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1// SPDX-License-Identifier: GPL-2.02/*3 * pptt.c - parsing of Processor Properties Topology Table (PPTT)4 *5 * Copyright (C) 2018, ARM6 *7 * This file implements parsing of the Processor Properties Topology Table8 * which is optionally used to describe the processor and cache topology.9 * Due to the relative pointers used throughout the table, this doesn't10 * leverage the existing subtable parsing in the kernel.11 *12 * The PPTT structure is an inverted tree, with each node potentially13 * holding one or two inverted tree data structures describing14 * the caches available at that level. Each cache structure optionally15 * contains properties describing the cache at a given level which can be16 * used to override hardware probed values.17 */18#define pr_fmt(fmt) "ACPI PPTT: " fmt19 20#include <linux/acpi.h>21#include <linux/cacheinfo.h>22#include <acpi/processor.h>23 24static struct acpi_subtable_header *fetch_pptt_subtable(struct acpi_table_header *table_hdr,25 u32 pptt_ref)26{27 struct acpi_subtable_header *entry;28 29 /* there isn't a subtable at reference 0 */30 if (pptt_ref < sizeof(struct acpi_subtable_header))31 return NULL;32 33 if (pptt_ref + sizeof(struct acpi_subtable_header) > table_hdr->length)34 return NULL;35 36 entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr, pptt_ref);37 38 if (entry->length == 0)39 return NULL;40 41 if (pptt_ref + entry->length > table_hdr->length)42 return NULL;43 44 return entry;45}46 47static struct acpi_pptt_processor *fetch_pptt_node(struct acpi_table_header *table_hdr,48 u32 pptt_ref)49{50 return (struct acpi_pptt_processor *)fetch_pptt_subtable(table_hdr, pptt_ref);51}52 53static struct acpi_pptt_cache *fetch_pptt_cache(struct acpi_table_header *table_hdr,54 u32 pptt_ref)55{56 return (struct acpi_pptt_cache *)fetch_pptt_subtable(table_hdr, pptt_ref);57}58 59static struct acpi_subtable_header *acpi_get_pptt_resource(struct acpi_table_header *table_hdr,60 struct acpi_pptt_processor *node,61 int resource)62{63 u32 *ref;64 65 if (resource >= node->number_of_priv_resources)66 return NULL;67 68 ref = ACPI_ADD_PTR(u32, node, sizeof(struct acpi_pptt_processor));69 ref += resource;70 71 return fetch_pptt_subtable(table_hdr, *ref);72}73 74static inline bool acpi_pptt_match_type(int table_type, int type)75{76 return ((table_type & ACPI_PPTT_MASK_CACHE_TYPE) == type ||77 table_type & ACPI_PPTT_CACHE_TYPE_UNIFIED & type);78}79 80/**81 * acpi_pptt_walk_cache() - Attempt to find the requested acpi_pptt_cache82 * @table_hdr: Pointer to the head of the PPTT table83 * @local_level: passed res reflects this cache level84 * @split_levels: Number of split cache levels (data/instruction).85 * @res: cache resource in the PPTT we want to walk86 * @found: returns a pointer to the requested level if found87 * @level: the requested cache level88 * @type: the requested cache type89 *90 * Attempt to find a given cache level, while counting the max number91 * of cache levels for the cache node.92 *93 * Given a pptt resource, verify that it is a cache node, then walk94 * down each level of caches, counting how many levels are found95 * as well as checking the cache type (icache, dcache, unified). If a96 * level & type match, then we set found, and continue the search.97 * Once the entire cache branch has been walked return its max98 * depth.99 *100 * Return: The cache structure and the level we terminated with.101 */102static unsigned int acpi_pptt_walk_cache(struct acpi_table_header *table_hdr,103 unsigned int local_level,104 unsigned int *split_levels,105 struct acpi_subtable_header *res,106 struct acpi_pptt_cache **found,107 unsigned int level, int type)108{109 struct acpi_pptt_cache *cache;110 111 if (res->type != ACPI_PPTT_TYPE_CACHE)112 return 0;113 114 cache = (struct acpi_pptt_cache *) res;115 while (cache) {116 local_level++;117 118 if (!