Add the LoongArch64 CPU Timer instance to CpuTimerLib, using CPUCFG 0x4 and 0x5 for Stable Counter frequency.
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4584 Cc: Eric Dong <eric.d...@intel.com> Cc: Ray Ni <ray...@intel.com> Cc: Rahul Kumar <rahul1.ku...@intel.com> Cc: Gerd Hoffmann <kra...@redhat.com> Signed-off-by: Chao Li <lic...@loongson.cn> --- .../Library/CpuTimerLib/BaseCpuTimerLib.inf | 9 +- .../CpuTimerLib/LoongArch64/CpuTimerLib.c | 251 ++++++++++++++++++ 2 files changed, 258 insertions(+), 2 deletions(-) create mode 100644 UefiCpuPkg/Library/CpuTimerLib/LoongArch64/CpuTimerLib.c diff --git a/UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.inf b/UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.inf index de0648de91..7e6152ef7e 100644 --- a/UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.inf +++ b/UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.inf @@ -5,6 +5,7 @@ # counter features are provided by the processors time stamp counter. # # Copyright (c) 2021, Intel Corporation. All rights reserved.<BR> +# Copyright (c) 2024, Loongson Technology Corporation Limited. All rights reserved.<BR> # SPDX-License-Identifier: BSD-2-Clause-Patent # ## @@ -18,18 +19,22 @@ LIBRARY_CLASS = TimerLib MODULE_UNI_FILE = BaseCpuTimerLib.uni -[Sources] +[Sources.IA32, Sources.X64] CpuTimerLib.c BaseCpuTimerLib.c +[Sources.LOONGARCH64] + LoongArch64/CpuTimerLib.c + [Packages] MdePkg/MdePkg.dec UefiCpuPkg/UefiCpuPkg.dec [LibraryClasses] BaseLib - PcdLib DebugLib + PcdLib + SafeIntLib [Pcd] gUefiCpuPkgTokenSpaceGuid.PcdCpuCoreCrystalClockFrequency ## CONSUMES diff --git a/UefiCpuPkg/Library/CpuTimerLib/LoongArch64/CpuTimerLib.c b/UefiCpuPkg/Library/CpuTimerLib/LoongArch64/CpuTimerLib.c new file mode 100644 index 0000000000..a5ae8d0185 --- /dev/null +++ b/UefiCpuPkg/Library/CpuTimerLib/LoongArch64/CpuTimerLib.c @@ -0,0 +1,251 @@ +/** @file + CPUCFG 0x4 and 0x5 for Stable Counter frequency instance of Timer Library. + + Copyright (c) 2024, Loongson Technology Corporation Limited. All rights reserved.<BR> + + SPDX-License-Identifier: BSD-2-Clause-Patent +**/ + +#include <Base.h> +#include <Library/BaseLib.h> +#include <Library/DebugLib.h> +#include <Library/SafeIntLib.h> +#include <Library/TimerLib.h> +#include <Register/LoongArch64/Cpucfg.h> + +/** + Calculate clock frequency using CPUCFG 0x4 and 0x5 registers. + + @param VOID. + + @return The frequency in Hz. + +**/ +STATIC +UINT64 +CalcConstFreq ( + VOID + ) +{ + UINT32 BaseFreq; + UINT64 ClockMultiplier; + UINT32 ClockDivide; + CPUCFG_REG4_INFO_DATA CcFreq; + CPUCFG_REG5_INFO_DATA CpucfgReg5Data; + UINT64 StableTimerFreq; + + // + // Get the the crystal frequency corresponding to the constant + // frequency timer and the clock used by the timer. + // + AsmCpucfg (CPUCFG_REG4_INFO, &CcFreq.Uint32); + + // + // Get the multiplication factor and frequency division factor + // corresponding to the constant frequency timer and the clock + // used by the timer. + // + AsmCpucfg (CPUCFG_REG5_INFO, &CpucfgReg5Data.Uint32); + + BaseFreq = CcFreq.Bits.CC_FREQ; + ClockMultiplier = CpucfgReg5Data.Bits.CC_MUL & 0xFFFF; + ClockDivide = CpucfgReg5Data.Bits.CC_DIV & 0xFFFF; + + if ((BaseFreq == 0x0) || (ClockMultiplier == 0x0) || (ClockDivide == 0x0)) { + DEBUG (( + DEBUG_ERROR, + "LoongArch Stable Timer is not available in the CPU, hence this library cannot be used.\n" + )); + ASSERT (FALSE); + CpuDeadLoop (); + } + + StableTimerFreq = ((ClockMultiplier * BaseFreq) / ClockDivide); + + if (StableTimerFreq == 0x0) { + ASSERT (FALSE); + } + + return StableTimerFreq; +} + +/** + 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 + ) +{ + UINT64 CurrentTicks, ExceptedTicks, Remaining; + RETURN_STATUS Status; + + Status = SafeUint64Mult (MicroSeconds, CalcConstFreq (), &Remaining); + ASSERT_RETURN_ERROR (Status); + + ExceptedTicks = DivU64x32 (Remaining, 1000000U); + CurrentTicks = AsmReadStableCounter (); + ExceptedTicks += CurrentTicks; + + do { + CurrentTicks = AsmReadStableCounter (); + } while (CurrentTicks < ExceptedTicks); + + 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 + ) +{ + UINTN MicroSeconds; + + // Round up to 1us Tick Number + MicroSeconds = NanoSeconds / 1000; + MicroSeconds += ((NanoSeconds % 1000) == 0) ? 0 : 1; + + MicroSecondDelay (MicroSeconds); + + return NanoSeconds; +} + +/** + Retrieves the current value of a 64-bit free running Stable Counter. + + The LoongArch defines a constant frequency timer, whose main body is a + 64-bit counter called StableCounter. StableCounter is set to 0 after + reset, and then increments by 1 every counting clock cycle. When the + count reaches all 1s, it automatically wraps around to 0 and continues + to increment. + The properties of the Stable Counter can be retrieved from + GetPerformanceCounterProperties(). + + @return The current value of the Stable Counter. + +**/ +UINT64 +EFIAPI +GetPerformanceCounter ( + VOID + ) +{ + // + // Just return the value of Stable Counter. + // + return AsmReadStableCounter (); +} + +/** + Retrieves the 64-bit frequency in Hz and the range of Stable Counter + values. + + If StartValue is not NULL, then the value that the stbale counter starts + with immediately after is it rolls over is returned in StartValue. If + EndValue is not NULL, then the value that the stable counter end with + immediately before it rolls over is returned in EndValue. The 64-bit + frequency of the system frequency in Hz is always returned. + + @param StartValue The value the stable counter starts with when it + rolls over. + @param EndValue The value that the stable 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 = 0xFFFFFFFFFFFFFFFFULL; + } + + return CalcConstFreq (); +} + +/** + 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; + RETURN_STATUS Status; + + Frequency = GetPerformanceCounterProperties (NULL, NULL); + + // + // Ticks + // Time = --------- x 1,000,000,000 + // Frequency + // + Status = SafeUint64Mult ( + DivU64x64Remainder (Ticks, Frequency, &Remainder), + 1000000000u, + &NanoSeconds + ); + + // + // 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); + + Status = SafeUint64Add ( + NanoSeconds, + DivU64x64Remainder ( + MultU64x32 (Remainder, 1000000000u), + Frequency, + NULL + ), + &NanoSeconds + ); + ASSERT_RETURN_ERROR (Status); + + return NanoSeconds; +} -- 2.27.0 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. 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