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 ReplaceableEntry;
66
67/**
68 * A common base class of Cache tagstore objects.
69 */
70class BaseTags : public ClockedObject
71{
72 protected:
73 /** The block size of the cache. */
74 const unsigned blkSize;
75 /** Mask out all bits that aren't part of the block offset. */
76 const Addr blkMask;
77 /** The size of the cache. */
78 const unsigned size;
79 /** The tag lookup latency of the cache. */
80 const Cycles lookupLatency;
81 /**
82 * The total access latency of the cache. This latency
83 * is different depending on the cache access mode
84 * (parallel or sequential)
85 */
86 const Cycles accessLatency;
87 /** Pointer to the parent cache. */
88 BaseCache *cache;
89
90 /**
91 * The number of tags that need to be touched to meet the warmup
92 * percentage.
93 */
94 const unsigned warmupBound;
95 /** Marked true when the cache is warmed up. */
96 bool warmedUp;
97
98 /** the number of blocks in the cache */
99 const unsigned numBlocks;
100
101 /** The data blocks, 1 per cache block. */
102 std::unique_ptr<uint8_t[]> dataBlks;
103
104 // Statistics
105 /**
106 * TODO: It would be good if these stats were acquired after warmup.
107 * @addtogroup CacheStatistics
108 * @{
109 */
110
111 /** Per cycle average of the number of tags that hold valid data. */
112 Stats::Average tagsInUse;
113
114 /** The total number of references to a block before it is replaced. */
115 Stats::Scalar totalRefs;
116
117 /**
118 * The number of reference counts sampled. This is different from
119 * replacements because we sample all the valid blocks when the simulator
120 * exits.
121 */
122 Stats::Scalar sampledRefs;
123
124 /**
125 * Average number of references to a block before is was replaced.
126 * @todo This should change to an average stat once we have them.
127 */
128 Stats::Formula avgRefs;
129
130 /** The cycle that the warmup percentage was hit. 0 on failure. */
131 Stats::Scalar warmupCycle;
132
133 /** Average occupancy of each requestor using the cache */
134 Stats::AverageVector occupancies;
135
136 /** Average occ % of each requestor using the cache */
137 Stats::Formula avgOccs;
138
139 /** Occupancy of each context/cpu using the cache */
140 Stats::Vector occupanciesTaskId;
141
142 /** Occupancy of each context/cpu using the cache */
143 Stats::Vector2d ageTaskId;
144
145 /** Occ % of each context/cpu using the cache */
146 Stats::Formula percentOccsTaskId;
147
148 /** Number of tags consulted over all accesses. */
149 Stats::Scalar tagAccesses;
150 /** Number of data blocks consulted over all accesses. */
151 Stats::Scalar dataAccesses;
152
153 /**
154 * @}
155 */
156
157 /**
158 * Set the parent cache back pointer.
159 *
160 * @param _cache Pointer to parent cache.
161 */
162 void setCache(BaseCache *_cache);
163
164 /**
165 * Find all possible block locations for insertion and replacement of
166 * an address. Should be called immediately before ReplacementPolicy's
167 * findVictim() not to break cache resizing.
168 * Returns blocks in all ways belonging to the set of the address.
169 *
170 * @param addr The addr to a find possible locations for.
171 * @return The possible locations.
172 */
173 virtual std::vector<ReplaceableEntry*> getPossibleLocations(
174 const Addr addr) const;
175
176 public:
177 typedef BaseTagsParams Params;
178 BaseTags(const Params *p);
179
180 /**
181 * Destructor.
182 */
183 virtual ~BaseTags() {}
184
185 /**
186 * Initialize blocks and set the parent cache back pointer.
187 *
188 * @param _cache Pointer to parent cache.
189 */
190 virtual void init(BaseCache *_cache) = 0;
191
192 /**
193 * Register local statistics.
194 */
195 void regStats();
196
197 /**
198 * Average in the reference count for valid blocks when the simulation
199 * exits.
200 */
201 void cleanupRefs();
202
203 /**
204 * Computes stats just prior to dump event
205 */
206 void computeStats();
207
208 /**
209 * Print all tags used
210 */
211 std::string print();
212
213 /**
214 * Finds the block in the cache without touching it.
215 *
216 * @param addr The address to look for.
217 * @param is_secure True if the target memory space is secure.
218 * @return Pointer to the cache block.
219 */
220 virtual CacheBlk *findBlock(Addr addr, bool is_secure) const;
221
222 /**
223 * Find a block given set and way.
224 *
225 * @param set The set of the block.
226 * @param way The way of the block.
227 * @return The block.
228 */
229 virtual ReplaceableEntry* findBlockBySetAndWay(int set, int way) const = 0;
230
231 /**
232 * Align an address to the block size.