(cache->flags & ACPI_PPTT_CACHE_TYPE_VALID)) {119 cache = fetch_pptt_cache(table_hdr, cache->next_level_of_cache);120 continue;121 }122 123 if (split_levels &&124 (acpi_pptt_match_type(cache->attributes, ACPI_PPTT_CACHE_TYPE_DATA) ||125 acpi_pptt_match_type(cache->attributes, ACPI_PPTT_CACHE_TYPE_INSTR)))126 *split_levels = local_level;127 128 if (local_level == level &&129 acpi_pptt_match_type(cache->attributes, type)) {130 if (*found != NULL && cache != *found)131 pr_warn("Found duplicate cache level/type unable to determine uniqueness\n");132 133 pr_debug("Found cache @ level %u\n", level);134 *found = cache;135 /*136 * continue looking at this node's resource list137 * to verify that we don't find a duplicate138 * cache node.139 */140 }141 cache = fetch_pptt_cache(table_hdr, cache->next_level_of_cache);142 }143 return local_level;144}145 146static struct acpi_pptt_cache *147acpi_find_cache_level(struct acpi_table_header *table_hdr,148 struct acpi_pptt_processor *cpu_node,149 unsigned int *starting_level, unsigned int *split_levels,150 unsigned int level, int type)151{152 struct acpi_subtable_header *res;153 unsigned int number_of_levels = *starting_level;154 int resource = 0;155 struct acpi_pptt_cache *ret = NULL;156 unsigned int local_level;157 158 /* walk down from processor node */159 while ((res = acpi_get_pptt_resource(table_hdr, cpu_node, resource))) {160 resource++;161 162 local_level = acpi_pptt_walk_cache(table_hdr, *starting_level,163 split_levels, res, &ret,164 level, type);165 /*166 * we are looking for the max depth. Since its potentially167 * possible for a given node to have resources with differing168 * depths verify that the depth we have found is the largest.169 */170 if (number_of_levels < local_level)171 number_of_levels = local_level;172 }173 if (number_of_levels > *starting_level)174 *starting_level = number_of_levels;175 176 return ret;177}178 179/**180 * acpi_count_levels() - Given a PPTT table, and a CPU node, count the cache181 * levels and split cache levels (data/instruction).182 * @table_hdr: Pointer to the head of the PPTT table183 * @cpu_node: processor node we wish to count caches for184 * @levels: Number of levels if success.185 * @split_levels: Number of split cache levels (data/instruction) if186 * success. Can by NULL.187 *188 * Given a processor node containing a processing unit, walk into it and count189 * how many levels exist solely for it, and then walk up each level until we hit190 * the root node (ignore the package level because it may be possible to have191 * caches that exist across packages). Count the number of cache levels and192 * split cache levels (data/instruction) that exist at each level on the way193 * up.194 */195static void acpi_count_levels(struct acpi_table_header *table_hdr,196 struct acpi_pptt_processor *cpu_node,197 unsigned int *levels, unsigned int *split_levels)198{199 do {200 acpi_find_cache_level(table_hdr, cpu_node, levels, split_levels, 0, 0);201 cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);202 } while (cpu_node);203}204 205/**206 * acpi_pptt_leaf_node() - Given a processor node, determine if its a leaf207 * @table_hdr: Pointer to the head of the PPTT table208 * @node: passed node is checked to see if its a leaf209 *210 * Determine if the *node parameter is a leaf node by iterating the211 * PPTT table, looking for nodes which reference it.212 *213 * Return: 0 if we find a node referencing the passed node (or table error),214 * or 1 if we don't.215 */216static int acpi_pptt_leaf_node(struct acpi_table_header *table_hdr,217 struct acpi_pptt_processor *node)218{219 struct acpi_subtable_header *entry;220 unsigned long table_end;221 u32 node_entry;222 struct acpi_pptt_processor *cpu_node;223 u32 proc_sz;224 225 if (table_hdr->revision > 1)226 return (node->flags & ACPI_PPTT_ACPI_LEAF_NODE);227 228 table_end = (unsigned long)table_hdr + table_hdr->length;229 node_entry = ACPI_PTR_DIFF(node, table_hdr);230 entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr,231 sizeof(struct acpi_table_pptt));232 proc_sz = sizeof(struct acpi_pptt_processor *);233 234 while ((unsigned long)entry + proc_sz < table_end) {235 cpu_node = (struct acpi_pptt_processor *)entry;236 if (entry->type == ACPI_PPTT_TYPE_PROCESSOR &&237 cpu_node->parent == node_entry)238 return 0;239 if (entry->length == 0)240 return 0;241 entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry,242 entry->length);243 244 }245 return 1;246}247 248/**249 * acpi_find_processor_node() - Given a PPTT table find the requested processor250 * @table_hdr: Pointer to the head of the PPTT table251 * @acpi_cpu_id: CPU we are searching for252 *253 * Find the subtable entry describing the provided processor.254 * This is done by iterating the PPTT table looking for processor nodes255 * which have an acpi_processor_id that matches the acpi_cpu_id parameter256 * passed into the function. If we find a node that matches this criteria257 * we verify that its a leaf node in the topology rather than depending258 * on the valid flag, which doesn't need to be set for leaf nodes.259 *260 * Return: NULL, or the processors acpi_pptt_processor*261 */262static struct acpi_pptt_processor *acpi_find_processor_node(struct acpi_table_header *table_hdr,263 u32 acpi_cpu_id)264{265 struct acpi_subtable_header *entry;266 unsigned long table_end;267 struct acpi_pptt_processor *cpu_node;268 u32 proc_sz;269 270 table_end = (unsigned long)table_hdr + table_hdr->length;271 entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr,272 sizeof(struct acpi_table_pptt));273 proc_sz = sizeof(struct acpi_pptt_processor *);274 275 /* find the processor structure associated with this cpuid */276 while ((unsigned long)entry + proc_sz < table_end) {277 cpu_node = (struct acpi_pptt_processor *)entry;278 279 if (entry->length == 0) {280 pr_warn("Invalid zero length subtable\n");281 break;282 }283 if (entry->type == ACPI_PPTT_TYPE_PROCESSOR &&284 acpi_cpu_id == cpu_node->acpi_processor_id &&285 acpi_pptt_leaf_node(table_hdr, cpu_node)) {286 return (struct acpi_pptt_processor *)entry;287 }288 289 entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry,290 entry->length);291 }292 293 return NULL;294}295 296static u8 acpi_cache_type(enum cache_type type)297{298 switch (type) {299 case CACHE_TYPE_DATA:300 pr_debug("Looking for data cache\n");301 return ACPI_PPTT_CACHE_TYPE_DATA;302 case CACHE_TYPE_INST:303 pr_debug("Looking for instruction cache\n");304 return ACPI_PPTT_CACHE_TYPE_INSTR;305 default:306 case CACHE_TYPE_UNIFIED:307 pr_debug("Looking for unified cache\n");308 /*309 * It is important that ACPI_PPTT_CACHE_TYPE_UNIFIED310 * contains the bit pattern that will match both311 * ACPI unified bit patterns because we use it later312 * to match both cases.313 */314 return ACPI_PPTT_CACHE_TYPE_UNIFIED;315 }316}317 318static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *table_hdr,319 u32 acpi_cpu_id,320 enum cache_type type,321 unsigned int level,322 struct acpi_pptt_processor **node)323{324 unsigned int total_levels = 0;325 struct acpi_pptt_cache *found = NULL;326 struct acpi_pptt_processor *cpu_node;327 u8 acpi_type = acpi_cache_type(type);328 329 pr_debug("Looking for CPU %d's level %u cache type %d\n",330 acpi_cpu_id, level, acpi_type);331 332 cpu_node = acpi_find_processor_node(table_hdr, acpi_cpu_id);333 334 while (cpu_node && !found) {335 found = acpi_find_cache_level(table_hdr, cpu_node,336 &total_levels, NULL, level, acpi_type);337 *node = cpu_node;338 cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);339 }340 341 return found;342}343 344/**345 * update_cache_properties() - Update cacheinfo for the given