OvmfPkg/Library/AcpiTimerLib/AcpiTimerLib.c

   1 /** @file
   2   ACPI Timer implements one instance of Timer Library.
   3
   4   Copyright (c) 2008 - 2011, Intel Corporation. All rights reserved.<BR>
   5   Copyright (c) 2011, Andrei Warkentin <andreiw@motorola.com>
   6
   7   This program and the accompanying materials are
   8   licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15 **/
  16
  17 #include <Base.h>
  18 #include <Library/TimerLib.h>
  19 #include <Library/BaseLib.h>
  20 #include <Library/IoLib.h>
  21 #include <Library/PciLib.h>
  22 #include <Library/DebugLib.h>
  23 #include <Library/PcdLib.h>
  24
  25 //
  26 // PIIX4 Power Management Base Address
  27 //
  28 STATIC UINT32 mPmba;
  29
  30 #define PCI_BAR_IO             0x1
  31 #define ACPI_TIMER_FREQUENCY   3579545
  32 #define ACPI_TIMER_COUNT_SIZE  0x01000000
  33 #define ACPI_TIMER_OFFSET      0x8
  34
  35 /**
  36   The constructor function enables ACPI IO space.
  37
  38   If ACPI I/O space not enabled, this function will enable it.
  39   It will always return RETURN_SUCCESS.
  40
  41   @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
  42
  43 **/
  44 RETURN_STATUS
  45 EFIAPI
  46 AcpiTimerLibConstructor (
  47   VOID
  48   )
  49 {
  50   UINT8 Device;
  51
  52   Device = 1;
  53   // Device = 7;
  54
  55   if (PciRead8 (PCI_LIB_ADDRESS (0,Device,3,0x80)) & 1) {
  56     mPmba = PciRead32 (PCI_LIB_ADDRESS (0,Device,3,0x40));
  57     ASSERT (mPmba & PCI_BAR_IO);
  58     mPmba &= ~PCI_BAR_IO;
  59   } else {
  60     mPmba = PcdGet16 (PcdAcpiPmBaseAddress);
  61
  62     PciAndThenOr32 (PCI_LIB_ADDRESS (0,Device,3,0x40),
  63                     (UINT32) ~0xfc0, mPmba);
  64     PciOr8         (PCI_LIB_ADDRESS (0,Device,3,0x04), 0x01);
  65   }
  66
  67   //
  68   // ACPI Timer enable is in Bus 0, Device ?, Function 3
  69   //
  70   PciOr8         (PCI_LIB_ADDRESS (0,Device,3,0x80), 0x01);
  71   return RETURN_SUCCESS;
  72 }
  73
  74 /**
  75   Internal function to read the current tick counter of ACPI.
  76
  77   Internal function to read the current tick counter of ACPI.
  78
  79   @return The tick counter read.
  80
  81 **/
  82 STATIC
  83 UINT32
  84 InternalAcpiGetTimerTick (
  85   VOID
  86   )
  87 {
  88   return IoRead32 (mPmba + ACPI_TIMER_OFFSET);
  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  Delay     A period of time to delay in ticks.
  98
  99 **/
 100 STATIC
 101 VOID
 102 InternalAcpiDelay (
 103   IN      UINT32                    Delay
 104   )
 105 {
 106   UINT32                            Ticks;
 107   UINT32                            Times;
 108
 109   Times    = Delay >> 22;
 110   Delay   &= BIT22 - 1;
 111   do {
 112     //
 113     // The target timer count is calculated here
 114     //
 115     Ticks    = InternalAcpiGetTimerTick () + Delay;
 116     Delay    = BIT22;
 117     //
 118     // Wait until time out
 119     // Delay >= 2^23 could not be handled by this function
 120     // Timer wrap-arounds are handled correctly by this function
 121     //
 122     while (((Ticks - InternalAcpiGetTimerTick ()) & BIT23) == 0) {
 123       CpuPause ();
 124     }
 125   } while (Times-- > 0);
 126 }
 127
 128 /**
 129   Stalls the CPU for at least the given number of microseconds.
 130
 131   Stalls the CPU for the number of microseconds specified by MicroSeconds.
 132
 133   @param  MicroSeconds  The minimum number of microseconds to delay.
