1
2/*
3 * Copyright (c) 2006 The Regents of The University of Michigan
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * Authors: Ali Saidi
30 * Steve Reinhardt
31 */
32
33/**
34 * @file
35 * Definition of a simple bus bridge without buffering.
36 */
37
38#include <algorithm>
39
40#include "base/trace.hh"
41#include "mem/bridge.hh"
42#include "sim/builder.hh"
43
44Bridge::BridgePort::BridgePort(const std::string &_name,
45 Bridge *_bridge, BridgePort *_otherPort,
46 int _delay, int _queueLimit,
47 bool fix_partial_write)
48 : Port(_name), bridge(_bridge), otherPort(_otherPort),
49 delay(_delay), fixPartialWrite(fix_partial_write),
| 1
2/*
3 * Copyright (c) 2006 The Regents of The University of Michigan
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are
8 * met: redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer;
10 * redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution;
13 * neither the name of the copyright holders nor the names of its
14 * contributors may be used to endorse or promote products derived from
15 * this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 * Authors: Ali Saidi
30 * Steve Reinhardt
31 */
32
33/**
34 * @file
35 * Definition of a simple bus bridge without buffering.
36 */
37
38#include <algorithm>
39
40#include "base/trace.hh"
41#include "mem/bridge.hh"
42#include "sim/builder.hh"
43
44Bridge::BridgePort::BridgePort(const std::string &_name,
45 Bridge *_bridge, BridgePort *_otherPort,
46 int _delay, int _queueLimit,
47 bool fix_partial_write)
48 : Port(_name), bridge(_bridge), otherPort(_otherPort),
49 delay(_delay), fixPartialWrite(fix_partial_write),
|
50 outstandingResponses(0), queueLimit(_queueLimit), sendEvent(this)
| 50 outstandingResponses(0), queuedRequests(0),
51 queueLimit(_queueLimit), sendEvent(this)
|
51{
52}
53
54Bridge::Bridge(const std::string &n, int qsa, int qsb,
55 Tick _delay, int write_ack, bool fix_partial_write_a,
56 bool fix_partial_write_b)
57 : MemObject(n),
58 portA(n + "-portA", this, &portB, _delay, qsa, fix_partial_write_a),
59 portB(n + "-portB", this, &portA, _delay, qsa, fix_partial_write_b),
60 ackWrites(write_ack)
61{
62 if (ackWrites)
63 panic("No support for acknowledging writes\n");
64}
65
66Port *
67Bridge::getPort(const std::string &if_name, int idx)
68{
69 BridgePort *port;
70
71 if (if_name == "side_a")
72 port = &portA;
73 else if (if_name == "side_b")
74 port = &portB;
75 else
76 return NULL;
77
78 if (port->getPeer() != NULL)
79 panic("bridge side %s already connected to.", if_name);
80 return port;
81}
82
83
84void
85Bridge::init()
86{
87 // Make sure that both sides are connected to.
88 if (portA.getPeer() == NULL || portB.getPeer() == NULL)
89 fatal("Both ports of bus bridge are not connected to a bus.\n");
90
91 if (portA.peerBlockSize() != portB.peerBlockSize())
92 fatal("Busses don't have the same block size... Not supported.\n");
93}
94
| 52{
53}
54
55Bridge::Bridge(const std::string &n, int qsa, int qsb,
56 Tick _delay, int write_ack, bool fix_partial_write_a,
57 bool fix_partial_write_b)
58 : MemObject(n),
59 portA(n + "-portA", this, &portB, _delay, qsa, fix_partial_write_a),
60 portB(n + "-portB", this, &portA, _delay, qsa, fix_partial_write_b),
61 ackWrites(write_ack)
62{
63 if (ackWrites)
64 panic("No support for acknowledging writes\n");
65}
66
67Port *
68Bridge::getPort(const std::string &if_name, int idx)
69{
70 BridgePort *port;
71
72 if (if_name == "side_a")
73 port = &portA;
74 else if (if_name == "side_b")
75 port = &portB;
76 else
77 return NULL;
78
79 if (port->getPeer() != NULL)
80 panic("bridge side %s already connected to.", if_name);
81 return port;
82}
83
84
85void
86Bridge::init()
87{
88 // Make sure that both sides are connected to.
