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