ETH_DEBUG
  printf("BD filled with 0x%08lx bytes.\n", bytes_read);
#endif
 
  /* Write result to BD.
 
     The OpenRISC MAC hardware passes on the CRC (which it should not). The
     Linux drivers have been written to expect a value (which they ignore). So
     for consistency, we pretend the length is 4 bytes longer.
 
     This is now controlled by a configuration parameter, dummy_crc. For
     backwards compatibility, it defaults to TRUE. */
  SET_FIELD (bd_info, ETH_RX_BD, LENGTH,
             packet_length + (eth->dummy_crc ? 4 : 0));
  CLEAR_FLAG (bd_info, ETH_RX_BD, READY);
  SET_FLAG (eth->regs.int_source, ETH_INT_SOURCE, RXB);
 
  eth->regs.bd_ram[eth->rx_bd_index] = bd_info;
 
  /* Advance to next BD. The Rx BDs start after the Tx BDs. */
  if (TEST_FLAG (bd_info, ETH_RX_BD, WRAP) ||
      (eth->rx_bd_index >= ETH_BD_COUNT))
    {
      eth->rx_bd_index = eth->regs.tx_bd_num * 2;
    }
  else
    {
      eth->rx_bd_index += 2;
    }
 
  /* Raise an interrupt if necessary. */
  if (TEST_FLAG (eth->regs.int_mask, ETH_INT_MASK, RXB_M) &&
      TEST_FLAG (bd_info, ETH_RX_BD, IRQ))
    {
      if (eth->int_line_stat)
        {
          fprintf (stderr, "Warning: Interrupt active during Rx.\n");
        }
      else
        {
#if ETH_DEBUG
          printf ("Rx successful receive interrupt\n");
#endif
          report_interrupt (eth->mac_int);
          eth->int_line_stat = 1;
        }
    }
}       /* eth_fill_bd () */
 
 
/* -------------------------------------------------------------------------- */
/*!Ignore a packet from the TAP interface.
 
   We don't have a BD ready, so any packets waiting should be thrown away.
 
   @param[in] eth  The Ethernet data structure.
 
   @return  1 (TRUE) if more or more packets were discarded, zero otherwise.  */
/* -------------------------------------------------------------------------- */
static int
eth_ignore_tap_packets (struct eth_device *eth)
{
  int  result = 0;
  int  n;
 
  /* Read packets until there are none left. */
  do
    {
      struct pollfd  fds[1];
 
      /* Poll to see if there is anything to be read. */
      fds[0].fd     = eth->rtx_fd;
      fds[0].events = POLLIN;
 
      n = poll (fds, 1, 0);
      if (n < 0)
        {
          /* Give up with a warning if poll fails */
          fprintf (stderr,
                   "Warning: Poll error while emptying TAP: %s: ignored.\n",
                   strerror (errno));
          return  result;
        }
      else if ((n > 0) && ((fds[0].revents & POLLIN) == POLLIN))
        {
          unsigned char  buf[ETH_MAXPL];
          ssize_t        nread = eth_read_packet (eth, buf);
 
          if (nread < 0)
            {
              /* Give up with a warning if read fails */
              fprintf (stderr,
                       "Warning: Read of when Ethernet busy failed %s.\n",
                       strerror (errno));
              return  result;
            }
          else if (nread > 0)
            {
              /* Record that a packet was thrown away. */
              result = 1;
#if ETH_DEBUG
              printf ("Ethernet discarding %d bytes from TAP while BD full.\n",
                      nread);
#endif
            }
        }
    }
  while (n > 0);
 
  return  result;
 
}       /* eth_ignore_tap_packets () */
 
 
/* -------------------------------------------------------------------------- */
/*!Rx clock function.
 
   Responsible for starting and completing any RX actions.
 
   The original version had 4 states, which allowed modeling the transfer of
   data one byte per cycle.  For now we use only the one state for
   efficiency. When the buffer is empty, we fill it from the external world.
 
   We schedule to wake up again each cycle. This means we will get called when
   the core is still processing the previous interrupt. To avoid races, we do
   nothing until the interrupt is cleared.
 
   @todo We should eventually reinstate the one byte per cycle transfer.
 
   @param[in] dat  The Ethernet data structure, passed as a void pointer.    */
/* -------------------------------------------------------------------------- */
static void
eth_controller_rx_clock (void *dat)
{
  struct eth_device *eth = dat;
 
  /* Only do anything if there is not an interrupt outstanding. */
  if (!eth->int_line_stat)
    {
      /* First word of the BD is flags, where we can test if it's ready. */
      if (TEST_FLAG (eth->regs.bd_ram[eth->rx_bd_index], ETH_RX_BD, READY))
        {
          /* The BD is empty, so we try to fill it with data from the outside
             world. */
          eth_fill_bd (eth);    /* BD ready to be filled. */
        }
      else if ((TEST_FLAG (eth->regs.moder, ETH_MODER, RXEN)) &&
               (ETH_RTX_FILE == eth->rtx_type))
        {
          /* The BD is full, Rx is enabled and we are reading from an external
             TAP interface. We can't take any more, so we'll throw oustanding
             input packets on the floor.
 
             @note We don't do this for file I/O, since it would discard
             everything immediately! */
          if (eth_ignore_tap_packets (eth))
            {
              /* A packet has been thrown away, so mark the INT_SOURCE
                 register accordingly. */
              SET_FLAG (eth->regs.int_source, ETH_INT_SOURCE, BUSY);
 
              /* Raise an interrupt if necessary. */
              if (TEST_FLAG (eth->regs.int_mask, ETH_INT_MASK, BUSY_M))
                {
                  if (eth->int_line_stat)
                    {
                      fprintf (stderr,
                               "Warning: Interrupt active during ignore.\n");
                    }
                  else
                    {
#if ETH_DEBUG
                      printf ("Ethernet Rx BUSY interrupt\n");
#endif
                      report_interrupt (eth->mac_int);
                      eth->int_line_stat = 1;
                    }
                }
            }
        }
    }
 
  /* Whatever happens, we reschedule a wake up in the future. */
  SCHED_ADD (eth_controller_rx_clock, dat, RTX_RESCHED_PERIOD);
 
}       /* eth_controller_rx_clock () */
 
 
/* -------------------------------------------------------------------------- */
/*!VAPI connection to outside.
 
   Used for remote testing of the interface. Currently does nothing.
 
   @param[in] id  The VAPI ID to use.
   @param[in] data  Any data associated (unused here).
   @param[in] dat   The Ethernet data structure, cast to a void pointer.      */
/* -------------------------------------------------------------------------- */
static void
eth_vapi_read (unsigned long int  id,
               unsigned long int  data,
               void              *dat)
{
  unsigned long int  which;
  struct eth_device *eth = dat;
 
  which = id - eth->base_vapi_id;
 
  if (!eth)
    {
      return;
    }
 
  switch (which)
    {
    case ETH_VAPI_DATA:
      break;
    case ETH_VAPI_CTRL:
      break;
    }
}
 
 
/* -------------------------------------------------------------------------- */
/*!Print register values on stdout
 
   @param[in] dat  The Ethernet interface data structure.                     */
/* -------------------------------------------------------------------------- */
static void
eth_status (void *dat)
{
  struct eth_device *eth = dat;
 
  PRINTF ("\nEthernet MAC at 0x%" PRIxADDR ":\n", eth->baseaddr);
  PRINTF ("MODER        : 0x%08lX\n", eth->regs.moder);
  PRINTF ("INT_SOURCE   : 0x%08lX\n", eth->regs.int_source);
  PRINTF ("INT_MASK     : 0x%08lX\n", eth->regs.int_mask);
  PRINTF ("IPGT         : 0x%08lX\n", eth->regs.ipgt);
  PRINTF ("IPGR1        : 0x%08lX\n", eth->regs.ipgr1);
  PRINTF ("IPGR2        : 0x%08lX\n", eth->regs.ipgr2);
  PRINTF ("PACKETLEN    : 0x%08lX\n", eth->regs.packetlen);
  PRINTF ("COLLCONF     : 0x%08lX\n", eth->regs.collconf);
  PRINTF ("TX_BD_NUM    : 0x%08lX\n", eth->regs.tx_bd_num);
  PRINTF ("CTRLMODER    : 0x%08lX\n", eth->regs.controlmoder);
  PRINTF ("MIIMODER     : 0x%08lX\n", eth->regs.miimoder);
  PRINTF ("MIICOMMAND   : 0x%08lX\n", eth->regs.miicommand);
  PRINTF ("MIIADDRESS   : 0x%08lX\n", eth->regs.miiaddress);
  PRINTF ("MIITX_DATA   : 0x%08lX\n", eth->regs.miitx_data);
  PRINTF ("MIIRX_DATA   : 0x%08lX\n", eth->regs.miirx_data);
  PRINTF ("MIISTATUS    : 0x%08lX\n", eth->regs.miistatus);
  PRINTF ("MAC Address  : %02X:%02X:%02X:%02X:%02X:%02X\n",
          eth->mac_address[5], eth->mac_address[4], eth->mac_address[3],
          eth->mac_address[2], eth->mac_address[1], eth->mac_address[0]);
  PRINTF ("HASH0        : 0x%08lX\n", eth->regs.hash0);
  PRINTF ("HASH1        : 0x%08lX\n", eth->regs.hash1);
 
}       /* eth_status () */
 
 
/* -------------------------------------------------------------------------- */
/*!Open the external file interface to the Ethernet
 
   The data is represented by an input and an output file.
 
