MdePkg/Library/SecPeiDxeTimerLibCpu/IpfTimerLib.c

   1 /** @file
   2   Timer Library functions built upon ITC on IPF.
   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 **/
  14
  15 #include <Base.h>
  16 #include <Library/TimerLib.h>
  17 #include <Library/BaseLib.h>
  18 #include <Library/PalCallLib.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 MicroSeconds
  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 NanoSeconds
  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.
 101
 102   Retrieves the current value of a 64-bit free running performance counter. The
 103   counter can either count up by 1 or count down by 1. If the physical
 104   performance counter counts by a larger increment, then the counter values
 105   must be translated. The properties of the counter can be retrieved from
 106   GetPerformanceCounterProperties().
 107
 108   @return The current value of the free running performance counter.
 109
 110 **/
 111 UINT64
 112 EFIAPI
 113 GetPerformanceCounter (
 114   VOID
 115   )
 116 {
 117   return AsmReadItc ();
 118 }
 119
 120 /**
 121   Retrieves the 64-bit frequency in Hz and the range of performance counter
 122   values.
 123
 124   If StartValue is not NULL, then the value that the performance counter starts
 125   with immediately after is it rolls over is returned in StartValue. If
 126   EndValue is not NULL, then the value that the performance counter end with
 127   immediately before it rolls over is returned in EndValue. The 64-bit
 128   frequency of the performance counter in Hz is always returned. If StartValue
 129   is less than EndValue, then the performance counter counts up. If StartValue
 130   is greater than EndValue, then the performance counter counts down. For
 131   example, a 64-bit free running counter that counts up would have a StartValue
 132   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 133   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 134
 135   @param  StartValue  The value the performance counter starts with when it
 136                       rolls over.
 137   @param  EndValue    The value that the performance counter ends with before
 138                       it rolls over.
 139
 140   @return The frequency in Hz.
 141
 142 **/
 143 UINT64
 144 EFIAPI
 145 GetPerformanceCounterProperties (
 146   OUT      UINT64                    *StartValue,  OPTIONAL
 147   OUT      UINT64                    *EndValue     OPTIONAL
 148   )
 149 {
 150   PAL_CALL_RETURN                   PalRet;
 151   UINT64                            BaseFrequence;
 152
 153   if (StartValue != NULL) {
 154     *StartValue = 0;
 155   }
 156
 157   if (EndValue != NULL) {
 158     *EndValue = (UINT64)(-1);
 159   }
 160
 161   PalRet = PalCall (PAL_FREQ_BASE, 0, 0, 0);
 162   if (PalRet.Status != 0) {
 163     return 1000000;
 164   }
 165   BaseFrequence = PalRet.r9;
 166
 167   PalRet = PalCall (PAL_FREQ_RATIOS, 0, 0, 0);
 168   if (PalRet.Status != 0) {
 169     return 1000000;
 170   }
 171
 172   return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;
 173 }