gdb/dcache.c

   1 /* Caching code for GDB, the GNU debugger.
   2
   3    Copyright (C) 1992-2014 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "dcache.h"
  22 #include "gdbcmd.h"
  23 #include <string.h>
  24 #include "gdbcore.h"
  25 #include "target-dcache.h"
  26 #include "inferior.h"
  27 #include "splay-tree.h"
  28
  29 /* Commands with a prefix of `{set,show} dcache'.  */
  30 static struct cmd_list_element *dcache_set_list = NULL;
  31 static struct cmd_list_element *dcache_show_list = NULL;
  32
  33 /* The data cache could lead to incorrect results because it doesn't
  34    know about volatile variables, thus making it impossible to debug
  35    functions which use memory mapped I/O devices.  Set the nocache
  36    memory region attribute in those cases.
  37
  38    In general the dcache speeds up performance.  Some speed improvement
  39    comes from the actual caching mechanism, but the major gain is in
  40    the reduction of the remote protocol overhead; instead of reading
  41    or writing a large area of memory in 4 byte requests, the cache
  42    bundles up the requests into LINE_SIZE chunks, reducing overhead
  43    significantly.  This is most useful when accessing a large amount
  44    of data, such as when performing a backtrace.
  45
  46    The cache is a splay tree along with a linked list for replacement.
  47    Each block caches a LINE_SIZE area of memory.  Within each line we
  48    remember the address of the line (which must be a multiple of
  49    LINE_SIZE) and the actual data block.
  50
  51    Lines are only allocated as needed, so DCACHE_SIZE really specifies the
  52    *maximum* number of lines in the cache.
  53
  54    At present, the cache is write-through rather than writeback: as soon
  55    as data is written to the cache, it is also immediately written to
  56    the target.  Therefore, cache lines are never "dirty".  Whether a given
  57    line is valid or not depends on where it is stored in the dcache_struct;
  58    there is no per-block valid flag.  */
  59
  60 /* NOTE: Interaction of dcache and memory region attributes
  61
  62    As there is no requirement that memory region attributes be aligned
  63    to or be a multiple of the dcache page size, dcache_read_line() and
  64    dcache_write_line() must break up the page by memory region.  If a
  65    chunk does not have the cache attribute set, an invalid memory type
  66    is set, etc., then the chunk is skipped.  Those chunks are handled
  67    in target_xfer_memory() (or target_xfer_memory_partial()).
  68
  69    This doesn't occur very often.  The most common occurance is when
  70    the last bit of the .text segment and the first bit of the .data
  71    segment fall within the same dcache page with a ro/cacheable memory
  72    region defined for the .text segment and a rw/non-cacheable memory
  73    region defined for the .data segment.  */
  74
  75 /* The maximum number of lines stored.  The total size of the cache is
  76    equal to DCACHE_SIZE times LINE_SIZE.  */
  77 #define DCACHE_DEFAULT_SIZE 4096
  78 static unsigned dcache_size = DCACHE_DEFAULT_SIZE;
  79
  80 /* The default size of a cache line.  Smaller values reduce the time taken to
  81    read a single byte and make the cache more granular, but increase
  82    overhead and reduce the effectiveness of the cache as a prefetcher.  */
  83 #define DCACHE_DEFAULT_LINE_SIZE 64
  84 static unsigned dcache_line_size = DCACHE_DEFAULT_LINE_SIZE;
  85
  86 /* Each cache block holds LINE_SIZE bytes of data
  87    starting at a multiple-of-LINE_SIZE address.  */
  88
  89 #define LINE_SIZE_MASK(dcache)  ((dcache->line_size - 1))
  90 #define XFORM(dcache, x)        ((x) & LINE_SIZE_MASK (dcache))
  91 #define MASK(dcache, x)         ((x) & ~LINE_SIZE_MASK (dcache))
  92
  93 struct dcache_block
  94 {
  95   /* For least-recently-allocated and free lists.  */
  96   struct dcache_block *prev;
  97   struct dcache_block *next;
  98
  99   CORE_ADDR addr;               /* address of data */
