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 | 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 | |
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 | |
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 | |
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, pptt_ref: *ref); |
72 | } |
73 | |
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 | */ |
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, pptt_ref: cache->next_level_of_cache); |
120 | continue; |
121 | } |
122 | |
123 | if (split_levels && |
124 | (acpi_pptt_match_type(table_type: cache->attributes, ACPI_PPTT_CACHE_TYPE_DATA) || |
125 | acpi_pptt_match_type(table_type: cache->attributes, ACPI_PPTT_CACHE_TYPE_INSTR))) |
126 | *split_levels = local_level; |
127 | |
128 | if (local_level == level && |
129 | acpi_pptt_match_type(table_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, pptt_ref: cache->next_level_of_cache); |
142 | } |
143 | return local_level; |
144 | } |
145 | |
146 | static struct acpi_pptt_cache * |
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, node: cpu_node, resource))) { |
160 | resource++; |
161 | |
162 | local_level = acpi_pptt_walk_cache(table_hdr, local_level: *starting_level, |
163 | split_levels, res, found: &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 | */ |
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, starting_level: levels, split_levels, level: 0, type: 0); |
201 | cpu_node = fetch_pptt_node(table_hdr, pptt_ref: 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 | */ |
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 | 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 processor |
250 | * @table_hdr: Pointer to the head of the PPTT table |
251 | * @acpi_cpu_id: CPU we are searching for |
252 | * |
253 | * Find the subtable entry describing the provided processor. |
254 | * This is done by iterating the PPTT table looking for processor nodes |
255 | * which have an acpi_processor_id that matches the acpi_cpu_id parameter |
256 | * passed into the function. If we find a node that matches this criteria |
257 | * we verify that its a leaf node in the topology rather than depending |
258 | * 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 | */ |
262 | static 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, node: 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 | |
296 | static 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_UNIFIED |
310 | * contains the bit pattern that will match both |
311 | * ACPI unified bit patterns because we use it later |
312 | * to match both cases. |
313 | */ |
314 | return ACPI_PPTT_CACHE_TYPE_UNIFIED; |
315 | } |
316 | } |
317 | |
318 | static 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 | starting_level: &total_levels, NULL, level, type: acpi_type); |
337 | *node = cpu_node; |
338 | cpu_node = fetch_pptt_node(table_hdr, pptt_ref: cpu_node->parent); |
339 | } |
340 | |
341 | return found; |
342 | } |
343 | |
344 | /** |
345 | * update_cache_properties() - Update cacheinfo for the given processor |
346 | * @this_leaf: Kernel cache info structure being updated |
347 | * @found_cache: The PPTT node describing this cache instance |
348 | * @cpu_node: A unique reference to describe this cache instance |
349 | * @revision: The revision of the PPTT table |
350 | * |
351 | * The ACPI spec implies that the fields in the cache structures are used to |
352 | * extend and correct the information probed from the hardware. Lets only |
353 | * set fields that we determine are VALID. |
354 | * |
355 | * Return: nothing. Side effect of updating the global cacheinfo |
356 | */ |
357 | static 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 specified |
400 | * via other mechanisms. Update the type if a cache type has been |
401 | * provided. |
402 | * |
403 | * Note, we assume such caches are unified based on conventional system |
404 | * design and known examples. Significant work is required elsewhere to |
405 | * fully support data/instruction only type caches which are only |
406 | * 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 | |
420 | static 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_hdr: table, acpi_cpu_id, |
433 | type: this_leaf->type, |
434 | level: this_leaf->level, |
435 | node: &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 | revision: table->revision); |
441 | |
442 | index++; |
443 | } |
444 | } |
445 | |
446 | static 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, pptt_ref: 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 | |
468 | static 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, pptt_ref: cpu->parent); |
483 | if (prev_node == NULL) |
484 | break; |
485 | cpu = prev_node; |
486 | level--; |
487 | } |
488 | return cpu; |
489 | } |
490 | |
491 | static 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 | */ |
509 | static 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_hdr: table, acpi_cpu_id); |
516 | if (cpu_node) { |
517 | cpu_node = acpi_find_processor_tag(table_hdr: table, cpu: 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 | |
535 | |
