[edk2-devel] [PATCH] UefiCpuPkg PiSmmCpuDxeSmm: Reduce SMRAM consumption in CpuS3.c
Zeng, Star
star.zeng at intel.com
Mon Jan 4 05:14:18 UTC 2021
This patch makes two refinements to reduce SMRAM consumption in CpuS3.c.
1. Only do CopyRegisterTable() when register table is not empty,
IsRegisterTableEmpty() is created to check whether the register table
is empty or not.
Take empty PreSmmInitRegisterTable as example, about 24K SMRAM consumption
could be reduced when mAcpiCpuData.NumberOfCpus=1024.
sizeof (CPU_REGISTER_TABLE) = 24
mAcpiCpuData.NumberOfCpus = 1024 = 1K
mAcpiCpuData.NumberOfCpus * sizeof (CPU_REGISTER_TABLE) = 24K
2. Only copy table entries buffer instead of whole buffer.
AllocatedSize in SourceRegisterTableList is the whole buffer size.
Actually, only the table entries buffer needs to be copied, and the size
is TableLength * sizeof (CPU_REGISTER_TABLE_ENTRY).
Take AllocatedSize=0x1000=4096, TableLength=100 and NumberOfCpus=1024 as example,
about 1696K SMRAM consumption could be reduced.
sizeof (CPU_REGISTER_TABLE_ENTRY) = 24
TableLength = 100
TableLength * sizeof (CPU_REGISTER_TABLE_ENTRY) = 2400
AllocatedSize = 0x1000 = 4096
AllocatedSize - TableLength * sizeof (CPU_REGISTER_TABLE_ENTRY) = 4096 - 2400 = 1696
NumberOfCpus = 1024 = 1K
NumberOfCpus * (AllocatedSize - TableLength * sizeof (CPU_REGISTER_TABLE_ENTRY)) = 1696K
This patch also corrects the CopyRegisterTable() function description.
Signed-off-by: Star Zeng <star.zeng at intel.com>
Cc: Ray Ni <ray.ni at intel.com>
Cc: Eric Dong <eric.dong at intel.com>
Cc: Laszlo Ersek <lersek at redhat.com>
---
UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c | 71 +++++++++++++++++++++++--------
1 file changed, 54 insertions(+), 17 deletions(-)
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c
index 9592430636ec..d87c2efb87e7 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuS3.c
@@ -1,7 +1,7 @@
/** @file
Code for Processor S3 restoration
-Copyright (c) 2006 - 2020, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2021, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
@@ -487,6 +487,9 @@ SetRegister (
} else {
RegisterTables = (CPU_REGISTER_TABLE *)(UINTN)mAcpiCpuData.RegisterTable;
}
+ if (RegisterTables == NULL) {
+ return;
+ }
InitApicId = GetInitialApicId ();
RegisterTable = NULL;
@@ -948,7 +951,7 @@ InitSmmS3ResumeState (
}
/**
- Copy register table from ACPI NVS memory into SMRAM.
+ Copy register table from non-SMRAM into SMRAM.
@param[in] DestinationRegisterTableList Points to destination register table.
@param[in] SourceRegisterTableList Points to source register table.
@@ -967,7 +970,8 @@ CopyRegisterTable (
CopyMem (DestinationRegisterTableList, SourceRegisterTableList, NumberOfCpus * sizeof (CPU_REGISTER_TABLE));
for (Index = 0; Index < NumberOfCpus; Index++) {
- if (DestinationRegisterTableList[Index].AllocatedSize != 0) {
+ if (DestinationRegisterTableList[Index].TableLength != 0) {
+ DestinationRegisterTableList[Index].AllocatedSize = (UINT32) MultU64x32 (DestinationRegisterTableList[Index].TableLength, sizeof (CPU_REGISTER_TABLE_ENTRY));
RegisterTableEntry = AllocateCopyPool (
DestinationRegisterTableList[Index].AllocatedSize,
(VOID *)(UINTN)SourceRegisterTableList[Index].RegisterTableEntry
@@ -978,6 +982,31 @@ CopyRegisterTable (
}
}
+/**
+ Check whether the register table is empty or not.
