1 /**@file 2 3 Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR> 4 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_UNSUPPORTED - 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 } 608