ArmPkg/TimerDxe: remove workaround for KVM timer handling

[mirror_edk2.git] / ArmPkg / Drivers / TimerDxe / TimerDxe.c

/** @file\r
  Timer Architecture Protocol driver of the ARM flavor\r
\r
  Copyright (c) 2011-2013 ARM Ltd. All rights reserved.<BR>\r
\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
\r
#include <PiDxe.h>\r
\r
#include <Library/ArmLib.h>\r
#include <Library/BaseLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
#include <Library/UefiLib.h>\r
#include <Library/PcdLib.h>\r
#include <Library/IoLib.h>\r
#include <Library/ArmGenericTimerCounterLib.h>\r
\r
#include <Protocol/Timer.h>\r
#include <Protocol/HardwareInterrupt.h>\r
\r
// The notification function to call on every timer interrupt.\r
EFI_TIMER_NOTIFY      mTimerNotifyFunction     = (EFI_TIMER_NOTIFY)NULL;\r
EFI_EVENT             EfiExitBootServicesEvent = (EFI_EVENT)NULL;\r
\r
// The current period of the timer interrupt\r
UINT64 mTimerPeriod = 0;\r
// The latest Timer Tick calculated for mTimerPeriod\r
UINT64 mTimerTicks = 0;\r
// Number of elapsed period since the last Timer interrupt\r
UINT64 mElapsedPeriod = 1;\r
\r
// Cached copy of the Hardware Interrupt protocol instance\r
EFI_HARDWARE_INTERRUPT_PROTOCOL *gInterrupt = NULL;\r
\r
/**\r
  This function registers the handler NotifyFunction so it is called every time\r
  the timer interrupt fires.  It also passes the amount of time since the last\r
  handler call to the NotifyFunction.  If NotifyFunction is NULL, then the\r
  handler is unregistered.  If the handler is registered, then EFI_SUCCESS is\r
  returned.  If the CPU does not support registering a timer interrupt handler,\r
  then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler\r
  when a handler is already registered, then EFI_ALREADY_STARTED is returned.\r
  If an attempt is made to unregister a handler when a handler is not registered,\r
  then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to\r
  register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR\r
  is returned.\r
\r
  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.\r
  @param  NotifyFunction   The function to call when a timer interrupt fires. This\r
                           function executes at TPL_HIGH_LEVEL. The DXE Core will\r
                           register a handler for the timer interrupt, so it can know\r
                           how much time has passed. This information is used to\r
                           signal timer based events. NULL will unregister the handler.\r
  @retval EFI_SUCCESS           The timer handler was registered.\r
  @retval EFI_UNSUPPORTED       The platform does not support timer interrupts.\r
  @retval EFI_ALREADY_STARTED   NotifyFunction is not NULL, and a handler is already\r
                                registered.\r
  @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not\r
                                previously registered.\r
  @retval EFI_DEVICE_ERROR      The timer handler could not be registered.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverRegisterHandler (\r
  IN EFI_TIMER_ARCH_PROTOCOL  *This,\r
  IN EFI_TIMER_NOTIFY         NotifyFunction\r
  )\r
{\r
  if ((NotifyFunction == NULL) && (mTimerNotifyFunction == NULL)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if ((NotifyFunction != NULL) && (mTimerNotifyFunction != NULL)) {\r
    return EFI_ALREADY_STARTED;\r
  }\r
\r
  mTimerNotifyFunction = NotifyFunction;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
    Disable the timer\r
**/\r
VOID\r
EFIAPI\r
ExitBootServicesEvent (\r
  IN EFI_EVENT  Event,\r
  IN VOID       *Context\r
  )\r
{\r
  ArmGenericTimerDisableTimer ();\r
}\r
\r
/**\r
\r
  This function adjusts the period of timer interrupts to the value specified\r
  by TimerPeriod.  If the timer period is updated, then the selected timer\r
  period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If\r
  the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.\r
