xbar.cc revision 2640 
1/*
2 * Copyright (c) 2006 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
29/**
30 * @file Definition of a bus object.
31 */
32
33
34#include "base/trace.hh"
35#include "mem/bus.hh"
36#include "sim/builder.hh"
37
38Port *
39Bus::getPort(const std::string &if_name)
40{
41    // if_name ignored?  forced to be empty?
42    int id = interfaces.size();
43    BusPort *bp = new BusPort(csprintf("%s-p%d", name(), id), this, id);
44    interfaces.push_back(bp);
45    return bp;
46}
47
48/** Get the ranges of anyone that we are connected to. */
49void
50Bus::init()
51{
52    std::vector<Port*>::iterator intIter;
53    for (intIter = interfaces.begin(); intIter != interfaces.end(); intIter++)
54        (*intIter)->sendStatusChange(Port::RangeChange);
55}
56
57
58/** Function called by the port when the bus is recieving a Timing
59 * transaction.*/
60bool
61Bus::recvTiming(Packet *pkt)
62{
63    Port *port;
64    if (pkt->dest == Packet::Broadcast) {
65        port = findPort(pkt->addr, pkt->src);
66    } else {
67        assert(pkt->dest >= 0 && pkt->dest < interfaces.size());
68        assert(pkt->dest != pkt->src); // catch infinite loops
69        port = interfaces[pkt->dest];
70    }
71    return port->sendTiming(pkt);
72}
73
74Port *
75Bus::findPort(Addr addr, int id)
76{
77    /* An interval tree would be a better way to do this. --ali. */
78    int dest_id = -1;
79    int i = 0;
80    bool found = false;
81
82    while (i < portList.size() && !found)
83    {
84        if (portList[i].range == addr) {
85            dest_id = portList[i].portId;
86            found = true;
87            DPRINTF(Bus, "Found Addr: %llx on device %d\n", addr, dest_id);
88        }
89        i++;
90    }
91    if (dest_id == -1)
92        panic("Unable to find destination for addr: %llx", addr);
93
94    // we shouldn't be sending this back to where it came from
95    assert(dest_id != id);
96
97    return interfaces[dest_id];
98}
99
100/** Function called by the port when the bus is recieving a Atomic
101 * transaction.*/
102Tick
103Bus::recvAtomic(Packet *pkt)
104{
105    assert(pkt->dest == Packet::Broadcast);
106    return findPort(pkt->addr, pkt->src)->sendAtomic(pkt);
107}
108
109/** Function called by the port when the bus is recieving a Functional
110 * transaction.*/
111void
112Bus::recvFunctional(Packet *pkt)
113{
114    assert(pkt->dest == Packet::Broadcast);
115    findPort(pkt->addr, pkt->src)->sendFunctional(pkt);
116}
117
118/** Function called by the port when the bus is recieving a status change.*/
119void
120Bus::recvStatusChange(Port::Status status, int id)
121{
122    DPRINTF(Bus, "Bus %d recieved status change from device id %d\n",
123            busId, id);
124    assert(status == Port::RangeChange &&
125           "The other statuses need to be implemented.");
126
127    assert(id < interfaces.size() && id >= 0);
128    int x;
129    Port *port = interfaces[id];
130    AddrRangeList ranges;
131    AddrRangeList snoops;
132    AddrRangeIter iter;
133    std::vector<DevMap>::iterator portIter;
134
135    // Clean out any previously existent ids
136    for (portIter = portList.begin(); portIter != portList.end(); ) {
137        if (portIter->portId == id)
138            portIter = portList.erase(portIter);
139        else
140            portIter++;
141    }
142
143    port->getPeerAddressRanges(ranges, snoops);
144
145    // not dealing with snooping yet either
146    assert(snoops.size() == 0);
147    for(iter = ranges.begin(); iter != ranges.end(); iter++) {
148        DevMap dm;
149        dm.portId = id;
150        dm.range = *iter;
151
152        DPRINTF(MMU, "Adding range %llx - %llx for id %d\n", dm.range.start,
153                dm.range.end, id);
154        portList.push_back(dm);
155    }
156    DPRINTF(MMU, "port list has %d entries\n", portList.size());
157
158    // tell all our peers that our address range has changed.
159    // Don't tell the device that caused this change, it already knows
160    for (x = 0; x < interfaces.size(); x++)
161        if (x != id)
162            interfaces[x]->sendStatusChange(Port::RangeChange);
163}
164
165void
166Bus::addressRanges(AddrRangeList &resp, AddrRangeList &snoop, int id)
167{
168    std::vector<DevMap>::iterator portIter;
169
170    resp.clear();
171    snoop.clear();
172
173    DPRINTF(Bus, "Bus id %d recieved address range request returning\n",
174            busId);
175    for (portIter = portList.begin(); portIter != portList.end(); portIter++) {
176        if (portIter->portId != id) {
177            resp.push_back(portIter->range);
178            DPRINTF(Bus, "-- %#llX : %#llX\n", portIter->range.start,
179                    portIter->range.end);
180        }
181    }
182}
183
184BEGIN_DECLARE_SIM_OBJECT_PARAMS(Bus)
185
186    Param<int> bus_id;
187
188END_DECLARE_SIM_OBJECT_PARAMS(Bus)
189
190BEGIN_INIT_SIM_OBJECT_PARAMS(Bus)
191    INIT_PARAM(bus_id, "a globally unique bus id")
192END_INIT_SIM_OBJECT_PARAMS(Bus)
193
194CREATE_SIM_OBJECT(Bus)
195{
196    return new Bus(getInstanceName(), bus_id);
197}
198
199REGISTER_SIM_OBJECT("Bus", Bus)
200