gem5  v21.1.0.2
Classes | Public Types | Public Member Functions | Protected Attributes | Private Member Functions | List of all members
gem5::BaseTags Class Referenceabstract

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

#include <base.hh>

Inheritance diagram for gem5::BaseTags:
gem5::ClockedObject gem5::SimObject gem5::Clocked gem5::EventManager gem5::Serializable gem5::Drainable gem5::statistics::Group gem5::Named gem5::BaseSetAssoc gem5::FALRU gem5::SectorTags gem5::CompressedTags

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 gem5::ClockedObject
using Params = ClockedObjectParams
 Parameters of ClockedObject. More...
 
- Public Types inherited from gem5::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 CacheBlkfindBlock (Addr addr, bool is_secure) const
 Finds the block in the cache without touching it. More...
 
virtual ReplaceableEntryfindBlockBySetAndWay (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 CacheBlkfindVictim (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 CacheBlkaccessBlock (const PacketPtr pkt, 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 void moveBlock (CacheBlk *src_blk, CacheBlk *dest_blk)
 Move a block's metadata to another location decided by the replacement policy. 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 gem5::ClockedObject
 ClockedObject (const ClockedObjectParams &p)
 
void serialize (CheckpointOut &cp) const override
 Serialize an object. More...
 
void unserialize (CheckpointIn &cp) override
 Unserialize an object. More...
 
- Public Member Functions inherited from gem5::SimObject
const Paramsparams () const
 
 SimObject (const Params &p)
 
virtual ~SimObject ()
 
virtual void 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...
 
ProbeManagergetProbeManager ()
 Get the probe manager for this object. More...
 
virtual PortgetPort (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 gem5::EventManager
EventQueueeventQueue () const
 
void schedule (Event &event, Tick when)
 
void deschedule (Event &event)
 
void reschedule (Event &event, Tick when, bool always=false)
 
void schedule (Event *event, Tick when)
 
void deschedule (Event *event)
 
void reschedule (Event *event, Tick when, bool always=false)
 
void wakeupEventQueue (Tick when=(Tick) -1)
 This function is not needed by the usual gem5 event loop but may be necessary in derived EventQueues which host gem5 on other schedulers. More...
 
void setCurTick (Tick newVal)
 
 EventManager (EventManager &em)
 Event manger manages events in the event queue. More...
 
 EventManager (EventManager *em)
 
 EventManager (EventQueue *eq)
 
- Public Member Functions inherited from gem5::Serializable
 Serializable ()
 
virtual ~Serializable ()
 
void serializeSection (CheckpointOut &cp, const char *name) const
 Serialize an object into a new section. More...
 
void serializeSection (CheckpointOut &cp, const std::string &name) const
 
void unserializeSection (CheckpointIn &cp, const char *name)
 Unserialize an a child object. More...
 
void unserializeSection (CheckpointIn &cp, const std::string &name)
 
- Public Member Functions inherited from gem5::Drainable
DrainState drainState () const
 Return the current drain state of an object. More...
 
virtual void notifyFork ()
 Notify a child process of a fork. More...
 
- Public Member Functions inherited from gem5::statistics::Group
 Group (Group *parent, const char *name=nullptr)
 Construct a new statistics group. More...
 
virtual ~Group ()
 
virtual void 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 InforesolveStat (std::string name) const
 Resolve a stat by its name within this group. More...
 
void mergeStatGroup (Group *block)
 Merge the contents (stats & children) of a block to this block. More...
 
 Group ()=delete
 
 Group (const Group &)=delete
 
Groupoperator= (const Group &)=delete
 
- Public Member Functions inherited from gem5::Named
 Named (const std::string &name_)
 
virtual ~Named ()=default
 
virtual std::string name () const
 
- Public Member Functions inherited from gem5::Clocked
void updateClockPeriod ()
 Update the tick to the current tick. More...
 
Tick clockEdge (Cycles cycles=Cycles(0)) const
 Determine the tick when a cycle begins, by default the current one, but the argument also enables the caller to determine a future cycle. More...
 
