gem5  v21.1.0.2
Classes | Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
gem5::CoherentXBar Class Reference

A coherent crossbar connects a number of (potentially) snooping requestors and responders, and routes the request and response packets based on the address, and also forwards all requests to the snoopers and deals with the snoop responses. More...

#include <coherent_xbar.hh>

Inheritance diagram for gem5::CoherentXBar:
gem5::BaseXBar gem5::ClockedObject gem5::SimObject gem5::Clocked gem5::EventManager gem5::Serializable gem5::Drainable gem5::statistics::Group gem5::Named

Classes

class  CoherentXBarRequestPort
 Declaration of the coherent crossbar memory-side port type, one will be instantiated for each of the CPU-side-port interfaces connecting to the crossbar. More...
 
class  CoherentXBarResponsePort
 Declaration of the coherent crossbar CPU-side port type, one will be instantiated for each of the mem_side_ports connecting to the crossbar. More...
 
class  SnoopRespPort
 Internal class to bridge between an incoming snoop response from a CPU-side port and forwarding it through an outgoing CPU-side port. More...
 

Public Member Functions

virtual void init ()
 init() is called after all C++ SimObjects have been created and all ports are connected. More...
 
 CoherentXBar (const CoherentXBarParams &p)
 
virtual ~CoherentXBar ()
 
virtual void regStats ()
 Callback to set stat parameters. More...
 
- Public Member Functions inherited from gem5::BaseXBar
virtual ~BaseXBar ()
 
PortgetPort (const std::string &if_name, PortID idx=InvalidPortID) override
 A function used to return the port associated with this object. More...
 
void regStats () override
 Callback to set stat parameters. More...
 
- Public Member Functions inherited from gem5::ClockedObject
 ClockedObject (const ClockedObjectParams &p)
 
void serialize (CheckpointOut &cp) const override
 Serialize an object. More...
 
void unserialize (CheckpointIn &cp) override
 Unserialize an object. More...
 
- Public Member Functions inherited from gem5::SimObject
const Paramsparams () const
 
 SimObject (const Params &p)
 
virtual ~SimObject ()
 
virtual void loadState (CheckpointIn &cp)
 loadState() is called on each SimObject when restoring from a checkpoint. More...
 
virtual void initState ()
 initState() is called on each SimObject when not 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...
 
ProbeManagergetProbeManager ()
 Get the probe manager for this object. 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 gem5::EventManager
EventQueueeventQueue () 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 gem5::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 gem5::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 gem5::statistics::Group
 Group (Group *parent, const char *name=nullptr)
 Construct a new statistics group. More...
 
virtual ~Group ()
 
virtual void resetStats ()
 Callback to reset stats. More...
 
virtual void preDumpStats ()
 Callback before stats are dumped. More...
 
void addStat (statistics::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 InforesolveStat (std::string name) const
 Resolve a stat by its name within this group. More...
 
void mergeStatGroup (Group *block)
 Merge the contents (stats & children) of a block to this block. More...
 
 Group ()=delete
 
 Group (const Group &)=delete
 
Groupoperator= (const Group &)=delete
 
- Public Member Functions inherited from gem5::Named
 Named (const std::string &name_)
 
virtual ~Named ()=default
 
virtual std::string name () const
 
- Public Member Functions inherited from gem5::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
 

Protected Member Functions

bool recvTimingReq (PacketPtr pkt, PortID cpu_side_port_id)
 
bool recvTimingResp (PacketPtr pkt, PortID mem_side_port_id)
 
void recvTimingSnoopReq (PacketPtr pkt, PortID mem_side_port_id)
 
bool recvTimingSnoopResp (PacketPtr pkt, PortID cpu_side_port_id)
 
void recvReqRetry (PortID mem_side_port_id)
 
void forwardTiming (PacketPtr pkt, PortID exclude_cpu_side_port_id)
 Forward a timing packet to our snoopers, potentially excluding one of the connected coherent requestors to avoid sending a packet back to where it came from. More...
 
void forwardTiming (PacketPtr pkt, PortID exclude_cpu_side_port_id, const std::vector< QueuedResponsePort * > &dests)
 Forward a timing packet to a selected list of snoopers, potentially excluding one of the connected coherent requestors to avoid sending a packet back to where it came from. More...
 
