UefiCpuPkg/Library/MpInitLib/DxeMpLib.c

   1 /** @file
   2   MP initialize support functions for DXE phase.
   3
   4   Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
   5   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 "MpLib.h"
  16
  17 #include <Library/UefiLib.h>
  18 #include <Library/UefiBootServicesTableLib.h>
  19
  20 #define  AP_CHECK_INTERVAL     (EFI_TIMER_PERIOD_MILLISECONDS (100))
  21
  22 CPU_MP_DATA      *mCpuMpData = NULL;
  23 EFI_EVENT        mCheckAllApsEvent = NULL;
  24 EFI_EVENT        mMpInitExitBootServicesEvent = NULL;
  25 EFI_EVENT        mLegacyBootEvent = NULL;
  26 volatile BOOLEAN mStopCheckAllApsStatus = TRUE;
  27 VOID             *mReservedApLoopFunc = NULL;
  28
  29 /**
  30   Get the pointer to CPU MP Data structure.
  31
  32   @return  The pointer to CPU MP Data structure.
  33 **/
  34 CPU_MP_DATA *
  35 GetCpuMpData (
  36   VOID
  37   )
  38 {
  39   ASSERT (mCpuMpData != NULL);
  40   return mCpuMpData;
  41 }
  42
  43 /**
  44   Save the pointer to CPU MP Data structure.
  45
  46   @param[in] CpuMpData  The pointer to CPU MP Data structure will be saved.
  47 **/
  48 VOID
  49 SaveCpuMpData (
  50   IN CPU_MP_DATA   *CpuMpData
  51   )
  52 {
  53   mCpuMpData = CpuMpData;
  54 }
  55
  56 /**
  57   Allocate reset vector buffer.
  58
  59   @param[in, out]  CpuMpData  The pointer to CPU MP Data structure.
  60 **/
  61 VOID
  62 AllocateResetVector (
  63   IN OUT CPU_MP_DATA          *CpuMpData
  64   )
  65 {
  66   EFI_STATUS            Status;
  67   UINTN                 ApResetVectorSize;
  68   EFI_PHYSICAL_ADDRESS  StartAddress;
  69
  70   if (CpuMpData->SaveRestoreFlag) {
  71     BackupAndPrepareWakeupBuffer (CpuMpData);
  72   } else {
  73     ApResetVectorSize = CpuMpData->AddressMap.RendezvousFunnelSize +
  74                         sizeof (MP_CPU_EXCHANGE_INFO);
  75
  76     StartAddress = BASE_1MB;
  77     Status = gBS->AllocatePages (
  78                     AllocateMaxAddress,
  79                     EfiACPIMemoryNVS,
  80                     EFI_SIZE_TO_PAGES (ApResetVectorSize),
  81                     &StartAddress
  82                     );
  83     ASSERT_EFI_ERROR (Status);
  84
  85     CpuMpData->WakeupBuffer      = (UINTN) StartAddress;
  86     CpuMpData->MpCpuExchangeInfo = (MP_CPU_EXCHANGE_INFO *) (UINTN)
  87                   (CpuMpData->WakeupBuffer + CpuMpData->AddressMap.RendezvousFunnelSize);
  88     //
  89     // copy AP reset code in it
  90     //
  91     CopyMem (
  92       (VOID *) CpuMpData->WakeupBuffer,
  93       (VOID *) CpuMpData->AddressMap.RendezvousFunnelAddress,
  94       CpuMpData->AddressMap.RendezvousFunnelSize
  95       );
  96   }
  97 }
  98
  99 /**
 100   Free AP reset vector buffer.
 101
 102   @param[in]  CpuMpData  The pointer to CPU MP Data structure.
