GenericWatchdogDxe.c File Reference

#include <PiDxe.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/IoLib.h>
#include <Library/PcdLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiRuntimeServicesTableLib.h>
#include <Library/UefiLib.h>
#include <Library/ArmGenericTimerCounterLib.h>
#include <Protocol/HardwareInterrupt2.h>
#include <Protocol/WatchdogTimer.h>
#include "GenericWatchdog.h"

Go to the source code of this file.

Macros
#define	TIME_UNITS_PER_SECOND   10000000
#define	MAX_UINT48   0xFFFFFFFFFFFFULL

Functions
STATIC UINT64	GetMaxWatchdogOffsetRegisterValue (VOID)
STATIC VOID	WatchdogWriteOffsetRegister (UINT64 Value)
STATIC VOID	WatchdogWriteCompareRegister (UINT64 Value)
STATIC VOID	WatchdogEnable (VOID)
STATIC VOID	WatchdogDisable (VOID)
STATIC VOID EFIAPI	WatchdogExitBootServicesEvent (IN EFI_EVENT Event, IN VOID *Context)
STATIC VOID EFIAPI	WatchdogInterruptHandler (IN HARDWARE_INTERRUPT_SOURCE Source, IN EFI_SYSTEM_CONTEXT SystemContext)
STATIC EFI_STATUS EFIAPI	WatchdogRegisterHandler (IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This, IN EFI_WATCHDOG_TIMER_NOTIFY NotifyFunction)
STATIC EFI_STATUS EFIAPI	WatchdogSetTimerPeriod (IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This, IN UINT64 TimerPeriod)
STATIC EFI_STATUS EFIAPI	WatchdogGetTimerPeriod (IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This, OUT UINT64 *TimerPeriod)
EFI_STATUS EFIAPI	GenericWatchdogEntry (IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable)

Variables
STATIC UINT64	mTimerPeriod = 0
STATIC BOOLEAN	mExitedBootServices = FALSE
STATIC EFI_HARDWARE_INTERRUPT2_PROTOCOL *	mInterruptProtocol
STATIC EFI_WATCHDOG_TIMER_NOTIFY	mWatchdogNotify
STATIC EFI_EVENT	mEfiExitBootServicesEvent
STATIC EFI_WATCHDOG_TIMER_ARCH_PROTOCOL	mWatchdogTimer

Detailed Description

Copyright (c) 2023, Ampere Computing LLC. All rights reserved.
Copyright (c) 2013-2018, ARM Limited. All rights reserved.

SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file GenericWatchdogDxe.c.

Macro Definition Documentation

MAX_UINT48

#define MAX_UINT48   0xFFFFFFFFFFFFULL

Definition at line 39 of file GenericWatchdogDxe.c.

TIME_UNITS_PER_SECOND

#define TIME_UNITS_PER_SECOND   10000000

Definition at line 29 of file GenericWatchdogDxe.c.

Function Documentation

GenericWatchdogEntry()

EFI_STATUS EFIAPI GenericWatchdogEntry	(	IN EFI_HANDLE	ImageHandle,
		IN EFI_SYSTEM_TABLE *	SystemTable
	)

Definition at line 355 of file GenericWatchdogDxe.c.

GetMaxWatchdogOffsetRegisterValue()

STATIC UINT64 GetMaxWatchdogOffsetRegisterValue

(

VOID

)

This function returns the maximum watchdog offset register value.

Return values

MAX_UINT32	The watchdog offset register holds a 32-bit value.
MAX_UINT48	The watchdog offset register holds a 48-bit value.

Definition at line 53 of file GenericWatchdogDxe.c.

WatchdogDisable()

STATIC VOID WatchdogDisable

(

VOID

)

Definition at line 106 of file GenericWatchdogDxe.c.

WatchdogEnable()

STATIC VOID WatchdogEnable

(

VOID

)

Definition at line 97 of file GenericWatchdogDxe.c.

WatchdogExitBootServicesEvent()

STATIC VOID EFIAPI WatchdogExitBootServicesEvent	(	IN EFI_EVENT	Event,
		IN VOID *	Context
	)

On exiting boot services we must make sure the Watchdog Timer is stopped.

Definition at line 119 of file GenericWatchdogDxe.c.

WatchdogGetTimerPeriod()

STATIC EFI_STATUS EFIAPI WatchdogGetTimerPeriod	(	IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *	This,
		OUT UINT64 *	TimerPeriod
	)

This function retrieves the period of timer interrupts in 100ns units, returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is returned, then the timer is currently disabled.

Parameters

This	The EFI_TIMER_ARCH_PROTOCOL instance.
TimerPeriod	A pointer to the timer period to retrieve in 100ns units. If 0 is returned, then the timer is currently disabled.

Return values

EFI_SUCCESS	The timer period was returned in TimerPeriod.
EFI_INVALID_PARAMETER	TimerPeriod is NULL.

Definition at line 301 of file GenericWatchdogDxe.c.