Tick recvAtomicBackdoor (PacketPtr pkt, PortID cpu_side_port_id, MemBackdoorPtr *backdoor=nullptr)
 
Tick recvAtomicSnoop (PacketPtr pkt, PortID mem_side_port_id)
 
std::pair< MemCmd, TickforwardAtomic (PacketPtr pkt, PortID exclude_cpu_side_port_id)
 Forward an atomic packet to our snoopers, potentially excluding one of the connected coherent requestors to avoid sending a packet back to where it came from. More...
 
std::pair< MemCmd, TickforwardAtomic (PacketPtr pkt, PortID exclude_cpu_side_port_id, PortID source_mem_side_port_id, const std::vector< QueuedResponsePort * > &dests)
 Forward an atomic packet to a selected list of snoopers, potentially excluding one of the connected coherent requestors to avoid sending a packet back to where it came from. More...
 
void recvFunctional (PacketPtr pkt, PortID cpu_side_port_id)
 Function called by the port when the crossbar is receiving a Functional transaction. More...
 
void recvFunctionalSnoop (PacketPtr pkt, PortID mem_side_port_id)
 Function called by the port when the crossbar is receiving a functional snoop transaction. More...
 
void forwardFunctional (PacketPtr pkt, PortID exclude_cpu_side_port_id)
 Forward a functional packet to our snoopers, potentially excluding one of the connected coherent requestors to avoid sending a packet back to where it came from. More...
 
bool sinkPacket (const PacketPtr pkt) const
 Determine if the crossbar should sink the packet, as opposed to forwarding it, or responding. More...
 
bool forwardPacket (const PacketPtr pkt)
 Determine if the crossbar should forward the packet, as opposed to responding to it. More...
 
bool isDestination (const PacketPtr pkt) const
 Determine if the packet's destination is the memory below. More...
 
- Protected Member Functions inherited from gem5::BaseXBar
virtual void recvRangeChange (PortID mem_side_port_id)
 Function called by the port when the crossbar is recieving a range change. More...
 
PortID findPort (AddrRange addr_range)
 Find which port connected to this crossbar (if any) should be given a packet with this address range. More...
 
AddrRangeList getAddrRanges () const
 Return the address ranges the crossbar is responsible for. More...
 
void calcPacketTiming (PacketPtr pkt, Tick header_delay)
 Calculate the timing parameters for the packet. More...
 
 BaseXBar (const BaseXBarParams &p)
 
- Protected Member Functions inherited from gem5::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 gem5::Clocked
 Clocked (ClockDomain &clk_domain)
 Create a clocked object and set the clock domain based on the parameters. More...
 
 Clocked (Clocked &)=delete
 
Clockedoperator= (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

std::vector< ReqLayer * > reqLayers
 Declare the layers of this crossbar, one vector for requests, one for responses, and one for snoop responses. More...
 
std::vector< RespLayer * > respLayers
 
std::vector< SnoopRespLayer * > snoopLayers
 
std::vector< SnoopRespPort * > snoopRespPorts
 
std::vector< QueuedResponsePort * > snoopPorts
 
std::unordered_set< RequestPtroutstandingSnoop
 Store the outstanding requests that we are expecting snoop responses from so we can determine which snoop responses we generated and which ones were merely forwarded. More...
 
std::unordered_map< PacketId, PacketPtroutstandingCMO
 Store the outstanding cache maintenance that we are expecting snoop responses from so we can determine when we received all snoop responses and if any of the agents satisfied the request. More...
 
Systemsystem
 Keep a pointer to the system to be allow to querying memory system properties. More...
 
