/*
+ * Copyright (c) 2012-2016 ARM Limited
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder. You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
* Copyright (c) 2006 The Regents of The University of Michigan
+ * Copyright (c) 2010,2015 Advanced Micro Devices, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* Authors: Ron Dreslinski
* Steve Reinhardt
* Ali Saidi
+ * Andreas Hansson
*/
/**
#ifndef __MEM_PACKET_HH__
#define __MEM_PACKET_HH__
+#include <bitset>
#include <cassert>
#include <list>
-#include <bitset>
+#include "base/cast.hh"
#include "base/compiler.hh"
-#include "base/fast_alloc.hh"
+#include "base/flags.hh"
#include "base/misc.hh"
#include "base/printable.hh"
+#include "base/types.hh"
#include "mem/request.hh"
-#include "sim/host.hh"
#include "sim/core.hh"
-
-struct Packet;
+class Packet;
typedef Packet *PacketPtr;
typedef uint8_t* PacketDataPtr;
typedef std::list<PacketPtr> PacketList;
class MemCmd
{
- public:
+ friend class Packet;
- /** List of all commands associated with a packet. */
+ public:
+ /**
+ * List of all commands associated with a packet.
+ */
enum Command
{
InvalidCmd,
ReadRespWithInvalidate,
WriteReq,
WriteResp,
- Writeback,
+ WritebackDirty,
+ WritebackClean,
+ CleanEvict,
SoftPFReq,
HardPFReq,
SoftPFResp,
HardPFResp,
- WriteInvalidateReq,
- WriteInvalidateResp,
+ WriteLineReq,
UpgradeReq,
+ SCUpgradeReq, // Special "weak" upgrade for StoreCond
UpgradeResp,
+ SCUpgradeFailReq, // Failed SCUpgradeReq in MSHR (never sent)
+ UpgradeFailResp, // Valid for SCUpgradeReq only
ReadExReq,
ReadExResp,
+ ReadCleanReq,
+ ReadSharedReq,
LoadLockedReq,
- LoadLockedResp,
StoreCondReq,
+ StoreCondFailReq, // Failed StoreCondReq in MSHR (never sent)
StoreCondResp,
SwapReq,
SwapResp,
+ MessageReq,
+ MessageResp,
+ MemFenceReq,
+ MemFenceResp,
// 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
+ FunctionalReadError, // unable to fulfill functional read
+ FunctionalWriteError, // unable to fulfill functional write
// Fake simulator-only commands
PrintReq, // Print state matching address
+ FlushReq, //request for a cache flush
+ InvalidateReq, // request for address to be invalidated
+ InvalidateResp,
NUM_MEM_CMDS
};
private:
- /** List of command attributes. */
+ /**
+ * 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
+ IsUpgrade,
IsInvalidate,
- NeedsExclusive, //!< Requires exclusive copy to complete in-cache
+ NeedsWritable, //!< Requires writable copy to complete in-cache
IsRequest, //!< Issued by requester
IsResponse, //!< Issue by responder
NeedsResponse, //!< Requester needs response from target
+ IsEviction,
IsSWPrefetch,
IsHWPrefetch,
- IsLocked, //!< Alpha/MIPS LL or SC access
+ IsLlsc, //!< Alpha/MIPS LL or SC access
HasData, //!< There is an associated payload
IsError, //!< Error response
IsPrint, //!< Print state matching address (for debugging)
+ IsFlush, //!< Flush the address from caches
+ FromCache, //!< Request originated from a caching agent
NUM_COMMAND_ATTRIBUTES
};
- /** Structure that defines attributes and other data associated
- * with a Command. */
- struct CommandInfo {
- /** Set of attribute flags. */
+ /**
+ * 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. */
+ /// Corresponding response for requests; InvalidCmd if no
+ /// response is applicable.
const Command response;
- /** String representation (for printing) */
+ /// String representation (for printing)
const std::string str;
};
- /** Array to map Command enum to associated info. */
+ /// Array to map Command enum to associated info.
static const CommandInfo commandInfo[];
private:
Command cmd;
- bool testCmdAttrib(MemCmd::Attribute attrib) const {
+ 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 isRead() const { return testCmdAttrib(IsRead); }
+ bool isWrite() const { return testCmdAttrib(IsWrite); }
+ bool isUpgrade() const { return testCmdAttrib(IsUpgrade); }
+ bool isRequest() const { return testCmdAttrib(IsRequest); }
+ bool isResponse() const { return testCmdAttrib(IsResponse); }
+ bool needsWritable() const { return testCmdAttrib(NeedsWritable); }
+ bool needsResponse() const { return testCmdAttrib(NeedsResponse); }
+ bool isInvalidate() const { return testCmdAttrib(IsInvalidate); }
+ bool isEviction() const { return testCmdAttrib(IsEviction); }
+ bool fromCache() const { return testCmdAttrib(FromCache); }
+
+ /**
+ * A writeback is an eviction that carries data.