 134
 135   @return MicroSeconds
 136
 137 **/
 138 UINTN
 139 EFIAPI
 140 MicroSecondDelay (
 141   IN      UINTN                     MicroSeconds
 142   )
 143 {
 144   InternalAcpiDelay (
 145     (UINT32)DivU64x32 (
 146               MultU64x32 (
 147                 MicroSeconds,
 148                 ACPI_TIMER_FREQUENCY
 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 NanoSeconds
 164
 165 **/
 166 UINTN
 167 EFIAPI
 168 NanoSecondDelay (
 169   IN      UINTN                     NanoSeconds
 170   )
 171 {
 172   InternalAcpiDelay (
 173     (UINT32)DivU64x32 (
 174               MultU64x32 (
 175                 NanoSeconds,
 176                 ACPI_TIMER_FREQUENCY
 177                 ),
 178               1000000000u
 179               )
 180     );
 181   return NanoSeconds;
 182 }
 183
 184 /**
 185   Retrieves the current value of a 64-bit free running performance counter.
 186
 187   Retrieves the current value of a 64-bit free running performance counter. The
 188   counter can either count up by 1 or count down by 1. If the physical
 189   performance counter counts by a larger increment, then the counter values
 190   must be translated. The properties of the counter can be retrieved from
 191   GetPerformanceCounterProperties().
 192
 193   @return The current value of the free running performance counter.
 194
 195 **/
 196 UINT64
 197 EFIAPI
 198 GetPerformanceCounter (
 199   VOID
 200   )
 201 {
 202   return (UINT64)InternalAcpiGetTimerTick ();
 203 }
 204
 205 /**
 206   Retrieves the 64-bit frequency in Hz and the range of performance counter
 207   values.
 208
 209   If StartValue is not NULL, then the value that the performance counter starts
 210   with immediately after is it rolls over is returned in StartValue. If
 211   EndValue is not NULL, then the value that the performance counter end with
 212   immediately before it rolls over is returned in EndValue. The 64-bit
 213   frequency of the performance counter in Hz is always returned. If StartValue
 214   is less than EndValue, then the performance counter counts up. If StartValue
 215   is greater than EndValue, then the performance counter counts down. For
 216   example, a 64-bit free running counter that counts up would have a StartValue
 217   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 218   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 219
 220   @param  StartValue  The value the performance counter starts with when it
 221                       rolls over.
 222   @param  EndValue    The value that the performance counter ends with before
 223                       it rolls over.
 224
 225   @return The frequency in Hz.
 226
 227 **/
 228 UINT64
 229 EFIAPI
 230 GetPerformanceCounterProperties (
 231   OUT      UINT64                    *StartValue,  OPTIONAL
 232   OUT      UINT64                    *EndValue     OPTIONAL
 233   )
 234 {
 235   if (StartValue != NULL) {
 236     *StartValue = 0;
 237   }
 238
 239   if (EndValue != NULL) {
 240     *EndValue = ACPI_TIMER_COUNT_SIZE - 1;
 241   }
 242
 243   return ACPI_TIMER_FREQUENCY;
 244 }
 245
 246 /**
 247   Converts elapsed ticks of performance counter to time in nanoseconds.
 248
 249   This function converts the elapsed ticks of running performance counter to
 250   time value in unit of nanoseconds.
 251
 252   @param  Ticks     The number of elapsed ticks of running performance counter.
 253
 254   @return The elapsed time in nanoseconds.
 255
 256 **/
 257 UINT64
 258 EFIAPI
 259 GetTimeInNanoSecond (
 260   IN      UINT64                     Ticks
 261   )
 262 {
 263   UINT64  NanoSeconds;
 264   UINT32  Remainder;
 265
 266   //
 267   //          Ticks
 268   // Time = --------- x 1,000,000,000
 269   //        Frequency
 270   //
 271   NanoSeconds = MultU64x32 (DivU64x32Remainder (Ticks, ACPI_TIMER_FREQUENCY, &Remainder), 1000000000u);
 272
 273   //
 274   // Frequency < 0x100000000, so Remainder < 0x100000000, then (Remainder * 1,000,000,000)
 275   // will not overflow 64-bit.
 276   //
 277   NanoSeconds += DivU64x32 (MultU64x32 ((UINT64) Remainder, 1000000000u), ACPI_TIMER_FREQUENCY);
 278
 279   return NanoSeconds;
 280 }