SnoopFiltersnoopFilter
 A snoop filter that tracks cache line residency and can restrict the broadcast needed for probes. More...
 
const Cycles snoopResponseLatency
 Cycles of snoop response latency. More...
 
const unsigned int maxOutstandingSnoopCheck
 Maximum number of outstading snoops sanity check. More...
 
const unsigned int maxRoutingTableSizeCheck
 Maximum routing table size sanity check. More...
 
const bool pointOfCoherency
 Is this crossbar the point of coherency? More...
 
const bool pointOfUnification
 Is this crossbar the point of unification? More...
 
std::unique_ptr< PacketpendingDelete
 Upstream caches need this packet until true is returned, so hold it for deletion until a subsequent call. More...
 
statistics::Scalar snoops
 
statistics::Scalar snoopTraffic
 
statistics::Distribution snoopFanout
 
- Protected Attributes inherited from gem5::BaseXBar
const Cycles frontendLatency
 Cycles of front-end pipeline including the delay to accept the request and to decode the address. More...
 
const Cycles forwardLatency
 
const Cycles responseLatency
 
const Cycles headerLatency
 Cycles the layer is occupied processing the packet header. More...
 
const uint32_t width
 the width of the xbar in bytes More...
 
AddrRangeMap< PortID, 3 > portMap
 
std::unordered_map< RequestPtr, PortIDrouteTo
 Remember where request packets came from so that we can route responses to the appropriate port. More...
 
AddrRangeList xbarRanges
 all contigous ranges seen by this crossbar More...
 
AddrRange defaultRange
 
std::vector< bool > gotAddrRanges
 Remember for each of the memory-side ports of the crossbar if we got an address range from the connected CPU-side ports. More...
 
bool gotAllAddrRanges
 
std::vector< QueuedResponsePort * > cpuSidePorts
 The memory-side ports and CPU-side ports of the crossbar. More...
 
std::vector< RequestPort * > memSidePorts
 
PortID defaultPortID
 Port that handles requests that don't match any of the interfaces. More...
 
const bool useDefaultRange
 If true, use address range provided by default device. More...
 
statistics::Vector transDist
 Stats for transaction distribution and data passing through the crossbar. More...
 
statistics::Vector2d pktCount
 
statistics::Vector2d pktSize
 
- Protected Attributes inherited from gem5::SimObject
const SimObjectParams & _params
 Cached copy of the object parameters. More...
 
- Protected Attributes inherited from gem5::EventManager
EventQueueeventq
 A pointer to this object's event queue. More...
 

Additional Inherited Members

- Public Types inherited from gem5::ClockedObject
using Params = ClockedObjectParams
 Parameters of ClockedObject. More...
 
- Public Types inherited from gem5::SimObject
typedef SimObjectParams Params
 
- Static Public Member Functions inherited from gem5::SimObject
static void serializeAll (const std::string &cpt_dir)
 Create a checkpoint by serializing all SimObjects in the system. More...
 
static SimObjectfind (const char *name)
 Find the SimObject with the given name and return a pointer to it. More...
 
static void setSimObjectResolver (SimObjectResolver *resolver)
 There is a single object name resolver, and it is only set when simulation is restoring from checkpoints. More...
 
static SimObjectResolvergetSimObjectResolver ()
 There is a single object name resolver, and it is only set when simulation is restoring from checkpoints. More...
 
- Static Public Member Functions inherited from gem5::Serializable
static const std::string & currentSection ()
 Gets the fully-qualified name of the active section. More...
 
static void generateCheckpointOut (const std::string &cpt_dir, std::ofstream &outstream)
 Generate a checkpoint file so that the serialization can be routed to it. More...
 
- Public Attributes inherited from gem5::ClockedObject
PowerStatepowerState
 

Detailed Description

A coherent crossbar connects a number of (potentially) snooping requestors and responders, and routes the request and response packets based on the address, and also forwards all requests to the snoopers and deals with the snoop responses.

The coherent crossbar can be used as a template for modelling QPI, HyperTransport, ACE and coherent OCP buses, and is typically used for the L1-to-L2 buses and as the main system interconnect.

