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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
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_cache
82 * @table_hdr: Pointer to the head of the PPTT table
83 * @local_level: passed res reflects this cache level
84 * @res: cache resource in the PPTT we want to walk
85 * @found: returns a pointer to the requested level if found
86 * @level: the requested cache level
87 * @type: the requested cache type
88 *
89 * Attempt to find a given cache level, while counting the max number
90 * of cache levels for the cache node.
91 *
92 * Given a pptt resource, verify that it is a cache node, then walk
93 * down each level of caches, counting how many levels are found
94 * as well as checking the cache type (icache, dcache, unified). If a
95 * level & type match, then we set found, and continue the search.
96 * Once the entire cache branch has been walked return its max
97 * depth.
98 *
99 * Return: The cache structure and the level we terminated with.
100 */
101static unsigned int acpi_pptt_walk_cache(struct acpi_table_header *table_hdr,
102 unsigned int local_level,
103 struct acpi_subtable_header *res,
104 struct acpi_pptt_cache **found,
105 unsigned int level, int type)
106{
107 struct acpi_pptt_cache *cache;
108
109 if (res->type != ACPI_PPTT_TYPE_CACHE)
110 return 0;
111
112 cache = (struct acpi_pptt_cache *) res;
113 while (cache) {
114 local_level++;
115
116 if (local_level == level &&
117 cache->flags & ACPI_PPTT_CACHE_TYPE_VALID &&
118 acpi_pptt_match_type(cache->attributes, type)) {
119 if (*found != NULL && cache != *found)
120 pr_warn("Found duplicate cache level/type unable to determine uniqueness\n");
121
122 pr_debug("Found cache @ level %u\n", level);
123 *found = cache;
124 /*
125 * continue looking at this node's resource list
126 * to verify that we don't find a duplicate
127 * cache node.
128 */
129 }
130 cache = fetch_pptt_cache(table_hdr, cache->next_level_of_cache);
131 }
132 return local_level;
133}
134
135static struct acpi_pptt_cache *
136acpi_find_cache_level(struct acpi_table_header *table_hdr,
137 struct acpi_pptt_processor *cpu_node,
138 unsigned int *starting_level, unsigned int level,
139 int type)
140{
141 struct acpi_subtable_header *res;
142 unsigned int number_of_levels = *starting_level;
143 int resource = 0;
144 struct acpi_pptt_cache *ret = NULL;
145 unsigned int local_level;
146
147 /* walk down from processor node */
148 while ((res = acpi_get_pptt_resource(table_hdr, cpu_node, resource))) {
149 resource++;
150
151 local_level = acpi_pptt_walk_cache(table_hdr, *starting_level,
152 res, &ret, level, type);
153 /*
154 * we are looking for the max depth. Since its potentially
155 * possible for a given node to have resources with differing
156 * depths verify that the depth we have found is the largest.
157 */
158 if (number_of_levels < local_level)
159 number_of_levels = local_level;
160 }
161 if (number_of_levels > *starting_level)
162 *starting_level = number_of_levels;
163
164 return ret;
165}
166
167/**
168 * acpi_count_levels() - Given a PPTT table, and a CPU node, count the caches
169 * @table_hdr: Pointer to the head of the PPTT table
170 * @cpu_node: processor node we wish to count caches for
171 *
172 * Given a processor node containing a processing unit, walk into it and count
173 * how many levels exist solely for it, and then walk up each level until we hit
174 * the root node (ignore the package level because it may be possible to have
175 * caches that exist across packages). Count the number of cache levels that
176 * exist at each level on the way up.
177 *
178 * Return: Total number of levels found.
179 */
180static int acpi_count_levels(struct acpi_table_header *table_hdr,
181 struct acpi_pptt_processor *cpu_node)
182{
183 int total_levels = 0;
184
185 do {
186 acpi_find_cache_level(table_hdr, cpu_node, &total_levels, 0, 0);
187 cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);
188 } while (cpu_node);
189
190 return total_levels;
191}
192
193/**
194 * acpi_pptt_leaf_node() - Given a processor node, determine if its a leaf
195 * @table_hdr: Pointer to the head of the PPTT table
196 * @node: passed node is checked to see if its a leaf
197 *
198 * Determine if the *node parameter is a leaf node by iterating the
199 * PPTT table, looking for nodes which reference it.
200 *
201 * Return: 0 if we find a node referencing the passed node (or table error),
202 * or 1 if we don't.
