UefiCpuPkg: Move AsmRelocateApLoopStart from Mpfuncs.nasm to AmdSev.nasm

[mirror_edk2.git] / ArmPlatformPkg / Drivers / SP805WatchdogDxe / SP805Watchdog.c

/** @file\r
\r
  Copyright (c) 2011-2013, ARM Limited. All rights reserved.\r
  Copyright (c) 2018, Linaro Limited. All rights reserved.\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include <PiDxe.h>\r
\r
#include <Library/BaseLib.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/IoLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
#include <Library/UefiRuntimeServicesTableLib.h>\r
\r
#include <Protocol/HardwareInterrupt.h>\r
#include <Protocol/WatchdogTimer.h>\r
\r
#include "SP805Watchdog.h"\r
\r
STATIC EFI_EVENT                        mEfiExitBootServicesEvent;\r
STATIC EFI_HARDWARE_INTERRUPT_PROTOCOL  *mInterrupt;\r
STATIC EFI_WATCHDOG_TIMER_NOTIFY        mWatchdogNotify;\r
STATIC UINT32                           mTimerPeriod;\r
\r
/**\r
  Make sure the SP805 registers are unlocked for writing.\r
\r
  Note: The SP805 Watchdog Timer supports locking of its registers,\r
  i.e. it inhibits all writes to avoid rogue software accidentally\r
  corrupting their contents.\r
**/\r
STATIC\r
VOID\r
SP805Unlock (\r
  VOID\r
  )\r
{\r
  if (MmioRead32 (SP805_WDOG_LOCK_REG) == SP805_WDOG_LOCK_IS_LOCKED) {\r
    MmioWrite32 (SP805_WDOG_LOCK_REG, SP805_WDOG_SPECIAL_UNLOCK_CODE);\r
  }\r
}\r
\r
/**\r
  Make sure the SP805 registers are locked and can not be overwritten.\r
\r
  Note: The SP805 Watchdog Timer supports locking of its registers,\r
  i.e. it inhibits all writes to avoid rogue software accidentally\r
  corrupting their contents.\r
**/\r
STATIC\r
VOID\r
SP805Lock (\r
  VOID\r
  )\r
{\r
  if (MmioRead32 (SP805_WDOG_LOCK_REG) == SP805_WDOG_LOCK_IS_UNLOCKED) {\r
    // To lock it, just write in any number (except the special unlock code).\r
    MmioWrite32 (SP805_WDOG_LOCK_REG, SP805_WDOG_LOCK_IS_LOCKED);\r
  }\r
}\r
\r
STATIC\r
VOID\r
EFIAPI\r
SP805InterruptHandler (\r
  IN  HARDWARE_INTERRUPT_SOURCE  Source,\r
  IN  EFI_SYSTEM_CONTEXT         SystemContext\r
  )\r
{\r
  SP805Unlock ();\r
  MmioWrite32 (SP805_WDOG_INT_CLR_REG, 0); // write of any value clears the irq\r
  SP805Lock ();\r
\r
  mInterrupt->EndOfInterrupt (mInterrupt, Source);\r
\r
  //\r
  // The notify function should be called with the elapsed number of ticks\r
  // since the watchdog was armed, which should exceed the timer period.\r
  // We don't actually know the elapsed number of ticks, so let's return\r
  // the timer period plus 1.\r
  //\r
  if (mWatchdogNotify != NULL) {\r
    mWatchdogNotify (mTimerPeriod + 1);\r
  }\r
\r
  gRT->ResetSystem (EfiResetCold, EFI_TIMEOUT, 0, NULL);\r
}\r
\r
/**\r
  Stop the SP805 watchdog timer from counting down by disabling interrupts.\r
**/\r
STATIC\r
VOID\r
SP805Stop (\r
  VOID\r
  )\r
{\r
  // Disable interrupts\r
  if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) != 0) {\r
    MmioAnd32 (SP805_WDOG_CONTROL_REG, ~SP805_WDOG_CTRL_INTEN);\r
  }\r
}\r
\r
/**\r
  Starts the SP805 counting down by enabling interrupts.\r
  The count down will start from the value stored in the Load register,\r
  not from the value where it was previously stopped.\r
**/\r
STATIC\r
VOID\r
SP805Start (\r
  VOID\r
  )\r
{\r
  // Enable interrupts\r
  if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) == 0) {\r
    MmioOr32 (SP805_WDOG_CONTROL_REG, SP805_WDOG_CTRL_INTEN);\r
  }\r
}\r
\r
/**\r
    On exiting boot services we must make sure the SP805 Watchdog Timer\r
    is stopped.\r
**/\r
STATIC\r
VOID\r
EFIAPI\r
ExitBootServicesEvent (\r
  IN EFI_EVENT  Event,\r
  IN VOID       *Context\r
  )\r
{\r
  SP805Unlock ();\r
  SP805Stop ();\r
