src/dev/io_device.hh

   1 /*
   2  * Copyright (c) 2004-2005 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  *          Nathan Binkert
  30  */
  31
  32 #ifndef __DEV_IO_DEVICE_HH__
  33 #define __DEV_IO_DEVICE_HH__
  34
  35 #include "mem/mem_object.hh"
  36 #include "mem/packet.hh"
  37 #include "mem/tport.hh"
  38 #include "params/BasicPioDevice.hh"
  39 #include "params/DmaDevice.hh"
  40 #include "params/PioDevice.hh"
  41 #include "sim/sim_object.hh"
  42
  43 class Event;
  44 class Platform;
  45 class PioDevice;
  46 class DmaDevice;
  47 class System;
  48
  49 /**
  50  * The PioPort class is a programmed i/o port that all devices that are
  51  * sensitive to an address range use. The port takes all the memory
  52  * access types and roles them into one read() and write() call that the device
  53  * must respond to. The device must also provide the addressRanges() function
  54  * with which it returns the address ranges it is interested in.
  55  */
  56 class PioPort : public SimpleTimingPort
  57 {
  58   protected:
  59     /** The device that this port serves. */
  60     PioDevice *device;
  61
  62     virtual Tick recvAtomic(PacketPtr pkt);
  63
  64     virtual void getDeviceAddressRanges(AddrRangeList &resp,
  65                                         bool &snoop);
  66
  67   public:
  68
  69     PioPort(PioDevice *dev, System *s, std::string pname = "-pioport");
  70 };
  71
  72
  73 class DmaPort : public Port
  74 {
  75   protected:
  76     struct DmaReqState : public Packet::SenderState
  77     {
  78         /** Event to call on the device when this transaction (all packets)
  79          * complete. */
  80         Event *completionEvent;
  81
  82         /** Where we came from for some sanity checking. */
  83         Port *outPort;
  84
  85         /** Total number of bytes that this transaction involves. */
  86         Addr totBytes;
  87
  88         /** Number of bytes that have been acked for this transaction. */
  89         Addr numBytes;
  90
  91         DmaReqState(Event *ce, Port *p, Addr tb)
  92             : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0)
  93         {}
  94     };
  95
  96     DmaDevice *device;
  97     std::list<PacketPtr> transmitList;
  98
  99     /** The system that device/port are in. This is used to select which mode
 100      * we are currently operating in. */
 101     System *sys;
 102
 103     /** Number of outstanding packets the dma port has. */
 104     int pendingCount;
 105
 106     /** If a dmaAction is in progress. */
 107     int actionInProgress;
 108
 109     /** If we need to drain, keep the drain event around until we're done
 110      * here.*/
 111     Event *drainEvent;
 112
 113     /** time to wait between sending another packet, increases as NACKs are
 114      * recived, decreases as responses are recived. */
 115     Tick backoffTime;
 116
 117     /** If the port is currently waiting for a retry before it can send whatever
 118      * it is that it's sending. */
 119     bool inRetry;
 120
 121     virtual bool recvTiming(PacketPtr pkt);
 122     virtual Tick recvAtomic(PacketPtr pkt)
 123     { panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN }
 124     virtual void recvFunctional(PacketPtr pkt)
 125     { panic("dma port shouldn't be used for pio access."); }
 126
 127     virtual void recvStatusChange(Status status)
 128     { ; }
 129
 130     virtual void recvRetry() ;
 131
 132     virtual void getDeviceAddressRanges(AddrRangeList &resp,
 133                                         bool &snoop)
 134     { resp.clear(); snoop = false; }
 135
 136     void queueDma(PacketPtr pkt, bool front = false);
 137     void sendDma();
 138
 139     /** event to give us a kick every time we backoff time is reached. */
 140     EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
 141
 142   public:
 143     DmaPort(DmaDevice *dev, System *s);
 144
 145     void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
 146                    uint8_t *data = NULL);
 147
 148     bool dmaPending() { return pendingCount > 0; }
 149
 150     int cacheBlockSize() { return peerBlockSize(); }
 151     unsigned int drain(Event *de);
 152 };
 153
 154 /**
 155  * This device is the base class which all devices senstive to an address range
 156  * inherit from. There are three pure virtual functions which all devices must
 157  * implement addressRanges(), read(), and write(). The magic do choose which
 158  * mode we are in, etc is handled by the PioPort so the device doesn't have to
 159  * bother.
