EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Library/BaseTimerLibLocalApic/x86TimerLib.c

   1 /*++
   2
   3 Copyright (c) 2004 - 2006, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12
  13 Module Name:
  14
  15   x86TimerLib.c
  16
  17 Abstract:
  18
  19   Timer Library functions built upon local APIC on IA32/x64.
  20
  21   @bug Should use PCD to retrieve all the constants including index of
  22   the IA32_APIC_BASE MSR, the offsets of InitialCount, CorrentCount
  23   and DivideConfiguration.
  24
  25 --*/
  26
  27 #include "EdkIIGlueBase.h"
  28
  29 //
  30 // The following array is used in calculating the frequency of local APIC
  31 // timer. Refer to IA-32 developers' manual for more details.
  32 //
  33 GLOBAL_REMOVE_IF_UNREFERENCED
  34 CONST UINT8                           mTimerLibLocalApicDivisor[] = {
  35   0x02, 0x04, 0x08, 0x10,
  36   0x02, 0x04, 0x08, 0x10,
  37   0x20, 0x40, 0x80, 0x01,
  38   0x20, 0x40, 0x80, 0x01
  39 };
  40
  41 /**
  42   Internal function to retrieve the base address of local APIC.
  43
  44   Internal function to retrieve the base address of local APIC.
  45
  46   @return The base address of local APIC
  47
  48 **/
  49 STATIC
  50 UINTN
  51 InternalX86GetApicBase (
  52   VOID
  53   )
  54 {
  55   return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;
  56 }
  57
  58 /**
  59   Internal function to return the frequency of the local APIC timer.
  60
  61   Internal function to return the frequency of the local APIC timer.
  62
  63   @param  ApicBase  The base address of memory mapped registers of local APIC.
  64
  65   @return The frequency of the timer in Hz.
  66
  67 **/
  68 STATIC
  69 UINT32
  70 InternalX86GetTimerFrequency (
  71   IN      UINTN                     ApicBase
  72   )
  73 {
  74   return
  75     PcdGet32(PcdFSBClock) /
  76     mTimerLibLocalApicDivisor[MmioBitFieldRead32 (ApicBase + 0x3e0, 0, 3)];
  77 }
  78
  79 /**
  80   Internal function to read the current tick counter of local APIC.
  81
  82   Internal function to read the current tick counter of local APIC.
  83
  84   @param  ApicBase  The base address of memory mapped registers of local APIC.
  85
  86   @return The tick counter read.
  87
  88 **/
  89 STATIC
  90 INT32
  91 InternalX86GetTimerTick (
  92   IN      UINTN                     ApicBase
  93   )
  94 {
  95   return MmioRead32 (ApicBase + 0x390);
  96 }
  97
  98 /**
  99   Stalls the CPU for at least the given number of ticks.
 100
 101   Stalls the CPU for at least the given number of ticks. It's invoked by
 102   MicroSecondDelay() and NanoSecondDelay().
 103
 104   @param  ApicBase  The base address of memory mapped registers of local APIC.
 105   @param  Delay     A period of time to delay in ticks.
 106
 107 **/
 108 STATIC
 109 VOID
 110 InternalX86Delay (
 111   IN      UINTN                     ApicBase,
 112   IN      UINT32                    Delay
 113   )
 114 {
 115   INT32                             Ticks;
 116
 117   //
 118   // The target timer count is calculated here
 119   //
 120   Ticks = InternalX86GetTimerTick (ApicBase) - Delay;
 121
 122   //
 123   // Wait until time out
 124   // Delay > 2^31 could not be handled by this function
 125   // Timer wrap-arounds are handled correctly by this function
 126   //
 127   while (InternalX86GetTimerTick (ApicBase) - Ticks >= 0);
 128 }
 129
 130 /**
 131   Stalls the CPU for at least the given number of microseconds.
 132
 133   Stalls the CPU for the number of microseconds specified by MicroSeconds.
 134
 135   @param  MicroSeconds  The minimum number of microseconds to delay.
