1/*
2 * Copyright (c) 2011-2012 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder. You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2002-2005 The Regents of The University of Michigan
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Ron Dreslinski
41 * Andreas Hansson
42 * William Wang
43 */
44
45/**
46 * @file
47 * Port Object Declaration.
48 */
49
50#ifndef __MEM_PORT_HH__
51#define __MEM_PORT_HH__
52
53#include <list>
54
55#include "base/addr_range.hh"
56#include "mem/packet.hh"
57
58/**
59 * This typedef is used to clean up getAddrRanges(). It's declared
60 * outside the Port object since it's also used by some mem objects.
61 * Eventually we should move this typedef to wherever Addr is
62 * defined.
63 */
64
65typedef std::list<AddrRange> AddrRangeList;
66typedef std::list<AddrRange>::iterator AddrRangeIter;
67typedef std::list<AddrRange>::const_iterator AddrRangeConstIter;
68
69class MemObject;
70
71/**
72 * Ports are used to interface memory objects to each other. A port is
73 * either a master or a slave and the connected peer is always of the
74 * opposite role. Each port has a name, an owner, and an identifier.
75 */
76class Port
77{
78
79 private:
80
81 /** Descriptive name (for DPRINTF output) */
82 std::string portName;
83
84 protected:
85
86 /**
87 * A numeric identifier to distinguish ports in a vector, and set
88 * to InvalidPortID in case this port is not part of a vector.
89 */
90 const PortID id;
91
92 /** A reference to the MemObject that owns this port. */
93 MemObject& owner;
94
95 /**
96 * Abstract base class for ports
97 *
98 * @param _name Port name including the owners name
99 * @param _owner The MemObject that is the structural owner of this port
100 * @param _id A port identifier for vector ports
101 */
102 Port(const std::string& _name, MemObject& _owner, PortID _id);
103
104 /**
105 * Virtual destructor due to inheritance.
106 */
107 virtual ~Port();
108
109 public:
110
111 /** Return port name (for DPRINTF). */
112 const std::string name() const { return portName; }
113
114 /** Get the port id. */
115 PortID getId() const { return id; }
116
117};
118
119/** Forward declaration */
120class BaseSlavePort;
121
122/**
123 * A BaseMasterPort is a protocol-agnostic master port, responsible
124 * only for the structural connection to a slave port. The final
125 * master port that inherits from the base class must override the
126 * bind member function for the specific slave port class.
127 */
128class BaseMasterPort : public Port
129{
130
131 protected:
132
133 BaseSlavePort* _baseSlavePort;
134
135 BaseMasterPort(const std::string& name, MemObject* owner,
136 PortID id = InvalidPortID);
137 virtual ~BaseMasterPort();
138
139 public:
140
141 virtual void bind(BaseSlavePort& slave_port) = 0;
142 virtual void unbind() = 0;
143 BaseSlavePort& getSlavePort() const;
144 bool isConnected() const;
145
146};
147
148/**
149 * A BaseSlavePort is a protocol-agnostic slave port, responsible
150 * only for the structural connection to a master port.
151 */
152class BaseSlavePort : public Port
153{
154
155 protected:
156
157 BaseMasterPort* _baseMasterPort;
158
159 BaseSlavePort(const std::string& name, MemObject* owner,
160 PortID id = InvalidPortID);
161 virtual ~BaseSlavePort();
162
163 public:
164
165 BaseMasterPort& getMasterPort() const;
166 bool isConnected() const;
167
168};
169
170/** Forward declaration */
171class SlavePort;
172
173/**
174 * A MasterPort is a specialisation of a BaseMasterPort, which
175 * implements the default protocol for the three different level of
176 * transport functions. In addition to the basic functionality of
177 * sending packets, it also has functions to receive range changes or
178 * determine if the port is snooping or not.
179 */
180class MasterPort : public BaseMasterPort
181{
182
183 friend class SlavePort;
184
185 private:
186
187 SlavePort* _slavePort;
188
189 public:
190
191 MasterPort(const std::string& name, MemObject* owner,
192 PortID id = InvalidPortID);
193 virtual ~MasterPort();
194
195 /**
196 * Bind this master port to a slave port. This also does the
197 * mirror action and binds the slave port to the master port.
