clocked_object.hh revision 10236
19157Sandreas.hansson@arm.com/* 29793Sakash.bagdia@arm.com * Copyright (c) 2012-2013 ARM Limited 310000Sclt67@cornell.edu * Copyright (c) 2013 Cornell University 49157Sandreas.hansson@arm.com * All rights reserved 59157Sandreas.hansson@arm.com * 69157Sandreas.hansson@arm.com * The license below extends only to copyright in the software and shall 79157Sandreas.hansson@arm.com * not be construed as granting a license to any other intellectual 89157Sandreas.hansson@arm.com * property including but not limited to intellectual property relating 99157Sandreas.hansson@arm.com * to a hardware implementation of the functionality of the software 109157Sandreas.hansson@arm.com * licensed hereunder. You may use the software subject to the license 119157Sandreas.hansson@arm.com * terms below provided that you ensure that this notice is replicated 129157Sandreas.hansson@arm.com * unmodified and in its entirety in all distributions of the software, 139157Sandreas.hansson@arm.com * modified or unmodified, in source code or in binary form. 149157Sandreas.hansson@arm.com * 159157Sandreas.hansson@arm.com * Redistribution and use in source and binary forms, with or without 169157Sandreas.hansson@arm.com * modification, are permitted provided that the following conditions are 179157Sandreas.hansson@arm.com * met: redistributions of source code must retain the above copyright 189157Sandreas.hansson@arm.com * notice, this list of conditions and the following disclaimer; 199157Sandreas.hansson@arm.com * redistributions in binary form must reproduce the above copyright 209157Sandreas.hansson@arm.com * notice, this list of conditions and the following disclaimer in the 219157Sandreas.hansson@arm.com * documentation and/or other materials provided with the distribution; 229157Sandreas.hansson@arm.com * neither the name of the copyright holders nor the names of its 239157Sandreas.hansson@arm.com * contributors may be used to endorse or promote products derived from 249157Sandreas.hansson@arm.com * this software without specific prior written permission. 259157Sandreas.hansson@arm.com * 269157Sandreas.hansson@arm.com * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 279157Sandreas.hansson@arm.com * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 289157Sandreas.hansson@arm.com * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 299157Sandreas.hansson@arm.com * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 309157Sandreas.hansson@arm.com * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 319157Sandreas.hansson@arm.com * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 329157Sandreas.hansson@arm.com * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 339157Sandreas.hansson@arm.com * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 349157Sandreas.hansson@arm.com * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 359157Sandreas.hansson@arm.com * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 369157Sandreas.hansson@arm.com * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 379157Sandreas.hansson@arm.com * 389157Sandreas.hansson@arm.com * Authors: Andreas Hansson 3910000Sclt67@cornell.edu * Christopher Torng 409157Sandreas.hansson@arm.com */ 419157Sandreas.hansson@arm.com 429157Sandreas.hansson@arm.com/** 439157Sandreas.hansson@arm.com * @file 449157Sandreas.hansson@arm.com * ClockedObject declaration and implementation. 459157Sandreas.hansson@arm.com */ 469157Sandreas.hansson@arm.com 479157Sandreas.hansson@arm.com#ifndef __SIM_CLOCKED_OBJECT_HH__ 489157Sandreas.hansson@arm.com#define __SIM_CLOCKED_OBJECT_HH__ 499157Sandreas.hansson@arm.com 509157Sandreas.hansson@arm.com#include "base/intmath.hh" 519418Sandreas.hansson@arm.com#include "base/misc.hh" 529157Sandreas.hansson@arm.com#include "params/ClockedObject.hh" 539356Snilay@cs.wisc.edu#include "sim/core.hh" 549793Sakash.bagdia@arm.com#include "sim/clock_domain.hh" 559157Sandreas.hansson@arm.com#include "sim/sim_object.hh" 569157Sandreas.hansson@arm.com 579157Sandreas.hansson@arm.com/** 589157Sandreas.hansson@arm.com * The ClockedObject class extends the SimObject with a clock and 599157Sandreas.hansson@arm.com * accessor functions to relate ticks to the cycles of the object. 