Add DisableLvtInterrupts() for the Local APIC library class.

[mirror_edk2.git] / UefiCpuPkg / Library / BaseXApicLib / BaseXApicLib.c

/** @file\r
  Local APIC Library.\r
\r
  This local APIC library instance supports xAPIC mode only.\r
\r
  Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>\r
  This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#include <Register/LocalApic.h>\r
\r
#include <Library/BaseLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/LocalApicLib.h>\r
#include <Library/IoLib.h>\r
#include <Library/TimerLib.h>\r
#include <Library/PcdLib.h>\r
\r
//\r
// Library internal functions\r
//\r
\r
/**\r
  Read from a local APIC register.\r
\r
  This function reads from a local APIC register either in xAPIC or x2APIC mode.\r
  It is required that in xAPIC mode wider registers (64-bit or 256-bit) must be\r
  accessed using multiple 32-bit loads or stores, so this function only performs\r
  32-bit read.\r
\r
  @param  MmioOffset  The MMIO offset of the local APIC register in xAPIC mode.\r
                      It must be 16-byte aligned.\r
\r
  @return 32-bit      Value read from the register.\r
**/\r
UINT32\r
EFIAPI\r
ReadLocalApicReg (\r
  IN UINTN  MmioOffset\r
  )\r
{\r
  ASSERT ((MmioOffset & 0xf) == 0);\r
  ASSERT (GetApicMode () == LOCAL_APIC_MODE_XAPIC);\r
\r
  return MmioRead32 (PcdGet32 (PcdCpuLocalApicBaseAddress) + MmioOffset);\r
}\r
\r
/**\r
  Write to a local APIC register.\r
\r
  This function writes to a local APIC register either in xAPIC or x2APIC mode.\r
  It is required that in xAPIC mode wider registers (64-bit or 256-bit) must be\r
  accessed using multiple 32-bit loads or stores, so this function only performs\r
  32-bit write.\r
\r
  if the register index is invalid or unsupported in current APIC mode, then ASSERT.\r
\r
  @param  MmioOffset  The MMIO offset of the local APIC register in xAPIC mode.\r
                      It must be 16-byte aligned.\r
  @param  Value       Value to be written to the register.\r
**/\r
VOID\r
EFIAPI\r
WriteLocalApicReg (\r
  IN UINTN  MmioOffset,\r
  IN UINT32 Value\r
  )\r
{\r
  ASSERT ((MmioOffset & 0xf) == 0);\r
  ASSERT (GetApicMode () == LOCAL_APIC_MODE_XAPIC);\r
\r
  MmioWrite32 (PcdGet32 (PcdCpuLocalApicBaseAddress) + MmioOffset, Value);\r
}\r
\r
/**\r
  Send an IPI by writing to ICR.\r
\r
  This function returns after the IPI has been accepted by the target processor. \r
\r
  @param  IcrLow 32-bit value to be written to the low half of ICR.\r
  @param  ApicId APIC ID of the target processor if this IPI is targeted for a specific processor.\r
**/\r
VOID\r
SendIpi (\r
  IN UINT32          IcrLow,\r
  IN UINT32          ApicId\r
  )\r
{\r
  LOCAL_APIC_ICR_LOW IcrLowReg;\r
\r
  ASSERT (GetApicMode () == LOCAL_APIC_MODE_XAPIC);\r
  ASSERT (ApicId <= 0xff);\r
\r
  //\r
  // For xAPIC, the act of writing to the low doubleword of the ICR causes the IPI to be sent.\r
  //\r
  WriteLocalApicReg (XAPIC_ICR_HIGH_OFFSET, ApicId << 24);\r
