/** @file SMM Periodic SMI Library. 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. **/ #include <PiSmm.h> #include <Protocol/SmmPeriodicTimerDispatch2.h> #include <Library/BaseLib.h> #include <Library/BaseMemoryLib.h> #include <Library/SynchronizationLib.h> #include <Library/DebugLib.h> #include <Library/TimerLib.h> #include <Library/MemoryAllocationLib.h> #include <Library/SmmServicesTableLib.h> #include <Library/SmmPeriodicSmiLib.h> /// /// Define the number of periodic SMI handler entries that should be allocated to the list /// of free periodic SMI handlers when the list of free periodic SMI handlers is empty. /// #define PERIODIC_SMI_LIBRARY_ALLOCATE_SIZE 0x08 /// /// Signature for a PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT structure /// #define PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_SIGNATURE SIGNATURE_32 ('P', 'S', 'M', 'I') /// /// Structure that contains state information for an enabled periodic SMI handler /// typedef struct { /// /// Signature value that must be set to PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_SIGNATURE /// UINT32 Signature; /// /// The link entry to be inserted to the list of periodic SMI handlers. /// LIST_ENTRY Link; /// /// The dispatch function to called to invoke an enabled periodic SMI handler. /// PERIODIC_SMI_LIBRARY_HANDLER DispatchFunction; /// /// The context to pass into DispatchFunction /// VOID *Context; /// /// The tick period in 100 ns units that DispatchFunction should be called. /// UINT64 TickPeriod; /// /// The Cpu number that is required to execute DispatchFunction. If Cpu is /// set to PERIODIC_SMI_LIBRARY_ANY_CPU, then DispatchFunction may be executed /// on any CPU. /// UINTN Cpu; /// /// The size, in bytes, of the stack allocated for a periodic SMI handler. /// This value must be a multiple of EFI_PAGE_SIZE. /// UINTN StackSize; /// /// A pointer to the stack allocated using AllocatePages(). This field will /// be NULL if StackSize is 0. /// VOID *Stack; /// /// Spin lock used to wait for an AP to complete the execution of a periodic SMI handler /// SPIN_LOCK DispatchLock; /// /// The rate in Hz of the performance counter that is used to measure the /// amount of time that a periodic SMI handler executes. /// UINT64 PerfomanceCounterRate; /// /// The start count value of the performance counter that is used to measure /// the amount of time that a periodic SMI handler executes. /// UINT64 PerfomanceCounterStartValue; /// /// The end count value of the performance counter that is used to measure /// the amount of time that a periodic SMI handler executes. /// UINT64 PerfomanceCounterEndValue; /// /// The context record passed into the Register() function of the SMM Periodic /// Timer Dispatch Protocol when a periodic SMI handler is enabled. /// EFI_SMM_PERIODIC_TIMER_REGISTER_CONTEXT RegisterContext; /// /// The handle returned from the Register() function of the SMM Periodic /// Timer Dispatch Protocol when a periodic SMI handler is enabled. /// EFI_HANDLE DispatchHandle; /// /// The total number of performance counter ticks that the periodic SMI handler /// has been executing in its current invocation. /// UINT64 DispatchTotalTime; /// /// The performance counter value that was captured the last time that the /// periodic SMI handler called PeriodcSmiExecutionTime(). This allows the /// time value returned by PeriodcSmiExecutionTime() to be accurate even when /// the performance counter rolls over. /// UINT64 DispatchCheckPointTime; /// /// Buffer used to save the context when control is transfer from this library /// to an enabled periodic SMI handler. This saved context is used when the /// periodic SMI handler exits or yields. /// BASE_LIBRARY_JUMP_BUFFER DispatchJumpBuffer; /// /// Flag that is set to TRUE when a periodic SMI handler requests to yield /// using PeriodicSmiYield(). When this flag IS TRUE, YieldJumpBuffer is /// valid. When this