gem5
v20.1.0.0
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General interface to memory device Includes functions and parameters shared across media types. More...
#include <mem_interface.hh>
Classes | |
class | Bank |
A basic class to track the bank state, i.e. More... | |
Public Types | |
typedef MemInterfaceParams | Params |
Public Types inherited from AbstractMemory | |
typedef AbstractMemoryParams | Params |
Public Types inherited from ClockedObject | |
typedef ClockedObjectParams | Params |
Parameters of ClockedObject. More... | |
Public Types inherited from SimObject | |
typedef SimObjectParams | Params |
Public Member Functions | |
void | setCtrl (MemCtrl *_ctrl, unsigned int command_window) |
Set a pointer to the controller and initialize interface based on controller parameters. More... | |
Addr | getCtrlAddr (Addr addr) |
Get an address in a dense range which starts from 0. More... | |
virtual void | setupRank (const uint8_t rank, const bool is_read)=0 |
Setup the rank based on packet received. More... | |
virtual bool | allRanksDrained () const =0 |
Check drain state of interface. More... | |
virtual std::pair< MemPacketQueue::iterator, Tick > | chooseNextFRFCFS (MemPacketQueue &queue, Tick min_col_at) const =0 |
For FR-FCFS policy, find first command that can issue Function will be overriden by interface to select based on media characteristics, used to determine when read or write can issue. More... | |
virtual Tick | accessLatency () const =0 |
uint32_t | bytesPerBurst () const |
virtual Tick | commandOffset () const =0 |
virtual bool | burstReady (MemPacket *pkt) const =0 |
Check if a burst operation can be issued to the interface. More... | |
Tick | rankDelay () const |
Determine the required delay for an access to a different rank. More... | |
Tick | minReadToWriteDataGap () const |
Tick | minWriteToReadDataGap () const |
MemPacket * | decodePacket (const PacketPtr pkt, Addr pkt_addr, unsigned int size, bool is_read, bool is_dram) |
Address decoder to figure out physical mapping onto ranks, banks, and rows. More... | |
virtual void | addRankToRankDelay (Tick cmd_at)=0 |
Add rank to rank delay to bus timing to all banks in all ranks when access to an alternate interface is issued. More... | |
MemInterface (const Params *_p) | |
Public Member Functions inherited from AbstractMemory | |
AbstractMemory (const Params *p) | |
virtual | ~AbstractMemory () |
void | initState () override |
initState() is called on each SimObject when not restoring from a checkpoint. More... | |
bool | isNull () const |
See if this is a null memory that should never store data and always return zero. More... | |
void | setBackingStore (uint8_t *pmem_addr) |
Set the host memory backing store to be used by this memory controller. More... | |
const std::list< LockedAddr > & | getLockedAddrList () const |
Get the list of locked addresses to allow checkpointing. More... | |
void | addLockedAddr (LockedAddr addr) |
Add a locked address to allow for checkpointing. More... | |
System * | system () const |
read the system pointer Implemented for completeness with the setter More... | |
void | system (System *sys) |
Set the system pointer on this memory This can't be done via a python parameter because the system needs pointers to all the memories and the reverse would create a cycle in the object graph. More... | |
const Params * | params () const |
AddrRange | getAddrRange () const |
Get the address range. More... | |
uint8_t * | toHostAddr (Addr addr) const |
Transform a gem5 address space address into its physical counterpart in the host address space. More... | |
uint64_t | size () const |
Get the memory size. More... | |
Addr | start () const |
Get the start address. More... | |
bool | isConfReported () const |
Should this memory be passed to the kernel and part of the OS physical memory layout. More... | |
bool | isInAddrMap () const |
Some memories are used as shadow memories or should for other reasons not be part of the global address map. More... | |
bool | isKvmMap () const |
When shadow memories are in use, KVM may want to make one or the other, but cannot map both into the guest address space. More... | |
void | access (PacketPtr pkt) |
Perform an untimed memory access and update all the state (e.g. More... | |
void | functionalAccess (PacketPtr pkt) |
Perform an untimed memory read or write without changing anything but the memory itself. More... | |
Public Member Functions inherited from ClockedObject | |
ClockedObject (const ClockedObjectParams *p) | |
const Params * | params () const |
void | serialize (CheckpointOut &cp) const override |
