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 ArchVectorConfig(
  47   IN  UINTN       VectorBaseAddress
  48   );
  49
  50 // these globals are provided by the architecture specific source (Arm or AArch64)
  51 extern UINTN                    gMaxExceptionNumber;
  52 extern EFI_EXCEPTION_CALLBACK   gExceptionHandlers[];
  53 extern EFI_EXCEPTION_CALLBACK   gDebuggerExceptionHandlers[];
  54 extern PHYSICAL_ADDRESS         gExceptionVectorAlignmentMask;
  55 extern UINTN                    gDebuggerNoHandlerValue;
  56
  57 // A compiler flag adjusts the compilation of this library to a variant where
  58 // the vectors are relocated (copied) to another location versus using the
  59 // vectors in-place.  Since this effects an assembly .align directive we must
  60 // address this at library build time.  Since this affects the build of the
  61 // library we cannot represent this in a PCD since PCDs are evaluated on
  62 // a per-module basis.
  63 #if defined(ARM_RELOCATE_VECTORS)
  64 STATIC CONST BOOLEAN gArmRelocateVectorTable = TRUE;
  65 #else
  66 STATIC CONST BOOLEAN gArmRelocateVectorTable = FALSE;
  67 #endif
  68
  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
 100     VectorBase = PcdGet64(PcdCpuVectorBaseAddress);
 101     Status = CopyExceptionHandlers(VectorBase);
 102
 103   }
 104   else { // use VBAR to point to where our exception handlers are
 105
 106     // The vector table must be aligned for the architecture.  If this
 107     // assertion fails ensure the appropriate FFS alignment is in effect,
 108     // which can be accomplished by ensuring the proper Align=X statement
 109     // in the platform packaging rules.  For ARM Align=32 is required and
 110     // for AArch64 Align=4K is required.  Align=Auto can be used but this
 111     // is known to cause an issue with populating the reset vector area
 112     // for encapsulated FVs.
 113     ASSERT(((UINTN)ExceptionHandlersStart & gExceptionVectorAlignmentMask) == 0);
 114
 115     // We do not copy the Exception Table at PcdGet64(PcdCpuVectorBaseAddress). We just set Vector
 116     // Base Address to point into CpuDxe code.
 117     VectorBase = (UINTN)ExceptionHandlersStart;
 118
 119     Status = RETURN_SUCCESS;
 120   }
 121
 122   if (!RETURN_ERROR(Status)) {
 123     // call the architecture-specific routine to prepare for the new vector
 124     // configuration to take effect
 125     ArchVectorConfig(VectorBase);
 126
 127     ArmWriteVBar(VectorBase);
 128   }
 129
 130   return RETURN_SUCCESS;
 131 }
 132
 133 /**
 134 Copies exception handlers to the specified address.
 135
 136 Caller should try to get an array of interrupt and/or exception vectors that are in use and need to
 137 persist by EFI_VECTOR_HANDOFF_INFO defined in PI 1.3 specification.
 138 If caller cannot get reserved vector list or it does not exists, set VectorInfo to NULL.
 139 If VectorInfo is not NULL, the exception vectors will be initialized per vector attribute accordingly.
 140
 141 @param[in]  VectorInfo    Pointer to reserved vector list.
 142
 143 @retval EFI_SUCCESS           CPU Exception Entries have been successfully initialized
 144 with default exception handlers.
 145 @retval EFI_INVALID_PARAMETER VectorInfo includes the invalid content if VectorInfo is not NULL.
 146 @retval EFI_UNSUPPORTED       This function is not supported.
 147
 148 **/
 149 STATIC
 150 RETURN_STATUS
 151 CopyExceptionHandlers(
 152   IN  PHYSICAL_ADDRESS        BaseAddress
 153   )
 154 {
 155   RETURN_STATUS        Status;
 156   UINTN                Length;
 157   UINTN                Index;
 158   UINT32               *VectorBase;
 159
 160   // ensure that the destination value specifies an address meeting the vector alignment requirements
 161   ASSERT ((BaseAddress & gExceptionVectorAlignmentMask) == 0);
 162
 163   //
 164   // Copy an implementation of the exception vectors to PcdCpuVectorBaseAddress.
