Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 644 insertions, 0 deletions

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+What:		/sys/devices/system/cpu/
+Date:		pre-git history
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:
+		A collection of both global and individual CPU attributes
+
+		Individual CPU attributes are contained in subdirectories
+		named by the kernel's logical CPU number, e.g.:
+
+		/sys/devices/system/cpu/cpu#/
+
+What:		/sys/devices/system/cpu/kernel_max
+		/sys/devices/system/cpu/offline
+		/sys/devices/system/cpu/online
+		/sys/devices/system/cpu/possible
+		/sys/devices/system/cpu/present
+Date:		December 2008
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	CPU topology files that describe kernel limits related to
+		hotplug. Briefly:
+
+		kernel_max: the maximum cpu index allowed by the kernel
+		configuration.
+
+		offline: cpus that are not online because they have been
+		HOTPLUGGED off or exceed the limit of cpus allowed by the
+		kernel configuration (kernel_max above).
+
+		online: cpus that are online and being scheduled.
+
+		possible: cpus that have been allocated resources and can be
+		brought online if they are present.
+
+		present: cpus that have been identified as being present in
+		the system.
+
+		See Documentation/admin-guide/cputopology.rst for more information.
+
+
+What:		/sys/devices/system/cpu/probe
+		/sys/devices/system/cpu/release
+Date:		November 2009
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	Dynamic addition and removal of CPU's.  This is not hotplug
+		removal, this is meant complete removal/addition of the CPU
+		from the system.
+
+		probe: writes to this file will dynamically add a CPU to the
+		system.  Information written to the file to add CPU's is
+		architecture specific.
+
+		release: writes to this file dynamically remove a CPU from
+		the system.  Information writtento the file to remove CPU's
+		is architecture specific.
+
+What:		/sys/devices/system/cpu/cpu#/node
+Date:		October 2009
+Contact:	Linux memory management mailing list <linux-mm@kvack.org>
+Description:	Discover NUMA node a CPU belongs to
+
+		When CONFIG_NUMA is enabled, a symbolic link that points
+		to the corresponding NUMA node directory.
+
+		For example, the following symlink is created for cpu42
+		in NUMA node 2:
+
+		/sys/devices/system/cpu/cpu42/node2 -> ../../node/node2
+
+
+What:		/sys/devices/system/cpu/cpu#/topology/core_id
+		/sys/devices/system/cpu/cpu#/topology/core_siblings
+		/sys/devices/system/cpu/cpu#/topology/core_siblings_list
+		/sys/devices/system/cpu/cpu#/topology/physical_package_id
+		/sys/devices/system/cpu/cpu#/topology/thread_siblings
+		/sys/devices/system/cpu/cpu#/topology/thread_siblings_list
+Date:		December 2008
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	CPU topology files that describe a logical CPU's relationship
+		to other cores and threads in the same physical package.
+
+		One cpu# directory is created per logical CPU in the system,
+		e.g. /sys/devices/system/cpu/cpu42/.
+
+		Briefly, the files above are:
+
+		core_id: the CPU core ID of cpu#. Typically it is the
+		hardware platform's identifier (rather than the kernel's).
+		The actual value is architecture and platform dependent.
+
+		core_siblings: internal kernel map of cpu#'s hardware threads
+		within the same physical_package_id.
+
+		core_siblings_list: human-readable list of the logical CPU
+		numbers within the same physical_package_id as cpu#.
+
+		physical_package_id: physical package id of cpu#. Typically
+		corresponds to a physical socket number, but the actual value
+		is architecture and platform dependent.
+
+		thread_siblings: internel kernel map of cpu#'s hardware
+		threads within the same core as cpu#
+
+		thread_siblings_list: human-readable list of cpu#'s hardware
+		threads within the same core as cpu#
+
+		See Documentation/admin-guide/cputopology.rst for more information.
