qport.hh revision 10722:886d2458e0d6 
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 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 */
109class 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__
175