packet_queue.hh revision 8914
11689SN/A/* 27598Sminkyu.jeong@arm.com * Copyright (c) 2012 ARM Limited 37598Sminkyu.jeong@arm.com * All rights reserved. 47598Sminkyu.jeong@arm.com * 57598Sminkyu.jeong@arm.com * The license below extends only to copyright in the software and shall 67598Sminkyu.jeong@arm.com * not be construed as granting a license to any other intellectual 77598Sminkyu.jeong@arm.com * property including but not limited to intellectual property relating 87598Sminkyu.jeong@arm.com * to a hardware implementation of the functionality of the software 97598Sminkyu.jeong@arm.com * licensed hereunder. You may use the software subject to the license 107598Sminkyu.jeong@arm.com * terms below provided that you ensure that this notice is replicated 117598Sminkyu.jeong@arm.com * unmodified and in its entirety in all distributions of the software, 127598Sminkyu.jeong@arm.com * modified or unmodified, in source code or in binary form. 137598Sminkyu.jeong@arm.com * 142326SN/A * Copyright (c) 2006 The Regents of The University of Michigan 151689SN/A * All rights reserved. 161689SN/A * 171689SN/A * Redistribution and use in source and binary forms, with or without 181689SN/A * modification, are permitted provided that the following conditions are 191689SN/A * met: redistributions of source code must retain the above copyright 201689SN/A * notice, this list of conditions and the following disclaimer; 211689SN/A * redistributions in binary form must reproduce the above copyright 221689SN/A * notice, this list of conditions and the following disclaimer in the 231689SN/A * documentation and/or other materials provided with the distribution; 241689SN/A * neither the name of the copyright holders nor the names of its 251689SN/A * contributors may be used to endorse or promote products derived from 261689SN/A * this software without specific prior written permission. 271689SN/A * 281689SN/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 291689SN/A * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 301689SN/A * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 311689SN/A * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 321689SN/A * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 331689SN/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 341689SN/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 351689SN/A * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 361689SN/A * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 371689SN/A * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 381689SN/A * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 392665Ssaidi@eecs.umich.edu * 402665Ssaidi@eecs.umich.edu * Authors: Ali Saidi 411689SN/A * Andreas Hansson 421689SN/A */ 431060SN/A 441060SN/A#ifndef __MEM_PACKET_QUEUE_HH__ 451689SN/A#define __MEM_PACKET_QUEUE_HH__ 461060SN/A 471060SN/A/** 481060SN/A * @file 497813Ssteve.reinhardt@amd.com * Declaration of a simple PacketQueue that is associated with 506658Snate@binkert.org * a port on which it attempts to send packets according to the time 512292SN/A * stamp given to them at insertion. The packet queue is responsible 521717SN/A * for the flow control of the port, but relies on the module 535529Snate@binkert.org * notifying the queue when a transfer ends. 541060SN/A */ 556221Snate@binkert.org 566221Snate@binkert.org#include <list> 571681SN/A 585529Snate@binkert.org#include "mem/port.hh" 592873Sktlim@umich.edu#include "sim/eventq.hh" 604329Sktlim@umich.edu 614329Sktlim@umich.edu/** 624329Sktlim@umich.edu * A packet queue is a class that holds deferred packets and later 632292SN/A * sends them using the associated slave port or master port. 642292SN/A */ 652292SN/Aclass PacketQueue 662292SN/A{ 672820Sktlim@umich.edu private: 682292SN/A /** A deferred packet, buffered to transmit later. */ 692820Sktlim@umich.edu class DeferredPacket { 702820Sktlim@umich.edu public: 715529Snate@binkert.org Tick tick; ///< The tick when the packet is ready to transmit 722307SN/A PacketPtr pkt; ///< Pointer to the packet to transmit 731060SN/A DeferredPacket(Tick t, PacketPtr p) 742292SN/A : tick(t), pkt(p) 752292SN/A {} 762292SN/A }; 771060SN/A 781060SN/A typedef std::list<DeferredPacket> DeferredPacketList; 791060SN/A typedef std::list<DeferredPacket>::iterator DeferredPacketIterator; 801060SN/A 811060SN/A /** A list of outgoing timing response packets that haven't been 821060SN/A * serviced yet. */ 831681SN/A DeferredPacketList transmitList; 846221Snate@binkert.org 856221Snate@binkert.org /** The manager which is used for the event queue */ 866221Snate@binkert.org EventManager& em; 876221Snate@binkert.org 882292SN/A /** Label to use for print request packets label stack. */ 892292SN/A const std::string label; 902820Sktlim@umich.edu 912820Sktlim@umich.edu /** This function attempts to send deferred packets. Scheduled to 922292SN/A * be called in the future via SendEvent. */ 932292SN/A void processSendEvent(); 942820Sktlim@umich.edu 952820Sktlim@umich.edu /** 962292SN/A * Event used to call processSendEvent. 972292SN/A **/ 982292SN/A EventWrapper<PacketQueue, &PacketQueue::processSendEvent> sendEvent; 992292SN/A 1002292SN/A /** If we need to drain, keep the drain event around until we're done 1012292SN/A * here.