   @param[in] eth  The Ethernet interface data structure.                     */
/* -------------------------------------------------------------------------- */
static void
eth_open_file_if (struct eth_device *eth)
{
  /* (Re-)open TX/RX files */
  if (eth->rxfd >= 0)
    {
      close (eth->rxfd);
    }
 
  if (eth->txfd >= 0)
    {
      close (eth->txfd);
    }
 
  eth->rxfd = -1;
  eth->txfd = -1;
 
  eth->rxfd = open (eth->rxfile, O_RDONLY);
  if (eth->rxfd < 0)
    {
      fprintf (stderr, "Warning: Cannot open Ethernet RX file \"%s\": %s\n",
               eth->rxfile, strerror (errno));
    }
 
  eth->txfd = open (eth->txfile,
#if defined(O_SYNC)             /* BSD/MacOS X doesn't know about O_SYNC */
                    O_SYNC |
#endif
                    O_RDWR | O_CREAT | O_APPEND,
                    S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
  if (eth->txfd < 0)
    {
      fprintf (stderr, "Warning: Cannot open Ethernet TX file \"%s\": %s\n",
               eth->txfile, strerror (errno));
    }
}       /* eth_open_file_if () */
 
 
/* -------------------------------------------------------------------------- */
/*!Open the external TAP interface to the Ethernet
 
   Packets are transferred over a TAP/TUN interface. We assume a persistent
   tap interface has been set up and is owned by the user, so they can open
   and manipulate it. See the User Guide for details of setting this up.
 
   @todo We don't flush the TAP interface. Should we?
 
   @param[in] eth  The Ethernet interface data structure.                     */
/* -------------------------------------------------------------------------- */
static void
eth_open_tap_if (struct eth_device *eth)
{
  struct ifreq       ifr;
 
  /* We don't support re-opening. If it's open, it stays open. */
  if (eth->rtx_fd >= 0)
    {
      return;
    }
 
  /* Open the TUN/TAP device */
  eth->rtx_fd = open ("/dev/net/tun", O_RDWR);
  if( eth->rtx_fd < 0 )
    {
      fprintf (stderr, "Warning: Failed to open TUN/TAP device: %s\n",
               strerror (errno));
      eth->rtx_fd = -1;
      return;
    }
 
  /* Turn it into a specific TAP device. If we haven't specified a specific
     (persistent) device, one will be created, but that requires superuser, or
     at least CAP_NET_ADMIN capabilities. */
  memset (&ifr, 0, sizeof(ifr));
  ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
  strncpy (ifr.ifr_name, eth->tap_dev, IFNAMSIZ);
 
  if (ioctl (eth->rtx_fd, TUNSETIFF, (void *) &ifr) < 0)
    {
      fprintf (stderr, "Warning: Failed to set TAP device %s: %s\n",
               eth->tap_dev, strerror (errno));
      close (eth->rtx_fd);
      eth->rtx_fd = -1;
      return;
    }
#if ETH_DEBUG
      PRINTF ("Opened TAP %s\n", ifr.ifr_name);
#endif
}       /* eth_open_tap_if () */
 
 
/* -------------------------------------------------------------------------- */
/*!Open the external interface to the Ethernet
 
   Calls the appropriate function for the interface type.
 
   @param[in] eth  The Ethernet interface data structure.                     */
/* -------------------------------------------------------------------------- */
static void
eth_open_if (struct eth_device *eth)
{
  switch (eth->rtx_type)
    {
    case ETH_RTX_FILE: eth_open_file_if (eth); break;
    case ETH_RTX_TAP:  eth_open_tap_if (eth);  break;
 
    default:
      fprintf (stderr, "Unknown Ethernet interface: ignored.\n");
      break;
    }
}       /* eth_open_if () */
 
 
/* -------------------------------------------------------------------------- */
/*!Reset the Ethernet.
 
   Open the correct type of simulation interface to the outside world.
 
   Initialize all registers to default and places devices in memory address
   space.
 
   @param[in] dat  The Ethernet interface data structure.                     */
/* -------------------------------------------------------------------------- */
static void
eth_reset (void *dat)
{
  struct eth_device *eth = dat;
 
#if ETH_DEBUG
  printf ("Resetting Ethernet\n");
#endif
 
  /* Nothing to do if we do not have a base address set, or we are not
     enabled. */
  if (!eth->enabled || (0 == eth->baseaddr))
    {
      return;
    }
 
  eth_open_if (eth);
 
  /* Set registers to default values */
  memset (&(eth->regs), 0, sizeof (eth->regs));
 
  eth->regs.moder     = 0x0000A000;     /* Padding & CRC enabled */
  eth->regs.ipgt      = 0x00000012;     /* Half duplex (matches MODER) */
  eth->regs.ipgr1     = 0x0000000C;     /* Recommended value */
  eth->regs.ipgr2     = 0x00000012;     /* Recommended value */
  eth->regs.packetlen = 0x003C0600;     /* MINFL 60, MAXFL 1,536 bytes */
  eth->regs.collconf  = 0x000F003F;     /* MAXRET 15, COLLVALID 63 */
  eth->regs.tx_bd_num = 0x00000040;     /* Max Tx BD */
  eth->regs.miimoder  = 0x00000064;     /* Send preamble, CLKDIV 100 */
 
  /* Reset TX/RX BD indexes. The Rx BD indexes start after the Tx BD indexes. */
  eth->tx_bd_index = 0;
  eth->rx_bd_index = eth->regs.tx_bd_num * 2;
 
  /* Reset IRQ line status */
  eth->int_line_stat = 0;
 
  /* Initialize VAPI */
  if (eth->base_vapi_id)
    {
      vapi_install_multi_handler (eth->base_vapi_id, ETH_NUM_VAPI_IDS,
                                  eth_vapi_read, dat);
    }
}       /* eth_reset () */
 
 
#if ETH_DEBUG
/* -------------------------------------------------------------------------- */
/*!Map a register address to its name
 
   @param[in[ addr  The address of the register to name (offset from base).
 
   @return  The name of the register.                                         */
/* -------------------------------------------------------------------------- */
static char *
eth_regname (oraddr_t  addr)
{
  static char  bdstr[8];                /* For "BD[nnn]" */
 
  switch (addr)
    {
    case ETH_MODER:      return  "MODER";
    case ETH_INT_SOURCE: return  "INT_SOURCE";
    case ETH_INT_MASK:   return  "INT_MASK";
    case ETH_IPGT:       return  "IPGT";
    case ETH_IPGR1:      return  "IPGR1";
    case ETH_IPGR2:      return  "IPGR2";
    case ETH_PACKETLEN:  return  "PACKETLEN";
    case ETH_COLLCONF:   return  "COLLCONF";
    case ETH_TX_BD_NUM:  return  "TX_BD_NUM";
    case ETH_CTRLMODER:  return  "CTRLMODER";
    case ETH_MIIMODER:   return  "MIIMODER";
    case ETH_MIICOMMAND: return  "MIICOMMAND";
    case ETH_MIIADDRESS: return  "MIIADDRESS";
    case ETH_MIITX_DATA: return  "MIITX_DATA";
    case ETH_MIIRX_DATA: return  "MIIRX_DATA";
    case ETH_MIISTATUS:  return  "MIISTATUS";
    case ETH_MAC_ADDR0:  return  "MAC_ADDR0";
    case ETH_MAC_ADDR1:  return  "MAC_ADDR1";
    case ETH_HASH0:      return  "HASH0";
    case ETH_HASH1:      return  "HASH1";
 
    default:
      /* Buffer descriptors are a special case. */
      if ((addr >= ETH_BD_BASE) && (addr < ETH_BD_BASE + ETH_BD_SPACE))
        {
          sprintf (bdstr, "BD[%.3d]", (addr - ETH_BD_BASE) / 4);
          return  bdstr;
        }
      else
        {
          return  "INVALID";
        }
    }
}       /* eth_regname () */
#endif
 
 
/* -------------------------------------------------------------------------- */
/*!Read a register
 
   @param[in] addr  The address of the register to read (offset from base).
   @param[in] dat   The Ethernet interface data structure, cast to a void
                    pointer.
 
