cpufreq: Allow arch_freq_get_on_cpu to return an error

Allow arch_freq_get_on_cpu to return an error for cases when retrieving
current CPU frequency is not possible, whether that being due to lack o

cpufreq: Allow arch_freq_get_on_cpu to return an error

Allow arch_freq_get_on_cpu to return an error for cases when retrieving
current CPU frequency is not possible, whether that being due to lack of
required arch support or due to other circumstances when the current
frequency cannot be determined at given point of time.

Signed-off-by: Beata Michalska <[email protected]>
Reviewed-by: Prasanna Kumar T S M <[email protected]>
Acked-by: Viresh Kumar <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>

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x86/cpu: Use str_yes_no() helper in show_cpuinfo_misc()

Remove hard-coded strings by using the str_yes_no() helper function.

Signed-off-by: Thorsten Blum <[email protected]>
Signed-off-by: Bo

x86/cpu: Use str_yes_no() helper in show_cpuinfo_misc()

Remove hard-coded strings by using the str_yes_no() helper function.

Signed-off-by: Thorsten Blum <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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x86/cpu: Move cpu_core_id into topology info

Rename it to core_id and stick it to the other ID fields.

No functional change.

Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Juergen

x86/cpu: Move cpu_core_id into topology info

Rename it to core_id and stick it to the other ID fields.

No functional change.

Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Juergen Gross <[email protected]>
Tested-by: Sohil Mehta <[email protected]>
Tested-by: Michael Kelley <[email protected]>
Tested-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Zhang Rui <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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x86/cpu: Move phys_proc_id into topology info

Rename it to pkg_id which is the terminology used in the kernel.

No functional change.

Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by:

x86/cpu: Move phys_proc_id into topology info

Rename it to pkg_id which is the terminology used in the kernel.

No functional change.

Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Juergen Gross <[email protected]>
Tested-by: Sohil Mehta <[email protected]>
Tested-by: Michael Kelley <[email protected]>
Tested-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Zhang Rui <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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x86/cpu: Encapsulate topology information in cpuinfo_x86

The topology related information is randomly scattered across cpuinfo_x86.

Create a new structure cpuinfo_topo and move in a first step init

x86/cpu: Encapsulate topology information in cpuinfo_x86

The topology related information is randomly scattered across cpuinfo_x86.

Create a new structure cpuinfo_topo and move in a first step initial_apicid
and apicid into it.

Aside of being better readable this is in preparation for replacing the
horribly fragile CPU topology evaluation code further down the road.

Consolidate APIC ID fields to u32 as that represents the hardware type.

No functional change.

Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Juergen Gross <[email protected]>
Tested-by: Sohil Mehta <[email protected]>
Tested-by: Michael Kelley <[email protected]>
Tested-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Zhang Rui <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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x86: Expose thread features in /proc/$PID/status

Applications and loaders can have logic to decide whether to enable
shadow stack. They usually don't report whether shadow stack has been
enabled or

x86: Expose thread features in /proc/$PID/status

Applications and loaders can have logic to decide whether to enable
shadow stack. They usually don't report whether shadow stack has been
enabled or not, so there is no way to verify whether an application
actually is protected by shadow stack.

Add two lines in /proc/$PID/status to report enabled and locked features.

Since, this involves referring to arch specific defines in asm/prctl.h,
implement an arch breakout to emit the feature lines.

[Switched to CET, added to commit log]

Co-developed-by: Kirill A. Shutemov <[email protected]>
Signed-off-by: Kirill A. Shutemov <[email protected]>
Signed-off-by: Rick Edgecombe <[email protected]>
Signed-off-by: Dave Hansen <[email protected]>
Reviewed-by: Borislav Petkov (AMD) <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Acked-by: Mike Rapoport (IBM) <[email protected]>
Tested-by: Pengfei Xu <[email protected]>
Tested-by: John Allen <[email protected]>
Tested-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/all/20230613001108.3040476-37-rick.p.edgecombe%40intel.com

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x86/aperfmperf: Integrate the fallback code from show_cpuinfo()

Due to the avoidance of IPIs to idle CPUs arch_freq_get_on_cpu() can return
0 when the last sample was too long ago.

show_cpuinfo() h

x86/aperfmperf: Integrate the fallback code from show_cpuinfo()

Due to the avoidance of IPIs to idle CPUs arch_freq_get_on_cpu() can return
0 when the last sample was too long ago.

show_cpuinfo() has a fallback to cpufreq_quick_get() and if that fails to
return cpu_khz, but the readout code for the per CPU scaling frequency in
sysfs does not.

