releases/5.0.1/x86-cpu-amd-set-the-cpb-bit-unconditionally-on-f17h.patch

   1 From 0237199186e7a4aa5310741f0a6498a20c820fd7 Mon Sep 17 00:00:00 2001
   2 From: Jiaxun Yang <jiaxun.yang@flygoat.com>
   3 Date: Tue, 20 Nov 2018 11:00:18 +0800
   4 Subject: x86/CPU/AMD: Set the CPB bit unconditionally on F17h
   5
   6 From: Jiaxun Yang <jiaxun.yang@flygoat.com>
   7
   8 commit 0237199186e7a4aa5310741f0a6498a20c820fd7 upstream.
   9
  10 Some F17h models do not have CPB set in CPUID even though the CPU
  11 supports it. Set the feature bit unconditionally on all F17h.
  12
  13  [ bp: Rewrite commit message and patch. ]
  14
  15 Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
  16 Signed-off-by: Borislav Petkov <bp@suse.de>
  17 Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
  18 Cc: "H. Peter Anvin" <hpa@zytor.com>
  19 Cc: Ingo Molnar <mingo@redhat.com>
  20 Cc: Sherry Hurwitz <sherry.hurwitz@amd.com>
  21 Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
  22 Cc: Thomas Gleixner <tglx@linutronix.de>
  23 Cc: x86-ml <x86@kernel.org>
  24 Link: https://lkml.kernel.org/r/20181120030018.5185-1-jiaxun.yang@flygoat.com
  25 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  26
  27 ---
  28  arch/x86/kernel/cpu/amd.c |    8 +++-----
  29  1 file changed, 3 insertions(+), 5 deletions(-)
  30
  31 --- a/arch/x86/kernel/cpu/amd.c
  32 +++ b/arch/x86/kernel/cpu/amd.c
  33 @@ -819,11 +819,9 @@ static void init_amd_bd(struct cpuinfo_x
  34  static void init_amd_zn(struct cpuinfo_x86 *c)
  35  {
  36         set_cpu_cap(c, X86_FEATURE_ZEN);
  37 -       /*
  38 -        * Fix erratum 1076: CPB feature bit not being set in CPUID. It affects
  39 -        * all up to and including B1.
  40 -        */
  41 -       if (c->x86_model <= 1 && c->x86_stepping <= 1)
  42 +
  43 +       /* Fix erratum 1076: CPB feature bit not being set in CPUID. */
  44 +       if (!cpu_has(c, X86_FEATURE_CPB))
  45                 set_cpu_cap(c, X86_FEATURE_CPB);
  46  }
  47