Reviewed-by: Feng Tian <[email protected]> -----Original Message----- From: Fan, Jeff Sent: Thursday, December 03, 2015 22:28 To: [email protected] Cc: Scott Duplichan; Tian, Feng; Kinney, Michael D Subject: [Patch] 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 <[email protected]> Cc: Feng Tian <[email protected]> Cc: Michael Kinney <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jeff Fan <[email protected]> Suggested-by: Scott Duplichan <[email protected]> --- UefiCpuPkg/Include/Library/MtrrLib.h | 3 ++- UefiCpuPkg/Library/MtrrLib/MtrrLib.c | 6 ++++-- UefiCpuPkg/Library/MtrrLib/MtrrLib.inf | 5 ++++- UefiCpuPkg/UefiCpuPkg.dec | 5 +++++ 4 files changed, 15 insertions(+), 4 deletions(-) diff --git a/UefiCpuPkg/Include/Library/MtrrLib.h b/UefiCpuPkg/Include/Library/MtrrLib.h index e06fff7..f9002e7 100644 --- a/UefiCpuPkg/Include/Library/MtrrLib.h +++ b/UefiCpuPkg/Include/Library/MtrrLib.h @@ -1,7 +1,7 @@ /** @file MTRR setting library - Copyright (c) 2008 - 2011, Intel Corporation. All rights reserved.<BR> + Copyright (c) 2008 - 2015, Intel Corporation. All rights + reserved.<BR> This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at @@ -26,6 +26,7 @@ #define MTRR_NUMBER_OF_VARIABLE_MTRR 32 // // Firmware need reserve 2 MTRR for OS +// Note: It is replaced by PCD PcdCpuNumberOfReservedVariableMtrrs // #define RESERVED_FIRMWARE_VARIABLE_MTRR_NUMBER 2 diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c index a655605..8222337 100644 --- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c +++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c @@ -140,13 +140,15 @@ GetFirmwareVariableMtrrCount ( ) { UINT32 VariableMtrrCount; + UINT32 ReservedMtrrNumber; VariableMtrrCount = GetVariableMtrrCount (); - if (VariableMtrrCount < RESERVED_FIRMWARE_VARIABLE_MTRR_NUMBER) { + ReservedMtrrNumber = PcdGet32 (PcdCpuNumberOfReservedVariableMtrrs); + if (VariableMtrrCount < ReservedMtrrNumber) { return 0; } - return VariableMtrrCount - RESERVED_FIRMWARE_VARIABLE_MTRR_NUMBER; + return VariableMtrrCount - ReservedMtrrNumber; } /** diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.inf b/UefiCpuPkg/Library/MtrrLib/MtrrLib.inf index 64ec9bd..01a4d84 100644 --- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.inf +++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.inf @@ -1,7 +1,7 @@ ## @file # MTRR library provides APIs for MTRR operation. # -# Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR> +# Copyright (c) 2006 - 2015, Intel Corporation. All rights +reserved.<BR> # This program and the accompanying materials # are licensed and made available under the terms and conditions of the BSD License # which accompanies this distribution. The full text of the license may be found at @@ -41,3 +41,6 @@ CpuLib DebugLib +[Pcd] + gUefiCpuPkgTokenSpaceGuid.PcdCpuNumberOfReservedVariableMtrrs ## SOMETIMES_CONSUMES + diff --git a/UefiCpuPkg/UefiCpuPkg.dec b/UefiCpuPkg/UefiCpuPkg.dec index e783a7b..a694146 100644 --- a/UefiCpuPkg/UefiCpuPkg.dec +++ b/UefiCpuPkg/UefiCpuPkg.dec @@ -167,6 +167,11 @@ # @Prompt SMM CPU Synchronization Method. gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmSyncMode|0x00|UINT8|0x60000014 + ## Specifies the number of variable MTRRs reserved for OS use. The + default number of # MTRRs reserved for OS use is 2. + # @Prompt Number of reserved variable MTRRs. + + gUefiCpuPkgTokenSpaceGuid.PcdCpuNumberOfReservedVariableMtrrs|0x2|UINT + 32|0x00000015 + [PcdsFixedAtBuild, PcdsPatchableInModule, PcdsDynamic, PcdsDynamicEx] ## Specifies timeout value in microseconds for the BSP to detect all APs for the first time. # @Prompt Timeout for the BSP to detect all APs for the first time. -- 1.9.5.msysgit.0 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
