1/*
2 * Copyright (c) 2002-2005 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Erik Hallnor
29 * Dave Greene
30 * Steve Reinhardt
31 * Ron Dreslinski
32 */
33
34/**
35 * @file
36 * Describes a cache based on template policies.
37 */
38
39#ifndef __CACHE_HH__
40#define __CACHE_HH__
41
42#include "base/compression/base.hh"
43#include "base/misc.hh" // fatal, panic, and warn
44#include "cpu/smt.hh" // SMT_MAX_THREADS
45
46#include "mem/cache/base_cache.hh"
47#include "mem/cache/cache_blk.hh"
48#include "mem/cache/miss/mshr.hh"
49
50#include "sim/eventq.hh"
51
52//Forward decleration
53class BasePrefetcher;
54
55/**
56 * A template-policy based cache. The behavior of the cache can be altered by
57 * supplying different template policies. TagStore handles all tag and data
58 * storage @sa TagStore. Buffering handles all misses and writes/writebacks
59 * @sa MissQueue. Coherence handles all coherence policy details @sa
60 * UniCoherence, SimpleMultiCoherence.
61 */
62template <class TagStore, class Coherence>
63class Cache : public BaseCache
64{
65 public:
66 /** Define the type of cache block to use. */
67 typedef typename TagStore::BlkType BlkType;
68 /** A typedef for a list of BlkType pointers. */
69 typedef typename TagStore::BlkList BlkList;
70
71 bool prefetchAccess;
72
73 protected:
74
75 class CpuSidePort : public CachePort
76 {
77 public:
78 CpuSidePort(const std::string &_name,
79 Cache<TagStore,Coherence> *_cache);
80
81 // BaseCache::CachePort just has a BaseCache *; this function
82 // lets us get back the type info we lost when we stored the
83 // cache pointer there.
84 Cache<TagStore,Coherence> *myCache() {
85 return static_cast<Cache<TagStore,Coherence> *>(cache);
86 }
87
88 virtual void getDeviceAddressRanges(AddrRangeList &resp,
89 bool &snoop);
90
91 virtual bool recvTiming(PacketPtr pkt);
92
93 virtual Tick recvAtomic(PacketPtr pkt);
94
95 virtual void recvFunctional(PacketPtr pkt);
96 };
97
98 class MemSidePort : public CachePort
99 {
100 public:
101 MemSidePort(const std::string &_name,
102 Cache<TagStore,Coherence> *_cache);
103
104 // BaseCache::CachePort just has a BaseCache *; this function
105 // lets us get back the type info we lost when we stored the
106 // cache pointer there.
107 Cache<TagStore,Coherence> *myCache() {
108 return static_cast<Cache<TagStore,Coherence> *>(cache);
109 }
110
111 void sendPacket();
112
113 void processSendEvent();
114
115 virtual void getDeviceAddressRanges(AddrRangeList &resp,
116 bool &snoop);
117
118 virtual bool recvTiming(PacketPtr pkt);
119
120 virtual void recvRetry();
121
122 virtual Tick recvAtomic(PacketPtr pkt);
123
124 virtual void recvFunctional(PacketPtr pkt);
125
126 typedef EventWrapper<MemSidePort, &MemSidePort::processSendEvent>
127 SendEvent;
128 };
129
130 /** Tag and data Storage */
131 TagStore *tags;
132
133 /** Coherence protocol. */
134 Coherence *coherence;
135
136 /** Prefetcher */
137 BasePrefetcher *prefetcher;
138
139 /** Temporary cache block for occasional transitory use */
140 BlkType *tempBlock;
141
142 /**
143 * Can this cache should allocate a block on a line-sized write miss.
144 */
145 const bool doFastWrites;
146
147 const bool prefetchMiss;
148
149 /**
150 * Handle a replacement for the given request.
151 * @param blk A pointer to the block, usually NULL
152 * @param pkt The memory request to satisfy.
153 * @param new_state The new state of the block.
154 * @param writebacks A list to store any generated writebacks.
155 */
156 BlkType* doReplacement(BlkType *blk, PacketPtr pkt,
157 CacheBlk::State new_state, PacketList &writebacks);
158
159 /**
160 * Does all the processing necessary to perform the provided request.
161 * @param pkt The memory request to perform.
162 * @param lat The latency of the access.
163 * @param writebacks List for any writebacks that need to be performed.
164 * @param update True if the replacement data should be updated.
165 * @return Pointer to the cache block touched by the request. NULL if it
166 * was a miss.
167 */
168 bool access(PacketPtr pkt, BlkType *&blk, int &lat);
169
170 /**
171 *Handle doing the Compare and Swap function for SPARC.
172 */
173 void cmpAndSwap(BlkType *blk, PacketPtr pkt);
174
175 /**
176 * Populates a cache block and handles all outstanding requests for the
177 * satisfied fill request. This version takes two memory requests. One
178 * contains the fill data, the other is an optional target to satisfy.