 103 **/
 104 VOID
 105 FreeResetVector (
 106   IN CPU_MP_DATA              *CpuMpData
 107   )
 108 {
 109   EFI_STATUS            Status;
 110   UINTN                 ApResetVectorSize;
 111
 112   if (CpuMpData->SaveRestoreFlag) {
 113     RestoreWakeupBuffer (CpuMpData);
 114   } else {
 115     ApResetVectorSize = CpuMpData->AddressMap.RendezvousFunnelSize +
 116                         sizeof (MP_CPU_EXCHANGE_INFO);
 117     Status = gBS->FreePages(
 118                (EFI_PHYSICAL_ADDRESS)CpuMpData->WakeupBuffer,
 119                EFI_SIZE_TO_PAGES (ApResetVectorSize)
 120                );
 121     ASSERT_EFI_ERROR (Status);
 122   }
 123 }
 124
 125 /**
 126   Checks APs status and updates APs status if needed.
 127
 128 **/
 129 VOID
 130 CheckAndUpdateApsStatus (
 131   VOID
 132   )
 133 {
 134   UINTN                   ProcessorNumber;
 135   EFI_STATUS              Status;
 136   CPU_MP_DATA             *CpuMpData;
 137
 138   CpuMpData = GetCpuMpData ();
 139
 140   //
 141   // First, check whether pending StartupAllAPs() exists.
 142   //
 143   if (CpuMpData->WaitEvent != NULL) {
 144
 145     Status = CheckAllAPs ();
 146     //
 147     // If all APs finish for StartupAllAPs(), signal the WaitEvent for it.
 148     //
 149     if (Status != EFI_NOT_READY) {
 150       Status = gBS->SignalEvent (CpuMpData->WaitEvent);
 151       CpuMpData->WaitEvent = NULL;
 152     }
 153   }
 154
 155   //
 156   // Second, check whether pending StartupThisAPs() callings exist.
 157   //
 158   for (ProcessorNumber = 0; ProcessorNumber < CpuMpData->CpuCount; ProcessorNumber++) {
 159
 160     if (CpuMpData->CpuData[ProcessorNumber].WaitEvent == NULL) {
 161       continue;
 162     }
 163
 164     Status = CheckThisAP (ProcessorNumber);
 165
 166     if (Status != EFI_NOT_READY) {
 167       gBS->SignalEvent (CpuMpData->CpuData[ProcessorNumber].WaitEvent);
 168      CpuMpData->CpuData[ProcessorNumber].WaitEvent = NULL;
 169     }
 170   }
 171 }
 172
 173 /**
 174   Checks APs' status periodically.
 175
 176   This function is triggered by timer periodically to check the
 177   state of APs for StartupAllAPs() and StartupThisAP() executed
 178   in non-blocking mode.
 179
 180   @param[in]  Event    Event triggered.
 181   @param[in]  Context  Parameter passed with the event.
 182
 183 **/
 184 VOID
 185 EFIAPI
 186 CheckApsStatus (
 187   IN  EFI_EVENT                           Event,
 188   IN  VOID                                *Context
 189   )
 190 {
 191   //
 192   // If CheckApsStatus() is not stopped, otherwise return immediately.
 193   //
 194   if (!mStopCheckAllApsStatus) {
 195     CheckAndUpdateApsStatus ();
 196   }
 197 }
 198
 199 /**
 200   Get Protected mode code segment from current GDT table.
 201
 202   @return  Protected mode code segment value.
 203 **/
 204 UINT16
 205 GetProtectedModeCS (
 206   VOID
 207   )
 208 {
 209   IA32_DESCRIPTOR          GdtrDesc;
 210   IA32_SEGMENT_DESCRIPTOR  *GdtEntry;
 211   UINTN                    GdtEntryCount;
 212   UINT16                   Index;
 213
 214   Index = (UINT16) -1;
 215   AsmReadGdtr (&GdtrDesc);
 216   GdtEntryCount = (GdtrDesc.Limit + 1) / sizeof (IA32_SEGMENT_DESCRIPTOR);
 217   GdtEntry = (IA32_SEGMENT_DESCRIPTOR *) GdtrDesc.Base;
 218   for (Index = 0; Index < GdtEntryCount; Index++) {
 219     if (GdtEntry->Bits.L == 0) {
 220       if (GdtEntry->Bits.Type > 8 && GdtEntry->Bits.L == 0) {
 221         break;
 222       }
 223     }
 224     GdtEntry++;
 225   }
 226   ASSERT (Index != -1);
 227   return Index * 8;
 228 }
 229
 230 /**
 231   Do sync on APs.
 232
 233   @param[in, out] Buffer  Pointer to private data buffer.
