qport.hh revision 13564:9bbd53a77887 
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 */
59class 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 trySatisfyFunctional(PacketPtr pkt)
97    { return respQueue.trySatisfyFunctional(pkt); }
98};
99
100/**
101 * The QueuedMasterPort combines two queues, a request queue and a
102 * snoop response queue, that both share the same port. The flow
103 * control for requests and snoop responses are completely
104 * independent, and so each queue manages its own flow control
105 * (retries).
106 */
107class QueuedMasterPort : public MasterPort
108{
109
110  protected:
111
112    /** Packet queue used to store outgoing requests. */
113    ReqPacketQueue &reqQueue;
114
115    /** Packet queue used to store outgoing snoop responses. */
116    SnoopRespPacketQueue &snoopRespQueue;
117
118    void recvReqRetry() { reqQueue.retry(); }
119
120    void recvRetrySnoopResp() { snoopRespQueue.retry(); }
121
122  public:
123
124    /**
125     * Create a QueuedPort with a given name, owner, and a supplied
126     * implementation of two packet queues. The external definition of
127     * the queues enables e.g. the cache to implement a specific queue
128     * behaviuor in a subclass, and provide the latter to the
129     * QueuePort constructor.
130     */
131    QueuedMasterPort(const std::string& name, MemObject* owner,
132                     ReqPacketQueue &req_queue,
133                     SnoopRespPacketQueue &snoop_resp_queue,
134                     PortID id = InvalidPortID) :
135        MasterPort(name, owner, id), reqQueue(req_queue),
136        snoopRespQueue(snoop_resp_queue)
137    { }
138
139    virtual ~QueuedMasterPort() { }
140
141    /**
142     * Schedule the sending of a timing request.
143     *
144     * @param pkt Packet to send
145     * @param when Absolute time (in ticks) to send packet
146     */
147    void schedTimingReq(PacketPtr pkt, Tick when)
148    { reqQueue.schedSendTiming(pkt, when); }
149
150    /**
151     * Schedule the sending of a timing snoop response.
152     *
153     * @param pkt Packet to send
154     * @param when Absolute time (in ticks) to send packet
155     */
156    void schedTimingSnoopResp(PacketPtr pkt, Tick when)
157    { snoopRespQueue.schedSendTiming(pkt, when); }
158
159    /** Check the list of buffered packets against the supplied
160     * functional request. */
161    bool trySatisfyFunctional(PacketPtr pkt)
162    {
163        return reqQueue.trySatisfyFunctional(pkt) ||
164            snoopRespQueue.trySatisfyFunctional(pkt);
165    }
166};
167
168#endif // __MEM_QPORT_HH__
169