  SP805Lock ();\r
}\r
\r
/**\r
  This function registers the handler NotifyFunction so it is called every time\r
  the watchdog timer expires.  It also passes the amount of time since the last\r
  handler call to the NotifyFunction.\r
  If NotifyFunction is not NULL and a handler is not already registered,\r
  then the new handler is registered and EFI_SUCCESS is returned.\r
  If NotifyFunction is NULL, and a handler is already registered,\r
  then that handler is unregistered.\r
  If an attempt is made to register a handler when a handler is already registered,\r
  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.\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
\r
  @retval EFI_SUCCESS           The watchdog timer handler was registered.\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
\r
**/\r
STATIC\r
EFI_STATUS\r
EFIAPI\r
SP805RegisterHandler (\r
  IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  *This,\r
  IN EFI_WATCHDOG_TIMER_NOTIFY         NotifyFunction\r
  )\r
{\r
  if ((mWatchdogNotify == NULL) && (NotifyFunction == NULL)) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if ((mWatchdogNotify != NULL) && (NotifyFunction != NULL)) {\r
    return EFI_ALREADY_STARTED;\r
  }\r
\r
  mWatchdogNotify = NotifyFunction;\r
  return EFI_SUCCESS;\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
STATIC\r
EFI_STATUS\r
EFIAPI\r
SP805SetTimerPeriod (\r
  IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  *This,\r
  IN UINT64                            TimerPeriod          // In 100ns units\r
  )\r
{\r
  EFI_STATUS  Status;\r
  UINT64      Ticks64bit;\r
\r
  SP805Unlock ();\r
\r
  Status = EFI_SUCCESS;\r
\r
  if (TimerPeriod == 0) {\r
    // This is a watchdog stop request\r
    SP805Stop ();\r
  } else {\r
    // Calculate the Watchdog ticks required for a delay of (TimerTicks * 100) nanoseconds\r
    // The SP805 will count down to zero and generate an interrupt.\r
    //\r
    // WatchdogTicks = ((TimerPeriod * 100 * SP805_CLOCK_FREQUENCY) / 1GHz);\r
    //\r
    // i.e.:\r
    //\r
    // WatchdogTicks = (TimerPeriod * SP805_CLOCK_FREQUENCY) / 10 MHz ;\r
\r
    Ticks64bit = MultU64x32 (TimerPeriod, PcdGet32 (PcdSP805WatchdogClockFrequencyInHz));\r
    Ticks64bit = DivU64x32 (Ticks64bit, 10 * 1000 * 1000);\r
\r
    // The registers in the SP805 are only 32 bits\r
    if (Ticks64bit > MAX_UINT32) {\r
      // We could load the watchdog with the maximum supported value but\r
      // if a smaller value was requested, this could have the watchdog\r
      // triggering before it was intended.\r
      // Better generate an error to let the caller know.\r
      Status = EFI_DEVICE_ERROR;\r
      goto EXIT;\r
    }\r
\r
    // Update the watchdog with a 32-bit value.\r
    MmioWrite32 (SP805_WDOG_LOAD_REG, (UINT32)Ticks64bit);\r
\r
    // Start the watchdog\r
    SP805Start ();\r
  }\r
\r
  mTimerPeriod = TimerPeriod;\r
\r
EXIT:\r
  // Ensure the watchdog is locked before exiting.\r
  SP805Lock ();\r
  ASSERT_EFI_ERROR (Status);\r
  return Status;\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
STATIC\r
EFI_STATUS\r
EFIAPI\r
SP805GetTimerPeriod (\r
  IN EFI_WATCHDOG_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
  Interface structure for the Watchdog Architectural Protocol.\r
\r
  @par Protocol Description:\r
  This protocol provides a service to set the amount of time to wait\r
  before firing the watchdog timer, and it also provides a service to\r
  register a handler that is invoked when the watchdog timer fires.\r
\r
  @par When the watchdog timer fires, control will be passed to a handler\r
  if one has been registered.  If no handler has been registered,\r
