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
fetch_pptt_subtable(struct acpi_table_header * table_hdr,u32 pptt_ref)24 static 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
fetch_pptt_node(struct acpi_table_header * table_hdr,u32 pptt_ref)47 static 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
fetch_pptt_cache(struct acpi_table_header * table_hdr,u32 pptt_ref)53 static 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
acpi_get_pptt_resource(struct acpi_table_header * table_hdr,struct acpi_pptt_processor * node,int resource)59 static 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
acpi_pptt_match_type(int table_type,int type)74 static 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 * @split_levels: Number of split cache levels (data/instruction).
85 * @res: cache resource in the PPTT we want to walk
86 * @found: returns a pointer to the requested level if found
87 * @level: the requested cache level
88 * @type: the requested cache type
89 *
90 * Attempt to find a given cache level, while counting the max number
91 * of cache levels for the cache node.
92 *
93 * Given a pptt resource, verify that it is a cache node, then walk
94 * down each level of caches, counting how many levels are found
95 * as well as checking the cache type (icache, dcache, unified). If a
96 * level & type match, then we set found, and continue the search.
97 * Once the entire cache branch has been walked return its max
98 * depth.
99 *
100 * Return: The cache structure and the level we terminated with.
101 */
acpi_pptt_walk_cache(struct acpi_table_header * table_hdr,unsigned int local_level,unsigned int * split_levels,struct acpi_subtable_header * res,struct acpi_pptt_cache ** found,unsigned int level,int type)102 static 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 list
137 * to verify that we don't find a duplicate
138 * cache node.
139 */
140 }
141 cache = fetch_pptt_cache(table_hdr, cache->next_level_of_cache);
142 }
143 return local_level;
144 }
145
146 static struct acpi_pptt_cache *
acpi_find_cache_level(struct acpi_table_header * table_hdr,struct acpi_pptt_processor * cpu_node,unsigned int * starting_level,unsigned int * split_levels,unsigned int level,int type)147 acpi_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 potentially
167 * possible for a given node to have resources with differing
168 * 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 cache
181 * levels and split cache levels (data/instruction).
182 * @table_hdr: Pointer to the head of the PPTT table
183 * @cpu_node: processor node we wish to count caches for
184 * @levels: Number of levels if success.
185 * @split_levels: Number of split cache levels (data/instruction) if
186 * success. Can by NULL.
187 *
188 * Given a processor node containing a processing unit, walk into it and count
189 * how many levels exist solely for it, and then walk up each level until we hit
190 * the root node (ignore the package level because it may be possible to have
191 * caches that exist across packages). Count the number of cache levels and
192 * split cache levels (data/instruction) that exist at each level on the way
193 * up.
194 */
acpi_count_levels(struct acpi_table_header * table_hdr,struct acpi_pptt_processor * cpu_node,unsigned int * levels,unsigned int * split_levels)195 static 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 leaf
207 * @table_hdr: Pointer to the head of the PPTT table
208 * @node: passed node is checked to see if its a leaf
209 *
210 * Determine if the *node parameter is a leaf node by iterating the
211 * 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 */
acpi_pptt_leaf_node(struct acpi_table_header * table_hdr,struct acpi_pptt_processor * node)216 static 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 /* ignore subtable types that are smaller than a processor node */
235 while ((unsigned long)entry + proc_sz <= table_end) {
236 cpu_node = (struct acpi_pptt_processor *)entry;
237
238 if (entry->type == ACPI_PPTT_TYPE_PROCESSOR &&
239 cpu_node->parent == node_entry)
240 return 0;
241 if (entry->length == 0)
242 return 0;
243
244 entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry,
245 entry->length);
246 }
247 return 1;
248 }
249
250 /**
251 * acpi_find_processor_node() - Given a PPTT table find the requested processor
252 * @table_hdr: Pointer to the head of the PPTT table
253 * @acpi_cpu_id: CPU we are searching for
254 *
255 * Find the subtable entry describing the provided processor.