179 * Used for Cache::probe.
180 * @param pkt The memory request with the fill data.
181 * @param blk The cache block if it already exists.
182 * @param writebacks List for any writebacks that need to be performed.
183 * @return Pointer to the new cache block.
184 */
185 BlkType *handleFill(PacketPtr pkt, BlkType *blk,
186 PacketList &writebacks);
187
188 void satisfyCpuSideRequest(PacketPtr pkt, BlkType *blk);
189 bool satisfyMSHR(MSHR *mshr, PacketPtr pkt, BlkType *blk);
190
191 void doTimingSupplyResponse(PacketPtr req_pkt, uint8_t *blk_data,
192 bool already_copied);
193
194 /**
195 * Sets the blk to the new state.
196 * @param blk The cache block being snooped.
197 * @param new_state The new coherence state for the block.
198 */
199 void handleSnoop(PacketPtr ptk, BlkType *blk,
200 bool is_timing, bool is_deferred);
201
202 /**
203 * Create a writeback request for the given block.
204 * @param blk The block to writeback.
205 * @return The writeback request for the block.
206 */
207 PacketPtr writebackBlk(BlkType *blk);
208
209 public:
210
211 class Params
212 {
213 public:
214 TagStore *tags;
215 Coherence *coherence;
216 BaseCache::Params baseParams;
217 BasePrefetcher*prefetcher;
218 bool prefetchAccess;
219 const bool doFastWrites;
220 const bool prefetchMiss;
221
222 Params(TagStore *_tags, Coherence *coh,
223 BaseCache::Params params,
224 BasePrefetcher *_prefetcher,
225 bool prefetch_access, int hit_latency,
226 bool do_fast_writes,
227 bool prefetch_miss)
228 : tags(_tags), coherence(coh),
229 baseParams(params),
230 prefetcher(_prefetcher), prefetchAccess(prefetch_access),
231 doFastWrites(do_fast_writes),
232 prefetchMiss(prefetch_miss)
233 {
234 }
235 };
236
237 /** Instantiates a basic cache object. */
238 Cache(const std::string &_name, Params &params);
239
240 virtual Port *getPort(const std::string &if_name, int idx = -1);
241 virtual void deletePortRefs(Port *p);
242
243 void regStats();
244
245 /**
246 * Performs the access specified by the request.
247 * @param pkt The request to perform.
248 * @return The result of the access.
249 */
250 bool timingAccess(PacketPtr pkt);
251
252 /**
253 * Performs the access specified by the request.
254 * @param pkt The request to perform.
255 * @return The result of the access.
256 */
257 Tick atomicAccess(PacketPtr pkt);
258
259 /**
260 * Performs the access specified by the request.
261 * @param pkt The request to perform.
262 * @return The result of the access.
263 */
264 void functionalAccess(PacketPtr pkt, CachePort *otherSidePort);
265
266 /**
267 * Handles a response (cache line fill/write ack) from the bus.
268 * @param pkt The request being responded to.
269 */
270 void handleResponse(PacketPtr pkt);
271
272 /**
273 * Snoops bus transactions to maintain coherence.
274 * @param pkt The current bus transaction.
275 */
276 void snoopTiming(PacketPtr pkt);
277
278 /**
279 * Snoop for the provided request in the cache and return the estimated
280 * time of completion.
281 * @param pkt The memory request to snoop
282 * @return The estimated completion time.
283 */
284 Tick snoopAtomic(PacketPtr pkt);
285
286 /**
287 * Squash all requests associated with specified thread.
288 * intended for use by I-cache.
289 * @param threadNum The thread to squash.
290 */
291 void squash(int threadNum);
292
293 /**
294 * Selects a outstanding request to service.
295 * @return The request to service, NULL if none found.
296 */
297 PacketPtr getBusPacket(PacketPtr cpu_pkt, BlkType *blk,
298 bool needsExclusive);
299 MSHR *getNextMSHR();
300 PacketPtr getTimingPacket();
301
302 /**
303 * Marks a request as in service (sent on the bus). This can have side
304 * effect since storage for no response commands is deallocated once they
305 * are successfully sent.
306 * @param pkt The request that was sent on the bus.
307 */
308 void markInService(MSHR *mshr);
309
310 /**
311 * Perform the given writeback request.
312 * @param pkt The writeback request.
313 */
314 void doWriteback(PacketPtr pkt);
315
316 /**
317 * Return whether there are any outstanding misses.
318 */
319 bool outstandingMisses() const
320 {
321 return mshrQueue.allocated != 0;
322 }
323
324 CacheBlk *findBlock(Addr addr) {
325 return tags->findBlock(addr);
326 }
327
328 bool inCache(Addr addr) {
329 return (tags->findBlock(addr) != 0);
330 }
331
332 bool inMissQueue(Addr addr) {
333 return (mshrQueue.findMatch(addr) != 0);
334 }
335};
336
337#endif // __CACHE_HH__