1 /*++ @file 2 Emu Emulation Timer Architectural Protocol Driver as defined in DXE CIS 3 4 This Timer module uses an Emu Thread to simulate the timer-tick driven 5 timer service. In the future, the Thread creation should possibly be 6 abstracted by the CPU architectural protocol 7 8 Copyright (c) 2004 - 2016, Intel Corporation. All rights reserved.<BR> 9 Portions copyright (c) 2010 - 2011, Apple Inc. All rights reserved. 10 This program and the accompanying materials 11 are licensed and made available under the terms and conditions of the BSD License 12 which accompanies this distribution. The full text of the license may be found at 13 http://opensource.org/licenses/bsd-license.php 14 15 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 16 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 17 18 19 **/ 20 21 #include "PiDxe.h" 22 #include <Protocol/Timer.h> 23 #include <Protocol/Cpu.h> 24 #include "Timer.h" 25 #include <Library/BaseLib.h> 26 #include <Library/DebugLib.h> 27 #include <Library/UefiLib.h> 28 #include <Library/UefiDriverEntryPoint.h> 29 #include <Library/MemoryAllocationLib.h> 30 #include <Library/UefiBootServicesTableLib.h> 31 #include <Library/EmuThunkLib.h> 32 33 // 34 // Pointer to the CPU Architectural Protocol instance 35 // 36 EFI_CPU_ARCH_PROTOCOL *mCpu; 37 38 // 39 // The Timer Architectural Protocol that this driver produces 40 // 41 EFI_TIMER_ARCH_PROTOCOL mTimer = { 42 EmuTimerDriverRegisterHandler, 43 EmuTimerDriverSetTimerPeriod, 44 EmuTimerDriverGetTimerPeriod, 45 EmuTimerDriverGenerateSoftInterrupt 46 }; 47 48 // 49 // The notification function to call on every timer interrupt 50 // 51 EFI_TIMER_NOTIFY mTimerNotifyFunction = NULL; 52 53 // 54 // The current period of the timer interrupt 55 // 56 UINT64 mTimerPeriodMs; 57 58 59 VOID 60 EFIAPI 61 TimerCallback (UINT64 DeltaMs) 62 { 63 EFI_TPL OriginalTPL; 64 EFI_TIMER_NOTIFY CallbackFunction; 65 66 67 OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL); 68 69 if (OriginalTPL < TPL_HIGH_LEVEL) { 70 CallbackFunction = mTimerNotifyFunction; 71 72 // 73 // Only invoke the callback function if a Non-NULL handler has been 74 // registered. Assume all other handlers are legal. 75 // 76 if (CallbackFunction != NULL) { 77 CallbackFunction (MultU64x32 (DeltaMs, 10000)); 78 } 79 } 80 81 gBS->RestoreTPL (OriginalTPL); 82 83 } 84 85 EFI_STATUS 86 EFIAPI 87 EmuTimerDriverRegisterHandler ( 88 IN EFI_TIMER_ARCH_PROTOCOL *This, 89 IN EFI_TIMER_NOTIFY NotifyFunction 90 ) 91 /*++ 92 93 Routine Description: 94 95 This function registers the handler NotifyFunction so it is called every time 96 the timer interrupt fires. It also passes the amount of time since the last 97 handler call to the NotifyFunction. If NotifyFunction is NULL, then the 98 handler is unregistered. If the handler is registered, then EFI_SUCCESS is 99 returned. If the CPU does not support registering a timer interrupt handler, 100 then EFI_UNSUPPORTED is returned. If an attempt is made to register a handler 101 when a handler is already registered, then EFI_ALREADY_STARTED is returned. 102 If an attempt is made to unregister a handler when a handler is not registered, 103 then EFI_INVALID_PARAMETER is returned. If an error occurs attempting to 104 register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR 105 is returned. 106 107 Arguments: 108 109 This - The EFI_TIMER_ARCH_PROTOCOL instance. 110 111 NotifyFunction - The function to call when a timer interrupt fires. This 112 function executes at TPL_HIGH_LEVEL. The DXE Core will 113 register a handler for the timer interrupt, so it can know 114 how much time has passed. This information is used to 115 signal timer based events. NULL will unregister the handler. 116 117 Returns: 118 119 EFI_SUCCESS - The timer handler was registered. 120 121 EFI_UNSUPPORTED - The platform does not support timer interrupts. 122 123 EFI_ALREADY_STARTED - NotifyFunction is not NULL, and a handler is already 124 registered. 125 126 EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not 127 previously registered. 128 129 EFI_DEVICE_ERROR - The timer handler could not be registered. 130 131 **/ 132 { 133 // 134 // Check for invalid parameters 135 // 136 if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) { 137 return EFI_INVALID_PARAMETER; 138 } 139 140 if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) { 141 return EFI_ALREADY_STARTED; 142 } 143 144 if (NotifyFunction == NULL) { 145 /* Disable timer. */ 146 gEmuThunk->SetTimer (0, TimerCallback); 147 } else if (mTimerNotifyFunction == NULL) { 148 /* Enable Timer. */ 149 gEmuThunk->SetTimer (mTimerPeriodMs, TimerCallback); 150 } 151 mTimerNotifyFunction = NotifyFunction; 152 153 return EFI_SUCCESS; 154 } 155 156 EFI_STATUS 157 EFIAPI 158 EmuTimerDriverSetTimerPeriod ( 159 IN EFI_TIMER_ARCH_PROTOCOL *This, 160 IN UINT64 TimerPeriod 161 ) 162 /*++ 163 164 Routine Description: 165 166 This function adjusts the period of timer interrupts to the value specified 167 by TimerPeriod. If the timer period is updated, then the selected timer 168 period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If 169 the timer hardware is not programmable, then EFI_UNSUPPORTED is returned. 