On Tue, Jul 14, 2020 at 10:06:20AM +0530, Srikar Dronamraju wrote:
> Add support for grouping cores based on the device-tree classification.
> - The last domain in the associativity domains always refers to the
> core.
> - If primary reference domain happens to be the penultimate domain in
> the associativity domains device-tree property, then there are no
> coregroups. However if its not a penultimate domain, then there are
> coregroups. There can be more than one coregroup. For now we would be
> interested in the last or the smallest coregroups.
>
> Cc: linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
> Cc: Michael Ellerman <micha...@au1.ibm.com>
> Cc: Nick Piggin <npig...@au1.ibm.com>
> Cc: Oliver OHalloran <olive...@au1.ibm.com>
> Cc: Nathan Lynch <nath...@linux.ibm.com>
> Cc: Michael Neuling <mi...@linux.ibm.com>
> Cc: Anton Blanchard <an...@au1.ibm.com>
> Cc: Gautham R Shenoy <e...@linux.vnet.ibm.com>
> Cc: Vaidyanathan Srinivasan <sva...@linux.ibm.com>
> Signed-off-by: Srikar Dronamraju <sri...@linux.vnet.ibm.com>
This looks good to me from the discovery of the core-group point of
view.
Reviewed-by: Gautham R. Shenoy <e...@linux.vnet.ibm.com>
> ---
> arch/powerpc/include/asm/smp.h | 1 +
> arch/powerpc/kernel/smp.c | 1 +
> arch/powerpc/mm/numa.c | 34 +++++++++++++++++++++-------------
> 3 files changed, 23 insertions(+), 13 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
> index 49a25e2400f2..5bdc17a7049f 100644
> --- a/arch/powerpc/include/asm/smp.h
> +++ b/arch/powerpc/include/asm/smp.h
> @@ -28,6 +28,7 @@
> extern int boot_cpuid;
> extern int spinning_secondaries;
> extern u32 *cpu_to_phys_id;
> +extern bool coregroup_enabled;
>
> extern void cpu_die(void);
> extern int cpu_to_chip_id(int cpu);
> diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
> index f8faf75135af..96e47450d9b3 100644
> --- a/arch/powerpc/kernel/smp.c
> +++ b/arch/powerpc/kernel/smp.c
> @@ -74,6 +74,7 @@ static DEFINE_PER_CPU(int, cpu_state) = { 0 };
>
> struct task_struct *secondary_current;
> bool has_big_cores;
> +bool coregroup_enabled;
>
> DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
> DEFINE_PER_CPU(cpumask_var_t, cpu_smallcore_map);
> diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
> index fc7b0505bdd8..a43eab455be4 100644
> --- a/arch/powerpc/mm/numa.c
> +++ b/arch/powerpc/mm/numa.c
> @@ -887,7 +887,9 @@ static void __init setup_node_data(int nid, u64
> start_pfn, u64 end_pfn)
> static void __init find_possible_nodes(void)
> {
> struct device_node *rtas;
> - u32 numnodes, i;
> + const __be32 *domains;
> + int prop_length, max_nodes;
> + u32 i;
>
> if (!numa_enabled)
> return;
> @@ -896,25 +898,31 @@ static void __init find_possible_nodes(void)
> if (!rtas)
> return;
>
> - if (of_property_read_u32_index(rtas,
> "ibm,current-associativity-domains",
> - min_common_depth, &numnodes)) {
> - /*
> - * ibm,current-associativity-domains is a fairly recent
> - * property. If it doesn't exist, then fallback on
> - * ibm,max-associativity-domains. Current denotes what the
> - * platform can support compared to max which denotes what the
> - * Hypervisor can support.
> - */
> - if (of_property_read_u32_index(rtas,
> "ibm,max-associativity-domains",
> - min_common_depth, &numnodes))
> + /*
> + * ibm,current-associativity-domains is a fairly recent property. If
> + * it doesn't exist, then fallback on ibm,max-associativity-domains.
> + * Current denotes what the platform can support compared to max
> + * which denotes what the Hypervisor can support.
> + */
> + domains = of_get_property(rtas, "ibm,current-associativity-domains",
> + &prop_length);
> + if (!domains) {
> + domains = of_get_property(rtas, "ibm,max-associativity-domains",
> + &prop_length);
> + if (!domains)
> goto out;
> }
>
> - for (i = 0; i < numnodes; i++) {
> + max_nodes = of_read_number(&domains[min_common_depth], 1);
> + for (i = 0; i < max_nodes; i++) {
> if (!node_possible(i))
> node_set(i, node_possible_map);
> }
>
> + prop_length /= sizeof(int);
> + if (prop_length > min_common_depth + 2)
> + coregroup_enabled = 1;
> +
> out:
> of_node_put(rtas);
> }
> --
> 2.17.1
>
