gem5/src/mem/packet.hh
Steve Reinhardt 3952e41ab1 Add functional PrintReq command for memory-system debugging.
--HG--
extra : convert_revision : 73b753e57c355b7e6873f047ddc8cb371c3136b7
2008-01-02 12:20:15 -08:00

647 lines
21 KiB
C++

/*
* Copyright (c) 2006 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Ron Dreslinski
* Steve Reinhardt
* Ali Saidi
*/
/**
* @file
* Declaration of the Packet class.
*/
#ifndef __MEM_PACKET_HH__
#define __MEM_PACKET_HH__
#include <cassert>
#include <list>
#include <bitset>
#include "base/compiler.hh"
#include "base/fast_alloc.hh"
#include "base/misc.hh"
#include "base/printable.hh"
#include "mem/request.hh"
#include "sim/host.hh"
#include "sim/core.hh"
struct Packet;
typedef Packet *PacketPtr;
typedef uint8_t* PacketDataPtr;
typedef std::list<PacketPtr> PacketList;
class MemCmd
{
public:
/** List of all commands associated with a packet. */
enum Command
{
InvalidCmd,
ReadReq,
ReadResp,
WriteReq,
WriteResp,
Writeback,
SoftPFReq,
HardPFReq,
SoftPFResp,
HardPFResp,
WriteInvalidateReq,
WriteInvalidateResp,
UpgradeReq,
UpgradeResp,
ReadExReq,
ReadExResp,
LoadLockedReq,
LoadLockedResp,
StoreCondReq,
StoreCondResp,
SwapReq,
SwapResp,
// Error responses
// @TODO these should be classified as responses rather than
// requests; coding them as requests initially for backwards
// compatibility
NetworkNackError, // nacked at network layer (not by protocol)
InvalidDestError, // packet dest field invalid
BadAddressError, // memory address invalid
// Fake simulator-only commands
PrintReq, // Print state matching address
NUM_MEM_CMDS
};
private:
/** List of command attributes. */
enum Attribute
{
IsRead, //!< Data flows from responder to requester
IsWrite, //!< Data flows from requester to responder
IsPrefetch, //!< Not a demand access
IsInvalidate,
NeedsExclusive, //!< Requires exclusive copy to complete in-cache
IsRequest, //!< Issued by requester
IsResponse, //!< Issue by responder
NeedsResponse, //!< Requester needs response from target
IsSWPrefetch,
IsHWPrefetch,
IsLocked, //!< Alpha/MIPS LL or SC access
HasData, //!< There is an associated payload
IsError, //!< Error response
IsPrint, //!< Print state matching address (for debugging)
NUM_COMMAND_ATTRIBUTES
};
/** Structure that defines attributes and other data associated
* with a Command. */
struct CommandInfo {
/** Set of attribute flags. */
const std::bitset<NUM_COMMAND_ATTRIBUTES> attributes;
/** Corresponding response for requests; InvalidCmd if no
* response is applicable. */
const Command response;
/** String representation (for printing) */
const std::string str;
};
/** Array to map Command enum to associated info. */
static const CommandInfo commandInfo[];
private:
Command cmd;
bool testCmdAttrib(MemCmd::Attribute attrib) const {
return commandInfo[cmd].attributes[attrib] != 0;
}
public:
bool isRead() const { return testCmdAttrib(IsRead); }
bool isWrite() const { return testCmdAttrib(IsWrite); }
bool isRequest() const { return testCmdAttrib(IsRequest); }
bool isResponse() const { return testCmdAttrib(IsResponse); }
bool needsExclusive() const { return testCmdAttrib(NeedsExclusive); }
bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
bool hasData() const { return testCmdAttrib(HasData); }
bool isReadWrite() const { return isRead() && isWrite(); }
bool isLocked() const { return testCmdAttrib(IsLocked); }
bool isError() const { return testCmdAttrib(IsError); }
bool isPrint() const { return testCmdAttrib(IsPrint); }
const Command responseCommand() const {
return commandInfo[cmd].response;
}
/** Return the string to a cmd given by idx. */
const std::string &toString() const {
return commandInfo[cmd].str;
}
int toInt() const { return (int)cmd; }
MemCmd(Command _cmd)
: cmd(_cmd)
{ }
MemCmd(int _cmd)
: cmd((Command)_cmd)
{ }
MemCmd()
: cmd(InvalidCmd)
{ }
bool operator==(MemCmd c2) { return (cmd == c2.cmd); }
bool operator!=(MemCmd c2) { return (cmd != c2.cmd); }
friend class Packet;
};
/**
* A Packet is used to encapsulate a transfer between two objects in
* the memory system (e.g., the L1 and L2 cache). (In contrast, a
* single Request travels all the way from the requester to the
* ultimate destination and back, possibly being conveyed by several
* different Packets along the way.)