609157Sandreas.hansson@arm.com */ 619157Sandreas.hansson@arm.comclass ClockedObject : public SimObject 629157Sandreas.hansson@arm.com{ 639157Sandreas.hansson@arm.com 649157Sandreas.hansson@arm.com private: 659157Sandreas.hansson@arm.com 669179Sandreas.hansson@arm.com // the tick value of the next clock edge (>= curTick()) at the 679179Sandreas.hansson@arm.com // time of the last call to update() 689179Sandreas.hansson@arm.com mutable Tick tick; 699179Sandreas.hansson@arm.com 709179Sandreas.hansson@arm.com // The cycle counter value corresponding to the current value of 719179Sandreas.hansson@arm.com // 'tick' 729180Sandreas.hansson@arm.com mutable Cycles cycle; 739179Sandreas.hansson@arm.com 749157Sandreas.hansson@arm.com /** 759157Sandreas.hansson@arm.com * Prevent inadvertent use of the copy constructor and assignment 769157Sandreas.hansson@arm.com * operator by making them private. 779157Sandreas.hansson@arm.com */ 789157Sandreas.hansson@arm.com ClockedObject(ClockedObject&); 799157Sandreas.hansson@arm.com ClockedObject& operator=(ClockedObject&); 809157Sandreas.hansson@arm.com 819179Sandreas.hansson@arm.com /** 8210236Sjthestness@gmail.com * Align cycle and tick to the next clock edge if not already done. When 8310236Sjthestness@gmail.com * complete, tick must be at least curTick(). 849179Sandreas.hansson@arm.com */ 859179Sandreas.hansson@arm.com void update() const 869179Sandreas.hansson@arm.com { 879179Sandreas.hansson@arm.com // both tick and cycle are up-to-date and we are done, note 889179Sandreas.hansson@arm.com // that the >= is important as it captures cases where tick 899179Sandreas.hansson@arm.com // has already passed curTick() 909179Sandreas.hansson@arm.com if (tick >= curTick()) 919179Sandreas.hansson@arm.com return; 929179Sandreas.hansson@arm.com 939179Sandreas.hansson@arm.com // optimise for the common case and see if the tick should be 949179Sandreas.hansson@arm.com // advanced by a single clock period 959793Sakash.bagdia@arm.com tick += clockPeriod(); 969179Sandreas.hansson@arm.com ++cycle; 979179Sandreas.hansson@arm.com 989179Sandreas.hansson@arm.com // see if we are done at this point 999179Sandreas.hansson@arm.com if (tick >= curTick()) 1009179Sandreas.hansson@arm.com return; 1019179Sandreas.hansson@arm.com 1029179Sandreas.hansson@arm.com // if not, we have to recalculate the cycle and tick, we 1039179Sandreas.hansson@arm.com // perform the calculations in terms of relative cycles to 1049179Sandreas.hansson@arm.com // allow changes to the clock period in the future 1059793Sakash.bagdia@arm.com Cycles elapsedCycles(divCeil(curTick() - tick, clockPeriod())); 1069179Sandreas.hansson@arm.com cycle += elapsedCycles; 1079793Sakash.bagdia@arm.com tick += elapsedCycles * clockPeriod(); 1089179Sandreas.hansson@arm.com } 1099179Sandreas.hansson@arm.com 1109793Sakash.bagdia@arm.com /** 1119793Sakash.bagdia@arm.com * The clock domain this clocked object belongs to 1129793Sakash.bagdia@arm.com */ 1139793Sakash.bagdia@arm.com ClockDomain &clockDomain; 1149157Sandreas.hansson@arm.com 1159545Sandreas.hansson@arm.com protected: 1169545Sandreas.hansson@arm.com 1179157Sandreas.hansson@arm.com /** 1189793Sakash.bagdia@arm.com * Create a clocked object and set the clock domain based on the 1199157Sandreas.hansson@arm.com * parameters. 1209157Sandreas.hansson@arm.com */ 1219179Sandreas.hansson@arm.com ClockedObject(const ClockedObjectParams* p) : 1229793Sakash.bagdia@arm.com SimObject(p), tick(0), cycle(0), clockDomain(*p->clk_domain) 1239418Sandreas.hansson@arm.com { 12410000Sclt67@cornell.edu // Register with the clock domain, so that if the clock domain 12510000Sclt67@cornell.edu // frequency changes, we can update this object's tick. 12610000Sclt67@cornell.edu clockDomain.registerWithClockDomain(this); 1279418Sandreas.hansson@arm.com } 1289157Sandreas.hansson@arm.com 1299157Sandreas.hansson@arm.com /** 1309157Sandreas.hansson@arm.com * Virtual destructor due to inheritance. 1319157Sandreas.hansson@arm.com */ 1329157Sandreas.hansson@arm.com virtual ~ClockedObject() { } 1339157Sandreas.hansson@arm.com 1349296Snilay@cs.wisc.edu /** 1359296Snilay@cs.wisc.edu * Reset the object's clock using the current global tick value. Likely 1369296Snilay@cs.wisc.edu * to be used only when the global clock is reset. Currently, this done 1379296Snilay@cs.wisc.edu * only when Ruby is done warming up the memory system. 