Re: [PATCH v3 01/10] x86/topology: Introduce topology_logical_core_id()

["Zhang, Rui" <rui.zhang@intel.com>]

>  For use cases such as the per-core RAPL PMU,
> there exists a need for a unique core ID across the entire system
> with
> multiple PKG domains.

Agreed. And there are other cases that a system unique core ID is
needed, like in drivers/hwmon/coretemp.c, where per-core temperature
info is saved in an array.

>  Introduce topology_logical_core_id() to derive a
> unique core ID across the system.
> 
> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
> Signed-off-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>

Reviewed-by: Zhang Rui <rui.zhang@intel.com>

thanks,
rui

> ---
>  Documentation/arch/x86/topology.rst   | 4 ++++
>  arch/x86/include/asm/processor.h      | 1 +
>  arch/x86/include/asm/topology.h       | 1 +
>  arch/x86/kernel/cpu/debugfs.c         | 1 +
>  arch/x86/kernel/cpu/topology_common.c | 1 +
>  5 files changed, 8 insertions(+)
> 
> diff --git a/Documentation/arch/x86/topology.rst
> b/Documentation/arch/x86/topology.rst
> index 7352ab89a55a..c12837e61bda 100644
> --- a/Documentation/arch/x86/topology.rst
> +++ b/Documentation/arch/x86/topology.rst
> @@ -135,6 +135,10 @@ Thread-related topology information in the
> kernel:
>      The ID of the core to which a thread belongs. It is also printed
> in /proc/cpuinfo
>      "core_id."
>  
> +  - topology_logical_core_id();
> +
> +    The logical core ID to which a thread belongs.
> +
>  
>  
>  System topology examples
> diff --git a/arch/x86/include/asm/processor.h
> b/arch/x86/include/asm/processor.h
> index 4fd3364dbc73..e1eeb42edeaf 100644
> --- a/arch/x86/include/asm/processor.h
> +++ b/arch/x86/include/asm/processor.h
> @@ -98,6 +98,7 @@ struct cpuinfo_topology {
>         // Logical ID mappings
>         u32                     logical_pkg_id;
>         u32                     logical_die_id;
> +       u32                     logical_core_id;
>  
>         // AMD Node ID and Nodes per Package info
>         u32                     amd_node_id;
> diff --git a/arch/x86/include/asm/topology.h
> b/arch/x86/include/asm/topology.h
> index abe3a8f22cbd..2a6dbf965d92 100644
> --- a/arch/x86/include/asm/topology.h
> +++ b/arch/x86/include/asm/topology.h
> @@ -137,6 +137,7 @@ extern const struct cpumask
> *cpu_clustergroup_mask(int cpu);
>  #define
> topology_logical_package_id(cpu)       (cpu_data(cpu).topo.logical_pk
> g_id)
>  #define
> topology_physical_package_id(cpu)      (cpu_data(cpu).topo.pkg_id)
>  #define
> topology_logical_die_id(cpu)           (cpu_data(cpu).topo.logical_di
> e_id)
> +#define
> topology_logical_core_id(cpu)          (cpu_data(cpu).topo.logical_co
> re_id)
>  #define
> topology_die_id(cpu)                   (cpu_data(cpu).topo.die_id)
>  #define
> topology_core_id(cpu)                  (cpu_data(cpu).topo.core_id)
>  #define topology_ppin(cpu)                     (cpu_data(cpu).ppin)
> diff --git a/arch/x86/kernel/cpu/debugfs.c
> b/arch/x86/kernel/cpu/debugfs.c
> index 3baf3e435834..b1eb6d7828db 100644
> --- a/arch/x86/kernel/cpu/debugfs.c
> +++ b/arch/x86/kernel/cpu/debugfs.c
> @@ -24,6 +24,7 @@ static int cpu_debug_show(struct seq_file *m, void
> *p)
>         seq_printf(m, "core_id:             %u\n", c->topo.core_id);
>         seq_printf(m, "logical_pkg_id:      %u\n", c-
> >topo.logical_pkg_id);
>         seq_printf(m, "logical_die_id:      %u\n", c-
> >topo.logical_die_id);
> +       seq_printf(m, "logical_core_id:     %u\n", c-
> >topo.logical_core_id);
>         seq_printf(m, "llc_id:              %u\n", c->topo.llc_id);
>         seq_printf(m, "l2c_id:              %u\n", c->topo.l2c_id);
>         seq_printf(m, "amd_node_id:         %u\n", c-
> >topo.amd_node_id);
> diff --git a/arch/x86/kernel/cpu/topology_common.c
> b/arch/x86/kernel/cpu/topology_common.c
> index 9a6069e7133c..23722aa21e2f 100644
> --- a/arch/x86/kernel/cpu/topology_common.c
> +++ b/arch/x86/kernel/cpu/topology_common.c
> @@ -151,6 +151,7 @@ static void topo_set_ids(struct topo_scan *tscan,
> bool early)
>         if (!early) {
>                 c->topo.logical_pkg_id =
> topology_get_logical_id(apicid, TOPO_PKG_DOMAIN);
>                 c->topo.logical_die_id =
> topology_get_logical_id(apicid, TOPO_DIE_DOMAIN);
> +               c->topo.logical_core_id =
> topology_get_logical_id(apicid, TOPO_CORE_DOMAIN);
>         }
>  
>         /* Package relative core ID */