Move that fallback into arch_freq_get_on_cpu() so the behaviour is the same
when reading /proc/cpuinfo and /sys/..../cur_scaling_freq.

Suggested-by: "Rafael J. Wysocki" <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Doug Smythies <[email protected]>
Link: https://lore.kernel.org/r/87pml5180p.ffs@tglx

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x86/aperfmperf: Replace arch_freq_get_on_cpu()

Reading the current CPU frequency from /sys/..../scaling_cur_freq involves
in the worst case two IPIs due to the ad hoc sampling.

The frequency invari

x86/aperfmperf: Replace arch_freq_get_on_cpu()

Reading the current CPU frequency from /sys/..../scaling_cur_freq involves
in the worst case two IPIs due to the ad hoc sampling.

The frequency invariance infrastructure provides the APERF/MPERF samples
already. Utilize them and consolidate this with the /proc/cpuinfo readout.

The sample is considered valid for 20ms. So for idle or isolated NOHZ full
CPUs the function returns 0, which is matching the previous behaviour.

The resulting text size vs. the original APERF/MPERF plus the separate
frequency invariance code:

text: 2411 -> 723
init.text: 0 -> 767

Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Eric Dumazet <[email protected]>
Reviewed-by: Rafael J. Wysocki <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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x86/cpu: Print VMX flags in /proc/cpuinfo using VMX_FEATURES_*

Add support for generating VMX feature names in capflags.c and use the
resulting x86_vmx_flags to print the VMX flags in /proc/cpuinfo.

x86/cpu: Print VMX flags in /proc/cpuinfo using VMX_FEATURES_*

Add support for generating VMX feature names in capflags.c and use the
resulting x86_vmx_flags to print the VMX flags in /proc/cpuinfo. Don't
print VMX flags if no bits are set in word 0, which holds Pin Controls.
Pin Control's INTR and NMI exiting are fundamental pillars of VMX, if
they are not supported then the CPU is broken, it does not actually
support VMX, or the kernel wasn't built with support for the target CPU.

Print the features in a dedicated "vmx flags" line to avoid polluting
the common "flags" and to avoid having to prefix all flags with "vmx_",
which results in horrendously long names.

Keep synthetic VMX flags in cpufeatures to preserve /proc/cpuinfo's ABI
for those flags. This means that "flags" and "vmx flags" will have
duplicate entries for tpr_shadow (virtual_tpr), vnmi, ept, flexpriority,
vpid and ept_ad, but caps the pollution of "flags" at those six VMX
features. The vendor-specific code that populates the synthetic flags
will be consolidated in a future patch to further minimize the lasting
damage.

Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]

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x86: Convert some slow-path static_cpu_has() callers to boot_cpu_has()

Using static_cpu_has() is pointless on those paths, convert them to the
boot_cpu_has() variant.

No functional changes.

Report

x86: Convert some slow-path static_cpu_has() callers to boot_cpu_has()

Using static_cpu_has() is pointless on those paths, convert them to the
boot_cpu_has() variant.

No functional changes.

Reported-by: Nadav Amit <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Rik van Riel <[email protected]>
Reviewed-by: Juergen Gross <[email protected]> # for paravirt
Cc: Aubrey Li <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Dominik Brodowski <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jann Horn <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Cc: Thomas Lendacky <[email protected]>
Cc: [email protected]
Cc: Masami Hiramatsu <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]

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x86/cpu: Change type of x86_cache_size variable to unsigned int

Currently, x86_cache_size is of type int, which makes no sense as we
will never have a valid cache size equal or less than 0. So inste

x86/cpu: Change type of x86_cache_size variable to unsigned int

Currently, x86_cache_size is of type int, which makes no sense as we
will never have a valid cache size equal or less than 0. So instead of
initializing this variable to -1, it can perfectly be initialized to 0
and use it as an unsigned variable instead.