 234 **/
 235 VOID
 236 EFIAPI
 237 RelocateApLoop (
 238   IN OUT VOID  *Buffer
 239   )
 240 {
 241   CPU_MP_DATA            *CpuMpData;
 242   BOOLEAN                MwaitSupport;
 243   ASM_RELOCATE_AP_LOOP   AsmRelocateApLoopFunc;
 244
 245   CpuMpData    = GetCpuMpData ();
 246   MwaitSupport = IsMwaitSupport ();
 247   AsmRelocateApLoopFunc = (ASM_RELOCATE_AP_LOOP) (UINTN) Buffer;
 248   AsmRelocateApLoopFunc (MwaitSupport, CpuMpData->ApTargetCState, CpuMpData->PmCodeSegment);
 249   //
 250   // It should never reach here
 251   //
 252   ASSERT (FALSE);
 253 }
 254
 255 /**
 256   Callback function for ExitBootServices.
 257
 258   @param[in]  Event             Event whose notification function is being invoked.
 259   @param[in]  Context           The pointer to the notification function's context,
 260                                 which is implementation-dependent.
 261
 262 **/
 263 VOID
 264 EFIAPI
 265 MpInitChangeApLoopCallback (
 266   IN EFI_EVENT                Event,
 267   IN VOID                     *Context
 268   )
 269 {
 270   CPU_MP_DATA               *CpuMpData;
 271
 272   CpuMpData = GetCpuMpData ();
 273   CpuMpData->SaveRestoreFlag = TRUE;
 274   CpuMpData->PmCodeSegment = GetProtectedModeCS ();
 275   CpuMpData->ApLoopMode = PcdGet8 (PcdCpuApLoopMode);
 276   WakeUpAP (CpuMpData, TRUE, 0, RelocateApLoop, mReservedApLoopFunc);
 277   DEBUG ((DEBUG_INFO, "%a() done!\n", __FUNCTION__));
 278 }
 279
 280 /**
 281   Initialize global data for MP support.
 282
 283   @param[in] CpuMpData  The pointer to CPU MP Data structure.
 284 **/
 285 VOID
 286 InitMpGlobalData (
 287   IN CPU_MP_DATA               *CpuMpData
 288   )
 289 {
 290   EFI_STATUS                 Status;
 291   EFI_PHYSICAL_ADDRESS       Address;
 292
 293   SaveCpuMpData (CpuMpData);
 294
 295   if (CpuMpData->CpuCount == 1) {
 296     //
 297     // If only BSP exists, return
 298     //
 299     return;
 300   }
 301
 302   //
 303   // Avoid APs access invalid buffer data which allocated by BootServices,
 304   // so we will allocate reserved data for AP loop code. We also need to
 305   // allocate this buffer below 4GB due to APs may be transferred to 32bit
 306   // protected mode on long mode DXE.
 307   // Allocating it in advance since memory services are not available in
 308   // Exit Boot Services callback function.
 309   //
 310   Address = BASE_4GB - 1;
 311   Status  = gBS->AllocatePages (
 312                    AllocateMaxAddress,
 313                    EfiReservedMemoryType,
 314                    EFI_SIZE_TO_PAGES (sizeof (CpuMpData->AddressMap.RelocateApLoopFuncSize)),
 315                    &Address
 316                    );
 317   ASSERT_EFI_ERROR (Status);
 318   mReservedApLoopFunc = (VOID *) (UINTN) Address;
 319   ASSERT (mReservedApLoopFunc != NULL);
 320   CopyMem (
 321     mReservedApLoopFunc,
 322     CpuMpData->AddressMap.RelocateApLoopFuncAddress,
 323     CpuMpData->AddressMap.RelocateApLoopFuncSize
 324     );
 325
 326   Status = gBS->CreateEvent (
 327                   EVT_TIMER | EVT_NOTIFY_SIGNAL,
 328                   TPL_NOTIFY,
 329                   CheckApsStatus,
 330                   NULL,
 331                   &mCheckAllApsEvent
 332                   );
 333   ASSERT_EFI_ERROR (Status);
 334
 335   //
 336   // Set timer to check all APs status.