   @return  The value read.                                                   */
/* -------------------------------------------------------------------------- */
static uint32_t
eth_read32 (oraddr_t  addr,
            void     *dat)
{
  struct eth_device *eth = dat;
  uint32_t           res;
 
  switch (addr)
    {
    case ETH_MODER:      res = eth->regs.moder;        break;
    case ETH_INT_SOURCE: res = eth->regs.int_source;   break;
    case ETH_INT_MASK:   res = eth->regs.int_mask;     break;
    case ETH_IPGT:       res = eth->regs.ipgt;         break;
    case ETH_IPGR1:      res = eth->regs.ipgr1;        break;
    case ETH_IPGR2:      res = eth->regs.ipgr2;        break;
    case ETH_PACKETLEN:  res = eth->regs.packetlen;    break;
    case ETH_COLLCONF:   res = eth->regs.collconf;     break;
    case ETH_TX_BD_NUM:  res = eth->regs.tx_bd_num;    break;
    case ETH_CTRLMODER:  res = eth->regs.controlmoder; break;
    case ETH_MIIMODER:   res = eth->regs.miimoder;     break;
    case ETH_MIICOMMAND: res = eth->regs.miicommand;   break;
    case ETH_MIIADDRESS: res = eth->regs.miiaddress;   break;
    case ETH_MIITX_DATA: res = eth->regs.miitx_data;   break;
    case ETH_MIIRX_DATA: res = eth->regs.miirx_data;   break;
    case ETH_MIISTATUS:  res = eth->regs.miistatus;    break;
    case ETH_MAC_ADDR0:
      res =
        (((unsigned long) eth->mac_address[2]) << 24) |
        (((unsigned long) eth->mac_address[3]) << 16) |
        (((unsigned long) eth->mac_address[4]) <<  8) |
          (unsigned long) eth->mac_address[5];
      break;
    case ETH_MAC_ADDR1:
      res =
        (((unsigned long) eth->mac_address[0]) <<  8) |
          (unsigned long) eth->mac_address[1];
      break;
    case ETH_HASH0:      res = eth->regs.hash0;        break;
    case ETH_HASH1:      res = eth->regs.hash1;        break;
 
    default:
      /* Buffer descriptors are a special case. */
      if ((addr >= ETH_BD_BASE) && (addr < ETH_BD_BASE + ETH_BD_SPACE))
        {
          res = eth->regs.bd_ram[(addr - ETH_BD_BASE) / 4];
          break;
        }
      else
        {
          fprintf (stderr,
                   "Warning: eth_read32( 0x%" PRIxADDR " ): Illegal address\n",
                   addr + eth->baseaddr);
          res = 0;
        }
    }
 
#if ETH_DEBUG
  /* Only trace registers of particular interest */
  switch (addr)
    {
    case ETH_MODER:
    case ETH_INT_SOURCE:
    case ETH_INT_MASK:
    case ETH_IPGT:
    case ETH_IPGR1:
    case ETH_IPGR2:
    case ETH_PACKETLEN:
    case ETH_COLLCONF:
    case ETH_TX_BD_NUM:
    case ETH_CTRLMODER:
    case ETH_MAC_ADDR0:
    case ETH_MAC_ADDR1:
      printf ("eth_read32: %s = 0x%08lx\n", eth_regname (addr),
              (unsigned long int) res);
    }
#endif
 
  return  res;
 
}       /* eth_read32 () */
 
 
/* -------------------------------------------------------------------------- */
/*!Emulate MIIM transaction to ethernet PHY
 
   @param[in] eth  Ethernet device datastruture.                              */
/* -------------------------------------------------------------------------- */
static void
eth_miim_trans (struct eth_device *eth)
{
  switch (eth->regs.miicommand)
    {
    case ((1 << ETH_MIICOMM_WCDATA_OFFSET)):
      /* Perhaps something to emulate here later, but for now do nothing */
      break;
 
    case ((1 << ETH_MIICOMM_RSTAT_OFFSET)):
      /*First check if it's the correct PHY to address */
      if (((eth->regs.miiaddress >> ETH_MIIADDR_FIAD_OFFSET)&
           ETH_MIIADDR_FIAD_MASK) == eth->phy_addr)
        {
          /* Correct PHY - now switch based on the register address in the PHY*/
          switch ((eth->regs.miiaddress >> ETH_MIIADDR_RGAD_OFFSET)&
                  ETH_MIIADDR_RGAD_MASK)
            {
            case MII_BMCR:
              eth->regs.miirx_data = BMCR_FULLDPLX;
              break;
            case MII_BMSR:
              eth->regs.miirx_data = BMSR_LSTATUS | BMSR_ANEGCOMPLETE |
                BMSR_10HALF | BMSR_10FULL | BMSR_100HALF | BMSR_100FULL;
              break;
            case MII_PHYSID1:
              eth->regs.miirx_data = 0x22; /* Micrel PHYID */
              break;
            case MII_PHYSID2:
              eth->regs.miirx_data = 0x1613; /* Micrel PHYID */
              break;
            case MII_ADVERTISE:
              eth->regs.miirx_data = ADVERTISE_FULL;
              break;
            case MII_LPA:
              eth->regs.miirx_data = LPA_DUPLEX | LPA_100;
              break;
            case MII_EXPANSION:
              eth->regs.miirx_data = 0;
              break;
            case MII_CTRL1000:
              eth->regs.miirx_data = 0;
              break;
            case MII_STAT1000:
              eth->regs.miirx_data = 0;
              break;
            case MII_ESTATUS:
              eth->regs.miirx_data = 0;
              break;
            case MII_DCOUNTER:
              eth->regs.miirx_data = 0;
              break;
            case MII_FCSCOUNTER:
              eth->regs.miirx_data = 0;
              break;
            case MII_NWAYTEST:
              eth->regs.miirx_data = 0;
              break;
            case MII_RERRCOUNTER:
              eth->regs.miirx_data = 0;
              break;
            case MII_SREVISION:
              eth->regs.miirx_data = 0;
              break;
            case MII_RESV1:
              eth->regs.miirx_data = 0;
              break;
            case MII_LBRERROR:
              eth->regs.miirx_data = 0;
              break;
            case MII_PHYADDR:
              eth->regs.miirx_data = eth->phy_addr;
              break;
            case MII_RESV2:
              eth->regs.miirx_data = 0;
              break;
            case MII_TPISTATUS:
              eth->regs.miirx_data = 0;
              break;
            case MII_NCONFIG:
              eth->regs.miirx_data = 0;
              break;
            default:
              eth->regs.miirx_data = 0xffff;
              break;
            }
        }
      else
        {
          eth->regs.miirx_data = 0xffff; /* PHY doesn't exist, read all 1's */
        }
 
      break;
 
    case ((1 << ETH_MIICOMM_SCANS_OFFSET)):
      /* From MAC's datasheet:
         A host initiates the Scan Status Operation by asserting the SCANSTAT
         signal. The MIIM performs a continuous read operation of the PHY
         Status register. The PHY is selected by the FIAD[4:0] signals. The
         link status LinkFail signal is asserted/deasserted by the MIIM module
         and reflects the link status bit of the PHY Status register. The
         signal NVALID is used for qualifying the validity of the LinkFail
         signals and the status data PRSD[15:0]. These signals are invalid
         until the first scan status operation ends. During the scan status
         operation, the BUSY signal is asserted until the last read is
         performed (the scan status operation is stopped).
 