flag is FALSE, YieldJumpBuffer is not valid. /// BOOLEAN YieldFlag; /// /// Buffer used to save the context when a periodic SMI handler requests to /// yield using PeriodicSmiYield(). This context is used to resume the /// execution of a periodic SMI handler the next time control is transferd /// to the periodic SMI handler that yielded. /// BASE_LIBRARY_JUMP_BUFFER YieldJumpBuffer; /// /// The amount of time, in 100 ns units, that have elapsed since the last /// time the periodic SMI handler was invoked. /// UINT64 ElapsedTime; } PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT; /** Macro that returns a pointer to a PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT structure based on a pointer to a RegisterContext field. **/ #define PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_FROM_REGISTER_CONTEXT(a) \ CR ( \ a, \ PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT, \ RegisterContext, \ PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_SIGNATURE \ ) /** Macro that returns a pointer to a PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT structure based on a pointer to a Link field. **/ #define PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_FROM_LINK(a) \ CR ( \ a, \ PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT, \ Link, \ PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_SIGNATURE \ ) /// /// Pointer to the SMM Periodic Timer Disatch Protocol that was located in the constuctor. /// EFI_SMM_PERIODIC_TIMER_DISPATCH2_PROTOCOL *gSmmPeriodicTimerDispatch2 = NULL; /// /// Pointer to a table of supported periodic SMI tick periods in 100 ns units /// sorted from largest to smallest terminated by a tick period value of 0. /// This table is allocated using AllocatePool() in the constructor and filled /// in based on the values returned from the SMM Periodic Timer Dispatch 2 Protocol /// function GetNextShorterInterval(). /// UINT64 *gSmiTickPeriodTable = NULL; /// /// Linked list of free periodic SMI handlers that this library can use. /// LIST_ENTRY gFreePeriodicSmiLibraryHandlers = INITIALIZE_LIST_HEAD_VARIABLE (gFreePeriodicSmiLibraryHandlers); /// /// Linked list of periodic SMI handlers that this library is currently managing. /// LIST_ENTRY gPeriodicSmiLibraryHandlers = INITIALIZE_LIST_HEAD_VARIABLE (gPeriodicSmiLibraryHandlers); /// /// Pointer to the periodic SMI handler that is currently being executed. /// Is set to NULL if no periodic SMI handler is currently being executed. /// PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *gActivePeriodicSmiLibraryHandler = NULL; /** Internal worker function that returns a pointer to the PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT structure associated with the periodic SMI handler that is currently being executed. If a periodic SMI handler is not currently being executed, the NULL is returned. @retval NULL A periodic SMI handler is not currently being executed. @retval other Pointer to the PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT associated with the active periodic SMI handler. **/ PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT * GetActivePeriodicSmiLibraryHandler ( VOID ) { return gActivePeriodicSmiLibraryHandler; } /** Internal worker function that returns a pointer to the PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT structure associated with the DispatchHandle that was returned when the periodic SMI handler was enabled with PeriodicSmiEnable(). If DispatchHandle is NULL, then the active periodic SMI handler is returned. If DispatchHandle is NULL and there is no active periodic SMI handler, then NULL is returned. @param[in] DispatchHandle DispatchHandle that was returned when the periodic SMI handler was enabled with PeriodicSmiEnable(). This is an optional parameter that may be NULL. If this parameter is NULL, then the active periodic SMI handler is returned. @retval NULL DispatchHandle is NULL and