DuetPkg/Library/DuetTimerLib/X86TimerLib.c

   1 /** @file
   2   Timer Library functions built upon ACPI on IA32/x64.
   3
   4   ACPI power management timer is a 24-bit or 32-bit fixed rate free running count-up
   5   timer that runs off a 3.579545 MHz clock.
   6   When startup, Duet will check the FADT to determine whether the PM timer is a
   7   32-bit or 25-bit timer.
   8
   9   Copyright (c) 2006 - 2007, Intel Corporation<BR>
  10   All rights reserved. This program and the accompanying materials
  11   are licensed and made available under the terms and conditions of the BSD License
  12   which accompanies this distribution.  The full text of the license may be found at
  13   http://opensource.org/licenses/bsd-license.php
  14
  15   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  16   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  17
  18 **/
  19
  20 #include <Base.h>
  21 #include <Library/TimerLib.h>
  22 #include <Library/BaseLib.h>
  23 #include <Library/DebugLib.h>
  24 #include <Library/HobLib.h>
  25 #include <Guid/AcpiDescription.h>
  26 #include <Library/IoLib.h>
  27 #include <Library/PciLib.h>
  28
  29 EFI_ACPI_DESCRIPTION *gAcpiDesc          = NULL;
  30
  31 /**
  32   Internal function to get Acpi information from HOB.
  33
  34   @return Pointer to ACPI description structure.
  35 **/
  36 EFI_ACPI_DESCRIPTION*
  37 InternalGetApciDescrptionTable (
  38   VOID
  39   )
  40 {
  41   EFI_PEI_HOB_POINTERS  GuidHob;
  42
  43   if (gAcpiDesc != NULL) {
  44     return gAcpiDesc;
  45   }
  46
  47   GuidHob.Raw = GetFirstGuidHob (&gEfiAcpiDescriptionGuid);
  48   if (GuidHob.Raw != NULL) {
  49     gAcpiDesc = GET_GUID_HOB_DATA (GuidHob.Guid);
  50     DEBUG ((EFI_D_INFO, "ACPI Timer: PM_TMR_BLK.RegisterBitWidth = 0x%X\n", gAcpiDesc->PM_TMR_BLK.RegisterBitWidth));
  51     DEBUG ((EFI_D_INFO, "ACPI Timer: PM_TMR_BLK.Address = 0x%X\n", gAcpiDesc->PM_TMR_BLK.Address));
  52     return gAcpiDesc;
  53   } else {
  54     DEBUG ((EFI_D_ERROR, "Fail to get Acpi description table from hob\n"));
  55     return NULL;
  56   }
  57 }
  58
  59 /**
  60   Internal function to read the current tick counter of ACPI.
  61
  62   @return The tick counter read.
  63
  64 **/
  65 STATIC
  66 UINT32
  67 InternalAcpiGetTimerTick (
  68   VOID
  69   )
  70 {
  71   return IoRead32 ((UINTN)gAcpiDesc->PM_TMR_BLK.Address);
  72 }
  73
  74 /**
  75   Stalls the CPU for at least the given number of ticks.
  76
  77   Stalls the CPU for at least the given number of ticks. It's invoked by
  78   MicroSecondDelay() and NanoSecondDelay().
  79
  80   @param  Delay     A period of time to delay in ticks.
  81
  82 **/
  83 STATIC
  84 VOID
  85 InternalAcpiDelay (
  86   IN      UINT32                    Delay
  87   )
  88 {
  89   UINT32                            Ticks;
  90   UINT32                            Times;
  91
  92   Times    = Delay >> (gAcpiDesc->PM_TMR_BLK.RegisterBitWidth - 2);
  93   Delay   &= (1 << (gAcpiDesc->PM_TMR_BLK.RegisterBitWidth - 2)) - 1;
  94   do {
  95     //
  96     // The target timer count is calculated here
  97     //
  98     Ticks    = InternalAcpiGetTimerTick () + Delay;
  99     Delay    = 1 << (gAcpiDesc->PM_TMR_BLK.RegisterBitWidth - 2);
 100     //
 101     // Wait until time out
 102     // Delay >= 2^23 (if ACPI provide 24-bit timer) or Delay >= 2^31 (if ACPI
 103     // provide 32-bit timer) could not be handled by this function
 104     // Timer wrap-arounds are handled correctly by this function
 105     //
 106     while (((Ticks - InternalAcpiGetTimerTick ()) & (1 << (gAcpiDesc->PM_TMR_BLK.RegisterBitWidth - 1))) == 0) {
 107       CpuPause ();
 108     }
 109   } while (Times-- > 0);
 110 }
 111
 112 /**
 113   Stalls the CPU for at least the given number of microseconds.
 114
 115   Stalls the CPU for the number of microseconds specified by MicroSeconds.
 116
 117   @param  MicroSeconds  The minimum number of microseconds to delay.
