UefiCpuPkg: Add BaseRiscV64CpuTimerLib library

[mirror_edk2.git] / UefiCpuPkg / Library / BaseRiscV64CpuTimerLib / CpuTimerLib.c

/** @file\r
  RISC-V instance of Timer Library.\r
\r
  Copyright (c) 2016 - 2022, Hewlett Packard Enterprise Development LP. All rights reserved.<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include <Uefi.h>\r
#include <Library/BaseLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/PcdLib.h>\r
#include <Register/RiscV64/RiscVImpl.h>\r
\r
/**\r
  Stalls the CPU for at least the given number of ticks.\r
\r
  Stalls the CPU for at least the given number of ticks. It's invoked by\r
  MicroSecondDelay() and NanoSecondDelay().\r
\r
  @param  Delay     A period of time to delay in ticks.\r
\r
**/\r
VOID\r
InternalRiscVTimerDelay (\r
  IN UINT32  Delay\r
  )\r
{\r
  UINT32  Ticks;\r
  UINT32  Times;\r
\r
  Times  = Delay >> (RISCV_TIMER_COMPARE_BITS - 2);\r
  Delay &= ((1 << (RISCV_TIMER_COMPARE_BITS - 2)) - 1);\r
  do {\r
    //\r
    // The target timer count is calculated here\r
    //\r
    Ticks = RiscVReadTimer () + Delay;\r
    Delay = 1 << (RISCV_TIMER_COMPARE_BITS - 2);\r
    while (((Ticks - RiscVReadTimer ()) & (1 << (RISCV_TIMER_COMPARE_BITS - 1))) == 0) {\r
      CpuPause ();\r
    }\r
  } while (Times-- > 0);\r
}\r
\r
/**\r
  Stalls the CPU for at least the given number of microseconds.\r
\r
  Stalls the CPU for the number of microseconds specified by MicroSeconds.\r
\r
  @param  MicroSeconds  The minimum number of microseconds to delay.\r
\r
  @return MicroSeconds\r
\r
**/\r
UINTN\r
EFIAPI\r
MicroSecondDelay (\r
  IN UINTN  MicroSeconds\r
  )\r
{\r
  InternalRiscVTimerDelay (\r
    (UINT32)DivU64x32 (\r
              MultU64x32 (\r
                MicroSeconds,\r
                PcdGet64 (PcdCpuCoreCrystalClockFrequency)\r
                ),\r
              1000000u\r
              )\r
    );\r
  return MicroSeconds;\r
}\r
\r
/**\r
  Stalls the CPU for at least the given number of nanoseconds.\r
\r
  Stalls the CPU for the number of nanoseconds specified by NanoSeconds.\r
\r
  @param  NanoSeconds The minimum number of nanoseconds to delay.\r
\r
  @return NanoSeconds\r
\r
**/\r
UINTN\r
EFIAPI\r
NanoSecondDelay (\r
  IN UINTN  NanoSeconds\r
  )\r
{\r
  InternalRiscVTimerDelay (\r
    (UINT32)DivU64x32 (\r
              MultU64x32 (\r
                NanoSeconds,\r
                PcdGet64 (PcdCpuCoreCrystalClockFrequency)\r
                ),\r
              1000000000u\r
              )\r
    );\r
  return NanoSeconds;\r
}\r
\r
/**\r
  Retrieves the current value of a 64-bit free running performance counter.\r
\r
  Retrieves the current value of a 64-bit free running performance counter. The\r
  counter can either count up by 1 or count down by 1. If the physical\r
  performance counter counts by a larger increment, then the counter values\r
  must be translated. The properties of the counter can be retrieved from\r
  GetPerformanceCounterProperties().\r
\r
  @return The current value of the free running performance counter.\r
\r
**/\r
UINT64\r
EFIAPI\r
GetPerformanceCounter (\r
  VOID\r
  )\r
{\r
  return (UINT64)RiscVReadTimer ();\r
}\r
\r
/**return\r
  Retrieves the 64-bit frequency in Hz and the range of performance counter\r
  values.\r
\r
  If StartValue is not NULL, then the value that the performance counter starts\r
  with immediately after is it rolls over is returned in StartValue. If\r
  EndValue is not NULL, then the value that the performance counter end with\r
  immediately before it rolls over is returned in EndValue. The 64-bit\r
  frequency of the performance counter in Hz is always returned. If StartValue\r
  is less than EndValue, then the performance counter counts up. If StartValue\r
  is greater than EndValue, then the performance counter counts down. For\r
  example, a 64-bit free running counter that counts up would have a StartValue\r
  of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter\r
  that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.\r
\r
  @param  StartValue  The value the performance counter starts with when it\r
                      rolls over.\r
  @param  EndValue    The value that the performance counter ends with before\r
                      it rolls over.\r
\r
  @return The frequency in Hz.\r
\r
**/\r
UINT64\r
EFIAPI\r
GetPerformanceCounterProperties (\r
  OUT      UINT64 *StartValue, OPTIONAL\r
  OUT      UINT64                    *EndValue     OPTIONAL\r
  )\r
{\r
  if (StartValue != NULL) {\r
    *StartValue = 0;\r
  }\r
\r
  if (EndValue != NULL) {\r
    *EndValue = 32 - 1;\r
  }\r
\r
  return PcdGet64 (PcdCpuCoreCrystalClockFrequency);\r
}\r
\r
/**\r
  Converts elapsed ticks of performance counter to time in nanoseconds.\r
\r
  This function converts the elapsed ticks of running performance counter to\r
  time value in unit of nanoseconds.\r
\r
  @param  Ticks     The number of elapsed ticks of running performance counter.\r
\r
  @return The elapsed time in nanoseconds.\r
\r
**/\r
UINT64\r
EFIAPI\r
GetTimeInNanoSecond (\r
  IN      UINT64  Ticks\r
  )\r
{\r
  UINT64  NanoSeconds;\r
  UINT32  Remainder;\r
\r
  //\r
  //          Ticks\r
  // Time = --------- x 1,000,000,000\r
  //        Frequency\r
  //\r
  NanoSeconds = MultU64x32 (DivU64x32Remainder (Ticks, PcdGet64 (PcdCpuCoreCrystalClockFrequency), &Remainder), 1000000000u);\r
\r
  //\r
  // Frequency < 0x100000000, so Remainder < 0x100000000, then (Remainder * 1,000,000,000)\r
  // will not overflow 64-bit.\r
  //\r
  NanoSeconds += DivU64x32 (MultU64x32 ((UINT64)Remainder, 1000000000u), PcdGet64 (PcdCpuCoreCrystalClockFrequency));\r
\r
  return NanoSeconds;\r
}\r