Nt32Pkg/TimerDxe/Timer.c

   1 /**@file
   2
   3 Copyright (c) 2006, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   Timer.c
  15
  16 Abstract:
  17
  18   NT Emulation Timer Architectural Protocol Driver as defined in DXE CIS
  19
  20   This Timer module uses an NT Thread to simulate the timer-tick driven
  21   timer service.  In the future, the Thread creation should possibly be
  22   abstracted by the CPU architectural protocol
  23
  24 **/
  25
  26 #include "Timer.h"
  27
  28 //
  29 // Pointer to the CPU Architectural Protocol instance
  30 //
  31 EFI_CPU_ARCH_PROTOCOL   *mCpu;
  32
  33 //
  34 // The Timer Architectural Protocol that this driver produces
  35 //
  36 EFI_TIMER_ARCH_PROTOCOL mTimer = {
  37   WinNtTimerDriverRegisterHandler,
  38   WinNtTimerDriverSetTimerPeriod,
  39   WinNtTimerDriverGetTimerPeriod,
  40   WinNtTimerDriverGenerateSoftInterrupt
  41 };
  42
  43 //
  44 // Define a global that we can use to shut down the NT timer thread when
  45 // the timer is canceled.
  46 //
  47 BOOLEAN                 mCancelTimerThread = FALSE;
  48
  49 //
  50 // The notification function to call on every timer interrupt
  51 //
  52 EFI_TIMER_NOTIFY        mTimerNotifyFunction = NULL;
  53
  54 //
  55 // The current period of the timer interrupt
  56 //
  57 UINT64                  mTimerPeriod;
  58
  59 //
  60 // The thread handle for this driver
  61 //
  62 HANDLE                  mNtMainThreadHandle;
  63
  64 //
  65 // The timer value from the last timer interrupt
  66 //
  67 UINT32                  mNtLastTick;
  68
  69 //
  70 // Critical section used to update varibles shared between the main thread and
  71 // the timer interrupt thread.
  72 //
  73 CRITICAL_SECTION        mNtCriticalSection;
  74
  75 //
  76 // Worker Functions
  77 //
  78 UINT                    mMMTimerThreadID = 0;
  79
  80 VOID
  81 CALLBACK
  82 MMTimerThread (
  83   UINT  wTimerID,
  84   UINT  msg,
  85   DWORD dwUser,
  86   DWORD dw1,
  87   DWORD dw2
  88   )
  89 /*++
  90
  91 Routine Description:
  92
  93   TODO: Add function description
  94
  95 Arguments:
  96
  97   wTimerID  - TODO: add argument description
  98   msg       - TODO: add argument description
  99   dwUser    - TODO: add argument description
 100   dw1       - TODO: add argument description
 101   dw2       - TODO: add argument description
 102
 103 Returns:
 104
 105   TODO: add return values
 106
 107 --*/
 108 {
 109   EFI_TPL           OriginalTPL;
 110   UINT32            CurrentTick;
 111   UINT32            Delta;
 112   EFI_TIMER_NOTIFY  CallbackFunction;
 113   BOOLEAN           InterruptState;
 114
 115   if (!mCancelTimerThread) {
 116
 117     //
 118     // Suspend the main thread until we are done.
 119     // Enter the critical section before suspending
 120     // and leave the critical section after resuming
 121     // to avoid deadlock between main and timer thread.
 122     //
 123     gWinNt->EnterCriticalSection (&mNtCriticalSection);
 124     gWinNt->SuspendThread (mNtMainThreadHandle);
 125
 126     //
 127     // If the timer thread is being canceled, then bail immediately.
 128     // We check again here because there's a small window of time from when
 129     // this thread was kicked off and when we suspended the main thread above.