1389296Snilay@cs.wisc.edu */ 1399296Snilay@cs.wisc.edu void resetClock() const 1409296Snilay@cs.wisc.edu { 1419793Sakash.bagdia@arm.com Cycles elapsedCycles(divCeil(curTick(), clockPeriod())); 1429296Snilay@cs.wisc.edu cycle = elapsedCycles; 1439793Sakash.bagdia@arm.com tick = elapsedCycles * clockPeriod(); 1449296Snilay@cs.wisc.edu } 1459296Snilay@cs.wisc.edu 1469157Sandreas.hansson@arm.com public: 1479157Sandreas.hansson@arm.com 1489157Sandreas.hansson@arm.com /** 14910000Sclt67@cornell.edu * Update the tick to the current tick. 15010000Sclt67@cornell.edu * 15110000Sclt67@cornell.edu */ 15210000Sclt67@cornell.edu inline void updateClockPeriod() const 15310000Sclt67@cornell.edu { 15410000Sclt67@cornell.edu update(); 15510000Sclt67@cornell.edu } 15610000Sclt67@cornell.edu 15710000Sclt67@cornell.edu /** 15810236Sjthestness@gmail.com * Determine the tick when a cycle begins, by default the current one, but 15910236Sjthestness@gmail.com * the argument also enables the caller to determine a future cycle. When 16010236Sjthestness@gmail.com * curTick() is on a clock edge, the number of cycles in the parameter is 16110236Sjthestness@gmail.com * added to curTick() to be returned. When curTick() is not aligned to a 16210236Sjthestness@gmail.com * clock edge, the number of cycles in the parameter is added to the next 16310236Sjthestness@gmail.com * clock edge. 1649179Sandreas.hansson@arm.com * 1659179Sandreas.hansson@arm.com * @param cycles The number of cycles into the future 1669179Sandreas.hansson@arm.com * 16710236Sjthestness@gmail.com * @return The start tick when the requested clock edge occurs. Precisely, 16810236Sjthestness@gmail.com * this tick can be 16910236Sjthestness@gmail.com * curTick() + [0, clockPeriod()) + clockPeriod() * cycles 1709179Sandreas.hansson@arm.com */ 1719180Sandreas.hansson@arm.com inline Tick clockEdge(Cycles cycles = Cycles(0)) const 1729179Sandreas.hansson@arm.com { 1739179Sandreas.hansson@arm.com // align tick to the next clock edge 1749179Sandreas.hansson@arm.com update(); 1759179Sandreas.hansson@arm.com 1769179Sandreas.hansson@arm.com // figure out when this future cycle is 1779793Sakash.bagdia@arm.com return tick + clockPeriod() * cycles; 1789179Sandreas.hansson@arm.com } 1799179Sandreas.hansson@arm.com 1809179Sandreas.hansson@arm.com /** 1819179Sandreas.hansson@arm.com * Determine the current cycle, corresponding to a tick aligned to 1829179Sandreas.hansson@arm.com * a clock edge. 1839179Sandreas.hansson@arm.com * 18410236Sjthestness@gmail.com * @return When curTick() is on a clock edge, return the Cycle corresponding 18510236Sjthestness@gmail.com * to that clock edge. When curTick() is not on a clock edge, return the 18610236Sjthestness@gmail.com * Cycle corresponding to the next clock edge. 1879179Sandreas.hansson@arm.com */ 1889180Sandreas.hansson@arm.com inline Cycles curCycle() const 1899179Sandreas.hansson@arm.com { 1909179Sandreas.hansson@arm.com // align cycle to the next clock edge. 1919179Sandreas.hansson@arm.com update(); 1929179Sandreas.hansson@arm.com 1939179Sandreas.hansson@arm.com return cycle; 1949179Sandreas.hansson@arm.com } 1959179Sandreas.hansson@arm.com 1969179Sandreas.hansson@arm.com /** 19710236Sjthestness@gmail.com * Based on the clock of the object, determine the start tick of the first 19810236Sjthestness@gmail.com * cycle that is at least one cycle in the future. When curTick() is at the 19910236Sjthestness@gmail.com * current cycle edge, this returns the next clock edge. When calling this 20010236Sjthestness@gmail.com * during the middle of a cycle, this returns 2 clock edges in the future. 2019157Sandreas.hansson@arm.com * 20210236Sjthestness@gmail.com * @return The start tick of the first cycle that is at least one cycle in 20310236Sjthestness@gmail.com * the future. Precisely, the returned tick can be in the range 20410236Sjthestness@gmail.com * curTick() + [clockPeriod(), 2 * clockPeriod()) 2059157Sandreas.hansson@arm.com */ 2069157Sandreas.hansson@arm.com Tick nextCycle() const 2079648Sdam.sunwoo@arm.com { return clockEdge(Cycles(1)); } 2089157Sandreas.hansson@arm.com 2099793Sakash.bagdia@arm.com inline uint64_t frequency() const 2109793Sakash.bagdia@arm.com { 2119793Sakash.bagdia@arm.com return SimClock::Frequency / clockPeriod(); 2129793Sakash.bagdia@arm.com } 2139157Sandreas.hansson@arm.com 2149793Sakash.bagdia@arm.com inline Tick clockPeriod() const 2159793Sakash.bagdia@arm.com { 2169793Sakash.bagdia@arm.com return clockDomain.clockPeriod(); 2179793Sakash.bagdia@arm.com } 2189157Sandreas.hansson@arm.com 2199550Sandreas.hansson@arm.com inline Cycles ticksToCycles(Tick t) const 2209987Snilay@cs.wisc.edu { return Cycles(divCeil(t, clockPeriod())); } 2219157Sandreas.hansson@arm.com 2229157Sandreas.hansson@arm.com}; 2239157Sandreas.hansson@arm.com 2249157Sandreas.hansson@arm.com#endif //__SIM_CLOCKED_OBJECT_HH__ 225