* Gautham R Shenoy <e...@linux.vnet.ibm.com> [2020-01-30 16:27:47]: > On Wed, Jan 29, 2020 at 07:21:21PM +0530, Srikar Dronamraju wrote: > > [..snip..] > > > --- a/arch/powerpc/kernel/smp.c > > +++ b/arch/powerpc/kernel/smp.c > > @@ -1185,10 +1185,34 @@ static inline void add_cpu_to_smallcore_masks(int > > cpu) > > } > > } > > > > +int get_physical_package_id(int cpu) > > +{ > > + int ppid = cpu_to_chip_id(cpu); > > + > > +#ifdef CONFIG_PPC_SPLPAR > > + /* > > + * If the platform is PowerNV or Guest on KVM, ibm,chip-id is > > + * defined. Hence we would return the chip-id as the > > + * get_physical_package_id. > > + */ > > + if (ppid == -1 && firmware_has_feature(FW_FEATURE_LPAR)) { > > + struct device_node *np = of_get_cpu_node(cpu, NULL); > > + > > + if (np) { > > + ppid = of_node_to_nid(np); > > + of_node_put(np); > > + } > > + } > > +#endif /* CONFIG_PPC_SPLPAR */ > > + > > + return ppid; > > +} > > static void add_cpu_to_masks(int cpu) > > { > > int first_thread = cpu_first_thread_sibling(cpu); > > - int chipid = cpu_to_chip_id(cpu); > > + int ppid = get_physical_package_id(cpu); > > int i; > > > > /* > > @@ -1217,11 +1241,11 @@ static void add_cpu_to_masks(int cpu) > > for_each_cpu(i, cpu_l2_cache_mask(cpu)) > > set_cpus_related(cpu, i, cpu_core_mask); > > > > - if (chipid == -1) > > + if (ppid == -1) > > return; > > Can get_physical_package_id() return -1 ? >
Yes, it can return -1, 1. A System doesnt have CONFIG_PPC_SPLPAR: cpu_to_chip_id() might return -1. 2. A System with CONFIG_PPC_SPLPAR: Still can return -1 for following cases. a. Not having firmware feature FW_FEATURE_LPAR b. If for some reason, of_get_cpu_node property is not present. > > > > for_each_cpu(i, cpu_online_mask) > > - if (cpu_to_chip_id(i) == chipid) > > + if (get_physical_package_id(i) == ppid) > > set_cpus_related(cpu, i, cpu_core_mask); > > } -- Thanks and Regards Srikar Dronamraju