1/*
2 * Copyright (c) 2012-2014,2016-2018 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 <cassert>
53#include <functional>
54#include <string>
55
56#include "base/callback.hh"
57#include "base/logging.hh"
58#include "base/statistics.hh"
59#include "base/types.hh"
60#include "mem/cache/blk.hh"
61#include "params/BaseTags.hh"
62#include "sim/clocked_object.hh"
63
64class BaseCache;
65class IndexingPolicy;
66class ReplaceableEntry;
67
68/**
69 * A common base class of Cache tagstore objects.
70 */
71class BaseTags : public ClockedObject
72{
73 protected:
74 /** The block size of the cache. */
75 const unsigned blkSize;
76 /** Mask out all bits that aren't part of the block offset. */
77 const Addr blkMask;
78 /** The size of the cache. */
79 const unsigned size;
80 /** The tag lookup latency of the cache. */
81 const Cycles lookupLatency;
82 /**
83 * The total access latency of the cache. This latency
84 * is different depending on the cache access mode
85 * (parallel or sequential)
86 */
87 const Cycles accessLatency;
88 /** Pointer to the parent cache. */
89 BaseCache *cache;
90
91 /** Indexing policy */
92 BaseIndexingPolicy *indexingPolicy;
93
94 /**
95 * The number of tags that need to be touched to meet the warmup
96 * percentage.
97 */
98 const unsigned warmupBound;
99 /** Marked true when the cache is warmed up. */
100 bool warmedUp;
101
102 /** the number of blocks in the cache */
103 const unsigned numBlocks;
104
105 /** The data blocks, 1 per cache block. */
106 std::unique_ptr<uint8_t[]> dataBlks;
107
108 // Statistics
109 /**
110 * TODO: It would be good if these stats were acquired after warmup.
111 * @addtogroup CacheStatistics
112 * @{
113 */
114
115 /** Per cycle average of the number of tags that hold valid data. */
116 Stats::Average tagsInUse;
117
118 /** The total number of references to a block before it is replaced. */
119 Stats::Scalar totalRefs;
120
121 /**
122 * The number of reference counts sampled. This is different from
123 * replacements because we sample all the valid blocks when the simulator
124 * exits.
125 */
126 Stats::Scalar sampledRefs;
127
128 /**
129 * Average number of references to a block before is was replaced.
130 * @todo This should change to an average stat once we have them.
131 */
132 Stats::Formula avgRefs;
133
134 /** The cycle that the warmup percentage was hit. 0 on failure. */
135 Stats::Scalar warmupCycle;
136
137 /** Average occupancy of each requestor using the cache */
138 Stats::AverageVector occupancies;
139
140 /** Average occ % of each requestor using the cache */
141 Stats::Formula avgOccs;
142
143 /** Occupancy of each context/cpu using the cache */
144 Stats::Vector occupanciesTaskId;
145
146 /** Occupancy of each context/cpu using the cache */
147 Stats::Vector2d ageTaskId;
148
149 /** Occ % of each context/cpu using the cache */
150 Stats::Formula percentOccsTaskId;
151
152 /** Number of tags consulted over all accesses. */
153 Stats::Scalar tagAccesses;
154 /** Number of data blocks consulted over all accesses. */
155 Stats::Scalar dataAccesses;
156
157 /**
158 * @}
159 */
160
161 /**
162 * Set the parent cache back pointer.
163 *
164 * @param _cache Pointer to parent cache.
165 */
166 void setCache(BaseCache *_cache);
167
168 public:
169 typedef BaseTagsParams Params;
170 BaseTags(const Params *p);
171
172 /**
173 * Destructor.
174 */
175 virtual ~BaseTags() {}
176
177 /**
178 * Initialize blocks and set the parent cache back pointer.
179 *
180 * @param _cache Pointer to parent cache.
181 */
182 virtual void init(BaseCache *_cache) = 0;
183
184 /**
185 * Register local statistics.
186 */
187 void regStats();
188
189 /**
190 * Average in the reference count for valid blocks when the simulation
191 * exits.
192 */
193 void cleanupRefs();
194
195 /**
196 * Computes stats just prior to dump event
197 */
198 void computeStats();
199
200 /**
201 * Print all tags used
202 */
203 std::string print();
204
205 /**
206 * Finds the block in the cache without touching it.
207 *
208 * @param addr The address to look for.
209 * @param is_secure True if the target memory space is secure.
210 * @return Pointer to the cache block.
211 */
212 virtual CacheBlk *findBlock(Addr addr, bool is_secure) const;
213
214 /**
215 * Find a block given set and way.
216 *
217 * @param set The set of the block.
218 * @param way The way of the block.
219 * @return The block.
220 */
221 virtual ReplaceableEntry* findBlockBySetAndWay(int set, int way) const;
222
223 /**
224 * Align an address to the block size.
