Commit ab28e944 authored by Tony Luck's avatar Tony Luck Committed by Borislav Petkov
Browse files

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: default avatarTony Luck <tony.luck@intel.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220131230111.2004669-6-tony.luck@intel.com
parent 182ecfaf

Documentation/ABI/stable/sysfs-devices-system-cpu

+4 −0
Original line number Diff line number Diff line
@@ -86,6 +86,10 @@ What: /sys/devices/system/cpu/cpuX/topology/die_cpus 
Description:    internal kernel map of CPUs within the same die.

Values:         hexadecimal bitmask.



What:           /sys/devices/system/cpu/cpuX/topology/ppin

Description:    per-socket protected processor inventory number

Values:         hexadecimal.



What:           /sys/devices/system/cpu/cpuX/topology/die_cpus_list

Description:    human-readable list of CPUs within the same die.

                The format is like 0-3, 8-11, 14,17.

Documentation/ABI/testing/sysfs-devices-system-cpu

+6 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ What: /sys/devices/system/cpu/cpuX/topology/core_id 
		/sys/devices/system/cpu/cpuX/topology/physical_package_id

		/sys/devices/system/cpu/cpuX/topology/thread_siblings

		/sys/devices/system/cpu/cpuX/topology/thread_siblings_list

		/sys/devices/system/cpu/cpuX/topology/ppin

Date:		December 2008

Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>

Description:	CPU topology files that describe a logical CPU's relationship
@@ -103,6 +104,11 @@ Description: CPU topology files that describe a logical CPU's relationship 
		thread_siblings_list: human-readable list of cpuX's hardware

		threads within the same core as cpuX



		ppin: human-readable Protected Processor Identification

		Number of the socket the cpu# belongs to. There should be

		one per physical_package_id. File is readable only to

		admin.



		See Documentation/admin-guide/cputopology.rst for more information.

arch/x86/include/asm/topology.h

+1 −0
Original line number Diff line number Diff line
@@ -110,6 +110,7 @@ extern const struct cpumask *cpu_clustergroup_mask(int cpu); 
#define topology_logical_die_id(cpu)		(cpu_data(cpu).logical_die_id)

#define topology_die_id(cpu)			(cpu_data(cpu).cpu_die_id)

#define topology_core_id(cpu)			(cpu_data(cpu).cpu_core_id)

#define topology_ppin(cpu)			(cpu_data(cpu).ppin)



extern unsigned int __max_die_per_package;

drivers/base/topology.c

+4 −0
Original line number Diff line number Diff line
@@ -58,6 +58,9 @@ static DEVICE_ATTR_RO(cluster_id); 
define_id_show_func(core_id, "%d");

static DEVICE_ATTR_RO(core_id);



define_id_show_func(ppin, "0x%llx");

static DEVICE_ATTR_ADMIN_RO(ppin);



define_siblings_read_func(thread_siblings, sibling_cpumask);

static BIN_ATTR_RO(thread_siblings, 0);

static BIN_ATTR_RO(thread_siblings_list, 0);
@@ -145,6 +148,7 @@ static struct attribute *default_attrs[] = { 
#ifdef TOPOLOGY_DRAWER_SYSFS

	&dev_attr_drawer_id.attr,

#endif

	&dev_attr_ppin.attr,

	NULL

};

include/linux/topology.h

+3 −0
Original line number Diff line number Diff line
@@ -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