This class helps to implement RISCV's physical memory protection (pmp) primitive. More...

#include <pmp.hh>

Inheritance diagram for gem5::PMP:

Classes
struct	PmpEntry
	single pmp entry struct More...

Public Member Functions
	PARAMS (PMP)

	PMP (const Params &params)

Fault	pmpCheck (const RequestPtr &req, BaseMMU::Mode mode, RiscvISA::PrivilegeMode pmode, ThreadContext *tc, Addr vaddr=0)
	pmpCheck checks if a particular memory access is allowed based on the pmp rules. More...

void	pmpUpdateCfg (uint32_t pmp_index, uint8_t this_cfg)
	pmpUpdateCfg updates the pmpcfg for a pmp entry and calls pmpUpdateRule to update the rule of corresponding pmp entry. More...

void	pmpUpdateAddr (uint32_t pmp_index, Addr this_addr)
	pmpUpdateAddr updates the pmpaddr for a pmp entry and calls pmpUpdateRule to update the rule of corresponding pmp entry. More...

Public Member Functions inherited from gem5::SimObject
const Params &	params () 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...

ProbeManager *	getProbeManager ()
	Get the probe manager for this object. More...

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

virtual void	startup ()
	startup() is the final initialization call before simulation. More...

DrainState	drain () override
	Provide a default implementation of the drain interface for objects that don't need draining. More...

virtual void	memWriteback ()
	Write back dirty buffers to memory using functional writes. More...

virtual void	memInvalidate ()
	Invalidate the contents of memory buffers. More...

void	serialize (CheckpointOut &cp) const override
	Serialize an object. More...

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

Public Member Functions inherited from 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

Private Types
enum	pmpAmatch { PMP_OFF , PMP_TOR , PMP_NA4 , PMP_NAPOT }
	This enum is used for encoding of address matching mode of pmp address register, which is present in bits 3-4 (A) of pmpcfg register for a pmp entry. More...

Private Member Functions
bool	shouldCheckPMP (RiscvISA::PrivilegeMode pmode, BaseMMU::Mode mode, ThreadContext *tc)
	This function is called during a memory access to determine if the pmp table should be consulted for this access. More...

Fault	createAddrfault (Addr vaddr, BaseMMU::Mode mode)
	createAddrfault creates an address fault if the pmp checks fail to pass for a given access. More...

void	pmpUpdateRule (uint32_t pmp_index)
	pmpUpdateRule updates the pmp rule for a given pmp entry depending on the value of pmpaddr and pmpcfg for that entry. More...

uint8_t	pmpGetAField (uint8_t cfg)
	pmpGetAField extracts the A field (address matching mode) from an input pmpcfg register More...

AddrRange	pmpDecodeNapot (Addr pmpaddr)
	This function decodes a pmpaddr register value into an address range when A field of pmpcfg register is set to NAPOT mode (naturally aligned power of two region). More...

Private Attributes
int	pmpEntries
	maximum number of entries in the pmp table More...

const uint8_t	PMP_READ = 1 << 0
	pmpcfg address range read permission mask More...

const uint8_t	PMP_WRITE = 1 << 1
	pmpcfg address range write permission mask More...

const uint8_t	PMP_EXEC = 1 << 2
	pmpcfg address range execute permission mask More...

const uint8_t	PMP_LOCK = 1 << 7
	pmpcfg address range locked mask More...

int	numRules
	variable to keep track of active number of rules any time More...

std::vector< PmpEntry >	pmpTable
	a table of pmp entries More...

Additional Inherited Members
Public Types inherited from gem5::SimObject
typedef SimObjectParams	Params

Static Public Member Functions inherited from gem5::SimObject
static void	serializeAll (const std::string &cpt_dir)
	Create a checkpoint by serializing all SimObjects in the system. More...

static 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...

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 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...

Detailed Description

This class helps to implement RISCV's physical memory protection (pmp) primitive.

Todo:: Add statistics and debug prints.

Definition at line 53 of file pmp.hh.

Member Enumeration Documentation

◆ pmpAmatch

enum gem5::PMP::pmpAmatch

private

This enum is used for encoding of address matching mode of pmp address register, which is present in bits 3-4 (A) of pmpcfg register for a pmp entry.

