port.hh revision 8708 
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 * Authors: Ron Dreslinski
29 */
30
31/**
32 * @file
33 * Port Object Declaration. Ports are used to interface memory objects to
34 * each other.  They will always come in pairs, and we refer to the other
35 * port object as the peer.  These are used to make the design more
36 * modular so that a specific interface between every type of objcet doesn't
37 * have to be created.
38 */
39
40#ifndef __MEM_PORT_HH__
41#define __MEM_PORT_HH__
42
43#include <list>
44
45#include "base/misc.hh"
46#include "base/range.hh"
47#include "base/types.hh"
48#include "mem/packet.hh"
49#include "mem/request.hh"
50
51/** This typedef is used to clean up the parameter list of
52 * getDeviceAddressRanges() and getPeerAddressRanges().  It's declared
53 * outside the Port object since it's also used by some mem objects.
54 * Eventually we should move this typedef to wherever Addr is
55 * defined.
56 */
57
58typedef std::list<Range<Addr> > AddrRangeList;
59typedef std::list<Range<Addr> >::iterator AddrRangeIter;
60
61class MemObject;
62
63/**
64 * Ports are used to interface memory objects to
65 * each other.  They will always come in pairs, and we refer to the other
66 * port object as the peer.  These are used to make the design more
67 * modular so that a specific interface between every type of objcet doesn't
68 * have to be created.
69 *
70 * Recv accesor functions are being called from the peer interface.
71 * Send accessor functions are being called from the device the port is
72 * associated with, and it will call the peer recv. accessor function.
73 */
74class Port
75{
76  protected:
77    /** Descriptive name (for DPRINTF output) */
78    mutable std::string portName;
79
80    /** A pointer to the peer port.  Ports always come in pairs, that way they
81        can use a standardized interface to communicate between different
82        memory objects. */
83    Port *peer;
84
85    /** A pointer to the MemObject that owns this port. This may not be set. */
86    MemObject *owner;
87
88  public:
89    /**
90     * Constructor.
91     *
92     * @param _name Port name for DPRINTF output.  Should include name
93     * of memory system object to which the port belongs.
94     * @param _owner Pointer to the MemObject that owns this port.
95     * Will not necessarily be set.
96     */
97    Port(const std::string &_name, MemObject *_owner);
98
99    /** Return port name (for DPRINTF). */
100    const std::string &name() const { return portName; }
101
102    virtual ~Port();
103
104    // mey be better to use subclasses & RTTI?
105    /** Holds the ports status.  Currently just that a range recomputation needs
106     * to be done. */
107    enum Status {
108        RangeChange
109    };
110
111    void setName(const std::string &name)
112    { portName = name; }
113
114    /** Function to set the pointer for the peer port. */
115    virtual void setPeer(Port *port);
116
117    /** Function to get the pointer to the peer port. */
118    Port *getPeer() { return peer; }
119
120    /** Function to set the owner of this port. */
121    void setOwner(MemObject *_owner);
122
123    /** Function to return the owner of this port. */
124    MemObject *getOwner() { return owner; }
125
126    /** Inform the peer port to delete itself and notify it's owner about it's
127     * demise. */
128    void removeConn();
129
130    virtual bool isDefaultPort() const { return false; }
131
132    bool isConnected() { return peer && !peer->isDefaultPort(); }
133
134  protected:
135
136    /** These functions are protected because they should only be
137     * called by a peer port, never directly by any outside object. */
138
139    /** Called to recive a timing call from the peer port. */
140    virtual bool recvTiming(PacketPtr pkt) = 0;
141
142    /** Called to recive a atomic call from the peer port. */
143    virtual Tick recvAtomic(PacketPtr pkt) = 0;
144
145    /** Called to recive a functional call from the peer port. */
146    virtual void recvFunctional(PacketPtr pkt) = 0;
147
148    /** Called to recieve a status change from the peer port. */
149    virtual void recvStatusChange(Status status) = 0;
150
151    /** Called by a peer port if the send was unsuccesful, and had to
152        wait.  This shouldn't be valid for response paths (IO Devices).
