tport.hh revision 3349:fec4a86fa212
14434Ssaidi@eecs.umich.edu/* 24434Ssaidi@eecs.umich.edu * Copyright (c) 2006 The Regents of The University of Michigan 34434Ssaidi@eecs.umich.edu * All rights reserved. 44434Ssaidi@eecs.umich.edu * 54434Ssaidi@eecs.umich.edu * Redistribution and use in source and binary forms, with or without 64434Ssaidi@eecs.umich.edu * modification, are permitted provided that the following conditions are 74434Ssaidi@eecs.umich.edu * met: redistributions of source code must retain the above copyright 84434Ssaidi@eecs.umich.edu * notice, this list of conditions and the following disclaimer; 94434Ssaidi@eecs.umich.edu * redistributions in binary form must reproduce the above copyright 104434Ssaidi@eecs.umich.edu * notice, this list of conditions and the following disclaimer in the 114434Ssaidi@eecs.umich.edu * documentation and/or other materials provided with the distribution; 124434Ssaidi@eecs.umich.edu * neither the name of the copyright holders nor the names of its 134434Ssaidi@eecs.umich.edu * contributors may be used to endorse or promote products derived from 144434Ssaidi@eecs.umich.edu * this software without specific prior written permission. 154434Ssaidi@eecs.umich.edu * 164434Ssaidi@eecs.umich.edu * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 174434Ssaidi@eecs.umich.edu * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 184434Ssaidi@eecs.umich.edu * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 194434Ssaidi@eecs.umich.edu * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 204434Ssaidi@eecs.umich.edu * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 214434Ssaidi@eecs.umich.edu * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 224434Ssaidi@eecs.umich.edu * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 234434Ssaidi@eecs.umich.edu * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 244434Ssaidi@eecs.umich.edu * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 254434Ssaidi@eecs.umich.edu * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 264434Ssaidi@eecs.umich.edu * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 274434Ssaidi@eecs.umich.edu * 284434Ssaidi@eecs.umich.edu * Authors: Ali Saidi 294434Ssaidi@eecs.umich.edu */ 304434Ssaidi@eecs.umich.edu 314434Ssaidi@eecs.umich.edu#ifndef __MEM_TPORT_HH__ 324434Ssaidi@eecs.umich.edu#define __MEM_TPORT_HH__ 334434Ssaidi@eecs.umich.edu 344434Ssaidi@eecs.umich.edu/** 354434Ssaidi@eecs.umich.edu * @file 364434Ssaidi@eecs.umich.edu * 374434Ssaidi@eecs.umich.edu * Declaration of SimpleTimingPort. 388706Sandreas.hansson@arm.com */ 394434Ssaidi@eecs.umich.edu 404434Ssaidi@eecs.umich.edu#include "mem/port.hh" 414434Ssaidi@eecs.umich.edu#include "sim/eventq.hh" 424434Ssaidi@eecs.umich.edu#include <list> 434434Ssaidi@eecs.umich.edu#include <string> 444434Ssaidi@eecs.umich.edu 4514020Sgabeblack@google.com/** 464434Ssaidi@eecs.umich.edu * A simple port for interfacing objects that basically have only 474434Ssaidi@eecs.umich.edu * functional memory behavior (e.g. I/O devices) to the memory system. 486227Snate@binkert.org * Both timing and functional accesses are implemented in terms of 498737Skoansin.tan@gmail.com * atomic accesses. A derived port class thus only needs to provide 5014010Sgabeblack@google.com * recvAtomic() to support all memory access modes. 518852Sandreas.hansson@arm.com * 524434Ssaidi@eecs.umich.edu * The tricky part is handling recvTiming(), where the response must 534434Ssaidi@eecs.umich.edu * be scheduled separately via a later call to sendTiming(). This 544434Ssaidi@eecs.umich.edu * feature is handled by scheduling an internal event that calls 554434Ssaidi@eecs.umich.edu * sendTiming() after a delay, and optionally rescheduling the 564434Ssaidi@eecs.umich.edu * response if it is nacked. 574434Ssaidi@eecs.umich.edu */ 5814010Sgabeblack@google.comclass SimpleTimingPort : public Port 594434Ssaidi@eecs.umich.edu{ 604434Ssaidi@eecs.umich.edu protected: 614434Ssaidi@eecs.umich.edu /** A list of outgoing timing response packets that haven't been 62 * serviced yet. */ 63 std::list<PacketPtr> transmitList; 64 65 /** 66 * This class is used to implemented sendTiming() with a delay. When 67 * a delay is requested a new event is created. When the event time 68 * expires it attempts to send the packet. If it cannot, the packet 69 * is pushed onto the transmit list to be sent when recvRetry() is 70 * called. */ 71 class SendEvent : public Event 72 { 73 SimpleTimingPort *port; 74 PacketPtr packet; 75 76 public: 77 SendEvent(SimpleTimingPort *p, PacketPtr pkt, Tick t) 78 : Event(&mainEventQueue), port(p), packet(pkt) 79 { setFlags(AutoDelete); schedule(curTick + t); } 80 81 virtual void process(); 82 83 virtual const char *description() 84 { return "Future scheduled sendTiming event"; } 85 }; 86 87 88 /** Number of timing requests that are emulating the device timing before 89 * attempting to end up on the bus. 90 */ 91 int outTiming; 92 93 /** If we need to drain, keep the drain event around until we're done 94 * here.*/ 95 Event *drainEvent; 96 97 /** Schedule a sendTiming() event to be called in the future. */ 98 void sendTimingLater(PacketPtr pkt, Tick time) 99 { outTiming++; new SendEvent(this, pkt, time); } 100 101 /** This function is notification that the device should attempt to send a 102 * packet again. */ 103 virtual void recvRetry(); 104 105 /** Implemented using recvAtomic(). */ 106 void recvFunctional(PacketPtr pkt); 107 108 /** Implemented using recvAtomic(). */ 109 bool recvTiming(PacketPtr pkt); 110 111 /** 112 * Simple ports generally don't care about any status 113 * changes... can always override this in cases where that's not 114 * true. */ 115 virtual void recvStatusChange(Status status) { } 116 117 118 public: 119 120 SimpleTimingPort(std::string pname) 121 : Port(pname), outTiming(0), drainEvent(NULL) 122 {} 123 124 /** Hook for draining timing accesses from the system. The 125 * associated SimObject's drain() functions should be implemented 126 * something like this when this class is used: 127 \code 128 PioDevice::drain(Event *de) 129 { 130 unsigned int count; 131 count = SimpleTimingPort->drain(de); 132 if (count) 133 changeState(Draining); 134 else 135 changeState(Drained); 136 return count; 137 } 138 \endcode 139 */ 140 unsigned int drain(Event *de); 141}; 142 143#endif // __MEM_TPORT_HH__ 144