/*
* Copyright (c) 2002-2005 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: Ron Dreslinski
* Ali Saidi
*/
/**
* @file
* Declaration of a bus object.
*/
#ifndef __MEM_BUS_HH__
#define __MEM_BUS_HH__
#include <string>
#include <list>
#include <inttypes.h>
#include "base/range.hh"
#include "base/range_map.hh"
#include "mem/mem_object.hh"
#include "mem/packet.hh"
#include "mem/port.hh"
#include "mem/request.hh"
#include "sim/eventq.hh"
class Bus : public MemObject
{
/** a globally unique id for this bus. */
int busId;
/** the clock speed for the bus */
int clock;
/** the width of the bus in bytes */
int width;
/** the next tick at which the bus will be idle */
Tick tickNextIdle;
Event * drainEvent;
static const int defaultId = -3; //Make it unique from Broadcast
struct DevMap {
int portId;
Range<Addr> range;
};
range_map<Addr, int> portMap;
AddrRangeList defaultRange;
std::vector<DevMap> portSnoopList;
/** Function called by the port when the bus is recieving a Timing
transaction.*/
bool recvTiming(PacketPtr pkt);
/** Function called by the port when the bus is recieving a Atomic
transaction.*/
Tick recvAtomic(PacketPtr pkt);
/** Function called by the port when the bus is recieving a Functional
transaction.*/
void recvFunctional(PacketPtr pkt);
/** Timing function called by port when it is once again able to process
* requests. */
void recvRetry(int id);
/** Function called by the port when the bus is recieving a status change.*/
void recvStatusChange(Port::Status status, int id);
/** Find which port connected to this bus (if any) should be given a packet
* with this address.
* @param addr Address to find port for.
* @param id Id of the port this packet was received from (to prevent
* loops)
* @return pointer to port that the packet should be sent out of.
*/
Port *findPort(Addr addr, int id);
/** Find all ports with a matching snoop range, except src port. Keep in mind
* that the ranges shouldn't overlap or you will get a double snoop to the same
* interface.and the cache will assert out.
* @param addr Address to find snoop prts for.
* @param id Id of the src port of the request to avoid calling snoop on src
* @return vector of IDs to snoop on
*/
std::vector<int> findSnoopPorts(Addr addr, int id);
/** Snoop all relevant ports atomicly. */
Tick atomicSnoop(PacketPtr pkt, Port* responder);
/** Snoop all relevant ports functionally. */
void functionalSnoop(PacketPtr pkt, Port *responder);
/** Call snoop on caches, be sure to set SNOOP_COMMIT bit if you want
* the snoop to happen
* @return True if succeds.
*/
bool timingSnoop(PacketPtr pkt, Port *responder);
/** Process address range request.
* @param resp addresses that we can respond to
* @param snoop addresses that we would like to snoop
* @param id ide of the busport that made the request.
*/
void addressRanges(AddrRangeList &resp, AddrRangeList &snoop, int id);
/** Occupy the bus with transmitting the packet pkt */
void occupyBus(PacketPtr pkt);
/** Declaration of the buses port type, one will be instantiated for each
of the interfaces connecting to the bus. */
class BusPort : public Port
{
bool _onRetryList;
/** A pointer to the bus to which this port belongs. */
Bus *bus;
/** A id to keep track of the intercafe ID this port is connected to. */
int id;
public:
/** Constructor for the BusPort.*/
BusPort(const std::string &_name, Bus *_bus, int _id)
: Port(_name, _bus), _onRetryList(false), bus(_bus), id(_id)
{ }
bool onRetryList()
{ return _onRetryList; }
void onRetryList(bool newVal)
{ _onRetryList = newVal; }
protected:
/** When reciving a timing request from the peer port (at id),
pass it to the bus. */
virtual bool recvTiming(PacketPtr pkt)
{ pkt->setSrc(id); return bus->recvTiming(pkt); }
/** When reciving a Atomic requestfrom the peer port (at id),
pass it to the bus. */
virtual Tick recvAtomic(PacketPtr pkt)
{ pkt->setSrc(id); return bus->recvAtomic(pkt); }
/** When reciving a Functional requestfrom the peer port (at id),
pass it to the bus. */
virtual void recvFunctional(PacketPtr pkt)
{ pkt->setSrc(id); bus->recvFunctional(pkt); }
/** When reciving a status changefrom the peer port (at id),
pass it to the bus. */
virtual void recvStatusChange(Status status)
{ bus->recvStatusChange(status, id); }
/** When reciving a retry from the peer port (at id),
pass it to the bus. */
virtual void recvRetry()
{ bus->recvRetry(id); }
// This should return all the 'owned' addresses that are
// downstream from this bus, yes? That is, the union of all
// the 'owned' address ranges of all the other interfaces on
// this bus...
virtual void getDeviceAddressRanges(AddrRangeList &resp,
AddrRangeList &snoop)
{ bus->addressRanges(resp, snoop, id); }
// Hack to make translating port work without changes
virtual int deviceBlockSize() { return 32; }
};
class BusFreeEvent : public Event
{
Bus * bus;
public:
BusFreeEvent(Bus * _bus);
void process();
const char *description();
};
BusFreeEvent busIdle;
bool inRetry;
/** An array of pointers to the peer port interfaces
connected to this bus.*/
std::vector<BusPort*> interfaces;
/** An array of pointers to ports that retry should be called on because the
* original send failed for whatever reason.*/
std::list<BusPort*> retryList;
void addToRetryList(BusPort * port)
{
if (!inRetry) {
// The device wasn't retrying a packet, or wasn't at an appropriate
// time.
assert(!port->onRetryList());
port->onRetryList(true);
retryList.push_back(port);
} else {
if (port->onRetryList()) {
// The device was retrying a packet. It didn't work, so we'll leave
// it at the head of the retry list.
assert(port == retryList.front());
inRetry = false;
}
else {
port->onRetryList(true);
retryList.push_back(port);
}
}
}
/** Port that handles requests that don't match any of the interfaces.*/
BusPort *defaultPort;
/** Has the user specified their own default responder? */
bool responderSet;
public:
/** A function used to return the port associated with this bus object. */
virtual Port *getPort(const std::string &if_name, int idx = -1);
virtual void init();
unsigned int drain(Event *de);
Bus(const std::string &n, int bus_id, int _clock, int _width,
bool responder_set)
: MemObject(n), busId(bus_id), clock(_clock), width(_width),
tickNextIdle(0), drainEvent(NULL), busIdle(this), inRetry(false),
defaultPort(NULL), responderSet(responder_set)
{
//Both the width and clock period must be positive
if (width <= 0)
fatal("Bus width must be positive\n");
if (clock <= 0)
fatal("Bus clock period must be positive\n");
}
};
#endif //__MEM_BUS_HH__