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 VOID
  19 ExceptionHandlersStart (
  20   VOID
  21   );
  22
  23 VOID
  24 ExceptionHandlersEnd (
  25   VOID
  26   );
  27
  28 VOID
  29 CommonExceptionEntry (
  30   VOID
  31   );
  32
  33 VOID
  34 AsmCommonExceptionEntry (
  35   VOID
  36   );
  37
  38
  39 EFI_EXCEPTION_CALLBACK  gExceptionHandlers[MAX_ARM_EXCEPTION + 1];
  40 EFI_EXCEPTION_CALLBACK  gDebuggerExceptionHandlers[MAX_ARM_EXCEPTION + 1];
  41
  42
  43
  44 /**
  45   This function registers and enables the handler specified by InterruptHandler for a processor
  46   interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
  47   handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
  48   The installed handler is called once for each processor interrupt or exception.
  49
  50   @param  InterruptType    A pointer to the processor's current interrupt state. Set to TRUE if interrupts
  51                            are enabled and FALSE if interrupts are disabled.
  52   @param  InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
  53                            when a processor interrupt occurs. If this parameter is NULL, then the handler
  54                            will be uninstalled.
  55
  56   @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
  57   @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was
  58                                 previously installed.
  59   @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
  60                                 previously installed.
  61   @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.
  62
  63 **/
  64 EFI_STATUS
  65 RegisterInterruptHandler (
  66   IN EFI_EXCEPTION_TYPE             InterruptType,
  67   IN EFI_CPU_INTERRUPT_HANDLER      InterruptHandler
  68   )
  69 {
  70   if (InterruptType > MAX_ARM_EXCEPTION) {
  71     return EFI_UNSUPPORTED;
  72   }
  73
  74   if ((InterruptHandler != NULL) && (gExceptionHandlers[InterruptType] != NULL)) {
  75     return EFI_ALREADY_STARTED;
  76   }
  77
  78   gExceptionHandlers[InterruptType] = InterruptHandler;
  79
  80   return EFI_SUCCESS;
  81 }
  82
  83
  84 /**
  85   This function registers and enables the handler specified by InterruptHandler for a processor
  86   interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
  87   handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
  88   The installed handler is called once for each processor interrupt or exception.
  89
  90   @param  InterruptType    A pointer to the processor's current interrupt state. Set to TRUE if interrupts
  91                            are enabled and FALSE if interrupts are disabled.
  92   @param  InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
  93                            when a processor interrupt occurs. If this parameter is NULL, then the handler
  94                            will be uninstalled.
  95
  96   @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
  97   @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was
  98                                 previously installed.
  99   @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
 100                                 previously installed.
 101   @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.
 102
 103 **/
 104 EFI_STATUS
 105 RegisterDebuggerInterruptHandler (
 106   IN EFI_EXCEPTION_TYPE             InterruptType,
 107   IN EFI_CPU_INTERRUPT_HANDLER      InterruptHandler
 108   )
 109 {
 110   if (InterruptType > MAX_ARM_EXCEPTION) {
 111     return EFI_UNSUPPORTED;
 112   }
 113
 114   if ((InterruptHandler != NULL) && (gDebuggerExceptionHandlers[InterruptType] != NULL)) {
 115     return EFI_ALREADY_STARTED;
 116   }
 117
 118   gDebuggerExceptionHandlers[InterruptType] = InterruptHandler;
 119
 120   return EFI_SUCCESS;
 121 }
 122
 123
 124
 125 VOID
 126 EFIAPI
 127 CommonCExceptionHandler (
 128   IN     EFI_EXCEPTION_TYPE           ExceptionType,
 129   IN OUT EFI_SYSTEM_CONTEXT           SystemContext
 130   )
 131 {
 132   BOOLEAN Dispatched = FALSE;
 133
 134   if (ExceptionType <= MAX_ARM_EXCEPTION) {
 135     if (gDebuggerExceptionHandlers[ExceptionType]) {
 136       //
 137       // If DebugSupport hooked the interrupt call the handler. This does not disable
 138       // the normal handler.
