//
// Copyright 2019 Ettus Research, A National Instruments Company
//
// SPDX-License-Identifier: LGPL-3.0-or-later
//
// Module: PkgRfnocBlockCtrlBfm
//
// Description: This package includes a high-level bus functional model (BFM)
// for a block controller. This models a software block controller and allows
// communication with a single RFNoC block. It includes the following:
//
//   - A CtrlIfaceBfm for an AXIS-Ctrl port connection of a block
//   - One or more ChdrIfaceBfm for the AXIS-CHDR port connections
//   - A connection for the backend interface of a block
//


//-----------------------------------------------------------------------------
// SV Interface for the RFNoC Backend Iface
//-----------------------------------------------------------------------------

typedef struct packed {
  bit [476:0] reserved0;
  bit         soft_chdr_rst;
  bit         soft_ctrl_rst;
  bit         flush_en;
  bit [31:0]  flush_timeout;
} backend_config_v1_t;

typedef struct packed {
  bit [439:0] reserved0;
  bit [5:0]   mtu;
  bit         flush_done;
  bit         flush_active;
  bit [31:0]  noc_id;
  bit [7:0]   ctrl_max_async_msgs;
  bit [5:0]   ctrl_fifosize;
  bit [5:0]   num_data_o;
  bit [5:0]   num_data_i;
  bit [5:0]   proto_ver;
} backend_status_v1_t;

typedef union packed {
  backend_config_v1_t v1;
} backend_config_t;

typedef union packed {
  backend_status_v1_t v1;
} backend_status_t;


interface RfnocBackendIf(
  input logic chdr_clk,
  input logic ctrl_clk
);
  backend_config_t cfg;
  backend_status_t sts;

  modport master (
    input  chdr_clk,
    input  ctrl_clk,
    output cfg,
    input  sts
  );
  modport slave (
    input  chdr_clk,
    input  ctrl_clk,
    input  cfg,
    output sts
  );
endinterface : RfnocBackendIf


//-----------------------------------------------------------------------------
// RFNoC Block Controller Bus Functional Model
//-----------------------------------------------------------------------------

package PkgRfnocBlockCtrlBfm;

  import PkgChdrUtils::*;
  import PkgChdrBfm::*;
  import PkgCtrlIfaceBfm::*;
  import PkgChdrIfaceBfm::*;

  export PkgChdrIfaceBfm::packet_info_t;


  //---------------------------------------------------------------------------
  // Block Controller BFM
  //---------------------------------------------------------------------------
  //
  // This class models a block controller in software
  //
  //---------------------------------------------------------------------------

  class RfnocBlockCtrlBfm #(CHDR_W = 64);

    local virtual RfnocBackendIf.master backend;
    local CtrlIfaceBfm              ctrl;
    local ChdrIfaceBfm #(CHDR_W)   m_data[$];
    local ChdrIfaceBfm #(CHDR_W)   s_data[$];
    local bit                           running;

    localparam CMD_PROP_CYC = 5;

    // Class constructor to create a new BFM instance.
    //
    //   backend:   Interface for the backend signals of a block
    //   m_ctrl:    Interface for the CTRL master connection (EP's AXIS-Ctrl output)
    //   s_ctrl:    Interface for the CTRL slave connection (EP's AXIS-Ctrl input)
    //   dst_port:  Destination port to use in generated control packets
    //   src_port:  Source port to use in generated control packets
    //
    function new(
      virtual RfnocBackendIf.master    backend,
      virtual AxiStreamIf #(32).master m_ctrl,
      virtual AxiStreamIf #(32).slave  s_ctrl,
      input   ctrl_port_t              dst_port = 10'd2,
      input   ctrl_port_t              src_port = 10'd1
    );
      this.backend = backend;
      this.ctrl = new(m_ctrl, s_ctrl, dst_port, src_port);
      this.running = 0;
    endfunction : new