+ */
+ bool isWriteback() const { return testCmdAttrib(IsEviction) &&
+ testCmdAttrib(HasData); }
+
+ /**
+ * Check if this particular packet type carries payload data. Note
+ * that this does not reflect if the data pointer of the packet is
+ * valid or not.
+ */
bool hasData() const { return testCmdAttrib(HasData); }
- bool isReadWrite() const { return isRead() && isWrite(); }
- bool isLocked() const { return testCmdAttrib(IsLocked); }
+ bool isLLSC() const { return testCmdAttrib(IsLlsc); }
+ bool isSWPrefetch() const { return testCmdAttrib(IsSWPrefetch); }
+ bool isHWPrefetch() const { return testCmdAttrib(IsHWPrefetch); }
+ bool isPrefetch() const { return testCmdAttrib(IsSWPrefetch) ||
+ testCmdAttrib(IsHWPrefetch); }
bool isError() const { return testCmdAttrib(IsError); }
bool isPrint() const { return testCmdAttrib(IsPrint); }
+ bool isFlush() const { return testCmdAttrib(IsFlush); }
- const Command responseCommand() 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;
- }
-
+ /// 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); }
+ MemCmd(Command _cmd) : cmd(_cmd) { }
+ MemCmd(int _cmd) : cmd((Command)_cmd) { }
+ MemCmd() : cmd(InvalidCmd) { }
- friend class Packet;
+ bool operator==(MemCmd c2) const { return (cmd == c2.cmd); }
+ bool operator!=(MemCmd c2) const { return (cmd != c2.cmd); }
};
/**
* ultimate destination and back, possibly being conveyed by several
* different Packets along the way.)
*/
-class Packet : public FastAlloc, public Printable
+class Packet : public Printable
{
public:
+ typedef uint32_t FlagsType;
+ typedef ::Flags<FlagsType> Flags;
+
+ private:
+
+ enum : FlagsType {
+ // Flags to transfer across when copying a packet
+ COPY_FLAGS = 0x0000000F,
+ // Does this packet have sharers (which means it should not be
+ // considered writable) or not. See setHasSharers below.
+ HAS_SHARERS = 0x00000001,
+
+ // Special control flags
+ /// Special timing-mode atomic snoop for multi-level coherence.
+ EXPRESS_SNOOP = 0x00000002,
+
+ /// Allow a responding cache to inform the cache hierarchy
+ /// that it had a writable copy before responding. See
+ /// setResponderHadWritable below.
+ RESPONDER_HAD_WRITABLE = 0x00000004,
+
+ // Snoop co-ordination flag to indicate that a cache is
+ // responding to a snoop. See setCacheResponding below.
+ CACHE_RESPONDING = 0x00000008,
+
+ /// Are the 'addr' and 'size' fields valid?
+ VALID_ADDR = 0x00000100,
+ VALID_SIZE = 0x00000200,
+
+ /// Is the data pointer set to a value that shouldn't be freed
+ /// when the packet is destroyed?
+ STATIC_DATA = 0x00001000,
+ /// The data pointer points to a value that should be freed when
+ /// the packet is destroyed. The pointer is assumed to be pointing
+ /// to an array, and delete [] is consequently called
+ DYNAMIC_DATA = 0x00002000,
+
+ /// suppress the error if this packet encounters a functional
+ /// access failure.
+ SUPPRESS_FUNC_ERROR = 0x00008000,
+
+ // Signal block present to squash prefetch and cache evict packets
+ // through express snoop flag
+ BLOCK_CACHED = 0x00010000
+ };
+
+ Flags flags;
+
+ public:
typedef MemCmd::Command Command;
- /** The command field of the packet. */
+ /// The command field of the packet.
MemCmd cmd;
- /** A pointer to the original request. */
- RequestPtr req;
+ /// A pointer to the original request.
+ const 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.
+ /**
+ * 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. */
+ /// 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
- };
+ /// True if the request targets the secure memory space.
+ bool _isSecure;
- /** Status flags */
- std::bitset<NUM_PACKET_FLAGS> flags;
+ /// The size of the request or transfer.
+ unsigned size;
- public:
+ /**
+ * Track the bytes found that satisfy a functional read.
+ */
+ std::vector<bool> bytesValid;
- /** Used to calculate latencies for each packet.*/
- Tick time;
+ public:
- /** The time at which the packet will be fully transmitted */
- Tick finishTime;
+ /**
+ * The extra delay from seeing the packet until the header is
+ * transmitted. This delay is used to communicate the crossbar
+ * forwarding latency to the neighbouring object (e.g. a cache)
+ * that actually makes the packet wait. As the delay is relative,
+ * a 32-bit unsigned should be sufficient.
