/////////////////////////////////////////////////////////////////////////
// $Id: pcipnic.cc,v 1.37 2009-04-23 15:52:53 vruppert Exp $
/////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2003  Fen Systems Ltd.
//  http://www.fensystems.co.uk/
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2 of the License, or (at your option) any later version.
//
//  This library 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
//  Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with this library; if not, write to the Free Software
//  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
/////////////////////////////////////////////////////////////////////////

// Define BX_PLUGGABLE in files that can be compiled into plugins.  For
// platforms that require a special tag on exported symbols, BX_PLUGGABLE
// is used to know when we are exporting symbols and when we are importing.

#define BX_PLUGGABLE

#include "iodev.h"
#if BX_SUPPORT_PCI && BX_SUPPORT_PCIPNIC

#include "pci.h"
#include "eth.h"
#include "pcipnic.h"

#define LOG_THIS thePNICDevice->

bx_pcipnic_c* thePNICDevice = NULL;

const Bit8u pnic_iomask[16] = {2, 0, 2, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

int libpcipnic_LTX_plugin_init(plugin_t *plugin, plugintype_t type, int argc, char *argv[])
{
  thePNICDevice = new bx_pcipnic_c();
  BX_REGISTER_DEVICE_DEVMODEL(plugin, type, thePNICDevice, BX_PLUGIN_PCIPNIC);
  return 0; // Success
}

void libpcipnic_LTX_plugin_fini(void)
{
  delete thePNICDevice;
}

bx_pcipnic_c::bx_pcipnic_c()
{
  put("PNIC");
}

bx_pcipnic_c::~bx_pcipnic_c()
{
  BX_DEBUG(("Exit"));
}

void bx_pcipnic_c::init(void)
{
  bx_list_c *base;

  // Read in values from config interface
  base = (bx_list_c*) SIM->get_param(BXPN_PNIC);
  memcpy(BX_PNIC_THIS s.macaddr, SIM->get_param_string("macaddr", base)->getptr(), 6);

  BX_PNIC_THIS s.devfunc = 0x00;
  DEV_register_pci_handlers(this, &BX_PNIC_THIS s.devfunc, BX_PLUGIN_PCIPNIC,
                            "Experimental PCI Pseudo NIC");

  for (unsigned i=0; i<256; i++) {
    BX_PNIC_THIS s.pci_conf[i] = 0x0;
  }

  // This code ripped wholesale from ne2k.cc:
  // Attach to the simulated ethernet dev
  const char *ethmod = SIM->get_param_enum("ethmod", base)->get_selected();
  BX_PNIC_THIS ethdev = eth_locator_c::create(ethmod,
                                              SIM->get_param_string("ethdev", base)->getptr(),
                                              (const char *) SIM->get_param_string("macaddr", base)->getptr(),
                                              rx_handler,
                                              this,
                                              SIM->get_param_string("script", base)->getptr());

  if (BX_PNIC_THIS ethdev == NULL) {
    BX_PANIC(("could not find eth module %s", ethmod));
    // if they continue, use null.
    BX_INFO(("could not find eth module %s - using null instead", ethmod));

    BX_PNIC_THIS ethdev = eth_locator_c::create("null", NULL,
                                                (const char *) SIM->get_param_string("macaddr", base)->getptr(),
                                                rx_handler,
                                                this, "");
    if (BX_PNIC_THIS ethdev == NULL)
      BX_PANIC(("could not locate null module"));
  }

  BX_PNIC_THIS s.base_ioaddr = 0;