*/ 1022292SN/A Event *drainEvent; 1032292SN/A 1041060SN/A protected: 1051060SN/A 1061681SN/A /** The port used to send the packets. */ 1071062SN/A Port& port; 1082292SN/A 1091062SN/A /** Remember whether we're awaiting a retry from the bus. */ 1102301SN/A bool waitingOnRetry; 1112301SN/A 1121062SN/A /** Check whether we have a packet ready to go on the transmit list. */ 1132727Sktlim@umich.edu bool deferredPacketReady() 1141062SN/A { return !transmitList.empty() && transmitList.front().tick <= curTick(); } 1151062SN/A 1161062SN/A Tick deferredPacketReadyTime() 1171062SN/A { return transmitList.empty() ? MaxTick : transmitList.front().tick; } 1181062SN/A 1191062SN/A /** 1201062SN/A * Attempt to send the packet at the head of the transmit 1211062SN/A * list. Caller must guarantee that the list is non-empty and that 1221062SN/A * the head packet is scheduled for curTick() (or earlier). Note 1231062SN/A * that a subclass of the PacketQueue can override this method and 1241062SN/A * thus change the behaviour (as done by the cache). 1251062SN/A */ 1261062SN/A virtual void sendDeferredPacket(); 1271062SN/A 1281062SN/A /** 1291062SN/A * Attempt to send the packet at the front of the transmit list, 1301062SN/A * and set waitingOnRetry accordingly. The packet is temporarily 1311062SN/A * taken off the list, but put back at the front if not 1321062SN/A * successfully sent. 1331062SN/A */ 1341062SN/A void trySendTiming(); 1351062SN/A 1361062SN/A /** 1371062SN/A * Based on the transmit list, or the provided time, schedule a 1381062SN/A * send event if there are packets to send. If we are idle and 1391062SN/A * asked to drain then do so. 1401062SN/A * 1411062SN/A * @param time an alternative time for the next send event 1421062SN/A */ 1431062SN/A void scheduleSend(Tick time = MaxTick); 1441062SN/A 1451062SN/A /** 1461062SN/A * Simple ports are generally used as slave ports (i.e. the 1471062SN/A * respond to requests) and thus do not expect to receive any 1481062SN/A * range changes (as the neighbouring port has a master role and 1491062SN/A * do not have any address ranges. A subclass can override the 1501062SN/A * default behaviuor if needed. 1511062SN/A */ 1521062SN/A virtual void recvRangeChange() { } 1531062SN/A 1541062SN/A public: 1552292SN/A 1562292SN/A /** 1572292SN/A * Create a packet queue, linked to an event manager, a port used 1582292SN/A * to send the packets, and potentially give it a label that will 1591062SN/A * be used for functional print request packets. 1601062SN/A * 1611062SN/A * @param _em Event manager used for scheduling this queue 1621062SN/A * @param _port Port used to send the packets 1631062SN/A * @param _label Label to push on the label stack for print request packets 1641062SN/A */ 1651062SN/A PacketQueue(EventManager& _em, Port& _port, 1662292SN/A const std::string _label = "PacketQueue"); 1672292SN/A 1682292SN/A /** 1692292SN/A * Virtual desctructor since the class may be used as a base class. 1702292SN/A */ 1712292SN/A virtual ~PacketQueue(); 1722292SN/A 1732292SN/A /** 1742292SN/A * Provide a name to simplify debugging. Base it on the port. 1752292SN/A * 1762301SN/A * @return A complete name, appended to module and port 1772727Sktlim@umich.edu */ 1782353SN/A const std::string name() const { return port.name() + "-queue"; } 1792727Sktlim@umich.edu 1802727Sktlim@umich.edu /** Check the list of buffered packets against the supplied 1812727Sktlim@umich.edu * functional request. */ 1826221Snate@binkert.org bool checkFunctional(PacketPtr pkt); 1832353SN/A 1842727Sktlim@umich.edu /** 1852727Sktlim@umich.edu * Schedule a send even if not already waiting for a retry. If the 1862727Sktlim@umich.edu * requested time is before an already scheduled send event it 1872727Sktlim@umich.edu * will be rescheduled. 1882353SN/A * 1892727Sktlim@umich.edu * @param when 1902727Sktlim@umich.edu */ 1912727Sktlim@umich.edu void schedSendEvent(Tick when); 1926221Snate@binkert.org 1932301SN/A /** 1942301SN/A * Add a packet to the transmit list, and ensure that a 1952727Sktlim@umich.edu * processSendEvent is called in the future. 1962301SN/A * 1972727Sktlim@umich.edu * @param pkt Packet to send 1986221Snate@binkert.org * @param when Absolute time (in ticks) to send packet 1992301SN/A */ 2002301SN/A void schedSendTiming(PacketPtr pkt, Tick when); 2012727Sktlim@umich.edu 2022301SN/A /** 2032727Sktlim@umich.edu * Used by a port to notify the queue that a retry was received 2046221Snate@binkert.org * and that the queue can proceed and retry sending the packet 2052301SN/A * that caused the wait. 2062301SN/A */ 2072727Sktlim@umich.edu void retry(); 2082301SN/A 2092727Sktlim@umich.edu /** 2106221Snate@binkert.org * Hook for draining the packet queue. 2112301SN/A * 2122301SN/A * @param de An event which is used to signal back to the caller 2132727Sktlim@umich.edu * @return A number indicating how many times process will be called 2142301SN/A */ 2152301SN/A unsigned int drain(Event *de); 2162301SN/A}; 2172301SN/A 2182727Sktlim@umich.edu#endif // __MEM_TPORT_HH__ 2192727Sktlim@umich.edu