 130     //
 131     if (mCancelTimerThread) {
 132       gWinNt->ResumeThread (mNtMainThreadHandle);
 133       gWinNt->LeaveCriticalSection (&mNtCriticalSection);
 134       gWinNt->timeKillEvent (wTimerID);
 135       mMMTimerThreadID = 0;
 136       return ;
 137     }
 138
 139     mCpu->GetInterruptState (mCpu, &InterruptState);
 140     while (!InterruptState) {
 141       //
 142       //  Resume the main thread
 143       //
 144       gWinNt->ResumeThread (mNtMainThreadHandle);
 145       gWinNt->LeaveCriticalSection (&mNtCriticalSection);
 146
 147       //
 148       //  Wait for interrupts to be enabled.
 149       //
 150       mCpu->GetInterruptState (mCpu, &InterruptState);
 151       while (!InterruptState) {
 152         gWinNt->Sleep (1);
 153         mCpu->GetInterruptState (mCpu, &InterruptState);
 154       }
 155
 156       //
 157       //  Suspend the main thread until we are done
 158       //
 159       gWinNt->EnterCriticalSection (&mNtCriticalSection);
 160       gWinNt->SuspendThread (mNtMainThreadHandle);
 161       mCpu->GetInterruptState (mCpu, &InterruptState);
 162     }
 163
 164     //
 165     //  Get the current system tick
 166     //
 167     CurrentTick = gWinNt->GetTickCount ();
 168     Delta       = CurrentTick - mNtLastTick;
 169     mNtLastTick = CurrentTick;
 170
 171     //
 172     //  If delay was more then 1 second, ignore it (probably debugging case)
 173     //
 174     if (Delta < 1000) {
 175
 176       OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
 177
 178       //
 179       //  Inform the firmware of an "timer interrupt".  The time
 180       //  expired since the last call is 10,000 times the number
 181       //  of ms.  (or 100ns units)
 182       //
 183       CallbackFunction = mTimerNotifyFunction;
 184
 185       //
 186       // Only invoke the callback function if a Non-NULL handler has been
 187       // registered. Assume all other handlers are legal.
 188       //
 189       if (CallbackFunction != NULL) {
 190         CallbackFunction ((UINT64) (Delta * 10000));
 191       }
 192
 193       gBS->RestoreTPL (OriginalTPL);
 194
 195     }
 196
 197     //
 198     //  Resume the main thread
 199     //
 200     gWinNt->ResumeThread (mNtMainThreadHandle);
 201     gWinNt->LeaveCriticalSection (&mNtCriticalSection);
 202   } else {
 203     gWinNt->timeKillEvent (wTimerID);
 204     mMMTimerThreadID = 0;
 205   }
 206
 207 }
 208
 209 UINT
 210 CreateNtTimer (
 211   VOID
 212   )
 213 /*++
 214
 215 Routine Description:
 216
 217    It is used to emulate a platform
 218   timer-driver interrupt handler.
 219
 220 Returns:
 221
 222   Timer ID
 223
 224 --*/
 225 // TODO: function comment is missing 'Arguments:'
 226 {
 227   UINT32  SleepCount;
 228
 229   //
 230   //  Set our thread priority higher than the "main" thread.
 231   //
 232   gWinNt->SetThreadPriority (
 233             gWinNt->GetCurrentThread (),
 234             THREAD_PRIORITY_HIGHEST
 235             );
 236
 237   //
 238   //  Calc the appropriate interval
 239   //
 240   gWinNt->EnterCriticalSection (&mNtCriticalSection);
 241   SleepCount = (UINT32) (mTimerPeriod + 5000) / 10000;
 242   gWinNt->LeaveCriticalSection (&mNtCriticalSection);
 243
 244   return gWinNt->timeSetEvent (
 245                   SleepCount,
 246                   0,
 247                   MMTimerThread,
 248                   (DWORD_PTR) NULL,
 249                   TIME_PERIODIC | TIME_KILL_SYNCHRONOUS | TIME_CALLBACK_FUNCTION
 250                   );
 251
 252 }
 253
 254 EFI_STATUS
 255 EFIAPI
 256 WinNtTimerDriverRegisterHandler (
 257   IN EFI_TIMER_ARCH_PROTOCOL           *This,
 258   IN EFI_TIMER_NOTIFY                  NotifyFunction
 259   )
 260 /*++
 261
 262 Routine Description:
 263
 264   This function registers the handler NotifyFunction so it is called every time
 265   the timer interrupt fires.  It also passes the amount of time since the last
 266   handler call to the NotifyFunction.  If NotifyFunction is NULL, then the
 267   handler is unregistered.  If the handler is registered, then EFI_SUCCESS is
 268   returned.  If the CPU does not support registering a timer interrupt handler,
 269   then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler
 270   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
 271   If an attempt is made to unregister a handler when a handler is not registered,
 272   then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to
 273   register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
 274   is returned.
