drivers/base/regmap/regcache.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 //
   3 // Register cache access API
   4 //
   5 // Copyright 2011 Wolfson Microelectronics plc
   6 //
   7 // Author: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
   8
   9 #include <linux/bsearch.h>
  10 #include <linux/device.h>
  11 #include <linux/export.h>
  12 #include <linux/slab.h>
  13 #include <linux/sort.h>
  14
  15 #include "trace.h"
  16 #include "internal.h"
  17
  18 static const struct regcache_ops *cache_types[] = {
  19         &regcache_rbtree_ops,
  20 #if IS_ENABLED(CONFIG_REGCACHE_COMPRESSED)
  21         &regcache_lzo_ops,
  22 #endif
  23         &regcache_flat_ops,
  24 };
  25
  26 static int regcache_hw_init(struct regmap *map)
  27 {
  28         int i, j;
  29         int ret;
  30         int count;
  31         unsigned int reg, val;
  32         void *tmp_buf;
  33
  34         if (!map->num_reg_defaults_raw)
  35                 return -EINVAL;
  36
  37         /* calculate the size of reg_defaults */
  38         for (count = 0, i = 0; i < map->num_reg_defaults_raw; i++)
  39                 if (regmap_readable(map, i * map->reg_stride) &&
  40                     !regmap_volatile(map, i * map->reg_stride))
  41                         count++;
  42
  43         /* all registers are unreadable or volatile, so just bypass */
  44         if (!count) {
  45                 map->cache_bypass = true;
  46                 return 0;
  47         }
  48
  49         map->num_reg_defaults = count;
  50         map->reg_defaults = kmalloc_array(count, sizeof(struct reg_default),
  51                                           GFP_KERNEL);
  52         if (!map->reg_defaults)
  53                 return -ENOMEM;
  54
  55         if (!map->reg_defaults_raw) {
  56                 bool cache_bypass = map->cache_bypass;
  57                 dev_warn(map->dev, "No cache defaults, reading back from HW\n");
  58
  59                 /* Bypass the cache access till data read from HW */
  60                 map->cache_bypass = true;
  61                 tmp_buf = kmalloc(map->cache_size_raw, GFP_KERNEL);
  62                 if (!tmp_buf) {
  63                         ret = -ENOMEM;
  64                         goto err_free;
  65                 }
  66                 ret = regmap_raw_read(map, 0, tmp_buf,
  67                                       map->cache_size_raw);
  68                 map->cache_bypass = cache_bypass;
  69                 if (ret == 0) {
  70                         map->reg_defaults_raw = tmp_buf;
  71                         map->cache_free = 1;
  72                 } else {
  73                         kfree(tmp_buf);
  74                 }
  75         }
  76
  77         /* fill the reg_defaults */
  78         for (i = 0, j = 0; i < map->num_reg_defaults_raw; i++) {
  79                 reg = i * map->reg_stride;
  80
  81                 if (!regmap_readable(map, reg))
  82                         continue;
  83
  84                 if (regmap_volatile(map, reg))
  85                         continue;
  86
  87                 if (map->reg_defaults_raw) {
  88                         val = regcache_get_val(map, map->reg_defaults_raw, i);
  89                 } else {
  90                         bool cache_bypass = map->cache_bypass;
  91
  92                         map->cache_bypass = true;
  93                         ret = regmap_read(map, reg, &val);
  94                         map->cache_bypass = cache_bypass;
  95                         if (ret != 0) {
  96                                 dev_err(map->dev, "Failed to read %d: %d\n",
  97                                         reg, ret);
  98                                 goto err_free;
  99                         }
 100                 }
 101
 102                 map->reg_defaults[j].reg = reg;
 103                 map->reg_defaults[j].def = val;
 104                 j++;
 105         }
 106
 107         return 0;
 108
 109 err_free:
 110         kfree(map->reg_defaults);
 111
 112         return ret;
 113 }
 114
 115 int regcache_init(struct regmap *map, const struct regmap_config *config)
 116 {
 117         int ret;
 118         int i;
 119         void *tmp_buf;
 120
 121         if (map->cache_type == REGCACHE_NONE) {
 122                 if (config->reg_defaults || config->num_reg_defaults_raw)
 123                         dev_warn(map->dev,
 124                                  "No cache used with register defaults set!\n");
 125
 126                 map->cache_bypass = true;
 127                 return 0;
