A basic cache interface. More...

#include <base.hh>

Inheritance diagram for gem5::BaseCache:

Classes
struct	CacheCmdStats

class	CacheReqPacketQueue
	Override the default behaviour of sendDeferredPacket to enable the memory-side cache port to also send requests based on the current MSHR status. More...

class	CacheRequestPort
	A cache request port is used for the memory-side port of the cache, and in addition to the basic timing port that only sends response packets through a transmit list, it also offers the ability to schedule and send request packets (requests & writebacks). More...

class	CacheResponsePort
	A cache response port is used for the CPU-side port of the cache, and it is basically a simple timing port that uses a transmit list for responses to the CPU (or connected requestor). More...

struct	CacheStats

class	CpuSidePort
	The CPU-side port extends the base cache response port with access functions for functional, atomic and timing requests. More...

struct	DataUpdate
	A data contents update is composed of the updated block's address, the old contents, and the new contents. More...

class	MemSidePort
	The memory-side port extends the base cache request port with access functions for functional, atomic and timing snoops. More...

Public Types
enum	BlockedCause { Blocked_NoMSHRs = MSHRQueue_MSHRs , Blocked_NoWBBuffers = MSHRQueue_WriteBuffer , Blocked_NoTargets , NUM_BLOCKED_CAUSES }
	Reasons for caches to be blocked. More...

Public Types inherited from gem5::ClockedObject
using	Params = ClockedObjectParams
	Parameters of ClockedObject. More...

Public Types inherited from gem5::SimObject
typedef SimObjectParams	Params

Public Member Functions
void	regProbePoints () override
	Registers probes. More...

	BaseCache (const BaseCacheParams &p, unsigned blk_size)

	~BaseCache ()

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

Port &	getPort (const std::string &if_name, PortID idx=InvalidPortID) override
	Get a port with a given name and index. More...

unsigned	getBlockSize () const
	Query block size of a cache. More...

const AddrRangeList &	getAddrRanges () const

MSHR *	allocateMissBuffer (PacketPtr pkt, Tick time, bool sched_send=true)

void	allocateWriteBuffer (PacketPtr pkt, Tick time)

bool	isBlocked () const
	Returns true if the cache is blocked for accesses. More...

void	setBlocked (BlockedCause cause)
	Marks the access path of the cache as blocked for the given cause. More...

void	clearBlocked (BlockedCause cause)
	Marks the cache as unblocked for the given cause. More...

void	schedMemSideSendEvent (Tick time)
	Schedule a send event for the memory-side port. More...

bool	inCache (Addr addr, bool is_secure) const

bool	hasBeenPrefetched (Addr addr, bool is_secure) const

bool	inMissQueue (Addr addr, bool is_secure) const

void	incMissCount (PacketPtr pkt)

void	incHitCount (PacketPtr pkt)

bool	coalesce () const
	Checks if the cache is coalescing writes. More...

void	writebackVisitor (CacheBlk &blk)
	Cache block visitor that writes back dirty cache blocks using functional writes. More...

void	invalidateVisitor (CacheBlk &blk)
	Cache block visitor that invalidates all blocks in the cache. More...

virtual bool	sendMSHRQueuePacket (MSHR *mshr)
	Take an MSHR, turn it into a suitable downstream packet, and send it out. More...

bool	sendWriteQueuePacket (WriteQueueEntry *wq_entry)
	Similar to sendMSHR, but for a write-queue entry instead. More...

void	serialize (CheckpointOut &cp) const override
	Serialize the state of the caches. More...

void	unserialize (CheckpointIn &cp) override
	Unserialize an object. 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 Params &	params () 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	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...

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
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 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	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 (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 Info *	resolveStat (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

Group &	operator= (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

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

gem5::BaseCache::CacheStats	stats

Public Attributes inherited from gem5::ClockedObject
PowerState *	powerState

Protected Types
enum	MSHRQueueIndex { MSHRQueue_MSHRs , MSHRQueue_WriteBuffer }
	Indexes to enumerate the MSHR queues. More...

Protected Member Functions
void	markInService (MSHR *mshr, bool pending_modified_resp)
	Mark a request as in service (sent downstream in the memory system), effectively making this MSHR the ordering point. More...

void	markInService (WriteQueueEntry *entry)

bool	allocOnFill (MemCmd cmd) const
	Determine whether we should allocate on a fill or not. More...

Addr	regenerateBlkAddr (CacheBlk *blk)
	Regenerate block address using tags. More...

Cycles	calculateTagOnlyLatency (const uint32_t delay, const Cycles lookup_lat) const
	Calculate latency of accesses that only touch the tag array. More...

Cycles	calculateAccessLatency (const CacheBlk *blk, const uint32_t delay, const Cycles lookup_lat) const
	Calculate access latency in ticks given a tag lookup latency, and whether access was a hit or miss. More...

virtual bool	access (PacketPtr pkt, CacheBlk *&blk, Cycles &lat, PacketList &writebacks)
	Does all the processing necessary to perform the provided request. More...

virtual void	handleTimingReqHit (PacketPtr pkt, CacheBlk *blk, Tick request_time)

virtual void	handleTimingReqMiss (PacketPtr pkt, CacheBlk *blk, Tick forward_time, Tick request_time)=0

void	handleTimingReqMiss (PacketPtr pkt, MSHR mshr, CacheBlk blk, Tick forward_time, Tick request_time)

virtual void	recvTimingReq (PacketPtr pkt)
	Performs the access specified by the request. More...

void	handleUncacheableWriteResp (PacketPtr pkt)
	Handling the special case of uncacheable write responses to make recvTimingResp less cluttered. More...

virtual void	serviceMSHRTargets (MSHR mshr, const PacketPtr pkt, CacheBlk blk)=0
	Service non-deferred MSHR targets using the received response. More...

virtual void	recvTimingResp (PacketPtr pkt)
	Handles a response (cache line fill/write ack) from the bus. More...

virtual void	recvTimingSnoopReq (PacketPtr pkt)=0
	Snoops bus transactions to maintain coherence. More...

virtual void	recvTimingSnoopResp (PacketPtr pkt)=0
	Handle a snoop response. More...

virtual Cycles	handleAtomicReqMiss (PacketPtr pkt, CacheBlk *&blk, PacketList &writebacks)=0
	Handle a request in atomic mode that missed in this cache. More...

virtual Tick	recvAtomic (PacketPtr pkt)
	Performs the access specified by the request. More...

virtual Tick	recvAtomicSnoop (PacketPtr pkt)=0
	Snoop for the provided request in the cache and return the estimated time taken. More...

virtual void	functionalAccess (PacketPtr pkt, bool from_cpu_side)
	Performs the access specified by the request. More...

void	updateBlockData (CacheBlk *blk, const PacketPtr cpkt, bool has_old_data)
	Update the data contents of a block. More...

void	cmpAndSwap (CacheBlk *blk, PacketPtr pkt)
	Handle doing the Compare and Swap function for SPARC. More...

QueueEntry *	getNextQueueEntry ()
	Return the next queue entry to service, either a pending miss from the MSHR queue, a buffered write from the write buffer, or something from the prefetcher. More...

virtual void	doWritebacks (PacketList &writebacks, Tick forward_time)=0
	Insert writebacks into the write buffer. More...

virtual void	doWritebacksAtomic (PacketList &writebacks)=0
	Send writebacks down the memory hierarchy in atomic mode. More...

virtual PacketPtr	createMissPacket (PacketPtr cpu_pkt, CacheBlk *blk, bool needs_writable, bool is_whole_line_write) const =0
	Create an appropriate downstream bus request packet. More...

void	writebackTempBlockAtomic ()
	Send the outstanding tempBlock writeback. More...

bool	updateCompressionData (CacheBlk &blk, const uint64_t data, PacketList &writebacks)
	When a block is overwriten, its compression information must be updated, and it may need to be recompressed. More...

virtual void	satisfyRequest (PacketPtr pkt, CacheBlk *blk, bool deferred_response=false, bool pending_downgrade=false)
	Perform any necessary updates to the block and perform any data exchange between the packet and the block. More...

void	maintainClusivity (bool from_cache, CacheBlk *blk)
	Maintain the clusivity of this cache by potentially invalidating a block. More...

bool	handleEvictions (std::vector< CacheBlk * > &evict_blks, PacketList &writebacks)
	Try to evict the given blocks. More...

CacheBlk *	handleFill (PacketPtr pkt, CacheBlk *blk, PacketList &writebacks, bool allocate)
	Handle a fill operation caused by a received packet. More...

CacheBlk *	allocateBlock (const PacketPtr pkt, PacketList &writebacks)
	Allocate a new block and perform any necessary writebacks. More...

virtual PacketPtr	evictBlock (CacheBlk *blk)=0
	Evict a cache block. More...

void	evictBlock (CacheBlk *blk, PacketList &writebacks)
	Evict a cache block. More...

void	invalidateBlock (CacheBlk *blk)
	Invalidate a cache block. More...

PacketPtr	writebackBlk (CacheBlk *blk)
	Create a writeback request for the given block. More...

PacketPtr	writecleanBlk (CacheBlk *blk, Request::Flags dest, PacketId id)
	Create a writeclean request for the given block. More...

virtual void	memWriteback () override
	Write back dirty blocks in the cache using functional accesses. More...

virtual void	memInvalidate () override
	Invalidates all blocks in the cache. More...

bool	isDirty () const
	Determine if there are any dirty blocks in the cache. More...

bool	inRange (Addr addr) const
	Determine if an address is in the ranges covered by this cache. More...

Tick	nextQueueReadyTime () const
	Find next request ready time from among possible sources. More...

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

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
CpuSidePort	cpuSidePort

MemSidePort	memSidePort

MSHRQueue	mshrQueue
	Miss status registers. More...

WriteQueue	writeBuffer
	Write/writeback buffer. More...

BaseTags *	tags
	Tag and data Storage. More...

compression::Base *	compressor
	Compression method being used. More...

prefetch::Base *	prefetcher
	Prefetcher. More...

ProbePointArg< PacketPtr > *	ppHit
	To probe when a cache hit occurs. More...

ProbePointArg< PacketPtr > *	ppMiss
	To probe when a cache miss occurs. More...

ProbePointArg< PacketPtr > *	ppFill
	To probe when a cache fill occurs. More...

