InOsEmuPkg/Library/DxeTimerLib/DxeTimerLib.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   This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php.
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include <PiPei.h>
  16 #include <Library/BaseLib.h>
  17 #include <Library/TimerLib.h>
  18 #include <Library/DebugLib.h>
  19 #include <Library/EmuThunkLib.h>
  20 #include <Library/UefiBootServicesTableLib.h>
  21 #include <Library/UefiLib.h>
  22
  23 #include <Protocol/Timer.h>
  24
  25
  26 STATIC UINT64                  gTimerPeriod = 0;
  27 STATIC EFI_TIMER_ARCH_PROTOCOL *gTimerAp = NULL;
  28 STATIC EFI_EVENT               gTimerEvent = NULL;
  29 STATIC VOID                    *gRegistration = NULL;
  30
  31 VOID
  32 EFIAPI
  33 RegisterTimerArchProtocol (
  34   IN EFI_EVENT     Event,
  35   IN VOID          *Context
  36   )
  37 {
  38   EFI_STATUS  Status;
  39
  40   Status = gBS->LocateProtocol (&gEfiTimerArchProtocolGuid, NULL, (VOID **)&gTimerAp);
  41   if (!EFI_ERROR (Status)) {
  42     Status = gTimerAp->GetTimerPeriod (gTimerAp, &gTimerPeriod);
  43     ASSERT_EFI_ERROR (Status);
  44
  45     // Convert to Nanoseconds.
  46     gTimerPeriod = MultU64x32 (gTimerPeriod, 100);
  47
  48     if (gTimerEvent == NULL) {
  49       Status = gBS->CreateEvent (EVT_TIMER, 0, NULL, NULL, (VOID **)&gTimerEvent);
  50       ASSERT_EFI_ERROR (Status);
  51     }
  52   }
  53 }
  54
  55
  56
  57 /**
  58   Stalls the CPU for at least the given number of microseconds.
  59
  60   Stalls the CPU for the number of microseconds specified by MicroSeconds.
  61
  62   @param  MicroSeconds  The minimum number of microseconds to delay.
  63
  64   @return The value of MicroSeconds inputted.
  65
  66 **/
  67 UINTN
  68 EFIAPI
  69 MicroSecondDelay (
  70   IN      UINTN                     MicroSeconds
  71   )
  72 {
  73   return NanoSecondDelay (MicroSeconds * 1000);
  74 }
  75
  76
  77 /**
  78   Stalls the CPU for at least the given number of nanoseconds.
  79
  80   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
  81
  82   @param  NanoSeconds The minimum number of nanoseconds to delay.
  83
  84   @return The value of NanoSeconds inputted.
  85
  86 **/
  87 UINTN
  88 EFIAPI
  89 NanoSecondDelay (
  90   IN      UINTN                     NanoSeconds
  91   )
  92 {
  93   EFI_STATUS  Status;
  94   UINT64      HundredNanoseconds;
  95   UINTN       Index;
  96
  97   if ((gTimerPeriod != 0) &&
  98       ((UINT64)NanoSeconds > gTimerPeriod) &&
  99       (EfiGetCurrentTpl () == TPL_APPLICATION)) {
 100     //
 101     // This stall is long, so use gBS->WaitForEvent () to yield CPU to DXE Core
 102     //
 103
 104     HundredNanoseconds = DivU64x32 (NanoSeconds, 100);
 105     Status = gBS->SetTimer (gTimerEvent, TimerRelative, HundredNanoseconds);
 106     ASSERT_EFI_ERROR (Status);
 107
 108     Status = gBS->WaitForEvent (sizeof (gTimerEvent)/sizeof (EFI_EVENT), &gTimerEvent, &Index);
 109     ASSERT_EFI_ERROR (Status);
 110
 111   } else {
 112     gEmuThunk->Sleep (NanoSeconds);
 113   }
 114   return NanoSeconds;
 115 }
 116
 117
 118 /**
 119   Retrieves the current value of a 64-bit free running performance counter.
 120
 121   The counter can either count up by 1 or count down by 1. If the physical
 122   performance counter counts by a larger increment, then the counter values
 123   must be translated. The properties of the counter can be retrieved from
 124   GetPerformanceCounterProperties().
 125
 126   @return The current value of the free running performance counter.
 127
 128 **/
 129 UINT64
 130 EFIAPI
 131 GetPerformanceCounter (
 132   VOID
 133   )
 134 {
 135   return gEmuThunk->QueryPerformanceCounter ();
 136 }
 137
 138 /**
 139   Retrieves the 64-bit frequency in Hz and the range of performance counter
 140   values.
 141
 142   If StartValue is not NULL, then the value that the performance counter starts
 143   with immediately after is it rolls over is returned in StartValue. If
 144   EndValue is not NULL, then the value that the performance counter end with
 145   immediately before it rolls over is returned in EndValue. The 64-bit
 146   frequency of the performance counter in Hz is always returned. If StartValue
 147   is less than EndValue, then the performance counter counts up. If StartValue
 148   is greater than EndValue, then the performance counter counts down. For
 149   example, a 64-bit free running counter that counts up would have a StartValue
 150   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 151   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 152
 153   @param  StartValue  The value the performance counter starts with when it
 154                       rolls over.
 155   @param  EndValue    The value that the performance counter ends with before
 156                       it rolls over.
 157
 158   @return The frequency in Hz.
 159
 160 **/
 161 UINT64
 162 EFIAPI
 163 GetPerformanceCounterProperties (
 164   OUT      UINT64                    *StartValue,  OPTIONAL
 165   OUT      UINT64                    *EndValue     OPTIONAL
 166   )
 167 {
 168
 169   if (StartValue != NULL) {
 170     *StartValue = 0ULL;
 171   }
 172   if (EndValue != NULL) {
 173     *EndValue = (UINT64)-1LL;
 174   }
 175
 176   return gEmuThunk->QueryPerformanceFrequency ();
 177 }
 178
 179
 180 /**
 181   Register for the Timer AP protocol.
 182
 183   @param  ImageHandle   The firmware allocated handle for the EFI image.
 184   @param  SystemTable   A pointer to the EFI System Table.
 185
 186   @retval EFI_SUCCESS   The constructor always returns EFI_SUCCESS.
 187
 188 **/
 189 EFI_STATUS
 190 EFIAPI
 191 DxeTimerLibConstructor (
 192   IN EFI_HANDLE        ImageHandle,
 193   IN EFI_SYSTEM_TABLE  *SystemTable
 194   )
 195 {
 196   EfiCreateProtocolNotifyEvent (
 197     &gEfiTimerArchProtocolGuid,
 198     TPL_CALLBACK,
 199     RegisterTimerArchProtocol,
 200     NULL,
 201     &gRegistration
 202     );
 203
 204   return EFI_SUCCESS;
 205 }
 206