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     virtual bool recvTiming(PacketPtr pkt);
 134     virtual Tick recvAtomic(PacketPtr pkt)
 135     { panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN }
 136     virtual void recvFunctional(PacketPtr pkt)
 137     { panic("dma port shouldn't be used for pio access."); }
 138
 139     virtual void recvStatusChange(Status status)
 140     { ; }
 141
 142     virtual void recvRetry() ;
 143
 144     virtual void getDeviceAddressRanges(AddrRangeList &resp,
 145                                         bool &snoop)
 146     { resp.clear(); snoop = false; }
 147
 148     void queueDma(PacketPtr pkt, bool front = false);
 149     void sendDma();
 150
 151     /** event to give us a kick every time we backoff time is reached. */
 152     EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
 153
 154   public:
 155     DmaPort(MemObject *dev, System *s, Tick min_backoff, Tick max_backoff);
 156
 157     void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
 158                    uint8_t *data, Tick delay, Request::Flags flag = 0);
 159
 160     bool dmaPending() { return pendingCount > 0; }
 161
 162     unsigned cacheBlockSize() const { return peerBlockSize(); }
 163     unsigned int drain(Event *de);
 164 };
 165
 166 /**
 167  * This device is the base class which all devices senstive to an address range
 168  * inherit from. There are three pure virtual functions which all devices must
 169  * implement addressRanges(), read(), and write(). The magic do choose which
 170  * mode we are in, etc is handled by the PioPort so the device doesn't have to
 171  * bother.
 172  */
 173 class PioDevice : public MemObject
 174 {
 175   protected:
 176
 177     /** The platform we are in. This is used to decide what type of memory
 178      * transaction we should perform. */
 179     Platform *platform;
 180
 181     System *sys;
 182
 183     /** The pioPort that handles the requests for us and provides us requests
 184      * that it sees. */
 185     PioPort *pioPort;
 186
 187     virtual void addressRanges(AddrRangeList &range_list) = 0;
 188
 189     /** Pure virtual function that the device must implement. Called
 190      * when a read command is recieved by the port.
 191      * @param pkt Packet describing this request
 192      * @return number of ticks it took to complete
 193      */
 194     virtual Tick read(PacketPtr pkt) = 0;
 195
 196     /** Pure virtual function that the device must implement. Called when a
 197      * write command is recieved by the port.
 198      * @param pkt Packet describing this request
 199      * @return number of ticks it took to complete
 200      */
 201     virtual Tick write(PacketPtr pkt) = 0;
 202
 203   public:
 204     typedef PioDeviceParams Params;
 205     PioDevice(const Params *p);
 206     virtual ~PioDevice();
 207
 208     const Params *
 209     params() const
 210     {
 211         return dynamic_cast<const Params *>(_params);
 212     }
 213
 214     virtual void init();
 215
 216     virtual unsigned int drain(Event *de);
 217
 218     virtual Port *getPort(const std::string &if_name, int idx = -1)
 219     {
 220         if (if_name == "pio") {
 221             if (pioPort != NULL)
 222                 fatal("%s: pio port already connected to %s",
 223                       name(), pioPort->getPeer()->name());
 224             pioPort = new PioPort(this, sys);
 225             return pioPort;
 226         } else
 227             return NULL;
 228     }
 229     friend class PioPort;
 230
 231 };
 232
 233 class BasicPioDevice : public PioDevice
 234 {
 235   protected:
 236     /** Address that the device listens to. */
 237     Addr pioAddr;
 238
 239     /** Size that the device's address range. */
 240     Addr pioSize;
 241
 242     /** Delay that the device experinces on an access. */
 243     Tick pioDelay;
 244
 245   public:
 246     typedef BasicPioDeviceParams Params;
 247     BasicPioDevice(const Params *p);
 248
 249     const Params *
 250     params() const
 251     {
 252         return dynamic_cast<const Params *>(_params);
 253     }
 254
 255     /** return the address ranges that this device responds to.
 256      * @param range_list range list to populate with ranges
 257      */
 258     void addressRanges(AddrRangeList &range_list);
 259
 260 };
 261
 262 class DmaDevice : public PioDevice
 263 {
 264    protected:
 265     DmaPort *dmaPort;
 266
 267   public:
 268     typedef DmaDeviceParams Params;
 269     DmaDevice(const Params *p);
 270     virtual ~DmaDevice();
 271
 272     const Params *
 273     params() const
 274     {
 275         return dynamic_cast<const Params *>(_params);
 276     }
 277
 278     void dmaWrite(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
 279     {
 280         dmaPort->dmaAction(MemCmd::WriteReq, addr, size, event, data, delay);
 281     }
 282
 283     void dmaRead(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
 284     {
 285         dmaPort->dmaAction(MemCmd::ReadReq, addr, size, event, data, delay);
 286     }
 287
 288     bool dmaPending() { return dmaPort->dmaPending(); }
 289
 290     virtual unsigned int drain(Event *de);
 291
 292     unsigned cacheBlockSize() const { return dmaPort->cacheBlockSize(); }
 293
 294     virtual Port *getPort(const std::string &if_name, int idx = -1)
 295     {
 296         if (if_name == "pio") {
 297             if (pioPort != NULL)
 298                 fatal("%s: pio port already connected to %s",
 299                       name(), pioPort->getPeer()->name());
 300             pioPort = new PioPort(this, sys);
 301             return pioPort;
 302         } else if (if_name == "dma") {
 303             if (dmaPort != NULL)
 304                 fatal("%s: dma port already connected to %s",
 305                       name(), dmaPort->getPeer()->name());
 306             dmaPort = new DmaPort(this, sys, params()->min_backoff_delay,
 307                     params()->max_backoff_delay);
 308             return dmaPort;
 309         } else
 310             return NULL;
 311     }
 312
 313     friend class DmaPort;
 314 };
 315
 316
 317 #endif // __DEV_IO_DEVICE_HH__