TimerDxe.c revision e703b085f6a3a2e7a61be97d9154437520b3ae75
1/** @file 2 Timer Architecture Protocol driver of the ARM flavor 3 4 Copyright (c) 2011-2013 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. 33EFI_TIMER_NOTIFY mTimerNotifyFunction = (EFI_TIMER_NOTIFY)NULL; 34EFI_EVENT EfiExitBootServicesEvent = (EFI_EVENT)NULL; 35 36// The current period of the timer interrupt 37UINT64 mTimerPeriod = 0; 38 39// Cached copy of the Hardware Interrupt protocol instance 40EFI_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**/ 70EFI_STATUS 71EFIAPI 72TimerDriverRegisterHandler ( 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**/ 93VOID 94EFIAPI 95ExitBootServicesEvent ( 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**/ 131EFI_STATUS 132EFIAPI 133TimerDriverSetTimerPeriod ( 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**/ 175EFI_STATUS 176EFIAPI 177TimerDriverGetTimerPeriod ( 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**/ 205EFI_STATUS 206EFIAPI 207TimerDriverGenerateSoftInterrupt ( 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**/ 248EFI_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**/ 268VOID 269EFIAPI 270TimerInterruptHandler ( 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**/ 318EFI_STATUS 319EFIAPI 320TimerInitialize ( 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 TimerCtrlReg = ArmArchTimerGetTimerCtrlReg (); 340 TimerCtrlReg |= ARM_ARCH_TIMER_IMASK; 341 TimerCtrlReg &= ~ARM_ARCH_TIMER_ENABLE; 342 ArmArchTimerSetTimerCtrlReg (TimerCtrlReg); 343 Status = TimerDriverSetTimerPeriod (&gTimer, 0); 344 ASSERT_EFI_ERROR (Status); 345 346 // Install secure and Non-secure interrupt handlers 347 // Note: Because it is not possible to determine the security state of the 348 // CPU dynamically, we just install interrupt handler for both sec and non-sec 349 // timer PPI 350 Status = gInterrupt->RegisterInterruptSource (gInterrupt, PcdGet32 (PcdArmArchTimerSecIntrNum), TimerInterruptHandler); 351 ASSERT_EFI_ERROR (Status); 352 353 Status = gInterrupt->RegisterInterruptSource (gInterrupt, PcdGet32 (PcdArmArchTimerIntrNum), TimerInterruptHandler); 354 ASSERT_EFI_ERROR (Status); 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 // Everything is ready, unmask and enable timer interrupts 369 TimerCtrlReg = ARM_ARCH_TIMER_ENABLE; 370 ArmArchTimerSetTimerCtrlReg (TimerCtrlReg); 371 372 // Register for an ExitBootServicesEvent 373 Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_NOTIFY, ExitBootServicesEvent, NULL, &EfiExitBootServicesEvent); 374 ASSERT_EFI_ERROR (Status); 375 376 return Status; 377} 378