1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
/*
* Copyright (c) 2006 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Ali Saidi
* Steve Reinhardt
*/
/**
* @file
* Declaration of a simple bus bridge object with no buffering
*/
#ifndef __MEM_BRIDGE_HH__
#define __MEM_BRIDGE_HH__
#include <list>
#include <queue>
#include <string>
#include "base/fast_alloc.hh"
#include "base/types.hh"
#include "mem/mem_object.hh"
#include "mem/packet.hh"
#include "mem/port.hh"
#include "params/Bridge.hh"
#include "sim/eventq.hh"
class Bridge : public MemObject
{
protected:
/** Declaration of the buses port type, one will be instantiated for each
of the interfaces connecting to the bus. */
class BridgePort : public Port
{
/** A pointer to the bridge to which this port belongs. */
Bridge *bridge;
/**
* Pointer to the port on the other side of the bridge
* (connected to the other bus).
*/
BridgePort *otherPort;
/** Minimum delay though this bridge. */
Tick delay;
/** Min delay to respond to a nack. */
Tick nackDelay;
/** Pass ranges from one side of the bridge to the other? */
std::vector<Range<Addr> > filterRanges;
class PacketBuffer : public Packet::SenderState, public FastAlloc {
public:
Tick ready;
PacketPtr pkt;
bool nackedHere;
Packet::SenderState *origSenderState;
short origSrc;
bool expectResponse;
PacketBuffer(PacketPtr _pkt, Tick t, bool nack = false)
: ready(t), pkt(_pkt), nackedHere(nack),
origSenderState(_pkt->senderState),
origSrc(nack ? _pkt->getDest() : _pkt->getSrc() ),
expectResponse(_pkt->needsResponse() && !nack)
{
if (!pkt->isResponse() && !nack)
pkt->senderState = this;
}
void fixResponse(PacketPtr pkt)
{
assert(pkt->senderState == this);
pkt->setDest(origSrc);
pkt->senderState = origSenderState;
}
};
/**
* Outbound packet queue. Packets are held in this queue for a
* specified delay to model the processing delay of the
* bridge.
*/
std::list<PacketBuffer*> sendQueue;
int outstandingResponses;
int queuedRequests;
/** If we're waiting for a retry to happen.*/
bool inRetry;
/** Max queue size for outbound packets */
int reqQueueLimit;
/** Max queue size for reserved responses. */
int respQueueLimit;
/**
* Is this side blocked from accepting outbound packets?
*/
bool respQueueFull();
bool reqQueueFull();
void queueForSendTiming(PacketPtr pkt);
void finishSend(PacketBuffer *buf);
void nackRequest(PacketPtr pkt);
/**
* Handle send event, scheduled when the packet at the head of
* the outbound queue is ready to transmit (for timing
* accesses only).
*/
void trySend();
class SendEvent : public Event
{
BridgePort *port;
public:
SendEvent(BridgePort *p) : port(p) {}
virtual void process() { port->trySend(); }
virtual const char *description() const { return "bridge send"; }
};
SendEvent sendEvent;
public:
/** Constructor for the BusPort.*/
BridgePort(const std::string &_name, Bridge *_bridge,
BridgePort *_otherPort, int _delay, int _nack_delay,
int _req_limit, int _resp_limit,
std::vector<Range<Addr> > filter_ranges);
protected:
/** When receiving a timing request from the peer port,
pass it to the bridge. */
virtual bool recvTiming(PacketPtr pkt);
/** When receiving a retry request from the peer port,
pass it to the bridge. */
virtual void recvRetry();
/** When receiving a Atomic requestfrom the peer port,
pass it to the bridge. */
virtual Tick recvAtomic(PacketPtr pkt);
/** When receiving a Functional request from the peer port,
pass it to the bridge. */
virtual void recvFunctional(PacketPtr pkt);
/** When receiving a status changefrom the peer port,
pass it to the bridge. */
virtual void recvStatusChange(Status status);
/** When receiving a address range request the peer port,
pass it to the bridge. */
virtual void getDeviceAddressRanges(AddrRangeList &resp,
bool &snoop);
};
BridgePort portA, portB;
/** If this bridge should acknowledge writes. */
bool ackWrites;
public:
typedef BridgeParams Params;
protected:
Params *_params;
public:
const Params *params() const { return _params; }
/** A function used to return the port associated with this bus object. */
virtual Port *getPort(const std::string &if_name, int idx = -1);
virtual void init();
Bridge(Params *p);
};
#endif //__MEM_BUS_HH__
|
