MdePkg/Library/SecPeiDxeTimerLibCpu/X86TimerLib.c

   1 /** @file
   2   Timer Library functions built upon local APIC on IA32/x64.
   3
   4   Copyright (c) 2006 - 2008, 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/IoLib.h>
  19 #include <Library/PcdLib.h>
  20 #include <Library/DebugLib.h>
  21
  22 #define APIC_LVTERR     0x370
  23 #define APIC_TMICT      0x380
  24 #define APIC_TMCCT      0x390
  25 #define APIC_TDCR       0x3e0
  26
  27 //
  28 // The following array is used in calculating the frequency of local APIC
  29 // timer. Refer to IA-32 developers' manual for more details.
  30 //
  31 GLOBAL_REMOVE_IF_UNREFERENCED
  32 CONST UINT8                           mTimerLibLocalApicDivisor[] = {
  33   0x02, 0x04, 0x08, 0x10,
  34   0x02, 0x04, 0x08, 0x10,
  35   0x20, 0x40, 0x80, 0x01,
  36   0x20, 0x40, 0x80, 0x01
  37 };
  38
  39 /**
  40   Internal function to retrieve the base address of local APIC.
  41
  42   @return The base address of local APIC
  43
  44 **/
  45 UINTN
  46 EFIAPI
  47 InternalX86GetApicBase (
  48   VOID
  49   )
  50 {
  51   return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;
  52 }
  53
  54 /**
  55   Internal function to return the frequency of the local APIC timer.
  56
  57   @param  ApicBase  The base address of memory mapped registers of local APIC.
  58
  59   @return The frequency of the timer in Hz.
  60
  61 **/
  62 UINT32
  63 EFIAPI
  64 InternalX86GetTimerFrequency (
  65   IN      UINTN                     ApicBase
  66   )
  67 {
  68   return
  69     PcdGet32(PcdFSBClock) /
  70     mTimerLibLocalApicDivisor[MmioBitFieldRead32 (ApicBase + APIC_TDCR, 0, 3)];
  71 }
  72
  73 /**
  74   Internal function to read the current tick counter of local APIC.
  75
  76   @param  ApicBase  The base address of memory mapped registers of local APIC.
  77
  78   @return The tick counter read.
  79
  80 **/
  81 INT32
  82 EFIAPI
  83 InternalX86GetTimerTick (
  84   IN      UINTN                     ApicBase
  85   )
  86 {
  87   return MmioRead32 (ApicBase + APIC_TMCCT);
  88 }
  89
  90 /**
  91   Stalls the CPU for at least the given number of ticks.
  92
  93   Stalls the CPU for at least the given number of ticks. It's invoked by
  94   MicroSecondDelay() and NanoSecondDelay().
  95
  96   @param  ApicBase  The base address of memory mapped registers of local APIC.
  97   @param  Delay     A period of time to delay in ticks.
  98
  99 **/
 100 VOID
 101 EFIAPI
 102 InternalX86Delay (
 103   IN      UINTN                     ApicBase,
 104   IN      UINT32                    Delay
 105   )
 106 {
 107   INT32                             Ticks;
 108
 109   //
 110   // The target timer count is calculated here
 111   //
 112   Ticks = InternalX86GetTimerTick (ApicBase) - Delay;
 113
 114   //
 115   // Wait until time out
 116   // Delay > 2^31 could not be handled by this function
 117   // Timer wrap-arounds are handled correctly by this function
 118   //
 119   while (((UINT32)(InternalX86GetTimerTick (ApicBase) - Ticks) & GetPowerOfTwo32 ((MmioRead32 (ApicBase + APIC_TMICT)))) == 0) {
 120     CpuPause ();
 121   }
 122 }
 123
 124 /**
 125   Stalls the CPU for at least the given number of microseconds.
 126
 127   Stalls the CPU for the number of microseconds specified by MicroSeconds.
 128
 129   @param  MicroSeconds  The minimum number of microseconds to delay.
 130
 131   @return The value of MicroSeconds inputted.
 132
 133 **/
 134 UINTN
 135 EFIAPI
 136 MicroSecondDelay (
 137   IN      UINTN                     MicroSeconds
 138   )
 139 {
 140   UINTN                             ApicBase;
 141
 142   ApicBase = InternalX86GetApicBase ();
 143   InternalX86Delay (
 144     ApicBase,
 145     (UINT32)DivU64x32 (
 146               MultU64x64 (
 147                 InternalX86GetTimerFrequency (ApicBase),
 148                 MicroSeconds
 149                 ),
 150               1000000u
 151               )
 152     );
 153   return MicroSeconds;
 154 }
 155
 156 /**
 157   Stalls the CPU for at least the given number of nanoseconds.
 158
 159   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
 160
 161   @param  NanoSeconds The minimum number of nanoseconds to delay.
 162
 163   @return The value of NanoSeconds inputted.
 164
 165 **/
 166 UINTN
 167 EFIAPI
 168 NanoSecondDelay (
 169   IN      UINTN                     NanoSeconds
 170   )
 171 {
 172   UINTN                             ApicBase;
 173
 174   ApicBase = InternalX86GetApicBase ();
 175   InternalX86Delay (
 176     ApicBase,
 177     (UINT32)DivU64x32 (
 178               MultU64x64 (
 179                 InternalX86GetTimerFrequency (ApicBase),
 180                 NanoSeconds
 181                 ),
 182               1000000000u
 183               )
 184     );
 185   return NanoSeconds;
 186 }
 187
 188 /**
 189   Retrieves the current value of a 64-bit free running performance counter.
 190
 191   The 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 + APIC_TMICT);
 244     //
 245     // make sure StartValue is all 1s from High Bit
 246     //
 247     ASSERT ((*StartValue & (*StartValue + 1)) == 0);
 248   }
 249
 250   if (EndValue != NULL) {
 251     *EndValue = 0;
 252   }
 253
 254   return (UINT64) InternalX86GetTimerFrequency (ApicBase);
 255 }