  WriteLocalApicReg (XAPIC_ICR_LOW_OFFSET, IcrLow);\r
  do {\r
    IcrLowReg.Uint32 = ReadLocalApicReg (XAPIC_ICR_LOW_OFFSET);\r
  } while (IcrLowReg.Bits.DeliveryStatus != 0);\r
}\r
\r
//\r
// Library API implementation functions\r
//\r
\r
/**\r
  Get the current local APIC mode.\r
\r
  If local APIC is disabled, then ASSERT.\r
\r
  @retval LOCAL_APIC_MODE_XAPIC  current APIC mode is xAPIC.\r
  @retval LOCAL_APIC_MODE_X2APIC current APIC mode is x2APIC.\r
**/\r
UINTN\r
EFIAPI\r
GetApicMode (\r
  VOID\r
  )\r
{\r
  DEBUG_CODE (\r
    {\r
      MSR_IA32_APIC_BASE ApicBaseMsr;\r
\r
      ApicBaseMsr.Uint64 = AsmReadMsr64 (MSR_IA32_APIC_BASE_ADDRESS);\r
      //\r
      // Local APIC should have been enabled\r
      //\r
      ASSERT (ApicBaseMsr.Bits.En != 0);\r
      ASSERT (ApicBaseMsr.Bits.Extd == 0);\r
    }\r
  );\r
  return LOCAL_APIC_MODE_XAPIC;\r
}\r
\r
/**\r
  Set the current local APIC mode.\r
\r
  If the specified local APIC mode is not valid, then ASSERT.\r
  If the specified local APIC mode can't be set as current, then ASSERT.\r
\r
  @param ApicMode APIC mode to be set.\r
**/\r
VOID\r
EFIAPI\r
SetApicMode (\r
  IN UINTN  ApicMode\r
  )\r
{\r
  ASSERT (ApicMode == LOCAL_APIC_MODE_XAPIC);\r
  ASSERT (GetApicMode () == LOCAL_APIC_MODE_XAPIC);\r
}\r
\r
/**\r
  Get the initial local APIC ID of the executing processor assigned by hardware upon power on or reset.\r
\r
  In xAPIC mode, the initial local APIC ID is 8-bit, and may be different from current APIC ID.\r
  In x2APIC mode, the local APIC ID can't be changed and there is no concept of initial APIC ID. In this case, \r
  the 32-bit local APIC ID is returned as initial APIC ID.\r
\r
  @return  32-bit initial local APIC ID of the executing processor.\r
**/\r
UINT32\r
EFIAPI\r
GetInitialApicId (\r
  VOID\r
  )\r
{\r
  UINT32 RegEbx;\r
\r
  ASSERT (GetApicMode () == LOCAL_APIC_MODE_XAPIC);\r
\r
  AsmCpuid (CPUID_VERSION_INFO, NULL, &RegEbx, NULL, NULL);\r
  return RegEbx >> 24;\r
}\r
\r
/**\r
  Get the local APIC ID of the executing processor.\r
\r
  @return  32-bit local APIC ID of the executing processor.\r
**/\r
UINT32\r
EFIAPI\r
GetApicId (\r
  VOID\r
  )\r
{\r
  UINT32 ApicId;\r
\r
  ASSERT (GetApicMode () == LOCAL_APIC_MODE_XAPIC);\r
\r
  ApicId = ReadLocalApicReg (XAPIC_ID_OFFSET);\r
  ApicId >>= 24;\r
  return ApicId;\r
}\r
\r
/**\r
  Get the value of the local APIC version register.\r
\r
  @return  the value of the local APIC version register.\r
**/\r
UINT32\r
EFIAPI\r
GetApicVersion (\r
  VOID\r
  )\r
{\r
  return ReadLocalApicReg (XAPIC_VERSION_OFFSET);\r
}\r
\r
/**\r
  Send a Fixed IPI to a specified target processor.\r
\r
  This function returns after the IPI has been accepted by the target processor. \r
\r
  @param  ApicId   The local APIC ID of the target processor.\r
  @param  Vector   The vector number of the interrupt being sent.\r
**/\r
VOID\r
EFIAPI\r
SendFixedIpi (\r
  IN UINT32          ApicId,\r
  IN UINT8           Vector\r
  )\r
{\r
  LOCAL_APIC_ICR_LOW IcrLow;\r
