port.hh revision 2630
1/* 2 * Copyright (c) 2002-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29/** 30 * @file 31 * Port Object Decleration. Ports are used to interface memory objects to 32 * each other. They will always come in pairs, and we refer to the other 33 * port object as the peer. These are used to make the design more 34 * modular so that a specific interface between every type of objcet doesn't 35 * have to be created. 36 */ 37 38#ifndef __MEM_PORT_HH__ 39#define __MEM_PORT_HH__ 40 41#include <list> 42#include <inttypes.h> 43 44#include "base/misc.hh" 45#include "base/range.hh" 46#include "mem/packet.hh" 47#include "mem/request.hh" 48 49/** This typedef is used to clean up the parameter list of 50 * getDeviceAddressRanges() and getPeerAddressRanges(). It's declared 51 * outside the Port object since it's also used by some mem objects. 52 * Eventually we should move this typedef to wherever Addr is 53 * defined. 54 */ 55 56typedef std::list<Range<Addr> > AddrRangeList; 57typedef std::list<Range<Addr> >::iterator AddrRangeIter; 58 59/** 60 * Ports are used to interface memory objects to 61 * each other. They will always come in pairs, and we refer to the other 62 * port object as the peer. These are used to make the design more 63 * modular so that a specific interface between every type of objcet doesn't 64 * have to be created. 65 * 66 * Recv accesor functions are being called from the peer interface. 67 * Send accessor functions are being called from the device the port is 68 * associated with, and it will call the peer recv. accessor function. 69 */ 70class Port 71{ 72 public: 73 74 virtual ~Port() {}; 75 // mey be better to use subclasses & RTTI? 76 /** Holds the ports status. Keeps track if it is blocked, or has 77 calculated a range change. */ 78 enum Status { 79 Blocked, 80 Unblocked, 81 RangeChange 82 }; 83 84 private: 85 86 /** A pointer to the peer port. Ports always come in pairs, that way they 87 can use a standardized interface to communicate between different 88 memory objects. */ 89 Port *peer; 90 91 public: 92 93 /** Function to set the pointer for the peer port. 94 @todo should be called by the configuration stuff (python). 95 */ 96 void setPeer(Port *port) { peer = port; } 97 98 /** Function to set the pointer for the peer port. 99 @todo should be called by the configuration stuff (python). 100 */ 101 Port *getPeer() { return peer; } 102 103 protected: 104 105 /** These functions are protected because they should only be 106 * called by a peer port, never directly by any outside object. */ 107 108 /** Called to recive a timing call from the peer port. */ 109 virtual bool recvTiming(Packet *pkt) = 0; 110 111 /** Called to recive a atomic call from the peer port. */ 112 virtual Tick recvAtomic(Packet *pkt) = 0; 113 114 /** Called to recive a functional call from the peer port. */ 115 virtual void recvFunctional(Packet *pkt) = 0; 116 117 /** Called to recieve a status change from the peer port. */ 118 virtual void recvStatusChange(Status status) = 0; 119 120 /** Called by a peer port if the send was unsuccesful, and had to 121 wait. This shouldn't be valid for response paths (IO Devices). 122 so it is set to panic if it isn't already defined. 123 */ 124 virtual Packet *recvRetry() { panic("??"); } 125 126 /** Called by a peer port in order to determine the block size of the 127 device connected to this port. It sometimes doesn't make sense for 128 this function to be called, a DMA interface doesn't really have a 129 block size, so it is defaulted to a panic. 130 */ 131 virtual int deviceBlockSize() { panic("??"); } 132 133 /** The peer port is requesting us to reply with a list of the ranges we 134 are responsible for. 135 @param resp is a list of ranges responded to 136 @param snoop is a list of ranges snooped 137 */ 138 virtual void getDeviceAddressRanges(AddrRangeList &resp, 139 AddrRangeList &snoop) 140 { panic("??"); } 141 142 public: 143 144 /** Function called by associated memory device (cache, memory, iodevice) 145 in order to send a timing request to the port. Simply calls the peer 146 port receive function. 