1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * pptt.c - parsing of Processor Properties Topology Table (PPTT) 4 * 5 * Copyright (C) 2018, ARM 6 * 7 * This file implements parsing of the Processor Properties Topology Table 8 * which is optionally used to describe the processor and cache topology. 9 * Due to the relative pointers used throughout the table, this doesn't 10 * leverage the existing subtable parsing in the kernel. 11 * 12 * The PPTT structure is an inverted tree, with each node potentially 13 * holding one or two inverted tree data structures describing 14 * the caches available at that level. Each cache structure optionally 15 * contains properties describing the cache at a given level which can be 16 * used to override hardware probed values. 17 */ 18 #define pr_fmt(fmt) "ACPI PPTT: " fmt 19 20 #include <linux/acpi.h> 21 #include <linux/cacheinfo.h> 22 #include <acpi/processor.h> 23 24 /* 25 * The acpi_pptt_cache_v1 in actbl2.h, which is imported from acpica, 26 * only contains the cache_id field rather than all the fields of the 27 * Cache Type Structure. Use this alternative structure until it is 28 * resolved in acpica. 29 */ 30 struct acpi_pptt_cache_v1_full { 31 struct acpi_subtable_header header; 32 u16 reserved; 33 u32 flags; 34 u32 next_level_of_cache; 35 u32 size; 36 u32 number_of_sets; 37 u8 associativity; 38 u8 attributes; 39 u16 line_size; 40 u32 cache_id; 41 } __packed; 42 43 static struct acpi_subtable_header *fetch_pptt_subtable(struct acpi_table_header *table_hdr, 44 u32 pptt_ref) 45 { 46 struct acpi_subtable_header *entry; 47 48 /* there isn't a subtable at reference 0 */ 49 if (pptt_ref < sizeof(struct acpi_subtable_header)) 50 return NULL; 51 52 if (pptt_ref + sizeof(struct acpi_subtable_header) > table_hdr->length) 53 return NULL; 54 55 entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr, pptt_ref); 56 57 if (entry->length == 0) 58 return NULL; 59 60 if (pptt_ref + entry->length > table_hdr->length) 61 return NULL; 62 63 return entry; 64 } 65 66 static struct acpi_pptt_processor *fetch_pptt_node(struct acpi_table_header *table_hdr, 67 u32 pptt_ref) 68 { 69 return (struct acpi_pptt_processor *)fetch_pptt_subtable(table_hdr, pptt_ref); 70 } 71 72 static struct acpi_pptt_cache *fetch_pptt_cache(struct acpi_table_header *table_hdr, 73 u32 pptt_ref) 74 { 75 return (struct acpi_pptt_cache *)fetch_pptt_subtable(table_hdr, pptt_ref); 76 } 77 78 static struct acpi_pptt_cache_v1_full *upgrade_pptt_cache(struct acpi_pptt_cache *cache) 79 { 80 if (cache->header.length < sizeof(struct acpi_pptt_cache_v1_full)) 81 return NULL; 82 83 /* No use for v1 if the only additional field is invalid */ 84 if (!(cache->flags & ACPI_PPTT_CACHE_ID_VALID)) 85 return NULL; 86 87 return (struct acpi_pptt_cache_v1_full *)cache; 88 } 89 90 static struct acpi_subtable_header *acpi_get_pptt_resource(struct acpi_table_header *table_hdr, 91 struct acpi_pptt_processor *node, 92 int resource) 93 { 94 u32 *ref; 95 96 if (resource >= node->number_of_priv_resources) 97 return NULL; 98 99 ref = ACPI_ADD_PTR(u32, node, sizeof(struct acpi_pptt_processor)); 100 ref += resource; 101 102 return fetch_pptt_subtable(table_hdr, *ref); 103 } 104 105 static inline bool acpi_pptt_match_type(int table_type, int type) 106 { 107 return ((table_type & ACPI_PPTT_MASK_CACHE_TYPE) == type || 108 table_type & ACPI_PPTT_CACHE_TYPE_UNIFIED & type); 109 } 110 111 /** 112 * acpi_pptt_walk_cache() - Attempt to find the requested acpi_pptt_cache 113 * @table_hdr: Pointer to the head of the PPTT table 114 * @local_level: passed res reflects this cache level 115 * @split_levels: Number of split cache levels (data/instruction). 116 * @res: cache resource in the PPTT we want to walk 117 * @found: returns a pointer to the requested level if found 118 * @level: the requested cache level 119 * @type: the requested cache type 120 * 121 * Attempt to find a given cache level, while counting the max number 122 * of cache levels for the cache node. 123 * 124 * Given a pptt resource, verify that it is a cache node, then walk 125 * down each level of caches, counting how many levels are found 126 * as well as checking the cache type (icache, dcache, unified). If a 127 * level & type match, then we set found, and continue the search. 128 * Once the entire cache branch has been walked return its max 129 * depth. 