xbar.hh revision 2772 
1/*
2 * Copyright (c) 2002-2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Ron Dreslinski
29 *          Ali Saidi
30 */
31
32/**
33 * @file Decleration of a bus object.
34 */
35
36#ifndef __MEM_BUS_HH__
37#define __MEM_BUS_HH__
38
39#include <string>
40#include <list>
41#include <inttypes.h>
42
43#include "base/range.hh"
44#include "mem/mem_object.hh"
45#include "mem/packet.hh"
46#include "mem/port.hh"
47#include "mem/request.hh"
48
49class Bus : public MemObject
50{
51    /** a globally unique id for this bus. */
52    int busId;
53
54    struct DevMap {
55        int portId;
56        Range<Addr> range;
57    };
58    std::vector<DevMap> portList;
59
60
61    /** Function called by the port when the bus is recieving a Timing
62        transaction.*/
63    bool recvTiming(Packet *pkt);
64
65    /** Function called by the port when the bus is recieving a Atomic
66        transaction.*/
67    Tick recvAtomic(Packet *pkt);
68
69    /** Function called by the port when the bus is recieving a Functional
70        transaction.*/
71    void recvFunctional(Packet *pkt);
72
73    /** Timing function called by port when it is once again able to process
74     * requests. */
75    void recvRetry(int id);
76
77    /** Function called by the port when the bus is recieving a status change.*/
78    void recvStatusChange(Port::Status status, int id);
79
80    /** Find which port connected to this bus (if any) should be given a packet
81     * with this address.
82     * @param addr Address to find port for.
83     * @param id Id of the port this packet was received from (to prevent
84     *             loops)
85     * @return pointer to port that the packet should be sent out of.
86     */
87    Port *findPort(Addr addr, int id);
88
89    /** Process address range request.
90     * @param resp addresses that we can respond to
91     * @param snoop addresses that we would like to snoop
92     * @param id ide of the busport that made the request.
93     */
94    void addressRanges(AddrRangeList &resp, AddrRangeList &snoop, int id);
95
96
97    /** Decleration of the buses port type, one will be instantiated for each
98        of the interfaces connecting to the bus. */
99    class BusPort : public Port
100    {
101        /** A pointer to the bus to which this port belongs. */
102        Bus *bus;
103
104        /** A id to keep track of the intercafe ID this port is connected to. */
105        int id;
106
107      public:
108
109        /** Constructor for the BusPort.*/
110        BusPort(const std::string &_name, Bus *_bus, int _id)
111            : Port(_name), bus(_bus), id(_id)
112        { }
113
114      protected:
115
116        /** When reciving a timing request from the peer port (at id),
117            pass it to the bus. */
118        virtual bool recvTiming(Packet *pkt)
119        { pkt->setSrc(id); return bus->recvTiming(pkt); }
120
121        /** When reciving a Atomic requestfrom the peer port (at id),
122            pass it to the bus. */
123        virtual Tick recvAtomic(Packet *pkt)
124        { pkt->setSrc(id); return bus->recvAtomic(pkt); }
125
126        /** When reciving a Functional requestfrom the peer port (at id),
127            pass it to the bus. */
128        virtual void recvFunctional(Packet *pkt)
129        { pkt->setSrc(id); bus->recvFunctional(pkt); }
130
131        /** When reciving a status changefrom the peer port (at id),
132            pass it to the bus. */
133        virtual void recvStatusChange(Status status)
134        { bus->recvStatusChange(status, id); }
135
136        /** When reciving a retry from the peer port (at id),
137            pass it to the bus. */
138        virtual void recvRetry()
139        { bus->recvRetry(id); }
140
141        // This should return all the 'owned' addresses that are
142        // downstream from this bus, yes?  That is, the union of all
143        // the 'owned' address ranges of all the other interfaces on
144        // this bus...
145        virtual void getDeviceAddressRanges(AddrRangeList &resp,
146                                            AddrRangeList &snoop)
147        { bus->addressRanges(resp, snoop, id); }
148
149        // Hack to make translating port work without changes
150        virtual int deviceBlockSize() { return 32; }
151
152    };
153
154    /** An array of pointers to the peer port interfaces
155        connected to this bus.*/
156    std::vector<Port*> interfaces;
157
158    /** An array of pointers to ports that retry should be called on because the
159     * original send failed for whatever reason.*/
160    std::list<Port*> retryList;
161
162  public:
163
164    /** A function used to return the port associated with this bus object. */
165    virtual Port *getPort(const std::string &if_name, int idx = -1);
166
167    virtual void init();
168
169    Bus(const std::string &n, int bus_id)
170        : MemObject(n), busId(bus_id)  {}
171
172};
173
174#endif //__MEM_BUS_HH__
175