PeiAcpiTimerLib.c

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#include <PiPei.h>
#include <Library/TimerLib.h>
#include <Library/BaseLib.h>
#include <Library/HobLib.h>
#include <Library/DebugLib.h>
 
extern GUID  mFrequencyHobGuid;
 
UINT64
InternalCalculateTscFrequency (
  VOID
  );
 
UINT64
InternalGetPerformanceCounterFrequency (
  VOID
  )
{
  UINT64             *PerformanceCounterFrequency;
  EFI_HOB_GUID_TYPE  *GuidHob;
 
  PerformanceCounterFrequency = NULL;
  GuidHob                     = GetFirstGuidHob (&mFrequencyHobGuid);
  if (GuidHob == NULL) {
    PerformanceCounterFrequency = (UINT64 *)BuildGuidHob (&mFrequencyHobGuid, sizeof (*PerformanceCounterFrequency));
    ASSERT (PerformanceCounterFrequency != NULL);
    *PerformanceCounterFrequency = InternalCalculateTscFrequency ();
  } else {
    PerformanceCounterFrequency = (UINT64 *)GET_GUID_HOB_DATA (GuidHob);
  }
 
  return *PerformanceCounterFrequency;
}