coherent_xbar.cc revision 2846 
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 * Authors: Ali Saidi
29 */
30
31/**
32 * @file Definition of a bus object.
33 */
34
35
36#include "base/misc.hh"
37#include "base/trace.hh"
38#include "mem/bus.hh"
39#include "sim/builder.hh"
40
41Port *
42Bus::getPort(const std::string &if_name, int idx)
43{
44    if (if_name == "default")
45        if (defaultPort == NULL) {
46            defaultPort = new BusPort(csprintf("%s-default",name()), this,
47                    defaultId);
48            return defaultPort;
49        } else
50            fatal("Default port already set\n");
51
52    // if_name ignored?  forced to be empty?
53    int id = interfaces.size();
54    BusPort *bp = new BusPort(csprintf("%s-p%d", name(), id), this, id);
55    interfaces.push_back(bp);
56    return bp;
57}
58
59/** Get the ranges of anyone other buses that we are connected to. */
60void
61Bus::init()
62{
63    std::vector<Port*>::iterator intIter;
64
65    for (intIter = interfaces.begin(); intIter != interfaces.end(); intIter++)
66        (*intIter)->sendStatusChange(Port::RangeChange);
67}
68
69
70/** Function called by the port when the bus is receiving a Timing
71 * transaction.*/
72bool
73Bus::recvTiming(Packet *pkt)
74{
75    Port *port;
76    DPRINTF(Bus, "recvTiming: packet src %d dest %d addr 0x%x cmd %s\n",
77            pkt->getSrc(), pkt->getDest(), pkt->getAddr(), pkt->cmdString());
78
79    short dest = pkt->getDest();
80    if (dest == Packet::Broadcast) {
81        port = findPort(pkt->getAddr(), pkt->getSrc());
82    } else {
83        assert(dest >= 0 && dest < interfaces.size());
84        assert(dest != pkt->getSrc()); // catch infinite loops
85        port = interfaces[dest];
86    }
87    if (port->sendTiming(pkt))  {
88        // packet was successfully sent, just return true.
89        return true;
90    }
91
92    // packet not successfully sent
93    retryList.push_back(interfaces[pkt->getSrc()]);
94    return false;
95}
96
97void
98Bus::recvRetry(int id)
99{
100    // Go through all the elements on the list calling sendRetry on each
101    // This is not very efficient at all but it works. Ultimately we should end
102    // up with something that is more intelligent.
103    int initialSize = retryList.size();
104    int i;
105    Port *p;
106
107    for (i = 0; i < initialSize; i++) {
108        assert(retryList.size() > 0);
109        p = retryList.front();
110        retryList.pop_front();
111        p->sendRetry();
112    }
113}
114
115
116Port *
117Bus::findPort(Addr addr, int id)
118{
119    /* An interval tree would be a better way to do this. --ali. */
120    int dest_id = -1;
121    int i = 0;
122    bool found = false;
123    AddrRangeIter iter;
124
125    while (i < portList.size() && !found)
126    {
127        if (portList[i].range == addr) {
128            dest_id = portList[i].portId;
129            found = true;
130            DPRINTF(Bus, "  found addr 0x%llx on device %d\n", addr, dest_id);
131        }
132        i++;
133    }
134
135    // Check if this matches the default range
136    if (dest_id == -1) {
137        for (iter = defaultRange.begin(); iter != defaultRange.end(); iter++) {
138            if (*iter == addr) {
139                DPRINTF(Bus, "  found addr 0x%llx on default\n", addr);
140                return defaultPort;
141            }
142        }
143        panic("Unable to find destination for addr: %llx", addr);
144    }
145
146
147    // we shouldn't be sending this back to where it came from
148    assert(dest_id != id);
149
150    return interfaces[dest_id];
151}
152
153/** Function called by the port when the bus is receiving a Atomic
154 * transaction.*/
155Tick
156Bus::recvAtomic(Packet *pkt)
157{
158    DPRINTF(Bus, "recvAtomic: packet src %d dest %d addr 0x%x cmd %s\n",
159            pkt->getSrc(), pkt->getDest(), pkt->getAddr(), pkt->cmdString());
160    assert(pkt->getDest() == Packet::Broadcast);
161    return findPort(pkt->getAddr(), pkt->getSrc())->sendAtomic(pkt);
162}
163
164/** Function called by the port when the bus is receiving a Functional
165 * transaction.*/
166void
167Bus::recvFunctional(Packet *pkt)
168{
169    DPRINTF(Bus, "recvFunctional: packet src %d dest %d addr 0x%x cmd %s\n",
170            pkt->getSrc(), pkt->getDest(), pkt->getAddr(), pkt->cmdString());
171    assert(pkt->getDest() == Packet::Broadcast);
172    findPort(pkt->getAddr(), pkt->getSrc())->sendFunctional(pkt);
173}
174
