EmulatorPkg/Library/DxeCoreTimerLib/DxeCoreTimerLib.c

   1 /** @file
   2   A non-functional instance of the Timer Library.
   3
   4   Copyright (c) 2007 - 2010, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include <PiPei.h>
  10 #include <Library/TimerLib.h>
  11 #include <Library/DebugLib.h>
  12 #include <Library/EmuThunkLib.h>
  13 #include <Library/UefiBootServicesTableLib.h>
  14 #include <Library/UefiLib.h>
  15
  16 #include <Protocol/Timer.h>
  17
  18
  19
  20 /**
  21   Stalls the CPU for at least the given number of microseconds.
  22
  23   Stalls the CPU for the number of microseconds specified by MicroSeconds.
  24
  25   @param  MicroSeconds  The minimum number of microseconds to delay.
  26
  27   @return The value of MicroSeconds inputted.
  28
  29 **/
  30 UINTN
  31 EFIAPI
  32 MicroSecondDelay (
  33   IN      UINTN                     MicroSeconds
  34   )
  35 {
  36   return NanoSecondDelay (MicroSeconds * 1000);
  37 }
  38
  39
  40 /**
  41   Stalls the CPU for at least the given number of nanoseconds.
  42
  43   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
  44
  45   @param  NanoSeconds The minimum number of nanoseconds to delay.
  46
  47   @return The value of NanoSeconds inputted.
  48
  49 **/
  50 UINTN
  51 EFIAPI
  52 NanoSecondDelay (
  53   IN      UINTN                     NanoSeconds
  54   )
  55 {
  56   gEmuThunk->Sleep (NanoSeconds);
  57   return NanoSeconds;
  58 }
  59
  60
  61 /**
  62   Retrieves the current value of a 64-bit free running performance counter.
  63
  64   The counter can either count up by 1 or count down by 1. If the physical
  65   performance counter counts by a larger increment, then the counter values
  66   must be translated. The properties of the counter can be retrieved from
  67   GetPerformanceCounterProperties().
  68
  69   @return The current value of the free running performance counter.
  70
  71 **/
  72 UINT64
  73 EFIAPI
  74 GetPerformanceCounter (
  75   VOID
  76   )
  77 {
  78   return gEmuThunk->QueryPerformanceCounter ();
  79 }
  80
  81 /**
  82   Retrieves the 64-bit frequency in Hz and the range of performance counter
  83   values.
  84
  85   If StartValue is not NULL, then the value that the performance counter starts
  86   with immediately after is it rolls over is returned in StartValue. If
  87   EndValue is not NULL, then the value that the performance counter end with
  88   immediately before it rolls over is returned in EndValue. The 64-bit
  89   frequency of the performance counter in Hz is always returned. If StartValue
  90   is less than EndValue, then the performance counter counts up. If StartValue
  91   is greater than EndValue, then the performance counter counts down. For
  92   example, a 64-bit free running counter that counts up would have a StartValue
  93   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
  94   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
  95
  96   @param  StartValue  The value the performance counter starts with when it
  97                       rolls over.
  98   @param  EndValue    The value that the performance counter ends with before
  99                       it rolls over.
 100
 101   @return The frequency in Hz.
 102
 103 **/
 104 UINT64
 105 EFIAPI
 106 GetPerformanceCounterProperties (
 107   OUT      UINT64                    *StartValue,  OPTIONAL
 108   OUT      UINT64                    *EndValue     OPTIONAL
 109   )
 110 {
 111
 112   if (StartValue != NULL) {
 113     *StartValue = 0ULL;
 114   }
 115   if (EndValue != NULL) {
 116     *EndValue = (UINT64)-1LL;
 117   }
 118
 119   return gEmuThunk->QueryPerformanceFrequency ();
 120 }
 121
 122