src/mem/qport.hh

   1 /*
   2  * Copyright (c) 2012,2015 ARM Limited
   3  * All rights reserved.
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are
  16  * met: redistributions of source code must retain the above copyright
  17  * notice, this list of conditions and the following disclaimer;
  18  * redistributions in binary form must reproduce the above copyright
  19  * notice, this list of conditions and the following disclaimer in the
  20  * documentation and/or other materials provided with the distribution;
  21  * neither the name of the copyright holders nor the names of its
  22  * contributors may be used to endorse or promote products derived from
  23  * this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  * Authors: Andreas Hansson
  38  */
  39
  40 #ifndef __MEM_QPORT_HH__
  41 #define __MEM_QPORT_HH__
  42
  43 /**
  44  * @file
  45  * Declaration of the queued port.
  46  */
  47
  48 #include "mem/packet_queue.hh"
  49 #include "mem/port.hh"
  50
  51 /**
  52  * A queued port is a port that has an infinite queue for outgoing
  53  * packets and thus decouples the module that wants to send
  54  * request/responses from the flow control (retry mechanism) of the
  55  * port. A queued port can be used by both a master and a slave. The
  56  * queue is a parameter to allow tailoring of the queue implementation
  57  * (used in the cache).
  58  */
  59 class QueuedSlavePort : public SlavePort
  60 {
  61
  62   protected:
  63
  64     /** Packet queue used to store outgoing responses. */
  65     RespPacketQueue &respQueue;
  66
  67     void recvRespRetry() { respQueue.retry(); }
  68
  69   public:
  70
  71     /**
  72      * Create a QueuedPort with a given name, owner, and a supplied
  73      * implementation of a packet queue. The external definition of
  74      * the queue enables e.g. the cache to implement a specific queue
  75      * behaviuor in a subclass, and provide the latter to the
  76      * QueuePort constructor.
  77      */
  78     QueuedSlavePort(const std::string& name, MemObject* owner,
  79                     RespPacketQueue &resp_queue, PortID id = InvalidPortID) :
  80         SlavePort(name, owner, id), respQueue(resp_queue)
  81     { }
  82
  83     virtual ~QueuedSlavePort() { }
  84
  85     /**
  86      * Schedule the sending of a timing response.
  87      *
  88      * @param pkt Packet to send
  89      * @param when Absolute time (in ticks) to send packet
  90      */
  91     void schedTimingResp(PacketPtr pkt, Tick when)
  92     { respQueue.schedSendTiming(pkt, when); }
  93
  94     /** Check the list of buffered packets against the supplied
  95      * functional request. */
  96     bool checkFunctional(PacketPtr pkt)
  97     { return respQueue.checkFunctional(pkt); }
  98
  99     unsigned int drain(DrainManager *dm) { return respQueue.drain(dm); }
 100 };
 101
 102 /**
 103  * The QueuedMasterPort combines two queues, a request queue and a
 104  * snoop response queue, that both share the same port. The flow
 105  * control for requests and snoop responses are completely
 106  * independent, and so each queue manages its own flow control
 107  * (retries).
 108  */
 109 class QueuedMasterPort : public MasterPort
 110 {
 111
 112   protected:
 113
 114     /** Packet queue used to store outgoing requests. */
 115     ReqPacketQueue &reqQueue;
 116
 117     /** Packet queue used to store outgoing snoop responses. */
 118     SnoopRespPacketQueue &snoopRespQueue;
 119
 120     void recvReqRetry() { reqQueue.retry(); }
 121
 122     void recvRetrySnoopResp() { snoopRespQueue.retry(); }
 123
 124   public:
 125
 126     /**
 127      * Create a QueuedPort with a given name, owner, and a supplied
 128      * implementation of two packet queues. The external definition of
 129      * the queues enables e.g. the cache to implement a specific queue
 130      * behaviuor in a subclass, and provide the latter to the
 131      * QueuePort constructor.
 132      */
 133     QueuedMasterPort(const std::string& name, MemObject* owner,
 134                      ReqPacketQueue &req_queue,
 135                      SnoopRespPacketQueue &snoop_resp_queue,
 136                      PortID id = InvalidPortID) :
 137         MasterPort(name, owner, id), reqQueue(req_queue),
 138         snoopRespQueue(snoop_resp_queue)
 139     { }
 140
 141     virtual ~QueuedMasterPort() { }
 142
 143     /**
 144      * Schedule the sending of a timing request.
 145      *
 146      * @param pkt Packet to send
 147      * @param when Absolute time (in ticks) to send packet
 148      */
 149     void schedTimingReq(PacketPtr pkt, Tick when)
 150     { reqQueue.schedSendTiming(pkt, when); }
 151
 152     /**
 153      * Schedule the sending of a timing snoop response.
 154      *
 155      * @param pkt Packet to send
 156      * @param when Absolute time (in ticks) to send packet
 157      */
 158     void schedTimingSnoopResp(PacketPtr pkt, Tick when, bool force_order =
 159                               false)
 160     { snoopRespQueue.schedSendTiming(pkt, when, force_order); }
 161
 162     /** Check the list of buffered packets against the supplied
 163      * functional request. */
 164     bool checkFunctional(PacketPtr pkt)
 165     {
 166         return reqQueue.checkFunctional(pkt) ||
 167             snoopRespQueue.checkFunctional(pkt);
 168     }
 169
 170     unsigned int drain(DrainManager *dm)
 171     { return reqQueue.drain(dm) + snoopRespQueue.drain(dm); }
 172 };
 173
 174 #endif // __MEM_QPORT_HH__