Suggested-by: Thomas Gleixner <[email protected]>
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Addresses-Coverity-ID: 1464429
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping

x86_mask is a confusing name which is hard to associate with the
processor's stepping.

Additionally, correct an indent issue in lib/cpu.c.

x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping

x86_mask is a confusing name which is hard to associate with the
processor's stepping.

Additionally, correct an indent issue in lib/cpu.c.

Signed-off-by: Jia Zhang <[email protected]>
[ Updated it to more recent kernels. ]
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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x86 / CPU: Always show current CPU frequency in /proc/cpuinfo

After commit 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get()
for /proc/cpuinfo "cpu MHz"") the "cpu MHz" number in /proc/cpuin

x86 / CPU: Always show current CPU frequency in /proc/cpuinfo

After commit 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get()
for /proc/cpuinfo "cpu MHz"") the "cpu MHz" number in /proc/cpuinfo
on x86 can be either the nominal CPU frequency (which is constant)
or the frequency most recently requested by a scaling governor in
cpufreq, depending on the cpufreq configuration. That is somewhat
inconsistent and is different from what it was before 4.13, so in
order to restore the previous behavior, make it report the current
CPU frequency like the scaling_cur_freq sysfs file in cpufreq.

To that end, modify the /proc/cpuinfo implementation on x86 to use
aperfmperf_snapshot_khz() to snapshot the APERF and MPERF feedback
registers, if available, and use their values to compute the CPU
frequency to be reported as "cpu MHz".

However, do that carefully enough to avoid accumulating delays that
lead to unacceptable access times for /proc/cpuinfo on systems with
many CPUs. Run aperfmperf_snapshot_khz() once on all CPUs
asynchronously at the /proc/cpuinfo open time, add a single delay
upfront (if necessary) at that point and simply compute the current
frequency while running show_cpuinfo() for each individual CPU.

Also, to avoid slowing down /proc/cpuinfo accesses too much, reduce
the default delay between consecutive APERF and MPERF reads to 10 ms,
which should be sufficient to get large enough numbers for the
frequency computation in all cases.

Fixes: 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"")
Signed-off-by: Rafael J. Wysocki <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Tested-by: Thomas Gleixner <[email protected]>
Acked-by: Ingo Molnar <[email protected]>

show more ...

Revert "x86: CPU: Fix up "cpu MHz" in /proc/cpuinfo"

This reverts commit 941f5f0f6ef5338814145cf2b813cf1f98873e2f.

Sadly, it turns out that we really can't just do the cross-CPU IPI to
all CPU's to

Revert "x86: CPU: Fix up "cpu MHz" in /proc/cpuinfo"

This reverts commit 941f5f0f6ef5338814145cf2b813cf1f98873e2f.

Sadly, it turns out that we really can't just do the cross-CPU IPI to
all CPU's to get their proper frequencies, because it's much too
expensive on systems with lots of cores.

So we'll have to revert this for now, and revisit it using a smarter
model (probably doing one system-wide IPI at open time, and doing all
the frequency calculations in parallel).

Reported-by: WANG Chao <[email protected]>
Reported-by: Ingo Molnar <[email protected]>
Cc: Rafael J Wysocki <[email protected]>
Cc: [email protected]
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

x86: CPU: Fix up "cpu MHz" in /proc/cpuinfo

Commit 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get() for
/proc/cpuinfo "cpu MHz"") is not sufficient to restore the previous
behavior of "cpu

x86: CPU: Fix up "cpu MHz" in /proc/cpuinfo

Commit 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get() for
/proc/cpuinfo "cpu MHz"") is not sufficient to restore the previous
behavior of "cpu MHz" in /proc/cpuinfo on x86 due to some changes
made after the commit it has reverted.

To address this, make the code in question use arch_freq_get_on_cpu()
which also is used by cpufreq for reporting the current frequency of
CPUs and since that function doesn't really depend on cpufreq in any
way, drop the CONFIG_CPU_FREQ dependency for the object file
containing it.