  If an error occurs while attempting to update the timer period, then the\r
  timer hardware will be put back in its state prior to this call, and\r
  EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt\r
  is disabled.  This is not the same as disabling the CPU's interrupts.\r
  Instead, it must either turn off the timer hardware, or it must adjust the\r
  interrupt controller so that a CPU interrupt is not generated when the timer\r
  interrupt fires.\r
\r
  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.\r
  @param  TimerPeriod      The rate to program the timer interrupt in 100 nS units. If\r
                           the timer hardware is not programmable, then EFI_UNSUPPORTED is\r
                           returned. If the timer is programmable, then the timer period\r
                           will be rounded up to the nearest timer period that is supported\r
                           by the timer hardware. If TimerPeriod is set to 0, then the\r
                           timer interrupts will be disabled.\r
\r
\r
  @retval EFI_SUCCESS           The timer period was changed.\r
  @retval EFI_UNSUPPORTED       The platform cannot change the period of the timer interrupt.\r
  @retval EFI_DEVICE_ERROR      The timer period could not be changed due to a device error.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverSetTimerPeriod (\r
  IN EFI_TIMER_ARCH_PROTOCOL  *This,\r
  IN UINT64                   TimerPeriod\r
  )\r
{\r
  UINT64      CounterValue;\r
  UINT64      TimerTicks;\r
  EFI_TPL     OriginalTPL;\r
\r
  // Always disable the timer\r
  ArmGenericTimerDisableTimer ();\r
\r
  if (TimerPeriod != 0) {\r
    // mTimerTicks = TimerPeriod in 1ms unit x Frequency.10^-3\r
    //             = TimerPeriod.10^-4 x Frequency.10^-3\r
    //             = (TimerPeriod x Frequency) x 10^-7\r
    TimerTicks = MultU64x32 (TimerPeriod, ArmGenericTimerGetTimerFreq ());\r
    TimerTicks = DivU64x32 (TimerTicks, 10000000U);\r
\r
    // Raise TPL to update the mTimerTicks and mTimerPeriod to ensure these values\r
    // are coherent in the interrupt handler\r
    OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r
\r
    mTimerTicks    = TimerTicks;\r
    mTimerPeriod   = TimerPeriod;\r
    mElapsedPeriod = 1;\r
\r
    gBS->RestoreTPL (OriginalTPL);\r
\r
    // Get value of the current timer\r
    CounterValue = ArmGenericTimerGetSystemCount ();\r
    // Set the interrupt in Current Time + mTimerTick\r
    ArmGenericTimerSetCompareVal (CounterValue + mTimerTicks);\r
\r
    // Enable the timer\r
    ArmGenericTimerEnableTimer ();\r
  } else {\r
    // Save the new timer period\r
    mTimerPeriod   = TimerPeriod;\r
    // Reset the elapsed period\r
    mElapsedPeriod = 1;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  This function retrieves the period of timer interrupts in 100 ns units,\r
  returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod\r
  is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is\r
  returned, then the timer is currently disabled.\r
\r
  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.\r
  @param  TimerPeriod      A pointer to the timer period to retrieve in 100 ns units. If\r
                           0 is returned, then the timer is currently disabled.\r
\r
\r
  @retval EFI_SUCCESS           The timer period was returned in TimerPeriod.\r
  @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverGetTimerPeriod (\r
  IN EFI_TIMER_ARCH_PROTOCOL   *This,\r
  OUT UINT64                   *TimerPeriod\r
  )\r
{\r
  if (TimerPeriod == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  *TimerPeriod = mTimerPeriod;\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  This function generates a soft timer interrupt. If the platform does not support soft\r
  timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.\r
  If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()\r
  service, then a soft timer interrupt will be generated. If the timer interrupt is\r
