[mirror_edk2.git] / MdeModulePkg / Core / PiSmmCore / Smi.c

/** @file\r
  SMI management.\r
\r
  Copyright (c) 2009 - 2013, Intel Corporation. All rights reserved.<BR>\r
  This program and the accompanying materials are licensed and made available \r
  under the terms and conditions of the BSD License which accompanies this \r
  distribution.  The full text of the license may be found at        \r
  http://opensource.org/licenses/bsd-license.php                                            \r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     \r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             \r
\r
**/\r
\r
#include "PiSmmCore.h"\r
\r
//\r
// SMM_HANDLER - used for each SMM handler\r
//\r
\r
#define SMI_ENTRY_SIGNATURE  SIGNATURE_32('s','m','i','e')\r
\r
 typedef struct {\r
  UINTN       Signature;\r
  LIST_ENTRY  AllEntries;  // All entries\r
\r
  EFI_GUID    HandlerType; // Type of interrupt\r
  LIST_ENTRY  SmiHandlers; // All handlers\r
} SMI_ENTRY;\r
\r
#define SMI_HANDLER_SIGNATURE  SIGNATURE_32('s','m','i','h')\r
\r
 typedef struct {\r
  UINTN                         Signature;\r
  LIST_ENTRY                    Link;        // Link on SMI_ENTRY.SmiHandlers\r
  EFI_SMM_HANDLER_ENTRY_POINT2  Handler;     // The smm handler's entry point\r
  SMI_ENTRY                     *SmiEntry;\r
} SMI_HANDLER;\r
\r
LIST_ENTRY  mRootSmiHandlerList = INITIALIZE_LIST_HEAD_VARIABLE (mRootSmiHandlerList);\r
LIST_ENTRY  mSmiEntryList       = INITIALIZE_LIST_HEAD_VARIABLE (mSmiEntryList);\r
\r
/**\r
  Finds the SMI entry for the requested handler type.\r
\r
  @param  HandlerType            The type of the interrupt\r
  @param  Create                 Create a new entry if not found\r
\r
  @return SMI entry\r
\r
**/\r
SMI_ENTRY  *\r
EFIAPI\r
SmmCoreFindSmiEntry (\r
  IN EFI_GUID  *HandlerType,\r
  IN BOOLEAN   Create\r
  )\r
{\r
  LIST_ENTRY  *Link;\r
  SMI_ENTRY   *Item;\r
  SMI_ENTRY   *SmiEntry;\r
\r
  //\r
  // Search the SMI entry list for the matching GUID\r
  //\r
  SmiEntry = NULL;\r
  for (Link = mSmiEntryList.ForwardLink;\r
       Link != &mSmiEntryList;\r
       Link = Link->ForwardLink) {\r
\r
    Item = CR (Link, SMI_ENTRY, AllEntries, SMI_ENTRY_SIGNATURE);\r
    if (CompareGuid (&Item->HandlerType, HandlerType)) {\r
      //\r
      // This is the SMI entry\r
      //\r
      SmiEntry = Item;\r
      break;\r
    }\r
  }\r
\r
  //\r
  // If the protocol entry was not found and Create is TRUE, then\r
  // allocate a new entry\r
  //\r
  if ((SmiEntry == NULL) && Create) {\r
    SmiEntry = AllocatePool (sizeof(SMI_ENTRY));\r
    if (SmiEntry != NULL) {\r
      //\r
      // Initialize new SMI entry structure\r
      //\r
      SmiEntry->Signature = SMI_ENTRY_SIGNATURE;\r
      CopyGuid ((VOID *)&SmiEntry->HandlerType, HandlerType);\r
      InitializeListHead (&SmiEntry->SmiHandlers);\r
\r
      //\r
      // Add it to SMI entry list\r
      //\r
      InsertTailList (&mSmiEntryList, &SmiEntry->AllEntries);\r
    }\r
  }\r
  return SmiEntry;\r
}\r
\r
/**\r
  Manage SMI of a particular type.\r
\r
  @param  HandlerType    Points to the handler type or NULL for root SMI handlers.\r
  @param  Context        Points to an optional context buffer.\r
