qport.hh revision 9163:3b5e13ac1940 
1/*
2 * Copyright (c) 2012 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 requests and responses. */
65    SlavePacketQueue &queue;
66
67     /** This function is notification that the device should attempt to send a
68      * packet again. */
69    virtual void recvRetry() { queue.retry(); }
70
71  public:
72
73    /**
74     * Create a QueuedPort with a given name, owner, and a supplied
75     * implementation of a packet queue. The external definition of
76     * the queue enables e.g. the cache to implement a specific queue
77     * behaviuor in a subclass, and provide the latter to the
78     * QueuePort constructor.
79     */
80    QueuedSlavePort(const std::string& name, MemObject* owner,
81                    SlavePacketQueue &queue) :
82        SlavePort(name, owner), queue(queue)
83    { }
84
85    virtual ~QueuedSlavePort() { }
86
87    /**
88     * Schedule the sending of a timing response.
89     *
90     * @param pkt Packet to send
91     * @param when Absolute time (in ticks) to send packet
92     */
93    void schedTimingResp(PacketPtr pkt, Tick when)
94    { queue.schedSendTiming(pkt, when); }
95
96    /** Check the list of buffered packets against the supplied
97     * functional request. */
98    bool checkFunctional(PacketPtr pkt) { return queue.checkFunctional(pkt); }
99
100    /**
101     * Hook for draining the queued port.
102     *
103     * @param de an event which is used to signal back to the caller
104     * @returns a number indicating how many times process will be called
105     */
106    unsigned int drain(Event *de) { return queue.drain(de); }
107};
108
109class QueuedMasterPort : public MasterPort
110{
111
112  protected:
113
114    /** Packet queue used to store outgoing requests and responses. */
115    MasterPacketQueue &queue;
116
117     /** This function is notification that the device should attempt to send a
118      * packet again. */
119    virtual void recvRetry() { queue.retry(); }
120
121  public:
122
123    /**
124     * Create a QueuedPort with a given name, owner, and a supplied
125     * implementation of a packet queue. The external definition of
126     * the queue enables e.g. the cache to implement a specific queue
127     * behaviuor in a subclass, and provide the latter to the
128     * QueuePort constructor.
129     */
130    QueuedMasterPort(const std::string& name, MemObject* owner,
131                     MasterPacketQueue &queue) :
132        MasterPort(name, owner), queue(queue)
133    { }
134
135    virtual ~QueuedMasterPort() { }
136
137    /**
138     * Schedule the sending of a timing request.
139     *
140     * @param pkt Packet to send
141     * @param when Absolute time (in ticks) to send packet
142     */
143    void schedTimingReq(PacketPtr pkt, Tick when)
144    { queue.schedSendTiming(pkt, when); }
145
146    /**
147     * Schedule the sending of a timing snoop response.
148     *
149     * @param pkt Packet to send
150     * @param when Absolute time (in ticks) to send packet
151     */
152    void schedTimingSnoopResp(PacketPtr pkt, Tick when)
153    { queue.schedSendTiming(pkt, when, true); }
154
155    /** Check the list of buffered packets against the supplied
156     * functional request. */
157    bool checkFunctional(PacketPtr pkt) { return queue.checkFunctional(pkt); }
158
159    /**
160     * Hook for draining the queued port.
161     *
162     * @param de an event which is used to signal back to the caller
163     * @returns a number indicating how many times process will be called
164     */
165    unsigned int drain(Event *de) { return queue.drain(de); }
166};
167
168#endif // __MEM_QPORT_HH__
169