1. 15 8月, 2019 1 次提交
    • F
      x86/cpufeatures: Combine word 11 and 12 into a new scattered features word · 74f65670
      Fenghua Yu 提交于
      commit acec0ce081de0c36459eea91647faf99296445a3 upstream.
      
      It's a waste for the four X86_FEATURE_CQM_* feature bits to occupy two
      whole feature bits words. To better utilize feature words, re-define
      word 11 to host scattered features and move the four X86_FEATURE_CQM_*
      features into Linux defined word 11. More scattered features can be
      added in word 11 in the future.
      
      Rename leaf 11 in cpuid_leafs to CPUID_LNX_4 to reflect it's a
      Linux-defined leaf.
      
      Rename leaf 12 as CPUID_DUMMY which will be replaced by a meaningful
      name in the next patch when CPUID.7.1:EAX occupies world 12.
      
      Maximum number of RMID and cache occupancy scale are retrieved from
      CPUID.0xf.1 after scattered CQM features are enumerated. Carve out the
      code into a separate function.
      
      KVM doesn't support resctrl now. So it's safe to move the
      X86_FEATURE_CQM_* features to scattered features word 11 for KVM.
      Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Aaron Lewis <aaronlewis@google.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Babu Moger <babu.moger@amd.com>
      Cc: "Chang S. Bae" <chang.seok.bae@intel.com>
      Cc: "Sean J Christopherson" <sean.j.christopherson@intel.com>
      Cc: Frederic Weisbecker <frederic@kernel.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jann Horn <jannh@google.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: kvm ML <kvm@vger.kernel.org>
      Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Masami Hiramatsu <mhiramat@kernel.org>
      Cc: Nadav Amit <namit@vmware.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
      Cc: Peter Feiner <pfeiner@google.com>
      Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
      Cc: "Radim Krčmář" <rkrcmar@redhat.com>
      Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
      Cc: Ravi V Shankar <ravi.v.shankar@intel.com>
      Cc: Sherry Hurwitz <sherry.hurwitz@amd.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Thomas Lendacky <Thomas.Lendacky@amd.com>
      Cc: x86 <x86@kernel.org>
      Link: https://lkml.kernel.org/r/1560794416-217638-2-git-send-email-fenghua.yu@intel.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: NShile Zhang <shile.zhang@linux.alibaba.com>
      Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      74f65670
  2. 04 6月, 2019 1 次提交
  3. 14 5月, 2018 1 次提交
  4. 20 3月, 2018 1 次提交
  5. 06 2月, 2018 2 次提交
  6. 26 1月, 2018 1 次提交
  7. 17 12月, 2017 1 次提交
    • T
      x86/cpufeatures: Make CPU bugs sticky · 6cbd2171
      Thomas Gleixner 提交于
      There is currently no way to force CPU bug bits like CPU feature bits. That
      makes it impossible to set a bug bit once at boot and have it stick for all
      upcoming CPUs.
      
      Extend the force set/clear arrays to handle bug bits as well.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NBorislav Petkov <bp@suse.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Borislav Petkov <bpetkov@suse.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Link: https://lkml.kernel.org/r/20171204150606.992156574@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      6cbd2171
  8. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman 提交于
      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: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  9. 17 10月, 2017 1 次提交
    • A
      x86/cpuid: Add generic table for CPUID dependencies · 0b00de85
      Andi Kleen 提交于
      Some CPUID features depend on other features. Currently it's
      possible to to clear dependent features, but not clear the base features,
      which can cause various interesting problems.
      
      This patch implements a generic table to describe dependencies
      between CPUID features, to be used by all code that clears
      CPUID.
      
      Some subsystems (like XSAVE) had an own implementation of this,
      but it's better to do it all in a single place for everyone.
      
      Then clear_cpu_cap and setup_clear_cpu_cap always look up
      this table and clear all dependencies too.
      