89 if (portA.getPeer() == NULL || portB.getPeer() == NULL)
90 fatal("Both ports of bus bridge are not connected to a bus.\n");
91
92 if (portA.peerBlockSize() != portB.peerBlockSize())
93 fatal("Busses don't have the same block size... Not supported.\n");
94}
95
|
| 96bool
97Bridge::BridgePort::queueFull()
98{
99 // use >= here because sendQueue could get larger because of
100 // nacks getting inserted
101 return queuedRequests + outstandingResponses >= queueLimit;
102}
|
95
96/** Function called by the port when the bus is receiving a Timing
97 * transaction.*/
98bool
99Bridge::BridgePort::recvTiming(PacketPtr pkt)
100{
| 103
104/** Function called by the port when the bus is receiving a Timing
105 * transaction.*/
106bool
107Bridge::BridgePort::recvTiming(PacketPtr pkt)
108{
|
101 if (pkt->flags & SNOOP_COMMIT) {
102 DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
| 109 if (!(pkt->flags & SNOOP_COMMIT))
110 return true;
111
112
113 DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
|
103 pkt->getSrc(), pkt->getDest(), pkt->getAddr());
104
| 114 pkt->getSrc(), pkt->getDest(), pkt->getAddr());
115
|
105 return otherPort->queueForSendTiming(pkt);
| 116 if (pkt->isRequest() && otherPort->queueFull()) {
117 DPRINTF(BusBridge, "Remote queue full, nacking\n");
118 nackRequest(pkt);
119 return true;
|
106 }
| 120 }
|
107 else {
108 // Else it's just a snoop, properly return if we are blocking
109 return !queueFull();
| 121
122 if (pkt->needsResponse() && pkt->result != Packet::Nacked)
123 if (queueFull()) {
124 DPRINTF(BusBridge, "Local queue full, no space for response, nacking\n");
125 DPRINTF(BusBridge, "queue size: %d outreq: %d outstanding resp: %d\n",
126 sendQueue.size(), queuedRequests, outstandingResponses);
127 nackRequest(pkt);
128 return true;
129 } else {
130 DPRINTF(BusBridge, "Request Needs response, reserving space\n");
131 ++outstandingResponses;
132 }
133
134 otherPort->queueForSendTiming(pkt);
135
136 return true;
137}
138
139void
140Bridge::BridgePort::nackRequest(PacketPtr pkt)
141{
142 // Nack the packet
143 pkt->result = Packet::Nacked;
144 pkt->setDest(pkt->getSrc());
145
146 //put it on the list to send
147 Tick readyTime = curTick + delay;
148 PacketBuffer *buf = new PacketBuffer(pkt, readyTime, true);
149 if (sendQueue.empty()) {
150 sendEvent.schedule(readyTime);
|
110 }
| 151 }
|
| 152 sendQueue.push_back(buf);
|
111}
112
113
| 153}
154
155
|
114bool
| 156void
|
115Bridge::BridgePort::queueForSendTiming(PacketPtr pkt)
116{
| 157Bridge::BridgePort::queueForSendTiming(PacketPtr pkt)
158{
|
117 if (queueFull()) {
118 DPRINTF(BusBridge, "Queue full, returning false\n");
119 return false;
120 }
121
122 if (pkt->isResponse()) {
| 159 if (pkt->isResponse() || pkt->result == Packet::Nacked) {
|
123 // This is a response for a request we forwarded earlier. The
124 // corresponding PacketBuffer should be stored in the packet's
125 // senderState field.
126 PacketBuffer *buf = dynamic_cast<PacketBuffer*>(pkt->senderState);
127 assert(buf != NULL);
128 // set up new packet dest & senderState based on values saved
129 // from original request
130 buf->fixResponse(pkt);
| 160 // This is a response for a request we forwarded earlier. The
161 // corresponding PacketBuffer should be stored in the packet's
162 // senderState field.