203 */
204static int acpi_pptt_leaf_node(struct acpi_table_header *table_hdr,
205 struct acpi_pptt_processor *node)
206{
207 struct acpi_subtable_header *entry;
208 unsigned long table_end;
209 u32 node_entry;
210 struct acpi_pptt_processor *cpu_node;
211 u32 proc_sz;
212
213 if (table_hdr->revision > 1)
214 return (node->flags & ACPI_PPTT_ACPI_LEAF_NODE);
215
216 table_end = (unsigned long)table_hdr + table_hdr->length;
217 node_entry = ACPI_PTR_DIFF(node, table_hdr);
218 entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr,
219 sizeof(struct acpi_table_pptt));
220 proc_sz = sizeof(struct acpi_pptt_processor *);
221
222 while ((unsigned long)entry + proc_sz < table_end) {
223 cpu_node = (struct acpi_pptt_processor *)entry;
224 if (entry->type == ACPI_PPTT_TYPE_PROCESSOR &&
225 cpu_node->parent == node_entry)
226 return 0;
227 if (entry->length == 0)
228 return 0;
229 entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry,
230 entry->length);
231
232 }
233 return 1;
234}
235
236/**
237 * acpi_find_processor_node() - Given a PPTT table find the requested processor
238 * @table_hdr: Pointer to the head of the PPTT table
239 * @acpi_cpu_id: CPU we are searching for
240 *
241 * Find the subtable entry describing the provided processor.
242 * This is done by iterating the PPTT table looking for processor nodes
243 * which have an acpi_processor_id that matches the acpi_cpu_id parameter
244 * passed into the function. If we find a node that matches this criteria
245 * we verify that its a leaf node in the topology rather than depending
246 * on the valid flag, which doesn't need to be set for leaf nodes.
247 *
248 * Return: NULL, or the processors acpi_pptt_processor*
249 */
250static struct acpi_pptt_processor *acpi_find_processor_node(struct acpi_table_header *table_hdr,
251 u32 acpi_cpu_id)
252{
253 struct acpi_subtable_header *entry;
254 unsigned long table_end;
255 struct acpi_pptt_processor *cpu_node;
256 u32 proc_sz;
257
258 table_end = (unsigned long)table_hdr + table_hdr->length;
259 entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr,
260 sizeof(struct acpi_table_pptt));
261 proc_sz = sizeof(struct acpi_pptt_processor *);
262
263 /* find the processor structure associated with this cpuid */
264 while ((unsigned long)entry + proc_sz < table_end) {
265 cpu_node = (struct acpi_pptt_processor *)entry;
266
267 if (entry->length == 0) {
268 pr_warn("Invalid zero length subtable\n");
269 break;
270 }
271 if (entry->type == ACPI_PPTT_TYPE_PROCESSOR &&
272 acpi_cpu_id == cpu_node->acpi_processor_id &&
273 acpi_pptt_leaf_node(table_hdr, cpu_node)) {
274 return (struct acpi_pptt_processor *)entry;
275 }
276
277 entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry,
278 entry->length);
279 }
280
281 return NULL;
282}
283
284static int acpi_find_cache_levels(struct acpi_table_header *table_hdr,
285 u32 acpi_cpu_id)
286{
287 int number_of_levels = 0;
288 struct acpi_pptt_processor *cpu;
289
290 cpu = acpi_find_processor_node(table_hdr, acpi_cpu_id);
291 if (cpu)
292 number_of_levels = acpi_count_levels(table_hdr, cpu);
293
294 return number_of_levels;
295}
296
297static u8 acpi_cache_type(enum cache_type type)
298{
299 switch (type) {
300 case CACHE_TYPE_DATA:
301 pr_debug("Looking for data cache\n");
302 return ACPI_PPTT_CACHE_TYPE_DATA;
303 case CACHE_TYPE_INST:
304 pr_debug("Looking for instruction cache\n");
305 return ACPI_PPTT_CACHE_TYPE_INSTR;
306 default:
307 case CACHE_TYPE_UNIFIED:
308 pr_debug("Looking for unified cache\n");
309 /*
310 * It is important that ACPI_PPTT_CACHE_TYPE_UNIFIED
311 * contains the bit pattern that will match both
312 * ACPI unified bit patterns because we use it later
313 * to match both cases.
