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
214
215
216
217
218
219
220
|
/*
* Copyright (c) 2002-2005 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: Erik Hallnor
* Dave Greene
*/
/**
* @file
* Miss Status and Handling Register (MSHR) definitions.
*/
#include <assert.h>
#include <string>
#include <vector>
#include <algorithm>
#include "mem/cache/miss/mshr.hh"
#include "sim/core.hh" // for curTick
#include "sim/host.hh"
#include "base/misc.hh"
#include "mem/cache/cache.hh"
using namespace std;
MSHR::MSHR()
{
inService = false;
ntargets = 0;
threadNum = -1;
}
void
MSHR::allocate(Addr _addr, int _size, PacketPtr target,
Tick when, Counter _order)
{
addr = _addr;
size = _size;
readyTick = when;
order = _order;
assert(target);
isCacheFill = false;
needsExclusive = target->needsExclusive();
_isUncacheable = target->req->isUncacheable();
inService = false;
threadNum = 0;
ntargets = 1;
// Don't know of a case where we would allocate a new MSHR for a
// snoop (mem-side request), so set cpuSide to true here.
targets.push_back(Target(target, when, _order, true));
assert(deferredTargets.empty());
deferredNeedsExclusive = false;
pendingInvalidate = false;
pendingShared = false;
data = NULL;
}
void
MSHR::deallocate()
{
assert(targets.empty());
assert(deferredTargets.empty());
assert(ntargets == 0);
inService = false;
//allocIter = NULL;
//readyIter = NULL;
}
/*
* Adds a target to an MSHR
*/
void
MSHR::allocateTarget(PacketPtr target, Tick when, Counter _order)
{
if (inService) {
if (!deferredTargets.empty() || pendingInvalidate ||
(!needsExclusive && target->needsExclusive())) {
// need to put on deferred list
deferredTargets.push_back(Target(target, when, _order, true));
if (target->needsExclusive()) {
deferredNeedsExclusive = true;
}
} else {
// still OK to append to outstanding request
targets.push_back(Target(target, when, _order, true));
}
} else {
if (target->needsExclusive()) {
needsExclusive = true;
}
targets.push_back(Target(target, when, _order, true));
}
++ntargets;
}
void
MSHR::allocateSnoopTarget(PacketPtr pkt, Tick when, Counter _order)
{
assert(inService); // don't bother to call otherwise
if (pendingInvalidate) {
// a prior snoop has already appended an invalidation, so
// logically we don't have the block anymore...
return;
}
DPRINTF(Cache, "deferred snoop on %x: %s %s\n", addr,
needsExclusive ? "needsExclusive" : "",
pkt->needsExclusive() ? "pkt->needsExclusive()" : "");
if (needsExclusive || pkt->needsExclusive()) {
// actual target device (typ. PhysicalMemory) will delete the
// packet on reception, so we need to save a copy here
targets.push_back(Target(new Packet(pkt), when, _order, false));
++ntargets;
if (needsExclusive) {
// We're awaiting an exclusive copy, so ownership is pending.
// It's up to us to respond once the data arrives.
pkt->assertMemInhibit();
}
if (pkt->needsExclusive()) {
// This transaction will take away our pending copy
pendingInvalidate = true;
}
} else {
// Read to a read: no conflict, so no need to record as
// target, but make sure neither reader thinks he's getting an
// exclusive copy
pendingShared = true;
pkt->assertShared();
}
}
bool
MSHR::promoteDeferredTargets()
{
if (deferredTargets.empty()) {
return false;
}
assert(targets.empty());
targets = deferredTargets;
deferredTargets.clear();
assert(targets.size() == ntargets);
needsExclusive = deferredNeedsExclusive;
pendingInvalidate = false;
pendingShared = false;
deferredNeedsExclusive = false;
order = targets.front().order;
readyTick = std::max(curTick, targets.front().time);
return true;
}
void
MSHR::handleFill(Packet *pkt, CacheBlk *blk)
{
if (pendingShared) {
// we snooped another read while this read was in
// service... assert shared line on its behalf
pkt->assertShared();
}
}
void
MSHR::dump()
{
ccprintf(cerr,
"inService: %d thread: %d\n"
"Addr: %x ntargets %d\n"
"Targets:\n",
inService, threadNum, addr, ntargets);
TargetListIterator tar_it = targets.begin();
for (int i = 0; i < ntargets; i++) {
assert(tar_it != targets.end());
ccprintf(cerr, "\t%d: Addr: %x cmd: %s\n",
i, tar_it->pkt->getAddr(), tar_it->pkt->cmdString());
tar_it++;
}
ccprintf(cerr, "\n");
}
MSHR::~MSHR()
{
}
|
