mshr.cc revision 2989 
1/*
2 * Copyright (c) 2002-2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Erik Hallnor
29 *          Dave Greene
30 */
31
32/**
33 * @file
34 * Miss Status and Handling Register (MSHR) definitions.
35 */
36
37#include <assert.h>
38#include <string>
39#include <vector>
40
41#include "mem/cache/miss/mshr.hh"
42#include "sim/root.hh" // for curTick
43#include "sim/host.hh"
44#include "base/misc.hh"
45#include "mem/cache/cache.hh"
46
47using namespace std;
48
49MSHR::MSHR()
50{
51    inService = false;
52    ntargets = 0;
53    threadNum = -1;
54}
55
56void
57MSHR::allocate(Packet::Command cmd, Addr _addr, int _asid, int size,
58               Packet * &target)
59{
60    addr = _addr;
61    if (target)
62    {
63        //Have a request, just use it
64        pkt = new Packet(target->req, cmd, Packet::Broadcast, size);
65        pkt->time = curTick;
66        pkt->allocate();
67        pkt->senderState = (Packet::SenderState *)this;
68        allocateTarget(target);
69    }
70    else
71    {
72        //need a request first
73        Request * req = new Request();
74        req->setPhys(addr, size, 0);
75        //Thread context??
76        pkt = new Packet(req, cmd, Packet::Broadcast, size);
77        pkt->time = curTick;
78        pkt->allocate();
79        pkt->senderState = (Packet::SenderState *)this;
80    }
81}
82
83// Since we aren't sure if data is being used, don't copy here.
84/**
85 * @todo When we have a "global" data flag, might want to copy data here.
86 */
87void
88MSHR::allocateAsBuffer(Packet * &target)
89{
90    addr = target->getAddr();
91    asid = target->req->getAsid();
92    threadNum = target->req->getThreadNum();
93    pkt = new Packet(target->req, target->cmd, -1);
94    pkt->allocate();
95    pkt->senderState = (Packet::SenderState*)this;
96    pkt->time = curTick;
97}
98
99void
100MSHR::deallocate()
101{
102    assert(targets.empty());
103    assert(ntargets == 0);
104    pkt = NULL;
105    inService = false;
106    //allocIter = NULL;
107    //readyIter = NULL;
108}
109
110/*
111 * Adds a target to an MSHR
112 */
113void
114MSHR::allocateTarget(Packet * &target)
115{
116    //If we append an invalidate and we issued a read to the bus,
117    //but now have some pending writes, we need to move
118    //the invalidate to before the first non-read
119    if (inService && pkt->isRead() && target->isInvalidate()) {
120        std::list<Packet *> temp;
121
122        while (!targets.empty()) {
123            if (!targets.front()->isRead()) break;
124            //Place on top of temp stack
125            temp.push_front(targets.front());
126            //Remove from targets
127            targets.pop_front();
128        }
129
130        //Now that we have all the reads off until first non-read, we can
131        //place the invalidate on
132        targets.push_front(target);
133
134        //Now we pop off the temp_stack and put them back
135        while (!temp.empty()) {
136            targets.push_front(temp.front());
137            temp.pop_front();
138        }
139    }
140    else {
141        targets.push_back(target);
142    }
143
144    ++ntargets;
145    assert(targets.size() == ntargets);
146    /**
147     * @todo really prioritize the target commands.
148     */
149
150    if (!inService && target->isWrite()) {
151        pkt->cmd = Packet::WriteReq;
152    }
153}
154
155
156
157void
158MSHR::dump()
159{
160    ccprintf(cerr,
161             "inService: %d thread: %d\n"
162             "Addr: %x asid: %d ntargets %d\n"
163             "Targets:\n",
164             inService, threadNum, addr, asid, ntargets);
165
166    TargetListIterator tar_it = targets.begin();
167    for (int i = 0; i < ntargets; i++) {
168        assert(tar_it != targets.end());
169
170        ccprintf(cerr, "\t%d: Addr: %x cmd: %d\n",
171                 i, (*tar_it)->getAddr(), (*tar_it)->cmdToIndex());
172
173        tar_it++;
174    }
175    ccprintf(cerr, "\n");
176}
177
178MSHR::~MSHR()
179{
180    if (pkt)
181        pkt = NULL;
182}
183