processor346 * @this_leaf: Kernel cache info structure being updated347 * @found_cache: The PPTT node describing this cache instance348 * @cpu_node: A unique reference to describe this cache instance349 * @revision: The revision of the PPTT table350 *351 * The ACPI spec implies that the fields in the cache structures are used to352 * extend and correct the information probed from the hardware. Lets only353 * set fields that we determine are VALID.354 *355 * Return: nothing. Side effect of updating the global cacheinfo356 */357static void update_cache_properties(struct cacheinfo *this_leaf,358 struct acpi_pptt_cache *found_cache,359 struct acpi_pptt_processor *cpu_node,360 u8 revision)361{362 struct acpi_pptt_cache_v1* found_cache_v1;363 364 this_leaf->fw_token = cpu_node;365 if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID)366 this_leaf->size = found_cache->size;367 if (found_cache->flags & ACPI_PPTT_LINE_SIZE_VALID)368 this_leaf->coherency_line_size = found_cache->line_size;369 if (found_cache->flags & ACPI_PPTT_NUMBER_OF_SETS_VALID)370 this_leaf->number_of_sets = found_cache->number_of_sets;371 if (found_cache->flags & ACPI_PPTT_ASSOCIATIVITY_VALID)372 this_leaf->ways_of_associativity = found_cache->associativity;373 if (found_cache->flags & ACPI_PPTT_WRITE_POLICY_VALID) {374 switch (found_cache->attributes & ACPI_PPTT_MASK_WRITE_POLICY) {375 case ACPI_PPTT_CACHE_POLICY_WT:376 this_leaf->attributes = CACHE_WRITE_THROUGH;377 break;378 case ACPI_PPTT_CACHE_POLICY_WB:379 this_leaf->attributes = CACHE_WRITE_BACK;380 break;381 }382 }383 if (found_cache->flags & ACPI_PPTT_ALLOCATION_TYPE_VALID) {384 switch (found_cache->attributes & ACPI_PPTT_MASK_ALLOCATION_TYPE) {385 case ACPI_PPTT_CACHE_READ_ALLOCATE:386 this_leaf->attributes |= CACHE_READ_ALLOCATE;387 break;388 case ACPI_PPTT_CACHE_WRITE_ALLOCATE:389 this_leaf->attributes |= CACHE_WRITE_ALLOCATE;390 break;391 case ACPI_PPTT_CACHE_RW_ALLOCATE:392 case ACPI_PPTT_CACHE_RW_ALLOCATE_ALT:393 this_leaf->attributes |=394 CACHE_READ_ALLOCATE | CACHE_WRITE_ALLOCATE;395 break;396 }397 }398 /*399 * If cache type is NOCACHE, then the cache hasn't been specified400 * via other mechanisms. Update the type if a cache type has been401 * provided.402 *403 * Note, we assume such caches are unified based on conventional system404 * design and known examples. Significant work is required elsewhere to405 * fully support data/instruction only type caches which are only406 * specified in PPTT.407 */408 if (this_leaf->type == CACHE_TYPE_NOCACHE &&409 found_cache->flags & ACPI_PPTT_CACHE_TYPE_VALID)410 this_leaf->type = CACHE_TYPE_UNIFIED;411 412 if (revision >= 3 && (found_cache->flags & ACPI_PPTT_CACHE_ID_VALID)) {413 found_cache_v1 = ACPI_ADD_PTR(struct acpi_pptt_cache_v1,414 found_cache, sizeof(struct acpi_pptt_cache));415 this_leaf->id = found_cache_v1->cache_id;416 this_leaf->attributes |= CACHE_ID;417 }418}419 420static void cache_setup_acpi_cpu(struct acpi_table_header *table,421 unsigned int cpu)422{423 struct acpi_pptt_cache *found_cache;424 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);425 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);426 struct cacheinfo *this_leaf;427 unsigned int index = 0;428 struct acpi_pptt_processor *cpu_node = NULL;429 430 while (index < get_cpu_cacheinfo(cpu)->num_leaves) {431 this_leaf = this_cpu_ci->info_list + index;432 found_cache = acpi_find_cache_node(table, acpi_cpu_id,433 this_leaf->type,434 this_leaf->level,435 &cpu_node);436 pr_debug("found = %p %p\n", found_cache, cpu_node);437 if (found_cache)438 update_cache_properties(this_leaf, found_cache,439 ACPI_TO_POINTER(ACPI_PTR_DIFF(cpu_node, table)),440 table->revision);441 442 index++;443 }444}445 446static bool flag_identical(struct acpi_table_header *table_hdr,447 struct acpi_pptt_processor *cpu)448{449 struct acpi_pptt_processor *next;450 451 /* heterogeneous machines must use PPTT revision > 1 */452 if (table_hdr->revision < 2)453 return false;454 455 /* Locate the last node in the tree with IDENTICAL set */456 if (cpu->flags & ACPI_PPTT_ACPI_IDENTICAL) {457 next = fetch_pptt_node(table_hdr, cpu->parent);458 if (!