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 #include <IndustryStandard/Pci22.h>
  25
  26 //
  27 // PIIX4 Power Management Base Address
  28 //
  29 STATIC UINT32 mPmba;
  30
  31 #define PCI_BAR_IO             0x1
  32 #define ACPI_TIMER_FREQUENCY   3579545
  33 #define ACPI_TIMER_COUNT_SIZE  0x01000000
  34 #define ACPI_TIMER_OFFSET      0x8
  35
  36 /**
  37   The constructor function enables ACPI IO space.
  38
  39   If ACPI I/O space not enabled, this function will enable it.
  40   It will always return RETURN_SUCCESS.
  41
  42   @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
  43
  44 **/
  45 RETURN_STATUS
  46 EFIAPI
  47 AcpiTimerLibConstructor (
  48   VOID
  49   )
  50 {
  51   UINT8 Device;
  52
  53   Device = 1;
  54   // Device = 7;
  55
  56   if (PciRead8 (PCI_LIB_ADDRESS (0,Device,3,0x80)) & 1) {
  57     mPmba = PciRead32 (PCI_LIB_ADDRESS (0,Device,3,0x40));
  58     ASSERT (mPmba & PCI_BAR_IO);
  59     mPmba &= ~PCI_BAR_IO;
  60   } else {
  61     mPmba = PcdGet16 (PcdAcpiPmBaseAddress);
  62
  63     PciAndThenOr32 (PCI_LIB_ADDRESS (0,Device,3,0x40),
  64                     (UINT32) ~0xFFC0, mPmba);
  65     PciOr8 (
  66       PCI_LIB_ADDRESS (0, Device, 3, PCI_COMMAND_OFFSET),
  67       EFI_PCI_COMMAND_IO_SPACE
  68       );
  69   }
  70
  71   //
  72   // ACPI Timer enable is in Bus 0, Device ?, Function 3
  73   //
  74   PciOr8         (PCI_LIB_ADDRESS (0,Device,3,0x80), 0x01);
  75   return RETURN_SUCCESS;
  76 }
  77
  78 /**
  79   Internal function to read the current tick counter of ACPI.
  80
  81   Internal function to read the current tick counter of ACPI.
  82
  83   @return The tick counter read.
  84
  85 **/
  86 STATIC
  87 UINT32
  88 InternalAcpiGetTimerTick (
  89   VOID
  90   )
  91 {
  92   return IoRead32 (mPmba + ACPI_TIMER_OFFSET);
  93 }
  94
  95 /**
  96   Stalls the CPU for at least the given number of ticks.
  97
  98   Stalls the CPU for at least the given number of ticks. It's invoked by
  99   MicroSecondDelay() and NanoSecondDelay().
 100
 101   @param  Delay     A period of time to delay in ticks.
 102
 103 **/
 104 STATIC
 105 VOID
 106 InternalAcpiDelay (
 107   IN      UINT32                    Delay
 108   )
 109 {
 110   UINT32                            Ticks;
 111   UINT32                            Times;
 112
 113   Times    = Delay >> 22;
 114   Delay   &= BIT22 - 1;
 115   do {
 116     //
 117     // The target timer count is calculated here
 118     //
 119     Ticks    = InternalAcpiGetTimerTick () + Delay;
 120     Delay    = BIT22;
 121     //
 122     // Wait until time out
 123     // Delay >= 2^23 could not be handled by this function
 124     // Timer wrap-arounds are handled correctly by this function
 125     //
 126     while (((Ticks - InternalAcpiGetTimerTick ()) & BIT23) == 0) {
 127       CpuPause ();
 128     }
 129   } while (Times-- > 0);
 130 }
 131
 132 /**
 133   Stalls the CPU for at least the given number of microseconds.
 134
 135   Stalls the CPU for the number of microseconds specified by MicroSeconds.
 136
 137   @param  MicroSeconds  The minimum number of microseconds to delay.
