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[/] [openrisc/] [trunk/] [or1ksim/] [mmu/] [dmmu.c] - Blame information for rev 557

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1 19 jeremybenn
/* dmmu.c -- Data MMU simulation
2
 
3
   Copyright (C) 1999 Damjan Lampret, lampret@opencores.org
4
   Copyright (C) 2008 Embecosm Limited
5
 
6
   Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>
7
 
8
   This file is part of Or1ksim, the OpenRISC 1000 Architectural Simulator.
9
 
10
   This program is free software; you can redistribute it and/or modify it
11
   under the terms of the GNU General Public License as published by the Free
12
   Software Foundation; either version 3 of the License, or (at your option)
13
   any later version.
14
 
15
   This program is distributed in the hope that it will be useful, but WITHOUT
16
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17
   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
18
   more details.
19
 
20
   You should have received a copy of the GNU General Public License along
21
   with this program.  If not, see <http://www.gnu.org/licenses/>.  */
22
 
23
/* This program is commented throughout in a fashion suitable for processing
24
   with Doxygen. */
25
 
26
/* DMMU model, perfectly functional. */
27
 
28
 
29
/* Autoconf and/or portability configuration */
30
#include "config.h"
31
#include "port.h"
32
 
33
/* System includes */
34
#include <stdlib.h>
35
 
36
/* Package includes */
37
#include "dmmu.h"
38
#include "sim-config.h"
39
#include "arch.h"
40
#include "execute.h"
41
#include "spr-defs.h"
42
#include "stats.h"
43
#include "except.h"
44
#include "sprs.h"
45
#include "misc.h"
46
#include "sim-cmd.h"
47 556 julius
#include "pcu.h"
48 19 jeremybenn
 
49
struct dmmu *dmmu_state;
50
 
51
/* Data MMU */
52
 
53
static uorreg_t *
54
dmmu_find_tlbmr (oraddr_t virtaddr, uorreg_t ** dtlbmr_lru, struct dmmu *dmmu)
55
{
56
  int set;
57
  int i;
58
  oraddr_t vpn;
59
  uorreg_t *dtlbmr;
60
 
61
  /* Which set to check out? */
62
  set = DADDR_PAGE (virtaddr) >> dmmu->pagesize_log2;
63
  set &= dmmu->set_mask;
64
  vpn = virtaddr & dmmu->vpn_mask;
65
 
66
  dtlbmr = &cpu_state.sprs[SPR_DTLBMR_BASE (0) + set];
67
  *dtlbmr_lru = dtlbmr;
68
 
69
  /* FIXME: Should this be reversed? */
70
  for (i = dmmu->nways; i; i--, dtlbmr += (128 * 2))
71
    {
72
      if (((*dtlbmr & dmmu->vpn_mask) == vpn) && (*dtlbmr & SPR_DTLBMR_V))
73
        return dtlbmr;
74
    }
75
 
76
  return NULL;
77
}
78
 
79
oraddr_t
80
dmmu_translate (oraddr_t virtaddr, int write_access)
81
{
82
  int i;
83
  uorreg_t *dtlbmr;
84
  uorreg_t *dtlbtr;
85
  uorreg_t *dtlbmr_lru;
86
  struct dmmu *dmmu = dmmu_state;
87
 
88
  if (!(cpu_state.sprs[SPR_SR] & SPR_SR_DME) ||
89
      !(cpu_state.sprs[SPR_UPR] & SPR_UPR_DMP))
90
    {
91
      data_ci = (virtaddr >= 0x80000000);
92
      return virtaddr;
93
    }
94
 
95
  dtlbmr = dmmu_find_tlbmr (virtaddr, &dtlbmr_lru, dmmu);
96
 
97
  /* Did we find our tlb entry? */
98
  if (dtlbmr)
99
    {                           /* Yes, we did. */
100
      dmmu_stats.loads_tlbhit++;
101
 
102
      dtlbtr = dtlbmr + 128;
103
 
104
      /* Set LRUs */
105
      for (i = 0; i < dmmu->nways; i++, dtlbmr_lru += (128 * 2))
106
        {
107
          if (*dtlbmr_lru & SPR_DTLBMR_LRU)
108
            *dtlbmr_lru = (*dtlbmr_lru & ~SPR_DTLBMR_LRU) |
109
              ((*dtlbmr_lru & SPR_DTLBMR_LRU) - 0x40);
110
        }
111
 