130 * 131 * Return: The cache structure and the level we terminated with. 132 */ 133 static unsigned int acpi_pptt_walk_cache(struct acpi_table_header *table_hdr, 134 unsigned int local_level, 135 unsigned int *split_levels, 136 struct acpi_subtable_header *res, 137 struct acpi_pptt_cache **found, 138 unsigned int level, int type) 139 { 140 struct acpi_pptt_cache *cache; 141 142 if (res->type != ACPI_PPTT_TYPE_CACHE) 143 return 0; 144 145 cache = (struct acpi_pptt_cache *) res; 146 while (cache) { 147 local_level++; 148 149 if (!(cache->flags & ACPI_PPTT_CACHE_TYPE_VALID)) { 150 cache = fetch_pptt_cache(table_hdr, cache->next_level_of_cache); 151 continue; 152 } 153 154 if (split_levels && 155 (acpi_pptt_match_type(cache->attributes, ACPI_PPTT_CACHE_TYPE_DATA) || 156 acpi_pptt_match_type(cache->attributes, ACPI_PPTT_CACHE_TYPE_INSTR))) 157 *split_levels = local_level; 158 159 if (local_level == level && 160 acpi_pptt_match_type(cache->attributes, type)) { 161 if (*found != NULL && cache != *found) 162 pr_warn("Found duplicate cache level/type unable to determine uniqueness\n"); 163 164 pr_debug("Found cache @ level %u\n", level); 165 *found = cache; 166 /* 167 * continue looking at this node's resource list 168 * to verify that we don't find a duplicate 169 * cache node. 170 */ 171 } 172 cache = fetch_pptt_cache(table_hdr, cache->next_level_of_cache); 173 } 174 return local_level; 175 } 176 177 static struct acpi_pptt_cache * 178 acpi_find_cache_level(struct acpi_table_header *table_hdr, 179 struct acpi_pptt_processor *cpu_node, 180 unsigned int *starting_level, unsigned int *split_levels, 181 unsigned int level, int type) 182 { 183 struct acpi_subtable_header *res; 184 unsigned int number_of_levels = *starting_level; 185 int resource = 0; 186 struct acpi_pptt_cache *ret = NULL; 187 unsigned int local_level; 188 189 /* walk down from processor node */ 190 while ((res = acpi_get_pptt_resource(table_hdr, cpu_node, resource))) { 191 resource++; 192 193 local_level = acpi_pptt_walk_cache(table_hdr, *starting_level, 194 split_levels, res, &ret, 195 level, type); 196 /* 197 * we are looking for the max depth. Since its potentially 198 * possible for a given node to have resources with differing 199 * depths verify that the depth we have found is the largest. 200 */ 201 if (number_of_levels < local_level) 202 number_of_levels = local_level; 203 } 204 if (number_of_levels > *starting_level) 205 *starting_level = number_of_levels; 206 207 return ret; 208 } 209 210 /** 211 * acpi_count_levels() - Given a PPTT table, and a CPU node, count the 212 * total number of levels and split cache levels (data/instruction). 213 * @table_hdr: Pointer to the head of the PPTT table 214 * @cpu_node: processor node we wish to count caches for 215 * @split_levels: Number of split cache levels (data/instruction) if 216 * success. Can by NULL. 217 * 218 * Return: number of levels. 219 * Given a processor node containing a processing unit, walk into it and count 220 * how many levels exist solely for it, and then walk up each level until we hit 221 * the root node (ignore the package level because it may be possible to have 222 * caches that exist across packages). Count the number of cache levels and 223 * split cache levels (data/instruction) that exist at each level on the way 224 * up. 225 */ 226 static int acpi_count_levels(struct acpi_table_header *table_hdr, 227 struct acpi_pptt_processor *cpu_node, 228 unsigned int *split_levels) 229 { 230 int current_level = 0; 231 232 do { 233 acpi_find_cache_level(table_hdr, cpu_node, ¤t_level, split_levels, 0, 0); 234 cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent); 235 } while (cpu_node); 236 237 return current_level; 238 } 239 240 /** 241 * acpi_pptt_leaf_node() - Given a processor node, determine if its a leaf 242 * @table_hdr: Pointer to the head of the PPTT table 243 * @node: passed node is checked to see if its a leaf 244 * 245 * Determine if the *node parameter is a leaf node by iterating the 246 * PPTT table, looking for nodes which reference it. 247 * 248 * Return: 0 if we find a node referencing the passed node (or table error), 249 * or 1 if we don't. 250 */ 251 static int acpi_pptt_leaf_node(struct acpi_table_header *table_hdr, 252 struct acpi_pptt_processor *node) 253 { 254 struct acpi_subtable_header *entry; 255 unsigned long table_end; 256 u32 node_entry; 257 struct acpi_pptt_processor *cpu_node; 258 u32 proc_sz; 