256 * This is done by iterating the PPTT table looking for processor nodes
257 * which have an acpi_processor_id that matches the acpi_cpu_id parameter
258 * passed into the function. If we find a node that matches this criteria
259 * we verify that its a leaf node in the topology rather than depending
260 * on the valid flag, which doesn't need to be set for leaf nodes.
261 *
262 * Return: NULL, or the processors acpi_pptt_processor*
263 */
acpi_find_processor_node(struct acpi_table_header * table_hdr,u32 acpi_cpu_id)264 static struct acpi_pptt_processor *acpi_find_processor_node(struct acpi_table_header *table_hdr,
265 u32 acpi_cpu_id)
266 {
267 struct acpi_subtable_header *entry;
268 unsigned long table_end;
269 struct acpi_pptt_processor *cpu_node;
270 u32 proc_sz;
271
272 table_end = (unsigned long)table_hdr + table_hdr->length;
273 entry = ACPI_ADD_PTR(struct acpi_subtable_header, table_hdr,
274 sizeof(struct acpi_table_pptt));
275 proc_sz = sizeof(struct acpi_pptt_processor);
276
277 /* find the processor structure associated with this cpuid */
278 while ((unsigned long)entry + proc_sz <= table_end) {
279 cpu_node = (struct acpi_pptt_processor *)entry;
280
281 if (entry->length == 0) {
282 pr_warn("Invalid zero length subtable\n");
283 break;
284 }
285 /* entry->length may not equal proc_sz, revalidate the processor structure length */
286 if (entry->type == ACPI_PPTT_TYPE_PROCESSOR &&
287 acpi_cpu_id == cpu_node->acpi_processor_id &&
288 (unsigned long)entry + entry->length <= table_end &&
289 entry->length == proc_sz + cpu_node->number_of_priv_resources * sizeof(u32) &&
290 acpi_pptt_leaf_node(table_hdr, cpu_node)) {
291 return (struct acpi_pptt_processor *)entry;
292 }
293
294 entry = ACPI_ADD_PTR(struct acpi_subtable_header, entry,
295 entry->length);
296 }
297
298 return NULL;
299 }
300
acpi_cache_type(enum cache_type type)301 static u8 acpi_cache_type(enum cache_type type)
302 {
303 switch (type) {
304 case CACHE_TYPE_DATA:
305 pr_debug("Looking for data cache\n");
306 return ACPI_PPTT_CACHE_TYPE_DATA;
307 case CACHE_TYPE_INST:
308 pr_debug("Looking for instruction cache\n");
309 return ACPI_PPTT_CACHE_TYPE_INSTR;
310 default:
311 case CACHE_TYPE_UNIFIED:
312 pr_debug("Looking for unified cache\n");
313 /*
314 * It is important that ACPI_PPTT_CACHE_TYPE_UNIFIED
315 * contains the bit pattern that will match both
316 * ACPI unified bit patterns because we use it later
317 * to match both cases.
318 */
319 return ACPI_PPTT_CACHE_TYPE_UNIFIED;
320 }
321 }
322
acpi_find_cache_node(struct acpi_table_header * table_hdr,u32 acpi_cpu_id,enum cache_type type,unsigned int level,struct acpi_pptt_processor ** node)323 static struct acpi_pptt_cache *acpi_find_cache_node(struct acpi_table_header *table_hdr,
324 u32 acpi_cpu_id,
325 enum cache_type type,
326 unsigned int level,
327 struct acpi_pptt_processor **node)
328 {
329 unsigned int total_levels = 0;
330 struct acpi_pptt_cache *found = NULL;
331 struct acpi_pptt_processor *cpu_node;
332 u8 acpi_type = acpi_cache_type(type);
333
334 pr_debug("Looking for CPU %d's level %u cache type %d\n",
335 acpi_cpu_id, level, acpi_type);
336
337 cpu_node = acpi_find_processor_node(table_hdr, acpi_cpu_id);
338
339 while (cpu_node && !found) {
340 found = acpi_find_cache_level(table_hdr, cpu_node,
341 &total_levels, NULL, level, acpi_type);
342 *node = cpu_node;
343 cpu_node = fetch_pptt_node(table_hdr, cpu_node->parent);
344 }
345
346 return found;
347 }
348
349 /**
350 * update_cache_properties() - Update cacheinfo for the given processor
351 * @this_leaf: Kernel cache info structure being updated
352 * @found_cache: The PPTT node describing this cache instance
353 * @cpu_node: A unique reference to describe this cache instance
354 * @revision: The revision of the PPTT table
355 *
356 * The ACPI spec implies that the fields in the cache structures are used to
357 * extend and correct the information probed from the hardware. Lets only
358 * set fields that we determine are VALID.