there is no active periodic SMI handler. @retval NULL DispatchHandle does not match any of the periodic SMI handlers that have been enabled with PeriodicSmiEnable(). @retval other Pointer to the PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT associated with the DispatchHandle. **/ PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT * LookupPeriodicSmiLibraryHandler ( IN EFI_HANDLE DispatchHandle OPTIONAL ) { LIST_ENTRY *Link; PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; // // If DispatchHandle is NULL, then return the active periodic SMI handler // if (DispatchHandle == NULL) { return GetActivePeriodicSmiLibraryHandler (); } // // Search the periodic SMI handler entries for a a matching DispatchHandle // for ( Link = GetFirstNode (&gPeriodicSmiLibraryHandlers) ; !IsNull (&gPeriodicSmiLibraryHandlers, Link) ; Link = GetNextNode (&gPeriodicSmiLibraryHandlers, Link) ) { PeriodicSmiLibraryHandler = PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_FROM_LINK (Link); if (PeriodicSmiLibraryHandler->DispatchHandle == DispatchHandle) { return PeriodicSmiLibraryHandler; } } // // No entries match DispatchHandle, so return NULL // return NULL; } /** Internal worker function that sets that active periodic SMI handler based on the Context used when the periodic SMI handler was registered with the SMM Periodic Timer Dispatch 2 Protocol. If Context is NULL, then the state is updated to show that there is not active periodic SMI handler. A pointer to the active PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT structure is returned. @retval NULL Context is NULL. @retval other Pointer to the PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT associated with Context. **/ PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT * SetActivePeriodicSmiLibraryHandler ( IN CONST VOID *Context OPTIONAL ) { if (Context == NULL) { gActivePeriodicSmiLibraryHandler = NULL; } else { gActivePeriodicSmiLibraryHandler = PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_FROM_REGISTER_CONTEXT (Context); } return gActivePeriodicSmiLibraryHandler; } /** Internal worker function that moves the specified periodic SMI handler from the list of managed periodic SMI handlers to the list of free periodic SMI handlers. @param[in] PeriodicSmiLibraryHandler Pointer to the periodic SMI handler to be reclaimed. **/ VOID ReclaimPeriodicSmiLibraryHandler ( PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler ) { ASSERT (PeriodicSmiLibraryHandler->DispatchHandle == NULL); if (PeriodicSmiLibraryHandler->Stack != NULL) { FreePages ( PeriodicSmiLibraryHandler->Stack, EFI_SIZE_TO_PAGES (PeriodicSmiLibraryHandler->StackSize) ); PeriodicSmiLibraryHandler->Stack = NULL; } RemoveEntryList (&PeriodicSmiLibraryHandler->Link); InsertHeadList (&gFreePeriodicSmiLibraryHandlers, &PeriodicSmiLibraryHandler->Link); } /** Add the additional entries to the list of free periodic SMI handlers. The function is assumed to be called only when the list of free periodic SMI handlers is empty. @retval TRUE The additional entries were added. @retval FALSE There was no available resource for the additional entries. **/ BOOLEAN EnlargeFreePeriodicSmiLibraryHandlerList ( VOID ) { UINTN Index; PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; // // Add the entries to the list // for (Index = 0; Index < PERIODIC_SMI_LIBRARY_ALLOCATE_SIZE; Index++) { PeriodicSmiLibraryHandler = AllocatePool (sizeof (PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT)); if (PeriodicSmiLibraryHandler == NULL) { break; } PeriodicSmiLibraryHandler->Signature = PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_SIGNATURE; InsertHeadList (&gFreePeriodicSmiLibraryHandlers, &PeriodicSmiLibraryHandler->Link); } return (BOOLEAN) (Index > 0); } /** Internal worker function that returns a free entry for a new periodic SMI handler. If no free entries are available, then additional entries are allocated. @retval