    // Add a master data port. This should connect to a DUT slave input.
    // 
    //   m_chdr:             Virtual master interface to connect new port to.
    //   max_payload_length: Maximum payload length to create when building
    //                       packets from data.
    //   ticks_per_word:     Number of timebase clock ticks to increment per
    //                       CHDR word.
    //
    function int add_master_data_port(
      virtual AxiStreamIf #(CHDR_W).master m_chdr,
      int max_payload_length = 2**$bits(chdr_length_t),
      int ticks_per_word     = CHDR_W/32
    );
      ChdrIfaceBfm #(CHDR_W) bfm = new(m_chdr, null, max_payload_length, ticks_per_word);
      m_data.push_back(bfm);
      return m_data.size() - 1;
    endfunction : add_master_data_port

    // Add a slave data port. This should connect to a DUT master output.
    // 
    //   s_chdr: Virtual slave interface to connect new port to
    //
    function int add_slave_data_port(
      virtual AxiStreamIf #(CHDR_W).slave s_chdr
    );
      ChdrIfaceBfm #(CHDR_W) bfm = new(null, s_chdr);
      s_data.push_back(bfm);
      return s_data.size() - 1;
    endfunction : add_slave_data_port

    // Add a master data port. This is equivalent to add_master_data_port() 
    // except it accepts a port number and it waits until the preceding ports 
    // are connected to ensure that ports are connected in the correct order.
    //
    //   port_num:           The port number to which m_chdr should be connected
    //   m_chdr:             Master CHDR interface to connect to the port
    //   max_payload_length: Maximum payload length to create when building
    //                       packets from data.
    //   ticks_per_word:     Number of timebase clock ticks to increment per
    //                       CHDR word.
    //
    task connect_master_data_port(
      int port_num,
      virtual AxiStreamIf #(CHDR_W).master m_chdr,
      int max_payload_length = 2**$bits(chdr_length_t),
      int ticks_per_word     = CHDR_W/32
    );
      ChdrIfaceBfm #(CHDR_W) bfm = new(m_chdr, null, max_payload_length, ticks_per_word);
      wait (m_data.size() == port_num);
      m_data.push_back(bfm);
    endtask : connect_master_data_port

    // Add a slave data port. This is equivalent to add_slave_data_port() 
    // except it accepts a port number and it waits until the preceding ports 
    // are connected to ensure that ports are connected in the correct order.
    //
    //   port_num:  The port number to which m_chdr should be connected
    //   s_chdr:    Master CHDR interface to connect to the port
    //
    task connect_slave_data_port(
      int port_num,
      virtual AxiStreamIf #(CHDR_W).slave s_chdr
    );
      ChdrIfaceBfm #(CHDR_W) bfm = new(null, s_chdr);
      wait (s_data.size() == port_num);
      s_data.push_back(bfm);
    endtask : connect_slave_data_port

    // Start the data and control BFM's processes running.
    task run();
      assert (backend.sts.v1.proto_ver == 1) else begin
        $fatal(1, "The connected block has an incompatible backend interface");
      end
      if (!running) begin
        ctrl.run();
        foreach (m_data[i]) 
          m_data[i].run();
        foreach (s_data[i]) 
          s_data[i].run();
        running = 1;
      end
    endtask : run

    // Return a handle to the control BFM
    function CtrlIfaceBfm get_ctrl_bfm();
      return ctrl;
    endfunction : get_ctrl_bfm

    // Return a handle to the indicated master port BFM
    function ChdrIfaceBfm #(CHDR_W) get_master_data_bfm(int port);
      assert (port >= 0 && port < m_data.size()) else begin
        $fatal(1, "Invalid master port number");
      end
      return m_data[port];
    endfunction : get_master_data_bfm

    // Return a handle to the indicated slave port BFM
    function ChdrIfaceBfm #(CHDR_W) get_slave_data_bfm(int port);
      assert (port >= 0 && port < m_data.size()) else begin
        $fatal(1, "Invalid slave port number");
      end
      return s_data[port];
    endfunction : get_slave_data_bfm

