port.hh revision 2439
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 <string> 42#include <list> 43#include <inttypes.h> 44 45#include "base/misc.hh" 46#include "base/range.hh" 47#include "mem/packet.hh" 48#include "mem/request.hh" 49 50/** This typedef is used to clean up the parameter list of 51 * getDeviceAddressRanges() and getPeerAddressRanges(). It's declared 52 * outside the Port object since it's also used by some mem objects. 53 * Eventually we should move this typedef to wherever Addr is 54 * defined. 55 */ 56 57typedef std::list<Range<Addr> > AddrRangeList; 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 // mey be better to use subclasses & RTTI? 75 /** Holds the ports status. Keeps track if it is blocked, or has 76 calculated a range change. */ 77 enum Status { 78 Blocked, 79 Unblocked, 80 RangeChange 81 }; 82 83 private: 84 85 /** A pointer to the peer port. Ports always come in pairs, that way they 86 can use a standardized interface to communicate between different 87 memory objects. */ 88 Port *peer; 89 90 public: 91 92 /** Function to set the pointer for the peer port. 93 @todo should be called by the configuration stuff (python). 94 */ 95 void setPeer(Port *port) { peer = port; } 96 97 /** Function to set the pointer for the peer port. 98 @todo should be called by the configuration stuff (python). 99 */ 100 Port *getPeer() { return peer; } 101 102 protected: 103 104 /** These functions are protected because they should only be 105 * called by a peer port, never directly by any outside object. */ 106 107 /** Called to recive a timing call from the peer port. */ 108 virtual bool recvTiming(Packet &pkt) = 0; 109 110 /** Called to recive a atomic call from the peer port. */ 111 virtual Tick recvAtomic(Packet &pkt) = 0; 112 113 /** Called to recive a functional call from the peer port. */ 114 virtual void recvFunctional(Packet &pkt) = 0; 115 116 /** Called to recieve a status change from the peer port. */ 117 virtual void recvStatusChange(Status status) = 0; 118 119 /** Called by a peer port if the send was unsuccesful, and had to 120 wait. This shouldn't be valid for response paths (IO Devices). 121 so it is set to panic if it isn't already defined. 122 */ 123 virtual Packet *recvRetry() { panic("??"); } 124 125 /** Called by a peer port in order to determine the block size of the 126 device connected to this port. It sometimes doesn't make sense for 127 this function to be called, a DMA interface doesn't really have a 128 block size, so it is defaulted to a panic. 129 */ 130 virtual int deviceBlockSize() { panic("??"); } 131 132 /** The peer port is requesting us to reply with a list of the ranges we 133 are responsible for. 134 @param owner is an output param that, if set, indicates that the 135 port is the owner of the specified ranges (i.e., slave, default 136 responder, etc.). If 'owner' is false, the interface is 137 interested in the specified ranges for snooping purposes. If 138 an object wants to own some ranges and snoop on others, it will 139 need to use two different ports. 140 */ 141 virtual void getDeviceAddressRanges(AddrRangeList &range_list, 142 bool &owner) 143 { panic("??"); } 144 145 public: 146 147 /** Function called by associated memory device (cache, memory, iodevice) 148 in order to send a timing request to the port. Simply calls the peer 149 port receive function. 150 @return This function returns if the send was succesful in it's 151 recieve. If it was a failure, then the port will wait for a recvRetry 152 at which point it can issue a successful sendTiming. This is used in 153 case a cache has a higher priority request come in while waiting for 154 the bus to arbitrate. 155 */ 156 bool sendTiming(Packet &pkt) { return peer->recvTiming(pkt); } 157 158 /** Function called by the associated device to send an atomic access, 159 an access in which the data is moved and the state is updated in one 160 cycle, without interleaving with other memory accesses. 161 */ 162 Tick sendAtomic(Packet &pkt) 163 { return peer->recvAtomic(pkt); } 164 165 /** Function called by the associated device to send a functional access, 166 an access in which the data is instantly updated everywhere in the 167 memory system, without affecting the current state of any block 168 or moving the block. 169 */ 170 void sendFunctional(Packet &pkt) 171 { return peer->recvFunctional(pkt); } 172 173 /** Called by the associated device to send a status change to the device 174 connected to the peer interface. 175 */ 176 void sendStatusChange(Status status) {peer->recvStatusChange(status); } 177 178 /** When a timing access doesn't return a success, some time later the 179 Retry will be sent. 180 */ 181 Packet *sendRetry() { return peer->recvRetry(); } 182 183 /** Called by the associated device if it wishes to find out the blocksize 184 of the device on attached to the peer port. 185 */ 186 int peerBlockSize() { return peer->deviceBlockSize(); } 187 188 /** Called by the associated device if it wishes to find out the address 189 ranges connected to the peer ports devices. 190 */ 191 void getPeerAddressRanges(AddrRangeList &range_list, bool &owner) 192 { peer->getDeviceAddressRanges(range_list, owner); } 193 194 // Do we need similar wrappers for sendAtomic()? If not, should 195 // we drop the "Functional" from the names? 196 197 /** This function is a wrapper around sendFunctional() 198 that breaks a larger, arbitrarily aligned access into 199 appropriate chunks. The default implementation can use 200 getBlockSize() to determine the block size and go from there. 201 */ 202 void readBlobFunctional(Addr addr, uint8_t *p, int size); 203 204 /** This function is a wrapper around sendFunctional() 205 that breaks a larger, arbitrarily aligned access into 206 appropriate chunks. The default implementation can use 207 getBlockSize() to determine the block size and go from there. 208 */ 209 void writeBlobFunctional(Addr addr, uint8_t *p, int size); 210 211 /** Fill size bytes starting at addr with byte value val. This 212 should not need to be virtual, since it can be implemented in 213 terms of writeBlobFunctional(). However, it shouldn't be 214 performance-critical either, so it could be if we wanted to. 215 Not even sure if this is actually needed anywhere (there's a 216 prot_memset on the old functional memory that's never used), 217 but Nate claims it is. 218 */ 219 void memsetBlobFunctional(Addr addr, uint8_t val, int size); 220 221 private: 222 223 /** Internal helper function for read/writeBlob(). 224 */ 225 void blobHelper(Addr addr, uint8_t *p, int size, Command cmd); 226}; 227 228#endif //__MEM_PORT_HH__ 229