\r
  IcrLow.Uint32 = 0;\r
  IcrLow.Bits.DeliveryMode = LOCAL_APIC_DELIVERY_MODE_FIXED;\r
  IcrLow.Bits.Level = 1;\r
  IcrLow.Bits.Vector = Vector;\r
  SendIpi (IcrLow.Uint32, ApicId);\r
}\r
\r
/**\r
  Send a Fixed IPI to all processors excluding self.\r
\r
  This function returns after the IPI has been accepted by the target processors. \r
\r
  @param  Vector   The vector number of the interrupt being sent.\r
**/\r
VOID\r
EFIAPI\r
SendFixedIpiAllExcludingSelf (\r
  IN UINT8           Vector\r
  )\r
{\r
  LOCAL_APIC_ICR_LOW IcrLow;\r
\r
  IcrLow.Uint32 = 0;\r
  IcrLow.Bits.DeliveryMode = LOCAL_APIC_DELIVERY_MODE_FIXED;\r
  IcrLow.Bits.Level = 1;\r
  IcrLow.Bits.DestinationShorthand = LOCAL_APIC_DESTINATION_SHORTHAND_ALL_EXCLUDING_SELF;\r
  IcrLow.Bits.Vector = Vector;\r
  SendIpi (IcrLow.Uint32, 0);\r
}\r
\r
/**\r
  Send a SMI IPI to a specified target processor.\r
\r
  This function returns after the IPI has been accepted by the target processor. \r
\r
  @param  ApicId   Specify the local APIC ID of the target processor.\r
**/\r
VOID\r
EFIAPI\r
SendSmiIpi (\r
  IN UINT32          ApicId\r
  )\r
{\r
  LOCAL_APIC_ICR_LOW IcrLow;\r
\r
  IcrLow.Uint32 = 0;\r
  IcrLow.Bits.DeliveryMode = LOCAL_APIC_DELIVERY_MODE_SMI;\r
  IcrLow.Bits.Level = 1;\r
  SendIpi (IcrLow.Uint32, ApicId);\r
}\r
\r
/**\r
  Send a SMI IPI to all processors excluding self.\r
\r
  This function returns after the IPI has been accepted by the target processors. \r
**/\r
VOID\r
EFIAPI\r
SendSmiIpiAllExcludingSelf (\r
  VOID\r
  )\r
{\r
  LOCAL_APIC_ICR_LOW IcrLow;\r
\r
  IcrLow.Uint32 = 0;\r
  IcrLow.Bits.DeliveryMode = LOCAL_APIC_DELIVERY_MODE_SMI;\r
  IcrLow.Bits.Level = 1;\r
  IcrLow.Bits.DestinationShorthand = LOCAL_APIC_DESTINATION_SHORTHAND_ALL_EXCLUDING_SELF;\r
  SendIpi (IcrLow.Uint32, 0);\r
}\r
\r
/**\r
  Send an INIT IPI to a specified target processor.\r
\r
  This function returns after the IPI has been accepted by the target processor. \r
\r
  @param  ApicId   Specify the local APIC ID of the target processor.\r
**/\r
VOID\r
EFIAPI\r
SendInitIpi (\r
  IN UINT32          ApicId\r
  )\r
{\r
  LOCAL_APIC_ICR_LOW IcrLow;\r
\r
  IcrLow.Uint32 = 0;\r
  IcrLow.Bits.DeliveryMode = LOCAL_APIC_DELIVERY_MODE_INIT;\r
  IcrLow.Bits.Level = 1;\r
  SendIpi (IcrLow.Uint32, ApicId);\r
}\r
\r
/**\r
  Send an INIT IPI to all processors excluding self.\r
\r
  This function returns after the IPI has been accepted by the target processors. \r
**/\r
VOID\r
EFIAPI\r
SendInitIpiAllExcludingSelf (\r
  VOID\r
  )\r
{\r
  LOCAL_APIC_ICR_LOW IcrLow;\r
\r
  IcrLow.Uint32 = 0;\r
  IcrLow.Bits.DeliveryMode = LOCAL_APIC_DELIVERY_MODE_INIT;\r
  IcrLow.Bits.Level = 1;\r
  IcrLow.Bits.DestinationShorthand = LOCAL_APIC_DESTINATION_SHORTHAND_ALL_EXCLUDING_SELF;\r
  SendIpi (IcrLow.Uint32, 0);\r
}\r
\r
/**\r
  Send an INIT-Start-up-Start-up IPI sequence to a specified target processor.\r
\r
  This function returns after the IPI has been accepted by the target processor. \r
\r
