MdePkg/Library/BaseTimerLibLocalApic/Ipf/IpfTimerLib.c

   1 /** @file
   2   Timer Library functions built upon local APIC on IA32/x64.
   3
   4   @bug Should use PCD to retrieve all the constants including index of
   5   the IA32_APIC_BASE MSR, the offsets of InitialCount, CorrentCount
   6   and DivideConfiguration.
   7
   8   Copyright (c) 2006, Intel Corporation<BR>
   9   All rights reserved. This program and the accompanying materials
  10   are licensed and made available under the terms and conditions of the BSD License
  11   which accompanies this distribution.  The full text of the license may be found at
  12   http://opensource.org/licenses/bsd-license.php
  13
  14   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  15   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  16
  17   Module Name:  IpfTimerLib.c
  18
  19 **/
  20
  21
  22
  23
  24 /**
  25   Performs a delay measured as number of ticks.
  26
  27   An internal function to perform a delay measured as number of ticks. It's
  28   invoked by MicroSecondDelay() and NanoSecondDelay().
  29
  30   @param  Delay Number of ticks to delay.
  31
  32 **/
  33 STATIC
  34 VOID
  35 InternalIpfDelay (
  36   IN      INT64                     Delay
  37   )
  38 {
  39   INT64                             Ticks;
  40
  41   //
  42   // The target timer count is calculated here
  43   //
  44   Ticks = IpfReadItc () + Delay;
  45
  46   //
  47   // Wait until time out
  48   // Delay > 2^63 could not be handled by this function
  49   // Timer wrap-arounds are handled correctly by this function
  50   //
  51   while (Ticks - IpfReadItc () >= 0);
  52 }
  53
  54 /**
  55   Stalls the CPU for at least the given number of microseconds.
  56
  57   Stalls the CPU for the number of microseconds specified by MicroSeconds.
  58
  59   @param  MicroSeconds  The minimum number of microseconds to delay.
  60
  61   @return MicroSeconds
  62
  63 **/
  64 UINTN
  65 EFIAPI
  66 MicroSecondDelay (
  67   IN      UINTN                     MicroSeconds
  68   )
  69 {
  70   InternalIpfDelay (
  71     GetPerformanceCounterProperties (NULL, NULL) *
  72     MicroSeconds /
  73     1000000
  74     );
  75   return MicroSeconds;
  76 }
  77
  78 /**
  79   Stalls the CPU for at least the given number of nanoseconds.
  80
  81   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
  82
  83   @param  NanoSeconds The minimum number of nanoseconds to delay.
  84
  85   @return NanoSeconds
  86
  87 **/
  88 UINTN
  89 EFIAPI
  90 NanoSecondDelay (
  91   IN      UINTN                     NanoSeconds
  92   )
  93 {
  94   InternalIpfDelay (
  95     GetPerformanceCounterProperties (NULL, NULL) *
  96     NanoSeconds /
  97     1000000000
  98     );
  99   return NanoSeconds;
 100 }
 101
 102 /**
 103   Retrieves the current value of a 64-bit free running performance counter.
 104
 105   Retrieves the current value of a 64-bit free running performance counter. The
 106   counter can either count up by 1 or count down by 1. If the physical
 107   performance counter counts by a larger increment, then the counter values
 108   must be translated. The properties of the counter can be retrieved from
 109   GetPerformanceCounterProperties().
 110
 111   @return The current value of the free running performance counter.
 112
 113 **/
 114 UINT64
 115 EFIAPI
 116 GetPerformanceCounter (
 117   VOID
 118   )
 119 {
 120   return IpfReadItc ();
 121 }
 122
 123 /**
 124   Retrieves the 64-bit frequency in Hz and the range of performance counter
 125   values.
 126
 127   If StartValue is not NULL, then the value that the performance counter starts
 128   with immediately after is it rolls over is returned in StartValue. If
 129   EndValue is not NULL, then the value that the performance counter end with
 130   immediately before it rolls over is returned in EndValue. The 64-bit
 131   frequency of the performance counter in Hz is always returned. If StartValue
 132   is less than EndValue, then the performance counter counts up. If StartValue
 133   is greater than EndValue, then the performance counter counts down. For
 134   example, a 64-bit free running counter that counts up would have a StartValue
 135   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 136   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 137
 138   @param  StartValue  The value the performance counter starts with when it
 139                       rolls over.
 140   @param  EndValue    The value that the performance counter ends with before
 141                       it rolls over.
 142
 143   @return The frequency in Hz.
 144
 145 **/
 146 UINT64
 147 EFIAPI
 148 GetPerformanceCounterProperties (
 149   OUT      UINT64                    *StartValue,  OPTIONAL
 150   OUT      UINT64                    *EndValue     OPTIONAL
 151   )
 152 {
 153   PAL_PROC_RETURN                   PalRet;
 154   UINT64                            BaseFrequence;
 155
 156   PalRet = PalCallStatic (NULL, 13, 0, 0, 0);
 157   ASSERT (PalRet.Status == 0);
 158   BaseFrequence = PalRet.r9;
 159
 160   PalRet = PalCallStatic (NULL, 14, 0, 0, 0);
 161   ASSERT (PalRet.Status == 0);
 162
 163   if (StartValue != NULL) {
 164     *StartValue = 0;
 165   }
 166
 167   if (EndValue != NULL) {
 168     *EndValue = (UINT64)(-1);
 169   }
 170
 171   return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;
 172 }