[mirror_edk2.git] / MdeModulePkg / Core / Pei / Dependency / Dependency.c

/** @file\r
  PEI Dispatcher Dependency Evaluator\r
\r
  This routine evaluates a dependency expression (DEPENDENCY_EXPRESSION) to determine\r
  if a driver can be scheduled for execution.  The criteria for\r
  schedulability is that the dependency expression is satisfied.\r
\r
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
This program and the accompanying materials\r
are licensed and made available under the terms and conditions of the BSD License\r
which accompanies this 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 "PeiMain.h"\r
#include "Dependency.h"\r
\r
/**\r
\r
  This routine determines if a PPI has been installed.\r
  The truth value of a GUID is determined by if the PPI has\r
  been published and can be queried from the PPI database.\r
\r
\r
  @param PeiServices     An indirect pointer to the EFI_PEI_SERVICES table published by the PEI Foundation\r
  @param Stack           Reference to EVAL_STACK_ENTRY that contains PPI GUID to check\r
\r
  @retval TRUE  if the PPI is already installed.\r
  @retval FALSE if the PPI has yet to be installed.\r
\r
**/\r
BOOLEAN\r
IsPpiInstalled (\r
  IN EFI_PEI_SERVICES  **PeiServices,\r
  IN EVAL_STACK_ENTRY  *Stack\r
  )\r
{\r
  VOID        *PeiInstance;\r
  EFI_STATUS  Status;\r
  EFI_GUID    PpiGuid;\r
\r
  //\r
  // If there is no GUID to evaluate, just return current result on stack.\r
  //\r
  if (Stack->Operator == NULL) {\r
    return Stack->Result;\r
  }\r
\r
  //\r
  // Copy the Guid into a locale variable so that there are no\r
  // possibilities of alignment faults for cross-compilation\r
  // environments such as Intel?Itanium(TM).\r
  //\r
  CopyMem(&PpiGuid, Stack->Operator, sizeof(EFI_GUID));\r
\r
  //\r
  // Check if the PPI is installed.\r
  //\r
  Status = PeiServicesLocatePpi(\r
             &PpiGuid,        // GUID\r
             0,               // INSTANCE\r
             NULL,            // EFI_PEI_PPI_DESCRIPTOR\r
             &PeiInstance     // PPI\r
             );\r
\r
  if (EFI_ERROR(Status)) {\r
    return FALSE;\r
  }\r
\r
  return TRUE;\r
}\r
\r
/**\r
\r
  This is the POSTFIX version of the dependency evaluator.  When a\r
  PUSH [PPI GUID] is encountered, a pointer to the GUID is stored on\r
  the evaluation stack.  When that entry is poped from the evaluation\r
  stack, the PPI is checked if it is installed.  This method allows\r
  some time savings as not all PPIs must be checked for certain\r
  operation types (AND, OR).\r
\r
\r
  @param PeiServices            An indirect pointer to the EFI_PEI_SERVICES table published by the PEI Foundation\r
  @param DependencyExpression   Pointer to a dependency expression.  The Grammar adheres to\r
                                the BNF described above and is stored in postfix notation.\r
\r
  @retval TRUE      if it is a well-formed Grammar\r
  @retval FALSE     if the dependency expression overflows the evaluation stack\r
                    if the dependency expression underflows the evaluation stack\r
                    if the dependency expression is not a well-formed Grammar.\r
\r
**/\r
BOOLEAN\r
PeimDispatchReadiness (\r
  IN EFI_PEI_SERVICES   **PeiServices,\r
  IN VOID               *DependencyExpression\r
  )\r
{\r
  DEPENDENCY_EXPRESSION_OPERAND  *Iterator;\r
  EVAL_STACK_ENTRY               *StackPtr;\r
  EVAL_STACK_ENTRY               EvalStack[MAX_GRAMMAR_SIZE];\r
\r
  Iterator  = DependencyExpression;\r
\r
  StackPtr = EvalStack;\r
\r
