From aa63a74d4535a1d97b60e46655a1361c42565b89 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Wed, 6 Apr 2022 15:01:50 -0700 Subject: [PATCH] topology/sysfs: Hide PPIN on systems that do not support it. Systems that do not support a Protected Processor Identification Number currently report: # cat /sys/devices/system/cpu/cpu0/topology/ppin 0x0 which is confusing/wrong. Add a ".is_visible" function to suppress inclusion of the ppin file. Fixes: ab28e944197f ("topology/sysfs: Add PPIN in sysfs under cpu topology") Signed-off-by: Tony Luck Link: https://lore.kernel.org/r/20220406220150.63855-1-tony.luck@intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/base/topology.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/base/topology.c b/drivers/base/topology.c index e9d1efcda89b..706dbf8bf249 100644 --- a/drivers/base/topology.c +++ b/drivers/base/topology.c @@ -152,9 +152,21 @@ static struct attribute *default_attrs[] = { NULL }; +static umode_t topology_is_visible(struct kobject *kobj, + struct attribute *attr, int unused) +{ + struct device *dev = kobj_to_dev(kobj); + + if (attr == &dev_attr_ppin.attr && !topology_ppin(dev->id)) + return 0; + + return attr->mode; +} + static const struct attribute_group topology_attr_group = { .attrs = default_attrs, .bin_attrs = bin_attrs, + .is_visible = topology_is_visible, .name = "topology" };