WatchdogInterruptHandler()

STATIC VOID EFIAPI WatchdogInterruptHandler	(	IN HARDWARE_INTERRUPT_SOURCE	Source,
		IN EFI_SYSTEM_CONTEXT	SystemContext
	)

Definition at line 135 of file GenericWatchdogDxe.c.

WatchdogRegisterHandler()

STATIC EFI_STATUS EFIAPI WatchdogRegisterHandler	(	IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *	This,
		IN EFI_WATCHDOG_TIMER_NOTIFY	NotifyFunction
	)

This function registers the handler NotifyFunction so it is called every time the watchdog timer expires. It also passes the amount of time since the last handler call to the NotifyFunction. If NotifyFunction is not NULL and a handler is not already registered, then the new handler is registered and EFI_SUCCESS is returned. If NotifyFunction is NULL, and a handler is already registered, then that handler is unregistered. If an attempt is made to register a handler when a handler is already registered, then EFI_ALREADY_STARTED is returned. If an attempt is made to unregister a handler when a handler is not registered, then EFI_INVALID_PARAMETER is returned.

Parameters

This	The EFI_TIMER_ARCH_PROTOCOL instance.
NotifyFunction	The function to call when a timer interrupt fires. This function executes at TPL_HIGH_LEVEL. The DXE Core will register a handler for the timer interrupt, so it can know how much time has passed. This information is used to signal timer based events. NULL will unregister the handler.

Return values

EFI_UNSUPPORTED

The code does not support NotifyFunction.

Definition at line 194 of file GenericWatchdogDxe.c.

WatchdogSetTimerPeriod()

STATIC EFI_STATUS EFIAPI WatchdogSetTimerPeriod	(	IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *	This,
		IN UINT64	TimerPeriod
	)

This function sets the amount of time to wait before firing the watchdog timer to TimerPeriod 100ns units. If TimerPeriod is 0, then the watchdog timer is disabled.

Parameters

This	The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
TimerPeriod	The amount of time in 100ns units to wait before the watchdog timer is fired. If TimerPeriod is zero, then the watchdog timer is disabled.

Return values

EFI_SUCCESS	The watchdog timer has been programmed to fire in TimerPeriod 100ns units.
EFI_DEVICE_ERROR	Boot Services has been exited but TimerPeriod is not zero.

Definition at line 230 of file GenericWatchdogDxe.c.

WatchdogWriteCompareRegister()

STATIC VOID WatchdogWriteCompareRegister

(

UINT64

Value

)

Definition at line 87 of file GenericWatchdogDxe.c.

WatchdogWriteOffsetRegister()

STATIC VOID WatchdogWriteOffsetRegister

(

UINT64

Value

)

Definition at line 75 of file GenericWatchdogDxe.c.

Variable Documentation

mEfiExitBootServicesEvent

STATIC EFI_EVENT mEfiExitBootServicesEvent

Definition at line 43 of file GenericWatchdogDxe.c.

mExitedBootServices

STATIC BOOLEAN mExitedBootServices = FALSE

Definition at line 37 of file GenericWatchdogDxe.c.

mInterruptProtocol

STATIC EFI_HARDWARE_INTERRUPT2_PROTOCOL* mInterruptProtocol

Definition at line 41 of file GenericWatchdogDxe.c.

mTimerPeriod

STATIC UINT64 mTimerPeriod = 0

Definition at line 34 of file GenericWatchdogDxe.c.

mWatchdogNotify

STATIC EFI_WATCHDOG_TIMER_NOTIFY mWatchdogNotify

Definition at line 42 of file GenericWatchdogDxe.c.

mWatchdogTimer

STATIC EFI_WATCHDOG_TIMER_ARCH_PROTOCOL mWatchdogTimer

Initial value:

= {
  WatchdogRegisterHandler,
  WatchdogSetTimerPeriod,
  WatchdogGetTimerPeriod
}

Interface structure for the Watchdog Architectural Protocol.

Protocol Description:

This protocol provides a service to set the amount of time to wait before firing the watchdog timer, and it also provides a service to register a handler that is invoked when the watchdog timer fires.

When the watchdog timer fires, control will be passed to a handler

if one has been registered. If no handler has been registered, or the registered handler returns, then the system will be reset by calling the Runtime Service ResetSystem().

Parameters

RegisterHandler	Registers a handler that will be called each time the watchdogtimer interrupt fires. TimerPeriod defines the minimum time between timer interrupts, so TimerPeriod will also be the minimum time between calls to the registered handler. NOTE: If the watchdog resets the system in hardware, then this function will not have any chance of executing.
SetTimerPeriod	Sets the period of the timer interrupt in 100ns units. This function is optional, and may return EFI_UNSUPPORTED. If this function is supported, then the timer period will be rounded up to the nearest supported timer period.
GetTimerPeriod	Retrieves the period of the timer interrupt in 100ns units.

Definition at line 347 of file GenericWatchdogDxe.c.