MdePkg/Library/SecPeiDxeTimerLibCpu/IpfTimerLib.c

   1 /** @file
   2   Timer Library functions built upon ITC on IPF.
   3
   4   Copyright (c) 2006 - 2008, 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 **/
  14
  15 #include <Base.h>
  16 #include <Library/TimerLib.h>
  17 #include <Library/BaseLib.h>
  18 #include <Library/PalLib.h>
  19
  20
  21 /**
  22   Performs a delay measured as number of ticks.
  23
  24   An internal function to perform a delay measured as number of ticks. It's
  25   invoked by MicroSecondDelay() and NanoSecondDelay().
  26
  27   @param  Delay Number of ticks to delay.
  28
  29 **/
  30 VOID
  31 EFIAPI
  32 InternalIpfDelay (
  33   IN      INT64                     Delay
  34   )
  35 {
  36   INT64                             Ticks;
  37
  38   //
  39   // The target timer count is calculated here
  40   //
  41   Ticks = (INT64)AsmReadItc () + Delay;
  42
  43   //
  44   // Wait until time out
  45   // Delay > 2^63 could not be handled by this function
  46   // Timer wrap-arounds are handled correctly by this function
  47   //
  48   while (Ticks - (INT64)AsmReadItc() >= 0);
  49 }
  50
  51 /**
  52   Stalls the CPU for at least the given number of microseconds.
  53
  54   Stalls the CPU for the number of microseconds specified by MicroSeconds.
  55
  56   @param  MicroSeconds  The minimum number of microseconds to delay.
  57
  58   @return The value of MicroSeconds inputted.
  59
  60 **/
  61 UINTN
  62 EFIAPI
  63 MicroSecondDelay (
  64   IN      UINTN                     MicroSeconds
  65   )
  66 {
  67   InternalIpfDelay (
  68     GetPerformanceCounterProperties (NULL, NULL) *
  69     MicroSeconds /
  70     1000000
  71     );
  72   return MicroSeconds;
  73 }
  74
  75 /**
  76   Stalls the CPU for at least the given number of nanoseconds.
  77
  78   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
  79
  80   @param  NanoSeconds The minimum number of nanoseconds to delay.
  81
  82   @return The value of NanoSeconds inputted.
  83
  84 **/
  85 UINTN
  86 EFIAPI
  87 NanoSecondDelay (
  88   IN      UINTN                     NanoSeconds
  89   )
  90 {
  91   InternalIpfDelay (
  92     GetPerformanceCounterProperties (NULL, NULL) *
  93     NanoSeconds /
  94     1000000000
  95     );
  96   return NanoSeconds;
  97 }
  98
  99 /**
 100   Retrieves the current value of a 64-bit free running performance counter. The
 101   counter can either count up by 1 or count down by 1. If the physical
 102   performance counter counts by a larger increment, then the counter values
 103   must be translated. The properties of the counter can be retrieved from
 104   GetPerformanceCounterProperties().
 105
 106   @return The current value of the free running performance counter.
 107
 108 **/
 109 UINT64
 110 EFIAPI
 111 GetPerformanceCounter (
 112   VOID
 113   )
 114 {
 115   return AsmReadItc ();
 116 }
 117
 118 /**
 119   Retrieves the 64-bit frequency in Hz and the range of performance counter
 120   values.
 121
 122   If StartValue is not NULL, then the value that the performance counter starts
 123   with immediately after is it rolls over is returned in StartValue. If
 124   EndValue is not NULL, then the value that the performance counter end with
 125   immediately before it rolls over is returned in EndValue. The 64-bit
 126   frequency of the performance counter in Hz is always returned. If StartValue
 127   is less than EndValue, then the performance counter counts up. If StartValue
 128   is greater than EndValue, then the performance counter counts down. For
 129   example, a 64-bit free running counter that counts up would have a StartValue
 130   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 131   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 132
 133   @param  StartValue  The value the performance counter starts with when it
 134                       rolls over.
 135   @param  EndValue    The value that the performance counter ends with before
 136                       it rolls over.
 137
 138   @return The frequency in Hz.
 139
 140 **/
 141 UINT64
 142 EFIAPI
 143 GetPerformanceCounterProperties (
 144   OUT      UINT64                    *StartValue,  OPTIONAL
 145   OUT      UINT64                    *EndValue     OPTIONAL
 146   )
 147 {
 148   PAL_CALL_RETURN                   PalRet;
 149   UINT64                            BaseFrequence;
 150
 151   if (StartValue != NULL) {
 152     *StartValue = 0;
 153   }
 154
 155   if (EndValue != NULL) {
 156     *EndValue = (UINT64)(-1);
 157   }
 158
 159   PalRet = PalCall (PAL_FREQ_BASE, 0, 0, 0);
 160   if (PalRet.Status != 0) {
 161     return 1000000;
 162   }
 163   BaseFrequence = PalRet.r9;
 164
 165   PalRet = PalCall (PAL_FREQ_RATIOS, 0, 0, 0);
 166   if (PalRet.Status != 0) {
 167     return 1000000;
 168   }
 169
 170   return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;
 171 }