See also
gem5 Memory System

Definition at line 70 of file coherent_xbar.hh.

Constructor & Destructor Documentation

◆ CoherentXBar()

gem5::CoherentXBar::CoherentXBar ( const CoherentXBarParams &  p)

◆ ~CoherentXBar()

gem5::CoherentXBar::~CoherentXBar ( )
virtual

Member Function Documentation

◆ forwardAtomic() [1/2]

std::pair<MemCmd, Tick> gem5::CoherentXBar::forwardAtomic ( PacketPtr  pkt,
PortID  exclude_cpu_side_port_id 
)
inlineprotected

Forward an atomic packet to our snoopers, potentially excluding one of the connected coherent requestors to avoid sending a packet back to where it came from.

Parameters
pktPacket to forward
exclude_cpu_side_port_idId of CPU-side port to exclude
Returns
a pair containing the snoop response and snoop latency

Definition at line 348 of file coherent_xbar.hh.

References gem5::InvalidPortID, and snoopPorts.

Referenced by recvAtomicBackdoor(), and recvAtomicSnoop().

◆ forwardAtomic() [2/2]

std::pair< MemCmd, Tick > gem5::CoherentXBar::forwardAtomic ( PacketPtr  pkt,
PortID  exclude_cpu_side_port_id,
PortID  source_mem_side_port_id,
const std::vector< QueuedResponsePort * > &  dests 
)
protected

Forward an atomic packet to a selected list of snoopers, potentially excluding one of the connected coherent requestors to avoid sending a packet back to where it came from.

Parameters
pktPacket to forward
exclude_cpu_side_port_idId of CPU-side port to exclude
source_mem_side_port_idId of the memory-side port for snoops from below
destsVector of destination ports for the forwarded pkt
Returns
a pair containing the snoop response and snoop latency

Definition at line 930 of file coherent_xbar.cc.

References gem5::System::bypassCaches(), gem5::Packet::cacheResponding(), gem5::Packet::cmd, gem5::BaseXBar::cpuSidePorts, gem5::MemCmd::InvalidCmd, gem5::InvalidPortID, gem5::Packet::isResponse(), gem5::BaseXBar::memSidePorts, gem5::MipsISA::p, gem5::statistics::DistBase< Derived, Stor >::sample(), snoopFanout, snoopFilter, system, gem5::SnoopFilter::updateSnoopForward(), and gem5::SnoopFilter::updateSnoopResponse().

◆ forwardFunctional()

void gem5::CoherentXBar::forwardFunctional ( PacketPtr  pkt,
PortID  exclude_cpu_side_port_id 
)
protected

Forward a functional packet to our snoopers, potentially excluding one of the connected coherent requestors to avoid sending a packet back to where it came from.

Parameters
pktPacket to forward
exclude_cpu_side_port_idId of CPU-side port to exclude

Definition at line 1058 of file coherent_xbar.cc.

References gem5::System::bypassCaches(), gem5::InvalidPortID, gem5::Packet::isResponse(), gem5::MipsISA::p, snoopPorts, and system.

Referenced by recvFunctional(), and recvFunctionalSnoop().

◆ forwardPacket()

bool gem5::CoherentXBar::forwardPacket ( const PacketPtr  pkt)
protected

Determine if the crossbar should forward the packet, as opposed to responding to it.

Definition at line 1104 of file coherent_xbar.cc.

References gem5::Packet::isClean(), isDestination(), gem5::Packet::isRead(), gem5::Packet::isWrite(), and pointOfCoherency.

Referenced by recvAtomicBackdoor(), and recvTimingReq().

◆ forwardTiming() [1/2]

void gem5::CoherentXBar::forwardTiming ( PacketPtr  pkt,
PortID  exclude_cpu_side_port_id 
)
inlineprotected

Forward a timing packet to our snoopers, potentially excluding one of the connected coherent requestors to avoid sending a packet back to where it came from.

