A common base class of Cache tagstore objects. More...

#include <base.hh>

Inheritance diagram for BaseTags:

Classes
struct	BaseTagStats
	TODO: It would be good if these stats were acquired after warmup. More...

Public Types
typedef BaseTagsParams	Params

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

Public Types inherited from SimObject
typedef SimObjectParams	Params

Public Member Functions
	BaseTags (const Params *p)

virtual	~BaseTags ()
	Destructor. More...

virtual void	tagsInit ()=0
	Initialize blocks. More...

void	cleanupRefs ()
	Average in the reference count for valid blocks when the simulation exits. More...

void	computeStats ()
	Computes stats just prior to dump event. More...

std::string	print ()
	Print all tags used. More...

virtual CacheBlk *	findBlock (Addr addr, bool is_secure) const
	Finds the block in the cache without touching it. More...

virtual ReplaceableEntry *	findBlockBySetAndWay (int set, int way) const
	Find a block given set and way. More...

Addr	blkAlign (Addr addr) const
	Align an address to the block size. More...

int	extractBlkOffset (Addr addr) const
	Calculate the block offset of an address. More...

virtual void	setWayAllocationMax (int ways)
	Limit the allocation for the cache ways. More...

virtual int	getWayAllocationMax () const
	Get the way allocation mask limit. More...

virtual void	invalidate (CacheBlk *blk)
	This function updates the tags when a block is invalidated. More...

virtual CacheBlk *	findVictim (Addr addr, const bool is_secure, const std::size_t size, std::vector< CacheBlk * > &evict_blks)=0
	Find replacement victim based on address. More...

virtual CacheBlk *	accessBlock (Addr addr, bool is_secure, Cycles &lat)=0
	Access block and update replacement data. More...

virtual Addr	extractTag (const Addr addr) const
	Generate the tag from the given address. More...

virtual void	insertBlock (const PacketPtr pkt, CacheBlk *blk)
	Insert the new block into the cache and update stats. More...

virtual Addr	regenerateBlkAddr (const CacheBlk *blk) const =0
	Regenerate the block address. More...

virtual void	forEachBlk (std::function< void(CacheBlk &)> visitor)=0
	Visit each block in the tags and apply a visitor. More...

virtual bool	anyBlk (std::function< bool(CacheBlk &)> visitor)=0
	Find if any of the blocks satisfies a condition. 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	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...

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

Protected Attributes
const unsigned	blkSize
	The block size of the cache. More...

const Addr	blkMask
	Mask out all bits that aren't part of the block offset. More...

const unsigned	size
	The size of the cache. More...

const Cycles	lookupLatency
	The tag lookup latency of the cache. More...

System *	system
	System we are currently operating in. More...

BaseIndexingPolicy *	indexingPolicy
	Indexing policy. More...

const unsigned	warmupBound
	The number of tags that need to be touched to meet the warmup percentage. More...

bool	warmedUp
	Marked true when the cache is warmed up. More...

const unsigned	numBlocks
	the number of blocks in the cache More...

std::unique_ptr< uint8_t[]>	dataBlks
	The data blocks, 1 per cache block. More...

BaseTags::BaseTagStats	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...

Private Member Functions
void	cleanupRefsVisitor (CacheBlk &blk)
	Update the reference stats using data from the input block. More...

void	computeStatsVisitor (CacheBlk &blk)
	Update the occupancy and age stats using data from the input block. 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)

Public Attributes inherited from ClockedObject
PowerState *	powerState

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...

Detailed Description

A common base class of Cache tagstore objects.

Definition at line 70 of file base.hh.

Member Typedef Documentation

◆ Params

typedef BaseTagsParams BaseTags::Params

Definition at line 158 of file base.hh.

Constructor & Destructor Documentation

◆ BaseTags()

BaseTags::BaseTags ( const Params * p )

Definition at line 58 of file base.cc.

References cleanupRefs(), and registerExitCallback().

◆ ~BaseTags()

virtual BaseTags::~BaseTags ( )

inlinevirtual

Destructor.

Definition at line 164 of file base.hh.

Member Function Documentation

◆ accessBlock()

virtual CacheBlk* BaseTags::accessBlock	(	Addr	addr,
		bool	is_secure,
		Cycles &	lat
	)

pure virtual

Access block and update replacement data.

May not succeed, in which case nullptr is returned. This has all the implications of a cache access and should only be used as such. Returns the tag lookup latency as a side effect.

Parameters

addr	The address to find.
is_secure	True if the target memory space is secure.
lat	The latency of the tag lookup.

Returns: Pointer to the cache block if found.

Implemented in FALRU, SectorTags, and BaseSetAssoc.