         So for now - do nothing, leave link status indicator as permanently
         with link.
      */
 
      break;
 
    default:
      break;
    }
}       /* eth_miim_trans () */
 
 
 
/* -------------------------------------------------------------------------- */
/*!Write a register
 
   @note Earlier versions of this code treated ETH_INT_SOURCE as an "interrupt
         pending" register and reissued interrupts if ETH_INT_MASK was
         changed, enabling an interrupt that had previously been cleared. This
         led to spurious double interrupt. In the present version, the only
         way an interrupt can be generated is at the time ETH_INT_SOURCE is
         set in the Tx/Rx controllers and the only way an interrupt can be
         cleared is by writing to ETH_INT_SOURCE.
 
   @param[in] addr   The address of the register to read (offset from base).
   @param[in] value  The value to write.
   @param[in] dat    The Ethernet interface data structure, cast to a void
                     pointer.                                                 */
/* -------------------------------------------------------------------------- */
static void
eth_write32 (oraddr_t addr, uint32_t value, void *dat)
{
  struct eth_device *eth = dat;
 
#if ETH_DEBUG
  /* Only trace registers of particular interest */
  switch (addr)
    {
    case ETH_MODER:
    case ETH_INT_SOURCE:
    case ETH_INT_MASK:
    case ETH_IPGT:
    case ETH_IPGR1:
    case ETH_IPGR2:
    case ETH_PACKETLEN:
    case ETH_COLLCONF:
    case ETH_TX_BD_NUM:
    case ETH_CTRLMODER:
    case ETH_MAC_ADDR0:
    case ETH_MAC_ADDR1:
      printf ("eth_write32: 0x%08lx to %s ", (unsigned long int) value,
              eth_regname (addr));
    }
 
  /* Detail register transitions on MODER, INT_SOURCE AND INT_MASK */
  switch (addr)
    {
    case ETH_MODER:
      printf (" 0x%08lx -> ", (unsigned long) eth->regs.moder);
      break;
    case ETH_INT_SOURCE:
      printf (" 0x%08lx -> ", (unsigned long) eth->regs.int_source);
      break;
    case ETH_INT_MASK:
      printf (" 0x%08lx -> ", (unsigned long) eth->regs.int_mask);
      break;
    }
#endif
 
  switch (addr)
    {
    case ETH_MODER:
      if (!TEST_FLAG (eth->regs.moder, ETH_MODER, RXEN) &&
          TEST_FLAG (value, ETH_MODER, RXEN))
        {
          /* Enabling receive, flush any oustanding input (TAP only), reset
             the BDs and schedule the Rx controller on the next clock
             cycle. */
          if (ETH_RTX_TAP == eth->rtx_type)
            {
              (void) eth_ignore_tap_packets (eth);
            }
 
          eth->rx_bd_index = eth->regs.tx_bd_num * 2;
          SCHED_ADD (eth_controller_rx_clock, dat, 1);
        }
      else if (!TEST_FLAG (value, ETH_MODER, RXEN) &&
               TEST_FLAG (eth->regs.moder, ETH_MODER, RXEN))
        {
          /* Disabling Rx, so stop scheduling the Rx controller. */
          SCHED_FIND_REMOVE (eth_controller_rx_clock, dat);
        }
 
      if (!TEST_FLAG (eth->regs.moder, ETH_MODER, TXEN) &&
          TEST_FLAG (value, ETH_MODER, TXEN))
        {
          /* Enabling transmit, reset the BD and schedule the Tx controller on
             the next clock cycle. */
          eth->tx_bd_index = 0;
          SCHED_ADD (eth_controller_tx_clock, dat, 1);
        }
      else if (!TEST_FLAG (value, ETH_MODER, TXEN) &&
               TEST_FLAG (eth->regs.moder, ETH_MODER, TXEN))
        {
          /* Disabling Tx, so stop scheduling the Tx controller. */
          SCHED_FIND_REMOVE (eth_controller_tx_clock, dat);
        }
 
      /* Reset the interface if so requested. */
      if (TEST_FLAG (value, ETH_MODER, RST))
        {
          eth_reset (dat);
        }
 
      eth->regs.moder = value;          /* Update the register */
      break;
 
    case ETH_INT_SOURCE:
      eth->regs.int_source &= ~value;
 
      /* Clear IRQ line if all interrupt sources have been dealt with
 
         @todo  Is this really right? */
      if (!(eth->regs.int_source & eth->regs.int_mask) && eth->int_line_stat)
        {
          clear_interrupt (eth->mac_int);
          eth->int_line_stat = 0;
        }
      break;
 
    case ETH_INT_MASK:
      eth->regs.int_mask = value;
 
      /* The old code would report an interrupt if we enabled an interrupt
         when if we enabled interrupts and the core was not currently
         processing an interrupt, and there was an interrupt pending.
 
         However this led (at least on some machines) to orphaned interrupts
         in the device driver. So in this version of the code we do not report
         interrupts on a mask change.
 
         This is not apparently consistent with the Verilog, but it does mean
         that the orphaned interrupts problem does not occur, and has no
         apparent effect on Ethernet performance. More investigation is needed
         to determine if this is a bug in Or1ksim interrupt handling, or a bug
         in the device driver, which does not manifest with real HW.
 
         Otherwise clear down the interrupt.
 
         @todo  Is this really right. */
      if ((eth->regs.int_source & eth->regs.int_mask) && !eth->int_line_stat)
        {
#if ETH_DEBUG
          printf ("ETH_MASK changed with apparent pending interrupt.\n");
#endif
        }
      else if (eth->int_line_stat)
        {
          clear_interrupt (eth->mac_int);
          eth->int_line_stat = 0;
        }
 
      break;
 
    case ETH_IPGT:       eth->regs.ipgt         = value; break;
    case ETH_IPGR1:      eth->regs.ipgr1        = value; break;
    case ETH_IPGR2:      eth->regs.ipgr2        = value; break;
    case ETH_PACKETLEN:  eth->regs.packetlen    = value; break;
    case ETH_COLLCONF:   eth->regs.collconf     = value; break;
 
    case ETH_TX_BD_NUM:
      /* When TX_BD_NUM is written, also reset current RX BD index */
      eth->regs.tx_bd_num = value & 0xFF;
      eth->rx_bd_index = eth->regs.tx_bd_num * 2;
      break;
 
    case ETH_CTRLMODER:  eth->regs.controlmoder = value; break;
    case ETH_MIIMODER:   eth->regs.miimoder     = value; break;
 
    case ETH_MIICOMMAND:
      eth->regs.miicommand = value;
      /* Perform MIIM transaction, if required */
      eth_miim_trans (eth);
      break;
 
    case ETH_MIIADDRESS: eth->regs.miiaddress   = value; break;
    case ETH_MIITX_DATA: eth->regs.miitx_data   = value; break;
    case ETH_MIIRX_DATA: /* Register is R/O */           break;
    case ETH_MIISTATUS:  /* Register is R/O */           break;
 
    case ETH_MAC_ADDR0:
      eth->mac_address[5] =  value        & 0xFF;
      eth->mac_address[4] = (value >>  8) & 0xFF;
      eth->mac_address[3] = (value >> 16) & 0xFF;
      eth->mac_address[2] = (value >> 24) & 0xFF;
      break;
 
    case ETH_MAC_ADDR1:
      eth->mac_address[1] =  value        & 0xFF;
      eth->mac_address[0] = (value >>  8) & 0xFF;
      break;
 
    case ETH_HASH0:      eth->regs.hash0 = value;        break;
    case ETH_HASH1:      eth->regs.hash1 = value;        break;
 
    default:
      if ((addr >= ETH_BD_BASE) && (addr < ETH_BD_BASE + ETH_BD_SPACE))
        {
          eth->regs.bd_ram[(addr - ETH_BD_BASE) / 4] = value;
        }
      else
        {
          fprintf (stderr,
                   "Warning: eth_write32( 0x%" PRIxADDR " ): Illegal address\n",
                   addr + eth->baseaddr);
        }
      break;
    }
 
#if ETH_DEBUG
  switch (addr)
    {
    case ETH_MODER:
      printf ("0x%08lx\n", (unsigned long) eth->regs.moder);
      break;
    case ETH_INT_SOURCE:
      printf ("0x%08lx\n", (unsigned long) eth->regs.int_source);
      break;
    case ETH_INT_MASK:
      printf ("0x%08lx\n", (unsigned long) eth->regs.int_mask);
      break;
    case ETH_IPGT:
    case ETH_IPGR1:
    case ETH_IPGR2:
    case ETH_PACKETLEN:
    case ETH_COLLCONF:
    case ETH_TX_BD_NUM:
    case ETH_CTRLMODER:
    case ETH_MAC_ADDR0:
    case ETH_MAC_ADDR1:
      printf("\n");
      break;
    }
 
#endif
 
}       /* eth_write32 () */
 
 
/*---------------------------------------------------------------------------*/
/*!Enable or disable the Ethernet interface
 
   @param[in] val  The value to use
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_enabled (union param_val  val,
             void            *dat)
{
  struct eth_device *eth = dat;
 
  eth->enabled = val.int_val;
 
}       /* eth_enabled() */
 
 
/*---------------------------------------------------------------------------*/
/*!Set the Ethernet interface base address
 
   @param[in] val  The value to use
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_baseaddr (union param_val  val,
              void            *dat)
{
  struct eth_device *eth = dat;
 
  eth->baseaddr = val.addr_val;
 
}       /* eth_baseaddr() */
 
 
/*---------------------------------------------------------------------------*/
/*!Set the Ethernet DMA port
 
   This is not currently supported, so a warning message is printed.
 
