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 Definition of a simple bus bridge without buffering.
35 */
36
37#include <algorithm>
38
39#include "base/trace.hh"
40#include "mem/bridge.hh"
41#include "sim/builder.hh"
42
43Bridge::BridgePort::BridgePort(const std::string &_name,
44 Bridge *_bridge, BridgePort *_otherPort,
45 int _delay, int _queueLimit)
46 : Port(_name), bridge(_bridge), otherPort(_otherPort),
47 delay(_delay), outstandingResponses(0),
48 queueLimit(_queueLimit), sendEvent(this)
49{
50}
51
52Bridge::Bridge(const std::string &n, int qsa, int qsb,
53 Tick _delay, int write_ack)
54 : MemObject(n),
55 portA(n + "-portA", this, &portB, _delay, qsa),
56 portB(n + "-portB", this, &portA, _delay, qsa),
57 ackWrites(write_ack)
58{
59}
60
61Port *
| 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 Definition of a simple bus bridge without buffering.
35 */
36
37#include <algorithm>
38
39#include "base/trace.hh"
40#include "mem/bridge.hh"
41#include "sim/builder.hh"
42
43Bridge::BridgePort::BridgePort(const std::string &_name,
44 Bridge *_bridge, BridgePort *_otherPort,
45 int _delay, int _queueLimit)
46 : Port(_name), bridge(_bridge), otherPort(_otherPort),
47 delay(_delay), outstandingResponses(0),
48 queueLimit(_queueLimit), sendEvent(this)
49{
50}
51
52Bridge::Bridge(const std::string &n, int qsa, int qsb,
53 Tick _delay, int write_ack)
54 : MemObject(n),
55 portA(n + "-portA", this, &portB, _delay, qsa),
56 portB(n + "-portB", this, &portA, _delay, qsa),
57 ackWrites(write_ack)
58{
59}
60
61Port *
|
62Bridge::getPort(const std::string &if_name)
| 62Bridge::getPort(const std::string &if_name, int idx)
|
63{
64 BridgePort *port;
65
66 if (if_name == "side_a")
67 port = &portA;
68 else if (if_name == "side_b")
69 port = &portB;
70 else
71 return NULL;
72
73 if (port->getPeer() != NULL)
74 panic("bridge side %s already connected to.", if_name);
75 return port;
76}
77
78
79void
80Bridge::init()
81{
82 // Make sure that both sides are connected to.
83 if (portA.getPeer() == NULL || portB.getPeer() == NULL)
84 panic("Both ports of bus bridge are not connected to a bus.\n");
85}
86
87
88/** Function called by the port when the bus is receiving a Timing
89 * transaction.*/
90bool
91Bridge::BridgePort::recvTiming(Packet *pkt)
92{
93 DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
94 pkt->getSrc(), pkt->getDest(), pkt->getAddr());
95
96 return otherPort->queueForSendTiming(pkt);
97}
98
99
100bool
101Bridge::BridgePort::queueForSendTiming(Packet *pkt)
102{
103 if (queueFull())
104 return false;
105
106 if (pkt->isResponse()) {
107 // This is a response for a request we forwarded earlier. The
108 // corresponding PacketBuffer should be stored in the packet's
109 // senderState field.
110 PacketBuffer *buf = dynamic_cast<PacketBuffer*>(pkt->senderState);
111 assert(buf != NULL);
112 // set up new packet dest & senderState based on values saved
113 // from original request
114 buf->fixResponse(pkt);
115 DPRINTF(BusBridge, "restoring sender state: %#X, from packet buffer: %#X\n",
116 pkt->senderState, buf);
117 DPRINTF(BusBridge, " is response, new dest %d\n", pkt->getDest());
118 delete buf;
119 }
120
121 Tick readyTime = curTick + delay;
122 PacketBuffer *buf = new PacketBuffer(pkt, readyTime);
123 DPRINTF(BusBridge, "old sender state: %#X, new sender state: %#X\n",
124 buf->origSenderState, buf);
125
126 // If we're about to put this packet at the head of the queue, we
127 // need to schedule an event to do the transmit. Otherwise there
128 // should already be an event scheduled for sending the head
129 // packet.
130 if (sendQueue.empty()) {
131 sendEvent.schedule(readyTime);
132 }
133
134 sendQueue.push_back(buf);
135
136 return true;
137}
138
139void
140Bridge::BridgePort::trySend()
141{
142 assert(!sendQueue.empty());
143
144 bool was_full = queueFull();
145
146 PacketBuffer *buf = sendQueue.front();
147
148 assert(buf->ready <= curTick);
149
150 Packet *pkt = buf->pkt;
151
152 DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n",
153 buf->origSrc, pkt->getDest(), pkt->getAddr());
154
155 if (sendTiming(pkt)) {
156 // send successful
157 sendQueue.pop_front();
158 buf->pkt = NULL; // we no longer own packet, so it's not safe to look at it
159
160 if (buf->expectResponse) {
161 // Must wait for response. We just need to count outstanding
162 // responses (in case we want to cap them); PacketBuffer
163 // pointer will be recovered on response.