112
      /* This is not necessary `*dtlbmr &= ~SPR_DTLBMR_LRU;' since SPR_DTLBMR_LRU
113
       * is always decremented and the number of sets is always a power of two and
114
       * as such lru_reload has all bits set that get touched during decrementing
115
       * SPR_DTLBMR_LRU */
116
      *dtlbmr |= dmmu->lru_reload;
117
 
118
      /* Check if page is cache inhibited */
119
      data_ci = *dtlbtr & SPR_DTLBTR_CI;
120
 
121
      runtime.sim.mem_cycles += dmmu->hitdelay;
122
 
123
      /* Test for page fault */
124
      if (cpu_state.sprs[SPR_SR] & SPR_SR_SM)
125
        {
126
          if ((write_access && !(*dtlbtr & SPR_DTLBTR_SWE))
127
              || (!write_access && !(*dtlbtr & SPR_DTLBTR_SRE)))
128
            except_handle (EXCEPT_DPF, virtaddr);
129
        }
130
      else
131
        {
132
          if ((write_access && !(*dtlbtr & SPR_DTLBTR_UWE))
133
              || (!write_access && !(*dtlbtr & SPR_DTLBTR_URE)))
134
            except_handle (EXCEPT_DPF, virtaddr);
135
        }
136
 
137
      return (*dtlbtr & SPR_DTLBTR_PPN) | (virtaddr &
138
                                           (dmmu->page_offset_mask));
139
    }
140
 
141
  /* No, we didn't. */
142
  dmmu_stats.loads_tlbmiss++;
143
 
144
  runtime.sim.mem_cycles += dmmu->missdelay;
145
  /* if tlb refill implemented in HW */
146
  /* return ((cpu_state.sprs[SPR_DTLBTR_BASE(minway) + set] & SPR_DTLBTR_PPN) >> 12) * dmmu->pagesize + (virtaddr % dmmu->pagesize); */
147
 
148
  except_handle (EXCEPT_DTLBMISS, virtaddr);
149 556 julius
 
150
  if (config.pcu.enabled)
151
    pcu_count_event(SPR_PCMR_DTLBM);
152
 
153 19 jeremybenn
  return 0;
154
}
155
 
156
/* DESC: try to find EA -> PA transaltion without changing
157
 *       any of precessor states. if this is not passible gives up
158
 *       (without triggering exceptions)
159
 *
160
 * PRMS: virtaddr     - EA for which to find translation
161
 *
162
 *       write_access - 0 ignore testing for write access
163
 *                      1 test for write access, if fails
164
 *                        do not return translation
165
 *
166
 *       through_dc   - 1 go through data cache
167
 *                      0 ignore data cache
168
 *
169
 * RTRN: 0            - no DMMU, DMMU disabled or ITLB miss
170
 *       else         - appropriate PA (note it DMMU is not present
171
 *                      PA === EA)
172
 */
173
oraddr_t
174
peek_into_dtlb (oraddr_t virtaddr, int write_access, int through_dc)
175
{
176
  uorreg_t *dtlbmr;
177
  uorreg_t *dtlbtr;
178
  uorreg_t *dtlbmr_lru;
179
  struct dmmu *dmmu = dmmu_state;
180
 
181
  if (!(cpu_state.sprs[SPR_SR] & SPR_SR_DME) ||
182
      !(cpu_state.sprs[SPR_UPR] & SPR_UPR_DMP))
183
    {
184
      if (through_dc)
185
        data_ci = (virtaddr >= 0x80000000);
186
      return virtaddr;
187
    }
188
 
189
  dtlbmr = dmmu_find_tlbmr (virtaddr, &dtlbmr_lru, dmmu);
190
 
191
  /* Did we find our tlb entry? */
192
  if (dtlbmr)
193
    {                           /* Yes, we did. */
194
      dmmu_stats.loads_tlbhit++;
195
 
196
      dtlbtr = dtlbmr + 128;
197
 
198
      /* Test for page fault */
199
      if (cpu_state.sprs[SPR_SR] & SPR_SR_SM)
200
        {
201
          if ((write_access && !(*dtlbtr & SPR_DTLBTR_SWE)) ||
202
              (!write_access && !(*dtlbtr & SPR_DTLBTR_SRE)))
203
 
