Re: [edk2-devel] [edk2-platforms][PATCH V1 06/16] Platform/Loongson: Add StableTimerLib.

["xianglai" <lixianglai@loongson.cn>]

Hi,Mike:
  Thank you for helping to review the code.
  I feel sorry for the late reply, September 10 to September 12 is our Mid-Autumn Festival holiday, 
  Happy Mid-Autumn Festival.

1.The list of s files in all patches is ：
./Library/MmuLib/Mmu.S                   This file is related to mmu and implements the page table refill exception.
./Library/StableTimerLib/Count.S         This file implements the interrupt enable function.
./Sec/LoongArch64/Start.S                This file implements the initialization of the SEC phase after the cpu starts
                                         and the code related to switching from the assembly environment to the C environment for execution.
./Drivers/CpuDxe/LoongArch64/Fpu.S       This file implements the fpu initialization function.
./Drivers/CpuDxe/LoongArch64/LoongArch.S This file is related to exceptions, including the implementation of the exception entry function,
                                         saving and replying to the scene, and setting the exception entry address.

loongarch structure cpu defines a series of control status registers (CSR), 
their read and write operations need to be completed through the csrrd and csrwr instructions, 
can not be accessed directly through the address, so these assemblies are not optimized.


2. I didn't find the Tab character in this patch.
I have tried several search methods:
grep $'\t' -nr  ./
grep '	'  -nr ./
/^I   in vim

Best wishes.
xianglai.

