arch_topology: Do not set llc_sibling if llc_id is invalid

commit 1dc9f1a66e1718479e1c4f95514e1750602a3cb9 upstream.

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.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 43407665918f323e4e961a50ed59e903b67b900d..ef4fc89f085d858d3fae56b8622ddf3868006849 100644 (file)
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -609,7 +609,7 @@ 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);
                }