163 PacketBuffer *buf = dynamic_cast<PacketBuffer*>(pkt->senderState);
164 assert(buf != NULL);
165 // set up new packet dest & senderState based on values saved
166 // from original request
167 buf->fixResponse(pkt);
|
| 168
169 // Check if this packet was expecting a response (this is either it or
170 // its a nacked packet and we won't be seeing that response)
171 if (buf->expectResponse)
172 --outstandingResponses;
173
174
|
131 DPRINTF(BusBridge, "restoring sender state: %#X, from packet buffer: %#X\n",
132 pkt->senderState, buf);
133 DPRINTF(BusBridge, " is response, new dest %d\n", pkt->getDest());
134 delete buf;
135 }
136
137 Tick readyTime = curTick + delay;
138 PacketBuffer *buf = new PacketBuffer(pkt, readyTime);
139 DPRINTF(BusBridge, "old sender state: %#X, new sender state: %#X\n",
140 buf->origSenderState, buf);
141
142 // If we're about to put this packet at the head of the queue, we
143 // need to schedule an event to do the transmit. Otherwise there
144 // should already be an event scheduled for sending the head
145 // packet.
146 if (sendQueue.empty()) {
147 sendEvent.schedule(readyTime);
148 }
| 175 DPRINTF(BusBridge, "restoring sender state: %#X, from packet buffer: %#X\n",
176 pkt->senderState, buf);
177 DPRINTF(BusBridge, " is response, new dest %d\n", pkt->getDest());
178 delete buf;
179 }
180
181 Tick readyTime = curTick + delay;
182 PacketBuffer *buf = new PacketBuffer(pkt, readyTime);
183 DPRINTF(BusBridge, "old sender state: %#X, new sender state: %#X\n",
184 buf->origSenderState, buf);
185
186 // If we're about to put this packet at the head of the queue, we
187 // need to schedule an event to do the transmit. Otherwise there
188 // should already be an event scheduled for sending the head
189 // packet.
190 if (sendQueue.empty()) {
191 sendEvent.schedule(readyTime);
192 }
|
149
| 193 ++queuedRequests;
|
150 sendQueue.push_back(buf);
| 194 sendQueue.push_back(buf);
|
151
152 return true;
| |
153}
154
155void
156Bridge::BridgePort::trySend()
157{
158 assert(!sendQueue.empty());
159
160 bool was_full = queueFull();
161 int pbs = peerBlockSize();
162
163 PacketBuffer *buf = sendQueue.front();
164
165 assert(buf->ready <= curTick);
166
167 PacketPtr pkt = buf->pkt;
168
169 pkt->flags &= ~SNOOP_COMMIT; //CLear it if it was set
170
171 if (pkt->cmd == MemCmd::WriteInvalidateReq && fixPartialWrite &&
| 195}
196
197void
198Bridge::BridgePort::trySend()
199{
200 assert(!sendQueue.empty());
201
202 bool was_full = queueFull();
203 int pbs = peerBlockSize();
204
205 PacketBuffer *buf = sendQueue.front();
206
207 assert(buf->ready <= curTick);
208
209 PacketPtr pkt = buf->pkt;
210
211 pkt->flags &= ~SNOOP_COMMIT; //CLear it if it was set
212
213 if (pkt->cmd == MemCmd::WriteInvalidateReq && fixPartialWrite &&
|
172 pkt->getOffset(pbs) && pkt->getSize() != pbs) {
| 214 pkt->result != Packet::Nacked && pkt->getOffset(pbs) &&
215 pkt->getSize() != pbs) {
|
173 buf->partialWriteFix(this);
174 pkt = buf->pkt;
175 }
176
177 DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n",
178 buf->origSrc, pkt->getDest(), pkt->getAddr());
179
180
181 if (sendTiming(pkt)) {
182 // send successful
183 sendQueue.pop_front();
184 buf->pkt = NULL; // we no longer own packet, so it's not safe to look at it
185
186 if (buf->expectResponse) {
| 216 buf->partialWriteFix(this);
217 pkt = buf->pkt;
218 }
219
220 DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n",
221 buf->origSrc, pkt->getDest(), pkt->getAddr());
222
223
224 if (sendTiming(pkt)) {
225 // send successful
226 sendQueue.pop_front();
227 buf->pkt = NULL; // we no longer own packet, so it's not safe to look at it
228
229 if (buf->expectResponse) {
|
187 // Must wait for response. We just need to count outstanding
188 // responses (in case we want to cap them); PacketBuffer
189 // pointer will be recovered on response.