> -----原始邮件-----
> 发件人: "Michael D Kinney" <michael.d.kinney@intel.com>
> 发送时间:2022-09-10 00:49:00 (星期六)
> 收件人: "devel@edk2.groups.io" <devel@edk2.groups.io>, "lixianglai@loongson.cn" <lixianglai@loongson.cn>, "Kinney, Michael D" <michael.d.kinney@intel.com>
> 抄送: "maobibo@loongson.cn" <maobibo@loongson.cn>
> 主题: Re: [edk2-devel] [edk2-platforms][PATCH V1 06/16] Platform/Loongson: Add StableTimerLib.
> 
> I see a mix of inline assembly and .S files.  Recommend avoiding inline assembly.
> 
> Also appears to be some TAB characters in this patch.  Convert tabs to spaces.
> 
> Mike
> 
> > -----Original Message-----
> > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of xianglai
> > Sent: Thursday, September 8, 2022 8:12 PM
> > To: devel@edk2.groups.io
> > Cc: maobibo@loongson.cn
> > Subject: [edk2-devel] [edk2-platforms][PATCH V1 06/16] Platform/Loongson: Add StableTimerLib.
> > 
> > This library provides a delay interface and a timing interface.
> > 
> > Signed-off-by: xianglai li <lixianglai@loongson.cn>
> > ---
> >  .../Include/Library/StableTimer.h             |  42 +++
> >  .../Library/StableTimerLib/Count.S            |  26 ++
> >  .../Library/StableTimerLib/TimerLib.c         | 262 ++++++++++++++++++
> >  .../Library/StableTimerLib/TimerLib.inf       |  28 ++
> >  4 files changed, 358 insertions(+)
> >  create mode 100644 Platform/Loongson/LoongArchQemuPkg/Include/Library/StableTimer.h
> >  create mode 100644 Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/Count.S
> >  create mode 100644 Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/TimerLib.c
> >  create mode 100644 Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/TimerLib.inf
> > 
> > diff --git a/Platform/Loongson/LoongArchQemuPkg/Include/Library/StableTimer.h
> > b/Platform/Loongson/LoongArchQemuPkg/Include/Library/StableTimer.h
> > new file mode 100644
> > index 0000000000..bd6a1eb90f
> > --- /dev/null
> > +++ b/Platform/Loongson/LoongArchQemuPkg/Include/Library/StableTimer.h
> > @@ -0,0 +1,42 @@
> > +/** @file
> > 
> > +
> > 
> > +  Copyright (c) 2021 Loongson Technology Corporation Limited. All rights reserved.<BR>
> > 
> > +
> > 
> > +  SPDX-License-Identifier: BSD-2-Clause-Patent
> > 
> > +
> > 
> > +  @par Glossary:
> > 
> > +    - Csr    - Cpu Status Register
> > 
> > +    - Calc   - Calculation
> > 
> > +    - Freq   - frequency
> > 
> > +**/
> > 
> > +
> > 
> > +#ifndef STABLE_TIMER_H_
> > 
> > +#define STABLE_TIMER_H_
> > 
> > +#include "Library/Cpu.h"
> > 
> > +
> > 
> > +/**
> > 
> > +  Gets the timer count value.
> > 
> > +
> > 
> > +  @param[] VOID
> > 
> > +
> > 
> > +  @retval  timer count value.
> > 
> > +**/
> > 
> > +UINTN
> > 
> > +EFIAPI
> > 
> > +CsrReadTime (
> > 
> > +  VOID
> > 
> > +  );
> > 
> > +
> > 
> > +/**
> > 
> > +  Calculate the timer frequency.
> > 
> > +
> > 
> > +  @param[] VOID
> > 
> > +
> > 
> > +  @retval  Timer frequency.
> > 
> > +**/
> > 
> > +UINT32
> > 
> > +EFIAPI
> > 
> > +CalcConstFreq (
> > 
> > +  VOID
> > 
> > +  );
> > 
> > +#endif
> > 
> > diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/Count.S
> > b/Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/Count.S
> > new file mode 100644
> > index 0000000000..42f878caf8
> > --- /dev/null
> > +++ b/Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/Count.S
> > @@ -0,0 +1,26 @@
> > +#------------------------------------------------------------------------------
> > 
> > +#
> > 
> > +# Count for LoongArch
> > 
> > +#
> > 
> > +# Copyright (c) 2021 Loongson Technology Corporation Limited. All rights reserved.<BR>
