ArmPkg/Drivers/CpuDxe/Exception.c

   1 /** @file
   2
   3   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   4   Portions Copyright (c) 2011 - 2021, Arm Limited. All rights reserved.<BR>
   5
   6   SPDX-License-Identifier: BSD-2-Clause-Patent
   7
   8 **/
   9
  10 #include "CpuDxe.h"
  11 #include <Library/CpuExceptionHandlerLib.h>
  12 #include <Guid/VectorHandoffTable.h>
  13
  14 EFI_STATUS
  15 InitializeExceptions (
  16   IN EFI_CPU_ARCH_PROTOCOL  *Cpu
  17   )
  18 {
  19   EFI_STATUS               Status;
  20   EFI_VECTOR_HANDOFF_INFO  *VectorInfoList;
  21   EFI_VECTOR_HANDOFF_INFO  *VectorInfo;
  22   BOOLEAN                  IrqEnabled;
  23   BOOLEAN                  FiqEnabled;
  24
  25   VectorInfo = (EFI_VECTOR_HANDOFF_INFO *)NULL;
  26   Status     = EfiGetSystemConfigurationTable (&gEfiVectorHandoffTableGuid, (VOID **)&VectorInfoList);
  27   if ((Status == EFI_SUCCESS) && (VectorInfoList != NULL)) {
  28     VectorInfo = VectorInfoList;
  29   }
  30
  31   // initialize the CpuExceptionHandlerLib so we take over the exception vector table from the DXE Core
  32   InitializeCpuExceptionHandlers (VectorInfo);
  33
  34   Status = EFI_SUCCESS;
  35
  36   //
  37   // Disable interrupts
  38   //
  39   Cpu->GetInterruptState (Cpu, &IrqEnabled);
  40   Cpu->DisableInterrupt (Cpu);
  41
  42   //
  43   // EFI does not use the FIQ, but a debugger might so we must disable
  44   // as we take over the exception vectors.
  45   //
  46   FiqEnabled = ArmGetFiqState ();
  47   ArmDisableFiq ();
  48
  49   if (FiqEnabled) {
  50     ArmEnableFiq ();
  51   }
  52
  53   if (IrqEnabled) {
  54     //
  55     // Restore interrupt state
  56     //
  57     Status = Cpu->EnableInterrupt (Cpu);
  58   }
  59
  60   //
  61   // On a DEBUG build, unmask SErrors so they are delivered right away rather
  62   // than when the OS unmasks them. This gives us a better chance of figuring
  63   // out the cause.
  64   //
  65   DEBUG_CODE (
  66     ArmEnableAsynchronousAbort ();
  67     );
  68
  69   return Status;
  70 }
  71
  72 /**
  73 This function registers and enables the handler specified by InterruptHandler for a processor
  74 interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
  75 handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
  76 The installed handler is called once for each processor interrupt or exception.
  77
  78 @param  InterruptType    A pointer to the processor's current interrupt state. Set to TRUE if interrupts
  79 are enabled and FALSE if interrupts are disabled.
  80 @param  InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
  81 when a processor interrupt occurs. If this parameter is NULL, then the handler
  82 will be uninstalled.
  83
  84 @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
  85 @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was
  86 previously installed.
  87 @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
  88 previously installed.
  89 @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.
  90
  91 **/
  92 EFI_STATUS
  93 RegisterInterruptHandler (
  94   IN EFI_EXCEPTION_TYPE         InterruptType,
  95   IN EFI_CPU_INTERRUPT_HANDLER  InterruptHandler
  96   )
  97 {
  98   // pass down to CpuExceptionHandlerLib
  99   return (EFI_STATUS)RegisterCpuInterruptHandler (InterruptType, InterruptHandler);
 100 }