359 *
360 * Return: nothing. Side effect of updating the global cacheinfo
361 */
update_cache_properties(struct cacheinfo * this_leaf,struct acpi_pptt_cache * found_cache,struct acpi_pptt_processor * cpu_node,u8 revision)362 static void update_cache_properties(struct cacheinfo *this_leaf,
363 struct acpi_pptt_cache *found_cache,
364 struct acpi_pptt_processor *cpu_node,
365 u8 revision)
366 {
367 struct acpi_pptt_cache_v1* found_cache_v1;
368
369 this_leaf->fw_token = cpu_node;
370 if (found_cache->flags & ACPI_PPTT_SIZE_PROPERTY_VALID)
371 this_leaf->size = found_cache->size;
372 if (found_cache->flags & ACPI_PPTT_LINE_SIZE_VALID)
373 this_leaf->coherency_line_size = found_cache->line_size;
374 if (found_cache->flags & ACPI_PPTT_NUMBER_OF_SETS_VALID)
375 this_leaf->number_of_sets = found_cache->number_of_sets;
376 if (found_cache->flags & ACPI_PPTT_ASSOCIATIVITY_VALID)
377 this_leaf->ways_of_associativity = found_cache->associativity;
378 if (found_cache->flags & ACPI_PPTT_WRITE_POLICY_VALID) {
379 switch (found_cache->attributes & ACPI_PPTT_MASK_WRITE_POLICY) {
380 case ACPI_PPTT_CACHE_POLICY_WT:
381 this_leaf->attributes = CACHE_WRITE_THROUGH;
382 break;
383 case ACPI_PPTT_CACHE_POLICY_WB:
384 this_leaf->attributes = CACHE_WRITE_BACK;
385 break;
386 }
387 }
388 if (found_cache->flags & ACPI_PPTT_ALLOCATION_TYPE_VALID) {
389 switch (found_cache->attributes & ACPI_PPTT_MASK_ALLOCATION_TYPE) {
390 case ACPI_PPTT_CACHE_READ_ALLOCATE:
391 this_leaf->attributes |= CACHE_READ_ALLOCATE;
392 break;
393 case ACPI_PPTT_CACHE_WRITE_ALLOCATE:
394 this_leaf->attributes |= CACHE_WRITE_ALLOCATE;
395 break;
396 case ACPI_PPTT_CACHE_RW_ALLOCATE:
397 case ACPI_PPTT_CACHE_RW_ALLOCATE_ALT:
398 this_leaf->attributes |=
399 CACHE_READ_ALLOCATE | CACHE_WRITE_ALLOCATE;
400 break;
401 }
402 }
403 /*
404 * If cache type is NOCACHE, then the cache hasn't been specified
405 * via other mechanisms. Update the type if a cache type has been
406 * provided.
407 *
408 * Note, we assume such caches are unified based on conventional system
409 * design and known examples. Significant work is required elsewhere to
410 * fully support data/instruction only type caches which are only
411 * specified in PPTT.
