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