It was added in commit 766121ba ("arm64/mte: Add userspace interface
for enabling asymmetric mode").
Signed-off-by: NEvgenii Stepanov <eugenis@google.com>
Reviewed-by: NMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220309215943.87831-1-eugenis@google.comSigned-off-by: NWill Deacon <will@kernel.org>

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: NTony Luck <tony.luck@intel.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20220131230111.2004669-6-tony.luck@intel.com

Add missing documentation of sysfs ABI for "isolated". It was added by
commit 59f30abe("show isolated cpus in sysfs"). However, there is
no documentation for these interface.
Signed-off-by: NKohei Tarumizu <tarumizu.kohei@fujitsu.com>
Link: https://lore.kernel.org/r/20211201115957.254224-3-tarumizu.kohei@fujitsu.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add missing documentation of sysfs ABI for "nohz_full". It was added
by commit 6570a9a1("show nohz_full cpus in sysfs"). However,
there is no documentation for these interface.
Signed-off-by: NKohei Tarumizu <tarumizu.kohei@fujitsu.com>
Link: https://lore.kernel.org/r/20211201115957.254224-2-tarumizu.kohei@fujitsu.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some What entries here use cpu# as a wildcard, while others
use, instead, cpuX.

As scripts/get_abi.pl doesn't consider "#" as a wildcard,
replace:

	cpu# -> cpuX

inside the file.
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/60b1a79189d1a9d9f1c9c9c299770e69b18972fd.1632994837.git.mchehab+huawei@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

An "N" upper letter is not a wildcard, nor can easily be identified
by script, specially since the USB sysfs define things like.
bNumInterfaces. Use, instead, <N>, in order to let script/get_abi.pl
to convert it into a Regex.
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/d18385a391b6797373a5d1382ea024857fb29987.1631782432.git.mchehab+huawei@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since 32-bit applications will be killed if they are caught trying to
execute on a 64-bit-only CPU in a mismatched system, advertise the set
of 32-bit capable CPUs to userspace in sysfs.
Signed-off-by: NWill Deacon <will@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-14-will@kernel.org

Document the functionality added in the previous patches.

Link: https://linux-review.googlesource.com/id/I48217cc3e8b8da33abc08cbaddc11cf4360a1b86Signed-off-by: NPeter Collingbourne <pcc@google.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NWill Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210727205300.2554659-6-pcc@google.comAcked-by: NWill Deacon <will@kernel.org>
[catalin.marinas@arm.com: clarify that the change happens on task scheduling]
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Fix the following typos in the Documentation/ABI/ directory:

- In file obsolete/sysfs-cpuidle, change "obselete" for "obsolete".

- In file removed/sysfs-kernel-uids, change "propotional" for "proportional".

- In directory stable/, fix the following words: "associtated" for "associated",
  "hexidecimal" for "hexadecimal", "vlue" for "value", "csed" for "caused" and
  "wrtie" for "write". This updates a total of five files.

- In directory testing/, fix the following words: "subystem" for "subsystem",
  "isochrnous" for "isochronous", "Desctiptors" for "Descriptors", "picutre" for
  "picture", "capture" for "capture", "occured" for "ocurred", "connnected" for
  "connected","agressively" for "aggressively","manufacturee" for "manufacturer"
  and "transaction" for "transaction", "malformatted" for "incorrectly formated"
  ,"internel" for "internal", "writtento" for "written to", "specificed" for
  "specified", "beyound" for "beyond", "Symetric" for "Symmetric". This updates
  a total of eleven files.
Signed-off-by: NCarlos Bilbao <bilbao@vt.edu>
Reviewed-by: NRandy Dunlap <rdunlap@infradead.org>
Reviewed-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/5710038.lOV4Wx5bFT@iron-maidenSigned-off-by: NJonathan Corbet <corbet@lwn.net>

correct URL to bios and kernel developer's guide on amd.com site
Signed-off-by: NAnatoly Pugachev <matorola@gmail.com>
Link: https://lore.kernel.org/r/20210428104851.GA10572@u164.east.ru
[jc: fixed resulting sphinx warning]
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Use the existing sysfs attribute "freqdomain_cpus" to expose
information to userspace about CPUs in the same frequency domain.
Signed-off-by: NIonela Voinescu <ionela.voinescu@arm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Tested-by: NMian Yousaf Kaukab <ykaukab@suse.de>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are some ABI documents that, while they don't generate
any warnings, they have issues when parsed by get_abi.pl script
on its output result.

Address them, in order to provide a clean output.

