lt_dmi_target.cpp

SystemC Transaction Level Modelling. 是基于SystemC之上的总线互联协议

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    source code Copyright (c) 1996-2008 by all Contributors.
    All Rights reserved.
 
    The contents of this file are subject to the restrictions and limitations
    set forth in the SystemC Open Source License Version 3.0 (the "License");
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//=====================================================================
/// @file lt_dmi_target.cpp
//
/// @brief Implements single phase AT target
//
//=====================================================================
//  Original Authors:
//    Jack Donovan, ESLX
//
//=====================================================================

#include "lt_dmi_target.h"                              // our header
#include "reporting.h"                                  // reporting macros
                    
using namespace  std;

static const char *filename = "lt_dmi_target.cpp"; ///< filename for reporting

SC_HAS_PROCESS(lt_dmi_target);

///Constructor
lt_dmi_target::lt_dmi_target                      
( sc_core::sc_module_name module_name                   ///< module name
, const unsigned int        ID                          ///< target ID
, const char                *memory_socket              ///< socket name
, sc_dt::uint64             memory_size                 ///< memory size (bytes)
, unsigned int              memory_width                ///< memory width (bytes)
, const sc_core::sc_time    accept_delay                ///< accept delay (SC_TIME)
, const sc_core::sc_time    read_response_delay         ///< read response delay (SC_TIME)
, const sc_core::sc_time    write_response_delay        ///< write response delay (SC_TIME)
, const sc_core::sc_time    start_dmi_delay             ///< start of dmi transactions
, const sc_core::sc_time    dmi_duration                ///< duration of dmi transactions
)
: sc_module                 ( module_name           )   ///< init module name
, m_memory_socket           ( memory_socket         )   ///< init socket name
, m_ID                      ( ID                    )   ///< init target ID
, m_memory_size             ( memory_size           )   ///< init memory size (bytes)
, m_memory_width            ( memory_width          )   ///< init memory width (bytes)
, m_accept_delay            ( accept_delay          )   ///< init accept delay
, m_read_response_delay     ( read_response_delay   )   ///< init read response delay
, m_write_response_delay    ( write_response_delay  )   ///< init write response delay
, m_dmi_enabled             ( true                  )
, m_start_dmi_delay         ( start_dmi_delay       )
, m_dmi_duration            ( dmi_duration          )
, m_start_address           ( 0                     )
, m_end_address             ( memory_size           )
, m_toggle_count            ( 0                     )
, m_max_dmi_toggle_count    ( 3                     )

, m_target_memory           ( m_ID                      // initiator ID for messaging
                            , m_read_response_delay     // delay for reads
                            , m_write_response_delay    // delay for writes
                            , m_memory_size             // memory size (bytes)
                            , m_memory_width            // memory width (bytes)      
                            )                           ///< target memory
{
  SC_METHOD(toggle_dmi_method);
  
  m_memory_socket.register_b_transport(this, &lt_dmi_target::custom_b_transport);
  m_memory_socket.register_get_direct_mem_ptr(this, &lt_dmi_target::get_direct_mem_ptr);
}

//==============================================================================
//  b_transport implementation calls from initiators 
//
//=============================================================================
void                                        
lt_dmi_target::custom_b_transport
( tlm::tlm_generic_payload  &payload                // ref to  Generic Payload 
, sc_core::sc_time          &delay_time             // delay time 
)
{
  sc_core::sc_time      mem_op_time;
  std::ostringstream    msg;
  
  msg.str("");   

  m_target_memory.operation(payload, mem_op_time);

  if(m_dmi_enabled)
  {
    payload.set_dmi_allowed(true);
    msg << "Target: " << m_ID
        << " has set dmi_allowed " 
        << endl << "      ";
  }
  else
  {
    payload.set_dmi_allowed(false);
  }

  msg << "Target: " << m_ID
      << " returned delay of " << delay_time
      << " + " << m_accept_delay << " + " << mem_op_time;

  delay_time = delay_time + m_accept_delay + mem_op_time;

  msg << " = " << delay_time;
  REPORT_INFO(filename,  __FUNCTION__, msg.str());
  
  return;
}

bool                                            
lt_dmi_target::get_direct_mem_ptr    
( tlm::tlm_generic_payload   &gp              ///< address + extensions
, tlm::tlm_dmi               &dmi_properties  ///< dmi data
)
{
  std::ostringstream  msg;
  msg.str("");
  sc_dt::uint64 address = gp.get_address();
  
  // First check to see if we are "open" to a dmi
  if(!m_dmi_enabled)
  {
    msg << "Target: " << m_ID
        << " DMI not enabled, not expecting call ";
    REPORT_INFO(filename, __FUNCTION__, msg.str());
  }
  else
  {                                  // dmi processing
    if (address < m_end_address+1)   // check that address is in our range              
    {
      // set up dmi properties object ======================================
      dmi_properties.allow_read_write   (                                );
      dmi_properties.set_start_address  ( m_start_address                );
      dmi_properties.set_end_address    ( m_end_address                  );
      dmi_properties.set_dmi_ptr        ( m_target_memory.get_mem_ptr () );
      dmi_properties.set_read_latency   ( m_read_response_delay          );
      dmi_properties.set_write_latency  ( m_write_response_delay         );

      msg << "Target: " << m_ID
          << " passing DMI pointer back to initiator";
      REPORT_INFO(filename, __FUNCTION__, msg.str());
      return true;
    }
    else
    {
      msg << "Target: " << m_ID
          << " DMI pointer request for address= " << address
          << " max address for this target = " << m_end_address+1;
      REPORT_INFO(filename, __FUNCTION__, msg.str());
    } // end else
  } // end else
  
  return false; 
} // end get_direct_mem_ptr

void
lt_dmi_target::toggle_dmi_method
(void
)
{
  std::ostringstream msg;
  msg.str("");
  m_toggle_count++;
  
  if (m_dmi_enabled)
  {
    m_dmi_enabled = false;

    msg << "Target: " << m_ID 
        << " invalidate_direct_ptr "
        << "(" << m_start_address << ", " << m_end_address << ");";
    REPORT_INFO(filename, __FUNCTION__, msg.str());  
    
    m_memory_socket->invalidate_direct_mem_ptr(m_start_address, m_end_address );
    
    next_trigger(m_start_dmi_delay);
  }
  else
  {
    m_dmi_enabled = true;
    next_trigger(m_dmi_duration);
    msg << "Target: " << m_ID 
        << " DMI has been enabled in this target";
    REPORT_INFO(filename, __FUNCTION__, msg.str());  
  }

  // Don't execute again
  if(m_toggle_count >= m_max_dmi_toggle_count)
  {
    next_trigger();
    m_dmi_enabled = false;
  }
}