175/** Function called by the port when the bus is receiving a status change.*/
176void
177Bus::recvStatusChange(Port::Status status, int id)
178{
179    AddrRangeList ranges;
180    AddrRangeList snoops;
181    int x;
182    AddrRangeIter iter;
183
184    assert(status == Port::RangeChange &&
185           "The other statuses need to be implemented.");
186
187    DPRINTF(BusAddrRanges, "received RangeChange from device id %d\n", id);
188
189    if (id == defaultId) {
190        defaultRange.clear();
191        defaultPort->getPeerAddressRanges(ranges, snoops);
192        assert(snoops.size() == 0);
193        for(iter = ranges.begin(); iter != ranges.end(); iter++) {
194            defaultRange.push_back(*iter);
195            DPRINTF(BusAddrRanges, "Adding range %llx - %llx for default\n",
196                    iter->start, iter->end);
197        }
198    } else {
199
200        assert((id < interfaces.size() && id >= 0) || id == -1);
201        Port *port = interfaces[id];
202        std::vector<DevMap>::iterator portIter;
203
204        // Clean out any previously existent ids
205        for (portIter = portList.begin(); portIter != portList.end(); ) {
206            if (portIter->portId == id)
207                portIter = portList.erase(portIter);
208            else
209                portIter++;
210        }
211
212        port->getPeerAddressRanges(ranges, snoops);
213
214        // not dealing with snooping yet either
215        assert(snoops.size() == 0);
216        for(iter = ranges.begin(); iter != ranges.end(); iter++) {
217            DevMap dm;
218            dm.portId = id;
219            dm.range = *iter;
220
221            DPRINTF(BusAddrRanges, "Adding range %llx - %llx for id %d\n",
222                    dm.range.start, dm.range.end, id);
223            portList.push_back(dm);
224        }
225    }
226    DPRINTF(MMU, "port list has %d entries\n", portList.size());
227
228    // tell all our peers that our address range has changed.
229    // Don't tell the device that caused this change, it already knows
230    for (x = 0; x < interfaces.size(); x++)
231        if (x != id)
232            interfaces[x]->sendStatusChange(Port::RangeChange);
233
234    if (id != defaultId && defaultPort)
235        defaultPort->sendStatusChange(Port::RangeChange);
236}
237
238void
239Bus::addressRanges(AddrRangeList &resp, AddrRangeList &snoop, int id)
240{
241    std::vector<DevMap>::iterator portIter;
242    AddrRangeIter dflt_iter;
243    bool subset;
244
245    resp.clear();
246    snoop.clear();
247
248    DPRINTF(BusAddrRanges, "received address range request, returning:\n");
249
250    for (dflt_iter = defaultRange.begin(); dflt_iter != defaultRange.end();
251            dflt_iter++) {
252        resp.push_back(*dflt_iter);
253        DPRINTF(BusAddrRanges, "  -- %#llX : %#llX\n",dflt_iter->start,
254                dflt_iter->end);
255    }
256    for (portIter = portList.begin(); portIter != portList.end(); portIter++) {
257        subset = false;
258        for (dflt_iter = defaultRange.begin(); dflt_iter != defaultRange.end();
259                dflt_iter++) {
260            if ((portIter->range.start < dflt_iter->start &&
261                portIter->range.end >= dflt_iter->start) ||
262               (portIter->range.start < dflt_iter->end &&
263                portIter->range.end >= dflt_iter->end))
264                fatal("Devices can not set ranges that itersect the default set\
265                        but are not a subset of the default set.\n");
266            if (portIter->range.start >= dflt_iter->start &&
267                portIter->range.end <= dflt_iter->end) {
268                subset = true;
269                DPRINTF(BusAddrRanges, "  -- %#llX : %#llX is a SUBSET\n",
270                    portIter->range.start, portIter->range.end);
271            }
272        }
273        if (portIter->portId != id && !subset) {
274            resp.push_back(portIter->range);
275            DPRINTF(BusAddrRanges, "  -- %#llX : %#llX\n",
276                    portIter->range.start, portIter->range.end);
277        }
278    }
279}
280
281BEGIN_DECLARE_SIM_OBJECT_PARAMS(Bus)
282
283    Param<int> bus_id;
284
285END_DECLARE_SIM_OBJECT_PARAMS(Bus)
286
287BEGIN_INIT_SIM_OBJECT_PARAMS(Bus)
288    INIT_PARAM(bus_id, "a globally unique bus id")
289END_INIT_SIM_OBJECT_PARAMS(Bus)
290
291CREATE_SIM_OBJECT(Bus)
292{
293    return new Bus(getInstanceName(), bus_id);
294}
295
296REGISTER_SIM_OBJECT("Bus", Bus)
297