30781febe2
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1909 Cc: Ray Ni <ray.ni@intel.com> Cc: Star Zeng <star.zeng@intel.com> Cc: Eric Dong <eric.dong@intel.com> Cc: Amy Chan <amy.chan@intel.com> Cc: Rangasai V Chaganty <rangasai.v.chaganty@intel.com> Signed-off-by: Donald Kuo <donald.kuo@intel.com> Reviewed-by: Eric Dong <eric.dong@intel.com>
86 lines
2.0 KiB
C
86 lines
2.0 KiB
C
/** @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;
|
|
}
|
|
|