  while (TRUE) {\r
\r
    switch (*(Iterator++)) {\r
\r
      //\r
      // For performance reason we put the frequently used items in front of\r
      // the rarely used  items\r
      //\r
\r
      case (EFI_DEP_PUSH):\r
        //\r
        // Check to make sure the dependency grammar doesn't overflow the\r
        // EvalStack on the push\r
        //\r
        if (StackPtr > &EvalStack[MAX_GRAMMAR_SIZE-1]) {\r
          DEBUG ((DEBUG_DISPATCH, "  RESULT = FALSE (Underflow Error)\n"));\r
          return FALSE;\r
        }\r
\r
        //\r
        // Push the pointer to the PUSH opcode operator (pointer to PPI GUID)\r
        // We will evaluate if the PPI is insalled on the POP operation.\r
        //\r
        StackPtr->Operator = (VOID *) Iterator;\r
        Iterator = Iterator + sizeof (EFI_GUID);\r
        DEBUG ((DEBUG_DISPATCH, "  PUSH GUID(%g) = %a\n", StackPtr->Operator, IsPpiInstalled (PeiServices, StackPtr) ? "TRUE" : "FALSE"));\r
        StackPtr++;\r
        break;\r
\r
      case (EFI_DEP_AND):\r
      case (EFI_DEP_OR):\r
        if (*(Iterator - 1) == EFI_DEP_AND) {\r
          DEBUG ((DEBUG_DISPATCH, "  AND\n"));\r
        } else {\r
          DEBUG ((DEBUG_DISPATCH, "  OR\n"));\r
        }\r
        //\r
        // Check to make sure the dependency grammar doesn't underflow the\r
        // EvalStack on the two POPs for the AND operation.  Don't need to\r
        // check for the overflow on PUSHing the result since we already\r
        // did two POPs.\r
        //\r
        if (StackPtr < &EvalStack[2]) {\r
          DEBUG ((DEBUG_DISPATCH, "  RESULT = FALSE (Underflow Error)\n"));\r
          return FALSE;\r
        }\r
\r
        //\r
        // Evaluate the first POPed operator only. If the operand is\r
        // EFI_DEP_AND and the POPed operator evaluates to FALSE, or the\r
        // operand is EFI_DEP_OR and the POPed operator evaluates to TRUE,\r
        // we don't need to check the second operator, and the result will be\r
        // evaluation of the POPed operator. Otherwise, don't POP the second\r
        // operator since it will now evaluate to the final result on the\r
        // next operand that causes a POP.\r
        //\r
        StackPtr--;\r
        //\r
        // Iterator has increased by 1 after we retrieve the operand, so here we\r
        // should get the value pointed by (Iterator - 1), in order to obtain the\r
        // same operand.\r
        //\r
        if (*(Iterator - 1) == EFI_DEP_AND) {\r
          if (!(IsPpiInstalled (PeiServices, StackPtr))) {\r
            (StackPtr-1)->Result = FALSE;\r
            (StackPtr-1)->Operator = NULL;\r
          }\r
        } else {\r
          if (IsPpiInstalled (PeiServices, StackPtr)) {\r
            (StackPtr-1)->Result = TRUE;\r
            (StackPtr-1)->Operator = NULL;\r
          }\r
        }\r
        break;\r
\r
      case (EFI_DEP_END):\r
        DEBUG ((DEBUG_DISPATCH, "  END\n"));\r
        StackPtr--;\r
        //\r
        // Check to make sure EvalStack is balanced.  If not, then there is\r
        // an error in the dependency grammar, so return EFI_INVALID_PARAMETER.\r
        //\r
        if (StackPtr != &EvalStack[0]) {\r
          DEBUG ((DEBUG_DISPATCH, "  RESULT = FALSE (Underflow Error)\n"));\r
          return FALSE;\r
        }\r
        DEBUG ((DEBUG_DISPATCH, "  RESULT = %a\n", IsPpiInstalled (PeiServices, StackPtr) ? "TRUE" : "FALSE"));\r
        return IsPpiInstalled (PeiServices, StackPtr);\r
\r
      case (EFI_DEP_NOT):\r
