packet_queue.hh revision 8948
12914SN/A/* 28856SN/A * Copyright (c) 2012 ARM Limited 38856SN/A * All rights reserved. 48856SN/A * 58856SN/A * The license below extends only to copyright in the software and shall 68856SN/A * not be construed as granting a license to any other intellectual 78856SN/A * property including but not limited to intellectual property relating 88856SN/A * to a hardware implementation of the functionality of the software 98856SN/A * licensed hereunder. You may use the software subject to the license 108856SN/A * terms below provided that you ensure that this notice is replicated 118856SN/A * unmodified and in its entirety in all distributions of the software, 128856SN/A * modified or unmodified, in source code or in binary form. 138856SN/A * 142914SN/A * Copyright (c) 2006 The Regents of The University of Michigan 152914SN/A * All rights reserved. 162914SN/A * 172914SN/A * Redistribution and use in source and binary forms, with or without 182914SN/A * modification, are permitted provided that the following conditions are 192914SN/A * met: redistributions of source code must retain the above copyright 202914SN/A * notice, this list of conditions and the following disclaimer; 212914SN/A * redistributions in binary form must reproduce the above copyright 222914SN/A * notice, this list of conditions and the following disclaimer in the 232914SN/A * documentation and/or other materials provided with the distribution; 242914SN/A * neither the name of the copyright holders nor the names of its 252914SN/A * contributors may be used to endorse or promote products derived from 262914SN/A * this software without specific prior written permission. 272914SN/A * 282914SN/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 292914SN/A * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 302914SN/A * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 312914SN/A * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 322914SN/A * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 332914SN/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 342914SN/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 352914SN/A * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 362914SN/A * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 372914SN/A * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 382914SN/A * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 392914SN/A * 402914SN/A * Authors: Ali Saidi 418856SN/A * Andreas Hansson 422914SN/A */ 432914SN/A 448914Sandreas.hansson@arm.com#ifndef __MEM_PACKET_QUEUE_HH__ 458914Sandreas.hansson@arm.com#define __MEM_PACKET_QUEUE_HH__ 463091SN/A 472914SN/A/** 482914SN/A * @file 498914Sandreas.hansson@arm.com * Declaration of a simple PacketQueue that is associated with 508914Sandreas.hansson@arm.com * a port on which it attempts to send packets according to the time 518914Sandreas.hansson@arm.com * stamp given to them at insertion. The packet queue is responsible 528914Sandreas.hansson@arm.com * for the flow control of the port, but relies on the module 538914Sandreas.hansson@arm.com * notifying the queue when a transfer ends. 542914SN/A */ 552914SN/A 568229SN/A#include <list> 578229SN/A 582914SN/A#include "mem/port.hh" 592914SN/A#include "sim/eventq.hh" 602914SN/A 613091SN/A/** 628914Sandreas.hansson@arm.com * A packet queue is a class that holds deferred packets and later 638914Sandreas.hansson@arm.com * sends them using the associated slave port or master port. 643091SN/A */ 658914Sandreas.hansson@arm.comclass PacketQueue 662914SN/A{ 678914Sandreas.hansson@arm.com private: 684490SN/A /** A deferred packet, buffered to transmit later. */ 694490SN/A class DeferredPacket { 704490SN/A public: 714490SN/A Tick tick; ///< The tick when the packet is ready to transmit 724490SN/A