port.hh revision 5283 
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#include <inttypes.h>
45
46#include "base/misc.hh"
47#include "base/range.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  private:
77
78    /** Descriptive name (for DPRINTF output) */
79    mutable std::string portName;
80
81    /** A pointer to the peer port.  Ports always come in pairs, that way they
82        can use a standardized interface to communicate between different
83        memory objects. */
84    Port *peer;
85
86    /** A pointer to the MemObject that owns this port. This may not be set. */
87    MemObject *owner;
88
89  public:
90
91    Port();
92
93    /**
94     * Constructor.
95     *
96     * @param _name Port name for DPRINTF output.  Should include name
97     * of memory system object to which the port belongs.
98     * @param _owner Pointer to the MemObject that owns this port.
99     * Will not necessarily be set.
100     */
101    Port(const std::string &_name, MemObject *_owner = NULL);
102
103    /** Return port name (for DPRINTF). */
104    const std::string &name() const { return portName; }
105
106    virtual ~Port() {};
107
108    // mey be better to use subclasses & RTTI?
109    /** Holds the ports status.  Currently just that a range recomputation needs
110     * to be done. */
111    enum Status {
112        RangeChange
113    };
114
115    void setName(const std::string &name)
116    { portName = name; }
117
118    /** Function to set the pointer for the peer port. */
119    virtual void setPeer(Port *port);
120
121    /** Function to get the pointer to the peer port. */
122    Port *getPeer() { return peer; }
123
124    /** Function to set the owner of this port. */
125    void setOwner(MemObject *_owner) { owner = _owner; }
126
127    /** Function to return the owner of this port. */
128    MemObject *getOwner() { return owner; }
129
130    /** Inform the peer port to delete itself and notify it's owner about it's
131     * demise. */
132    void removeConn();
133
134    virtual bool isDefaultPort() { return false; }
135
136  protected:
137
138    /** These functions are protected because they should only be
139     * called by a peer port, never directly by any outside object. */
140
141    /** Called to recive a timing call from the peer port. */
142    virtual bool recvTiming(PacketPtr pkt) = 0;
143
144    /** Called to recive a atomic call from the peer port. */
145    virtual Tick recvAtomic(PacketPtr pkt) = 0;
146
147    /** Called to recive a functional call from the peer port. */
148    virtual void recvFunctional(PacketPtr pkt) = 0;
149
150    /** Called to recieve a status change from the peer port. */
151    virtual void recvStatusChange(Status status) = 0;
152
153    /** Called by a peer port if the send was unsuccesful, and had to
154        wait.  This shouldn't be valid for response paths (IO Devices).
155        so it is set to panic if it isn't already defined.
156    */
157    virtual void recvRetry() { panic("??"); }
158
159    /** Called by a peer port in order to determine the block size of the
160        device connected to this port.  It sometimes doesn't make sense for
161        this function to be called, so it just returns 0. Anytthing that is
162        concerned with the size should just ignore that.
163    */
164    virtual int deviceBlockSize() { return 0; }
165
166    /** The peer port is requesting us to reply with a list of the ranges we
167        are responsible for.
168        @param resp is a list of ranges responded to
169        @param snoop is a list of ranges snooped
170    */
171    virtual void getDeviceAddressRanges(AddrRangeList &resp,
172                                        bool &snoop)
173    { panic("??"); }
174
175  public:
176
177    /** Function called by associated memory device (cache, memory, iodevice)
178        in order to send a timing request to the port.  Simply calls the peer
179        port receive function.
180        @return This function returns if the send was succesful in it's
181        recieve. If it was a failure, then the port will wait for a recvRetry
182        at which point it can possibly issue a successful sendTiming.  This is used in
183        case a cache has a higher priority request come in while waiting for
184        the bus to arbitrate.
