SmmPeriodicSmiLib.h File Reference

Macros
#define	PERIODIC_SMI_LIBRARY_ANY_CPU   0xffffffff

Typedefs
typedef IN UINT64	ElapsedTime

Functions
UINT64 *EFIAPI	PeriodicSmiSupportedTickPeriod (VOID)
UINT64 EFIAPI	PeriodicSmiExecutionTime (VOID)
VOID EFIAPI	PeriodicSmiExit (VOID)
UINT64 EFIAPI	PeriodicSmiYield (VOID)
typedef	VOID (EFIAPI *PERIODIC_SMI_LIBRARY_HANDLER)(IN CONST VOID *Context
EFI_STATUS EFIAPI	PeriodicSmiEnable (IN OUT EFI_HANDLE *DispatchHandle, IN PERIODIC_SMI_LIBRARY_HANDLER DispatchFunction, IN CONST VOID *Context, IN UINT64 TickPeriod, IN UINTN Cpu, IN UINTN StackSize)
BOOLEAN EFIAPI	PeriodicSmiDisable (IN EFI_HANDLE DispatchHandle)

Detailed Description

Provides services to enable and disable periodic SMI handlers.

Copyright (c) 2011 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Macro Definition Documentation

#define PERIODIC_SMI_LIBRARY_ANY_CPU   0xffffffff

Typedef Documentation

typedef IN UINT64 ElapsedTime

Function Documentation

BOOLEAN EFIAPI PeriodicSmiDisable

(

IN EFI_HANDLE

DispatchHandle

)

This function disables a periodic SMI handler that has been previously enabled with PeriodicSmiEnable().

Parameters

[in]

DispatchHandle

A handle associated with a previously enabled periodic SMI handler. This is an optional parameter that may be NULL. If it is NULL, then the active periodic SMI handlers is disabled.

Return values

FALSE	DispatchHandle is NULL and there is no active periodic SMI handler.
FALSE	The periodic SMI handler specified by DispatchHandle has not been enabled with PeriodicSmiEnable().
TRUE	The periodic SMI handler specified by DispatchHandle has been disabled. If DispatchHandle is NULL, then the active periodic SMI handler has been disabled.

EFI_STATUS EFIAPI PeriodicSmiEnable	(	IN OUT EFI_HANDLE *	DispatchHandle,
		IN PERIODIC_SMI_LIBRARY_HANDLER	DispatchFunction,
		IN CONST VOID *	Context,
		IN UINT64	TickPeriod,
		IN UINTN	Cpu,
		IN UINTN	StackSize
	)

This function enables a periodic SMI handler.

Parameters

[in,out]	DispatchHandle	A pointer to the handle associated with the enabled periodic SMI handler. This is an optional parameter that may be NULL. If it is NULL, then the handle will not be returned, which means that the periodic SMI handler can never be disabled.
[in]	DispatchFunction	A pointer to a periodic SMI handler function.
[in]	Context	Optional content to pass into DispatchFunction.
[in]	TickPeriod	The requested tick period in 100ns units that control should be given to the periodic SMI handler. Must be one of the supported values returned by PeriodicSmiSupportedPickPeriod().
[in]	Cpu	Specifies the CPU that is required to execute the periodic SMI handler. If Cpu is PERIODIC_SMI_LIBRARY_ANY_CPU, then the periodic SMI handler will always be executed on the SMST CurrentlyExecutingCpu, which may vary across periodic SMIs. If Cpu is between 0 and the SMST NumberOfCpus, then the periodic SMI will always be executed on the requested CPU.
[in]	StackSize	The size, in bytes, of the stack to allocate for use by the periodic SMI handler. If 0, then the default stack will be used.

Return values

EFI_INVALID_PARAMETER	DispatchFunction is NULL.
EFI_UNSUPPORTED	TickPeriod is not a supported tick period. The supported tick periods can be retrieved using PeriodicSmiSupportedTickPeriod().
EFI_INVALID_PARAMETER	Cpu is not PERIODIC_SMI_LIBRARY_ANY_CPU or in the range 0 to SMST NumberOfCpus.
EFI_OUT_OF_RESOURCES	There are not enough resources to enable the periodic SMI handler.
EFI_OUT_OF_RESOURCES	There are not enough resources to allocate the stack specified by StackSize.
EFI_SUCCESS	The periodic SMI handler was enabled.

UINT64 EFIAPI PeriodicSmiExecutionTime

(

VOID

)

This function returns the time in 100ns units since the periodic SMI handler function was called. If the periodic SMI handler was resumed through PeriodicSmiYield(), then the time returned is the time in 100ns units since PeriodicSmiYield() returned.

Returns

The actual time in 100ns units that the periodic SMI handler has been executing. If this function is not called from within an enabled periodic SMI handler, then 0 is returned.

VOID EFIAPI PeriodicSmiExit

(

VOID

)

This function returns control back to the SMM Foundation. When the next periodic SMI for the currently executing handler is triggered, the periodic SMI handler will restarted from its registered DispatchFunction entry point. If this function is not called from within an enabled periodic SMI handler, then control is returned to the calling function.

UINT64* EFIAPI PeriodicSmiSupportedTickPeriod

(

VOID

)

This function returns a pointer to a table of supported periodic SMI tick periods in 100 ns units sorted from largest to smallest. The table contains a array of UINT64 values terminated by a tick period value of 0. The returned table must be treated as read-only data and must not be freed.

Returns

A pointer to a table of UINT64 tick period values in 100ns units sorted from largest to smallest terminated by a tick period of 0.

UINT64 EFIAPI PeriodicSmiYield

(

VOID

)

This function yields control back to the SMM Foundation. When the next periodic SMI for the currently executing handler is triggered, the periodic SMI handler will be resumed and this function will return. Use of this function requires a separate stack for the periodic SMI handler. A non zero stack size must be specified in PeriodicSmiEnable() for this function to be used.

If the stack size passed into PeriodicSmiEnable() was zero, the 0 is returned.

If this function is not called from within an enabled periodic SMI handler, then 0 is returned.

Returns

The actual time in 100ns units elapsed since this function was called. A value of 0 indicates an unknown amount of time.

typedef VOID

(

EFIAPI *

PERIODIC_SMI_LIBRARY_HANDLER

)

This function is a prototype for a periodic SMI handler function that may be enabled with PeriodicSmiEnable() and disabled with PeriodicSmiDisable().

Parameters

[in]	Context	Content registered with PeriodicSmiEnable().
[in]	ElapsedTime	The actual time in 100ns units elapsed since this function was called. A value of 0 indicates an unknown amount of time.