PMP_OFF = null region (pmp disabled) MP_TOR = top of range mode PMP_NA4 = naturally aligned four byte region PMP_NAPOT = naturally aligned power of two region, >= 8 bytes

Enumerator
PMP_OFF
PMP_TOR
PMP_NA4
PMP_NAPOT

Definition at line 71 of file pmp.hh.

Constructor & Destructor Documentation

◆ PMP()

gem5::PMP::PMP ( const Params & params )

Definition at line 47 of file pmp.cc.

References pmpEntries, and pmpTable.

Member Function Documentation

◆ createAddrfault()

Fault gem5::PMP::createAddrfault	(	Addr	vaddr,
		BaseMMU::Mode	mode
	)

private

createAddrfault creates an address fault if the pmp checks fail to pass for a given access.

This function is used by pmpCheck(). given pmp entry depending on the value of pmpaddr and pmpcfg for that entry.

Parameters

vaddr	virtual address of the access.
mode	mode of access(read, write, execute).

Returns: Fault.

Definition at line 130 of file pmp.cc.

References gem5::RiscvISA::INST_ACCESS, gem5::RiscvISA::LOAD_ACCESS, gem5::ArmISA::mode, gem5::BaseMMU::Read, gem5::RiscvISA::STORE_ACCESS, gem5::MipsISA::vaddr, warn, and gem5::BaseMMU::Write.

Referenced by pmpCheck().

◆ PARAMS()

gem5::PMP::PARAMS ( PMP )

◆ pmpCheck()

Fault gem5::PMP::pmpCheck	(	const RequestPtr &	req,
		BaseMMU::Mode	mode,
		RiscvISA::PrivilegeMode	pmode,
		ThreadContext *	tc,
		Addr	vaddr = `0`
	)

pmpCheck checks if a particular memory access is allowed based on the pmp rules.

Parameters

req	memory request.
mode	mode of request (read, write, execute).
pmode	current privilege mode of execution (U, S, M).
tc	thread context.
vaddr	optional parameter to pass vaddr of original request for which a page table walk is consulted by pmp unit

Returns: Fault.

Definition at line 56 of file pmp.cc.

References gem5::AddrRange::contains(), createAddrfault(), DPRINTF, gem5::ArmISA::i, gem5::ArmISA::mode, gem5::NoFault, numRules, PMP_EXEC, PMP_OFF, PMP_READ, PMP_WRITE, pmpGetAField(), pmpTable, gem5::RiscvISA::PRV_M, shouldCheckPMP(), and gem5::MipsISA::vaddr.

◆ pmpDecodeNapot()

AddrRange gem5::PMP::pmpDecodeNapot ( Addr pmpaddr )

inlineprivate

This function decodes a pmpaddr register value into an address range when A field of pmpcfg register is set to NAPOT mode (naturally aligned power of two region).

Parameters

pmpaddr input address from a pmp entry.

Returns: an address range.

Definition at line 254 of file pmp.cc.

References gem5::X86ISA::base, gem5::ctz64(), gem5::mbits(), and gem5::ArmISA::t1.

Referenced by pmpUpdateRule().

◆ pmpGetAField()

uint8_t gem5::PMP::pmpGetAField ( uint8_t cfg )

inlineprivate

pmpGetAField extracts the A field (address matching mode) from an input pmpcfg register

Parameters

cfg	pmpcfg register value.

Returns: The A field.

Definition at line 145 of file pmp.cc.

References gem5::ArmISA::a.

Referenced by pmpCheck(), and pmpUpdateRule().

◆ pmpUpdateAddr()

void gem5::PMP::pmpUpdateAddr	(	uint32_t	pmp_index,
		Addr	this_addr
	)

pmpUpdateAddr updates the pmpaddr for a pmp entry and calls pmpUpdateRule to update the rule of corresponding pmp entry.

Parameters

pmp_index	pmp entry index.
this_addr	value to be written to pmpaddr.

Definition at line 216 of file pmp.cc.

References DPRINTF, gem5::MipsISA::index, pmpEntries, pmpTable, and pmpUpdateRule().

