diff options
| author |   Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
|---|---|---|
| committer | Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
| commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
| tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/edk2/UefiCpuPkg/Library/CpuTimerLib/DxeCpuTimerLib.c | |
| parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) | |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/edk2/UefiCpuPkg/Library/CpuTimerLib/DxeCpuTimerLib.c')
| -rw-r--r-- | roms/edk2/UefiCpuPkg/Library/CpuTimerLib/DxeCpuTimerLib.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/roms/edk2/UefiCpuPkg/Library/CpuTimerLib/DxeCpuTimerLib.c b/roms/edk2/UefiCpuPkg/Library/CpuTimerLib/DxeCpuTimerLib.c new file mode 100644 index 000000000..269e5a3e8 --- /dev/null +++ b/roms/edk2/UefiCpuPkg/Library/CpuTimerLib/DxeCpuTimerLib.c @@ -0,0 +1,85 @@ +/** @file
+ CPUID Leaf 0x15 for Core Crystal Clock frequency instance of Timer Library.
+
+ Copyright (c) 2019 Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiDxe.h>
+#include <Library/TimerLib.h>
+#include <Library/BaseLib.h>
+#include <Library/HobLib.h>
+
+extern GUID mCpuCrystalFrequencyHobGuid;
+
+/**
+ CPUID Leaf 0x15 for Core Crystal Clock Frequency.
+
+ The TSC counting frequency is determined by using CPUID leaf 0x15. Frequency in MHz = Core XTAL frequency * EBX/EAX.
+ In newer flavors of the CPU, core xtal frequency is returned in ECX or 0 if not supported.
+ @return The number of TSC counts per second.
+
+**/
+UINT64
+CpuidCoreClockCalculateTscFrequency (
+ VOID
+ );
+
+//
+// Cached CPU Crystal counter frequency
+//
+UINT64 mCpuCrystalCounterFrequency = 0;
+
+
+/**
+ Internal function to retrieves the 64-bit frequency in Hz.
+
+ Internal function to retrieves the 64-bit frequency in Hz.
+
+ @return The frequency in Hz.
+
+**/
+UINT64
+InternalGetPerformanceCounterFrequency (
+ VOID
+ )
+{
+ return mCpuCrystalCounterFrequency;
+}
+
+/**
+ The constructor function is to initialize CpuCrystalCounterFrequency.
+
+ @param ImageHandle The firmware allocated handle for the EFI image.
+ @param SystemTable A pointer to the EFI System Table.
+
+ @retval EFI_SUCCESS The constructor always returns RETURN_SUCCESS.
+
+**/
+EFI_STATUS
+EFIAPI
+DxeCpuTimerLibConstructor (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_HOB_GUID_TYPE *GuidHob;
+
+ //
+ // Initialize CpuCrystalCounterFrequency
+ //
+ GuidHob = GetFirstGuidHob (&mCpuCrystalFrequencyHobGuid);
+ if (GuidHob != NULL) {
+ mCpuCrystalCounterFrequency = *(UINT64*)GET_GUID_HOB_DATA (GuidHob);
+ } else {
+ mCpuCrystalCounterFrequency = CpuidCoreClockCalculateTscFrequency ();
+ }
+
+ if (mCpuCrystalCounterFrequency == 0) {
+ return EFI_UNSUPPORTED;
+ }
+
+ return EFI_SUCCESS;
+}
+
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