diff options
Diffstat (limited to 'UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c')
-rw-r--r-- | UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c b/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c new file mode 100644 index 0000000..3ca3ca8 --- /dev/null +++ b/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c @@ -0,0 +1,195 @@ +/** @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, 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().
+
+ @param Delay A period of time to delay in ticks.
+
+**/
+VOID
+EFIAPI
+InternalX86Delay (
+ IN UINT32 Delay
+ )
+{
+ INT32 Ticks;
+ UINT32 PowerOfTwoCounter;
+
+ //
+ // The target timer count is calculated here
+ //
+ Ticks = GetApicTimerCurrentCount () - Delay;
+
+ //
+ // Wait until time out
+ // Delay > 2^31 could not be handled by this function
+ // Timer wrap-arounds are handled correctly by this function
+ //
+ PowerOfTwoCounter = GetPowerOfTwo32 (GetApicTimerInitCount ());
+ while (((UINT32)(GetApicTimerCurrentCount () - Ticks) & PowerOfTwoCounter) == 0) {
+ CpuPause ();
+ }
+}
+
+/**
+ 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 ();
+ //
+ // make sure StartValue is all 1s from High Bit
+ //
+ ASSERT ((*StartValue & (*StartValue + 1)) == 0);
+ }
+
+ if (EndValue != NULL) {
+ *EndValue = 0;
+ }
+
+ return (UINT64) InternalX86GetTimerFrequency ();
+}
|