The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 1dc9f1a66e1718479e1c4f95514e1750602a3cb9 Mon Sep 17 00:00:00 2001
From: Wang Qing <wangqing@xxxxxxxx>
Date: Sun, 10 Apr 2022 19:36:19 -0700
Subject: [PATCH] arch_topology: Do not set llc_sibling if llc_id is invalid
When ACPI is not enabled, cpuid_topo->llc_id = cpu_topo->llc_id = -1, which
will set llc_sibling 0xff(...), this is misleading.
Don't set llc_sibling(default 0) if we don't know the cache topology.
Reviewed-by: Sudeep Holla <sudeep.holla@xxxxxxx>
Signed-off-by: Wang Qing <wangqing@xxxxxxxx>
Fixes: 37c3ec2d810f ("arm64: topology: divorce MC scheduling domain from core_siblings")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/1649644580-54626-1-git-send-email-wangqing@xxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 5497c5ab7318..f73b836047cf 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -693,7 +693,7 @@ void update_siblings_masks(unsigned int cpuid)
for_each_online_cpu(cpu) {
cpu_topo = &cpu_topology[cpu];
- if (cpuid_topo->llc_id == cpu_topo->llc_id) {
+ if (cpu_topo->llc_id != -1 && cpuid_topo->llc_id == cpu_topo->llc_id) {
cpumask_set_cpu(cpu, &cpuid_topo->llc_sibling);
cpumask_set_cpu(cpuid, &cpu_topo->llc_sibling);
}