Serialize an object. More... | |
void | unserialize (CheckpointIn &cp) override |
Unserialize an object. More... | |
Public Member Functions inherited from SimObject | |
const Params * | params () const |
SimObject (const Params *_params) | |
virtual | ~SimObject () |
virtual const std::string | name () const |
virtual void | init () |
init() is called after all C++ SimObjects have been created and all ports are connected. More... | |
virtual void | loadState (CheckpointIn &cp) |
loadState() is called on each SimObject when restoring from a checkpoint. More... | |
virtual void | regProbePoints () |
Register probe points for this object. More... | |
virtual void | regProbeListeners () |
Register probe listeners for this object. More... | |
ProbeManager * | getProbeManager () |
Get the probe manager for this object. More... | |
virtual Port & | getPort (const std::string &if_name, PortID idx=InvalidPortID) |
Get a port with a given name and index. More... | |
virtual void | startup () |
startup() is the final initialization call before simulation. More... | |
DrainState | drain () override |
Provide a default implementation of the drain interface for objects that don't need draining. More... | |
virtual void | memWriteback () |
Write back dirty buffers to memory using functional writes. More... | |
virtual void | memInvalidate () |
Invalidate the contents of memory buffers. More... | |
void | serialize (CheckpointOut &cp) const override |
Serialize an object. More... | |
void | unserialize (CheckpointIn &cp) override |
Unserialize an object. More... | |
Public Member Functions inherited from EventManager | |
EventQueue * | eventQueue () const |
void | schedule (Event &event, Tick when) |
void | deschedule (Event &event) |
void | reschedule (Event &event, Tick when, bool always=false) |
void | schedule (Event *event, Tick when) |
void | deschedule (Event *event) |
void | reschedule (Event *event, Tick when, bool always=false) |
void | wakeupEventQueue (Tick when=(Tick) -1) |
This function is not needed by the usual gem5 event loop but may be necessary in derived EventQueues which host gem5 on other schedulers. More... | |
void | setCurTick (Tick newVal) |
EventManager (EventManager &em) | |
Event manger manages events in the event queue. More... | |
EventManager (EventManager *em) | |
EventManager (EventQueue *eq) | |
Public Member Functions inherited from Serializable | |
Serializable () | |
virtual | ~Serializable () |
void | serializeSection (CheckpointOut &cp, const char *name) const |
Serialize an object into a new section. More... | |
void | serializeSection (CheckpointOut &cp, const std::string &name) const |
void | unserializeSection (CheckpointIn &cp, const char *name) |
Unserialize an a child object. More... | |
void | unserializeSection (CheckpointIn &cp, const std::string &name) |
Public Member Functions inherited from Drainable | |
DrainState | drainState () const |
Return the current drain state of an object. More... | |
virtual void | notifyFork () |
Notify a child process of a fork. More... | |
Public Member Functions inherited from Stats::Group | |
Group (Group *parent, const char *name=nullptr) | |
Construct a new statistics group. More... | |
virtual | ~Group () |
virtual void | regStats () |
Callback to set stat parameters. More... | |
virtual void | resetStats () |
Callback to reset stats. More... | |
virtual void | preDumpStats () |
Callback before stats are dumped. More... | |
void | addStat (Stats::Info *info) |
Register a stat with this group. More... | |
const std::map< std::string, Group * > & | getStatGroups () const |
Get all child groups associated with this object. More... | |
const std::vector< Info * > & | getStats () const |
Get all stats associated with this object. More... | |
void | addStatGroup (const char *name, Group *block) |
Add a stat block as a child of this block. More... | |
const Info * | resolveStat (std::string name) const |
Resolve a stat by its name within this group. More... | |
Group ()=delete | |
Group (const Group &)=delete | |
Group & | operator= (const Group &)=delete |
Public Member Functions inherited from Clocked | |
void | updateClockPeriod () |
Update the tick to the current tick. More... | |
Tick | clockEdge (Cycles cycles=Cycles(0)) const |
Determine the tick when a cycle begins, by default the current one, but the argument also enables the caller to determine a future cycle. More... | |
Cycles | curCycle () const |
Determine the current cycle, corresponding to a tick aligned to a clock edge. More... | |
Tick | nextCycle () const |