> > 
> > +#
> > 
> > +# SPDX-License-Identifier: BSD-2-Clause-Patent
> > 
> > +#
> > 
> > +#------------------------------------------------------------------------------
> > 
> > +
> > 
> > +#ifndef __ASSEMBLY__
> > 
> > +#define  __ASSEMBLY__
> > 
> > +#endif
> > 
> > +
> > 
> > +#include "Library/Cpu.h"
> > 
> > +#include "LoongArchAsmMacro.h"
> > 
> > +#
> > 
> > +# Set cpu interrupts
> > 
> > +# @param A0 The interrupt number
> > 
> > +#
> > 
> > +ASM_FUNC(CpuSetIP)
> > 
> > +    csrrd   T0, LOONGARCH_CSR_ECFG
> > 
> > +    or      T0, T0, A0
> > 
> > +    csrwr   T0, LOONGARCH_CSR_ECFG
> > 
> > +    jirl    ZERO, RA,0
> > 
> > +
> > 
> > diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/TimerLib.c
> > b/Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/TimerLib.c
> > new file mode 100644
> > index 0000000000..21e3749ee6
> > --- /dev/null
> > +++ b/Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/TimerLib.c
> > @@ -0,0 +1,262 @@
> > +/** @file
> > 
> > +  Generic LoongArch implementation of TimerLib.h
> > 
> > +
> > 
> > +  Copyright (c) 2021 Loongson Technology Corporation Limited. All rights reserved.<BR>
> > 
> > +
> > 
> > +  SPDX-License-Identifier: BSD-2-Clause-Patent
> > 
> > +
> > 
> > +  @par Glossary:
> > 
> > +    - Freq - Frequency
> > 
> > +    - Csr  - Cpu Status Register
> > 
> > +    - calc - calculate
> > 
> > +**/
> > 
> > +
> > 
> > +#include <Base.h>
> > 
> > +#include <Library/TimerLib.h>
> > 
> > +#include <Library/BaseLib.h>
> > 
> > +#include <Library/DebugLib.h>
> > 
> > +#include "Library/StableTimer.h"
> > 
> > +#include "Library/Cpu.h"
> > 
> > +
> > 
> > +UINT32 StableTimerFreq = 0;
> > 
> > +
> > 
> > +/**
> > 
> > +  Gets the timer count value.
> > 
> > +
> > 
> > +  @param[] VOID
> > 
> > +
> > 
> > +  @retval  timer count value.
> > 
> > +**/
> > 
> > +UINTN
> > 
> > +EFIAPI
> > 
> > +CsrReadTime (
> > 
> > +  VOID
> > 
> > +  )
> > 
> > +{
> > 
> > +  UINTN Value = 0;
> > 
> > +  __asm__ __volatile__(
> > 
> > +      " rdtime.d   %0, $r0\n"
> > 
> > +      : "=r" (Value));
> > 
> > +  return Value;
> > 
> > +}
> > 
> > +
> > 
> > +/**
> > 
> > +  Calculate the timer frequency.
> > 
> > +
> > 
> > +  @param[] VOID
> > 
> > +
> > 
> > +  @retval  Timer frequency.
> > 
> > +**/
> > 
> > +UINT32
> > 
> > +EFIAPI
> > 
> > +CalcConstFreq (
> > 
> > +  VOID
> > 
> > +  )
> > 
> > +{
> > 
> > +  UINT32 Result;
> > 
> > +  UINT32 BaseFreq;
> > 
> > +  UINT32 ClockMultiplier;
> > 
> > +  UINT32 ClockDivide;
> > 
> > +
> > 
> > +  LOONGARCH_GET_CPUCFG (BaseFreq, LOONGARCH_CPUCFG4);
> > 
> > +  LOONGARCH_GET_CPUCFG (Result, LOONGARCH_CPUCFG5);
> > 
> > +  ClockMultiplier = Result & 0xffff;
> > 
> > +  ClockDivide = (Result >> 16) & 0xffff;
> > 
> > +
> > 
> > +  if ((!BaseFreq)
> > 
> > +    || (!ClockMultiplier)
> > 
> > +    || (!ClockDivide))
> > 
> > +  {
> > 
> > +    return 0;
> > 
> > +  }
> > 
> > +  else {
> > 
> > +    return (BaseFreq * ClockMultiplier / ClockDivide);
> > 
> > +  }
> > 
> > +}
> > 
> > +/**
> > 
> > +  Get the timer frequency.
> > 
> > +
> > 
> > +  @param[] VOID
> > 
> > +
> > 
> > +  @retval  Timer frequency.
> > 
> > +**/
> > 
> > +UINT32
> > 
> > +EFIAPI
> > 
> > +GetFreq (
> > 
> > +  VOID
> > 
> > +  )
> > 
> > +{
> > 
> > +  if (StableTimerFreq) {
> > 
> > +  } else {
> > 
> > +    StableTimerFreq = CalcConstFreq ();
> > 
> > +  }
> > 
> > +
> > 
> > +  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
> > 
> > +  )
> > 
> > +{
> > 
> > +
> > 
> > +  UINTN Count;