 165   //
 166   Length = (UINTN)ExceptionHandlersEnd - (UINTN)ExceptionHandlersStart;
 167
 168   VectorBase = (UINT32 *)(UINTN)BaseAddress;
 169
 170   if (FeaturePcdGet(PcdDebuggerExceptionSupport) == TRUE) {
 171     // Save existing vector table, in case debugger is already hooked in
 172     CopyMem((VOID *)gDebuggerExceptionHandlers, (VOID *)VectorBase, sizeof (EFI_EXCEPTION_CALLBACK)* (gMaxExceptionNumber+1));
 173   }
 174
 175   // Copy our assembly code into the page that contains the exception vectors.
 176   CopyMem((VOID *)VectorBase, (VOID *)ExceptionHandlersStart, Length);
 177
 178   //
 179   // Initialize the C entry points for interrupts
 180   //
 181   for (Index = 0; Index <= gMaxExceptionNumber; Index++) {
 182     if (!FeaturePcdGet(PcdDebuggerExceptionSupport) ||
 183       (gDebuggerExceptionHandlers[Index] == 0) || (gDebuggerExceptionHandlers[Index] == (VOID *)gDebuggerNoHandlerValue)) {
 184
 185       Status = RegisterExceptionHandler(Index, NULL);
 186       ASSERT_EFI_ERROR(Status);
 187     }
 188     else {
 189       // If the debugger has already hooked put its vector back
 190       VectorBase[Index] = (UINT32)(UINTN)gDebuggerExceptionHandlers[Index];
 191     }
 192   }
 193
 194   // Flush Caches since we updated executable stuff
 195   InvalidateInstructionCacheRange((VOID *)(UINTN)BaseAddress, Length);
 196
 197   return RETURN_SUCCESS;
 198 }
 199
 200
 201 /**
 202 Initializes all CPU interrupt/exceptions entries and provides the default interrupt/exception handlers.
 203
 204 Caller should try to get an array of interrupt and/or exception vectors that are in use and need to
 205 persist by EFI_VECTOR_HANDOFF_INFO defined in PI 1.3 specification.
 206 If caller cannot get reserved vector list or it does not exists, set VectorInfo to NULL.
 207 If VectorInfo is not NULL, the exception vectors will be initialized per vector attribute accordingly.
 208
 209 @param[in]  VectorInfo    Pointer to reserved vector list.
 210
 211 @retval EFI_SUCCESS           All CPU interrupt/exception entries have been successfully initialized
 212 with default interrupt/exception handlers.
 213 @retval EFI_INVALID_PARAMETER VectorInfo includes the invalid content if VectorInfo is not NULL.
 214 @retval EFI_UNSUPPORTED       This function is not supported.
 215
 216 **/
 217 EFI_STATUS
 218 EFIAPI
 219 InitializeCpuInterruptHandlers(
 220 IN EFI_VECTOR_HANDOFF_INFO       *VectorInfo OPTIONAL
 221 )
 222 {
 223   // not needed, this is what the CPU driver is for
 224   return EFI_UNSUPPORTED;
 225 }
 226
 227 /**
 228 Registers a function to be called from the processor exception handler. (On ARM/AArch64 this only
 229 provides exception handlers, not interrupt handling which is provided through the Hardware Interrupt
 230 Protocol.)
 231
 232 This function registers and enables the handler specified by ExceptionHandler for a processor
 233 interrupt or exception type specified by ExceptionType. If ExceptionHandler is NULL, then the
 234 handler for the processor interrupt or exception type specified by ExceptionType is uninstalled.
 235 The installed handler is called once for each processor interrupt or exception.
 236 NOTE: This function should be invoked after InitializeCpuExceptionHandlers() or
 237 InitializeCpuInterruptHandlers() invoked, otherwise EFI_UNSUPPORTED returned.
 238
 239 @param[in]  ExceptionType     Defines which interrupt or exception to hook.
 240 @param[in]  ExceptionHandler  A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
 241 when a processor interrupt occurs. If this parameter is NULL, then the handler
 242 will be uninstalled.
 243
 244 @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
 245 @retval EFI_ALREADY_STARTED   ExceptionHandler is not NULL, and a handler for ExceptionType was
 246 previously installed.
 247 @retval EFI_INVALID_PARAMETER ExceptionHandler is NULL, and a handler for ExceptionType was not
 248 previously installed.
 249 @retval EFI_UNSUPPORTED       The interrupt specified by ExceptionType is not supported,
 250 or this function is not supported.
