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authorAkash Bagdia <akash.bagdia@arm.com>2014-09-20 17:18:23 -0400
committerAkash Bagdia <akash.bagdia@arm.com>2014-09-20 17:18:23 -0400
commit04e51e5e3e0d2c8af658e5ae29a240a0aac78f6e (patch)
tree009e17167757db81dad20a00ea469815ea0867bf
parent4422d1322a8ed47bc9d743894ad47d82f33eba7c (diff)
downloadgem5-04e51e5e3e0d2c8af658e5ae29a240a0aac78f6e.tar.xz
energy: Memory-mapped Energy Controller component
This patch provides an Energy Controller device that provides software (driver) access to a DVFS handler. The device is currently residing in the dev/arm tree, but there is nothing inherently ARM specific in the behaviour. It is currently only tested and supported for ARM Linux, hence the location.
-rw-r--r--src/dev/arm/EnergyCtrl.py47
-rw-r--r--src/dev/arm/SConscript3
-rw-r--r--src/dev/arm/energy_ctrl.cc264
-rw-r--r--src/dev/arm/energy_ctrl.hh187
4 files changed, 501 insertions, 0 deletions
diff --git a/src/dev/arm/EnergyCtrl.py b/src/dev/arm/EnergyCtrl.py
new file mode 100644
index 000000000..4e504bf80
--- /dev/null
+++ b/src/dev/arm/EnergyCtrl.py
@@ -0,0 +1,47 @@
+# 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
+
+from m5.params import *
+from m5.SimObject import SimObject
+from Device import BasicPioDevice
+from m5.proxy import *
+
+class EnergyCtrl(BasicPioDevice):
+ type = 'EnergyCtrl'
+ cxx_header = "dev/arm/energy_ctrl.hh"
+ dvfs_handler = Param.DVFSHandler(Parent.dvfs_handler, "DVFS handler")
diff --git a/src/dev/arm/SConscript b/src/dev/arm/SConscript
index 419e2f471..ad6a22b55 100644
--- a/src/dev/arm/SConscript
+++ b/src/dev/arm/SConscript
@@ -42,6 +42,7 @@ Import('*')
if env['TARGET_ISA'] == 'arm':
SimObject('Gic.py')
SimObject('RealView.py')
+ SimObject('EnergyCtrl.py')
Source('a9scu.cc')
Source('amba_device.cc')
@@ -59,6 +60,7 @@ if env['TARGET_ISA'] == 'arm':
Source('rtc_pl031.cc')
Source('timer_cpulocal.cc')
Source('vgic.cc')
+ Source('energy_ctrl.cc')
DebugFlag('AMBA')
DebugFlag('HDLcd')
@@ -66,4 +68,5 @@ if env['TARGET_ISA'] == 'arm':
DebugFlag('Pl050')
DebugFlag('GIC')
DebugFlag('RVCTRL')
+ DebugFlag('EnergyCtrl')
DebugFlag('VGIC')
diff --git a/src/dev/arm/energy_ctrl.cc b/src/dev/arm/energy_ctrl.cc
new file mode 100644
index 000000000..cbfa5aa79
--- /dev/null
+++ b/src/dev/arm/energy_ctrl.cc
@@ -0,0 +1,264 @@
+/*
+ * 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
+ */
+
+#include "debug/EnergyCtrl.hh"
+#include "dev/arm/energy_ctrl.hh"
+#include "mem/packet.hh"
+#include "mem/packet_access.hh"
+#include "params/EnergyCtrl.hh"
+#include "sim/dvfs_handler.hh"
+
+EnergyCtrl::EnergyCtrl(const Params *p)
+ : BasicPioDevice(p, PIO_NUM_FIELDS * 4), // each field is 32 bit
+ dvfsHandler(p->dvfs_handler),
+ domainID(0),
+ domainIDIndexToRead(0),
+ perfLevelAck(0),
+ perfLevelToRead(0),
+ updateAckEvent(this)
+{
+ fatal_if(!p->dvfs_handler, "EnergyCtrl: Needs a DVFSHandler for a "
+ "functioning system.\n");
+}
+
+Tick
+EnergyCtrl::read(PacketPtr pkt)
+{
+ assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
+ assert(pkt->getSize() == 4);
+ pkt->allocate();
+
+ Addr daddr = pkt->getAddr() - pioAddr;
+ assert((daddr & 3) == 0);
+ Registers reg = Registers(daddr / 4);
+
+ if (!dvfsHandler->isEnabled()) {
+ // NB: Zero is a good response if the handler is disabled
+ pkt->set<uint32_t>(0);
+ warn_once("EnergyCtrl: Disabled handler, ignoring read from reg %i\n",
+ reg);