 138
 139   @return MicroSeconds
 140
 141 **/
 142 UINTN
 143 EFIAPI
 144 MicroSecondDelay (
 145   IN      UINTN                     MicroSeconds
 146   )
 147 {
 148   InternalAcpiDelay (
 149     (UINT32)DivU64x32 (
 150               MultU64x32 (
 151                 MicroSeconds,
 152                 ACPI_TIMER_FREQUENCY
 153                 ),
 154               1000000u
 155               )
 156     );
 157   return MicroSeconds;
 158 }
 159
 160 /**
 161   Stalls the CPU for at least the given number of nanoseconds.
 162
 163   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
 164
 165   @param  NanoSeconds The minimum number of nanoseconds to delay.
 166
 167   @return NanoSeconds
 168
 169 **/
 170 UINTN
 171 EFIAPI
 172 NanoSecondDelay (
 173   IN      UINTN                     NanoSeconds
 174   )
 175 {
 176   InternalAcpiDelay (
 177     (UINT32)DivU64x32 (
 178               MultU64x32 (
 179                 NanoSeconds,
 180                 ACPI_TIMER_FREQUENCY
 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   Retrieves the current value of a 64-bit free running performance counter. The
 192   counter can either count up by 1 or count down by 1. If the physical
 193   performance counter counts by a larger increment, then the counter values
 194   must be translated. The properties of the counter can be retrieved from
 195   GetPerformanceCounterProperties().
 196
 197   @return The current value of the free running performance counter.
 198
 199 **/
 200 UINT64
 201 EFIAPI
 202 GetPerformanceCounter (
 203   VOID
 204   )
 205 {
 206   return (UINT64)InternalAcpiGetTimerTick ();
 207 }
 208
 209 /**
 210   Retrieves the 64-bit frequency in Hz and the range of performance counter
 211   values.
 212
 213   If StartValue is not NULL, then the value that the performance counter starts
 214   with immediately after is it rolls over is returned in StartValue. If
 215   EndValue is not NULL, then the value that the performance counter end with
 216   immediately before it rolls over is returned in EndValue. The 64-bit
 217   frequency of the performance counter in Hz is always returned. If StartValue
 218   is less than EndValue, then the performance counter counts up. If StartValue
 219   is greater than EndValue, then the performance counter counts down. For
 220   example, a 64-bit free running counter that counts up would have a StartValue
 221   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 222   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 223
 224   @param  StartValue  The value the performance counter starts with when it
 225                       rolls over.
 226   @param  EndValue    The value that the performance counter ends with before
 227                       it rolls over.
 228
 229   @return The frequency in Hz.
 230
 231 **/
 232 UINT64
 233 EFIAPI
 234 GetPerformanceCounterProperties (
 235   OUT      UINT64                    *StartValue,  OPTIONAL
 236   OUT      UINT64                    *EndValue     OPTIONAL
 237   )
 238 {
 239   if (StartValue != NULL) {
 240     *StartValue = 0;
 241   }
 242
 243   if (EndValue != NULL) {
 244     *EndValue = ACPI_TIMER_COUNT_SIZE - 1;
 245   }
 246
 247   return ACPI_TIMER_FREQUENCY;
 248 }
 249
 250 /**
 251   Converts elapsed ticks of performance counter to time in nanoseconds.
 252
 253   This function converts the elapsed ticks of running performance counter to
 254   time value in unit of nanoseconds.
 255
 256   @param  Ticks     The number of elapsed ticks of running performance counter.
 257
 258   @return The elapsed time in nanoseconds.
 259
 260 **/
 261 UINT64
 262 EFIAPI
 263 GetTimeInNanoSecond (
 264   IN      UINT64                     Ticks
 265   )
 266 {
 267   UINT64  NanoSeconds;
 268   UINT32  Remainder;
 269
 270   //
 271   //          Ticks
 272   // Time = --------- x 1,000,000,000
 273   //        Frequency
 274   //
 275   NanoSeconds = MultU64x32 (DivU64x32Remainder (Ticks, ACPI_TIMER_FREQUENCY, &Remainder), 1000000000u);
 276
 277   //
 278   // Frequency < 0x100000000, so Remainder < 0x100000000, then (Remainder * 1,000,000,000)
 279   // will not overflow 64-bit.
 280   //
 281   NanoSeconds += DivU64x32 (MultU64x32 ((UINT64) Remainder, 1000000000u), ACPI_TIMER_FREQUENCY);
 282
 283   return NanoSeconds;
 284 }