 128         }
 129
 130         if (config->reg_defaults && !config->num_reg_defaults) {
 131                 dev_err(map->dev,
 132                          "Register defaults are set without the number!\n");
 133                 return -EINVAL;
 134         }
 135
 136         for (i = 0; i < config->num_reg_defaults; i++)
 137                 if (config->reg_defaults[i].reg % map->reg_stride)
 138                         return -EINVAL;
 139
 140         for (i = 0; i < ARRAY_SIZE(cache_types); i++)
 141                 if (cache_types[i]->type == map->cache_type)
 142                         break;
 143
 144         if (i == ARRAY_SIZE(cache_types)) {
 145                 dev_err(map->dev, "Could not match compress type: %d\n",
 146                         map->cache_type);
 147                 return -EINVAL;
 148         }
 149
 150         map->num_reg_defaults = config->num_reg_defaults;
 151         map->num_reg_defaults_raw = config->num_reg_defaults_raw;
 152         map->reg_defaults_raw = config->reg_defaults_raw;
 153         map->cache_word_size = DIV_ROUND_UP(config->val_bits, 8);
 154         map->cache_size_raw = map->cache_word_size * config->num_reg_defaults_raw;
 155
 156         map->cache = NULL;
 157         map->cache_ops = cache_types[i];
 158
 159         if (!map->cache_ops->read ||
 160             !map->cache_ops->write ||
 161             !map->cache_ops->name)
 162                 return -EINVAL;
 163
 164         /* We still need to ensure that the reg_defaults
 165          * won't vanish from under us.  We'll need to make
 166          * a copy of it.
 167          */
 168         if (config->reg_defaults) {
 169                 tmp_buf = kmemdup(config->reg_defaults, map->num_reg_defaults *
 170                                   sizeof(struct reg_default), GFP_KERNEL);
 171                 if (!tmp_buf)
 172                         return -ENOMEM;
 173                 map->reg_defaults = tmp_buf;
 174         } else if (map->num_reg_defaults_raw) {
 175                 /* Some devices such as PMICs don't have cache defaults,
 176                  * we cope with this by reading back the HW registers and
 177                  * crafting the cache defaults by hand.
 178                  */
 179                 ret = regcache_hw_init(map);
 180                 if (ret < 0)
 181                         return ret;
 182                 if (map->cache_bypass)
 183                         return 0;
 184         }
 185
 186         if (!map->max_register)
 187                 map->max_register = map->num_reg_defaults_raw;
 188
 189         if (map->cache_ops->init) {
 190                 dev_dbg(map->dev, "Initializing %s cache\n",
 191                         map->cache_ops->name);
 192                 ret = map->cache_ops->init(map);
 193                 if (ret)
 194                         goto err_free;
 195         }
 196         return 0;
 197
 198 err_free:
 199         kfree(map->reg_defaults);
 200         if (map->cache_free)
 201                 kfree(map->reg_defaults_raw);
 202
 203         return ret;
 204 }
 205
 206 void regcache_exit(struct regmap *map)
 207 {
 208         if (map->cache_type == REGCACHE_NONE)
 209                 return;
 210
 211         BUG_ON(!map->cache_ops);
 212
 213         kfree(map->reg_defaults);
 214         if (map->cache_free)
 215                 kfree(map->reg_defaults_raw);
 216
 217         if (map->cache_ops->exit) {
 218                 dev_dbg(map->dev, "Destroying %s cache\n",
 219                         map->cache_ops->name);
 220                 map->cache_ops->exit(map);
 221         }
 222 }
 223
 224 /**
 225  * regcache_read - Fetch the value of a given register from the cache.
 226  *
 227  * @map: map to configure.
 228  * @reg: The register index.
 229  * @value: The value to be returned.
 230  *
 231  * Return a negative value on failure, 0 on success.
 232  */
 233 int regcache_read(struct regmap *map,
 234                   unsigned int reg, unsigned int *value)
 235 {
 236         int ret;
 237
 238         if (map->cache_type == REGCACHE_NONE)
 239                 return -ENOSYS;
 240
 241         BUG_ON(!map->cache_ops);
 242
 243         if (!regmap_volatile(map, reg)) {
 244                 ret = map->cache_ops->read(map, reg, value);
 245
 246                 if (ret == 0)
 247                         trace_regmap_reg_read_cache(map, reg, *value);
 248
 249                 return ret;
 250         }
 251
 252         return -EINVAL;
 253 }
 254
 255 /**
 256  * regcache_write - Set the value of a given register in the cache.