259 260 if (table_hdr->revision > 1) 261 return (node->flags & ACPI_PPTT_ACPI_LEAF_NODE); 262 263 table_end = (unsigned long)table_hdr + table_hdr->length; 264 node_entry = ACPI_PTR_DIFF(node, table_hdr); 265 entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr, 266 sizeof(struct acpi_table_pptt)); 267 proc_sz = sizeof(struct acpi_pptt_processor); 268 269 /* ignore subtable types that are smaller than a processor node */ 270 while ((unsigned long)entry + proc_sz <= table_end) { 271 cpu_node = (struct acpi_pptt_processor *)entry; 272 273 if (entry->type == ACPI_PPTT_TYPE_PROCESSOR && 274 cpu_node->parent == node_entry) 275 return 0; 276 if (entry->length == 0) 277 return 0; 278 279 entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry, 280 entry->length); 281 } 282 return 1; 283 } 284 285 /** 286 * acpi_find_processor_node() - Given a PPTT table find the requested processor 287 * @table_hdr: Pointer to the head of the PPTT table 288 * @acpi_cpu_id: CPU we are searching for 289 * 290 * Find the subtable entry describing the provided processor. 291 * This is done by iterating the PPTT table looking for processor nodes 292 * which have an acpi_processor_id that matches the acpi_cpu_id parameter 293 * passed into the function. If we find a node that matches this criteria 294 * we verify that its a leaf node in the topology rather than depending 295 * on the valid flag, which doesn't need to be set for leaf nodes. 296 * 297 * Return: NULL, or the processors acpi_pptt_processor* 298 */ 299 static struct acpi_pptt_processor *acpi_find_processor_node(struct acpi_table_header *table_hdr, 300 u32 acpi_cpu_id) 301 { 302 struct acpi_subtable_header *entry; 303 unsigned long table_end; 304 struct acpi_pptt_processor *cpu_node; 305 u32 proc_sz; 306 307 table_end = (unsigned long)table_hdr + table_hdr->length; 308 entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr, 309 sizeof(struct acpi_table_pptt)); 310 proc_sz = sizeof(struct acpi_pptt_processor); 311 312 /* find the processor structure associated with this cpuid */ 313 while ((unsigned long)entry + proc_sz <= table_end) { 314 cpu_node = (struct acpi_pptt_processor *)entry; 315 316 if (entry->length == 0) { 317 pr_warn("Invalid zero length subtable\n"); 318 break; 319 } 320 /* entry->length may not equal proc_sz, revalidate the processor structure length */ 321 if (entry->type == ACPI_PPTT_TYPE_PROCESSOR && 322 acpi_cpu_id == cpu_node->acpi_processor_id && 323 (unsigned long)entry + entry->length <= table_end && 324 entry->length == proc_sz + cpu_node->number_of_priv_resources * sizeof(u32) && 325 acpi_pptt_leaf_node(table_hdr, cpu_node)) { 326 return (struct acpi_pptt_processor *)entry; 327 } 328 329 entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry, 330 entry->length); 331 } 332 333 return NULL; 334 } 335 336 static u8 acpi_cache_type(enum cache_type type) 337 { 338 switch (type) { 339 case CACHE_TYPE_DATA: 340 pr_debug("Looking for data cache\n"); 341 return ACPI_PPTT_CACHE_TYPE_DATA; 342 case CACHE_TYPE_INST: 343 pr_debug("Looking for instruction cache\n"); 344 return ACPI_PPTT_CACHE_TYPE_INSTR; 345 default: 346 case CACHE_TYPE_UNIFIED: 347 pr_debug("Looking for unified cache\n"); 348 /* 349 * It is important that ACPI_PPTT_CACHE_TYPE_UNIFIED 350 * contains the bit pattern that will match both 351 * ACPI unified bit patterns because we use it later 352 * to match both cases. 353 */ 354 return ACPI_PPTT_CACHE_TYPE_UNIFIED; 355 } 356 } 357 358 static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *table_hdr, 359 u32 acpi_cpu_id, 360 enum cache_type type, 361 unsigned int level, 362 struct acpi_pptt_processor **node) 363 { 364 unsigned int total_levels = 0; 365 struct acpi_pptt_cache *found = NULL; 366 struct acpi_pptt_processor *cpu_node; 367 u8 acpi_type = acpi_cache_type(type); 368 369 pr_debug("Looking for CPU %d's level %u cache type %d\n", 370 acpi_cpu_id, level, acpi_type); 371 372 cpu_node = acpi_find_processor_node(table_hdr, acpi_cpu_id); 373 374 while (cpu_node && !found) { 375 found = acpi_find_cache_level(table_hdr, cpu_node, 376 &total_levels, NULL, level, acpi_type); 377 *node = cpu_node; 378 cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent); 379 } 380 381 return found; 382 } 383 384 /** 385 * update_cache_properties() - Update cacheinfo for the given processor 386 * @this_leaf: Kernel cache info structure being updated 387 * @found_cache: The PPTT node describing this cache instance 388 * @cpu_node: A unique reference to describe this cache instance 389 * 390 * The ACPI spec implies that the fields in the cache structures are used to 391 * extend and correct the information probed from the hardware. Lets only 392 * set fields that we determine are VALID. 