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 getAddrRanges() 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 AddrRangeList getAddrRanges();
  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, public FastAlloc
  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         /** Amount to delay completion of dma by */
  92         Tick delay;
  93
  94
  95         DmaReqState(Event *ce, Port *p, Addr tb, Tick _delay)
  96             : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0),
  97               delay(_delay)
  98         {}
  99     };
 100
 101     MemObject *device;
 102     std::list<PacketPtr> transmitList;
 103
 104     /** The system that device/port are in. This is used to select which mode
 105      * we are currently operating in. */
 106     System *sys;
 107
 108     /** Number of outstanding packets the dma port has. */
 109     int pendingCount;
 110
 111     /** If a dmaAction is in progress. */
 112     int actionInProgress;
 113
 114     /** If we need to drain, keep the drain event around until we're done
 115      * here.*/
 116     Event *drainEvent;
 117
 118     /** time to wait between sending another packet, increases as NACKs are
 119      * recived, decreases as responses are recived. */
 120     Tick backoffTime;
 121
 122     /** Minimum time that device should back off for after failed sendTiming */
 123     Tick minBackoffDelay;
 124
 125     /** Maximum time that device should back off for after failed sendTiming */
 126     Tick maxBackoffDelay;
 127
 128     /** If the port is currently waiting for a retry before it can send whatever
 129      * it is that it's sending. */
 130     bool inRetry;
 131
 132     /** Port accesses a cache which requires snooping */
 133     bool recvSnoops;
 134
 135     virtual bool recvTiming(PacketPtr pkt);
 136     virtual Tick recvAtomic(PacketPtr pkt)
 137     {
 138         if (recvSnoops) return 0;
 139
 140         panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN
 141     }
 142     virtual void recvFunctional(PacketPtr pkt)
 143     {
 144         if (recvSnoops) return;
 145
 146         panic("dma port shouldn't be used for pio access.");
 147     }
 148
 149     virtual void recvRangeChange()
 150     {
 151         // DMA port is a master with a single slave so there is no choice and
 152         // thus no need to worry about any address changes
 153     }
 154
 155     virtual void recvRetry() ;
 156
 157     virtual bool isSnooping()
 158     { return recvSnoops; }
 159
 160     void queueDma(PacketPtr pkt, bool front = false);
 161     void sendDma();
 162
 163     /** event to give us a kick every time we backoff time is reached. */
 164     EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
 165
 166   public:
 167     DmaPort(MemObject *dev, System *s, Tick min_backoff, Tick max_backoff,
 168             bool recv_snoops = false);
 169
 170     void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
 171                    uint8_t *data, Tick delay, Request::Flags flag = 0);
 172
 173     bool dmaPending() { return pendingCount > 0; }
 174
 175     unsigned cacheBlockSize() const { return peerBlockSize(); }
 176     unsigned int drain(Event *de);
 177 };
 178
 179 /**
 180  * This device is the base class which all devices senstive to an address range
 181  * inherit from. There are three pure virtual functions which all devices must
 182  * implement getAddrRanges(), read(), and write(). The magic do choose which
 183  * mode we are in, etc is handled by the PioPort so the device doesn't have to
 184  * bother.
 185  */
 186 class PioDevice : public MemObject
 187 {
 188   protected:
 189
 190     /** The platform we are in. This is used to decide what type of memory
 191      * transaction we should perform. */
 192     Platform *platform;
 193
 194     System *sys;
 195
 196     /** The pioPort that handles the requests for us and provides us requests
 197      * that it sees. */
 198     PioPort *pioPort;
 199
 200     /**
 201      * Every PIO device is obliged to provide an implementation that
 202      * returns the address ranges the device responds to.
 203      *
 204      * @return a list of non-overlapping address ranges
 205      */
 206     virtual AddrRangeList getAddrRanges() = 0;
 207
 208     /** Pure virtual function that the device must implement. Called
 209      * when a read command is recieved by the port.
 210      * @param pkt Packet describing this request
 211      * @return number of ticks it took to complete
 212      */
 213     virtual Tick read(PacketPtr pkt) = 0;
 214
 215     /** Pure virtual function that the device must implement. Called when a
 216      * write command is recieved by the port.
 217      * @param pkt Packet describing this request
 218      * @return number of ticks it took to complete
 219      */
 220     virtual Tick write(PacketPtr pkt) = 0;
 221
 222   public:
 223     typedef PioDeviceParams Params;
 224     PioDevice(const Params *p);
 225     virtual ~PioDevice();
 226
 227     const Params *
 228     params() const
 229     {
 230         return dynamic_cast<const Params *>(_params);
 231     }
 232
 233     virtual void init();
 234
 235     virtual unsigned int drain(Event *de);
 236
 237     virtual Port *getPort(const std::string &if_name, int idx = -1);
 238
 239     friend class PioPort;
 240
 241 };
 242
 243 class BasicPioDevice : public PioDevice
 244 {
 245   protected:
 246     /** Address that the device listens to. */
 247     Addr pioAddr;
 248
 249     /** Size that the device's address range. */
 250     Addr pioSize;
 251
 252     /** Delay that the device experinces on an access. */
 253     Tick pioDelay;
 254
 255   public:
 256     typedef BasicPioDeviceParams Params;
 257     BasicPioDevice(const Params *p);
 258
 259     const Params *
 260     params() const
 261     {
 262         return dynamic_cast<const Params *>(_params);
 263     }
 264
 265     /**
 266      * Determine the address ranges that this device responds to.
 267      *
 268      * @return a list of non-overlapping address ranges
 269      */
 270     virtual AddrRangeList getAddrRanges();
 271
 272 };
 273
 274 class DmaDevice : public PioDevice
 275 {
 276    protected:
 277     DmaPort *dmaPort;
 278
 279   public:
 280     typedef DmaDeviceParams Params;
 281     DmaDevice(const Params *p);
 282     virtual ~DmaDevice();
 283
 284     const Params *
 285     params() const
 286     {
 287         return dynamic_cast<const Params *>(_params);
 288     }
 289
 290     void dmaWrite(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
 291     {
 292         dmaPort->dmaAction(MemCmd::WriteReq, addr, size, event, data, delay);
 293     }
 294
 295     void dmaRead(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
 296     {
 297         dmaPort->dmaAction(MemCmd::ReadReq, addr, size, event, data, delay);
 298     }
 299
 300     bool dmaPending() { return dmaPort->dmaPending(); }
 301
 302     virtual unsigned int drain(Event *de);
 303
 304     unsigned cacheBlockSize() const { return dmaPort->cacheBlockSize(); }
 305
 306     virtual Port *getPort(const std::string &if_name, int idx = -1);
 307
 308     friend class DmaPort;
 309 };
 310
 311
 312 #endif // __DEV_IO_DEVICE_HH__