  enabled when this service is called, then the registered handler will be invoked. The\r
  registered handler should not be able to distinguish a hardware-generated timer\r
  interrupt from a software-generated timer interrupt.\r
\r
  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.\r
\r
  @retval EFI_SUCCESS           The soft timer interrupt was generated.\r
  @retval EFI_UNSUPPORTED       The platform does not support the generation of soft timer interrupts.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverGenerateSoftInterrupt (\r
  IN EFI_TIMER_ARCH_PROTOCOL  *This\r
  )\r
{\r
  return EFI_UNSUPPORTED;\r
}\r
\r
/**\r
  Interface structure for the Timer Architectural Protocol.\r
\r
  @par Protocol Description:\r
  This protocol provides the services to initialize a periodic timer\r
  interrupt, and to register a handler that is called each time the timer\r
  interrupt fires.  It may also provide a service to adjust the rate of the\r
  periodic timer interrupt.  When a timer interrupt occurs, the handler is\r
  passed the amount of time that has passed since the previous timer\r
  interrupt.\r
\r
  @param RegisterHandler\r
  Registers a handler that will be called each time the\r
  timer interrupt fires.  TimerPeriod defines the minimum\r
  time between timer interrupts, so TimerPeriod will also\r
  be the minimum time between calls to the registered\r
  handler.\r
\r
  @param SetTimerPeriod\r
  Sets the period of the timer interrupt in 100 nS units.\r
  This function is optional, and may return EFI_UNSUPPORTED.\r
  If this function is supported, then the timer period will\r
  be rounded up to the nearest supported timer period.\r
\r
\r
  @param GetTimerPeriod\r
  Retrieves the period of the timer interrupt in 100 nS units.\r
\r
  @param GenerateSoftInterrupt\r
  Generates a soft timer interrupt that simulates the firing of\r
  the timer interrupt. This service can be used to invoke the   registered handler if the timer interrupt has been masked for\r
  a period of time.\r
\r
**/\r
EFI_TIMER_ARCH_PROTOCOL   gTimer = {\r
  TimerDriverRegisterHandler,\r
  TimerDriverSetTimerPeriod,\r
  TimerDriverGetTimerPeriod,\r
  TimerDriverGenerateSoftInterrupt\r
};\r
\r
/**\r
\r
  C Interrupt Handler called in the interrupt context when Source interrupt is active.\r
\r
\r
  @param Source         Source of the interrupt. Hardware routing off a specific platform defines\r
                        what source means.\r
\r
  @param SystemContext  Pointer to system register context. Mostly used by debuggers and will\r
                        update the system context after the return from the interrupt if\r
                        modified. Don't change these values unless you know what you are doing\r
\r
**/\r
VOID\r
EFIAPI\r
TimerInterruptHandler (\r
  IN  HARDWARE_INTERRUPT_SOURCE   Source,\r
  IN  EFI_SYSTEM_CONTEXT          SystemContext\r
  )\r
{\r
  EFI_TPL      OriginalTPL;\r
  UINT64       CurrentValue;\r
  UINT64       CompareValue;\r
\r
  //\r
  // DXE core uses this callback for the EFI timer tick. The DXE core uses locks\r
  // that raise to TPL_HIGH and then restore back to current level. Thus we need\r
  // to make sure TPL level is set to TPL_HIGH while we are handling the timer tick.\r
  //\r
  OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r
\r
  // Signal end of interrupt early to help avoid losing subsequent ticks\r
  // from long duration handlers\r
  gInterrupt->EndOfInterrupt (gInterrupt, Source);\r
\r
  // Check if the timer interrupt is active\r
  if ((ArmGenericTimerGetTimerCtrlReg () ) & ARM_ARCH_TIMER_ISTATUS) {\r
\r
    if (mTimerNotifyFunction) {\r
      mTimerNotifyFunction (mTimerPeriod * mElapsedPeriod);\r
    }\r
\r
    //\r
    // Reload the Timer\r
    //\r
\r
    // Get current counter value\r
    CurrentValue = ArmGenericTimerGetSystemCount ();\r
    // Get the counter value to compare with\r
    CompareValue = ArmGenericTimerGetCompareVal ();\r