 257  *
 258  * @map: map to configure.
 259  * @reg: The register index.
 260  * @value: The new register value.
 261  *
 262  * Return a negative value on failure, 0 on success.
 263  */
 264 int regcache_write(struct regmap *map,
 265                    unsigned int reg, unsigned int value)
 266 {
 267         if (map->cache_type == REGCACHE_NONE)
 268                 return 0;
 269
 270         BUG_ON(!map->cache_ops);
 271
 272         if (!regmap_volatile(map, reg))
 273                 return map->cache_ops->write(map, reg, value);
 274
 275         return 0;
 276 }
 277
 278 static bool regcache_reg_needs_sync(struct regmap *map, unsigned int reg,
 279                                     unsigned int val)
 280 {
 281         int ret;
 282
 283         /* If we don't know the chip just got reset, then sync everything. */
 284         if (!map->no_sync_defaults)
 285                 return true;
 286
 287         /* Is this the hardware default?  If so skip. */
 288         ret = regcache_lookup_reg(map, reg);
 289         if (ret >= 0 && val == map->reg_defaults[ret].def)
 290                 return false;
 291         return true;
 292 }
 293
 294 static int regcache_default_sync(struct regmap *map, unsigned int min,
 295                                  unsigned int max)
 296 {
 297         unsigned int reg;
 298
 299         for (reg = min; reg <= max; reg += map->reg_stride) {
 300                 unsigned int val;
 301                 int ret;
 302
 303                 if (regmap_volatile(map, reg) ||
 304                     !regmap_writeable(map, reg))
 305                         continue;
 306
 307                 ret = regcache_read(map, reg, &val);
 308                 if (ret)
 309                         return ret;
 310
 311                 if (!regcache_reg_needs_sync(map, reg, val))
 312                         continue;
 313
 314                 map->cache_bypass = true;
 315                 ret = _regmap_write(map, reg, val);
 316                 map->cache_bypass = false;
 317                 if (ret) {
 318                         dev_err(map->dev, "Unable to sync register %#x. %d\n",
 319                                 reg, ret);
 320                         return ret;
 321                 }
 322                 dev_dbg(map->dev, "Synced register %#x, value %#x\n", reg, val);
 323         }
 324
 325         return 0;
 326 }
 327
 328 /**
 329  * regcache_sync - Sync the register cache with the hardware.
 330  *
 331  * @map: map to configure.
 332  *
 333  * Any registers that should not be synced should be marked as
 334  * volatile.  In general drivers can choose not to use the provided
 335  * syncing functionality if they so require.
 336  *
 337  * Return a negative value on failure, 0 on success.
 338  */
 339 int regcache_sync(struct regmap *map)
 340 {
 341         int ret = 0;
 342         unsigned int i;
 343         const char *name;
 344         bool bypass;
 345
 346         BUG_ON(!map->cache_ops);
 347
 348         map->lock(map->lock_arg);
 349         /* Remember the initial bypass state */
 350         bypass = map->cache_bypass;
 351         dev_dbg(map->dev, "Syncing %s cache\n",
 352                 map->cache_ops->name);
 353         name = map->cache_ops->name;
 354         trace_regcache_sync(map, name, "start");
 355
 356         if (!map->cache_dirty)
 357                 goto out;
 358
 359         map->async = true;
 360
 361         /* Apply any patch first */
 362         map->cache_bypass = true;
 363         for (i = 0; i < map->patch_regs; i++) {
 364                 ret = _regmap_write(map, map->patch[i].reg, map->patch[i].def);
 365                 if (ret != 0) {
 366                         dev_err(map->dev, "Failed to write %x = %x: %d\n",
 367                                 map->patch[i].reg, map->patch[i].def, ret);
 368                         goto out;
 369                 }
 370         }
 371         map->cache_bypass = false;
 372
 373         if (map->cache_ops->sync)
 374                 ret = map->cache_ops->sync(map, 0, map->max_register);
 375         else
 376                 ret = regcache_default_sync(map, 0, map->max_register);
 377
 378         if (ret == 0)
 379                 map->cache_dirty = false;
 380
 381 out:
 382         /* Restore the bypass state */
 383         map->async = false;
 384         map->cache_bypass = bypass;
 385         map->no_sync_defaults = false;
 386         map->unlock(map->lock_arg);
 387
 388         regmap_async_complete(map);
 389
 390         trace_regcache_sync(map, name, "stop");
 391
 392         return ret;
 393 }
 394 EXPORT_SYMBOL_GPL(regcache_sync);
 395
 396 /**
 397  * regcache_sync_region - Sync part  of the register cache with the hardware.
