src/dev/arm/energy_ctrl.hh - public/gem5 - Git at Google

 /*
  * Copyright (c) 2012-2014 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.
  */

 /**
  * @file
  * The energy controller is a device being used to manage power and energy
  * related control operations within the system. It provides the necessary
  * software interface to the kernel. The kernel will require gem5 specific
  * drivers to access this device.
  *
  * Tasks handled by the controller are:
  * a) Dynamic voltage and frequency scaling control operations
  *
  * Note that the registers defined do not resemble any specific controller
  * device in real hardware. They are currently design to accomodate the gem5
  * system requirements.
  */

 #ifndef __DEV_ARM_ENERGY_CTRL_HH__
 #define __DEV_ARM_ENERGY_CTRL_HH__

 #include "dev/io_device.hh"
 #include "params/EnergyCtrl.hh"

 class DVFSHandler;

 class EnergyCtrl : public BasicPioDevice
 {
   public:
     /**
      * Discovery flows:
      * ----------------
      *   * get basic DVFS handler information
      *     read(DVFS_HANDLER_STATUS)
      *     read(DVFS_HANDLER_TRANS_LATENCY)
      *
      *   * get the number of domain IDs
      *     read(DVFS_NUM_DOMAINS) -> domains
      *
      *   * query the driver to get the IDs for all i in domains
      *     write(DVFS_DOMAINID_AT_INDEX <- i)
      *     read(DOMAIN_ID) -> domainID_i
      *
      *   * for each domainID i get voltage / frequency pairs
      *     write(DOMAIN_ID <- domainID_i)
      *     read(NUM_OF_PERF_LEVELS) -> levels_i
      *     * for each l in levels_i
      *       write(PERF_LEVEL_TO_READ <- l)
      *       read(FREQ_AT_PERF_LEVEL) -> freq_l_i
      *       read(VOLT_AT_PERF_LEVEL) -> volt_l_i
      *
      *
      * Setting a specific performance level (V/F combination)
      * ------------------------------------------------------
      *   * get performance for domain_ID i
      *     write(DOMAIN_ID <- i)
      *     read(PERF_LEVEL) -> perf_level_i
      *
      *   * set performance for domain_ID i
      *     write(DOMAIN_ID <- i)
      *     write(PERF_LEVEL <- perf_level_i)
      *     * wait for DVFS transition completion
      *       while (!read(PERF_LEVEL_ACK));
      */

     enum Registers {
         DVFS_HANDLER_STATUS = 0,
         DVFS_NUM_DOMAINS,
         DVFS_DOMAINID_AT_INDEX,
         DVFS_HANDLER_TRANS_LATENCY,
         DOMAIN_ID,
         PERF_LEVEL,
         PERF_LEVEL_ACK,
         NUM_OF_PERF_LEVELS,
         PERF_LEVEL_TO_READ,
         FREQ_AT_PERF_LEVEL,
         VOLT_AT_PERF_LEVEL,
         PIO_NUM_FIELDS
     };

     typedef EnergyCtrlParams Params;
     EnergyCtrl(const Params &p);

     /**
      * Read command sent to the device
      * @param pkt Packet describing this request
      * @return number of ticks it took to complete
      */
     Tick read(PacketPtr pkt) override;
     /**
      * Write command sent to the device
      * @param pkt Packet describing this request
      * @return number of ticks it took to complete
      */
     Tick write(PacketPtr pkt) override;

     void serialize(CheckpointOut &cp) const override;
     void unserialize(CheckpointIn &cp) override;

     void startup() override;
     void init() override;

   private:
     DVFSHandler *dvfsHandler;

     /**
      * Cluster ID (DOMAIN_ID) R/W register, programmed to ID of the domain for
      * which the set/get performance level command can be issued
      */
     uint32_t domainID;

     /**
      * Index for getting the domain ID from the domain ID list available with
      * the DVFS handler
      */
     uint32_t domainIDIndexToRead;

     /**
      * Acknowledgment (PERF_LEVEL_ACK) RO register, software polls this
      * register to read back the status of the last programmed change in the
      * domain ID and/or the performance level. Valid values are:
      * '0' - Ack is not OK yet
      * '1' - Ack is OK
      * It is a read destructive register with a read of '1' resets the ack to
      * '0'.
      */
     uint32_t perfLevelAck;

     uint32_t perfLevelToRead;

     static uint32_t ticksTokHz(Tick period) {
         return (uint32_t)(SimClock::Int::ms / period);
     }

     static uint32_t toMicroVolt(double voltage) {
         return (uint32_t)(voltage * 1000000);
     }

     /**
       * Update the acknowledgment that is read back by the software to confirm
       * newly requested performance level has been set.
      */
     void updatePLAck() {
         perfLevelAck = 1;
     }