    // Set the maximum payload size for packets. This value is used to split 
    // large send requests across multiple packets.
    //
    //   port:        Master port whose maximum length you want to set
    //   max_length:  Maximum payload length in bytes for each packet
    //
    function void set_max_payload_length(int port, int max_length);
      assert (port >= 0 && port < m_data.size()) else begin
        $fatal(1, "Invalid master port number");
      end
      m_data[port].set_max_payload_length(max_length);
    endfunction

    // Return the maximum payload size for packets. This value is used to split 
    // large send requests across multiple packets.
    //
    //   port: Master port whose maximum length you want to get
    //
    function int get_max_payload_length(int port);
      assert (port >= 0 && port < m_data.size()) else begin
        $fatal(1, "Invalid master port number");
      end
      return m_data[port].get_max_payload_length();
    endfunction

    // Set the timestamp ticks per CHDR_W sized word.
    //
    //   port:            Master port whose timestamp increment you want to set
    //   ticks_per_word:  Amount to increment the timestamp per CHDR_W sized word
    //
    function void set_ticks_per_word(int port, int ticks_per_word);
      assert (port >= 0 && port < m_data.size()) else begin
        $fatal(1, "Invalid master port number");
      end
      m_data[port].set_ticks_per_word(ticks_per_word);
    endfunction

    // Return the timestamp ticks per CHDR_W sized word.
    //
    //   port:  Master port whose timestamp increment you want to get
    //
    function int get_ticks_per_word(int port);
      assert (port >= 0 && port < m_data.size()) else begin
        $fatal(1, "Invalid master port number");
      end
      return m_data[port].get_ticks_per_word();
    endfunction

    // Get static info about the block
    function logic [7:0] get_proto_ver();
      return backend.sts.v1.proto_ver;
    endfunction : get_proto_ver

    function logic [31:0] get_noc_id();
      return backend.sts.v1.noc_id;
    endfunction : get_noc_id

    function logic [5:0] get_num_data_i();
      return backend.sts.v1.num_data_i;
    endfunction : get_num_data_i

    function logic [5:0] get_num_data_o();
      return backend.sts.v1.num_data_o;
    endfunction : get_num_data_o

    function logic [5:0] get_ctrl_fifosize();
      return backend.sts.v1.ctrl_fifosize;
    endfunction : get_ctrl_fifosize

    function logic [5:0] get_mtu();
      return backend.sts.v1.mtu;
    endfunction : get_mtu

    // Soft-Reset the CHDR path 
    //
    //   rst_cyc: Number of cycles to wait for reset completion
    //
    task reset_chdr(input int rst_cyc = 100);
      assert (running) else begin
        $fatal(1, "Cannot call flush_and_reset until RfnocBlockCtrlBfm is running");
      end

      // Assert soft_chdr_rst then wait
      // Note: soft_chdr_rst must be driven in the ctrl_clk domain
      @(posedge backend.ctrl_clk);
      backend.cfg.v1.soft_chdr_rst = 1;
      repeat (CMD_PROP_CYC) @(posedge backend.ctrl_clk);
      backend.cfg.v1.soft_chdr_rst = 0;
      @(posedge backend.ctrl_clk);
      repeat (rst_cyc) @(posedge backend.ctrl_clk);
    endtask : reset_chdr

    // Soft-Reset the Control path 
    //
    //   rst_cyc: Number of cycles to wait for reset completion
    //
    task reset_ctrl(input int rst_cyc = 100);
      assert (running) else begin
        $fatal(1, "Cannot call flush_and_reset until RfnocBlockCtrlBfm is running");
      end

      // Assert soft_ctrl_rst then wait
      @(posedge backend.ctrl_clk);
      backend.cfg.v1.soft_ctrl_rst = 1;
      repeat (CMD_PROP_CYC) @(posedge backend.ctrl_clk);
      backend.cfg.v1.soft_ctrl_rst = 0;
      repeat (rst_cyc) @(posedge backend.ctrl_clk);
    endtask : reset_ctrl