170 If an error occurs while attempting to update the timer period, then the 171 timer hardware will be put back in its state prior to this call, and 172 EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt 173 is disabled. This is not the same as disabling the CPU's interrupts. 174 Instead, it must either turn off the timer hardware, or it must adjust the 175 interrupt controller so that a CPU interrupt is not generated when the timer 176 interrupt fires. 177 178 Arguments: 179 180 This - The EFI_TIMER_ARCH_PROTOCOL instance. 181 182 TimerPeriod - The rate to program the timer interrupt in 100 nS units. If 183 the timer hardware is not programmable, then EFI_UNSUPPORTED is 184 returned. If the timer is programmable, then the timer period 185 will be rounded up to the nearest timer period that is supported 186 by the timer hardware. If TimerPeriod is set to 0, then the 187 timer interrupts will be disabled. 188 189 Returns: 190 191 EFI_SUCCESS - The timer period was changed. 192 193 EFI_UNSUPPORTED - The platform cannot change the period of the timer interrupt. 194 195 EFI_DEVICE_ERROR - The timer period could not be changed due to a device error. 196 197 **/ 198 { 199 200 // 201 // If TimerPeriod is 0, then the timer thread should be canceled 202 // If the TimerPeriod is valid, then create and/or adjust the period of the timer thread 203 // 204 if (TimerPeriod == 0 205 || ((TimerPeriod > TIMER_MINIMUM_VALUE) 206 && (TimerPeriod < TIMER_MAXIMUM_VALUE))) { 207 mTimerPeriodMs = DivU64x32 (TimerPeriod + 5000, 10000); 208 209 gEmuThunk->SetTimer (mTimerPeriodMs, TimerCallback); 210 } 211 212 return EFI_SUCCESS; 213 } 214 215 EFI_STATUS 216 EFIAPI 217 EmuTimerDriverGetTimerPeriod ( 218 IN EFI_TIMER_ARCH_PROTOCOL *This, 219 OUT UINT64 *TimerPeriod 220 ) 221 /*++ 222 223 Routine Description: 224 225 This function retrieves the period of timer interrupts in 100 ns units, 226 returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod 227 is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is 228 returned, then the timer is currently disabled. 229 230 Arguments: 231 232 This - The EFI_TIMER_ARCH_PROTOCOL instance. 233 234 TimerPeriod - A pointer to the timer period to retrieve in 100 ns units. If 235 0 is returned, then the timer is currently disabled. 236 237 Returns: 238 239 EFI_SUCCESS - The timer period was returned in TimerPeriod. 240 241 EFI_INVALID_PARAMETER - TimerPeriod is NULL. 242 243 **/ 244 { 245 if (TimerPeriod == NULL) { 246 return EFI_INVALID_PARAMETER; 247 } 248 249 *TimerPeriod = MultU64x32 (mTimerPeriodMs, 10000); 250 251 return EFI_SUCCESS; 252 } 253 254 EFI_STATUS 255 EFIAPI 256 EmuTimerDriverGenerateSoftInterrupt ( 257 IN EFI_TIMER_ARCH_PROTOCOL *This 258 ) 259 /*++ 260 261 Routine Description: 262 263 This function generates a soft timer interrupt. If the platform does not support soft 264 timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned. 265 If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler() 266 service, then a soft timer interrupt will be generated. If the timer interrupt is 267 enabled when this service is called, then the registered handler will be invoked. The 268 registered handler should not be able to distinguish a hardware-generated timer 269 interrupt from a software-generated timer interrupt. 270 271 Arguments: 272 273 This - The EFI_TIMER_ARCH_PROTOCOL instance. 274 275 Returns: 276 277 EFI_SUCCESS - The soft timer interrupt was generated. 278 279 EFI_UNSUPPORTED - The platform does not support the generation of soft timer interrupts. 280 281 **/ 282 { 283 return EFI_UNSUPPORTED; 284 } 285 286 EFI_STATUS 287 EFIAPI 288 EmuTimerDriverInitialize ( 289 IN EFI_HANDLE ImageHandle, 290 IN EFI_SYSTEM_TABLE *SystemTable 291 ) 292 /*++ 293 294 Routine Description: 295 296 Initialize the Timer Architectural Protocol driver 297 298 Arguments: 299 300 ImageHandle - ImageHandle of the loaded driver 301 302 SystemTable - Pointer to the System Table 303 304 Returns: 305 306 EFI_SUCCESS - Timer Architectural Protocol created 307 308 EFI_OUT_OF_RESOURCES - Not enough resources available to initialize driver. 309 310 EFI_DEVICE_ERROR - A device error occured attempting to initialize the driver. 311 312 **/ 313 { 314 EFI_STATUS Status; 315 EFI_HANDLE Handle; 316 317 // 318 // Make sure the Timer Architectural Protocol is not already installed in the system 319 // 320 ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiTimerArchProtocolGuid); 321 322 // 323 // Get the CPU Architectural Protocol instance 324 // 325 Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (void *)&mCpu); 326 ASSERT_EFI_ERROR (Status); 327 328 // 329 // Start the timer thread at the default timer period 330 // 331 Status = mTimer.SetTimerPeriod (&mTimer, DEFAULT_TIMER_TICK_DURATION); 332 if (EFI_ERROR (Status)) { 333 return Status; 334 } 335 336 // 337 // Install the Timer Architectural Protocol onto a new handle 338 // 339 Handle = NULL; 340 Status = gBS->InstallProtocolInterface ( 341 &Handle, 342 &gEfiTimerArchProtocolGuid, 343 EFI_NATIVE_INTERFACE, 344 &mTimer 345 ); 346 if (EFI_ERROR (Status)) { 347 return Status; 348 } 349 350 351 return EFI_SUCCESS; 352 } 353
