gem5  v22.1.0.0
energy_ctrl.cc
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37 
38 #include "dev/arm/energy_ctrl.hh"
39 
40 #include "base/trace.hh"
41 #include "debug/EnergyCtrl.hh"
42 #include "mem/packet.hh"
43 #include "mem/packet_access.hh"
44 #include "params/EnergyCtrl.hh"
45 #include "sim/dvfs_handler.hh"
46 #include "sim/serialize.hh"
47 
48 namespace gem5
49 {
50 
52  : BasicPioDevice(p, PIO_NUM_FIELDS * 4), // each field is 32 bit
53  dvfsHandler(p.dvfs_handler),
54  domainID(0),
55  domainIDIndexToRead(0),
56  perfLevelAck(0),
57  perfLevelToRead(0),
58  updateAckEvent([this]{ updatePLAck(); }, name())
59 {
60  fatal_if(!p.dvfs_handler, "EnergyCtrl: Needs a DVFSHandler for a "
61  "functioning system.\n");
62 }
63 
64 Tick
66 {
67  assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
68  assert(pkt->getSize() == 4);
69 
70  Addr daddr = pkt->getAddr() - pioAddr;
71  assert((daddr & 3) == 0);
72  Registers reg = Registers(daddr / 4);
73 
74  if (!dvfsHandler->isEnabled()) {
75  // NB: Zero is a good response if the handler is disabled
76  pkt->setLE<uint32_t>(0);
77  warn_once("EnergyCtrl: Disabled handler, ignoring read from reg %i\n",
78  reg);
79  DPRINTF(EnergyCtrl, "dvfs handler disabled, return 0 for read from "\
80  "reg %i\n", reg);
81  pkt->makeAtomicResponse();
82  return pioDelay;
83  }
84 
85  uint32_t result = 0;
86  Tick period;
87  double voltage;
88 
89  switch(reg) {
91  result = 1;
92  DPRINTF(EnergyCtrl, "dvfs handler enabled\n");
93  break;
94  case DVFS_NUM_DOMAINS:
95  result = dvfsHandler->numDomains();
96  DPRINTF(EnergyCtrl, "reading number of domains %d\n", result);
97  break;
100  DPRINTF(EnergyCtrl, "reading domain id at index %d as %d\n",
101  domainIDIndexToRead, result);
102  break;
104  // Return transition latency in nanoseconds
106  DPRINTF(EnergyCtrl, "reading dvfs handler trans latency %d ns\n",
107  result);
108  break;
109  case DOMAIN_ID:
110  result = domainID;
111  DPRINTF(EnergyCtrl, "reading domain id:%d\n", result);
112  break;
113  case PERF_LEVEL:
114  result = dvfsHandler->perfLevel(domainID);
115  DPRINTF(EnergyCtrl, "reading domain %d perf level: %d\n",
116  domainID, result);
117  break;
118  case PERF_LEVEL_ACK:
119  result = perfLevelAck;
120  DPRINTF(EnergyCtrl, "reading ack:%d\n", result);
121  // Signal is set for a single read only
122  if (result == 1)
123  perfLevelAck = 0;
124  break;
125  case NUM_OF_PERF_LEVELS:
127  DPRINTF(EnergyCtrl, "reading num of perf level:%d\n", result);
128  break;
129  case FREQ_AT_PERF_LEVEL:
131  result = ticksTokHz(period);
132  DPRINTF(EnergyCtrl, "reading freq %d KHz at perf level: %d\n",
133  result, perfLevelToRead);
134  break;
135  case VOLT_AT_PERF_LEVEL:
137  result = toMicroVolt(voltage);
138  DPRINTF(EnergyCtrl, "reading voltage %d u-volt at perf level: %d\n",
139  result, perfLevelToRead);
140  break;
141  default:
142  panic("Tried to read EnergyCtrl at offset %#x / reg %i\n", daddr,
143  reg);
144  }
145  pkt->setLE<uint32_t>(result);
146  pkt->makeAtomicResponse();
147  return pioDelay;
148 }
149 
150 Tick
152 {
153  assert(pkt->getAddr() >= pioAddr && pkt->getAddr() < pioAddr + pioSize);
154  assert(pkt->getSize() == 4);
155 
156  uint32_t data;
157  data = pkt->getLE<uint32_t>();
158 
159  Addr daddr = pkt->getAddr() - pioAddr;
160  assert((daddr & 3) == 0);