 275
 276 Arguments:
 277
 278   This           - The EFI_TIMER_ARCH_PROTOCOL instance.
 279
 280   NotifyFunction - The function to call when a timer interrupt fires.  This
 281                    function executes at TPL_HIGH_LEVEL.  The DXE Core will
 282                    register a handler for the timer interrupt, so it can know
 283                    how much time has passed.  This information is used to
 284                    signal timer based events.  NULL will unregister the handler.
 285
 286 Returns:
 287
 288   EFI_SUCCESS           - The timer handler was registered.
 289
 290   EFI_UNSUPPORTED       - The platform does not support timer interrupts.
 291
 292   EFI_ALREADY_STARTED   - NotifyFunction is not NULL, and a handler is already
 293                           registered.
 294
 295   EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not
 296                           previously registered.
 297
 298   EFI_DEVICE_ERROR      - The timer handler could not be registered.
 299
 300 --*/
 301 {
 302   //
 303   // Check for invalid parameters
 304   //
 305   if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {
 306     return EFI_INVALID_PARAMETER;
 307   }
 308
 309   if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {
 310     return EFI_ALREADY_STARTED;
 311   }
 312
 313   //
 314   // Use Critical Section to update the notification function that is
 315   // used from the timer interrupt thread.
 316   //
 317   gWinNt->EnterCriticalSection (&mNtCriticalSection);
 318
 319   mTimerNotifyFunction = NotifyFunction;
 320
 321   gWinNt->LeaveCriticalSection (&mNtCriticalSection);
 322
 323   return EFI_SUCCESS;
 324 }
 325
 326 EFI_STATUS
 327 EFIAPI
 328 WinNtTimerDriverSetTimerPeriod (
 329   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 330   IN UINT64                   TimerPeriod
 331   )
 332 /*++
 333
 334 Routine Description:
 335
 336   This function adjusts the period of timer interrupts to the value specified
 337   by TimerPeriod.  If the timer period is updated, then the selected timer
 338   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
 339   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
 340   If an error occurs while attempting to update the timer period, then the
 341   timer hardware will be put back in its state prior to this call, and
 342   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 343   is disabled.  This is not the same as disabling the CPU's interrupts.
 344   Instead, it must either turn off the timer hardware, or it must adjust the
 345   interrupt controller so that a CPU interrupt is not generated when the timer
 346   interrupt fires.
 347
 348 Arguments:
 349
 350   This        - The EFI_TIMER_ARCH_PROTOCOL instance.
 351
 352   TimerPeriod - The rate to program the timer interrupt in 100 nS units.  If
 353                 the timer hardware is not programmable, then EFI_UNSUPPORTED is
 354                 returned.  If the timer is programmable, then the timer period
 355                 will be rounded up to the nearest timer period that is supported
 356                 by the timer hardware.  If TimerPeriod is set to 0, then the
 357                 timer interrupts will be disabled.