 139       //
 140       gDebuggerExceptionHandlers[ExceptionType] (ExceptionType, SystemContext);
 141       Dispatched = TRUE;
 142     }
 143     if (gExceptionHandlers[ExceptionType]) {
 144       gExceptionHandlers[ExceptionType] (ExceptionType, SystemContext);
 145       Dispatched = TRUE;
 146     }
 147   }
 148
 149   if (Dispatched) {
 150     //
 151     // We did work so this was an expected ExceptionType
 152     //
 153     return;
 154   }
 155
 156   if (ExceptionType == EXCEPT_ARM_SOFTWARE_INTERRUPT) {
 157     //
 158     // ARM JTAG debuggers some times use this vector, so it is not an error to get one
 159     //
 160     return;
 161   }
 162
 163   //
 164   // Code after here is the default exception handler...
 165   //
 166   DEBUG ((EFI_D_ERROR, "Exception %d from %08x\n", ExceptionType, SystemContext.SystemContextArm->PC));
 167   ASSERT (FALSE);
 168
 169 }
 170
 171
 172
 173 EFI_STATUS
 174 InitializeExceptions (
 175   IN EFI_CPU_ARCH_PROTOCOL    *Cpu
 176   )
 177 {
 178   EFI_STATUS           Status;
 179   UINTN                Offset;
 180   UINTN                Length;
 181   UINTN                Index;
 182   BOOLEAN              Enabled;
 183   EFI_PHYSICAL_ADDRESS Base;
 184
 185   //
 186   // Disable interrupts
 187   //
 188   Cpu->GetInterruptState (Cpu, &Enabled);
 189   Cpu->DisableInterrupt (Cpu);
 190
 191   //
 192   // Initialize the C entry points for interrupts
 193   //
 194   for (Index = 0; Index <= MAX_ARM_EXCEPTION; Index++) {
 195     Status = RegisterInterruptHandler (Index, NULL);
 196     ASSERT_EFI_ERROR (Status);
 197
 198     Status = RegisterDebuggerInterruptHandler (Index, NULL);
 199     ASSERT_EFI_ERROR (Status);
 200   }
 201
 202   //
 203   // Copy an implementation of the ARM exception vectors to 0x0.
 204   //
 205   Length = (UINTN)ExceptionHandlersEnd - (UINTN)ExceptionHandlersStart;
 206
 207   //
 208   // Reserve space for the exception handlers
 209   //
 210   Base = (EFI_PHYSICAL_ADDRESS)PcdGet32 (PcdCpuVectorBaseAddress);
 211   Status = gBS->AllocatePages (AllocateAddress, EfiBootServicesCode, EFI_SIZE_TO_PAGES (Length), &Base);
 212   // If the request was for memory that's not in the memory map (which is often the case for 0x00000000
 213   // on embedded systems, for example, we don't want to hang up.  So we'll check here for a status of
 214   // EFI_NOT_FOUND, and continue in that case.
 215   if (EFI_ERROR(Status) && (Status != EFI_NOT_FOUND)) {
 216   ASSERT_EFI_ERROR (Status);
 217   }
 218
 219   CopyMem ((VOID *)(UINTN)PcdGet32 (PcdCpuVectorBaseAddress), (VOID *)ExceptionHandlersStart, Length);
 220
 221   //
 222   // Patch in the common Assembly exception handler
 223   //
 224   Offset = (UINTN)CommonExceptionEntry - (UINTN)ExceptionHandlersStart;
 225   *(UINTN *) ((UINT8 *)(UINTN)PcdGet32 (PcdCpuVectorBaseAddress) + Offset) = (UINTN)AsmCommonExceptionEntry;
 226
 227   // Flush Caches since we updated executable stuff
 228   InvalidateInstructionCacheRange((VOID *)PcdGet32(PcdCpuVectorBaseAddress), Length);
 229
 230   if (Enabled) {
 231     //
 232     // Restore interrupt state
 233     //
 234     Status = Cpu->EnableInterrupt (Cpu);
 235   }
 236
 237   return Status;
 238 }