225 * @param addr the address to align.
226 * @return The block address.
227 */
228 Addr blkAlign(Addr addr) const
229 {
230 return addr & ~blkMask;
231 }
232
233 /**
234 * Calculate the block offset of an address.
235 * @param addr the address to get the offset of.
236 * @return the block offset.
237 */
238 int extractBlkOffset(Addr addr) const
239 {
240 return (addr & blkMask);
241 }
242
243 /**
244 * Limit the allocation for the cache ways.
245 * @param ways The maximum number of ways available for replacement.
246 */
247 virtual void setWayAllocationMax(int ways)
248 {
249 panic("This tag class does not implement way allocation limit!\n");
250 }
251
252 /**
253 * Get the way allocation mask limit.
254 * @return The maximum number of ways available for replacement.
255 */
256 virtual int getWayAllocationMax() const
257 {
258 panic("This tag class does not implement way allocation limit!\n");
259 return -1;
260 }
261
262 /**
263 * This function updates the tags when a block is invalidated
264 *
265 * @param blk A valid block to invalidate.
266 */
267 virtual void invalidate(CacheBlk *blk)
268 {
269 assert(blk);
270 assert(blk->isValid());
271
272 occupancies[blk->srcMasterId]--;
273 totalRefs += blk->refCount;
274 sampledRefs++;
275
276 blk->invalidate();
277 }
278
279 /**
280 * Find replacement victim based on address. If the address requires
281 * blocks to be evicted, their locations are listed for eviction. If a
282 * conventional cache is being used, the list only contains the victim.
283 * However, if using sector or compressed caches, the victim is one of
284 * the blocks to be evicted, but its location is the only one that will
285 * be assigned to the newly allocated block associated to this address.
286 * @sa insertBlock
287 *
288 * @param addr Address to find a victim for.
289 * @param is_secure True if the target memory space is secure.
290 * @param evict_blks Cache blocks to be evicted.
291 * @return Cache block to be replaced.
292 */
293 virtual CacheBlk* findVictim(Addr addr, const bool is_secure,
294 std::vector<CacheBlk*>& evict_blks) const = 0;
295
296 virtual CacheBlk* accessBlock(Addr addr, bool is_secure, Cycles &lat) = 0;
297
298 /**
299 * Generate the tag from the given address.
300 *
301 * @param addr The address to get the tag from.
302 * @return The tag of the address.
303 */
304 virtual Addr extractTag(const Addr addr) const;
305
306 /**
307 * Insert the new block into the cache and update stats.
308 *
309 * @param addr Address of the block.
310 * @param is_secure Whether the block is in secure space or not.
311 * @param src_master_ID The source requestor ID.
312 * @param task_ID The new task ID.
313 * @param blk The block to update.
314 */
315 virtual void insertBlock(const Addr addr, const bool is_secure,
316 const int src_master_ID, const uint32_t task_ID,
317 CacheBlk *blk);
318
319 /**
320 * Regenerate the block address.
321 *
322 * @param block The block.
323 * @return the block address.
324 */
325 virtual Addr regenerateBlkAddr(const CacheBlk* blk) const = 0;
326
327 /**
328 * Visit each block in the tags and apply a visitor
329 *
330 * The visitor should be a std::function that takes a cache block
331 * reference as its parameter.
332 *
333 * @param visitor Visitor to call on each block.
334 */
335 virtual void forEachBlk(std::function<void(CacheBlk &)> visitor) = 0;
336
337 /**
338 * Find if any of the blocks satisfies a condition
339 *
340 * The visitor should be a std::function that takes a cache block
341 * reference as its parameter. The visitor will terminate the
342 * traversal early if the condition is satisfied.
343 *
344 * @param visitor Visitor to call on each block.
345 */
346 virtual bool anyBlk(std::function<bool(CacheBlk &)> visitor) = 0;
347
348 private:
349 /**
350 * Update the reference stats using data from the input block
351 *
352 * @param blk The input block
353 */
354 void cleanupRefsVisitor(CacheBlk &blk);
355
356 /**
357 * Update the occupancy and age stats using data from the input block
358 *
359 * @param blk The input block
360 */
361 void computeStatsVisitor(CacheBlk &blk);
362};
363
364class BaseTagsCallback : public Callback
365{
366 BaseTags *tags;
367 public:
368 BaseTagsCallback(BaseTags *t) : tags(t) {}
369 virtual void process() { tags->cleanupRefs(); };
370};
371
372class BaseTagsDumpCallback : public Callback
373{
374 BaseTags *tags;
375 public:
376 BaseTagsDumpCallback(BaseTags *t) : tags(t) {}
377 virtual void process() { tags->computeStats(); };
378};
379
380#endif //__MEM_CACHE_TAGS_BASE_HH__