+ */
+ uint32_t headerDelay;
- /** The time at which the first chunk of the packet will be transmitted */
- Tick firstWordTime;
+ /**
+ * Keep track of the extra delay incurred by snooping upwards
+ * before sending a request down the memory system. This is used
+ * by the coherent crossbar to account for the additional request
+ * delay.
+ */
+ uint32_t snoopDelay;
- /** The special destination address indicating that the packet
- * should be routed based on its address. */
- static const short Broadcast = -1;
+ /**
+ * The extra pipelining delay from seeing the packet until the end of
+ * payload is transmitted by the component that provided it (if
+ * any). This includes the header delay. Similar to the header
+ * delay, this is used to make up for the fact that the
+ * crossbar does not make the packet wait. As the delay is
+ * relative, a 32-bit unsigned should be sufficient.
+ */
+ uint32_t payloadDelay;
- /** 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:
+ /**
+ * A virtual base opaque structure used to hold state associated
+ * with the packet (e.g., an MSHR), specific to a MemObject that
+ * sees the packet. A pointer to this state is returned in the
+ * packet's response so that the MemObject in question 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.
+ *
+ * As multiple MemObjects may add their SenderState throughout the
+ * memory system, the SenderStates create a stack, where a
+ * MemObject can add a new Senderstate, as long as the
+ * predecessing SenderState is restored when the response comes
+ * back. For this reason, the predecessor should always be
+ * populated with the current SenderState of a packet before
+ * modifying the senderState field in the request packet.
+ */
+ struct SenderState
+ {
+ SenderState* predecessor;
+ SenderState() : predecessor(NULL) {}
virtual ~SenderState() {}
};
* Object used to maintain state of a PrintReq. The senderState
* field of a PrintReq should always be of this type.
*/
- class PrintReqState : public SenderState, public FastAlloc {
- /** An entry in the label stack. */
- class LabelStackEntry {
- public:
+ class PrintReqState : public SenderState
+ {
+ private:
+ /**
+ * An entry in the label stack.
+ */
+ struct LabelStackEntry
+ {
const std::string label;
std::string *prefix;
bool labelPrinted;
- LabelStackEntry(const std::string &_label,
- std::string *_prefix);
+ LabelStackEntry(const std::string &_label, std::string *_prefix);
};
typedef std::list<LabelStackEntry> LabelStack;
PrintReqState(std::ostream &os, int verbosity = 0);
~PrintReqState();
- /** Returns the current line prefix. */
+ /**
+ * Returns the current line prefix.
+ */
const std::string &curPrefix() { return *curPrefixPtr; }
- /** Push a label onto the label stack, and prepend the given
+ /**
+ * Push a label onto the label stack, and prepend the given
* prefix string onto the current prefix. Labels will only be
- * printed if an object within the label's scope is
- * printed. */
+ * printed if an object within the label's scope is printed.
+ */
void pushLabel(const std::string &lbl,
const std::string &prefix = " ");
- /** Pop a label off the label stack. */
+
+ /**
+ * Pop a label off the label stack.
+ */
void popLabel();
- /** Print all of the pending unprinted labels on the
+
+ /**
+ * Print all of the pending unprinted labels on the
* stack. Called by printObj(), so normally not called by
- * users unless bypassing printObj(). */
+ * users unless bypassing printObj().
+ */
void printLabels();
- /** Print a Printable object to os, because it matched the
- * address on a PrintReq. */
+
+ /**
+ * Print a Printable object to os, because it matched the
+ * address on a PrintReq.
+ */
void printObj(Printable *obj);
};
- /** This packet's sender state. Devices should use dynamic_cast<>
- * to cast to the state appropriate to the sender. */
+ /**
+ * This packet's sender state. Devices should use dynamic_cast<>
+ * to cast to the state appropriate to the sender. The intent of
+ * this variable is to allow a device to attach extra information
+ * to a request. A response packet must return the sender state
+ * that was attached to the original request (even if a new packet
+ * is created).
+ */
SenderState *senderState;
- /** Return the string name of the cmd field (for debugging and
- * tracing). */
+ /**
+ * Push a new sender state to the packet and make the current
+ * sender state the predecessor of the new one. This should be
+ * prefered over direct manipulation of the senderState member
+ * variable.
+ *
+ * @param sender_state SenderState to push at the top of the stack
+ */
+ void pushSenderState(SenderState *sender_state);
+
+ /**
+ * Pop the top of the state stack and return a pointer to it. This
+ * assumes the current sender state is not NULL. This should be
+ * preferred over direct manipulation of the senderState member
+ * variable.
