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/*
* 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 "mem/request.hh"
#include "sim/host.hh"
#include "sim/root.hh"
#include <list>
#include <cassert>
struct Packet;
typedef Packet* PacketPtr;
typedef uint8_t* PacketDataPtr;
typedef std::list<PacketPtr> PacketList;
//Coherence Flags
#define NACKED_LINE 1 << 0
#define SATISFIED 1 << 1
#define SHARED_LINE 1 << 2
#define CACHE_LINE_FILL 1 << 3
#define COMPRESSED 1 << 4
#define NO_ALLOCATE 1 << 5
#define SNOOP_COMMIT 1 << 6
/**
* 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:
/** Temporary FLAGS field until cache gets working, this should be in coherence/sender state. */
uint64_t flags;
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;
/** Are the 'addr' and 'size' fields valid? */
bool addrSizeValid;
/** Is the 'src' field valid? */
bool srcValid;
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 pointer to the original request. */
RequestPtr req;
/** A virtual base opaque structure used to hold coherence-related
* state. A specific subclass would be derived from this to
* carry state specific to a particular coherence protocol. */
class CoherenceState {
public:
virtual ~CoherenceState() {}
};
/** This packet's coherence state. Caches should use
* dynamic_cast<> to cast to the state appropriate for the
* system's coherence protocol. */
CoherenceState *coherence;
/** 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:
virtual ~SenderState() {}
};
/** This packet's sender state. Devices should use dynamic_cast<>
* to cast to the state appropriate to the sender. */
SenderState *senderState;
private:
/** List of command attributes. */
// If you add a new CommandAttribute, make sure to increase NUM_MEM_CMDS
// as well.
enum CommandAttribute
{
IsRead = 1 << 0,
IsWrite = 1 << 1,
IsPrefetch = 1 << 2,
IsInvalidate = 1 << 3,
IsRequest = 1 << 4,
IsResponse = 1 << 5,
NeedsResponse = 1 << 6,
IsSWPrefetch = 1 << 7,
IsHWPrefetch = 1 << 8,
HasData = 1 << 9
};
//For statistics we need max number of commands, hard code it at
//20 for now. @todo fix later
#define NUM_MEM_CMDS 1 << 10
public:
/** List of all commands associated with a packet. */
enum Command
{
InvalidCmd = 0,
ReadReq = IsRead | IsRequest | NeedsResponse,
WriteReq = IsWrite | IsRequest | NeedsResponse | HasData,
WriteReqNoAck = IsWrite | IsRequest | HasData,
ReadResp = IsRead | IsResponse | NeedsResponse | HasData,
WriteResp = IsWrite | IsResponse | NeedsResponse,
Writeback = IsWrite | IsRequest | HasData,
SoftPFReq = IsRead | IsRequest | IsSWPrefetch | NeedsResponse,
HardPFReq = IsRead | IsRequest | IsHWPrefetch | NeedsResponse,
SoftPFResp = IsRead | IsResponse | IsSWPrefetch
| NeedsResponse | HasData,
HardPFResp = IsRead | IsResponse | IsHWPrefetch
| NeedsResponse | HasData,
InvalidateReq = IsInvalidate | IsRequest,
WriteInvalidateReq = IsWrite | IsInvalidate | IsRequest | HasData,
UpgradeReq = IsInvalidate | IsRequest,
ReadExReq = IsRead | IsInvalidate | IsRequest | NeedsResponse,
ReadExResp = IsRead | IsInvalidate | IsResponse
| NeedsResponse | HasData
};
/** Return the string name of the cmd field (for debugging and
* tracing). */
const std::string &cmdString() const;
/** Reutrn the string to a cmd given by idx. */
const std::string &cmdIdxToString(Command idx);
/** Return the index of this command. */
inline int cmdToIndex() const { return (int) cmd; }
/** The command field of the packet. */
Command cmd;
bool isRead() { return (cmd & IsRead) != 0; }
bool isWrite() { return (cmd & IsWrite) != 0; }
bool isRequest() { return (cmd & IsRequest) != 0; }
bool isResponse() { return (cmd & IsResponse) != 0; }
bool needsResponse() { return (cmd & NeedsResponse) != 0; }
