A coherent crossbar connects a number of (potentially) snooping masters and slaves, 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 CoherentXBar:

Classes
class	CoherentXBarMasterPort
	Declaration of the coherent crossbar master port type, one will be instantiated for each of the slave interfaces connecting to the crossbar. More...

class	CoherentXBarSlavePort
	Declaration of the coherent crossbar slave port type, one will be instantiated for each of the master ports connecting to the crossbar. More...

class	SnoopRespPort
	Internal class to bridge between an incoming snoop response from a slave port and forwarding it through an outgoing slave 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 ()
	Register statistics for this object. More...

Public Member Functions inherited from BaseXBar
virtual	~BaseXBar ()

BaseMasterPort &	getMasterPort (const std::string &if_name, PortID idx=InvalidPortID)
	A function used to return the port associated with this object. More...

BaseSlavePort &	getSlavePort (const std::string &if_name, PortID idx=InvalidPortID)
	Get a slave port with a given name and index. More...

Public Member Functions inherited from MemObject
const Params *	params () const

	MemObject (const Params *params)

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...

Enums::PwrState	pwrState () const

std::string	pwrStateName () const

std::vector< double >	pwrStateWeights () const
	Returns the percentage residency for each power state. More...

void	computeStats ()
	Record stats values like state residency by computing the time difference from previous update. More...

void	pwrState (Enums::PwrState)

void	regStats () override
	Register statistics for this 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	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	resetStats ()
	Reset statistics associated with this object. 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 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
	EventManager (EventManager &em)

	EventManager (EventManager *em)

	EventManager (EventQueue *eq)

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)

void	setCurTick (Tick newVal)

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 Clocked
void	updateClockPeriod () const
	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 slave_port_id)
	Function called by the port when the crossbar is recieving a Timing request packet. More...

bool	recvTimingResp (PacketPtr pkt, PortID master_port_id)
	Function called by the port when the crossbar is recieving a Timing response packet. More...

void	recvTimingSnoopReq (PacketPtr pkt, PortID master_port_id)
	Function called by the port when the crossbar is recieving a timing snoop request. More...

bool	recvTimingSnoopResp (PacketPtr pkt, PortID slave_port_id)
	Function called by the port when the crossbar is recieving a timing snoop response. More...

void	recvReqRetry (PortID master_port_id)
	Timing function called by port when it is once again able to process requests. More...

void	forwardTiming (PacketPtr pkt, PortID exclude_slave_port_id)
	Forward a timing packet to our snoopers, potentially excluding one of the connected coherent masters to avoid sending a packet back to where it came from. More...

void	forwardTiming (PacketPtr pkt, PortID exclude_slave_port_id, const std::vector< QueuedSlavePort * > &dests)
	Forward a timing packet to a selected list of snoopers, potentially excluding one of the connected coherent masters to avoid sending a packet back to where it came from. More...

Tick	recvAtomic (PacketPtr pkt, PortID slave_port_id)
	Function called by the port when the crossbar is recieving a Atomic transaction. More...

Tick	recvAtomicSnoop (PacketPtr pkt, PortID master_port_id)
	Function called by the port when the crossbar is recieving an atomic snoop transaction. More...

std::pair< MemCmd, Tick >	forwardAtomic (PacketPtr pkt, PortID exclude_slave_port_id)
	Forward an atomic packet to our snoopers, potentially excluding one of the connected coherent masters to avoid sending a packet back to where it came from. More...

std::pair< MemCmd, Tick >	forwardAtomic (PacketPtr pkt, PortID exclude_slave_port_id, PortID source_master_port_id, const std::vector< QueuedSlavePort * > &dests)
	Forward an atomic packet to a selected list of snoopers, potentially excluding one of the connected coherent masters to avoid sending a packet back to where it came from. More...

void	recvFunctional (PacketPtr pkt, PortID slave_port_id)
	Function called by the port when the crossbar is recieving a Functional transaction. More...

void	recvFunctionalSnoop (PacketPtr pkt, PortID master_port_id)
	Function called by the port when the crossbar is recieving a functional snoop transaction. More...

void	forwardFunctional (PacketPtr pkt, PortID exclude_slave_port_id)
	Forward a functional packet to our snoopers, potentially excluding one of the connected coherent masters 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...