+
+
+What:		/sys/devices/system/cpu/cpuidle/available_governors
+		/sys/devices/system/cpu/cpuidle/current_driver
+		/sys/devices/system/cpu/cpuidle/current_governor
+		/sys/devices/system/cpu/cpuidle/current_governer_ro
+Date:		September 2007
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	Discover cpuidle policy and mechanism
+
+		Various CPUs today support multiple idle levels that are
+		differentiated by varying exit latencies and power
+		consumption during idle.
+
+		Idle policy (governor) is differentiated from idle mechanism
+		(driver).
+
+		available_governors: (RO) displays a space separated list of
+		available governors.
+
+		current_driver: (RO) displays current idle mechanism.
+
+		current_governor: (RW) displays current idle policy. Users can
+		switch the governor at runtime by writing to this file.
+
+		current_governor_ro: (RO) displays current idle policy.
+
+		See Documentation/admin-guide/pm/cpuidle.rst and
+		Documentation/driver-api/pm/cpuidle.rst for more information.
+
+
+What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/name
+		/sys/devices/system/cpu/cpuX/cpuidle/stateN/latency
+		/sys/devices/system/cpu/cpuX/cpuidle/stateN/power
+		/sys/devices/system/cpu/cpuX/cpuidle/stateN/time
+		/sys/devices/system/cpu/cpuX/cpuidle/stateN/usage
+		/sys/devices/system/cpu/cpuX/cpuidle/stateN/above
+		/sys/devices/system/cpu/cpuX/cpuidle/stateN/below
+Date:		September 2007
+KernelVersion:	v2.6.24
+Contact:	Linux power management list <linux-pm@vger.kernel.org>
+Description:
+		The directory /sys/devices/system/cpu/cpuX/cpuidle contains per
+		logical CPU specific cpuidle information for each online cpu X.
+		The processor idle states which are available for use have the
+		following attributes:
+
+		======== ==== =================================================
+		name:	 (RO) Name of the idle state (string).
+
+		latency: (RO) The latency to exit out of this idle state (in
+			      microseconds).
+
+		power:   (RO) The power consumed while in this idle state (in
+			      milliwatts).
+
+		time:    (RO) The total time spent in this idle state
+			      (in microseconds).
+
+		usage:	 (RO) Number of times this state was entered (a count).
+
+		above:	 (RO) Number of times this state was entered, but the
+			      observed CPU idle duration was too short for it
+			      (a count).
+
+		below:	 (RO) Number of times this state was entered, but the
+			      observed CPU idle duration was too long for it
+			      (a count).
+		======== ==== =================================================
+
+What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/desc
+Date:		February 2008
+KernelVersion:	v2.6.25
+Contact:	Linux power management list <linux-pm@vger.kernel.org>
+Description:
+		(RO) A small description about the idle state (string).
+
+
+What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/disable
+Date:		March 2012
+KernelVersion:	v3.10
+Contact:	Linux power management list <linux-pm@vger.kernel.org>
+Description:
+		(RW) Option to disable this idle state (bool). The behavior and
+		the effect of the disable variable depends on the implementation
+		of a particular governor. In the ladder governor, for example,
+		it is not coherent, i.e. if one is disabling a light state, then
+		all deeper states are disabled as well, but the disable variable
+		does not reflect it. Likewise, if one enables a deep state but a
+		lighter state still is disabled, then this has no effect.
+
+What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/default_status
+Date:		December 2019
+KernelVersion:	v5.6
+Contact:	Linux power management list <linux-pm@vger.kernel.org>
+Description:
+		(RO) The default status of this state, "enabled" or "disabled".
+
+What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/residency
+Date:		March 2014
+KernelVersion:	v3.15
+Contact:	Linux power management list <linux-pm@vger.kernel.org>
+Description:
+		(RO) Display the target residency i.e. the minimum amount of
+		time (in microseconds) this cpu should spend in this idle state
+		to make the transition worth the effort.
+
+What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/
+Date:		March 2018
+KernelVersion:	v4.17
+Contact:	Linux power management list <linux-pm@vger.kernel.org>
+Description:
+		Idle state usage statistics related to suspend-to-idle.
+
+		This attribute group is only present for states that can be
+		used in suspend-to-idle with suspended timekeeping.