      This is intended to be a practical table: only for features
      that make sense to clear. If someone for example clears FPU,
      or other features that are essentially part of the required
      base feature set, not much is going to work. Handling
      that is right now out of scope. We're only handling
      features which can be usefully cleared.
      Signed-off-by: NAndi Kleen <ak@linux.intel.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Jonathan McDowell <noodles@earth.li>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/20171013215645.23166-3-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      0b00de85
  10. 10 12月, 2016 1 次提交
  11. 30 6月, 2016 3 次提交
    • D
      x86/cpufeature: Add helper macro for mask check macros · 8eda072e
      Dave Hansen 提交于
      Every time we add a word to our cpu features, we need to add
      something like this in two places:
      
      	(((bit)>>5)==16 && (1UL<<((bit)&31) & REQUIRED_MASK16))
      
      The trick is getting the "16" in this case in both places.  I've
      now screwed this up twice, so as pennance, I've come up with
      this patch to keep me and other poor souls from doing the same.
      
      I also commented the logic behind the bit manipulation showcased
      above.
      Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20160629200110.1BA8949E@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      8eda072e
    • D
      x86/cpufeature: Make sure DISABLED/REQUIRED macros are updated · 1e61f78b
      Dave Hansen 提交于
      x86 has two macros which allow us to evaluate some CPUID-based
      features at compile time:
      
      	REQUIRED_MASK_BIT_SET()
      	DISABLED_MASK_BIT_SET()
      
      They're both defined by having the compiler check the bit
      argument against some constant masks of features.
      
      But, when adding new CPUID leaves, we need to check new words
      for these macros.  So make sure that those macros and the
      REQUIRED_MASK* and DISABLED_MASK* get updated when necessary.
      
      This looks kinda silly to have an open-coded value ("18" in
      this case) open-coded in 5 places in the code.  But, we really do
      need 5 places updated when NCAPINTS gets bumped, so now we just
      force the issue.
      Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20160629200108.92466F6F@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      1e61f78b
    • D
      x86/cpufeature: Update cpufeaure macros · 6e17cb9c
      Dave Hansen 提交于
      We had a new CPUID "NCAPINT" word added, but the REQUIRED_MASK and
      DISABLED_MASK macros did not get updated.  Update them.
      
      None of the features was needed in these masks, so there was no
      harm, but we should keep them updated anyway.
      Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20160629200107.8D3C9A31@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      6e17cb9c
  12. 16 5月, 2016 1 次提交
    • D
      x86/cpufeature, x86/mm/pkeys: Fix broken compile-time disabling of pkeys · e8df1a95
      Dave Hansen 提交于
      When I added support for the Memory Protection Keys processor
      feature, I had to reindent the REQUIRED/DISABLED_MASK macros, and
      also consult the later cpufeature words.
      
      I'm not quite sure how I bungled it, but I consulted the wrong
      word at the end.  This only affected required or disabled cpu
      features in cpufeature words 14, 15 and 16.  So, only Protection
      Keys itself was screwed over here.
      
      The result was that if you disabled pkeys in your .config, you
      might still see some code show up that should have been compiled
      out.  There should be no functional problems, though.
      
      In verifying this patch I also realized that the DISABLE_PKU/OSPKE
      macros were defined backwards and that the cpu_has() check in
      setup_pku() was not doing the compile-time disabled checks.
      
      So also fix the macro for DISABLE_PKU/OSPKE and add a compile-time
      check for pkeys being enabled in setup_pku().
      Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
      Cc: <stable@vger.kernel.org>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Vince Weaver <vincent.weaver@maine.edu>
      Fixes: dfb4a70f ("x86/cpufeature, x86/mm/pkeys: Add protection keys related CPUID definitions")
      Link: http://lkml.kernel.org/r/20160513221328.C200930B@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      e8df1a95
  13. 12 5月, 2016 1 次提交
  14. 13 4月, 2016 10 次提交
  15. 31 3月, 2016 10 次提交
  16. 11 3月, 2016 1 次提交
  17. 04 3月, 2016 1 次提交
    • C
      x86/tsc: Always Running Timer (ART) correlated clocksource · f9677e0f
      Christopher S. Hall 提交于
      On modern Intel systems TSC is derived from the new Always Running Timer
      (ART). ART can be captured simultaneous to the capture of
      audio and network device clocks, allowing a correlation between timebases
      to be constructed. Upon capture, the driver converts the captured ART
      value to the appropriate system clock using the correlated clocksource
      mechanism.
      
