/* * 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 #include #include #include "base/range.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 bits */ int width; /** the next tick at which the bus will be idle */ Tick tickNextIdle; static const int defaultId = -1; struct DevMap { int portId; Range range; }; std::vector portList; AddrRangeList defaultRange; std::vector portSnoopList; std::vector snoopCallbacks; /** Function called by the port when the bus is recieving a Timing transaction.*/ bool recvTiming(Packet *pkt); /** Function called by the port when the bus is recieving a Atomic transaction.*/ Tick recvAtomic(Packet *pkt); /** Function called by the port when the bus is recieving a Functional transaction.*/ void recvFunctional(Packet *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); /** Finds the port a packet should be sent to. If the bus is blocked, no port * is returned. * @param pkt Packet to find a destination port for. * @param id Id of the port this packet was received from * (to prevent loops) */ Port *findDestPort(PacketPtr pkt, 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 findSnoopPorts(Addr addr, int id); /** Snoop all relevant ports atomicly. */ void atomicSnoop(Packet *pkt); /** Snoop for NACK and Blocked in phase 1 * @return True if succeds. */ bool timingSnoopPhase1(Packet *pkt); /** @todo Don't need to commit all snoops just those that need it *(register somehow). */ /** Commit all snoops now that we know if any of them would have blocked. */ void timingSnoopPhase2(Packet *pkt); /** 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); /** Declaration of the buses port type, one will be instantiated for each of the interfaces connecting to the bus. */ class BusPort : public Port { /** 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(_bus), id(_id) { } protected: /** When reciving a timing request from the peer port (at id), pass it to the bus. */ virtual bool recvTiming(Packet *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(Packet *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(Packet *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; void occupyBus(int numCycles); Port * retryingPort; /** An array of pointers to the peer port interfaces connected to this bus.*/ std::vector interfaces; /** An array of pointers to ports that retry should be called on because the * original send failed for whatever reason.*/ std::list retryList; void addToRetryList(Port * port) { if (!retryingPort) { // The device wasn't retrying a packet, or wasn't at an appropriate // time. retryList.push_back(port); } else { // The device was retrying a packet. It didn't work, so we'll leave // it at the head of the retry list. retryingPort = 0; // We shouldn't be receiving a packet from one port when a different // one is retrying. assert(port == retryingPort); } } /** Port that handles requests that don't match any of the interfaces.*/ Port *defaultPort; 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(); Bus(const std::string &n, int bus_id, int _clock, int _width) : MemObject(n), busId(bus_id), clock(_clock), width(_width), tickNextIdle(0), busIdle(this), retryingPort(0), defaultPort(NULL) { //Both the width and clock period must be positive assert(width); assert(clock); } }; #endif //__MEM_BUS_HH__