412 */
413 if (this_leaf->type == CACHE_TYPE_NOCACHE &&
414 found_cache->flags & ACPI_PPTT_CACHE_TYPE_VALID)
415 this_leaf->type = CACHE_TYPE_UNIFIED;
416
417 if (revision >= 3 && (found_cache->flags & ACPI_PPTT_CACHE_ID_VALID)) {
418 found_cache_v1 = ACPI_ADD_PTR(struct acpi_pptt_cache_v1,
419 found_cache, sizeof(struct acpi_pptt_cache));
420 this_leaf->id = found_cache_v1->cache_id;
421 this_leaf->attributes |= CACHE_ID;
422 }
423 }
424
cache_setup_acpi_cpu(struct acpi_table_header * table,unsigned int cpu)425 static void cache_setup_acpi_cpu(struct acpi_table_header *table,
426 unsigned int cpu)
427 {
428 struct acpi_pptt_cache *found_cache;
429 struct cpu_cacheinfo *this_cpu_ci = get_cpu_cacheinfo(cpu);
430 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
431 struct cacheinfo *this_leaf;
432 unsigned int index = 0;
433 struct acpi_pptt_processor *cpu_node = NULL;
434
435 while (index < get_cpu_cacheinfo(cpu)->num_leaves) {
436 this_leaf = this_cpu_ci->info_list + index;
437 found_cache = acpi_find_cache_node(table, acpi_cpu_id,
438 this_leaf->type,
439 this_leaf->level,
440 &cpu_node);
441 pr_debug("found = %p %p\n", found_cache, cpu_node);
442 if (found_cache)
443 update_cache_properties(this_leaf, found_cache,
444 ACPI_TO_POINTER(ACPI_PTR_DIFF(cpu_node, table)),
445 table->revision);
446
447 index++;
448 }
449 }
450
flag_identical(struct acpi_table_header * table_hdr,struct acpi_pptt_processor * cpu)451 static bool flag_identical(struct acpi_table_header *table_hdr,
452 struct acpi_pptt_processor *cpu)
453 {
454 struct acpi_pptt_processor *next;
455
456 /* heterogeneous machines must use PPTT revision > 1 */
457 if (table_hdr->revision < 2)
458 return false;
459
460 /* Locate the last node in the tree with IDENTICAL set */
461 if (cpu->flags & ACPI_PPTT_ACPI_IDENTICAL) {
462 next = fetch_pptt_node(table_hdr, cpu->parent);
463 if (!(next && next->flags & ACPI_PPTT_ACPI_IDENTICAL))
464 return true;
465 }
466
467 return false;
468 }
469
470 /* Passing level values greater than this will result in search termination */
471 #define PPTT_ABORT_PACKAGE 0xFF
472
acpi_find_processor_tag(struct acpi_table_header * table_hdr,struct acpi_pptt_processor * cpu,int level,int flag)473 static struct acpi_pptt_processor *acpi_find_processor_tag(struct acpi_table_header *table_hdr,
474 struct acpi_pptt_processor *cpu,
475 int level, int flag)
476 {
477 struct acpi_pptt_processor *prev_node;
478
479 while (cpu && level) {
480 /* special case the identical flag to find last identical */
481 if (flag == ACPI_PPTT_ACPI_IDENTICAL) {
482 if (flag_identical(table_hdr, cpu))
483 break;
484 } else if (cpu->flags & flag)
485 break;
486 pr_debug("level %d\n", level);
487 prev_node = fetch_pptt_node(table_hdr, cpu->parent);
488 if (prev_node == NULL)
489 break;
490 cpu = prev_node;
491 level--;
492 }
493 return cpu;
494 }
495
acpi_pptt_warn_missing(void)496 static void acpi_pptt_warn_missing(void)
497 {
498 pr_warn_once("No PPTT table found, CPU and cache topology may be inaccurate\n");
499 }
500
501 /**
502 * topology_get_acpi_cpu_tag() - Find a unique topology value for a feature
503 * @table: Pointer to the head of the PPTT table
504 * @cpu: Kernel logical CPU number
505 * @level: A level that terminates the search
506 * @flag: A flag which terminates the search
507 *
508 * Get a unique value given a CPU, and a topology level, that can be
509 * matched to determine which cpus share common topological features
510 * at that level.
