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 "sim/sim_object.hh"
  39
  40 class Event;
  41 class Platform;
  42 class PioDevice;
  43 class DmaDevice;
  44 class System;
  45
  46 /**
  47  * The PioPort class is a programmed i/o port that all devices that are
  48  * sensitive to an address range use. The port takes all the memory
  49  * access types and roles them into one read() and write() call that the device
  50  * must respond to. The device must also provide the addressRanges() function
  51  * with which it returns the address ranges it is interested in.
  52  */
  53 class PioPort : public SimpleTimingPort
  54 {
  55   protected:
  56     /** The device that this port serves. */
  57     PioDevice *device;
  58
  59     virtual Tick recvAtomic(PacketPtr pkt);
  60
  61     virtual void getDeviceAddressRanges(AddrRangeList &resp,
  62                                         AddrRangeList &snoop);
  63
  64   public:
  65
  66     PioPort(PioDevice *dev, System *s, std::string pname = "-pioport");
  67 };
  68
  69
  70 class DmaPort : public Port
  71 {
  72   protected:
  73     struct DmaReqState : public Packet::SenderState
  74     {
  75         /** Event to call on the device when this transaction (all packets)
  76          * complete. */
  77         Event *completionEvent;
  78
  79         /** Where we came from for some sanity checking. */
  80         Port *outPort;
  81
  82         /** Total number of bytes that this transaction involves. */
  83         Addr totBytes;
  84
  85         /** Number of bytes that have been acked for this transaction. */
  86         Addr numBytes;
  87
  88         DmaReqState(Event *ce, Port *p, Addr tb)
  89             : completionEvent(ce), outPort(p), totBytes(tb), numBytes(0)
  90         {}
  91     };
  92
  93     DmaDevice *device;
  94     std::list<PacketPtr> transmitList;
  95
  96     /** The system that device/port are in. This is used to select which mode
  97      * we are currently operating in. */
  98     System *sys;
  99
 100     /** Number of outstanding packets the dma port has. */
 101     int pendingCount;
 102
 103     /** If a dmaAction is in progress. */
 104     int actionInProgress;
 105
 106     /** If we need to drain, keep the drain event around until we're done
 107      * here.*/
 108     Event *drainEvent;
 109
 110     /** time to wait between sending another packet, increases as NACKs are
 111      * recived, decreases as responses are recived. */
 112     Tick backoffTime;
 113
 114     /** If the port is currently waiting for a retry before it can send whatever
 115      * it is that it's sending. */
 116     bool inRetry;
 117
 118     virtual bool recvTiming(PacketPtr pkt);
 119     virtual Tick recvAtomic(PacketPtr pkt)
 120     { panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN }
 121     virtual void recvFunctional(PacketPtr pkt)
 122     { panic("dma port shouldn't be used for pio access."); }
 123
 124     virtual void recvStatusChange(Status status)
 125     { ; }
 126
 127     virtual void recvRetry() ;
 128
 129     virtual void getDeviceAddressRanges(AddrRangeList &resp,
 130                                         AddrRangeList &snoop)
 131     { resp.clear(); snoop.clear(); }
 132
 133     void queueDma(PacketPtr pkt, bool front = false);
 134     void sendDma();
 135
 136     /** event to give us a kick every time we backoff time is reached. */
 137     EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
 138
 139   public:
 140     DmaPort(DmaDevice *dev, System *s);
 141
 142     void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
 143                    uint8_t *data = NULL);
 144
 145     bool dmaPending() { return pendingCount > 0; }
 146
 147     int cacheBlockSize() { return peerBlockSize(); }
 148     unsigned int drain(Event *de);
 149 };
 150
 151 /**
 152  * This device is the base class which all devices senstive to an address range
 153  * inherit from. There are three pure virtual functions which all devices must
 154  * implement addressRanges(), read(), and write(). The magic do choose which
 155  * mode we are in, etc is handled by the PioPort so the device doesn't have to
 156  * bother.
 157  */
 158 class PioDevice : public MemObject
 159 {
 160   protected:
 161
 162     /** The platform we are in. This is used to decide what type of memory
 163      * transaction we should perform. */
 164     Platform *platform;
 165
 166     System *sys;
 167
 168     /** The pioPort that handles the requests for us and provides us requests
 169      * that it sees. */
 170     PioPort *pioPort;
 171
 172     virtual void addressRanges(AddrRangeList &range_list) = 0;
 173
 174     /** Pure virtual function that the device must implement. Called
 175      * when a read command is recieved by the port.
