X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fmem%2Fpacket.hh;h=3a7286a697caed5cb95bb54b47b6ac3d650d08e4;hb=404b2a951d82bde00e607296c5e7de2997df8058;hp=83f52ede5b1d94eb3429e1622939b37439dbc2e5;hpb=4a5b51b516853c9fcaabc44caacdd7e8e93dc0ef;p=gem5.git diff --git a/src/mem/packet.hh b/src/mem/packet.hh index 83f52ede5..3a7286a69 100644 --- a/src/mem/packet.hh +++ b/src/mem/packet.hh @@ -24,104 +24,151 @@ * 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, a packet is a transaction occuring - * between a single level of the memory heirarchy (ie L1->L2). + * Declaration of the Packet class. */ #ifndef __MEM_PACKET_HH__ #define __MEM_PACKET_HH__ #include "mem/request.hh" -#include "arch/isa_traits.hh" +#include "sim/host.hh" #include "sim/root.hh" +#include +#include struct Packet; typedef Packet* PacketPtr; typedef uint8_t* PacketDataPtr; - +typedef std::list 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 + +//for now. @todo fix later +#define NUM_MEM_CMDS 1 << 11 /** - * A Packet is the structure to handle requests between two levels - * of the memory system. The Request is a global object that trancends - * all of the memory heirarchy, but at each levels interface a packet - * is created to transfer data/requests. For example, a request would - * be used to initiate a request to go to memory/IOdevices, as the request - * passes through the memory system several packets will be created. One - * will be created to go between the L1 and L2 caches and another to go to - * the next level and so forth. - * - * Packets are assumed to be returned in the case of a single response. If - * the transaction has no response, then the consumer will delete the 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: + /** 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. + /** 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? */ + /** 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. */ + /** 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.*/ + /** 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, could be virtual or physical (depending on - cache configurations). */ + /** The address of the request. This address could be virtual or + * physical, depending on the system configuration. */ Addr addr; - /** Indicates the size of the request. */ + /** The size of the request or transfer. */ int size; - /** A index of the source of the transaction. */ + /** 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; - /** A index to the destination of the transaction. */ + /** 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; - bool addrValid; - bool sizeValid; + /** 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 overall request. */ + /** 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() {} }; - /** A virtual base opaque structure used to hold - coherence status messages. */ - CoherenceState *coherence; // virtual base opaque, - // assert(dynamic_cast) etc. - + /** 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() {} }; - /** A virtual base opaque structure used to hold the senders state. */ - SenderState *senderState; // virtual base opaque, - // assert(dynamic_cast) etc. + /** 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, @@ -131,51 +178,74 @@ class Packet IsRequest = 1 << 4, IsResponse = 1 << 5, NeedsResponse = 1 << 6, + IsSWPrefetch = 1 << 7, + IsHWPrefetch = 1 << 8, + IsUpgrade = 1 << 9, + HasData = 1 << 10 }; public: /** List of all commands associated with a packet. */ enum Command { + InvalidCmd = 0, ReadReq = IsRead | IsRequest | NeedsResponse, - WriteReq = IsWrite | IsRequest | NeedsResponse, - WriteReqNoAck = IsWrite | IsRequest, - ReadResp = IsRead | IsResponse, - WriteResp = IsWrite | IsResponse + 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 | IsUpgrade, + 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; - /** The command of the transaction. */ + /** 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; } - void makeTimingResponse() { - assert(needsResponse()); - int icmd = (int)cmd; - icmd &= ~(IsRequest | NeedsResponse); - icmd |= IsResponse; - cmd = (Command)icmd; - dest = src; - srcValid = false; - } + bool isCacheFill() { return (flags & CACHE_LINE_FILL) != 0; } + bool isNoAllocate() { return (flags & NO_ALLOCATE) != 0; } + bool isCompressed() { return (flags & COMPRESSED) != 0; } - /** The time this request was responded to. Used to calculate latencies. */ - Tick time; + bool nic_pkt() { assert("Unimplemented\n" && 0); return false; } - /** The result of a particular packets request. */ + /** Possible results of a packet's request. */ enum Result { Success, BadAddress, + Nacked, Unknown }; - /** The result of the packet transaction. */ + /** The result of this packet's request. */ Result result; /** Accessor function that returns the source index of the packet. */ @@ -187,35 +257,110 @@ class Packet short getDest() const { return dest; } void setDest(short _dest) { dest = _dest; } - Addr getAddr() const { assert(addrValid); return addr; } - void setAddr(Addr _addr) { addr = _addr; addrValid = true; } - - int getSize() const { assert(sizeValid); return size; } - void setSize(int _size) { size = _size; sizeValid = 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); } + 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), - addrValid(_req->validPaddr), sizeValid(_req->validSize), + addrSizeValid(_req->validPaddr), srcValid(false), req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), - time(curTick), result(Unknown) + 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; + if (isRead()) + icmd |= HasData; + if (isWrite()) + icmd &= ~HasData; + cmd = (Command)icmd; + dest = src; + srcValid = false; + } - /** Minimally reset a packet so something like simple cpu can reuse it. */ - void reset(); + /** 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; + } - void reinitFromRequest() { - if (req->validPaddr) setAddr(req->paddr); - if (req->validSize) setSize(req->size); + /** 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 void dataStatic(T *p);