base.cc revision 13551:f352df8e2863 
1/*
2 * Copyright (c) 2013-2014 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) 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
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Ron Dreslinski
41 *          Mitch Hayenga
42 */
43
44/**
45 * @file
46 * Hardware Prefetcher Definition.
47 */
48
49#include "mem/cache/prefetch/base.hh"
50
51#include <cassert>
52
53#include "base/intmath.hh"
54#include "cpu/base.hh"
55#include "mem/cache/base.hh"
56#include "params/BasePrefetcher.hh"
57#include "sim/system.hh"
58
59BasePrefetcher::PrefetchInfo::PrefetchInfo(PacketPtr pkt, Addr addr)
60  : address(addr), pc(pkt->req->hasPC() ? pkt->req->getPC() : 0),
61    masterId(pkt->req->masterId()), validPC(pkt->req->hasPC()),
62    secure(pkt->isSecure())
63{
64}
65
66BasePrefetcher::PrefetchInfo::PrefetchInfo(PrefetchInfo const &pfi, Addr addr)
67  : address(addr), pc(pfi.pc), masterId(pfi.masterId), validPC(pfi.validPC),
68    secure(pfi.secure)
69{
70}
71
72void
73BasePrefetcher::PrefetchListener::notify(const PacketPtr &pkt)
74{
75    parent.probeNotify(pkt);
76}
77
78BasePrefetcher::BasePrefetcher(const BasePrefetcherParams *p)
79    : ClockedObject(p), listeners(), cache(nullptr), blkSize(p->block_size),
80      lBlkSize(floorLog2(blkSize)), onMiss(p->on_miss), onRead(p->on_read),
81      onWrite(p->on_write), onData(p->on_data), onInst(p->on_inst),
82      masterId(p->sys->getMasterId(this)), pageBytes(p->sys->getPageBytes()),
83      prefetchOnAccess(p->prefetch_on_access),
84      useVirtualAddresses(p->use_virtual_addresses)
85{
86}
87
88void
89BasePrefetcher::setCache(BaseCache *_cache)
90{
91    assert(!cache);
92    cache = _cache;
93
94    // If the cache has a different block size from the system's, save it
95    blkSize = cache->getBlockSize();
96    lBlkSize = floorLog2(blkSize);
97}
98
99void
100BasePrefetcher::regStats()
101{
102    ClockedObject::regStats();
103
104    pfIssued
105        .name(name() + ".num_hwpf_issued")
106        .desc("number of hwpf issued")
107        ;
108
109}
110
111bool
112BasePrefetcher::observeAccess(const PacketPtr &pkt) const
113{
114    Addr addr = pkt->getAddr();
115    bool fetch = pkt->req->isInstFetch();
116    bool read = pkt->isRead();
117    bool inv = pkt->isInvalidate();
118    bool is_secure = pkt->isSecure();
119
120    if (pkt->req->isUncacheable()) return false;
121    if (fetch && !onInst) return false;
122    if (!fetch && !onData) return false;
123    if (!fetch && read && !onRead) return false;
124    if (!fetch && !read && !onWrite) return false;
125    if (!fetch && !read && inv) return false;
126    if (pkt->cmd == MemCmd::CleanEvict) return false;
127
128    if (onMiss) {
129        return !inCache(addr, is_secure) &&
130               !inMissQueue(addr, is_secure);
131    }
132
133    return true;
134}
135
136bool
137BasePrefetcher::inCache(Addr addr, bool is_secure) const
138{
139    return cache->inCache(addr, is_secure);
140}
141
142bool
143BasePrefetcher::inMissQueue(Addr addr, bool is_secure) const
144{
145    return cache->inMissQueue(addr, is_secure);
146}
147
148bool
149BasePrefetcher::samePage(Addr a, Addr b) const
150{
151    return roundDown(a, pageBytes) == roundDown(b, pageBytes);
152}
153
154Addr
155BasePrefetcher::blockAddress(Addr a) const
156{
157    return a & ~((Addr)blkSize-1);
158}
159
160Addr
161BasePrefetcher::blockIndex(Addr a) const
162{
163    return a >> lBlkSize;
164}
165
166Addr
167BasePrefetcher::pageAddress(Addr a) const
168{
169    return roundDown(a, pageBytes);
170}
171
172Addr
173BasePrefetcher::pageOffset(Addr a) const
174{
175    return a & (pageBytes - 1);
176}
177
178Addr
179BasePrefetcher::pageIthBlockAddress(Addr page, uint32_t blockIndex) const
180{
181    return page + (blockIndex << lBlkSize);
182}
183
184void
185BasePrefetcher::probeNotify(const PacketPtr &pkt)
186{
187    // Don't notify prefetcher on SWPrefetch, cache maintenance
188    // operations or for writes that we are coaslescing.
189    if (pkt->cmd.isSWPrefetch()) return;
190    if (pkt->req->isCacheMaintenance()) return;
191    if (pkt->isWrite() && cache != nullptr && cache->coalesce()) return;
192
193    // Verify this access type is observed by prefetcher
194    if (observeAccess(pkt)) {
195        if (useVirtualAddresses && pkt->req->hasVaddr()) {
196            PrefetchInfo pfi(pkt, pkt->req->getVaddr());
197            notify(pkt, pfi);
198        } else if (!useVirtualAddresses && pkt->req->hasPaddr()) {
199            PrefetchInfo pfi(pkt, pkt->req->getPaddr());
200            notify(pkt, pfi);
201        }
202    }
203}
204
205void
206BasePrefetcher::regProbeListeners()
207{
208    /**
209     * If no probes were added by the configuration scripts, connect to the
210     * parent cache using the probe "Miss". Also connect to "Hit", if the
211     * cache is configured to prefetch on accesses.
212     */
213    if (listeners.empty() && cache != nullptr) {
214        ProbeManager *pm(cache->getProbeManager());
215        listeners.push_back(new PrefetchListener(*this, pm, "Miss"));
216        if (prefetchOnAccess) {
217            listeners.push_back(new PrefetchListener(*this, pm, "Hit"));
218        }
219    }
220}
221
222void
223BasePrefetcher::addEventProbe(SimObject *obj, const char *name)
224{
225    ProbeManager *pm(obj->getProbeManager());
226    listeners.push_back(new PrefetchListener(*this, pm, name));
227}
228