  BX_INFO(("PCI Pseudo NIC initialized - I/O base and IRQ assigned by PCI BIOS"));
}

void bx_pcipnic_c::reset(unsigned type)
{
  unsigned i;

  static const struct reset_vals_t {
    unsigned      addr;
    unsigned char val;
  } reset_vals[] = {
    { 0x00, PNIC_PCI_VENDOR & 0xff },
    { 0x01, PNIC_PCI_VENDOR >> 8 },
    { 0x02, PNIC_PCI_DEVICE & 0xff },
    { 0x03, PNIC_PCI_DEVICE >> 8 },
    { 0x04, 0x05 }, { 0x05, 0x00 },	// command_io
    { 0x06, 0x80 }, { 0x07, 0x02 },	// status
    { 0x08, 0x01 },                 // revision number
    { 0x09, 0x00 },                 // interface
    { 0x0a, 0x00 },                 // class_sub
    { 0x0b, 0x02 },                 // class_base Network Controller
    { 0x0D, 0x20 },                 // bus latency
    { 0x0e, 0x00 },                 // header_type_generic
    // address space 0x20 - 0x23
    { 0x20, 0x01 }, { 0x21, 0x00 },
    { 0x22, 0x00 }, { 0x23, 0x00 },
    { 0x3c, 0x00, },                // IRQ
    { 0x3d, BX_PCI_INTA },          // INT
    { 0x6a, 0x01 },                 // PNIC clock
    { 0xc1, 0x20 }                  // PIRQ enable

  };
  for (i = 0; i < sizeof(reset_vals) / sizeof(*reset_vals); ++i) {
      BX_PNIC_THIS s.pci_conf[reset_vals[i].addr] = reset_vals[i].val;
  }

  // Set up initial register values
  BX_PNIC_THIS s.rCmd = PNIC_CMD_NOOP;
  BX_PNIC_THIS s.rStatus = PNIC_STATUS_OK;
  BX_PNIC_THIS s.rLength = 0;
  BX_PNIC_THIS s.rDataCursor = 0;
  BX_PNIC_THIS s.recvIndex = 0;
  BX_PNIC_THIS s.recvQueueLength = 0;
  BX_PNIC_THIS s.irqEnabled = 0;

  // Deassert IRQ
  set_irq_level(0);
}

void bx_pcipnic_c::register_state(void)
{
  unsigned i;
  char name[6];

  bx_list_c *list = new bx_list_c(SIM->get_bochs_root(), "pcipnic", "PCI Pseudo NIC State", 11);
  new bx_shadow_num_c(list, "irqEnabled", &BX_PNIC_THIS s.irqEnabled);
  new bx_shadow_num_c(list, "rCmd", &BX_PNIC_THIS s.rCmd);
  new bx_shadow_num_c(list, "rStatus", &BX_PNIC_THIS s.rStatus);
  new bx_shadow_num_c(list, "rLength", &BX_PNIC_THIS s.rLength);
  new bx_shadow_num_c(list, "rDataCursor", &BX_PNIC_THIS s.rDataCursor);
  new bx_shadow_num_c(list, "recvIndex", &BX_PNIC_THIS s.recvIndex);
  new bx_shadow_num_c(list, "recvQueueLength", &BX_PNIC_THIS s.recvQueueLength);
  bx_list_c *recvRL = new bx_list_c(list, "recvRingLength", PNIC_RECV_RINGS);
  for (i=0; i<PNIC_RECV_RINGS; i++) {
    sprintf(name, "%d", i);
    new bx_shadow_num_c(recvRL, name, &BX_PNIC_THIS s.recvRingLength[i]);
  }
  new bx_shadow_data_c(list, "rData", BX_PNIC_THIS s.rData, PNIC_DATA_SIZE);
  new bx_shadow_data_c(list, "recvRing", (Bit8u*)BX_PNIC_THIS s.recvRing, PNIC_RECV_RINGS*PNIC_DATA_SIZE);
  register_pci_state(list, BX_PNIC_THIS s.pci_conf);
}

void bx_pcipnic_c::after_restore_state(void)
{
  if (DEV_pci_set_base_io(BX_PNIC_THIS_PTR, read_handler, write_handler,
                          &BX_PNIC_THIS s.base_ioaddr,
                          &BX_PNIC_THIS s.pci_conf[0x10],
                          16, &pnic_iomask[0], "PNIC")) {
    BX_INFO(("new base address: 0x%04x", BX_PNIC_THIS s.base_ioaddr));
  }
}

void bx_pcipnic_c::set_irq_level(bx_bool level)
{
  DEV_pci_set_irq(BX_PNIC_THIS s.devfunc, BX_PNIC_THIS s.pci_conf[0x3d], level);
}