NULL There are not enough resources available to to allocate a free entry. @retval other Pointer to a free PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT structure. **/ PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT * FindFreePeriodicSmiLibraryHandler ( VOID ) { PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; if (IsListEmpty (&gFreePeriodicSmiLibraryHandlers)) { if (!EnlargeFreePeriodicSmiLibraryHandlerList ()) { return NULL; } } // // Get one from the list of free periodic SMI handlers. // PeriodicSmiLibraryHandler = PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_FROM_LINK ( GetFirstNode (&gFreePeriodicSmiLibraryHandlers) ); RemoveEntryList (&PeriodicSmiLibraryHandler->Link); InsertTailList (&gPeriodicSmiLibraryHandlers, &PeriodicSmiLibraryHandler->Link); return PeriodicSmiLibraryHandler; } /** 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 ) { // // Return the table allocated and populated by SmmPeriodicSmiLibConstructor() // return gSmiTickPeriodTable; } /** 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 ) { PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; UINT64 Current; UINT64 Count; // // If there is no active periodic SMI handler, then return 0 // PeriodicSmiLibraryHandler = GetActivePeriodicSmiLibraryHandler (); if (PeriodicSmiLibraryHandler == NULL) { return 0; } // // Get the current performance counter value // Current = GetPerformanceCounter (); // // Count the number of performance counter ticks since the periodic SMI handler // was dispatched or the last time this function was called. // if (PeriodicSmiLibraryHandler->PerfomanceCounterEndValue > PeriodicSmiLibraryHandler->PerfomanceCounterStartValue) { // // The performance counter counts up. Check for roll over condition. // if (Current > PeriodicSmiLibraryHandler->DispatchCheckPointTime) { Count = Current - PeriodicSmiLibraryHandler->DispatchCheckPointTime; } else { Count = (Current - PeriodicSmiLibraryHandler->PerfomanceCounterStartValue) + (PeriodicSmiLibraryHandler->PerfomanceCounterEndValue - PeriodicSmiLibraryHandler->DispatchCheckPointTime); } } else { // // The performance counter counts down. Check for roll over condition. // if (PeriodicSmiLibraryHandler->DispatchCheckPointTime > Current) { Count = PeriodicSmiLibraryHandler->DispatchCheckPointTime - Current; } else { Count = (PeriodicSmiLibraryHandler->DispatchCheckPointTime - PeriodicSmiLibraryHandler->PerfomanceCounterEndValue) + (PeriodicSmiLibraryHandler->PerfomanceCounterStartValue - Current); } } // // Accumulate the total number of performance counter ticks since the periodic // SMI handler was dispatched or resumed. // PeriodicSmiLibraryHandler->DispatchTotalTime += Count; // // Update the checkpoint value to the current performance counter value // PeriodicSmiLibraryHandler->DispatchCheckPointTime = Current; // // Convert the total number of performance counter ticks to 100 ns units // return DivU64x64Remainder ( MultU64x32 (PeriodicSmiLibraryHandler->DispatchTotalTime, 10000000), PeriodicSmiLibraryHandler->PerfomanceCounterRate, NULL ); } /** 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 ) { PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; // // If there is no active periodic SMI handler, then return // PeriodicSmiLibraryHandler = GetActivePeriodicSmiLibraryHandler (); if (PeriodicSmiLibraryHandler == NULL) { return; } // // Perform a long jump back to the point when the currently executing dispatch // function was dispatched. // LongJump (&PeriodicSmiLibraryHandler->DispatchJumpBuffer, 1); // // Must never return // ASSERT (FALSE); CpuDeadLoop(); } /** 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 ) { PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; UINTN SetJumpFlag; // // If there is no active periodic SMI handler, then return // PeriodicSmiLibraryHandler = GetActivePeriodicSmiLibraryHandler (); if (PeriodicSmiLibraryHandler == NULL) { return 0; } // // If PeriodicSmiYield() is called without an allocated stack, then just return // immediately with an elapsed time of 0. // if (PeriodicSmiLibraryHandler->Stack == NULL) { return 0; } // // Set a flag so the next periodic SMI event will resume at where SetJump() // is called below. // PeriodicSmiLibraryHandler->YieldFlag = TRUE; // // Save context in YieldJumpBuffer // SetJumpFlag = SetJump (&PeriodicSmiLibraryHandler->YieldJumpBuffer); if (SetJumpFlag == 0) { // // The intial call to SetJump() always returns 0. // If this is the initial call, then exit the current periodic SMI handler // PeriodicSmiExit (); } // // We get here when a LongJump is performed from PeriodicSmiDispatchFunctionOnCpu() // to resume a periodic SMI handler that called PeriodicSmiYield() on the // previous time this periodic SMI handler was dispatched. // // Clear the flag so the next periodic SMI dispatch will not resume. // PeriodicSmiLibraryHandler->YieldFlag = FALSE; // // Return the amount elapsed time that occured while yielded // return PeriodicSmiLibraryHandler->ElapsedTime; } /** Internal worker function that transfers control to an enabled periodic SMI handler. If the enabled periodic SMI handler was allocated its own stack, then this function is called on that allocated stack through the BaseLin function SwitchStack(). @param[in] Context1 Context1 parameter passed into SwitchStack(). @param[in] Context2 Context2 parameter passed into SwitchStack(). **/ VOID EFIAPI PeriodicSmiDispatchFunctionSwitchStack ( IN VOID *Context1, OPTIONAL IN VOID *Context2 OPTIONAL ) { PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; // // Convert Context1 to PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT * // PeriodicSmiLibraryHandler = (PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *)Context1; // // Dispatch the registered handler passing in the context that was registered // and the amount of time that has elapsed since the previous time this // periodic SMI handler was dispacthed. // PeriodicSmiLibraryHandler->DispatchFunction ( PeriodicSmiLibraryHandler->Context, PeriodicSmiLibraryHandler->ElapsedTime ); // // If this DispatchFunction() returns, then unconditially call PeriodicSmiExit() // to perform a LongJump() back to PeriodicSmiDispatchFunctionOnCpu(). The // LongJump() will resume exection on the original stack. // PeriodicSmiExit (); } /** Internal worker function that transfers control to an enabled periodic SMI handler on the specified logial CPU. This function determines if the periodic SMI handler yielded and needs to be resumed. It also and switches to an allocated stack if one was allocated in PeriodicSmiEnable(). @param[in] PeriodicSmiLibraryHandler A pointer to the context for the periodic SMI handler to execute. **/ VOID EFIAPI PeriodicSmiDispatchFunctionOnCpu ( PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler ) { // // Save context in DispatchJumpBuffer. The intial call to SetJump() always // returns 0. If this is the initial call, then either resume from a prior // call to PeriodicSmiYield() or call the DispatchFunction registerd in // PeriodicSmiEnable() using an allocated stack if one was specified. // if (SetJump (&PeriodicSmiLibraryHandler->DispatchJumpBuffer) != 0) { return; } // // Capture the performance counter value just before the periodic SMI handler // is resumed so the amount of time the periodic SMI handler executes can be // calculated. // PeriodicSmiLibraryHandler->DispatchTotalTime = 0; PeriodicSmiLibraryHandler->DispatchCheckPointTime = GetPerformanceCounter(); if (PeriodicSmiLibraryHandler->YieldFlag) { // // Perform a long jump back to the point where the previously dispatched // function called PeriodicSmiYield(). // LongJump (&PeriodicSmiLibraryHandler->YieldJumpBuffer, 1); } else if (PeriodicSmiLibraryHandler->Stack == NULL) { // // If Stack is NULL then call DispatchFunction using current