+++ /dev/null
-/*++ \r
-\r
-Copyright (c) 2006, Intel Corporation \r
-All rights reserved. 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
-Module Name:\r
-\r
- dependency.c\r
-\r
-Abstract:\r
-\r
- DXE 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
---*/\r
-\r
-#include <DxeMain.h>\r
-\r
-//\r
-// Global stack used to evaluate dependency expressions\r
-//\r
-BOOLEAN *mDepexEvaluationStack = NULL;\r
-BOOLEAN *mDepexEvaluationStackEnd = NULL;\r
-BOOLEAN *mDepexEvaluationStackPointer = NULL;\r
-\r
-//\r
-// Worker functions\r
-//\r
-\r
-STATIC\r
-EFI_STATUS\r
-GrowDepexStack (\r
- VOID\r
- )\r
-/*++\r
-\r
-Routine Description:\r
-\r
- Grow size of the Depex stack\r
-\r
-Arguments:\r
-\r
- Stack - Old stack on the way in and new stack on the way out\r
-\r
- StackSize - New size of the stack\r
-\r
-Returns:\r
-\r
- EFI_SUCCESS - Stack successfully growed.\r
- \r
- EFI_OUT_OF_RESOURCES - There is not enough system memory to grow the stack.\r
- \r
- \r
-\r
---*/\r
-{\r
- BOOLEAN *NewStack;\r
- UINTN Size;\r
-\r
- Size = DEPEX_STACK_SIZE_INCREMENT;\r
- if (mDepexEvaluationStack != NULL) {\r
- Size = Size + (mDepexEvaluationStackEnd - mDepexEvaluationStack);\r
- }\r
-\r
- NewStack = CoreAllocateBootServicesPool (Size * sizeof (BOOLEAN));\r
- if (NewStack == NULL) {\r
- return EFI_OUT_OF_RESOURCES;\r
- }\r
-\r
- if (mDepexEvaluationStack != NULL) {\r
- //\r
- // Copy to Old Stack to the New Stack\r
- //\r
- CopyMem (\r
- NewStack, \r
- mDepexEvaluationStack, \r
- (mDepexEvaluationStackEnd - mDepexEvaluationStack) * sizeof (BOOLEAN)\r
- );\r
-\r
- //\r
- // Free The Old Stack\r
- //\r
- CoreFreePool (mDepexEvaluationStack);\r
- }\r
-\r
- //\r
- // Make the Stack pointer point to the old data in the new stack\r
- //\r
- mDepexEvaluationStackPointer = NewStack + (mDepexEvaluationStackPointer - mDepexEvaluationStack);\r
- mDepexEvaluationStack = NewStack;\r
- mDepexEvaluationStackEnd = NewStack + Size;\r
-\r
- return EFI_SUCCESS;\r
-}\r
-\r
-\r
-STATIC\r
-EFI_STATUS\r
-PushBool (\r
- IN BOOLEAN Value\r
- )\r
-/*++\r
-\r
-Routine Description:\r
-\r
- Push an element onto the Boolean Stack\r
-\r
-Arguments:\r
-\r
- Value - BOOLEAN to push.\r
-\r
-Returns:\r
-\r
- EFI_SUCCESS - The value was pushed onto the stack.\r
-\r
- EFI_OUT_OF_RESOURCES - There is not enough system memory to grow the stack.\r
-\r
---*/\r
-{\r
- EFI_STATUS Status;\r
-\r
- //\r
- // Check for a stack overflow condition\r
- //\r
- if (mDepexEvaluationStackPointer == mDepexEvaluationStackEnd) {\r
- //\r
- // Grow the stack\r
- //\r
- Status = GrowDepexStack ();\r
- if (EFI_ERROR (Status)) {\r
- return Status;\r
- }\r
- }\r
-\r
- //\r
- // Push the item onto the stack\r
- //\r
- *mDepexEvaluationStackPointer = Value;\r
- mDepexEvaluationStackPointer++;\r
-\r
- return EFI_SUCCESS;\r
-}\r
-\r
-\r
-STATIC\r
-EFI_STATUS \r
-PopBool (\r
- OUT BOOLEAN *Value\r
- )\r
-/*++\r
-\r
-Routine Description:\r
-\r
- Pop an element from the Boolean stack.\r
-\r
-Arguments:\r
-\r
- Value - BOOLEAN to pop.\r
-\r
-Returns:\r
-\r
- EFI_SUCCESS - The value was popped onto the stack.\r
-\r
- EFI_ACCESS_DENIED - The pop operation underflowed the stack\r
-\r
---*/\r
-{\r
- //\r
- // Check for a stack underflow condition\r
- //\r