> > 
> > +  UINTN Ticks;
> > 
> > +  UINTN Start;
> > 
> > +  UINTN End;
> > 
> > +
> > 
> > +  Count = GetFreq ();
> > 
> > +  Count = (Count * MicroSeconds) / 1000000;
> > 
> > +  Start = CsrReadTime ();
> > 
> > +  End = Start + Count;
> > 
> > +
> > 
> > +  do {
> > 
> > +    Ticks = CsrReadTime ();
> > 
> > +  } while (Ticks < End);
> > 
> > +
> > 
> > +  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
> > 
> > +  )
> > 
> > +{
> > 
> > +  UINT32  MicroSeconds;
> > 
> > +
> > 
> > +  if (NanoSeconds % 1000 == 0) {
> > 
> > +    MicroSeconds = NanoSeconds/1000;
> > 
> > +  }else {
> > 
> > +    MicroSeconds = NanoSeconds/1000 + 1;
> > 
> > +  }
> > 
> > +  MicroSecondDelay (MicroSeconds);
> > 
> > +
> > 
> > +  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 CsrReadTime ();
> > 
> > +}
> > 
> > +/**
> > 
> > +  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 = BIT2;
> > 
> > +  }
> > 
> > +
> > 
> > +  if (EndValue != NULL) {
> > 
> > +    *EndValue = BIT48 - 1;
> > 
> > +  }
> > 
> > +
> > 
> > +  return GetFreq ();
> > 
> > +}
> > 
> > +
> > 
> > +/**
> > 
> > +  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;
> > 
> > +
> > 
> > +  Frequency = GetPerformanceCounterProperties (NULL, NULL);
> > 
> > +
> > 
> > +  //
> > 
> > +  //          Ticks
> > 
> > +  // Time = --------- x 1,000,000,000
> > 
> > +  //        Frequency
> > 
> > +  //
> > 
> > +  NanoSeconds = MultU64x32 (DivU64x64Remainder (Ticks, Frequency, &Remainder), 1000000000u);
> > 
> > +
> > 
> > +  //
> > 
> > +  // 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);
> > 
> > +  NanoSeconds += DivU64x64Remainder (MultU64x32 (Remainder, 1000000000u), Frequency, NULL);
> > 
> > +
> > 
> > +  return NanoSeconds;
> > 
> > +}
> > 
> > diff --git a/Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/TimerLib.inf
> > b/Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/TimerLib.inf
> > new file mode 100644
> > index 0000000000..fef0fac08c
> > --- /dev/null
> > +++ b/Platform/Loongson/LoongArchQemuPkg/Library/StableTimerLib/TimerLib.inf
> > @@ -0,0 +1,28 @@
> > +## @file
> > 
> > +#  Generic LoongArch implementation of TimerLib.h
> > 
> > +#
> > 
> > +#  Copyright (c) 2021 Loongson Technology Corporation Limited. All rights reserved.<BR>
> > 
> > +#
> > 
> > +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> > 
> > +#
> > 
> > +##
> > 
> > +
> > 
> > +[Defines]
> > 
> > +  INF_VERSION                       = 0x00010005
> > 
> > +  BASE_NAME                         = TimerLib
> > 
> > +  FILE_GUID                         = 740389C7-CC44-4A2F-88DC-89D97D312E7C
> > 
> > +  MODULE_TYPE                       = BASE
> > 
> > +  VERSION_STRING                    = 1.0
> > 
> > +  LIBRARY_CLASS                     = TimerLib
> > 
> > +
> > 
> > +[Sources.common]
> > 
> > +  TimerLib.c
> > 
> > +  Count.S
> > 
> > +
> > 
> > +[Packages]
> > 
> > +  Platform/Loongson/LoongArchQemuPkg/Loongson.dec
> > 
> > +  MdePkg/MdePkg.dec
> > 
> > +
> > 
> > +[LibraryClasses]
> > 
> > +  DebugLib
> > 
> > +  IoLib
> > 
> > --
> > 2.31.1
> > 
> > 
> > 
> > -=-=-=-=-=-=
> > Groups.io Links: You receive all messages sent to this group.
> > View/Reply Online (#93560): https://edk2.groups.io/g/devel/message/93560
> > Mute This Topic: https://groups.io/mt/93565582/1643496
> > Group Owner: devel+owner@edk2.groups.io
> > Unsubscribe: https://edk2.groups.io/g/devel/unsub [michael.d.kinney@intel.com]
> > -=-=-=-=-=-=
> > 
> 
> 
> 
> 
> 
> 


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