diff options
| -rw-r--r-- | arch/x86/include/asm/topology.h | 9 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/topology.c | 28 |
2 files changed, 37 insertions, 0 deletions
diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h index 94ef1a620234..bdd6a984b22c 100644 --- a/arch/x86/include/asm/topology.h +++ b/arch/x86/include/asm/topology.h @@ -156,6 +156,15 @@ static inline unsigned int topology_max_die_per_package(void) return __max_dies_per_package; } +#ifdef CONFIG_X86_LOCAL_APIC +int topology_get_logical_id(u32 apicid, enum x86_topology_domains at_level); +#else +static inline int topology_get_logical_id(u32 apicid, enum x86_topology_domains at_level) +{ + return 0; +} +#endif + #ifdef CONFIG_SMP #define topology_cluster_id(cpu) (cpu_data(cpu).topo.l2c_id) #define topology_die_cpumask(cpu) (per_cpu(cpu_die_map, cpu)) diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c index aea408de3be4..29759b4f7213 100644 --- a/arch/x86/kernel/cpu/topology.c +++ b/arch/x86/kernel/cpu/topology.c @@ -229,6 +229,34 @@ void __init topology_register_boot_apic(u32 apic_id) topo_register_apic(apic_id, CPU_ACPIID_INVALID, true); } +/** + * topology_get_logical_id - Retrieve the logical ID at a given topology domain level + * @apicid: The APIC ID for which to lookup the logical ID + * @at_level: The topology domain level to use + * + * @apicid must be a full APIC ID, not the normalized variant. It's valid to have + * all bits below the domain level specified by @at_level to be clear. So both + * real APIC IDs and backshifted normalized APIC IDs work correctly. + * + * Returns: + * - >= 0: The requested logical ID + * - -ERANGE: @apicid is out of range + * - -ENODEV: @apicid is not registered + */ +int topology_get_logical_id(u32 apicid, enum x86_topology_domains at_level) +{ + /* Remove the bits below @at_level to get the proper level ID of @apicid */ + unsigned int lvlid = topo_apicid(apicid, at_level); + + if (lvlid >= MAX_LOCAL_APIC) + return -ERANGE; + if (!test_bit(lvlid, apic_maps[at_level].map)) + return -ENODEV; + /* Get the number of set bits before @lvlid. */ + return bitmap_weight(apic_maps[at_level].map, lvlid); +} +EXPORT_SYMBOL_GPL(topology_get_logical_id); + #ifdef CONFIG_ACPI_HOTPLUG_CPU /** * topology_hotplug_apic - Handle a physical hotplugged APIC after boot |