diff options
Diffstat (limited to 'src/mem/packet.hh')
| -rw-r--r-- | src/mem/packet.hh | 169 |
1 files changed, 75 insertions, 94 deletions
diff --git a/src/mem/packet.hh b/src/mem/packet.hh index fc1c283ed..10b9f490c 100644 --- a/src/mem/packet.hh +++ b/src/mem/packet.hh @@ -84,6 +84,13 @@ class MemCmd 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 NUM_MEM_CMDS }; @@ -103,6 +110,7 @@ class MemCmd IsHWPrefetch, IsLocked, //!< Alpha/MIPS LL or SC access HasData, //!< There is an associated payload + IsError, //!< Error response NUM_COMMAND_ATTRIBUTES }; @@ -135,12 +143,13 @@ class MemCmd 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 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); } const Command responseCommand() const { return commandInfo[cmd].response; @@ -184,6 +193,12 @@ class Packet : public FastAlloc 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 @@ -223,19 +238,28 @@ class Packet : public FastAlloc * (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 SnoopFlag { + enum Flag { + // Snoop flags MemInhibit, Shared, - NUM_SNOOP_FLAGS + NUM_PACKET_FLAGS }; - /** Coherence snoopFlags for snooping */ - std::bitset<NUM_SNOOP_FLAGS> snoopFlags; + /** Status flags */ + std::bitset<NUM_PACKET_FLAGS> flags; public: @@ -252,22 +276,6 @@ class Packet : public FastAlloc * 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 FastAlloc { - 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 @@ -284,11 +292,6 @@ class Packet : public FastAlloc * to cast to the state appropriate to the sender. */ SenderState *senderState; - public: - - /** The command field of the packet. */ - MemCmd cmd; - /** Return the string name of the cmd field (for debugging and * tracing). */ const std::string &cmdString() const { return cmd.toString(); } @@ -296,68 +299,59 @@ class Packet : public FastAlloc /** Return the index of this command. */ inline int cmdToIndex() const { return cmd.toInt(); } - public: - 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 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(); } - - void assertMemInhibit() { snoopFlags[MemInhibit] = true; } - void assertShared() { snoopFlags[Shared] = true; } - bool memInhibitAsserted() { return snoopFlags[MemInhibit]; } - bool sharedAsserted() { return snoopFlags[Shared]; } + bool isError() const { return cmd.isError(); } + + // Snoop flags + void assertMemInhibit() { flags[MemInhibit] = true; } + void assertShared() { flags[Shared] = true; } + bool memInhibitAsserted() { return flags[MemInhibit]; } + bool sharedAsserted() { return flags[Shared]; } + + // Network error conditions... encapsulate them as methods since + // their encoding keeps changing (from result field to command + // field, etc.) + void setNacked() { origCmd = cmd; cmd = MemCmd::NetworkNackError; } + void setBadAddress() { origCmd = cmd; cmd = MemCmd::BadAddressError; } + bool wasNacked() { return cmd == MemCmd::NetworkNackError; } + bool hadBadAddress() { return cmd == MemCmd::BadAddressError; } bool nic_pkt() { panic("Unimplemented"); M5_DUMMY_RETURN } - /** 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; } + 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 { return dest; } - void setDest(short _dest) { dest = _dest; } + 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; } + 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(MemCmd 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, MemCmd _cmd, short _dest) - : data(NULL), staticData(false), dynamicData(false), arrayData(false), + : 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), - snoopFlags(0), - time(curTick), - req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), - result(Unknown) + addrSizeValid(_req->validPaddr), srcValid(false), destValid(true), + flags(0), time(curTick), senderState(NULL) { } @@ -365,13 +359,11 @@ class Packet : public FastAlloc * 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) - : data(NULL), staticData(false), dynamicData(false), arrayData(false), + : 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), - snoopFlags(0), - time(curTick), - req(_req), coherence(NULL), senderState(NULL), cmd(_cmd), - result(Unknown) + addrSizeValid(_req->validPaddr), srcValid(false), destValid(true), + flags(0), time(curTick), senderState(NULL) { } @@ -382,15 +374,14 @@ class Packet : public FastAlloc * dynamic data, user must guarantee that the new packet's * lifetime is less than that of the original packet. */ Packet(Packet *origPkt) - : data(NULL), staticData(false), dynamicData(false), arrayData(false), + : cmd(origPkt->cmd), req(origPkt->req), + data(NULL), staticData(false), dynamicData(false), arrayData(false), addr(origPkt->addr), size(origPkt->size), src(origPkt->src), dest(origPkt->dest), - addrSizeValid(origPkt->addrSizeValid), srcValid(origPkt->srcValid), - snoopFlags(origPkt->snoopFlags), - time(curTick), - req(origPkt->req), coherence(origPkt->coherence), - senderState(origPkt->senderState), cmd(origPkt->cmd), - result(origPkt->result) + addrSizeValid(origPkt->addrSizeValid), + srcValid(origPkt->srcValid), destValid(origPkt->destValid), + flags(origPkt->flags), + time(curTick), senderState(origPkt->senderState) { } @@ -405,12 +396,11 @@ class Packet : public FastAlloc * multiple transactions. */ void reinitFromRequest() { assert(req->validPaddr); - snoopFlags = 0; + flags = 0; addr = req->paddr; size = req->size; time = req->time; addrSizeValid = true; - result = Unknown; if (dynamicData) { deleteData(); dynamicData = false; @@ -424,34 +414,24 @@ class Packet : public FastAlloc * destination fields are *not* modified, as is appropriate for * atomic accesses. */ - void makeAtomicResponse() + void makeResponse() { assert(needsResponse()); assert(isRequest()); - assert(result == Unknown); cmd = cmd.responseCommand(); - result = Success; + dest = src; + destValid = srcValid; + srcValid = false; } - /** - * Perform the additional work required for timing responses above - * and beyond atomic responses; i.e., change the destination to - * point back to the requester and clear the source field. - */ - void convertAtomicToTimingResponse() + void makeAtomicResponse() { - dest = getSrc(); - srcValid = false; + makeResponse(); } - /** - * Take a request packet and modify it in place to be suitable for - * returning as a response to a timing request. - */ void makeTimingResponse() { - makeAtomicResponse(); - convertAtomicToTimingResponse(); + makeResponse(); } /** @@ -462,9 +442,10 @@ class Packet : public FastAlloc void reinitNacked() { - assert(needsResponse() && result == Nacked); - dest = Broadcast; - result = Unknown; + assert(wasNacked()); + cmd = origCmd; + assert(needsResponse()); + setDest(Broadcast); } |