 100   int refs;                     /* # hits */
 101   gdb_byte data[1];             /* line_size bytes at given address */
 102 };
 103
 104 struct dcache_struct
 105 {
 106   splay_tree tree;
 107   struct dcache_block *oldest; /* least-recently-allocated list.  */
 108
 109   /* The free list is maintained identically to OLDEST to simplify
 110      the code: we only need one set of accessors.  */
 111   struct dcache_block *freelist;
 112
 113   /* The number of in-use lines in the cache.  */
 114   int size;
 115   CORE_ADDR line_size;  /* current line_size.  */
 116
 117   /* The ptid of last inferior to use cache or null_ptid.  */
 118   ptid_t ptid;
 119 };
 120
 121 typedef void (block_func) (struct dcache_block *block, void *param);
 122
 123 static struct dcache_block *dcache_hit (DCACHE *dcache, CORE_ADDR addr);
 124
 125 static int dcache_read_line (DCACHE *dcache, struct dcache_block *db);
 126
 127 static struct dcache_block *dcache_alloc (DCACHE *dcache, CORE_ADDR addr);
 128
 129 static void dcache_info (char *exp, int tty);
 130
 131 void _initialize_dcache (void);
 132
 133 static int dcache_enabled_p = 0; /* OBSOLETE */
 134
 135 static void
 136 show_dcache_enabled_p (struct ui_file *file, int from_tty,
 137                        struct cmd_list_element *c, const char *value)
 138 {
 139   fprintf_filtered (file, _("Deprecated remotecache flag is %s.\n"), value);
 140 }
 141
 142 /* Add BLOCK to circular block list BLIST, behind the block at *BLIST.
 143    *BLIST is not updated (unless it was previously NULL of course).
 144    This is for the least-recently-allocated list's sake:
 145    BLIST points to the oldest block.
 146    ??? This makes for poor cache usage of the free list,
 147    but is it measurable?  */
 148
 149 static void
 150 append_block (struct dcache_block **blist, struct dcache_block *block)
 151 {
 152   if (*blist)
 153     {
 154       block->next = *blist;
 155       block->prev = (*blist)->prev;
 156       block->prev->next = block;
 157       (*blist)->prev = block;
 158       /* We don't update *BLIST here to maintain the invariant that for the
 159          least-recently-allocated list *BLIST points to the oldest block.  */
 160     }
 161   else
 162     {
 163       block->next = block;
 164       block->prev = block;
 165       *blist = block;
 166     }
 167 }
 168
 169 /* Remove BLOCK from circular block list BLIST.  */
 170
 171 static void
 172 remove_block (struct dcache_block **blist, struct dcache_block *block)
 173 {
 174   if (block->next == block)
 175     {
 176       *blist = NULL;
 177     }
 178   else
 179     {
 180       block->next->prev = block->prev;
 181       block->prev->next = block->next;
 182       /* If we removed the block *BLIST points to, shift it to the next block
 183          to maintain the invariant that for the least-recently-allocated list
 184          *BLIST points to the oldest block.  */
 185       if (*blist == block)
 186         *blist = block->next;
 187     }
 188 }
 189
 190 /* Iterate over all elements in BLIST, calling FUNC.
 191    PARAM is passed to FUNC.
 192    FUNC may remove the block it's passed, but only that block.  */
 193
 194 static void
 195 for_each_block (struct dcache_block **blist, block_func *func, void *param)
 196 {
 197   struct dcache_block *db;
 198
 199   if (*blist == NULL)
 200     return;
 201
 202   db = *blist;
 203   do
 204     {
 205       struct dcache_block *next = db->next;
 206
 207       func (db, param);
 208       db = next;
 209     }
 210   while (*blist && db != *blist);
 211 }
 212
 213 /* BLOCK_FUNC routine for dcache_free.  */
 214
 215 static void
 216 free_block (struct dcache_block *block, void *param)
 217 {
 218   xfree (block);
 219 }
 220
 221 /* Free a data cache.  */
 222
 223 void
 224 dcache_free (DCACHE *dcache)
 225 {
 226   splay_tree_delete (dcache->tree);
 227   for_each_block (&dcache->oldest, free_block, NULL);
 228   for_each_block (&dcache->freelist, free_block, NULL);
 229   xfree (dcache);
 230 }
 231
 232
 233 /* BLOCK_FUNC function for dcache_invalidate.
