1 /* Cache support for the FRV simulator
2 Copyright (C) 1999, 2000, 2003, 2007, 2008, 2009, 2010, 2011
3 Free Software Foundation, Inc.
4 Contributed by Red Hat.
6 This file is part of the GNU Simulators.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
24 /* A representation of a set-associative cache with LRU replacement,
25 cache line locking, non-blocking support and multiple read ports. */
27 /* An enumeration of cache pipeline request kinds. */
37 } FRV_CACHE_REQUEST_KIND;
39 /* The cache pipeline requests. */
43 } FRV_CACHE_WAR_REQUEST;
48 } FRV_CACHE_STORE_REQUEST;
53 } FRV_CACHE_INVALIDATE_REQUEST;
58 } FRV_CACHE_PRELOAD_REQUEST;
60 /* A cache pipeline request. */
61 typedef struct frv_cache_request
63 struct frv_cache_request *next;
64 struct frv_cache_request *prev;
65 FRV_CACHE_REQUEST_KIND kind;
70 FRV_CACHE_STORE_REQUEST store;
71 FRV_CACHE_INVALIDATE_REQUEST invalidate;
72 FRV_CACHE_PRELOAD_REQUEST preload;
73 FRV_CACHE_WAR_REQUEST WAR;
77 /* The buffer for returning data to the caller. */
83 } FRV_CACHE_RETURN_BUFFER;
85 /* The status of flush requests. */
90 } FRV_CACHE_FLUSH_STATUS;
92 /* Communicate status of requests to the caller. */
94 FRV_CACHE_FLUSH_STATUS flush;
95 FRV_CACHE_RETURN_BUFFER return_buffer;
98 /* A cache pipeline stage. */
100 FRV_CACHE_REQUEST *request;
105 A_STAGE = FIRST_STAGE, /* Addressing stage */
106 I_STAGE, /* Interference stage */
107 LAST_STAGE = I_STAGE,
111 /* Representation of the WAR register. */
122 /* A cache pipeline. */
125 FRV_CACHE_REQUEST *requests;
126 FRV_CACHE_STAGE stages[FRV_CACHE_STAGES];
127 FRV_CACHE_WAR WAR[NUM_WARS];
128 FRV_CACHE_STATUS status;
129 } FRV_CACHE_PIPELINE;
131 enum {LS, LD, FRV_CACHE_PIPELINES};
133 /* Representation of the xARS registers. */
146 USI tag; /* Address tag. */
147 int lru; /* Lower values indicates less recently used. */
148 char *line; /* Points to storage for line in data_storage. */
149 char dirty; /* line has been written to since last stored? */
150 char locked; /* line is locked? */
151 char valid; /* tag is valid? */
154 /* Cache statistics. */
156 unsigned long accesses; /* number of cache accesses. */
157 unsigned long hits; /* number of cache hits. */
158 } FRV_CACHE_STATISTICS;
162 - line_size must be a power of 2
163 - sets must be a power of 2
164 - ways must be a power of 2
168 unsigned configured_ways; /* Number of ways configured in each set. */
169 unsigned configured_sets; /* Number of sets configured in the cache. */
170 unsigned ways; /* Number of ways in each set. */
171 unsigned sets; /* Number of sets in the cache. */
172 unsigned line_size; /* Size of each cache line. */
173 unsigned memory_latency; /* Latency of main memory in cycles. */
174 FRV_CACHE_TAG *tag_storage; /* Storage for tags. */
175 char *data_storage; /* Storage for data (cache lines). */
176 FRV_CACHE_PIPELINE pipeline[2]; /* Cache pipelines. */
177 FRV_CACHE_ARS BARS; /* BARS register. */
178 FRV_CACHE_ARS NARS; /* BARS register. */
179 FRV_CACHE_STATISTICS statistics; /* Operation statistics. */
182 /* The tags are stored by ways within sets in order to make computations
184 #define CACHE_TAG(cache, set, way) ( \
185 & ((cache)->tag_storage[(set) * (cache)->ways + (way)]) \
188 /* Compute the address tag corresponding to the given address. */
189 #define CACHE_ADDRESS_TAG(cache, address) ( \
190 (address) & ~(((cache)->line_size * (cache)->sets) - 1) \
193 /* Determine the index at which the set containing this tag starts. */
194 #define CACHE_TAG_SET_START(cache, tag) ( \
195 ((tag) - (cache)->tag_storage) & ~((cache)->ways - 1) \
198 /* Determine the number of the set which this cache tag is in. */
199 #define CACHE_TAG_SET_NUMBER(cache, tag) ( \
200 CACHE_TAG_SET_START ((cache), (tag)) / (cache)->ways \
203 #define CACHE_RETURN_DATA(cache, slot, address, mode, N) ( \
204 T2H_##N (*(mode *)(& (cache)->pipeline[slot].status.return_buffer.data \
205 [((address) & ((cache)->line_size - 1))])) \
207 #define CACHE_RETURN_DATA_ADDRESS(cache, slot, address, N) ( \
208 ((void *)& (cache)->pipeline[slot].status.return_buffer.data[(address) \
209 & ((cache)->line_size - 1)]) \
212 #define DATA_CROSSES_CACHE_LINE(cache, address, size) ( \
213 ((address) & ((cache)->line_size - 1)) + (size) > (cache)->line_size \
216 #define CACHE_INITIALIZED(cache) ((cache)->data_storage != NULL)
218 /* These functions are used to initialize and terminate a cache. */
220 frv_cache_init (SIM_CPU *, FRV_CACHE *);
222 frv_cache_term (FRV_CACHE *);
224 frv_cache_reconfigure (SIM_CPU *, FRV_CACHE *);
226 frv_cache_enabled (FRV_CACHE *);
228 /* These functions are used to operate the cache in non-cycle-accurate mode.
229 Each request is handled individually and immediately using the current
230 cache internal state. */
232 frv_cache_read (FRV_CACHE *, int, SI);
234 frv_cache_write (FRV_CACHE *, SI, char *, unsigned);
236 frv_cache_preload (FRV_CACHE *, SI, USI, int);
238 frv_cache_invalidate (FRV_CACHE *, SI, int);
240 frv_cache_invalidate_all (FRV_CACHE *, int);
242 /* These functions are used to operate the cache in cycle-accurate mode.
243 The internal operation of the cache is simulated down to the cycle level. */
244 #define NO_REQNO 0xffffffff
246 frv_cache_request_load (FRV_CACHE *, unsigned, SI, int);
248 frv_cache_request_store (FRV_CACHE *, SI, int, char *, unsigned);
250 frv_cache_request_invalidate (FRV_CACHE *, unsigned, SI, int, int, int);
252 frv_cache_request_preload (FRV_CACHE *, SI, int, int, int);
254 frv_cache_request_unlock (FRV_CACHE *, SI, int);
257 frv_cache_run (FRV_CACHE *, int);
260 frv_cache_data_in_buffer (FRV_CACHE*, int, SI, unsigned);
262 frv_cache_data_flushed (FRV_CACHE*, int, SI, unsigned);
265 frv_cache_read_passive_SI (FRV_CACHE *, SI, SI *);