- if (mDepexEvaluationStackPointer == mDepexEvaluationStack) {\r
- return EFI_ACCESS_DENIED;\r
- }\r
-\r
- //\r
- // Pop the item off the stack\r
- //\r
- mDepexEvaluationStackPointer--;\r
- *Value = *mDepexEvaluationStackPointer;\r
- return EFI_SUCCESS; \r
-}\r
-\r
-\r
-EFI_STATUS\r
-CorePreProcessDepex (\r
- IN EFI_CORE_DRIVER_ENTRY *DriverEntry \r
- )\r
-/*++\r
-\r
-Routine Description:\r
-\r
- Preprocess dependency expression and update DriverEntry to reflect the\r
- state of Before, After, and SOR dependencies. If DriverEntry->Before\r
- or DriverEntry->After is set it will never be cleared. If SOR is set\r
- it will be cleared by CoreSchedule(), and then the driver can be \r
- dispatched.\r
-\r
-Arguments:\r
-\r
- DriverEntry - DriverEntry element to update\r
-\r
-Returns:\r
-\r
- EFI_SUCCESS - It always works.\r
-\r
---*/\r
-{\r
- UINT8 *Iterator;\r
- \r
- Iterator = DriverEntry->Depex;\r
- if (*Iterator == EFI_DEP_SOR) {\r
- DriverEntry->Unrequested = TRUE;\r
- } else {\r
- DriverEntry->Dependent = TRUE;\r
- }\r
- \r
- if (*Iterator == EFI_DEP_BEFORE) {\r
- DriverEntry->Before = TRUE;\r
- } else if (*Iterator == EFI_DEP_AFTER) {\r
- DriverEntry->After = TRUE;\r
- } \r
-\r
- if (DriverEntry->Before || DriverEntry->After) {\r
- CopyMem (&DriverEntry->BeforeAfterGuid, Iterator + 1, sizeof (EFI_GUID));\r
- }\r
-\r
- return EFI_SUCCESS;\r
-}\r
-\r
-\r
-BOOLEAN\r
-CoreIsSchedulable (\r
- IN EFI_CORE_DRIVER_ENTRY *DriverEntry \r
- )\r
-/*++\r
-\r
-Routine Description:\r
-\r
- This is the POSTFIX version of the dependency evaluator. This code does \r
- not need to handle Before or After, as it is not valid to call this \r
- routine in this case. The SOR is just ignored and is a nop in the grammer.\r
-\r
- POSTFIX means all the math is done on top of the stack.\r
-\r
-Arguments:\r
-\r
- DriverEntry - DriverEntry element to update\r
- \r
-Returns:\r
-\r
- TRUE - If driver is ready to run.\r
-\r
- FALSE - If driver is not ready to run or some fatal error was found.\r
-\r
---*/\r
-{\r
- EFI_STATUS Status;\r
- UINT8 *Iterator;\r
- BOOLEAN Operator;\r
- BOOLEAN Operator2;\r
- EFI_GUID DriverGuid;\r
- VOID *Interface;\r
-\r
- if (DriverEntry->After || DriverEntry->Before) {\r
- //\r
- // If Before or After Depex skip as CoreInsertOnScheduledQueueWhileProcessingBeforeAndAfter ()\r
- // processes them.\r
- //\r
- return FALSE;\r
- }\r
-\r
- if (DriverEntry->Depex == NULL) {\r
- //\r
- // A NULL Depex means treat the driver like an EFI 1.0 thing.\r
- //\r
- Status = CoreAllEfiServicesAvailable ();\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
- return TRUE;\r
- }\r
-\r
- //\r
- // Clean out memory leaks in Depex Boolean stack. Leaks are only caused by\r
- // incorrectly formed DEPEX expressions\r
- //\r
- mDepexEvaluationStackPointer = mDepexEvaluationStack;\r
-\r
-\r
- Iterator = DriverEntry->Depex;\r
- \r
- while (TRUE) {\r
- //\r
- // Check to see if we are attempting to fetch dependency expression instructions\r
- // past the end of the dependency expression.\r
- //\r
- if (((UINTN)Iterator - (UINTN)DriverEntry->Depex) >= DriverEntry->DepexSize) {\r
- return FALSE;\r
- }\r
-\r
- //\r
- // Look at the opcode of the dependency expression instruction.\r
- //\r
- switch (*Iterator) {\r
- case EFI_DEP_BEFORE:\r
