queue-4.9/powerpc-pseries-query-hypervisor-for-count-cache-flu.patch

   1 From 9ebac65e5fbd657e77979e2416b19cb21ddcf804 Mon Sep 17 00:00:00 2001
   2 From: Michael Ellerman <mpe@ellerman.id.au>
   3 Date: Thu, 11 Apr 2019 21:46:16 +1000
   4 Subject: powerpc/pseries: Query hypervisor for count cache flush settings
   5
   6 commit ba72dc171954b782a79d25e0f4b3ed91090c3b1e upstream.
   7
   8 Use the existing hypercall to determine the appropriate settings for
   9 the count cache flush, and then call the generic powerpc code to set
  10 it up based on the security feature flags.
  11
  12 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
  13 Signed-off-by: Sasha Levin <sashal@kernel.org>
  14 ---
  15  arch/powerpc/include/asm/hvcall.h      | 2 ++
  16  arch/powerpc/platforms/pseries/setup.c | 7 +++++++
  17  2 files changed, 9 insertions(+)
  18
  19 diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
  20 index 9d978102bf0d..9587d301db55 100644
  21 --- a/arch/powerpc/include/asm/hvcall.h
  22 +++ b/arch/powerpc/include/asm/hvcall.h
  23 @@ -316,10 +316,12 @@
  24  #define H_CPU_CHAR_BRANCH_HINTS_HONORED        (1ull << 58) // IBM bit 5
  25  #define H_CPU_CHAR_THREAD_RECONFIG_CTRL        (1ull << 57) // IBM bit 6
  26  #define H_CPU_CHAR_COUNT_CACHE_DISABLED        (1ull << 56) // IBM bit 7
  27 +#define H_CPU_CHAR_BCCTR_FLUSH_ASSIST  (1ull << 54) // IBM bit 9
  28
  29  #define H_CPU_BEHAV_FAVOUR_SECURITY    (1ull << 63) // IBM bit 0
  30  #define H_CPU_BEHAV_L1D_FLUSH_PR       (1ull << 62) // IBM bit 1
  31  #define H_CPU_BEHAV_BNDS_CHK_SPEC_BAR  (1ull << 61) // IBM bit 2
  32 +#define H_CPU_BEHAV_FLUSH_COUNT_CACHE  (1ull << 58) // IBM bit 5
  33
  34  #ifndef __ASSEMBLY__
  35  #include <linux/types.h>
  36 diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
  37 index 91ade7755823..adb09ab87f7c 100644
  38 --- a/arch/powerpc/platforms/pseries/setup.c
  39 +++ b/arch/powerpc/platforms/pseries/setup.c
  40 @@ -475,6 +475,12 @@ static void init_cpu_char_feature_flags(struct h_cpu_char_result *result)
  41         if (result->character & H_CPU_CHAR_COUNT_CACHE_DISABLED)
  42                 security_ftr_set(SEC_FTR_COUNT_CACHE_DISABLED);
  43
  44 +       if (result->character & H_CPU_CHAR_BCCTR_FLUSH_ASSIST)
  45 +               security_ftr_set(SEC_FTR_BCCTR_FLUSH_ASSIST);
  46 +
  47 +       if (result->behaviour & H_CPU_BEHAV_FLUSH_COUNT_CACHE)
  48 +               security_ftr_set(SEC_FTR_FLUSH_COUNT_CACHE);
  49 +
  50         /*
  51          * The features below are enabled by default, so we instead look to see
  52          * if firmware has *disabled* them, and clear them if so.
  53 @@ -525,6 +531,7 @@ void pseries_setup_rfi_flush(void)
  54                  security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR);
  55
  56         setup_rfi_flush(types, enable);
  57 +       setup_count_cache_flush();
  58  }
  59
  60  static void __init pSeries_setup_arch(void)
  61 --
  62 2.19.1
  63