204
            /* otherwise exception DPF would be raised */
205
            return (0);
206
        }
207
      else
208
        {
209
          if ((write_access && !(*dtlbtr & SPR_DTLBTR_UWE)) ||
210
              (!write_access && !(*dtlbtr & SPR_DTLBTR_URE)))
211
 
212
            /* otherwise exception DPF would be raised */
213
            return (0);
214
        }
215
 
216
      if (through_dc)
217
        {
218
          /* Check if page is cache inhibited */
219
          data_ci = *dtlbtr & SPR_DTLBTR_CI;
220
        }
221
 
222
      return (*dtlbtr & SPR_DTLBTR_PPN) | (virtaddr &
223
                                           (dmmu->page_offset_mask));
224
    }
225
 
226
  return (0);
227
}
228
 
229
/* FIXME: Is this comment valid? */
230
/* First check if virtual address is covered by DTLB and if it is:
231
    - increment DTLB read hit stats,
232
    - set 'lru' at this way to dmmu->ustates - 1 and
233
      decrement 'lru' of other ways unless they have reached 0,
234
    - check page access attributes and invoke DMMU page fault exception
235
      handler if necessary
236
   and if not:
237
    - increment DTLB read miss stats
238
    - find lru way and entry and invoke DTLB miss exception handler
239
    - set 'lru' with dmmu->ustates - 1 and decrement 'lru' of other
240
      ways unless they have reached 0
241
*/
242
 
243
static void
244
dtlb_status (void *dat)
245
{
246
  struct dmmu *dmmu = dat;
247
  int set;
248
  int way;
249
  int end_set = dmmu->nsets;
250
 
251
  if (!(cpu_state.sprs[SPR_UPR] & SPR_UPR_DMP))
252
    {
253
      PRINTF ("DMMU not implemented. Set UPR[DMP].\n");
254
      return;
255
    }
256
 
257
  if (0 < end_set)
258
    PRINTF ("\nDMMU: ");
259
  /* Scan set(s) and way(s). */
260
  for (set = 0; set < end_set; set++)
261
    {
262
      for (way = 0; way < dmmu->nways; way++)
263
        {
264
          PRINTF ("%s\n", dump_spr (SPR_DTLBMR_BASE (way) + set,
265
                                    cpu_state.sprs[SPR_DTLBMR_BASE (way) +
266
                                                   set]));
267
          PRINTF ("%s\n",
268
                  dump_spr (SPR_DTLBTR_BASE (way) + set,
269
                            cpu_state.sprs[SPR_DTLBTR_BASE (way) + set]));
270
        }
271
    }
272
  if (0 < end_set)
273
    PRINTF ("\n");
274
}
275
 
276
/*---------------------------------------------------[ DMMU configuration ]---*/
277
 
278
/*---------------------------------------------------------------------------*/
279
/*!Enable or disable the DMMU
280
 
281
   Set the corresponding field in the UPR
282
 
283
   @param[in] val  The value to use
284
   @param[in] dat  The config data structure                                 */
285
/*---------------------------------------------------------------------------*/
286
static void
287
dmmu_enabled (union param_val val, void *dat)
288
{
289
  struct dmmu *dmmu = dat;
290
 
291
  if (val.int_val)
292
    {
293
      cpu_state.sprs[SPR_UPR] |= SPR_UPR_DMP;
294
    }
295
  else
296
    {
297
      cpu_state.sprs[SPR_UPR] &= ~SPR_UPR_DMP;
298
    }
299
 
300
  dmmu->enabled = val.int_val;
301
 
302
}       /* dmmu_enabled() */
303
 
304
 
305
/*---------------------------------------------------------------------------*/
306
/*!Set the number of DMMU sets
307
 
308
   Value must be a power of 2 <= 256. Ignore any other values with a
309
   warning. Set the corresponding DMMU configuration flags.
310
 
311
   @param[in] val  The value to use
312
   @param[in] dat  The config data structure                                 */
313
/*---------------------------------------------------------------------------*/
314
static void
315
dmmu_nsets (union param_val  val,
316
            void            *dat)
317
{
318
  struct dmmu *dmmu = dat;
319
 
320
  if (is_power2 (val.int_val) && val.int_val <= 128)
321
    {
322
      int  set_bits = log2_int (val.int_val);
323
 