    // Flush the data ports of the block
    //
    //   idle_cyc: Number of idle cycles before done is asserted
    //
    task flush(input logic [31:0] idle_cyc = 100);
      assert (running) else begin
        $fatal(1, "Cannot call flush until RfnocBlockCtrlBfm is running");
      end

      // Set flush timeout then wait
      backend.cfg.v1.flush_timeout = idle_cyc;
      repeat (CMD_PROP_CYC) @(posedge backend.ctrl_clk);
      repeat (CMD_PROP_CYC) @(posedge backend.chdr_clk);
      // Start flush then wait for done
      @(posedge backend.ctrl_clk);
      backend.cfg.v1.flush_en = 1;
      @(posedge backend.ctrl_clk);
      while (~backend.sts.v1.flush_done) @(posedge backend.ctrl_clk);
      // Deassert flush then wait
      backend.cfg.v1.flush_en = 0;
      while (backend.sts.v1.flush_active) @(posedge backend.ctrl_clk);
      repeat (CMD_PROP_CYC) @(posedge backend.ctrl_clk);
      repeat (CMD_PROP_CYC) @(posedge backend.chdr_clk);
    endtask : flush

    // Flush the data ports of the block then reset the CHDR
    // path, wait then reset the ctrl path
    //
    //   idle_cyc: Number of idle cycles before done is asserted
    //   chdr_rst_cyc: Number of cycles to wait for chdr_rst completion
    //   ctrl_rst_cyc: Number of cycles to wait for ctrl_rst completion
    //
    task flush_and_reset(
      input logic [31:0] idle_cyc     = 100,
      input int          chdr_rst_cyc = 100,
      input int          ctrl_rst_cyc = 100
    );
      assert (running) else begin
        $fatal(1, "Cannot call flush_and_reset until RfnocBlockCtrlBfm is running");
      end

      // Set flush timeout then wait
      backend.cfg.v1.flush_timeout = idle_cyc;
      repeat (CMD_PROP_CYC) @(posedge backend.ctrl_clk);
      repeat (CMD_PROP_CYC) @(posedge backend.chdr_clk);
      // Start flush then wait for done
      @(posedge backend.ctrl_clk);
      backend.cfg.v1.flush_en = 1;
      @(posedge backend.ctrl_clk);
      while (~backend.sts.v1.flush_done) @(posedge backend.ctrl_clk);
      // Assert chdr_rst then wait
      reset_chdr(chdr_rst_cyc);
      // Assert ctrl_rst then wait
      reset_ctrl(ctrl_rst_cyc);
      // Deassert flush then wait
      backend.cfg.v1.flush_en = 0;
      while (backend.sts.v1.flush_active) @(posedge backend.ctrl_clk);
      repeat (CMD_PROP_CYC) @(posedge backend.ctrl_clk);
      repeat (CMD_PROP_CYC) @(posedge backend.chdr_clk);
    endtask : flush_and_reset


    // Send a CHDR data packet out the CHDR data interface.
    //
    //   port:       Port to send the CHDR packet on.
    //   data:       Data words to insert into the CHDR packet.
    //   data_bytes: Size of data in bytes. If omitted or -1, data_bytes will
    //               be calculated based on the number of words in data.
    //   metadata:   Metadata words to insert into the CHDR packet. Omit this
    //               argument (or set to an empty array) to not include
    //               metadata.
    //   pkt_info:   Data structure containing packet header information.
    //
    task send(
      input int           port,
      input chdr_word_t   data[$],
      input int           data_bytes  = -1,
      input chdr_word_t   metadata[$] = {},
      input packet_info_t pkt_info    = 0
    );
      assert (running) else begin
        $fatal(1, "Cannot call send until RfnocBlockCtrlBfm is running");
      end
      assert (port >= 0 && port < m_data.size()) else begin
        $fatal(1, "Invalid master port number");
      end