393 * 394 * Return: nothing. Side effect of updating the global cacheinfo 395 */ 396 static void update_cache_properties(struct cacheinfo *this_leaf, 397 struct acpi_pptt_cache *found_cache, 398 struct acpi_pptt_processor *cpu_node) 399 { 400 struct acpi_pptt_cache_v1_full *found_cache_v1; 401 402 this_leaf->fw_token = cpu_node; 403 if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID) 404 this_leaf->size = found_cache->size; 405 if (found_cache->flags & ACPI_PPTT_LINE_SIZE_VALID) 406 this_leaf->coherency_line_size = found_cache->line_size; 407 if (found_cache->flags & ACPI_PPTT_NUMBER_OF_SETS_VALID) 408 this_leaf->number_of_sets = found_cache->number_of_sets; 409 if (found_cache->flags & ACPI_PPTT_ASSOCIATIVITY_VALID) 410 this_leaf->ways_of_associativity = found_cache->associativity; 411 if (found_cache->flags & ACPI_PPTT_WRITE_POLICY_VALID) { 412 switch (found_cache->attributes & ACPI_PPTT_MASK_WRITE_POLICY) { 413 case ACPI_PPTT_CACHE_POLICY_WT: 414 this_leaf->attributes = CACHE_WRITE_THROUGH; 415 break; 416 case ACPI_PPTT_CACHE_POLICY_WB: 417 this_leaf->attributes = CACHE_WRITE_BACK; 418 break; 419 } 420 } 421 if (found_cache->flags & ACPI_PPTT_ALLOCATION_TYPE_VALID) { 422 switch (found_cache->attributes & ACPI_PPTT_MASK_ALLOCATION_TYPE) { 423 case ACPI_PPTT_CACHE_READ_ALLOCATE: 424 this_leaf->attributes |= CACHE_READ_ALLOCATE; 425 break; 426 case ACPI_PPTT_CACHE_WRITE_ALLOCATE: 427 this_leaf->attributes |= CACHE_WRITE_ALLOCATE; 428 break; 429 case ACPI_PPTT_CACHE_RW_ALLOCATE: 430 case ACPI_PPTT_CACHE_RW_ALLOCATE_ALT: 431 this_leaf->attributes |= 432 CACHE_READ_ALLOCATE | CACHE_WRITE_ALLOCATE; 433 break; 434 } 435 } 436 /* 437 * If cache type is NOCACHE, then the cache hasn't been specified 438 * via other mechanisms. Update the type if a cache type has been 439 * provided. 440 * 441 * Note, we assume such caches are unified based on conventional system 442 * design and known examples. Significant work is required elsewhere to 443 * fully support data/instruction only type caches which are only 444 * specified in PPTT. 445 */ 446 if (this_leaf->type == CACHE_TYPE_NOCACHE && 447 found_cache->flags & ACPI_PPTT_CACHE_TYPE_VALID) 448 this_leaf->type = CACHE_TYPE_UNIFIED; 449 450 found_cache_v1 = upgrade_pptt_cache(found_cache); 451 if (found_cache_v1) { 452 this_leaf->id = found_cache_v1->cache_id; 453 this_leaf->attributes |= CACHE_ID; 454 } 455 } 456 457 static void cache_setup_acpi_cpu(struct acpi_table_header *table, 458 unsigned int cpu) 459 { 460 struct acpi_pptt_cache *found_cache; 461 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu); 462 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); 463 struct cacheinfo *this_leaf; 464 unsigned int index = 0; 465 struct acpi_pptt_processor *cpu_node = NULL; 466 467 while (index < get_cpu_cacheinfo(cpu)->num_leaves) { 468 this_leaf = this_cpu_ci->info_list + index; 469 found_cache = acpi_find_cache_node(table, acpi_cpu_id, 470 this_leaf->type, 471 this_leaf->level, 472 &cpu_node); 473 pr_debug("found = %p %p\n", found_cache, cpu_node); 474 if (found_cache) 475 update_cache_properties(this_leaf, found_cache, 476 ACPI_TO_POINTER(ACPI_PTR_DIFF(cpu_node, table))); 477 478 index++; 479 } 480 } 481 482 static bool flag_identical(struct acpi_table_header *table_hdr, 483 struct acpi_pptt_processor *cpu) 484 { 485 struct acpi_pptt_processor *next; 486 487 /* heterogeneous machines must use PPTT revision > 1 */ 488 if (table_hdr->revision < 2) 489 return false; 490 491 /* Locate the last node in the tree with IDENTICAL set */ 492 if (cpu->flags & ACPI_PPTT_ACPI_IDENTICAL) { 493 next = fetch_pptt_node(table_hdr, cpu->parent); 494 if (!