*/
class Packet : public FastAlloc, public Printable
{
public:
typedef MemCmd::Command Command;
/** The command field of the packet. */
MemCmd cmd;
/** A pointer to the original request. */
RequestPtr req;
private:
/** A pointer to the data being transfered. It can be differnt
* sizes at each level of the heirarchy so it belongs in the
* packet, not request. This may or may not be populated when a
* responder recieves the packet. If not populated it memory
* should be allocated.
*/
PacketDataPtr data;
/** Is the data pointer set to a value that shouldn't be freed
* when the packet is destroyed? */
bool staticData;
/** The data pointer points to a value that should be freed when
* the packet is destroyed. */
bool dynamicData;
/** the data pointer points to an array (thus delete [] ) needs to
* be called on it rather than simply delete.*/
bool arrayData;
/** The address of the request. This address could be virtual or
* physical, depending on the system configuration. */
Addr addr;
/** The size of the request or transfer. */
int size;
/** Device address (e.g., bus ID) of the source of the
* transaction. The source is not responsible for setting this
* field; it is set implicitly by the interconnect when the
* packet is first sent. */
short src;
/** Device address (e.g., bus ID) of the destination of the
* transaction. The special value Broadcast indicates that the
* packet should be routed based on its address. This field is
* initialized in the constructor and is thus always valid
* (unlike * addr, size, and src). */
short dest;
/** The original value of the command field. Only valid when the
* current command field is an error condition; in that case, the
* previous contents of the command field are copied here. This
* field is *not* set on non-error responses.
*/
MemCmd origCmd;
/** Are the 'addr' and 'size' fields valid? */
bool addrSizeValid;
/** Is the 'src' field valid? */
bool srcValid;
bool destValid;
enum Flag {
// Snoop response flags
MemInhibit,
Shared,
// Special control flags
/// Special timing-mode atomic snoop for multi-level coherence.
ExpressSnoop,
/// Does supplier have exclusive copy?
/// Useful for multi-level coherence.
SupplyExclusive,
NUM_PACKET_FLAGS
};
/** Status flags */
std::bitset<NUM_PACKET_FLAGS> flags;
public:
/** Used to calculate latencies for each packet.*/
Tick time;
/** The time at which the packet will be fully transmitted */
Tick finishTime;
/** The time at which the first chunk of the packet will be transmitted */
Tick firstWordTime;
/** The special destination address indicating that the packet
* should be routed based on its address. */
static const short Broadcast = -1;
/** A virtual base opaque structure used to hold state associated
* with the packet but specific to the sending device (e.g., an
* MSHR). A pointer to this state is returned in the packet's
* response so that the sender can quickly look up the state
* needed to process it. A specific subclass would be derived
* from this to carry state specific to a particular sending
* device. */
class SenderState : public FastAlloc {
public:
virtual ~SenderState() {}
};
class PrintReqState : public SenderState {
class LabelStackEntry {
public:
const std::string label;
std::string *prefix;
bool labelPrinted;
LabelStackEntry(const std::string &_label,
std::string *_prefix);
};
typedef std::list<LabelStackEntry> LabelStack;
LabelStack labelStack;
std::string *curPrefixPtr;
public:
std::ostream &os;
const int verbosity;
PrintReqState(std::ostream &os, int verbosity = 0);
~PrintReqState();
const std::string &curPrefix() { return *curPrefixPtr; }
void pushLabel(const std::string &lbl,
const std::string &prefix = " ");
void popLabel();
void printLabels();
void printObj(Printable *obj);
};
/** This packet's sender state. Devices should use dynamic_cast<>
* to cast to the state appropriate to the sender. */
SenderState *senderState;
/** Return the string name of the cmd field (for debugging and
* tracing). */
const std::string &cmdString() const { return cmd.toString(); }
/** Return the index of this command. */
inline int cmdToIndex() const { return cmd.toInt(); }
bool isRead() const { return cmd.isRead(); }
bool isWrite() const { return cmd.isWrite(); }
bool isRequest() const { return cmd.isRequest(); }
bool isResponse() const { return cmd.isResponse(); }
bool needsExclusive() const { return cmd.needsExclusive(); }
bool needsResponse() const { return cmd.needsResponse(); }
bool isInvalidate() const { return cmd.isInvalidate(); }
bool hasData() const { return cmd.hasData(); }
bool isReadWrite() const { return cmd.isReadWrite(); }
bool isLocked() const { return cmd.isLocked(); }
bool isError() const { return cmd.isError(); }
bool isPrint() const { return cmd.isPrint(); }
// Snoop flags
void assertMemInhibit() { flags[MemInhibit] = true; }
bool memInhibitAsserted() { return flags[MemInhibit]; }
void assertShared() { flags[Shared] = true; }
bool sharedAsserted() { return flags[Shared]; }
// Special control flags
void setExpressSnoop() { flags[ExpressSnoop] = true; }
bool isExpressSnoop() { return flags[ExpressSnoop]; }
void setSupplyExclusive() { flags[SupplyExclusive] = true; }
bool isSupplyExclusive() { return flags[SupplyExclusive]; }
// Network error conditions... encapsulate them as methods since
// their encoding keeps changing (from result field to command
// field, etc.)