Cycles curCycle () const
 Determine the current cycle, corresponding to a tick aligned to a clock edge. More...
 
Tick nextCycle () const
 Based on the clock of the object, determine the start tick of the first cycle that is at least one cycle in the future. More...
 
uint64_t frequency () const
 
Tick clockPeriod () const
 
double voltage () const
 
Cycles ticksToCycles (Tick t) const
 
Tick cyclesToTicks (Cycles c) const
 

Protected 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...
 
Systemsystem
 System we are currently operating in. More...
 
BaseIndexingPolicyindexingPolicy
 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...
 
gem5::BaseTags::BaseTagStats stats
 
- Protected Attributes inherited from gem5::SimObject
const SimObjectParams & _params
 Cached copy of the object parameters. More...
 
- Protected Attributes inherited from gem5::EventManager
EventQueueeventq
 A pointer to this object's event queue. More...
 

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 gem5::SimObject
static void serializeAll (const std::string &cpt_dir)
 Create a checkpoint by serializing all SimObjects in the system. More...
 
static SimObjectfind (const char *name)
 Find the SimObject with the given name and return a pointer to it. More...
 
static void setSimObjectResolver (SimObjectResolver *resolver)
 There is a single object name resolver, and it is only set when simulation is restoring from checkpoints. More...
 
static SimObjectResolvergetSimObjectResolver ()
 There is a single object name resolver, and it is only set when simulation is restoring from checkpoints. More...
 
- Static Public Member Functions inherited from gem5::Serializable
static const std::string & currentSection ()
 Gets the fully-qualified name of the active section. More...
 
static void generateCheckpointOut (const std::string &cpt_dir, std::ofstream &outstream)
 Generate a checkpoint file so that the serialization can be routed to it. More...
 
- Public Attributes inherited from gem5::ClockedObject
PowerStatepowerState
 
- Protected Member Functions inherited from gem5::Drainable
 Drainable ()
 
virtual ~Drainable ()
 
virtual void drainResume ()
 Resume execution after a successful drain. More...
 
void signalDrainDone () const
 Signal that an object is drained. More...
 
- Protected Member Functions inherited from gem5::Clocked
 Clocked (ClockDomain &clk_domain)
 Create a clocked object and set the clock domain based on the parameters. More...
 
 Clocked (Clocked &)=delete
 
Clockedoperator= (Clocked &)=delete
 
virtual ~Clocked ()
 Virtual destructor due to inheritance. More...
 
void resetClock () const
 Reset the object's clock using the current global tick value. More...
 
virtual void clockPeriodUpdated ()
 A hook subclasses can implement so they can do any extra work that's needed when the clock rate is changed. More...
 

Detailed Description

A common base class of Cache tagstore objects.

Definition at line 73 of file base.hh.

Member Typedef Documentation

◆ Params

typedef BaseTagsParams gem5::BaseTags::Params

Definition at line 161 of file base.hh.

Constructor & Destructor Documentation

◆ BaseTags()

gem5::BaseTags::BaseTags ( const Params p)

Definition at line 61 of file base.cc.

References cleanupRefs(), and gem5::registerExitCallback().

◆ ~BaseTags()

virtual gem5::BaseTags::~BaseTags ( )
inlinevirtual

Destructor.

Definition at line 167 of file base.hh.

Member Function Documentation

◆ accessBlock()

virtual CacheBlk* gem5::BaseTags::accessBlock ( const PacketPtr  pkt,
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
pktThe packet holding the address to find.
latThe latency of the tag lookup.
Returns
Pointer to the cache block if found.

Implemented in gem5::FALRU, gem5::SectorTags, and gem5::BaseSetAssoc.

Referenced by gem5::BaseCache::access().

◆ anyBlk()

virtual bool gem5::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
visitorVisitor to call on each block.

Implemented in gem5::FALRU, gem5::BaseSetAssoc, gem5::SectorTags, and gem5::CompressedTags.

Referenced by gem5::BaseCache::isDirty().

◆ blkAlign()

Addr gem5::BaseTags::blkAlign ( Addr  addr) const
inline

Align an address to the block size.