536 | static 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 we |
544 | * 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, instance: 0, out_table: &pptt); |
548 | if (ACPI_FAILURE(status)) |
549 | acpi_pptt_warn_missing(); |
550 | |
551 | is_pptt_checked = true; |
552 | } |
553 | |
554 | return pptt; |
555 | } |
556 | |
557 | static 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 set |
575 | * @cpu: Kernel logical CPU number |
576 | * @rev: The minimum PPTT revision defining the flag |
577 | * @flag: The flag itself |
578 | * |
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 or |
582 | * the table revision isn't new enough. |
583 | * 1, any passed flag set |
584 | * 0, flag unset |
585 | */ |
586 | static 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_hdr: 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 and |
608 | * split cache levels (data/instruction) and for a PE. |
609 | * @cpu: Kernel logical CPU number |
610 | * @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 represented |
615 | * in the PPTT. Errors caused by lack of a PPTT table, or otherwise, return 0 |
616 | * 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 | */ |
621 | int 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_hdr: table, acpi_cpu_id); |
640 | if (!cpu_node) |
641 | return -ENOENT; |
642 | |
643 | acpi_count_levels(table_hdr: 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 PPTT |
653 | * @cpu: Kernel logical CPU number |
654 | * |
655 | * Updates the global cache info provided by cpu_get_cacheinfo() |
656 | * when there are valid properties in the acpi_pptt_cache nodes. A |
657 | * successful parse may not result in any updates if none of the |
658 | * cache levels have any valid flags set. Further, a unique value is |
659 | * associated with each known CPU cache entry. This unique value |
660 | * can be used to determine whether caches are shared between CPUs. |
661 | * |
662 | * Return: -ENOENT on failure to find table, or 0 on success |
663 | */ |
664 | int 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 thread |
681 | * @cpu: Kernel logical CPU number |
682 | * |
683 | * Return: 1, a thread |
684 | * 0, not a thread |
685 | * -ENOENT ,if the PPTT doesn't exist, the CPU cannot be found or |
686 | * the table revision isn't new enough. |
687 | */ |
688 | int acpi_pptt_cpu_is_thread(unsigned int cpu) |
689 | { |
690 | return check_acpi_cpu_flag(cpu, rev: 2, ACPI_PPTT_ACPI_PROCESSOR_IS_THREAD); |
691 | } |
692 | |
693 | /** |
694 | * find_acpi_cpu_topology() - Determine a unique topology value for a given CPU |
695 | * @cpu: Kernel logical CPU number |
696 | * @level: The topological level for which we would like a unique ID |
697 | * |
698 | * Determine a topology unique ID for each thread/core/cluster/mc_grouping |
699 | * /socket/etc. This ID can then be used to group peers, which will have |
700 | * matching ids. |
701 | * |
702 | * The search terminates when either the requested level is found or |
703 | * we reach a root node. Levels beyond the termination point will return the |
704 | * same unique ID. The unique id for level 0 is the acpi processor id. All |
705 | * other levels beyond this use a generated value to uniquely identify |
706 | * 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 | */ |
711 | int find_acpi_cpu_topology(unsigned int cpu, int level) |
712 | { |
713 | return find_acpi_cpu_topology_tag(cpu, level, flag: 0); |
714 | } |
715 | |
716 | /** |
717 | * find_acpi_cpu_topology_package() - Determine a unique CPU package value |
718 | * @cpu: Kernel logical CPU number |
719 | * |
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_PACKAGE |
724 | * 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 | */ |
729 | int 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 value |
737 | * @cpu: Kernel logical CPU number |
738 | * |
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 a |
743 | * 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 found |
748 | * or there is no toplogy level above the CPU.. |
749 | * Otherwise returns a value which represents the package for this CPU. |
750 | */ |
751 | |
752 | int 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_hdr: 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_hdr: table, pptt_ref: 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_hdr: table, pptt_ref: 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 | else |
785 | 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 tag |
792 | * @cpu: Kernel logical CPU number |
793 | * |
794 | * Determine a unique heterogeneous tag for the given CPU. CPUs with the same |
795 | * 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 implementation |
800 | * flag set or we reach a root node. |
801 | * |
802 | * Due to limitations in the PPTT data structure, there may be rare situations |
803 | * where two cores in a heterogeneous machine may be identical, but won't have |
804 | * 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 cores |
808 | * similar to this CPU. |
809 | */ |
810 | int 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 | |