◆ pmpUpdateCfg()

void gem5::PMP::pmpUpdateCfg	(	uint32_t	pmp_index,
		uint8_t	this_cfg
	)

pmpUpdateCfg updates the pmpcfg for a pmp entry and calls pmpUpdateRule to update the rule of corresponding pmp entry.

Parameters

pmp_index	pmp entry index.
this_cfg	value to be written to pmpcfg.

Definition at line 154 of file pmp.cc.

References DPRINTF, PMP_LOCK, pmpTable, pmpUpdateRule(), and warn_if.

◆ pmpUpdateRule()

void gem5::PMP::pmpUpdateRule ( uint32_t pmp_index )

private

pmpUpdateRule updates the pmp rule for a given pmp entry depending on the value of pmpaddr and pmpcfg for that entry.

Parameters

pmp_index pmp entry index.

Definition at line 167 of file pmp.cc.

References gem5::ArmISA::i, numRules, PMP_NA4, PMP_NAPOT, PMP_OFF, PMP_TOR, pmpDecodeNapot(), pmpEntries, pmpGetAField(), and pmpTable.

Referenced by pmpUpdateAddr(), and pmpUpdateCfg().

◆ shouldCheckPMP()

bool gem5::PMP::shouldCheckPMP	(	RiscvISA::PrivilegeMode	pmode,
		BaseMMU::Mode	mode,
		ThreadContext *	tc
	)

private

This function is called during a memory access to determine if the pmp table should be consulted for this access.

Parameters

pmode	current privilege mode of execution (U, S, M).
mode	mode of request (read, write, execute).
tc	thread context.

Returns: true or false.

Definition at line 231 of file pmp.cc.

References gem5::BaseMMU::Execute, gem5::RiscvISA::MISCREG_STATUS, gem5::ArmISA::mode, gem5::RiscvISA::PRV_M, gem5::ThreadContext::readMiscRegNoEffect(), and gem5::ArmISA::status.

Referenced by pmpCheck().

Member Data Documentation

◆ numRules

int gem5::PMP::numRules

private

variable to keep track of active number of rules any time

Definition at line 92 of file pmp.hh.

Referenced by pmpCheck(), and pmpUpdateRule().

◆ PMP_EXEC

const uint8_t gem5::PMP::PMP_EXEC = 1 << 2

private

pmpcfg address range execute permission mask

Definition at line 86 of file pmp.hh.

Referenced by pmpCheck().

◆ PMP_LOCK

const uint8_t gem5::PMP::PMP_LOCK = 1 << 7

private

pmpcfg address range locked mask

Definition at line 89 of file pmp.hh.

Referenced by pmpUpdateCfg().

◆ PMP_READ

const uint8_t gem5::PMP::PMP_READ = 1 << 0

private

pmpcfg address range read permission mask

Definition at line 80 of file pmp.hh.

Referenced by pmpCheck().

◆ PMP_WRITE

const uint8_t gem5::PMP::PMP_WRITE = 1 << 1

private

pmpcfg address range write permission mask

Definition at line 83 of file pmp.hh.

Referenced by pmpCheck().

◆ pmpEntries

int gem5::PMP::pmpEntries

private

maximum number of entries in the pmp table

Definition at line 61 of file pmp.hh.

Referenced by PMP(), pmpUpdateAddr(), and pmpUpdateRule().

◆ pmpTable

std::vector<PmpEntry> gem5::PMP::pmpTable

private

a table of pmp entries

Definition at line 106 of file pmp.hh.

Referenced by PMP(), pmpCheck(), pmpUpdateAddr(), pmpUpdateCfg(), and pmpUpdateRule().

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

arch/riscv/pmp.hh
arch/riscv/pmp.cc

Classes

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ pmpAmatch

Constructor & Destructor Documentation

◆ PMP()

Member Function Documentation

◆ createAddrfault()

◆ PARAMS()

◆ pmpCheck()

◆ pmpDecodeNapot()

◆ pmpGetAField()

◆ pmpUpdateAddr()

◆ pmpUpdateCfg()

◆ pmpUpdateRule()

◆ shouldCheckPMP()

Member Data Documentation

◆ numRules

◆ PMP_EXEC

◆ PMP_LOCK

◆ PMP_READ

◆ PMP_WRITE

◆ pmpEntries

◆ pmpTable