Protected Member Functions inherited from BaseXBar
virtual void	recvRangeChange (PortID master_port_id)
	Function called by the port when the crossbar is recieving a range change. More...

PortID	findPort (Addr addr)
	Find which port connected to this crossbar (if any) should be given a packet with this address. More...

PortID	checkPortCache (Addr addr) const

void	updatePortCache (short id, const AddrRange &range)

void	clearPortCache ()

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 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...

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< QueuedSlavePort * >	snoopPorts

std::unordered_set< RequestPtr >	outstandingSnoop
	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...

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

SnoopFilter *	snoopFilter
	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 bool	pointOfCoherency
	Is this crossbar the point of coherency? More...

std::unique_ptr< Packet >	pendingDelete
	Upstream caches need this packet until true is returned, so hold it for deletion until a subsequent call. More...

Stats::Scalar	snoops

Stats::Scalar	snoopTraffic

Stats::Distribution	snoopFanout

Protected Attributes inherited from 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
	Cycles of forward latency. More...

const Cycles	responseLatency
	Cycles of response latency. More...

const uint32_t	width
	the width of the xbar in bytes More...

AddrRangeMap< PortID >	portMap

std::unordered_map< RequestPtr, PortID >	routeTo
	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

PortCache	portCache [3]

std::vector< bool >	gotAddrRanges
	Remember for each of the master ports of the crossbar if we got an address range from the connected slave. More...

bool	gotAllAddrRanges

std::vector< QueuedSlavePort * >	slavePorts
	The master and slave ports of the crossbar. More...

std::vector< MasterPort * >	masterPorts

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...

Stats::Vector	transDist
	Stats for transaction distribution and data passing through the crossbar. More...

Stats::Vector2d	pktCount

Stats::Vector2d	pktSize

Protected Attributes inherited from ClockedObject
Enums::PwrState	_currPwrState
	To keep track of the current power state. More...

Tick	prvEvalTick

Stats::Scalar	numPwrStateTransitions

Stats::Distribution	pwrStateClkGateDist

Stats::Vector	pwrStateResidencyTicks

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
Public Types inherited from MemObject
typedef MemObjectParams	Params

Public Types inherited from ClockedObject
typedef ClockedObjectParams	Params
	Parameters of ClockedObject. More...

Public Types inherited from SimObject
typedef SimObjectParams	Params

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 ()
	Get the fully-qualified name of the active section. More...

static void	serializeAll (const std::string &cpt_dir)

static void	unserializeGlobals (CheckpointIn &cp)

Static Public Attributes inherited from Serializable
static int	ckptCount = 0

static int	ckptMaxCount = 0

static int	ckptPrevCount = -1

Detailed Description

A coherent crossbar connects a number of (potentially) snooping masters and slaves, 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 71 of file coherent_xbar.hh.

Constructor & Destructor Documentation

CoherentXBar::CoherentXBar ( const CoherentXBarParams * p )

Definition at line 58 of file coherent_xbar.cc.

References BaseXBar::clearPortCache(), csprintf(), BaseXBar::defaultPortID, ArmISA::i, BaseXBar::masterPorts, SimObject::name(), reqLayers, respLayers, BaseXBar::slavePorts, snoopLayers, and snoopRespPorts.

CoherentXBar::~CoherentXBar ( )

virtual

Definition at line 104 of file coherent_xbar.cc.

References MipsISA::l, MipsISA::p, reqLayers, respLayers, snoopLayers, and snoopRespPorts.

Member Function Documentation

std::pair<MemCmd, Tick> CoherentXBar::forwardAtomic	(	PacketPtr	pkt,
		PortID	exclude_slave_port_id
	)

inlineprotected

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

Parameters

pkt	Packet to forward
exclude_slave_port_id	Id of slave port to exclude

Returns: a pair containing the snoop response and snoop latency

Definition at line 349 of file coherent_xbar.hh.