// static IO port read callback handler
// redirects to non-static class handler to avoid virtual functions

Bit32u bx_pcipnic_c::read_handler(void *this_ptr, Bit32u address, unsigned io_len)
{
#if !BX_USE_PCIPNIC_SMF
  bx_pcipnic_c *class_ptr = (bx_pcipnic_c *) this_ptr;
  return class_ptr->read(address, io_len);
}

Bit32u bx_pcipnic_c::read(Bit32u address, unsigned io_len)
{
#else
  UNUSED(this_ptr);
#endif // !BX_USE_PCIPNIC_SMF
  Bit32u val = 0x0;
  Bit8u  offset;

  BX_DEBUG(("register read from address 0x%04x - ", (unsigned) address));

  offset = address - BX_PNIC_THIS s.base_ioaddr;

  switch (offset) {
  case PNIC_REG_STAT:
    val = BX_PNIC_THIS s.rStatus;
    break;

  case PNIC_REG_LEN:
    val = BX_PNIC_THIS s.rLength;
    break;

  case PNIC_REG_DATA:
    if (BX_PNIC_THIS s.rDataCursor >= BX_PNIC_THIS s.rLength)
      BX_PANIC(("PNIC read at %u, beyond end of data register array",
		BX_PNIC_THIS s.rDataCursor));
    val = BX_PNIC_THIS s.rData[BX_PNIC_THIS s.rDataCursor++];
    break;

  default :
    val = 0; // keep compiler happy
    BX_PANIC(("unsupported io read from address=0x%04x!", (unsigned) address));
    break;
  }

  BX_DEBUG(("val =  0x%04x", (Bit16u) val));

  return(val);
}

// static IO port write callback handler
// redirects to non-static class handler to avoid virtual functions

void bx_pcipnic_c::write_handler(void *this_ptr, Bit32u address, Bit32u value, unsigned io_len)
{
#if !BX_USE_PCIPNIC_SMF
  bx_pcipnic_c *class_ptr = (bx_pcipnic_c *) this_ptr;

  class_ptr->write(address, value, io_len);
}

void bx_pcipnic_c::write(Bit32u address, Bit32u value, unsigned io_len)
{
#else
  UNUSED(this_ptr);
#endif // !BX_USE_PCIPNIC_SMF
  Bit8u  offset;

  BX_DEBUG(("register write to address 0x%04x - ", (unsigned) address));

  offset = address - BX_PNIC_THIS s.base_ioaddr;

  switch (offset) {
  case PNIC_REG_CMD:
    BX_PNIC_THIS s.rCmd = value;
    BX_PNIC_THIS exec_command();
    break;

  case PNIC_REG_LEN:
    if (value > PNIC_DATA_SIZE)
      BX_PANIC(("PNIC bad length %u written to length register, max is %u",
		value, PNIC_DATA_SIZE));
    BX_PNIC_THIS s.rLength = value;
    BX_PNIC_THIS s.rDataCursor = 0;
    break;

  case PNIC_REG_DATA:
    if (BX_PNIC_THIS s.rDataCursor >= BX_PNIC_THIS s.rLength)
      BX_PANIC(("PNIC write at %u, beyond end of data register array",
		BX_PNIC_THIS s.rDataCursor));
    BX_PNIC_THIS s.rData[BX_PNIC_THIS s.rDataCursor++] = value;
    break;

  default:
    BX_PANIC(("unsupported io write to address=0x%04x!", (unsigned) address));
    break;
  }
}

void bx_pcipnic_c::pnic_timer_handler(void *this_ptr)
{
  bx_pcipnic_c *class_ptr = (bx_pcipnic_c *) this_ptr;
  class_ptr->pnic_timer();
}

// Called once every 1ms
void bx_pcipnic_c::pnic_timer(void)
{
  // Do nothing atm