Reviewed-by: Tom Rix <trix@redhat.com> # for fpga-manager
Reviewed-By: Kajol Jain<kjain@linux.ibm.com> # for sysfs-bus-event_source-devices-hv_gpci and sysfs-bus-event_source-devices-hv_24x7
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for IIO
Acked-by: Oded Gabbay <oded.gabbay@gmail.com> # for Habanalabs
Acked-by: Vaibhav Jain <vaibhav@linux.ibm.com> # for sysfs-bus-papr-pmem
Acked-by: Cezary Rojewski <cezary.rojewski@intel.com> # for catpt
Acked-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Ilya Dryomov <idryomov@gmail.com> # for rbd
Acked-by: NJonathan Corbet <corbet@lwn.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/5bc78e5b68ed1e9e39135173857cb2e753be868f.1604042072.git.mchehab+huawei@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some files over there won't parse well by Sphinx.

Fix them.

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # for IIO
Acked-by: NFabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: NJonathan Corbet <corbet@lwn.net>
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/58cf3c2d611e0197fb215652719ebd82ca2658db.1604042072.git.mchehab+huawei@kernel.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Update the document after the remove of cpuidle_sysfs_switch.
Signed-off-by: NHanjun Guo <guohanjun@huawei.com>
Reviewed-by: NDoug Smythies <dsmythies@telus.net>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Add documentation for the following sysfs interfaces:
/sys/devices/system/cpu/cpuX/purr
/sys/devices/system/cpu/cpuX/spurr
/sys/devices/system/cpu/cpuX/idle_purr
/sys/devices/system/cpu/cpuX/idle_spurr
Signed-off-by: NGautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1586249263-14048-6-git-send-email-ego@linux.vnet.ibm.com

SRBDS is an MDS-like speculative side channel that can leak bits from the
random number generator (RNG) across cores and threads. New microcode
serializes the processor access during the execution of RDRAND and
RDSEED. This ensures that the shared buffer is overwritten before it is
released for reuse.

While it is present on all affected CPU models, the microcode mitigation
is not needed on models that enumerate ARCH_CAPABILITIES[MDS_NO] in the
cases where TSX is not supported or has been disabled with TSX_CTRL.

The mitigation is activated by default on affected processors and it
increases latency for RDRAND and RDSEED instructions. Among other
effects this will reduce throughput from /dev/urandom.

* Enable administrator to configure the mitigation off when desired using
  either mitigations=off or srbds=off.

* Export vulnerability status via sysfs

* Rename file-scoped macros to apply for non-whitelist table initializations.

 [ bp: Massage,
   - s/VULNBL_INTEL_STEPPING/VULNBL_INTEL_STEPPINGS/g,
   - do not read arch cap MSR a second time in tsx_fused_off() - just pass it in,
   - flip check in cpu_set_bug_bits() to save an indentation level,
   - reflow comments.
   jpoimboe: s/Mitigated/Mitigation/ in user-visible strings
   tglx: Dropped the fused off magic for now
 ]
Signed-off-by: NMark Gross <mgross@linux.intel.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NTony Luck <tony.luck@intel.com>
Reviewed-by: NPawan Gupta <pawan.kumar.gupta@linux.intel.com>
Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Tested-by: NNeelima Krishnan <neelima.krishnan@intel.com>

In certain situations it may be useful to prevent some idle states
from being used by default while allowing user space to enable them
later on.

For this purpose, introduce a new state flag, CPUIDLE_FLAG_OFF, to
mark idle states that should be disabled by default, make the core
set CPUIDLE_STATE_DISABLED_BY_USER for those states at the
initialization time and add a new state attribute in sysfs,
"default_status", to inform user space of the initial status of
the given idle state ("disabled" if CPUIDLE_FLAG_OFF is set for it,
"enabled" otherwise).
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Some processors may incur a machine check error possibly resulting in an
unrecoverable CPU lockup when an instruction fetch encounters a TLB
multi-hit in the instruction TLB. This can occur when the page size is
changed along with either the physical address or cache type. The relevant
erratum can be found here:

   https://bugzilla.kernel.org/show_bug.cgi?id=205195

There are other processors affected for which the erratum does not fully
disclose the impact.

This issue affects both bare-metal x86 page tables and EPT.

It can be mitigated by either eliminating the use of large pages or by
using careful TLB invalidations when changing the page size in the page
tables.

Just like Spectre, Meltdown, L1TF and MDS, a new bit has been allocated in
MSR_IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) and will be set on CPUs which
are mitigated against this issue.
Signed-off-by: NVineela Tummalapalli <vineela.tummalapalli@intel.com>
Co-developed-by: NPawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: NPawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Add the documenation for TSX Async Abort. Include the description of
the issue, how to check the mitigation state, control the mitigation,
guidance for system administrators.

