ArmPkg/Library/ArmExceptionLib/ArmExceptionLib.c

   1 /* @file
   2 *  Main file supporting the SEC Phase for Versatile Express
   3 *
   4 *  Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   5 *  Copyright (c) 2011-2021, Arm Limited. All rights reserved.<BR>
   6 *  Copyright (c) 2016 HP Development Company, L.P.
   7 *
   8 *  SPDX-License-Identifier: BSD-2-Clause-Patent
   9 *
  10 **/
  11
  12 #include <Uefi.h>
  13 #include <Library/CpuExceptionHandlerLib.h>
  14
  15 #include <Library/ArmLib.h>
  16 #include <Library/PcdLib.h>
  17 #include <Library/CacheMaintenanceLib.h>
  18 #include <Library/BaseLib.h>
  19 #include <Library/BaseMemoryLib.h>
  20 #include <Library/DebugLib.h>
  21 #include <Library/DefaultExceptionHandlerLib.h>
  22
  23 STATIC
  24 RETURN_STATUS
  25 CopyExceptionHandlers (
  26   IN  PHYSICAL_ADDRESS  BaseAddress
  27   );
  28
  29 EFI_STATUS
  30 EFIAPI
  31 RegisterExceptionHandler (
  32   IN EFI_EXCEPTION_TYPE         ExceptionType,
  33   IN EFI_CPU_INTERRUPT_HANDLER  InterruptHandler
  34   );
  35
  36 VOID
  37 ExceptionHandlersStart (
  38   VOID
  39   );
  40
  41 VOID
  42 ExceptionHandlersEnd (
  43   VOID
  44   );
  45
  46 RETURN_STATUS
  47 ArchVectorConfig (
  48   IN  UINTN  VectorBaseAddress
  49   );
  50
  51 // these globals are provided by the architecture specific source (Arm or AArch64)
  52 extern UINTN                   gMaxExceptionNumber;
  53 extern EFI_EXCEPTION_CALLBACK  gExceptionHandlers[];
  54 extern EFI_EXCEPTION_CALLBACK  gDebuggerExceptionHandlers[];
  55 extern PHYSICAL_ADDRESS        gExceptionVectorAlignmentMask;
  56 extern UINTN                   gDebuggerNoHandlerValue;
  57
  58 // A compiler flag adjusts the compilation of this library to a variant where
  59 // the vectors are relocated (copied) to another location versus using the
  60 // vectors in-place.  Since this effects an assembly .align directive we must
  61 // address this at library build time.  Since this affects the build of the
  62 // library we cannot represent this in a PCD since PCDs are evaluated on
  63 // a per-module basis.
  64 #if defined (ARM_RELOCATE_VECTORS)
  65 STATIC CONST BOOLEAN  gArmRelocateVectorTable = TRUE;
  66 #else
  67 STATIC CONST BOOLEAN  gArmRelocateVectorTable = FALSE;
  68 #endif
  69
  70 /**
  71 Initializes all CPU exceptions entries and provides the default exception handlers.
  72
  73 Caller should try to get an array of interrupt and/or exception vectors that are in use and need to
  74 persist by EFI_VECTOR_HANDOFF_INFO defined in PI 1.3 specification.
  75 If caller cannot get reserved vector list or it does not exists, set VectorInfo to NULL.
  76 If VectorInfo is not NULL, the exception vectors will be initialized per vector attribute accordingly.
  77
  78 @param[in]  VectorInfo    Pointer to reserved vector list.
  79
  80 @retval EFI_SUCCESS           CPU Exception Entries have been successfully initialized
  81 with default exception handlers.
  82 @retval EFI_INVALID_PARAMETER VectorInfo includes the invalid content if VectorInfo is not NULL.
  83 @retval EFI_UNSUPPORTED       This function is not supported.