 234    This doesn't remove the block from the oldest list on purpose.
 235    dcache_invalidate will do it later.  */
 236
 237 static void
 238 invalidate_block (struct dcache_block *block, void *param)
 239 {
 240   DCACHE *dcache = (DCACHE *) param;
 241
 242   splay_tree_remove (dcache->tree, (splay_tree_key) block->addr);
 243   append_block (&dcache->freelist, block);
 244 }
 245
 246 /* Free all the data cache blocks, thus discarding all cached data.  */
 247
 248 void
 249 dcache_invalidate (DCACHE *dcache)
 250 {
 251   for_each_block (&dcache->oldest, invalidate_block, dcache);
 252
 253   dcache->oldest = NULL;
 254   dcache->size = 0;
 255   dcache->ptid = null_ptid;
 256
 257   if (dcache->line_size != dcache_line_size)
 258     {
 259       /* We've been asked to use a different line size.
 260          All of our freelist blocks are now the wrong size, so free them.  */
 261
 262       for_each_block (&dcache->freelist, free_block, dcache);
 263       dcache->freelist = NULL;
 264       dcache->line_size = dcache_line_size;
 265     }
 266 }
 267
 268 /* Invalidate the line associated with ADDR.  */
 269
 270 static void
 271 dcache_invalidate_line (DCACHE *dcache, CORE_ADDR addr)
 272 {
 273   struct dcache_block *db = dcache_hit (dcache, addr);
 274
 275   if (db)
 276     {
 277       splay_tree_remove (dcache->tree, (splay_tree_key) db->addr);
 278       remove_block (&dcache->oldest, db);
 279       append_block (&dcache->freelist, db);
 280       --dcache->size;
 281     }
 282 }
 283
 284 /* If addr is present in the dcache, return the address of the block
 285    containing it.  Otherwise return NULL.  */
 286
 287 static struct dcache_block *
 288 dcache_hit (DCACHE *dcache, CORE_ADDR addr)
 289 {
 290   struct dcache_block *db;
 291
 292   splay_tree_node node = splay_tree_lookup (dcache->tree,
 293                                             (splay_tree_key) MASK (dcache, addr));
 294
 295   if (!node)
 296     return NULL;
 297
 298   db = (struct dcache_block *) node->value;
 299   db->refs++;
 300   return db;
 301 }
 302
 303 /* Fill a cache line from target memory.
 304    The result is 1 for success, 0 if the (entire) cache line
 305    wasn't readable.  */
 306
 307 static int
 308 dcache_read_line (DCACHE *dcache, struct dcache_block *db)
 309 {
 310   CORE_ADDR memaddr;
 311   gdb_byte *myaddr;
 312   int len;
 313   int res;
 314   int reg_len;
 315   struct mem_region *region;
 316
 317   len = dcache->line_size;
 318   memaddr = db->addr;
 319   myaddr  = db->data;
 320
 321   while (len > 0)
 322     {
 323       /* Don't overrun if this block is right at the end of the region.  */
 324       region = lookup_mem_region (memaddr);
 325       if (region->hi == 0 || memaddr + len < region->hi)
 326         reg_len = len;
 327       else
 328         reg_len = region->hi - memaddr;
 329
 330       /* Skip non-readable regions.  The cache attribute can be ignored,
 331          since we may be loading this for a stack access.  */
 332       if (region->attrib.mode == MEM_WO)
 333         {
 334           memaddr += reg_len;
 335           myaddr  += reg_len;
 336           len     -= reg_len;
 337           continue;
 338         }
 339
 340       res = target_read_raw_memory (memaddr, myaddr, reg_len);
 341       if (res != 0)
 342         return 0;
 343
 344       memaddr += reg_len;
 345       myaddr += reg_len;
 346       len -= reg_len;
 347     }
 348
 349   return 1;
 350 }
 351
 352 /* Get a free cache block, put or keep it on the valid list,
 353    and return its address.  */
 354
 355 static struct dcache_block *
 356 dcache_alloc (DCACHE *dcache, CORE_ADDR addr)
 357 {
 358   struct dcache_block *db;
 359
 360   if (dcache->size >= dcache_size)
 361     {
 362       /* Evict the least recently allocated line.  */
 363       db = dcache->oldest;
 364       remove_block (&dcache->oldest, db);
 365
 366       splay_tree_remove (dcache->tree, (splay_tree_key) db->addr);
 367     }
 368   else
 369     {
 370       db = dcache->freelist;
 371       if (db)
 372         remove_block (&dcache->freelist, db);
 373       else
 374         db = xmalloc (offsetof (struct dcache_block, data) +
 375                       dcache->line_size);
 376
 377       dcache->size++;
 378     }
 379
 380   db->addr = MASK (dcache, addr);
 381   db->refs = 0;
 382
 383   /* Put DB at the end of the list, it's the newest.  */
 384   append_block (&dcache->oldest, db);
 385
 386   splay_tree_insert (dcache->tree, (splay_tree_key) db->addr,
 387                      (splay_tree_value) db);
 388
 389   return db;
 390 }
 391
 392 /* Using the data cache DCACHE, store in *PTR the contents of the byte at
 393    address ADDR in the remote machine.