PacketPtr pkt; ///< Pointer to the packet to transmit 738948Sandreas.hansson@arm.com bool sendAsSnoop; ///< Should it be sent as a snoop or not 748948Sandreas.hansson@arm.com DeferredPacket(Tick t, PacketPtr p, bool send_as_snoop) 758948Sandreas.hansson@arm.com : tick(t), pkt(p), sendAsSnoop(send_as_snoop) 764490SN/A {} 774490SN/A }; 784490SN/A 794490SN/A typedef std::list<DeferredPacket> DeferredPacketList; 804490SN/A typedef std::list<DeferredPacket>::iterator DeferredPacketIterator; 814490SN/A 823090SN/A /** A list of outgoing timing response packets that haven't been 833090SN/A * serviced yet. */ 844490SN/A DeferredPacketList transmitList; 854490SN/A 868914Sandreas.hansson@arm.com /** The manager which is used for the event queue */ 878914Sandreas.hansson@arm.com EventManager& em; 888914Sandreas.hansson@arm.com 898856SN/A /** Label to use for print request packets label stack. */ 908856SN/A const std::string label; 918856SN/A 924490SN/A /** This function attempts to send deferred packets. Scheduled to 934490SN/A * be called in the future via SendEvent. */ 944490SN/A void processSendEvent(); 953091SN/A 962914SN/A /** 978914Sandreas.hansson@arm.com * Event used to call processSendEvent. 983403SN/A **/ 998914Sandreas.hansson@arm.com EventWrapper<PacketQueue, &PacketQueue::processSendEvent> sendEvent; 1002914SN/A 1012914SN/A /** If we need to drain, keep the drain event around until we're done 1022914SN/A * here.*/ 1032914SN/A Event *drainEvent; 1042914SN/A 1058914Sandreas.hansson@arm.com protected: 1068914Sandreas.hansson@arm.com 1078914Sandreas.hansson@arm.com /** The port used to send the packets. */ 1088914Sandreas.hansson@arm.com Port& port; 1098914Sandreas.hansson@arm.com 1104492SN/A /** Remember whether we're awaiting a retry from the bus. */ 1114492SN/A bool waitingOnRetry; 1124492SN/A 1134492SN/A /** Check whether we have a packet ready to go on the transmit list. */ 1144492SN/A bool deferredPacketReady() 1157823SN/A { return !transmitList.empty() && transmitList.front().tick <= curTick(); } 1164492SN/A 1174871SN/A Tick deferredPacketReadyTime() 1184666SN/A { return transmitList.empty() ? MaxTick : transmitList.front().tick; } 1194666SN/A 1208708SN/A /** 1218914Sandreas.hansson@arm.com * Attempt to send the packet at the head of the transmit 1228914Sandreas.hansson@arm.com * list. Caller must guarantee that the list is non-empty and that 1238914Sandreas.hansson@arm.com * the head packet is scheduled for curTick() (or earlier). Note 1248914Sandreas.hansson@arm.com * that a subclass of the PacketQueue can override this method and 1258914Sandreas.hansson@arm.com * thus change the behaviour (as done by the cache). 1264492SN/A */ 1278856SN/A virtual void sendDeferredPacket(); 1288856SN/A 1298856SN/A /** 1308856SN/A * Attempt to send the packet at the front of the transmit list, 1318856SN/A * and set waitingOnRetry accordingly. The packet is temporarily 1328856SN/A * taken off the list, but put back at the front if not 1338856SN/A * successfully sent. 1348856SN/A */ 1358856SN/A void trySendTiming(); 1368856SN/A 1378856SN/A /** 1388856SN/A * Based on the transmit list, or the provided time, schedule a 1398856SN/A * send event if there are packets to send. If we are idle and 1408856SN/A * asked to drain then do so. 1418856SN/A * 1428856SN/A * @param time an alternative time for the next send event 1438856SN/A */ 1448856SN/A void scheduleSend(Tick time = MaxTick); 1452914SN/A 1463091SN/A /** 1478711SN/A * Simple ports are generally used as slave ports (i.e. the 1488711SN/A * respond to requests) and thus do not expect to receive any 1498711SN/A * range changes (as the neighbouring port has a master role and 1508711SN/A * do not have any address ranges. A subclass can override the 1518711SN/A * default behaviuor if needed. 