external_slave.cc revision 11793:ef606668d247 
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 "debug/ExternalPort.hh"
46
47/** Implement a `stub' port which just responds to requests by printing
48 *  a message.  The stub port can be used to configure and test a system
49 *  where the external port is used for a peripheral before connecting
50 *  the external port */
51class StubSlavePort : public ExternalSlave::Port
52{
53  public:
54    class ResponseEvent : public Event
55    {
56      public:
57        StubSlavePort &owner;
58
59        ResponseEvent(StubSlavePort &owner_) : owner(owner_) { }
60
61        void process();
62    };
63
64    ResponseEvent responseEvent;
65
66    /** Stub can handle a single request at a time.  This will be
67     *  NULL when no packet is in flight */
68    PacketPtr responsePacket;
69
70    /** Received a new request while processing a first.  Need to ask for
71     *  a retry after completing this packet */
72    bool mustRetry;
73
74    StubSlavePort(const std::string &name_,
75        ExternalSlave &owner_) :
76        ExternalSlave::Port(name_, owner_),
77        responseEvent(*this), responsePacket(NULL), mustRetry(false)
78    { }
79
80    Tick recvAtomic(PacketPtr packet);
81    void recvFunctional(PacketPtr packet);
82    bool recvTimingReq(PacketPtr packet);
83    bool recvTimingSnoopResp(PacketPtr packet);
84    void recvRespRetry();
85    void recvFunctionalSnoop(PacketPtr packet);
86};
87
88class StubSlavePortHandler : public
89    ExternalSlave::Handler
90{
91  public:
92    ExternalSlave::Port *getExternalPort(
93        const std::string &name_,
94        ExternalSlave &owner,
95        const std::string &port_data)
96    {
97        StringWrap name(name_);
98
99        DPRINTF(ExternalPort, "finding stub port '%s'\n", port_data);
100        return new StubSlavePort(name_, owner);
101    }
102};
103
104Tick
105StubSlavePort::recvAtomic(PacketPtr packet)
106{
107    if (DTRACE(ExternalPort)) {
108        unsigned int M5_VAR_USED size = packet->getSize();
109
110        DPRINTF(ExternalPort, "StubSlavePort: recvAtomic a: 0x%x size: %d"
111            " data: ...\n", packet->getAddr(), size);
112        DDUMP(ExternalPort, packet->getConstPtr<uint8_t>(), size);
113    }
114
115    return 0;
116}
117
118void
119StubSlavePort::recvFunctional(PacketPtr packet)
120{
121    recvAtomic(packet);
122}
123
124void
125StubSlavePort::ResponseEvent::process()
126{
127    owner.responsePacket->makeResponse();
128    owner.responsePacket->headerDelay = 0;
129    owner.responsePacket->payloadDelay = 0;
130
131    if (owner.sendTimingResp(owner.responsePacket)) {
132        owner.responsePacket = NULL;
133
134        if (owner.mustRetry)
135            owner.sendRetryReq();
136        owner.mustRetry = false;
137    }
138}
139
140bool
141StubSlavePort::recvTimingReq(PacketPtr packet)
142{
143    if (responsePacket) {
144        mustRetry = true;
145
146        return false;
147    } else {
148        recvAtomic(packet);
149
150        responsePacket = packet;
151        owner.schedule(responseEvent, curTick());
152
153        return true;
154    }
155}
156
157bool
158StubSlavePort::recvTimingSnoopResp(PacketPtr packet)
159{
160    fatal("StubSlavePort: function: %s\n", __func__);
161    return false;
162}
163
164void
165StubSlavePort::recvRespRetry()
166{
167    assert(responsePacket);
168    /* Stub handles only one response at a time so responseEvent should never
169     *  be scheduled at this point.  Retrys shouldn't need to schedule, we
170     *  can safely send the response here */
171    responseEvent.process();
172}
173
174void
175StubSlavePort::recvFunctionalSnoop(PacketPtr packet)
176{
177    fatal("StubSlavePort: unimplemented function: %s\n", __func__);
178}
179
180std::map<std::string, ExternalSlave::Handler *>
181    ExternalSlave::portHandlers;
182
183AddrRangeList
184ExternalSlave::Port::getAddrRanges() const
185{
186    return owner.addrRanges;
187}
188
189ExternalSlave::ExternalSlave(ExternalSlaveParams *params) :
190    MemObject(params),
191    externalPort(NULL),
192    portName(params->name + ".port"),
193    portType(params->port_type),
194    portData(params->port_data),
195    addrRanges(params->addr_ranges.begin(), params->addr_ranges.end())
196{
197    /* Register the stub handler if it hasn't already been registered */
198    if (portHandlers.find("stub") == portHandlers.end())
199        registerHandler("stub", new StubSlavePortHandler);
200}
201
202BaseSlavePort &
203ExternalSlave::getSlavePort(const std::string &if_name,
204    PortID idx)
205{
206    if (if_name == "port") {
207        DPRINTF(ExternalPort, "Trying to bind external port: %s %s\n",
208            portType, portName);
209
210        if (!externalPort) {
211            auto handlerIter = portHandlers.find(portType);
212
213            if (handlerIter == portHandlers.end())
214                fatal("Can't find port handler type '%s'\n", portType);
215
216            externalPort = portHandlers[portType]->getExternalPort(portName,
217                *this, portData);
218
219            if (!externalPort) {
220                fatal("%s: Can't find external port type: %s"
221                    " port_data: '%s'\n", portName, portType, portData);
222            }
223        }
224        return *externalPort;
225    } else {
226        return MemObject::getSlavePort(if_name, idx);
227    }
228}
229
230void
231ExternalSlave::init()
232{
233    if (!externalPort) {
234        fatal("ExternalSlave %s: externalPort not set!\n", name());
235    } else if (!externalPort->isConnected()) {
236        fatal("ExternalSlave %s is unconnected!\n", name());
237    } else {
238        externalPort->sendRangeChange();
239    }
240}
241
242ExternalSlave *
243ExternalSlaveParams::create()
244{
245    return new ExternalSlave(this);
246}
247
248void
249ExternalSlave::registerHandler(const std::string &handler_name,
250    Handler *handler)
251{
252    portHandlers[handler_name] = handler;
253}
254