stack passing // in the context that was registered and the amount of time that has // elapsed since the previous time this periodic SMI handler was dispacthed. // PeriodicSmiLibraryHandler->DispatchFunction ( PeriodicSmiLibraryHandler->Context, PeriodicSmiLibraryHandler->ElapsedTime ); // // If this DispatchFunction() returns, then unconditially call PeriodicSmiExit() // to perform a LongJump() back to this function. // PeriodicSmiExit (); } else { // // If Stack is not NULL then call DispatchFunction switching to the allocated stack // SwitchStack ( PeriodicSmiDispatchFunctionSwitchStack, PeriodicSmiLibraryHandler, NULL, (UINT8 *)PeriodicSmiLibraryHandler->Stack + PeriodicSmiLibraryHandler->StackSize ); } // // Must never return // ASSERT (FALSE); CpuDeadLoop(); } /** Internal worker function that transfers control to an enabled periodic SMI handler on the specified logial CPU. This worker function is only called using the SMM Services Table function SmmStartupThisAp() to execute the periodic SMI handler on a logical CPU that is different than the one that is running the SMM Foundation. When the periodic SMI handler returns, a lock is released to notify the CPU that is running the SMM Foundation that the periodic SMI handler execution has finished its execution. @param[in, out] Buffer A pointer to the context for the periodic SMI handler. **/ VOID EFIAPI PeriodicSmiDispatchFunctionWithLock ( IN OUT VOID *Buffer ) { PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; // // Get context // PeriodicSmiLibraryHandler = (PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *)Buffer; // // Execute dispatch function on the currently excuting logical CPU // PeriodicSmiDispatchFunctionOnCpu (PeriodicSmiLibraryHandler); // // Release the dispatch spin lock // ReleaseSpinLock (&PeriodicSmiLibraryHandler->DispatchLock); } /** Internal worker function that transfers control to a periodic SMI handler that was enabled using PeriodicSmiEnable(). @param[in] DispatchHandle The unique handle assigned to this handler by SmiHandlerRegister(). @param[in] Context Points to an optional handler context which was specified when the handler was registered. @param[in, out] CommBuffer A pointer to a collection of data in memory that will be conveyed from a non-SMM environment into an SMM environment. @param[in, out] CommBufferSize The size of the CommBuffer. @retval EFI_SUCCESS The interrupt was handled and quiesced. No other handlers should still be called. @retval EFI_WARN_INTERRUPT_SOURCE_QUIESCED The interrupt has been quiesced but other handlers should still be called. @retval EFI_WARN_INTERRUPT_SOURCE_PENDING The interrupt is still pending and other handlers should still be called. @retval EFI_INTERRUPT_PENDING The interrupt could not be quiesced. **/ EFI_STATUS EFIAPI PeriodicSmiDispatchFunction ( IN EFI_HANDLE DispatchHandle, IN CONST VOID *Context OPTIONAL, IN OUT VOID *CommBuffer OPTIONAL, IN OUT UINTN *CommBufferSize OPTIONAL ) { PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; EFI_SMM_PERIODIC_TIMER_CONTEXT *TimerContext; EFI_STATUS Status; // // Set the active periodic SMI handler // PeriodicSmiLibraryHandler = SetActivePeriodicSmiLibraryHandler (Context); if (PeriodicSmiLibraryHandler == NULL) { return EFI_NOT_FOUND; } // // Retrieve the elapsed time since the last time this periodic SMI handler was called // PeriodicSmiLibraryHandler->ElapsedTime = 0; if (CommBuffer != NULL) { TimerContext = (EFI_SMM_PERIODIC_TIMER_CONTEXT *)CommBuffer; PeriodicSmiLibraryHandler->ElapsedTime = TimerContext->ElapsedTime; } // // Dispatch the periodic SMI handler // if ((PeriodicSmiLibraryHandler->Cpu == PERIODIC_SMI_LIBRARY_ANY_CPU) || (PeriodicSmiLibraryHandler->Cpu == gSmst->CurrentlyExecutingCpu) ) { // // Dispatch on the currently execution CPU if the CPU specified in PeriodicSmiEnable() // was PERIODIC_SMI_LIBARRY_ANY_CPU or the currently executing CPU matches the CPU // that was specified in PeriodicSmiEnable(). // PeriodicSmiDispatchFunctionOnCpu (PeriodicSmiLibraryHandler); } else { // // Acquire spin lock for ths periodic SMI handler. The AP will release the // spin lock when it is done executing the periodic SMI handler. // AcquireSpinLock (&PeriodicSmiLibraryHandler->DispatchLock); // // Execute the periodic SMI handler on the CPU that was specified in // PeriodicSmiEnable(). // Status = gSmst->SmmStartupThisAp ( PeriodicSmiDispatchFunctionWithLock, PeriodicSmiLibraryHandler->Cpu, PeriodicSmiLibraryHandler ); if (!EFI_ERROR (Status)) { // // Wait for the AP to release the spin lock. // while (!AcquireSpinLockOrFail (&PeriodicSmiLibraryHandler->DispatchLock)) { CpuPause (); } } // // Release the spin lock for the periodic SMI handler. // ReleaseSpinLock (&PeriodicSmiLibraryHandler->DispatchLock); } // // Reclaim the active periodic SMI handler if it was disabled during the current dispatch. // if (PeriodicSmiLibraryHandler->DispatchHandle == NULL) { ReclaimPeriodicSmiLibraryHandler (PeriodicSmiLibraryHandler); } // // Update state to show that there is no active periodic SMI handler // SetActivePeriodicSmiLibraryHandler (NULL); return EFI_SUCCESS; } /** 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 ) { EFI_STATUS Status; UINTN Index; PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; // // Make sure all the input parameters are valid // if (DispatchFunction == NULL) { return EFI_INVALID_PARAMETER; } for (Index = 0; gSmiTickPeriodTable[Index] != 0; Index++) { if (gSmiTickPeriodTable[Index] == TickPeriod) { break; } } if (gSmiTickPeriodTable[Index] == 0) { return EFI_UNSUPPORTED; } if (Cpu != PERIODIC_SMI_LIBRARY_ANY_CPU && Cpu >= gSmst->NumberOfCpus) { return EFI_INVALID_PARAMETER; } // // Find a free periodic SMI handler entry // PeriodicSmiLibraryHandler = FindFreePeriodicSmiLibraryHandler(); if (PeriodicSmiLibraryHandler == NULL) { return EFI_OUT_OF_RESOURCES; } // // Initialize a new periodic SMI handler entry // PeriodicSmiLibraryHandler->YieldFlag = FALSE; PeriodicSmiLibraryHandler->DispatchHandle = NULL; PeriodicSmiLibraryHandler->DispatchFunction = DispatchFunction; PeriodicSmiLibraryHandler->Context = (VOID *)Context; PeriodicSmiLibraryHandler->Cpu = Cpu; PeriodicSmiLibraryHandler->StackSize = ALIGN_VALUE (StackSize, EFI_PAGE_SIZE); if (PeriodicSmiLibraryHandler->StackSize > 0) { PeriodicSmiLibraryHandler->Stack = AllocatePages (EFI_SIZE_TO_PAGES (PeriodicSmiLibraryHandler->StackSize)); if (PeriodicSmiLibraryHandler->Stack == NULL) { return EFI_OUT_OF_RESOURCES; } ZeroMem (PeriodicSmiLibraryHandler->Stack, PeriodicSmiLibraryHandler->StackSize); } else { PeriodicSmiLibraryHandler->Stack = NULL; } InitializeSpinLock (&PeriodicSmiLibraryHandler->DispatchLock); PeriodicSmiLibraryHandler->PerfomanceCounterRate = GetPerformanceCounterProperties ( &PeriodicSmiLibraryHandler->PerfomanceCounterStartValue, &PeriodicSmiLibraryHandler->PerfomanceCounterEndValue ); PeriodicSmiLibraryHandler->RegisterContext.Period = TickPeriod; PeriodicSmiLibraryHandler->RegisterContext.SmiTickInterval = TickPeriod; Status = gSmmPeriodicTimerDispatch2->Register ( gSmmPeriodicTimerDispatch2, PeriodicSmiDispatchFunction, &PeriodicSmiLibraryHandler->RegisterContext, &PeriodicSmiLibraryHandler->DispatchHandle ); if (EFI_ERROR (Status)) { PeriodicSmiLibraryHandler->DispatchHandle = NULL; ReclaimPeriodicSmiLibraryHandler (PeriodicSmiLibraryHandler); return EFI_OUT_OF_RESOURCES; } // // Return the registered handle if the optional DispatchHandle parameter is not NULL // if (DispatchHandle != NULL) { *DispatchHandle = PeriodicSmiLibraryHandler->DispatchHandle; } return EFI_SUCCESS; } /** 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 ) { PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; EFI_STATUS Status; // // Lookup the periodic SMI handler specified by DispatchHandle // PeriodicSmiLibraryHandler = LookupPeriodicSmiLibraryHandler (DispatchHandle); if (PeriodicSmiLibraryHandler == NULL) { return FALSE; } // // Unregister the periodic SMI handler from the SMM Periodic Timer Dispatch 2 Protocol // Status = gSmmPeriodicTimerDispatch2->UnRegister ( gSmmPeriodicTimerDispatch2, PeriodicSmiLibraryHandler->DispatchHandle ); if (EFI_ERROR (Status)) { return FALSE; } // // Mark the entry for the disabled periodic SMI handler as free, and // call ReclaimPeriodicSmiLibraryHandler to move it to the list of free // periodic SMI handlers. // PeriodicSmiLibraryHandler->DispatchHandle = NULL; if (PeriodicSmiLibraryHandler != GetActivePeriodicSmiLibraryHandler ()) { ReclaimPeriodicSmiLibraryHandler (PeriodicSmiLibraryHandler); } return TRUE; } /** This constructor function caches the pointer to the SMM Periodic Timer Dispatch 2 Protocol and collects the list SMI tick rates that the hardware supports. @param[in] ImageHandle The firmware allocated handle for the EFI image. @param[in] SystemTable A pointer to the EFI System Table. @retval EFI_SUCCESS The constructor always returns EFI_SUCCESS. **/ EFI_STATUS EFIAPI SmmPeriodicSmiLibConstructor ( IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable ) { EFI_STATUS Status; UINT64 *SmiTickInterval; UINTN Count; // // Locate the SMM Periodic Timer Dispatch 2 Protocol // Status = gSmst->SmmLocateProtocol ( &gEfiSmmPeriodicTimerDispatch2ProtocolGuid, NULL, (VOID **)&gSmmPeriodicTimerDispatch2 ); ASSERT_EFI_ERROR (Status); ASSERT (gSmmPeriodicTimerDispatch2 != NULL); // // Count the number of periodic SMI tick intervals that the SMM Periodic Timer // Dipatch 2 Protocol supports. // SmiTickInterval = NULL; Count = 0; do { Status = gSmmPeriodicTimerDispatch2->GetNextShorterInterval ( gSmmPeriodicTimerDispatch2, &SmiTickInterval ); Count++; } while (SmiTickInterval != NULL); // // Allocate a buffer for the table of supported periodic SMI tick periods. // gSmiTickPeriodTable = AllocateZeroPool (Count * sizeof (UINT64)); ASSERT (gSmiTickPeriodTable != NULL); // // Fill in the table of supported periodic SMI tick periods. // SmiTickInterval = NULL; Count = 0; do { gSmiTickPeriodTable[Count] = 0; Status = gSmmPeriodicTimerDispatch2->GetNextShorterInterval ( gSmmPeriodicTimerDispatch2, &SmiTickInterval ); if (SmiTickInterval != NULL) { gSmiTickPeriodTable[Count] = *SmiTickInterval; } Count++; } while (SmiTickInterval != NULL); // // Allocate buffer for initial set of periodic SMI handlers // EnlargeFreePeriodicSmiLibraryHandlerList (); return EFI_SUCCESS; } /** The constructor function caches the pointer to the SMM Periodic Timer Dispatch 2 Protocol and collects the list SMI tick rates that the hardware supports. @param[in] ImageHandle The firmware allocated handle for the EFI image. @param[in] SystemTable A pointer to the EFI System Table. @retval EFI_SUCCESS The constructor always returns EFI_SUCCESS. **/ EFI_STATUS EFIAPI SmmPeriodicSmiLibDestructor ( IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable ) { LIST_ENTRY *Link; PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT *PeriodicSmiLibraryHandler; // // Free the table of supported periodic SMI tick rates // if (gSmiTickPeriodTable != NULL) { FreePool (gSmiTickPeriodTable); } // // Disable all periodic SMI handlers // for (Link = GetFirstNode (&gPeriodicSmiLibraryHandlers); !IsNull (&gPeriodicSmiLibraryHandlers, Link);) { PeriodicSmiLibraryHandler = PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_FROM_LINK (Link); Link = GetNextNode (&gPeriodicSmiLibraryHandlers, Link); PeriodicSmiDisable (PeriodicSmiLibraryHandler->DispatchHandle); } // // Free all the periodic SMI handler entries // for (Link = GetFirstNode (&gFreePeriodicSmiLibraryHandlers); !IsNull (&gFreePeriodicSmiLibraryHandlers, Link);) { PeriodicSmiLibraryHandler = PERIODIC_SMI_LIBRARY_HANDLER_CONTEXT_FROM_LINK (Link); Link = RemoveEntryList (Link); FreePool (PeriodicSmiLibraryHandler); } return EFI_SUCCESS; }