port.hh revision 8853
1/* 2 * Copyright (c) 2011-2012 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Copyright (c) 2002-2005 The Regents of The University of Michigan 15 * All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions are 19 * met: redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer; 21 * redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution; 24 * neither the name of the copyright holders nor the names of its 25 * contributors may be used to endorse or promote products derived from 26 * this software without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 39 * 40 * Authors: Ron Dreslinski 41 * Andreas Hansson 42 */ 43 44/** 45 * @file 46 * Port Object Declaration. Ports are used to interface memory objects to 47 * each other. They will always come in pairs, and we refer to the other 48 * port object as the peer. These are used to make the design more 49 * modular so that a specific interface between every type of objcet doesn't 50 * have to be created. 51 */ 52 53#ifndef __MEM_PORT_HH__ 54#define __MEM_PORT_HH__ 55 56#include <list> 57 58#include "base/range.hh" 59#include "mem/packet.hh" 60 61/** This typedef is used to clean up getAddrRanges(). It's declared 62 * outside the Port object since it's also used by some mem objects. 63 * Eventually we should move this typedef to wherever Addr is 64 * defined. 65 */ 66 67typedef std::list<Range<Addr> > AddrRangeList; 68typedef std::list<Range<Addr> >::iterator AddrRangeIter; 69 70class MemObject; 71 72/** 73 * Ports are used to interface memory objects to 74 * each other. They will always come in pairs, and we refer to the other 75 * port object as the peer. These are used to make the design more 76 * modular so that a specific interface between every type of objcet doesn't 77 * have to be created. 78 * 79 * Recv accesor functions are being called from the peer interface. 80 * Send accessor functions are being called from the device the port is 81 * associated with, and it will call the peer recv. accessor function. 82 */ 83class Port 84{ 85 protected: 86 /** Descriptive name (for DPRINTF output) */ 87 mutable std::string portName; 88 89 /** A pointer to the peer port. Ports always come in pairs, that way they 90 can use a standardized interface to communicate between different 91 memory objects. */ 92 Port *peer; 93 94 /** A pointer to the MemObject that owns this port. This may not be set. */ 95 MemObject *owner; 96 97 public: 98 /** 99 * Constructor. 100 * 101 * @param _name Port name for DPRINTF output. Should include name 102 * of memory system object to which the port belongs. 103 * @param _owner Pointer to the MemObject that owns this port. 104 * Will not necessarily be set. 105 */ 106 Port(const std::string &_name, MemObject *_owner); 107 108 /** Return port name (for DPRINTF). */ 109 const std::string &name() const { return portName; } 110 111 virtual ~Port(); 112 113 void setName(const std::string &name) 114 { portName = name; } 115 116 /** Function to set the pointer for the peer port. */ 117 virtual void setPeer(Port *port); 118 119 /** Function to get the pointer to the peer port. */ 120 Port *getPeer() { return peer; } 121 122 /** Function to set the owner of this port. */ 123 void setOwner(MemObject *_owner); 124 125 /** Function to return the owner of this port. */ 126 MemObject *getOwner() { return owner; } 127 128 bool isConnected() { return peer != NULL; } 129 130 protected: 131 132 /** These functions are protected because they should only be 133 * called by a peer port, never directly by any outside object. */ 134 135 /** Called to recive a timing call from the peer port. */ 136 virtual bool recvTiming(PacketPtr pkt) = 0; 137 138 /** Called to recive a atomic call from the peer port. */ 139 virtual Tick recvAtomic(PacketPtr pkt) = 0; 140 141 /** Called to recive a functional call from the peer port. */ 142 virtual void recvFunctional(PacketPtr pkt) = 0; 143 144 /** Called to recieve an address range change from the peer port. */ 145 virtual void recvRangeChange() = 0; 146 147 /** Called by a peer port if the send was unsuccesful, and had to 148 wait. This shouldn't be valid for response paths (IO Devices). 149 so it is set to panic if it isn't already defined. 150 */ 151 virtual void recvRetry() { panic("??"); } 152 153 /** Called by a peer port in order to determine the block size of the 154 device connected to this port. It sometimes doesn't make sense for 155 this function to be called, so it just returns 0. Anytthing that is 156 concerned with the size should just ignore that. 157 */ 158 virtual unsigned deviceBlockSize() const { return 0; } 159 160 public: 161 162 /** 163 * Get a list of the non-overlapping address ranges we are 164 * responsible for. The default implementation returns an empty 165 * list and thus no address ranges. Any slave port must override 166 * this function and return a populated list with at least one 167 * item. 168 * 169 * @return a list of ranges responded to 170 */ 171 virtual AddrRangeList getAddrRanges() 172 { AddrRangeList ranges; return ranges; } 173 174 /** 175 * Determine if this port is snooping or not. The default 176 * implementation returns false and thus tells the neighbour we 177 * are not snooping. Any port that is to snoop (e.g. a cache 178 * connected to a bus) has to override this function. 179 * 180 * @return true if the port should be considered a snooper 181 */ 182 virtual bool isSnooping() 183 { return false; } 184 185 /** Function called by associated memory device (cache, memory, iodevice) 186 in order to send a timing request to the port. Simply calls the peer 187 port receive function. 188 @return This function returns if the send was succesful in it's 189 recieve. If it was a failure, then the port will wait for a recvRetry 190 at which point it can possibly issue a successful sendTiming. This is used in 191 case a cache has a higher priority request come in while waiting for 192 the bus to arbitrate. 193 */ 194 bool sendTiming(PacketPtr pkt) { return peer->recvTiming(pkt); } 195 196 /** Function called by the associated device to send an atomic 197 * access, an access in which the data is moved and the state is 198 * updated in one cycle, without interleaving with other memory 199 * accesses. Returns estimated latency of access. 200 */ 201 Tick sendAtomic(PacketPtr pkt) 202 { return peer->recvAtomic(pkt); } 203 204 /** Function called by the associated device to send a functional access, 205 an access in which the data is instantly updated everywhere in the 206 memory system, without affecting the current state of any block or 207 moving the block. 208 */ 209 void sendFunctional(PacketPtr pkt) 210 { return peer->recvFunctional(pkt); } 211 212 /** 213 * Called by the associated device to send a status range to the 214 * peer interface. 215 */ 216 void sendRangeChange() const { peer->recvRangeChange(); } 217 218 /** When a timing access doesn't return a success, some time later the 219 Retry will be sent. 220 */ 221 void sendRetry() { return peer->recvRetry(); } 222 223 /** Called by the associated device if it wishes to find out the blocksize 224 of the device on attached to the peer port. 225 */ 226 unsigned peerBlockSize() const { return peer->deviceBlockSize(); } 227 228 /** Inject a PrintReq for the given address to print the state of 229 * that address throughout the memory system. For debugging. 230 */ 231 void printAddr(Addr a); 232}; 233 234#endif //__MEM_PORT_HH__ 235