Referenced by BaseCache::access().

◆ anyBlk()

virtual bool BaseTags::anyBlk ( std::function< bool(CacheBlk &)> visitor )

pure virtual

Find if any of the blocks satisfies a condition.

The visitor should be a std::function that takes a cache block reference as its parameter. The visitor will terminate the traversal early if the condition is satisfied.

Parameters

visitor Visitor to call on each block.

Implemented in FALRU, BaseSetAssoc, SectorTags, and CompressedTags.

Referenced by BaseCache::isDirty().

◆ blkAlign()

Addr BaseTags::blkAlign ( Addr addr ) const

inline

Align an address to the block size.

Parameters

addr	the address to align.

Returns: The block address.

Definition at line 212 of file base.hh.

References addr, and blkMask.

Referenced by FALRU::extractTag().

◆ cleanupRefs()

void BaseTags::cleanupRefs ( )

Average in the reference count for valid blocks when the simulation exits.

Definition at line 143 of file base.cc.

References cleanupRefsVisitor(), and forEachBlk().

Referenced by BaseTags().

◆ cleanupRefsVisitor()

void BaseTags::cleanupRefsVisitor ( CacheBlk & blk )

private

Update the reference stats using data from the input block.

Parameters

blk	The input block

Definition at line 134 of file base.cc.

References CacheBlk::isValid(), CacheBlk::refCount, BaseTags::BaseTagStats::sampledRefs, stats, and BaseTags::BaseTagStats::totalRefs.

Referenced by cleanupRefs().

◆ computeStats()

void BaseTags::computeStats ( )

Computes stats just prior to dump event.

Definition at line 174 of file base.cc.

References BaseTags::BaseTagStats::ageTaskId, computeStatsVisitor(), forEachBlk(), ArmISA::i, ArmISA::j, ContextSwitchTaskId::NumTaskId, BaseTags::BaseTagStats::occupanciesTaskId, and stats.

◆ computeStatsVisitor()

void BaseTags::computeStatsVisitor ( CacheBlk & blk )

private

Update the occupancy and age stats using data from the input block.

Parameters

blk	The input block

Definition at line 149 of file base.cc.

References BaseTags::BaseTagStats::ageTaskId, curTick(), CacheBlk::isValid(), SimClock::Int::ms, ContextSwitchTaskId::NumTaskId, BaseTags::BaseTagStats::occupanciesTaskId, stats, CacheBlk::task_id, CacheBlk::tickInserted, and SimClock::Int::us.

Referenced by computeStats().

◆ extractBlkOffset()

int BaseTags::extractBlkOffset ( Addr addr ) const

inline

Calculate the block offset of an address.

Parameters

addr	the address to get the offset of.

Returns: the block offset.

Definition at line 222 of file base.hh.

References addr, and blkMask.

Referenced by BaseCache::satisfyRequest().

◆ extractTag()

Addr BaseTags::extractTag ( const Addr addr ) const

virtual

Generate the tag from the given address.

Parameters

addr	The address to get the tag from.

Returns: The tag of the address.

Reimplemented in FALRU.

Definition at line 128 of file base.cc.

References addr, BaseIndexingPolicy::extractTag(), and indexingPolicy.

Referenced by SectorTags::findBlock(), findBlock(), CompressedTags::findVictim(), SectorTags::findVictim(), and insertBlock().

◆ findBlock()

CacheBlk * BaseTags::findBlock	(	Addr	addr,
		bool	is_secure
	)		const

virtual

Finds the block in the cache without touching it.

Parameters

addr	The address to look for.
is_secure	True if the target memory space is secure.

Returns: Pointer to the cache block.

Reimplemented in FALRU, and SectorTags.

Definition at line 77 of file base.cc.

References addr, extractTag(), BaseIndexingPolicy::getPossibleEntries(), indexingPolicy, CacheBlk::isSecure(), CacheBlk::isValid(), and CacheBlk::tag.

Referenced by Cache::access(), BaseSetAssoc::accessBlock(), BaseCache::functionalAccess(), BaseCache::getNextQueueEntry(), BaseCache::hasBeenPrefetched(), BaseCache::inCache(), Cache::recvAtomicSnoop(), BaseCache::recvTimingResp(), Cache::recvTimingSnoopReq(), Cache::sendMSHRQueuePacket(), and BaseCache::sendMSHRQueuePacket().

◆ findBlockBySetAndWay()

ReplaceableEntry * BaseTags::findBlockBySetAndWay	(	int	set,
		int	way
	)		const

virtual

Find a block given set and way.

Parameters

set	The set of the block.
way	The way of the block.

Returns: The block.

Reimplemented in FALRU.

Definition at line 71 of file base.cc.

