ArmPkg/Drivers/CpuDxe/AArch64/Exception.c

   1 /** @file
   2
   3   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   4   Portions Copyright (c) 2011 - 2013, ARM Ltd. All rights reserved.<BR>
   5
   6   This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #include "CpuDxe.h"
  17
  18 #include <Chipset/AArch64.h>
  19
  20 VOID
  21 ExceptionHandlersStart (
  22   VOID
  23   );
  24
  25 VOID
  26 ExceptionHandlersEnd (
  27   VOID
  28   );
  29
  30 VOID
  31 CommonExceptionEntry (
  32   VOID
  33   );
  34
  35 VOID
  36 AsmCommonExceptionEntry (
  37   VOID
  38   );
  39
  40
  41 EFI_EXCEPTION_CALLBACK  gExceptionHandlers[MAX_ARM_EXCEPTION + 1];
  42 EFI_EXCEPTION_CALLBACK  gDebuggerExceptionHandlers[MAX_ARM_EXCEPTION + 1];
  43
  44
  45
  46 /**
  47   This function registers and enables the handler specified by InterruptHandler for a processor
  48   interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
  49   handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
  50   The installed handler is called once for each processor interrupt or exception.
  51
  52   @param  InterruptType    A pointer to the processor's current interrupt state. Set to TRUE if interrupts
  53                            are enabled and FALSE if interrupts are disabled.
  54   @param  InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
  55                            when a processor interrupt occurs. If this parameter is NULL, then the handler
  56                            will be uninstalled.
  57
  58   @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
  59   @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was
  60                                 previously installed.
  61   @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
  62                                 previously installed.
  63   @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.
  64
  65 **/
  66 EFI_STATUS
  67 RegisterInterruptHandler (
  68   IN EFI_EXCEPTION_TYPE             InterruptType,
  69   IN EFI_CPU_INTERRUPT_HANDLER      InterruptHandler
  70   )
  71 {
  72   if (InterruptType > MAX_ARM_EXCEPTION) {
  73     return EFI_UNSUPPORTED;
  74   }
  75
  76   if ((InterruptHandler != NULL) && (gExceptionHandlers[InterruptType] != NULL)) {
  77     return EFI_ALREADY_STARTED;
  78   }
  79
  80   gExceptionHandlers[InterruptType] = InterruptHandler;
  81
  82   return EFI_SUCCESS;
  83 }
  84
  85
  86
  87 VOID
  88 EFIAPI
  89 CommonCExceptionHandler (
  90   IN     EFI_EXCEPTION_TYPE           ExceptionType,
  91   IN OUT EFI_SYSTEM_CONTEXT           SystemContext
  92   )
  93 {
  94   if (ExceptionType <= MAX_AARCH64_EXCEPTION) {
  95     if (gExceptionHandlers[ExceptionType]) {
  96       gExceptionHandlers[ExceptionType] (ExceptionType, SystemContext);
  97       return;
  98     }
  99   } else {
 100     DEBUG ((EFI_D_ERROR, "Unknown exception type %d from %016lx\n", ExceptionType, SystemContext.SystemContextAArch64->ELR));
 101     ASSERT (FALSE);
 102   }
 103
 104   DefaultExceptionHandler (ExceptionType, SystemContext);
 105 }
 106
 107
 108
 109 EFI_STATUS
 110 InitializeExceptions (
 111   IN EFI_CPU_ARCH_PROTOCOL    *Cpu
 112   )
 113 {
 114   EFI_STATUS           Status;
 115   BOOLEAN              IrqEnabled;
 116   BOOLEAN              FiqEnabled;
 117
 118   Status = EFI_SUCCESS;
 119   ZeroMem (gExceptionHandlers,sizeof(*gExceptionHandlers));
 120
 121   //
 122   // Disable interrupts
 123   //
 124   Cpu->GetInterruptState (Cpu, &IrqEnabled);
 125   Cpu->DisableInterrupt (Cpu);
 126
 127   //
 128   // EFI does not use the FIQ, but a debugger might so we must disable
 129   // as we take over the exception vectors.
 130   //
 131   FiqEnabled = ArmGetFiqState ();
 132   ArmDisableFiq ();
 133
 134   // AArch64 alignment? The Vector table must be 2k-byte aligned (bottom 11 bits zero)?
 135   //DEBUG ((EFI_D_ERROR, "vbar set addr: 0x%016lx\n",(UINTN)ExceptionHandlersStart));
 136   //ASSERT(((UINTN)ExceptionHandlersStart & ((1 << 11)-1)) == 0);
 137
 138   // We do not copy the Exception Table at PcdGet32(PcdCpuVectorBaseAddress). We just set Vector Base Address to point into CpuDxe code.
 139   ArmWriteVBar ((UINTN)ExceptionHandlersStart);
 140
 141   if (FiqEnabled) {
 142     ArmEnableFiq ();
 143   }
 144
 145   if (IrqEnabled) {
 146     //
 147     // Restore interrupt state
 148     //
 149     Status = Cpu->EnableInterrupt (Cpu);
 150   }
 151
 152   return Status;
 153 }