Parameters
pktPacket to forward
exclude_cpu_side_port_idId of CPU-side port to exclude

Definition at line 316 of file coherent_xbar.hh.

References snoopPorts.

Referenced by recvTimingReq(), and recvTimingSnoopReq().

◆ forwardTiming() [2/2]

void gem5::CoherentXBar::forwardTiming ( PacketPtr  pkt,
PortID  exclude_cpu_side_port_id,
const std::vector< QueuedResponsePort * > &  dests 
)
protected

Forward a timing packet to a selected list of snoopers, potentially excluding one of the connected coherent requestors to avoid sending a packet back to where it came from.

Parameters
pktPacket to forward
exclude_cpu_side_port_idId of CPU-side port to exclude
destsVector of destination ports for the forwarded pkt

Definition at line 700 of file coherent_xbar.cc.

References gem5::System::bypassCaches(), DPRINTF, gem5::InvalidPortID, gem5::MipsISA::p, gem5::Packet::print(), gem5::statistics::DistBase< Derived, Stor >::sample(), snoopFanout, and system.

◆ init()

void gem5::CoherentXBar::init ( )
virtual

init() is called after all C++ SimObjects have been created and all ports are connected.

Initializations that are independent of unserialization but rely on a fully instantiated and connected SimObject graph should be done here.

Reimplemented from gem5::SimObject.

Definition at line 124 of file coherent_xbar.cc.

References gem5::BaseXBar::cpuSidePorts, DPRINTF, gem5::SimObject::init(), gem5::Named::name(), gem5::MipsISA::p, gem5::SnoopFilter::setCPUSidePorts(), snoopFilter, snoopPorts, and warn.

◆ isDestination()

bool gem5::CoherentXBar::isDestination ( const PacketPtr  pkt) const
inlineprotected

Determine if the packet's destination is the memory below.

The memory below is the destination for a cache mainteance operation to the Point of Coherence/Unification if this is the Point of Coherence/Unification.

Parameters
pktThe processed packet
Returns
Whether the memory below is the destination for the packet

Definition at line 415 of file coherent_xbar.hh.

References pointOfCoherency, pointOfUnification, and gem5::Packet::req.

Referenced by forwardPacket(), recvAtomicBackdoor(), and recvTimingReq().

◆ recvAtomicBackdoor()

Tick gem5::CoherentXBar::recvAtomicBackdoor ( PacketPtr  pkt,
PortID  cpu_side_port_id,
MemBackdoorPtr backdoor = nullptr 
)
protected

◆ recvAtomicSnoop()

Tick gem5::CoherentXBar::recvAtomicSnoop ( PacketPtr  pkt,
PortID  mem_side_port_id 
)
protected

◆ recvFunctional()

void gem5::CoherentXBar::recvFunctional ( PacketPtr  pkt,
PortID  cpu_side_port_id 
)
protected

◆ recvFunctionalSnoop()

void gem5::CoherentXBar::recvFunctionalSnoop ( PacketPtr  pkt,
PortID  mem_side_port_id 
)
protected

◆ recvReqRetry()

void gem5::CoherentXBar::recvReqRetry ( PortID  mem_side_port_id)
protected

Definition at line 728 of file coherent_xbar.cc.

References reqLayers.

Referenced by gem5::CoherentXBar::CoherentXBarRequestPort::recvReqRetry().

◆ recvTimingReq()

bool gem5::CoherentXBar::recvTimingReq ( PacketPtr  pkt,
PortID  cpu_side_port_id 
)
protected

Definition at line 149 of file coherent_xbar.cc.