198 */
199 void bind(BaseSlavePort& slave_port);
200
201 /**
202 * Unbind this master port and the associated slave port.
203 */
204 void unbind();
205
206 /**
207 * Send an atomic request packet, where the data is moved and the
208 * state is updated in zero time, without interleaving with other
209 * memory accesses.
210 *
211 * @param pkt Packet to send.
212 *
213 * @return Estimated latency of access.
214 */
215 Tick sendAtomic(PacketPtr pkt);
216
217 /**
218 * Send a functional request packet, where the data is instantly
219 * updated everywhere in the memory system, without affecting the
220 * current state of any block or moving the block.
221 *
222 * @param pkt Packet to send.
223 */
224 void sendFunctional(PacketPtr pkt);
225
226 /**
227 * Attempt to send a timing request to the slave port by calling
228 * its corresponding receive function. If the send does not
229 * succeed, as indicated by the return value, then the sender must
230 * wait for a recvRetry at which point it can re-issue a
231 * sendTimingReq.
232 *
233 * @param pkt Packet to send.
234 *
235 * @return If the send was succesful or not.
236 */
237 bool sendTimingReq(PacketPtr pkt);
238
239 /**
240 * Attempt to send a timing snoop response packet to the slave
241 * port by calling its corresponding receive function. If the send
242 * does not succeed, as indicated by the return value, then the
243 * sender must wait for a recvRetry at which point it can re-issue
244 * a sendTimingSnoopResp.
245 *
246 * @param pkt Packet to send.
247 */
248 bool sendTimingSnoopResp(PacketPtr pkt);
249
250 /**
251 * Send a retry to the slave port that previously attempted a
252 * sendTimingResp to this master port and failed.
253 */
254 virtual void sendRetry();
255
256 /**
257 * Determine if this master port is snooping or not. The default
258 * implementation returns false and thus tells the neighbour we
259 * are not snooping. Any master port that wants to receive snoop
260 * requests (e.g. a cache connected to a bus) has to override this
261 * function.
262 *
263 * @return true if the port should be considered a snooper
264 */
265 virtual bool isSnooping() const { return false; }
266
267 /**
268 * Called by a peer port in order to determine the block size of
269 * the owner of this port.
270 */
271 virtual unsigned deviceBlockSize() const { return 0; }
272
273 /** Called by the associated device if it wishes to find out the blocksize
274 of the device on attached to the peer port.
275 */
276 unsigned peerBlockSize() const;
277
278 /**
279 * Get the address ranges of the connected slave port.
280 */
281 AddrRangeList getAddrRanges() const;
282
283 /** Inject a PrintReq for the given address to print the state of
284 * that address throughout the memory system. For debugging.
285 */
286 void printAddr(Addr a);
287
288 protected:
289
290 /**
291 * Receive an atomic snoop request packet from the slave port.
292 */
293 virtual Tick recvAtomicSnoop(PacketPtr pkt)
294 {
295 panic("%s was not expecting an atomic snoop request\n", name());
296 return 0;
297 }
298
299 /**
300 * Receive a functional snoop request packet from the slave port.
301 */
302 virtual void recvFunctionalSnoop(PacketPtr pkt)
303 {
304 panic("%s was not expecting a functional snoop request\n", name());
305 }
306
307 /**
308 * Receive a timing response from the slave port.
309 */
310 virtual bool recvTimingResp(PacketPtr pkt) = 0;
311
312 /**
313 * Receive a timing snoop request from the slave port.
314 */
315 virtual void recvTimingSnoopReq(PacketPtr pkt)
316 {
317 panic("%s was not expecting a timing snoop request\n", name());
318 }
319
320 /**
321 * Called by the slave port if sendTimingReq or
322 * sendTimingSnoopResp was called on this master port (causing
323 * recvTimingReq and recvTimingSnoopResp to be called on the
324 * slave port) and was unsuccesful.
325 */
326 virtual void recvRetry() = 0;
327
328 /**
329 * Called to receive an address range change from the peer slave
330 * port. The default implementation ignores the change and does
331 * nothing. Override this function in a derived class if the owner
332 * needs to be aware of the address ranges, e.g. in an
333 * interconnect component like a bus.
