ArmPkg/Drivers/CpuDxe/Exception.c

   1 /** @file
   2
   3   Copyright (c) 2008-2009, Apple Inc. All rights reserved.
   4
   5   All rights reserved. This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include "CpuDxe.h"
  16 #include <Library/CacheMaintenanceLib.h>
  17
  18 extern BOOLEAN gExceptionContext;
  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   This function registers and enables the handler specified by InterruptHandler for a processor
  88   interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
  89   handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
  90   The installed handler is called once for each processor interrupt or exception.
  91
  92   @param  InterruptType    A pointer to the processor's current interrupt state. Set to TRUE if interrupts
  93                            are enabled and FALSE if interrupts are disabled.
  94   @param  InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
  95                            when a processor interrupt occurs. If this parameter is NULL, then the handler
  96                            will be uninstalled.
  97
  98   @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
  99   @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was
 100                                 previously installed.
 101   @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
 102                                 previously installed.
 103   @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.
 104
 105 **/
 106 EFI_STATUS
 107 RegisterDebuggerInterruptHandler (
 108   IN EFI_EXCEPTION_TYPE             InterruptType,
 109   IN EFI_CPU_INTERRUPT_HANDLER      InterruptHandler
 110   )
 111 {
 112   if (InterruptType > MAX_ARM_EXCEPTION) {
 113     return EFI_UNSUPPORTED;
 114   }
 115
 116   if ((InterruptHandler != NULL) && (gDebuggerExceptionHandlers[InterruptType] != NULL)) {
 117     return EFI_ALREADY_STARTED;
 118   }
 119
 120   gDebuggerExceptionHandlers[InterruptType] = InterruptHandler;
 121
 122   return EFI_SUCCESS;
 123 }
 124
 125 CHAR8 *gExceptionTypeString[] = {
 126   "Reset",
 127   "Undefined Instruction",
 128   "SWI",
 129   "Prefetch Abort",
 130   "Data Abort",
 131   "Undefined",
 132   "IRQ",
 133   "FIQ"
 134 };
 135
 136 VOID
 137 EFIAPI
 138 CommonCExceptionHandler (
 139   IN     EFI_EXCEPTION_TYPE           ExceptionType,
 140   IN OUT EFI_SYSTEM_CONTEXT           SystemContext
 141   )
 142 {
 143   BOOLEAN Dispatched = FALSE;
 144
 145   gExceptionContext = TRUE;
 146
 147   if (ExceptionType <= MAX_ARM_EXCEPTION) {
 148     if (gDebuggerExceptionHandlers[ExceptionType]) {
 149       //
 150       // If DebugSupport hooked the interrupt call the handler. This does not disable
 151       // the normal handler.
 152       //
 153       gDebuggerExceptionHandlers[ExceptionType] (ExceptionType, SystemContext);
 154       Dispatched = TRUE;
 155     }
 156     if (gExceptionHandlers[ExceptionType]) {
 157       gExceptionHandlers[ExceptionType] (ExceptionType, SystemContext);
 158       Dispatched = TRUE;
 159     }
 160   } else {
 161     DEBUG ((EFI_D_ERROR, "Unknown exception type %d from %08x\n", ExceptionType, SystemContext.SystemContextArm->PC));
 162     ASSERT (FALSE);
 163   }
 164
 165   gExceptionContext = FALSE;
 166
 167   if (Dispatched) {
 168     //
 169     // We did work so this was an expected ExceptionType
 170     //
 171     return;
 172   }
 173
 174   if (ExceptionType == EXCEPT_ARM_SOFTWARE_INTERRUPT) {
 175     //
 176     // ARM JTAG debuggers some times use this vector, so it is not an error to get one
 177     //
 178     return;
 179   }
 180
 181   //
 182   // Code after here is the default exception handler...
 183   //
 184   DEBUG ((EFI_D_ERROR, "%a Exception from %08x\n", gExceptionTypeString[ExceptionType], SystemContext.SystemContextArm->PC));
 185   ASSERT (FALSE);
 186
 187 }
 188
 189
 190
 191 EFI_STATUS
 192 InitializeExceptions (
 193   IN EFI_CPU_ARCH_PROTOCOL    *Cpu
 194   )
 195 {
 196   EFI_STATUS           Status;
 197   UINTN                Offset;
 198   UINTN                Length;
 199   UINTN                Index;
 200   BOOLEAN              Enabled;
 201   EFI_PHYSICAL_ADDRESS Base;
 202
 203   //
 204   // Disable interrupts
 205   //
 206   Cpu->GetInterruptState (Cpu, &Enabled);
 207   Cpu->DisableInterrupt (Cpu);
 208
 209   //
 210   // Initialize the C entry points for interrupts
 211   //
 212   for (Index = 0; Index <= MAX_ARM_EXCEPTION; Index++) {
 213     Status = RegisterInterruptHandler (Index, NULL);
 214     ASSERT_EFI_ERROR (Status);
 215
 216     Status = RegisterDebuggerInterruptHandler (Index, NULL);
 217     ASSERT_EFI_ERROR (Status);
 218   }
 219
 220   //
 221   // Copy an implementation of the ARM exception vectors to PcdCpuVectorBaseAddress.
 222   //
 223   Length = (UINTN)ExceptionHandlersEnd - (UINTN)ExceptionHandlersStart;
 224
 225   //
 226   // Reserve space for the exception handlers
 227   //
 228   Base = (EFI_PHYSICAL_ADDRESS)PcdGet32 (PcdCpuVectorBaseAddress);
 229   Status = gBS->AllocatePages (AllocateAddress, EfiBootServicesCode, EFI_SIZE_TO_PAGES (Length), &Base);
 230   // If the request was for memory that's not in the memory map (which is often the case for 0x00000000
 231   // on embedded systems, for example, we don't want to hang up.  So we'll check here for a status of
 232   // EFI_NOT_FOUND, and continue in that case.
 233   if (EFI_ERROR(Status) && (Status != EFI_NOT_FOUND)) {
 234     ASSERT_EFI_ERROR (Status);
 235   }
 236
 237   CopyMem ((VOID *)(UINTN)PcdGet32 (PcdCpuVectorBaseAddress), (VOID *)ExceptionHandlersStart, Length);
 238
 239   //
 240   // Patch in the common Assembly exception handler
 241   //
 242   Offset = (UINTN)CommonExceptionEntry - (UINTN)ExceptionHandlersStart;
 243   *(UINTN *) ((UINT8 *)(UINTN)PcdGet32 (PcdCpuVectorBaseAddress) + Offset) = (UINTN)AsmCommonExceptionEntry;
 244
 245   // Flush Caches since we updated executable stuff
 246   InvalidateInstructionCacheRange ((VOID *)PcdGet32(PcdCpuVectorBaseAddress), Length);
 247
 248   if (Enabled) {
 249     //
 250     // Restore interrupt state
 251     //
 252     Status = Cpu->EnableInterrupt (Cpu);
 253   }
 254
 255   return Status;
 256 }