References gem5::X86ISA::addr, gem5::System::bypassCaches(), gem5::Packet::cacheResponding(), gem5::BaseXBar::calcPacketTiming(), gem5::Packet::clearWriteThrough(), gem5::Clocked::clockEdge(), gem5::Clocked::clockPeriod(), gem5::Packet::cmd, gem5::Packet::cmdToIndex(), gem5::BaseXBar::cpuSidePorts, DPRINTF, gem5::BaseXBar::findPort(), gem5::SnoopFilter::finishRequest(), gem5::BaseXBar::forwardLatency, forwardPacket(), forwardTiming(), gem5::BaseXBar::frontendLatency, gem5::Packet::getAddr(), gem5::Packet::getAddrRange(), gem5::Packet::getSize(), gem5::Packet::hasData(), gem5::Packet::headerDelay, gem5::BaseXBar::headerLatency, gem5::Packet::id, gem5::InvalidPortID, gem5::Packet::isClean(), isDestination(), gem5::Packet::isEviction(), gem5::Packet::isExpressSnoop(), gem5::Packet::isSecure(), gem5::Packet::isWrite(), gem5::SnoopFilter::lookupRequest(), gem5::Packet::makeResponse(), maxOutstandingSnoopCheck, maxRoutingTableSizeCheck, gem5::BaseXBar::memSidePorts, gem5::Named::name(), gem5::Port::name(), gem5::Packet::needsResponse(), outstandingCMO, outstandingSnoop, panic_if, gem5::Packet::payloadDelay, pendingDelete, gem5::BaseXBar::pktCount, gem5::BaseXBar::pktSize, gem5::Packet::print(), gem5::Packet::req, reqLayers, respLayers, gem5::BaseXBar::routeTo, gem5::Packet::satisfied(), gem5::Packet::setBlockCached(), gem5::Packet::setExpressSnoop(), sinkPacket(), gem5::Packet::snoopDelay, snoopFilter, snoops, snoopTraffic, system, gem5::BaseXBar::transDist, gem5::SnoopFilter::updateResponse(), and gem5::MemCmd::WriteClean.

Referenced by gem5::CoherentXBar::CoherentXBarResponsePort::recvTimingReq().

◆ recvTimingResp()

bool gem5::CoherentXBar::recvTimingResp ( PacketPtr  pkt,
PortID  mem_side_port_id 
)
protected

◆ recvTimingSnoopReq()

void gem5::CoherentXBar::recvTimingSnoopReq ( PacketPtr  pkt,
PortID  mem_side_port_id 
)
protected

◆ recvTimingSnoopResp()

bool gem5::CoherentXBar::recvTimingSnoopResp ( PacketPtr  pkt,
PortID  cpu_side_port_id 
)
protected

◆ regStats()

void gem5::CoherentXBar::regStats ( )
virtual

Callback to set stat parameters.

This callback is typically used for complex stats (e.g., distributions) that need parameters in addition to a name and a description. Stat names and descriptions should typically be set from the constructor usingo from the constructor using the ADD_STAT macro.

Reimplemented from gem5::statistics::Group.

Definition at line 1119 of file coherent_xbar.cc.

References gem5::statistics::Distribution::init(), gem5::BaseXBar::regStats(), snoopFanout, and snoopPorts.

◆ sinkPacket()

bool gem5::CoherentXBar::sinkPacket ( const PacketPtr  pkt) const
protected

Member Data Documentation

◆ maxOutstandingSnoopCheck

const unsigned int gem5::CoherentXBar::maxOutstandingSnoopCheck
protected

Maximum number of outstading snoops sanity check.

Definition at line 284 of file coherent_xbar.hh.

Referenced by recvTimingReq().

◆ maxRoutingTableSizeCheck

const unsigned int gem5::CoherentXBar::maxRoutingTableSizeCheck
protected

Maximum routing table size sanity check.

Definition at line 287 of file coherent_xbar.hh.

Referenced by recvTimingReq().

◆ outstandingCMO

std::unordered_map<PacketId, PacketPtr> gem5::CoherentXBar::outstandingCMO
protected

Store the outstanding cache maintenance that we are expecting snoop responses from so we can determine when we received all snoop responses and if any of the agents satisfied the request.

Definition at line 268 of file coherent_xbar.hh.

Referenced by recvAtomicBackdoor(), and recvTimingReq().