+
+What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/time
+Date:		March 2018
+KernelVersion:	v4.17
+Contact:	Linux power management list <linux-pm@vger.kernel.org>
+Description:
+		Total time spent by the CPU in suspend-to-idle (with scheduler
+		tick suspended) after requesting this state.
+
+What:		/sys/devices/system/cpu/cpuX/cpuidle/stateN/s2idle/usage
+Date:		March 2018
+KernelVersion:	v4.17
+Contact:	Linux power management list <linux-pm@vger.kernel.org>
+Description:
+		Total number of times this state has been requested by the CPU
+		while entering suspend-to-idle.
+
+What:		/sys/devices/system/cpu/cpu#/cpufreq/*
+Date:		pre-git history
+Contact:	linux-pm@vger.kernel.org
+Description:	Discover and change clock speed of CPUs
+
+		Clock scaling allows you to change the clock speed of the
+		CPUs on the fly. This is a nice method to save battery
+		power, because the lower the clock speed, the less power
+		the CPU consumes.
+
+		There are many knobs to tweak in this directory.
+
+		See files in Documentation/cpu-freq/ for more information.
+
+
+What:		/sys/devices/system/cpu/cpu#/cpufreq/freqdomain_cpus
+Date:		June 2013
+Contact:	linux-pm@vger.kernel.org
+Description:	Discover CPUs in the same CPU frequency coordination domain
+
+		freqdomain_cpus is the list of CPUs (online+offline) that share
+		the same clock/freq domain (possibly at the hardware level).
+		That information may be hidden from the cpufreq core and the
+		value of related_cpus may be different from freqdomain_cpus. This
+		attribute is useful for user space DVFS controllers to get better
+		power/performance results for platforms using acpi-cpufreq.
+
+		This file is only present if the acpi-cpufreq driver is in use.
+
+
+What:		/sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1}
+Date:		August 2008
+KernelVersion:	2.6.27
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	Disable L3 cache indices
+
+		These files exist in every CPU's cache/index3 directory. Each
+		cache_disable_{0,1} file corresponds to one disable slot which
+		can be used to disable a cache index. Reading from these files
+		on a processor with this functionality will return the currently
+		disabled index for that node. There is one L3 structure per
+		node, or per internal node on MCM machines. Writing a valid
+		index to one of these files will cause the specificed cache
+		index to be disabled.
+
+		All AMD processors with L3 caches provide this functionality.
+		For details, see BKDGs at
+		http://developer.amd.com/documentation/guides/Pages/default.aspx
+
+
+What:		/sys/devices/system/cpu/cpufreq/boost
+Date:		August 2012
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	Processor frequency boosting control
+
+		This switch controls the boost setting for the whole system.
+		Boosting allows the CPU and the firmware to run at a frequency
+		beyound it's nominal limit.
+
+		More details can be found in
+		Documentation/admin-guide/pm/cpufreq.rst
+
+
+What:		/sys/devices/system/cpu/cpu#/crash_notes
+		/sys/devices/system/cpu/cpu#/crash_notes_size
+Date:		April 2013
+Contact:	kexec@lists.infradead.org
+Description:	address and size of the percpu note.
+
+		crash_notes: the physical address of the memory that holds the
+		note of cpu#.
+
+		crash_notes_size: size of the note of cpu#.
+
+
+What:		/sys/devices/system/cpu/intel_pstate/max_perf_pct
+		/sys/devices/system/cpu/intel_pstate/min_perf_pct
+		/sys/devices/system/cpu/intel_pstate/no_turbo
+Date:		February 2013
+Contact:	linux-pm@vger.kernel.org
+Description:	Parameters for the Intel P-state driver
+
+		Logic for selecting the current P-state in Intel
+		Sandybridge+ processors. The three knobs control
+		limits for the P-state that will be requested by the
+		driver.
+
+		max_perf_pct: limits the maximum P state that will be requested by
+		the driver stated as a percentage of the available performance.
+
+		min_perf_pct: limits the minimum P state that will be requested by
+		the driver stated as a percentage of the available performance.