References InvalidPortID, and snoopPorts.

Referenced by recvAtomic(), and recvAtomicSnoop().

std::pair< MemCmd, Tick > CoherentXBar::forwardAtomic	(	PacketPtr	pkt,
		PortID	exclude_slave_port_id,
		PortID	source_master_port_id,
		const std::vector< QueuedSlavePort * > &	dests
	)

protected

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

Parameters

pkt	Packet to forward
exclude_slave_port_id	Id of slave port to exclude
source_master_port_id	Id of the master port for snoops from below
dests	Vector of destination ports for the forwarded pkt

Returns: a pair containing the snoop response and snoop latency

Definition at line 774 of file coherent_xbar.cc.

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

void CoherentXBar::forwardFunctional	(	PacketPtr	pkt,
		PortID	exclude_slave_port_id
	)

protected

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

Parameters

pkt	Packet to forward
exclude_slave_port_id	Id of slave port to exclude

Definition at line 901 of file coherent_xbar.cc.

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

Referenced by recvFunctional(), and recvFunctionalSnoop().

void CoherentXBar::forwardTiming	(	PacketPtr	pkt,
		PortID	exclude_slave_port_id
	)

inlineprotected

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

Parameters

pkt	Packet to forward
exclude_slave_port_id	Id of slave port to exclude

Definition at line 315 of file coherent_xbar.hh.

References snoopPorts.

Referenced by recvTimingReq(), and recvTimingSnoopReq().

void CoherentXBar::forwardTiming	(	PacketPtr	pkt,
		PortID	exclude_slave_port_id,
		const std::vector< QueuedSlavePort * > &	dests
	)

protected

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

Parameters

pkt	Packet to forward
exclude_slave_port_id	Id of slave port to exclude
dests	Vector of destination ports for the forwarded pkt

Definition at line 598 of file coherent_xbar.cc.

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

void 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 BaseXBar.

Definition at line 117 of file coherent_xbar.cc.

References DPRINTF, BaseXBar::init(), SimObject::name(), MipsISA::p, SnoopFilter::setSlavePorts(), BaseXBar::slavePorts, snoopFilter, snoopPorts, and warn.

Tick CoherentXBar::recvAtomic	(	PacketPtr	pkt,
		PortID	slave_port_id
	)

protected

Function called by the port when the crossbar is recieving a Atomic transaction.

Definition at line 635 of file coherent_xbar.cc.

References System::bypassCaches(), Clocked::clockPeriod(), Packet::cmd, Packet::cmdToIndex(), DPRINTF, BaseXBar::findPort(), SnoopFilter::finishRequest(), forwardAtomic(), Packet::getAddr(), Packet::getSize(), Packet::hasData(), MemCmd::InvalidCmd, InvalidPortID, Packet::isRead(), Packet::isResponse(), Packet::isSecure(), Packet::isWrite(), SnoopFilter::lookupRequest(), Packet::makeResponse(), BaseXBar::masterPorts, SimObject::name(), Packet::needsResponse(), Packet::payloadDelay, BaseXBar::pktCount, BaseXBar::pktSize, pointOfCoherency, Packet::print(), sinkPacket(), BaseXBar::slavePorts, snoopFilter, system, BaseXBar::transDist, and SnoopFilter::updateResponse().

Referenced by CoherentXBar::CoherentXBarSlavePort::recvAtomic().

Tick CoherentXBar::recvAtomicSnoop	(	PacketPtr	pkt,
		PortID	master_port_id
	)

protected

Function called by the port when the crossbar is recieving an atomic snoop transaction.

Definition at line 733 of file coherent_xbar.cc.

References Clocked::clockPeriod(), Packet::cmd, DPRINTF, forwardAtomic(), Packet::getSize(), Packet::hasData(), MemCmd::InvalidCmd, InvalidPortID, Packet::isResponse(), SnoopFilter::lookupSnoop(), BaseXBar::masterPorts, SimObject::name(), Packet::payloadDelay, Packet::print(), snoopFilter, snoops, and snoopTraffic.