ProbePointArg< DataUpdate > *	ppDataUpdate
	To probe when the contents of a block are updated. More...

WriteAllocator *const	writeAllocator
	The writeAllocator drive optimizations for streaming writes. More...

TempCacheBlk *	tempBlock
	Temporary cache block for occasional transitory use. 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...

const bool	writebackClean
	Determine if clean lines should be written back or not. More...

PacketPtr	tempBlockWriteback
	Writebacks from the tempBlock, resulting on the response path in atomic mode, must happen after the call to recvAtomic has finished (for the right ordering of the packets). More...

EventFunctionWrapper	writebackTempBlockAtomicEvent
	An event to writeback the tempBlock after recvAtomic finishes. More...

const unsigned	blkSize
	Block size of this cache. More...

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

const Cycles	dataLatency
	The latency of data access of a cache. More...

const Cycles	forwardLatency
	This is the forward latency of the cache. More...

const Cycles	fillLatency
	The latency to fill a cache block. More...

const Cycles	responseLatency
	The latency of sending reponse to its upper level cache/core on a linefill. More...

const bool	sequentialAccess
	Whether tags and data are accessed sequentially. More...

const int	numTarget
	The number of targets for each MSHR. More...

bool	forwardSnoops
	Do we forward snoops from mem side port through to cpu side port? More...

const enums::Clusivity	clusivity
	Clusivity with respect to the upstream cache, determining if we fill into both this cache and the cache above on a miss. More...

const bool	isReadOnly
	Is this cache read only, for example the instruction cache, or table-walker cache. More...

const bool	replaceExpansions
	when a data expansion of a compressed block happens it will not be able to co-allocate where it is at anymore. More...

const bool	moveContractions
	Similar to data expansions, after a block improves its compression, it may need to be moved elsewhere compatible with the new compression factor, or, if not required by the compaction method, it may be moved to co-allocate with an existing block and thus free an entry. More...

uint8_t	blocked
	Bit vector of the blocking reasons for the access path. More...

uint64_t	order
	Increasing order number assigned to each incoming request. More...

Cycles	blockedCycle
	Stores time the cache blocked for statistics. More...

MSHR *	noTargetMSHR
	Pointer to the MSHR that has no targets. More...

Counter	missCount
	The number of misses to trigger an exit event. More...

const AddrRangeList	addrRanges
	The address range to which the cache responds on the CPU side. More...

Protected Attributes inherited from gem5::SimObject
const SimObjectParams &	_params
	Cached copy of the object parameters. More...

Protected Attributes inherited from gem5::EventManager
EventQueue *	eventq
	A pointer to this object's event queue. More...

Additional Inherited Members
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 SimObject *	find (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 SimObjectResolver *	getSimObjectResolver ()
	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...

Detailed Description

A basic cache interface.

Implements some common functions for speed.

Definition at line 95 of file base.hh.

Member Enumeration Documentation

◆ BlockedCause

enum gem5::BaseCache::BlockedCause

Reasons for caches to be blocked.

Enumerator
Blocked_NoMSHRs
Blocked_NoWBBuffers
Blocked_NoTargets
NUM_BLOCKED_CAUSES

Definition at line 111 of file base.hh.

◆ MSHRQueueIndex

enum gem5::BaseCache::MSHRQueueIndex

protected

Indexes to enumerate the MSHR queues.

Enumerator
MSHRQueue_MSHRs
MSHRQueue_WriteBuffer

Definition at line 101 of file base.hh.

Constructor & Destructor Documentation

◆ BaseCache()

gem5::BaseCache::BaseCache	(	const BaseCacheParams &	p,
		unsigned	blk_size
	)

Definition at line 79 of file base.cc.

References writebackTempBlockAtomic().

◆ ~BaseCache()

gem5::BaseCache::~BaseCache ( )

Definition at line 139 of file base.cc.

References tempBlock.

Member Function Documentation

◆ access()

bool gem5::BaseCache::access	(	PacketPtr	pkt,
		CacheBlk *&	blk,
		Cycles &	lat,
		PacketList &	writebacks
	)

protectedvirtual

Does all the processing necessary to perform the provided request.

Parameters

pkt	The memory request to perform.
blk	The cache block to be updated.
lat	The latency of the access.
writebacks	List for any writebacks that need to be performed.

Returns: Boolean indicating whether the request was satisfied.

Reimplemented in gem5::NoncoherentCache, and gem5::Cache.

Definition at line 1228 of file base.cc.

References gem5::BaseTags::accessBlock(), allocateBlock(), blkSize, calculateAccessLatency(), calculateTagOnlyLatency(), gem5::MemCmd::CleanEvict, gem5::Packet::clearBlockCached(), gem5::Clocked::clockEdge(), gem5::Packet::cmd, compressor, gem5::Clocked::cyclesToTicks(), gem5::CacheBlk::DirtyBit, DPRINTF, fillLatency, gem5::Queue< Entry >::findMatch(), gem5::Packet::fromCache(), gem5_assert, gem5::Packet::getAddr(), gem5::Packet::getConstPtr(), gem5::compression::Base::getDecompressionLatency(), gem5::WriteQueueEntry::getNumTargets(), gem5::Packet::getSize(), gem5::WriteQueueEntry::getTarget(), gem5::Packet::hasSharers(), gem5::Packet::headerDelay, incHitCount(), incMissCount(), invalidateBlock(), gem5::Packet::isCleanEviction(), gem5::Packet::isEviction(), gem5::Packet::isLLSC(), gem5::Packet::isRead(), isReadOnly, gem5::Packet::isRequest(), gem5::Packet::isSecure(), gem5::CacheBlk::isSet(), gem5::TaggedEntry::isValid(), gem5::Packet::isWrite(), gem5::Packet::isWriteback(), maintainClusivity(), markInService(), mshrQueue, gem5::Named::name(), gem5::Packet::needsResponse(), gem5::Packet::needsWritable(), gem5::Packet::payloadDelay, gem5::QueueEntry::Target::pkt, gem5::CacheBlk::print(), gem5::Packet::print(), gem5::CacheBlk::ReadableBit, gem5::Packet::req, satisfyRequest(), gem5::CacheBlk::setCoherenceBits(), gem5::CacheBlk::setWhenReady(), tags, updateBlockData(), updateCompressionData(), gem5::CacheBlk::WritableBit, gem5::MemCmd::WritebackClean, gem5::MemCmd::WritebackDirty, writeBuffer, gem5::MemCmd::WriteClean, and gem5::Packet::writeThrough().

Referenced by gem5::Cache::access(), gem5::NoncoherentCache::access(), recvAtomic(), and recvTimingReq().

◆ allocateBlock()

CacheBlk * gem5::BaseCache::allocateBlock	(	const PacketPtr	pkt,
		PacketList &	writebacks
	)

protected

Allocate a new block and perform any necessary writebacks.

Find a victim block and if necessary prepare writebacks for any existing data. May return nullptr if there are no replaceable blocks. If a replaceable block is found, it inserts the new block in its place. The new block, however, is not set as valid yet.

Parameters

pkt	Packet holding the address to update
writebacks	A list of writeback packets for the evicted blocks

Returns: the allocated block

Definition at line 1605 of file base.cc.

References gem5::X86ISA::addr, blkSize, gem5::compression::Base::compress(), compressor, DPRINTF, gem5::BaseTags::findVictim(), gem5::Packet::getAddr(), gem5::Packet::getConstPtr(), handleEvictions(), gem5::Packet::hasData(), gem5::BaseTags::insertBlock(), gem5::Packet::isSecure(), gem5::CacheBlk::print(), gem5::compression::Base::setDecompressionLatency(), gem5::compression::Base::setSizeBits(), and tags.

Referenced by access(), and handleFill().

◆ allocateMissBuffer()

MSHR* gem5::BaseCache::allocateMissBuffer	(	PacketPtr	pkt,
		Tick	time,
		bool	sched_send = `true`
	)

inline

Definition at line 1173 of file base.hh.

References gem5::MSHRQueue::allocate(), allocOnFill(), blkSize, gem5::Packet::cmd, gem5::Packet::getBlockAddr(), gem5::Queue< Entry >::isFull(), mshrQueue, MSHRQueue_MSHRs, order, schedMemSideSendEvent(), and setBlocked().

Referenced by getNextQueueEntry(), handleTimingReqHit(), gem5::Cache::handleTimingReqMiss(), and handleTimingReqMiss().

◆ allocateWriteBuffer()

void gem5::BaseCache::allocateWriteBuffer	(	PacketPtr	pkt,
		Tick	time
	)

inline

◆ allocOnFill()

bool gem5::BaseCache::allocOnFill ( MemCmd cmd ) const

inlineprotected

Determine whether we should allocate on a fill or not.

If this cache is mostly inclusive with regards to the upstream cache(s) we always allocate (for any non-forwarded and cacheable requests). In the case of a mostly exclusive cache, we allocate on fill if the packet did not come from a cache, thus if we: are dealing with a whole-line write (the latter behaves much like a writeback), the original target packet came from a non-caching source, or if we are performing a prefetch or LLSC.

Parameters

cmd	Command of the incoming requesting packet

Returns: Whether we should allocate on the fill

Definition at line 441 of file base.hh.

References clusivity, gem5::MemCmd::isLLSC(), gem5::MemCmd::isPrefetch(), gem5::MemCmd::ReadReq, gem5::MemCmd::WriteLineReq, and gem5::MemCmd::WriteReq.

Referenced by allocateMissBuffer(), gem5::Cache::handleAtomicReqMiss(), gem5::NoncoherentCache::handleAtomicReqMiss(), and handleTimingReqMiss().

◆ calculateAccessLatency()

Cycles gem5::BaseCache::calculateAccessLatency	(	const CacheBlk *	blk,
		const uint32_t	delay,
		const Cycles	lookup_lat
	)		const

protected

Calculate access latency in ticks given a tag lookup latency, and whether access was a hit or miss.

Parameters

blk	The cache block that was accessed.
delay	The delay until the packet's metadata is present.
lookup_lat	Latency of the respective tag lookup.

Returns: The number of ticks that pass due to a block access.

Definition at line 1194 of file base.cc.

References calculateTagOnlyLatency(), gem5::curTick(), dataLatency, gem5::CacheBlk::getWhenReady(), sequentialAccess, gem5::Clocked::tick, and gem5::Clocked::ticksToCycles().

Referenced by access().

