From ab28e944197fa78e6af7c4a0ffd6bba9a5bbacf0 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Mon, 31 Jan 2022 15:01:11 -0800 Subject: topology/sysfs: Add PPIN in sysfs under cpu topology PPIN is the Protected Processor Identification Number. This is used to identify the socket as a Field Replaceable Unit (FRU). Existing code only displays this when reporting errors. But this makes it inconvenient for large clusters to use it for its intended purpose of inventory control. Add ppin to /sys/devices/system/cpu/cpu*/topology to make what is already available using RDMSR more easily accessible. Make the file read only for root in case there are still people concerned about making a unique system "serial number" available. Signed-off-by: Tony Luck Signed-off-by: Borislav Petkov Acked-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20220131230111.2004669-6-tony.luck@intel.com --- include/linux/topology.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/linux/topology.h b/include/linux/topology.h index a6e201758ae9..f19bc3626297 100644 --- a/include/linux/topology.h +++ b/include/linux/topology.h @@ -211,6 +211,9 @@ static inline int cpu_to_mem(int cpu) #ifndef topology_drawer_id #define topology_drawer_id(cpu) ((void)(cpu), -1) #endif +#ifndef topology_ppin +#define topology_ppin(cpu) ((void)(cpu), 0ull) +#endif #ifndef topology_sibling_cpumask #define topology_sibling_cpumask(cpu) cpumask_of(cpu) #endif -- cgit v1.2.3