Parameters
addrthe address to align.
Returns
The block address.

Definition at line 215 of file base.hh.

References gem5::X86ISA::addr, and blkMask.

Referenced by gem5::FALRU::extractTag().

◆ cleanupRefs()

void gem5::BaseTags::cleanupRefs ( )

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

Definition at line 158 of file base.cc.

References cleanupRefsVisitor(), and forEachBlk().

Referenced by BaseTags().

◆ cleanupRefsVisitor()

void gem5::BaseTags::cleanupRefsVisitor ( CacheBlk blk)
private

Update the reference stats using data from the input block.

Parameters
blkThe input block

Definition at line 149 of file base.cc.

References gem5::CacheBlk::getRefCount(), gem5::TaggedEntry::isValid(), gem5::BaseTags::BaseTagStats::sampledRefs, stats, and gem5::BaseTags::BaseTagStats::totalRefs.

Referenced by cleanupRefs().

◆ computeStats()

void gem5::BaseTags::computeStats ( )

◆ computeStatsVisitor()

void gem5::BaseTags::computeStatsVisitor ( CacheBlk blk)
private

◆ extractBlkOffset()

int gem5::BaseTags::extractBlkOffset ( Addr  addr) const
inline

Calculate the block offset of an address.

Parameters
addrthe address to get the offset of.
Returns
the block offset.

Definition at line 225 of file base.hh.

References gem5::X86ISA::addr, and blkMask.

Referenced by gem5::BaseCache::satisfyRequest().

◆ extractTag()

Addr gem5::BaseTags::extractTag ( const Addr  addr) const
virtual

Generate the tag from the given address.

Parameters
addrThe address to get the tag from.
Returns
The tag of the address.

Reimplemented in gem5::FALRU.

Definition at line 143 of file base.cc.

References gem5::X86ISA::addr, gem5::BaseIndexingPolicy::extractTag(), and indexingPolicy.

Referenced by gem5::SectorTags::findBlock(), findBlock(), gem5::CompressedTags::findVictim(), gem5::SectorTags::findVictim(), and insertBlock().

◆ findBlock()

CacheBlk * gem5::BaseTags::findBlock ( Addr  addr,
bool  is_secure 
) const
virtual

◆ findBlockBySetAndWay()

ReplaceableEntry * gem5::BaseTags::findBlockBySetAndWay ( int  set,
int  way 
) const
virtual

Find a block given set and way.

Parameters
setThe set of the block.
wayThe way of the block.
Returns
The block.

Reimplemented in gem5::FALRU.

Definition at line 74 of file base.cc.

References gem5::BaseIndexingPolicy::getEntry(), and indexingPolicy.

◆ findVictim()

virtual CacheBlk* gem5::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
addrAddress to find a victim for.
is_secureTrue if the target memory space is secure.
sizeSize, in bits, of new block to allocate.
evict_blksCache blocks to be evicted.
Returns
Cache block to be replaced.

Implemented in gem5::FALRU, gem5::SectorTags, gem5::BaseSetAssoc, and gem5::CompressedTags.

Referenced by gem5::BaseCache::allocateBlock(), and gem5::BaseCache::updateCompressionData().

◆ forEachBlk()

virtual void gem5::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
visitorVisitor to call on each block.

Implemented in gem5::FALRU, gem5::BaseSetAssoc, gem5::SectorTags, and gem5::CompressedTags.

Referenced by cleanupRefs(), computeStats(), gem5::BaseCache::memInvalidate(), gem5::BaseCache::memWriteback(), and print().

◆ getWayAllocationMax()

virtual int gem5::BaseTags::getWayAllocationMax ( ) const
inlinevirtual

Get the way allocation mask limit.

Returns
The maximum number of ways available for replacement.

Reimplemented in gem5::BaseSetAssoc.

Definition at line 243 of file base.hh.

References panic.