314 */
315 return ACPI_PPTT_CACHE_TYPE_UNIFIED;
316 }
317}
318
319static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *table_hdr,
320 u32 acpi_cpu_id,
321 enum cache_type type,
322 unsigned int level,
323 struct acpi_pptt_processor **node)
324{
325 unsigned int total_levels = 0;
326 struct acpi_pptt_cache *found = NULL;
327 struct acpi_pptt_processor *cpu_node;
328 u8 acpi_type = acpi_cache_type(type);
329
330 pr_debug("Looking for CPU %d's level %u cache type %d\n",
331 acpi_cpu_id, level, acpi_type);
332
333 cpu_node = acpi_find_processor_node(table_hdr, acpi_cpu_id);
334
335 while (cpu_node && !found) {
336 found = acpi_find_cache_level(table_hdr, cpu_node,
337 &total_levels, level, acpi_type);
338 *node = cpu_node;
339 cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);
340 }
341
342 return found;
343}
344
345/**
346 * update_cache_properties() - Update cacheinfo for the given processor
347 * @this_leaf: Kernel cache info structure being updated
348 * @found_cache: The PPTT node describing this cache instance
349 * @cpu_node: A unique reference to describe this cache instance
350 * @revision: The revision of the PPTT table
351 *
352 * The ACPI spec implies that the fields in the cache structures are used to
353 * extend and correct the information probed from the hardware. Lets only
354 * set fields that we determine are VALID.
355 *
356 * Return: nothing. Side effect of updating the global cacheinfo
357 */
358static void update_cache_properties(struct cacheinfo *this_leaf,
359 struct acpi_pptt_cache *found_cache,
360 struct acpi_pptt_processor *cpu_node,
361 u8 revision)
362{
363 struct acpi_pptt_cache_v1* found_cache_v1;
364
365 this_leaf->fw_token = cpu_node;
366 if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID)
367 this_leaf->size = found_cache->size;
368 if (found_cache->flags & ACPI_PPTT_LINE_SIZE_VALID)
369 this_leaf->coherency_line_size = found_cache->line_size;
370 if (found_cache->flags & ACPI_PPTT_NUMBER_OF_SETS_VALID)
371 this_leaf->number_of_sets = found_cache->number_of_sets;
372 if (found_cache->flags & ACPI_PPTT_ASSOCIATIVITY_VALID)
373 this_leaf->ways_of_associativity = found_cache->associativity;
374 if (found_cache->flags & ACPI_PPTT_WRITE_POLICY_VALID) {
375 switch (found_cache->attributes & ACPI_PPTT_MASK_WRITE_POLICY) {
376 case ACPI_PPTT_CACHE_POLICY_WT:
377 this_leaf->attributes = CACHE_WRITE_THROUGH;
378 break;
379 case ACPI_PPTT_CACHE_POLICY_WB:
380 this_leaf->attributes = CACHE_WRITE_BACK;
381 break;
382 }
383 }
384 if (found_cache->flags & ACPI_PPTT_ALLOCATION_TYPE_VALID) {
385 switch (found_cache->attributes & ACPI_PPTT_MASK_ALLOCATION_TYPE) {
386 case ACPI_PPTT_CACHE_READ_ALLOCATE:
387 this_leaf->attributes |= CACHE_READ_ALLOCATE;
388 break;
389 case ACPI_PPTT_CACHE_WRITE_ALLOCATE:
390 this_leaf->attributes |= CACHE_WRITE_ALLOCATE;
391 break;
392 case ACPI_PPTT_CACHE_RW_ALLOCATE:
393 case ACPI_PPTT_CACHE_RW_ALLOCATE_ALT:
394 this_leaf->attributes |=
395 CACHE_READ_ALLOCATE | CACHE_WRITE_ALLOCATE;
396 break;
397 }
398 }
399 /*
400 * If cache type is NOCACHE, then the cache hasn't been specified
401 * via other mechanisms. Update the type if a cache type has been
402 * provided.
403 *
404 * Note, we assume such caches are unified based on conventional system
405 * design and known examples. Significant work is required elsewhere to
406 * fully support data/instruction only type caches which are only
407 * specified in PPTT.