161  Registers reg = Registers(daddr / 4);
162 
163  if (!dvfsHandler->isEnabled()) {
164  // Ignore writes to a disabled controller
165  warn_once("EnergyCtrl: Disabled handler, ignoring write %u to "\
166  "reg %i\n", data, reg);
167  DPRINTF(EnergyCtrl, "dvfs handler disabled, ignoring write %u to "\
168  "reg %i\n", data, reg);
169  pkt->makeAtomicResponse();
170  return pioDelay;
171  }
172 
173  switch(reg) {
176  DPRINTF(EnergyCtrl, "writing domain id index:%d\n",
178  break;
179  case DOMAIN_ID:
180  // Extra check to ensure that a valid domain ID is being queried
182  domainID = data;
183  DPRINTF(EnergyCtrl, "writing domain id:%d\n", domainID);
184  } else {
185  DPRINTF(EnergyCtrl, "invalid domain id:%d\n", domainID);
186  }
187  break;
188  case PERF_LEVEL:
190  if (updateAckEvent.scheduled()) {
191  // The OS driver is trying to change the perf level while
192  // another change is in flight. This is fine, but only a
193  // single acknowledgment will be sent.
194  DPRINTF(EnergyCtrl, "descheduling previous pending ack "\
195  "event\n");
197  }
199  DPRINTF(EnergyCtrl, "writing domain %d perf level: %d\n",
200  domainID, data);
201  } else {
202  DPRINTF(EnergyCtrl, "invalid / ineffective perf level:%d for "\
203  "domain:%d\n", data, domainID);
204  }
205  break;
206  case PERF_LEVEL_TO_READ:
208  DPRINTF(EnergyCtrl, "writing perf level to read opp at: %d\n",
209  data);
210  break;
211  default:
212  panic("Tried to write EnergyCtrl at offset %#x\n", daddr);
213  break;
214  }
215 
216  pkt->makeAtomicResponse();
217  return pioDelay;
218 }
219 
220 void
222 {
227 
228  Tick next_event = updateAckEvent.scheduled() ? updateAckEvent.when() : 0;
229  SERIALIZE_SCALAR(next_event);
230 }
231 
232 void
234 {
239  Tick next_event = 0;
240  UNSERIALIZE_SCALAR(next_event);
241 
242  // restore scheduled events
243  if (next_event != 0) {
244  schedule(updateAckEvent, next_event);
245  }
246 }
247 
248 void
250 {
251  if (!dvfsHandler->isEnabled()) {
252  warn("Existing EnergyCtrl, but no enabled DVFSHandler found.\n");
253  }
254 }
255 
256 void
258 {
260 }
261 
262 } // namespace gem5
#define DPRINTF(x,...)
Definition: trace.hh:186
const char data[]
Addr pioAddr
Address that the device listens to.
Definition: io_device.hh:151
Tick pioDelay
Delay that the device experinces on an access.
Definition: io_device.hh:157
Addr pioSize
Size that the device's address range.
Definition: io_device.hh:154
double voltage() const
Tick transLatency() const
Get transition latency to switch between performance levels.
Tick clkPeriodAtPerfLevel(DomainID domain_id, PerfLevel perf_level) const
Read the clock period of the specified domain at the specified performance level.
bool perfLevel(DomainID domain_id, PerfLevel perf_level)
Set a new performance level for the specified domain.
bool isEnabled() const
Check enable status of the DVFS handler, when the handler is disabled, no request should be sent to t...
DomainID domainID(uint32_t index) const
Get the n-th domain ID, from the domains managed by this handler.
Definition: dvfs_handler.cc:94
double voltageAtPerfLevel(DomainID domain_id, PerfLevel perf_level) const
Read the voltage of the specified domain at the specified performance level.
uint32_t numDomains() const
Get the number of domains assigned to this DVFS handler.