 118
 119   @return MicroSeconds
 120
 121 **/
 122 UINTN
 123 EFIAPI
 124 MicroSecondDelay (
 125   IN      UINTN                     MicroSeconds
 126   )
 127 {
 128
 129   if (InternalGetApciDescrptionTable() == NULL) {
 130     return MicroSeconds;
 131   }
 132
 133   InternalAcpiDelay (
 134     (UINT32)DivU64x32 (
 135               MultU64x32 (
 136                 MicroSeconds,
 137                 3579545
 138                 ),
 139               1000000u
 140               )
 141     );
 142   return MicroSeconds;
 143 }
 144
 145 /**
 146   Stalls the CPU for at least the given number of nanoseconds.
 147
 148   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
 149
 150   @param  NanoSeconds The minimum number of nanoseconds to delay.
 151
 152   @return NanoSeconds
 153
 154 **/
 155 UINTN
 156 EFIAPI
 157 NanoSecondDelay (
 158   IN      UINTN                     NanoSeconds
 159   )
 160 {
 161   if (InternalGetApciDescrptionTable() == NULL) {
 162     return NanoSeconds;
 163   }
 164
 165   InternalAcpiDelay (
 166     (UINT32)DivU64x32 (
 167               MultU64x32 (
 168                 NanoSeconds,
 169                 3579545
 170                 ),
 171               1000000000u
 172               )
 173     );
 174   return NanoSeconds;
 175 }
 176
 177 /**
 178   Retrieves the current value of a 64-bit free running performance counter.
 179
 180   Retrieves the current value of a 64-bit free running performance counter. The
 181   counter can either count up by 1 or count down by 1. If the physical
 182   performance counter counts by a larger increment, then the counter values
 183   must be translated. The properties of the counter can be retrieved from
 184   GetPerformanceCounterProperties().
 185
 186   @return The current value of the free running performance counter.
 187
 188 **/
 189 UINT64
 190 EFIAPI
 191 GetPerformanceCounter (
 192   VOID
 193   )
 194 {
 195   if (InternalGetApciDescrptionTable() == NULL) {
 196     return 0;
 197   }
 198
 199   return (UINT64)InternalAcpiGetTimerTick ();
 200 }
 201
 202 /**
 203   Retrieves the 64-bit frequency in Hz and the range of performance counter
 204   values.
 205
 206   If StartValue is not NULL, then the value that the performance counter starts
 207   with immediately after is it rolls over is returned in StartValue. If
 208   EndValue is not NULL, then the value that the performance counter end with
 209   immediately before it rolls over is returned in EndValue. The 64-bit
 210   frequency of the performance counter in Hz is always returned. If StartValue
 211   is less than EndValue, then the performance counter counts up. If StartValue
 212   is greater than EndValue, then the performance counter counts down. For
 213   example, a 64-bit free running counter that counts up would have a StartValue
 214   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 215   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 216
 217   @param  StartValue  The value the performance counter starts with when it
 218                       rolls over.
 219   @param  EndValue    The value that the performance counter ends with before
 220                       it rolls over.
 221
 222   @return The frequency in Hz.
 223
 224 **/
 225 UINT64
 226 EFIAPI
 227 GetPerformanceCounterProperties (
 228   OUT      UINT64                    *StartValue,  OPTIONAL
 229   OUT      UINT64                    *EndValue     OPTIONAL
 230   )
 231 {
 232   if (InternalGetApciDescrptionTable() == NULL) {
 233     return 0;
 234   }
 235
 236   if (StartValue != NULL) {
 237     *StartValue = 0;
 238   }
 239
 240   if (EndValue != NULL) {
 241     *EndValue = (1 << gAcpiDesc->PM_TMR_BLK.RegisterBitWidth) - 1;
 242   }
 243
 244   return 3579545;
 245 }