\r
    // This loop is needed in case we missed interrupts (eg: case when the interrupt handling\r
    // has taken longer than mTickPeriod).\r
    // Note: Physical Counter is counting up\r
    mElapsedPeriod = 0;\r
    do {\r
      CompareValue += mTimerTicks;\r
      mElapsedPeriod++;\r
    } while (CompareValue < CurrentValue);\r
\r
    // Set next compare value\r
    ArmGenericTimerSetCompareVal (CompareValue);\r
    ArmInstructionSynchronizationBarrier ();\r
  }\r
\r
  gBS->RestoreTPL (OriginalTPL);\r
}\r
\r
\r
/**\r
  Initialize the state information for the Timer Architectural Protocol and\r
  the Timer Debug support protocol that allows the debugger to break into a\r
  running program.\r
\r
  @param  ImageHandle   of the loaded driver\r
  @param  SystemTable   Pointer to the System Table\r
\r
  @retval EFI_SUCCESS           Protocol registered\r
  @retval EFI_OUT_OF_RESOURCES  Cannot allocate protocol data structure\r
  @retval EFI_DEVICE_ERROR      Hardware problems\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerInitialize (\r
  IN EFI_HANDLE         ImageHandle,\r
  IN EFI_SYSTEM_TABLE   *SystemTable\r
  )\r
{\r
  EFI_HANDLE  Handle = NULL;\r
  EFI_STATUS  Status;\r
  UINTN       TimerCtrlReg;\r
  UINT32      TimerHypIntrNum;\r
\r
  if (ArmIsArchTimerImplemented () == 0) {\r
    DEBUG ((EFI_D_ERROR, "ARM Architectural Timer is not available in the CPU, hence cann't use this Driver \n"));\r
    ASSERT (0);\r
  }\r
\r
  // Find the interrupt controller protocol.  ASSERT if not found.\r
  Status = gBS->LocateProtocol (&gHardwareInterruptProtocolGuid, NULL, (VOID **)&gInterrupt);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  // Disable the timer\r
  TimerCtrlReg = ArmGenericTimerGetTimerCtrlReg ();\r
  TimerCtrlReg |= ARM_ARCH_TIMER_IMASK;\r
  TimerCtrlReg &= ~ARM_ARCH_TIMER_ENABLE;\r
  ArmGenericTimerSetTimerCtrlReg (TimerCtrlReg);\r
  Status = TimerDriverSetTimerPeriod (&gTimer, 0);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  // Install secure and Non-secure interrupt handlers\r
  // Note: Because it is not possible to determine the security state of the\r
  // CPU dynamically, we just install interrupt handler for both sec and non-sec\r
  // timer PPI\r
  Status = gInterrupt->RegisterInterruptSource (gInterrupt, PcdGet32 (PcdArmArchTimerVirtIntrNum), TimerInterruptHandler);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // The hypervisor timer interrupt may be omitted by implementations that\r
  // execute under virtualization.\r
  //\r
  TimerHypIntrNum = PcdGet32 (PcdArmArchTimerHypIntrNum);\r
  if (TimerHypIntrNum != 0) {\r
    Status = gInterrupt->RegisterInterruptSource (gInterrupt, TimerHypIntrNum, TimerInterruptHandler);\r
    ASSERT_EFI_ERROR (Status);\r
  }\r
\r
  Status = gInterrupt->RegisterInterruptSource (gInterrupt, PcdGet32 (PcdArmArchTimerSecIntrNum), TimerInterruptHandler);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  Status = gInterrupt->RegisterInterruptSource (gInterrupt, PcdGet32 (PcdArmArchTimerIntrNum), TimerInterruptHandler);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  // Set up default timer\r
  Status = TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32(PcdTimerPeriod)); // TIMER_DEFAULT_PERIOD\r
  ASSERT_EFI_ERROR (Status);\r
\r
  // Install the Timer Architectural Protocol onto a new handle\r
  Status = gBS->InstallMultipleProtocolInterfaces(\r
                  &Handle,\r
                  &gEfiTimerArchProtocolGuid,      &gTimer,\r
                  NULL\r
                  );\r
  ASSERT_EFI_ERROR(Status);\r
\r
  // Everything is ready, unmask and enable timer interrupts\r
  TimerCtrlReg = ARM_ARCH_TIMER_ENABLE;\r
  ArmGenericTimerSetTimerCtrlReg (TimerCtrlReg);\r
\r
  // Register for an ExitBootServicesEvent\r
  Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_NOTIFY, ExitBootServicesEvent, NULL, &EfiExitBootServicesEvent);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  return Status;\r
}\r