 251 **/
 252 RETURN_STATUS
 253 RegisterCpuInterruptHandler(
 254   IN EFI_EXCEPTION_TYPE             ExceptionType,
 255   IN EFI_CPU_INTERRUPT_HANDLER      ExceptionHandler
 256   )
 257 {
 258   if (ExceptionType > gMaxExceptionNumber) {
 259     return RETURN_UNSUPPORTED;
 260   }
 261
 262   if ((ExceptionHandler != NULL) && (gExceptionHandlers[ExceptionType] != NULL)) {
 263     return RETURN_ALREADY_STARTED;
 264   }
 265
 266   gExceptionHandlers[ExceptionType] = ExceptionHandler;
 267
 268   return RETURN_SUCCESS;
 269 }
 270
 271 /**
 272 Register exception handler.
 273
 274 @param  This                  A pointer to the SMM_CPU_SERVICE_PROTOCOL instance.
 275 @param  ExceptionType         Defines which interrupt or exception to hook. Type EFI_EXCEPTION_TYPE and
 276 the valid values for this parameter are defined in EFI_DEBUG_SUPPORT_PROTOCOL
 277 of the UEFI 2.0 specification.
 278 @param  InterruptHandler      A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER
 279 that is called when a processor interrupt occurs.
 280 If this parameter is NULL, then the handler will be uninstalled.
 281
 282 @retval EFI_SUCCESS           The handler for the processor interrupt was successfully installed or uninstalled.
 283 @retval EFI_ALREADY_STARTED   InterruptHandler is not NULL, and a handler for InterruptType was previously installed.
 284 @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not previously installed.
 285 @retval EFI_UNSUPPORTED       The interrupt specified by InterruptType is not supported.
 286
 287 **/
 288 EFI_STATUS
 289 EFIAPI
 290 RegisterExceptionHandler(
 291   IN EFI_EXCEPTION_TYPE            ExceptionType,
 292   IN EFI_CPU_INTERRUPT_HANDLER     InterruptHandler
 293   )
 294 {
 295   return RegisterCpuInterruptHandler(ExceptionType, InterruptHandler);
 296 }
 297
 298 VOID
 299 EFIAPI
 300 CommonCExceptionHandler(
 301   IN     EFI_EXCEPTION_TYPE           ExceptionType,
 302   IN OUT EFI_SYSTEM_CONTEXT           SystemContext
 303   )
 304 {
 305   if (ExceptionType <= gMaxExceptionNumber) {
 306     if (gExceptionHandlers[ExceptionType]) {
 307       gExceptionHandlers[ExceptionType](ExceptionType, SystemContext);
 308       return;
 309     }
 310   }
 311   else {
 312     DEBUG((EFI_D_ERROR, "Unknown exception type %d\n", ExceptionType));
 313     ASSERT(FALSE);
 314   }
 315
 316   DefaultExceptionHandler(ExceptionType, SystemContext);
 317 }
 318
 319 /**
 320   Initializes all CPU exceptions entries with optional extra initializations.
 321
 322   By default, this method should include all functionalities implemented by
 323   InitializeCpuExceptionHandlers(), plus extra initialization works, if any.
 324   This could be done by calling InitializeCpuExceptionHandlers() directly
 325   in this method besides the extra works.
 326
 327   InitData is optional and its use and content are processor arch dependent.
 328   The typical usage of it is to convey resources which have to be reserved
 329   elsewhere and are necessary for the extra initializations of exception.
 330
 331   @param[in]  VectorInfo    Pointer to reserved vector list.
 332   @param[in]  InitData      Pointer to data optional for extra initializations
 333                             of exception.
 334
 335   @retval EFI_SUCCESS             The exceptions have been successfully
 336                                   initialized.
 337   @retval EFI_INVALID_PARAMETER   VectorInfo or InitData contains invalid
 338                                   content.
 339
 340 **/
 341 EFI_STATUS
 342 EFIAPI
 343 InitializeCpuExceptionHandlersEx (
 344   IN EFI_VECTOR_HANDOFF_INFO            *VectorInfo OPTIONAL,
 345   IN CPU_EXCEPTION_INIT_DATA            *InitData OPTIONAL
 346   )
 347 {
 348   return InitializeCpuExceptionHandlers (VectorInfo);
 349 }
 350