 337   //
 338   Status = gBS->SetTimer (
 339                   mCheckAllApsEvent,
 340                   TimerPeriodic,
 341                   AP_CHECK_INTERVAL
 342                   );
 343   ASSERT_EFI_ERROR (Status);
 344
 345   Status = gBS->CreateEvent (
 346                   EVT_SIGNAL_EXIT_BOOT_SERVICES,
 347                   TPL_CALLBACK,
 348                   MpInitChangeApLoopCallback,
 349                   NULL,
 350                   &mMpInitExitBootServicesEvent
 351                   );
 352   ASSERT_EFI_ERROR (Status);
 353
 354   Status = gBS->CreateEventEx (
 355                   EVT_NOTIFY_SIGNAL,
 356                   TPL_CALLBACK,
 357                   MpInitChangeApLoopCallback,
 358                   NULL,
 359                   &gEfiEventLegacyBootGuid,
 360                   &mLegacyBootEvent
 361                   );
 362   ASSERT_EFI_ERROR (Status);
 363 }
 364
 365 /**
 366   This service executes a caller provided function on all enabled APs.
 367
 368   @param[in]  Procedure               A pointer to the function to be run on
 369                                       enabled APs of the system. See type
 370                                       EFI_AP_PROCEDURE.
 371   @param[in]  SingleThread            If TRUE, then all the enabled APs execute
 372                                       the function specified by Procedure one by
 373                                       one, in ascending order of processor handle
 374                                       number.  If FALSE, then all the enabled APs
 375                                       execute the function specified by Procedure
 376                                       simultaneously.
 377   @param[in]  WaitEvent               The event created by the caller with CreateEvent()
 378                                       service.  If it is NULL, then execute in
 379                                       blocking mode. BSP waits until all APs finish
 380                                       or TimeoutInMicroSeconds expires.  If it's
 381                                       not NULL, then execute in non-blocking mode.
 382                                       BSP requests the function specified by
 383                                       Procedure to be started on all the enabled
 384                                       APs, and go on executing immediately. If
 385                                       all return from Procedure, or TimeoutInMicroSeconds
 386                                       expires, this event is signaled. The BSP
 387                                       can use the CheckEvent() or WaitForEvent()
 388                                       services to check the state of event.  Type
 389                                       EFI_EVENT is defined in CreateEvent() in
 390                                       the Unified Extensible Firmware Interface
 391                                       Specification.
 392   @param[in]  TimeoutInMicrosecsond   Indicates the time limit in microseconds for
 393                                       APs to return from Procedure, either for
 394                                       blocking or non-blocking mode. Zero means
 395                                       infinity.  If the timeout expires before
 396                                       all APs return from Procedure, then Procedure
 397                                       on the failed APs is terminated. All enabled
 398                                       APs are available for next function assigned
 399                                       by MpInitLibStartupAllAPs() or
 400                                       MPInitLibStartupThisAP().
 401                                       If the timeout expires in blocking mode,
 402                                       BSP returns EFI_TIMEOUT.  If the timeout
 403                                       expires in non-blocking mode, WaitEvent
 404                                       is signaled with SignalEvent().
 405   @param[in]  ProcedureArgument       The parameter passed into Procedure for
 406                                       all APs.
 407   @param[out] FailedCpuList           If NULL, this parameter is ignored. Otherwise,
 408                                       if all APs finish successfully, then its
 409                                       content is set to NULL. If not all APs
 410                                       finish before timeout expires, then its
 411                                       content is set to address of the buffer
 412                                       holding handle numbers of the failed APs.
 413                                       The buffer is allocated by MP Initialization
 414                                       library, and it's the caller's responsibility to
 415                                       free the buffer with FreePool() service.