+ DPRINTF(EnergyCtrl, "dvfs handler disabled, return 0 for read from "\
+ "reg %i\n", reg);
+ pkt->makeAtomicResponse();
+ return pioDelay;
+ }
+
+ uint32_t result = 0;
+ Tick period;
+ double voltage;
+
+ switch(reg) {
+ case DVFS_HANDLER_STATUS:
+ result = 1;
+ DPRINTF(EnergyCtrl, "dvfs handler enabled\n");
+ break;
+ case DVFS_NUM_DOMAINS:
+ result = dvfsHandler->numDomains();
+ DPRINTF(EnergyCtrl, "reading number of domains %d\n", result);
+ break;
+ case DVFS_DOMAINID_AT_INDEX:
+ result = dvfsHandler->domainID(domainIDIndexToRead);
+ DPRINTF(EnergyCtrl, "reading domain id at index %d as %d\n",
+ domainIDIndexToRead, result);
+ break;
+ case DVFS_HANDLER_TRANS_LATENCY:
+ // Return transition latency in nanoseconds
+ result = dvfsHandler->transLatency() / SimClock::Int::ns;
+ DPRINTF(EnergyCtrl, "reading dvfs handler trans latency %d ns\n",
+ result);
+ break;
+ case DOMAIN_ID:
+ result = domainID;
+ DPRINTF(EnergyCtrl, "reading domain id:%d\n", result);
+ break;
+ case PERF_LEVEL:
+ result = dvfsHandler->perfLevel(domainID);
+ DPRINTF(EnergyCtrl, "reading domain %d perf level: %d\n",
+ domainID, result);
+ break;
+ case PERF_LEVEL_ACK:
+ result = perfLevelAck;
+ DPRINTF(EnergyCtrl, "reading ack:%d\n", result);
+ // Signal is set for a single read only
+ if (result == 1)
+ perfLevelAck = 0;
+ break;
+ case NUM_OF_PERF_LEVELS:
+ result = dvfsHandler->numPerfLevels(domainID);
+ DPRINTF(EnergyCtrl, "reading num of perf level:%d\n", result);
+ break;
+ case FREQ_AT_PERF_LEVEL:
+ period = dvfsHandler->clkPeriodAtPerfLevel(domainID, perfLevelToRead);
+ result = ticksTokHz(period);
+ DPRINTF(EnergyCtrl, "reading freq %d KHz at perf level: %d\n",
+ result, perfLevelToRead);
+ break;
+ case VOLT_AT_PERF_LEVEL:
+ voltage = dvfsHandler->voltageAtPerfLevel(domainID, perfLevelToRead);
+ result = toMicroVolt(voltage);
+ DPRINTF(EnergyCtrl, "reading voltage %d u-volt at perf level: %d\n",
+ result, perfLevelToRead);
+ break;
+ default:
+ panic("Tried to read EnergyCtrl at offset %#x / reg %i\n", daddr,
+ reg);
+ }
+ pkt->set<uint32_t>(result);
+ pkt->makeAtomicResponse();
+ return pioDelay;
+}
+
+Tick
+EnergyCtrl::write(PacketPtr pkt)
+{
+ assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
+ assert(pkt->getSize() == 4);
+
+ uint32_t data;
+ data = pkt->get<uint32_t>();
+
+ Addr daddr = pkt->getAddr() - pioAddr;
+ assert((daddr & 3) == 0);
+ Registers reg = Registers(daddr / 4);
+
+ if (!dvfsHandler->isEnabled()) {
+ // Ignore writes to a disabled controller
+ warn_once("EnergyCtrl: Disabled handler, ignoring write %u to "\
+ "reg %i\n", data, reg);
+ DPRINTF(EnergyCtrl, "dvfs handler disabled, ignoring write %u to "\
+ "reg %i\n", data, reg);
+ pkt->makeAtomicResponse();
+ return pioDelay;
+ }
+
+ switch(reg) {
+ case DVFS_DOMAINID_AT_INDEX:
+ domainIDIndexToRead = data;
+ DPRINTF(EnergyCtrl, "writing domain id index:%d\n",
+ domainIDIndexToRead);
+ break;
+ case DOMAIN_ID:
+ // Extra check to ensure that a valid domain ID is being queried
+ if (dvfsHandler->validDomainID(data)) {
+ domainID = data;
+ DPRINTF(EnergyCtrl, "writing domain id:%d\n", domainID);
+ } else {
+ DPRINTF(EnergyCtrl, "invalid domain id:%d\n", domainID);
+ }
+ break;
+ case PERF_LEVEL:
+ if (dvfsHandler->perfLevel(domainID, data)) {
+ if (updateAckEvent.scheduled()) {
+ // The OS driver is trying to change the perf level while
+ // another change is in flight. This is fine, but only a
+ // single acknowledgment will be sent.
