diff options
Diffstat (limited to 'Core/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c')
| -rw-r--r-- | Core/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/Core/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c b/Core/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c new file mode 100644 index 0000000000..f703d7e477 --- /dev/null +++ b/Core/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c @@ -0,0 +1,266 @@ +/** @file
+ Timer Library functions built upon local APIC on IA32/x64.
+
+ This library uses the local APIC library so that it supports x2APIC mode.
+
+ Copyright (c) 2010 - 2015, Intel Corporation. All rights reserved.<BR>
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php.
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include <Base.h>
+#include <Library/TimerLib.h>
+#include <Library/BaseLib.h>
+#include <Library/PcdLib.h>
+#include <Library/DebugLib.h>
+#include <Library/LocalApicLib.h>
+
+/**
+ Internal function to return the frequency of the local APIC timer.
+
+ @return The frequency of the timer in Hz.
+
+**/
+UINT32
+EFIAPI
+InternalX86GetTimerFrequency (
+ VOID
+ )
+{
+ UINTN Divisor;
+
+ GetApicTimerState (&Divisor, NULL, NULL);
+ return PcdGet32(PcdFSBClock) / (UINT32)Divisor;
+}
+
+/**
+ 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().
+
+ This function will ASSERT if the APIC timer intial count returned from
+ GetApicTimerInitCount() is zero.
+
+ @param Delay A period of time to delay in ticks.
+
+**/
+VOID
+EFIAPI
+InternalX86Delay (
+ IN UINT32 Delay
+ )
+{
+ INT32 Ticks;
+ UINT32 Times;
+ UINT32 InitCount;
+ UINT32 StartTick;
+
+ //
+ // In case Delay is too larger, separate it into several small delay slot.
+ // Devided Delay by half value of Init Count is to avoid Delay close to
+ // the Init Count, timeout maybe missing if the time consuming between 2
+ // GetApicTimerCurrentCount() invoking is larger than the time gap between
+ // Delay and the Init Count.
+ //
+ InitCount = GetApicTimerInitCount ();
+ ASSERT (InitCount != 0);
+ Times = Delay / (InitCount / 2);
+ Delay = Delay % (InitCount / 2);
+
+ //
+ // Get Start Tick and do delay
+ //
+ StartTick = GetApicTimerCurrentCount ();
+ do {
+ //
+ // Wait until time out by Delay value
+ //
+ do {
+ CpuPause ();
+ //
+ // Get Ticks from Start to Current.
+ //
+ Ticks = StartTick - GetApicTimerCurrentCount ();
+ //
+ // Ticks < 0 means Timer wrap-arounds happens.
+ //
+ if (Ticks < 0) {
+ Ticks += InitCount;
+ }
+ } while ((UINT32)Ticks < Delay);
+
+ //
+ // Update StartTick and Delay for next delay slot
+ //
+ StartTick -= (StartTick > Delay) ? Delay : (Delay - InitCount);
+ Delay = InitCount / 2;
+ } while (Times-- > 0);
+}
+
+/**
+ Stalls the CPU for at least the given number of microseconds.
+
+ Stalls the CPU for the number of microseconds specified by MicroSeconds.
+
+ @param MicroSeconds The minimum number of microseconds to delay.
+
+ @return The value of MicroSeconds inputted.
+
+**/
+UINTN
+EFIAPI
+MicroSecondDelay (
+ IN UINTN MicroSeconds
+ )
+{
+ InternalX86Delay (
+ (UINT32)DivU64x32 (
+ MultU64x64 (
+ InternalX86GetTimerFrequency (),
+ MicroSeconds
+ ),
+ 1000000u
+ )
+ );
+ return MicroSeconds;
+}
+
+/**
+ Stalls the CPU for at least the given number of nanoseconds.
+
+ Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
+
+ @param NanoSeconds The minimum number of nanoseconds to delay.
+
+ @return The value of NanoSeconds inputted.
+
+**/
+UINTN
+EFIAPI
+NanoSecondDelay (
+ IN UINTN NanoSeconds
+ )
+{
+ InternalX86Delay (
+ (UINT32)DivU64x32 (
+ MultU64x64 (
+ InternalX86GetTimerFrequency (),
+ NanoSeconds
+ ),
+ 1000000000u
+ )
+ );
+ return NanoSeconds;
+}
+
+/**
+ 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)GetApicTimerCurrentCount ();
+}
+
+/**
+ Retrieves the 64-bit frequency in Hz and the range of performance counter
+ values.
+
+ If StartValue is not NULL, then the value that the performance counter starts
+ with immediately after is it rolls over is returned in StartValue. If
+ EndValue is not NULL, then the value that the performance counter end with
+ immediately before it rolls over is returned in EndValue. The 64-bit
+ frequency of the performance counter in Hz is always returned. If StartValue
+ is less than EndValue, then the performance counter counts up. If StartValue
+ is greater than EndValue, then the performance counter counts down. For
+ example, a 64-bit free running counter that counts up would have a StartValue
+ of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
+ that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
+
+ @param StartValue The value the performance counter starts with when it
+ rolls over.
+ @param EndValue The value that the performance counter ends with before
+ it rolls over.
+
+ @return The frequency in Hz.
+
+**/
+UINT64
+EFIAPI
+GetPerformanceCounterProperties (
+ OUT UINT64 *StartValue, OPTIONAL
+ OUT UINT64 *EndValue OPTIONAL
+ )
+{
+ if (StartValue != NULL) {
+ *StartValue = (UINT64)GetApicTimerInitCount ();
+ }
+
+ if (EndValue != NULL) {
+ *EndValue = 0;
+ }
+
+ return (UINT64) InternalX86GetTimerFrequency ();
+}
+
+/**
+ Converts elapsed ticks of performance counter to time in nanoseconds.
+
+ This function converts the elapsed ticks of running performance counter to
+ time value in unit of nanoseconds.
+
+ @param Ticks The number of elapsed ticks of running performance counter.
+
+ @return The elapsed time in nanoseconds.
+
+**/
+UINT64
+EFIAPI
+GetTimeInNanoSecond (
+ IN UINT64 Ticks
+ )
+{
+ UINT64 Frequency;
+ UINT64 NanoSeconds;
+ UINT64 Remainder;
+ INTN Shift;
+
+ Frequency = GetPerformanceCounterProperties (NULL, NULL);
+
+ //
+ // Ticks
+ // Time = --------- x 1,000,000,000
+ // Frequency
+ //
+ NanoSeconds = MultU64x32 (DivU64x64Remainder (Ticks, Frequency, &Remainder), 1000000000u);
+
+ //
+ // Ensure (Remainder * 1,000,000,000) will not overflow 64-bit.
+ // Since 2^29 < 1,000,000,000 = 0x3B9ACA00 < 2^30, Remainder should < 2^(64-30) = 2^34,
+ // i.e. highest bit set in Remainder should <= 33.
+ //
+ Shift = MAX (0, HighBitSet64 (Remainder) - 33);
+ Remainder = RShiftU64 (Remainder, (UINTN) Shift);
+ Frequency = RShiftU64 (Frequency, (UINTN) Shift);
+ NanoSeconds += DivU64x64Remainder (MultU64x32 (Remainder, 1000000000u), Frequency, NULL);
+
+ return NanoSeconds;
+}
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