Also refactor arch_freq_get_on_cpu() somewhat to avoid IPIs and
return cached values right away if it is called very often over a
short time (to prevent user space from triggering IPI storms through
it).

Fixes: 890da9cf0983 (Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"")
Cc: [email protected] # 4.13 - together with 890da9cf0983
Signed-off-by: Rafael J. Wysocki <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz""

This reverts commit 51204e0639c49ada02fd823782ad673b6326d748.

There wasn't really any good reason for it, and people are com

Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz""

This reverts commit 51204e0639c49ada02fd823782ad673b6326d748.

There wasn't really any good reason for it, and people are complaining
(rightly) that it broke existing practice.

Cc: Len Brown <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <[email protected]>
Reviewed-by: Philippe Ombredanne <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"

cpufreq_quick_get() allows cpufreq drivers to over-ride cpu_khz
that is otherwise reported in x86 /proc/cpuinfo "cpu MHz".

There are

x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz"

cpufreq_quick_get() allows cpufreq drivers to over-ride cpu_khz
that is otherwise reported in x86 /proc/cpuinfo "cpu MHz".

There are four problems with this scheme,
any of them is sufficient justification to delete it.

1. Depending on which cpufreq driver is loaded, the behavior
of this field is different.

2. Distros complain that they have to explain to users
why and how this field changes. Distros have requested a constant.

3. The two major providers of this information, acpi_cpufreq
and intel_pstate, both "get it wrong" in different ways.

acpi_cpufreq lies to the user by telling them that
they are running at whatever frequency was last
requested by software.

intel_pstate lies to the user by telling them that
they are running at the average frequency computed
over an undefined measurement. But an average computed
over an undefined interval, is itself, undefined...

4. On modern processors, user space utilities, such as
turbostat(1), are more accurate and more precise, while
supporing concurrent measurement over arbitrary intervals.

Users who have been consulting /proc/cpuinfo to
track changing CPU frequency will be dissapointed that
it no longer wiggles -- perhaps being unaware of the
limitations of the information they have been consuming.

Yes, they can change their scripts to look in sysfs
cpufreq/scaling_cur_frequency. Here they will find the same
data of dubious quality here removed from /proc/cpuinfo.
The value in sysfs will be addressed in a subsequent patch
to address issues 1-3, above.

Issue 4 will remain -- users that really care about
accurate frequency information should not be using either
proc or sysfs kernel interfaces.
They should be using using turbostat(8), or a similar
purpose-built analysis tool.

Signed-off-by: Len Brown <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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x86/cpu: Drop wp_works_ok member of struct cpuinfo_x86

Remove the wp_works_ok member of struct cpuinfo_x86. It's an
optimization back from Linux v0.99 times where we had no fixup support
yet and did

x86/cpu: Drop wp_works_ok member of struct cpuinfo_x86

Remove the wp_works_ok member of struct cpuinfo_x86. It's an
optimization back from Linux v0.99 times where we had no fixup support
yet and did the CR0.WP test via special code in the page fault handler.
The < 0 test was an optimization to not do the special casing for each
NULL ptr access violation but just for the first one doing the WP test.
Today it serves no real purpose as the test no longer needs special code
in the page fault handler and the only call side -- mem_init() -- calls
it just once, anyway. However, Xen pre-initializes it to 1, to skip the
test.

Doing the test again for Xen should be no issue at all, as even the
commit introducing skipping the test (commit d560bc61575e ("x86, xen:
Suppress WP test on Xen")) mentioned it being ban aid only. And, in
fact, testing the patch on Xen showed nothing breaks.

The pre-fixup times are long gone and with the removal of the fallback
handling code in commit a5c2a893dbd4 ("x86, 386 removal: Remove
CONFIG_X86_WP_WORKS_OK") the kernel requires a working CR0.WP anyway.
So just get rid of the "optimization" and do the test unconditionally.