}

// pci configuration space read callback handler
Bit32u bx_pcipnic_c::pci_read_handler(Bit8u address, unsigned io_len)
{
  Bit32u value = 0;

  for (unsigned i=0; i<io_len; i++) {
    value |= (BX_PNIC_THIS s.pci_conf[address+i] << (i*8));
  }

  if (io_len == 1)
    BX_DEBUG(("read  PCI register 0x%02x value 0x%02x", address, value));
  else if (io_len == 2)
    BX_DEBUG(("read  PCI register 0x%02x value 0x%04x", address, value));
  else if (io_len == 4)
    BX_DEBUG(("read  PCI register 0x%02x value 0x%08x", address, value));

  return value;
}


// pci configuration space write callback handler
void bx_pcipnic_c::pci_write_handler(Bit8u address, Bit32u value, unsigned io_len)
{
  Bit8u value8, oldval;
  bx_bool baseaddr_change = 0;

  if (((address >= 0x10) && (address < 0x20)) ||
      ((address > 0x23) && (address < 0x34)))
    return;

  for (unsigned i=0; i<io_len; i++) {
    value8 = (value >> (i*8)) & 0xFF;
    oldval = BX_PNIC_THIS s.pci_conf[address+i];
    switch (address+i) {
      case 0x3d: //
      case 0x05: // disallowing write to command hi-byte
      case 0x06: // disallowing write to status lo-byte (is that expected?)
        break;
      case 0x3c:
        if (value8 != oldval) {
          BX_INFO(("new irq line = %d", value8));
          BX_PNIC_THIS s.pci_conf[address+i] = value8;
        }
        break;
      case 0x20:
        value8 = (value8 & 0xfc) | 0x01;
      case 0x21:
      case 0x22:
      case 0x23:
        baseaddr_change = (value8 != oldval);
      default:
        BX_PNIC_THIS s.pci_conf[address+i] = value8;
    }
  }
  if (baseaddr_change) {
    if (DEV_pci_set_base_io(BX_PNIC_THIS_PTR, read_handler, write_handler,
                            &BX_PNIC_THIS s.base_ioaddr,
                            &BX_PNIC_THIS s.pci_conf[0x20],
                            16, &pnic_iomask[0], "PNIC")) {
      BX_INFO(("new base address: 0x%04x", BX_PNIC_THIS s.base_ioaddr));
    }
  }

  if (io_len == 1)
    BX_DEBUG(("write PCI register 0x%02x value 0x%02x", address, value));
  else if (io_len == 2)
    BX_DEBUG(("write PCI register 0x%02x value 0x%04x", address, value));
  else if (io_len == 4)
    BX_DEBUG(("write PCI register 0x%02x value 0x%08x", address, value));
}


/*
 * Execute a hardware command.
 */
void bx_pcipnic_c::exec_command(void)
{
  Bit16u command = BX_PNIC_THIS s.rCmd;
  Bit16u ilength = BX_PNIC_THIS s.rLength;
  Bit8u *data	 = BX_PNIC_THIS s.rData;
  // Default return values
  Bit16u status  = PNIC_STATUS_UNKNOWN_CMD;
  Bit16u olength = 0;

  if (ilength != BX_PNIC_THIS s.rDataCursor)
    BX_PANIC(("PNIC command issued with incomplete data (should be %u, is %u)",
	      ilength, BX_PNIC_THIS s.rDataCursor));

  switch (command) {
  case PNIC_CMD_NOOP:
    status = PNIC_STATUS_OK;
    break;

  case PNIC_CMD_API_VER:
    Bit16u api_version;

    api_version = PNIC_API_VERSION;
    olength = sizeof(api_version);
    memcpy (data, &api_version, sizeof(api_version));
    status = PNIC_STATUS_OK;
    break;

  case PNIC_CMD_READ_MAC:
    olength = sizeof (BX_PNIC_THIS s.macaddr);
    memcpy (data, BX_PNIC_THIS s.macaddr, olength);
    status = PNIC_STATUS_OK;
    break;

  case PNIC_CMD_RESET:
    /* Flush the receive queue */
    BX_PNIC_THIS s.recvQueueLength = 0;
    status = PNIC_STATUS_OK;
    break;