◆ calculateTagOnlyLatency()

Cycles gem5::BaseCache::calculateTagOnlyLatency	(	const uint32_t	delay,
		const Cycles	lookup_lat
	)		const

protected

Calculate latency of accesses that only touch the tag array.

See also: calculateAccessLatency

Parameters

delay	The delay until the packet's metadata is present.
lookup_lat	Latency of the respective tag lookup.

Returns: The number of ticks that pass due to a tag-only access.

Definition at line 1185 of file base.cc.

References gem5::Clocked::ticksToCycles().

Referenced by access(), and calculateAccessLatency().

◆ clearBlocked()

void gem5::BaseCache::clearBlocked ( BlockedCause cause )

inline

Marks the cache as unblocked for the given cause.

This also clears the blocked flags in the appropriate interfaces.

Parameters

cause The newly unblocked cause.

Warning: Calling this function can cause a blocked request on the bus to access the cache. The cache must be in a state to handle that request.

Definition at line 1255 of file base.hh.

References blocked, blockedCycle, gem5::BaseCache::CacheStats::blockedCycles, gem5::BaseCache::CacheResponsePort::clearBlocked(), cpuSidePort, gem5::Clocked::curCycle(), DPRINTF, and stats.

Referenced by markInService(), recvTimingResp(), and gem5::Cache::sendMSHRQueuePacket().

◆ cmpAndSwap()

void gem5::BaseCache::cmpAndSwap	(	CacheBlk *	blk,
		PacketPtr	pkt
	)

protected

Handle doing the Compare and Swap function for SPARC.

Definition at line 795 of file base.cc.

References blkSize, gem5::CacheBlk::data, gem5::CacheBlk::DirtyBit, gem5::Packet::getOffset(), gem5::Packet::getSize(), gem5::Packet::isRequest(), gem5::TaggedEntry::isSecure(), gem5::BaseCache::DataUpdate::newData, gem5::ArmISA::offset, gem5::BaseCache::DataUpdate::oldData, panic, ppDataUpdate, regenerateBlkAddr(), gem5::Packet::req, gem5::CacheBlk::setCoherenceBits(), gem5::Packet::setData(), and gem5::Packet::writeData().

Referenced by satisfyRequest().

◆ coalesce()

bool gem5::BaseCache::coalesce ( ) const

Checks if the cache is coalescing writes.

Returns: True if the cache is coalescing writes

Definition at line 1806 of file base.cc.

References gem5::WriteAllocator::coalesce(), and writeAllocator.

Referenced by gem5::prefetch::Base::probeNotify().

◆ createMissPacket()

virtual PacketPtr gem5::BaseCache::createMissPacket	(	PacketPtr	cpu_pkt,
		CacheBlk *	blk,
		bool	needs_writable,
		bool	is_whole_line_write
	)		const

protectedpure virtual

Create an appropriate downstream bus request packet.

Creates a new packet with the request to be send to the memory below, or nullptr if the current request in cpu_pkt should just be forwarded on.

Parameters

cpu_pkt	The miss packet that needs to be satisfied.
blk	The referenced block, can be nullptr.
needs_writable	Indicates that the block must be writable even if the request in cpu_pkt doesn't indicate that.
is_whole_line_write	True if there are writes for the whole line

Returns: A packet send to the memory below

Implemented in gem5::NoncoherentCache, and gem5::Cache.

Referenced by sendMSHRQueuePacket().

◆ doWritebacks()

virtual void gem5::BaseCache::doWritebacks	(	PacketList &	writebacks,
		Tick	forward_time
	)

protectedpure virtual

Insert writebacks into the write buffer.

Implemented in gem5::NoncoherentCache, and gem5::Cache.

Referenced by recvTimingReq(), recvTimingResp(), and sendMSHRQueuePacket().

◆ doWritebacksAtomic()

virtual void gem5::BaseCache::doWritebacksAtomic ( PacketList & writebacks )

protectedpure virtual

Send writebacks down the memory hierarchy in atomic mode.

Implemented in gem5::NoncoherentCache, and gem5::Cache.

Referenced by recvAtomic(), and writebackTempBlockAtomic().

◆ evictBlock() [1/2]

virtual PacketPtr gem5::BaseCache::evictBlock ( CacheBlk * blk )

protectedpure virtual

Evict a cache block.

Performs a writeback if necesssary and invalidates the block

Parameters

blk	Block to invalidate

Returns: A packet with the writeback, can be nullptr

Implemented in gem5::NoncoherentCache, and gem5::Cache.

Referenced by gem5::Cache::access(), evictBlock(), handleEvictions(), recvAtomic(), and recvTimingResp().

◆ evictBlock() [2/2]

void gem5::BaseCache::evictBlock	(	CacheBlk *	blk,
		PacketList &	writebacks
	)

protected

Evict a cache block.

Performs a writeback if necesssary and invalidates the block

Parameters

blk	Block to invalidate
writebacks	Return a list of packets with writebacks

Definition at line 1682 of file base.cc.

References evictBlock().

◆ functionalAccess()

void gem5::BaseCache::functionalAccess	(	PacketPtr	pkt,
		bool	from_cpu_side
	)

protectedvirtual

Performs the access specified by the request.

Parameters

pkt	The request to perform.
fromCpuSide	from the CPU side port or the memory side port

Reimplemented in gem5::NoncoherentCache.

Definition at line 713 of file base.cc.

References blkSize, cpuSidePort, gem5::CacheBlk::data, gem5::CacheBlk::DirtyBit, DPRINTF, gem5::BaseTags::findBlock(), gem5::Queue< Entry >::findMatch(), gem5::Packet::getAddr(), gem5::Packet::getBlockAddr(), gem5::QueueEntry::inService, gem5::MSHR::isPendingModified(), gem5::Packet::isSecure(), gem5::CacheBlk::isSet(), gem5::ResponsePort::isSnooping(), gem5::TaggedEntry::isValid(), gem5::Packet::makeResponse(), memSidePort, mshrQueue, gem5::Named::name(), gem5::Packet::popLabel(), gem5::Packet::print(), gem5::Packet::pushLabel(), gem5::RequestPort::sendFunctional(), gem5::ResponsePort::sendFunctionalSnoop(), tags, gem5::Packet::trySatisfyFunctional(), gem5::Queue< Entry >::trySatisfyFunctional(), gem5::QueuedResponsePort::trySatisfyFunctional(), gem5::QueuedRequestPort::trySatisfyFunctional(), and writeBuffer.

Referenced by gem5::NoncoherentCache::functionalAccess().

◆ getAddrRanges()

const AddrRangeList& gem5::BaseCache::getAddrRanges ( ) const

inline

Definition at line 1171 of file base.hh.

References addrRanges.

◆ getBlockSize()

unsigned gem5::BaseCache::getBlockSize ( ) const

inline

Query block size of a cache.

Returns: The block size

Definition at line 1166 of file base.hh.

References blkSize.

Referenced by gem5::prefetch::Base::setCache().

◆ getNextQueueEntry()

QueueEntry * gem5::BaseCache::getNextQueueEntry ( )

protected

Return the next queue entry to service, either a pending miss from the MSHR queue, a buffered write from the write buffer, or something from the prefetcher.

This function is responsible for prioritizing among those sources on the fly.

Definition at line 848 of file base.cc.

References allocateMissBuffer(), blkSize, gem5::MSHRQueue::canPrefetch(), gem5::BaseCache::CacheStats::cmdStats(), gem5::curTick(), DPRINTF, gem5::BaseTags::findBlock(), gem5::Queue< Entry >::findMatch(), gem5::Queue< Entry >::findPending(), gem5::Packet::getBlockAddr(), gem5::Queue< Entry >::getNext(), gem5::prefetch::Base::getPacket(), isBlocked(), gem5::Queue< Entry >::isFull(), gem5::Packet::isSecure(), gem5::System::maxRequestors(), gem5::BaseCache::CacheCmdStats::mshrMisses, mshrQueue, gem5::QueueEntry::order, gem5::prefetch::Base::pfHitInCache(), gem5::prefetch::Base::pfHitInMSHR(), gem5::prefetch::Base::pfHitInWB(), prefetcher, gem5::Packet::req, stats, system, tags, and writeBuffer.

◆ getPort()

Port & gem5::BaseCache::getPort	(	const std::string &	if_name,
		PortID	idx = `InvalidPortID`
	)

overridevirtual

Get a port with a given name and index.

This is used at binding time and returns a reference to a protocol-agnostic port.

gem5 has a request and response port interface. All memory objects are connected together via ports. These ports provide a rigid interface between these memory objects. These ports implement three different memory system modes: timing, atomic, and functional. The most important mode is the timing mode and here timing mode is used for conducting cycle-level timing experiments. The other modes are only used in special circumstances and should not be used to conduct cycle-level timing experiments. The other modes are only used in special circumstances. These ports allow SimObjects to communicate with each other.

Parameters

if_name	Port name
idx	Index in the case of a VectorPort

Returns: A reference to the given port

Reimplemented from gem5::SimObject.

Definition at line 201 of file base.cc.

References cpuSidePort, gem5::SimObject::getPort(), and memSidePort.

◆ handleAtomicReqMiss()

virtual Cycles gem5::BaseCache::handleAtomicReqMiss	(	PacketPtr	pkt,
		CacheBlk *&	blk,
		PacketList &	writebacks
	)

protectedpure virtual

Handle a request in atomic mode that missed in this cache.

Creates a downstream request, sends it to the memory below and handles the response. As we are in atomic mode all operations are performed immediately.

Parameters

pkt	The packet with the requests
blk	The referenced block
writebacks	A list with packets for any performed writebacks

Returns: Cycles for handling the request

Implemented in gem5::NoncoherentCache, and gem5::Cache.

Referenced by recvAtomic().

◆ handleEvictions()

bool gem5::BaseCache::handleEvictions	(	std::vector< CacheBlk * > &	evict_blks,
		PacketList &	writebacks
	)

protected

Try to evict the given blocks.

If any of them is a transient eviction, that is, the block is present in the MSHR queue all evictions are cancelled since handling such cases has not been implemented.

Parameters

evict_blks	Blocks marked for eviction.
writebacks	List for any writebacks that need to be performed.

Returns: False if any of the evicted blocks is in transient state.

Definition at line 939 of file base.cc.

