ArmPkg/Drivers/TimerDxe/TimerDxe.c

   1 /** @file
   2   Timer Architecture Protocol driver of the ARM flavor
   3
   4   Copyright (c) 2011 ARM Ltd. All rights reserved.<BR>
   5
   6   This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16
  17 #include <PiDxe.h>
  18
  19 #include <Library/ArmLib.h>
  20 #include <Library/BaseLib.h>
  21 #include <Library/DebugLib.h>
  22 #include <Library/BaseMemoryLib.h>
  23 #include <Library/UefiBootServicesTableLib.h>
  24 #include <Library/UefiLib.h>
  25 #include <Library/PcdLib.h>
  26 #include <Library/IoLib.h>
  27 #include <Library/ArmV7ArchTimerLib.h>
  28
  29 #include <Protocol/Timer.h>
  30 #include <Protocol/HardwareInterrupt.h>
  31
  32 // The notification function to call on every timer interrupt.
  33 EFI_TIMER_NOTIFY      mTimerNotifyFunction     = (EFI_TIMER_NOTIFY)NULL;
  34 EFI_EVENT             EfiExitBootServicesEvent = (EFI_EVENT)NULL;
  35
  36 // The current period of the timer interrupt
  37 UINT64 mTimerPeriod = 0;
  38
  39 // Cached copy of the Hardware Interrupt protocol instance
  40 EFI_HARDWARE_INTERRUPT_PROTOCOL *gInterrupt = NULL;
  41
  42 /**
  43   This function registers the handler NotifyFunction so it is called every time
  44   the timer interrupt fires.  It also passes the amount of time since the last
  45   handler call to the NotifyFunction.  If NotifyFunction is NULL, then the
  46   handler is unregistered.  If the handler is registered, then EFI_SUCCESS is
  47   returned.  If the CPU does not support registering a timer interrupt handler,
  48   then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler
  49   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
  50   If an attempt is made to unregister a handler when a handler is not registered,
  51   then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to
  52   register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
  53   is returned.
  54
  55   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
  56   @param  NotifyFunction   The function to call when a timer interrupt fires. This
  57                            function executes at TPL_HIGH_LEVEL. The DXE Core will
  58                            register a handler for the timer interrupt, so it can know
  59                            how much time has passed. This information is used to
  60                            signal timer based events. NULL will unregister the handler.
  61   @retval EFI_SUCCESS           The timer handler was registered.
  62   @retval EFI_UNSUPPORTED       The platform does not support timer interrupts.
  63   @retval EFI_ALREADY_STARTED   NotifyFunction is not NULL, and a handler is already
  64                                 registered.
  65   @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not
  66                                 previously registered.
  67   @retval EFI_DEVICE_ERROR      The timer handler could not be registered.
  68
  69 **/
  70 EFI_STATUS
  71 EFIAPI
  72 TimerDriverRegisterHandler (
  73   IN EFI_TIMER_ARCH_PROTOCOL  *This,
  74   IN EFI_TIMER_NOTIFY         NotifyFunction
  75   )
  76 {
  77   if ((NotifyFunction == NULL) && (mTimerNotifyFunction == NULL)) {
  78     return EFI_INVALID_PARAMETER;
  79   }
  80
  81   if ((NotifyFunction != NULL) && (mTimerNotifyFunction != NULL)) {
  82     return EFI_ALREADY_STARTED;
  83   }
  84
  85   mTimerNotifyFunction = NotifyFunction;
  86
  87   return EFI_SUCCESS;
  88 }
  89
  90 /**
  91     Disable the timer
  92 **/
  93 VOID
  94 EFIAPI
  95 ExitBootServicesEvent (
  96   IN EFI_EVENT  Event,
  97   IN VOID       *Context
  98   )
  99 {
 100   ArmArchTimerDisableTimer ();
 101 }
 102
 103 /**
 104
 105   This function adjusts the period of timer interrupts to the value specified
 106   by TimerPeriod.  If the timer period is updated, then the selected timer
 107   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
 108   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
 109   If an error occurs while attempting to update the timer period, then the
 110   timer hardware will be put back in its state prior to this call, and
 111   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 112   is disabled.  This is not the same as disabling the CPU's interrupts.
 113   Instead, it must either turn off the timer hardware, or it must adjust the
 114   interrupt controller so that a CPU interrupt is not generated when the timer
 115   interrupt fires.
 116
 117   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 118   @param  TimerPeriod      The rate to program the timer interrupt in 100 nS units. If
 119                            the timer hardware is not programmable, then EFI_UNSUPPORTED is
 120                            returned. If the timer is programmable, then the timer period
 121                            will be rounded up to the nearest timer period that is supported
 122                            by the timer hardware. If TimerPeriod is set to 0, then the
 123                            timer interrupts will be disabled.
 124
 125
 126   @retval EFI_SUCCESS           The timer period was changed.
 127   @retval EFI_UNSUPPORTED       The platform cannot change the period of the timer interrupt.
 128   @retval EFI_DEVICE_ERROR      The timer period could not be changed due to a device error.