+
+ @param[in] RegisterTable Point to the register table.
+
+ @retval TRUE The register table is empty.
+ @retval FALSE The register table is not empty.
+**/
+BOOLEAN
+IsRegisterTableEmpty (
+ IN CPU_REGISTER_TABLE *RegisterTable,
+ IN UINT32 NumberOfCpus
+ )
+{
+ UINTN Index;
+
+ for (Index = 0; Index < NumberOfCpus; Index++) {
+ if (RegisterTable[Index].TableLength != 0) {
+ return FALSE;
+ }
+ }
+
+ return TRUE;
+}
+
/**
Get ACPI CPU data.
@@ -1032,23 +1061,31 @@ GetAcpiCpuData (
CopyMem ((VOID *)(UINTN)mAcpiCpuData.IdtrProfile, (VOID *)(UINTN)AcpiCpuData->IdtrProfile, sizeof (IA32_DESCRIPTOR));
- mAcpiCpuData.PreSmmInitRegisterTable = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocatePool (mAcpiCpuData.NumberOfCpus * sizeof (CPU_REGISTER_TABLE));
- ASSERT (mAcpiCpuData.PreSmmInitRegisterTable != 0);
+ if (!IsRegisterTableEmpty ((CPU_REGISTER_TABLE *)(UINTN)AcpiCpuData->PreSmmInitRegisterTable, mAcpiCpuData.NumberOfCpus)) {
+ mAcpiCpuData.PreSmmInitRegisterTable = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocatePool (mAcpiCpuData.NumberOfCpus * sizeof (CPU_REGISTER_TABLE));
+ ASSERT (mAcpiCpuData.PreSmmInitRegisterTable != 0);
- CopyRegisterTable (
- (CPU_REGISTER_TABLE *)(UINTN)mAcpiCpuData.PreSmmInitRegisterTable,
- (CPU_REGISTER_TABLE *)(UINTN)AcpiCpuData->PreSmmInitRegisterTable,
- mAcpiCpuData.NumberOfCpus
- );
+ CopyRegisterTable (
+ (CPU_REGISTER_TABLE *)(UINTN)mAcpiCpuData.PreSmmInitRegisterTable,
+ (CPU_REGISTER_TABLE *)(UINTN)AcpiCpuData->PreSmmInitRegisterTable,
+ mAcpiCpuData.NumberOfCpus
+ );
+ } else {
+ mAcpiCpuData.PreSmmInitRegisterTable = 0;
+ }
- mAcpiCpuData.RegisterTable = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocatePool (mAcpiCpuData.NumberOfCpus * sizeof (CPU_REGISTER_TABLE));
- ASSERT (mAcpiCpuData.RegisterTable != 0);
+ if (!IsRegisterTableEmpty ((CPU_REGISTER_TABLE *)(UINTN)AcpiCpuData->RegisterTable, mAcpiCpuData.NumberOfCpus)) {
+ mAcpiCpuData.RegisterTable = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocatePool (mAcpiCpuData.NumberOfCpus * sizeof (CPU_REGISTER_TABLE));
+ ASSERT (mAcpiCpuData.RegisterTable != 0);
- CopyRegisterTable (
- (CPU_REGISTER_TABLE *)(UINTN)mAcpiCpuData.RegisterTable,
- (CPU_REGISTER_TABLE *)(UINTN)AcpiCpuData->RegisterTable,
- mAcpiCpuData.NumberOfCpus
- );
+ CopyRegisterTable (
+ (CPU_REGISTER_TABLE *)(UINTN)mAcpiCpuData.RegisterTable,
+ (CPU_REGISTER_TABLE *)(UINTN)AcpiCpuData->RegisterTable,
+ mAcpiCpuData.NumberOfCpus
+ );
+ } else {
+ mAcpiCpuData.RegisterTable = 0;
+ }
//
// Copy AP's GDT, IDT and Machine Check handler into SMRAM.
--
2.21.0.windows.1
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