334 */
335 virtual void recvRangeChange() { }
336};
337
338/**
339 * A SlavePort is a specialisation of a port. In addition to the
340 * basic functionality of sending packets to its master peer, it also
341 * has functions specific to a slave, e.g. to send range changes
342 * and get the address ranges that the port responds to.
343 */
344class SlavePort : public BaseSlavePort
345{
346
347 friend class MasterPort;
348
349 private:
350
351 MasterPort* _masterPort;
352
353 public:
354
355 SlavePort(const std::string& name, MemObject* owner,
356 PortID id = InvalidPortID);
357 virtual ~SlavePort();
358
359 /**
360 * Send an atomic snoop request packet, where the data is moved
361 * and the state is updated in zero time, without interleaving
362 * with other memory accesses.
363 *
364 * @param pkt Snoop packet to send.
365 *
366 * @return Estimated latency of access.
367 */
368 Tick sendAtomicSnoop(PacketPtr pkt);
369
370 /**
371 * Send a functional snoop request packet, where the data is
372 * instantly updated everywhere in the memory system, without
373 * affecting the current state of any block or moving the block.
374 *
375 * @param pkt Snoop packet to send.
376 */
377 void sendFunctionalSnoop(PacketPtr pkt);
378
379 /**
380 * Attempt to send a timing response to the master port by calling
381 * its corresponding receive function. If the send does not
382 * succeed, as indicated by the return value, then the sender must
383 * wait for a recvRetry at which point it can re-issue a
384 * sendTimingResp.
385 *
386 * @param pkt Packet to send.
387 *
388 * @return If the send was succesful or not.
389 */
390 bool sendTimingResp(PacketPtr pkt);
391
392 /**
393 * Attempt to send a timing snoop request packet to the master port
394 * by calling its corresponding receive function. Snoop requests
395 * always succeed and hence no return value is needed.
396 *
397 * @param pkt Packet to send.
398 */
399 void sendTimingSnoopReq(PacketPtr pkt);
400
401 /**
402 * Send a retry to the master port that previously attempted a
403 * sendTimingReq or sendTimingSnoopResp to this slave port and
404 * failed.
405 */
406 void sendRetry();
407
408 /**
409 * Called by a peer port in order to determine the block size of
410 * the owner of this port.
411 */
412 virtual unsigned deviceBlockSize() const { return 0; }
413
414 /** Called by the associated device if it wishes to find out the blocksize
415 of the device on attached to the peer port.
416 */
417 unsigned peerBlockSize() const;
418
419 /**
420 * Find out if the peer master port is snooping or not.
421 *
422 * @return true if the peer master port is snooping
423 */
424 bool isSnooping() const { return _masterPort->isSnooping(); }
425
426 /**
427 * Called by the owner to send a range change
428 */
429 void sendRangeChange() const { _masterPort->recvRangeChange(); }
430
431 /**
432 * Get a list of the non-overlapping address ranges the owner is
433 * responsible for. All slave ports must override this function
434 * and return a populated list with at least one item.
435 *
436 * @return a list of ranges responded to
437 */
438 virtual AddrRangeList getAddrRanges() const = 0;
439
440 protected:
441
442 /**
443 * Called by the master port to unbind. Should never be called
444 * directly.
445 */
446 void unbind();
447
448 /**
449 * Called by the master port to bind. Should never be called
450 * directly.
451 */
452 void bind(MasterPort& master_port);
453
454 /**
455 * Receive an atomic request packet from the master port.
456 */
457 virtual Tick recvAtomic(PacketPtr pkt) = 0;
458
459 /**
460 * Receive a functional request packet from the master port.
461 */
462 virtual void recvFunctional(PacketPtr pkt) = 0;
463
464 /**
465 * Receive a timing request from the master port.
466 */
467 virtual bool recvTimingReq(PacketPtr pkt) = 0;
468
469 /**
470 * Receive a timing snoop response from the master port.
471 */
472 virtual bool recvTimingSnoopResp(PacketPtr pkt)
473 {
474 panic("%s was not expecting a timing snoop response\n", name());
475 }
476
477 /**
478 * Called by the master port if sendTimingResp was called on this
479 * slave port (causing recvTimingResp to be called on the master
480 * port) and was unsuccesful.
481 */
482 virtual void recvRetry() = 0;
483
484};
485
486#endif //__MEM_PORT_HH__