OvmfPkg/Library/AcpiTimerLib/AcpiTimerLib.c

   1 /** @file
   2   ACPI Timer implements one instance of Timer Library.
   3
   4   Copyright (c) 2008 - 2012, 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 #include <IndustryStandard/Acpi.h>
  26
  27 //
  28 // PCI Location of PIIX4 Power Management PCI Configuration Registers
  29 //
  30 #define PIIX4_POWER_MANAGEMENT_BUS       0x00
  31 #define PIIX4_POWER_MANAGEMENT_DEVICE    0x01
  32 #define PIIX4_POWER_MANAGEMENT_FUNCTION  0x03
  33
  34 //
  35 // Macro to access PIIX4 Power Management PCI Configuration Registers
  36 //
  37 #define PIIX4_PCI_POWER_MANAGEMENT_REGISTER(Register) \
  38   PCI_LIB_ADDRESS (                                   \
  39     PIIX4_POWER_MANAGEMENT_BUS,                       \
  40     PIIX4_POWER_MANAGEMENT_DEVICE,                    \
  41     PIIX4_POWER_MANAGEMENT_FUNCTION,                  \
  42     Register                                          \
  43     )
  44
  45 //
  46 // PIIX4 Power Management PCI Configuration Registers
  47 //
  48 #define PMBA                PIIX4_PCI_POWER_MANAGEMENT_REGISTER (0x40)
  49 #define   PMBA_RTE          BIT0
  50 #define PMREGMISC           PIIX4_PCI_POWER_MANAGEMENT_REGISTER (0x80)
  51 #define   PMIOSE            BIT0
  52
  53 //
  54 // The ACPI Time in the PIIX4 is a 24-bit counter
  55 //
  56 #define ACPI_TIMER_COUNT_SIZE  BIT24
  57
  58 //
  59 // Offset in the PIIX4 Power Management Base Address to the ACPI Timer
  60 //
  61 #define ACPI_TIMER_OFFSET      0x8
  62
  63 /**
  64   The constructor function enables ACPI IO space.
  65
  66   If ACPI I/O space not enabled, this function will enable it.
  67   It will always return RETURN_SUCCESS.
  68
  69   @retval EFI_SUCCESS   The constructor always returns RETURN_SUCCESS.
  70
  71 **/
  72 RETURN_STATUS
  73 EFIAPI
  74 AcpiTimerLibConstructor (
  75   VOID
  76   )
  77 {
  78   //
  79   // Check to see if the PIIX4 Power Management Base Address is already enabled
  80   //
  81   if ((PciRead8 (PMREGMISC) & PMIOSE) == 0) {
  82     //
  83     // If the PIIX4 Power Management Base Address is not programmed,
  84     // then program the PIIX4 Power Management Base Address from a PCD.
  85     //
  86     PciAndThenOr32 (PMBA, (UINT32)(~0x0000FFC0), PcdGet16 (PcdAcpiPmBaseAddress));
  87
  88     //
  89     // Enable PMBA I/O port decodes in PMREGMISC
  90     //
  91     PciOr8 (PMREGMISC, PMIOSE);
  92   }
  93
  94   return RETURN_SUCCESS;
  95 }
  96
  97 /**
  98   Internal function to read the current tick counter of ACPI.
  99
 100   Internal function to read the current tick counter of ACPI.
 101
 102   @return The tick counter read.
 103
 104 **/
 105 UINT32
 106 InternalAcpiGetTimerTick (
 107   VOID
 108   )
 109 {
 110   //
 111   //   Read PMBA to read and return the current ACPI timer value.
 112   //
 113   return IoRead32 ((PciRead32 (PMBA) & ~PMBA_RTE) + ACPI_TIMER_OFFSET);
 114 }
 115
 116 /**
 117   Stalls the CPU for at least the given number of ticks.
 118
 119   Stalls the CPU for at least the given number of ticks. It's invoked by
 120   MicroSecondDelay() and NanoSecondDelay().
 121
 122   @param  Delay     A period of time to delay in ticks.
 123
 124 **/
 125 VOID
 126 InternalAcpiDelay (
 127   IN      UINT32                    Delay
 128   )
 129 {
 130   UINT32                            Ticks;
 131   UINT32                            Times;
 132
 133   Times    = Delay >> 22;
 134   Delay   &= BIT22 - 1;
 135   do {
 136     //
 137     // The target timer count is calculated here
 138     //
 139     Ticks    = InternalAcpiGetTimerTick () + Delay;
 140     Delay    = BIT22;
 141     //
 142     // Wait until time out
 143     // Delay >= 2^23 could not be handled by this function
 144     // Timer wrap-arounds are handled correctly by this function
 145     //
 146     while (((Ticks - InternalAcpiGetTimerTick ()) & BIT23) == 0) {
 147       CpuPause ();
 148     }
 149   } while (Times-- > 0);
 150 }
 151
 152 /**
 153   Stalls the CPU for at least the given number of microseconds.
 154
 155   Stalls the CPU for the number of microseconds specified by MicroSeconds.
 156
 157   @param  MicroSeconds  The minimum number of microseconds to delay.