void setNacked() { assert(isResponse()); cmd = MemCmd::NetworkNackError; }
void setBadAddress() { assert(isResponse()); cmd = MemCmd::BadAddressError; }
bool wasNacked() { return cmd == MemCmd::NetworkNackError; }
bool hadBadAddress() { return cmd == MemCmd::BadAddressError; }
void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
bool nic_pkt() { panic("Unimplemented"); M5_DUMMY_RETURN }
/** Accessor function that returns the source index of the packet. */
short getSrc() const { assert(srcValid); return src; }
void setSrc(short _src) { src = _src; srcValid = true; }
/** Reset source field, e.g. to retransmit packet on different bus. */
void clearSrc() { srcValid = false; }
/** Accessor function that returns the destination index of
the packet. */
short getDest() const { assert(destValid); return dest; }
void setDest(short _dest) { dest = _dest; destValid = true; }
Addr getAddr() const { assert(addrSizeValid); return addr; }
int getSize() const { assert(addrSizeValid); return size; }
Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); }
/** Constructor. Note that a Request object must be constructed
* first, but the Requests's physical address and size fields
* need not be valid. The command and destination addresses
* must be supplied. */
Packet(Request *_req, MemCmd _cmd, short _dest)
: cmd(_cmd), req(_req),
data(NULL), staticData(false), dynamicData(false), arrayData(false),
addr(_req->paddr), size(_req->size), dest(_dest),
addrSizeValid(_req->validPaddr), srcValid(false), destValid(true),
flags(0), time(curTick), senderState(NULL)
{
}
/** Alternate constructor if you are trying to create a packet with
* a request that is for a whole block, not the address from the req.
* this allows for overriding the size/addr of the req.*/
Packet(Request *_req, MemCmd _cmd, short _dest, int _blkSize)
: cmd(_cmd), req(_req),
data(NULL), staticData(false), dynamicData(false), arrayData(false),
addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize), dest(_dest),
addrSizeValid(_req->validPaddr), srcValid(false), destValid(true),
flags(0), time(curTick), senderState(NULL)
{
}
/** Alternate constructor for copying a packet. Copy all fields
* *except* if the original packet's data was dynamic, don't copy
* that, as we can't guarantee that the new packet's lifetime is
* less than that of the original packet. In this case the new
* packet should allocate its own data. */
Packet(Packet *origPkt, bool clearFlags = false)
: cmd(origPkt->cmd), req(origPkt->req),
data(origPkt->staticData ? origPkt->data : NULL),
staticData(origPkt->staticData),
dynamicData(false), arrayData(false),
addr(origPkt->addr), size(origPkt->size),
src(origPkt->src), dest(origPkt->dest),
addrSizeValid(origPkt->addrSizeValid),
srcValid(origPkt->srcValid), destValid(origPkt->destValid),
flags(clearFlags ? 0 : origPkt->flags),
time(curTick), senderState(origPkt->senderState)
{
}
/** Destructor. */
~Packet()
{ if (staticData || dynamicData) deleteData(); }
/** Reinitialize packet address and size from the associated
* Request object, and reset other fields that may have been
* modified by a previous transaction. Typically called when a
* statically allocated Request/Packet pair is reused for
* multiple transactions. */
void reinitFromRequest() {
assert(req->validPaddr);
flags = 0;
addr = req->paddr;
size = req->size;
time = req->time;
addrSizeValid = true;
if (dynamicData) {
deleteData();
dynamicData = false;
arrayData = false;
}
}
/**
* Take a request packet and modify it in place to be suitable for
* returning as a response to that request. The source and
* destination fields are *not* modified, as is appropriate for
* atomic accesses.