 398  *
 399  * @map: map to sync.
 400  * @min: first register to sync
 401  * @max: last register to sync
 402  *
 403  * Write all non-default register values in the specified region to
 404  * the hardware.
 405  *
 406  * Return a negative value on failure, 0 on success.
 407  */
 408 int regcache_sync_region(struct regmap *map, unsigned int min,
 409                          unsigned int max)
 410 {
 411         int ret = 0;
 412         const char *name;
 413         bool bypass;
 414
 415         BUG_ON(!map->cache_ops);
 416
 417         map->lock(map->lock_arg);
 418
 419         /* Remember the initial bypass state */
 420         bypass = map->cache_bypass;
 421
 422         name = map->cache_ops->name;
 423         dev_dbg(map->dev, "Syncing %s cache from %d-%d\n", name, min, max);
 424
 425         trace_regcache_sync(map, name, "start region");
 426
 427         if (!map->cache_dirty)
 428                 goto out;
 429
 430         map->async = true;
 431
 432         if (map->cache_ops->sync)
 433                 ret = map->cache_ops->sync(map, min, max);
 434         else
 435                 ret = regcache_default_sync(map, min, max);
 436
 437 out:
 438         /* Restore the bypass state */
 439         map->cache_bypass = bypass;
 440         map->async = false;
 441         map->no_sync_defaults = false;
 442         map->unlock(map->lock_arg);
 443
 444         regmap_async_complete(map);
 445
 446         trace_regcache_sync(map, name, "stop region");
 447
 448         return ret;
 449 }
 450 EXPORT_SYMBOL_GPL(regcache_sync_region);
 451
 452 /**
 453  * regcache_drop_region - Discard part of the register cache
 454  *
 455  * @map: map to operate on
 456  * @min: first register to discard
 457  * @max: last register to discard
 458  *
 459  * Discard part of the register cache.
 460  *
 461  * Return a negative value on failure, 0 on success.
 462  */
 463 int regcache_drop_region(struct regmap *map, unsigned int min,
 464                          unsigned int max)
 465 {
 466         int ret = 0;
 467
 468         if (!map->cache_ops || !map->cache_ops->drop)
 469                 return -EINVAL;
 470
 471         map->lock(map->lock_arg);
 472
 473         trace_regcache_drop_region(map, min, max);
 474
 475         ret = map->cache_ops->drop(map, min, max);
 476
 477         map->unlock(map->lock_arg);
 478
 479         return ret;
 480 }
 481 EXPORT_SYMBOL_GPL(regcache_drop_region);
 482
 483 /**
 484  * regcache_cache_only - Put a register map into cache only mode
 485  *
 486  * @map: map to configure
 487  * @enable: flag if changes should be written to the hardware
 488  *
 489  * When a register map is marked as cache only writes to the register
 490  * map API will only update the register cache, they will not cause
 491  * any hardware changes.  This is useful for allowing portions of
 492  * drivers to act as though the device were functioning as normal when
 493  * it is disabled for power saving reasons.
 494  */
 495 void regcache_cache_only(struct regmap *map, bool enable)
 496 {
 497         map->lock(map->lock_arg);
 498         WARN_ON(map->cache_bypass && enable);
 499         map->cache_only = enable;
 500         trace_regmap_cache_only(map, enable);
 501         map->unlock(map->lock_arg);
 502 }
 503 EXPORT_SYMBOL_GPL(regcache_cache_only);
 504
 505 /**
 506  * regcache_mark_dirty - Indicate that HW registers were reset to default values
 507  *
 508  * @map: map to mark
 509  *
 510  * Inform regcache that the device has been powered down or reset, so that
 511  * on resume, regcache_sync() knows to write out all non-default values
 512  * stored in the cache.