 176      * @param pkt Packet describing this request
 177      * @return number of ticks it took to complete
 178      */
 179     virtual Tick read(PacketPtr pkt) = 0;
 180
 181     /** Pure virtual function that the device must implement. Called when a
 182      * write command is recieved by the port.
 183      * @param pkt Packet describing this request
 184      * @return number of ticks it took to complete
 185      */
 186     virtual Tick write(PacketPtr pkt) = 0;
 187
 188   public:
 189     /** Params struct which is extended through each device based on
 190      * the parameters it needs. Since we are re-writing everything, we
 191      * might as well start from the bottom this time. */
 192     struct Params
 193     {
 194         std::string name;
 195         Platform *platform;
 196         System *system;
 197     };
 198
 199   protected:
 200     Params *_params;
 201
 202   public:
 203     const Params *params() const { return _params; }
 204
 205     PioDevice(Params *p)
 206               : MemObject(p->name),  platform(p->platform), sys(p->system),
 207               pioPort(NULL), _params(p)
 208               {}
 209
 210     virtual ~PioDevice();
 211
 212     virtual void init();
 213
 214     virtual unsigned int drain(Event *de);
 215
 216     virtual Port *getPort(const std::string &if_name, int idx = -1)
 217     {
 218         if (if_name == "pio") {
 219             if (pioPort != NULL)
 220                 panic("pio port already connected to.");
 221             pioPort = new PioPort(this, sys);
 222             return pioPort;
 223         } else
 224             return NULL;
 225     }
 226     friend class PioPort;
 227
 228 };
 229
 230 class BasicPioDevice : public PioDevice
 231 {
 232   public:
 233     struct Params :  public PioDevice::Params
 234     {
 235         Addr pio_addr;
 236         Tick pio_delay;
 237     };
 238
 239   protected:
 240     /** Address that the device listens to. */
 241     Addr pioAddr;
 242
 243     /** Size that the device's address range. */
 244     Addr pioSize;
 245
 246     /** Delay that the device experinces on an access. */
 247     Tick pioDelay;
 248
 249   public:
 250     BasicPioDevice(Params *p)
 251         : PioDevice(p), pioAddr(p->pio_addr), pioSize(0),
 252           pioDelay(p->pio_delay)
 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   public:
 265     struct Params :  public PioDevice::Params
 266     {
 267         Tick min_backoff_delay;
 268         Tick max_backoff_delay;
 269     };
 270
 271    protected:
 272     DmaPort *dmaPort;
 273     Tick minBackoffDelay;
 274     Tick maxBackoffDelay;
 275
 276   public:
 277     DmaDevice(Params *p);
 278     virtual ~DmaDevice();
 279
 280     void dmaWrite(Addr addr, int size, Event *event, uint8_t *data)
 281     {
 282         dmaPort->dmaAction(MemCmd::WriteInvalidateReq,
 283                            addr, size, event, data);
 284     }
 285
 286     void dmaRead(Addr addr, int size, Event *event, uint8_t *data)
 287     {
 288         dmaPort->dmaAction(MemCmd::ReadReq, addr, size, event, data);
 289     }
 290
 291     bool dmaPending() { return dmaPort->dmaPending(); }
 292
 293     virtual unsigned int drain(Event *de);
 294
 295     int cacheBlockSize() { return dmaPort->cacheBlockSize(); }
 296
 297     virtual Port *getPort(const std::string &if_name, int idx = -1)
 298     {
 299         if (if_name == "pio") {
 300             if (pioPort != NULL)
 301                 panic("pio port already connected to.");
 302             pioPort = new PioPort(this, sys);
 303             return pioPort;
 304         } else if (if_name == "dma") {
 305             if (dmaPort != NULL)
 306                 panic("dma port already connected to.");
 307             dmaPort = new DmaPort(this, sys);
 308             return dmaPort;
 309         } else
 310             return NULL;
 311     }
 312
 313     friend class DmaPort;
 314 };
 315
 316
 317 #endif // __DEV_IO_DEVICE_HH__