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         /** Amount to delay completion of dma by */
  93         Tick delay;
  94
  95
  96         DmaReqState(Event *ce, Port *p, Addr tb, Tick _delay)
  97             : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0),
  98               delay(_delay)
  99         {}
 100     };
 101
 102     MemObject *device;
 103     std::list<PacketPtr> transmitList;
 104
 105     /** The system that device/port are in. This is used to select which mode
 106      * we are currently operating in. */
 107     System *sys;
 108
 109     /** Number of outstanding packets the dma port has. */
 110     int pendingCount;
 111
 112     /** If a dmaAction is in progress. */
 113     int actionInProgress;
 114
 115     /** If we need to drain, keep the drain event around until we're done
 116      * here.*/
 117     Event *drainEvent;
 118
 119     /** time to wait between sending another packet, increases as NACKs are
 120      * recived, decreases as responses are recived. */
 121     Tick backoffTime;
 122
 123     /** Minimum time that device should back off for after failed sendTiming */
 124     Tick minBackoffDelay;
 125
 126     /** Maximum time that device should back off for after failed sendTiming */
 127     Tick maxBackoffDelay;
 128
 129     /** If the port is currently waiting for a retry before it can send whatever
 130      * it is that it's sending. */
 131     bool inRetry;
 132
 133     /** Port accesses a cache which requires snooping */
 134     bool recvSnoops;
 135
 136     /** Records snoop response so we only reply once to a status change */
 137     bool snoopRangeSent;
 138
 139     virtual bool recvTiming(PacketPtr pkt);
 140     virtual Tick recvAtomic(PacketPtr pkt)
 141     {
 142         if (recvSnoops) return 0;
 143
 144         panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN
 145     }
 146     virtual void recvFunctional(PacketPtr pkt)
 147     {
 148         if (recvSnoops) return;
 149
 150         panic("dma port shouldn't be used for pio access.");
 151     }
 152
 153     virtual void recvStatusChange(Status status)
 154     {
 155         if (recvSnoops) {
 156             if (status == RangeChange) {
 157                 if (!snoopRangeSent) {
 158                     snoopRangeSent = true;
 159                     sendStatusChange(Port::RangeChange);
 160                 }
 161                 return;
 162             }
 163             panic("Unexpected recvStatusChange\n");
 164         }
 165     }
 166
 167     virtual void recvRetry() ;
 168
 169     virtual void getDeviceAddressRanges(AddrRangeList &resp,
 170                                         bool &snoop)
 171     { resp.clear(); snoop = recvSnoops; }
 172
 173     void queueDma(PacketPtr pkt, bool front = false);
 174     void sendDma();
 175
 176     /** event to give us a kick every time we backoff time is reached. */
 177     EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
 178
 179   public:
 180     DmaPort(MemObject *dev, System *s, Tick min_backoff, Tick max_backoff,
 181             bool recv_snoops = false);
 182
 183     void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
 184                    uint8_t *data, Tick delay, Request::Flags flag = 0);
 185
 186     bool dmaPending() { return pendingCount > 0; }
 187
 188     unsigned cacheBlockSize() const { return peerBlockSize(); }
 189     unsigned int drain(Event *de);
 190 };
 191
 192 /**
 193  * This device is the base class which all devices senstive to an address range
 194  * inherit from. There are three pure virtual functions which all devices must
 195  * implement addressRanges(), read(), and write(). The magic do choose which
 196  * mode we are in, etc is handled by the PioPort so the device doesn't have to
 197  * bother.
 198  */
 199 class PioDevice : public MemObject
 200 {
 201   protected:
 202
 203     /** The platform we are in. This is used to decide what type of memory
 204      * transaction we should perform. */
 205     Platform *platform;
 206
 207     System *sys;
 208
 209     /** The pioPort that handles the requests for us and provides us requests
 210      * that it sees. */
 211     PioPort *pioPort;
 212
 213     virtual void addressRanges(AddrRangeList &range_list) = 0;
 214
 215     /** Pure virtual function that the device must implement. Called
 216      * when a read 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 read(PacketPtr pkt) = 0;
 221
 222     /** Pure virtual function that the device must implement. Called when a
 223      * write command is recieved by the port.
 224      * @param pkt Packet describing this request
 225      * @return number of ticks it took to complete
 226      */
 227     virtual Tick write(PacketPtr pkt) = 0;
 228
 229   public:
 230     typedef PioDeviceParams Params;
 231     PioDevice(const Params *p);
 232     virtual ~PioDevice();
 233
 234     const Params *
 235     params() const
 236     {
 237         return dynamic_cast<const Params *>(_params);
 238     }
 239
 240     virtual void init();
 241
 242     virtual unsigned int drain(Event *de);
 243
 244     virtual Port *getPort(const std::string &if_name, int idx = -1);
 245
 246     friend class PioPort;
 247
 248 };
 249
 250 class BasicPioDevice : public PioDevice
 251 {
 252   protected:
 253     /** Address that the device listens to. */
 254     Addr pioAddr;
 255
 256     /** Size that the device's address range. */
 257     Addr pioSize;
 258
 259     /** Delay that the device experinces on an access. */
 260     Tick pioDelay;
 261
 262   public:
 263     typedef BasicPioDeviceParams Params;
 264     BasicPioDevice(const Params *p);
 265
 266     const Params *
 267     params() const
 268     {
 269         return dynamic_cast<const Params *>(_params);
 270     }
 271
 272     /** return the address ranges that this device responds to.
 273      * @param range_list range list to populate with ranges
 274      */
 275     void addressRanges(AddrRangeList &range_list);
 276
 277 };
 278
 279 class DmaDevice : public PioDevice
 280 {
 281    protected:
 282     DmaPort *dmaPort;
 283
 284   public:
 285     typedef DmaDeviceParams Params;
 286     DmaDevice(const Params *p);
 287     virtual ~DmaDevice();
 288
 289     const Params *
 290     params() const
 291     {
 292         return dynamic_cast<const Params *>(_params);
 293     }
 294
 295     void dmaWrite(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
 296     {
 297         dmaPort->dmaAction(MemCmd::WriteReq, addr, size, event, data, delay);
 298     }
 299
 300     void dmaRead(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
 301     {
 302         dmaPort->dmaAction(MemCmd::ReadReq, addr, size, event, data, delay);
 303     }
 304
 305     bool dmaPending() { return dmaPort->dmaPending(); }
 306
 307     virtual unsigned int drain(Event *de);
 308
 309     unsigned cacheBlockSize() const { return dmaPort->cacheBlockSize(); }
 310
 311     virtual Port *getPort(const std::string &if_name, int idx = -1);
 312
 313     friend class DmaPort;
 314 };
 315
 316
 317 #endif // __DEV_IO_DEVICE_HH__