1. 29 10月, 2019 1 次提交
    • F
      CPX: x86/cpufeatures: Enumerate the new AVX512 BFLOAT16 instructions · 61c73dc7
      Fenghua Yu 提交于
      commit b302e4b176d00e1cbc80148c5d0aee36751f7480 upstream.
      
      AVX512 BFLOAT16 instructions support 16-bit BFLOAT16 floating-point
      format (BF16) for deep learning optimization.
      
      BF16 is a short version of 32-bit single-precision floating-point
      format (FP32) and has several advantages over 16-bit half-precision
      floating-point format (FP16). BF16 keeps FP32 accumulation after
      multiplication without loss of precision, offers more than enough
      range for deep learning training tasks, and doesn't need to handle
      hardware exception.
      
      AVX512 BFLOAT16 instructions are enumerated in CPUID.7.1:EAX[bit 5]
      AVX512_BF16.
      
      CPUID.7.1:EAX contains only feature bits. Reuse the currently empty
      word 12 as a pure features word to hold the feature bits including
      AVX512_BF16.
      
      Detailed information of the CPUID bit and AVX512 BFLOAT16 instructions
      can be found in the latest Intel Architecture Instruction Set Extensions
      and Future Features Programming Reference.
      
       [ bp: Check CPUID(7) subleaf validity before accessing subleaf 1. ]
      Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: "Chang S. Bae" <chang.seok.bae@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: Masahiro Yamada <yamada.masahiro@socionext.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      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: Radim Krcmar <rkrcmar@redhat.com>
      Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
      Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
      Cc: Robert Hoo <robert.hu@linux.intel.com>
      Cc: "Sean J Christopherson" <sean.j.christopherson@intel.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/1560794416-217638-3-git-send-email-fenghua.yu@intel.comSigned-off-by: NLin Wang <lin.x.wang@intel.com>
      Signed-off-by: NJeffle Xu <jefflexu@linux.alibaba.com>
      Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
      61c73dc7
  2. 07 8月, 2019 1 次提交
    • F
      x86/cpufeatures: Combine word 11 and 12 into a new scattered features word · b5dd7f61
      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>
      b5dd7f61
  3. 08 3月, 2018 1 次提交
  4. 02 11月, 2017 1 次提交
  5. 31 10月, 2017 1 次提交
  6. 19 10月, 2017 1 次提交
  7. 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