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