  @param  CommBuffer     Points to the optional communication buffer.\r
  @param  CommBufferSize Points to the size of the optional communication buffer.\r
\r
  @retval EFI_WARN_INTERRUPT_SOURCE_PENDING  Interrupt source was processed successfully but not quiesced.\r
  @retval EFI_INTERRUPT_PENDING              One or more SMI sources could not be quiesced.\r
  @retval EFI_NOT_FOUND                      Interrupt source was not handled or quiesced.\r
  @retval EFI_SUCCESS                        Interrupt source was handled and quiesced.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
SmiManage (\r
  IN     CONST EFI_GUID  *HandlerType,\r
  IN     CONST VOID      *Context         OPTIONAL,\r
  IN OUT VOID            *CommBuffer      OPTIONAL,\r
  IN OUT UINTN           *CommBufferSize  OPTIONAL\r
  )\r
{\r
  LIST_ENTRY   *Link;\r
  LIST_ENTRY   *Head;\r
  SMI_ENTRY    *SmiEntry;\r
  SMI_HANDLER  *SmiHandler;\r
  BOOLEAN      SuccessReturn;\r
  EFI_STATUS   Status;\r
  \r
  Status = EFI_NOT_FOUND;\r
  SuccessReturn = FALSE;\r
  if (HandlerType == NULL) {\r
    //\r
    // Root SMI handler\r
    //\r
\r
    Head = &mRootSmiHandlerList;\r
  } else {\r
    //\r
    // Non-root SMI handler\r
    //\r
    SmiEntry = SmmCoreFindSmiEntry ((EFI_GUID *) HandlerType, FALSE);\r
    if (SmiEntry == NULL) {\r
      //\r
      // There is no handler registered for this interrupt source\r
      //\r
      return Status;\r
    }\r
\r
    Head = &SmiEntry->SmiHandlers;\r
  }\r
\r
  for (Link = Head->ForwardLink; Link != Head; Link = Link->ForwardLink) {\r
    SmiHandler = CR (Link, SMI_HANDLER, Link, SMI_HANDLER_SIGNATURE);\r
\r
    Status = SmiHandler->Handler (\r
               (EFI_HANDLE) SmiHandler,\r
               Context,\r
               CommBuffer,\r
               CommBufferSize\r
               );\r
\r
    switch (Status) {\r
    case EFI_INTERRUPT_PENDING:\r
      //\r
      // If a handler returns EFI_INTERRUPT_PENDING and HandlerType is not NULL then\r
      // no additional handlers will be processed and EFI_INTERRUPT_PENDING will be returned.\r
      //\r
      if (HandlerType != NULL) {\r
        return EFI_INTERRUPT_PENDING;\r
      }\r
      break;\r
\r
    case EFI_SUCCESS:\r
      //\r
      // If at least one of the handlers returns EFI_SUCCESS then the function will return\r
      // EFI_SUCCESS. If a handler returns EFI_SUCCESS and HandlerType is not NULL then no\r
      // additional handlers will be processed.\r
      //\r
      if (HandlerType != NULL) {\r
        return EFI_SUCCESS;\r
      }\r
      SuccessReturn = TRUE;\r
      break;\r
\r
    case EFI_WARN_INTERRUPT_SOURCE_QUIESCED:\r
      //\r
      // If at least one of the handlers returns EFI_WARN_INTERRUPT_SOURCE_QUIESCED\r
      // then the function will return EFI_SUCCESS. \r
      //\r
      SuccessReturn = TRUE;\r
      break;\r
\r
    case EFI_WARN_INTERRUPT_SOURCE_PENDING:\r
      //\r
      // If all the handlers returned EFI_WARN_INTERRUPT_SOURCE_PENDING\r
      // then EFI_WARN_INTERRUPT_SOURCE_PENDING will be returned.\r
      //\r
      break;\r
\r
    default:\r
      //\r
      // Unexpected status code returned.\r
      //\r
      ASSERT (FALSE);\r
      break;\r
    }\r
