queue-4.14/powerpc-64s-add-new-security-feature-flags-for-count-cache-flush.patch

   1 From foo@baz Fri Mar 29 15:53:50 CET 2019
   2 From: Michael Ellerman <mpe@ellerman.id.au>
   3 Date: Fri, 29 Mar 2019 22:26:04 +1100
   4 Subject: powerpc/64s: Add new security feature flags for count cache flush
   5 To: stable@vger.kernel.org, gregkh@linuxfoundation.org
   6 Cc: linuxppc-dev@ozlabs.org, diana.craciun@nxp.com, msuchanek@suse.de, christophe.leroy@c-s.fr
   7 Message-ID: <20190329112620.14489-17-mpe@ellerman.id.au>
   8
   9 From: Michael Ellerman <mpe@ellerman.id.au>
  10
  11 commit dc8c6cce9a26a51fc19961accb978217a3ba8c75 upstream.
  12
  13 Add security feature flags to indicate the need for software to flush
  14 the count cache on context switch, and for the presence of a hardware
  15 assisted count cache flush.
  16
  17 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
  18 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  19 ---
  20  arch/powerpc/include/asm/security_features.h |    6 ++++++
  21  1 file changed, 6 insertions(+)
  22
  23 --- a/arch/powerpc/include/asm/security_features.h
  24 +++ b/arch/powerpc/include/asm/security_features.h
  25 @@ -59,6 +59,9 @@ static inline bool security_ftr_enabled(
  26  // Indirect branch prediction cache disabled
  27  #define SEC_FTR_COUNT_CACHE_DISABLED   0x0000000000000020ull
  28
  29 +// bcctr 2,0,0 triggers a hardware assisted count cache flush
  30 +#define SEC_FTR_BCCTR_FLUSH_ASSIST     0x0000000000000800ull
  31 +
  32
  33  // Features indicating need for Spectre/Meltdown mitigations
  34
  35 @@ -74,6 +77,9 @@ static inline bool security_ftr_enabled(
  36  // Firmware configuration indicates user favours security over performance
  37  #define SEC_FTR_FAVOUR_SECURITY                0x0000000000000200ull
  38
  39 +// Software required to flush count cache on context switch
  40 +#define SEC_FTR_FLUSH_COUNT_CACHE      0x0000000000000400ull
  41 +
  42
  43  // Features enabled by default
  44  #define SEC_FTR_DEFAULT \