      m_data[port].send(data, data_bytes, metadata, pkt_info);
    endtask : send


    // Send data as one or more CHDR data packets out the CHDR data interface.
    //
    //   port:       Port to send the CHDR packet(s) on.
    //   data:       Data words to insert into the CHDR packet.
    //   data_bytes: Size of data in bytes. If omitted or -1, data_bytes will
    //               be calculated based on the number of words in data.
    //   metadata:   Metadata words to insert into the CHDR packet(s). Omit 
    //               this argument (or set to an empty array) to not include 
    //               metadata.
    //   pkt_info:   Data structure containing packet header information.
    //
    task send_packets(
      input int           port,
      input chdr_word_t   data[$],
      input int           data_bytes  = -1,
      input chdr_word_t   metadata[$] = {},
      input packet_info_t pkt_info    = 0
    );
      assert (running) else begin
        $fatal(1, "Cannot call send_packets until RfnocBlockCtrlBfm is running");
      end
      assert (port >= 0 && port < m_data.size()) else begin
        $fatal(1, "Invalid master port number");
      end

      m_data[port].send_packets(data, data_bytes, metadata, pkt_info);
    endtask : send_packets


    // Receive a CHDR data packet on the CHDR data interface and extract its
    // contents.
    //
    //   port:        Port to receive the CHDR packet from.
    //   data:        Data words from the received CHDR packet.
    //   data_bytes:  The number of data bytes in the CHDR packet. This
    //                is useful if the data is not a multiple of the
    //                chdr_word_t size.
    //   metadata:    Metadata words from the received CHDR packet. This
    //                will be an empty array if there was no metadata.
    //   pkt_info:    Data structure to receive packet header information.
    //
    task recv_adv(
      input  int           port,
      output chdr_word_t   data[$],
      output int           data_bytes,
      output chdr_word_t   metadata[$],
      output packet_info_t pkt_info
    );
      assert (running) else begin
        $fatal(1, "Cannot call recv_adv until RfnocBlockCtrlBfm is running");
      end
      assert (port >= 0 && port < s_data.size()) else begin
        $fatal(1, "Invalid slave port number");
      end

      s_data[port].recv_adv(data, data_bytes, metadata, pkt_info);
    endtask : recv_adv


    // Receive a CHDR data packet on the CHDR data interface and extract the
    // data. Any metadata or timestamp, if present, are discarded.
    //
    //   port:        Port number for the block to receive from
    //   data:        Data words from the received CHDR packet
    //   data_bytes:  The number of data bytes in the CHDR packet. This
    //                is useful if the data is not a multiple of the
    //                chdr_word_t size.
    //
    task recv(
      input  int         port,
      output chdr_word_t data[$],
      output int         data_bytes
    );
      assert (running) else begin
        $fatal(1, "Cannot call recv until RfnocBlockCtrlBfm is running");
      end
      assert (port >= 0 && port < s_data.size()) else begin
        $fatal(1, "Invalid slave port number");
      end

      s_data[port].recv(data, data_bytes);
    endtask : recv


    // Transmit a raw CHDR packet.
    //
    //   port:    Port number on which to transmit the packet
    //   packet:  Packet to transmit
    //
    task put_chdr(
      input int                  port,
      input ChdrPacket #(CHDR_W) packet
    );
      assert (running) else begin
        $fatal(1, "Cannot call put_chdr until RfnocBlockCtrlBfm is running");
      end
      assert (port >= 0 && port < m_data.size()) else begin
        $fatal(1, "Invalid master port number");
      end

      m_data[port].put_chdr(packet);
    endtask : put_chdr


    // Receive a raw CHDR packet.
    //
    //   port:    Port number on which to receive the packet
    //   packet:  Data structure to store received packet
    //
    task get_chdr(
      input  int                  port,
      output ChdrPacket #(CHDR_W) packet
    );
      assert (running) else begin
        $fatal(1, "Cannot call get_chdr until RfnocBlockCtrlBfm is running");
      end
      assert (port >= 0 && port < s_data.size()) else begin
        $fatal(1, "Invalid slave port number");
      end

