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