 513  *
 514  * If this function is not called, regcache_sync() will assume that
 515  * the hardware state still matches the cache state, modulo any writes that
 516  * happened when cache_only was true.
 517  */
 518 void regcache_mark_dirty(struct regmap *map)
 519 {
 520         map->lock(map->lock_arg);
 521         map->cache_dirty = true;
 522         map->no_sync_defaults = true;
 523         map->unlock(map->lock_arg);
 524 }
 525 EXPORT_SYMBOL_GPL(regcache_mark_dirty);
 526
 527 /**
 528  * regcache_cache_bypass - Put a register map into cache bypass mode
 529  *
 530  * @map: map to configure
 531  * @enable: flag if changes should not be written to the cache
 532  *
 533  * When a register map is marked with the cache bypass option, writes
 534  * to the register map API will only update the hardware and not the
 535  * the cache directly.  This is useful when syncing the cache back to
 536  * the hardware.
 537  */
 538 void regcache_cache_bypass(struct regmap *map, bool enable)
 539 {
 540         map->lock(map->lock_arg);
 541         WARN_ON(map->cache_only && enable);
 542         map->cache_bypass = enable;
 543         trace_regmap_cache_bypass(map, enable);
 544         map->unlock(map->lock_arg);
 545 }
 546 EXPORT_SYMBOL_GPL(regcache_cache_bypass);
 547
 548 bool regcache_set_val(struct regmap *map, void *base, unsigned int idx,
 549                       unsigned int val)
 550 {
 551         if (regcache_get_val(map, base, idx) == val)
 552                 return true;
 553
 554         /* Use device native format if possible */
 555         if (map->format.format_val) {
 556                 map->format.format_val(base + (map->cache_word_size * idx),
 557                                        val, 0);
 558                 return false;
 559         }
 560
 561         switch (map->cache_word_size) {
 562         case 1: {
 563                 u8 *cache = base;
 564
 565                 cache[idx] = val;
 566                 break;
 567         }
 568         case 2: {
 569                 u16 *cache = base;
 570
 571                 cache[idx] = val;
 572                 break;
 573         }
 574         case 4: {
 575                 u32 *cache = base;
 576
 577                 cache[idx] = val;
 578                 break;
 579         }
 580 #ifdef CONFIG_64BIT
 581         case 8: {
 582                 u64 *cache = base;
 583
 584                 cache[idx] = val;
 585                 break;
 586         }
 587 #endif
 588         default:
 589                 BUG();
 590         }
 591         return false;
 592 }
 593
 594 unsigned int regcache_get_val(struct regmap *map, const void *base,
 595                               unsigned int idx)
 596 {
 597         if (!base)
 598                 return -EINVAL;
 599
 600         /* Use device native format if possible */
 601         if (map->format.parse_val)
 602                 return map->format.parse_val(regcache_get_val_addr(map, base,
 603                                                                    idx));
 604
 605         switch (map->cache_word_size) {
 606         case 1: {
 607                 const u8 *cache = base;
 608
 609                 return cache[idx];
 610         }
 611         case 2: {
 612                 const u16 *cache = base;
 613
 614                 return cache[idx];
 615         }
 616         case 4: {
 617                 const u32 *cache = base;
 618
 619                 return cache[idx];
 620         }
 621 #ifdef CONFIG_64BIT
 622         case 8: {
 623                 const u64 *cache = base;
 624
 625                 return cache[idx];
 626         }
 627 #endif
 628         default:
 629                 BUG();
 630         }
 631         /* unreachable */
 632         return -1;
 633 }
 634
 635 static int regcache_default_cmp(const void *a, const void *b)
 636 {
 637         const struct reg_default *_a = a;
 638         const struct reg_default *_b = b;
 639
 640         return _a->reg - _b->reg;
 641 }
 642
 643 int regcache_lookup_reg(struct regmap *map, unsigned int reg)
 644 {
 645         struct reg_default key;
 646         struct reg_default *r;
 647
 648         key.reg = reg;
 649         key.def = 0;
 650
 651         r = bsearch(&key, map->reg_defaults, map->num_reg_defaults,
 652                     sizeof(struct reg_default), regcache_default_cmp);
 653
 654         if (r)
 655                 return r - map->reg_defaults;
 656         else
 657                 return -ENOENT;
 658 }
 659
 660 static bool regcache_reg_present(unsigned long *cache_present, unsigned int idx)
 661 {
 662         if (!cache_present)
 663                 return true;
 664
 665         return test_bit(idx, cache_present);
 666 }
 667
 668 static int regcache_sync_block_single(struct regmap *map, void *block,
