queue-4.4/powerpc-powernv-use-the-security-flags-in-pnv_setup_rfi_flush.patch

   1 From foo@baz Mon 29 Apr 2019 11:38:37 AM CEST
   2 From: Michael Ellerman <mpe@ellerman.id.au>
   3 Date: Mon, 22 Apr 2019 00:20:01 +1000
   4 Subject: powerpc/powernv: Use the security flags in pnv_setup_rfi_flush()
   5 To: stable@vger.kernel.org, gregkh@linuxfoundation.org
   6 Cc: linuxppc-dev@ozlabs.org, diana.craciun@nxp.com, msuchanek@suse.de, npiggin@gmail.com, christophe.leroy@c-s.fr
   7 Message-ID: <20190421142037.21881-17-mpe@ellerman.id.au>
   8
   9 From: Michael Ellerman <mpe@ellerman.id.au>
  10
  11 commit 37c0bdd00d3ae83369ab60a6712c28e11e6458d5 upstream.
  12
  13 Now that we have the security flags we can significantly simplify the
  14 code in pnv_setup_rfi_flush(), because we can use the flags instead of
  15 checking device tree properties and because the security flags have
  16 pessimistic defaults.
  17
  18 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
  19 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  20 ---
  21  arch/powerpc/platforms/powernv/setup.c |   41 ++++++++-------------------------
  22  1 file changed, 10 insertions(+), 31 deletions(-)
  23
  24 --- a/arch/powerpc/platforms/powernv/setup.c
  25 +++ b/arch/powerpc/platforms/powernv/setup.c
  26 @@ -65,7 +65,7 @@ static void init_fw_feat_flags(struct de
  27         if (fw_feature_is("enabled", "fw-bcctrl-serialized", np))
  28                 security_ftr_set(SEC_FTR_BCCTRL_SERIALISED);
  29
  30 -       if (fw_feature_is("enabled", "inst-spec-barrier-ori31,31,0", np))
  31 +       if (fw_feature_is("enabled", "inst-l1d-flush-ori30,30,0", np))
  32                 security_ftr_set(SEC_FTR_L1D_FLUSH_ORI30);
  33
  34         if (fw_feature_is("enabled", "inst-l1d-flush-trig2", np))
  35 @@ -98,11 +98,10 @@ static void pnv_setup_rfi_flush(void)
  36  {
  37         struct device_node *np, *fw_features;
  38         enum l1d_flush_type type;
  39 -       int enable;
  40 +       bool enable;
  41
  42         /* Default to fallback in case fw-features are not available */
  43         type = L1D_FLUSH_FALLBACK;
  44 -       enable = 1;
  45
  46         np = of_find_node_by_name(NULL, "ibm,opal");
  47         fw_features = of_get_child_by_name(np, "fw-features");
  48 @@ -110,40 +109,20 @@ static void pnv_setup_rfi_flush(void)
  49
  50         if (fw_features) {
  51                 init_fw_feat_flags(fw_features);
  52 +               of_node_put(fw_features);
  53
  54 -               np = of_get_child_by_name(fw_features, "inst-l1d-flush-trig2");
  55 -               if (np && of_property_read_bool(np, "enabled"))
  56 +               if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_TRIG2))
  57                         type = L1D_FLUSH_MTTRIG;
  58
  59 -               of_node_put(np);
  60 -
  61 -               np = of_get_child_by_name(fw_features, "inst-l1d-flush-ori30,30,0");
  62 -               if (np && of_property_read_bool(np, "enabled"))
  63 +               if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_ORI30))
  64                         type = L1D_FLUSH_ORI;
  65 -
  66 -               of_node_put(np);
  67 -
  68 -               /* Enable unless firmware says NOT to */
  69 -               enable = 2;
  70 -               np = of_get_child_by_name(fw_features, "needs-l1d-flush-msr-hv-1-to-0");
  71 -               if (np && of_property_read_bool(np, "disabled"))
  72 -                       enable--;
  73 -
  74 -               of_node_put(np);
  75 -
  76 -               np = of_get_child_by_name(fw_features, "needs-l1d-flush-msr-pr-0-to-1");
  77 -               if (np && of_property_read_bool(np, "disabled"))
  78 -                       enable--;
  79 -
  80 -               np = of_get_child_by_name(fw_features, "speculation-policy-favor-security");
  81 -               if (np && of_property_read_bool(np, "disabled"))
  82 -                       enable = 0;
  83 -
  84 -               of_node_put(np);
  85 -               of_node_put(fw_features);
  86         }
  87
  88 -       setup_rfi_flush(type, enable > 0);
  89 +       enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && \
  90 +                (security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR)   || \
  91 +                 security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV));
  92 +
  93 +       setup_rfi_flush(type, enable);
  94  }
  95
  96  static void __init pnv_setup_arch(void)