324
      dmmu->nsets = val.int_val;
325
 
326
      cpu_state.sprs[SPR_DMMUCFGR] &= ~SPR_DMMUCFGR_NTS;
327
      cpu_state.sprs[SPR_DMMUCFGR] |= set_bits << SPR_DMMUCFGR_NTS_OFF;
328
    }
329
  else
330
    {
331
      fprintf (stderr, "Warning DMMU nsets not a power of 2 <= 128: ignored\n");
332
    }
333
}       /* dmmu_nsets() */
334
 
335
 
336
/*---------------------------------------------------------------------------*/
337
/*!Set the number of DMMU ways
338
 
339
   Value must be in the range 1-4. Ignore other values with a warning. Set the
340
   corresponding DMMU configuration flags.
341
 
342
   @param[in] val  The value to use
343
   @param[in] dat  The config data structure                                 */
344
/*---------------------------------------------------------------------------*/
345
static void
346
dmmu_nways (union param_val  val,
347
            void            *dat)
348
{
349
  struct dmmu *dmmu = dat;
350
 
351
  if (val.int_val >= 1 && val.int_val <= 4)
352
    {
353
      int  way_bits = val.int_val - 1;
354
 
355
      dmmu->nways = val.int_val;
356
 
357
      cpu_state.sprs[SPR_DMMUCFGR] &= ~SPR_DMMUCFGR_NTW;
358
      cpu_state.sprs[SPR_DMMUCFGR] |= way_bits << SPR_DMMUCFGR_NTW_OFF;
359
    }
360
  else
361
    {
362
      fprintf (stderr, "Warning DMMU nways not in range 1-4: ignored\n");
363
    }
364
}       /* dmmu_nways() */
365
 
366
 
367
/*---------------------------------------------------------------------------*/
368
/*!Set the DMMU page size
369
 
370
   Value must be a power of 2. Ignore other values with a warning
371
 
372
   @param[in] val  The value to use
373
   @param[in] dat  The config data structure                                 */
374
/*---------------------------------------------------------------------------*/
375
static void
376
dmmu_pagesize (union param_val  val,
377
               void            *dat)
378
{
379
  struct dmmu *dmmu = dat;
380
 
381
  if (is_power2 (val.int_val))
382
    {
383
      dmmu->pagesize = val.int_val;
384
    }
385
  else
386
    {
387
      fprintf (stderr, "Warning DMMU page size must be power of 2: ignored\n");
388
    }
389
}       /* dmmu_pagesize() */
390
 
391
 
392
/*---------------------------------------------------------------------------*/
393
/*!Set the DMMU entry size
394
 
395
   Value must be a power of 2. Ignore other values with a warning
396
 
397
   @param[in] val  The value to use
398
   @param[in] dat  The config data structure                                 */
399
/*---------------------------------------------------------------------------*/
400
static void
401
dmmu_entrysize (union param_val  val,
402
                void            *dat)
403
{
404
  struct dmmu *dmmu = dat;
405
 
406
  if (is_power2 (val.int_val))
407
    {
408
      dmmu->entrysize = val.int_val;
409
    }
410
  else
411
    {
412
      fprintf (stderr, "Warning DMMU entry size must be power of 2: ignored\n");
413
    }
414
}       /* dmmu_entrysize() */
415
 
416
 
417
/*---------------------------------------------------------------------------*/
418
/*!Set the number of DMMU usage states
419
 
420
   Value must be 2, 3 or 4. Ignore other values with a warning
421
 
422
   @param[in] val  The value to use
423
   @param[in] dat  The config data structure                                 */
424
/*---------------------------------------------------------------------------*/
425
static void
426
dmmu_ustates (union param_val  val,
427
              void            *dat)
428
{
429
  struct dmmu *dmmu = dat;
430
 
431
  if ((val.int_val >= 2) && (val.int_val <= 4))
432
    {
433
      dmmu->ustates = val.int_val;
434
    }
435
  else
436
    {
437
      fprintf (stderr, "Warning number of DMMU usage states must be 2, 3 or 4:"
438
               "ignored\n");
439
    }
440
}       /* dmmu_ustates() */
441
 
442
 
443
static void
444
dmmu_missdelay (union param_val val, void *dat)
445
{
446
  struct dmmu *dmmu = dat;
447
 
448
  dmmu->missdelay = val.int_val;
449
}
450
 
451
static void
452
dmmu_hitdelay (union param_val val, void *dat)
453
{
454
  struct dmmu *dmmu = dat;
455
 
