diff options
Diffstat (limited to 'UefiCpuPkg/Library/SmmRelocationLib/X64/Semaphore.c')
-rw-r--r-- | UefiCpuPkg/Library/SmmRelocationLib/X64/Semaphore.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/UefiCpuPkg/Library/SmmRelocationLib/X64/Semaphore.c b/UefiCpuPkg/Library/SmmRelocationLib/X64/Semaphore.c new file mode 100644 index 0000000..53f3084 --- /dev/null +++ b/UefiCpuPkg/Library/SmmRelocationLib/X64/Semaphore.c @@ -0,0 +1,69 @@ +/** @file
+ Semaphore mechanism to indicate to the BSP that an AP has exited SMM
+ after SMBASE relocation.
+
+ Copyright (c) 2024, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "InternalSmmRelocationLib.h"
+
+X86_ASSEMBLY_PATCH_LABEL gPatchSmmRelocationOriginalAddressPtr32;
+X86_ASSEMBLY_PATCH_LABEL gPatchRebasedFlagAddr32;
+
+UINTN mSmmRelocationOriginalAddress;
+volatile BOOLEAN *mRebasedFlag;
+
+/**
+AP Semaphore operation in 32-bit mode while BSP runs in 64-bit mode.
+**/
+VOID
+SmmRelocationSemaphoreComplete32 (
+ VOID
+ );
+
+/**
+ Hook return address of SMM Save State so that semaphore code
+ can be executed immediately after AP exits SMM to indicate to
+ the BSP that an AP has exited SMM after SMBASE relocation.
+
+ @param[in] CpuIndex The processor index.
+ @param[in] RebasedFlag A pointer to a flag that is set to TRUE
+ immediately after AP exits SMM.
+
+**/
+VOID
+SemaphoreHook (
+ IN UINTN CpuIndex,
+ IN volatile BOOLEAN *RebasedFlag
+ )
+{
+ SMRAM_SAVE_STATE_MAP *CpuState;
+ UINTN TempValue;
+
+ mRebasedFlag = RebasedFlag;
+ PatchInstructionX86 (
+ gPatchRebasedFlagAddr32,
+ (UINT32)(UINTN)mRebasedFlag,
+ 4
+ );
+
+ CpuState = (SMRAM_SAVE_STATE_MAP *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET);
+ mSmmRelocationOriginalAddress = HookReturnFromSmm (
+ CpuIndex,
+ CpuState,
+ (UINT64)(UINTN)&SmmRelocationSemaphoreComplete32,
+ (UINT64)(UINTN)&SmmRelocationSemaphoreComplete
+ );
+
+ //
+ // Use temp value to fix ICC compiler warning
+ //
+ TempValue = (UINTN)&mSmmRelocationOriginalAddress;
+ PatchInstructionX86 (
+ gPatchSmmRelocationOriginalAddressPtr32,
+ (UINT32)TempValue,
+ 4
+ );
+}
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