gem5/src/dev/io_device.hh
2009-06-04 23:21:12 -07:00

311 lines
9.3 KiB
C++

/*
* Copyright (c) 2004-2005 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Ali Saidi
* Nathan Binkert
*/
#ifndef __DEV_IO_DEVICE_HH__
#define __DEV_IO_DEVICE_HH__
#include "base/fast_alloc.hh"
#include "mem/mem_object.hh"
#include "mem/packet.hh"
#include "mem/tport.hh"
#include "params/BasicPioDevice.hh"
#include "params/DmaDevice.hh"
#include "params/PioDevice.hh"
#include "sim/sim_object.hh"
class Event;
class Platform;
class PioDevice;
class DmaDevice;
class System;
/**
* The PioPort class is a programmed i/o port that all devices that are
* sensitive to an address range use. The port takes all the memory
* access types and roles them into one read() and write() call that the device
* must respond to. The device must also provide the addressRanges() function
* with which it returns the address ranges it is interested in.
*/
class PioPort : public SimpleTimingPort
{
protected:
/** The device that this port serves. */
PioDevice *device;
virtual Tick recvAtomic(PacketPtr pkt);
virtual void getDeviceAddressRanges(AddrRangeList &resp,
bool &snoop);
public:
PioPort(PioDevice *dev, System *s, std::string pname = "-pioport");
};
class DmaPort : public Port
{
protected:
struct DmaReqState : public Packet::SenderState, public FastAlloc
{
/** Event to call on the device when this transaction (all packets)
* complete. */
Event *completionEvent;
/** Where we came from for some sanity checking. */
Port *outPort;
/** Total number of bytes that this transaction involves. */
Addr totBytes;
/** Number of bytes that have been acked for this transaction. */
Addr numBytes;
/** Amount to delay completion of dma by */
Tick delay;
DmaReqState(Event *ce, Port *p, Addr tb, Tick _delay)
: completionEvent(ce), outPort(p), totBytes(tb), numBytes(0),
delay(_delay)
{}
};
DmaDevice *device;
std::list<PacketPtr> transmitList;
/** The system that device/port are in. This is used to select which mode
* we are currently operating in. */
System *sys;
/** Number of outstanding packets the dma port has. */
int pendingCount;
/** If a dmaAction is in progress. */
int actionInProgress;
/** If we need to drain, keep the drain event around until we're done
* here.*/
Event *drainEvent;
/** time to wait between sending another packet, increases as NACKs are
* recived, decreases as responses are recived. */
Tick backoffTime;
/** If the port is currently waiting for a retry before it can send whatever
* it is that it's sending. */
bool inRetry;
virtual bool recvTiming(PacketPtr pkt);
virtual Tick recvAtomic(PacketPtr pkt)
{ panic("dma port shouldn't be used for pio access."); M5_DUMMY_RETURN }
virtual void recvFunctional(PacketPtr pkt)
{ panic("dma port shouldn't be used for pio access."); }
virtual void recvStatusChange(Status status)
{ ; }
virtual void recvRetry() ;
virtual void getDeviceAddressRanges(AddrRangeList &resp,
bool &snoop)
{ resp.clear(); snoop = false; }
void queueDma(PacketPtr pkt, bool front = false);
void sendDma();
/** event to give us a kick every time we backoff time is reached. */
EventWrapper<DmaPort, &DmaPort::sendDma> backoffEvent;
public:
DmaPort(DmaDevice *dev, System *s);
void dmaAction(Packet::Command cmd, Addr addr, int size, Event *event,
uint8_t *data, Tick delay);
bool dmaPending() { return pendingCount > 0; }
unsigned cacheBlockSize() const { return peerBlockSize(); }
unsigned int drain(Event *de);
};
/**
* This device is the base class which all devices senstive to an address range
* inherit from. There are three pure virtual functions which all devices must
* implement addressRanges(), read(), and write(). The magic do choose which
* mode we are in, etc is handled by the PioPort so the device doesn't have to
* bother.
*/
class PioDevice : public MemObject
{
protected:
/** The platform we are in. This is used to decide what type of memory
* transaction we should perform. */
Platform *platform;
System *sys;
/** The pioPort that handles the requests for us and provides us requests
* that it sees. */
PioPort *pioPort;
virtual void addressRanges(AddrRangeList &range_list) = 0;
/** Pure virtual function that the device must implement. Called
* when a read command is recieved by the port.
* @param pkt Packet describing this request
* @return number of ticks it took to complete
*/
virtual Tick read(PacketPtr pkt) = 0;
/** Pure virtual function that the device must implement. Called when a
* write command is recieved by the port.
* @param pkt Packet describing this request
* @return number of ticks it took to complete
*/
virtual Tick write(PacketPtr pkt) = 0;
public:
typedef PioDeviceParams Params;
PioDevice(const Params *p);
virtual ~PioDevice();
const Params *
params() const
{
return dynamic_cast<const Params *>(_params);
}
virtual void init();
virtual unsigned int drain(Event *de);
virtual Port *getPort(const std::string &if_name, int idx = -1)
{
if (if_name == "pio") {
if (pioPort != NULL)
fatal("%s: pio port already connected to %s",
name(), pioPort->getPeer()->name());
pioPort = new PioPort(this, sys);
return pioPort;
} else
return NULL;
}
friend class PioPort;
};
class BasicPioDevice : public PioDevice
{
protected:
/** Address that the device listens to. */
Addr pioAddr;
/** Size that the device's address range. */
Addr pioSize;
/** Delay that the device experinces on an access. */
Tick pioDelay;
public:
typedef BasicPioDeviceParams Params;
BasicPioDevice(const Params *p);
const Params *
params() const
{
return dynamic_cast<const Params *>(_params);
}
/** return the address ranges that this device responds to.
* @param range_list range list to populate with ranges
*/
void addressRanges(AddrRangeList &range_list);
};
class DmaDevice : public PioDevice
{
protected:
DmaPort *dmaPort;
Tick minBackoffDelay;
Tick maxBackoffDelay;
public:
typedef DmaDeviceParams Params;
DmaDevice(const Params *p);
virtual ~DmaDevice();
const Params *
params() const
{
return dynamic_cast<const Params *>(_params);
}
void dmaWrite(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
{
dmaPort->dmaAction(MemCmd::WriteReq, addr, size, event, data, delay);
}
void dmaRead(Addr addr, int size, Event *event, uint8_t *data, Tick delay = 0)
{
dmaPort->dmaAction(MemCmd::ReadReq, addr, size, event, data, delay);
}
bool dmaPending() { return dmaPort->dmaPending(); }
virtual unsigned int drain(Event *de);
unsigned cacheBlockSize() const { return dmaPort->cacheBlockSize(); }
virtual Port *getPort(const std::string &if_name, int idx = -1)
{
if (if_name == "pio") {
if (pioPort != NULL)
fatal("%s: pio port already connected to %s",
name(), pioPort->getPeer()->name());
pioPort = new PioPort(this, sys);
return pioPort;
} else if (if_name == "dma") {
if (dmaPort != NULL)
fatal("%s: dma port already connected to %s",
name(), dmaPort->getPeer()->name());
dmaPort = new DmaPort(this, sys);
return dmaPort;
} else
return NULL;
}
friend class DmaPort;
};
#endif // __DEV_IO_DEVICE_HH__