1/*
2 * Copyright (c) 2012-2014,2016-2017 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
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: Erik Hallnor
41 * Ron Dreslinski
42 */
43
44/**
45 * @file
46 * Declaration of a common base class for cache tagstore objects.
47 */
48
49#ifndef __MEM_CACHE_TAGS_BASE_HH__
50#define __MEM_CACHE_TAGS_BASE_HH__
51
52#include <string>
53
54#include "base/callback.hh"
55#include "base/statistics.hh"
56#include "mem/cache/blk.hh"
57#include "mem/cache/replacement_policies/base.hh"
58#include "params/BaseTags.hh"
59#include "sim/clocked_object.hh"
60
61class BaseCache;
62
63/**
64 * A common base class of Cache tagstore objects.
65 */
66class BaseTags : public ClockedObject
67{
68 protected:
69 /** The block size of the cache. */
70 const unsigned blkSize;
71 /** Mask out all bits that aren't part of the block offset. */
72 const Addr blkMask;
73 /** The size of the cache. */
74 const unsigned size;
75 /** The tag lookup latency of the cache. */
76 const Cycles lookupLatency;
77 /**
78 * The total access latency of the cache. This latency
79 * is different depending on the cache access mode
80 * (parallel or sequential)
81 */
82 const Cycles accessLatency;
83 /** Pointer to the parent cache. */
84 BaseCache *cache;
85
86 /**
87 * The number of tags that need to be touched to meet the warmup
88 * percentage.
89 */
90 const unsigned warmupBound;
91 /** Marked true when the cache is warmed up. */
92 bool warmedUp;
93
94 /** the number of blocks in the cache */
95 const unsigned numBlocks;
96
97 /** The data blocks, 1 per cache block. */
98 std::unique_ptr<uint8_t[]> dataBlks;
99
100 // Statistics
101 /**
102 * TODO: It would be good if these stats were acquired after warmup.
103 * @addtogroup CacheStatistics
104 * @{
105 */
106
107 /** Per cycle average of the number of tags that hold valid data. */
108 Stats::Average tagsInUse;
109
110 /** The total number of references to a block before it is replaced. */
111 Stats::Scalar totalRefs;
112
113 /**
114 * The number of reference counts sampled. This is different from
115 * replacements because we sample all the valid blocks when the simulator
116 * exits.
117 */
118 Stats::Scalar sampledRefs;
119
120 /**
121 * Average number of references to a block before is was replaced.
122 * @todo This should change to an average stat once we have them.
123 */
124 Stats::Formula avgRefs;
125
126 /** The cycle that the warmup percentage was hit. 0 on failure. */
127 Stats::Scalar warmupCycle;
128
129 /** Average occupancy of each requestor using the cache */
130 Stats::AverageVector occupancies;
131
132 /** Average occ % of each requestor using the cache */
133 Stats::Formula avgOccs;
134
135 /** Occupancy of each context/cpu using the cache */
136 Stats::Vector occupanciesTaskId;
137
138 /** Occupancy of each context/cpu using the cache */
139 Stats::Vector2d ageTaskId;
140
141 /** Occ % of each context/cpu using the cache */
142 Stats::Formula percentOccsTaskId;
143
144 /** Number of tags consulted over all accesses. */
145 Stats::Scalar tagAccesses;
146 /** Number of data blocks consulted over all accesses. */
147 Stats::Scalar dataAccesses;
148
149 /**
150 * @}
151 */
152
153 public:
154 typedef BaseTagsParams Params;
155 BaseTags(const Params *p);
156
157 /**
158 * Destructor.
159 */
160 virtual ~BaseTags() {}
161
162 /**
163 * Set the parent cache back pointer.
164 * @param _cache Pointer to parent cache.
165 */
166 void setCache(BaseCache *_cache);
167
168 /**
169 * Register local statistics.
170 */
171 void regStats();
172
173 /**
174 * Average in the reference count for valid blocks when the simulation
175 * exits.
176 */
177 virtual void cleanupRefs() {}
178
179 /**
180 * Computes stats just prior to dump event
181 */
182 virtual void computeStats() {}
183
184 /**
185 * Print all tags used
186 */
187 virtual std::string print() const = 0;
188
189 /**
190 * Find a block using the memory address
191 */
192 virtual CacheBlk * findBlock(Addr addr, bool is_secure) const = 0;
193
194 /**
195 * Align an address to the block size.
196 * @param addr the address to align.
197 * @return The block address.
198 */
199 Addr blkAlign(Addr addr) const
200 {
201 return addr & ~blkMask;
202 }
203
204 /**
205 * Calculate the block offset of an address.
206 * @param addr the address to get the offset of.
207 * @return the block offset.
208 */
209 int extractBlkOffset(Addr addr) const
210 {
211 return (addr & blkMask);
212 }
213
214 /**
215 * Find the cache block given set and way
216 * @param set The set of the block.
217 * @param way The way of the block.
218 * @return The cache block.
219 */
220 virtual CacheBlk *findBlockBySetAndWay(int set, int way) const = 0;
221
222 /**
223 * Limit the allocation for the cache ways.
224 * @param ways The maximum number of ways available for replacement.
225 */
226 virtual void setWayAllocationMax(int ways)
227 {
228 panic("This tag class does not implement way allocation limit!\n");
229 }
230
231 /**
232 * Get the way allocation mask limit.
233 * @return The maximum number of ways available for replacement.
234 */
235 virtual int getWayAllocationMax() const
236 {
237 panic("This tag class does not implement way allocation limit!\n");
238 return -1;
239 }
240
241 /**
242 * This function updates the tags when a block is invalidated
243 *
244 * @param blk A valid block to invalidate.
245 */
246 virtual void invalidate(CacheBlk *blk)
247 {
248 assert(blk);
249 assert(blk->isValid());
250
251 tagsInUse--;
252 occupancies[blk->srcMasterId]--;
253 totalRefs += blk->refCount;
254 sampledRefs++;
255
256 blk->invalidate();
257 }
258
259 /**
260 * Find replacement victim based on address.
261 *
262 * @param addr Address to find a victim for.
263 * @return Cache block to be replaced.
264 */
265 virtual CacheBlk* findVictim(Addr addr) = 0;
266
267 virtual CacheBlk* accessBlock(Addr addr, bool is_secure, Cycles &lat) = 0;
268
269 virtual Addr extractTag(Addr addr) const = 0;
270
271 /**
272 * Insert the new block into the cache and update stats.
273 *
274 * @param pkt Packet holding the address to update
275 * @param blk The block to update.
276 */
277 virtual void insertBlock(PacketPtr pkt, CacheBlk *blk);
278
279 /**
280 * Regenerate the block address.
281 *
282 * @param block The block.
283 * @return the block address.
284 */
285 virtual Addr regenerateBlkAddr(const CacheBlk* blk) const = 0;
286
287 virtual int extractSet(Addr addr) const = 0;
288
289 virtual void forEachBlk(CacheBlkVisitor &visitor) = 0;
290};
291
292class BaseTagsCallback : public Callback
293{
294 BaseTags *tags;
295 public:
296 BaseTagsCallback(BaseTags *t) : tags(t) {}
297 virtual void process() { tags->cleanupRefs(); };
298};
299
300class BaseTagsDumpCallback : public Callback
301{
302 BaseTags *tags;
303 public:
304 BaseTagsDumpCallback(BaseTags *t) : tags(t) {}
305 virtual void process() { tags->computeStats(); };
306};
307
308#endif //__MEM_CACHE_TAGS_BASE_HH__