(next && next->flags & ACPI_PPTT_ACPI_IDENTICAL)) 495 return true; 496 } 497 498 return false; 499 } 500 501 /* Passing level values greater than this will result in search termination */ 502 #define PPTT_ABORT_PACKAGE 0xFF 503 504 static struct acpi_pptt_processor *acpi_find_processor_tag(struct acpi_table_header *table_hdr, 505 struct acpi_pptt_processor *cpu, 506 int level, int flag) 507 { 508 struct acpi_pptt_processor *prev_node; 509 510 while (cpu && level) { 511 /* special case the identical flag to find last identical */ 512 if (flag == ACPI_PPTT_ACPI_IDENTICAL) { 513 if (flag_identical(table_hdr, cpu)) 514 break; 515 } else if (cpu->flags & flag) 516 break; 517 pr_debug("level %d\n", level); 518 prev_node = fetch_pptt_node(table_hdr, cpu->parent); 519 if (prev_node == NULL) 520 break; 521 cpu = prev_node; 522 level--; 523 } 524 return cpu; 525 } 526 527 static void acpi_pptt_warn_missing(void) 528 { 529 pr_warn_once("No PPTT table found, CPU and cache topology may be inaccurate\n"); 530 } 531 532 /** 533 * topology_get_acpi_cpu_tag() - Find a unique topology value for a feature 534 * @table: Pointer to the head of the PPTT table 535 * @cpu: Kernel logical CPU number 536 * @level: A level that terminates the search 537 * @flag: A flag which terminates the search 538 * 539 * Get a unique value given a CPU, and a topology level, that can be 540 * matched to determine which cpus share common topological features 541 * at that level. 542 * 543 * Return: Unique value, or -ENOENT if unable to locate CPU 544 */ 545 static int topology_get_acpi_cpu_tag(struct acpi_table_header *table, 546 unsigned int cpu, int level, int flag) 547 { 548 struct acpi_pptt_processor *cpu_node; 549 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); 550 551 cpu_node = acpi_find_processor_node(table, acpi_cpu_id); 552 if (cpu_node) { 553 cpu_node = acpi_find_processor_tag(table, cpu_node, 554 level, flag); 555 /* 556 * As per specification if the processor structure represents 557 * an actual processor, then ACPI processor ID must be valid. 558 * For processor containers ACPI_PPTT_ACPI_PROCESSOR_ID_VALID 559 * should be set if the UID is valid 560 */ 561 if (level == 0 || 562 cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID) 563 return cpu_node->acpi_processor_id; 564 return ACPI_PTR_DIFF(cpu_node, table); 565 } 566 pr_warn_once("PPTT table found, but unable to locate core %d (%d)\n", 567 cpu, acpi_cpu_id); 568 return -ENOENT; 569 } 570 571 572 static struct acpi_table_header *acpi_get_pptt(void) 573 { 574 static struct acpi_table_header *pptt; 575 static bool is_pptt_checked; 576 acpi_status status; 577 578 /* 579 * PPTT will be used at runtime on every CPU hotplug in path, so we 580 * don't need to call acpi_put_table() to release the table mapping. 581 */ 582 if (!pptt && !is_pptt_checked) { 583 status = acpi_get_table(ACPI_SIG_PPTT, 0, &pptt); 584 if (ACPI_FAILURE(status)) 585 acpi_pptt_warn_missing(); 586 587 is_pptt_checked = true; 588 } 589 590 return pptt; 591 } 592 593 static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag) 594 { 595 struct acpi_table_header *table; 596 int retval; 597 598 table = acpi_get_pptt(); 599 if (!table) 600 return -ENOENT; 601 602 retval = topology_get_acpi_cpu_tag(table, cpu, level, flag); 603 pr_debug("Topology Setup ACPI CPU %d, level %d ret = %d\n", 604 cpu, level, retval); 605 606 return retval; 607 } 608 609 /** 610 * check_acpi_cpu_flag() - Determine if CPU node has a flag set 611 * @cpu: Kernel logical CPU number 612 * @rev: The minimum PPTT revision defining the flag 613 * @flag: The flag itself 614 * 615 * Check the node representing a CPU for a given flag. 616 * 617 * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found or 618 * the table revision isn't new enough. 619 * 1, any passed flag set 620 * 0, flag unset 621 */ 622 static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag) 623 { 624 struct acpi_table_header *table; 625 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); 626 struct acpi_pptt_processor *cpu_node = NULL; 627 int ret = -ENOENT; 628 629 table = acpi_get_pptt(); 630 if (!table) 631 return -ENOENT; 632 633 if (table->revision >= rev) 634 cpu_node = acpi_find_processor_node(table, acpi_cpu_id); 635 636 if (cpu_node) 637 ret = (cpu_node->flags & flag) != 0; 638 639 return ret; 640 } 641 642 /** 643 * acpi_get_cache_info() - Determine the number of cache levels and 644 * split cache levels (data/instruction) and for a PE. 645 * @cpu: Kernel logical CPU number 646 * @levels: Number of levels if success. 647 * @split_levels: Number of levels being split (i.e. data/instruction) 648 * if success. Can by NULL. 649 * 650 * Given a logical CPU number, returns the number of levels of cache represented 651 * in the PPTT. Errors caused by lack of a PPTT table, or otherwise, return 0 652 * indicating we didn't find any cache levels. 