UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/IpfTimerLib.c

   1 /** @file
   2   Timer Library functions built upon ITC on IPF.
   3
   4   Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
   5   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 The 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.
 101
 102   The 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 AsmReadItc ();
 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_CALL_RETURN                   PalRet;
 150   UINT64                            BaseFrequence;
 151
 152   if (StartValue != NULL) {
 153     *StartValue = 0;
 154   }
 155
 156   if (EndValue != NULL) {
 157     *EndValue = (UINT64)(-1);
 158   }
 159
 160   PalRet = PalCall (PAL_FREQ_BASE, 0, 0, 0);
 161   if (PalRet.Status != 0) {
 162     return 1000000;
 163   }
 164   BaseFrequence = PalRet.r9;
 165
 166   PalRet = PalCall (PAL_FREQ_RATIOS, 0, 0, 0);
 167   if (PalRet.Status != 0) {
 168     return 1000000;
 169   }
 170
 171   return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;
 172 }
 173
 174 /**
 175   Converts elapsed ticks of performance counter to time in nanoseconds.
 176
 177   This function converts the elapsed ticks of running performance counter to
 178   time value in unit of nanoseconds.
 179
 180   @param  Ticks     The number of elapsed ticks of running performance counter.
 181
 182   @return The elapsed time in nanoseconds.
 183
 184 **/
 185 UINT64
 186 EFIAPI
 187 GetTimeInNanoSecond (
 188   IN      UINT64                     Ticks
 189   )
 190 {
 191   UINT64  Frequency;
 192   UINT64  NanoSeconds;
 193   UINT64  Remainder;
 194   INTN    Shift;
 195
 196   Frequency = GetPerformanceCounterProperties (NULL, NULL);
 197
 198   //
 199   //          Ticks
 200   // Time = --------- x 1,000,000,000
 201   //        Frequency
 202   //
 203   NanoSeconds = MultU64x32 (DivU64x64Remainder (Ticks, Frequency, &Remainder), 1000000000u);
 204
 205   //
 206   // Ensure (Remainder * 1,000,000,000) will not overflow 64-bit.
 207   // Since 2^29 < 1,000,000,000 = 0x3B9ACA00 < 2^30, Remainder should < 2^(64-30) = 2^34,
 208   // i.e. highest bit set in Remainder should <= 33.
 209   //
 210   Shift = MAX (0, HighBitSet64 (Remainder) - 33);
 211   Remainder = RShiftU64 (Remainder, (UINTN) Shift);
 212   Frequency = RShiftU64 (Frequency, (UINTN) Shift);
 213   NanoSeconds += DivU64x64Remainder (MultU64x32 (Remainder, 1000000000u), Frequency, NULL);
 214
 215   return NanoSeconds;
 216 }