  }\r
\r
  if (SuccessReturn) {\r
    Status = EFI_SUCCESS;\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  Registers a handler to execute within SMM.\r
\r
  @param  Handler        Handler service funtion pointer.\r
  @param  HandlerType    Points to the handler type or NULL for root SMI handlers.\r
  @param  DispatchHandle On return, contains a unique handle which can be used to later unregister the handler function.\r
\r
  @retval EFI_SUCCESS           Handler register success.\r
  @retval EFI_INVALID_PARAMETER Handler or DispatchHandle is NULL.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
SmiHandlerRegister (\r
  IN  EFI_SMM_HANDLER_ENTRY_POINT2  Handler,\r
  IN  CONST EFI_GUID                *HandlerType  OPTIONAL,\r
  OUT EFI_HANDLE                    *DispatchHandle\r
  )\r
{\r
  SMI_HANDLER  *SmiHandler;\r
  SMI_ENTRY    *SmiEntry;\r
  LIST_ENTRY   *List;\r
\r
  if (Handler == NULL || DispatchHandle == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  SmiHandler = AllocateZeroPool (sizeof (SMI_HANDLER));\r
  if (SmiHandler == NULL) {\r
    return EFI_OUT_OF_RESOURCES;\r
  }\r
\r
  SmiHandler->Signature = SMI_HANDLER_SIGNATURE;\r
  SmiHandler->Handler = Handler;\r
\r
  if (HandlerType == NULL) {\r
    //\r
    // This is root SMI handler\r
    //\r
    SmiEntry = NULL;\r
    List = &mRootSmiHandlerList;\r
  } else {\r
    //\r
    // None root SMI handler\r
    //\r
    SmiEntry = SmmCoreFindSmiEntry ((EFI_GUID *) HandlerType, TRUE);\r
    if (SmiEntry == NULL) {\r
      return EFI_OUT_OF_RESOURCES;\r
    }\r
\r
    List = &SmiEntry->SmiHandlers;\r
  }\r
\r
  SmiHandler->SmiEntry = SmiEntry;\r
  InsertTailList (List, &SmiHandler->Link);\r
\r
  *DispatchHandle = (EFI_HANDLE) SmiHandler;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Unregister a handler in SMM.\r
\r
  @param  DispatchHandle  The handle that was specified when the handler was registered.\r
\r
  @retval EFI_SUCCESS           Handler function was successfully unregistered.\r
  @retval EFI_INVALID_PARAMETER DispatchHandle does not refer to a valid handle.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
SmiHandlerUnRegister (\r
  IN EFI_HANDLE  DispatchHandle\r
  )\r
{\r
  SMI_HANDLER  *SmiHandler;\r
  SMI_ENTRY    *SmiEntry;\r
\r
  SmiHandler = (SMI_HANDLER *) DispatchHandle;\r
\r
  if (SmiHandler == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if (SmiHandler->Signature != SMI_HANDLER_SIGNATURE) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  SmiEntry = SmiHandler->SmiEntry;\r
\r
  RemoveEntryList (&SmiHandler->Link);\r
  FreePool (SmiHandler);\r
\r
  if (SmiEntry == NULL) {\r
    //\r
    // This is root SMI handler\r
    //\r
    return EFI_SUCCESS;\r
  }\r
\r
  if (IsListEmpty (&SmiEntry->SmiHandlers)) {\r
    //\r
    // No handler registered for this interrupt now, remove the SMI_ENTRY\r
    //\r
    RemoveEntryList (&SmiEntry->AllEntries);\r
\r
    FreePool (SmiEntry);\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
Commit	Line	Data
e42e9404	1	/** @file\r
	2	SMI management.\r
	3	\r
510ed431	4	Copyright (c) 2009 - 2013, Intel Corporation. All rights reserved.<BR>\r
e42e9404	5	This program and the accompanying materials are licensed and made available \r