References evictBlock(), gem5::Queue< Entry >::findMatch(), gem5::MSHR::isCleaning(), mshrQueue, gem5::MSHR::needsWritable(), regenerateBlkAddr(), gem5::BaseCache::CacheStats::replacements, stats, and gem5::CacheBlk::WritableBit.

Referenced by allocateBlock(), and updateCompressionData().

◆ handleFill()

CacheBlk * gem5::BaseCache::handleFill	(	PacketPtr	pkt,
		CacheBlk *	blk,
		PacketList &	writebacks,
		bool	allocate
	)

protected

Handle a fill operation caused by a received packet.

Populates a cache block and handles all outstanding requests for the satisfied fill request. This version takes two memory requests. One contains the fill data, the other is an optional target to satisfy. Note that the reason we return a list of writebacks rather than inserting them directly in the write buffer is that this function is called by both atomic and timing-mode accesses, and in atomic mode we don't mess with the write buffer (we just perform the writebacks atomically once the original request is complete).

Parameters

pkt	The memory request with the fill data.
blk	The cache block if it already exists.
writebacks	List for any writebacks that need to be performed.
allocate	Whether to allocate a block or use the temp block

Returns: Pointer to the new cache block.

Definition at line 1509 of file base.cc.

References gem5::X86ISA::addr, allocateBlock(), blkSize, gem5::Packet::cacheResponding(), gem5::Clocked::clockEdge(), gem5::Packet::cmd, gem5::CacheBlk::DirtyBit, DPRINTF, fillLatency, gem5::Queue< Entry >::findMatch(), gem5_assert, gem5::Packet::getAddr(), gem5::Packet::getBlockAddr(), gem5::Packet::getSize(), gem5::Packet::hasData(), gem5::Packet::hasSharers(), gem5::Packet::headerDelay, gem5::TempCacheBlk::insert(), gem5::MemCmd::InvalidateResp, gem5::Packet::isRead(), isReadOnly, gem5::Packet::isResponse(), gem5::TaggedEntry::isSecure(), gem5::Packet::isSecure(), gem5::TaggedEntry::isValid(), gem5::Named::name(), gem5::Packet::payloadDelay, gem5::CacheBlk::print(), gem5::CacheBlk::ReadableBit, regenerateBlkAddr(), gem5::CacheBlk::setCoherenceBits(), gem5::CacheBlk::setWhenReady(), tempBlock, updateBlockData(), gem5::CacheBlk::WritableBit, and writeBuffer.

Referenced by gem5::Cache::handleAtomicReqMiss(), gem5::NoncoherentCache::handleAtomicReqMiss(), and recvTimingResp().

◆ handleTimingReqHit()

void gem5::BaseCache::handleTimingReqHit	(	PacketPtr	pkt,
		CacheBlk *	blk,
		Tick	request_time
	)

protectedvirtual

Reimplemented in gem5::Cache.

Definition at line 224 of file base.cc.

References allocateMissBuffer(), blkSize, gem5::CacheBlk::clearCoherenceBits(), gem5::Packet::cmd, cpuSidePort, gem5::curTick(), DPRINTF, gem5::Queue< Entry >::findMatch(), gem5::Packet::getBlockAddr(), gem5::Packet::headerDelay, gem5::Packet::isLockedRMW(), gem5::Packet::isRead(), gem5::Packet::isSecure(), gem5::Packet::isWrite(), gem5::MemCmd::LockedRMWWriteResp, gem5::Packet::makeTimingResponse(), gem5::MSHRQueue::markInService(), mshrQueue, gem5::Packet::needsResponse(), gem5::Packet::payloadDelay, pendingDelete, gem5::Packet::print(), gem5::CacheBlk::ReadableBit, recvTimingResp(), gem5::Packet::req, gem5::QueuedResponsePort::schedTimingResp(), gem5::Packet::senderState, and gem5::CacheBlk::WritableBit.

Referenced by gem5::Cache::handleTimingReqHit(), and recvTimingReq().

◆ handleTimingReqMiss() [1/2]

virtual void gem5::BaseCache::handleTimingReqMiss	(	PacketPtr	pkt,
		CacheBlk *	blk,
		Tick	forward_time,
		Tick	request_time
	)

protectedpure virtual

Implemented in gem5::NoncoherentCache, and gem5::Cache.

Referenced by gem5::Cache::handleTimingReqMiss(), gem5::NoncoherentCache::handleTimingReqMiss(), and recvTimingReq().

◆ handleTimingReqMiss() [2/2]

void gem5::BaseCache::handleTimingReqMiss	(	PacketPtr	pkt,
		MSHR *	mshr,
		CacheBlk *	blk,
		Tick	forward_time,
		Tick	request_time
	)

protected

MSHR hit

Note: writebacks will be checked in getNextMSHR() for any conflicting requests to the same block

Definition at line 305 of file base.cc.

References allocateMissBuffer(), gem5::MSHR::allocateTarget(), allocateWriteBuffer(), allocOnFill(), blkSize, Blocked_NoTargets, gem5::MemCmd::CleanEvict, gem5::CacheBlk::clearCoherenceBits(), gem5::Packet::cmd, gem5::BaseCache::CacheStats::cmdStats(), DPRINTF, gem5::Packet::getAddr(), gem5::Packet::getBlockAddr(), gem5::MSHR::getNumTargets(), gem5::Packet::getSize(), gem5::prefetch::Base::incrDemandMhsrMisses(), gem5::Packet::isDemand(), gem5::Packet::isEviction(), gem5::CacheBlk::isSet(), gem5::TaggedEntry::isValid(), gem5::Packet::isWrite(), gem5::Packet::isWriteback(), gem5::System::maxRequestors(), gem5::BaseCache::CacheCmdStats::mshrHits, gem5::BaseCache::CacheCmdStats::mshrMisses, gem5::Packet::needsWritable(), noTargetMSHR, numTarget, order, pendingDelete, prefetcher, gem5::Packet::print(), gem5::CacheBlk::ReadableBit, gem5::Packet::req, setBlocked(), stats, system, gem5::WriteAllocator::updateMode(), gem5::CacheBlk::WritableBit, writeAllocator, and gem5::MemCmd::WriteClean.

◆ handleUncacheableWriteResp()

void gem5::BaseCache::handleUncacheableWriteResp ( PacketPtr pkt )

protected

Handling the special case of uncacheable write responses to make recvTimingResp less cluttered.

Definition at line 475 of file base.cc.

References gem5::Clocked::clockEdge(), cpuSidePort, gem5::Packet::headerDelay, gem5::Packet::payloadDelay, responseLatency, and gem5::QueuedResponsePort::schedTimingResp().

Referenced by recvTimingResp().

◆ hasBeenPrefetched()

bool gem5::BaseCache::hasBeenPrefetched	(	Addr	addr,
		bool	is_secure
	)		const

inline

Definition at line 1283 of file base.hh.

References gem5::X86ISA::addr, gem5::BaseTags::findBlock(), tags, and gem5::CacheBlk::wasPrefetched().

Referenced by gem5::prefetch::Base::hasBeenPrefetched().

◆ inCache()

bool gem5::BaseCache::inCache	(	Addr	addr,
		bool	is_secure
	)		const

inline

Definition at line 1279 of file base.hh.

References gem5::X86ISA::addr, gem5::BaseTags::findBlock(), and tags.

Referenced by gem5::prefetch::Base::inCache().

◆ incHitCount()

void gem5::BaseCache::incHitCount ( PacketPtr pkt )

inline

Definition at line 1307 of file base.hh.

References gem5::BaseCache::CacheStats::cmdStats(), gem5::BaseCache::CacheCmdStats::hits, gem5::System::maxRequestors(), gem5::Packet::req, stats, and system.

Referenced by access().

◆ incMissCount()

void gem5::BaseCache::incMissCount ( PacketPtr pkt )

inline

Definition at line 1296 of file base.hh.

References gem5::BaseCache::CacheStats::cmdStats(), gem5::exitSimLoop(), gem5::System::maxRequestors(), missCount, gem5::BaseCache::CacheCmdStats::misses, gem5::Packet::req, stats, and system.

Referenced by access().

◆ init()

void gem5::BaseCache::init ( )

overridevirtual

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 192 of file base.cc.

References cpuSidePort, fatal, forwardSnoops, gem5::Port::isConnected(), gem5::ResponsePort::isSnooping(), memSidePort, gem5::Named::name(), and gem5::ResponsePort::sendRangeChange().

◆ inMissQueue()

bool gem5::BaseCache::inMissQueue	(	Addr	addr,
		bool	is_secure
	)		const

inline

Definition at line 1292 of file base.hh.

References gem5::X86ISA::addr, gem5::Queue< Entry >::findMatch(), and mshrQueue.

Referenced by gem5::prefetch::Base::inMissQueue().

◆ inRange()

bool gem5::BaseCache::inRange ( Addr addr ) const

protected

Determine if an address is in the ranges covered by this cache.

This is useful to filter snoops.

Parameters

addr	Address to check against

Returns: If the address in question is in range

Definition at line 213 of file base.cc.

References gem5::X86ISA::addr, addrRanges, and gem5::VegaISA::r.

Referenced by gem5::Cache::recvAtomicSnoop(), and gem5::Cache::recvTimingSnoopReq().

◆ invalidateBlock()

void gem5::BaseCache::invalidateBlock ( CacheBlk * blk )

protected

Invalidate a cache block.

Parameters

blk	Block to invalidate

Definition at line 1662 of file base.cc.

References gem5::TempCacheBlk::invalidate(), gem5::BaseTags::invalidate(), gem5::TaggedEntry::isValid(), prefetcher, gem5::prefetch::Base::prefetchUnused(), tags, tempBlock, updateBlockData(), and gem5::CacheBlk::wasPrefetched().

Referenced by access(), gem5::Cache::evictBlock(), gem5::NoncoherentCache::evictBlock(), gem5::Cache::handleAtomicReqMiss(), gem5::Cache::handleSnoop(), invalidateVisitor(), maintainClusivity(), satisfyRequest(), and gem5::Cache::serviceMSHRTargets().

◆ invalidateVisitor()

void gem5::BaseCache::invalidateVisitor ( CacheBlk & blk )

Cache block visitor that invalidates all blocks in the cache.

@warn Dirty cache lines will not be written back to memory.

Definition at line 1835 of file base.cc.