Signed-off-by: Mathias Krause <[email protected]>
Acked-by: Borislav Petkov <[email protected]>
Cc: Jesper Nilsson <[email protected]>
Cc: Jeremy Fitzhardinge <[email protected]>
Cc: Arnd Hannemann <[email protected]>
Cc: Mikael Starvik <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: "David S. Miller" <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Thomas Gleixner <[email protected]>

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x86: Replace cpu_**_mask() with topology_**_cpumask()

The former duplicate the functionalities of the latter but are
neither documented nor arch-independent.

Signed-off-by: Bartosz Golaszewski <bgo

x86: Replace cpu_**_mask() with topology_**_cpumask()

The former duplicate the functionalities of the latter but are
neither documented nor arch-independent.

Signed-off-by: Bartosz Golaszewski <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Cc: Benoit Cousson <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Jean Delvare <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Oleg Drokin <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Russell King <[email protected]>
Cc: Viresh Kumar <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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x86: Replace seq_printf() with seq_puts()

seq_puts is a lot cheaper than seq_printf, so use that to print
literal strings.

Signed-off-by: Rasmus Villemoes <[email protected]>
Link: http://lk

x86: Replace seq_printf() with seq_puts()

seq_puts is a lot cheaper than seq_printf, so use that to print
literal strings.

Signed-off-by: Rasmus Villemoes <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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x86/cpufeature: Add bug flags to /proc/cpuinfo

Dump the flags which denote we have detected and/or have applied bug
workarounds to the CPU we're executing on, in a similar manner to the
feature flag

x86/cpufeature: Add bug flags to /proc/cpuinfo

Dump the flags which denote we have detected and/or have applied bug
workarounds to the CPU we're executing on, in a similar manner to the
feature flags.

The advantage is that those are not accumulating over time like the CPU
features.

Signed-off-by: Borislav Petkov <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: H. Peter Anvin <[email protected]>

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x86/cpu: Always print SMP information in /proc/cpuinfo

Currently show_cpuinfo_core() displays cpu core information only if
the number of threads per a whole cores is 2 or larger.

However, this cond

x86/cpu: Always print SMP information in /proc/cpuinfo

Currently show_cpuinfo_core() displays cpu core information only if
the number of threads per a whole cores is 2 or larger.

However, this condition doesn't care about the number of
sockets. For example, this condition doesn't hold on systems
with two logical cpus consisting of two sockets and a single
core on each socket - yet the topology information would be
interesting to see in that case as well.

I don't know whether or not there are processors in real world
by which such configurations are possible, but at least on
vitual machine environments, such configuration can occur,
typically when no explicit SMP information is provided in
advance.

For example, on qemu/KVM, SMP information is specified via -smp
command-line option, more specifically, its syntax is:

-smp n[,cores=cores][,threads=threads][,sockets=sockets][,maxcpus=maxcpus]

If this is not specified, qemu tells configuration with
n-sockets, 1-core and 1-thread to the guest machine, on which
guest, MP information is not displayed in /proc/cpuinfo.

I saw this situation on VMWare guest environment, too.

To fix this issue, this patch simply removes the condition
because this information is useful even if there's only 1
thread.

Signed-off-by: HATAYAMA Daisuke <[email protected]>
Cc: Vivek Goyal <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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x86: Get rid of ->hard_math and all the FPU asm fu

Reimplement FPU detection code in C and drop old, not-so-recommended
detection method in asm. Move all the relevant stuff into i387.c where
it conc

x86: Get rid of ->hard_math and all the FPU asm fu

Reimplement FPU detection code in C and drop old, not-so-recommended
detection method in asm. Move all the relevant stuff into i387.c where
it conceptually belongs. Finally drop cpuinfo_x86.hard_math.

[ hpa: huge thanks to Borislav for taking my original concept patch
and productizing it ]

[ Boris, note to self: do not use static_cpu_has before alternatives! ]

Signed-off-by: H. Peter Anvin <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Borislav Petkov <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>

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x86, cpu: Convert Cyrix coma bug detection

... to the new facility.

Signed-off-by: Borislav Petkov <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-

x86, cpu: Convert Cyrix coma bug detection

... to the new facility.

Signed-off-by: Borislav Petkov <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: H. Peter Anvin <[email protected]>

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