+ DPRINTF(EnergyCtrl, "descheduling previous pending ack "\
+ "event\n");
+ deschedule(updateAckEvent);
+ }
+ schedule(updateAckEvent, curTick() + dvfsHandler->transLatency());
+ DPRINTF(EnergyCtrl, "writing domain %d perf level: %d\n",
+ domainID, data);
+ } else {
+ DPRINTF(EnergyCtrl, "invalid / ineffective perf level:%d for "\
+ "domain:%d\n", data, domainID);
+ }
+ break;
+ case PERF_LEVEL_TO_READ:
+ perfLevelToRead = data;
+ DPRINTF(EnergyCtrl, "writing perf level to read opp at: %d\n",
+ data);
+ break;
+ default:
+ panic("Tried to write EnergyCtrl at offset %#x\n", daddr);
+ break;
+ }
+
+ pkt->makeAtomicResponse();
+ return pioDelay;
+}
+
+void
+EnergyCtrl::serialize(std::ostream &os)
+{
+ SERIALIZE_SCALAR(domainID);
+ SERIALIZE_SCALAR(domainIDIndexToRead);
+ SERIALIZE_SCALAR(perfLevelToRead);
+ SERIALIZE_SCALAR(perfLevelAck);
+
+ Tick next_event = updateAckEvent.scheduled() ? updateAckEvent.when() : 0;
+ SERIALIZE_SCALAR(next_event);
+}
+
+void
+EnergyCtrl::unserialize(Checkpoint *cp, const std::string &section)
+{
+ UNSERIALIZE_SCALAR(domainID);
+ UNSERIALIZE_SCALAR(domainIDIndexToRead);
+ UNSERIALIZE_SCALAR(perfLevelToRead);
+ UNSERIALIZE_SCALAR(perfLevelAck);
+ Tick next_event = 0;
+ UNSERIALIZE_SCALAR(next_event);
+
+ // restore scheduled events
+ if (next_event != 0) {
+ schedule(updateAckEvent, next_event);
+ }
+}
+
+EnergyCtrl * EnergyCtrlParams::create()
+{
+ return new EnergyCtrl(this);
+}
+
+void
+EnergyCtrl::startup()
+{
+ if (!dvfsHandler->isEnabled()) {
+ warn("Existing EnergyCtrl, but no enabled DVFSHandler found.\n");
+ }
+}
+
+void
+EnergyCtrl::init()
+{
+ BasicPioDevice::init();
+}
diff --git a/src/dev/arm/energy_ctrl.hh b/src/dev/arm/energy_ctrl.hh
new file mode 100644
index 000000000..54a690679
--- /dev/null
+++ b/src/dev/arm/energy_ctrl.hh
@@ -0,0 +1,187 @@
+/*
+ * 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
+ */
+ virtual Tick read(PacketPtr pkt);
+ /**
+ * Write command sent to the device
+ * @param pkt Packet describing this request
+ * @return number of ticks it took to complete
+ */
+ virtual Tick write(PacketPtr pkt);
+
+ void serialize(std::ostream &os);
+ void unserialize(Checkpoint *cp, const std::string &section);
+
+ void startup();
+ void init();
+
+ 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;
+ }
+
+ EventWrapper<EnergyCtrl, &EnergyCtrl::updatePLAck> updateAckEvent;
+};
+#endif //__DEV_ARM_ENERGY_CTRL_HH__