-----Original Message-----
From: Sravanthi, K KavyaX <k.kavyax.sravanthi@intel.com>
Sent: Monday, December 6, 2021 2:16 PM
To: devel@edk2.groups.io
Cc: Sravanthi, K KavyaX <k.kavyax.sravanthi@intel.com>; Chiu, Chasel <chasel.chiu@intel.com>; Desimone, Nathaniel L <nathaniel.l.desimone@intel.com>; Liming Gao <gaoliming@byosoft.com.cn>; Dong, Eric <eric.dong@intel.com>
Subject: [Patch V2] MinPlatformPkg: Check if Acpi table is already installed.

Check if Acpi table is already installed by locating the first ACPI table in XSDT/RSDT based on Signature

Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Eric Dong <eric.dong@intel.com>
Signed-off-by: kavya <k.kavyax.sravanthi@intel.com>
Reviewed-by: Zhiguang Liu <zhiguang.liu@intel.com>
---
Platform/Intel/MinPlatformPkg/Acpi/AcpiTables/AcpiPlatform.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/Platform/Intel/MinPlatformPkg/Acpi/AcpiTables/AcpiPlatform.c b/Platform/Intel/MinPlatformPkg/Acpi/AcpiTables/AcpiPlatform.c
index 785cf4c2f9..dcbb8b7c7f 100644
--- a/Platform/Intel/MinPlatformPkg/Acpi/AcpiTables/AcpiPlatform.c
+++ b/Platform/Intel/MinPlatformPkg/Acpi/AcpiTables/AcpiPlatform.c
@@ -1048,12 +1048,21 @@ InstallMcfgFromScratch ( {
EFI_STATUS Status;
EFI_ACPI_MEMORY_MAPPED_CONFIGURATION_BASE_ADDRESS_TABLE_HEADER *McfgTable;
+ EFI_ACPI_COMMON_HEADER *Mcfg;
EFI_ACPI_MEMORY_MAPPED_ENHANCED_CONFIGURATION_SPACE_BASE_ADDRESS_ALLOCATION_STRUCTURE *Segment;
UINTN Index;
UINTN SegmentCount;
PCI_SEGMENT_INFO *PciSegmentInfo;
UINTN TableHandle;

+ Mcfg = (EFI_ACPI_COMMON_HEADER *) EfiLocateFirstAcpiTable (
+ EFI_ACPI_3_0_PCI_EXPRESS_MEMORY_MAPPED_CONFIGURATION_SPACE_BASE_ADDRESS_DESCRIPTION_TABLE_SIGNATURE
+ ); if (Mcfg != NULL) {
+ DEBUG ((DEBUG_INFO, "MCFG table already installed\n"));
+ return EFI_SUCCESS;
+ }
+
PciSegmentInfo = GetPciSegmentInfo (&SegmentCount);

McfgTable = AllocateZeroPool (
@@ -1365,6 +1374,7 @@ UpdateLocalTable ( {
EFI_STATUS Status;
EFI_ACPI_COMMON_HEADER *CurrentTable;
+ EFI_ACPI_COMMON_HEADER *Table;
EFI_ACPI_TABLE_VERSION Version;
UINTN TableHandle;
UINTN Index;
@@ -1372,6 +1382,14 @@ UpdateLocalTable (
for (Index = 0; Index < sizeof(mLocalTable)/sizeof(mLocalTable[0]); Index++) {
CurrentTable = mLocalTable[Index];

+ Table = (EFI_ACPI_COMMON_HEADER *) EfiLocateFirstAcpiTable (CurrentTable->Signature);
+ if (Table != NULL) {
+ DEBUG ((DEBUG_INFO, "Acpi table with signature=%c%c%c%c already installed\n",
+ ((CHAR8*)&CurrentTable->Signature)[0], ((CHAR8*)&CurrentTable->Signature)[1],
+ ((CHAR8*)&CurrentTable->Signature)[2], ((CHAR8*)&CurrentTable->Signature)[3]));
+ continue;
+ }
+
PlatformUpdateTables (CurrentTable, &Version);

TableHandle = 0;
--
2.16.2.windows.1