Based on the clock of the object, determine the start tick of the first cycle that is at least one cycle in the future. More... | |
uint64_t | frequency () const |
Tick | clockPeriod () const |
double | voltage () const |
Cycles | ticksToCycles (Tick t) const |
Tick | cyclesToTicks (Cycles c) const |
Public Attributes | |
const uint32_t | readBufferSize |
Buffer sizes for read and write queues in the controller These are passed to the controller on instantiation Defining them here allows for buffers to be resized based on memory type / configuration. More... | |
const uint32_t | writeBufferSize |
Public Attributes inherited from ClockedObject | |
PowerState * | powerState |
Protected Member Functions | |
virtual Tick | writeToReadDelay () const |
Tick | readToWriteDelay () const |
Tick | rankToRankDelay () const |
Protected Member Functions inherited from AbstractMemory | |
bool | checkLockedAddrList (PacketPtr pkt) |
void | trackLoadLocked (PacketPtr pkt) |
bool | writeOK (PacketPtr pkt) |
Protected Member Functions inherited from Drainable | |
Drainable () | |
virtual | ~Drainable () |
virtual void | drainResume () |
Resume execution after a successful drain. More... | |
void | signalDrainDone () const |
Signal that an object is drained. More... | |
Protected Member Functions inherited from Clocked | |
Clocked (ClockDomain &clk_domain) | |
Create a clocked object and set the clock domain based on the parameters. More... | |
Clocked (Clocked &)=delete | |
Clocked & | operator= (Clocked &)=delete |
virtual | ~Clocked () |
Virtual destructor due to inheritance. More... | |
void | resetClock () const |
Reset the object's clock using the current global tick value. More... | |
virtual void | clockPeriodUpdated () |
A hook subclasses can implement so they can do any extra work that's needed when the clock rate is changed. More... | |
Protected Attributes | |
MemCtrl * | ctrl |
A pointer to the parent MemCtrl instance. More... | |
unsigned int | maxCommandsPerWindow |
Number of commands that can issue in the defined controller command window, used to verify command bandwidth. More... | |
Enums::AddrMap | addrMapping |
Memory controller configuration initialized based on parameter values. More... | |
const uint32_t | burstSize |
General device and channel characteristics The rowsPerBank is determined based on the capacity, number of ranks and banks, the burst size, and the row buffer size. More... | |
const uint32_t | deviceSize |
const uint32_t | deviceRowBufferSize |
const uint32_t | devicesPerRank |
const uint32_t | rowBufferSize |
const uint32_t | burstsPerRowBuffer |
const uint32_t | burstsPerStripe |
const uint32_t | ranksPerChannel |
const uint32_t | banksPerRank |
uint32_t | rowsPerBank |
const Tick M5_CLASS_VAR_USED | tCK |
General timing requirements. More... | |
const Tick | tCS |
const Tick | tBURST |
const Tick | tRTW |
const Tick | tWTR |
Protected Attributes inherited from AbstractMemory | |
AddrRange | range |
uint8_t * | pmemAddr |
MemBackdoor | backdoor |
const bool | confTableReported |
const bool | inAddrMap |
const bool | kvmMap |
std::list< LockedAddr > | lockedAddrList |
System * | _system |
Pointer to the System object. More... | |
AbstractMemory::MemStats | stats |
Protected Attributes inherited from SimObject | |
const SimObjectParams * | _params |
Cached copy of the object parameters. More... | |
Protected Attributes inherited from EventManager | |
EventQueue * | eventq |
A pointer to this object's event queue. More... | |
Additional Inherited Members | |
Static Public Member Functions inherited from SimObject | |
static void | serializeAll (CheckpointOut &cp) |
Serialize all SimObjects in the system. More... | |
static SimObject * | find (const char *name) |
Find the SimObject with the given name and return a pointer to it. More... | |
Static Public Member Functions inherited from Serializable | |
static const std::string & | currentSection () |
Gets the fully-qualified name of the active section. More... | |
static void | serializeAll (const std::string &cpt_dir) |
Serializes all the SimObjects. More... | |
static void | unserializeGlobals (CheckpointIn &cp) |
General interface to memory device Includes functions and parameters shared across media types.
Definition at line 70 of file mem_interface.hh.
typedef MemInterfaceParams MemInterface::Params |
Definition at line 291 of file mem_interface.hh.
MemInterface::MemInterface | ( | const Params * | _p | ) |
Definition at line 54 of file mem_interface.cc.
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pure virtual |
Implemented in NVMInterface, and DRAMInterface.