190 ++outstandingResponses;
| 230 // Must wait for response
|
191 DPRINTF(BusBridge, " successful: awaiting response (%d)\n",
192 outstandingResponses);
193 } else {
194 // no response expected... deallocate packet buffer now.
195 DPRINTF(BusBridge, " successful: no response expected\n");
196 delete buf;
197 }
198
| 231 DPRINTF(BusBridge, " successful: awaiting response (%d)\n",
232 outstandingResponses);
233 } else {
234 // no response expected... deallocate packet buffer now.
235 DPRINTF(BusBridge, " successful: no response expected\n");
236 delete buf;
237 }
238
|
| 239 if (!buf->nacked)
240 --queuedRequests;
241
|
199 // If there are more packets to send, schedule event to try again.
200 if (!sendQueue.empty()) {
201 buf = sendQueue.front();
| 242 // If there are more packets to send, schedule event to try again.
243 if (!sendQueue.empty()) {
244 buf = sendQueue.front();
|
| 245 DPRINTF(BusBridge, "Scheduling next send\n");
|
202 sendEvent.schedule(std::max(buf->ready, curTick + 1));
203 }
204 // Let things start sending again
| 246 sendEvent.schedule(std::max(buf->ready, curTick + 1));
247 }
248 // Let things start sending again
|
205 if (was_full) {
| 249 if (was_full && !queueFull()) {
|
206 DPRINTF(BusBridge, "Queue was full, sending retry\n");
207 otherPort->sendRetry();
208 }
209
210 } else {
211 DPRINTF(BusBridge, " unsuccessful\n");
212 buf->undoPartialWriteFix();
213 }
| 250 DPRINTF(BusBridge, "Queue was full, sending retry\n");
251 otherPort->sendRetry();
252 }
253
254 } else {
255 DPRINTF(BusBridge, " unsuccessful\n");
256 buf->undoPartialWriteFix();
257 }
|
| 258 DPRINTF(BusBridge, "trySend: queue size: %d outreq: %d outstanding resp: %d\n",
259 sendQueue.size(), queuedRequests, outstandingResponses);
|
214}
215
216
217void
218Bridge::BridgePort::recvRetry()
219{
220 trySend();
221}
222
223/** Function called by the port when the bus is receiving a Atomic
224 * transaction.*/
225Tick
226Bridge::BridgePort::recvAtomic(PacketPtr pkt)
227{
228 return otherPort->sendAtomic(pkt) + delay;
229}
230
231/** Function called by the port when the bus is receiving a Functional
232 * transaction.*/
233void
234Bridge::BridgePort::recvFunctional(PacketPtr pkt)
235{
236 std::list<PacketBuffer*>::iterator i;
237 bool pktContinue = true;
238
239 for (i = sendQueue.begin(); i != sendQueue.end(); ++i) {
240 if (pkt->intersect((*i)->pkt)) {
241 pktContinue &= fixPacket(pkt, (*i)->pkt);
242 }
243 }
244
245 if (pktContinue) {
246 otherPort->sendFunctional(pkt);
247 }
248}
249
250/** Function called by the port when the bus is receiving a status change.*/
251void
252Bridge::BridgePort::recvStatusChange(Port::Status status)
253{
254 otherPort->sendStatusChange(status);
255}
256
257void
258Bridge::BridgePort::getDeviceAddressRanges(AddrRangeList &resp,
259 AddrRangeList &snoop)
260{
261 otherPort->getPeerAddressRanges(resp, snoop);
262}
263
264BEGIN_DECLARE_SIM_OBJECT_PARAMS(Bridge)
265
266 Param<int> queue_size_a;
267 Param<int> queue_size_b;
268 Param<Tick> delay;
269 Param<bool> write_ack;
270 Param<bool> fix_partial_write_a;