References BaseIndexingPolicy::getEntry(), and indexingPolicy.

◆ findVictim()

virtual CacheBlk* BaseTags::findVictim	(	Addr	addr,
		const bool	is_secure,
		const std::size_t	size,
		std::vector< CacheBlk * > &	evict_blks
	)

pure virtual

Find replacement victim based on address.

If the address requires blocks to be evicted, their locations are listed for eviction. If a conventional cache is being used, the list only contains the victim. However, if using sector or compressed caches, the victim is one of the blocks to be evicted, but its location is the only one that will be assigned to the newly allocated block associated to this address.

See also: insertBlock

Parameters

addr	Address to find a victim for.
is_secure	True if the target memory space is secure.
size	Size, in bits, of new block to allocate.
evict_blks	Cache blocks to be evicted.

Returns: Cache block to be replaced.

Implemented in FALRU, SectorTags, BaseSetAssoc, and CompressedTags.

Referenced by BaseCache::allocateBlock().

◆ forEachBlk()

virtual void BaseTags::forEachBlk ( std::function< void(CacheBlk &)> visitor )

pure virtual

Visit each block in the tags and apply a visitor.

The visitor should be a std::function that takes a cache block reference as its parameter.

Parameters

visitor Visitor to call on each block.

Implemented in FALRU, BaseSetAssoc, SectorTags, and CompressedTags.

Referenced by cleanupRefs(), computeStats(), BaseCache::memInvalidate(), BaseCache::memWriteback(), and print().

◆ getWayAllocationMax()

virtual int BaseTags::getWayAllocationMax ( ) const

inlinevirtual

Get the way allocation mask limit.

Returns: The maximum number of ways available for replacement.

Reimplemented in BaseSetAssoc.

Definition at line 240 of file base.hh.

References panic.

◆ insertBlock()

void BaseTags::insertBlock	(	const PacketPtr	pkt,
		CacheBlk *	blk
	)

virtual

Insert the new block into the cache and update stats.

Parameters

pkt	Packet holding the address to update
blk	The block to update.

Reimplemented in FALRU, BaseSetAssoc, SectorTags, and CompressedTags.

Definition at line 100 of file base.cc.

References curTick(), BaseTags::BaseTagStats::dataAccesses, extractTag(), Packet::getAddr(), CacheBlk::insert(), Packet::isSecure(), CacheBlk::isValid(), BaseTags::BaseTagStats::occupancies, Packet::req, stats, BaseTags::BaseTagStats::tagAccesses, BaseTags::BaseTagStats::tagsInUse, Stats::ScalarBase< Derived, Stor >::value(), warmedUp, warmupBound, and BaseTags::BaseTagStats::warmupCycle.

Referenced by BaseCache::allocateBlock(), SectorTags::insertBlock(), BaseSetAssoc::insertBlock(), and FALRU::insertBlock().

◆ invalidate()

virtual void BaseTags::invalidate ( CacheBlk * blk )

inlinevirtual

This function updates the tags when a block is invalidated.

Parameters

blk	A valid block to invalidate.

Reimplemented in FALRU, SectorTags, and BaseSetAssoc.

Definition at line 251 of file base.hh.

References CacheBlk::invalidate(), CacheBlk::isValid(), BaseTags::BaseTagStats::occupancies, CacheBlk::refCount, BaseTags::BaseTagStats::sampledRefs, CacheBlk::srcRequestorId, stats, and BaseTags::BaseTagStats::totalRefs.

Referenced by BaseSetAssoc::invalidate(), SectorTags::invalidate(), FALRU::invalidate(), and BaseCache::invalidateBlock().

◆ print()

std::string BaseTags::print ( )

Print all tags used.

Definition at line 187 of file base.cc.

References csprintf(), and forEachBlk().

Referenced by Cache::recvTimingReq().

◆ regenerateBlkAddr()

virtual Addr BaseTags::regenerateBlkAddr ( const CacheBlk * blk ) const

pure virtual

Regenerate the block address.

Parameters

block The block.

Returns: the block address.

Implemented in FALRU, BaseSetAssoc, and SectorTags.

Referenced by BaseCache::regenerateBlkAddr().

◆ setWayAllocationMax()

virtual void BaseTags::setWayAllocationMax ( int ways )

inlinevirtual

Limit the allocation for the cache ways.

Parameters

ways	The maximum number of ways available for replacement.

Reimplemented in BaseSetAssoc.

Definition at line 231 of file base.hh.

References panic.

◆ tagsInit()

virtual void BaseTags::tagsInit ( )

pure virtual

Initialize blocks.

Must be overriden by every subclass that uses a block type different from its parent's, as the current Python code generation does not allow templates.

