src/mem/external_slave.cc

   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 */
  52 class 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
  89 class 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
 105 Tick
 106 StubSlavePort::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
 119 void
 120 StubSlavePort::recvFunctional(PacketPtr packet)
 121 {
 122     recvAtomic(packet);
 123 }
 124
 125 void
 126 StubSlavePort::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
 141 bool
 142 StubSlavePort::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
 158 bool
 159 StubSlavePort::recvTimingSnoopResp(PacketPtr packet)
 160 {
 161     fatal("StubSlavePort: function: %s\n", __func__);
 162     return false;
 163 }
 164
 165 void
 166 StubSlavePort::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
 175 void
 176 StubSlavePort::recvFunctionalSnoop(PacketPtr packet)
 177 {
 178     fatal("StubSlavePort: unimplemented function: %s\n", __func__);
 179 }
 180
 181 std::map<std::string, ExternalSlave::Handler *>
 182     ExternalSlave::portHandlers;
 183
 184 AddrRangeList
 185 ExternalSlave::Port::getAddrRanges() const
 186 {
 187     return owner.addrRanges;
 188 }
 189
 190 ExternalSlave::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
 203 BaseSlavePort &
 204 ExternalSlave::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
 231 void
 232 ExternalSlave::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
 243 ExternalSlave *
 244 ExternalSlaveParams::create()
 245 {
 246     return new ExternalSlave(this);
 247 }
 248
 249 void
 250 ExternalSlave::registerHandler(const std::string &handler_name,
 251     Handler *handler)
 252 {
 253     portHandlers[handler_name] = handler;
 254 }