/** @file 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 **/ #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 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. @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 given 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 specified 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