Re: [PATCH 05/11] powerpc/smp: Dont assume l2-cache to be superset of sibling

Cc: linuxppc-dev <redacted>
Cc: Michael Ellerman <redacted>
Cc: Nick Piggin <redacted>
Cc: Oliver OHalloran <redacted>
Cc: Nathan Lynch <redacted>
Cc: Michael Neuling <redacted>
Cc: Anton Blanchard <redacted>
Cc: Gautham R Shenoy <redacted>
Cc: Vaidyanathan Srinivasan <redacted>
Signed-off-by: Srikar Dronamraju <redacted>
---
 arch/powerpc/kernel/smp.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 7d430fc536cc..875f57e41355 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c

@@ -1198,6 +1198,7 @@ static bool update_mask_by_l2(int cpu, struct cpumask *(*mask_fn)(int))
        struct device_node *l2_cache, *np;
        int i;

+       cpumask_set_cpu(cpu, mask_fn(cpu));

        l2_cache = cpu_to_l2cache(cpu);
        if (!l2_cache)
                return false;

@@ -1284,29 +1285,30 @@ static void add_cpu_to_masks(int cpu)
         * add it to it's own thread sibling mask.
         */
        cpumask_set_cpu(cpu, cpu_sibling_mask(cpu));
+       cpumask_set_cpu(cpu, cpu_core_mask(cpu));

        for (i = first_thread; i < first_thread + threads_per_core; i++)
                if (cpu_online(i))
                        set_cpus_related(i, cpu, cpu_sibling_mask);

        add_cpu_to_smallcore_masks(cpu);
-       /*
-        * Copy the thread sibling mask into the cache sibling mask
-        * and mark any CPUs that share an L2 with this CPU.
-        */
-       for_each_cpu(i, cpu_sibling_mask(cpu))
-               set_cpus_related(cpu, i, cpu_l2_cache_mask);
        update_mask_by_l2(cpu, cpu_l2_cache_mask);

-       /*
-        * Copy the cache sibling mask into core sibling mask and mark
-        * any CPUs on the same chip as this CPU.
-        */
-       for_each_cpu(i, cpu_l2_cache_mask(cpu))
-               set_cpus_related(cpu, i, cpu_core_mask);
+       if (pkg_id == -1) {
+               struct cpumask *(*mask)(int) = cpu_sibling_mask;
+
+               /*
+                * Copy the sibling mask into core sibling mask and
+                * mark any CPUs on the same chip as this CPU.
+                */
+               if (shared_caches)
+                       mask = cpu_l2_cache_mask;
+
+               for_each_cpu(i, mask(cpu))
+                       set_cpus_related(cpu, i, cpu_core_mask);

-       if (pkg_id == -1)
                return;
+       }

        for_each_cpu(i, cpu_online_mask)
                if (get_physical_package_id(i) == pkg_id)
--

2.17.1