233 * @param addr the address to align.
234 * @return The block address.
235 */
236 Addr blkAlign(Addr addr) const
237 {
238 return addr & ~blkMask;
239 }
240
241 /**
242 * Calculate the block offset of an address.
243 * @param addr the address to get the offset of.
244 * @return the block offset.
245 */
246 int extractBlkOffset(Addr addr) const
247 {
248 return (addr & blkMask);
249 }
250
251 /**
252 * Limit the allocation for the cache ways.
253 * @param ways The maximum number of ways available for replacement.
254 */
255 virtual void setWayAllocationMax(int ways)
256 {
257 panic("This tag class does not implement way allocation limit!\n");
258 }
259
260 /**
261 * Get the way allocation mask limit.
262 * @return The maximum number of ways available for replacement.
263 */
264 virtual int getWayAllocationMax() const
265 {
266 panic("This tag class does not implement way allocation limit!\n");
267 return -1;
268 }
269
270 /**
271 * This function updates the tags when a block is invalidated
272 *
273 * @param blk A valid block to invalidate.
274 */
275 virtual void invalidate(CacheBlk *blk)
276 {
277 assert(blk);
278 assert(blk->isValid());
279
280 occupancies[blk->srcMasterId]--;
281 totalRefs += blk->refCount;
282 sampledRefs++;
283
284 blk->invalidate();
285 }
286
287 /**
288 * Find replacement victim based on address. If the address requires
289 * blocks to be evicted, their locations are listed for eviction. If a
290 * conventional cache is being used, the list only contains the victim.
291 * However, if using sector or compressed caches, the victim is one of
292 * the blocks to be evicted, but its location is the only one that will
293 * be assigned to the newly allocated block associated to this address.
294 * @sa insertBlock
295 *
296 * @param addr Address to find a victim for.
297 * @param is_secure True if the target memory space is secure.
298 * @param evict_blks Cache blocks to be evicted.
299 * @return Cache block to be replaced.
300 */
301 virtual CacheBlk* findVictim(Addr addr, const bool is_secure,
302 std::vector<CacheBlk*>& evict_blks) const = 0;
303
304 virtual CacheBlk* accessBlock(Addr addr, bool is_secure, Cycles &lat) = 0;
305
306 virtual Addr extractTag(Addr addr) const = 0;
307
308 /**
309 * Insert the new block into the cache and update stats.
310 *
311 * @param addr Address of the block.
312 * @param is_secure Whether the block is in secure space or not.
313 * @param src_master_ID The source requestor ID.
314 * @param task_ID The new task ID.
315 * @param blk The block to update.
316 */
317 virtual void insertBlock(const Addr addr, const bool is_secure,
318 const int src_master_ID, const uint32_t task_ID,
319 CacheBlk *blk);
320
321 /**
322 * Regenerate the block address.
323 *
324 * @param block The block.
325 * @return the block address.
326 */
327 virtual Addr regenerateBlkAddr(const CacheBlk* blk) const = 0;
328
329 /**
330 * Visit each block in the tags and apply a visitor
331 *
332 * The visitor should be a std::function that takes a cache block
333 * reference as its parameter.
334 *
335 * @param visitor Visitor to call on each block.
336 */
337 virtual void forEachBlk(std::function<void(CacheBlk &)> visitor) = 0;
338
339 /**
340 * Find if any of the blocks satisfies a condition
341 *
342 * The visitor should be a std::function that takes a cache block
343 * reference as its parameter. The visitor will terminate the
344 * traversal early if the condition is satisfied.
345 *
346 * @param visitor Visitor to call on each block.
347 */
348 virtual bool anyBlk(std::function<bool(CacheBlk &)> visitor) = 0;
349
350 private:
351 /**
352 * Update the reference stats using data from the input block
353 *
354 * @param blk The input block
355 */
356 void cleanupRefsVisitor(CacheBlk &blk);
357
358 /**
359 * Update the occupancy and age stats using data from the input block
360 *
361 * @param blk The input block
362 */
363 void computeStatsVisitor(CacheBlk &blk);
364};
365
366class BaseTagsCallback : public Callback
367{
368 BaseTags *tags;
369 public:
370 BaseTagsCallback(BaseTags *t) : tags(t) {}
371 virtual void process() { tags->cleanupRefs(); };
372};
373
374class BaseTagsDumpCallback : public Callback
375{
376 BaseTags *tags;
377 public:
378 BaseTagsDumpCallback(BaseTags *t) : tags(t) {}
379 virtual void process() { tags->computeStats(); };
380};
381
382#endif //__MEM_CACHE_TAGS_BASE_HH__