Re: [PATCH v3 openEuler-22.03-LTS-SP2 3/4] ACPI / PPTT: Find PPTT processor node by cache id

Reviewed-by: Xie XiuQi xiexiuqi@huawei.com

On 2023/6/8 21:03, Yu Liao wrote:

openeuler inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I77UDW CVE: NA

---

The MPAM table identifies caches by id, but the driver also wants to know the processor node.

Add a helper that walks every possible cache, until it finds the one identified by id, then return processor node.

Signed-off-by: Yu Liao liaoyu15@huawei.com

drivers/acpi/pptt.c | 55 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 5 ++++ 2 files changed, 60 insertions(+)

diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index 3d9403ded527..0208db018aaf 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -958,3 +958,58 @@ int __init acpi_pptt_init(void)

return 0; }

+struct acpi_pptt_processor *find_acpi_processor_node_from_cache_id(u32 cache_id) +{

• u32 acpi_cpu_id;
• acpi_status status;
• int level, cpu, num_levels;
• struct acpi_pptt_cache *cache;
• struct acpi_table_header *table;
• struct acpi_pptt_cache_v1* cache_v1;
• struct acpi_pptt_processor *cpu_node;
• status = acpi_get_table(ACPI_SIG_PPTT, 0, &table);
• if (ACPI_FAILURE(status)) {

• acpi_pptt_warn_missing();
  

• return NULL;
  

• }
• if (table->revision < 3) {

• acpi_put_table(table);
  

• return NULL;
  

• }
• /*

• * If we found the cache first, we'd still need to walk from each CPU
  

• * to find the level...
  

• */
  

• for_each_possible_cpu(cpu) {

• acpi_cpu_id = get_acpi_id_for_cpu(cpu);
  

• cpu_node = acpi_find_processor_node(table, acpi_cpu_id);
  

• if (!cpu_node)
  

• 	break;
  

• num_levels = acpi_count_levels(table, cpu_node);
  

• for (level = 0; level <= num_levels; level++) {
  

• 	cache = acpi_find_cache_node(table, acpi_cpu_id,
  

• 				     ACPI_PPTT_CACHE_TYPE_UNIFIED,
  

• 				     level, &cpu_node);
  

• 	if (!cache)
  

• 		continue;
  

• 	cache_v1 = ACPI_ADD_PTR(struct acpi_pptt_cache_v1,
  

• 				cache,
  

• 				sizeof(struct acpi_pptt_cache));
  

• 	if (cache->flags & ACPI_PPTT_CACHE_ID_VALID &&
  

• 	    cache_v1->cache_id == cache_id) {
  

• 		acpi_put_table(table);
  

• 		return cpu_node;
  

• 	}
  

• }
  

• }
• acpi_put_table(table);
• return NULL;

+} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 7c14b71464df..ce073553510f 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1367,6 +1367,7 @@ int find_acpi_cpu_topology_cluster(unsigned int cpu); int find_acpi_cpu_topology_package(unsigned int cpu); int find_acpi_cpu_topology_hetero_id(unsigned int cpu); int find_acpi_cpu_cache_topology(unsigned int cpu, int level); +struct acpi_pptt_processor *find_acpi_processor_node_from_cache_id(u32 cache_id); #else static inline int acpi_pptt_cpu_is_thread(unsigned int cpu) { @@ -1392,6 +1393,10 @@ static inline int find_acpi_cpu_cache_topology(unsigned int cpu, int level) { return -EINVAL; } +static inline struct acpi_pptt_processor *find_acpi_processor_node_from_cache_id(u32 cache_id) +{

• return NULL;

+} #endif

#ifdef CONFIG_ACPI