[edk2-devel] [RFC PATCH V2 07/19] MdePkg: Add ArchTimerLib library
Heinrich Schuchardt
heinrich.schuchardt at canonical.com
Thu Dec 8 01:59:55 UTC 2022
On 9/7/22 13:36, Sunil V L wrote:
> This library implements the TimerLib.h functionality. This library
> is similar to CpuTimerLib but needs the library constructor.
>
> Signed-off-by: Sunil V L <sunilvl at ventanamicro.com>
> ---
> MdePkg/Library/ArchTimerLib/ArchTimerLib.inf | 40 +++
> MdePkg/Library/ArchTimerLib/RiscV64/CpuTimerLib.c | 299 ++++++++++++++++++++
> MdePkg/Library/ArchTimerLib/ArchTimerLib.uni | 14 +
> 3 files changed, 353 insertions(+)
>
> diff --git a/MdePkg/Library/ArchTimerLib/ArchTimerLib.inf b/MdePkg/Library/ArchTimerLib/ArchTimerLib.inf
> new file mode 100644
> index 000000000000..b61ae58d0142
> --- /dev/null
> +++ b/MdePkg/Library/ArchTimerLib/ArchTimerLib.inf
> @@ -0,0 +1,40 @@
> +## @file
> +# Timer Library Instance which needs a constructor for the architecture.
> +#
> +# Copyright (c) 2016 - 2019, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
> +# Copyright (c) 2022, Ventana Micro System Inc. All rights reserved.<BR>
> +#
> +# SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> + INF_VERSION = 0x0001001b
> + BASE_NAME = ArchTimerLib
> + FILE_GUID = D3CF51A9-1CEA-4776-A8AB-CCFD14D7DAAF
> + MODULE_TYPE = BASE
> + VERSION_STRING = 1.0
> + LIBRARY_CLASS = TimerLib
> + MODULE_UNI_FILE = ArchTimerLib.uni
> + CONSTRUCTOR = ArchTimerLibConstructor
> +
> +[Sources.RISCV64]
> + RiscV64/CpuTimerLib.c
> +
> +[Packages]
> + MdePkg/MdePkg.dec
> + MdeModulePkg/MdeModulePkg.dec
> + UefiCpuPkg/UefiCpuPkg.dec
> + EmbeddedPkg/EmbeddedPkg.dec
> +
> +[LibraryClasses]
> + BaseLib
> + DebugLib
> + FdtLib
> + HobLib
> +
> +[Pcd]
> + gUefiCpuPkgTokenSpaceGuid.PcdRiscVTimerFrequencyInHz ## CONSUMES
> +
> +[Guids]
> + gFdtHobGuid
> diff --git a/MdePkg/Library/ArchTimerLib/RiscV64/CpuTimerLib.c b/MdePkg/Library/ArchTimerLib/RiscV64/CpuTimerLib.c
> new file mode 100644
> index 000000000000..a81ac8c37cad
> --- /dev/null
> +++ b/MdePkg/Library/ArchTimerLib/RiscV64/CpuTimerLib.c
> @@ -0,0 +1,299 @@
> +/** @file
> + RISC-V instance of Timer Library.
> +
> + Copyright (c) 2016 - 2022, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
> + Copyright (c) 2022, Ventana Micro Systems Inc. All rights reserved.<BR>
> +
> + SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include <Uefi.h>
> +#include <PiDxe.h>
> +#include <Library/BaseLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/PcdLib.h>
> +#include <Library/UefiDriverEntryPoint.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include <Library/HobLib.h>
> +#include <Guid/FdtHob.h>
> +#include <Register/RiscV64/RiscVAsm.h>
> +#include <Register/RiscV64/RiscVImpl.h>
> +#include <libfdt.h>
> +
> +
> +STATIC UINT32 mTimeBaseFrequency;
> +STATIC BOOLEAN mTimeBaseFreqInitialized;
> +
> +UINT32
> +InternalGetTimerFrequency(
> + VOID
> + )
> +{
> + return mTimeBaseFrequency;
> +}
> +
> +
> +/**
> + 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 = csr_read(CSR_TIME) + Delay;
> + Delay = 1 << (RISCV_TIMER_COMPARE_BITS - 2);
> + while (((Ticks - csr_read(CSR_TIME)) & (1 << (RISCV_TIMER_COMPARE_BITS - 1))) == 0) {
> + CpuPause ();
Is CpuPause() guaranteed to return before two ticks have elapsed?
'== 0' might be too strict especially when considering that interrupts
might have to be handled in future.
You don't want this routine to hang for another 2^32 ticks.