653 * 654 * Return: -ENOENT if no PPTT table or no PPTT processor struct found. 655 * 0 on success. 656 */ 657 int acpi_get_cache_info(unsigned int cpu, unsigned int *levels, 658 unsigned int *split_levels) 659 { 660 struct acpi_pptt_processor *cpu_node; 661 struct acpi_table_header *table; 662 u32 acpi_cpu_id; 663 664 *levels = 0; 665 if (split_levels) 666 *split_levels = 0; 667 668 table = acpi_get_pptt(); 669 if (!table) 670 return -ENOENT; 671 672 pr_debug("Cache Setup: find cache levels for CPU=%d\n", cpu); 673 674 acpi_cpu_id = get_acpi_id_for_cpu(cpu); 675 cpu_node = acpi_find_processor_node(table, acpi_cpu_id); 676 if (!cpu_node) 677 return -ENOENT; 678 679 *levels = acpi_count_levels(table, cpu_node, split_levels); 680 681 pr_debug("Cache Setup: last_level=%d split_levels=%d\n", 682 *levels, split_levels ? *split_levels : -1); 683 684 return 0; 685 } 686 687 /** 688 * cache_setup_acpi() - Override CPU cache topology with data from the PPTT 689 * @cpu: Kernel logical CPU number 690 * 691 * Updates the global cache info provided by cpu_get_cacheinfo() 692 * when there are valid properties in the acpi_pptt_cache nodes. A 693 * successful parse may not result in any updates if none of the 694 * cache levels have any valid flags set. Further, a unique value is 695 * associated with each known CPU cache entry. This unique value 696 * can be used to determine whether caches are shared between CPUs. 697 * 698 * Return: -ENOENT on failure to find table, or 0 on success 699 */ 700 int cache_setup_acpi(unsigned int cpu) 701 { 702 struct acpi_table_header *table; 703 704 table = acpi_get_pptt(); 705 if (!table) 706 return -ENOENT; 707 708 pr_debug("Cache Setup ACPI CPU %d\n", cpu); 709 710 cache_setup_acpi_cpu(table, cpu); 711 712 return 0; 713 } 714 715 /** 716 * acpi_pptt_cpu_is_thread() - Determine if CPU is a thread 717 * @cpu: Kernel logical CPU number 718 * 719 * Return: 1, a thread 720 * 0, not a thread 721 * -ENOENT ,if the PPTT doesn't exist, the CPU cannot be found or 722 * the table revision isn't new enough. 723 */ 724 int acpi_pptt_cpu_is_thread(unsigned int cpu) 725 { 726 return check_acpi_cpu_flag(cpu, 2, ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD); 727 } 728 729 /** 730 * find_acpi_cpu_topology() - Determine a unique topology value for a given CPU 731 * @cpu: Kernel logical CPU number 732 * @level: The topological level for which we would like a unique ID 733 * 734 * Determine a topology unique ID for each thread/core/cluster/mc_grouping 735 * /socket/etc. This ID can then be used to group peers, which will have 736 * matching ids. 737 * 738 * The search terminates when either the requested level is found or 739 * we reach a root node. Levels beyond the termination point will return the 740 * same unique ID. The unique id for level 0 is the acpi processor id. All 741 * other levels beyond this use a generated value to uniquely identify 742 * a topological feature. 743 * 744 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found. 745 * Otherwise returns a value which represents a unique topological feature. 746 */ 747 int find_acpi_cpu_topology(unsigned int cpu, int level) 748 { 749 return find_acpi_cpu_topology_tag(cpu, level, 0); 750 } 751 752 /** 753 * find_acpi_cpu_topology_package() - Determine a unique CPU package value 754 * @cpu: Kernel logical CPU number 755 * 756 * Determine a topology unique package ID for the given CPU. 757 * This ID can then be used to group peers, which will have matching ids. 758 * 759 * The search terminates when either a level is found with the PHYSICAL_PACKAGE 760 * flag set or we reach a root node. 761 * 762 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found. 763 * Otherwise returns a value which represents the package for this CPU. 764 */ 765 int find_acpi_cpu_topology_package(unsigned int cpu) 766 { 767 return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, 768 ACPI_PPTT_PHYSICAL_PACKAGE); 769 } 770 771 /** 772 * find_acpi_cpu_topology_cluster() - Determine a unique CPU cluster value 773 * @cpu: Kernel logical CPU number 774 * 775 * Determine a topology unique cluster ID for the given CPU/thread. 776 * This ID can then be used to group peers, which will have matching ids. 777 * 778 * The cluster, if present is the level of topology above CPUs. In a 779 * multi-thread CPU, it will be the level above the CPU, not the thread. 