	6	under the terms and conditions of the BSD License which accompanies this \r
	7	distribution. The full text of the license may be found at \r
	8	http://opensource.org/licenses/bsd-license.php \r
	9	\r
	10	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r
	11	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r
	12	\r
	13	**/\r
	14	\r
	15	#include "PiSmmCore.h"\r
	16	\r
	17	//\r
	18	// SMM_HANDLER - used for each SMM handler\r
	19	//\r
	20	\r
	21	#define SMI_ENTRY_SIGNATURE SIGNATURE_32('s','m','i','e')\r
	22	\r
	23	typedef struct {\r
	24	UINTN Signature;\r
	25	LIST_ENTRY AllEntries; // All entries\r
	26	\r
	27	EFI_GUID HandlerType; // Type of interrupt\r
	28	LIST_ENTRY SmiHandlers; // All handlers\r
	29	} SMI_ENTRY;\r
	30	\r
	31	#define SMI_HANDLER_SIGNATURE SIGNATURE_32('s','m','i','h')\r
	32	\r
	33	typedef struct {\r
	34	UINTN Signature;\r
	35	LIST_ENTRY Link; // Link on SMI_ENTRY.SmiHandlers\r
	36	EFI_SMM_HANDLER_ENTRY_POINT2 Handler; // The smm handler's entry point\r
	37	SMI_ENTRY *SmiEntry;\r
	38	} SMI_HANDLER;\r
	39	\r
	40	LIST_ENTRY mRootSmiHandlerList = INITIALIZE_LIST_HEAD_VARIABLE (mRootSmiHandlerList);\r
	41	LIST_ENTRY mSmiEntryList = INITIALIZE_LIST_HEAD_VARIABLE (mSmiEntryList);\r
	42	\r
	43	/**\r
	44	Finds the SMI entry for the requested handler type.\r
	45	\r
	46	@param HandlerType The type of the interrupt\r
	47	@param Create Create a new entry if not found\r
	48	\r
	49	@return SMI entry\r
	50	\r
	51	**/\r
	52	SMI_ENTRY *\r
	53	EFIAPI\r
	54	SmmCoreFindSmiEntry (\r
	55	IN EFI_GUID *HandlerType,\r
	56	IN BOOLEAN Create\r
	57	)\r
	58	{\r
	59	LIST_ENTRY *Link;\r
	60	SMI_ENTRY *Item;\r
	61	SMI_ENTRY *SmiEntry;\r
	62	\r
	63	//\r
	64	// Search the SMI entry list for the matching GUID\r
	65	//\r
	66	SmiEntry = NULL;\r
	67	for (Link = mSmiEntryList.ForwardLink;\r
	68	Link != &mSmiEntryList;\r
69	Link = Link->ForwardLink) {\r
70	\r
71	Item = CR (Link, SMI_ENTRY, AllEntries, SMI_ENTRY_SIGNATURE);\r
72	if (CompareGuid (&Item->HandlerType, HandlerType)) {\r
73	//\r
74	// This is the SMI entry\r
75	//\r
76	SmiEntry = Item;\r
77	break;\r
78	}\r
79	}\r
80	\r
81	//\r
82	// If the protocol entry was not found and Create is TRUE, then\r
83	// allocate a new entry\r
84	//\r
85	if ((SmiEntry == NULL) && Create) {\r
86	SmiEntry = AllocatePool (sizeof(SMI_ENTRY));\r
87	if (SmiEntry != NULL) {\r
88	//\r
89	// Initialize new SMI entry structure\r
90	//\r
91	SmiEntry->Signature = SMI_ENTRY_SIGNATURE;\r
92	CopyGuid ((VOID *)&SmiEntry->HandlerType, HandlerType);\r
93	InitializeListHead (&SmiEntry->SmiHandlers);\r
94	\r
95	//\r
96	// Add it to SMI entry list\r
97	//\r
98	InsertTailList (&mSmiEntryList, &SmiEntry->AllEntries);\r
99	}\r
100	}\r
101	return SmiEntry;\r
102	}\r
103	\r
104	/**\r
105	Manage SMI of a particular type.\r
106	\r
107	@param HandlerType Points to the handler type or NULL for root SMI handlers.\r
108	@param Context Points to an optional context buffer.\r
109	@param CommBuffer Points to the optional communication buffer.\r
110	@param CommBufferSize Points to the size of the optional communication buffer.\r
111	\r
d5b339a9	112	@retval EFI_WARN_INTERRUPT_SOURCE_PENDING Interrupt source was processed successfully but not quiesced.\r