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pure virtual |
Add rank to rank delay to bus timing to all banks in all ranks when access to an alternate interface is issued.
param cmd_at Time of current command used as starting point for addition of rank-to-rank delay
Implemented in NVMInterface, and DRAMInterface.
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pure virtual |
Check drain state of interface.
Implemented in NVMInterface, and DRAMInterface.
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pure virtual |
Check if a burst operation can be issued to the interface.
Return | true if RD/WR can issue |
Implemented in NVMInterface, and DRAMInterface.
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inline |
Definition at line 233 of file mem_interface.hh.
References burstSize.
Referenced by MemCtrl::addToReadQueue(), MemCtrl::addToWriteQueue(), MemCtrl::burstAlign(), MemCtrl::processNextReqEvent(), and MemCtrl::recvTimingReq().
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pure virtual |
For FR-FCFS policy, find first command that can issue Function will be overriden by interface to select based on media characteristics, used to determine when read or write can issue.
queue | Queued requests to consider |
min_col_at | Minimum tick for 'seamless' issue |
Implemented in NVMInterface, and DRAMInterface.
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pure virtual |
Implemented in NVMInterface, and DRAMInterface.
MemPacket * MemInterface::decodePacket | ( | const PacketPtr | pkt, |
Addr | pkt_addr, | ||
unsigned int | size, | ||
bool | is_read, | ||
bool | is_dram | ||
) |
Address decoder to figure out physical mapping onto ranks, banks, and rows.
This function is called multiple times on the same system packet if the pakcet is larger than burst of the memory. The pkt_addr is used for the offset within the packet.
pkt | The packet from the outside world |
pkt_addr | The starting address of the packet |
size | The size of the packet in bytes |
is_read | Is the request for a read or a write to memory |
is_dram | Is the request to a DRAM interface |
Definition at line 83 of file mem_interface.cc.
References addr, addrMapping, banksPerRank, burstSize, burstsPerRowBuffer, burstsPerStripe, DPRINTF, getCtrlAddr(), MemInterface::Bank::NO_ROW, panic, ranksPerChannel, rowsPerBank, and AbstractMemory::size().
Referenced by MemCtrl::addToReadQueue(), and MemCtrl::addToWriteQueue().
Get an address in a dense range which starts from 0.
The input address is the physical address of the request in an address space that contains other SimObjects apart from this controller.
addr | The intput address which should be in the addrRange |
Definition at line 193 of file mem_interface.hh.
References addr, AddrRange::getOffset(), and AbstractMemory::range.
Referenced by decodePacket().
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inline |
Definition at line 258 of file mem_interface.hh.
Referenced by MemCtrl::minReadToWriteDataGap().
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inline |
Definition at line 264 of file mem_interface.hh.
Referenced by MemCtrl::minWriteToReadDataGap().
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inline |
Determine the required delay for an access to a different rank.
Definition at line 252 of file mem_interface.hh.
References tCS.
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inlineprotected |
Definition at line 162 of file mem_interface.hh.
Referenced by DRAMInterface::addRankToRankDelay(), NVMInterface::addRankToRankDelay(), DRAMInterface::doBurstAccess(), and NVMInterface::doBurstAccess().
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inlineprotected |
Definition at line 157 of file mem_interface.hh.
Referenced by DRAMInterface::doBurstAccess(), and NVMInterface::doBurstAccess().
void MemInterface::setCtrl | ( | MemCtrl * | _ctrl, |
unsigned int | command_window | ||
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Set a pointer to the controller and initialize interface based on controller parameters.
_ctrl | pointer to the parent controller |
command_window | size of command window used to check command bandwidth |
Definition at line 76 of file mem_interface.cc.
References ctrl, maxCommandsPerWindow, and tCK.
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pure virtual |
Setup the rank based on packet received.
integer | value of rank to be setup. used to index ranks vector |
are | we setting up rank for read or write packet? |
Implemented in NVMInterface, and DRAMInterface.
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inlineprotectedvirtual |
Reimplemented in DRAMInterface.
Definition at line 152 of file mem_interface.hh.
Referenced by NVMInterface::doBurstAccess().
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protected |
Memory controller configuration initialized based on parameter values.
Definition at line 122 of file mem_interface.hh.
Referenced by decodePacket(), and DRAMInterface::init().
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protected |
Definition at line 137 of file mem_interface.hh.