   @param[in] val  The value to use
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_dma (union param_val  val,
         void            *dat)
{
  struct eth_device *eth = dat;
 
  fprintf (stderr, "Warning: External Ethernet DMA not currently supported\n");
  eth->dma = val.addr_val;
 
}       /* eth_dma() */
 
 
/*---------------------------------------------------------------------------*/
/*!Set the Ethernet IRQ
 
   @param[in] val  The value to use
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_irq (union param_val  val,
         void            *dat)
{
  struct eth_device *eth = dat;
 
  eth->mac_int = val.int_val;
 
}       /* eth_irq() */
 
 
/*---------------------------------------------------------------------------*/
/*!Set the Ethernet interface type
 
   Currently two types are supported, file and tap.
 
   @param[in] val  The value to use. Currently "file" and "tap" are supported.
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_rtx_type (union param_val  val,
              void            *dat)
{
  struct eth_device *eth = dat;
 
  if (0 == strcasecmp ("file", val.str_val))
    {
      printf ("Ethernet FILE type\n");
      eth->rtx_type = ETH_RTX_FILE;
    }
  else if (0 == strcasecmp ("tap", val.str_val))
    {
      printf ("Ethernet TAP type\n");
      eth->rtx_type = ETH_RTX_TAP;
    }
  else
    {
      fprintf (stderr, "Warning: Unknown Ethernet type: file assumed.\n");
      eth->rtx_type = ETH_RTX_FILE;
    }
}       /* eth_rtx_type() */
 
 
/*---------------------------------------------------------------------------*/
/*!Set the Ethernet DMA Rx channel
 
   External DMA is not currently supported, so a warning message is printed.
 
   @param[in] val  The value to use
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_rx_channel (union param_val  val,
                void            *dat)
{
  struct eth_device *eth = dat;
 
  fprintf (stderr, "Warning: External Ethernet DMA not currently supported: "
           "Rx channel ignored\n");
  eth->rx_channel = val.int_val;
 
}       /* eth_rx_channel() */
 
 
/*---------------------------------------------------------------------------*/
/*!Set the Ethernet DMA Tx channel
 
   External DMA is not currently supported, so a warning message is printed.
 
   @param[in] val  The value to use
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_tx_channel (union param_val  val,
                void            *dat)
{
  struct eth_device *eth = dat;
 
  fprintf (stderr, "Warning: External Ethernet DMA not currently supported: "
           "Tx channel ignored\n");
  eth->tx_channel = val.int_val;
 
}       /* eth_tx_channel() */
 
 
/*---------------------------------------------------------------------------*/
/*!Set the Ethernet DMA Rx file
 
   Free any previously allocated value.
 
   @param[in] val  The value to use
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_rxfile (union param_val  val,
            void            *dat)
{
  struct eth_device *eth = dat;
 
  if (NULL != eth->rxfile)
    {
      free (eth->rxfile);
      eth->rxfile = NULL;
    }
 
  if (!(eth->rxfile = strdup (val.str_val)))
    {
      fprintf (stderr, "Peripheral Ethernet: Run out of memory\n");
      exit (-1);
    }
}       /* eth_rxfile() */
 
 
/*---------------------------------------------------------------------------*/
/*!Set the Ethernet DMA Tx file
 
   Free any previously allocated value.
 
   @param[in] val  The value to use
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_txfile (union param_val  val,
            void            *dat)
{
  struct eth_device *eth = dat;
 
  if (NULL != eth->txfile)
    {
      free (eth->txfile);
      eth->txfile = NULL;
    }
 
  if (!(eth->txfile = strdup (val.str_val)))
    {
      fprintf (stderr, "Peripheral Ethernet: Run out of memory\n");
      exit (-1);
    }
}       /* eth_txfile() */
 
 
/*---------------------------------------------------------------------------*/
/*!Set the Ethernet TAP device.
 
   If we are not superuser (or do not have CAP_NET_ADMIN priviledges), then we
   must work with a persistent TAP device that is already set up. This option
   specifies the device to user.
 
   @param[in] val  The value to use.
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_tap_dev (union param_val  val,
              void            *dat)
{
  struct eth_device *eth = dat;
 
  if (NULL != eth->tap_dev)
    {
      free (eth->tap_dev);
      eth->tap_dev = NULL;
    }
 
  eth->tap_dev = strdup (val.str_val);
 
  if (NULL == eth->tap_dev)
    {
      fprintf (stderr, "ERROR: Peripheral Ethernet: Run out of memory\n");
      exit (-1);
    }
}       /* eth_tap_dev() */
 
 
/*---------------------------------------------------------------------------*/
/*!Set the PHY address
 
   Used to identify different physical interfaces (important for MII).
 
   @param[in] val  The value to use.
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_phy_addr (union param_val  val,
              void            *dat)
{
  struct eth_device *eth = dat;
  eth->phy_addr = val.int_val & ETH_MIIADDR_FIAD_MASK;
 
}       /* eth_phy_addr () */
 
 
/*---------------------------------------------------------------------------*/
/*!Enable or disable a dummy CRC
 
   The MAC should not report anything about the CRC back to the core. However
   the hardware implementation of the OpenRISC MAC does, and the Linux drivers
   have been written to expect the value (which they ignore).
 
   Setting this parameter causes a dummy CRC to be added. For consistency with
   the hardware, its default setting is TRUE.
 
   @param[in] val  The value to use
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_dummy_crc (union param_val  val,
             void            *dat)
{
  struct eth_device *eth = dat;
 
  eth->dummy_crc = val.int_val;
 
}       /* eth_dummy_crc() */
 
 
/*---------------------------------------------------------------------------*/
/*!Set the VAPI id
 
   Used for remote testing of the interface.
 
   @param[in] val  The value to use.
   @param[in] dat  The config data structure                                 */
/*---------------------------------------------------------------------------*/
static void
eth_vapi_id (union param_val  val,
             void            *dat)
{
  struct eth_device *eth = dat;
  eth->base_vapi_id = val.int_val;
 
}       /* eth_vapi_id () */
 
 
/*---------------------------------------------------------------------------*/
/*!Start the initialization of a new Ethernet configuration
 
   ALL parameters are set explicitly to default values.                      */
/*---------------------------------------------------------------------------*/
static void *
eth_sec_start (void)
{
  struct eth_device *new = malloc (sizeof (struct eth_device));
 
  if (!new)
    {
      fprintf (stderr, "Peripheral Eth: Run out of memory\n");
      exit (-1);
    }
 
  memset (new, 0, sizeof (struct eth_device));
 
  new->enabled      = 1;
  new->baseaddr     = 0;
  new->dma          = 0;
  new->mac_int      = 0;
  new->int_line_stat= 0;
  new->rtx_type     = ETH_RTX_FILE;
  new->rx_channel   = 0;
  new->tx_channel   = 0;
  new->rtx_fd       = -1;
  new->rxfile       = strdup ("eth_rx");
  new->txfile       = strdup ("eth_tx");
  new->tap_dev      = strdup ("");
  new->phy_addr     = 0;
  new->dummy_crc    = 1;
  new->base_vapi_id = 0;
 
  return new;
 
}       /* eth_sec_start () */
 
 
/*---------------------------------------------------------------------------*/
/*!Complete the initialization of a new Ethernet configuration
 