 158
 159   @return MicroSeconds
 160
 161 **/
 162 UINTN
 163 EFIAPI
 164 MicroSecondDelay (
 165   IN      UINTN                     MicroSeconds
 166   )
 167 {
 168   InternalAcpiDelay (
 169     (UINT32)DivU64x32 (
 170               MultU64x32 (
 171                 MicroSeconds,
 172                 ACPI_TIMER_FREQUENCY
 173                 ),
 174               1000000u
 175               )
 176     );
 177   return MicroSeconds;
 178 }
 179
 180 /**
 181   Stalls the CPU for at least the given number of nanoseconds.
 182
 183   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
 184
 185   @param  NanoSeconds The minimum number of nanoseconds to delay.
 186
 187   @return NanoSeconds
 188
 189 **/
 190 UINTN
 191 EFIAPI
 192 NanoSecondDelay (
 193   IN      UINTN                     NanoSeconds
 194   )
 195 {
 196   InternalAcpiDelay (
 197     (UINT32)DivU64x32 (
 198               MultU64x32 (
 199                 NanoSeconds,
 200                 ACPI_TIMER_FREQUENCY
 201                 ),
 202               1000000000u
 203               )
 204     );
 205   return NanoSeconds;
 206 }
 207
 208 /**
 209   Retrieves the current value of a 64-bit free running performance counter.
 210
 211   Retrieves the current value of a 64-bit free running performance counter. The
 212   counter can either count up by 1 or count down by 1. If the physical
 213   performance counter counts by a larger increment, then the counter values
 214   must be translated. The properties of the counter can be retrieved from
 215   GetPerformanceCounterProperties().
 216
 217   @return The current value of the free running performance counter.
 218
 219 **/
 220 UINT64
 221 EFIAPI
 222 GetPerformanceCounter (
 223   VOID
 224   )
 225 {
 226   return (UINT64)InternalAcpiGetTimerTick ();
 227 }
 228
 229 /**
 230   Retrieves the 64-bit frequency in Hz and the range of performance counter
 231   values.
 232
 233   If StartValue is not NULL, then the value that the performance counter starts
 234   with immediately after is it rolls over is returned in StartValue. If
 235   EndValue is not NULL, then the value that the performance counter end with
 236   immediately before it rolls over is returned in EndValue. The 64-bit
 237   frequency of the performance counter in Hz is always returned. If StartValue
 238   is less than EndValue, then the performance counter counts up. If StartValue
 239   is greater than EndValue, then the performance counter counts down. For
 240   example, a 64-bit free running counter that counts up would have a StartValue
 241   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 242   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 243
 244   @param  StartValue  The value the performance counter starts with when it
 245                       rolls over.
 246   @param  EndValue    The value that the performance counter ends with before
 247                       it rolls over.
 248
 249   @return The frequency in Hz.
 250
 251 **/
 252 UINT64
 253 EFIAPI
 254 GetPerformanceCounterProperties (
 255   OUT      UINT64                    *StartValue,  OPTIONAL
 256   OUT      UINT64                    *EndValue     OPTIONAL
 257   )
 258 {
 259   if (StartValue != NULL) {
 260     *StartValue = 0;
 261   }
 262
 263   if (EndValue != NULL) {
 264     *EndValue = ACPI_TIMER_COUNT_SIZE - 1;
 265   }
 266
 267   return ACPI_TIMER_FREQUENCY;
 268 }
 269
 270 /**
 271   Converts elapsed ticks of performance counter to time in nanoseconds.
 272
 273   This function converts the elapsed ticks of running performance counter to
 274   time value in unit of nanoseconds.
 275
 276   @param  Ticks     The number of elapsed ticks of running performance counter.
 277
 278   @return The elapsed time in nanoseconds.
 279
 280 **/
 281 UINT64
 282 EFIAPI
 283 GetTimeInNanoSecond (
 284   IN      UINT64                     Ticks
 285   )
 286 {
 287   UINT64  NanoSeconds;
 288   UINT32  Remainder;
 289
 290   //
 291   //          Ticks
 292   // Time = --------- x 1,000,000,000
 293   //        Frequency
 294   //
 295   NanoSeconds = MultU64x32 (DivU64x32Remainder (Ticks, ACPI_TIMER_FREQUENCY, &Remainder), 1000000000u);
 296
 297   //
 298   // Frequency < 0x100000000, so Remainder < 0x100000000, then (Remainder * 1,000,000,000)
 299   // will not overflow 64-bit.
 300   //
 301   NanoSeconds += DivU64x32 (MultU64x32 ((UINT64) Remainder, 1000000000u), ACPI_TIMER_FREQUENCY);
 302
 303   return NanoSeconds;
 304 }