Best regards
Heinrich
> + }
> + } 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,
> + InternalGetTimerFrequency()
> + ),
> + 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,
> + InternalGetTimerFrequency()
> + ),
> + 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)csr_read (CSR_TIME);
> +}
> +
> +/**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 InternalGetTimerFrequency();
> +}
> +
> +/**
> + 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, InternalGetTimerFrequency(), &Remainder), 1000000000u);
> +
> + //
> + // Frequency < 0x100000000, so Remainder < 0x100000000, then (Remainder * 1,000,000,000)
> + // will not overflow 64-bit.
> + //
> + NanoSeconds += DivU64x32 (MultU64x32 ((UINT64)Remainder, 1000000000u), InternalGetTimerFrequency());
> +
> + return NanoSeconds;
> +}
> +
> +STATIC
> +RETURN_STATUS
> +EFIAPI
> +FdtInitializeTimerFrequency (
> + VOID
> + )
> +{
> + VOID *Hob;
> + VOID *Fdt;
> + INT32 CpusNode, Len;
> + const fdt32_t *Prop;
> +
> + Hob = GetFirstGuidHob (&gFdtHobGuid);
> + if ((Hob == NULL) || (GET_GUID_HOB_DATA_SIZE (Hob) != sizeof (UINT64))) {
> + DEBUG ((DEBUG_ERROR, "%a: No FDT Hob found\n", __FUNCTION__));
> + return EFI_NOT_FOUND;
> + }
> +
> + Fdt = (VOID *)(UINTN)*(UINT64 *)GET_GUID_HOB_DATA (Hob);
> +
> + if (fdt_check_header (Fdt) != 0) {
> + DEBUG ((
> + DEBUG_ERROR,
> + "%a: No DTB found @ 0x%p\n",
> + __FUNCTION__,
> + Fdt
> + ));
> + return EFI_NOT_FOUND;
> + }
> +
> + // The "cpus" node resides at the the root of the DT. Fetch it.
> + CpusNode = fdt_path_offset (Fdt, "/cpus");
> + if (CpusNode < 0) {
> + DEBUG ((DEBUG_ERROR, "%a: Invalid /cpus node\n", __FUNCTION__));
> + return EFI_NOT_FOUND;
> + }
> +
> + Prop = fdt_getprop((void *)Fdt, CpusNode, "timebase-frequency", &Len);
> + if (!Prop) {
> + DEBUG ((DEBUG_ERROR, "%a: timebase-frequency propertynot found\n", __FUNCTION__));
> + return EFI_NOT_FOUND;
> + }
> +
> + mTimeBaseFrequency = fdt32_to_cpu(*Prop);
> + DEBUG((DEBUG_INFO, "%a: Timer Frequency (DT) is set to 0x%x\n", __FUNCTION__, mTimeBaseFrequency));
> +
> + return EFI_SUCCESS;
> +}
> +/**
> + Initializes the Timer Frequency by reading it from the DTB
> +
> +**/
> +RETURN_STATUS
> +EFIAPI
> +ArchTimerLibConstructor (
> + VOID
> + )
> +{
> + EFI_STATUS Status;
> +
> + /*
> + * Initialize only once
> + */
> + if (mTimeBaseFreqInitialized) {
> + return EFI_SUCCESS;
> + }
> +
> + mTimeBaseFreqInitialized = 1;
> +
> + Status = FdtInitializeTimerFrequency();
> +
> + if (EFI_ERROR(Status)) {
> + mTimeBaseFrequency = PcdGet32 (PcdRiscVTimerFrequencyInHz);
> + DEBUG((DEBUG_INFO, "%a: Timer Frequency (PCD) is set to 0x%x\n", __FUNCTION__, mTimeBaseFrequency));
> + }
> +
> + return EFI_SUCCESS;
> +}
> diff --git a/MdePkg/Library/ArchTimerLib/ArchTimerLib.uni b/MdePkg/Library/ArchTimerLib/ArchTimerLib.uni
> new file mode 100644
> index 000000000000..1c900bea42bf
> --- /dev/null
> +++ b/MdePkg/Library/ArchTimerLib/ArchTimerLib.uni
> @@ -0,0 +1,14 @@
> +// /** @file
> +// Base CPU Timer Library
> +//
> +// Provides basic timer support using architecture specific methods.
> +//
> +// Copyright (c) 2022, Ventana Micro Systems Inc. All rights reserved.<BR>
> +//
> +// SPDX-License-Identifier: BSD-2-Clause-Patent
> +//
> +// **/
> +
> +#string STR_MODULE_ABSTRACT #language en-US "CPU Timer Library"
> +
> +#string STR_MODULE_DESCRIPTION #language en-US "Provides basic timer support using architecture specific methods"
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