 394
 395    Returns 1 for success, 0 for error.  */
 396
 397 static int
 398 dcache_peek_byte (DCACHE *dcache, CORE_ADDR addr, gdb_byte *ptr)
 399 {
 400   struct dcache_block *db = dcache_hit (dcache, addr);
 401
 402   if (!db)
 403     {
 404       db = dcache_alloc (dcache, addr);
 405
 406       if (!dcache_read_line (dcache, db))
 407          return 0;
 408     }
 409
 410   *ptr = db->data[XFORM (dcache, addr)];
 411   return 1;
 412 }
 413
 414 /* Write the byte at PTR into ADDR in the data cache.
 415
 416    The caller should have written the data through to target memory
 417    already.
 418
 419    If ADDR is not in cache, this function does nothing; writing to an
 420    area of memory which wasn't present in the cache doesn't cause it
 421    to be loaded in.  */
 422
 423 static void
 424 dcache_poke_byte (DCACHE *dcache, CORE_ADDR addr, const gdb_byte *ptr)
 425 {
 426   struct dcache_block *db = dcache_hit (dcache, addr);
 427
 428   if (db)
 429     db->data[XFORM (dcache, addr)] = *ptr;
 430 }
 431
 432 static int
 433 dcache_splay_tree_compare (splay_tree_key a, splay_tree_key b)
 434 {
 435   if (a > b)
 436     return 1;
 437   else if (a == b)
 438     return 0;
 439   else
 440     return -1;
 441 }
 442
 443 /* Allocate and initialize a data cache.  */
 444
 445 DCACHE *
 446 dcache_init (void)
 447 {
 448   DCACHE *dcache;
 449
 450   dcache = (DCACHE *) xmalloc (sizeof (*dcache));
 451
 452   dcache->tree = splay_tree_new (dcache_splay_tree_compare,
 453                                  NULL,
 454                                  NULL);
 455
 456   dcache->oldest = NULL;
 457   dcache->freelist = NULL;
 458   dcache->size = 0;
 459   dcache->line_size = dcache_line_size;
 460   dcache->ptid = null_ptid;
 461
 462   return dcache;
 463 }
 464
 465
 466 /* Read LEN bytes from dcache memory at MEMADDR, transferring to
 467    debugger address MYADDR.  If the data is presently cached, this
 468    fills the cache.  Arguments/return are like the target_xfer_partial
 469    interface.  */
 470
 471 enum target_xfer_status
 472 dcache_read_memory_partial (struct target_ops *ops, DCACHE *dcache,
 473                             CORE_ADDR memaddr, gdb_byte *myaddr,
 474                             ULONGEST len, ULONGEST *xfered_len)
 475 {
 476   ULONGEST i;
 477
 478   /* If this is a different inferior from what we've recorded,
 479      flush the cache.  */
 480
 481   if (! ptid_equal (inferior_ptid, dcache->ptid))
 482     {
 483       dcache_invalidate (dcache);
 484       dcache->ptid = inferior_ptid;
 485     }
 486
 487   for (i = 0; i < len; i++)
 488     {
 489       if (!dcache_peek_byte (dcache, memaddr + i, myaddr + i))
 490         {
 491           /* That failed.  Discard its cache line so we don't have a
 492              partially read line.  */
 493           dcache_invalidate_line (dcache, memaddr + i);
 494           break;
 495         }
 496     }
 497
 498   if (i == 0)
 499     {
 500       /* Even though reading the whole line failed, we may be able to
 501          read a piece starting where the caller wanted.  */
 502       return ops->to_xfer_partial (ops, TARGET_OBJECT_MEMORY, NULL,
 503                                    myaddr, NULL, memaddr, len,
 504                                    xfered_len);
 505     }
 506   else
 507     {
 508       *xfered_len = i;
 509       return TARGET_XFER_OK;
 510     }
 511 }
 512
 513 /* FIXME: There would be some benefit to making the cache write-back and
 514    moving the writeback operation to a higher layer, as it could occur
 515    after a sequence of smaller writes have been completed (as when a stack
