/* * Copyright (c) 2013-2014 ARM Limited * All rights reserved * * The license below extends only to copyright in the software and shall * not be construed as granting a license to any other intellectual * property including but not limited to intellectual property relating * to a hardware implementation of the functionality of the software * licensed hereunder. You may use the software subject to the license * terms below provided that you ensure that this notice is replicated * unmodified and in its entirety in all distributions of the software, * modified or unmodified, in source code or in binary form. * * 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: Vasileios Spiliopoulos * Akash Bagdia * Stephan Diestelhorst */ /** * @file * DVFSHandler and DomainConfig class declaration used for managing voltage * and frequency scaling of the various DVFS domains in the system (with each * domain having their independent domain configuration information) */ #ifndef __SIM_DVFS_HANDLER_HH__ #define __SIM_DVFS_HANDLER_HH__ #include #include "debug/DVFS.hh" #include "params/DVFSHandler.hh" #include "sim/clock_domain.hh" #include "sim/eventq.hh" #include "sim/sim_object.hh" /** * DVFS Handler class, maintains a list of all the domains it can handle. * Each entry of that list is an object of the DomainConfig class, and the * handler uses the methods provided by that class to get access to the * configuration of each domain. The handler is responsible for setting/getting * clock periods and voltages from clock/voltage domains. * The handler acts the bridge between software configurable information * for each domain as provided to the controller and the hardware * implementation details for those domains. */ class DVFSHandler : public SimObject { public: typedef DVFSHandlerParams Params; DVFSHandler(const Params *p); typedef SrcClockDomain::DomainID DomainID; typedef SrcClockDomain::PerfLevel PerfLevel; /** * Get the number of domains assigned to this DVFS handler. * @return Number of domains */ uint32_t numDomains() const { return domainIDList.size(); } /** * Get the n-th domain ID, from the domains managed by this handler. * @return Domain ID */ DomainID domainID(uint32_t index) const; /** * Check whether a domain ID is known to the handler or not. * @param domain_id Domain ID to check * @return Domain ID known to handler? */ bool validDomainID(DomainID domain_id) const; /** * Get transition latency to switch between performance levels. * @return Transition latency */ Tick transLatency() const { return _transLatency; } /** * Set a new performance level for the specified domain. The actual update * will be delayed by transLatency(). * * @param domain_id Software visible ID of the domain to be configured * @param perf_level Requested performance level (0 - fast, >0 slower) * @return status whether the setting was successful */ bool perfLevel(DomainID domain_id, PerfLevel perf_level); /** * Get the current performance level of a domain. While a change request is * in-flight, will return the current (i.e. old, unmodified) value. * * @param domain_id Domain ID to query * @return Current performance level of the specified domain */ PerfLevel perfLevel(DomainID domain_id) const { assert(isEnabled()); return findDomain(domain_id)->perfLevel(); } /** * Read the clock period of the specified domain at the specified * performance level. * @param domain_id Domain ID to query * @param perf_level Performance level of interest * @return Clock period in ticks for the requested performance level of * the respective domain */ Tick clkPeriodAtPerfLevel(DomainID domain_id, PerfLevel perf_level) const { SrcClockDomain *d = findDomain(domain_id); assert(d); PerfLevel n = d->numPerfLevels(); if (perf_level < n) return d->clkPeriodAtPerfLevel(perf_level); warn("DVFSHandler %s reads illegal frequency level %u from "\ "SrcClockDomain %s. Returning 0\n", name(), perf_level, d->name()); return Tick(0); } /** * Read the voltage of the specified domain at the specified * performance level. * @param domain_id Domain ID to query * @param perf_level Performance level of interest * @return Voltage for the requested performance level of the respective * domain */ double voltageAtPerfLevel(DomainID domain_id, PerfLevel perf_level) const; /** * Get the total number of available performance levels. * * @param domain_id Domain ID to query * @return Number of performance levels that where configured for the * respective domain */ PerfLevel numPerfLevels(PerfLevel domain_id) const { return findDomain(domain_id)->numPerfLevels(); } /** * Check enable status of the DVFS handler, when the handler is disabled, no * request should be sent to the handler. * @return True, if the handler is enabled */ bool isEnabled() const { return enableHandler; } void serialize(CheckpointOut &cp) const override; void unserialize(CheckpointIn &cp) override; private: typedef std::map Domains; Domains domains; /** * List of IDs avaiable in the domain list */ std::vector domainIDList; /** * Clock domain of the system the handler is instantiated. */ SrcClockDomain* sysClkDomain; /** * Search for a domain based on the domain ID. * * @param domain_id Domain ID to search for * @return Pointer to the source clock domain with matching ID. */ SrcClockDomain *findDomain(DomainID domain_id) const { auto it = domains.find(domain_id); panic_if(it == domains.end(), "DVFS: Could not find a domain for ID %d.\n",domain_id ); return domains.find(domain_id)->second; } /** * Disabling the DVFS handler ensures that all the DVFS migration requests * are ignored. Domains remain at their default frequency and voltage. */ bool enableHandler; /** * This corresponds to the maximum transition latency associated with the * hardware transitioning from a particular performance level to the other */ const Tick _transLatency; /** * Update performance level event, encapsulates all the required information * for a future call to change a domain's performance level. */ struct UpdateEvent : public Event { UpdateEvent() : Event(DVFS_Update_Pri), domainIDToSet(0), perfLevelToSet(0) {} /** * Static pointer to the single DVFS hander for all the update events */ static DVFSHandler *dvfsHandler; /** * ID of the domain that will be changed by the in-flight event */ DomainID domainIDToSet; /** * Target performance level of the in-flight event */ PerfLevel perfLevelToSet; /** * Updates the performance level by modifying the clock and the voltage * of the associated clocked objects. Gets information from * domainIDToSet and perfLevelToSet for easier calling through an * event. */ void updatePerfLevel(); void process() { updatePerfLevel(); } }; typedef std::map UpdatePerfLevelEvents; /** * Map from domain IDs -> perf level update events, records in-flight change * requests per domain ID. */ UpdatePerfLevelEvents updatePerfLevelEvents; }; #endif // __SIM_DVFS_HANDLER_HH__