+ *
+ * @return The current top of the stack
+ */
+ SenderState *popSenderState();
+
+ /**
+ * Go through the sender state stack and return the first instance
+ * that is of type T (as determined by a dynamic_cast). If there
+ * is no sender state of type T, NULL is returned.
+ *
+ * @return The topmost state of type T
+ */
+ template <typename T>
+ T * findNextSenderState() const
+ {
+ T *t = NULL;
+ SenderState* sender_state = senderState;
+ while (t == NULL && sender_state != NULL) {
+ t = dynamic_cast<T*>(sender_state);
+ sender_state = sender_state->predecessor;
+ }
+ return t;
+ }
+
+ /// 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. */
+ /// 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]; }
+ bool isRead() const { return cmd.isRead(); }
+ bool isWrite() const { return cmd.isWrite(); }
+ bool isUpgrade() const { return cmd.isUpgrade(); }
+ bool isRequest() const { return cmd.isRequest(); }
+ bool isResponse() const { return cmd.isResponse(); }
+ bool needsWritable() const
+ {
+ // we should never check if a response needsWritable, the
+ // request has this flag, and for a response we should rather
+ // look at the hasSharers flag (if not set, the response is to
+ // be considered writable)
+ assert(isRequest());
+ return cmd.needsWritable();
+ }
+ bool needsResponse() const { return cmd.needsResponse(); }
+ bool isInvalidate() const { return cmd.isInvalidate(); }
+ bool isEviction() const { return cmd.isEviction(); }
+ bool fromCache() const { return cmd.fromCache(); }
+ bool isWriteback() const { return cmd.isWriteback(); }
+ bool hasData() const { return cmd.hasData(); }
+ bool hasRespData() const
+ {
+ MemCmd resp_cmd = cmd.responseCommand();
+ return resp_cmd.hasData();
+ }
+ bool isLLSC() const { return cmd.isLLSC(); }
+ bool isError() const { return cmd.isError(); }
+ bool isPrint() const { return cmd.isPrint(); }
+ bool isFlush() const { return cmd.isFlush(); }
+
+ //@{
+ /// Snoop flags
+ /**
+ * Set the cacheResponding flag. This is used by the caches to
+ * signal another cache that they are responding to a request. A
+ * cache will only respond to snoops if it has the line in either
+ * Modified or Owned state. Note that on snoop hits we always pass
+ * the line as Modified and never Owned. In the case of an Owned
+ * line we proceed to invalidate all other copies.
+ *
+ * On a cache fill (see Cache::handleFill), we check hasSharers
+ * first, ignoring the cacheResponding flag if hasSharers is set.
+ * A line is consequently allocated as:
+ *
+ * hasSharers cacheResponding state
+ * true false Shared
+ * true true Shared
+ * false false Exclusive
+ * false true Modified
+ */
+ void setCacheResponding()
+ {
+ assert(isRequest());
+ assert(!flags.isSet(CACHE_RESPONDING));
+ flags.set(CACHE_RESPONDING);
+ }
+ bool cacheResponding() const { return flags.isSet(CACHE_RESPONDING); }
+ /**
+ * On fills, the hasSharers flag is used by the caches in
+ * combination with the cacheResponding flag, as clarified
+ * above. If the hasSharers flag is not set, the packet is passing
+ * writable. Thus, a response from a memory passes the line as
+ * writable by default.
+ *
+ * The hasSharers flag is also used by upstream caches to inform a
+ * downstream cache that they have the block (by calling
+ * setHasSharers on snoop request packets that hit in upstream
+ * cachs tags or MSHRs). If the snoop packet has sharers, a
+ * downstream cache is prevented from passing a dirty line upwards
+ * if it was not explicitly asked for a writable copy. See
+ * Cache::satisfyCpuSideRequest.
+ *
+ * The hasSharers flag is also used on writebacks, in
+ * combination with the WritbackClean or WritebackDirty commands,
+ * to allocate the block downstream either as:
+ *
+ * command hasSharers state
+ * WritebackDirty false Modified
+ * WritebackDirty true Owned
+ * WritebackClean false Exclusive
+ * WritebackClean true Shared
+ */
+ void setHasSharers() { flags.set(HAS_SHARERS); }
+ bool hasSharers() const { return flags.isSet(HAS_SHARERS); }
+ //@}
+
+ /**
+ * The express snoop flag is used for two purposes. Firstly, it is
+ * used to bypass flow control for normal (non-snoop) requests
+ * going downstream in the memory system. In cases where a cache
+ * is responding to a snoop from another cache (it had a dirty
+ * line), but the line is not writable (and there are possibly
+ * other copies), the express snoop flag is set by the downstream
+ * cache to invalidate all other copies in zero time. Secondly,
+ * the express snoop flag is also set to be able to distinguish
+ * snoop packets that came from a downstream cache, rather than
+ * snoop packets from neighbouring caches.