Referenced by DRAMInterface::activateBank(), DRAMInterface::addRankToRankDelay(), NVMInterface::addRankToRankDelay(), decodePacket(), DRAMInterface::doBurstAccess(), NVMInterface::doBurstAccess(), DRAMInterface::DRAMInterface(), DRAMInterface::minBankPrep(), and DRAMInterface::prechargeBank().
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protected |
General device and channel characteristics The rowsPerBank is determined based on the capacity, number of ranks and banks, the burst size, and the row buffer size.
Definition at line 129 of file mem_interface.hh.
Referenced by bytesPerBurst(), NVMInterface::chooseRead(), decodePacket(), DRAMInterface::doBurstAccess(), NVMInterface::doBurstAccess(), and DRAMInterface::DRAMInterface().
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Definition at line 134 of file mem_interface.hh.
Referenced by decodePacket(), DRAMInterface::DRAMInterface(), and DRAMInterface::init().
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Definition at line 135 of file mem_interface.hh.
Referenced by decodePacket(), and DRAMInterface::init().
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A pointer to the parent MemCtrl instance.
Definition at line 110 of file mem_interface.hh.
Referenced by DRAMInterface::activateBank(), NVMInterface::burstReady(), NVMInterface::chooseRead(), DRAMInterface::doBurstAccess(), NVMInterface::doBurstAccess(), NVMInterface::isBusy(), DRAMInterface::minBankPrep(), DRAMInterface::prechargeBank(), NVMInterface::processReadReadyEvent(), NVMInterface::processWriteRespondEvent(), and setCtrl().
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Definition at line 131 of file mem_interface.hh.
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Definition at line 130 of file mem_interface.hh.
Referenced by DRAMInterface::DRAMInterface().
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Definition at line 132 of file mem_interface.hh.
Referenced by DRAMInterface::DRAMInterface().
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Number of commands that can issue in the defined controller command window, used to verify command bandwidth.
Definition at line 116 of file mem_interface.hh.
Referenced by DRAMInterface::activateBank(), NVMInterface::chooseRead(), DRAMInterface::doBurstAccess(), NVMInterface::doBurstAccess(), DRAMInterface::prechargeBank(), and setCtrl().
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protected |
Definition at line 136 of file mem_interface.hh.
Referenced by DRAMInterface::chooseNextFRFCFS(), decodePacket(), DRAMInterface::doBurstAccess(), DRAMInterface::DRAMInterface(), DRAMInterface::isBusy(), and DRAMInterface::minBankPrep().
const uint32_t MemInterface::readBufferSize |
Buffer sizes for read and write queues in the controller These are passed to the controller on instantiation Defining them here allows for buffers to be resized based on memory type / configuration.
Definition at line 173 of file mem_interface.hh.
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Definition at line 133 of file mem_interface.hh.
Referenced by DRAMInterface::DRAMInterface(), and DRAMInterface::init().
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Definition at line 138 of file mem_interface.hh.
Referenced by decodePacket(), and DRAMInterface::DRAMInterface().
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Definition at line 145 of file mem_interface.hh.
Referenced by DRAMInterface::burstDelay(), NVMInterface::commandOffset(), DRAMInterface::doBurstAccess(), NVMInterface::doBurstAccess(), DRAMInterface::DRAMInterface(), rankToRankDelay(), readToWriteDelay(), writeToReadDelay(), and DRAMInterface::writeToReadDelay().
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protected |
General timing requirements.
Definition at line 143 of file mem_interface.hh.
Referenced by DRAMInterface::activateBank(), NVMInterface::chooseRead(), DRAMInterface::doBurstAccess(), NVMInterface::doBurstAccess(), DRAMInterface::prechargeBank(), setCtrl(), and DRAMInterface::startup().
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Definition at line 144 of file mem_interface.hh.
Referenced by minReadToWriteDataGap(), minWriteToReadDataGap(), rankDelay(), and rankToRankDelay().
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protected |
Definition at line 146 of file mem_interface.hh.
Referenced by minReadToWriteDataGap(), and readToWriteDelay().
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Definition at line 147 of file mem_interface.hh.
Referenced by minWriteToReadDataGap(), writeToReadDelay(), and DRAMInterface::writeToReadDelay().
const uint32_t MemInterface::writeBufferSize |
Definition at line 174 of file mem_interface.hh.