511 *
512 * Return: Unique value, or -ENOENT if unable to locate CPU
513 */
topology_get_acpi_cpu_tag(struct acpi_table_header * table,unsigned int cpu,int level,int flag)514 static int topology_get_acpi_cpu_tag(struct acpi_table_header *table,
515 unsigned int cpu, int level, int flag)
516 {
517 struct acpi_pptt_processor *cpu_node;
518 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
519
520 cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
521 if (cpu_node) {
522 cpu_node = acpi_find_processor_tag(table, cpu_node,
523 level, flag);
524 /*
525 * As per specification if the processor structure represents
526 * an actual processor, then ACPI processor ID must be valid.
527 * For processor containers ACPI_PPTT_ACPI_PROCESSOR_ID_VALID
528 * should be set if the UID is valid
529 */
530 if (level == 0 ||
531 cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID)
532 return cpu_node->acpi_processor_id;
533 return ACPI_PTR_DIFF(cpu_node, table);
534 }
535 pr_warn_once("PPTT table found, but unable to locate core %d (%d)\n",
536 cpu, acpi_cpu_id);
537 return -ENOENT;
538 }
539
540
acpi_get_pptt(void)541 static struct acpi_table_header *acpi_get_pptt(void)
542 {
543 static struct acpi_table_header *pptt;
544 static bool is_pptt_checked;
545 acpi_status status;
546
547 /*
548 * PPTT will be used at runtime on every CPU hotplug in path, so we
549 * don't need to call acpi_put_table() to release the table mapping.
550 */
551 if (!pptt && !is_pptt_checked) {
552 status = acpi_get_table(ACPI_SIG_PPTT, 0, &pptt);
553 if (ACPI_FAILURE(status))
554 acpi_pptt_warn_missing();
555
556 is_pptt_checked = true;
557 }
558
559 return pptt;
560 }
561
find_acpi_cpu_topology_tag(unsigned int cpu,int level,int flag)562 static int find_acpi_cpu_topology_tag(unsigned int cpu, int level, int flag)
563 {
564 struct acpi_table_header *table;
565 int retval;
566
567 table = acpi_get_pptt();
568 if (!table)
569 return -ENOENT;
570
571 retval = topology_get_acpi_cpu_tag(table, cpu, level, flag);
572 pr_debug("Topology Setup ACPI CPU %d, level %d ret = %d\n",
573 cpu, level, retval);
574
575 return retval;
576 }
577
578 /**
579 * check_acpi_cpu_flag() - Determine if CPU node has a flag set
580 * @cpu: Kernel logical CPU number
581 * @rev: The minimum PPTT revision defining the flag
582 * @flag: The flag itself
583 *
584 * Check the node representing a CPU for a given flag.
585 *
586 * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found or
587 * the table revision isn't new enough.
588 * 1, any passed flag set
589 * 0, flag unset
590 */
check_acpi_cpu_flag(unsigned int cpu,int rev,u32 flag)591 static int check_acpi_cpu_flag(unsigned int cpu, int rev, u32 flag)
592 {
593 struct acpi_table_header *table;
594 u32 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
595 struct acpi_pptt_processor *cpu_node = NULL;
596 int ret = -ENOENT;
597
598 table = acpi_get_pptt();
599 if (!table)
600 return -ENOENT;
601
602 if (table->revision >= rev)
603 cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
604
605 if (cpu_node)
606 ret = (cpu_node->flags & flag) != 0;
607
608 return ret;
609 }
610
611 /**
612 * acpi_get_cache_info() - Determine the number of cache levels and
613 * split cache levels (data/instruction) and for a PE.
614 * @cpu: Kernel logical CPU number
615 * @levels: Number of levels if success.
616 * @split_levels: Number of levels being split (i.e. data/instruction)
617 * if success. Can by NULL.