+ */
+ void setExpressSnoop() { flags.set(EXPRESS_SNOOP); }
+ bool isExpressSnoop() const { return flags.isSet(EXPRESS_SNOOP); }
+
+ /**
+ * On responding to a snoop request (which only happens for
+ * Modified or Owned lines), make sure that we can transform an
+ * Owned response to a Modified one. If this flag is not set, the
+ * responding cache had the line in the Owned state, and there are
+ * possibly other Shared copies in the memory system. A downstream
+ * cache helps in orchestrating the invalidation of these copies
+ * by sending out the appropriate express snoops.
+ */
+ void setResponderHadWritable()
+ {
+ assert(cacheResponding());
+ assert(!responderHadWritable());
+ flags.set(RESPONDER_HAD_WRITABLE);
+ }
+ bool responderHadWritable() const
+ { return flags.isSet(RESPONDER_HAD_WRITABLE); }
+
+ void setSuppressFuncError() { flags.set(SUPPRESS_FUNC_ERROR); }
+ bool suppressFuncError() const { return flags.isSet(SUPPRESS_FUNC_ERROR); }
+ void setBlockCached() { flags.set(BLOCK_CACHED); }
+ bool isBlockCached() const { return flags.isSet(BLOCK_CACHED); }
+ void clearBlockCached() { flags.clear(BLOCK_CACHED); }
// 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
+ setBadAddress()
+ {
+ assert(isResponse());
+ cmd = MemCmd::BadAddressError;
+ }
+
void copyError(Packet *pkt) { assert(pkt->isError()); cmd = pkt->cmd; }
- bool nic_pkt() { panic("Unimplemented"); M5_DUMMY_RETURN }
+ Addr getAddr() const { assert(flags.isSet(VALID_ADDR)); return addr; }
+ /**
+ * Update the address of this packet mid-transaction. This is used
+ * by the address mapper to change an already set address to a new
+ * one based on the system configuration. It is intended to remap
+ * an existing address, so it asserts that the current address is
+ * valid.
+ */
+ void setAddr(Addr _addr) { assert(flags.isSet(VALID_ADDR)); addr = _addr; }
+
+ unsigned getSize() const { assert(flags.isSet(VALID_SIZE)); return size; }
- /** 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; }
+ Addr getOffset(unsigned int blk_size) const
+ {
+ return getAddr() & Addr(blk_size - 1);
+ }
- /** 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 getBlockAddr(unsigned int blk_size) const
+ {
+ return getAddr() & ~(Addr(blk_size - 1));
+ }
- Addr getAddr() const { assert(addrSizeValid); return addr; }
- int getSize() const { assert(addrSizeValid); return size; }
- Addr getOffset(int blkSize) const { return addr & (Addr)(blkSize - 1); }
+ bool isSecure() const
+ {
+ assert(flags.isSet(VALID_ADDR));
+ return _isSecure;
+ }
+
+ /**
+ * Accessor function to atomic op.
+ */
+ AtomicOpFunctor *getAtomicOp() const { return req->getAtomicOpFunctor(); }
+ bool isAtomicOp() const { return req->isAtomic(); }
+
+ /**
+ * It has been determined that the SC packet should successfully update
+ * memory. Therefore, convert this SC packet to a normal write.
+ */
+ void
+ convertScToWrite()
+ {
+ assert(isLLSC());
+ assert(isWrite());
+ cmd = MemCmd::WriteReq;
+ }
+
+ /**
+ * When ruby is in use, Ruby will monitor the cache line and the
+ * phys memory should treat LL ops as normal reads.
+ */
+ void
+ convertLlToRead()
+ {
+ assert(isLLSC());
+ assert(isRead());
+ cmd = MemCmd::ReadReq;
+ }
- /** 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)
+ /**
+ * 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 must be supplied.
+ */
+ Packet(const RequestPtr _req, MemCmd _cmd)
+ : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false),
+ size(0), headerDelay(0), snoopDelay(0), payloadDelay(0),
+ senderState(NULL)
{
+ if (req->hasPaddr()) {
+ addr = req->getPaddr();
+ flags.set(VALID_ADDR);
+ _isSecure = req->isSecure();
+ }
+ if (req->hasSize()) {
+ size = req->getSize();
+ flags.set(VALID_SIZE);
+ }
}
- /** 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 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(const RequestPtr _req, MemCmd _cmd, int _blkSize)
+ : cmd(_cmd), req(_req), data(nullptr), addr(0), _isSecure(false),
+ headerDelay(0), snoopDelay(0), payloadDelay(0),
+ senderState(NULL)
{
+ if (req->hasPaddr()) {
+ addr = req->getPaddr() & ~(_blkSize - 1);
+ flags.set(VALID_ADDR);
+ _isSecure = req->isSecure();
+ }
+ size = _blkSize;
+ flags.set(VALID_SIZE);
}
- /** Alternate constructor for copying a packet. Copy all fields
+ /**
+ * 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 should allocate its own data.