        DEBUG ((DEBUG_DISPATCH, "  NOT\n"));\r
        //\r
        // Check to make sure the dependency grammar doesn't underflow the\r
        // EvalStack on the POP for the NOT operation.  Don't need to\r
        // check for the overflow on PUSHing the result since we already\r
        // did a POP.\r
        //\r
        if (StackPtr < &EvalStack[1]) {\r
          DEBUG ((DEBUG_DISPATCH, "  RESULT = FALSE (Underflow Error)\n"));\r
          return FALSE;\r
        }\r
        (StackPtr-1)->Result = (BOOLEAN) !IsPpiInstalled (PeiServices, (StackPtr-1));\r
        (StackPtr-1)->Operator = NULL;\r
        break;\r
\r
      case (EFI_DEP_TRUE):\r
      case (EFI_DEP_FALSE):\r
        if (*(Iterator - 1) == EFI_DEP_TRUE) {\r
          DEBUG ((DEBUG_DISPATCH, "  TRUE\n"));\r
        } else {\r
          DEBUG ((DEBUG_DISPATCH, "  FALSE\n"));\r
        }\r
        //\r
        // Check to make sure the dependency grammar doesn't overflow the\r
        // EvalStack on the push\r
        //\r
        if (StackPtr > &EvalStack[MAX_GRAMMAR_SIZE-1]) {\r
          DEBUG ((DEBUG_DISPATCH, "  RESULT = FALSE (Underflow Error)\n"));\r
          return FALSE;\r
        }\r
        //\r
        // Iterator has increased by 1 after we retrieve the operand, so here we\r
        // should get the value pointed by (Iterator - 1), in order to obtain the\r
        // same operand.\r
        //\r
        if (*(Iterator - 1) == EFI_DEP_TRUE) {\r
          StackPtr->Result = TRUE;\r
        } else {\r
          StackPtr->Result = FALSE;\r
        }\r
        StackPtr->Operator = NULL;\r
        StackPtr++;\r
        break;\r
\r
      default:\r
        DEBUG ((DEBUG_DISPATCH, "  RESULT = FALSE (Invalid opcode)\n"));\r
        //\r
        // The grammar should never arrive here\r
        //\r
        return FALSE;\r
    }\r
  }\r
}\r
Commit	Line	Data
	1	/** @file\r
	2	PEI Dispatcher Dependency Evaluator\r
	3	\r
	4	This routine evaluates a dependency expression (DEPENDENCY_EXPRESSION) to determine\r
	5	if a driver can be scheduled for execution. The criteria for\r
	6	schedulability is that the dependency expression is satisfied.\r
	7	\r
	8	Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
	9	This program and the accompanying materials\r
	10	are licensed and made available under the terms and conditions of the BSD License\r
	11	which accompanies this distribution. The full text of the license may be found at\r
	12	http://opensource.org/licenses/bsd-license.php\r
	13	\r
	14	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	15	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	16	\r
	17	**/\r
	18	\r
	19	#include "PeiMain.h"\r
	20	#include "Dependency.h"\r
	21	\r
	22	/**\r
	23	\r
	24	This routine determines if a PPI has been installed.\r
	25	The truth value of a GUID is determined by if the PPI has\r
	26	been published and can be queried from the PPI database.\r
	27	\r
	28	\r
	29	@param PeiServices An indirect pointer to the EFI_PEI_SERVICES table published by the PEI Foundation\r
	30	@param Stack Reference to EVAL_STACK_ENTRY that contains PPI GUID to check\r
	31	\r
	32	@retval TRUE if the PPI is already installed.\r
	33	@retval FALSE if the PPI has yet to be installed.\r
	34	\r
	35	**/\r
	36	BOOLEAN\r
	37	IsPpiInstalled (\r
	38	IN EFI_PEI_SERVICES **PeiServices,\r
	39	IN EVAL_STACK_ENTRY *Stack\r
	40	)\r
	41	{\r
	42	VOID *PeiInstance;\r
	43	EFI_STATUS Status;\r
	44	EFI_GUID PpiGuid;\r
	45	\r
	46	//\r
	47	// If there is no GUID to evaluate, just return current result on stack.\r
	48	//\r