618 *
619 * Given a logical CPU number, returns the number of levels of cache represented
620 * in the PPTT. Errors caused by lack of a PPTT table, or otherwise, return 0
621 * indicating we didn't find any cache levels.
622 *
623 * Return: -ENOENT if no PPTT table or no PPTT processor struct found.
624 * 0 on success.
625 */
acpi_get_cache_info(unsigned int cpu,unsigned int * levels,unsigned int * split_levels)626 int acpi_get_cache_info(unsigned int cpu, unsigned int *levels,
627 unsigned int *split_levels)
628 {
629 struct acpi_pptt_processor *cpu_node;
630 struct acpi_table_header *table;
631 u32 acpi_cpu_id;
632
633 *levels = 0;
634 if (split_levels)
635 *split_levels = 0;
636
637 table = acpi_get_pptt();
638 if (!table)
639 return -ENOENT;
640
641 pr_debug("Cache Setup: find cache levels for CPU=%d\n", cpu);
642
643 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
644 cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
645 if (!cpu_node)
646 return -ENOENT;
647
648 acpi_count_levels(table, cpu_node, levels, split_levels);
649
650 pr_debug("Cache Setup: last_level=%d split_levels=%d\n",
651 *levels, split_levels ? *split_levels : -1);
652
653 return 0;
654 }
655
656 /**
657 * cache_setup_acpi() - Override CPU cache topology with data from the PPTT
658 * @cpu: Kernel logical CPU number
659 *
660 * Updates the global cache info provided by cpu_get_cacheinfo()
661 * when there are valid properties in the acpi_pptt_cache nodes. A
662 * successful parse may not result in any updates if none of the
663 * cache levels have any valid flags set. Further, a unique value is
664 * associated with each known CPU cache entry. This unique value
665 * can be used to determine whether caches are shared between CPUs.
666 *
667 * Return: -ENOENT on failure to find table, or 0 on success
668 */
cache_setup_acpi(unsigned int cpu)669 int cache_setup_acpi(unsigned int cpu)
670 {
671 struct acpi_table_header *table;
672
673 table = acpi_get_pptt();
674 if (!table)
675 return -ENOENT;
676
677 pr_debug("Cache Setup ACPI CPU %d\n", cpu);
678
679 cache_setup_acpi_cpu(table, cpu);
680
681 return 0;
682 }
683
684 /**
685 * acpi_pptt_cpu_is_thread() - Determine if CPU is a thread
686 * @cpu: Kernel logical CPU number
687 *
688 * Return: 1, a thread
689 * 0, not a thread
690 * -ENOENT ,if the PPTT doesn't exist, the CPU cannot be found or
691 * the table revision isn't new enough.
692 */
acpi_pptt_cpu_is_thread(unsigned int cpu)693 int acpi_pptt_cpu_is_thread(unsigned int cpu)
694 {
695 return check_acpi_cpu_flag(cpu, 2, ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD);
696 }
697
698 /**
699 * find_acpi_cpu_topology() - Determine a unique topology value for a given CPU
700 * @cpu: Kernel logical CPU number
701 * @level: The topological level for which we would like a unique ID
702 *
703 * Determine a topology unique ID for each thread/core/cluster/mc_grouping
704 * /socket/etc. This ID can then be used to group peers, which will have
705 * matching ids.
706 *
707 * The search terminates when either the requested level is found or
708 * we reach a root node. Levels beyond the termination point will return the
709 * same unique ID. The unique id for level 0 is the acpi processor id. All
710 * other levels beyond this use a generated value to uniquely identify
711 * a topological feature.
712 *
713 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.
714 * Otherwise returns a value which represents a unique topological feature.
715 */
find_acpi_cpu_topology(unsigned int cpu,int level)716 int find_acpi_cpu_topology(unsigned int cpu, int level)
717 {
718 return find_acpi_cpu_topology_tag(cpu, level, 0);
719 }
720
721 /**
722 * find_acpi_cpu_topology_package() - Determine a unique CPU package value
723 * @cpu: Kernel logical CPU number
724 *
725 * Determine a topology unique package ID for the given CPU.