References gem5::CacheBlk::DirtyBit, invalidateBlock(), gem5::CacheBlk::isSet(), gem5::TaggedEntry::isValid(), and warn_once.

Referenced by memInvalidate().

◆ isBlocked()

bool gem5::BaseCache::isBlocked ( ) const

inline

Returns true if the cache is blocked for accesses.

Definition at line 1226 of file base.hh.

References blocked.

Referenced by getNextQueueEntry(), nextQueueReadyTime(), and recvTimingResp().

◆ isDirty()

bool gem5::BaseCache::isDirty ( ) const

protected

Determine if there are any dirty blocks in the cache.

Returns: true if at least one block is dirty, false otherwise.

Definition at line 1799 of file base.cc.

References gem5::BaseTags::anyBlk(), gem5::CacheBlk::DirtyBit, gem5::CacheBlk::isSet(), and tags.

Referenced by serialize().

◆ maintainClusivity()

void gem5::BaseCache::maintainClusivity	(	bool	from_cache,
		CacheBlk *	blk
	)

protected

Maintain the clusivity of this cache by potentially invalidating a block.

This method works in conjunction with satisfyRequest, but is separate to allow us to handle all MSHR targets before potentially dropping a block.

Parameters

from_cache	Whether we have dealt with a packet from a cache
blk	The block that should potentially be dropped

Definition at line 1497 of file base.cc.

References clusivity, gem5::CacheBlk::DirtyBit, invalidateBlock(), gem5::CacheBlk::isSet(), and gem5::TaggedEntry::isValid().

Referenced by access(), gem5::Cache::handleAtomicReqMiss(), gem5::NoncoherentCache::handleAtomicReqMiss(), and gem5::Cache::serviceMSHRTargets().

◆ markInService() [1/2]

void gem5::BaseCache::markInService	(	MSHR *	mshr,
		bool	pending_modified_resp
	)

inlineprotected

Mark a request as in service (sent downstream in the memory system), effectively making this MSHR the ordering point.

Definition at line 408 of file base.hh.

References Blocked_NoMSHRs, clearBlocked(), gem5::Queue< Entry >::isFull(), gem5::MSHRQueue::markInService(), and mshrQueue.

Referenced by access(), gem5::Cache::recvTimingSnoopReq(), sendMSHRQueuePacket(), gem5::Cache::sendMSHRQueuePacket(), and sendWriteQueuePacket().

◆ markInService() [2/2]

void gem5::BaseCache::markInService ( WriteQueueEntry * entry )

inlineprotected

Definition at line 418 of file base.hh.

References Blocked_NoWBBuffers, clearBlocked(), gem5::Queue< Entry >::isFull(), gem5::WriteQueue::markInService(), and writeBuffer.

◆ memInvalidate()

void gem5::BaseCache::memInvalidate ( )

overrideprotectedvirtual

Invalidates all blocks in the cache.

@warn Dirty cache lines will not be written back to memory. Make sure to call functionalWriteback() first if you want the to write them to memory.

Reimplemented from gem5::SimObject.

Definition at line 1793 of file base.cc.

References gem5::BaseTags::forEachBlk(), invalidateVisitor(), and tags.

◆ memWriteback()

void gem5::BaseCache::memWriteback ( )

overrideprotectedvirtual

Write back dirty blocks in the cache using functional accesses.

Reimplemented from gem5::SimObject.

Definition at line 1787 of file base.cc.

References gem5::BaseTags::forEachBlk(), tags, and writebackVisitor().

◆ nextQueueReadyTime()

Tick gem5::BaseCache::nextQueueReadyTime ( ) const

protected

Find next request ready time from among possible sources.

Definition at line 1848 of file base.cc.

References gem5::MSHRQueue::canPrefetch(), isBlocked(), mshrQueue, gem5::prefetch::Base::nextPrefetchReadyTime(), gem5::Queue< Entry >::nextReadyTime(), prefetcher, and writeBuffer.

◆ recvAtomic()

Tick gem5::BaseCache::recvAtomic ( PacketPtr pkt )

protectedvirtual

Performs the access specified by the request.

Parameters

pkt	The request to perform.

Returns: The number of ticks required for the access.

Reimplemented in gem5::NoncoherentCache, and gem5::Cache.

Definition at line 633 of file base.cc.

References access(), gem5::Clocked::clockPeriod(), gem5::curTick(), gem5::CacheBlk::DirtyBit, doWritebacksAtomic(), DPRINTF, evictBlock(), handleAtomicReqMiss(), gem5::Packet::id, gem5::Packet::isClean(), gem5::CacheBlk::isSet(), gem5::TaggedEntry::isValid(), lookupLatency, gem5::Packet::makeAtomicResponse(), gem5::Packet::needsResponse(), gem5::CacheBlk::print(), gem5::Packet::print(), gem5::Packet::req, gem5::EventManager::schedule(), gem5::Packet::setSatisfied(), tempBlock, tempBlockWriteback, writebackTempBlockAtomic(), writebackTempBlockAtomicEvent, and writecleanBlk().

Referenced by gem5::Cache::recvAtomic(), and gem5::NoncoherentCache::recvAtomic().

◆ recvAtomicSnoop()

virtual Tick gem5::BaseCache::recvAtomicSnoop ( PacketPtr pkt )

protectedpure virtual

Snoop for the provided request in the cache and return the estimated time taken.

Parameters

pkt	The memory request to snoop

Returns: The number of ticks required for the snoop.

Implemented in gem5::NoncoherentCache, and gem5::Cache.

◆ recvTimingReq()

void gem5::BaseCache::recvTimingReq ( PacketPtr pkt )

protectedvirtual

Performs the access specified by the request.

Parameters

pkt	The request to perform.

Reimplemented in gem5::NoncoherentCache, and gem5::Cache.

Definition at line 403 of file base.cc.

References access(), gem5::CacheBlk::clearPrefetched(), gem5::Clocked::clockEdge(), gem5::Packet::cmd, doWritebacks(), DPRINTF, gem5::BaseTags::findBlock(), forwardLatency, gem5::Packet::getAddr(), handleTimingReqHit(), handleTimingReqMiss(), gem5::Packet::headerDelay, gem5::Packet::isSecure(), gem5::CacheBlk::isSet(), gem5::TaggedEntry::isValid(), gem5::MemCmd::LockedRMWWriteReq, gem5::MaxTick, gem5::prefetch::Base::nextPrefetchReadyTime(), gem5::Packet::payloadDelay, ppHit, ppMiss, prefetcher, gem5::CacheBlk::ReadableBit, schedMemSideSendEvent(), gem5::CacheBlk::setCoherenceBits(), tags, gem5::CacheBlk::wasPrefetched(), and gem5::CacheBlk::WritableBit.

Referenced by gem5::Cache::recvTimingReq(), and gem5::NoncoherentCache::recvTimingReq().

◆ recvTimingResp()

void gem5::BaseCache::recvTimingResp ( PacketPtr pkt )

protectedvirtual

Handles a response (cache line fill/write ack) from the bus.

Parameters

pkt	The response packet

Reimplemented in gem5::NoncoherentCache.

Definition at line 487 of file base.cc.

References gem5::WriteAllocator::allocate(), gem5::MSHR::allocOnFill(), Blocked_NoMSHRs, Blocked_NoTargets, gem5::MSHRQueue::canPrefetch(), clearBlocked(), gem5::CacheBlk::clearCoherenceBits(), gem5::Clocked::clockEdge(), gem5::Packet::cmd, gem5::BaseCache::CacheStats::cmdStats(), gem5::curTick(), gem5::MSHRQueue::deallocate(), doWritebacks(), DPRINTF, evictBlock(), gem5::BaseTags::findBlock(), forwardLatency, gem5::Packet::getAddr(), gem5::MSHR::getTarget(), handleFill(), handleUncacheableWriteResp(), gem5::MemCmd::HardPFResp, gem5::MSHR::hasLockedRMWReadTarget(), gem5::Packet::headerDelay, isBlocked(), gem5::Packet::isClean(), gem5::Packet::isError(), gem5::MSHR::isForward, gem5::Queue< Entry >::isFull(), gem5::Packet::isInvalidate(), gem5::Packet::isRead(), gem5::Packet::isResponse(), gem5::Packet::isSecure(), gem5::CacheBlk::isSet(), gem5::TaggedEntry::isValid(), gem5::Packet::isWrite(), gem5::MemCmd::LockedRMWWriteResp, gem5::MSHRQueue::markPending(), gem5::System::maxRequestors(), gem5::MaxTick, gem5::BaseCache::CacheCmdStats::mshrMissLatency, mshrQueue, gem5::BaseCache::CacheCmdStats::mshrUncacheableLatency, gem5::Named::name(), gem5::prefetch::Base::nextPrefetchReadyTime(), noTargetMSHR, panic_if, gem5::Packet::payloadDelay, gem5::QueueEntry::Target::pkt, gem5::Packet::popSenderState(), ppFill, prefetcher, gem5::Packet::print(), gem5::MSHR::promoteDeferredTargets(), gem5::MSHR::promoteReadable(), gem5::MSHR::promoteWritable(), gem5::CacheBlk::ReadableBit, gem5::QueueEntry::Target::recvTime, gem5::Packet::req, schedMemSideSendEvent(), serviceMSHRTargets(), gem5::CacheBlk::setCoherenceBits(), stats, system, tags, tempBlock, gem5::MemCmd::UpgradeResp, gem5::MSHR::wasWholeLineWrite, gem5::CacheBlk::WritableBit, and writeAllocator.

Referenced by handleTimingReqHit(), gem5::NoncoherentCache::recvTimingResp(), and gem5::Cache::recvTimingSnoopResp().

◆ recvTimingSnoopReq()

virtual void gem5::BaseCache::recvTimingSnoopReq ( PacketPtr pkt )

protectedpure virtual

Snoops bus transactions to maintain coherence.

Parameters

pkt	The current bus transaction.

Implemented in gem5::NoncoherentCache, and gem5::Cache.

◆ recvTimingSnoopResp()

virtual void gem5::BaseCache::recvTimingSnoopResp ( PacketPtr pkt )

protectedpure virtual

Handle a snoop response.

Parameters

pkt	Snoop response packet

Implemented in gem5::NoncoherentCache, and gem5::Cache.

◆ regenerateBlkAddr()

Addr gem5::BaseCache::regenerateBlkAddr ( CacheBlk * blk )

protected

Regenerate block address using tags.

