UnixPkg/TimerDxe/Timer.c

   1 /*++
   2
   3 Copyright (c) 2004, 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   UNIX Emulation Timer Architectural Protocol Driver as defined in DXE CIS
  19
  20   This Timer module uses an UNIX 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 #include "PiDxe.h"
  26 #include <Protocol/Timer.h>
  27 #include <Protocol/Cpu.h>
  28 #include "Timer.h"
  29 #include <Library/BaseLib.h>
  30 #include <Library/DebugLib.h>
  31 #include <Library/UefiLib.h>
  32 #include <Library/UefiDriverEntryPoint.h>
  33 #include <Library/MemoryAllocationLib.h>
  34 #include <Library/UefiBootServicesTableLib.h>
  35 #include "UnixDxe.h"
  36 #include <Library/UnixLib.h>
  37
  38 //
  39 // Pointer to the CPU Architectural Protocol instance
  40 //
  41 EFI_CPU_ARCH_PROTOCOL   *mCpu;
  42
  43 //
  44 // The Timer Architectural Protocol that this driver produces
  45 //
  46 EFI_TIMER_ARCH_PROTOCOL mTimer = {
  47   UnixTimerDriverRegisterHandler,
  48   UnixTimerDriverSetTimerPeriod,
  49   UnixTimerDriverGetTimerPeriod,
  50   UnixTimerDriverGenerateSoftInterrupt
  51 };
  52
  53 //
  54 // The notification function to call on every timer interrupt
  55 //
  56 EFI_TIMER_NOTIFY        mTimerNotifyFunction = NULL;
  57
  58 //
  59 // The current period of the timer interrupt
  60 //
  61 UINT64                  mTimerPeriodMs;
  62
  63
  64 VOID
  65 TimerCallback (UINT64 DeltaMs)
  66 /*++
  67
  68 Routine Description:
  69
  70   TODO: Add function description
  71
  72 Arguments:
  73
  74   wTimerID  - TODO: add argument description
  75   msg       - TODO: add argument description
  76   dwUser    - TODO: add argument description
  77   dw1       - TODO: add argument description
  78   dw2       - TODO: add argument description
  79
  80 Returns:
  81
  82   TODO: add return values
  83
  84 --*/
  85 {
  86   EFI_TPL           OriginalTPL;
  87   EFI_TIMER_NOTIFY  CallbackFunction;
  88
  89
  90   OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
  91
  92   if (OriginalTPL < TPL_HIGH_LEVEL) {
  93     CallbackFunction = mTimerNotifyFunction;
  94
  95     //
  96     // Only invoke the callback function if a Non-NULL handler has been
  97     // registered. Assume all other handlers are legal.
  98     //
  99     if (CallbackFunction != NULL) {
 100       CallbackFunction ((UINT64) (DeltaMs * 10000));
 101     }
 102   }
 103
 104   gBS->RestoreTPL (OriginalTPL);
 105
 106 }
 107
 108 EFI_STATUS
 109 EFIAPI
 110 UnixTimerDriverRegisterHandler (
 111   IN EFI_TIMER_ARCH_PROTOCOL           *This,
 112   IN EFI_TIMER_NOTIFY                  NotifyFunction
 113   )
 114 /*++
 115
 116 Routine Description:
 117
 118   This function registers the handler NotifyFunction so it is called every time
 119   the timer interrupt fires.  It also passes the amount of time since the last
 120   handler call to the NotifyFunction.  If NotifyFunction is NULL, then the
 121   handler is unregistered.  If the handler is registered, then EFI_SUCCESS is
 122   returned.  If the CPU does not support registering a timer interrupt handler,
 123   then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler
 124   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
 125   If an attempt is made to unregister a handler when a handler is not registered,
 126   then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to
 127   register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
 128   is returned.
 129
 130 Arguments:
 131
 132   This           - The EFI_TIMER_ARCH_PROTOCOL instance.
 133
 134   NotifyFunction - The function to call when a timer interrupt fires.  This
 135                    function executes at TPL_HIGH_LEVEL.  The DXE Core will
 136                    register a handler for the timer interrupt, so it can know
 137                    how much time has passed.  This information is used to
 138                    signal timer based events.  NULL will unregister the handler.