      On systems that support ART a new CPUID leaf (0x15) returns parameters
      “m” and “n” such that:
      
      TSC_value = (ART_value * m) / n + k [n >= 1]
      
      [k is an offset that can adjusted by a privileged agent. The
      IA32_TSC_ADJUST MSR is an example of an interface to adjust k.
      See 17.14.4 of the Intel SDM for more details]
      
      Cc: Prarit Bhargava <prarit@redhat.com>
      Cc: Richard Cochran <richardcochran@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: kevin.b.stanton@intel.com
      Cc: kevin.j.clarke@intel.com
      Cc: hpa@zytor.com
      Cc: jeffrey.t.kirsher@intel.com
      Cc: netdev@vger.kernel.org
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NChristopher S. Hall <christopher.s.hall@intel.com>
      [jstultz: Tweaked to fix build issue, also reworked math for
      64bit division on 32bit systems, as well as !CONFIG_CPU_FREQ build
      fixes]
      Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      f9677e0f
  18. 16 2月, 2016 2 次提交
    • D
      x86/cpufeature, x86/mm/pkeys: Add protection keys related CPUID definitions · dfb4a70f
      Dave Hansen 提交于
      There are two CPUID bits for protection keys.  One is for whether
      the CPU contains the feature, and the other will appear set once
      the OS enables protection keys.  Specifically:
      
      	Bit 04: OSPKE. If 1, OS has set CR4.PKE to enable
      	Protection keys (and the RDPKRU/WRPKRU instructions)
      
      This is because userspace can not see CR4 contents, but it can
      see CPUID contents.
      
      X86_FEATURE_PKU is referred to as "PKU" in the hardware documentation:
      
      	CPUID.(EAX=07H,ECX=0H):ECX.PKU [bit 3]
      
      X86_FEATURE_OSPKE is "OSPKU":
      
      	CPUID.(EAX=07H,ECX=0H):ECX.OSPKE [bit 4]
      
      These are the first CPU features which need to look at the
      ECX word in CPUID leaf 0x7, so this patch also includes
      fetching that word in to the cpuinfo->x86_capability[] array.
      
      Add it to the disabled-features mask when its config option is
      off.  Even though we are not using it here, we also extend the
      REQUIRED_MASK_BIT_SET() macro to keep it mirroring the
      DISABLED_MASK_BIT_SET() version.
      
      This means that in almost all code, you should use:
      
      	cpu_has(c, X86_FEATURE_PKU)
      
      and *not* the CONFIG option.
      Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: linux-mm@kvack.org
      Link: http://lkml.kernel.org/r/20160212210201.7714C250@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      dfb4a70f
    • B
      x86/cpufeature: Speed up cpu_feature_enabled() · f2cc8e07
      Borislav Petkov 提交于
      When GCC cannot do constant folding for this macro, it falls back to
      cpu_has(). But static_cpu_has() is optimal and it works at all times
      now. So use it and speedup the fallback case.
      
      Before we had this:
      
        mov    0x99d674(%rip),%rdx        # ffffffff81b0d9f4 <boot_cpu_data+0x34>
        shr    $0x2e,%rdx
        and    $0x1,%edx
        jne    ffffffff811704e9 <do_munmap+0x3f9>
      
      After alternatives patching, it turns into:
      
      		  jmp    0xffffffff81170390
      		  nopl   (%rax)
      		  ...
      		  callq  ffffffff81056e00 <mpx_notify_unmap>
      ffffffff81170390: mov    0x170(%r12),%rdi
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1455578358-28347-1-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      f2cc8e07