 136
 137   @return MicroSeconds
 138
 139 **/
 140 UINTN
 141 EFIAPI
 142 MicroSecondDelay (
 143   IN      UINTN                     MicroSeconds
 144   )
 145 {
 146   UINTN                             ApicBase;
 147
 148   ApicBase = InternalX86GetApicBase ();
 149   InternalX86Delay (
 150     ApicBase,
 151     (UINT32)DivU64x32 (
 152               MultU64x64 (
 153                 InternalX86GetTimerFrequency (ApicBase),
 154                 MicroSeconds
 155                 ),
 156               1000000u
 157               )
 158     );
 159   return MicroSeconds;
 160 }
 161
 162 /**
 163   Stalls the CPU for at least the given number of nanoseconds.
 164
 165   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
 166
 167   @param  NanoSeconds The minimum number of nanoseconds to delay.
 168
 169   @return NanoSeconds
 170
 171 **/
 172 UINTN
 173 EFIAPI
 174 NanoSecondDelay (
 175   IN      UINTN                     NanoSeconds
 176   )
 177 {
 178   UINTN                             ApicBase;
 179
 180   ApicBase = InternalX86GetApicBase ();
 181   InternalX86Delay (
 182     ApicBase,
 183     (UINT32)DivU64x32 (
 184               MultU64x64 (
 185                 InternalX86GetTimerFrequency (ApicBase),
 186                 NanoSeconds
 187                 ),
 188               1000000000u
 189               )
 190     );
 191   return NanoSeconds;
 192 }
 193
 194 /**
 195   Retrieves the current value of a 64-bit free running performance counter.
 196
 197   Retrieves the current value of a 64-bit free running performance counter. The
 198   counter can either count up by 1 or count down by 1. If the physical
 199   performance counter counts by a larger increment, then the counter values
 200   must be translated. The properties of the counter can be retrieved from
 201   GetPerformanceCounterProperties().
 202
 203   @return The current value of the free running performance counter.
 204
 205 **/
 206 UINT64
 207 EFIAPI
 208 GetPerformanceCounter (
 209   VOID
 210   )
 211 {
 212   return (UINT64)(UINT32)InternalX86GetTimerTick (InternalX86GetApicBase ());
 213 }
 214
 215 /**
 216   Retrieves the 64-bit frequency in Hz and the range of performance counter
 217   values.
 218
 219   If StartValue is not NULL, then the value that the performance counter starts
 220   with immediately after is it rolls over is returned in StartValue. If
 221   EndValue is not NULL, then the value that the performance counter end with
 222   immediately before it rolls over is returned in EndValue. The 64-bit
 223   frequency of the performance counter in Hz is always returned. If StartValue
 224   is less than EndValue, then the performance counter counts up. If StartValue
 225   is greater than EndValue, then the performance counter counts down. For
 226   example, a 64-bit free running counter that counts up would have a StartValue
 227   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 228   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 229
 230   @param  StartValue  The value the performance counter starts with when it
 231                       rolls over.
 232   @param  EndValue    The value that the performance counter ends with before
 233                       it rolls over.
 234
 235   @return The frequency in Hz.
 236
 237 **/
 238 UINT64
 239 EFIAPI
 240 GetPerformanceCounterProperties (
 241   OUT      UINT64                    *StartValue,  OPTIONAL
 242   OUT      UINT64                    *EndValue     OPTIONAL
 243   )
 244 {
 245   UINTN                             ApicBase;
 246
 247   ApicBase = InternalX86GetApicBase ();
 248
 249   if (StartValue != NULL) {
 250     *StartValue = MmioRead32 (ApicBase + 0x380);
 251   }
 252
 253   if (EndValue != NULL) {
 254     *EndValue = 0;
 255   }
 256
 257   return (UINT64) InternalX86GetTimerFrequency (ApicBase);;
 258 }