Block address regeneration depends on whether we're using a temporary block or not.

Parameters

blk	The block to regenerate address.

Returns: The block's address.

Definition at line 182 of file base.cc.

References gem5::TempCacheBlk::getAddr(), gem5::BaseTags::regenerateBlkAddr(), tags, and tempBlock.

Referenced by gem5::Cache::cleanEvictBlk(), cmpAndSwap(), handleEvictions(), handleFill(), satisfyRequest(), updateBlockData(), updateCompressionData(), writebackBlk(), writebackVisitor(), and writecleanBlk().

◆ regProbePoints()

void gem5::BaseCache::regProbePoints ( )

overridevirtual

Registers probes.

Reimplemented from gem5::SimObject.

Definition at line 2506 of file base.cc.

References gem5::SimObject::getProbeManager(), ppDataUpdate, ppFill, ppHit, and ppMiss.

◆ satisfyRequest()

void gem5::BaseCache::satisfyRequest	(	PacketPtr	pkt,
		CacheBlk *	blk,
		bool	deferred_response = `false`,
		bool	pending_downgrade = `false`
	)

protectedvirtual

Perform any necessary updates to the block and perform any data exchange between the packet and the block.

The flags of the packet are also set accordingly.

Parameters

pkt	Request packet from upstream that hit a block
blk	Cache block that the packet hit
deferred_response	Whether this request originally missed
pending_downgrade	Whether the writable flag is to be removed

Reimplemented in gem5::NoncoherentCache, and gem5::Cache.

Definition at line 1087 of file base.cc.

Referenced by access(), gem5::Cache::satisfyRequest(), and gem5::NoncoherentCache::satisfyRequest().

◆ schedMemSideSendEvent()

void gem5::BaseCache::schedMemSideSendEvent ( Tick time )

inline

Schedule a send event for the memory-side port.

If already scheduled, this may reschedule the event at an earlier time. When the specified time is reached, the port is free to send either a response, a request, or a prefetch request.

Parameters

time	The time when to attempt sending a packet.

Definition at line 1274 of file base.hh.

References memSidePort, and gem5::BaseCache::CacheRequestPort::schedSendEvent().

Referenced by allocateMissBuffer(), allocateWriteBuffer(), recvTimingReq(), and recvTimingResp().

◆ sendMSHRQueuePacket()

bool gem5::BaseCache::sendMSHRQueuePacket ( MSHR * mshr )

virtual

Take an MSHR, turn it into a suitable downstream packet, and send it out.

This construct allows a queue entry to choose a suitable approach based on its type.

Parameters

mshr	The MSHR to turn into a packet and send

Returns: True if the port is waiting for a retry

Reimplemented in gem5::Cache.

Definition at line 1865 of file base.cc.

References gem5::QueueEntry::blkAddr, blkSize, gem5::Packet::cacheResponding(), gem5::Clocked::clockPeriod(), gem5::WriteAllocator::coalesce(), createMissPacket(), gem5::WriteAllocator::delay(), gem5::MSHRQueue::delay(), gem5::CacheBlk::DirtyBit, doWritebacks(), DPRINTF, gem5::BaseTags::findBlock(), gem5::Packet::getSize(), gem5::MSHR::getTarget(), gem5::Packet::hasSharers(), gem5::Packet::id, gem5::Packet::isClean(), gem5::MSHR::isForward, gem5::QueueEntry::isSecure, gem5::CacheBlk::isSet(), gem5::MSHR::isWholeLineWrite(), gem5::Packet::isWrite(), markInService(), memSidePort, mshrQueue, gem5::MSHR::needsWritable(), gem5::QueueEntry::Target::pkt, gem5::CacheBlk::print(), gem5::Packet::print(), gem5::Packet::pushSenderState(), gem5::Packet::req, gem5::WriteAllocator::reset(), gem5::WriteAllocator::resetDelay(), gem5::RequestPort::sendTimingReq(), gem5::Packet::setSatisfied(), tags, writeAllocator, and writecleanBlk().

Referenced by gem5::Cache::sendMSHRQueuePacket(), and gem5::MSHR::sendPacket().

◆ sendWriteQueuePacket()

bool gem5::BaseCache::sendWriteQueuePacket ( WriteQueueEntry * wq_entry )

Similar to sendMSHR, but for a write-queue entry instead.

Create the packet, and send it, and if successful also mark the entry in service.

Parameters

wq_entry The write-queue entry to turn into a packet and send

Returns: True if the port is waiting for a retry

Definition at line 1968 of file base.cc.

References DPRINTF, gem5::WriteQueueEntry::getTarget(), markInService(), memSidePort, gem5::QueueEntry::Target::pkt, gem5::Packet::print(), and gem5::RequestPort::sendTimingReq().

Referenced by gem5::WriteQueueEntry::sendPacket().

◆ serialize()

void gem5::BaseCache::serialize ( CheckpointOut & cp ) const

overridevirtual

Serialize the state of the caches.

We currently don't support checkpointing cache state, so this panics.

Implements gem5::Serializable.

Definition at line 1992 of file base.cc.

References isDirty(), SERIALIZE_SCALAR, and warn.

◆ serviceMSHRTargets()

virtual void gem5::BaseCache::serviceMSHRTargets	(	MSHR *	mshr,
		const PacketPtr	pkt,
		CacheBlk *	blk
	)

protectedpure virtual

Service non-deferred MSHR targets using the received response.

Iterates through the list of targets that can be serviced with the current response.

Parameters

mshr	The MSHR that corresponds to the reponse
pkt	The response packet
blk	The reference block

Implemented in gem5::NoncoherentCache, and gem5::Cache.

Referenced by recvTimingResp().

◆ setBlocked()

void gem5::BaseCache::setBlocked ( BlockedCause cause )

inline

Marks the access path of the cache as blocked for the given cause.

This also sets the blocked flag in the response interface.

Parameters

cause The reason for the cache blocking.

Definition at line 1236 of file base.hh.

References blocked, gem5::BaseCache::CacheStats::blockedCauses, blockedCycle, cpuSidePort, gem5::Clocked::curCycle(), DPRINTF, gem5::BaseCache::CacheResponsePort::setBlocked(), and stats.

Referenced by allocateMissBuffer(), allocateWriteBuffer(), and handleTimingReqMiss().

◆ unserialize()

void gem5::BaseCache::unserialize ( CheckpointIn & cp )

overridevirtual

Unserialize an object.

Read an object's state from the current checkpoint section.

Parameters

cp	Checkpoint state

Implements gem5::Serializable.

Definition at line 2012 of file base.cc.

References fatal, and UNSERIALIZE_SCALAR.

◆ updateBlockData()

void gem5::BaseCache::updateBlockData	(	CacheBlk *	blk,
		const PacketPtr	cpkt,
		bool	has_old_data
	)

protected

Update the data contents of a block.

When no packet is provided no data will be written to the block, which means that this was likely triggered by an invalidation.

Parameters

blk	The block being updated.
cpkt	The packet containing the new data.
has_old_data	Whether this block had data previously.

Definition at line 769 of file base.cc.

References blkSize, gem5::CacheBlk::data, gem5::TaggedEntry::isSecure(), gem5::BaseCache::DataUpdate::newData, gem5::BaseCache::DataUpdate::oldData, ppDataUpdate, regenerateBlkAddr(), and gem5::Packet::writeDataToBlock().

Referenced by access(), handleFill(), invalidateBlock(), and satisfyRequest().

◆ updateCompressionData()

bool gem5::BaseCache::updateCompressionData	(	CacheBlk *&	blk,
		const uint64_t *	data,
		PacketList &	writebacks
	)

protected

When a block is overwriten, its compression information must be updated, and it may need to be recompressed.

If the compression size changes, the block may either become smaller, in which case there is no side effect, or bigger (data expansion; fat write), in which case the block might not fit in its current location anymore. If that happens, there are usually two options to be taken:

The co-allocated blocks must be evicted to make room for this block. Simpler, but ignores replacement data.
The block itself is moved elsewhere (used in policies where the CF determines the location of the block).

This implementation uses the first approach.

Notice that this is only called for writebacks, which means that L1 caches (which see regular Writes), do not support compression.

See also: CompressedTags

Parameters

blk	The block to be overwriten.
data	A pointer to the data to be compressed (blk's new data).
writebacks	List for any writebacks that need to be performed.

Returns: Whether operation is successful or not.

Definition at line 976 of file base.cc.

References gem5::SectorBlk::blks, gem5::CompressionBlk::checkExpansionContraction(), gem5::compression::Base::compress(), compressor, data, gem5::CompressionBlk::DATA_CONTRACTION, gem5::CompressionBlk::DATA_EXPANSION, gem5::BaseCache::CacheStats::dataContractions, gem5::BaseCache::CacheStats::dataExpansions, DPRINTF, gem5::BaseTags::findVictim(), gem5::SectorSubBlk::getSectorBlock(), gem5::CompressionBlk::getSizeBits(), handleEvictions(), gem5::TaggedEntry::isSecure(), gem5::BaseTags::moveBlock(), moveContractions, gem5::CacheBlk::print(), regenerateBlkAddr(), replaceExpansions, gem5::CompressionBlk::setDecompressionLatency(), gem5::CompressionBlk::setSizeBits(), stats, tags, and tempBlock.

Referenced by access().

◆ writebackBlk()

PacketPtr gem5::BaseCache::writebackBlk ( CacheBlk * blk )

protected

Create a writeback request for the given block.

Parameters

blk	The block to writeback.

Returns: The writeback request for the block.

Definition at line 1691 of file base.cc.

References gem5::Packet::allocate(), blkSize, gem5::CacheBlk::clearCoherenceBits(), compressor, gem5::CacheBlk::data, gem5::CacheBlk::DirtyBit, DPRINTF, gem5_assert, gem5::compression::Base::getDecompressionLatency(), gem5::CacheBlk::getTaskId(), isReadOnly, gem5::TaggedEntry::isSecure(), gem5::CacheBlk::isSet(), gem5::TaggedEntry::isValid(), gem5::Packet::payloadDelay, gem5::Packet::print(), regenerateBlkAddr(), gem5::Request::SECURE, gem5::Packet::setDataFromBlock(), gem5::Packet::setHasSharers(), stats, gem5::Request::wbRequestorId, gem5::CacheBlk::WritableBit, writebackClean, gem5::MemCmd::WritebackClean, gem5::MemCmd::WritebackDirty, and gem5::BaseCache::CacheStats::writebacks.