185    */
186    bool sendTiming(PacketPtr pkt) { return peer->recvTiming(pkt); }
187
188    /** Function called by the associated device to send an atomic
189     *   access, an access in which the data is moved and the state is
190     *   updated in one cycle, without interleaving with other memory
191     *   accesses.  Returns estimated latency of access.
192     */
193    Tick sendAtomic(PacketPtr pkt)
194        { return peer->recvAtomic(pkt); }
195
196    /** Function called by the associated device to send a functional access,
197        an access in which the data is instantly updated everywhere in the
198        memory system, without affecting the current state of any block or
199        moving the block.
200    */
201    void sendFunctional(PacketPtr pkt)
202        { return peer->recvFunctional(pkt); }
203
204    /** Called by the associated device to send a status change to the device
205        connected to the peer interface.
206    */
207    void sendStatusChange(Status status) {peer->recvStatusChange(status); }
208
209    /** When a timing access doesn't return a success, some time later the
210        Retry will be sent.
211    */
212    void sendRetry() { return peer->recvRetry(); }
213
214    /** Called by the associated device if it wishes to find out the blocksize
215        of the device on attached to the peer port.
216    */
217    int peerBlockSize() { return peer->deviceBlockSize(); }
218
219    /** Called by the associated device if it wishes to find out the address
220        ranges connected to the peer ports devices.
221    */
222    void getPeerAddressRanges(AddrRangeList &resp, bool &snoop)
223    { peer->getDeviceAddressRanges(resp, snoop); }
224
225    /** This function is a wrapper around sendFunctional()
226        that breaks a larger, arbitrarily aligned access into
227        appropriate chunks.  The default implementation can use
228        getBlockSize() to determine the block size and go from there.
229    */
230    virtual void readBlob(Addr addr, uint8_t *p, int size);
231
232    /** This function is a wrapper around sendFunctional()
233        that breaks a larger, arbitrarily aligned access into
234        appropriate chunks.  The default implementation can use
235        getBlockSize() to determine the block size and go from there.
236    */
237    virtual void writeBlob(Addr addr, uint8_t *p, int size);
238
239    /** Fill size bytes starting at addr with byte value val.  This
240        should not need to be virtual, since it can be implemented in
241        terms of writeBlob().  However, it shouldn't be
242        performance-critical either, so it could be if we wanted to.
243    */
244    virtual void memsetBlob(Addr addr, uint8_t val, int size);
245
246  private:
247
248    /** Internal helper function for read/writeBlob().
249     */
250    void blobHelper(Addr addr, uint8_t *p, int size, MemCmd cmd);
251};
252
253/** A simple functional port that is only meant for one way communication to
254 * physical memory. It is only meant to be used to load data into memory before
255 * the simulation begins.
256 */
257
258class FunctionalPort : public Port
259{
260  public:
261    FunctionalPort(const std::string &_name, MemObject *_owner = NULL)
262        : Port(_name, _owner)
263    {}
264
265  protected:
266    virtual bool recvTiming(PacketPtr pkt) { panic("FuncPort is UniDir");
267        M5_DUMMY_RETURN }
268    virtual Tick recvAtomic(PacketPtr pkt) { panic("FuncPort is UniDir");
269        M5_DUMMY_RETURN }
270    virtual void recvFunctional(PacketPtr pkt) { panic("FuncPort is UniDir"); }
271    virtual void recvStatusChange(Status status) {}
272
273  public:
274    /** a write function that also does an endian conversion. */
275    template <typename T>
276    inline void writeHtoG(Addr addr, T d);
277
278    /** a read function that also does an endian conversion. */
279    template <typename T>
280    inline T readGtoH(Addr addr);
281
282    template <typename T>
283    inline void write(Addr addr, T d)
284    {
285        writeBlob(addr, (uint8_t*)&d, sizeof(T));
286    }
287
288    template <typename T>
289    inline T read(Addr addr)
290    {
291        T d;
292        readBlob(addr, (uint8_t*)&d, sizeof(T));
293        return d;
294    }
295};
296
297#endif //__MEM_PORT_HH__
298