	49	if (Stack->Operator == NULL) {\r
	50	return Stack->Result;\r
	51	}\r
	52	\r
	53	//\r
	54	// Copy the Guid into a locale variable so that there are no\r
	55	// possibilities of alignment faults for cross-compilation\r
	56	// environments such as Intel?Itanium(TM).\r
	57	//\r
	58	CopyMem(&PpiGuid, Stack->Operator, sizeof(EFI_GUID));\r
	59	\r
	60	//\r
	61	// Check if the PPI is installed.\r
	62	//\r
	63	Status = PeiServicesLocatePpi(\r
	64	&PpiGuid, // GUID\r
	65	0, // INSTANCE\r
	66	NULL, // EFI_PEI_PPI_DESCRIPTOR\r
	67	&PeiInstance // PPI\r
	68	);\r
	69	\r
	70	if (EFI_ERROR(Status)) {\r
	71	return FALSE;\r
	72	}\r
	73	\r
	74	return TRUE;\r
	75	}\r
	76	\r
	77	/**\r
	78	\r
	79	This is the POSTFIX version of the dependency evaluator. When a\r
	80	PUSH [PPI GUID] is encountered, a pointer to the GUID is stored on\r
	81	the evaluation stack. When that entry is poped from the evaluation\r
	82	stack, the PPI is checked if it is installed. This method allows\r
	83	some time savings as not all PPIs must be checked for certain\r
	84	operation types (AND, OR).\r
	85	\r
	86	\r
	87	@param PeiServices An indirect pointer to the EFI_PEI_SERVICES table published by the PEI Foundation\r
	88	@param DependencyExpression Pointer to a dependency expression. The Grammar adheres to\r
	89	the BNF described above and is stored in postfix notation.\r
	90	\r
	91	@retval TRUE if it is a well-formed Grammar\r
	92	@retval FALSE if the dependency expression overflows the evaluation stack\r
	93	if the dependency expression underflows the evaluation stack\r
	94	if the dependency expression is not a well-formed Grammar.\r
	95	\r
	96	**/\r
	97	BOOLEAN\r
	98	PeimDispatchReadiness (\r
	99	IN EFI_PEI_SERVICES **PeiServices,\r
	100	IN VOID *DependencyExpression\r
	101	)\r
	102	{\r
	103	DEPENDENCY_EXPRESSION_OPERAND *Iterator;\r
	104	EVAL_STACK_ENTRY *StackPtr;\r
	105	EVAL_STACK_ENTRY EvalStack[MAX_GRAMMAR_SIZE];\r
	106	\r
	107	Iterator = DependencyExpression;\r
	108	\r
	109	StackPtr = EvalStack;\r
	110	\r
	111	while (TRUE) {\r
	112	\r
	113	switch (*(Iterator++)) {\r
	114	\r
	115	//\r
	116	// For performance reason we put the frequently used items in front of\r
	117	// the rarely used items\r
	118	//\r
	119	\r
	120	case (EFI_DEP_PUSH):\r
	121	//\r
	122	// Check to make sure the dependency grammar doesn't overflow the\r
	123	// EvalStack on the push\r
	124	//\r
	125	if (StackPtr > &EvalStack[MAX_GRAMMAR_SIZE-1]) {\r
	126	DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Underflow Error)\n"));\r
	127	return FALSE;\r
	128	}\r
	129	\r
	130	//\r
	131	// Push the pointer to the PUSH opcode operator (pointer to PPI GUID)\r
	132	// We will evaluate if the PPI is insalled on the POP operation.\r
	133	//\r
	134	StackPtr->Operator = (VOID *) Iterator;\r
	135	Iterator = Iterator + sizeof (EFI_GUID);\r
	136	DEBUG ((DEBUG_DISPATCH, " PUSH GUID(%g) = %a\n", StackPtr->Operator, IsPpiInstalled (PeiServices, StackPtr) ? "TRUE" : "FALSE"));\r
	137	StackPtr++;\r
	138	break;\r
	139	\r
	140	case (EFI_DEP_AND):\r
	141	case (EFI_DEP_OR):\r
	142	if (*(Iterator - 1) == EFI_DEP_AND) {\r
	143	DEBUG ((DEBUG_DISPATCH, " AND\n"));\r
	144	} else {\r
	145	DEBUG ((DEBUG_DISPATCH, " OR\n"));\r
	146	}\r
	147	//\r
	148	// Check to make sure the dependency grammar doesn't underflow the\r
	149	// EvalStack on the two POPs for the AND operation. Don't need to\r
	150	// check for the overflow on PUSHing the result since we already\r
	151	// did two POPs.\r
	152	//\r
	153	if (StackPtr < &EvalStack[2]) {\r
