diff options
Diffstat (limited to 'UefiCpuPkg/Library/BaseRiscV64CpuTimerLib/CpuTimerLib.c')
| -rw-r--r-- | UefiCpuPkg/Library/BaseRiscV64CpuTimerLib/CpuTimerLib.c | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/UefiCpuPkg/Library/BaseRiscV64CpuTimerLib/CpuTimerLib.c b/UefiCpuPkg/Library/BaseRiscV64CpuTimerLib/CpuTimerLib.c new file mode 100644 index 0000000000..9c8efc0f35 --- /dev/null +++ b/UefiCpuPkg/Library/BaseRiscV64CpuTimerLib/CpuTimerLib.c @@ -0,0 +1,199 @@ +/** @file
+ RISC-V instance of Timer Library.
+
+ Copyright (c) 2016 - 2022, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/PcdLib.h>
+#include <Register/RiscV64/RiscVImpl.h>
+
+/**
+ 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
+InternalRiscVTimerDelay (
+ IN UINT32 Delay
+ )
+{
+ UINT32 Ticks;
+ UINT32 Times;
+
+ Times = Delay >> (RISCV_TIMER_COMPARE_BITS - 2);
+ Delay &= ((1 << (RISCV_TIMER_COMPARE_BITS - 2)) - 1);
+ do {
+ //
+ // The target timer count is calculated here
+ //
+ Ticks = RiscVReadTimer () + Delay;
+ Delay = 1 << (RISCV_TIMER_COMPARE_BITS - 2);
+ while (((Ticks - RiscVReadTimer ()) & (1 << (RISCV_TIMER_COMPARE_BITS - 1))) == 0) {
+ CpuPause ();
+ }
+ } 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 MicroSeconds
+
+**/
+UINTN
+EFIAPI
+MicroSecondDelay (
+ IN UINTN MicroSeconds
+ )
+{
+ InternalRiscVTimerDelay (
+ (UINT32)DivU64x32 (
+ MultU64x32 (
+ MicroSeconds,
+ PcdGet64 (PcdCpuCoreCrystalClockFrequency)
+ ),
+ 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 NanoSeconds
+
+**/
+UINTN
+EFIAPI
+NanoSecondDelay (
+ IN UINTN NanoSeconds
+ )
+{
+ InternalRiscVTimerDelay (
+ (UINT32)DivU64x32 (
+ MultU64x32 (
+ NanoSeconds,
+ PcdGet64 (PcdCpuCoreCrystalClockFrequency)
+ ),
+ 1000000000u
+ )
+ );
+ return NanoSeconds;
+}
+
+/**
+ 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)RiscVReadTimer ();
+}
+
+/**return
+ 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 = 0;
+ }
+
+ if (EndValue != NULL) {
+ *EndValue = 32 - 1;
+ }
+
+ return PcdGet64 (PcdCpuCoreCrystalClockFrequency);
+}
+
+/**
+ 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 NanoSeconds;
+ UINT32 Remainder;
+
+ //
+ // Ticks
+ // Time = --------- x 1,000,000,000
+ // Frequency
+ //
+ NanoSeconds = MultU64x32 (DivU64x32Remainder (Ticks, PcdGet64 (PcdCpuCoreCrystalClockFrequency), &Remainder), 1000000000u);
+
+ //
+ // Frequency < 0x100000000, so Remainder < 0x100000000, then (Remainder * 1,000,000,000)
+ // will not overflow 64-bit.
+ //
+ NanoSeconds += DivU64x32 (MultU64x32 ((UINT64)Remainder, 1000000000u), PcdGet64 (PcdCpuCoreCrystalClockFrequency));
+
+ return NanoSeconds;
+}
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