+ */
+ Packet(const PacketPtr pkt, bool clear_flags, bool alloc_data)
+ : cmd(pkt->cmd), req(pkt->req),
+ data(nullptr),
+ addr(pkt->addr), _isSecure(pkt->_isSecure), size(pkt->size),
+ bytesValid(pkt->bytesValid),
+ headerDelay(pkt->headerDelay),
+ snoopDelay(0),
+ payloadDelay(pkt->payloadDelay),
+ senderState(pkt->senderState)
+ {
+ if (!clear_flags)
+ flags.set(pkt->flags & COPY_FLAGS);
+
+ flags.set(pkt->flags & (VALID_ADDR|VALID_SIZE));
+
+ // should we allocate space for data, or not, the express
+ // snoops do not need to carry any data as they only serve to
+ // co-ordinate state changes
+ if (alloc_data) {
+ // even if asked to allocate data, if the original packet
+ // holds static data, then the sender will not be doing
+ // any memcpy on receiving the response, thus we simply
+ // carry the pointer forward
+ if (pkt->flags.isSet(STATIC_DATA)) {
+ data = pkt->data;
+ flags.set(STATIC_DATA);
+ } else {
+ allocate();
+ }
+ }
+ }
+
+ /**
+ * Generate the appropriate read MemCmd based on the Request flags.
+ */
+ static MemCmd
+ makeReadCmd(const RequestPtr req)
+ {
+ if (req->isLLSC())
+ return MemCmd::LoadLockedReq;
+ else if (req->isPrefetch())
+ return MemCmd::SoftPFReq;
+ else
+ return MemCmd::ReadReq;
+ }
+
+ /**
+ * Generate the appropriate write MemCmd based on the Request flags.
+ */
+ static MemCmd
+ makeWriteCmd(const RequestPtr req)
+ {
+ if (req->isLLSC())
+ return MemCmd::StoreCondReq;
+ else if (req->isSwap())
+ return MemCmd::SwapReq;
+ else
+ return MemCmd::WriteReq;
+ }
+
+ /**
+ * Constructor-like methods that return Packets based on Request objects.
+ * Fine-tune the MemCmd type if it's not a vanilla read or write.
+ */
+ static PacketPtr
+ createRead(const RequestPtr req)
+ {
+ return new Packet(req, makeReadCmd(req));
+ }
+
+ static PacketPtr
+ createWrite(const RequestPtr req)
+ {
+ return new Packet(req, makeWriteCmd(req));
+ }
+
+ /**
+ * clean up packet variables
+ */
~Packet()
{
- // If this is a request packet for which there's no response,
- // delete the request object here, since the requester will
- // never get the chance.
- if (req && isRequest() && !needsResponse())
+ // Delete the request object if this is a request packet which
+ // does not need a response, because the requester will not get
+ // a chance. If the request packet needs a response then the
+ // request will be deleted on receipt of the response
+ // packet. We also make sure to never delete the request for
+ // express snoops, even for cases when responses are not
+ // needed (CleanEvict and Writeback), since the snoop packet
+ // re-uses the same request.
+ if (req && isRequest() && !needsResponse() &&
+ !isExpressSnoop()) {
delete req;
- 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;
}
+ deleteData();
}
/**
* 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.
+ * returning as a response to that request.
*/
- void makeResponse()
+ void
+ makeResponse()
{
assert(needsResponse());
assert(isRequest());
- origCmd = cmd;
cmd = cmd.responseCommand();
- dest = src;
- destValid = srcValid;
- srcValid = false;
+
+ // responses are never express, even if the snoop that
+ // triggered them was
+ flags.clear(EXPRESS_SNOOP);
}
- void makeAtomicResponse()
+ void
+ makeAtomicResponse()
{
makeResponse();
}
- void makeTimingResponse()
+ 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()
+ setFunctionalResponseStatus(bool success)
{
- assert(wasNacked());
- cmd = origCmd;
- assert(needsResponse());
- setDest(Broadcast);
+ if (!success) {
+ if (isWrite()) {
+ cmd = MemCmd::FunctionalWriteError;
+ } else {
+ cmd = MemCmd::FunctionalReadError;
+ }
+ }
+ }
+
+ void
+ setSize(unsigned size)
+ {
+ assert(!flags.isSet(VALID_SIZE));
+
+ this->size = size;
+ flags.set(VALID_SIZE);
}
+ public:
+ /**
+ * @{
+ * @name Data accessor mehtods
+ */
+
/**
* Set the data pointer to the following value that should not be
- * freed.