780 * It may not exist in single CPU systems. In simple multi-CPU systems, 781 * it may be equal to the package topology level. 782 * 783 * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found 784 * or there is no toplogy level above the CPU.. 785 * Otherwise returns a value which represents the package for this CPU. 786 */ 787 788 int find_acpi_cpu_topology_cluster(unsigned int cpu) 789 { 790 struct acpi_table_header *table; 791 struct acpi_pptt_processor *cpu_node, *cluster_node; 792 u32 acpi_cpu_id; 793 int retval; 794 int is_thread; 795 796 table = acpi_get_pptt(); 797 if (!table) 798 return -ENOENT; 799 800 acpi_cpu_id = get_acpi_id_for_cpu(cpu); 801 cpu_node = acpi_find_processor_node(table, acpi_cpu_id); 802 if (!cpu_node || !cpu_node->parent) 803 return -ENOENT; 804 805 is_thread = cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD; 806 cluster_node = fetch_pptt_node(table, cpu_node->parent); 807 if (!cluster_node) 808 return -ENOENT; 809 810 if (is_thread) { 811 if (!cluster_node->parent) 812 return -ENOENT; 813 814 cluster_node = fetch_pptt_node(table, cluster_node->parent); 815 if (!cluster_node) 816 return -ENOENT; 817 } 818 if (cluster_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID) 819 retval = cluster_node->acpi_processor_id; 820 else 821 retval = ACPI_PTR_DIFF(cluster_node, table); 822 823 return retval; 824 } 825 826 /** 827 * find_acpi_cpu_topology_hetero_id() - Get a core architecture tag 828 * @cpu: Kernel logical CPU number 829 * 830 * Determine a unique heterogeneous tag for the given CPU. CPUs with the same 831 * implementation should have matching tags. 832 * 833 * The returned tag can be used to group peers with identical implementation. 834 * 835 * The search terminates when a level is found with the identical implementation 836 * flag set or we reach a root node. 837 * 838 * Due to limitations in the PPTT data structure, there may be rare situations 839 * where two cores in a heterogeneous machine may be identical, but won't have 840 * the same tag. 841 * 842 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found. 843 * Otherwise returns a value which represents a group of identical cores 844 * similar to this CPU. 845 */ 846 int find_acpi_cpu_topology_hetero_id(unsigned int cpu) 847 { 848 return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE, 849 ACPI_PPTT_ACPI_IDENTICAL); 850 } 851 852 /** 853 * acpi_pptt_get_child_cpus() - Find all the CPUs below a PPTT 854 * processor hierarchy node 855 * 856 * @table_hdr: A reference to the PPTT table 857 * @parent_node: A pointer to the processor hierarchy node in the 858 * table_hdr 859 * @cpus: A cpumask to fill with the CPUs below @parent_node 860 * 861 * Walks up the PPTT from every possible CPU to find if the provided 862 * @parent_node is a parent of this CPU. 863 */ 864 static void acpi_pptt_get_child_cpus(struct acpi_table_header *table_hdr, 865 struct acpi_pptt_processor *parent_node, 866 cpumask_t *cpus) 867 { 868 struct acpi_pptt_processor *cpu_node; 869 u32 acpi_id; 870 int cpu; 871 872 cpumask_clear(cpus); 873 874 for_each_possible_cpu(cpu) { 875 acpi_id = get_acpi_id_for_cpu(cpu); 876 cpu_node = acpi_find_processor_node(table_hdr, acpi_id); 877 878 while (cpu_node) { 879 if (cpu_node == parent_node) { 880 cpumask_set_cpu(cpu, cpus); 881 break; 882 } 883 cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent); 884 } 885 } 886 } 887 888 /** 889 * acpi_pptt_get_cpus_from_container() - Populate a cpumask with all CPUs in a 890 * processor container 891 * @acpi_cpu_id: The UID of the processor container 892 * @cpus: The resulting CPU mask 893 * 894 * Find the specified Processor Container, and fill @cpus with all the cpus 895 * below it. 896 * 897 * Not all 'Processor Hierarchy' entries in the PPTT are either a CPU 898 * or a Processor Container, they may exist purely to describe a 899 * Private resource. CPUs have to be leaves, so a Processor Container 900 * is a non-leaf that has the 'ACPI Processor ID valid' flag set. 901 */ 902 void acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, cpumask_t *cpus) 903 { 904 struct acpi_table_header *table_hdr; 905 struct acpi_subtable_header *entry; 906 unsigned long table_end; 907 u32 proc_sz; 908 909 cpumask_clear(cpus); 910 911 table_hdr = acpi_get_pptt(); 912 if (!table_hdr) 913 