  or the registered handler returns, then the system will be\r
  reset by calling the Runtime Service ResetSystem().\r
\r
  @param RegisterHandler\r
  Registers a handler that will be called each time the\r
  watchdogtimer 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
  NOTE: If the watchdog resets the system in hardware, then\r
        this function will not have any chance of executing.\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
  @param GetTimerPeriod\r
  Retrieves the period of the timer interrupt in 100 nS units.\r
\r
**/\r
STATIC EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  mWatchdogTimer = {\r
  SP805RegisterHandler,\r
  SP805SetTimerPeriod,\r
  SP805GetTimerPeriod\r
};\r
\r
/**\r
  Initialize the state information for the Watchdog Timer Architectural Protocol.\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
SP805Initialize (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
{\r
  EFI_STATUS  Status;\r
  EFI_HANDLE  Handle;\r
\r
  // Find the interrupt controller protocol.  ASSERT if not found.\r
  Status = gBS->LocateProtocol (\r
                  &gHardwareInterruptProtocolGuid,\r
                  NULL,\r
                  (VOID **)&mInterrupt\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  // Unlock access to the SP805 registers\r
  SP805Unlock ();\r
\r
  // Stop the watchdog from triggering unexpectedly\r
  SP805Stop ();\r
\r
  // Set the watchdog to reset the board when triggered\r
  // This is a last resort in case the interrupt handler fails\r
  if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_RESEN) == 0) {\r
    MmioOr32 (SP805_WDOG_CONTROL_REG, SP805_WDOG_CTRL_RESEN);\r
  }\r
\r
  // Clear any pending interrupts\r
  MmioWrite32 (SP805_WDOG_INT_CLR_REG, 0); // write of any value clears the irq\r
\r
  // Prohibit any rogue access to SP805 registers\r
  SP805Lock ();\r
\r
  if (PcdGet32 (PcdSP805WatchdogInterrupt) > 0) {\r
    Status = mInterrupt->RegisterInterruptSource (\r
                           mInterrupt,\r
                           PcdGet32 (PcdSP805WatchdogInterrupt),\r
                           SP805InterruptHandler\r
                           );\r
    if (EFI_ERROR (Status)) {\r
      DEBUG ((\r
        DEBUG_ERROR,\r
        "%a: failed to register watchdog interrupt - %r\n",\r
        __FUNCTION__,\r
        Status\r
        ));\r
      return Status;\r
    }\r
  } else {\r
    DEBUG ((\r
      DEBUG_WARN,\r
      "%a: no interrupt specified, running in RESET mode only\n",\r
      __FUNCTION__\r
      ));\r
  }\r
\r
  //\r
  // Make sure the Watchdog Timer Architectural Protocol has not been installed in the system yet.\r
  // This will avoid conflicts with the universal watchdog\r
  //\r
  ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiWatchdogTimerArchProtocolGuid);\r
\r
  // Register for an ExitBootServicesEvent\r
  Status = gBS->CreateEvent (\r
                  EVT_SIGNAL_EXIT_BOOT_SERVICES,\r
                  TPL_NOTIFY,\r
                  ExitBootServicesEvent,\r
                  NULL,\r
                  &mEfiExitBootServicesEvent\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    Status = EFI_OUT_OF_RESOURCES;\r
    goto EXIT;\r
  }\r
\r
  // Install the Timer Architectural Protocol onto a new handle\r
  Handle = NULL;\r
  Status = gBS->InstallMultipleProtocolInterfaces (\r
                  &Handle,\r
                  &gEfiWatchdogTimerArchProtocolGuid,\r
                  &mWatchdogTimer,\r
                  NULL\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    Status = EFI_OUT_OF_RESOURCES;\r
    goto EXIT;\r
  }\r
\r
EXIT:\r
  ASSERT_EFI_ERROR (Status);\r
  return Status;\r
}\r