/** @file
Provides services to enable and disable periodic SMI handlers.
Copyright (c) 2011, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#ifndef __PERIODIC_SMI_LIB_H__
#define __PERIODIC_SMI_LIB_H__
#define PERIODIC_SMI_LIBRARY_ANY_CPU 0xffffffff
/**
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.
@return 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
PeriodicSmiSupportedTickPeriod (
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.
@return 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.
**/
UINT64
EFIAPI
PeriodicSmiExecutionTime (
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.
**/
VOID
EFIAPI
PeriodicSmiExit (
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 seperate 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.
@return The actual time in 100ns units elapsed since this function was
called. A value of 0 indicates an unknown amount of time.
**/
UINT64
EFIAPI
PeriodicSmiYield (
VOID
);
/**
This function is a prototype for a periodic SMI handler function
that may be enabled with PeriodicSmiEnable() and disabled with
PeriodicSmiDisable().
@param[in] Context Content registered with PeriodicSmiEnable().
@param[in] ElapsedTime 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) (
IN CONST VOID *Context OPTIONAL,
IN UINT64 ElapsedTime
);
/**
This function enables a periodic SMI handler.
@param[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.
@param[in] DispatchFunction A pointer to a periodic SMI handler function.
@param[in] Context Optional content to pass into DispatchFunction.
@param[in] TickPeriod The requested tick period in 100ns units that
control should be givien to the periodic SMI
handler. Must be one of the supported values
returned by PeriodicSmiSupportedPickPeriod().
@param[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.
@param[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.
@retval EFI_INVALID_PARAMETER DispatchFunction is NULL.
@retval EFI_UNSUPPORTED TickPeriod is not a supported tick period. The
supported tick periods can be retrieved using
PeriodicSmiSupportedTickPeriod().
@retval EFI_INVALID_PARAMETER Cpu is not PERIODIC_SMI_LIBRARY_ANY_CPU or in
the range 0 to SMST NumberOfCpus.
@retval EFI_OUT_OF_RESOURCES There are not enough resources to enable the
periodic SMI handler.
@retval EFI_OUT_OF_RESOURCES There are not enough resources to allocate the
stack speficied by StackSize.
@retval EFI_SUCCESS The periodic SMI handler was enabled.
**/
EFI_STATUS
EFIAPI
PeriodicSmiEnable (
IN OUT EFI_HANDLE *DispatchHandle, OPTIONAL
IN PERIODIC_SMI_LIBRARY_HANDLER DispatchFunction,
IN CONST VOID *Context, OPTIONAL
IN UINT64 TickPeriod,
IN UINTN Cpu,
IN UINTN StackSize
);
/**
This function disables a periodic SMI handler that has been previously
enabled with PeriodicSmiEnable().
@param[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.
@retval FALSE DispatchHandle is NULL and there is no active periodic SMI handler.
@retval FALSE The periodic SMI handler specified by DispatchHandle has
not been enabled with PeriodicSmiEnable().
@retval TRUE The periodic SMI handler specified by DispatchHandle has
been disabled. If DispatchHandle is NULL, then the active
periodic SMI handler has been disabled.
**/
BOOLEAN
EFIAPI
PeriodicSmiDisable (
IN EFI_HANDLE DispatchHandle OPTIONAL
);
#endif