408 */
409 if (this_leaf->type == CACHE_TYPE_NOCACHE &&
410 found_cache->flags & ACPI_PPTT_CACHE_TYPE_VALID)
411 this_leaf->type = CACHE_TYPE_UNIFIED;
412
413 if (revision >= 3 && (found_cache->flags & ACPI_PPTT_CACHE_ID_VALID)) {
414 found_cache_v1 = ACPI_ADD_PTR(struct acpi_pptt_cache_v1,
415 found_cache, sizeof(struct acpi_pptt_cache));
416 this_leaf->id = found_cache_v1->cache_id;
417 this_leaf->attributes |= CACHE_ID;
418 }
419}
420
421static void cache_setup_acpi_cpu(struct acpi_table_header *table,
422 unsigned int cpu)
423{
424 struct acpi_pptt_cache *found_cache;
425 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
426 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
427 struct cacheinfo *this_leaf;
428 unsigned int index = 0;
429 struct acpi_pptt_processor *cpu_node = NULL;
430
431 while (index < get_cpu_cacheinfo(cpu)->num_leaves) {
432 this_leaf = this_cpu_ci->info_list + index;
433 found_cache = acpi_find_cache_node(table, acpi_cpu_id,
434 this_leaf->type,
435 this_leaf->level,
436 &cpu_node);
437 pr_debug("found = %p %p\n", found_cache, cpu_node);
438 if (found_cache)
439 update_cache_properties(this_leaf, found_cache,
440 cpu_node, 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 0xFF
467
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 feature
498 * @table: Pointer to the head of the PPTT table
499 * @cpu: Kernel logical CPU number
500 * @level: A level that terminates the search
501 * @flag: A flag which terminates the search
502 *
503 * Get a unique value given a CPU, and a topology level, that can be
504 * matched to determine which cpus share common topological features
505 * at that level.
506 *
507 * Return: Unique value, or -ENOENT if unable to locate CPU
508 */
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 represents
521 * an actual processor, then ACPI processor ID must be valid.
522 * For processor containers ACPI_PPTT_ACPI_PROCESSOR_ID_VALID
523 * should be set if the UID is valid
524 */
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
535static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag)
536{
537 struct acpi_table_header *table;
538 acpi_status status;
539 int retval;
540
541 status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
542 if (ACPI_FAILURE(status)) {
543 acpi_pptt_warn_missing();
544 return -ENOENT;
545 }
546 retval = topology_get_acpi_cpu_tag(table, cpu, level, flag);
547 pr_debug("Topology Setup ACPI CPU %d, level %d ret = %d\n",
548 cpu, level, retval);
549 acpi_put_table(table);
550
551 return retval;
552}
553
554/**
555 * check_acpi_cpu_flag() - Determine if CPU node has a flag set
556 * @cpu: Kernel logical CPU number
557 * @rev: The minimum PPTT revision defining the flag
558 * @flag: The flag itself
559 *
560 * Check the node representing a CPU for a given flag.
561 *
562 * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found or
563 * the table revision isn't new enough.
564 * 1, any passed flag set
565 * 0, flag unset
566 */
567static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag)
568{
569 struct acpi_table_header *table;
570 acpi_status status;
571 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
572 struct acpi_pptt_processor *cpu_node = NULL;
573 int ret = -ENOENT;
574
575 status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
576 if (ACPI_FAILURE(status)) {
577 acpi_pptt_warn_missing();
578 return ret;
579 }
580
581 if (table->revision >= rev)
582 cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
583
584 if (cpu_node)
585 ret = (cpu_node->flags & flag) != 0;
586
587 acpi_put_table(table);
588
589 return ret;
590}
591
592/**
593 * acpi_find_last_cache_level() - Determines the number of cache levels for a PE
594 * @cpu: Kernel logical CPU number
595 *
596 * Given a logical CPU number, returns the number of levels of cache represented
597 * in the PPTT. Errors caused by lack of a PPTT table, or otherwise, return 0
598 * indicating we didn't find any cache levels.
599 *
600 * Return: Cache levels visible to this core.
601 */
602int acpi_find_last_cache_level(unsigned int cpu)
603{
604 u32 acpi_cpu_id;
605 struct acpi_table_header *table;
606 int number_of_levels = 0;
607 acpi_status status;
608
609 pr_debug("Cache Setup find last level CPU=%d\n", cpu);
610
611 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
612 status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
613 if (ACPI_FAILURE(status)) {
614 acpi_pptt_warn_missing();
615 } else {
616 number_of_levels = acpi_find_cache_levels(table, acpi_cpu_id);
617 acpi_put_table(table);
618 }
619 pr_debug("Cache Setup find last level level=%d\n", number_of_levels);
620
621 return number_of_levels;
622}
623
624/**
625 * cache_setup_acpi() - Override CPU cache topology with data from the PPTT
626 * @cpu: Kernel logical CPU number
627 *
628 * Updates the global cache info provided by cpu_get_cacheinfo()
629 * when there are valid properties in the acpi_pptt_cache nodes. A
630 * successful parse may not result in any updates if none of the
631 * cache levels have any valid flags set. Further, a unique value is
632 * associated with each known CPU cache entry. This unique value
633 * can be used to determine whether caches are shared between CPUs.