271 Param<bool> fix_partial_write_b;
272
273END_DECLARE_SIM_OBJECT_PARAMS(Bridge)
274
275BEGIN_INIT_SIM_OBJECT_PARAMS(Bridge)
276
277 INIT_PARAM(queue_size_a, "The size of the queue for data coming into side a"),
278 INIT_PARAM(queue_size_b, "The size of the queue for data coming into side b"),
279 INIT_PARAM(delay, "The miminum delay to cross this bridge"),
280 INIT_PARAM(write_ack, "Acknowledge any writes that are received."),
281 INIT_PARAM(fix_partial_write_a, "Fixup any partial block writes that are received"),
282 INIT_PARAM(fix_partial_write_b, "Fixup any partial block writes that are received")
283
284END_INIT_SIM_OBJECT_PARAMS(Bridge)
285
286CREATE_SIM_OBJECT(Bridge)
287{
288 return new Bridge(getInstanceName(), queue_size_a, queue_size_b, delay,
289 write_ack, fix_partial_write_a, fix_partial_write_b);
290}
291
292REGISTER_SIM_OBJECT("Bridge", Bridge)
| 260}
261
262
263void
264Bridge::BridgePort::recvRetry()
265{
266 trySend();
267}
268
269/** Function called by the port when the bus is receiving a Atomic
270 * transaction.*/
271Tick
272Bridge::BridgePort::recvAtomic(PacketPtr pkt)
273{
274 return otherPort->sendAtomic(pkt) + delay;
275}
276
277/** Function called by the port when the bus is receiving a Functional
278 * transaction.*/
279void
280Bridge::BridgePort::recvFunctional(PacketPtr pkt)
281{
282 std::list<PacketBuffer*>::iterator i;
283 bool pktContinue = true;
284
285 for (i = sendQueue.begin(); i != sendQueue.end(); ++i) {
286 if (pkt->intersect((*i)->pkt)) {
287 pktContinue &= fixPacket(pkt, (*i)->pkt);
288 }
289 }
290
291 if (pktContinue) {
292 otherPort->sendFunctional(pkt);
293 }
294}
295
296/** Function called by the port when the bus is receiving a status change.*/
297void
298Bridge::BridgePort::recvStatusChange(Port::Status status)
299{
300 otherPort->sendStatusChange(status);
301}
302
303void
304Bridge::BridgePort::getDeviceAddressRanges(AddrRangeList &resp,
305 AddrRangeList &snoop)
306{
307 otherPort->getPeerAddressRanges(resp, snoop);
308}
309
310BEGIN_DECLARE_SIM_OBJECT_PARAMS(Bridge)
311
312 Param<int> queue_size_a;
313 Param<int> queue_size_b;
314 Param<Tick> delay;
315 Param<bool> write_ack;
316 Param<bool> fix_partial_write_a;
317 Param<bool> fix_partial_write_b;
318
319END_DECLARE_SIM_OBJECT_PARAMS(Bridge)
320
321BEGIN_INIT_SIM_OBJECT_PARAMS(Bridge)
322
323 INIT_PARAM(queue_size_a, "The size of the queue for data coming into side a"),
324 INIT_PARAM(queue_size_b, "The size of the queue for data coming into side b"),
325 INIT_PARAM(delay, "The miminum delay to cross this bridge"),
326 INIT_PARAM(write_ack, "Acknowledge any writes that are received."),
327 INIT_PARAM(fix_partial_write_a, "Fixup any partial block writes that are received"),
328 INIT_PARAM(fix_partial_write_b, "Fixup any partial block writes that are received")
329
330END_INIT_SIM_OBJECT_PARAMS(Bridge)
331
332CREATE_SIM_OBJECT(Bridge)
333{
334 return new Bridge(getInstanceName(), queue_size_a, queue_size_b, delay,
335 write_ack, fix_partial_write_a, fix_partial_write_b);
336}
337
338REGISTER_SIM_OBJECT("Bridge", Bridge)
|
| 339
|
| |