1528711SN/A */ 1538711SN/A virtual void recvRangeChange() { } 1543091SN/A 1558914Sandreas.hansson@arm.com public: 1563091SN/A 1578914Sandreas.hansson@arm.com /** 1588914Sandreas.hansson@arm.com * Create a packet queue, linked to an event manager, a port used 1598914Sandreas.hansson@arm.com * to send the packets, and potentially give it a label that will 1608914Sandreas.hansson@arm.com * be used for functional print request packets. 1618914Sandreas.hansson@arm.com * 1628914Sandreas.hansson@arm.com * @param _em Event manager used for scheduling this queue 1638914Sandreas.hansson@arm.com * @param _port Port used to send the packets 1648914Sandreas.hansson@arm.com * @param _label Label to push on the label stack for print request packets 1658914Sandreas.hansson@arm.com */ 1668914Sandreas.hansson@arm.com PacketQueue(EventManager& _em, Port& _port, 1678914Sandreas.hansson@arm.com const std::string _label = "PacketQueue"); 1688914Sandreas.hansson@arm.com 1698914Sandreas.hansson@arm.com /** 1708914Sandreas.hansson@arm.com * Virtual desctructor since the class may be used as a base class. 1718914Sandreas.hansson@arm.com */ 1728914Sandreas.hansson@arm.com virtual ~PacketQueue(); 1738914Sandreas.hansson@arm.com 1748914Sandreas.hansson@arm.com /** 1758914Sandreas.hansson@arm.com * Provide a name to simplify debugging. Base it on the port. 1768914Sandreas.hansson@arm.com * 1778914Sandreas.hansson@arm.com * @return A complete name, appended to module and port 1788914Sandreas.hansson@arm.com */ 1798914Sandreas.hansson@arm.com const std::string name() const { return port.name() + "-queue"; } 1804490SN/A 1818856SN/A /** Check the list of buffered packets against the supplied 1828856SN/A * functional request. */ 1838856SN/A bool checkFunctional(PacketPtr pkt); 1848856SN/A 1858914Sandreas.hansson@arm.com /** 1868914Sandreas.hansson@arm.com * Schedule a send even if not already waiting for a retry. If the 1878914Sandreas.hansson@arm.com * requested time is before an already scheduled send event it 1888914Sandreas.hansson@arm.com * will be rescheduled. 1898914Sandreas.hansson@arm.com * 1908914Sandreas.hansson@arm.com * @param when 1918914Sandreas.hansson@arm.com */ 1928914Sandreas.hansson@arm.com void schedSendEvent(Tick when); 1938914Sandreas.hansson@arm.com 1948914Sandreas.hansson@arm.com /** 1958914Sandreas.hansson@arm.com * Add a packet to the transmit list, and ensure that a 1968914Sandreas.hansson@arm.com * processSendEvent is called in the future. 1978914Sandreas.hansson@arm.com * 1988914Sandreas.hansson@arm.com * @param pkt Packet to send 1998914Sandreas.hansson@arm.com * @param when Absolute time (in ticks) to send packet 2008948Sandreas.hansson@arm.com * @param send_as_snoop Send the packet as a snoop or not 2018914Sandreas.hansson@arm.com */ 2028948Sandreas.hansson@arm.com void schedSendTiming(PacketPtr pkt, Tick when, bool send_as_snoop = false); 2038914Sandreas.hansson@arm.com 2048914Sandreas.hansson@arm.com /** 2058914Sandreas.hansson@arm.com * Used by a port to notify the queue that a retry was received 2068914Sandreas.hansson@arm.com * and that the queue can proceed and retry sending the packet 2078914Sandreas.hansson@arm.com * that caused the wait. 2088914Sandreas.hansson@arm.com */ 2098914Sandreas.hansson@arm.com void retry(); 2108914Sandreas.hansson@arm.com 2118914Sandreas.hansson@arm.com /** 2128914Sandreas.hansson@arm.com * Hook for draining the packet queue. 2138914Sandreas.hansson@arm.com * 2148914Sandreas.hansson@arm.com * @param de An event which is used to signal back to the caller 2158914Sandreas.hansson@arm.com * @return A number indicating how many times process will be called 2168914Sandreas.hansson@arm.com */ 2172914SN/A unsigned int drain(Event *de); 2182914SN/A}; 2192914SN/A 2208948Sandreas.hansson@arm.com#endif // __MEM_PACKET_QUEUE_HH__ 221