 416                                       In blocking mode, it is ready for consumption
 417                                       when the call returns. In non-blocking mode,
 418                                       it is ready when WaitEvent is signaled.  The
 419                                       list of failed CPU is terminated by
 420                                       END_OF_CPU_LIST.
 421
 422   @retval EFI_SUCCESS             In blocking mode, all APs have finished before
 423                                   the timeout expired.
 424   @retval EFI_SUCCESS             In non-blocking mode, function has been dispatched
 425                                   to all enabled APs.
 426   @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
 427                                   UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
 428                                   signaled.
 429   @retval EFI_UNSUPPORTED         WaitEvent is not NULL if non-blocking mode is not
 430                                   supported.
 431   @retval EFI_DEVICE_ERROR        Caller processor is AP.
 432   @retval EFI_NOT_STARTED         No enabled APs exist in the system.
 433   @retval EFI_NOT_READY           Any enabled APs are busy.
 434   @retval EFI_NOT_READY           MP Initialize Library is not initialized.
 435   @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
 436                                   all enabled APs have finished.
 437   @retval EFI_INVALID_PARAMETER   Procedure is NULL.
 438
 439 **/
 440 EFI_STATUS
 441 EFIAPI
 442 MpInitLibStartupAllAPs (
 443   IN  EFI_AP_PROCEDURE          Procedure,
 444   IN  BOOLEAN                   SingleThread,
 445   IN  EFI_EVENT                 WaitEvent               OPTIONAL,
 446   IN  UINTN                     TimeoutInMicroseconds,
 447   IN  VOID                      *ProcedureArgument      OPTIONAL,
 448   OUT UINTN                     **FailedCpuList         OPTIONAL
 449   )
 450 {
 451   EFI_STATUS              Status;
 452
 453   //
 454   // Temporarily stop checkAllApsStatus for avoid resource dead-lock.
 455   //
 456   mStopCheckAllApsStatus = TRUE;
 457
 458   Status = StartupAllAPsWorker (
 459              Procedure,
 460              SingleThread,
 461              WaitEvent,
 462              TimeoutInMicroseconds,
 463              ProcedureArgument,
 464              FailedCpuList
 465              );
 466
 467   //
 468   // Start checkAllApsStatus
 469   //
 470   mStopCheckAllApsStatus = FALSE;
 471
 472   return Status;
 473 }
 474
 475 /**
 476   This service lets the caller get one enabled AP to execute a caller-provided
 477   function.
 478
 479   @param[in]  Procedure               A pointer to the function to be run on the
 480                                       designated AP of the system. See type
 481                                       EFI_AP_PROCEDURE.
 482   @param[in]  ProcessorNumber         The handle number of the AP. The range is
 483                                       from 0 to the total number of logical
 484                                       processors minus 1. The total number of
 485                                       logical processors can be retrieved by
 486                                       MpInitLibGetNumberOfProcessors().
 487   @param[in]  WaitEvent               The event created by the caller with CreateEvent()
 488                                       service.  If it is NULL, then execute in
 489                                       blocking mode. BSP waits until this AP finish
 490                                       or TimeoutInMicroSeconds expires.  If it's
 491                                       not NULL, then execute in non-blocking mode.
 492                                       BSP requests the function specified by
 493                                       Procedure to be started on this AP,
 494                                       and go on executing immediately. If this AP
 495                                       return from Procedure or TimeoutInMicroSeconds
 496                                       expires, this event is signaled. The BSP
 497                                       can use the CheckEvent() or WaitForEvent()
 498                                       services to check the state of event.  Type
 499                                       EFI_EVENT is defined in CreateEvent() in
 500                                       the Unified Extensible Firmware Interface
 501                                       Specification.
 502   @param[in]  TimeoutInMicrosecsond   Indicates the time limit in microseconds for
 503                                       this AP to finish this Procedure, either for
 504                                       blocking or non-blocking mode. Zero means
 505                                       infinity.  If the timeout expires before
 506                                       this AP returns from Procedure, then Procedure
 507                                       on the AP is terminated. The
 508                                       AP is available for next function assigned
 509                                       by MpInitLibStartupAllAPs() or
 510                                       MpInitLibStartupThisAP().
 511                                       If the timeout expires in blocking mode,
 512                                       BSP returns EFI_TIMEOUT.  If the timeout
 513                                       expires in non-blocking mode, WaitEvent
 514                                       is signaled with SignalEvent().
