xref: /gem5/src/mem/ruby/system/DMASequencer.cc

/*
 * Copyright (c) 2008 Mark D. Hill and David A. Wood
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "mem/ruby/system/DMASequencer.hh"
#include "mem/ruby/buffers/MessageBuffer.hh"
#include "mem/ruby/slicc_interface/AbstractController.hh"

/* SLICC generated types */
#include "mem/protocol/SequencerMsg.hh"
#include "mem/protocol/SequencerRequestType.hh"
#include "mem/ruby/system/System.hh"

//
// Fix me: This code needs comments!
//

DMASequencer::DMASequencer(const Params *p)
  : RubyPort(p)
{
}

void DMASequencer::init()
{
  RubyPort::init();
  m_is_busy = false;
  m_data_block_mask = ~ (~0 << RubySystem::getBlockSizeBits());
}

RequestStatus DMASequencer::makeRequest(const RubyRequest & request)
{
  uint64_t paddr = request.paddr;
  uint8_t* data = request.data;
  int len = request.len;
  bool write = false;
  switch(request.type) {
  case RubyRequestType_LD:
    write = false;
    break;
  case RubyRequestType_ST:
    write = true;
    break;
  case RubyRequestType_NULL:
  case RubyRequestType_IFETCH:
  case RubyRequestType_Locked_Read:
  case RubyRequestType_Locked_Write:
  case RubyRequestType_RMW_Read:
  case RubyRequestType_RMW_Write:
  case RubyRequestType_NUM:
    panic("DMASequencer::makeRequest does not support the RubyRequestType");
    return RequestStatus_NULL;
  }

  assert(!m_is_busy);  // only support one outstanding DMA request
  m_is_busy = true;

  active_request.start_paddr = paddr;
  active_request.write = write;
  active_request.data = data;
  active_request.len = len;
  active_request.bytes_completed = 0;
  active_request.bytes_issued = 0;
  active_request.pkt = request.pkt;

  SequencerMsg msg;
  msg.getPhysicalAddress() = Address(paddr);
  msg.getLineAddress() = line_address(msg.getPhysicalAddress());
  msg.getType() = write ? SequencerRequestType_ST : SequencerRequestType_LD;
  int offset = paddr & m_data_block_mask;

  msg.getLen() = (offset + len) <= RubySystem::getBlockSizeBytes() ?
    len :
    RubySystem::getBlockSizeBytes() - offset;

  if (write) {
    msg.getDataBlk().setData(data, offset, msg.getLen());
  }

  assert(m_mandatory_q_ptr != NULL);
  m_mandatory_q_ptr->enqueue(msg);
  active_request.bytes_issued += msg.getLen();

  return RequestStatus_Issued;
}

void DMASequencer::issueNext()
{
  assert(m_is_busy == true);
  active_request.bytes_completed = active_request.bytes_issued;
  if (active_request.len == active_request.bytes_completed) {
    ruby_hit_callback(active_request.pkt);
    m_is_busy = false;
    return;
  }

  SequencerMsg msg;
  msg.getPhysicalAddress() = Address(active_request.start_paddr +
                                     active_request.bytes_completed);

  assert((msg.getPhysicalAddress().getAddress() & m_data_block_mask) == 0);
  msg.getLineAddress() = line_address(msg.getPhysicalAddress());

  msg.getType() = (active_request.write ? SequencerRequestType_ST :
		   SequencerRequestType_LD);

  msg.getLen() = (active_request.len -
		  active_request.bytes_completed < RubySystem::getBlockSizeBytes() ?
		  active_request.len - active_request.bytes_completed :
		  RubySystem::getBlockSizeBytes());

  if (active_request.write) {
    msg.getDataBlk().setData(&active_request.data[active_request.bytes_completed],
			     0, msg.getLen());
    msg.getType() = SequencerRequestType_ST;
  } else {
    msg.getType() = SequencerRequestType_LD;
  }

  assert(m_mandatory_q_ptr != NULL);
  m_mandatory_q_ptr->enqueue(msg);
  active_request.bytes_issued += msg.getLen();
}

void DMASequencer::dataCallback(const DataBlock & dblk)
{
  assert(m_is_busy == true);
  int len = active_request.bytes_issued - active_request.bytes_completed;
  int offset = 0;
  if (active_request.bytes_completed == 0)
    offset = active_request.start_paddr & m_data_block_mask;
  assert( active_request.write == false );
  memcpy(&active_request.data[active_request.bytes_completed],
	 dblk.getData(offset, len), len);
  issueNext();
}

void DMASequencer::ackCallback()
{
  issueNext();
}

void DMASequencer::printConfig(ostream & out)
{

}


DMASequencer *
DMASequencerParams::create()
{
    return new DMASequencer(this);
}