 139
 140 Returns:
 141
 142   EFI_SUCCESS           - The timer handler was registered.
 143
 144   EFI_UNSUPPORTED       - The platform does not support timer interrupts.
 145
 146   EFI_ALREADY_STARTED   - NotifyFunction is not NULL, and a handler is already
 147                           registered.
 148
 149   EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not
 150                           previously registered.
 151
 152   EFI_DEVICE_ERROR      - The timer handler could not be registered.
 153
 154 --*/
 155 {
 156   //
 157   // Check for invalid parameters
 158   //
 159   if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {
 160     return EFI_INVALID_PARAMETER;
 161   }
 162
 163   if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {
 164     return EFI_ALREADY_STARTED;
 165   }
 166
 167   if (NotifyFunction == NULL) {
 168     /* Disable timer.  */
 169     gUnix->SetTimer (0, TimerCallback);
 170   } else if (mTimerNotifyFunction == NULL) {
 171     /* Enable Timer.  */
 172     gUnix->SetTimer (mTimerPeriodMs, TimerCallback);
 173   }
 174   mTimerNotifyFunction = NotifyFunction;
 175
 176   return EFI_SUCCESS;
 177 }
 178
 179 EFI_STATUS
 180 EFIAPI
 181 UnixTimerDriverSetTimerPeriod (
 182   IN EFI_TIMER_ARCH_PROTOCOL  *This,
 183   IN UINT64                   TimerPeriod
 184   )
 185 /*++
 186
 187 Routine Description:
 188
 189   This function adjusts the period of timer interrupts to the value specified
 190   by TimerPeriod.  If the timer period is updated, then the selected timer
 191   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
 192   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
 193   If an error occurs while attempting to update the timer period, then the
 194   timer hardware will be put back in its state prior to this call, and
 195   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 196   is disabled.  This is not the same as disabling the CPU's interrupts.
 197   Instead, it must either turn off the timer hardware, or it must adjust the
 198   interrupt controller so that a CPU interrupt is not generated when the timer
 199   interrupt fires.
 200
 201 Arguments:
 202
 203   This        - The EFI_TIMER_ARCH_PROTOCOL instance.
 204
 205   TimerPeriod - The rate to program the timer interrupt in 100 nS units.  If
 206                 the timer hardware is not programmable, then EFI_UNSUPPORTED is
 207                 returned.  If the timer is programmable, then the timer period
 208                 will be rounded up to the nearest timer period that is supported
 209                 by the timer hardware.  If TimerPeriod is set to 0, then the
 210                 timer interrupts will be disabled.
 211
 212 Returns:
 213
 214   EFI_SUCCESS      - The timer period was changed.
 215
 216   EFI_UNSUPPORTED  - The platform cannot change the period of the timer interrupt.
 217
 218   EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.
 219
 220 --*/
 221 {
 222
 223   //
 224   // If TimerPeriod is 0, then the timer thread should be canceled
 225   // If the TimerPeriod is valid, then create and/or adjust the period of the timer thread
 226   //
 227   if (TimerPeriod == 0
 228       || ((TimerPeriod > TIMER_MINIMUM_VALUE)
 229           && (TimerPeriod < TIMER_MAXIMUM_VALUE))) {
 230     mTimerPeriodMs = DivU64x32 (TimerPeriod + 5000, 10000);
 231
 232     gUnix->SetTimer (mTimerPeriodMs, TimerCallback);
 233   }
 234
 235   return EFI_SUCCESS;
 236 }
 237
 238 EFI_STATUS
 239 EFIAPI
 240 UnixTimerDriverGetTimerPeriod (
 241   IN EFI_TIMER_ARCH_PROTOCOL            *This,
 242   OUT UINT64                            *TimerPeriod
 243   )
 244 /*++
 245
 246 Routine Description:
 247
 248   This function retrieves the period of timer interrupts in 100 ns units,
 249   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 250   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 251   returned, then the timer is currently disabled.
