[PATCH 5.10+5.4 3/3] ia64: ensure proper NUMA distance and possible map initialization

[dann frazier]

From: Valentin Schneider <valentin.schneider@xxxxxxx>

commit b22a8f7b4bde4e4ab73b64908ffd5d90ecdcdbfd upstream.

John Paul reported a warning about bogus NUMA distance values spurred by
commit:

  620a6dc40754 ("sched/topology: Make sched_init_numa() use a set for the deduplicating sort")

In this case, the afflicted machine comes up with a reported 256 possible
nodes, all of which are 0 distance away from one another.  This was
previously silently ignored, but is now caught by the aforementioned
commit.

The culprit is ia64's node_possible_map which remains unchanged from its
initialization value of NODE_MASK_ALL.  In John's case, the machine
doesn't have any SRAT nor SLIT table, but AIUI the possible map remains
untouched regardless of what ACPI tables end up being parsed.  Thus,
!online && possible nodes remain with a bogus distance of 0 (distances \in
[0, 9] are "reserved and have no meaning" as per the ACPI spec).

Follow x86 / drivers/base/arch_numa's example and set the possible map to
the parsed map, which in this case seems to be the online map.

Link: http://lore.kernel.org/r/255d6b5d-194e-eb0e-ecdd-97477a534441@xxxxxxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/20210318130617.896309-1-valentin.schneider@xxxxxxx
Fixes: 620a6dc40754 ("sched/topology: Make sched_init_numa() use a set for the deduplicating sort")
Signed-off-by: Valentin Schneider <valentin.schneider@xxxxxxx>
Reported-by: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Tested-by: John Paul Adrian Glaubitz <glaubitz@xxxxxxxxxxxxxxxxxxx>
Tested-by: Sergei Trofimovich <slyfox@xxxxxxxxxx>
Cc: "Peter Zijlstra (Intel)" <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Cc: Anatoly Pugachev <matorola@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: dann frazier <dann.frazier@xxxxxxxxxxxxx>
---
 arch/ia64/kernel/acpi.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index a5636524af76..e2af6b172200 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -446,7 +446,8 @@ void __init acpi_numa_fixup(void)
 	if (srat_num_cpus == 0) {
 		node_set_online(0);
 		node_cpuid[0].phys_id = hard_smp_processor_id();
-		return;
+		slit_distance(0, 0) = LOCAL_DISTANCE;
+		goto out;
 	}
 
 	/*
@@ -489,7 +490,7 @@ void __init acpi_numa_fixup(void)
 			for (j = 0; j < MAX_NUMNODES; j++)
 				slit_distance(i, j) = i == j ?
 					LOCAL_DISTANCE : REMOTE_DISTANCE;
-		return;
+		goto out;
 	}
 
 	memset(numa_slit, -1, sizeof(numa_slit));
@@ -514,6 +515,8 @@ void __init acpi_numa_fixup(void)
 		printk("\n");
 	}
 #endif
+out:
+	node_possible_map = node_online_map;
 }
 #endif				/* CONFIG_ACPI_NUMA */
 
-- 
2.25.1