From: James Morse james.morse@arm.com
MPAM identifies CPUs by the cache_id in the PPTT cache structure.
The driver needs to know which CPUs are associated with the cache, the CPUs may not all be online, so cacheinfo does not have the information.
Add a helper to pull this information out of the PPTT.
CC: Rohit Mathew Rohit.Mathew@arm.com Signed-off-by: James Morse james.morse@arm.com --- drivers/acpi/pptt.c | 79 ++++++++++++++++++++++++++++++++++++++++++-- include/linux/acpi.h | 6 ++++ 2 files changed, 83 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/pptt.c b/drivers/acpi/pptt.c index 9fbeed61cd87..201df60e4a79 100644 --- a/drivers/acpi/pptt.c +++ b/drivers/acpi/pptt.c @@ -183,9 +183,10 @@ acpi_find_cache_level(struct acpi_table_header *table_hdr, * levels and split cache levels (data/instruction). * @table_hdr: Pointer to the head of the PPTT table * @cpu_node: processor node we wish to count caches for - * @levels: Number of levels if success. + * @levels: Number of levels if success. (*levels) should be initialized by + * the caller with the value to be used as the starting level. * @split_levels: Number of split cache levels (data/instruction) if - * success. Can by NULL. + * success. Can be NULL. * * Given a processor node containing a processing unit, walk into it and count * how many levels exist solely for it, and then walk up each level until we hit @@ -982,6 +983,8 @@ int find_acpi_cache_level_from_id(u32 cache_id) * to find the level... */ for_each_possible_cpu(cpu) { + + num_levels = 0; acpi_cpu_id = get_acpi_id_for_cpu(cpu); cpu_node = acpi_find_processor_node(table, acpi_cpu_id); if (!cpu_node) @@ -1011,3 +1014,75 @@ int find_acpi_cache_level_from_id(u32 cache_id) acpi_put_table(table); return -ENOENT; } + +/** + * acpi_pptt_get_cpumask_from_cache_id() - Get the cpus associated with the + * specified cache + * @cache_id: The id field of the unified cache + * @cpus: Where to buidl the cpumask + * + * Determine which CPUs are below this cache in the PPTT. This allows the property + * to be found even if the CPUs are offline. + * + * The PPTT table must be rev 3 or later, + * + * Return: -ENOENT if the PPTT doesn't exist, or the cache cannot be found. + * Otherwise returns 0 and sets the cpus in the provided cpumask. + */ +int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id, cpumask_t *cpus) +{ + 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; + + cpumask_clear(cpus); + + status = acpi_get_table(ACPI_SIG_PPTT, 0, &table); + if (ACPI_FAILURE(status)) { + acpi_pptt_warn_missing(); + return -ENOENT; + } + + if (table->revision < 3) { + acpi_put_table(table); + return -ENOENT; + } + + /* + * If we found the cache first, we'd still need to walk from each cpu. + */ + for_each_possible_cpu(cpu) { + + num_levels = 0; + acpi_cpu_id = get_acpi_id_for_cpu(cpu); + cpu_node = acpi_find_processor_node(table, acpi_cpu_id); + if (!cpu_node) + break; + acpi_count_levels(table, cpu_node, &num_levels, NULL); + + /* Start at 1 for L1 */ + for (level = 1; 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) { + cpumask_set_cpu(cpu, cpus); + } + } + } + + acpi_put_table(table); + return 0; +} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 51c6551f9b63..7749d71e49fe 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -1497,6 +1497,7 @@ int find_acpi_cpu_topology_package(unsigned int cpu); int find_acpi_cpu_topology_hetero_id(unsigned int cpu); int find_acpi_cache_level_from_id(u32 cache_id); int acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, cpumask_t *cpus); +int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id, cpumask_t *cpus); #else static inline int acpi_pptt_cpu_is_thread(unsigned int cpu) { @@ -1527,6 +1528,11 @@ static inline int acpi_pptt_get_cpus_from_container(u32 acpi_cpu_id, { return -EINVAL; } +static inline int acpi_pptt_get_cpumask_from_cache_id(u32 cache_id, + cpumask_t *cpus) +{ + return -EINVAL; +} #endif
#ifdef CONFIG_ARM64