return; 914 915 table_end = (unsigned long)table_hdr + table_hdr->length; 916 entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr, 917 sizeof(struct acpi_table_pptt)); 918 proc_sz = sizeof(struct acpi_pptt_processor); 919 while ((unsigned long)entry + proc_sz <= table_end) { 920 if (entry->type == ACPI_PPTT_TYPE_PROCESSOR) { 921 struct acpi_pptt_processor *cpu_node; 922 923 cpu_node = (struct acpi_pptt_processor *)entry; 924 if (cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID && 925 !acpi_pptt_leaf_node(table_hdr, cpu_node) && 926 cpu_node->acpi_processor_id == acpi_cpu_id) { 927 acpi_pptt_get_child_cpus(table_hdr, cpu_node, cpus); 928 break; 929 } 930 } 931 entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry, 932 entry->length); 933 } 934 } 935 936 /** 937 * find_acpi_cache_level_from_id() - Get the level of the specified cache 938 * @cache_id: The id field of the cache 939 * 940 * Determine the level relative to any CPU for the cache identified by 941 * cache_id. This allows the property to be found even if the CPUs are offline. 942 * 943 * The returned level can be used to group caches that are peers. 944 * 945 * The PPTT table must be rev 3 or later. 946 * 947 * If one CPU's L2 is shared with another CPU as L3, this function will return 948 * an unpredictable value. 949 * 950 * Return: -ENOENT if the PPTT doesn't exist, the revision isn't supported or 951 * the cache cannot be found. 952 * Otherwise returns a value which represents the level of the specified cache. 953 */ 954 int find_acpi_cache_level_from_id(u32 cache_id) 955 { 956 int cpu; 957 struct acpi_table_header *table; 958 959 table = acpi_get_pptt(); 960 if (!table) 961 return -ENOENT; 962 963 if (table->revision < 3) 964 return -ENOENT; 965 966 for_each_possible_cpu(cpu) { 967 bool empty; 968 int level = 1; 969 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); 970 struct acpi_pptt_cache *cache; 971 struct acpi_pptt_processor *cpu_node; 972 973 cpu_node = acpi_find_processor_node(table, acpi_cpu_id); 974 if (!cpu_node) 975 continue; 976 977 do { 978 int cache_type[] = {CACHE_TYPE_INST, CACHE_TYPE_DATA, CACHE_TYPE_UNIFIED}; 979 980 empty = true; 981 for (int i = 0; i < ARRAY_SIZE(cache_type); i++) { 982 struct acpi_pptt_cache_v1_full *cache_v1; 983 984 cache = acpi_find_cache_node(table, acpi_cpu_id, cache_type[i], 985 level, &cpu_node); 986 if (!cache) 987 continue; 988 989 empty = false; 990 991 cache_v1 = upgrade_pptt_cache(cache); 992 if (cache_v1 && cache_v1->cache_id == cache_id) 993 return level; 994 } 995 level++; 996 } while (!empty); 997 } 998 999 return -ENOENT; 1000 } 1001 1002 /** 1003 * acpi_pptt_get_cpumask_from_cache_id() - Get the cpus associated with the 1004 * specified cache 1005 * @cache_id: The id field of the cache 1006 * @cpus: Where to build the cpumask 1007 * 1008 * Determine which CPUs are below this cache in the PPTT. This allows the property 1009 * to be found even if the CPUs are offline. 1010 * 1011 * The PPTT table must be rev 3 or later, 1012 * 1013 * Return: -ENOENT if the PPTT doesn't exist, or the cache cannot be found. 1014 * Otherwise returns 0 and sets the cpus in the provided cpumask. 1015 */ 1016 int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id, cpumask_t *cpus) 1017 { 1018 int cpu; 1019 struct acpi_table_header *table; 1020 1021 cpumask_clear(cpus); 1022 1023 table = acpi_get_pptt(); 1024 if (!table) 1025 return -ENOENT; 1026 1027 if (table->revision < 3) 1028 return -ENOENT; 1029 1030 for_each_possible_cpu(cpu) { 1031 bool empty; 1032 int level = 1; 1033 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu); 1034 struct acpi_pptt_cache *cache; 1035 struct acpi_pptt_processor *cpu_node; 1036 1037 cpu_node = acpi_find_processor_node(table, acpi_cpu_id); 1038 if (!cpu_node) 1039 continue; 1040 1041 do { 1042 int cache_type[] = {CACHE_TYPE_INST, CACHE_TYPE_DATA, CACHE_TYPE_UNIFIED}; 1043 1044 empty = true; 1045 for (int i = 0; i < ARRAY_SIZE(cache_type); i++) { 1046 struct acpi_pptt_cache_v1_full *cache_v1; 1047 1048 cache = acpi_find_cache_node(table, acpi_cpu_id, cache_type[i], 1049 level, &cpu_node); 1050 1051 if (!cache) 1052 continue; 1053 1054 empty = false; 1055 1056 cache_v1 = upgrade_pptt_cache(cache); 1057 if (cache_v1 && cache_v1->cache_id == cache_id) 1058 cpumask_set_cpu(cpu, cpus); 1059 } 1060 level++; 1061 } while (!empty); 1062 } 1063 1064 return 0; 1065 } 1066