164 ++outstandingResponses;
165 DPRINTF(BusBridge, " successful: awaiting response (%d)\n",
166 outstandingResponses);
167 } else {
168 // no response expected... deallocate packet buffer now.
169 DPRINTF(BusBridge, " successful: no response expected\n");
170 delete buf;
171 }
172
173 // If there are more packets to send, schedule event to try again.
174 if (!sendQueue.empty()) {
175 buf = sendQueue.front();
176 sendEvent.schedule(std::max(buf->ready, curTick + 1));
177 }
178 // Let things start sending again
179 if (was_full) {
180 DPRINTF(BusBridge, "Queue was full, sending retry\n");
181 otherPort->sendRetry();
182 }
183
184 } else {
185 DPRINTF(BusBridge, " unsuccessful\n");
186 }
187}
188
189
190void
191Bridge::BridgePort::recvRetry()
192{
193 trySend();
194}
195
196/** Function called by the port when the bus is receiving a Atomic
197 * transaction.*/
198Tick
199Bridge::BridgePort::recvAtomic(Packet *pkt)
200{
201 return otherPort->sendAtomic(pkt) + delay;
202}
203
204/** Function called by the port when the bus is receiving a Functional
205 * transaction.*/
206void
207Bridge::BridgePort::recvFunctional(Packet *pkt)
208{
209 std::list<PacketBuffer*>::iterator i;
210 bool pktContinue = true;
211
212 for (i = sendQueue.begin(); i != sendQueue.end(); ++i) {
213 if (pkt->intersect((*i)->pkt)) {
214 pktContinue &= fixPacket(pkt, (*i)->pkt);
215 }
216 }
217
218 if (pktContinue) {
219 otherPort->sendFunctional(pkt);
220 }
221}
222
223/** Function called by the port when the bus is receiving a status change.*/
224void
225Bridge::BridgePort::recvStatusChange(Port::Status status)
226{
227 otherPort->sendStatusChange(status);
228}
229
230void
231Bridge::BridgePort::getDeviceAddressRanges(AddrRangeList &resp,
232 AddrRangeList &snoop)
233{
234 otherPort->getPeerAddressRanges(resp, snoop);
235}
236
237BEGIN_DECLARE_SIM_OBJECT_PARAMS(Bridge)
238
239 Param<int> queue_size_a;
240 Param<int> queue_size_b;
241 Param<Tick> delay;
242 Param<bool> write_ack;
243
244END_DECLARE_SIM_OBJECT_PARAMS(Bridge)
245
246BEGIN_INIT_SIM_OBJECT_PARAMS(Bridge)
247
248 INIT_PARAM(queue_size_a, "The size of the queue for data coming into side a"),
249 INIT_PARAM(queue_size_b, "The size of the queue for data coming into side b"),
250 INIT_PARAM(delay, "The miminum delay to cross this bridge"),
251 INIT_PARAM(write_ack, "Acknowledge any writes that are received.")
252
253END_INIT_SIM_OBJECT_PARAMS(Bridge)
254
255CREATE_SIM_OBJECT(Bridge)
256{
257 return new Bridge(getInstanceName(), queue_size_a, queue_size_b, delay,
258 write_ack);
259}
260
261REGISTER_SIM_OBJECT("Bridge", Bridge)
| 63{
64 BridgePort *port;
65
66 if (if_name == "side_a")
67 port = &portA;
68 else if (if_name == "side_b")
69 port = &portB;
70 else
71 return NULL;
72
73 if (port->getPeer() != NULL)
74 panic("bridge side %s already connected to.", if_name);
75 return port;
76}
77
78
79void
80Bridge::init()
81{
82 // Make sure that both sides are connected to.
83 if (portA.getPeer() == NULL || portB.getPeer() == NULL)
84 panic("Both ports of bus bridge are not connected to a bus.\n");
85}
86
87
88/** Function called by the port when the bus is receiving a Timing
89 * transaction.*/
90bool
91Bridge::BridgePort::recvTiming(Packet *pkt)
92{
93 DPRINTF(BusBridge, "recvTiming: src %d dest %d addr 0x%x\n",
94 pkt->getSrc(), pkt->getDest(), pkt->getAddr());
95
96 return otherPort->queueForSendTiming(pkt);
97}
98
99
100bool
101Bridge::BridgePort::queueForSendTiming(Packet *pkt)
102{
103 if (queueFull())
104 return false;
105
106 if (pkt->isResponse()) {
107 // This is a response for a request we forwarded earlier. The
108 // corresponding PacketBuffer should be stored in the packet's
109 // senderState field.
