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