 516    frame is constructed for an inferior function call).  Note that only
 517    moving it up one level to target_xfer_memory[_partial]() is not
 518    sufficient since we want to coalesce memory transfers that are
 519    "logically" connected but not actually a single call to one of the
 520    memory transfer functions.  */
 521
 522 /* Just update any cache lines which are already present.  This is
 523    called by the target_xfer_partial machinery when writing raw
 524    memory.  */
 525
 526 void
 527 dcache_update (DCACHE *dcache, enum target_xfer_status status,
 528                CORE_ADDR memaddr, const gdb_byte *myaddr,
 529                ULONGEST len)
 530 {
 531   ULONGEST i;
 532
 533   for (i = 0; i < len; i++)
 534     if (status == TARGET_XFER_OK)
 535       dcache_poke_byte (dcache, memaddr + i, myaddr + i);
 536     else
 537       {
 538         /* Discard the whole cache line so we don't have a partially
 539            valid line.  */
 540         dcache_invalidate_line (dcache, memaddr + i);
 541       }
 542 }
 543
 544 /* Print DCACHE line INDEX.  */
 545
 546 static void
 547 dcache_print_line (DCACHE *dcache, int index)
 548 {
 549   splay_tree_node n;
 550   struct dcache_block *db;
 551   int i, j;
 552
 553   if (dcache == NULL)
 554     {
 555       printf_filtered (_("No data cache available.\n"));
 556       return;
 557     }
 558
 559   n = splay_tree_min (dcache->tree);
 560
 561   for (i = index; i > 0; --i)
 562     {
 563       if (!n)
 564         break;
 565       n = splay_tree_successor (dcache->tree, n->key);
 566     }
 567
 568   if (!n)
 569     {
 570       printf_filtered (_("No such cache line exists.\n"));
 571       return;
 572     }
 573
 574   db = (struct dcache_block *) n->value;
 575
 576   printf_filtered (_("Line %d: address %s [%d hits]\n"),
 577                    index, paddress (target_gdbarch (), db->addr), db->refs);
 578
 579   for (j = 0; j < dcache->line_size; j++)
 580     {
 581       printf_filtered ("%02x ", db->data[j]);
 582
 583       /* Print a newline every 16 bytes (48 characters).  */
 584       if ((j % 16 == 15) && (j != dcache->line_size - 1))
 585         printf_filtered ("\n");
 586     }
 587   printf_filtered ("\n");
 588 }
 589
 590 /* Parse EXP and show the info about DCACHE.  */
 591
 592 static void
 593 dcache_info_1 (DCACHE *dcache, char *exp)
 594 {
 595   splay_tree_node n;
 596   int i, refcount;
 597
 598   if (exp)
 599     {
 600       char *linestart;
 601
 602       i = strtol (exp, &linestart, 10);
 603       if (linestart == exp || i < 0)
 604         {
 605           printf_filtered (_("Usage: info dcache [linenumber]\n"));
 606           return;
 607         }
 608
 609       dcache_print_line (dcache, i);
 610       return;
 611     }
 612
 613   printf_filtered (_("Dcache %u lines of %u bytes each.\n"),
 614                    dcache_size,
 615                    dcache ? (unsigned) dcache->line_size
 616                    : dcache_line_size);
 617
 618   if (dcache == NULL || ptid_equal (dcache->ptid, null_ptid))
 619     {
 620       printf_filtered (_("No data cache available.\n"));
 621       return;
 622     }
 623
 624   printf_filtered (_("Contains data for %s\n"),
 625                    target_pid_to_str (dcache->ptid));
 626
 627   refcount = 0;
 628
 629   n = splay_tree_min (dcache->tree);
 630   i = 0;
 631
 632   while (n)
 633     {
 634       struct dcache_block *db = (struct dcache_block *) n->value;
 635
 636       printf_filtered (_("Line %d: address %s [%d hits]\n"),
 637                        i, paddress (target_gdbarch (), db->addr), db->refs);
 638       i++;
 639       refcount += db->refs;
 640
 641       n = splay_tree_successor (dcache->tree, n->key);