     EventFunctionWrapper updateAckEvent;
 };
 #endif //__DEV_ARM_ENERGY_CTRL_HH__
	/*
	* Copyright (c) 2012-2014 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.
	*/

	/**
	* @file
	* The energy controller is a device being used to manage power and energy
	* related control operations within the system. It provides the necessary
	* software interface to the kernel. The kernel will require gem5 specific
	* drivers to access this device.
	*
	* Tasks handled by the controller are:
	* a) Dynamic voltage and frequency scaling control operations
	*
	* Note that the registers defined do not resemble any specific controller
	* device in real hardware. They are currently design to accomodate the gem5
	* system requirements.
	*/

	#ifndef __DEV_ARM_ENERGY_CTRL_HH__
	#define __DEV_ARM_ENERGY_CTRL_HH__

	#include "dev/io_device.hh"
	#include "params/EnergyCtrl.hh"

	class DVFSHandler;

	class EnergyCtrl : public BasicPioDevice
	{
	public:
	/**
	* Discovery flows:
	* ----------------
	* * get basic DVFS handler information
	* read(DVFS_HANDLER_STATUS)
	* read(DVFS_HANDLER_TRANS_LATENCY)
	*
	* * get the number of domain IDs
	* read(DVFS_NUM_DOMAINS) -> domains
	*
	* * query the driver to get the IDs for all i in domains
	* write(DVFS_DOMAINID_AT_INDEX <- i)
	* read(DOMAIN_ID) -> domainID_i
	*
	* * for each domainID i get voltage / frequency pairs
	* write(DOMAIN_ID <- domainID_i)
	* read(NUM_OF_PERF_LEVELS) -> levels_i
	* * for each l in levels_i
	* write(PERF_LEVEL_TO_READ <- l)
	* read(FREQ_AT_PERF_LEVEL) -> freq_l_i
	* read(VOLT_AT_PERF_LEVEL) -> volt_l_i
	*
	*
	* Setting a specific performance level (V/F combination)
	* ------------------------------------------------------
	* * get performance for domain_ID i
	* write(DOMAIN_ID <- i)
	* read(PERF_LEVEL) -> perf_level_i
	*
	* * set performance for domain_ID i
	* write(DOMAIN_ID <- i)
	* write(PERF_LEVEL <- perf_level_i)
	* * wait for DVFS transition completion
	* while (!read(PERF_LEVEL_ACK));
	*/

	enum Registers {
	DVFS_HANDLER_STATUS = 0,
	DVFS_NUM_DOMAINS,
	DVFS_DOMAINID_AT_INDEX,
	DVFS_HANDLER_TRANS_LATENCY,
	DOMAIN_ID,
	PERF_LEVEL,
	PERF_LEVEL_ACK,
	NUM_OF_PERF_LEVELS,
	PERF_LEVEL_TO_READ,
	FREQ_AT_PERF_LEVEL,
	VOLT_AT_PERF_LEVEL,
	PIO_NUM_FIELDS
	};

	typedef EnergyCtrlParams Params;
	EnergyCtrl(const Params &p);

	/**
	* Read command sent to the device
	* @param pkt Packet describing this request
	* @return number of ticks it took to complete
	*/
	Tick read(PacketPtr pkt) override;
	/**
	* Write command sent to the device
	* @param pkt Packet describing this request
	* @return number of ticks it took to complete
	*/
	Tick write(PacketPtr pkt) override;

	void serialize(CheckpointOut &cp) const override;
	void unserialize(CheckpointIn &cp) override;

	void startup() override;
	void init() override;

	private:
	DVFSHandler *dvfsHandler;

	/**
	* Cluster ID (DOMAIN_ID) R/W register, programmed to ID of the domain for
	* which the set/get performance level command can be issued
	*/
	uint32_t domainID;

	/**
	* Index for getting the domain ID from the domain ID list available with
	* the DVFS handler
	*/
	uint32_t domainIDIndexToRead;

	/**
	* Acknowledgment (PERF_LEVEL_ACK) RO register, software polls this
	* register to read back the status of the last programmed change in the
	* domain ID and/or the performance level. Valid values are:
	* '0' - Ack is not OK yet
	* '1' - Ack is OK
	* It is a read destructive register with a read of '1' resets the ack to
	* '0'.
	*/
	uint32_t perfLevelAck;

	uint32_t perfLevelToRead;

	static uint32_t ticksTokHz(Tick period) {
	return (uint32_t)(SimClock::Int::ms / period);
	}

	static uint32_t toMicroVolt(double voltage) {
	return (uint32_t)(voltage * 1000000);
	}

	/**
	* Update the acknowledgment that is read back by the software to confirm
	* newly requested performance level has been set.
	*/
	void updatePLAck() {
	perfLevelAck = 1;
	}

	EventFunctionWrapper updateAckEvent;
	};
	#endif //__DEV_ARM_ENERGY_CTRL_HH__