Referenced by CoherentXBar::CoherentXBarMasterPort::recvAtomicSnoop().

void CoherentXBar::recvFunctional	(	PacketPtr	pkt,
		PortID	slave_port_id
	)

protected

Function called by the port when the crossbar is recieving a Functional transaction.

Definition at line 845 of file coherent_xbar.cc.

References System::bypassCaches(), DPRINTF, BaseXBar::findPort(), forwardFunctional(), Packet::getAddr(), Packet::isPrint(), Packet::isResponse(), Packet::makeResponse(), BaseXBar::masterPorts, SimObject::name(), Packet::needsResponse(), MipsISA::p, Packet::print(), BaseXBar::slavePorts, and system.

Referenced by CoherentXBar::CoherentXBarSlavePort::recvFunctional().

void CoherentXBar::recvFunctionalSnoop	(	PacketPtr	pkt,
		PortID	master_port_id
	)

protected

Function called by the port when the crossbar is recieving a functional snoop transaction.

Definition at line 880 of file coherent_xbar.cc.

References DPRINTF, forwardFunctional(), InvalidPortID, Packet::isPrint(), Packet::makeResponse(), BaseXBar::masterPorts, SimObject::name(), Packet::needsResponse(), MipsISA::p, Packet::print(), and BaseXBar::slavePorts.

Referenced by CoherentXBar::CoherentXBarMasterPort::recvFunctionalSnoop().

void CoherentXBar::recvReqRetry ( PortID master_port_id )

protected

Timing function called by port when it is once again able to process requests.

Definition at line 626 of file coherent_xbar.cc.

References reqLayers.

Referenced by CoherentXBar::CoherentXBarMasterPort::recvReqRetry().

bool CoherentXBar::recvTimingReq	(	PacketPtr	pkt,
		PortID	slave_port_id
	)

protected

Function called by the port when the crossbar is recieving a Timing request packet.

Definition at line 142 of file coherent_xbar.cc.

References addr, System::bypassCaches(), Packet::cacheResponding(), BaseXBar::calcPacketTiming(), Clocked::clockEdge(), Clocked::clockPeriod(), Packet::cmdToIndex(), DPRINTF, BaseXBar::findPort(), SnoopFilter::finishRequest(), BaseXBar::forwardLatency, forwardTiming(), BaseXBar::frontendLatency, Packet::getAddr(), Packet::getSize(), Packet::hasData(), Packet::headerDelay, Packet::isEviction(), Packet::isExpressSnoop(), Packet::isRead(), Packet::isSecure(), Packet::isWrite(), SnoopFilter::lookupRequest(), Packet::makeResponse(), BaseXBar::masterPorts, Port::name(), Packet::needsResponse(), outstandingSnoop, panic_if(), Packet::payloadDelay, pendingDelete, BaseXBar::pktCount, BaseXBar::pktSize, pointOfCoherency, Packet::print(), Packet::req, reqLayers, BaseXBar::routeTo, Packet::setBlockCached(), Packet::setExpressSnoop(), sinkPacket(), BaseXBar::slavePorts, Packet::snoopDelay, snoopFilter, snoops, snoopTraffic, system, BaseXBar::transDist, and SnoopFilter::updateResponse().

Referenced by CoherentXBar::CoherentXBarSlavePort::recvTimingReq().

bool CoherentXBar::recvTimingResp	(	PacketPtr	pkt,
		PortID	master_port_id
	)

protected

Function called by the port when the crossbar is recieving a Timing response packet.

Definition at line 350 of file coherent_xbar.cc.

References System::bypassCaches(), BaseXBar::calcPacketTiming(), Clocked::clockEdge(), Clocked::clockPeriod(), Packet::cmdToIndex(), curTick(), DPRINTF, Packet::getSize(), Packet::hasData(), Packet::headerDelay, InvalidPortID, BaseXBar::masterPorts, Port::name(), Packet::payloadDelay, BaseXBar::pktCount, BaseXBar::pktSize, Packet::print(), Packet::req, respLayers, BaseXBar::responseLatency, BaseXBar::routeTo, BaseXBar::slavePorts, snoopFilter, system, BaseXBar::transDist, and SnoopFilter::updateResponse().