 642     }
 643
 644   printf_filtered (_("Cache state: %d active lines, %d hits\n"), i, refcount);
 645 }
 646
 647 static void
 648 dcache_info (char *exp, int tty)
 649 {
 650   dcache_info_1 (target_dcache_get (), exp);
 651 }
 652
 653 static void
 654 set_dcache_size (char *args, int from_tty,
 655                  struct cmd_list_element *c)
 656 {
 657   if (dcache_size == 0)
 658     {
 659       dcache_size = DCACHE_DEFAULT_SIZE;
 660       error (_("Dcache size must be greater than 0."));
 661     }
 662   target_dcache_invalidate ();
 663 }
 664
 665 static void
 666 set_dcache_line_size (char *args, int from_tty,
 667                       struct cmd_list_element *c)
 668 {
 669   if (dcache_line_size < 2
 670       || (dcache_line_size & (dcache_line_size - 1)) != 0)
 671     {
 672       unsigned d = dcache_line_size;
 673       dcache_line_size = DCACHE_DEFAULT_LINE_SIZE;
 674       error (_("Invalid dcache line size: %u (must be power of 2)."), d);
 675     }
 676   target_dcache_invalidate ();
 677 }
 678
 679 static void
 680 set_dcache_command (char *arg, int from_tty)
 681 {
 682   printf_unfiltered (
 683      "\"set dcache\" must be followed by the name of a subcommand.\n");
 684   help_list (dcache_set_list, "set dcache ", -1, gdb_stdout);
 685 }
 686
 687 static void
 688 show_dcache_command (char *args, int from_tty)
 689 {
 690   cmd_show_list (dcache_show_list, from_tty, "");
 691 }
 692
 693 void
 694 _initialize_dcache (void)
 695 {
 696   add_setshow_boolean_cmd ("remotecache", class_support,
 697                            &dcache_enabled_p, _("\
 698 Set cache use for remote targets."), _("\
 699 Show cache use for remote targets."), _("\
 700 This used to enable the data cache for remote targets.  The cache\n\
 701 functionality is now controlled by the memory region system and the\n\
 702 \"stack-cache\" flag; \"remotecache\" now does nothing and\n\
 703 exists only for compatibility reasons."),
 704                            NULL,
 705                            show_dcache_enabled_p,
 706                            &setlist, &showlist);
 707
 708   add_info ("dcache", dcache_info,
 709             _("\
 710 Print information on the dcache performance.\n\
 711 With no arguments, this command prints the cache configuration and a\n\
 712 summary of each line in the cache.  Use \"info dcache <lineno> to dump\"\n\
 713 the contents of a given line."));
 714
 715   add_prefix_cmd ("dcache", class_obscure, set_dcache_command, _("\
 716 Use this command to set number of lines in dcache and line-size."),
 717                   &dcache_set_list, "set dcache ", /*allow_unknown*/0, &setlist);
 718   add_prefix_cmd ("dcache", class_obscure, show_dcache_command, _("\
 719 Show dcachesettings."),
 720                   &dcache_show_list, "show dcache ", /*allow_unknown*/0, &showlist);
 721
 722   add_setshow_zuinteger_cmd ("line-size", class_obscure,
 723                              &dcache_line_size, _("\
 724 Set dcache line size in bytes (must be power of 2)."), _("\
 725 Show dcache line size."),
 726                              NULL,
 727                              set_dcache_line_size,
 728                              NULL,
 729                              &dcache_set_list, &dcache_show_list);
 730   add_setshow_zuinteger_cmd ("size", class_obscure,
 731                              &dcache_size, _("\
 732 Set number of dcache lines."), _("\
 733 Show number of dcache lines."),
 734                              NULL,
 735                              set_dcache_size,
 736                              NULL,
 737                              &dcache_set_list, &dcache_show_list);
 738 }