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From: "Michael D Kinney" <michael.d.kinney@intel.com>
To: devel@edk2.groups.io
Cc: Liming Gao <liming.gao@intel.com>
Subject: [Patch V2 2/6] MdePkg/BaseLib: Use PcdSpeculationBarrierType
Date: Mon, 29 Apr 2019 18:30:08 -0700	[thread overview]
Message-ID: <20190430013012.24008-3-michael.d.kinney@intel.com> (raw)
In-Reply-To: <20190430013012.24008-1-michael.d.kinney@intel.com>

Use PcdSpeculationBarrierType in the x86 implementation
of SpeculationBarrier() to select between AsmLfence(),
AsmCpuid(), and no operation.

Cc: Liming Gao <liming.gao@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
---
 MdePkg/Library/BaseLib/BaseLib.inf             | 1 +
 MdePkg/Library/BaseLib/X86SpeculationBarrier.c | 8 ++++++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/MdePkg/Library/BaseLib/BaseLib.inf b/MdePkg/Library/BaseLib/BaseLib.inf
index 533e83e0b2..3586beb0ab 100644
--- a/MdePkg/Library/BaseLib/BaseLib.inf
+++ b/MdePkg/Library/BaseLib/BaseLib.inf
@@ -394,6 +394,7 @@ [Pcd]
   gEfiMdePkgTokenSpaceGuid.PcdMaximumAsciiStringLength     ## SOMETIMES_CONSUMES
   gEfiMdePkgTokenSpaceGuid.PcdMaximumUnicodeStringLength   ## SOMETIMES_CONSUMES
   gEfiMdePkgTokenSpaceGuid.PcdControlFlowEnforcementPropertyMask   ## SOMETIMES_CONSUMES
+  gEfiMdePkgTokenSpaceGuid.PcdSpeculationBarrierType       ## SOMETIMES_CONSUMES
 
 [FeaturePcd]
   gEfiMdePkgTokenSpaceGuid.PcdVerifyNodeInList  ## CONSUMES
diff --git a/MdePkg/Library/BaseLib/X86SpeculationBarrier.c b/MdePkg/Library/BaseLib/X86SpeculationBarrier.c
index 8e5f983bb8..b28fd8de9b 100644
--- a/MdePkg/Library/BaseLib/X86SpeculationBarrier.c
+++ b/MdePkg/Library/BaseLib/X86SpeculationBarrier.c
@@ -1,7 +1,7 @@
 /** @file
   SpeculationBarrier() function for IA32 and x64.
 
-  Copyright (C) 2018, Intel Corporation. All rights reserved.<BR>
+  Copyright (C) 2018 - 2019, Intel Corporation. All rights reserved.<BR>
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
@@ -22,5 +22,9 @@ SpeculationBarrier (
   VOID
   )
 {
-  AsmLfence ();
+  if (PcdGet8 (PcdSpeculationBarrierType) == 0x01) {
+    AsmLfence ();
+  } else if (PcdGet8 (PcdSpeculationBarrierType) == 0x02) {
+    AsmCpuid (0x01, NULL, NULL, NULL, NULL);
+  }
 }
-- 
2.21.0.windows.1


  parent reply	other threads:[~2019-04-30  1:30 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-30  1:30 [Patch V2 0/6] Resolve Quark build and boot issues Michael D Kinney
2019-04-30  1:30 ` [Patch V2 1/6] MdePkg: Add PcdSpeculationBarrierType Michael D Kinney
2019-04-30 11:47   ` [edk2-devel] " Laszlo Ersek
2019-04-30 15:16     ` Michael D Kinney
2019-04-30 15:43       ` Laszlo Ersek
2019-04-30  1:30 ` Michael D Kinney [this message]
2019-04-30 11:49   ` [edk2-devel] [Patch V2 2/6] MdePkg/BaseLib: Use PcdSpeculationBarrierType Laszlo Ersek
2019-04-30 15:17     ` Michael D Kinney
2019-04-30 22:24   ` Brian J. Johnson
2019-04-30  1:30 ` [Patch V2 3/6] QuarkPlatformPkg: Set PcdSpeculationBarrierType to CPUID Michael D Kinney
2019-04-30  1:30 ` [Patch V2 4/6] UefiCpuPkg/MpInitLib: Avoid MSR_IA32_APIC_BASE for single core Michael D Kinney
2019-04-30 10:31   ` Laszlo Ersek
2019-04-30  1:30 ` [Patch V2 5/6] QuarkSocPkg/SmmAccessDxe: Set region to UC on SMRAM close Michael D Kinney
2019-04-30  1:30 ` [Patch V2 6/6] QuarkPlatformPkg/PlatformInit: Resolve ResetSystemLib name collision Michael D Kinney

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