* Srikar Dronamraju <sri...@linux.vnet.ibm.com> [2020-07-14 10:06:13]:
>
> On Power 9 (with device-tree enablement to show coregroups).
> -----------------------------------------------------------
With help of Gautham, I tried to kexec into a newer kernel with a modified
dtb. However when passing with the dtb option, kexec would get stuck.
Hence alternatively, I hardcoded some assumptions to test the same.
These hunks apply on top of all the patches.
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 8ec7ff05ae47..762aa573c313 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -56,6 +56,12 @@ static int n_mem_addr_cells, n_mem_size_cells;
static int form1_affinity;
#define MAX_DISTANCE_REF_POINTS 4
+/*
+ * HAck2: On Power9, there are 12 SMT8 cores per chip.
+ * Hard code this for now.
+ */
+#define CORES_PER_CHIP 12
+#define CORES_PER_COREGROUP (CORES_PER_CHIP / 2)
static int distance_ref_points_depth;
static const __be32 *distance_ref_points;
static int distance_lookup_table[MAX_NUMNODES][MAX_DISTANCE_REF_POINTS];
@@ -326,6 +332,13 @@ static int __init find_min_common_depth(void)
if (form1_affinity) {
depth = of_read_number(distance_ref_points, 1);
+ /*
+ * Hack: Hack: Hack:
+ * For now only on Phyp machines.
+ */
+ if (!firmware_has_feature(FW_FEATURE_OPAL))
+ depth--;
} else {
if (distance_ref_points_depth < 2) {
printk(KERN_WARNING "NUMA: "
@@ -1247,8 +1260,8 @@ int cpu_to_coregroup_id(int cpu)
goto out;
index = of_read_number(associativity, 1);
- if ((index > min_common_depth + 1) && coregroup_enabled)
- return of_read_number(&associativity[index - 1], 1);
+ if ((index > min_common_depth + 1) && coregroup_enabled &&
has_big_cores)
+ return of_read_number(&associativity[index], 1) /
CORES_PER_COREGROUP;
out:
return cpu_to_core_id(cpu);
--
Thanks and Regards
Srikar Dronamraju