153        so it is set to panic if it isn't already defined.
154    */
155    virtual void recvRetry() { panic("??"); }
156
157    /** Called by a peer port in order to determine the block size of the
158        device connected to this port.  It sometimes doesn't make sense for
159        this function to be called, so it just returns 0. Anytthing that is
160        concerned with the size should just ignore that.
161    */
162    virtual unsigned deviceBlockSize() const { return 0; }
163
164    /** The peer port is requesting us to reply with a list of the ranges we
165        are responsible for.
166        @param resp is a list of ranges responded to
167        @param snoop is a list of ranges snooped
168    */
169    virtual void getDeviceAddressRanges(AddrRangeList &resp,
170                                        bool &snoop)
171    { panic("??"); }
172
173  public:
174
175    /** Function called by associated memory device (cache, memory, iodevice)
176        in order to send a timing request to the port.  Simply calls the peer
177        port receive function.
178        @return This function returns if the send was succesful in it's
179        recieve. If it was a failure, then the port will wait for a recvRetry
180        at which point it can possibly issue a successful sendTiming.  This is used in
181        case a cache has a higher priority request come in while waiting for
182        the bus to arbitrate.
183    */
184    bool sendTiming(PacketPtr pkt) { return peer->recvTiming(pkt); }
185
186    /** Function called by the associated device to send an atomic
187     *   access, an access in which the data is moved and the state is
188     *   updated in one cycle, without interleaving with other memory
189     *   accesses.  Returns estimated latency of access.
190     */
191    Tick sendAtomic(PacketPtr pkt)
192        { return peer->recvAtomic(pkt); }
193
194    /** Function called by the associated device to send a functional access,
195        an access in which the data is instantly updated everywhere in the
196        memory system, without affecting the current state of any block or
197        moving the block.
198    */
199    void sendFunctional(PacketPtr pkt)
200        { return peer->recvFunctional(pkt); }
201
202    /** Called by the associated device to send a status change to the device
203        connected to the peer interface.
204    */
205    void sendStatusChange(Status status) {peer->recvStatusChange(status); }
206
207    /** When a timing access doesn't return a success, some time later the
208        Retry will be sent.
209    */
210    void sendRetry() { return peer->recvRetry(); }
211
212    /** Called by the associated device if it wishes to find out the blocksize
213        of the device on attached to the peer port.
214    */
215    unsigned peerBlockSize() const { return peer->deviceBlockSize(); }
216
217    /** Called by the associated device if it wishes to find out the address
218        ranges connected to the peer ports devices.
219    */
220    void getPeerAddressRanges(AddrRangeList &resp, bool &snoop)
221    { peer->getDeviceAddressRanges(resp, snoop); }
222
223    /** This function is a wrapper around sendFunctional()
224        that breaks a larger, arbitrarily aligned access into
225        appropriate chunks.  The default implementation can use
226        getBlockSize() to determine the block size and go from there.
227    */
228    virtual void readBlob(Addr addr, uint8_t *p, int size);
229
230    /** This function is a wrapper around sendFunctional()
231        that breaks a larger, arbitrarily aligned access into
232        appropriate chunks.  The default implementation can use
233        getBlockSize() to determine the block size and go from there.
234    */
235    virtual void writeBlob(Addr addr, uint8_t *p, int size);
236
237    /** Fill size bytes starting at addr with byte value val.  This
238        should not need to be virtual, since it can be implemented in
239        terms of writeBlob().  However, it shouldn't be
240        performance-critical either, so it could be if we wanted to.
241    */
242    virtual void memsetBlob(Addr addr, uint8_t val, int size);
243
244    /** Inject a PrintReq for the given address to print the state of
245     * that address throughout the memory system.  For debugging.
246     */
247    void printAddr(Addr a);
248
249  private:
250
251    /** Internal helper function for read/writeBlob().
252     */
253    void blobHelper(Addr addr, uint8_t *p, int size, MemCmd cmd);
254};
255
256#endif //__MEM_PORT_HH__
257