UefiCpuPkg/MtrrLib: Add PCD PcdCpuNumberOfReservedVariableMtrrs

Current MtrrLib reserves 2 variable MTRRs for some legacy OS boot (CSM boots)
may require some MTRRs to be reserved for OS use. But UEFI OS boot will not use
MTRRs.

Per Scott's suggestion in
link: http://article.gmane.org/gmane.comp.bios.edk2.devel/4099
Add one PCD PcdCpuNumberOfReservedVariableMtrrs to specify the number of
variable MTRRs reserved for OS use. Setting its default value to 2 is for
back-compatibility.

Cc: Scott Duplichan <scott@notabs.org>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Suggested-by: Scott Duplichan <scott@notabs.org>
Reviewed-by: Feng Tian <feng.tian@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19151 6f19259b-4bc3-4df7-8a09-765794883524

diff --git a/UefiCpuPkg/Include/Library/MtrrLib.h b/UefiCpuPkg/Include/Library/MtrrLib.h
index e06fff7f017867d5d38b8531980ba2f330898c05..f9002e7cbfc710aaef68dc6fb67716293bd032d9 100644 (file)
--- a/UefiCpuPkg/Include/Library/MtrrLib.h
+++ b/UefiCpuPkg/Include/Library/MtrrLib.h
@@ -1,7 +1,7 @@
 /** @file\r
   MTRR setting library\r
 \r
-  Copyright (c) 2008 - 2011, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2008 - 2015, Intel Corporation. All rights reserved.<BR>\r
   This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
   which accompanies this distribution.  The full text of the license may be found at\r
@@ -26,6 +26,7 @@
 #define  MTRR_NUMBER_OF_VARIABLE_MTRR  32\r
 //\r
 // Firmware need reserve 2 MTRR for OS\r
+// Note: It is replaced by PCD PcdCpuNumberOfReservedVariableMtrrs\r
 //\r
 #define  RESERVED_FIRMWARE_VARIABLE_MTRR_NUMBER  2\r
 \r

diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
index a65560542c88f186c9eb0137b60b9d0def565dbc..82223379e773962211af2b0c4a42ca57afe1f272 100644 (file)
--- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
+++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
@@ -140,13 +140,15 @@ GetFirmwareVariableMtrrCount (
   )\r
 {\r
   UINT32  VariableMtrrCount;\r
+  UINT32  ReservedMtrrNumber;\r
 \r
   VariableMtrrCount = GetVariableMtrrCount ();\r
-  if (VariableMtrrCount < RESERVED_FIRMWARE_VARIABLE_MTRR_NUMBER) {\r
+  ReservedMtrrNumber = PcdGet32 (PcdCpuNumberOfReservedVariableMtrrs);\r
+  if (VariableMtrrCount < ReservedMtrrNumber) {\r
     return 0;\r
   }\r
 \r
-  return VariableMtrrCount - RESERVED_FIRMWARE_VARIABLE_MTRR_NUMBER;\r
+  return VariableMtrrCount - ReservedMtrrNumber;\r
 }\r
 \r
 /**\r

diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.inf b/UefiCpuPkg/Library/MtrrLib/MtrrLib.inf
index 64ec9bd0b0fae5c9f3134121c0522d09e5747c17..01a4d84da0ed668e3e5b710e26a779d1a2fcb3d8 100644 (file)
--- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.inf
+++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.inf
@@ -1,7 +1,7 @@
 ## @file\r
 #  MTRR library provides APIs for MTRR operation.\r
 #\r
-#  Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>\r
+#  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>\r
 #  This program and the accompanying materials\r
 #  are licensed and made available under the terms and conditions of the BSD License\r
 #  which accompanies this distribution.  The full text of the license may be found at\r
@@ -41,3 +41,6 @@
   CpuLib\r
   DebugLib\r
 \r
+[Pcd]\r
+  gUefiCpuPkgTokenSpaceGuid.PcdCpuNumberOfReservedVariableMtrrs   ## SOMETIMES_CONSUMES\r
+\r

diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec
index e783a7b53616403ca7b899bf4ce5ef2ca9e283a5..a6941466891e80851d9d9637a778188c2f4c7aa3 100644 (file)
--- a/UefiCpuPkg/UefiCpuPkg.dec
+++ b/UefiCpuPkg/UefiCpuPkg.dec
@@ -167,6 +167,11 @@
   # @Prompt SMM CPU Synchronization Method.\r
   gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmSyncMode|0x00|UINT8|0x60000014\r
 \r
+  ## Specifies the number of variable MTRRs reserved for OS use. The default number of\r
+  #  MTRRs reserved for OS use is 2.\r
+  # @Prompt Number of reserved variable MTRRs.\r
+  gUefiCpuPkgTokenSpaceGuid.PcdCpuNumberOfReservedVariableMtrrs|0x2|UINT32|0x00000015\r
+\r
 [PcdsFixedAtBuild, PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx]\r
   ## Specifies timeout value in microseconds for the BSP to detect all APs for the first time.\r
   # @Prompt Timeout for the BSP to detect all APs for the first time.\r