MdePkg/Library/SecPeiDxeTimerLibCpu/x86TimerLib.c

   1 /** @file
   2   Timer Library functions built upon local APIC 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:  x86TimerLib.c
  14
  15 **/
  16
  17 //
  18 // Include common header file for this module.
  19 //
  20 #include "CommonHeader.h"
  21
  22 //
  23 // The following array is used in calculating the frequency of local APIC
  24 // timer. Refer to IA-32 developers' manual for more details.
  25 //
  26 GLOBAL_REMOVE_IF_UNREFERENCED
  27 CONST UINT8                           mTimerLibLocalApicDivisor[] = {
  28   0x02, 0x04, 0x08, 0x10,
  29   0x02, 0x04, 0x08, 0x10,
  30   0x20, 0x40, 0x80, 0x01,
  31   0x20, 0x40, 0x80, 0x01
  32 };
  33
  34 /**
  35   Internal function to retrieve the base address of local APIC.
  36
  37   Internal function to retrieve the base address of local APIC.
  38
  39   @return The base address of local APIC
  40
  41 **/
  42 STATIC
  43 UINTN
  44 InternalX86GetApicBase (
  45   VOID
  46   )
  47 {
  48   return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;
  49 }
  50
  51 /**
  52   Internal function to return the frequency of the local APIC timer.
  53
  54   Internal function to return the frequency of the local APIC timer.
  55
  56   @param  ApicBase  The base address of memory mapped registers of local APIC.
  57
  58   @return The frequency of the timer in Hz.
  59
  60 **/
  61 STATIC
  62 UINT32
  63 InternalX86GetTimerFrequency (
  64   IN      UINTN                     ApicBase
  65   )
  66 {
  67   return
  68     PcdGet32(PcdFSBClock) /
  69     mTimerLibLocalApicDivisor[MmioBitFieldRead32 (ApicBase + 0x3e0, 0, 3)];
  70 }
  71
  72 /**
  73   Internal function to read the current tick counter of local APIC.
  74
  75   Internal function to read the current tick counter of local APIC.
  76
  77   @param  ApicBase  The base address of memory mapped registers of local APIC.
  78
  79   @return The tick counter read.
  80
  81 **/
  82 STATIC
  83 INT32
  84 InternalX86GetTimerTick (
  85   IN      UINTN                     ApicBase
  86   )
  87 {
  88   return MmioRead32 (ApicBase + 0x390);
  89 }
  90
  91 /**
  92   Stalls the CPU for at least the given number of ticks.
  93
  94   Stalls the CPU for at least the given number of ticks. It's invoked by
  95   MicroSecondDelay() and NanoSecondDelay().
  96
  97   @param  ApicBase  The base address of memory mapped registers of local APIC.
  98   @param  Delay     A period of time to delay in ticks.
  99
 100 **/
 101 STATIC
 102 VOID
 103 InternalX86Delay (
 104   IN      UINTN                     ApicBase,
 105   IN      UINT32                    Delay
 106   )
 107 {
 108   INT32                             Ticks;
 109
 110   //
 111   // The target timer count is calculated here
 112   //
 113   Ticks = InternalX86GetTimerTick (ApicBase) - Delay;
 114
 115   //
 116   // Wait until time out
 117   // Delay > 2^31 could not be handled by this function
 118   // Timer wrap-arounds are handled correctly by this function
 119   //
 120   while (InternalX86GetTimerTick (ApicBase) - Ticks >= 0);
 121 }
 122
 123 /**
 124   Stalls the CPU for at least the given number of microseconds.
 125
 126   Stalls the CPU for the number of microseconds specified by MicroSeconds.
 127
 128   @param  MicroSeconds  The minimum number of microseconds to delay.
 129
 130   @return MicroSeconds
 131
 132 **/
 133 UINTN
 134 EFIAPI
 135 MicroSecondDelay (
 136   IN      UINTN                     MicroSeconds
 137   )
 138 {
 139   UINTN                             ApicBase;
 140
 141   ApicBase = InternalX86GetApicBase ();
 142   InternalX86Delay (
 143     ApicBase,
 144     (UINT32)DivU64x32 (
 145               MultU64x64 (
 146                 InternalX86GetTimerFrequency (ApicBase),
 147                 MicroSeconds
 148                 ),
 149               1000000u
 150               )
 151     );
 152   return MicroSeconds;
 153 }
 154
 155 /**
 156   Stalls the CPU for at least the given number of nanoseconds.
 157
 158   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
 159
 160   @param  NanoSeconds The minimum number of nanoseconds to delay.
 161
 162   @return NanoSeconds
 163
 164 **/
 165 UINTN
 166 EFIAPI
 167 NanoSecondDelay (
 168   IN      UINTN                     NanoSeconds
 169   )
 170 {
 171   UINTN                             ApicBase;
 172
 173   ApicBase = InternalX86GetApicBase ();
 174   InternalX86Delay (
 175     ApicBase,
 176     (UINT32)DivU64x32 (
 177               MultU64x64 (
 178                 InternalX86GetTimerFrequency (ApicBase),
 179                 NanoSeconds
 180                 ),
 181               1000000000u
 182               )
 183     );
 184   return NanoSeconds;
 185 }
 186
 187 /**
 188   Retrieves the current value of a 64-bit free running performance counter.
 189
 190   Retrieves the current value of a 64-bit free running performance counter. The
 191   counter can either count up by 1 or count down by 1. If the physical
 192   performance counter counts by a larger increment, then the counter values
 193   must be translated. The properties of the counter can be retrieved from
 194   GetPerformanceCounterProperties().
 195
 196   @return The current value of the free running performance counter.
 197
 198 **/
 199 UINT64
 200 EFIAPI
 201 GetPerformanceCounter (
 202   VOID
 203   )
 204 {
 205   return (UINT64)(UINT32)InternalX86GetTimerTick (InternalX86GetApicBase ());
 206 }
 207
 208 /**
 209   Retrieves the 64-bit frequency in Hz and the range of performance counter
 210   values.
 211
 212   If StartValue is not NULL, then the value that the performance counter starts
 213   with immediately after is it rolls over is returned in StartValue. If
 214   EndValue is not NULL, then the value that the performance counter end with
 215   immediately before it rolls over is returned in EndValue. The 64-bit
 216   frequency of the performance counter in Hz is always returned. If StartValue
 217   is less than EndValue, then the performance counter counts up. If StartValue
 218   is greater than EndValue, then the performance counter counts down. For
 219   example, a 64-bit free running counter that counts up would have a StartValue
 220   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 221   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 222
 223   @param  StartValue  The value the performance counter starts with when it
 224                       rolls over.
 225   @param  EndValue    The value that the performance counter ends with before
 226                       it rolls over.
 227
 228   @return The frequency in Hz.
 229
 230 **/
 231 UINT64
 232 EFIAPI
 233 GetPerformanceCounterProperties (
 234   OUT      UINT64                    *StartValue,  OPTIONAL
 235   OUT      UINT64                    *EndValue     OPTIONAL
 236   )
 237 {
 238   UINTN                             ApicBase;
 239
 240   ApicBase = InternalX86GetApicBase ();
 241
 242   if (StartValue != NULL) {
 243     *StartValue = MmioRead32 (ApicBase + 0x380);
 244   }
 245
 246   if (EndValue != NULL) {
 247     *EndValue = 0;
 248   }
 249
 250   return (UINT64) InternalX86GetTimerFrequency (ApicBase);;
 251 }