  84
  85 **/
  86 EFI_STATUS
  87 EFIAPI
  88 InitializeCpuExceptionHandlers (
  89   IN EFI_VECTOR_HANDOFF_INFO  *VectorInfo OPTIONAL
  90   )
  91 {
  92   RETURN_STATUS  Status;
  93   UINTN          VectorBase;
  94
  95   Status = EFI_SUCCESS;
  96
  97   // if we are requested to copy exception handlers to another location
  98   if (gArmRelocateVectorTable) {
  99     VectorBase = PcdGet64 (PcdCpuVectorBaseAddress);
 100     Status     = CopyExceptionHandlers (VectorBase);
 101   } else {
 102     // use VBAR to point to where our exception handlers are
 103
 104     // The vector table must be aligned for the architecture.  If this
 105     // assertion fails ensure the appropriate FFS alignment is in effect,
 106     // which can be accomplished by ensuring the proper Align=X statement
 107     // in the platform packaging rules.  For ARM Align=32 is required and
 108     // for AArch64 Align=4K is required.  Align=Auto can be used but this
 109     // is known to cause an issue with populating the reset vector area
 110     // for encapsulated FVs.
 111     ASSERT (((UINTN)ExceptionHandlersStart & gExceptionVectorAlignmentMask) == 0);
 112
 113     // We do not copy the Exception Table at PcdGet64(PcdCpuVectorBaseAddress). We just set Vector
 114     // Base Address to point into CpuDxe code.
 115     VectorBase = (UINTN)ExceptionHandlersStart;
 116
 117     Status = RETURN_SUCCESS;
 118   }
 119
 120   if (!RETURN_ERROR (Status)) {
 121     // call the architecture-specific routine to prepare for the new vector
 122     // configuration to take effect
 123     ArchVectorConfig (VectorBase);
 124
 125     ArmWriteVBar (VectorBase);
 126   }
 127
 128   return RETURN_SUCCESS;
 129 }
 130
 131 /**
 132 Copies exception handlers to the specified address.
 133
 134 Caller should try to get an array of interrupt and/or exception vectors that are in use and need to
 135 persist by EFI_VECTOR_HANDOFF_INFO defined in PI 1.3 specification.
 136 If caller cannot get reserved vector list or it does not exists, set VectorInfo to NULL.
 137 If VectorInfo is not NULL, the exception vectors will be initialized per vector attribute accordingly.
 138
 139 @param[in]  VectorInfo    Pointer to reserved vector list.
 140
 141 @retval EFI_SUCCESS           CPU Exception Entries have been successfully initialized
 142 with default exception handlers.
 143 @retval EFI_INVALID_PARAMETER VectorInfo includes the invalid content if VectorInfo is not NULL.
 144 @retval EFI_UNSUPPORTED       This function is not supported.
 145
 146 **/
 147 STATIC
 148 RETURN_STATUS
 149 CopyExceptionHandlers (
 150   IN  PHYSICAL_ADDRESS  BaseAddress
 151   )
 152 {
 153   RETURN_STATUS  Status;
 154   UINTN          Length;
 155   UINTN          Index;
 156   UINT32         *VectorBase;
 157
 158   // ensure that the destination value specifies an address meeting the vector alignment requirements
 159   ASSERT ((BaseAddress & gExceptionVectorAlignmentMask) == 0);
 160
 161   //
 162   // Copy an implementation of the exception vectors to PcdCpuVectorBaseAddress.
 163   //
 164   Length = (UINTN)ExceptionHandlersEnd - (UINTN)ExceptionHandlersStart;
 165
 166   VectorBase = (UINT32 *)(UINTN)BaseAddress;
 167
 168   if (FeaturePcdGet (PcdDebuggerExceptionSupport) == TRUE) {
 169     // Save existing vector table, in case debugger is already hooked in
 170     CopyMem ((VOID *)gDebuggerExceptionHandlers, (VOID *)VectorBase, sizeof (EFI_EXCEPTION_CALLBACK)* (gMaxExceptionNumber+1));
 171   }
 172
 173   // Copy our assembly code into the page that contains the exception vectors.