      s_data[port].get_chdr(packet);
    endtask : get_chdr


    // Receive a raw CHDR packet, but don't remove it from the receive queue.
    //
    //   port:    Port number on which to peek
    //   packet:  Data structure to store received packet
    //
    task peek_chdr(
      input  int                  port,
      output ChdrPacket #(CHDR_W) packet
    );
      assert (running) else begin
        $fatal(1, "Cannot call peek_chdr until RfnocBlockCtrlBfm is running");
      end
      assert (port >= 0 && port < s_data.size()) else begin
        $fatal(1, "Invalid slave port number");
      end

      s_data[port].peek_chdr(packet);
    endtask : peek_chdr


    // Return the number of packets available in the receive queue for the 
    // given port.
    //
    //   port:  Port for which to get the number of received packets
    //
    function int num_received(int port);
      assert (port >= 0 && port < s_data.size()) else begin
        $fatal(1, "Invalid slave port number");
      end

      return s_data[port].num_received();
    endfunction


    // Wait until packets have completed transmission.
    //
    //   port:  Port for which to wait
    //   num:   Number of packets to wait for. Set to -1 or omit the argument 
    //          to wait for all currently queued packets to complete 
    //          transmission.
    //
    task wait_complete(int port, int num = -1);
      assert (running) else begin
        $fatal(1, "Cannot call wait_complete until RfnocBlockCtrlBfm is running");
      end
      assert (port >= 0 && port < m_data.size()) else begin
        $fatal(1, "Invalid master port number");
      end

      m_data[port].wait_complete(num);
    endtask


    // Set the stall probability for the indicated slave port.
    //
    //   port:        Port for which to set the probability
    //   stall_prob:  Probability as a percentage (0-100)
    //
    function void set_slave_stall_prob(int port, int stall_prob);
      assert (port >= 0 && port < s_data.size()) else begin
        $fatal(1, "Invalid slave port number");
      end

      s_data[port].set_slave_stall_prob(stall_prob);
    endfunction


    // Set the stall probability for the indicated master port.
    //
    //   port:        Port for which to set the probability
    //   stall_prob:  Probability as a percentage (0-100)
    //
    function void set_master_stall_prob(int port, int stall_prob);
      assert (port >= 0 && port < m_data.size()) else begin
        $fatal(1, "Invalid master port number");
      end

      m_data[port].set_master_stall_prob(stall_prob);
    endfunction


    // Send a read request packet on the AXIS-Ctrl interface and get the
    // response.
    //
    //   addr:   Address for the read request
    //   word:   Data word that was returned in response to the read
    //
    task reg_read(
      input  ctrl_address_t addr,
      output ctrl_word_t    word
    );
      assert (running) else begin
        $fatal(1, "Cannot call reg_read until RfnocBlockCtrlBfm is running");
      end

      ctrl.reg_read(addr, word);
    endtask : reg_read


    // Send a a write request packet on the AXIS-Ctrl interface and get the
    // response.
    //
    //   addr:   Address for the write request
    //   word:   Data word to write
    //
    task reg_write(
      ctrl_address_t addr,
      ctrl_word_t    word
    );
      assert (running) else begin
        $fatal(1, "Cannot call reg_write until RfnocBlockCtrlBfm is running");
      end

      ctrl.reg_write(addr, word);
    endtask : reg_write

    // Compare data vectors
    static function bit compare_data(
      input chdr_word_t lhs[$],
      input chdr_word_t rhs[$],
      input int         bytes = -1
    );
      int bytes_left;
      if (lhs.size() != rhs.size()) return 0;
      bytes_left = (bytes > 0) ? bytes : ((lhs.size()*$size(chdr_word_t))/8);
      for (int i = 0; i < lhs.size(); i++) begin
        chdr_word_t mask = {$size(chdr_word_t){1'b1}};
        if (bytes_left < $size(chdr_word_t)/8) begin
          mask = (1 << (bytes_left * 8)) - 1;
        end else if (bytes_left < 0) begin
          return 1;
        end
        if ((lhs[i] & mask) != (rhs[i] & mask)) return 0;
      end
      return 1;
    endfunction : compare_data

  endclass : RfnocBlockCtrlBfm


endpackage : PkgRfnocBlockCtrlBfm