 [ bp: Add proper SPDX tags, touch ups by Josh and me. ]
Co-developed-by: NAntonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
Signed-off-by: NPawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: NAntonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NMark Gross <mgross@linux.intel.com>
Reviewed-by: NTony Luck <tony.luck@intel.com>
Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com>

User space might want to know it's running in a secure VM.  It can't do
a mfmsr because mfmsr is a privileged instruction.

The solution here is to create a cpu attribute:

/sys/devices/system/cpu/svm

which will read 0 or 1 based on the S bit of the current CPU.
Signed-off-by: NRyan Grimm <grimm@linux.vnet.ibm.com>
Signed-off-by: NThiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820021326.6884-12-bauerman@linux.ibm.com

There are lots of documents that belong to the admin-guide but
are on random places (most under Documentation root dir).

Move them to the admin guide.
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

Since two new sysfs interface files are created for umwait control, add
an ABI document entry for the files:

   /sys/devices/system/cpu/umwait_control/enable_c02
   /sys/devices/system/cpu/umwait_control/max_time

[ tglx: Made the write value instructions readable ]
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NAshok Raj <ashok.raj@intel.com>
Cc: "Borislav Petkov" <bp@alien8.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Andy Lutomirski" <luto@kernel.org>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Link: https://lkml.kernel.org/r/1560994438-235698-6-git-send-email-fenghua.yu@intel.com

The cpuidle doc was split on two, one at the admin guide
and another one at the driver API guide. Instead of pointing
to a non-existent file, point to both (admin guide being
the first one).
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

The Performance and Energy Bias Hint (EPB) is expected to be set by
user space through the generic MSR interface, but that interface is
not particularly nice and there are security concerns regarding it,
so it is not always available.

For this reason, add a sysfs interface for reading and updating the
EPB, in the form of a new attribute, energy_perf_bias, located
under /sys/devices/system/cpu/cpu#/power/ for online CPUs that
support the EPB feature.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NBorislav Petkov <bp@suse.de>

Make the /sys/devices/system/cpu/smt/* files available on all arches, so
user space has a consistent way to detect whether SMT is enabled.

The 'control' file now shows 'notimplemented' for architectures which
don't yet have CONFIG_HOTPLUG_SMT.

[ tglx: Make notimplemented a real state ]
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Link: https://lkml.kernel.org/r/469c2b98055f2c41e75748e06447d592a64080c9.1553635520.git.jpoimboe@redhat.com

Add the initial MDS vulnerability documentation.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NJon Masters <jcm@redhat.com>

Move L!TF to a separate directory so the MDS stuff can be added at the
side. Otherwise the all hardware vulnerabilites have their own top level
entry. Should have done that right away.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NJon Masters <jcm@redhat.com>

Add the sysfs reporting file for MDS. It exposes the vulnerability and
mitigation state similar to the existing files for the other speculative
hardware vulnerabilities.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NJon Masters <jcm@redhat.com>
Tested-by: NJon Masters <jcm@redhat.com>

Add two new metrics for CPU idle states, "above" and "below", to count
the number of times the given state had been asked for (or entered
from the kernel's perspective), but the observed idle duration turned
out to be too short or too long for it (respectively).

These metrics help to estimate the quality of the CPU idle governor
in use.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Introduce the 'l1tf=' kernel command line option to allow for boot-time
switching of mitigation that is used on processors affected by L1TF.

The possible values are:

  full
	Provides all available mitigations for the L1TF vulnerability. Disables
	SMT and enables all mitigations in the hypervisors. SMT control via
	/sys/devices/system/cpu/smt/control is still possible after boot.
	Hypervisors will issue a warning when the first VM is started in
	a potentially insecure configuration, i.e. SMT enabled or L1D flush
	disabled.

  full,force
	Same as 'full', but disables SMT control. Implies the 'nosmt=force'
	command line option. sysfs control of SMT and the hypervisor flush
	control is disabled.

  flush
	Leaves SMT enabled and enables the conditional hypervisor mitigation.
	Hypervisors will issue a warning when the first VM is started in a
	potentially insecure configuration, i.e. SMT enabled or L1D flush
	disabled.

  flush,nosmt
	Disables SMT and enables the conditional hypervisor mitigation. SMT
	control via /sys/devices/system/cpu/smt/control is still possible
	after boot. If SMT is reenabled or flushing disabled at runtime
	hypervisors will issue a warning.

  flush,nowarn
	Same as 'flush', but hypervisors will not warn when
	a VM is started in a potentially insecure configuration.

  off
	Disables hypervisor mitigations and doesn't emit any warnings.

Default is 'flush'.