Definition: dvfs_handler.hh:87
PerfLevel numPerfLevels(PerfLevel domain_id) const
Get the total number of available performance levels.
bool validDomainID(DomainID domain_id) const
Check whether a domain ID is known to the handler or not.
static uint32_t toMicroVolt(double voltage)
Definition: energy_ctrl.hh:173
void unserialize(CheckpointIn &cp) override
Unserialize an object.
Definition: energy_ctrl.cc:233
static uint32_t ticksTokHz(Tick period)
Definition: energy_ctrl.hh:169
Tick read(PacketPtr pkt) override
Read command sent to the device.
Definition: energy_ctrl.cc:65
void startup() override
startup() is the final initialization call before simulation.
Definition: energy_ctrl.cc:249
DVFSHandler * dvfsHandler
Definition: energy_ctrl.hh:142
EventFunctionWrapper updateAckEvent
Definition: energy_ctrl.hh:185
EnergyCtrl(const Params &p)
Definition: energy_ctrl.cc:51
void init() override
init() is called after all C++ SimObjects have been created and all ports are connected.
Definition: energy_ctrl.cc:257
EnergyCtrlParams Params
Definition: energy_ctrl.hh:119
Tick write(PacketPtr pkt) override
Write command sent to the device.
Definition: energy_ctrl.cc:151
void updatePLAck()
Update the acknowledgment that is read back by the software to confirm newly requested performance le...
Definition: energy_ctrl.hh:181
void serialize(CheckpointOut &cp) const override
Serialize an object.
Definition: energy_ctrl.cc:221
uint32_t perfLevelAck
Acknowledgment (PERF_LEVEL_ACK) RO register, software polls this register to read back the status of ...
Definition: energy_ctrl.hh:165
uint32_t perfLevelToRead
Definition: energy_ctrl.hh:167
uint32_t domainIDIndexToRead
Index for getting the domain ID from the domain ID list available with the DVFS handler.
Definition: energy_ctrl.hh:154
uint32_t domainID
Cluster ID (DOMAIN_ID) R/W register, programmed to ID of the domain for which the set/get performance...
Definition: energy_ctrl.hh:148
A Packet is used to encapsulate a transfer between two objects in the memory system (e....
Definition: packet.hh:294
Addr getAddr() const
Definition: packet.hh:805
void setLE(T v)
Set the value in the data pointer to v as little endian.
unsigned getSize() const
Definition: packet.hh:815
void makeAtomicResponse()
Definition: packet.hh:1071
T getLE() const
Get the data in the packet byte swapped from little endian to host endian.
void init() override
init() is called after all C++ SimObjects have been created and all ports are connected.
Definition: io_device.cc:59
DVFSHandler and DomainConfig class declaration used for managing voltage and frequency scaling of the...
The energy controller is a device being used to manage power and energy related control operations wi...
void deschedule(Event &event)
Definition: eventq.hh:1028
bool scheduled() const
Determine if the current event is scheduled.
Definition: eventq.hh:465
void schedule(Event &event, Tick when)
Definition: eventq.hh:1019
Tick when() const
Get the time that the event is scheduled.
Definition: eventq.hh:508
#define panic(...)
This implements a cprintf based panic() function.
Definition: logging.hh:178
#define fatal_if(cond,...)
Conditional fatal macro that checks the supplied condition and only causes a fatal error if the condi...
Definition: logging.hh:226
#define warn(...)
Definition: logging.hh:246
#define warn_once(...)
Definition: logging.hh:250
Bitfield< 54 > p
Definition: pagetable.hh:70
Bitfield< 5, 3 > reg
Definition: types.hh:92
Tick ns
nanosecond
Definition: core.cc:71
Reference material can be found at the JEDEC website: UFS standard http://www.jedec....
Tick curTick()
The universal simulation clock.
Definition: cur_tick.hh:46
std::ostream CheckpointOut
Definition: serialize.hh:66
uint64_t Addr
Address type This will probably be moved somewhere else in the near future.
Definition: types.hh:147
uint64_t Tick
Tick count type.
Definition: types.hh:58
Declaration of the Packet class.
#define UNSERIALIZE_SCALAR(scalar)
Definition: serialize.hh:575
#define SERIALIZE_SCALAR(scalar)
Definition: serialize.hh:568
const std::string & name()
Definition: trace.cc:49

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