MdePkg/Library/SecPeiDxeTimerLibCpu/IpfTimerLib.c

   1 /** @file
   2   Timer Library functions built upon ITC on IA32/x64.
   3
   4   Copyright (c) 2006 - 2007, Intel Corporation<BR>
   5   All rights reserved. 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   Module Name:  IpfTimerLib.c
  14
  15 **/
  16
  17
  18
  19
  20 /**
  21   Performs a delay measured as number of ticks.
  22
  23   An internal function to perform a delay measured as number of ticks. It's
  24   invoked by MicroSecondDelay() and NanoSecondDelay().
  25
  26   @param  Delay Number of ticks to delay.
  27
  28 **/
  29 STATIC
  30 VOID
  31 InternalIpfDelay (
  32   IN      INT64                     Delay
  33   )
  34 {
  35   INT64                             Ticks;
  36
  37   //
  38   // The target timer count is calculated here
  39   //
  40   Ticks = IpfReadItc () + Delay;
  41
  42   //
  43   // Wait until time out
  44   // Delay > 2^63 could not be handled by this function
  45   // Timer wrap-arounds are handled correctly by this function
  46   //
  47   while (Ticks - IpfReadItc () >= 0);
  48 }
  49
  50 /**
  51   Stalls the CPU for at least the given number of microseconds.
  52
  53   Stalls the CPU for the number of microseconds specified by MicroSeconds.
  54
  55   @param  MicroSeconds  The minimum number of microseconds to delay.
  56
  57   @return MicroSeconds
  58
  59 **/
  60 UINTN
  61 EFIAPI
  62 MicroSecondDelay (
  63   IN      UINTN                     MicroSeconds
  64   )
  65 {
  66   InternalIpfDelay (
  67     GetPerformanceCounterProperties (NULL, NULL) *
  68     MicroSeconds /
  69     1000000
  70     );
  71   return MicroSeconds;
  72 }
  73
  74 /**
  75   Stalls the CPU for at least the given number of nanoseconds.
  76
  77   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
  78
  79   @param  NanoSeconds The minimum number of nanoseconds to delay.
  80
  81   @return NanoSeconds
  82
  83 **/
  84 UINTN
  85 EFIAPI
  86 NanoSecondDelay (
  87   IN      UINTN                     NanoSeconds
  88   )
  89 {
  90   InternalIpfDelay (
  91     GetPerformanceCounterProperties (NULL, NULL) *
  92     NanoSeconds /
  93     1000000000
  94     );
  95   return NanoSeconds;
  96 }
  97
  98 /**
  99   Retrieves the current value of a 64-bit free running performance counter.
 100
 101   Retrieves the current value of a 64-bit free running performance counter. The
 102   counter can either count up by 1 or count down by 1. If the physical
 103   performance counter counts by a larger increment, then the counter values
 104   must be translated. The properties of the counter can be retrieved from
 105   GetPerformanceCounterProperties().
 106
 107   @return The current value of the free running performance counter.
 108
 109 **/
 110 UINT64
 111 EFIAPI
 112 GetPerformanceCounter (
 113   VOID
 114   )
 115 {
 116   return IpfReadItc ();
 117 }
 118
 119 /**
 120   Retrieves the 64-bit frequency in Hz and the range of performance counter
 121   values.
 122
 123   If StartValue is not NULL, then the value that the performance counter starts
 124   with immediately after is it rolls over is returned in StartValue. If
 125   EndValue is not NULL, then the value that the performance counter end with
 126   immediately before it rolls over is returned in EndValue. The 64-bit
 127   frequency of the performance counter in Hz is always returned. If StartValue
 128   is less than EndValue, then the performance counter counts up. If StartValue
 129   is greater than EndValue, then the performance counter counts down. For
 130   example, a 64-bit free running counter that counts up would have a StartValue
 131   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 132   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 133
 134   @param  StartValue  The value the performance counter starts with when it
 135                       rolls over.
 136   @param  EndValue    The value that the performance counter ends with before
 137                       it rolls over.
 138
 139   @return The frequency in Hz.
 140
 141 **/
 142 UINT64
 143 EFIAPI
 144 GetPerformanceCounterProperties (
 145   OUT      UINT64                    *StartValue,  OPTIONAL
 146   OUT      UINT64                    *EndValue     OPTIONAL
 147   )
 148 {
 149   PAL_PROC_RETURN                   PalRet;
 150   UINT64                            BaseFrequence;
 151
 152   PalRet = PalCallStatic (NULL, 13, 0, 0, 0);
 153   ASSERT (PalRet.Status == 0);
 154   BaseFrequence = PalRet.r9;
 155
 156   PalRet = PalCallStatic (NULL, 14, 0, 0, 0);
 157   ASSERT (PalRet.Status == 0);
 158
 159   if (StartValue != NULL) {
 160     *StartValue = 0;
 161   }
 162
 163   if (EndValue != NULL) {
 164     *EndValue = (UINT64)(-1);
 165   }
 166
 167   return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;
 168 }