   ALL parameters are set explicitly to default values.                      */
/*---------------------------------------------------------------------------*/
static void
eth_sec_end (void *dat)
{
  struct eth_device *eth = dat;
  struct mem_ops ops;
 
  if (!eth->enabled)
    {
      free (eth->rxfile);
      free (eth->txfile);
      free (eth->tap_dev);
      free (eth);
      return;
    }
 
  memset (&ops, 0, sizeof (struct mem_ops));
 
  ops.readfunc32 = eth_read32;
  ops.writefunc32 = eth_write32;
  ops.read_dat32 = dat;
  ops.write_dat32 = dat;
 
  /* FIXME: Correct delay? */
  ops.delayr = 2;
  ops.delayw = 2;
  reg_mem_area (eth->baseaddr, ETH_ADDR_SPACE, 0, &ops);
  reg_sim_stat (eth_status, dat);
  reg_sim_reset (eth_reset, dat);
 
}       /* eth_sec_end () */
 
 
/*---------------------------------------------------------------------------*/
/*!Register a new Ethernet configuration                                     */
/*---------------------------------------------------------------------------*/
void
reg_ethernet_sec ()
{
  struct config_section *sec =
    reg_config_sec ("ethernet", eth_sec_start, eth_sec_end);
 
  reg_config_param (sec, "enabled",    PARAMT_INT,  eth_enabled);
  reg_config_param (sec, "baseaddr",   PARAMT_ADDR, eth_baseaddr);
  reg_config_param (sec, "dma",        PARAMT_INT,  eth_dma);
  reg_config_param (sec, "irq",        PARAMT_INT,  eth_irq);
  reg_config_param (sec, "rtx_type",   PARAMT_STR,  eth_rtx_type);
  reg_config_param (sec, "rx_channel", PARAMT_INT,  eth_rx_channel);
  reg_config_param (sec, "tx_channel", PARAMT_INT,  eth_tx_channel);
  reg_config_param (sec, "rxfile",     PARAMT_STR,  eth_rxfile);
  reg_config_param (sec, "txfile",     PARAMT_STR,  eth_txfile);
  reg_config_param (sec, "tap_dev",    PARAMT_STR,  eth_tap_dev);
  reg_config_param (sec, "phy_addr",   PARAMT_INT,  eth_phy_addr);
  reg_config_param (sec, "dummy_crc",  PARAMT_INT,  eth_dummy_crc);
  reg_config_param (sec, "vapi_id",    PARAMT_INT,  eth_vapi_id);
 