e42e9404	113	@retval EFI_INTERRUPT_PENDING One or more SMI sources could not be quiesced.\r
d5b339a9	114	@retval EFI_NOT_FOUND Interrupt source was not handled or quiesced.\r
d5b339a9	115	@retval EFI_SUCCESS Interrupt source was handled and quiesced.\r
e42e9404	116	\r
	117	**/\r
	118	EFI_STATUS\r
	119	EFIAPI\r
	120	SmiManage (\r
	121	IN CONST EFI_GUID *HandlerType,\r
	122	IN CONST VOID *Context OPTIONAL,\r
	123	IN OUT VOID *CommBuffer OPTIONAL,\r
	124	IN OUT UINTN *CommBufferSize OPTIONAL\r
	125	)\r
	126	{\r
	127	LIST_ENTRY *Link;\r
	128	LIST_ENTRY *Head;\r
	129	SMI_ENTRY *SmiEntry;\r
	130	SMI_HANDLER *SmiHandler;\r
510ed431	131	BOOLEAN SuccessReturn;\r
e42e9404	132	EFI_STATUS Status;\r
e42e9404	133	\r
d5b339a9	134	Status = EFI_NOT_FOUND;\r
510ed431	135	SuccessReturn = FALSE;\r
e42e9404	136	if (HandlerType == NULL) {\r
	137	//\r
	138	// Root SMI handler\r
	139	//\r
e42e9404	140	\r
e42e9404	141	Head = &mRootSmiHandlerList;\r
d5b339a9	142	} else {\r
e42e9404	143	//\r
d5b339a9	144	// Non-root SMI handler\r
e42e9404	145	//\r
d5b339a9	146	SmiEntry = SmmCoreFindSmiEntry ((EFI_GUID *) HandlerType, FALSE);\r
	147	if (SmiEntry == NULL) {\r
	148	//\r
	149	// There is no handler registered for this interrupt source\r
	150	//\r
	151	return Status;\r
	152	}\r
	153	\r
	154	Head = &SmiEntry->SmiHandlers;\r
e42e9404	155	}\r
e42e9404	156	\r
e42e9404	157	for (Link = Head->ForwardLink; Link != Head; Link = Link->ForwardLink) {\r
	158	SmiHandler = CR (Link, SMI_HANDLER, Link, SMI_HANDLER_SIGNATURE);\r
	159	\r
	160	Status = SmiHandler->Handler (\r
	161	(EFI_HANDLE) SmiHandler,\r
	162	Context,\r
	163	CommBuffer,\r
	164	CommBufferSize\r
	165	);\r
	166	\r
	167	switch (Status) {\r
	168	case EFI_INTERRUPT_PENDING:\r
	169	//\r
510ed431	170	// If a handler returns EFI_INTERRUPT_PENDING and HandlerType is not NULL then\r
510ed431	171	// no additional handlers will be processed and EFI_INTERRUPT_PENDING will be returned.\r
e42e9404	172	//\r
6b52b72f	173	if (HandlerType != NULL) {\r
	174	return EFI_INTERRUPT_PENDING;\r
	175	}\r
	176	break;\r
e42e9404	177	\r
	178	case EFI_SUCCESS:\r
	179	//\r
510ed431	180	// If at least one of the handlers returns EFI_SUCCESS then the function will return\r
	181	// EFI_SUCCESS. If a handler returns EFI_SUCCESS and HandlerType is not NULL then no\r
	182	// additional handlers will be processed.\r
e42e9404	183	//\r
6b52b72f	184	if (HandlerType != NULL) {\r
	185	return EFI_SUCCESS;\r
	186	}\r
510ed431	187	SuccessReturn = TRUE;\r
6b52b72f	188	break;\r
e42e9404	189	\r
	190	case EFI_WARN_INTERRUPT_SOURCE_QUIESCED:\r
	191	//\r
d5b339a9	192	// If at least one of the handlers returns EFI_WARN_INTERRUPT_SOURCE_QUIESCED\r
d5b339a9	193	// then the function will return EFI_SUCCESS. \r
e42e9404	194	//\r
510ed431	195	SuccessReturn = TRUE;\r
e42e9404	196	break;\r
e42e9404	197	\r
d5b339a9	198	case EFI_WARN_INTERRUPT_SOURCE_PENDING:\r
	199	//\r
	200	// If all the handlers returned EFI_WARN_INTERRUPT_SOURCE_PENDING\r
	201	// then EFI_WARN_INTERRUPT_SOURCE_PENDING will be returned.\r
	202	//\r
	203	break;\r
	204	\r
e42e9404	205	default:\r
d5b339a9	206	//\r
	207	// Unexpected status code returned.\r
	208	//\r
	209	ASSERT (FALSE);\r
e42e9404	210	break;\r
	211	}\r
	212	}\r