+
+		no_turbo: limits the driver to selecting P states below the turbo
+		frequency range.
+
+		More details can be found in
+		Documentation/admin-guide/pm/intel_pstate.rst
+
+What:		/sys/devices/system/cpu/cpu*/cache/index*/<set_of_attributes_mentioned_below>
+Date:		July 2014(documented, existed before August 2008)
+Contact:	Sudeep Holla <sudeep.holla@arm.com>
+		Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	Parameters for the CPU cache attributes
+
+		allocation_policy:
+			- WriteAllocate:
+					allocate a memory location to a cache line
+					on a cache miss because of a write
+			- ReadAllocate:
+					allocate a memory location to a cache line
+					on a cache miss because of a read
+			- ReadWriteAllocate:
+					both writeallocate and readallocate
+
+		attributes:
+			    LEGACY used only on IA64 and is same as write_policy
+
+		coherency_line_size:
+				     the minimum amount of data in bytes that gets
+				     transferred from memory to cache
+
+		level:
+			the cache hierarchy in the multi-level cache configuration
+
+		number_of_sets:
+				total number of sets in the cache, a set is a
+				collection of cache lines with the same cache index
+
+		physical_line_partition:
+				number of physical cache line per cache tag
+
+		shared_cpu_list:
+				the list of logical cpus sharing the cache
+
+		shared_cpu_map:
+				logical cpu mask containing the list of cpus sharing
+				the cache
+
+		size:
+			the total cache size in kB
+
+		type:
+			- Instruction: cache that only holds instructions
+			- Data: cache that only caches data
+			- Unified: cache that holds both data and instructions
+
+		ways_of_associativity:
+			degree of freedom in placing a particular block
+			of memory in the cache
+
+		write_policy:
+			- WriteThrough:
+					data is written to both the cache line
+					and to the block in the lower-level memory
+			- WriteBack:
+				     data is written only to the cache line and
+				     the modified cache line is written to main
+				     memory only when it is replaced
+
+
+What:		/sys/devices/system/cpu/cpu*/cache/index*/id
+Date:		September 2016
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	Cache id
+
+		The id provides a unique number for a specific instance of
+		a cache of a particular type. E.g. there may be a level
+		3 unified cache on each socket in a server and we may
+		assign them ids 0, 1, 2, ...
+
+		Note that id value can be non-contiguous. E.g. level 1
+		caches typically exist per core, but there may not be a
+		power of two cores on a socket, so these caches may be
+		numbered 0, 1, 2, 3, 4, 5, 8, 9, 10, ...
+
+What:		/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats
+		/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/turbo_stat
+		/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/sub_turbo_stat
+		/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/unthrottle
+		/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/powercap
+		/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overtemp
+		/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/supply_fault
+		/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/overcurrent
+		/sys/devices/system/cpu/cpuX/cpufreq/throttle_stats/occ_reset
+Date:		March 2016
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+		Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:	POWERNV CPUFreq driver's frequency throttle stats directory and
+		attributes
+
+		'cpuX/cpufreq/throttle_stats' directory contains the CPU frequency
+		throttle stat attributes for the chip. The throttle stats of a cpu
+		is common across all the cpus belonging to a chip. Below are the
+		throttle attributes exported in the 'throttle_stats' directory:
+
+		- turbo_stat : This file gives the total number of times the max
+		  frequency is throttled to lower frequency in turbo (at and above
+		  nominal frequency) range of frequencies.
+
+		- sub_turbo_stat : This file gives the total number of times the
+		  max frequency is throttled to lower frequency in sub-turbo(below
+		  nominal frequency) range of frequencies.
+
+		- unthrottle : This file gives the total number of times the max
+		  frequency is unthrottled after being throttled.
+
+		- powercap : This file gives the total number of times the max
+		  frequency is throttled due to 'Power Capping'.
+
+		- overtemp : This file gives the total number of times the max
+		  frequency is throttled due to 'CPU Over Temperature'.
+
+		- supply_fault : This file gives the total number of times the
+		  max frequency is throttled due to 'Power Supply Failure'.