 129
 130 **/
 131 EFI_STATUS
 132 EFIAPI
 133 TimerDriverSetTimerPeriod (
 134   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 135   IN UINT64                   TimerPeriod
 136   )
 137 {
 138   UINT64      TimerTicks;
 139
 140   // Always disable the timer
 141   ArmArchTimerDisableTimer ();
 142
 143   if (TimerPeriod != 0) {
 144     // Convert TimerPeriod to micro sec units
 145     TimerTicks = DivU64x32 (TimerPeriod, 10);
 146
 147     TimerTicks = MultU64x32 (TimerTicks, (PcdGet32(PcdArmArchTimerFreqInHz)/1000000));
 148
 149     ArmArchTimerSetTimerVal((UINTN)TimerTicks);
 150
 151     // Enable the timer
 152     ArmArchTimerEnableTimer ();
 153   }
 154
 155   // Save the new timer period
 156   mTimerPeriod = TimerPeriod;
 157   return EFI_SUCCESS;
 158 }
 159
 160 /**
 161   This function retrieves the period of timer interrupts in 100 ns units,
 162   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 163   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 164   returned, then the timer is currently disabled.
 165
 166   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 167   @param  TimerPeriod      A pointer to the timer period to retrieve in 100 ns units. If
 168                            0 is returned, then the timer is currently disabled.
 169
 170
 171   @retval EFI_SUCCESS           The timer period was returned in TimerPeriod.
 172   @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.
 173
 174 **/
 175 EFI_STATUS
 176 EFIAPI
 177 TimerDriverGetTimerPeriod (
 178   IN EFI_TIMER_ARCH_PROTOCOL   *This,
 179   OUT UINT64                   *TimerPeriod
 180   )
 181 {
 182   if (TimerPeriod == NULL) {
 183     return EFI_INVALID_PARAMETER;
 184   }
 185
 186   *TimerPeriod = mTimerPeriod;
 187   return EFI_SUCCESS;
 188 }
 189
 190 /**
 191   This function generates a soft timer interrupt. If the platform does not support soft
 192   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 193   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 194   service, then a soft timer interrupt will be generated. If the timer interrupt is
 195   enabled when this service is called, then the registered handler will be invoked. The
 196   registered handler should not be able to distinguish a hardware-generated timer
 197   interrupt from a software-generated timer interrupt.
 198
 199   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 200
 201   @retval EFI_SUCCESS           The soft timer interrupt was generated.
 202   @retval EFI_UNSUPPORTED       The platform does not support the generation of soft timer interrupts.
 203
 204 **/
 205 EFI_STATUS
 206 EFIAPI
 207 TimerDriverGenerateSoftInterrupt (
 208   IN EFI_TIMER_ARCH_PROTOCOL  *This
 209   )
 210 {
 211   return EFI_UNSUPPORTED;
 212 }
 213
 214 /**
 215   Interface structure for the Timer Architectural Protocol.
 216
 217   @par Protocol Description:
 218   This protocol provides the services to initialize a periodic timer
 219   interrupt, and to register a handler that is called each time the timer
 220   interrupt fires.  It may also provide a service to adjust the rate of the
 221   periodic timer interrupt.  When a timer interrupt occurs, the handler is
 222   passed the amount of time that has passed since the previous timer
 223   interrupt.
 224
 225   @param RegisterHandler
 226   Registers a handler that will be called each time the
 227   timer interrupt fires.  TimerPeriod defines the minimum
 228   time between timer interrupts, so TimerPeriod will also
 229   be the minimum time between calls to the registered
 230   handler.
 231
 232   @param SetTimerPeriod
 233   Sets the period of the timer interrupt in 100 nS units.
 234   This function is optional, and may return EFI_UNSUPPORTED.
 235   If this function is supported, then the timer period will
 236   be rounded up to the nearest supported timer period.
 237
 238
 239   @param GetTimerPeriod
 240   Retrieves the period of the timer interrupt in 100 nS units.
 241
 242   @param GenerateSoftInterrupt
 243   Generates a soft timer interrupt that simulates the firing of
 244   the timer interrupt. This service can be used to invoke the   registered handler if the timer interrupt has been masked for
 245   a period of time.
 246
 247 **/
 248 EFI_TIMER_ARCH_PROTOCOL   gTimer = {
 249   TimerDriverRegisterHandler,
 250   TimerDriverSetTimerPeriod,
 251   TimerDriverGetTimerPeriod,
 252   TimerDriverGenerateSoftInterrupt
 253 };
 254
 255 /**
 256
 257   C Interrupt Handler called in the interrupt context when Source interrupt is active.
 258
 259
 260   @param Source         Source of the interrupt. Hardware routing off a specific platform defines
 261                         what source means.
