Re: [edk2-devel] [edk2-staging/RISC-V-V2 PATCH v2 17/29] RiscVPkg/Library: Add RISC-V timer library

["Leif Lindholm" <leif.lindholm@linaro.org>]

On Mon, Sep 23, 2019 at 08:31:43AM +0800, Abner Chang wrote:
> Timer library for RISC-V
> 
> Signed-off-by: Abner Chang <abner.chang@hpe.com>
> ---
>  .../Library/RiscVTimerLib/BaseRiscVTimerLib.inf    |  34 ++++
>  RiscVPkg/Library/RiscVTimerLib/RiscVTimerLib.c     | 195 +++++++++++++++++++++
>  RiscVPkg/Library/RiscVTimerLib/RiscVTimerLib.h     |  21 +++
>  RiscVPkg/RiscVPkg.dec                              |   9 +
>  4 files changed, 259 insertions(+)
>  create mode 100644 RiscVPkg/Library/RiscVTimerLib/BaseRiscVTimerLib.inf
>  create mode 100644 RiscVPkg/Library/RiscVTimerLib/RiscVTimerLib.c
>  create mode 100644 RiscVPkg/Library/RiscVTimerLib/RiscVTimerLib.h
> 
> diff --git a/RiscVPkg/Library/RiscVTimerLib/BaseRiscVTimerLib.inf b/RiscVPkg/Library/RiscVTimerLib/BaseRiscVTimerLib.inf
> new file mode 100644
> index 0000000..af27049
> --- /dev/null
> +++ b/RiscVPkg/Library/RiscVTimerLib/BaseRiscVTimerLib.inf
> @@ -0,0 +1,34 @@
> +## @file
> +# RISC-V Timer Library Instance.
> +#
> +#  Copyright (c) 2016 - 2019, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
> +#
> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> +#
> +##
> +
> +[Defines]
> +  INF_VERSION    = 0x0001001b
> +  BASE_NAME      = BaseRiscVTimerLib
> +  FILE_GUID      = FB648CF5-91BE-4737-9023-FD807AC6D96D
> +  MODULE_TYPE    = BASE
> +  VERSION_STRING = 1.0
> +  LIBRARY_CLASS  = TimerLib
> +
> +[Sources]
> +  RiscVTimerLib.c
> +
> +[Packages]
> +  MdePkg/MdePkg.dec
> +  RiscVPkg/RiscVPkg.dec
> +
> +[Pcd]
> +  gUefiRiscVPkgTokenSpaceGuid.PcdRiscVMachineTimerTickInNanoSecond
> +  gUefiRiscVPkgTokenSpaceGuid.PcdRiscVMachineTimerFrequencyInHerz
> +
> +[LibraryClasses]
> +  BaseLib
> +  PcdLib
> +  RiscVCpuLib
> +  RiscVPlatformTimerLib
> +
> diff --git a/RiscVPkg/Library/RiscVTimerLib/RiscVTimerLib.c b/RiscVPkg/Library/RiscVTimerLib/RiscVTimerLib.c
> new file mode 100644
> index 0000000..acb8c77
> --- /dev/null
> +++ b/RiscVPkg/Library/RiscVTimerLib/RiscVTimerLib.c
> @@ -0,0 +1,195 @@
> +/** @file
> +  RISC-V instance of Timer Library.
> +
> +  Copyright (c) 2016 - 2019, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
> +
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +#include <RiscVTimerLib.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 = RiscVReadMachineTimer () + Delay;
> +    Delay = 1 << (RISCV_TIMER_COMPARE_BITS - 2);
> +    while (((Ticks - RiscVReadMachineTimer ()) & ( 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 (PcdRiscVMachineTimerFrequencyInHerz)
> +                ),
> +              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 (PcdRiscVMachineTimerFrequencyInHerz)
> +                ),
> +              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)RiscVReadMachineTimer ();
> +}
> +
> +/**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 (PcdRiscVMachineTimerFrequencyInHerz);
> +}
> +
> +/**
> +  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 (PcdRiscVMachineTimerFrequencyInHerz), &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 (PcdRiscVMachineTimerFrequencyInHerz));
> +
> +  return NanoSeconds;
> +}
> diff --git a/RiscVPkg/Library/RiscVTimerLib/RiscVTimerLib.h b/RiscVPkg/Library/RiscVTimerLib/RiscVTimerLib.h
> new file mode 100644
> index 0000000..bac3a70
> --- /dev/null
> +++ b/RiscVPkg/Library/RiscVTimerLib/RiscVTimerLib.h
> @@ -0,0 +1,21 @@
> +/** @file
> +  RISC-V timer library definitions.
> +
> +  Copyright (c) 2016 - 2019, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>
> +
> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> +
> +**/
> +
> +
> +#ifndef _RISCV_TIMER_LIB_INTERNAL_H_
> +#define _RISCV_TIMER_LIB_INTERNAL_H_
> +
> +#include <Uefi.h>
> +#include <Library/PcdLib.h>
> +#include <Library/DebugLib.h>
> +#include <Library/BaseLib.h>
> +
> +#include <Library/RiscVCpuLib.h>

This header file includes only include statements.
Please delete the file and move the includes to the .c file, sorted
alphabtically.

/
    Leif

> +
> +#endif // _RISCV_TIMER_LIB_INTERNAL_H_
> diff --git a/RiscVPkg/RiscVPkg.dec b/RiscVPkg/RiscVPkg.dec
> index 74314e8..a91392f 100644
> --- a/RiscVPkg/RiscVPkg.dec
> +++ b/RiscVPkg/RiscVPkg.dec
> @@ -23,5 +23,14 @@
>  [Guids]
>    gUefiRiscVPkgTokenSpaceGuid  = { 0x4261e9c8, 0x52c0, 0x4b34, { 0x85, 0x3d, 0x48, 0x46, 0xea, 0xd3, 0xb7, 0x2c}}
>  
> +[PcdsFixedAtBuild]
> +  #
> +  #                                                   1000000000
> +  # PcdRiscVMachineTimerTickInNanoSecond = ---------------------------------------
> +  #                                          PcdRiscVMachineTimerFrequencyInHerz
> +  #
> +  gUefiRiscVPkgTokenSpaceGuid.PcdRiscVMachineTimerTickInNanoSecond|100|UINT64|0x00001010
> +  gUefiRiscVPkgTokenSpaceGuid.PcdRiscVMachineTimerFrequencyInHerz|10000000|UINT64|0x00001011
> +
>  [UserExtensions.TianoCore."ExtraFiles"]
>    RiscVPkgExtra.uni
> -- 
> 2.7.4
> 
> 
> 
>