  if StartupRoutine >= 1M, then ASSERT.\r
  if StartupRoutine is not multiple of 4K, then ASSERT.\r
\r
  @param  ApicId          Specify the local APIC ID of the target processor.\r
  @param  StartupRoutine  Points to a start-up routine which is below 1M physical\r
                          address and 4K aligned.\r
**/\r
VOID\r
EFIAPI\r
SendInitSipiSipi (\r
  IN UINT32          ApicId,\r
  IN UINT32          StartupRoutine\r
  )\r
{\r
  LOCAL_APIC_ICR_LOW IcrLow;\r
\r
  ASSERT (StartupRoutine < 0x100000);\r
  ASSERT ((StartupRoutine & 0xfff) == 0);\r
\r
  SendInitIpi (ApicId);\r
  MicroSecondDelay (10);\r
  IcrLow.Uint32 = 0;\r
  IcrLow.Bits.Vector = (StartupRoutine >> 12);\r
  IcrLow.Bits.DeliveryMode = LOCAL_APIC_DELIVERY_MODE_STARTUP;\r
  IcrLow.Bits.Level = 1;\r
  SendIpi (IcrLow.Uint32, ApicId);\r
  MicroSecondDelay (200);\r
  SendIpi (IcrLow.Uint32, ApicId);\r
}\r
\r
/**\r
  Send an INIT-Start-up-Start-up IPI sequence to all processors excluding self.\r
\r
  This function returns after the IPI has been accepted by the target processors. \r
\r
  if StartupRoutine >= 1M, then ASSERT.\r
  if StartupRoutine is not multiple of 4K, then ASSERT.\r
\r
  @param  StartupRoutine    Points to a start-up routine which is below 1M physical\r
                            address and 4K aligned.\r
**/\r
VOID\r
EFIAPI\r
SendInitSipiSipiAllExcludingSelf (\r
  IN UINT32          StartupRoutine\r
  )\r
{\r
  LOCAL_APIC_ICR_LOW IcrLow;\r
\r
  ASSERT (StartupRoutine < 0x100000);\r
  ASSERT ((StartupRoutine & 0xfff) == 0);\r
\r
  SendInitIpiAllExcludingSelf ();\r
  MicroSecondDelay (10);\r
  IcrLow.Uint32 = 0;\r
  IcrLow.Bits.Vector = (StartupRoutine >> 12);\r
  IcrLow.Bits.DeliveryMode = LOCAL_APIC_DELIVERY_MODE_STARTUP;\r
  IcrLow.Bits.Level = 1;\r
  IcrLow.Bits.DestinationShorthand = LOCAL_APIC_DESTINATION_SHORTHAND_ALL_EXCLUDING_SELF;\r
  SendIpi (IcrLow.Uint32, 0);\r
  MicroSecondDelay (200);\r
  SendIpi (IcrLow.Uint32, 0);\r
}\r
\r
/**\r
  Programming Virtual Wire Mode.\r
\r
  This function programs the local APIC for virtual wire mode following\r
  the example described in chapter A.3 of the MP 1.4 spec.\r
\r
  IOxAPIC is not involved in this type of virtual wire mode.\r
**/\r
VOID\r
EFIAPI\r
ProgramVirtualWireMode (\r
  VOID\r
  )\r
{\r
  LOCAL_APIC_SVR      Svr;\r
  LOCAL_APIC_LVT_LINT Lint;\r
\r
  //\r
  // Enable the APIC via SVR and set the spurious interrupt to use Int 00F.\r
  //\r
  Svr.Uint32 = ReadLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET);\r
  Svr.Bits.SpuriousVector = 0xf;\r
  Svr.Bits.SoftwareEnable = 1;\r
  WriteLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET, Svr.Uint32);\r
\r
  //\r
  // Program the LINT0 vector entry as ExtInt. Not masked, edge, active high.\r
  //\r
  Lint.Uint32 = ReadLocalApicReg (XAPIC_LVT_LINT0_OFFSET);\r
  Lint.Bits.DeliveryMode = LOCAL_APIC_DELIVERY_MODE_EXTINT;\r
  Lint.Bits.InputPinPolarity = 0;\r
  Lint.Bits.TriggerMode = 0;\r
  Lint.Bits.Mask = 0;\r
  WriteLocalApicReg (XAPIC_LVT_LINT0_OFFSET, Lint.Uint32);\r