 262
 263   @param SystemContext  Pointer to system register context. Mostly used by debuggers and will
 264                         update the system context after the return from the interrupt if
 265                         modified. Don't change these values unless you know what you are doing
 266
 267 **/
 268 VOID
 269 EFIAPI
 270 TimerInterruptHandler (
 271   IN  HARDWARE_INTERRUPT_SOURCE   Source,
 272   IN  EFI_SYSTEM_CONTEXT          SystemContext
 273   )
 274 {
 275   EFI_TPL      OriginalTPL;
 276
 277   //
 278   // DXE core uses this callback for the EFI timer tick. The DXE core uses locks
 279   // that raise to TPL_HIGH and then restore back to current level. Thus we need
 280   // to make sure TPL level is set to TPL_HIGH while we are handling the timer tick.
 281   //
 282   OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
 283
 284   // Check if the timer interrupt is active
 285   if ((ArmArchTimerGetTimerCtrlReg () ) & ARM_ARCH_TIMER_ISTATUS) {
 286
 287     // Signal end of interrupt early to help avoid losing subsequent ticks from long duration handlers
 288     gInterrupt->EndOfInterrupt (gInterrupt, Source);
 289
 290     if (mTimerNotifyFunction) {
 291       mTimerNotifyFunction (mTimerPeriod);
 292     }
 293
 294     // Reload the Timer
 295     TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32(PcdTimerPeriod));
 296   }
 297
 298   // Enable timer interrupts
 299   gInterrupt->EnableInterruptSource (gInterrupt, Source);
 300
 301   gBS->RestoreTPL (OriginalTPL);
 302 }
 303
 304
 305 /**
 306   Initialize the state information for the Timer Architectural Protocol and
 307   the Timer Debug support protocol that allows the debugger to break into a
 308   running program.
 309
 310   @param  ImageHandle   of the loaded driver
 311   @param  SystemTable   Pointer to the System Table
 312
 313   @retval EFI_SUCCESS           Protocol registered
 314   @retval EFI_OUT_OF_RESOURCES  Cannot allocate protocol data structure
 315   @retval EFI_DEVICE_ERROR      Hardware problems
 316
 317 **/
 318 EFI_STATUS
 319 EFIAPI
 320 TimerInitialize (
 321   IN EFI_HANDLE         ImageHandle,
 322   IN EFI_SYSTEM_TABLE   *SystemTable
 323   )
 324 {
 325   EFI_HANDLE  Handle = NULL;
 326   EFI_STATUS  Status;
 327   UINTN TimerCtrlReg;
 328
 329   if (ArmIsArchTimerImplemented () == 0) {
 330     DEBUG ((EFI_D_ERROR, "ARM Architectural Timer is not available in the CPU, hence cann't use this Driver \n"));
 331     ASSERT (0);
 332   }
 333
 334   // Find the interrupt controller protocol.  ASSERT if not found.
 335   Status = gBS->LocateProtocol (&gHardwareInterruptProtocolGuid, NULL, (VOID **)&gInterrupt);
 336   ASSERT_EFI_ERROR (Status);
 337
 338   // Disable the timer
 339   Status = TimerDriverSetTimerPeriod (&gTimer, 0);
 340   ASSERT_EFI_ERROR (Status);
 341
 342   // Install secure and Non-secure interrupt handlers
 343   // Note: Because it is not possible to determine the security state of the
 344   // CPU dynamically, we just install interrupt handler for both sec and non-sec
 345   // timer PPI
 346   Status = gInterrupt->RegisterInterruptSource (gInterrupt, PcdGet32 (PcdArmArchTimerSecIntrNum), TimerInterruptHandler);
 347   ASSERT_EFI_ERROR (Status);
 348
 349   Status = gInterrupt->RegisterInterruptSource (gInterrupt, PcdGet32 (PcdArmArchTimerIntrNum), TimerInterruptHandler);
 350   ASSERT_EFI_ERROR (Status);
 351
 352   // Unmask timer interrupts
 353   TimerCtrlReg = ArmArchTimerGetTimerCtrlReg ();
 354   TimerCtrlReg &= ~ARM_ARCH_TIMER_IMASK;
 355   ArmArchTimerSetTimerCtrlReg (TimerCtrlReg);
 356
 357   // Set up default timer
 358   Status = TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32(PcdTimerPeriod)); // TIMER_DEFAULT_PERIOD
 359   ASSERT_EFI_ERROR (Status);
 360
 361   // Install the Timer Architectural Protocol onto a new handle
 362   Status = gBS->InstallMultipleProtocolInterfaces(
 363                   &Handle,
 364                   &gEfiTimerArchProtocolGuid,      &gTimer,
 365                   NULL
 366                   );
 367   ASSERT_EFI_ERROR(Status);
 368
 369   // enable Secure timer interrupts
 370   Status = gInterrupt->EnableInterruptSource (gInterrupt, PcdGet32 (PcdArmArchTimerSecIntrNum));
 371
 372   // enable NonSecure timer interrupts
 373   Status = gInterrupt->EnableInterruptSource (gInterrupt, PcdGet32 (PcdArmArchTimerIntrNum));
 374
 375   // Register for an ExitBootServicesEvent
 376   Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_NOTIFY, ExitBootServicesEvent, NULL, &EfiExitBootServicesEvent);
 377   ASSERT_EFI_ERROR (Status);
 378
 379   return Status;
 380 }