Referenced by CoherentXBar::CoherentXBarMasterPort::recvTimingResp().

void CoherentXBar::recvTimingSnoopReq	(	PacketPtr	pkt,
		PortID	master_port_id
	)

protected

Function called by the port when the crossbar is recieving a timing snoop request.

Definition at line 412 of file coherent_xbar.cc.

References Packet::cacheResponding(), BaseXBar::calcPacketTiming(), Clocked::clockPeriod(), Packet::cmdToIndex(), DPRINTF, BaseXBar::findPort(), BaseXBar::forwardLatency, forwardTiming(), Packet::getAddr(), Packet::getSize(), Packet::hasData(), Packet::headerDelay, InvalidPortID, Packet::isExpressSnoop(), SnoopFilter::lookupSnoop(), BaseXBar::masterPorts, SimObject::name(), Packet::print(), Packet::req, BaseXBar::routeTo, Packet::snoopDelay, snoopFilter, snoops, snoopTraffic, and BaseXBar::transDist.

Referenced by CoherentXBar::CoherentXBarMasterPort::recvTimingSnoopReq().

bool CoherentXBar::recvTimingSnoopResp	(	PacketPtr	pkt,
		PortID	slave_port_id
	)

protected

Function called by the port when the crossbar is recieving a timing snoop response.

Definition at line 472 of file coherent_xbar.cc.

References BaseXBar::calcPacketTiming(), Clocked::clockEdge(), Clocked::clockPeriod(), Packet::cmdToIndex(), curTick(), DPRINTF, Packet::getSize(), Packet::hasData(), Packet::headerDelay, InvalidPortID, Packet::isExpressSnoop(), M5_VAR_USED, BaseXBar::masterPorts, Port::name(), outstandingSnoop, Packet::payloadDelay, BaseXBar::pktCount, BaseXBar::pktSize, Packet::print(), Packet::req, respLayers, BaseXBar::responseLatency, BaseXBar::routeTo, BaseXBar::slavePorts, snoopFilter, snoopLayers, snoopResponseLatency, snoopRespPorts, snoops, snoopTraffic, BaseXBar::transDist, SnoopFilter::updateSnoopForward(), and SnoopFilter::updateSnoopResponse().

Referenced by CoherentXBar::CoherentXBarSlavePort::recvTimingSnoopResp().

void CoherentXBar::regStats ( )

virtual

Register statistics for this object.

Reimplemented from BaseXBar.

Definition at line 947 of file coherent_xbar.cc.

References Stats::DataWrap< Derived, InfoProxyType >::desc(), Stats::Distribution::init(), MipsISA::l, SimObject::name(), Stats::DataWrap< Derived, InfoProxyType >::name(), BaseXBar::regStats(), reqLayers, respLayers, snoopFanout, snoopLayers, snoopPorts, snoops, and snoopTraffic.

bool CoherentXBar::sinkPacket ( const PacketPtr pkt ) const

protected

Determine if the crossbar should sink the packet, as opposed to forwarding it, or responding.

Definition at line 923 of file coherent_xbar.cc.

References Packet::cacheResponding(), Packet::isBlockCached(), Packet::isCleanEviction(), Packet::isRead(), Packet::isWrite(), Packet::needsResponse(), Packet::needsWritable(), pointOfCoherency, and Packet::responderHadWritable().

Referenced by recvAtomic(), and recvTimingReq().

Member Data Documentation

std::unordered_set<RequestPtr> 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 263 of file coherent_xbar.hh.

Referenced by recvTimingReq(), and recvTimingSnoopResp().

std::unique_ptr<Packet> CoherentXBar::pendingDelete

protected

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

Definition at line 285 of file coherent_xbar.hh.

Referenced by recvTimingReq().

const bool CoherentXBar::pointOfCoherency

protected

Is this crossbar the point of coherency?

Definition at line 279 of file coherent_xbar.hh.

Referenced by recvAtomic(), recvTimingReq(), and sinkPacket().