456
  dmmu->hitdelay = val.int_val;
457
}
458
 
459
/*---------------------------------------------------------------------------*/
460
/*!Initialize a new DMMU configuration
461
 
462
   ALL parameters are set explicitly to default values. Corresponding SPR
463
   flags are set as appropriate.
464
 
465
   @return  The new memory configuration data structure                      */
466
/*---------------------------------------------------------------------------*/
467
static void *
468
dmmu_start_sec ()
469
{
470
  struct dmmu *dmmu;
471
  int          set_bits;
472
  int          way_bits;
473
 
474
  if (NULL == (dmmu = malloc (sizeof (struct dmmu))))
475
    {
476
      fprintf (stderr, "OOM\n");
477
      exit (1);
478
    }
479
 
480
  dmmu->enabled   = 0;
481
  dmmu->nsets     = 1;
482
  dmmu->nways     = 1;
483
  dmmu->pagesize  = 8192;
484
  dmmu->entrysize = 1;          /* Not currently used */
485
  dmmu->ustates   = 2;
486
  dmmu->hitdelay  = 1;
487
  dmmu->missdelay = 1;
488
 
489
  if (dmmu->enabled)
490
    {
491
      cpu_state.sprs[SPR_UPR] |= SPR_UPR_DMP;
492
    }
493
  else
494
    {
495
      cpu_state.sprs[SPR_UPR] &= ~SPR_UPR_DMP;
496
    }
497
 
498
  set_bits = log2_int (dmmu->nsets);
499
  cpu_state.sprs[SPR_DMMUCFGR] &= ~SPR_DMMUCFGR_NTS;
500
  cpu_state.sprs[SPR_DMMUCFGR] |= set_bits << SPR_DMMUCFGR_NTS_OFF;
501
 
502
  way_bits = dmmu->nways - 1;
503
  cpu_state.sprs[SPR_DMMUCFGR] &= ~SPR_DMMUCFGR_NTW;
504
  cpu_state.sprs[SPR_DMMUCFGR] |= way_bits << SPR_DMMUCFGR_NTW_OFF;
505
 
506
  dmmu_state = dmmu;
507
  return dmmu;
508
 
509
}       /* dmmu_start_sec() */
510
 
511
 
512
static void
513
dmmu_end_sec (void *dat)
514
{
515
  struct dmmu *dmmu = dat;
516
 
517
  /* Precalculate some values for use during address translation */
518
  dmmu->pagesize_log2 = log2_int (dmmu->pagesize);
519
  dmmu->page_offset_mask = dmmu->pagesize - 1;
520
  dmmu->page_mask = ~dmmu->page_offset_mask;
521
  dmmu->vpn_mask = ~((dmmu->pagesize * dmmu->nsets) - 1);
522
  dmmu->set_mask = dmmu->nsets - 1;
523
  dmmu->lru_reload = (dmmu->set_mask << 6) & SPR_DTLBMR_LRU;
524
 
525
  if (dmmu->enabled)
526
    {
527
      PRINTF ("Data MMU %dKB: %d ways, %d sets, entry size %d bytes\n",
528
              dmmu->nsets * dmmu->entrysize * dmmu->nways / 1024, dmmu->nways,
529
              dmmu->nsets, dmmu->entrysize);
530
      reg_sim_stat (dtlb_status, dmmu);
531
    }
532
}
533
 
534
void
535
reg_dmmu_sec (void)
536
{
537
  struct config_section *sec = reg_config_sec ("dmmu", dmmu_start_sec,
538
                                               dmmu_end_sec);
539
 
540 224 jeremybenn
  reg_config_param (sec, "enabled",   PARAMT_INT, dmmu_enabled);
541
  reg_config_param (sec, "nsets",     PARAMT_INT, dmmu_nsets);
542
  reg_config_param (sec, "nways",     PARAMT_INT, dmmu_nways);
543
  reg_config_param (sec, "pagesize",  PARAMT_INT, dmmu_pagesize);
544
  reg_config_param (sec, "entrysize", PARAMT_INT, dmmu_entrysize);
545
  reg_config_param (sec, "ustates",   PARAMT_INT, dmmu_ustates);
546
  reg_config_param (sec, "hitdelay",  PARAMT_INT, dmmu_hitdelay);
547
  reg_config_param (sec, "missdelay", PARAMT_INT, dmmu_missdelay);
548 19 jeremybenn
}

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