- case EFI_DEP_AFTER:\r
- //\r
- // For a well-formed Dependency Expression, the code should never get here.\r
- // The BEFORE and AFTER are processed prior to this routine's invocation.\r
- // If the code flow arrives at this point, there was a BEFORE or AFTER\r
- // that were not the first opcodes.\r
- //\r
- ASSERT (FALSE);\r
- case EFI_DEP_SOR:\r
- //\r
- // These opcodes can only appear once as the first opcode. If it is found \r
- // at any other location, then the dependency expression evaluates to FALSE\r
- //\r
- if (Iterator != DriverEntry->Depex) {\r
- return FALSE;\r
- }\r
- //\r
- // Otherwise, it is the first opcode and should be treated as a NOP.\r
- //\r
- break;\r
-\r
- case EFI_DEP_PUSH: \r
- //\r
- // Push operator is followed by a GUID. Test to see if the GUID protocol\r
- // is installed and push the boolean result on the stack.\r
- //\r
- CopyMem (&DriverGuid, Iterator + 1, sizeof (EFI_GUID));\r
-\r
- Status = CoreLocateProtocol (&DriverGuid, NULL, &Interface);\r
-\r
- if (EFI_ERROR (Status)) {\r
- Status = PushBool (FALSE);\r
- } else {\r
- *Iterator = EFI_DEP_REPLACE_TRUE;\r
- Status = PushBool (TRUE);\r
- }\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
-\r
- Iterator += sizeof (EFI_GUID);\r
- break;\r
-\r
- case EFI_DEP_AND: \r
- Status = PopBool (&Operator);\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
-\r
- Status = PopBool (&Operator2);\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
-\r
- Status = PushBool ((BOOLEAN)(Operator && Operator2));\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
- break;\r
-\r
- case EFI_DEP_OR: \r
- Status = PopBool (&Operator);\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
-\r
- Status = PopBool (&Operator2);\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
-\r
- Status = PushBool ((BOOLEAN)(Operator || Operator2));\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
- break;\r
-\r
- case EFI_DEP_NOT: \r
- Status = PopBool (&Operator);\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
-\r
- Status = PushBool ((BOOLEAN)(!Operator));\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
- break;\r
-\r
- case EFI_DEP_TRUE: \r
- Status = PushBool (TRUE);\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
- break;\r
-\r
- case EFI_DEP_FALSE: \r
- Status = PushBool (FALSE);\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
- break;\r
-\r
- case EFI_DEP_END: \r
- Status = PopBool (&Operator);\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
- return Operator;\r
-\r
- case EFI_DEP_REPLACE_TRUE:\r
- Status = PushBool (TRUE);\r
- if (EFI_ERROR (Status)) {\r
- return FALSE;\r
- }\r
-\r
- Iterator += sizeof (EFI_GUID);\r
- break;\r
-\r
- default: \r
- goto Done;\r
- }\r
- \r
- //\r
- // Skip over the Dependency Op Code we just processed in the switch.\r
- // The math is done out of order, but it should not matter. That is\r
- // we may add in the sizeof (EFI_GUID) before we account for the OP Code.\r
- // This is not an issue, since we just need the correct end result. You\r
- // need to be careful using Iterator in the loop as it's intermediate value\r
- // may be strange.\r
- //\r
- Iterator++;\r
- }\r
-\r
-Done:\r
- return FALSE;\r
-}\r
-\r
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