/*
* 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.
*
* Authors: Vasileios Spiliopoulos
* Akash Bagdia
* Stephan Diestelhorst
*/
/**
* @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__