Referenced by gem5::Cache::evictBlock(), and gem5::NoncoherentCache::evictBlock().

◆ writebackTempBlockAtomic()

void gem5::BaseCache::writebackTempBlockAtomic ( )

inlineprotected

Send the outstanding tempBlock writeback.

To be called after recvAtomic finishes in cases where the block we filled is in fact the tempBlock, and now needs to be written back.

Definition at line 691 of file base.hh.

References doWritebacksAtomic(), and tempBlockWriteback.

Referenced by BaseCache(), and recvAtomic().

◆ writebackVisitor()

void gem5::BaseCache::writebackVisitor ( CacheBlk & blk )

Cache block visitor that writes back dirty cache blocks using functional writes.

Definition at line 1812 of file base.cc.

References blkSize, gem5::CacheBlk::clearCoherenceBits(), gem5::CacheBlk::data, gem5::Packet::dataStatic(), gem5::CacheBlk::DirtyBit, gem5::Request::funcRequestorId, gem5::CacheBlk::getTaskId(), gem5::TaggedEntry::isSecure(), gem5::CacheBlk::isSet(), gem5::TaggedEntry::isValid(), memSidePort, regenerateBlkAddr(), gem5::Request::SECURE, gem5::RequestPort::sendFunctional(), and gem5::MemCmd::WriteReq.

Referenced by memWriteback().

◆ writecleanBlk()

PacketPtr gem5::BaseCache::writecleanBlk	(	CacheBlk *	blk,
		Request::Flags	dest,
		PacketId	id
	)

protected

Create a writeclean request for the given block.

Creates a request that writes the block to the cache below without evicting the block from the current cache.

Parameters

blk	The block to write clean.
dest	The destination of the write clean operation.
id	Use the given packet id for the write clean operation.

Returns: The generated write clean packet.

Definition at line 1741 of file base.cc.

References gem5::Packet::allocate(), blkSize, gem5::CacheBlk::clearCoherenceBits(), compressor, gem5::CacheBlk::data, gem5::CacheBlk::DirtyBit, DPRINTF, gem5::compression::Base::getDecompressionLatency(), gem5::CacheBlk::getTaskId(), gem5::TaggedEntry::isSecure(), gem5::CacheBlk::isSet(), gem5::Packet::payloadDelay, gem5::Packet::print(), regenerateBlkAddr(), gem5::Request::SECURE, gem5::Packet::setDataFromBlock(), gem5::Packet::setHasSharers(), gem5::Packet::setWriteThrough(), gem5::Request::wbRequestorId, gem5::CacheBlk::WritableBit, and gem5::MemCmd::WriteClean.

Referenced by gem5::Cache::handleSnoop(), recvAtomic(), and sendMSHRQueuePacket().

Member Data Documentation

◆ addrRanges

const AddrRangeList gem5::BaseCache::addrRanges

protected

The address range to which the cache responds on the CPU side.

Normally this is all possible memory addresses.

Definition at line 982 of file base.hh.

Referenced by getAddrRanges(), and inRange().

◆ blkSize

const unsigned gem5::BaseCache::blkSize

protected

Block size of this cache.

Definition at line 888 of file base.hh.

Referenced by access(), allocateBlock(), allocateMissBuffer(), allocateWriteBuffer(), gem5::BaseCache::CacheReqPacketQueue::checkConflictingSnoop(), gem5::Cache::cleanEvictBlk(), cmpAndSwap(), gem5::Cache::createMissPacket(), gem5::NoncoherentCache::createMissPacket(), gem5::Cache::doTimingSupplyResponse(), functionalAccess(), getBlockSize(), getNextQueueEntry(), gem5::Cache::handleAtomicReqMiss(), gem5::NoncoherentCache::handleAtomicReqMiss(), handleFill(), gem5::Cache::handleSnoop(), handleTimingReqHit(), gem5::Cache::handleTimingReqMiss(), gem5::NoncoherentCache::handleTimingReqMiss(), handleTimingReqMiss(), gem5::Cache::promoteWholeLineWrites(), gem5::Cache::recvTimingSnoopReq(), satisfyRequest(), gem5::Cache::satisfyRequest(), sendMSHRQueuePacket(), gem5::Cache::serviceMSHRTargets(), gem5::NoncoherentCache::serviceMSHRTargets(), updateBlockData(), writebackBlk(), writebackVisitor(), and writecleanBlk().

◆ blocked

uint8_t gem5::BaseCache::blocked

protected

Bit vector of the blocking reasons for the access path.

See also: BlockedCause

Definition at line 965 of file base.hh.

Referenced by gem5::BaseCache::CacheResponsePort::clearBlocked(), clearBlocked(), isBlocked(), setBlocked(), and gem5::BaseCache::CpuSidePort::tryTiming().

◆ blockedCycle

Cycles gem5::BaseCache::blockedCycle

protected

Stores time the cache blocked for statistics.

Definition at line 971 of file base.hh.

Referenced by clearBlocked(), and setBlocked().

◆ clusivity

const enums::Clusivity gem5::BaseCache::clusivity

protected

Clusivity with respect to the upstream cache, determining if we fill into both this cache and the cache above on a miss.

Note that we currently do not support strict clusivity policies.

Definition at line 935 of file base.hh.

Referenced by allocOnFill(), gem5::Cache::createMissPacket(), and maintainClusivity().

◆ compressor

compression::Base* gem5::BaseCache::compressor

protected

Compression method being used.

Definition at line 353 of file base.hh.

Referenced by access(), allocateBlock(), allocateWriteBuffer(), gem5::Cache::handleSnoop(), updateCompressionData(), writebackBlk(), and writecleanBlk().

◆ cpuSidePort

CpuSidePort gem5::BaseCache::cpuSidePort

protected

Definition at line 338 of file base.hh.

Referenced by clearBlocked(), functionalAccess(), getPort(), gem5::Cache::handleSnoop(), handleTimingReqHit(), gem5::Cache::handleTimingReqMiss(), handleUncacheableWriteResp(), init(), gem5::Cache::isCachedAbove(), gem5::Cache::sendMSHRQueuePacket(), gem5::Cache::serviceMSHRTargets(), gem5::NoncoherentCache::serviceMSHRTargets(), and setBlocked().

◆ dataLatency

const Cycles gem5::BaseCache::dataLatency

protected

The latency of data access of a cache.

It occurs when there is an access to the cache.

Definition at line 900 of file base.hh.

Referenced by calculateAccessLatency().

◆ fillLatency

const Cycles gem5::BaseCache::fillLatency

protected

The latency to fill a cache block.

Definition at line 910 of file base.hh.

Referenced by access(), and handleFill().

◆ forwardLatency

const Cycles gem5::BaseCache::forwardLatency

protected

This is the forward latency of the cache.

It occurs when there is a cache miss and a request is forwarded downstream, in particular an outbound miss.

Definition at line 907 of file base.hh.

Referenced by gem5::Cache::doTimingSupplyResponse(), gem5::Cache::handleSnoop(), recvTimingReq(), recvTimingResp(), and gem5::Cache::recvTimingSnoopResp().

◆ forwardSnoops

bool gem5::BaseCache::forwardSnoops

protected

Do we forward snoops from mem side port through to cpu side port?

Definition at line 928 of file base.hh.

Referenced by gem5::Cache::handleSnoop(), init(), gem5::Cache::isCachedAbove(), and gem5::Cache::sendMSHRQueuePacket().

◆ isReadOnly

const bool gem5::BaseCache::isReadOnly

protected

Is this cache read only, for example the instruction cache, or table-walker cache.

A cache that is read only should never see any writes, and should never get any dirty data (and hence never have to do any writebacks).

Definition at line 943 of file base.hh.

Referenced by access(), gem5::Cache::access(), gem5::Cache::createMissPacket(), handleFill(), gem5::Cache::handleSnoop(), gem5::Cache::serviceMSHRTargets(), and writebackBlk().

◆ lookupLatency

const Cycles gem5::BaseCache::lookupLatency

protected

The latency of tag lookup of a cache.

It occurs when there is an access to the cache.

Definition at line 894 of file base.hh.

Referenced by gem5::Cache::access(), recvAtomic(), gem5::Cache::recvAtomicSnoop(), and gem5::Cache::recvTimingSnoopReq().

◆ memSidePort

MemSidePort gem5::BaseCache::memSidePort

protected

Definition at line 339 of file base.hh.

Referenced by gem5::Cache::doTimingSupplyResponse(), gem5::Cache::doWritebacksAtomic(), gem5::NoncoherentCache::doWritebacksAtomic(), functionalAccess(), getPort(), gem5::Cache::handleAtomicReqMiss(), gem5::NoncoherentCache::handleAtomicReqMiss(), init(), gem5::Cache::recvAtomic(), gem5::Cache::recvTimingReq(), gem5::Cache::recvTimingSnoopResp(), schedMemSideSendEvent(), sendMSHRQueuePacket(), sendWriteQueuePacket(), and writebackVisitor().

◆ missCount

Counter gem5::BaseCache::missCount

protected

The number of misses to trigger an exit event.

Definition at line 977 of file base.hh.

Referenced by incMissCount().

◆ moveContractions

const bool gem5::BaseCache::moveContractions

protected

Similar to data expansions, after a block improves its compression, it may need to be moved elsewhere compatible with the new compression factor, or, if not required by the compaction method, it may be moved to co-allocate with an existing block and thus free an entry.

Definition at line 959 of file base.hh.

Referenced by updateCompressionData().

◆ mshrQueue

MSHRQueue gem5::BaseCache::mshrQueue

protected

Miss status registers.

Definition at line 344 of file base.hh.

Referenced by access(), allocateMissBuffer(), functionalAccess(), getNextQueueEntry(), handleEvictions(), handleTimingReqHit(), gem5::Cache::handleTimingReqMiss(), gem5::NoncoherentCache::handleTimingReqMiss(), inMissQueue(), markInService(), nextQueueReadyTime(), recvTimingResp(), gem5::Cache::recvTimingSnoopReq(), sendMSHRQueuePacket(), and gem5::Cache::sendMSHRQueuePacket().

