mshr_queue.cc revision 11375:f98df9231cdd 
1/*
2 * Copyright (c) 2012-2013, 2015-2016 ARM Limited
3 * All rights reserved.
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2003-2005 The Regents of The University of Michigan
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
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25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Erik Hallnor
41 *          Andreas Sandberg
42 */
43
44/** @file
45 * Definition of MSHRQueue class functions.
46 */
47
48#include "mem/cache/mshr_queue.hh"
49
50using namespace std;
51
52MSHRQueue::MSHRQueue(const std::string &_label,
53                     int num_entries, int reserve, int demand_reserve)
54    : Queue<MSHR>(_label, num_entries, reserve),
55      demandReserve(demand_reserve)
56{}
57
58MSHR *
59MSHRQueue::allocate(Addr blk_addr, unsigned blk_size, PacketPtr pkt,
60                    Tick when_ready, Counter order, bool alloc_on_fill)
61{
62    assert(!freeList.empty());
63    MSHR *mshr = freeList.front();
64    assert(mshr->getNumTargets() == 0);
65    freeList.pop_front();
66
67    mshr->allocate(blk_addr, blk_size, pkt, when_ready, order, alloc_on_fill);
68    mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
69    mshr->readyIter = addToReadyList(mshr);
70
71    allocated += 1;
72    return mshr;
73}
74
75void
76MSHRQueue::moveToFront(MSHR *mshr)
77{
78    if (!mshr->inService) {
79        assert(mshr == *(mshr->readyIter));
80        readyList.erase(mshr->readyIter);
81        mshr->readyIter = readyList.insert(readyList.begin(), mshr);
82    }
83}
84
85void
86MSHRQueue::markInService(MSHR *mshr, bool pending_modified_resp)
87{
88    mshr->markInService(pending_modified_resp);
89    readyList.erase(mshr->readyIter);
90    _numInService += 1;
91}
92
93void
94MSHRQueue::markPending(MSHR *mshr)
95{
96    assert(mshr->inService);
97    mshr->inService = false;
98    --_numInService;
99    /**
100     * @ todo might want to add rerequests to front of pending list for
101     * performance.
102     */
103    mshr->readyIter = addToReadyList(mshr);
104}
105
106bool
107MSHRQueue::forceDeallocateTarget(MSHR *mshr)
108{
109    bool was_full = isFull();
110    assert(mshr->hasTargets());
111    // Pop the prefetch off of the target list
112    mshr->popTarget();
113    // Delete mshr if no remaining targets
114    if (!mshr->hasTargets() && !mshr->promoteDeferredTargets()) {
115        deallocate(mshr);
116    }
117
118    // Notify if MSHR queue no longer full
119    return was_full && !isFull();
120}
121