bool isInvalidate() { return (cmd & IsInvalidate) != 0; }
bool hasData() { return (cmd & HasData) != 0; }
bool isCacheFill() { return (flags & CACHE_LINE_FILL) != 0; }
bool isNoAllocate() { return (flags & NO_ALLOCATE) != 0; }
bool isCompressed() { return (flags & COMPRESSED) != 0; }
bool nic_pkt() { assert("Unimplemented\n" && 0); return false; }
/** Possible results of a packet's request. */
enum Result
{
Success,
BadAddress,
Nacked,
Unknown
};
/** The result of this packet's request. */
Result result;
/** 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; }
/** Accessor function that returns the destination index of
the packet. */
short getDest() const { return dest; }
void setDest(short _dest) { dest = _dest; }
Addr getAddr() const { assert(addrSizeValid); return addr; }
int getSize() const { assert(addrSizeValid); return size; }
Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); }
void addrOverride(Addr newAddr) { assert(addrSizeValid); addr = newAddr; }
void cmdOverride(Command newCmd) { cmd = newCmd; }
/** 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, Command _cmd, short _dest)
: data(NULL), staticData(false), dynamicData(false), arrayData(false),
addr(_req->paddr), size(_req->size), dest(_dest),
addrSizeValid(_req->validPaddr),
srcValid(false),
req(_req), coherence(NULL), senderState(NULL), cmd(_cmd),
result(Unknown)
{
flags = 0;
time = curTick;
}
/** 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, Command _cmd, short _dest, int _blkSize)
: data(NULL), staticData(false), dynamicData(false), arrayData(false),
addr(_req->paddr & ~(_blkSize - 1)), size(_blkSize),
dest(_dest),
addrSizeValid(_req->validPaddr), srcValid(false),
req(_req), coherence(NULL), senderState(NULL), cmd(_cmd),
result(Unknown)
{
flags = 0;
time = curTick;
}
/** Destructor. */
~Packet()
{ 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);
addr = req->paddr;
size = req->size;
time = req->time;
addrSizeValid = true;
result = Unknown;
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. Used for timing
* accesses only. For atomic and functional accesses, the
* request packet is always implicitly passed back *without*
* modifying the destination fields, so this function
* should not be called. */
void makeTimingResponse() {
assert(needsResponse());
assert(isRequest());
int icmd = (int)cmd;
icmd &= ~(IsRequest);
icmd |= IsResponse;
cmd = (Command)icmd;
dest = src;
srcValid = false;
}
/** Take a request packet and modify it in place to be suitable
* for returning as a response to that request.
*/
void makeAtomicResponse() {
assert(needsResponse());
assert(isRequest());
int icmd = (int)cmd;
icmd &= ~(IsRequest);
icmd |= IsResponse;
cmd = (Command)icmd;
}
/** 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(needsResponse() && result == Nacked);
dest = Broadcast;
result = Unknown;
}
/** Set the data pointer to the following value that should not be freed. */
template <typename T>
void dataStatic(T *p);
/** Set the data pointer to a value that should have delete [] called on it.
*/
template <typename T>
void dataDynamicArray(T *p);
/** set the data pointer to a value that should have delete called on it. */
template <typename T>
void dataDynamic(T *p);
/** return the value of what is pointed to in the packet. */
template <typename T>
T get();
/** get a pointer to the data ptr. */
template <typename T>
T* getPtr();
/** set the value in the data pointer to v. */
template <typename T>
void set(T v);
/** 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();
/** Do the packet modify the same addresses. */
bool intersect(Packet *p);
};
bool fixPacket(Packet *func, Packet *timing);
#endif //__MEM_PACKET_HH
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