+
+		- overcurrent : This file gives the total number of times the
+		  max frequency is throttled due to 'Overcurrent'.
+
+		- occ_reset : This file gives the total number of times the max
+		  frequency is throttled due to 'OCC Reset'.
+
+		The sysfs attributes representing different throttle reasons like
+		powercap, overtemp, supply_fault, overcurrent and occ_reset map to
+		the reasons provided by OCC firmware for throttling the frequency.
+
+What:		/sys/devices/system/cpu/cpufreq/policyX/throttle_stats
+		/sys/devices/system/cpu/cpufreq/policyX/throttle_stats/turbo_stat
+		/sys/devices/system/cpu/cpufreq/policyX/throttle_stats/sub_turbo_stat
+		/sys/devices/system/cpu/cpufreq/policyX/throttle_stats/unthrottle
+		/sys/devices/system/cpu/cpufreq/policyX/throttle_stats/powercap
+		/sys/devices/system/cpu/cpufreq/policyX/throttle_stats/overtemp
+		/sys/devices/system/cpu/cpufreq/policyX/throttle_stats/supply_fault
+		/sys/devices/system/cpu/cpufreq/policyX/throttle_stats/overcurrent
+		/sys/devices/system/cpu/cpufreq/policyX/throttle_stats/occ_reset
+Date:		March 2016
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+		Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:	POWERNV CPUFreq driver's frequency throttle stats directory and
+		attributes
+
+		'policyX/throttle_stats' directory and all the attributes are same as
+		the /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats directory and
+		attributes which give the frequency throttle information of the chip.
+
+What:		/sys/devices/system/cpu/cpuX/regs/
+		/sys/devices/system/cpu/cpuX/regs/identification/
+		/sys/devices/system/cpu/cpuX/regs/identification/midr_el1
+		/sys/devices/system/cpu/cpuX/regs/identification/revidr_el1
+Date:		June 2016
+Contact:	Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org>
+Description:	AArch64 CPU registers
+
+		'identification' directory exposes the CPU ID registers for
+		identifying model and revision of the CPU.
+
+What:		/sys/devices/system/cpu/cpu#/cpu_capacity
+Date:		December 2016
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	information about CPUs heterogeneity.
+
+		cpu_capacity: capacity of cpu#.
+
+What:		/sys/devices/system/cpu/vulnerabilities
+		/sys/devices/system/cpu/vulnerabilities/gather_data_sampling
+		/sys/devices/system/cpu/vulnerabilities/itlb_multihit
+		/sys/devices/system/cpu/vulnerabilities/l1tf
+		/sys/devices/system/cpu/vulnerabilities/mds
+		/sys/devices/system/cpu/vulnerabilities/meltdown
+		/sys/devices/system/cpu/vulnerabilities/mmio_stale_data
+		/sys/devices/system/cpu/vulnerabilities/retbleed
+		/sys/devices/system/cpu/vulnerabilities/spec_store_bypass
+		/sys/devices/system/cpu/vulnerabilities/spectre_v1
+		/sys/devices/system/cpu/vulnerabilities/spectre_v2
+		/sys/devices/system/cpu/vulnerabilities/srbds
+		/sys/devices/system/cpu/vulnerabilities/tsx_async_abort
+Date:		January 2018
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	Information about CPU vulnerabilities
+
+		The files are named after the code names of CPU
+		vulnerabilities. The output of those files reflects the
+		state of the CPUs in the system. Possible output values:
+
+		================  ==============================================
+		"Not affected"	  CPU is not affected by the vulnerability
+		"Vulnerable"	  CPU is affected and no mitigation in effect
+		"Mitigation: $M"  CPU is affected and mitigation $M is in effect
+		================  ==============================================
+
+		See also: Documentation/admin-guide/hw-vuln/index.rst
+
+What:		/sys/devices/system/cpu/smt
+		/sys/devices/system/cpu/smt/active
+		/sys/devices/system/cpu/smt/control
+Date:		June 2018
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	Control Symetric Multi Threading (SMT)
+
+		active:  Tells whether SMT is active (enabled and siblings online)
+
+		control: Read/write interface to control SMT. Possible
+			 values:
+
+			 ================ =========================================
+			 "on"		  SMT is enabled
+			 "off"		  SMT is disabled
+			 "forceoff"	  SMT is force disabled. Cannot be changed.
