port.hh revision 2405 
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/range.hh"
46#include "mem/packet.hh"
47#include "mem/request.hh"
48
49/**
50 * Ports are used to interface memory objects to
51 * each other.  They will always come in pairs, and we refer to the other
52 * port object as the peer.  These are used to make the design more
53 * modular so that a specific interface between every type of objcet doesn't
54 * have to be created.
55 *
56 * Recv accesor functions are being called from the peer interface.
57 * Send accessor functions are being called from the device the port is
58 * associated with, and it will call the peer recv. accessor function.
59 */
60class Port
61{
62  public:
63
64    // mey be better to use subclasses & RTTI?
65    /** Holds the ports status.  Keeps track if it is blocked, or has
66        calculated a range change. */
67    enum Status {
68        Blocked,
69        Unblocked,
70        RangeChange
71    };
72
73  private:
74
75    /** A pointer to the peer port.  Ports always come in pairs, that way they
76        can use a standardized interface to communicate between different
77        memory objects. */
78    Port *peer;
79
80  public:
81
82    /** Function to set the pointer for the peer port.
83        @todo should be called by the configuration stuff (python).
84    */
85    void setPeer(Port *port) { peer = port; }
86
87  protected:
88
89    /** Called to recive a timing call from the peer port. */
90    virtual bool recvTiming(Packet &pkt) = 0;
91
92    /** Called to recive a atomic call from the peer port. */
93    virtual Tick recvAtomic(Packet &pkt) = 0;
94
95    /** Called to recive a functional call from the peer port. */
96    virtual void recvFunctional(Packet &pkt) = 0;
97
98    /** Called to recieve a status change from the peer port. */
99    virtual void recvStatusChange(Status status) = 0;
100
101    /** Called by a peer port if the send was unsuccesful, and had to
102        wait.  This shouldn't be valid for response paths (IO Devices).
103        so it is set to panic if it isn't already defined.
104    */
105    virtual Packet *recvRetry() { panic("??"); }
106
107    /** Called by a peer port in order to determine the block size of the
108        device connected to this port.  It sometimes doesn't make sense for
109        this function to be called, a DMA interface doesn't really have a
110        block size, so it is defaulted to a panic.
111    */
112    virtual int recvBlockSizeQuery() { panic("??"); }
113
114    /** The peer port is requesting us to reply with a list of the ranges we
115        are responsible for.
116        @param owner is an output param that, if set, indicates that the
117        port is the owner of the specified ranges (i.e., slave, default
118        responder, etc.).  If 'owner' is false, the interface is
119        interested in the specified ranges for snooping purposes.  If
120        an object wants to own some ranges and snoop on others, it will
121        need to use two different ports.
122    */
123    virtual void recvAddressRangesQuery(std::list<Range<Addr> > &range_list,
124                                        bool &owner) { panic("??"); }
125
126  public:
127
128    /** Function called by associated memory device (cache, memory, iodevice)
129        in order to send a timing request to the port.  Simply calls the peer
130        port receive function.
131        @return This function returns if the send was succesful in it's
132        recieve. If it was a failure, then the port will wait for a recvRetry
133        at which point it can issue a successful sendTiming.  This is used in
134        case a cache has a higher priority request come in while waiting for
135        the bus to arbitrate.
136    */
137    bool sendTiming(Packet &pkt) { return peer->recvTiming(pkt); }
138
139    /** Function called by the associated device to send an atomic access,
140        an access in which the data is moved and the state is updated in one
141        cycle, without interleaving with other memory accesses.
142    */
143    Tick sendAtomic(Packet &pkt)
144        { return peer->recvAtomic(pkt); }
145
146    /** Function called by the associated device to send a functional access,
147        an access in which the data is instantly updated everywhere in the
148        memory system, without affecting the current state of any block
149        or moving the block.
150    */
151    void sendFunctional(Packet &pkt)
152        { return peer->recvFunctional(pkt); }
153
154    /** Called by the associated device to send a status change to the device
155        connected to the peer interface.
156    */
157    void sendStatusChange(Status status) {peer->recvStatusChange(status); }
158
159    /** When a timing access doesn't return a success, some time later the
160        Retry will be sent.
161    */
162    Packet *sendRetry() { return peer->recvRetry(); }
163
164    /** Called by the associated device if it wishes to find out the blocksize
165        of the device on attached to the peer port.
166    */
167    int sendBlockSizeQuery() { return peer->recvBlockSizeQuery(); }
168
169    /** Called by the associated device if it wishes to find out the address
170        ranges connected to the peer ports devices.
171    */
172    void sendAddressRangesQuery(std::list<Range<Addr> > &range_list,
173                                bool &owner)
174    { peer->recvAddressRangesQuery(range_list, owner); }
175
176    // Do we need similar wrappers for sendAtomic()?  If not, should
177    // we drop the "Functional" from the names?
178
179    /** This function is a wrapper around sendFunctional()
180        that breaks a larger, arbitrarily aligned access into
181        appropriate chunks.  The default implementation can use
182        getBlockSize() to determine the block size and go from there.
183    */
184    void readBlobFunctional(Addr addr, uint8_t *p, int size);
185
186    /** This function is a wrapper around sendFunctional()
187        that breaks a larger, arbitrarily aligned access into
188        appropriate chunks.  The default implementation can use
189        getBlockSize() to determine the block size and go from there.
190    */
191    void writeBlobFunctional(Addr addr, uint8_t *p, int size);
192
193    /** Fill size bytes starting at addr with byte value val.  This
194        should not need to be virtual, since it can be implemented in
195        terms of writeBlobFunctional().  However, it shouldn't be
196        performance-critical either, so it could be if we wanted to.
197        Not even sure if this is actually needed anywhere (there's a
198        prot_memset on the old functional memory that's never used),
199        but Nate claims it is.
200    */
201    void memsetBlobFunctional(Addr addr, uint8_t val, int size);
202
203  private:
204
205    /** Internal helper function for read/writeBlob().
206     */
207    void blobHelper(Addr addr, uint8_t *p, int size, Command cmd);
208};
209
210#endif //__MEM_PORT_HH__
211