726 * This ID can then be used to group peers, which will have matching ids.
727 *
728 * The search terminates when either a level is found with the PHYSICAL_PACKAGE
729 * flag set or we reach a root node.
730 *
731 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.
732 * Otherwise returns a value which represents the package for this CPU.
733 */
find_acpi_cpu_topology_package(unsigned int cpu)734 int find_acpi_cpu_topology_package(unsigned int cpu)
735 {
736 return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE,
737 ACPI_PPTT_PHYSICAL_PACKAGE);
738 }
739
740 /**
741 * find_acpi_cpu_topology_cluster() - Determine a unique CPU cluster value
742 * @cpu: Kernel logical CPU number
743 *
744 * Determine a topology unique cluster ID for the given CPU/thread.
745 * This ID can then be used to group peers, which will have matching ids.
746 *
747 * The cluster, if present is the level of topology above CPUs. In a
748 * multi-thread CPU, it will be the level above the CPU, not the thread.
749 * It may not exist in single CPU systems. In simple multi-CPU systems,
750 * it may be equal to the package topology level.
751 *
752 * Return: -ENOENT if the PPTT doesn't exist, the CPU cannot be found
753 * or there is no toplogy level above the CPU..
754 * Otherwise returns a value which represents the package for this CPU.
755 */
756
find_acpi_cpu_topology_cluster(unsigned int cpu)757 int find_acpi_cpu_topology_cluster(unsigned int cpu)
758 {
759 struct acpi_table_header *table;
760 struct acpi_pptt_processor *cpu_node, *cluster_node;
761 u32 acpi_cpu_id;
762 int retval;
763 int is_thread;
764
765 table = acpi_get_pptt();
766 if (!table)
767 return -ENOENT;
768
769 acpi_cpu_id = get_acpi_id_for_cpu(cpu);
770 cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
771 if (!cpu_node || !cpu_node->parent)
772 return -ENOENT;
773
774 is_thread = cpu_node->flags & ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD;
775 cluster_node = fetch_pptt_node(table, cpu_node->parent);
776 if (!cluster_node)
777 return -ENOENT;
778
779 if (is_thread) {
780 if (!cluster_node->parent)
781 return -ENOENT;
782
783 cluster_node = fetch_pptt_node(table, cluster_node->parent);
784 if (!cluster_node)
785 return -ENOENT;
786 }
787 if (cluster_node->flags & ACPI_PPTT_ACPI_PROCESSOR_ID_VALID)
788 retval = cluster_node->acpi_processor_id;
789 else
790 retval = ACPI_PTR_DIFF(cluster_node, table);
791
792 return retval;
793 }
794
795 /**
796 * find_acpi_cpu_topology_hetero_id() - Get a core architecture tag
797 * @cpu: Kernel logical CPU number
798 *
799 * Determine a unique heterogeneous tag for the given CPU. CPUs with the same
800 * implementation should have matching tags.
801 *
802 * The returned tag can be used to group peers with identical implementation.
803 *
804 * The search terminates when a level is found with the identical implementation
805 * flag set or we reach a root node.
806 *
807 * Due to limitations in the PPTT data structure, there may be rare situations
808 * where two cores in a heterogeneous machine may be identical, but won't have
809 * the same tag.
810 *
811 * Return: -ENOENT if the PPTT doesn't exist, or the CPU cannot be found.
812 * Otherwise returns a value which represents a group of identical cores
813 * similar to this CPU.
814 */
find_acpi_cpu_topology_hetero_id(unsigned int cpu)815 int find_acpi_cpu_topology_hetero_id(unsigned int cpu)
816 {
817 return find_acpi_cpu_topology_tag(cpu, PPTT_ABORT_PACKAGE,
818 ACPI_PPTT_ACPI_IDENTICAL);
819 }
820