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   1 From 65c7d070850e109a8a75a431f5a7f6eb4c007b77 Mon Sep 17 00:00:00 2001
   2 From: Nicholas Piggin <npiggin@gmail.com>
   3 Date: Mon, 3 May 2021 23:02:40 +1000
   4 Subject: powerpc/pseries: Get entry and uaccess flush required bits from H_GET_CPU_CHARACTERISTICS
   5
   6 From: Nicholas Piggin <npiggin@gmail.com>
   7
   8 commit 65c7d070850e109a8a75a431f5a7f6eb4c007b77 upstream.
   9
  10 This allows the hypervisor / firmware to describe these workarounds to
  11 the guest.
  12
  13 Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
  14 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
  15 Link: https://lore.kernel.org/r/20210503130243.891868-2-npiggin@gmail.com
  16 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  17 ---
  18  arch/powerpc/include/asm/hvcall.h      |    2 ++
  19  arch/powerpc/platforms/pseries/setup.c |    6 ++++++
  20  2 files changed, 8 insertions(+)
  21
  22 --- a/arch/powerpc/include/asm/hvcall.h
  23 +++ b/arch/powerpc/include/asm/hvcall.h
  24 @@ -382,6 +382,8 @@
  25  #define H_CPU_BEHAV_BNDS_CHK_SPEC_BAR  (1ull << 61) // IBM bit 2
  26  #define H_CPU_BEHAV_FLUSH_COUNT_CACHE  (1ull << 58) // IBM bit 5
  27  #define H_CPU_BEHAV_FLUSH_LINK_STACK   (1ull << 57) // IBM bit 6
  28 +#define H_CPU_BEHAV_NO_L1D_FLUSH_ENTRY (1ull << 56) // IBM bit 7
  29 +#define H_CPU_BEHAV_NO_L1D_FLUSH_UACCESS (1ull << 55) // IBM bit 8
  30
  31  /* Flag values used in H_REGISTER_PROC_TBL hcall */
  32  #define PROC_TABLE_OP_MASK     0x18
  33 --- a/arch/powerpc/platforms/pseries/setup.c
  34 +++ b/arch/powerpc/platforms/pseries/setup.c
  35 @@ -538,6 +538,12 @@ static void init_cpu_char_feature_flags(
  36         if (!(result->behaviour & H_CPU_BEHAV_L1D_FLUSH_PR))
  37                 security_ftr_clear(SEC_FTR_L1D_FLUSH_PR);
  38
  39 +       if (result->behaviour & H_CPU_BEHAV_NO_L1D_FLUSH_ENTRY)
  40 +               security_ftr_clear(SEC_FTR_L1D_FLUSH_ENTRY);
  41 +
  42 +       if (result->behaviour & H_CPU_BEHAV_NO_L1D_FLUSH_UACCESS)
  43 +               security_ftr_clear(SEC_FTR_L1D_FLUSH_UACCESS);
  44 +
  45         if (!(result->behaviour & H_CPU_BEHAV_BNDS_CHK_SPEC_BAR))
  46                 security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
  47  }