 160  */
 161 class PioDevice : public MemObject
 162 {
 163   protected:
 164
 165     /** The platform we are in. This is used to decide what type of memory
 166      * transaction we should perform. */
 167     Platform *platform;
 168
 169     System *sys;
 170
 171     /** The pioPort that handles the requests for us and provides us requests
 172      * that it sees. */
 173     PioPort *pioPort;
 174
 175     virtual void addressRanges(AddrRangeList &range_list) = 0;
 176
 177     /** Pure virtual function that the device must implement. Called
 178      * when a read command is recieved by the port.
 179      * @param pkt Packet describing this request
 180      * @return number of ticks it took to complete
 181      */
 182     virtual Tick read(PacketPtr pkt) = 0;
 183
 184     /** Pure virtual function that the device must implement. Called when a
 185      * write command is recieved by the port.
 186      * @param pkt Packet describing this request
 187      * @return number of ticks it took to complete
 188      */
 189     virtual Tick write(PacketPtr pkt) = 0;
 190
 191   public:
 192     typedef PioDeviceParams Params;
 193     PioDevice(const Params *p);
 194     virtual ~PioDevice();
 195
 196     const Params *
 197     params() const
 198     {
 199         return dynamic_cast<const Params *>(_params);
 200     }
 201
 202     virtual void init();
 203
 204     virtual unsigned int drain(Event *de);
 205
 206     virtual Port *getPort(const std::string &if_name, int idx = -1)
 207     {
 208         if (if_name == "pio") {
 209             if (pioPort != NULL)
 210                 panic("pio port already connected to.");
 211             pioPort = new PioPort(this, sys);
 212             return pioPort;
 213         } else
 214             return NULL;
 215     }
 216     friend class PioPort;
 217
 218 };
 219
 220 class BasicPioDevice : public PioDevice
 221 {
 222   protected:
 223     /** Address that the device listens to. */
 224     Addr pioAddr;
 225
 226     /** Size that the device's address range. */
 227     Addr pioSize;
 228
 229     /** Delay that the device experinces on an access. */
 230     Tick pioDelay;
 231
 232   public:
 233     typedef BasicPioDeviceParams Params;
 234     BasicPioDevice(const Params *p);
 235
 236     const Params *
 237     params() const
 238     {
 239         return dynamic_cast<const Params *>(_params);
 240     }
 241
 242     /** return the address ranges that this device responds to.
 243      * @param range_list range list to populate with ranges
 244      */
 245     void addressRanges(AddrRangeList &range_list);
 246
 247 };
 248
 249 class DmaDevice : public PioDevice
 250 {
 251    protected:
 252     DmaPort *dmaPort;
 253     Tick minBackoffDelay;
 254     Tick maxBackoffDelay;
 255
 256   public:
 257     typedef DmaDeviceParams Params;
 258     DmaDevice(const Params *p);
 259     virtual ~DmaDevice();
 260
 261     const Params *
 262     params() const
 263     {
 264         return dynamic_cast<const Params *>(_params);
 265     }
 266
 267     void dmaWrite(Addr addr, int size, Event *event, uint8_t *data)
 268     {
 269         dmaPort->dmaAction(MemCmd::WriteInvalidateReq,
 270                            addr, size, event, data);
 271     }
 272
 273     void dmaRead(Addr addr, int size, Event *event, uint8_t *data)
 274     {
 275         dmaPort->dmaAction(MemCmd::ReadReq, addr, size, event, data);
 276     }
 277
 278     bool dmaPending() { return dmaPort->dmaPending(); }
 279
 280     virtual unsigned int drain(Event *de);
 281
 282     int cacheBlockSize() { return dmaPort->cacheBlockSize(); }
 283
 284     virtual Port *getPort(const std::string &if_name, int idx = -1)
 285     {
 286         if (if_name == "pio") {
 287             if (pioPort != NULL)
 288                 panic("pio port already connected to.");
 289             pioPort = new PioPort(this, sys);
 290             return pioPort;
 291         } else if (if_name == "dma") {
 292             if (dmaPort != NULL)
 293                 panic("dma port already connected to.");
 294             dmaPort = new DmaPort(this, sys);
 295             return dmaPort;
 296         } else
 297             return NULL;
 298     }
 299
 300     friend class DmaPort;
 301 };
 302
 303
 304 #endif // __DEV_IO_DEVICE_HH__