+			 "notsupported"   SMT is not supported by the CPU
+			 "notimplemented" SMT runtime toggling is not
+					  implemented for the architecture
+			 ================ =========================================
+
+			 If control status is "forceoff" or "notsupported" writes
+			 are rejected.
+
+What:		/sys/devices/system/cpu/cpu#/power/energy_perf_bias
+Date:		March 2019
+Contact:	linux-pm@vger.kernel.org
+Description:	Intel Energy and Performance Bias Hint (EPB)
+
+		EPB for the given CPU in a sliding scale 0 - 15, where a value
+		of 0 corresponds to a hint preference for highest performance
+		and a value of 15 corresponds to the maximum energy savings.
+
+		In order to change the EPB value for the CPU, write either
+		a number in the 0 - 15 sliding scale above, or one of the
+		strings: "performance", "balance-performance", "normal",
+		"balance-power", "power" (that represent values reflected by
+		their meaning), to this attribute.
+
+		This attribute is present for all online CPUs supporting the
+		Intel EPB feature.
+
+What:		/sys/devices/system/cpu/umwait_control
+		/sys/devices/system/cpu/umwait_control/enable_c02
+		/sys/devices/system/cpu/umwait_control/max_time
+Date:		May 2019
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+Description:	Umwait control
+
+		enable_c02: Read/write interface to control umwait C0.2 state
+			Read returns C0.2 state status:
+				0: C0.2 is disabled
+				1: C0.2 is enabled
+
+			Write 'y' or '1'  or 'on' to enable C0.2 state.
+			Write 'n' or '0'  or 'off' to disable C0.2 state.
+
+			The interface is case insensitive.
+
+		max_time: Read/write interface to control umwait maximum time
+			  in TSC-quanta that the CPU can reside in either C0.1
+			  or C0.2 state. The time is an unsigned 32-bit number.
+			  Note that a value of zero means there is no limit.
+			  Low order two bits must be zero.
+
+What:		/sys/devices/system/cpu/svm
+Date:		August 2019
+Contact:	Linux kernel mailing list <linux-kernel@vger.kernel.org>
+		Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:	Secure Virtual Machine
+
+		If 1, it means the system is using the Protected Execution
+		Facility in POWER9 and newer processors. i.e., it is a Secure
+		Virtual Machine.
+
+What:		/sys/devices/system/cpu/cpuX/purr
+Date:		Apr 2005
+Contact:	Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:	PURR ticks for this CPU since the system boot.
+
+		The Processor Utilization Resources Register (PURR) is
+		a 64-bit counter which provides an estimate of the
+		resources used by the CPU thread. The contents of this
+		register increases monotonically. This sysfs interface
+		exposes the number of PURR ticks for cpuX.
+
+What: 		/sys/devices/system/cpu/cpuX/spurr
+Date:		Dec 2006
+Contact:	Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:	SPURR ticks for this CPU since the system boot.
+
+		The Scaled Processor Utilization Resources Register
+		(SPURR) is a 64-bit counter that provides a frequency
+		invariant estimate of the resources used by the CPU
+		thread. The contents of this register increases
+		monotonically. This sysfs interface exposes the number
+		of SPURR ticks for cpuX.
+
+What: 		/sys/devices/system/cpu/cpuX/idle_purr
+Date:		Apr 2020
+Contact:	Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:	PURR ticks for cpuX when it was idle.
+
+		This sysfs interface exposes the number of PURR ticks
+		for cpuX when it was idle.
+
+What: 		/sys/devices/system/cpu/cpuX/idle_spurr
+Date:		Apr 2020
+Contact:	Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description:	SPURR ticks for cpuX when it was idle.
+
+		This sysfs interface exposes the number of SPURR ticks
+		for cpuX when it was idle.