147 @return This function returns if the send was succesful in it's 148 recieve. If it was a failure, then the port will wait for a recvRetry 149 at which point it can issue a successful sendTiming. This is used in 150 case a cache has a higher priority request come in while waiting for 151 the bus to arbitrate. 152 */ 153 bool sendTiming(Packet *pkt) { return peer->recvTiming(pkt); } 154 155 /** Function called by the associated device to send an atomic access, 156 an access in which the data is moved and the state is updated in one 157 cycle, without interleaving with other memory accesses. 158 */ 159 Tick sendAtomic(Packet *pkt) 160 { return peer->recvAtomic(pkt); } 161 162 /** Function called by the associated device to send a functional access, 163 an access in which the data is instantly updated everywhere in the 164 memory system, without affecting the current state of any block or 165 moving the block. 166 */ 167 void sendFunctional(Packet *pkt) 168 { return peer->recvFunctional(pkt); } 169 170 /** Called by the associated device to send a status change to the device 171 connected to the peer interface. 172 */ 173 void sendStatusChange(Status status) {peer->recvStatusChange(status); } 174 175 /** When a timing access doesn't return a success, some time later the 176 Retry will be sent. 177 */ 178 Packet *sendRetry() { return peer->recvRetry(); } 179 180 /** Called by the associated device if it wishes to find out the blocksize 181 of the device on attached to the peer port. 182 */ 183 int peerBlockSize() { return peer->deviceBlockSize(); } 184 185 /** Called by the associated device if it wishes to find out the address 186 ranges connected to the peer ports devices. 187 */ 188 void getPeerAddressRanges(AddrRangeList &resp, AddrRangeList &snoop) 189 { peer->getDeviceAddressRanges(resp, snoop); } 190 191 /** This function is a wrapper around sendFunctional() 192 that breaks a larger, arbitrarily aligned access into 193 appropriate chunks. The default implementation can use 194 getBlockSize() to determine the block size and go from there. 195 */ 196 virtual void readBlob(Addr addr, uint8_t *p, int size); 197 198 /** This function is a wrapper around sendFunctional() 199 that breaks a larger, arbitrarily aligned access into 200 appropriate chunks. The default implementation can use 201 getBlockSize() to determine the block size and go from there. 202 */ 203 virtual void writeBlob(Addr addr, uint8_t *p, int size); 204 205 /** Fill size bytes starting at addr with byte value val. This 206 should not need to be virtual, since it can be implemented in 207 terms of writeBlob(). However, it shouldn't be 208 performance-critical either, so it could be if we wanted to. 209 */ 210 virtual void memsetBlob(Addr addr, uint8_t val, int size); 211 212 private: 213 214 /** Internal helper function for read/writeBlob(). 215 */ 216 void blobHelper(Addr addr, uint8_t *p, int size, Command cmd); 217}; 218 219/** A simple functional port that is only meant for one way communication to 220 * physical memory. It is only meant to be used to load data into memory before 221 * the simulation begins. 222 */ 223 224class FunctionalPort : public Port 225{ 226 public: 227 virtual bool recvTiming(Packet *pkt) { panic("FuncPort is UniDir"); } 228 virtual Tick recvAtomic(Packet *pkt) { panic("FuncPort is UniDir"); } 229 virtual void recvFunctional(Packet *pkt) { panic("FuncPort is UniDir"); } 230 virtual void recvStatusChange(Status status) {} 231 232 template <typename T> 233 inline void write(Addr addr, T d) 234 { 235 writeBlob(addr, (uint8_t*)&d, sizeof(T)); 236 } 237 238 template <typename T> 239 inline T read(Addr addr) 240 { 241 T d; 242 readBlob(addr, (uint8_t*)&d, sizeof(T)); 243 return d; 244 } 245}; 246 247#endif //__MEM_PORT_HH__ 248