noncoherent_xbar.hh revision 13808 
1/*
2 * Copyright (c) 2011-2015 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 * Copyright (c) 2002-2005 The Regents of The University of Michigan
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Ron Dreslinski
41 *          Ali Saidi
42 *          Andreas Hansson
43 *          William Wang
44 */
45
46/**
47 * @file
48 * Declaration of a non-coherent crossbar.
49 */
50
51#ifndef __MEM_NONCOHERENT_XBAR_HH__
52#define __MEM_NONCOHERENT_XBAR_HH__
53
54#include "mem/xbar.hh"
55#include "params/NoncoherentXBar.hh"
56
57/**
58 * A non-coherent crossbar connects a number of non-snooping masters
59 * and slaves, and routes the request and response packets based on
60 * the address. The request packets issued by the master connected to
61 * a non-coherent crossbar could still snoop in caches attached to a
62 * coherent crossbar, as is the case with the I/O bus and memory bus
63 * in most system configurations. No snoops will, however, reach any
64 * master on the non-coherent crossbar itself.
65 *
66 * The non-coherent crossbar can be used as a template for modelling
67 * PCIe, and non-coherent AMBA and OCP buses, and is typically used
68 * for the I/O buses.
69 */
70class NoncoherentXBar : public BaseXBar
71{
72
73  protected:
74
75    /**
76     * Declare the layers of this crossbar, one vector for requests
77     * and one for responses.
78     */
79    std::vector<ReqLayer*> reqLayers;
80    std::vector<RespLayer*> respLayers;
81
82    /**
83     * Declaration of the non-coherent crossbar slave port type, one
84     * will be instantiated for each of the master ports connecting to
85     * the crossbar.
86     */
87    class NoncoherentXBarSlavePort : public QueuedSlavePort
88    {
89      private:
90
91        /** A reference to the crossbar to which this port belongs. */
92        NoncoherentXBar &xbar;
93
94        /** A normal packet queue used to store responses. */
95        RespPacketQueue queue;
96
97      public:
98
99        NoncoherentXBarSlavePort(const std::string &_name,
100                                NoncoherentXBar &_xbar, PortID _id)
101            : QueuedSlavePort(_name, &_xbar, queue, _id), xbar(_xbar),
102              queue(_xbar, *this)
103        { }
104
105      protected:
106
107        bool
108        recvTimingReq(PacketPtr pkt) override
109        {
110            return xbar.recvTimingReq(pkt, id);
111        }
112
113        Tick
114        recvAtomic(PacketPtr pkt) override
115        {
116            return xbar.recvAtomic(pkt, id);
117        }
118
119        void
120        recvFunctional(PacketPtr pkt) override
121        {
122            xbar.recvFunctional(pkt, id);
123        }
124
125        AddrRangeList
126        getAddrRanges() const override
127        {
128            return xbar.getAddrRanges();
129        }
130    };
131
132    /**
133     * Declaration of the crossbar master port type, one will be
134     * instantiated for each of the slave ports connecting to the
135     * crossbar.
136     */
137    class NoncoherentXBarMasterPort : public MasterPort
138    {
139      private:
140
141        /** A reference to the crossbar to which this port belongs. */
142        NoncoherentXBar &xbar;
143
144      public:
145
146        NoncoherentXBarMasterPort(const std::string &_name,
147                                 NoncoherentXBar &_xbar, PortID _id)
148            : MasterPort(_name, &_xbar, _id), xbar(_xbar)
149        { }
150
151      protected:
152
153        bool
154        recvTimingResp(PacketPtr pkt) override
155        {
156            return xbar.recvTimingResp(pkt, id);
157        }
158
159        void
160        recvRangeChange() override
161        {
162            xbar.recvRangeChange(id);
163        }
164
165        void
166        recvReqRetry() override
167        {
168            xbar.recvReqRetry(id);
169        }
170    };
171
172    virtual bool recvTimingReq(PacketPtr pkt, PortID slave_port_id);
173    virtual bool recvTimingResp(PacketPtr pkt, PortID master_port_id);
174    void recvReqRetry(PortID master_port_id);
175    Tick recvAtomic(PacketPtr pkt, PortID slave_port_id);
176    void recvFunctional(PacketPtr pkt, PortID slave_port_id);
177
178  public:
179
180    NoncoherentXBar(const NoncoherentXBarParams *p);
181
182    virtual ~NoncoherentXBar();
183
184    void regStats() override;
185    Stats::Scalar totPktSize;
186};
187
188#endif //__MEM_NONCOHERENT_XBAR_HH__
189