(next && next->flags & ACPI_PPTT_ACPI_IDENTICAL))459 return true;460 }461 462 return false;463}464 465/* Passing level values greater than this will result in search termination */466#define PPTT_ABORT_PACKAGE 0xFF467 468static struct acpi_pptt_processor *acpi_find_processor_tag(struct acpi_table_header *table_hdr,469 struct acpi_pptt_processor *cpu,470 int level, int flag)471{472 struct acpi_pptt_processor *prev_node;473 474 while (cpu && level) {475 /* special case the identical flag to find last identical */476 if (flag == ACPI_PPTT_ACPI_IDENTICAL) {477 if (flag_identical(table_hdr, cpu))478 break;479 } else if (cpu->flags & flag)480 break;481 pr_debug("level %d\n", level);482 prev_node = fetch_pptt_node(table_hdr, cpu->parent);483 if (prev_node == NULL)484 break;485 cpu = prev_node;486 level--;487 }488 return cpu;489}490 491static void acpi_pptt_warn_missing(void)492{493 pr_warn_once("No PPTT table found, CPU and cache topology may be inaccurate\n");494}495 496/**497 * topology_get_acpi_cpu_tag() - Find a unique topology value for a feature498 * @table: Pointer to the head of the PPTT table499 * @cpu: Kernel logical CPU number500 * @level: A level that terminates the search501 * @flag: A flag which terminates the search502 *503 * Get a unique value given a CPU, and a topology level, that can be504 * matched to determine which cpus share common topological features505 * at that level.506 *507 * Return: Unique value, or -ENOENT if unable to locate CPU508 */509static int topology_get_acpi_cpu_tag(struct acpi_table_header *table,510 unsigned int cpu, int level, int flag)511{512 struct acpi_pptt_processor *cpu_node;513 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);514 515 cpu_node = acpi_find_processor_node(table, acpi_cpu_id);516 if (cpu_node) {517 cpu_node = acpi_find_processor_tag(table, cpu_node,518 level, flag);519 /*520 * As per specification if the processor structure represents521 * an actual processor, then ACPI processor ID must be valid.522 * For processor containers ACPI_PPTT_ACPI_PROCESSOR_ID_VALID523 * should be set if the UID is valid524 */525 if (level == 0 ||526 cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID)527 return cpu_node->acpi_processor_id;528 return ACPI_PTR_DIFF(cpu_node, table);529 }530 pr_warn_once("PPTT table found, but unable to locate core %d (%d)\n",531 cpu, acpi_cpu_id);532 return -ENOENT;533}534 535 536static struct acpi_table_header *acpi_get_pptt(void)537{538 static struct acpi_table_header *pptt;539 static bool is_pptt_checked;540 acpi_status status;541 542 /*543 * PPTT will be used at runtime on every CPU hotplug in path, so we544 * don't need to call acpi_put_table() to release the table mapping.545 */546 if (!pptt && !is_pptt_checked) {547 status = acpi_get_table(ACPI_SIG_PPTT, 0, &pptt);548 if (ACPI_FAILURE(status))549 acpi_pptt_warn_missing();550 551 is_pptt_checked = true;552 }553 554 return pptt;555}556 557static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag)558{559 struct acpi_table_header *table;560 int retval;561 562 table = acpi_get_pptt();563 if (!table)564 return -ENOENT;565 566 retval = topology_get_acpi_cpu_tag(table, cpu, level, flag);567 pr_debug("Topology Setup ACPI CPU %d, level %d ret = %d\n",568 cpu, level, retval);569 570 return retval;571}572 573/**574 * check_acpi_cpu_flag() - Determine if CPU node has a flag set575 * @cpu: Kernel logical CPU number576 * @rev: The minimum PPTT revision defining the flag577 * @flag: The flag itself578 *579 * Check the node representing a CPU for a given flag.580 *581 * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found or582 * the table revision isn't new enough.583 * 1, any passed flag set584 * 0, flag unset585 */586static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag)587{588 struct acpi_table_header *table;589 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);590 struct acpi_pptt_processor *cpu_node = NULL;591 int ret = -ENOENT;592 593 table = acpi_get_pptt();594 if (!table)595 return -ENOENT;596 597 if (table->revision >= rev)598 cpu_node = acpi_find_processor_node(table, acpi_cpu_id);599 600 if (cpu_node)601 ret = (cpu_node->flags & flag) != 0;602 603 return ret;604}605 606/**607 * acpi_get_cache_info() - Determine the number of cache levels and608 * split cache levels (data/instruction) and for a PE.609 * @cpu: Kernel logical CPU number610 * @levels: Number of levels if success.611 * @split_levels: Number of levels being split (i.e. data/instruction)612 * if success. Can by NULL.613 *614 * Given a logical CPU number, returns the number of levels of cache represented615 * in the PPTT. Errors caused by lack of a PPTT table, or otherwise, return 0616 * indicating we didn't find any cache levels.617 *618 * Return: -ENOENT if no PPTT table or no PPTT processor struct found.619 * 0 on success.620 */621int acpi_get_cache_info(unsigned int cpu, unsigned int *levels,622 unsigned int *split_levels)623{624 struct acpi_pptt_processor *cpu_node;625 struct acpi_table_header *table;626 u32 acpi_cpu_id;627 628 *levels = 0;629 if (split_levels)630 *split_levels = 0;631 632 table = acpi_get_pptt();633 if (!table)634 return -ENOENT;635 636 pr_debug("Cache Setup: find cache levels for CPU=%d\n", cpu);637 638 acpi_cpu_id = get_acpi_id_for_cpu(cpu);639 cpu_node = acpi_find_processor_node(table, acpi_cpu_id);640 if (!cpu_node)641 return -ENOENT;642 643 acpi_count_levels(table, cpu_node, levels, split_levels);644 645 pr_debug("Cache Setup: last_level=%d split_levels=%d\n",646 *levels, split_levels ? *split_levels : -1);647 648 return 0;649}650 651/**652 * cache_setup_acpi() - Override CPU cache topology with data from the PPTT653 * @cpu: Kernel logical CPU number654 *655 * Updates the global cache info provided by cpu_get_cacheinfo()656 * when there are valid properties in the acpi_pptt_cache nodes. A657 * successful parse may not result in any updates if none of the658 * cache levels have any valid flags set. Further, a unique value is659 * associated with each known CPU cache entry. This unique value660 * can be used to determine whether caches are shared between CPUs.661 *662 * Return: -ENOENT on failure to find table, or 0 on success663 */664int cache_setup_acpi(unsigned int cpu)665{666 struct acpi_table_header *table;667 668 table = acpi_get_pptt();669 if (!table)670 return -ENOENT;671 672 pr_debug("Cache Setup ACPI CPU %d\n", cpu);673 674 cache_setup_acpi_cpu(table, cpu);675 676 return 0;677}678 679/**680 * acpi_pptt_cpu_is_thread() - Determine if CPU is a thread681 * @cpu: Kernel logical CPU number682 *683 * Return: 1, a thread684 * 0, not a thread685 * -ENOENT ,if the PPTT doesn't exist, the CPU cannot be found or686 * the table revision isn't new enough.687 */688int acpi_pptt_cpu_is_thread(unsigned int cpu)689{690 return check_acpi_cpu_flag(cpu, 2, ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD);691}692 693/**694 * find_acpi_cpu_topology() - Determine a unique topology value for a given CPU695 * @cpu: Kernel logical CPU number696 * @level: The topological level for which we would like a unique ID697 *698 * Determine a topology unique ID for each thread/core/cluster/mc_grouping699 * /socket/etc. This ID can then be used to group peers, which will have700 * matching ids.701 *702 * The search terminates when either the requested level is found or703 * we reach a root node. Levels beyond the termination point will return the704 * same unique ID. The