Implemented in FALRU, SectorTags, BaseSetAssoc, and CompressedTags.

Member Data Documentation

◆ blkMask

const Addr BaseTags::blkMask

protected

Mask out all bits that aren't part of the block offset.

Definition at line 76 of file base.hh.

Referenced by blkAlign(), and extractBlkOffset().

◆ blkSize

const unsigned BaseTags::blkSize

protected

The block size of the cache.

Definition at line 74 of file base.hh.

Referenced by BaseSetAssoc::BaseSetAssoc(), FALRU::FALRU(), FALRU::CacheTracking::init(), SectorTags::SectorTags(), CompressedTags::tagsInit(), BaseSetAssoc::tagsInit(), SectorTags::tagsInit(), and FALRU::tagsInit().

◆ dataBlks

std::unique_ptr<uint8_t[]> BaseTags::dataBlks

protected

The data blocks, 1 per cache block.

Definition at line 100 of file base.hh.

Referenced by CompressedTags::tagsInit(), BaseSetAssoc::tagsInit(), SectorTags::tagsInit(), and FALRU::tagsInit().

◆ indexingPolicy

BaseIndexingPolicy* BaseTags::indexingPolicy

protected

Indexing policy.

Definition at line 86 of file base.hh.

Referenced by extractTag(), SectorTags::findBlock(), findBlock(), findBlockBySetAndWay(), CompressedTags::findVictim(), BaseSetAssoc::findVictim(), SectorTags::findVictim(), SectorTags::regenerateBlkAddr(), BaseSetAssoc::regenerateBlkAddr(), CompressedTags::tagsInit(), BaseSetAssoc::tagsInit(), and SectorTags::tagsInit().

◆ lookupLatency

const Cycles BaseTags::lookupLatency

protected

The tag lookup latency of the cache.

Definition at line 80 of file base.hh.

Referenced by BaseSetAssoc::accessBlock(), SectorTags::accessBlock(), and FALRU::accessBlock().

◆ numBlocks

const unsigned BaseTags::numBlocks

protected

the number of blocks in the cache

Definition at line 97 of file base.hh.

Referenced by FALRU::anyBlk(), FALRU::FALRU(), FALRU::forEachBlk(), CompressedTags::tagsInit(), BaseSetAssoc::tagsInit(), SectorTags::tagsInit(), and FALRU::tagsInit().

◆ size

const unsigned BaseTags::size

protected

The size of the cache.

Definition at line 78 of file base.hh.

Referenced by FALRU::FALRU(), and printSize().

◆ stats

BaseTags::BaseTagStats BaseTags::stats

protected

Referenced by BaseSetAssoc::accessBlock(), SectorTags::accessBlock(), cleanupRefsVisitor(), computeStats(), computeStatsVisitor(), SectorTags::insertBlock(), BaseSetAssoc::insertBlock(), FALRU::insertBlock(), insertBlock(), BaseSetAssoc::invalidate(), SectorTags::invalidate(), FALRU::invalidate(), and invalidate().

◆ system

System* BaseTags::system

protected

System we are currently operating in.

Definition at line 83 of file base.hh.

Referenced by BaseTags::BaseTagStats::regStats().

◆ warmedUp

bool BaseTags::warmedUp

protected

Marked true when the cache is warmed up.

Definition at line 94 of file base.hh.

Referenced by insertBlock().

◆ warmupBound

const unsigned BaseTags::warmupBound

protected

The number of tags that need to be touched to meet the warmup percentage.

Definition at line 92 of file base.hh.

Referenced by insertBlock().

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

mem/cache/tags/base.hh
mem/cache/tags/base.cc

Classes

Public Types

Public Member Functions

Protected Attributes

Private Member Functions

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ Params

Constructor & Destructor Documentation

◆ BaseTags()

◆ ~BaseTags()

Member Function Documentation

◆ accessBlock()

◆ anyBlk()

◆ blkAlign()

◆ cleanupRefs()

◆ cleanupRefsVisitor()

◆ computeStats()

◆ computeStatsVisitor()

◆ extractBlkOffset()

◆ extractTag()

◆ findBlock()

◆ findBlockBySetAndWay()

◆ findVictim()

◆ forEachBlk()

◆ getWayAllocationMax()

◆ insertBlock()

◆ invalidate()

◆ print()

◆ regenerateBlkAddr()

◆ setWayAllocationMax()

◆ tagsInit()

Member Data Documentation

◆ blkMask

◆ blkSize

◆ dataBlks

◆ indexingPolicy

◆ lookupLatency

◆ numBlocks

◆ size

◆ stats

◆ system

◆ warmedUp

◆ warmupBound