110 PacketBuffer *buf = dynamic_cast<PacketBuffer*>(pkt->senderState);
111 assert(buf != NULL);
112 // set up new packet dest & senderState based on values saved
113 // from original request
114 buf->fixResponse(pkt);
115 DPRINTF(BusBridge, "restoring sender state: %#X, from packet buffer: %#X\n",
116 pkt->senderState, buf);
117 DPRINTF(BusBridge, " is response, new dest %d\n", pkt->getDest());
118 delete buf;
119 }
120
121 Tick readyTime = curTick + delay;
122 PacketBuffer *buf = new PacketBuffer(pkt, readyTime);
123 DPRINTF(BusBridge, "old sender state: %#X, new sender state: %#X\n",
124 buf->origSenderState, buf);
125
126 // If we're about to put this packet at the head of the queue, we
127 // need to schedule an event to do the transmit. Otherwise there
128 // should already be an event scheduled for sending the head
129 // packet.
130 if (sendQueue.empty()) {
131 sendEvent.schedule(readyTime);
132 }
133
134 sendQueue.push_back(buf);
135
136 return true;
137}
138
139void
140Bridge::BridgePort::trySend()
141{
142 assert(!sendQueue.empty());
143
144 bool was_full = queueFull();
145
146 PacketBuffer *buf = sendQueue.front();
147
148 assert(buf->ready <= curTick);
149
150 Packet *pkt = buf->pkt;
151
152 DPRINTF(BusBridge, "trySend: origSrc %d dest %d addr 0x%x\n",
153 buf->origSrc, pkt->getDest(), pkt->getAddr());
154
155 if (sendTiming(pkt)) {
156 // send successful
157 sendQueue.pop_front();
158 buf->pkt = NULL; // we no longer own packet, so it's not safe to look at it
159
160 if (buf->expectResponse) {
161 // Must wait for response. We just need to count outstanding
162 // responses (in case we want to cap them); PacketBuffer
163 // pointer will be recovered on response.
164 ++outstandingResponses;
165 DPRINTF(BusBridge, " successful: awaiting response (%d)\n",
166 outstandingResponses);
167 } else {
168 // no response expected... deallocate packet buffer now.
169 DPRINTF(BusBridge, " successful: no response expected\n");
170 delete buf;
171 }
172
173 // If there are more packets to send, schedule event to try again.
174 if (!sendQueue.empty()) {
175 buf = sendQueue.front();
176 sendEvent.schedule(std::max(buf->ready, curTick + 1));
177 }
178 // Let things start sending again
179 if (was_full) {
180 DPRINTF(BusBridge, "Queue was full, sending retry\n");
181 otherPort->sendRetry();
182 }
183
184 } else {
185 DPRINTF(BusBridge, " unsuccessful\n");
186 }
187}
188
189
190void
191Bridge::BridgePort::recvRetry()
192{
193 trySend();
194}
195
196/** Function called by the port when the bus is receiving a Atomic
197 * transaction.*/
198Tick
199Bridge::BridgePort::recvAtomic(Packet *pkt)
200{
201 return otherPort->sendAtomic(pkt) + delay;
202}
203
204/** Function called by the port when the bus is receiving a Functional
205 * transaction.*/
206void
207Bridge::BridgePort::recvFunctional(Packet *pkt)
208{
209 std::list<PacketBuffer*>::iterator i;
210 bool pktContinue = true;
211
212 for (i = sendQueue.begin(); i != sendQueue.end(); ++i) {
213 if (pkt->intersect((*i)->pkt)) {
214 pktContinue &= fixPacket(pkt, (*i)->pkt);
215 }
216 }
217
218 if (pktContinue) {
219 otherPort->sendFunctional(pkt);
220 }
221}
222
223/** Function called by the port when the bus is receiving a status change.*/
224void
225Bridge::BridgePort::recvStatusChange(Port::Status status)
226{
227 otherPort->sendStatusChange(status);
228}
229
230void
231Bridge::BridgePort::getDeviceAddressRanges(AddrRangeList &resp,
232 AddrRangeList &snoop)
233{
234 otherPort->getPeerAddressRanges(resp, snoop);
235}
236
237BEGIN_DECLARE_SIM_OBJECT_PARAMS(Bridge)
238
239 Param<int> queue_size_a;
240 Param<int> queue_size_b;
241 Param<Tick> delay;
242 Param<bool> write_ack;
243
244END_DECLARE_SIM_OBJECT_PARAMS(Bridge)
245
246BEGIN_INIT_SIM_OBJECT_PARAMS(Bridge)
247
248 INIT_PARAM(queue_size_a, "The size of the queue for data coming into side a"),
249 INIT_PARAM(queue_size_b, "The size of the queue for data coming into side b"),
250 INIT_PARAM(delay, "The miminum delay to cross this bridge"),
251 INIT_PARAM(write_ack, "Acknowledge any writes that are received.")
252
253END_INIT_SIM_OBJECT_PARAMS(Bridge)
254
255CREATE_SIM_OBJECT(Bridge)
256{
257 return new Bridge(getInstanceName(), queue_size_a, queue_size_b, delay,
258 write_ack);
259}
260
261REGISTER_SIM_OBJECT("Bridge", Bridge)
|