unique id for level 0 is the acpi processor id. All705 * other levels beyond this use a generated value to uniquely identify706 * a topological feature.707 *708 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.709 * Otherwise returns a value which represents a unique topological feature.710 */711int find_acpi_cpu_topology(unsigned int cpu, int level)712{713 return find_acpi_cpu_topology_tag(cpu, level, 0);714}715 716/**717 * find_acpi_cpu_topology_package() - Determine a unique CPU package value718 * @cpu: Kernel logical CPU number719 *720 * Determine a topology unique package ID for the given CPU.721 * This ID can then be used to group peers, which will have matching ids.722 *723 * The search terminates when either a level is found with the PHYSICAL_PACKAGE724 * flag set or we reach a root node.725 *726 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.727 * Otherwise returns a value which represents the package for this CPU.728 */729int find_acpi_cpu_topology_package(unsigned int cpu)730{731 return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE,732 ACPI_PPTT_PHYSICAL_PACKAGE);733}734 735/**736 * find_acpi_cpu_topology_cluster() - Determine a unique CPU cluster value737 * @cpu: Kernel logical CPU number738 *739 * Determine a topology unique cluster ID for the given CPU/thread.740 * This ID can then be used to group peers, which will have matching ids.741 *742 * The cluster, if present is the level of topology above CPUs. In a743 * multi-thread CPU, it will be the level above the CPU, not the thread.744 * It may not exist in single CPU systems. In simple multi-CPU systems,745 * it may be equal to the package topology level.746 *747 * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found748 * or there is no toplogy level above the CPU..749 * Otherwise returns a value which represents the package for this CPU.750 */751 752int find_acpi_cpu_topology_cluster(unsigned int cpu)753{754 struct acpi_table_header *table;755 struct acpi_pptt_processor *cpu_node, *cluster_node;756 u32 acpi_cpu_id;757 int retval;758 int is_thread;759 760 table = acpi_get_pptt();761 if (!table)762 return -ENOENT;763 764 acpi_cpu_id = get_acpi_id_for_cpu(cpu);765 cpu_node = acpi_find_processor_node(table, acpi_cpu_id);766 if (!cpu_node || !cpu_node->parent)767 return -ENOENT;768 769 is_thread = cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD;770 cluster_node = fetch_pptt_node(table, cpu_node->parent);771 if (!cluster_node)772 return -ENOENT;773 774 if (is_thread) {775 if (!cluster_node->parent)776 return -ENOENT;777 778 cluster_node = fetch_pptt_node(table, cluster_node->parent);779 if (!cluster_node)780 return -ENOENT;781 }782 if (cluster_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID)783 retval = cluster_node->acpi_processor_id;784 else785 retval = ACPI_PTR_DIFF(cluster_node, table);786 787 return retval;788}789 790/**791 * find_acpi_cpu_topology_hetero_id() - Get a core architecture tag792 * @cpu: Kernel logical CPU number793 *794 * Determine a unique heterogeneous tag for the given CPU. CPUs with the same795 * implementation should have matching tags.796 *797 * The returned tag can be used to group peers with identical implementation.798 *799 * The search terminates when a level is found with the identical implementation800 * flag set or we reach a root node.801 *802 * Due to limitations in the PPTT data structure, there may be rare situations803 * where two cores in a heterogeneous machine may be identical, but won't have804 * the same tag.805 *806 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.807 * Otherwise returns a value which represents a group of identical cores808 * similar to this CPU.809 */810int find_acpi_cpu_topology_hetero_id(unsigned int cpu)811{812 return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE,813 ACPI_PPTT_ACPI_IDENTICAL);814}815