port.hh revision 8922
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 * William Wang 43 */ 44 45/** 46 * @file 47 * Port Object Declaration. 48 */ 49 50#ifndef __MEM_PORT_HH__ 51#define __MEM_PORT_HH__ 52 53#include <list> 54 55#include "base/range.hh" 56#include "mem/packet.hh" 57 58/** 59 * This typedef is used to clean up getAddrRanges(). It's declared 60 * outside the Port object since it's also used by some mem objects. 61 * Eventually we should move this typedef to wherever Addr is 62 * defined. 63 */ 64 65typedef std::list<Range<Addr> > AddrRangeList; 66typedef std::list<Range<Addr> >::iterator AddrRangeIter; 67 68class MemObject; 69 70/** 71 * Ports are used to interface memory objects to each other. A port is 72 * either a master or a slave and the connected peer is always of the 73 * opposite role. 74 * 75 * Each port has a name and an owner, and enables three basic types of 76 * accesses to the peer port: sendFunctional, sendAtomic and 77 * sendTiming. 78 */ 79class Port 80{ 81 82 private: 83 84 /** Descriptive name (for DPRINTF output) */ 85 std::string portName; 86 87 protected: 88 89 /** A pointer to the peer port. */ 90 Port* peer; 91 92 /** A reference to the MemObject that owns this port. */ 93 MemObject& owner; 94 95 /** 96 * Abstract base class for ports 97 * 98 * @param _name Port name including the owners name 99 * @param _owner The MemObject that is the structural owner of this port 100 */ 101 Port(const std::string& _name, MemObject& _owner); 102 103 /** 104 * Virtual destructor due to inheritance. 105 */ 106 virtual ~Port(); 107 108 public: 109 110 /** Return port name (for DPRINTF). */ 111 const std::string name() const { return portName; } 112 113 protected: 114 115 /** These functions are protected because they should only be 116 * called by a peer port, never directly by any outside object. */ 117 118 /** Called to recive a timing call from the peer port. */ 119 virtual bool recvTiming(PacketPtr pkt) = 0; 120 121 /** Called to recive a atomic call from the peer port. */ 122 virtual Tick recvAtomic(PacketPtr pkt) = 0; 123 124 /** Called to recive a functional call from the peer port. */ 125 virtual void recvFunctional(PacketPtr pkt) = 0; 126 127 /** 128 * Called by a peer port if sendTiming was unsuccesful, and had to 129 * wait. 130 */ 131 virtual void recvRetry() = 0; 132 133 public: 134 135 /** 136 * Attempt to send a timing packet to the peer port by calling its 137 * receive function. If the send does not succeed, as indicated by 138 * the return value, then the sender must wait for a recvRetry at 139 * which point it can re-issue a sendTiming. 140 * 141 * @param pkt Packet to send. 142 * 143 * @return If the send was succesful or not. 144 */ 145 bool sendTiming(PacketPtr pkt) { return peer->recvTiming(pkt); } 146 147 /** 148 * Send a retry to a peer port that previously attempted a sendTiming 149 * which was unsuccessful. 150 */ 151 void sendRetry() { return peer->recvRetry(); } 152 153 /** 154 * Send an atomic packet, where the data is moved and the state 155 * is updated in zero time, without interleaving with other 156 * memory accesses. 157 * 158 * @param pkt Packet to send. 159 * 160 * @return Estimated latency of access. 161 */ 162 Tick sendAtomic(PacketPtr pkt) { return peer->recvAtomic(pkt); } 163 164 /** 165 * Send a functional packet, where the data is instantly updated 166 * everywhere in the memory system, without affecting the current 167 * state of any block or moving the block. 168 * 169 * @param pkt Packet to send. 170 */ 171 void sendFunctional(PacketPtr pkt) { return peer->recvFunctional(pkt); } 172 173}; 174 175/** Forward declaration */ 176class SlavePort; 177 178/** 179 * A MasterPort is a specialisation of a port. In addition to the 180 * basic functionality of sending packets to its slave peer, it also 181 * has functions specific to a master, e.g. to receive range changes 182 * or determine if the port is snooping or not. 183 */ 184class MasterPort : public Port 185{ 186 187 private: 188 189 SlavePort* _slavePort; 190 191 public: 192 193 MasterPort(const std::string& name, MemObject* owner); 194 virtual ~MasterPort(); 195 196 void bind(SlavePort& slave_port); 197 SlavePort& getSlavePort() const; 198 bool isConnected() const; 199 200 /** 201 * Called to receive an address range change from the peer slave 202 * port. the default implementation ignored the change and does 203 * nothing. Override this function in a derived class if the owner 204 * needs to be aware of he laesddress ranges, e.g. in an 205 * interconnect component like a bus. 206 */ 207 virtual void recvRangeChange() { } 208 209 /** 210 * Determine if this master port is snooping or not. The default 211 * implementation returns false and thus tells the neighbour we 212 * are not snooping. Any master port that wants to receive snoop 213 * requests (e.g. a cache connected to a bus) has to override this 214 * function. 215 * 216 * @return true if the port should be considered a snooper 217 */ 218 virtual bool isSnooping() const { return false; } 219 220 /** 221 * Called by a peer port in order to determine the block size of 222 * the owner of this port. 223 */ 224 virtual unsigned deviceBlockSize() const { return 0; } 225 226 /** Called by the associated device if it wishes to find out the blocksize 227 of the device on attached to the peer port. 228 */ 229 unsigned peerBlockSize() const; 230 231 /** Inject a PrintReq for the given address to print the state of 232 * that address throughout the memory system. For debugging. 233 */ 234 void printAddr(Addr a); 235}; 236 237/** 238 * A SlavePort is a specialisation of a port. In addition to the 239 * basic functionality of sending packets to its master peer, it also 240 * has functions specific to a slave, e.g. to send range changes 241 * and get the address ranges that the port responds to. 242 */ 243class SlavePort : public Port 244{ 245 246 private: 247 248 MasterPort* _masterPort; 249 250 public: 251 252 SlavePort(const std::string& name, MemObject* owner); 253 virtual ~SlavePort(); 254 255 void bind(MasterPort& master_port); 256 MasterPort& getMasterPort() const; 257 bool isConnected() const; 258 259 /** 260 * Called by a peer port in order to determine the block size of 261 * the owner of this port. 262 */ 263 virtual unsigned deviceBlockSize() const { return 0; } 264 265 /** Called by the associated device if it wishes to find out the blocksize 266 of the device on attached to the peer port. 267 */ 268 unsigned peerBlockSize() const; 269 270 /** 271 * Called by the owner to send a range change 272 */ 273 void sendRangeChange() const { _masterPort->recvRangeChange(); } 274 275 /** 276 * Get a list of the non-overlapping address ranges the owner is 277 * responsible for. All slave ports must override this function 278 * and return a populated list with at least one item. 279 * 280 * @return a list of ranges responded to 281 */ 282 virtual AddrRangeList getAddrRanges() = 0; 283}; 284 285#endif //__MEM_PORT_HH__ 286