\r
  //\r
  // Program the LINT0 vector entry as NMI. Not masked, edge, active high.\r
  //\r
  Lint.Uint32 = ReadLocalApicReg (XAPIC_LVT_LINT1_OFFSET);\r
  Lint.Bits.DeliveryMode = LOCAL_APIC_DELIVERY_MODE_NMI;\r
  Lint.Bits.InputPinPolarity = 0;\r
  Lint.Bits.TriggerMode = 0;\r
  Lint.Bits.Mask = 0;\r
  WriteLocalApicReg (XAPIC_LVT_LINT1_OFFSET, Lint.Uint32);\r
}\r
\r
/**\r
  Disable LINT0 & LINT1 interrupts.\r
\r
  This function sets the mask flag in the LVT LINT0 & LINT1 registers.\r
**/\r
VOID\r
EFIAPI\r
DisableLvtInterrupts (\r
  VOID\r
  )\r
{\r
  LOCAL_APIC_LVT_LINT LvtLint;\r
\r
  LvtLint.Uint32 = ReadLocalApicReg (XAPIC_LVT_LINT0_OFFSET);\r
  LvtLint.Bits.Mask = 1;\r
  WriteLocalApicReg (XAPIC_LVT_LINT0_OFFSET, LvtLint.Uint32);\r
\r
  LvtLint.Uint32 = ReadLocalApicReg (XAPIC_LVT_LINT1_OFFSET);\r
  LvtLint.Bits.Mask = 1;\r
  WriteLocalApicReg (XAPIC_LVT_LINT1_OFFSET, LvtLint.Uint32);\r
}\r
\r
/**\r
  Read the initial count value from the init-count register.\r
\r
  @return The initial count value read from the init-count register.\r
**/\r
UINT32\r
EFIAPI\r
GetApicTimerInitCount (\r
  VOID\r
  )\r
{\r
  return ReadLocalApicReg (XAPIC_TIMER_INIT_COUNT_OFFSET);\r
}\r
\r
/**\r
  Read the current count value from the current-count register.\r
\r
  @return The current count value read from the current-count register.\r
**/\r
UINT32\r
EFIAPI\r
GetApicTimerCurrentCount (\r
  VOID\r
  )\r
{\r
  return ReadLocalApicReg (XAPIC_TIMER_CURRENT_COUNT_OFFSET);\r
}\r
\r
/**\r
  Initialize the local APIC timer.\r
\r
  The local APIC timer is initialized and enabled.\r
\r
  @param DivideValue   The divide value for the DCR. It is one of 1,2,4,8,16,32,64,128.\r
                       If it is 0, then use the current divide value in the DCR.\r
  @param InitCount     The initial count value.\r
  @param PeriodicMode  If TRUE, timer mode is peridoic. Othewise, timer mode is one-shot.\r
  @param Vector        The timer interrupt vector number.\r
**/\r
VOID\r
EFIAPI\r
InitializeApicTimer (\r
  IN UINTN   DivideValue,\r
  IN UINT32  InitCount,\r
  IN BOOLEAN PeriodicMode,\r
  IN UINT8   Vector\r
  )\r
{\r
  LOCAL_APIC_SVR       Svr;\r
  LOCAL_APIC_DCR       Dcr;\r
  LOCAL_APIC_LVT_TIMER LvtTimer;\r
  UINT32               Divisor;\r
\r
  //\r
  // Ensure local APIC is in software-enabled state.\r
  //\r
  Svr.Uint32 = ReadLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET);\r
  Svr.Bits.SoftwareEnable = 1;\r
  WriteLocalApicReg (XAPIC_SPURIOUS_VECTOR_OFFSET, Svr.Uint32);\r
\r
  //\r
  // Program init-count register.\r
  //\r
  WriteLocalApicReg (XAPIC_TIMER_INIT_COUNT_OFFSET, InitCount);\r
\r
  if (DivideValue != 0) {\r
    ASSERT (DivideValue <= 128);\r
    ASSERT (DivideValue == GetPowerOfTwo32((UINT32)DivideValue));\r
    Divisor = (UINT32)((HighBitSet32 ((UINT32)DivideValue) - 1) & 0x7);\r
\r
    Dcr.Uint32 = ReadLocalApicReg (XAPIC_TIMER_DIVIDE_CONFIGURATION_OFFSET);\r
    Dcr.Bits.DivideValue1 = (Divisor & 0x3);\r