 358
 359 Returns:
 360
 361   EFI_SUCCESS      - The timer period was changed.
 362
 363   EFI_UNSUPPORTED  - The platform cannot change the period of the timer interrupt.
 364
 365   EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.
 366
 367 --*/
 368 {
 369
 370   //
 371   // If TimerPeriod is 0, then the timer thread should be canceled
 372   //
 373   if (TimerPeriod == 0) {
 374     //
 375     // Cancel the timer thread
 376     //
 377     gWinNt->EnterCriticalSection (&mNtCriticalSection);
 378
 379     mCancelTimerThread = TRUE;
 380
 381     gWinNt->LeaveCriticalSection (&mNtCriticalSection);
 382
 383     //
 384     // Wait for the timer thread to exit
 385     //
 386
 387     if (mMMTimerThreadID) {
 388       gWinNt->timeKillEvent (mMMTimerThreadID);
 389     }
 390
 391     mMMTimerThreadID = 0;
 392
 393     //
 394     // Update the timer period
 395     //
 396     gWinNt->EnterCriticalSection (&mNtCriticalSection);
 397
 398     mTimerPeriod = TimerPeriod;
 399
 400     gWinNt->LeaveCriticalSection (&mNtCriticalSection);
 401
 402     //
 403     // NULL out the thread handle so it will be re-created if the timer is enabled again
 404     //
 405
 406   } else if ((TimerPeriod > TIMER_MINIMUM_VALUE) && (TimerPeriod < TIMER_MAXIMUM_VALUE)) {
 407     //
 408     // If the TimerPeriod is valid, then create and/or adjust the period of the timer thread
 409     //
 410     gWinNt->EnterCriticalSection (&mNtCriticalSection);
 411
 412     mTimerPeriod        = TimerPeriod;
 413
 414     mCancelTimerThread  = FALSE;
 415
 416     gWinNt->LeaveCriticalSection (&mNtCriticalSection);
 417
 418     //
 419     //  Get the starting tick location if we are just starting the timer thread
 420     //
 421     mNtLastTick = gWinNt->GetTickCount ();
 422
 423     if (mMMTimerThreadID) {
 424       gWinNt->timeKillEvent (mMMTimerThreadID);
 425     }
 426
 427     mMMTimerThreadID  = 0;
 428
 429     mMMTimerThreadID  = CreateNtTimer ();
 430
 431   }
 432
 433   return EFI_SUCCESS;
 434 }
 435
 436 EFI_STATUS
 437 EFIAPI
 438 WinNtTimerDriverGetTimerPeriod (
 439   IN EFI_TIMER_ARCH_PROTOCOL            *This,
 440   OUT UINT64                            *TimerPeriod
 441   )
 442 /*++
 443
 444 Routine Description:
 445
 446   This function retrieves the period of timer interrupts in 100 ns units,
 447   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 448   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 449   returned, then the timer is currently disabled.
 450
 451 Arguments:
 452
 453   This        - The EFI_TIMER_ARCH_PROTOCOL instance.
 454
 455   TimerPeriod - A pointer to the timer period to retrieve in 100 ns units.  If
 456                 0 is returned, then the timer is currently disabled.
 457
 458 Returns:
 459
 460   EFI_SUCCESS           - The timer period was returned in TimerPeriod.
 461
 462   EFI_INVALID_PARAMETER - TimerPeriod is NULL.
 463
 464 --*/
 465 {
 466   if (TimerPeriod == NULL) {
 467     return EFI_INVALID_PARAMETER;
 468   }
 469
 470   *TimerPeriod = mTimerPeriod;
 471
 472   return EFI_SUCCESS;
 473 }
 474
 475 EFI_STATUS
 476 EFIAPI
 477 WinNtTimerDriverGenerateSoftInterrupt (
 478   IN EFI_TIMER_ARCH_PROTOCOL  *This
 479   )
 480 /*++
 481
 482 Routine Description:
 483
 484   This function generates a soft timer interrupt. If the platform does not support soft
 485   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 486   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 487   service, then a soft timer interrupt will be generated. If the timer interrupt is
 488   enabled when this service is called, then the registered handler will be invoked. The
 489   registered handler should not be able to distinguish a hardware-generated timer
 490   interrupt from a software-generated timer interrupt.