+ * freed. Static data allows us to do a single memcpy even if
+ * multiple packets are required to get from source to destination
+ * and back. In essence the pointer is set calling dataStatic on
+ * the original packet, and whenever this packet is copied and
+ * forwarded the same pointer is passed on. When a packet
+ * eventually reaches the destination holding the data, it is
+ * copied once into the location originally set. On the way back
+ * to the source, no copies are necessary.
*/
template <typename T>
void
dataStatic(T *p)
{
- if(dynamicData)
- dynamicData = false;
+ assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
data = (PacketDataPtr)p;
- staticData = true;
+ flags.set(STATIC_DATA);
}
/**
- * Set the data pointer to a value that should have delete []
- * called on it.
+ * Set the data pointer to the following value that should not be
+ * freed. This version of the function allows the pointer passed
+ * to us to be const. To avoid issues down the line we cast the
+ * constness away, the alternative would be to keep both a const
+ * and non-const data pointer and cleverly choose between
+ * them. Note that this is only allowed for static data.
*/
template <typename T>
void
- dataDynamicArray(T *p)
+ dataStaticConst(const T *p)
{
- assert(!staticData && !dynamicData);
- data = (PacketDataPtr)p;
- dynamicData = true;
- arrayData = true;
+ assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
+ data = const_cast<PacketDataPtr>(p);
+ flags.set(STATIC_DATA);
}
/**
- * set the data pointer to a value that should have delete called
- * on it.
+ * Set the data pointer to a value that should have delete []
+ * called on it. Dynamic data is local to this packet, and as the
+ * packet travels from source to destination, forwarded packets
+ * will allocate their own data. When a packet reaches the final
+ * destination it will populate the dynamic data of that specific
+ * packet, and on the way back towards the source, memcpy will be
+ * invoked in every step where a new packet was created e.g. in
+ * the caches. Ultimately when the response reaches the source a
+ * final memcpy is needed to extract the data from the packet
+ * before it is deallocated.
*/
template <typename T>
void
dataDynamic(T *p)
{
- assert(!staticData && !dynamicData);
+ assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
data = (PacketDataPtr)p;
- dynamicData = true;
- arrayData = false;
+ flags.set(DYNAMIC_DATA);
}
- /** get a pointer to the data ptr. */
+ /**
+ * get a pointer to the data ptr.
+ */
template <typename T>
T*
getPtr()
{
- assert(staticData || dynamicData);
+ assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
return (T*)data;
}
- /** return the value of what is pointed to in the packet. */
template <typename T>
- T get();
+ const T*
+ getConstPtr() const
+ {
+ assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
+ return (const T*)data;
+ }
- /** set the value in the data pointer to v. */
+ /**
+ * Get the data in the packet byte swapped from big endian to
+ * host endian.
+ */
+ template <typename T>
+ T getBE() const;
+
+ /**
+ * Get the data in the packet byte swapped from little endian to
+ * host endian.
+ */
+ template <typename T>
+ T getLE() const;
+
+ /**
+ * Get the data in the packet byte swapped from the specified
+ * endianness.
+ */
+ template <typename T>
+ T get(ByteOrder endian) const;
+
+ /**
+ * Get the data in the packet byte swapped from guest to host
+ * endian.
+ */
+ template <typename T>
+ T get() const;
+
+ /** Set the value in the data pointer to v as big endian. */
+ template <typename T>
+ void setBE(T v);
+
+ /** Set the value in the data pointer to v as little endian. */
+ template <typename T>
+ void setLE(T v);
+
+ /**
+ * Set the value in the data pointer to v using the specified
+ * endianness.
+ */
+ template <typename T>
+ void set(T v, ByteOrder endian);
+
+ /** Set the value in the data pointer to v as guest endian. */
template <typename T>
void set(T v);
/**
* Copy data into the packet from the provided pointer.
*/
- void setData(uint8_t *p)
+ void
+ setData(const uint8_t *p)
{
- std::memcpy(getPtr<uint8_t>(), p, getSize());
+ // we should never be copying data onto itself, which means we
+ // must idenfity packets with static data, as they carry the
+ // same pointer from source to destination and back
+ assert(p != getPtr<uint8_t>() || flags.isSet(STATIC_DATA));
+
+ if (p != getPtr<uint8_t>())
+ // for packet with allocated dynamic data, we copy data from
+ // one to the other, e.g. a forwarded response to a response
+ 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)
+ void
+ setDataFromBlock(const 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)
+ void
+ writeData(uint8_t *p) const
{
- std::memcpy(p, getPtr<uint8_t>(), getSize());
+ std::memcpy(p, getConstPtr<uint8_t>(), getSize());
}
/**
* Copy data from the packet to the memory at the provided pointer.