 174   CopyMem ((VOID *)VectorBase, (VOID *)ExceptionHandlersStart, Length);
 175
 176   //
 177   // Initialize the C entry points for interrupts
 178   //
 179   for (Index = 0; Index <= gMaxExceptionNumber; Index++) {
 180     if (!FeaturePcdGet (PcdDebuggerExceptionSupport) ||
 181         (gDebuggerExceptionHandlers[Index] == 0) || (gDebuggerExceptionHandlers[Index] == (VOID *)gDebuggerNoHandlerValue))
 182     {
 183       Status = RegisterExceptionHandler (Index, NULL);
 184       ASSERT_EFI_ERROR (Status);
 185     } else {
 186       // If the debugger has already hooked put its vector back
 187       VectorBase[Index] = (UINT32)(UINTN)gDebuggerExceptionHandlers[Index];
 188     }
 189   }
 190
 191   // Flush Caches since we updated executable stuff
 192   InvalidateInstructionCacheRange ((VOID *)(UINTN)BaseAddress, Length);
 193
 194   return RETURN_SUCCESS;
 195 }
 196
 197 /**
 198 Initializes all CPU interrupt/exceptions entries and provides the default interrupt/exception handlers.
 199
 200 Caller should try to get an array of interrupt and/or exception vectors that are in use and need to
 201 persist by EFI_VECTOR_HANDOFF_INFO defined in PI 1.3 specification.
 202 If caller cannot get reserved vector list or it does not exists, set VectorInfo to NULL.
 203 If VectorInfo is not NULL, the exception vectors will be initialized per vector attribute accordingly.
 204
 205 @param[in]  VectorInfo    Pointer to reserved vector list.
 206
 207 @retval EFI_SUCCESS           All CPU interrupt/exception entries have been successfully initialized
 208 with default interrupt/exception handlers.
 209 @retval EFI_INVALID_PARAMETER VectorInfo includes the invalid content if VectorInfo is not NULL.
 210 @retval EFI_UNSUPPORTED       This function is not supported.
 211
 212 **/
 213 EFI_STATUS
 214 EFIAPI
 215 InitializeCpuInterruptHandlers (
 216   IN EFI_VECTOR_HANDOFF_INFO  *VectorInfo OPTIONAL
 217   )
 218 {
 219   // not needed, this is what the CPU driver is for
 220   return EFI_UNSUPPORTED;
 221 }
 222
 223 /**
 224 Registers a function to be called from the processor exception handler. (On ARM/AArch64 this only
 225 provides exception handlers, not interrupt handling which is provided through the Hardware Interrupt
 226 Protocol.)
 227
 228 This function registers and enables the handler specified by ExceptionHandler for a processor
 229 interrupt or exception type specified by ExceptionType. If ExceptionHandler is NULL, then the
 230 handler for the processor interrupt or exception type specified by ExceptionType is uninstalled.
 231 The installed handler is called once for each processor interrupt or exception.
 232 NOTE: This function should be invoked after InitializeCpuExceptionHandlers() or
 233 InitializeCpuInterruptHandlers() invoked, otherwise EFI_UNSUPPORTED returned.
 234
 235 @param[in]  ExceptionType     Defines which interrupt or exception to hook.
 236 @param[in]  ExceptionHandler  A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
 237 when a processor interrupt occurs. If this parameter is NULL, then the handler
 238 will be uninstalled.
 239
 240 @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
 241 @retval EFI_ALREADY_STARTED   ExceptionHandler is not NULL, and a handler for ExceptionType was
 242 previously installed.
 243 @retval EFI_INVALID_PARAMETER ExceptionHandler is NULL, and a handler for ExceptionType was not
 244 previously installed.
 245 @retval EFI_UNSUPPORTED       The interrupt specified by ExceptionType is not supported,
 246 or this function is not supported.
