mshr_queue.cc revision 12637:bfc3cb9c7e6c 
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
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
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
50MSHRQueue::MSHRQueue(const std::string &_label,
51                     int num_entries, int reserve, int demand_reserve)
52    : Queue<MSHR>(_label, num_entries, reserve),
53      demandReserve(demand_reserve)
54{}
55
56MSHR *
57MSHRQueue::allocate(Addr blk_addr, unsigned blk_size, PacketPtr pkt,
58                    Tick when_ready, Counter order, bool alloc_on_fill)
59{
60    assert(!freeList.empty());
61    MSHR *mshr = freeList.front();
62    assert(mshr->getNumTargets() == 0);
63    freeList.pop_front();
64
65    mshr->allocate(blk_addr, blk_size, pkt, when_ready, order, alloc_on_fill);
66    mshr->allocIter = allocatedList.insert(allocatedList.end(), mshr);
67    mshr->readyIter = addToReadyList(mshr);
68
69    allocated += 1;
70    return mshr;
71}
72
73void
74MSHRQueue::moveToFront(MSHR *mshr)
75{
76    if (!mshr->inService) {
77        assert(mshr == *(mshr->readyIter));
78        readyList.erase(mshr->readyIter);
79        mshr->readyIter = readyList.insert(readyList.begin(), mshr);
80    }
81}
82
83void
84MSHRQueue::markInService(MSHR *mshr, bool pending_modified_resp)
85{
86    mshr->markInService(pending_modified_resp);
87    readyList.erase(mshr->readyIter);
88    _numInService += 1;
89}
90
91void
92MSHRQueue::markPending(MSHR *mshr)
93{
94    assert(mshr->inService);
95    mshr->inService = false;
96    --_numInService;
97    /**
98     * @ todo might want to add rerequests to front of pending list for
99     * performance.
100     */
101    mshr->readyIter = addToReadyList(mshr);
102}
103
104bool
105MSHRQueue::forceDeallocateTarget(MSHR *mshr)
106{
107    bool was_full = isFull();
108    assert(mshr->hasTargets());
109    // Pop the prefetch off of the target list
110    mshr->popTarget();
111    // Delete mshr if no remaining targets
112    if (!mshr->hasTargets() && !mshr->promoteDeferredTargets()) {
113        deallocate(mshr);
114    }
115
116    // Notify if MSHR queue no longer full
117    return was_full && !isFull();
118}
119