verif/model/pcie/pcie_common/tlm/tlm_data_channel.hpp

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//
// OpenSPARC T2 Processor File: tlm_data_channel.hpp
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#ifndef INC_tlm_data_channel_hpp__
#define INC_tlm_data_channel_hpp__

#include <systemc.h>

#include "pcie_common/logger.hpp"
#include "pcie_common/packet_if.hpp"

namespace pcie {

  USING_NAMESPACE(Logger)

        template < typename DATA >
  class tlm_data_channel : public packet_if <DATA>, public sc_module
  {
  public:
        /**
         *  This channel constructor is used for reset-able modules. This makes access to the
         *  data channel non-blocking.
         */
        tlm_data_channel(sc_event *parent_global_ev, uint8 *global_event_type, int fifo_size = 256) :
          sc_module( sc_module_name( sc_gen_unique_name("tlm_data_channel") ) ) ,
          in_reset(false),
          data_fifo( fifo_size )
        {
          this->global_ev = parent_global_ev;
          this->global_event_type = global_event_type;
          LOG_INFO << "TLM Data Channel: " << name()
                           << " Init with fifo size " << fifo_size << "\n";
          SC_THREAD(reset);
        }

        tlm_data_channel( sc_module_name module_name ,
                                          sc_event *parent_global_ev, uint8 *global_event_type, int fifo_size = 256) :
          sc_module( module_name ) ,
          in_reset(false),
          data_fifo( fifo_size )
        {
          this->global_ev = parent_global_ev;
          this->global_event_type = global_event_type;
          LOG_INFO << "TLM Data Channel: " << name()
                           << " Init with fifo size " << fifo_size << "\n";
          SC_THREAD(reset);
        }

        tlm_data_channel( int fifo_size = 256) :
          sc_module( sc_module_name( sc_gen_unique_name("tlm_data_channel") ) ) ,
          in_reset(false),
          data_fifo( fifo_size )
        {
          this->global_ev=&dummy;
          LOG_INFO << "TLM Data Channel: " << name()
                           << " Init with fifo size " << fifo_size << "\n";
          SC_THREAD(reset);
        }

        tlm_data_channel( sc_module_name module_name ,
                                          int fifo_size = 256) :
          sc_module( module_name ) ,
          in_reset(false),
          data_fifo( fifo_size )
        {
          this->global_ev=&dummy;
          LOG_INFO << "TLM Data Channel: " << name()
                           << " Init with fifo size " << fifo_size << "\n";
          SC_THREAD(reset);
        }

        /**
         * Blocking interface Returns packet from the channel
         * Throws an exception if the channel is in reset
         */
        int get_packet(DATA &p) {
          if (in_reset) {
                throw sc_exception();
          }
          if (data_fifo.nb_can_get()) {
                p = data_fifo.get();
                return 0;
          } else {
                wait (data_fifo.ok_to_get() | local_ev);
                if (in_reset) {
                  throw sc_exception();
                }
                p = data_fifo.get();
                return 0;
          }
          return 0;
        }

        bool get_packet_nb(DATA &p) {
          if (!in_reset) {
                return data_fifo.nb_get(p);
          } else {
                LOG_DEBUG<<"DEBUG: TLM data channel throwing an exception";
                throw sc_exception();
          }
          return false;
        }

        bool is_packet_ready() {
          if (!in_reset) {
                return data_fifo.nb_can_get();
          }
          return false;
        }

        int send_packet(const DATA &p) {
          if (in_reset) {
                throw sc_exception();
          }
          if (data_fifo.nb_can_put()) {
                data_fifo.put(p);
                return 0;
          } else {
                wait (data_fifo.ok_to_put() | local_ev);
                if (in_reset) {
                  throw sc_exception();
                }
                data_fifo.put(p);
          }
          return 0;
        }

        void purge_channel(){
            while(data_fifo.nb_can_get()) data_fifo.get();
        }

        SC_HAS_PROCESS( tlm_data_channel );

  protected:

        bool    in_reset;               ///< flag indicates that this channel is in reset
        tlm_fifo<DATA> data_fifo;
        sc_event *global_ev;            ///< Global event pointer
        sc_event local_ev;              ///< local reset event to prevent channel blocking
        uint8    *global_event_type;    ///< Global event type
        sc_event dummy;

        void reset () {
          while (true) {
                wait (*global_ev);
                switch (*global_event_type) {

                case POR_RESET_ENTER:
                case WMR_RESET_ENTER:
                  LOG_WARNING<<"TLM DATA Channel " << name() << " IN reset";
                  in_reset = true;
                  local_ev.notify();
                  while(data_fifo.nb_can_get()) data_fifo.get();
                  break;

                case SW_RESET_CHNL_EXIT:
                  LOG_INFO<<"TLM DATA Channel " << name() << " OUT reset";
                  local_ev.notify();
                  in_reset = false;
                  break;
                }
          }
        }

        void init () {
        }
  };
}
#endif