}       /* reg_ethernet_sec() */

Line No.	Rev	Author	Line
1	19	jeremybenn	`/* ethernet.c -- Simulation of Ethernet MAC`
2
3			`Copyright (C) 2001 by Erez Volk, erez@opencores.org`
4			`Ivan Guzvinec, ivang@opencores.org`
5	443	jeremybenn	`Copyright (C) 2008, 2001 Embecosm Limited`
6	437	julius	`Copyright (C) 2010 ORSoC`
7	19	jeremybenn
8			`Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>`
9	437	julius	`Contributor Julius Baxter <julius@orsoc.se>`
10	19	jeremybenn
11			`This file is part of Or1ksim, the OpenRISC 1000 Architectural Simulator.`
12
13			`This program is free software; you can redistribute it and/or modify it`
14			`under the terms of the GNU General Public License as published by the Free`
15			`Software Foundation; either version 3 of the License, or (at your option)`
16			`any later version.`
17
18			`This program is distributed in the hope that it will be useful, but WITHOUT`
19			`ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or`
20			`FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for`
21			`more details.`
22
23			`You should have received a copy of the GNU General Public License along`
24			`with this program. If not, see <http://www.gnu.org/licenses/>. */`
25
26			`/* This program is commented throughout in a fashion suitable for processing`
27			`with Doxygen. */`
28
29
30			`/* Autoconf and/or portability configuration */`
31			`#include "config.h"`
32			`#include "port.h"`
33
34			`/* System includes */`
35			`#include <stdlib.h>`
36			`#include <stdio.h>`
37	434	jeremybenn
38			`#include <sys/socket.h>`
39			`#include <sys/ioctl.h>`
40			`#include <sys/stat.h>`
41	19	jeremybenn	`#include <sys/types.h>`
42			`#include <fcntl.h>`
43	434	jeremybenn
44	19	jeremybenn	`#include <sys/poll.h>`
45			`#include <unistd.h>`
46			`#include <errno.h>`
47
48	434	jeremybenn	`#include <linux/if.h>`
49			`#include <linux/if_tun.h>`
50
51	19	jeremybenn	`/* Package includes */`
52			`#include "arch.h"`
53			`#include "config.h"`
54			`#include "abstract.h"`
55			`#include "eth.h"`
56			`#include "dma.h"`
57			`#include "sim-config.h"`
58			`#include "fields.h"`
59			`#include "crc32.h"`
60			`#include "vapi.h"`
61			`#include "pic.h"`
62			`#include "sched.h"`
63			`#include "toplevel-support.h"`
64			`#include "sim-cmd.h"`
65
66	443	jeremybenn
67			`/* Control debug messages */`
68	450	jeremybenn	`#define ETH_DEBUG 0`
69	443	jeremybenn	`#ifndef ETH_DEBUG`
70			`# define ETH_DEBUG 1`
71			`#endif`
72
73	460	jeremybenn	`/*! Period (clock cycles) for rescheduling Rx and Tx controllers.`
74			`Experimenting with FTP on one machine suggests that a value of 500-2000 is`
75			`optimal. It's a trade off between prompt response and extra computational`
76			`load for Or1ksim. */`
77			`#define RTX_RESCHED_PERIOD 2000`
78	443	jeremybenn
79	450	jeremybenn	`/! MAC address that is always accepted. /`
80			`static const unsigned char mac_broadcast[ETHER_ADDR_LEN] =`
81			`{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };`
82
83	443	jeremybenn	`/* -------------------------------------------------------------------------- */`
84			`/!Structure describing the Ethernet device /`
85			`/* -------------------------------------------------------------------------- */`
86	19	jeremybenn	`struct eth_device`
87			`{`
88	443	jeremybenn	`/* Basic stuff about the device */`
89			`int enabled; /* Is peripheral enabled */`
90			`oraddr_t baseaddr; /* Base address in memory */`
91			`unsigned long int base_vapi_id; /* Start of VAPI ID block */`
92	19	jeremybenn
93	443	jeremybenn	`/* DMA controller this MAC is connected to, and associated channels */`
94	19	jeremybenn	`unsigned dma;`
95			`unsigned tx_channel;`
96			`unsigned rx_channel;`
97
98	443	jeremybenn	`/* Details of the hardware */`
99			`unsigned char mac_address[ETHER_ADDR_LEN]; /* Ext HW address */`
100			`unsigned long int phy_addr; /* Int HW address */`
101			`unsigned long int mac_int; /* interrupt line number */`
102	451	jeremybenn	`int dummy_crc; /* Flag indicating if we add CRC */`
103	443	jeremybenn	`int int_line_stat; /* interrupt line status */`
104	19	jeremybenn
105	443	jeremybenn	`/* External interface deatils */`
106			`int rtx_type; /* Type of external i/f: FILE or TAP */`
107	19	jeremybenn
108	434	jeremybenn	`/* RX and TX file names and handles for FILE type connection. */`
109	443	jeremybenn	`char rxfile; / Rx filename */`
110			`char txfile; / Tx filename */`
111			`int txfd; /* Rx file handle */`
112			`int rxfd; /* Tx file handle */`
113	19	jeremybenn
114	434	jeremybenn	`/* Info for TAP type connections */`
115	443	jeremybenn	`char tap_dev; / The TAP device */`
116			`int rtx_fd; /* TAP device handle */`
117	19	jeremybenn
118	450	jeremybenn	`/* Indices into the buffer descriptors. */`
119			`unsigned long int tx_bd_index;`
120			`unsigned long int rx_bd_index;`
121	19	jeremybenn
122			`/* Visible registers */`
123			`struct`
124			`{`
125	443	jeremybenn	`unsigned long int moder;`
126			`unsigned long int int_source;`
127			`unsigned long int int_mask;`
128			`unsigned long int ipgt;`
129			`unsigned long int ipgr1;`
130			`unsigned long int ipgr2;`
131			`unsigned long int packetlen;`
132			`unsigned long int collconf;`
133			`unsigned long int tx_bd_num;`
134			`unsigned long int controlmoder;`
135			`unsigned long int miimoder;`
136			`unsigned long int miicommand;`
137			`unsigned long int miiaddress;`
138			`unsigned long int miitx_data;`
139			`unsigned long int miirx_data;`
140			`unsigned long int miistatus;`
141			`unsigned long int hash0;`
142			`unsigned long int hash1;`
143	19	jeremybenn
144			`/* Buffer descriptors */`
145	443	jeremybenn	`unsigned long int bd_ram[ETH_BD_SPACE / 4];`
146	19	jeremybenn	`} regs;`
147			`};`
148
149
150	443	jeremybenn	`/* -------------------------------------------------------------------------- */`
151	450	jeremybenn	`/*!Write an Ethernet packet to a FILE interface.`
152	443	jeremybenn
153	450	jeremybenn	`This writes a single Ethernet packet to a FILE interface. The format is to`
154			`write the length, then the data.`
155	443	jeremybenn
156	450	jeremybenn	`@param[in] eth Pointer to the relevant Ethernet data structure.`
157			`@param[in] buf Where to get the data.`
158			`@param[in] length Length of data to write.`
159	443	jeremybenn
160	450	jeremybenn	`@return The length if successful, a negative value otherwise. */`
161			`/* -------------------------------------------------------------------------- */`
162			`static ssize_t`
163			`eth_write_file_packet (struct eth_device *eth,`
164			`unsigned char *buf,`
165			`unsigned long int length)`
166			`{`
167			`ssize_t nwritten;`
168	443	jeremybenn
169	450	jeremybenn	`/* Write length to file. */`
170			`nwritten = write (eth->txfd, &(length), sizeof (length));`
171			`if (nwritten != sizeof (length))`
172			`{`
173			`fprintf (stderr, "ERROR: Failed to write Ethernet packet length: %s.\n",`
174			`strerror (errno));`
175			`return -1;`
176			`}`
177	443	jeremybenn
178	450	jeremybenn	`/* write data to file */`
179			`nwritten = write (eth->txfd, buf, length);`
180			`if (nwritten != length)`
181			`{`
182			`fprintf (stderr, "ERROR: Failed to write Ethernet packet data: %s.\n",`
183			`strerror (errno));`
184			`return -1;`
185			`}`
186	443	jeremybenn
187	450	jeremybenn	`return nwritten;`
188
189			`} /* eth_write_file_packet () */`
190
191
192	443	jeremybenn	`/* -------------------------------------------------------------------------- */`
193	450	jeremybenn	`/*!Write an Ethernet packet to a TAP interface.`
194
195			`This writes a single Ethernet packet to a TAP interface.`
196
197			`@param[in] eth Pointer to the relevant Ethernet data structure.`
198			`@param[in] buf Where to get the data.`
199			`@param[in] length Length of data to write.`
200
201			`@return The length if successful, a negative value otherwise. */`
202			`/* -------------------------------------------------------------------------- */`
203			`static ssize_t`
204			`eth_write_tap_packet (struct eth_device *eth,`
205			`unsigned char *buf,`
206			`unsigned long int length)`
207	443	jeremybenn	`{`
208	450	jeremybenn	`ssize_t nwritten;`
209	443	jeremybenn
210	450	jeremybenn	`#if ETH_DEBUG`
211			`int j;`
212	443	jeremybenn
213	450	jeremybenn	`printf ("Writing TAP\n");`
214			`printf (" packet %d bytes:", (int) length);`
215
216			`for (j = 0; j < length; j++)`
217	443	jeremybenn	`{`
218	450	jeremybenn	`if (0 == (j % 16))`
219			`{`
220			`printf ("\n");`
221			`}`
222			`else if (0 == (j % 8))`
223			`{`
224			`printf (" ");`
225			`}`
226
227			`printf ("%.2x ", buf[j]);`
228			`}`
229
230			`printf("\nend packet:\n");`
231			`#endif`
232	443	jeremybenn
233	450	jeremybenn	`/* Write the data to the TAP */`
234			`nwritten = write (eth->rtx_fd, buf, length);`
235			`if (nwritten != length)`
236			`{`
237			`fprintf (stderr, "ERROR: Failed to write Ethernet packet data: %s.\n",`
238			`strerror (errno));`
239			`return -1;`
240			`}`
241	443	jeremybenn
242	450	jeremybenn	`return nwritten;`
243	443	jeremybenn
244	450	jeremybenn	`} /* eth_write_tap_packet () */`
245	443	jeremybenn
246
247	450	jeremybenn	`/* -------------------------------------------------------------------------- */`
248			`/*!Write an Ethernet packet.`
249	443	jeremybenn
250	450	jeremybenn	`This writes a single Ethernet packet to the outside world from the supplied`
251			`buffer. It deals with the different types of external interface.`
252	443	jeremybenn
253	450	jeremybenn	`@param[in] eth Pointer to the relevant Ethernet data structure.`
254			`@param[in] buf Where to get the data.`
255			`@param[in] length Length of data to write.`
256	443	jeremybenn
257	450	jeremybenn	`@return The length if successful, zero if no packet was available,`
258			`a negative value otherwise. */`
259			`/* -------------------------------------------------------------------------- */`