 252
 253 Arguments:
 254
 255   This        - The EFI_TIMER_ARCH_PROTOCOL instance.
 256
 257   TimerPeriod - A pointer to the timer period to retrieve in 100 ns units.  If
 258                 0 is returned, then the timer is currently disabled.
 259
 260 Returns:
 261
 262   EFI_SUCCESS           - The timer period was returned in TimerPeriod.
 263
 264   EFI_INVALID_PARAMETER - TimerPeriod is NULL.
 265
 266 --*/
 267 {
 268   if (TimerPeriod == NULL) {
 269     return EFI_INVALID_PARAMETER;
 270   }
 271
 272   *TimerPeriod = mTimerPeriodMs * 10000;
 273
 274   return EFI_SUCCESS;
 275 }
 276
 277 EFI_STATUS
 278 EFIAPI
 279 UnixTimerDriverGenerateSoftInterrupt (
 280   IN EFI_TIMER_ARCH_PROTOCOL  *This
 281   )
 282 /*++
 283
 284 Routine Description:
 285
 286   This function generates a soft timer interrupt. If the platform does not support soft
 287   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 288   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 289   service, then a soft timer interrupt will be generated. If the timer interrupt is
 290   enabled when this service is called, then the registered handler will be invoked. The
 291   registered handler should not be able to distinguish a hardware-generated timer
 292   interrupt from a software-generated timer interrupt.
 293
 294 Arguments:
 295
 296   This  -  The EFI_TIMER_ARCH_PROTOCOL instance.
 297
 298 Returns:
 299
 300   EFI_SUCCESS       - The soft timer interrupt was generated.
 301
 302   EFI_UNSUPPORTEDT  - The platform does not support the generation of soft timer interrupts.
 303
 304 --*/
 305 {
 306   return EFI_UNSUPPORTED;
 307 }
 308
 309 EFI_STATUS
 310 EFIAPI
 311 UnixTimerDriverInitialize (
 312   IN EFI_HANDLE        ImageHandle,
 313   IN EFI_SYSTEM_TABLE  *SystemTable
 314   )
 315 /*++
 316
 317 Routine Description:
 318
 319   Initialize the Timer Architectural Protocol driver
 320
 321 Arguments:
 322
 323   ImageHandle - ImageHandle of the loaded driver
 324
 325   SystemTable - Pointer to the System Table
 326
 327 Returns:
 328
 329   EFI_SUCCESS           - Timer Architectural Protocol created
 330
 331   EFI_OUT_OF_RESOURCES  - Not enough resources available to initialize driver.
 332
 333   EFI_DEVICE_ERROR      - A device error occured attempting to initialize the driver.
 334
 335 --*/
 336 {
 337   EFI_STATUS  Status;
 338   EFI_HANDLE  Handle;
 339
 340   //
 341   // Make sure the Timer Architectural Protocol is not already installed in the system
 342   //
 343   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiTimerArchProtocolGuid);
 344
 345   //
 346   // Get the CPU Architectural Protocol instance
 347   //
 348   Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (void *)&mCpu);
 349   ASSERT_EFI_ERROR (Status);
 350
 351   //
 352   // Install the Timer Architectural Protocol onto a new handle
 353   //
 354   Handle = NULL;
 355   Status = gBS->InstallProtocolInterface (
 356                   &Handle,
 357                   &gEfiTimerArchProtocolGuid,
 358                   EFI_NATIVE_INTERFACE,
 359                   &mTimer
 360                   );
 361   if (EFI_ERROR (Status)) {
 362     return Status;
 363   }
 364
 365   //
 366   // Start the timer thread at the default timer period
 367   //
 368   Status = mTimer.SetTimerPeriod (&mTimer, DEFAULT_TIMER_TICK_DURATION);
 369   if (EFI_ERROR (Status)) {
 370     return Status;
 371   }
 372
 373   return EFI_SUCCESS;
 374 }