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@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 1dc9f1a66e1718479e1c4f95514e1750602a3cb9 Mon Sep 17 00:00:00 2001 From: Wang Qing wangqing@vivo.com 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@arm.com Signed-off-by: Wang Qing wangqing@vivo.com Fixes: 37c3ec2d810f ("arm64: topology: divorce MC scheduling domain from core_siblings") Cc: stable stable@vger.kernel.org Link: https://lore.kernel.org/r/1649644580-54626-1-git-send-email-wangqing@vivo.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

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); }