/**
Stalls the CPU for at least the given number of ticks.
Stalls the CPU for at least the given number of ticks. It's invoked by
MicroSecondDelay() and NanoSecondDelay().
@param Delay A period of time to delay in ticks.
**/
STATIC
VOID
InternalAcpiDelay (
IN UINT32 Delay
)
{
UINT32 Ticks;
UINT32 Times;
Times = Delay >> (gAcpiDesc->PM_TMR_BLK.RegisterBitWidth - 2);
Delay &= (1 << (gAcpiDesc->PM_TMR_BLK.RegisterBitWidth - 2)) - 1;
do {
//
// The target timer count is calculated here
//
Ticks = InternalAcpiGetTimerTick () + Delay;
Delay = 1 << (gAcpiDesc->PM_TMR_BLK.RegisterBitWidth - 2);
//
// Wait until time out
// Delay >= 2^23 (if ACPI provide 24-bit timer) or Delay >= 2^31 (if ACPI
// provide 32-bit timer) could not be handled by this function
// Timer wrap-arounds are handled correctly by this function
//
while (((Ticks - InternalAcpiGetTimerTick ()) & (1 << (gAcpiDesc->PM_TMR_BLK.RegisterBitWidth - 1))) == 0) {
CpuPause ();
}
} while (Times-- > 0);
}
/**
Stalls the CPU for at least the given number of ticks.
Stalls the CPU for at least the given number of ticks. It's invoked by
MicroSecondDelay() and NanoSecondDelay().
@param Delay A period of time to delay in ticks.
**/
STATIC
VOID
InternalAcpiDelay (
IN UINT32 Delay
)
{
UINT32 Ticks;
UINT32 Times;
Times = Delay >> 22;
Delay &= BIT22 - 1;
do {
//
// The target timer count is calculated here
//
Ticks = InternalAcpiGetTimerTick () + Delay;
Delay = BIT22;
//
// Wait until time out
// Delay >= 2^23 could not be handled by this function
// Timer wrap-arounds are handled correctly by this function
//
while (((Ticks - InternalAcpiGetTimerTick ()) & BIT23) == 0) {
CpuPause ();
}
} while (Times-- > 0);
}
/**
Retrieves the current value of a 64-bit free running performance counter.
Retrieves the current value of a 64-bit free running performance counter. The
counter can either count up by 1 or count down by 1. If the physical
performance counter counts by a larger increment, then the counter values
must be translated. The properties of the counter can be retrieved from
GetPerformanceCounterProperties().
@return The current value of the free running performance counter.
**/
UINT64
EFIAPI
GetPerformanceCounter (
VOID
)
{
return (UINT64)InternalAcpiGetTimerTick ();
}
/**
Retrieves the current value of a 64-bit free running performance counter.
Retrieves the current value of a 64-bit free running performance counter. The
counter can either count up by 1 or count down by 1. If the physical
performance counter counts by a larger increment, then the counter values
must be translated. The properties of the counter can be retrieved from
GetPerformanceCounterProperties().
@return The current value of the free running performance counter.
**/
UINT64
EFIAPI
GetPerformanceCounter (
VOID
)
{
if (InternalGetApciDescrptionTable() == NULL) {
return 0;
}
return (UINT64)InternalAcpiGetTimerTick ();
}