*/
void makeResponse()
{
assert(needsResponse());
assert(isRequest());
origCmd = cmd;
cmd = cmd.responseCommand();
dest = src;
destValid = srcValid;
srcValid = false;
}
void makeAtomicResponse()
{
makeResponse();
}
void makeTimingResponse()
{
makeResponse();
}
/**
* Take a request packet that has been returned as NACKED and
* modify it so that it can be sent out again. Only packets that
* need a response can be NACKED, so verify that that is true.
*/
void
reinitNacked()
{
assert(wasNacked());
cmd = origCmd;
assert(needsResponse());
setDest(Broadcast);
}
/**
* Set the data pointer to the following value that should not be
* freed.
*/
template <typename T>
void
dataStatic(T *p)
{
if(dynamicData)
dynamicData = false;
data = (PacketDataPtr)p;
staticData = true;
}
/**
* Set the data pointer to a value that should have delete []
* called on it.
*/
template <typename T>
void
dataDynamicArray(T *p)
{
assert(!staticData && !dynamicData);
data = (PacketDataPtr)p;
dynamicData = true;
arrayData = true;
}
/**
* set the data pointer to a value that should have delete called
* on it.
*/
template <typename T>
void
dataDynamic(T *p)
{
assert(!staticData && !dynamicData);
data = (PacketDataPtr)p;
dynamicData = true;
arrayData = false;
}
/** get a pointer to the data ptr. */
template <typename T>
T*
getPtr()
{
assert(staticData || dynamicData);
return (T*)data;
}
/** return the value of what is pointed to in the packet. */
template <typename T>
T get();
/** set the value in the data pointer to v. */
template <typename T>
void set(T v);
/**
* Copy data into the packet from the provided pointer.
*/
void setData(uint8_t *p)
{
std::memcpy(getPtr<uint8_t>(), p, getSize());
}
/**
* Copy data into the packet from the provided block pointer,
* which is aligned to the given block size.
*/
void setDataFromBlock(uint8_t *blk_data, int blkSize)
{
setData(blk_data + getOffset(blkSize));
}
/**
* Copy data from the packet to the provided block pointer, which
* is aligned to the given block size.
*/
void writeData(uint8_t *p)
{
std::memcpy(p, getPtr<uint8_t>(), getSize());
}
/**
* Copy data from the packet to the memory at the provided pointer.
*/
void writeDataToBlock(uint8_t *blk_data, int blkSize)
{
writeData(blk_data + getOffset(blkSize));
}
/**
* delete the data pointed to in the data pointer. Ok to call to
* matter how data was allocted.
*/
void deleteData();
/** If there isn't data in the packet, allocate some. */
void allocate();
/**
* Check a functional request against a memory value represented
* by a base/size pair and an associated data array. If the
* functional request is a read, it may be satisfied by the memory
* value. If the functional request is a write, it may update the
* memory value.
*/
bool checkFunctional(Printable *obj, Addr base, int size, uint8_t *data);
/**
* Check a functional request against a memory value stored in
* another packet (i.e. an in-transit request or response). If
* possible, the request will be satisfied and transformed
* in-place into a response (at which point no further checking
* need be done).
*
* @return True if the memory location addressed by the request
* overlaps with the location addressed by otherPkt.
*/
bool checkFunctional(PacketPtr otherPkt) {
return checkFunctional(otherPkt,
otherPkt->getAddr(), otherPkt->getSize(),
otherPkt->hasData() ?
otherPkt->getPtr<uint8_t>() : NULL);
}
void pushLabel(const std::string &lbl) {
if (isPrint()) {
dynamic_cast<PrintReqState*>(senderState)->pushLabel(lbl);
}
}
void popLabel() {
if (isPrint()) {
dynamic_cast<PrintReqState*>(senderState)->popLabel();
}
}
void print(std::ostream &o, int verbosity = 0,
const std::string &prefix = "") const;
};
#endif //__MEM_PACKET_HH