 491
 492 Arguments:
 493
 494   This  -  The EFI_TIMER_ARCH_PROTOCOL instance.
 495
 496 Returns:
 497
 498   EFI_SUCCESS       - The soft timer interrupt was generated.
 499
 500   EFI_UNSUPPORTEDT  - The platform does not support the generation of soft timer interrupts.
 501
 502 --*/
 503 {
 504   return EFI_UNSUPPORTED;
 505 }
 506
 507
 508 EFI_STATUS
 509 EFIAPI
 510 WinNtTimerDriverInitialize (
 511   IN EFI_HANDLE        ImageHandle,
 512   IN EFI_SYSTEM_TABLE  *SystemTable
 513   )
 514 /*++
 515
 516 Routine Description:
 517
 518   Initialize the Timer Architectural Protocol driver
 519
 520 Arguments:
 521
 522   ImageHandle - ImageHandle of the loaded driver
 523
 524   SystemTable - Pointer to the System Table
 525
 526 Returns:
 527
 528   EFI_SUCCESS           - Timer Architectural Protocol created
 529
 530   EFI_OUT_OF_RESOURCES  - Not enough resources available to initialize driver.
 531
 532   EFI_DEVICE_ERROR      - A device error occured attempting to initialize the driver.
 533
 534 --*/
 535 {
 536   EFI_STATUS  Status;
 537   UINTN       Result;
 538   EFI_HANDLE  Handle;
 539   EFI_HANDLE  hSourceProcessHandle;
 540   EFI_HANDLE  hSourceHandle;
 541   EFI_HANDLE  hTargetProcessHandle;
 542   //
 543   // Make sure the Timer Architectural Protocol is not already installed in the system
 544   //
 545   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiTimerArchProtocolGuid);
 546
 547   //
 548   // Get the CPU Architectural Protocol instance
 549   //
 550   Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID**)&mCpu);
 551   ASSERT_EFI_ERROR (Status);
 552
 553   //
 554   //  Get our handle so the timer tick thread can suspend
 555   //
 556   hSourceProcessHandle = gWinNt->GetCurrentProcess ();
 557   hSourceHandle        = gWinNt->GetCurrentThread ();
 558   hTargetProcessHandle = gWinNt->GetCurrentProcess ();
 559   Result = gWinNt->DuplicateHandle (
 560                     hSourceProcessHandle,
 561                     hSourceHandle,
 562                     hTargetProcessHandle,
 563                     &mNtMainThreadHandle,
 564                     0,
 565                     FALSE,
 566                     DUPLICATE_SAME_ACCESS
 567                     );
 568   if (Result == 0) {
 569     return EFI_DEVICE_ERROR;
 570   }
 571
 572   //
 573   // Initialize Critical Section used to update variables shared between the main
 574   // thread and the timer interrupt thread.
 575   //
 576   gWinNt->InitializeCriticalSection (&mNtCriticalSection);
 577
 578   //
 579   // Start the timer thread at the default timer period
 580   //
 581   Status = mTimer.SetTimerPeriod (&mTimer, DEFAULT_TIMER_TICK_DURATION);
 582   if (EFI_ERROR (Status)) {
 583     gWinNt->DeleteCriticalSection (&mNtCriticalSection);
 584     return Status;
 585   }
 586
 587   //
 588   // Install the Timer Architectural Protocol onto a new handle
 589   //
 590   Handle = NULL;
 591   Status = gBS->InstallProtocolInterface (
 592                   &Handle,
 593                   &gEfiTimerArchProtocolGuid,
 594                   EFI_NATIVE_INTERFACE,
 595                   &mTimer
 596                   );
 597   if (EFI_ERROR (Status)) {
 598     //
 599     // Cancel the timer
 600     //
 601     mTimer.SetTimerPeriod (&mTimer, 0);
 602     gWinNt->DeleteCriticalSection (&mNtCriticalSection);
 603     return Status;
 604   }
 605
 606   return EFI_SUCCESS;
 607 }