260			`static ssize_t`
261			`eth_write_packet (struct eth_device *eth,`
262			`unsigned char *buf,`
263			`ssize_t length)`
264			`{`
265			`/* Send packet according to interface type. */`
266			`switch (eth->rtx_type)`
267			`{`
268			`case ETH_RTX_FILE: return eth_write_file_packet (eth, buf, length);`
269			`case ETH_RTX_TAP: return eth_write_tap_packet (eth, buf, length);`
270	443	jeremybenn
271	450	jeremybenn	`default:`
272			`fprintf (stderr, "Unknown Ethernet write interface: ignored.\n");`
273			`return (ssize_t) -1;`
274			`}`
275			`} /* eth_write_packet () */`
276	443	jeremybenn
277
278	450	jeremybenn	`/* -------------------------------------------------------------------------- */`
279			`/*!Flush a Tx buffer descriptor to the outside world.`
280	19	jeremybenn
281	450	jeremybenn	`We know the buffer descriptor is full, so write it to the appropriate`
282			`outside interface.`
283
284			`@param[in] eth The Ethernet data structure. */`
285			`/* -------------------------------------------------------------------------- */`
286			`static void`
287			`eth_flush_bd (struct eth_device *eth)`
288			`{`
289			`/* First word of BD is flags and length, second is pointer to buffer */`
290			`unsigned long int bd_info = eth->regs.bd_ram[eth->tx_bd_index];`
291			`unsigned long int bd_addr = eth->regs.bd_ram[eth->tx_bd_index + 1];`
292			`unsigned char buf[ETH_MAXPL];`
293			`long int packet_length;`
294			`long int bytes_sent;`
295	460	jeremybenn	`int ok_to_int_p;`
296	450	jeremybenn
297			`/* Get the packet length */`
298			`packet_length = GET_FIELD (bd_info, ETH_TX_BD, LENGTH);`
299
300			`/* Clear error status bits and retry count. */`
301			`CLEAR_FLAG (bd_info, ETH_TX_BD, DEFER);`
302			`CLEAR_FLAG (bd_info, ETH_TX_BD, COLLISION);`
303			`CLEAR_FLAG (bd_info, ETH_TX_BD, RETRANSMIT);`
304			`CLEAR_FLAG (bd_info, ETH_TX_BD, UNDERRUN);`
305			`CLEAR_FLAG (bd_info, ETH_TX_BD, NO_CARRIER);`
306
307			`SET_FIELD (bd_info, ETH_TX_BD, RETRY, 0);`
308
309			`/* Copy data from buffer descriptor address into our local buf. */`
310			`for (bytes_sent = 0; bytes_sent < packet_length; bytes_sent +=4)`
311			`{`
312			`unsigned long int read_word =`
313			`eval_direct32 (bytes_sent + bd_addr, 0, 0);`
314
315			`buf[bytes_sent] = (unsigned char) (read_word >> 24);`
316			`buf[bytes_sent + 1] = (unsigned char) (read_word >> 16);`
317			`buf[bytes_sent + 2] = (unsigned char) (read_word >> 8);`
318			`buf[bytes_sent + 3] = (unsigned char) (read_word);`
319			`}`
320
321			`/* Send packet according to interface type and set BD status. If we didn't`
322			`write the whole packet, then we retry. */`
323			`if (eth_write_packet (eth, buf, packet_length) == packet_length)`
324			`{`
325			`CLEAR_FLAG (bd_info, ETH_TX_BD, READY);`
326			`SET_FLAG (eth->regs.int_source, ETH_INT_SOURCE, TXB);`
327	460	jeremybenn	`ok_to_int_p = TEST_FLAG (eth->regs.int_mask, ETH_INT_MASK, TXB_M);`
328	450	jeremybenn	`}`
329			`else`
330			`{`
331			`/* Does this retry mechanism really work? */`
332			`CLEAR_FLAG (bd_info, ETH_TX_BD, READY);`
333			`CLEAR_FLAG (bd_info, ETH_TX_BD, COLLISION);`
334			`SET_FLAG (eth->regs.int_source, ETH_INT_SOURCE, TXE);`
335	460	jeremybenn	`ok_to_int_p = TEST_FLAG (eth->regs.int_mask, ETH_INT_MASK, TXE_M);`
336	443	jeremybenn	`#if ETH_DEBUG`
337	450	jeremybenn	`printf ("Transmit retry request.\n");`
338	443	jeremybenn	`#endif`
339	450	jeremybenn	`}`
340	19	jeremybenn
341	450	jeremybenn	`/* Update the flags in the buffer descriptor */`
342			`eth->regs.bd_ram[eth->tx_bd_index] = bd_info;`
343	19	jeremybenn
344	450	jeremybenn	`/* Generate interrupt to indicate transfer complete, under the`
345			`following criteria all being met:`
346			`- either INT_MASK flag for Tx (OK or error) is set`
347	460	jeremybenn	`- the buffer descriptor has its IRQ flag set`
348	450	jeremybenn	`- there is no interrupt in progress.`
349	437	julius
350	450	jeremybenn	`@todo We ought to warn if we get here and fail to set an IRQ. */`
351	460	jeremybenn	`if (ok_to_int_p && TEST_FLAG (bd_info, ETH_TX_BD, IRQ))`
352	450	jeremybenn	`{`
353			`if (eth->int_line_stat)`
354	19	jeremybenn	`{`
355	450	jeremybenn	`fprintf (stderr, "Warning: Interrupt active during Tx.\n");`
356			`}`
357			`else`
358			`{`
359	437	julius	`#if ETH_DEBUG`
360	443	jeremybenn	`printf ("TRANSMIT interrupt\n");`
361	437	julius	`#endif`
362	443	jeremybenn	`report_interrupt (eth->mac_int);`
363			`eth->int_line_stat = 1;`
364	19	jeremybenn	`}`
365	450	jeremybenn	`}`
366	19	jeremybenn
367	450	jeremybenn	`/* Advance to next BD, wrapping around if appropriate. */`
368			`if (TEST_FLAG (bd_info, ETH_TX_BD, WRAP) \|\|`
369			`eth->tx_bd_index >= ((eth->regs.tx_bd_num - 1) * 2))`
370			`{`
371			`eth->tx_bd_index = 0;`
372	19	jeremybenn	`}`
373	450	jeremybenn	`else`
374			`{`
375			`eth->tx_bd_index += 2;`
376			`}`
377			`} /* eth_flush_bd () */`
378	19	jeremybenn
379
380	443	jeremybenn	`/* -------------------------------------------------------------------------- */`
381	450	jeremybenn	`/*!Tx clock function.`
382	443	jeremybenn
383	450	jeremybenn	`Responsible for starting and completing any TX actions.`
384	443	jeremybenn
385			`The original version had 4 states, which allowed modeling the transfer of`
386	450	jeremybenn	`data one byte per cycle. For now we use only the one state for`
387			`efficiency. When we find something in a buffer descriptor, we transmit`
388			`it.`
389	443	jeremybenn
390	450	jeremybenn	`We reschedule every cycle. There is no point in trying to do anything if`
391			`there is an interrupt still being processed by the core.`
392	443	jeremybenn
393			`@todo We should eventually reinstate the one byte per cycle transfer.`
394
395			`@param[in] dat The Ethernet data structure, passed as a void pointer. */`
396			`/* -------------------------------------------------------------------------- */`
397	19	jeremybenn	`static void`
398	450	jeremybenn	`eth_controller_tx_clock (void *dat)`
399	19	jeremybenn	`{`
400			`struct eth_device *eth = dat;`
401
402	450	jeremybenn	`/* Only do anything if there is not an interrupt outstanding. */`
403			`if (!eth->int_line_stat)`
404	19	jeremybenn	`{`
405	450	jeremybenn	`/* First word of BD is flags. If we have a buffer ready, get it and`
406			`transmit it. */`
407			`if (TEST_FLAG (eth->regs.bd_ram[eth->tx_bd_index], ETH_TX_BD, READY))`
408			`{`
409			`eth_flush_bd (eth);`
410			`}`
411			`}`
412	19	jeremybenn
413	460	jeremybenn	`/* Reschedule to wake up again. */`
414	451	jeremybenn	`SCHED_ADD (eth_controller_tx_clock, dat, RTX_RESCHED_PERIOD);`
415	434	jeremybenn
416	450	jeremybenn	`} /* eth_controller_tx_clock () */`
417	19	jeremybenn
418
419	450	jeremybenn	`/* -------------------------------------------------------------------------- */`
420			`/*!Read an Ethernet packet from a FILE interface.`
421	437	julius
422	450	jeremybenn	`This reads a single Ethernet packet from the outside world via a FILE`
423			`interface.`
424	434	jeremybenn
425	450	jeremybenn	`The format is 4 bytes of packet length, followed by the packet data.`
426	434	jeremybenn
427	450	jeremybenn	`@param[in] eth Pointer to the relevant Ethernet data structure`
428			`@param[out] buf Where to put the data`
429	434	jeremybenn
430	450	jeremybenn	`@return The length if successful, zero if no packet was available`
431			`(i.e. EOF), a negative value otherwise. */`
432			`/* -------------------------------------------------------------------------- */`
433			`static ssize_t`
434			`eth_read_file_packet (struct eth_device *eth,`
435			`unsigned char *buf)`
436			`{`
437			`ssize_t packet_length;`
438			`ssize_t nread;`
439	434	jeremybenn
440	450	jeremybenn	`/* Read packet length. We may be at EOF. */`
441			`nread = read (eth->rxfd, &(packet_length), sizeof (packet_length));`
442	19	jeremybenn
443	450	jeremybenn	`if (0 == nread)`
444			`{`
445			`return 0; /* No more packets */`
446			`}`
447			`else if (nread < sizeof (packet_length))`
448			`{`
449			`fprintf (stderr, "ERROR: Failed to read length from file.\n");`
450			`return -1;`
451			`}`
452	460	jeremybenn
453	450	jeremybenn	`/* Packet must be big enough to hold a header */`
454			`if (packet_length < ETHER_HDR_LEN)`
455			`{`
456			`fprintf (stderr, "Warning: Ethernet packet length %zd too small.\n",`
457			`packet_length);`
458			`return -1;`
459			`}`
460	19	jeremybenn
461	450	jeremybenn	`/* Read the packet proper. */`
462			`nread = read (eth->rxfd, buf, packet_length);`
463	19	jeremybenn
464	450	jeremybenn	`if (nread != packet_length)`
465			`{`
466			`fprintf (stderr, "ERROR: Failed to read packet from file.\n");`
467			`return -1;`
468			`}`
469	19	jeremybenn
470	450	jeremybenn	`return packet_length;`
471	19	jeremybenn
472	450	jeremybenn	`} /* eth_read_file_packet () */`
473	19	jeremybenn
474
475	450	jeremybenn	`/* -------------------------------------------------------------------------- */`
476			`/*!Read an Ethernet packet from a FILE interface.`
477	19	jeremybenn
478	450	jeremybenn	`This reads a single Ethernet packet from the outside world via a TAP`
479			`interface.`
480	19	jeremybenn
481	450	jeremybenn	`A complete packet is always read, so its length (minus CRC) is the amount`
482			`read.`
483
484			`@param[in] eth Pointer to the relevant Ethernet data structure`
485			`@param[out] buf Where to put the data`
486
487			`@return The length if successful, zero if no packet was available,`
488			`a negative value otherwise. */`
489			`/* -------------------------------------------------------------------------- */`
490			`static ssize_t`
491			`eth_read_tap_packet (struct eth_device *eth,`
492			`unsigned char *buf)`
493			`{`
494			`struct pollfd fds[1];`
495			`int n;`
496			`ssize_t packet_length;`
497
498			`/* Poll to see if there is data to read */`
499			`fds[0].fd = eth->rtx_fd;`
500			`fds[0].events = POLLIN;`

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