◆ insertBlock()

void gem5::BaseTags::insertBlock ( const PacketPtr  pkt,
CacheBlk blk 
)
virtual

◆ invalidate()

virtual void gem5::BaseTags::invalidate ( CacheBlk blk)
inlinevirtual

◆ moveBlock()

void gem5::BaseTags::moveBlock ( CacheBlk src_blk,
CacheBlk dest_blk 
)
virtual

Move a block's metadata to another location decided by the replacement policy.

It behaves as a swap, however, since the destination block should be invalid, the result is a move.

Parameters
src_blkThe source block.
dest_blkThe destination block. Must be invalid.

Reimplemented in gem5::FALRU, gem5::BaseSetAssoc, and gem5::SectorTags.

Definition at line 130 of file base.cc.

References gem5::TaggedEntry::isValid().

Referenced by gem5::SectorTags::moveBlock(), gem5::BaseSetAssoc::moveBlock(), and gem5::BaseCache::updateCompressionData().

◆ print()

std::string gem5::BaseTags::print ( )

Print all tags used.

Definition at line 202 of file base.cc.

References gem5::csprintf(), and forEachBlk().

Referenced by gem5::Cache::recvTimingReq().

◆ regenerateBlkAddr()

virtual Addr gem5::BaseTags::regenerateBlkAddr ( const CacheBlk blk) const
pure virtual

Regenerate the block address.

Parameters
blockThe block.
Returns
the block address.

Implemented in gem5::FALRU, gem5::BaseSetAssoc, and gem5::SectorTags.

Referenced by gem5::BaseCache::regenerateBlkAddr().

◆ setWayAllocationMax()

virtual void gem5::BaseTags::setWayAllocationMax ( int  ways)
inlinevirtual

Limit the allocation for the cache ways.

Parameters
waysThe maximum number of ways available for replacement.

Reimplemented in gem5::BaseSetAssoc.

Definition at line 234 of file base.hh.

References panic.

◆ tagsInit()

virtual void gem5::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 gem5::FALRU, gem5::SectorTags, gem5::BaseSetAssoc, and gem5::CompressedTags.

Member Data Documentation

◆ blkMask

const Addr gem5::BaseTags::blkMask
protected

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

Definition at line 79 of file base.hh.

Referenced by blkAlign(), and extractBlkOffset().

◆ blkSize

const unsigned gem5::BaseTags::blkSize
protected

◆ dataBlks

std::unique_ptr<uint8_t[]> gem5::BaseTags::dataBlks
protected

The data blocks, 1 per cache block.

Definition at line 103 of file base.hh.

Referenced by gem5::CompressedTags::tagsInit(), gem5::BaseSetAssoc::tagsInit(), gem5::SectorTags::tagsInit(), and gem5::FALRU::tagsInit().

◆ indexingPolicy

BaseIndexingPolicy* gem5::BaseTags::indexingPolicy
protected

◆ lookupLatency

const Cycles gem5::BaseTags::lookupLatency
protected

The tag lookup latency of the cache.

Definition at line 83 of file base.hh.

Referenced by gem5::BaseSetAssoc::accessBlock(), gem5::SectorTags::accessBlock(), and gem5::FALRU::accessBlock().

◆ numBlocks

const unsigned gem5::BaseTags::numBlocks
protected

◆ size

const unsigned gem5::BaseTags::size
protected

The size of the cache.

Definition at line 81 of file base.hh.

Referenced by gem5::FALRU::FALRU().

◆ stats

gem5::BaseTags::BaseTagStats gem5::BaseTags::stats
protected

◆ system

System* gem5::BaseTags::system
protected

System we are currently operating in.

Definition at line 86 of file base.hh.

Referenced by gem5::BaseTags::BaseTagStats::regStats().

◆ warmedUp

bool gem5::BaseTags::warmedUp
protected

Marked true when the cache is warmed up.

Definition at line 97 of file base.hh.

Referenced by insertBlock().

◆ warmupBound

const unsigned gem5::BaseTags::warmupBound
protected

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

Definition at line 95 of file base.hh.

Referenced by insertBlock().


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

Generated on Tue Sep 21 2021 12:27:20 for gem5 by doxygen 1.8.17