	213	\r
510ed431	214	if (SuccessReturn) {\r
d5b339a9	215	Status = EFI_SUCCESS;\r
e42e9404	216	}\r
d5b339a9	217	\r
e42e9404	218	return Status;\r
	219	}\r
	220	\r
	221	/**\r
	222	Registers a handler to execute within SMM.\r
	223	\r
	224	@param Handler Handler service funtion pointer.\r
	225	@param HandlerType Points to the handler type or NULL for root SMI handlers.\r
	226	@param DispatchHandle On return, contains a unique handle which can be used to later unregister the handler function.\r
	227	\r
	228	@retval EFI_SUCCESS Handler register success.\r
	229	@retval EFI_INVALID_PARAMETER Handler or DispatchHandle is NULL.\r
	230	\r
	231	**/\r
	232	EFI_STATUS\r
	233	EFIAPI\r
	234	SmiHandlerRegister (\r
	235	IN EFI_SMM_HANDLER_ENTRY_POINT2 Handler,\r
	236	IN CONST EFI_GUID *HandlerType OPTIONAL,\r
	237	OUT EFI_HANDLE *DispatchHandle\r
	238	)\r
	239	{\r
	240	SMI_HANDLER *SmiHandler;\r
	241	SMI_ENTRY *SmiEntry;\r
	242	LIST_ENTRY *List;\r
	243	\r
	244	if (Handler == NULL \|\| DispatchHandle == NULL) {\r
	245	return EFI_INVALID_PARAMETER;\r
	246	}\r
	247	\r
	248	SmiHandler = AllocateZeroPool (sizeof (SMI_HANDLER));\r
	249	if (SmiHandler == NULL) {\r
	250	return EFI_OUT_OF_RESOURCES;\r
	251	}\r
	252	\r
	253	SmiHandler->Signature = SMI_HANDLER_SIGNATURE;\r
	254	SmiHandler->Handler = Handler;\r
	255	\r
	256	if (HandlerType == NULL) {\r
	257	//\r
	258	// This is root SMI handler\r
	259	//\r
	260	SmiEntry = NULL;\r
	261	List = &mRootSmiHandlerList;\r
	262	} else {\r
	263	//\r
	264	// None root SMI handler\r
	265	//\r
	266	SmiEntry = SmmCoreFindSmiEntry ((EFI_GUID *) HandlerType, TRUE);\r
	267	if (SmiEntry == NULL) {\r
	268	return EFI_OUT_OF_RESOURCES;\r
	269	}\r
	270	\r
	271	List = &SmiEntry->SmiHandlers;\r
	272	}\r
	273	\r
	274	SmiHandler->SmiEntry = SmiEntry;\r
	275	InsertTailList (List, &SmiHandler->Link);\r
	276	\r
	277	*DispatchHandle = (EFI_HANDLE) SmiHandler;\r
	278	\r
	279	return EFI_SUCCESS;\r
	280	}\r
	281	\r
282	/**\r
283	Unregister a handler in SMM.\r
284	\r
285	@param DispatchHandle The handle that was specified when the handler was registered.\r
286	\r
287	@retval EFI_SUCCESS Handler function was successfully unregistered.\r
288	@retval EFI_INVALID_PARAMETER DispatchHandle does not refer to a valid handle.\r
289	\r
290	**/\r
291	EFI_STATUS\r
292	EFIAPI\r
293	SmiHandlerUnRegister (\r
294	IN EFI_HANDLE DispatchHandle\r
295	)\r
296	{\r
297	SMI_HANDLER *SmiHandler;\r
298	SMI_ENTRY *SmiEntry;\r
299	\r
300	SmiHandler = (SMI_HANDLER *) DispatchHandle;\r
301	\r
302	if (SmiHandler == NULL) {\r
303	return EFI_INVALID_PARAMETER;\r
304	}\r
305	\r
306	if (SmiHandler->Signature != SMI_HANDLER_SIGNATURE) {\r
307	return EFI_INVALID_PARAMETER;\r
308	}\r
309	\r
310	SmiEntry = SmiHandler->SmiEntry;\r
311	\r
312	RemoveEntryList (&SmiHandler->Link);\r
313	FreePool (SmiHandler);\r
314	\r
315	if (SmiEntry == NULL) {\r
316	//\r
317	// This is root SMI handler\r
318	//\r
319	return EFI_SUCCESS;\r
320	}\r
321	\r
322	if (IsListEmpty (&SmiEntry->SmiHandlers)) {\r
323	//\r
324	// No handler registered for this interrupt now, remove the SMI_ENTRY\r
325	//\r
326	RemoveEntryList (&SmiEntry->AllEntries);\r
327	\r
328	FreePool (SmiEntry);\r
329	}\r
330	\r
331	return EFI_SUCCESS;\r
332	}\r