Let KVM adhere to these semantics, which means:

  - 'lt1f=full,force'	: Performe L1D flushes. No runtime control
    			  possible.

  - 'l1tf=full'
  - 'l1tf-flush'
  - 'l1tf=flush,nosmt'	: Perform L1D flushes and warn on VM start if
			  SMT has been runtime enabled or L1D flushing
			  has been run-time enabled
			  
  - 'l1tf=flush,nowarn'	: Perform L1D flushes and no warnings are emitted.
  
  - 'l1tf=off'		: L1D flushes are not performed and no warnings
			  are emitted.

KVM can always override the L1D flushing behavior using its 'vmentry_l1d_flush'
module parameter except when lt1f=full,force is set.

This makes KVM's private 'nosmt' option redundant, and as it is a bit
non-systematic anyway (this is something to control globally, not on
hypervisor level), remove that option.

Add the missing Documentation entry for the l1tf vulnerability sysfs file
while at it.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NJiri Kosina <jkosina@suse.cz>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142323.202758176@linutronix.de

Provide a command line and a sysfs knob to control SMT.

The command line options are:

 'nosmt':	Enumerate secondary threads, but do not online them
 		
 'nosmt=force': Ignore secondary threads completely during enumeration
 		via MP table and ACPI/MADT.

The sysfs control file has the following states (read/write):

 'on':		 SMT is enabled. Secondary threads can be freely onlined
 'off':		 SMT is disabled. Secondary threads, even if enumerated
 		 cannot be onlined
 'forceoff':	 SMT is permanentely disabled. Writes to the control
 		 file are rejected.
 'notsupported': SMT is not supported by the CPU

The command line option 'nosmt' sets the sysfs control to 'off'. This
can be changed to 'on' to reenable SMT during runtime.

The command line option 'nosmt=force' sets the sysfs control to
'forceoff'. This cannot be changed during runtime.

When SMT is 'on' and the control file is changed to 'off' then all online
secondary threads are offlined and attempts to online a secondary thread
later on are rejected.

When SMT is 'off' and the control file is changed to 'on' then secondary
threads can be onlined again. The 'off' -> 'on' transition does not
automatically online the secondary threads.

When the control file is set to 'forceoff', the behaviour is the same as
setting it to 'off', but the operation is irreversible and later writes to
the control file are rejected.

When the control status is 'notsupported' then writes to the control file
are rejected.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NIngo Molnar <mingo@kernel.org>

This file doesn't exist anymore:
	Documentation/cpu-freq/user-guide.txt

As the ABI already points to Documentation/cpu-freq, just
remove the broken link and the associated text.
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: NJonathan Corbet <corbet@lwn.net>

Add the sysfs file for the new vulerability. It does not do much except
show the words 'Vulnerable' for recent x86 cores.

Intel cores prior to family 6 are known not to be vulnerable, and so are
some Atoms and some Xeon Phi.

It assumes that older Cyrix, Centaur, etc. cores are immune.
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NIngo Molnar <mingo@kernel.org>

Add a new attribute group called "s2idle" under the sysfs directory
of each cpuidle state that supports the ->enter_s2idle callback
and put two new attributes, "usage" and "time", into that group to
represent the number of times the given state was requested for
suspend-to-idle and the total time spent in suspend-to-idle after
requesting that state, respectively.

That will allow diagnostic information related to suspend-to-idle
to be collected without enabling advanced debug features and
analyzing dmesg output.
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Update cpuidle documentation using git logs and existing documentation
in Documentation/cpuidle/sysfs.txt. This might be useful for scripting
and tracking changes in the ABI.
Signed-off-by: NAishwarya Pant <aishpant@gmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Fixes: 87590ce6 ("sysfs/cpu: Add vulnerability folder")
Signed-off-by: NDavid Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

As the meltdown/spectre problem affects several CPU architectures, it makes
sense to have common way to express whether a system is affected by a
particular vulnerability or not. If affected the way to express the
mitigation should be common as well.

Create /sys/devices/system/cpu/vulnerabilities folder and files for
meltdown, spectre_v1 and spectre_v2.

Allow architectures to override the show function.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180107214913.096657732@linutronix.de

Make admin-guide document refs valid.
Signed-off-by: NTom Saeger <tom.saeger@oracle.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

/sys/devices/system/cpu/cpu#/cpu_capacity describe information about
CPUs heterogeneity (ref. to Documentation/devicetree/bindings/arm/
cpu-capacity.txt).

Add such description.
Signed-off-by: NJuri Lelli <juri.lelli@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add an ABI document entry for /sys/devices/system/cpu/cpu*/cache/index*/id.
Signed-off-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477142405-32078-2-git-send-email-fenghua.yu@intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>