◆ noTargetMSHR

MSHR* gem5::BaseCache::noTargetMSHR

protected

Pointer to the MSHR that has no targets.

Definition at line 974 of file base.hh.

Referenced by handleTimingReqMiss(), and recvTimingResp().

◆ numTarget

const int gem5::BaseCache::numTarget

protected

The number of targets for each MSHR.

Definition at line 925 of file base.hh.

Referenced by handleTimingReqMiss(), and gem5::Cache::recvTimingSnoopReq().

◆ order

uint64_t gem5::BaseCache::order

protected

Increasing order number assigned to each incoming request.

Definition at line 968 of file base.hh.

Referenced by allocateMissBuffer(), allocateWriteBuffer(), handleTimingReqMiss(), and gem5::Cache::recvTimingSnoopReq().

◆ pendingDelete

std::unique_ptr<Packet> gem5::BaseCache::pendingDelete

protected

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

Definition at line 402 of file base.hh.

Referenced by handleTimingReqHit(), handleTimingReqMiss(), and gem5::Cache::recvTimingReq().

◆ ppDataUpdate

ProbePointArg<DataUpdate>* gem5::BaseCache::ppDataUpdate

protected

To probe when the contents of a block are updated.

Content updates include data fills, overwrites, and invalidations, which means that this probe partially overlaps with other probes.

Definition at line 372 of file base.hh.

Referenced by cmpAndSwap(), regProbePoints(), satisfyRequest(), and updateBlockData().

◆ ppFill

ProbePointArg<PacketPtr>* gem5::BaseCache::ppFill

protected

To probe when a cache fill occurs.

Definition at line 365 of file base.hh.

Referenced by recvTimingResp(), and regProbePoints().

◆ ppHit

ProbePointArg<PacketPtr>* gem5::BaseCache::ppHit

protected

To probe when a cache hit occurs.

Definition at line 359 of file base.hh.

Referenced by recvTimingReq(), and regProbePoints().

◆ ppMiss

ProbePointArg<PacketPtr>* gem5::BaseCache::ppMiss

protected

To probe when a cache miss occurs.

Definition at line 362 of file base.hh.

Referenced by recvTimingReq(), and regProbePoints().

◆ prefetcher

prefetch::Base* gem5::BaseCache::prefetcher

protected

Prefetcher.

Definition at line 356 of file base.hh.

Referenced by getNextQueueEntry(), handleTimingReqMiss(), invalidateBlock(), nextQueueReadyTime(), recvTimingReq(), and recvTimingResp().

◆ replaceExpansions

const bool gem5::BaseCache::replaceExpansions

protected

when a data expansion of a compressed block happens it will not be able to co-allocate where it is at anymore.

If true, the replacement policy is called to chose a new location for the block. Otherwise, all co-allocated blocks are evicted.

Definition at line 951 of file base.hh.

Referenced by updateCompressionData().

◆ responseLatency

const Cycles gem5::BaseCache::responseLatency

protected

The latency of sending reponse to its upper level cache/core on a linefill.

The responseLatency parameter captures this latency.

Definition at line 917 of file base.hh.

Referenced by handleUncacheableWriteResp(), gem5::Cache::serviceMSHRTargets(), and gem5::NoncoherentCache::serviceMSHRTargets().

◆ sequentialAccess

const bool gem5::BaseCache::sequentialAccess

protected

Whether tags and data are accessed sequentially.

Definition at line 922 of file base.hh.

Referenced by calculateAccessLatency().

◆ stats

gem5::BaseCache::CacheStats gem5::BaseCache::stats

Referenced by clearBlocked(), getNextQueueEntry(), handleEvictions(), gem5::Cache::handleTimingReqMiss(), handleTimingReqMiss(), incHitCount(), incMissCount(), recvTimingResp(), gem5::Cache::serviceMSHRTargets(), gem5::NoncoherentCache::serviceMSHRTargets(), setBlocked(), updateCompressionData(), and writebackBlk().

◆ system

System* gem5::BaseCache::system

System we are currently operating in.

Definition at line 986 of file base.hh.

Referenced by getNextQueueEntry(), handleTimingReqMiss(), incHitCount(), incMissCount(), gem5::prefetch::Queued::insert(), recvTimingResp(), gem5::BaseCache::CacheStats::regStats(), gem5::BaseCache::CacheCmdStats::regStatsFromParent(), gem5::Cache::serviceMSHRTargets(), and gem5::NoncoherentCache::serviceMSHRTargets().

◆ tags

BaseTags* gem5::BaseCache::tags

protected

Tag and data Storage.

Definition at line 350 of file base.hh.

Referenced by access(), gem5::Cache::access(), allocateBlock(), functionalAccess(), getNextQueueEntry(), hasBeenPrefetched(), inCache(), invalidateBlock(), isDirty(), memInvalidate(), memWriteback(), gem5::Cache::recvAtomicSnoop(), recvTimingReq(), gem5::Cache::recvTimingReq(), recvTimingResp(), gem5::Cache::recvTimingSnoopReq(), regenerateBlkAddr(), satisfyRequest(), sendMSHRQueuePacket(), gem5::Cache::sendMSHRQueuePacket(), and updateCompressionData().

◆ tempBlock

TempCacheBlk* gem5::BaseCache::tempBlock

protected

Temporary cache block for occasional transitory use.

We use the tempBlock to fill when allocation fails (e.g., when there is an outstanding request that accesses the victim block) or when we want to avoid allocation (e.g., exclusive caches)

Definition at line 396 of file base.hh.

Referenced by handleFill(), invalidateBlock(), recvAtomic(), recvTimingResp(), regenerateBlkAddr(), updateCompressionData(), and ~BaseCache().

◆ tempBlockWriteback

PacketPtr gem5::BaseCache::tempBlockWriteback

protected

Writebacks from the tempBlock, resulting on the response path in atomic mode, must happen after the call to recvAtomic has finished (for the right ordering of the packets).

We therefore need to hold on to the packets, and have a method and an event to send them.

Definition at line 684 of file base.hh.

Referenced by recvAtomic(), and writebackTempBlockAtomic().

◆ writeAllocator

WriteAllocator* const gem5::BaseCache::writeAllocator

protected

The writeAllocator drive optimizations for streaming writes.

It first determines whether a WriteReq MSHR should be delayed, thus ensuring that we wait longer in cases when we are write coalescing and allowing all the bytes of the line to be written before the MSHR packet is sent downstream. This works in unison with the tracking in the MSHR to check if the entire line is written. The write mode also affects the behaviour on filling any whole-line writes. Normally the cache allocates the line when receiving the InvalidateResp, but after seeing enough consecutive lines we switch to using the tempBlock, and thus end up not allocating the line, and instead turning the whole-line write into a writeback straight away.

Definition at line 388 of file base.hh.

Referenced by coalesce(), gem5::Cache::handleAtomicReqMiss(), handleTimingReqMiss(), recvTimingResp(), and sendMSHRQueuePacket().

◆ writebackClean

const bool gem5::BaseCache::writebackClean

protected

Determine if clean lines should be written back or not.

In cases where a downstream cache is mostly inclusive we likely want it to act as a victim cache also for lines that have not been modified. Hence, we cannot simply drop the line (or send a clean evict), but rather need to send the actual data.

Definition at line 675 of file base.hh.

Referenced by gem5::Cache::cleanEvictBlk(), gem5::Cache::doWritebacks(), gem5::Cache::evictBlock(), gem5::NoncoherentCache::evictBlock(), and writebackBlk().

◆ writebackTempBlockAtomicEvent

EventFunctionWrapper gem5::BaseCache::writebackTempBlockAtomicEvent

protected

An event to writeback the tempBlock after recvAtomic finishes.

To avoid other calls to recvAtomic getting in between, we create this event with a higher priority.

Definition at line 703 of file base.hh.

Referenced by recvAtomic().

◆ writeBuffer

WriteQueue gem5::BaseCache::writeBuffer

protected

Write/writeback buffer.

Definition at line 347 of file base.hh.

Referenced by access(), allocateWriteBuffer(), functionalAccess(), getNextQueueEntry(), handleFill(), markInService(), nextQueueReadyTime(), and gem5::Cache::recvTimingSnoopReq().

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

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

Classes

Public Types

Public Member Functions

Public Attributes

Protected Types

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ BlockedCause

◆ MSHRQueueIndex

Constructor & Destructor Documentation

◆ BaseCache()

◆ ~BaseCache()

Member Function Documentation

◆ access()

◆ allocateBlock()

◆ allocateMissBuffer()

◆ allocateWriteBuffer()

◆ allocOnFill()

◆ calculateAccessLatency()

◆ calculateTagOnlyLatency()

◆ clearBlocked()

◆ cmpAndSwap()

◆ coalesce()

◆ createMissPacket()

◆ doWritebacks()

◆ doWritebacksAtomic()

◆ evictBlock() [1/2]

◆ evictBlock() [2/2]

◆ functionalAccess()

◆ getAddrRanges()

◆ getBlockSize()

◆ getNextQueueEntry()

◆ getPort()

◆ handleAtomicReqMiss()

◆ handleEvictions()

◆ handleFill()

◆ handleTimingReqHit()

◆ handleTimingReqMiss() [1/2]

◆ handleTimingReqMiss() [2/2]

◆ handleUncacheableWriteResp()

◆ hasBeenPrefetched()

◆ inCache()

◆ incHitCount()

◆ incMissCount()

◆ init()

◆ inMissQueue()

◆ inRange()

◆ invalidateBlock()

◆ invalidateVisitor()

◆ isBlocked()

◆ isDirty()

◆ maintainClusivity()

◆ markInService() [1/2]

◆ markInService() [2/2]

◆ memInvalidate()

◆ memWriteback()

◆ nextQueueReadyTime()

◆ recvAtomic()

◆ recvAtomicSnoop()

◆ recvTimingReq()

◆ recvTimingResp()

◆ recvTimingSnoopReq()

◆ recvTimingSnoopResp()

◆ regenerateBlkAddr()

◆ regProbePoints()

◆ satisfyRequest()

◆ schedMemSideSendEvent()

◆ sendMSHRQueuePacket()

◆ sendWriteQueuePacket()

◆ serialize()

◆ serviceMSHRTargets()

◆ setBlocked()

◆ unserialize()

◆ updateBlockData()

◆ updateCompressionData()

◆ writebackBlk()

◆ writebackTempBlockAtomic()