◆ outstandingSnoop

std::unordered_set<RequestPtr> gem5::CoherentXBar::outstandingSnoop
protected

Store the outstanding requests that we are expecting snoop responses from so we can determine which snoop responses we generated and which ones were merely forwarded.

Definition at line 261 of file coherent_xbar.hh.

Referenced by recvTimingReq(), and recvTimingSnoopResp().

◆ pendingDelete

std::unique_ptr<Packet> gem5::CoherentXBar::pendingDelete
protected

Upstream caches need this packet until true is returned, so hold it for deletion until a subsequent call.

Definition at line 299 of file coherent_xbar.hh.

Referenced by recvTimingReq().

◆ pointOfCoherency

const bool gem5::CoherentXBar::pointOfCoherency
protected

Is this crossbar the point of coherency?

Definition at line 290 of file coherent_xbar.hh.

Referenced by forwardPacket(), isDestination(), and sinkPacket().

◆ pointOfUnification

const bool gem5::CoherentXBar::pointOfUnification
protected

Is this crossbar the point of unification?

Definition at line 293 of file coherent_xbar.hh.

Referenced by isDestination().

◆ reqLayers

std::vector<ReqLayer*> gem5::CoherentXBar::reqLayers
protected

Declare the layers of this crossbar, one vector for requests, one for responses, and one for snoop responses.

Definition at line 79 of file coherent_xbar.hh.

Referenced by CoherentXBar(), recvReqRetry(), recvTimingReq(), and ~CoherentXBar().

◆ respLayers

std::vector<RespLayer*> gem5::CoherentXBar::respLayers
protected

◆ snoopFanout

statistics::Distribution gem5::CoherentXBar::snoopFanout
protected

Definition at line 423 of file coherent_xbar.hh.

Referenced by forwardAtomic(), forwardTiming(), and regStats().

◆ snoopFilter

SnoopFilter* gem5::CoherentXBar::snoopFilter
protected

A snoop filter that tracks cache line residency and can restrict the broadcast needed for probes.

NULL denotes an absent filter.

Definition at line 278 of file coherent_xbar.hh.

Referenced by forwardAtomic(), init(), recvAtomicBackdoor(), recvAtomicSnoop(), recvTimingReq(), recvTimingResp(), recvTimingSnoopReq(), and recvTimingSnoopResp().

◆ snoopLayers

std::vector<SnoopRespLayer*> gem5::CoherentXBar::snoopLayers
protected

Definition at line 81 of file coherent_xbar.hh.

Referenced by CoherentXBar(), recvTimingSnoopResp(), and ~CoherentXBar().

◆ snoopPorts

std::vector<QueuedResponsePort*> gem5::CoherentXBar::snoopPorts
protected

Definition at line 254 of file coherent_xbar.hh.

Referenced by forwardAtomic(), forwardFunctional(), forwardTiming(), init(), and regStats().

◆ snoopResponseLatency

const Cycles gem5::CoherentXBar::snoopResponseLatency
protected

Cycles of snoop response latency.

Definition at line 281 of file coherent_xbar.hh.

Referenced by recvTimingSnoopResp().

◆ snoopRespPorts

std::vector<SnoopRespPort*> gem5::CoherentXBar::snoopRespPorts
protected

Definition at line 252 of file coherent_xbar.hh.

Referenced by CoherentXBar(), recvTimingSnoopResp(), and ~CoherentXBar().

◆ snoops

statistics::Scalar gem5::CoherentXBar::snoops
protected

◆ snoopTraffic

statistics::Scalar gem5::CoherentXBar::snoopTraffic
protected

◆ system

System* gem5::CoherentXBar::system
protected

Keep a pointer to the system to be allow to querying memory system properties.

Definition at line 274 of file coherent_xbar.hh.

Referenced by forwardAtomic(), forwardFunctional(), forwardTiming(), recvAtomicBackdoor(), recvFunctional(), recvTimingReq(), and recvTimingResp().


The documentation for this class was generated from the following files:

Generated on Tue Sep 21 2021 12:27:24 for gem5 by doxygen 1.8.17