/*
 * Copyright (c) 2021 ARM Limited
 * All rights reserved.
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * Copyright (c) 1999-2008 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.
 */

/*
 * Perfect switch, of course it is perfect and no latency or what so
 * ever. Every cycle it is woke up and perform all the necessary
 * routings that must be done. Note, this switch also has number of
 * input ports/output ports and has a routing table as well.
 */

#ifndef __MEM_RUBY_NETWORK_SIMPLE_PERFECTSWITCH_HH__
#define __MEM_RUBY_NETWORK_SIMPLE_PERFECTSWITCH_HH__

#include <iostream>
#include <string>
#include <vector>

#include "mem/ruby/common/Consumer.hh"
#include "mem/ruby/common/TypeDefines.hh"

namespace gem5
{

namespace ruby
{

class MessageBuffer;
class NetDest;
class SimpleNetwork;
class Switch;

class PerfectSwitch : public Consumer
{
  public:
    PerfectSwitch(SwitchID sid, Switch *, uint32_t);
    ~PerfectSwitch();

    std::string name()
    { return csprintf("PerfectSwitch-%i", m_switch_id); }

    void init(SimpleNetwork *);
    void addInPort(const std::vector<MessageBuffer*>& in);
    void addOutPort(const std::vector<MessageBuffer*>& out,
                    const NetDest& routing_table_entry,
                    const PortDirection &dst_inport,
                    Tick routing_latency,
                    int link_weight);

    int getInLinks() const { return m_in.size(); }
    int getOutLinks() const { return m_out.size(); }

    void wakeup();
    void storeEventInfo(int info);

    void clearStats();
    void collateStats();
    void print(std::ostream& out) const;

  private:
    // Private copy constructor and assignment operator
    PerfectSwitch(const PerfectSwitch& obj);
    PerfectSwitch& operator=(const PerfectSwitch& obj);

    void operateVnet(int vnet);
    void operateMessageBuffer(MessageBuffer *b, int vnet);

    const SwitchID m_switch_id;
    Switch * const m_switch;

    // Vector of queues associated to each port.
    std::vector<std::vector<MessageBuffer*> > m_in;

    // Each output port also has a latency for routing to that port
    struct OutputPort
    {
        Tick latency;
        std::vector<MessageBuffer*> buffers;
    };
    std::vector<OutputPort> m_out;

    // input ports ordered by priority; indexed by vnet first
    std::vector<std::vector<MessageBuffer*> > m_in_prio;
    // input ports grouped by priority; indexed by vnet,prio_lv
    std::vector<std::vector<std::vector<MessageBuffer*>>> m_in_prio_groups;

    void updatePriorityGroups(int vnet, MessageBuffer* buf);

    uint32_t m_virtual_networks;
    int m_wakeups_wo_switch;

    SimpleNetwork* m_network_ptr;
    std::vector<int> m_pending_message_count;

    MessageBuffer* inBuffer(int in_port, int vnet) const;
};

inline std::ostream&
operator<<(std::ostream& out, const PerfectSwitch& obj)
{
    obj.print(out);
    out << std::flush;
    return out;
}

} // namespace ruby
} // namespace gem5

#endif // __MEM_RUBY_NETWORK_SIMPLE_PERFECTSWITCH_HH__