 515   @param[in]  ProcedureArgument       The parameter passed into Procedure on the
 516                                       specified AP.
 517   @param[out] Finished                If NULL, this parameter is ignored.  In
 518                                       blocking mode, this parameter is ignored.
 519                                       In non-blocking mode, if AP returns from
 520                                       Procedure before the timeout expires, its
 521                                       content is set to TRUE. Otherwise, the
 522                                       value is set to FALSE. The caller can
 523                                       determine if the AP returned from Procedure
 524                                       by evaluating this value.
 525
 526   @retval EFI_SUCCESS             In blocking mode, specified AP finished before
 527                                   the timeout expires.
 528   @retval EFI_SUCCESS             In non-blocking mode, the function has been
 529                                   dispatched to specified AP.
 530   @retval EFI_UNSUPPORTED         A non-blocking mode request was made after the
 531                                   UEFI event EFI_EVENT_GROUP_READY_TO_BOOT was
 532                                   signaled.
 533   @retval EFI_UNSUPPORTED         WaitEvent is not NULL if non-blocking mode is not
 534                                   supported.
 535   @retval EFI_DEVICE_ERROR        The calling processor is an AP.
 536   @retval EFI_TIMEOUT             In blocking mode, the timeout expired before
 537                                   the specified AP has finished.
 538   @retval EFI_NOT_READY           The specified AP is busy.
 539   @retval EFI_NOT_READY           MP Initialize Library is not initialized.
 540   @retval EFI_NOT_FOUND           The processor with the handle specified by
 541                                   ProcessorNumber does not exist.
 542   @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP or disabled AP.
 543   @retval EFI_INVALID_PARAMETER   Procedure is NULL.
 544
 545 **/
 546 EFI_STATUS
 547 EFIAPI
 548 MpInitLibStartupThisAP (
 549   IN  EFI_AP_PROCEDURE          Procedure,
 550   IN  UINTN                     ProcessorNumber,
 551   IN  EFI_EVENT                 WaitEvent               OPTIONAL,
 552   IN  UINTN                     TimeoutInMicroseconds,
 553   IN  VOID                      *ProcedureArgument      OPTIONAL,
 554   OUT BOOLEAN                   *Finished               OPTIONAL
 555   )
 556 {
 557   EFI_STATUS              Status;
 558
 559   //
 560   // temporarily stop checkAllApsStatus for avoid resource dead-lock.
 561   //
 562   mStopCheckAllApsStatus = TRUE;
 563
 564   Status = StartupThisAPWorker (
 565              Procedure,
 566              ProcessorNumber,
 567              WaitEvent,
 568              TimeoutInMicroseconds,
 569              ProcedureArgument,
 570              Finished
 571              );
 572
 573   mStopCheckAllApsStatus = FALSE;
 574
 575   return Status;
 576 }
 577
 578 /**
 579   This service switches the requested AP to be the BSP from that point onward.
 580   This service changes the BSP for all purposes. This call can only be performed
 581   by the current BSP.
 582
 583   @param[in] ProcessorNumber   The handle number of AP that is to become the new
 584                                BSP. The range is from 0 to the total number of
 585                                logical processors minus 1. The total number of
 586                                logical processors can be retrieved by
 587                                MpInitLibGetNumberOfProcessors().
 588   @param[in] EnableOldBSP      If TRUE, then the old BSP will be listed as an
 589                                enabled AP. Otherwise, it will be disabled.
 590
 591   @retval EFI_SUCCESS             BSP successfully switched.
 592   @retval EFI_UNSUPPORTED         Switching the BSP cannot be completed prior to
 593                                   this service returning.
 594   @retval EFI_UNSUPPORTED         Switching the BSP is not supported.
 595   @retval EFI_DEVICE_ERROR        The calling processor is an AP.