    Dcr.Bits.DivideValue2 = (Divisor >> 2);\r
    WriteLocalApicReg (XAPIC_TIMER_DIVIDE_CONFIGURATION_OFFSET, Dcr.Uint32); \r
  }\r
\r
  //\r
  // Enable APIC timer interrupt with specified timer mode.\r
  //\r
  LvtTimer.Uint32 = ReadLocalApicReg (XAPIC_LVT_TIMER_OFFSET);\r
  if (PeriodicMode) {\r
    LvtTimer.Bits.TimerMode = 1;\r
  } else {\r
    LvtTimer.Bits.TimerMode = 0;\r
  }\r
  LvtTimer.Bits.Mask = 0;\r
  LvtTimer.Bits.Vector = Vector;\r
  WriteLocalApicReg (XAPIC_LVT_TIMER_OFFSET, LvtTimer.Uint32);\r
}\r
\r
/**\r
  Get the state of the local APIC timer.\r
\r
  @param DivideValue   Return the divide value for the DCR. It is one of 1,2,4,8,16,32,64,128.\r
  @param PeriodicMode  Return the timer mode. If TRUE, timer mode is peridoic. Othewise, timer mode is one-shot.\r
  @param Vector        Return the timer interrupt vector number.\r
**/\r
VOID\r
EFIAPI\r
GetApicTimerState (\r
  OUT UINTN    *DivideValue  OPTIONAL,\r
  OUT BOOLEAN  *PeriodicMode  OPTIONAL,\r
  OUT UINT8    *Vector  OPTIONAL\r
  )\r
{\r
  UINT32 Divisor;\r
  LOCAL_APIC_DCR Dcr;\r
  LOCAL_APIC_LVT_TIMER LvtTimer;\r
\r
  if (DivideValue != NULL) {\r
    Dcr.Uint32 = ReadLocalApicReg (XAPIC_TIMER_DIVIDE_CONFIGURATION_OFFSET);\r
    Divisor = Dcr.Bits.DivideValue1 | (Dcr.Bits.DivideValue2 << 2);\r
    Divisor = (Divisor + 1) & 0x7;\r
    *DivideValue = ((UINTN)1) << Divisor;\r
  }\r
\r
  if (PeriodicMode != NULL || Vector != NULL) {\r
    LvtTimer.Uint32 = ReadLocalApicReg (XAPIC_LVT_TIMER_OFFSET);\r
    if (PeriodicMode != NULL) {\r
      if (LvtTimer.Bits.TimerMode == 1) {\r
        *PeriodicMode = TRUE;\r
      } else {\r
        *PeriodicMode = FALSE;\r
      }\r
    }\r
    if (Vector != NULL) {\r
      *Vector = (UINT8) LvtTimer.Bits.Vector;\r
    }\r
  }\r
}\r
\r
/**\r
  Enable the local APIC timer interrupt.\r
**/\r
VOID\r
EFIAPI\r
EnableApicTimerInterrupt (\r
  VOID\r
  )\r
{\r
  LOCAL_APIC_LVT_TIMER LvtTimer;\r
\r
  LvtTimer.Uint32 = ReadLocalApicReg (XAPIC_LVT_TIMER_OFFSET);\r
  LvtTimer.Bits.Mask = 0;\r
  WriteLocalApicReg (XAPIC_LVT_TIMER_OFFSET, LvtTimer.Uint32);\r
}\r
\r
/**\r
  Disable the local APIC timer interrupt.\r
**/\r
VOID\r
EFIAPI\r
DisableApicTimerInterrupt (\r
  VOID\r
  )\r
{\r
  LOCAL_APIC_LVT_TIMER LvtTimer;\r
\r
  LvtTimer.Uint32 = ReadLocalApicReg (XAPIC_LVT_TIMER_OFFSET);\r
  LvtTimer.Bits.Mask = 1;\r
  WriteLocalApicReg (XAPIC_LVT_TIMER_OFFSET, LvtTimer.Uint32);\r
}\r
\r
/**\r
  Get the local APIC timer interrupt state.\r
\r
  @retval TRUE  The local APIC timer interrupt is enabled.\r
  @retval FALSE The local APIC timer interrupt is disabled.\r
**/\r
BOOLEAN\r
EFIAPI\r
GetApicTimerInterruptState (\r
  VOID\r
  )\r
{\r
  LOCAL_APIC_LVT_TIMER LvtTimer;\r
\r
  LvtTimer.Uint32 = ReadLocalApicReg (XAPIC_LVT_TIMER_OFFSET);\r
  return (BOOLEAN)(LvtTimer.Bits.Mask == 0);\r
}\r
\r
/**\r
  Send EOI to the local APIC.\r
**/\r
VOID\r
EFIAPI\r
SendApicEoi (\r
  VOID\r
  )\r
{\r
  WriteLocalApicReg (XAPIC_EOI_OFFSET, 0);\r
}\r
\r