*/
- void writeDataToBlock(uint8_t *blk_data, int blkSize)
+ void
+ writeDataToBlock(uint8_t *blk_data, int blkSize) const
{
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();
+ void
+ deleteData()
+ {
+ if (flags.isSet(DYNAMIC_DATA))
+ delete [] data;
+
+ flags.clear(STATIC_DATA|DYNAMIC_DATA);
+ data = NULL;
+ }
+
+ /** Allocate memory for the packet. */
+ void
+ allocate()
+ {
+ // if either this command or the response command has a data
+ // payload, actually allocate space
+ if (hasData() || hasRespData()) {
+ assert(flags.noneSet(STATIC_DATA|DYNAMIC_DATA));
+ flags.set(DYNAMIC_DATA);
+ data = new uint8_t[getSize()];
+ }
+ }
+
+ /** @} */
+
+ private: // Private data accessor methods
+ /** Get the data in the packet without byte swapping. */
+ template <typename T>
+ T getRaw() const;
- /** If there isn't data in the packet, allocate some. */
- void allocate();
+ /** Set the value in the data pointer to v without byte swapping. */
+ template <typename T>
+ void setRaw(T v);
+ public:
/**
- * 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.
+ * Check a functional request against a memory value stored in
+ * another packet (i.e. an in-transit request or
+ * response). Returns true if the current packet is a read, and
+ * the other packet provides the data, which is then copied to the
+ * current packet. If the current packet is a write, and the other
+ * packet intersects this one, then we update the data
+ * accordingly.
*/
- bool checkFunctional(Printable *obj, Addr base, int size, uint8_t *data);
+ bool
+ checkFunctional(PacketPtr other)
+ {
+ // all packets that are carrying a payload should have a valid
+ // data pointer
+ return checkFunctional(other, other->getAddr(), other->isSecure(),
+ other->getSize(),
+ other->hasData() ?
+ other->getPtr<uint8_t>() : NULL);
+ }
/**
- * Check a functional request against a memory value stored in
- * another packet (i.e. an in-transit request or response).
+ * Does the request need to check for cached copies of the same block
+ * in the memory hierarchy above.
+ **/
+ bool
+ mustCheckAbove() const
+ {
+ return cmd == MemCmd::HardPFReq || isEviction();
+ }
+
+ /**
+ * Is this packet a clean eviction, including both actual clean
+ * evict packets, but also clean writebacks.
*/
- bool checkFunctional(PacketPtr otherPkt) {
- return checkFunctional(otherPkt,
- otherPkt->getAddr(), otherPkt->getSize(),
- otherPkt->hasData() ?
- otherPkt->getPtr<uint8_t>() : NULL);
+ bool
+ isCleanEviction() const
+ {
+ return cmd == MemCmd::CleanEvict || cmd == MemCmd::WritebackClean;
}
+ /**
+ * Check a functional request against a memory value represented
+ * by a base/size pair and an associated data array. If the
+ * current packet is a read, it may be satisfied by the memory
+ * value. If the current packet is a write, it may update the
+ * memory value.
+ */
+ bool
+ checkFunctional(Printable *obj, Addr base, bool is_secure, int size,
+ uint8_t *_data);
+
/**
* Push label for PrintReq (safe to call unconditionally).
*/
- void pushLabel(const std::string &lbl) {
- if (isPrint()) {
- dynamic_cast<PrintReqState*>(senderState)->pushLabel(lbl);
- }
+ void
+ pushLabel(const std::string &lbl)
+ {
+ if (isPrint())
+ safe_cast<PrintReqState*>(senderState)->pushLabel(lbl);
}
/**
* Pop label for PrintReq (safe to call unconditionally).
*/
- void popLabel() {
- if (isPrint()) {
- dynamic_cast<PrintReqState*>(senderState)->popLabel();
- }
+ void
+ popLabel()
+ {
+ if (isPrint())
+ safe_cast<PrintReqState*>(senderState)->popLabel();
}
void print(std::ostream &o, int verbosity = 0,
const std::string &prefix = "") const;
+
+ /**
+ * A no-args wrapper of print(std::ostream...)
+ * meant to be invoked from DPRINTFs
+ * avoiding string overheads in fast mode
+ * @return string with the request's type and start<->end addresses
+ */
+ std::string print() const;
};
#endif //__MEM_PACKET_HH
projects / gem5.git / blobdiff