 669                                       unsigned long *cache_present,
 670                                       unsigned int block_base,
 671                                       unsigned int start, unsigned int end)
 672 {
 673         unsigned int i, regtmp, val;
 674         int ret;
 675
 676         for (i = start; i < end; i++) {
 677                 regtmp = block_base + (i * map->reg_stride);
 678
 679                 if (!regcache_reg_present(cache_present, i) ||
 680                     !regmap_writeable(map, regtmp))
 681                         continue;
 682
 683                 val = regcache_get_val(map, block, i);
 684                 if (!regcache_reg_needs_sync(map, regtmp, val))
 685                         continue;
 686
 687                 map->cache_bypass = true;
 688
 689                 ret = _regmap_write(map, regtmp, val);
 690
 691                 map->cache_bypass = false;
 692                 if (ret != 0) {
 693                         dev_err(map->dev, "Unable to sync register %#x. %d\n",
 694                                 regtmp, ret);
 695                         return ret;
 696                 }
 697                 dev_dbg(map->dev, "Synced register %#x, value %#x\n",
 698                         regtmp, val);
 699         }
 700
 701         return 0;
 702 }
 703
 704 static int regcache_sync_block_raw_flush(struct regmap *map, const void **data,
 705                                          unsigned int base, unsigned int cur)
 706 {
 707         size_t val_bytes = map->format.val_bytes;
 708         int ret, count;
 709
 710         if (*data == NULL)
 711                 return 0;
 712
 713         count = (cur - base) / map->reg_stride;
 714
 715         dev_dbg(map->dev, "Writing %zu bytes for %d registers from 0x%x-0x%x\n",
 716                 count * val_bytes, count, base, cur - map->reg_stride);
 717
 718         map->cache_bypass = true;
 719
 720         ret = _regmap_raw_write(map, base, *data, count * val_bytes, false);
 721         if (ret)
 722                 dev_err(map->dev, "Unable to sync registers %#x-%#x. %d\n",
 723                         base, cur - map->reg_stride, ret);
 724
 725         map->cache_bypass = false;
 726
 727         *data = NULL;
 728
 729         return ret;
 730 }
 731
 732 static int regcache_sync_block_raw(struct regmap *map, void *block,
 733                             unsigned long *cache_present,
 734                             unsigned int block_base, unsigned int start,
 735                             unsigned int end)
 736 {
 737         unsigned int i, val;
 738         unsigned int regtmp = 0;
 739         unsigned int base = 0;
 740         const void *data = NULL;
 741         int ret;
 742
 743         for (i = start; i < end; i++) {
 744                 regtmp = block_base + (i * map->reg_stride);
 745
 746                 if (!regcache_reg_present(cache_present, i) ||
 747                     !regmap_writeable(map, regtmp)) {
 748                         ret = regcache_sync_block_raw_flush(map, &data,
 749                                                             base, regtmp);
 750                         if (ret != 0)
 751                                 return ret;
 752                         continue;
 753                 }
 754
 755                 val = regcache_get_val(map, block, i);
 756                 if (!regcache_reg_needs_sync(map, regtmp, val)) {
 757                         ret = regcache_sync_block_raw_flush(map, &data,
 758                                                             base, regtmp);
 759                         if (ret != 0)
 760                                 return ret;
 761                         continue;
 762                 }
 763
 764                 if (!data) {
 765                         data = regcache_get_val_addr(map, block, i);
 766                         base = regtmp;
 767                 }
 768         }
 769
 770         return regcache_sync_block_raw_flush(map, &data, base, regtmp +
 771                         map->reg_stride);
 772 }
 773
 774 int regcache_sync_block(struct regmap *map, void *block,
 775                         unsigned long *cache_present,
 776                         unsigned int block_base, unsigned int start,
 777                         unsigned int end)
 778 {
 779         if (regmap_can_raw_write(map) && !map->use_single_write)
 780                 return regcache_sync_block_raw(map, block, cache_present,
 781                                                block_base, start, end);
 782         else
 783                 return regcache_sync_block_single(map, block, cache_present,
 784                                                   block_base, start, end);
 785 }