 247 **/
 248 RETURN_STATUS
 249 RegisterCpuInterruptHandler (
 250   IN EFI_EXCEPTION_TYPE         ExceptionType,
 251   IN EFI_CPU_INTERRUPT_HANDLER  ExceptionHandler
 252   )
 253 {
 254   if (ExceptionType > gMaxExceptionNumber) {
 255     return RETURN_UNSUPPORTED;
 256   }
 257
 258   if ((ExceptionHandler != NULL) && (gExceptionHandlers[ExceptionType] != NULL)) {
 259     return RETURN_ALREADY_STARTED;
 260   }
 261
 262   gExceptionHandlers[ExceptionType] = ExceptionHandler;
 263
 264   return RETURN_SUCCESS;
 265 }
 266
 267 /**
 268 Register exception handler.
 269
 270 @param  This                  A pointer to the SMM_CPU_SERVICE_PROTOCOL instance.
 271 @param  ExceptionType         Defines which interrupt or exception to hook. Type EFI_EXCEPTION_TYPE and
 272 the valid values for this parameter are defined in EFI_DEBUG_SUPPORT_PROTOCOL
 273 of the UEFI 2.0 specification.
 274 @param  InterruptHandler      A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER
 275 that is called when a processor interrupt occurs.
 276 If this parameter is NULL, then the handler will be uninstalled.
 277
 278 @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
 279 @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was previously installed.
 280 @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not previously installed.
 281 @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.
 282
 283 **/
 284 EFI_STATUS
 285 EFIAPI
 286 RegisterExceptionHandler (
 287   IN EFI_EXCEPTION_TYPE         ExceptionType,
 288   IN EFI_CPU_INTERRUPT_HANDLER  InterruptHandler
 289   )
 290 {
 291   return RegisterCpuInterruptHandler (ExceptionType, InterruptHandler);
 292 }
 293
 294 VOID
 295 EFIAPI
 296 CommonCExceptionHandler (
 297   IN     EFI_EXCEPTION_TYPE  ExceptionType,
 298   IN OUT EFI_SYSTEM_CONTEXT  SystemContext
 299   )
 300 {
 301   if (ExceptionType <= gMaxExceptionNumber) {
 302     if (gExceptionHandlers[ExceptionType]) {
 303       gExceptionHandlers[ExceptionType](ExceptionType, SystemContext);
 304       return;
 305     }
 306   } else {
 307     DEBUG ((DEBUG_ERROR, "Unknown exception type %d\n", ExceptionType));
 308     ASSERT (FALSE);
 309   }
 310
 311   DefaultExceptionHandler (ExceptionType, SystemContext);
 312 }
 313
 314 /**
 315   Initializes all CPU exceptions entries with optional extra initializations.
 316
 317   By default, this method should include all functionalities implemented by
 318   InitializeCpuExceptionHandlers(), plus extra initialization works, if any.
 319   This could be done by calling InitializeCpuExceptionHandlers() directly
 320   in this method besides the extra works.
 321
 322   InitData is optional and its use and content are processor arch dependent.
 323   The typical usage of it is to convey resources which have to be reserved
 324   elsewhere and are necessary for the extra initializations of exception.
 325
 326   @param[in]  VectorInfo    Pointer to reserved vector list.
 327   @param[in]  InitData      Pointer to data optional for extra initializations
 328                             of exception.
 329
 330   @retval EFI_SUCCESS             The exceptions have been successfully
 331                                   initialized.
 332   @retval EFI_INVALID_PARAMETER   VectorInfo or InitData contains invalid
 333                                   content.
 334
 335 **/
 336 EFI_STATUS
 337 EFIAPI
 338 InitializeCpuExceptionHandlersEx (
 339   IN EFI_VECTOR_HANDOFF_INFO  *VectorInfo OPTIONAL,
 340   IN CPU_EXCEPTION_INIT_DATA  *InitData OPTIONAL
 341   )
 342 {
 343   return InitializeCpuExceptionHandlers (VectorInfo);
 344 }