 596   @retval EFI_NOT_FOUND           The processor with the handle specified by
 597                                   ProcessorNumber does not exist.
 598   @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the current BSP or
 599                                   a disabled AP.
 600   @retval EFI_NOT_READY           The specified AP is busy.
 601   @retval EFI_NOT_READY           MP Initialize Library is not initialized.
 602
 603 **/
 604 EFI_STATUS
 605 EFIAPI
 606 MpInitLibSwitchBSP (
 607   IN UINTN                     ProcessorNumber,
 608   IN BOOLEAN                   EnableOldBSP
 609   )
 610 {
 611   EFI_STATUS            Status;
 612   BOOLEAN               OldInterruptState;
 613
 614   //
 615   // Before send both BSP and AP to a procedure to exchange their roles,
 616   // interrupt must be disabled. This is because during the exchange role
 617   // process, 2 CPU may use 1 stack. If interrupt happens, the stack will
 618   // be corrupted, since interrupt return address will be pushed to stack
 619   // by hardware.
 620   //
 621   OldInterruptState = SaveAndDisableInterrupts ();
 622
 623   //
 624   // Mask LINT0 & LINT1 for the old BSP
 625   //
 626   DisableLvtInterrupts ();
 627
 628   Status = SwitchBSPWorker (ProcessorNumber, EnableOldBSP);
 629
 630   //
 631   // Restore interrupt state.
 632   //
 633   SetInterruptState (OldInterruptState);
 634
 635   return Status;
 636 }
 637
 638 /**
 639   This service lets the caller enable or disable an AP from this point onward.
 640   This service may only be called from the BSP.
 641
 642   @param[in] ProcessorNumber   The handle number of AP.
 643                                The range is from 0 to the total number of
 644                                logical processors minus 1. The total number of
 645                                logical processors can be retrieved by
 646                                MpInitLibGetNumberOfProcessors().
 647   @param[in] EnableAP          Specifies the new state for the processor for
 648                                enabled, FALSE for disabled.
 649   @param[in] HealthFlag        If not NULL, a pointer to a value that specifies
 650                                the new health status of the AP. This flag
 651                                corresponds to StatusFlag defined in
 652                                EFI_MP_SERVICES_PROTOCOL.GetProcessorInfo(). Only
 653                                the PROCESSOR_HEALTH_STATUS_BIT is used. All other
 654                                bits are ignored.  If it is NULL, this parameter
 655                                is ignored.
 656
 657   @retval EFI_SUCCESS             The specified AP was enabled or disabled successfully.
 658   @retval EFI_UNSUPPORTED         Enabling or disabling an AP cannot be completed
 659                                   prior to this service returning.
 660   @retval EFI_UNSUPPORTED         Enabling or disabling an AP is not supported.
 661   @retval EFI_DEVICE_ERROR        The calling processor is an AP.
 662   @retval EFI_NOT_FOUND           Processor with the handle specified by ProcessorNumber
 663                                   does not exist.
 664   @retval EFI_INVALID_PARAMETER   ProcessorNumber specifies the BSP.
 665   @retval EFI_NOT_READY           MP Initialize Library is not initialized.
 666
 667 **/
 668 EFI_STATUS
 669 EFIAPI
 670 MpInitLibEnableDisableAP (
 671   IN  UINTN                     ProcessorNumber,
 672   IN  BOOLEAN                   EnableAP,
 673   IN  UINT32                    *HealthFlag OPTIONAL
 674   )
 675 {
 676   EFI_STATUS     Status;
 677   BOOLEAN        TempStopCheckState;
 678
 679   TempStopCheckState = FALSE;
 680   //
 681   // temporarily stop checkAllAPsStatus for initialize parameters.
 682   //
 683   if (!mStopCheckAllApsStatus) {
 684     mStopCheckAllApsStatus = TRUE;
 685     TempStopCheckState     = TRUE;
 686   }
 687
 688   Status = EnableDisableApWorker (ProcessorNumber, EnableAP, HealthFlag);
 689
 690   if (TempStopCheckState) {
 691     mStopCheckAllApsStatus = FALSE;
 692   }
 693
 694   return Status;
 695 }