	154	DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Underflow Error)\n"));\r
	155	return FALSE;\r
	156	}\r
	157	\r
	158	//\r
	159	// Evaluate the first POPed operator only. If the operand is\r
	160	// EFI_DEP_AND and the POPed operator evaluates to FALSE, or the\r
	161	// operand is EFI_DEP_OR and the POPed operator evaluates to TRUE,\r
	162	// we don't need to check the second operator, and the result will be\r
	163	// evaluation of the POPed operator. Otherwise, don't POP the second\r
	164	// operator since it will now evaluate to the final result on the\r
	165	// next operand that causes a POP.\r
	166	//\r
	167	StackPtr--;\r
	168	//\r
	169	// Iterator has increased by 1 after we retrieve the operand, so here we\r
	170	// should get the value pointed by (Iterator - 1), in order to obtain the\r
	171	// same operand.\r
	172	//\r
	173	if (*(Iterator - 1) == EFI_DEP_AND) {\r
	174	if (!(IsPpiInstalled (PeiServices, StackPtr))) {\r
	175	(StackPtr-1)->Result = FALSE;\r
	176	(StackPtr-1)->Operator = NULL;\r
	177	}\r
	178	} else {\r
	179	if (IsPpiInstalled (PeiServices, StackPtr)) {\r
	180	(StackPtr-1)->Result = TRUE;\r
	181	(StackPtr-1)->Operator = NULL;\r
	182	}\r
	183	}\r
	184	break;\r
	185	\r
	186	case (EFI_DEP_END):\r
	187	DEBUG ((DEBUG_DISPATCH, " END\n"));\r
	188	StackPtr--;\r
	189	//\r
	190	// Check to make sure EvalStack is balanced. If not, then there is\r
	191	// an error in the dependency grammar, so return EFI_INVALID_PARAMETER.\r
	192	//\r
	193	if (StackPtr != &EvalStack[0]) {\r
	194	DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Underflow Error)\n"));\r
	195	return FALSE;\r
	196	}\r
	197	DEBUG ((DEBUG_DISPATCH, " RESULT = %a\n", IsPpiInstalled (PeiServices, StackPtr) ? "TRUE" : "FALSE"));\r
	198	return IsPpiInstalled (PeiServices, StackPtr);\r
	199	\r
	200	case (EFI_DEP_NOT):\r
	201	DEBUG ((DEBUG_DISPATCH, " NOT\n"));\r
	202	//\r
	203	// Check to make sure the dependency grammar doesn't underflow the\r
	204	// EvalStack on the POP for the NOT operation. Don't need to\r
	205	// check for the overflow on PUSHing the result since we already\r
	206	// did a POP.\r
	207	//\r
	208	if (StackPtr < &EvalStack[1]) {\r
	209	DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Underflow Error)\n"));\r
	210	return FALSE;\r
	211	}\r
	212	(StackPtr-1)->Result = (BOOLEAN) !IsPpiInstalled (PeiServices, (StackPtr-1));\r
	213	(StackPtr-1)->Operator = NULL;\r
	214	break;\r
	215	\r
	216	case (EFI_DEP_TRUE):\r
	217	case (EFI_DEP_FALSE):\r
	218	if (*(Iterator - 1) == EFI_DEP_TRUE) {\r
	219	DEBUG ((DEBUG_DISPATCH, " TRUE\n"));\r
	220	} else {\r
	221	DEBUG ((DEBUG_DISPATCH, " FALSE\n"));\r
	222	}\r
	223	//\r
	224	// Check to make sure the dependency grammar doesn't overflow the\r
	225	// EvalStack on the push\r
	226	//\r
	227	if (StackPtr > &EvalStack[MAX_GRAMMAR_SIZE-1]) {\r
	228	DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Underflow Error)\n"));\r
	229	return FALSE;\r
	230	}\r
	231	//\r
	232	// Iterator has increased by 1 after we retrieve the operand, so here we\r
	233	// should get the value pointed by (Iterator - 1), in order to obtain the\r
	234	// same operand.\r
	235	//\r
	236	if (*(Iterator - 1) == EFI_DEP_TRUE) {\r
	237	StackPtr->Result = TRUE;\r
	238	} else {\r
	239	StackPtr->Result = FALSE;\r
	240	}\r
	241	StackPtr->Operator = NULL;\r
	242	StackPtr++;\r
	243	break;\r
	244	\r
	245	default:\r
	246	DEBUG ((DEBUG_DISPATCH, " RESULT = FALSE (Invalid opcode)\n"));\r
	247	//\r
	248	// The grammar should never arrive here\r
	249	//\r
	250	return FALSE;\r
	251	}\r
	252	}\r
	253	}\r