ACPI 6.3 adds a flag to the CPU node to indicate whether the given CPU is a thread. Add a function to return that information for a given linux logical CPU and then utilize it while building the arm64 topology. v3->v4: Remove table revision cache as this code path is only called during boot and there aren't any indications that it presents a perf issue. Rebase to 5.3 v2->v3: Clarify and tweak the return from check_acpi_cpu_flag() Cache the PPTT table revision to avoid repeat acpi_table_get/put calls in the case of missing or old PPTT tables. v1->v2: Return ENOENT instead on ENONET. Jeremy Linton (2): ACPI/PPTT: Add support for ACPI 6.3 thread flag arm64: topology: Use PPTT to determine if PE is a thread arch/arm64/kernel/topology.c | 8 ++++-- drivers/acpi/pptt.c | 54 +++++++++++++++++++++++++++++++++++- include/linux/acpi.h | 5 ++++ 3 files changed, 63 insertions(+), 4 deletions(-) -- 2.21.0