  case PNIC_CMD_XMIT:
    BX_PNIC_THIS ethdev->sendpkt(data, ilength);
    if (BX_PNIC_THIS s.irqEnabled) {
      set_irq_level(1);
    }
    status = PNIC_STATUS_OK;
    break;

  case PNIC_CMD_RECV:
    if (BX_PNIC_THIS s.recvQueueLength > 0) {
      int idx = (BX_PNIC_THIS s.recvIndex - BX_PNIC_THIS s.recvQueueLength
		  + PNIC_RECV_RINGS) % PNIC_RECV_RINGS;
      olength = BX_PNIC_THIS s.recvRingLength[idx];
      memcpy (data, BX_PNIC_THIS s.recvRing[idx], olength);
      BX_PNIC_THIS s.recvQueueLength--;
    }
    if (! BX_PNIC_THIS s.recvQueueLength) {
      set_irq_level(0);
    }
    status = PNIC_STATUS_OK;
    break;

  case PNIC_CMD_RECV_QLEN:
    Bit16u qlen;

    qlen = BX_PNIC_THIS s.recvQueueLength;
    olength = sizeof(qlen);
    memcpy (data, &qlen, sizeof(qlen));
    status = PNIC_STATUS_OK;
    break;

  case PNIC_CMD_MASK_IRQ:
    Bit8u enabled;

    enabled = *((Bit8u*)data);
    BX_PNIC_THIS s.irqEnabled = enabled;
    if (enabled && BX_PNIC_THIS s.recvQueueLength) {
      set_irq_level(1);
    } else {
      set_irq_level(0);
    }
    status = PNIC_STATUS_OK;
    break;

  case PNIC_CMD_FORCE_IRQ:
    set_irq_level(1);
    status = PNIC_STATUS_OK;
    break;

  default:
    BX_ERROR(("Unknown PNIC command %x (data length %u)", command, ilength));
    status = PNIC_STATUS_UNKNOWN_CMD;
    break;
  }

  // Set registers
  BX_PNIC_THIS s.rStatus = status;
  BX_PNIC_THIS s.rLength = olength;
  BX_PNIC_THIS s.rDataCursor = 0;
}

/*
 * Callback from the eth system driver when a frame has arrived
 */
void bx_pcipnic_c::rx_handler(void *arg, const void *buf, unsigned len)
{
    // BX_DEBUG(("rx_handler with length %d", len));
  bx_pcipnic_c *class_ptr = (bx_pcipnic_c *) arg;
  class_ptr->rx_frame(buf, len);
}

/*
 * rx_frame() - called by the platform-specific code when an
 * ethernet frame has been received. The destination address
 * is tested to see if it should be accepted, and if the
 * rx ring has enough room, it is copied into it and
 * the receive process is updated
 */
void bx_pcipnic_c::rx_frame(const void *buf, unsigned io_len)
{
  // Check packet length
  if (io_len > PNIC_DATA_SIZE) {
    BX_PANIC(("PNIC receive: data size %u exceeded buffer size %u",
       io_len, PNIC_DATA_SIZE));
    // Truncate if user continues
    io_len = PNIC_DATA_SIZE;
  }
  // Check receive ring is not full
  if (BX_PNIC_THIS s.recvQueueLength == PNIC_RECV_RINGS) {
    BX_ERROR(("PNIC receive: receive ring full, discarding packet"));
    return;
  }
  // Copy data to receive ring and record length
  memcpy (BX_PNIC_THIS s.recvRing[BX_PNIC_THIS s.recvIndex], buf, io_len);
  BX_PNIC_THIS s.recvRingLength[BX_PNIC_THIS s.recvIndex] = io_len;
  // Move to next ring entry
  BX_PNIC_THIS s.recvIndex = (BX_PNIC_THIS s.recvIndex + 1) % PNIC_RECV_RINGS;
  BX_PNIC_THIS s.recvQueueLength++;

  // Generate interrupt if enabled
  if (BX_PNIC_THIS s.irqEnabled) {
    set_irq_level(1);
  }
}

#endif // BX_SUPPORT_PCI && BX_SUPPORT_PCIPNIC