external_slave.cc revision 11800:54436a1784dc 
1/*
2 * Copyright (c) 2012-2014 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: Andrew Bardsley
38 */
39
40#include "mem/external_slave.hh"
41
42#include <cctype>
43#include <iomanip>
44
45#include "base/trace.hh"
46#include "debug/ExternalPort.hh"
47
48/** Implement a `stub' port which just responds to requests by printing
49 *  a message.  The stub port can be used to configure and test a system
50 *  where the external port is used for a peripheral before connecting
51 *  the external port */
52class StubSlavePort : public ExternalSlave::Port
53{
54  public:
55    class ResponseEvent : public Event
56    {
57      public:
58        StubSlavePort &owner;
59
60        ResponseEvent(StubSlavePort &owner_) : owner(owner_) { }
61
62        void process();
63    };
64
65    ResponseEvent responseEvent;
66
67    /** Stub can handle a single request at a time.  This will be
68     *  NULL when no packet is in flight */
69    PacketPtr responsePacket;
70
71    /** Received a new request while processing a first.  Need to ask for
72     *  a retry after completing this packet */
73    bool mustRetry;
74
75    StubSlavePort(const std::string &name_,
76        ExternalSlave &owner_) :
77        ExternalSlave::Port(name_, owner_),
78        responseEvent(*this), responsePacket(NULL), mustRetry(false)
79    { }
80
81    Tick recvAtomic(PacketPtr packet);
82    void recvFunctional(PacketPtr packet);
83    bool recvTimingReq(PacketPtr packet);
84    bool recvTimingSnoopResp(PacketPtr packet);
85    void recvRespRetry();
86    void recvFunctionalSnoop(PacketPtr packet);
87};
88
89class StubSlavePortHandler : public
90    ExternalSlave::Handler
91{
92  public:
93    ExternalSlave::Port *getExternalPort(
94        const std::string &name_,
95        ExternalSlave &owner,
96        const std::string &port_data)
97    {
98        StringWrap name(name_);
99
100        DPRINTF(ExternalPort, "finding stub port '%s'\n", port_data);
101        return new StubSlavePort(name_, owner);
102    }
103};
104
105Tick
106StubSlavePort::recvAtomic(PacketPtr packet)
107{
108    if (DTRACE(ExternalPort)) {
109        unsigned int M5_VAR_USED size = packet->getSize();
110
111        DPRINTF(ExternalPort, "StubSlavePort: recvAtomic a: 0x%x size: %d"
112            " data: ...\n", packet->getAddr(), size);
113        DDUMP(ExternalPort, packet->getConstPtr<uint8_t>(), size);
114    }
115
116    return 0;
117}
118
119void
120StubSlavePort::recvFunctional(PacketPtr packet)
121{
122    recvAtomic(packet);
123}
124
125void
126StubSlavePort::ResponseEvent::process()
127{
128    owner.responsePacket->makeResponse();
129    owner.responsePacket->headerDelay = 0;
130    owner.responsePacket->payloadDelay = 0;
131
132    if (owner.sendTimingResp(owner.responsePacket)) {
133        owner.responsePacket = NULL;
134
135        if (owner.mustRetry)
136            owner.sendRetryReq();
137        owner.mustRetry = false;
138    }
139}
140
141bool
142StubSlavePort::recvTimingReq(PacketPtr packet)
143{
144    if (responsePacket) {
145        mustRetry = true;
146
147        return false;
148    } else {
149        recvAtomic(packet);
150
151        responsePacket = packet;
152        owner.schedule(responseEvent, curTick());
153
154        return true;
155    }
156}
157
158bool
159StubSlavePort::recvTimingSnoopResp(PacketPtr packet)
160{
161    fatal("StubSlavePort: function: %s\n", __func__);
162    return false;
163}
164
165void
166StubSlavePort::recvRespRetry()
167{
168    assert(responsePacket);
169    /* Stub handles only one response at a time so responseEvent should never
170     *  be scheduled at this point.  Retrys shouldn't need to schedule, we
171     *  can safely send the response here */
172    responseEvent.process();
173}
174
175void
176StubSlavePort::recvFunctionalSnoop(PacketPtr packet)
177{
178    fatal("StubSlavePort: unimplemented function: %s\n", __func__);
179}
180
181std::map<std::string, ExternalSlave::Handler *>
182    ExternalSlave::portHandlers;
183
184AddrRangeList
185ExternalSlave::Port::getAddrRanges() const
186{
187    return owner.addrRanges;
188}
189
190ExternalSlave::ExternalSlave(ExternalSlaveParams *params) :
191    MemObject(params),
192    externalPort(NULL),
193    portName(params->name + ".port"),
194    portType(params->port_type),
195    portData(params->port_data),
196    addrRanges(params->addr_ranges.begin(), params->addr_ranges.end())
197{
198    /* Register the stub handler if it hasn't already been registered */
199    if (portHandlers.find("stub") == portHandlers.end())
200        registerHandler("stub", new StubSlavePortHandler);
201}
202
203BaseSlavePort &
204ExternalSlave::getSlavePort(const std::string &if_name,
205    PortID idx)
206{
207    if (if_name == "port") {
208        DPRINTF(ExternalPort, "Trying to bind external port: %s %s\n",
209            portType, portName);
210
211        if (!externalPort) {
212            auto handlerIter = portHandlers.find(portType);
213
214            if (handlerIter == portHandlers.end())
215                fatal("Can't find port handler type '%s'\n", portType);
216
217            externalPort = portHandlers[portType]->getExternalPort(portName,
218                *this, portData);
219
220            if (!externalPort) {
221                fatal("%s: Can't find external port type: %s"
222                    " port_data: '%s'\n", portName, portType, portData);
223            }
224        }
225        return *externalPort;
226    } else {
227        return MemObject::getSlavePort(if_name, idx);
228    }
229}
230
231void
232ExternalSlave::init()
233{
234    if (!externalPort) {
235        fatal("ExternalSlave %s: externalPort not set!\n", name());
236    } else if (!externalPort->isConnected()) {
237        fatal("ExternalSlave %s is unconnected!\n", name());
238    } else {
239        externalPort->sendRangeChange();
240    }
241}
242
243ExternalSlave *
244ExternalSlaveParams::create()
245{
246    return new ExternalSlave(this);
247}
248
249void
250ExternalSlave::registerHandler(const std::string &handler_name,
251    Handler *handler)
252{
253    portHandlers[handler_name] = handler;
254}
255