634 *
635 * Return: -ENOENT on failure to find table, or 0 on success
636 */
637int cache_setup_acpi(unsigned int cpu)
638{
639 struct acpi_table_header *table;
640 acpi_status status;
641
642 pr_debug("Cache Setup ACPI CPU %d\n", cpu);
643
644 status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
645 if (ACPI_FAILURE(status)) {
646 acpi_pptt_warn_missing();
647 return -ENOENT;
648 }
649
650 cache_setup_acpi_cpu(table, cpu);
651 acpi_put_table(table);
652
653 return status;
654}
655
656/**
657 * acpi_pptt_cpu_is_thread() - Determine if CPU is a thread
658 * @cpu: Kernel logical CPU number
659 *
660 * Return: 1, a thread
661 * 0, not a thread
662 * -ENOENT ,if the PPTT doesn't exist, the CPU cannot be found or
663 * the table revision isn't new enough.
664 */
665int acpi_pptt_cpu_is_thread(unsigned int cpu)
666{
667 return check_acpi_cpu_flag(cpu, 2, ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD);
668}
669
670/**
671 * find_acpi_cpu_topology() - Determine a unique topology value for a given CPU
672 * @cpu: Kernel logical CPU number
673 * @level: The topological level for which we would like a unique ID
674 *
675 * Determine a topology unique ID for each thread/core/cluster/mc_grouping
676 * /socket/etc. This ID can then be used to group peers, which will have
677 * matching ids.
678 *
679 * The search terminates when either the requested level is found or
680 * we reach a root node. Levels beyond the termination point will return the
681 * same unique ID. The unique id for level 0 is the acpi processor id. All
682 * other levels beyond this use a generated value to uniquely identify
683 * a topological feature.
684 *
685 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.
686 * Otherwise returns a value which represents a unique topological feature.
687 */
688int find_acpi_cpu_topology(unsigned int cpu, int level)
689{
690 return find_acpi_cpu_topology_tag(cpu, level, 0);
691}
692
693/**
694 * find_acpi_cpu_cache_topology() - Determine a unique cache topology value
695 * @cpu: Kernel logical CPU number
696 * @level: The cache level for which we would like a unique ID
697 *
698 * Determine a unique ID for each unified cache in the system
699 *
700 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.
701 * Otherwise returns a value which represents a unique topological feature.
702 */
703int find_acpi_cpu_cache_topology(unsigned int cpu, int level)
704{
705 struct acpi_table_header *table;
706 struct acpi_pptt_cache *found_cache;
707 acpi_status status;
708 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
709 struct acpi_pptt_processor *cpu_node = NULL;
710 int ret = -1;
711
712 status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
713 if (ACPI_FAILURE(status)) {
714 acpi_pptt_warn_missing();
715 return -ENOENT;
716 }
717
718 found_cache = acpi_find_cache_node(table, acpi_cpu_id,
719 CACHE_TYPE_UNIFIED,
720 level,
721 &cpu_node);
722 if (found_cache)
723 ret = ACPI_PTR_DIFF(cpu_node, table);
724
725 acpi_put_table(table);
726
727 return ret;
728}
729
730/**
731 * find_acpi_cpu_topology_package() - Determine a unique CPU package value
732 * @cpu: Kernel logical CPU number
733 *
734 * Determine a topology unique package ID for the given CPU.
735 * This ID can then be used to group peers, which will have matching ids.
736 *
737 * The search terminates when either a level is found with the PHYSICAL_PACKAGE
738 * flag set or we reach a root node.
739 *
740 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.
741 * Otherwise returns a value which represents the package for this CPU.
742 */
743int find_acpi_cpu_topology_package(unsigned int cpu)
744{
745 return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE,
746 ACPI_PPTT_PHYSICAL_PACKAGE);
747}
748
749/**
750 * find_acpi_cpu_topology_hetero_id() - Get a core architecture tag
751 * @cpu: Kernel logical CPU number
752 *
753 * Determine a unique heterogeneous tag for the given CPU. CPUs with the same
754 * implementation should have matching tags.
755 *
756 * The returned tag can be used to group peers with identical implementation.
757 *
758 * The search terminates when a level is found with the identical implementation
759 * flag set or we reach a root node.
760 *
761 * Due to limitations in the PPTT data structure, there may be rare situations
762 * where two cores in a heterogeneous machine may be identical, but won't have
763 * the same tag.
764 *
765 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.
766 * Otherwise returns a value which represents a group of identical cores
767 * similar to this CPU.
768 */
769int find_acpi_cpu_topology_hetero_id(unsigned int cpu)
770{
771 return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE,
772 ACPI_PPTT_ACPI_IDENTICAL);
773}