1 /** @file 2 Implementation of Watchdog Timer Architectural Protocol using UEFI APIs. 3 4 Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR> 5 This program and the accompanying materials 6 are licensed and made available under the terms and conditions of the BSD License 7 which accompanies this distribution. The full text of the license may be found at 8 http://opensource.org/licenses/bsd-license.php 9 10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 12 13 **/ 14 15 #include "WatchdogTimer.h" 16 17 // 18 // Handle for the Watchdog Timer Architectural Protocol instance produced by this driver 19 // 20 EFI_HANDLE mWatchdogTimerHandle = NULL; 21 22 // 23 // The Watchdog Timer Architectural Protocol instance produced by this driver 24 // 25 EFI_WATCHDOG_TIMER_ARCH_PROTOCOL mWatchdogTimer = { 26 WatchdogTimerDriverRegisterHandler, 27 WatchdogTimerDriverSetTimerPeriod, 28 WatchdogTimerDriverGetTimerPeriod 29 }; 30 31 // 32 // The watchdog timer period in 100 ns units 33 // 34 UINT64 mWatchdogTimerPeriod = 0; 35 36 // 37 // The notification function to call if the watchdig timer fires 38 // 39 EFI_WATCHDOG_TIMER_NOTIFY mWatchdogTimerNotifyFunction = NULL; 40 41 // 42 // The one-shot timer event that is armed when the watchdog timer is enabled 43 // 44 EFI_EVENT mWatchdogTimerEvent; 45 46 47 /** 48 Notification function that is called if the watchdog timer is fired. 49 50 Notification function for the one-shot timer event that was signaled 51 when the watchdog timer expired. If a handler has been registered with 52 the Watchdog Timer Architectural Protocol, then that handler is called 53 passing in the time period that has passed that cause the watchdog timer 54 to fire. Then, a call to the Runtime Service ResetSystem() is made to 55 reset the platform. 56 57 @param Timer The one-shot timer event that was signaled when the 58 watchdog timer expired. 59 @param Context The context that was registered when the event Timer was created. 60 61 **/ 62 VOID 63 EFIAPI 64 WatchdogTimerDriverExpires ( 65 IN EFI_EVENT Timer, 66 IN VOID *Context 67 ) 68 { 69 REPORT_STATUS_CODE (EFI_ERROR_CODE | EFI_ERROR_MINOR, (EFI_COMPUTING_UNIT_HOST_PROCESSOR | EFI_CU_HP_EC_TIMER_EXPIRED)); 70 71 // 72 // If a notification function has been registered, then call it 73 // 74 if (mWatchdogTimerNotifyFunction != NULL) { 75 mWatchdogTimerNotifyFunction (mWatchdogTimerPeriod); 76 } 77 78 DEBUG ((EFI_D_ERROR, "Watchdog Timer resetting system\n")); 79 80 // 81 // Reset the platform 82 // 83 gRT->ResetSystem (EfiResetCold, EFI_TIMEOUT, 0, NULL); 84 } 85 86 87 /** 88 Registers a handler that is to be invoked when the watchdog timer fires. 89 90 This function registers a handler that is to be invoked when the watchdog 91 timer fires. By default, the EFI_WATCHDOG_TIMER protocol will call the 92 Runtime Service ResetSystem() when the watchdog timer fires. If a 93 NotifyFunction is registered, then the NotifyFunction will be called before 94 the Runtime Service ResetSystem() is called. If NotifyFunction is NULL, then 95 the watchdog handler is unregistered. If a watchdog handler is registered, 96 then EFI_SUCCESS is returned. If an attempt is made to register a handler 97 when a handler is already registered, then EFI_ALREADY_STARTED is returned. 98 If an attempt is made to uninstall a handler when a handler is not installed, 99 then return EFI_INVALID_PARAMETER. 100 101 @param This The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance. 102 @param NotifyFunction The function to call when the watchdog timer fires. If this 103 is NULL, then the handler will be unregistered. 104 105 @retval EFI_SUCCESS The watchdog timer handler was registered or unregistered. 106 @retval EFI_ALREADY_STARTED NotifyFunction is not NULL, and a handler is already registered. 107 @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not previously registered. 108 109 **/ 110 EFI_STATUS 111 EFIAPI 112 WatchdogTimerDriverRegisterHandler ( 113 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This, 114 IN EFI_WATCHDOG_TIMER_NOTIFY NotifyFunction 115 ) 116 { 117 // 118 // If NotifyFunction is NULL, and a handler was not previously registered, 119 // return EFI_INVALID_PARAMETER. 120 // 121 if (NotifyFunction == NULL && mWatchdogTimerNotifyFunction == NULL) { 122 return EFI_INVALID_PARAMETER; 123 } 124 // 125 // If NotifyFunction is not NULL, and a handler is already registered, 126 // return EFI_ALREADY_STARTED. 127 // 128 if (NotifyFunction != NULL && mWatchdogTimerNotifyFunction != NULL) { 129 return EFI_ALREADY_STARTED; 130 } 131 132 mWatchdogTimerNotifyFunction = NotifyFunction; 133 134 return EFI_SUCCESS; 135 } 136 137 /** 138 Sets the amount of time in the future to fire the watchdog timer. 139 140 This function sets the amount of time to wait before firing the watchdog 141 timer to TimerPeriod 100 ns units. If TimerPeriod is 0, then the watchdog 142 timer is disabled. 143 144 @param This The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance. 145 @param TimerPeriod The amount of time in 100 ns units to wait before the watchdog 146 timer is fired. If TimerPeriod is zero, then the watchdog 147 timer is disabled. 148 149 @retval EFI_SUCCESS The watchdog timer has been programmed to fire in Time 150 100 ns units. 151 @retval EFI_DEVICE_ERROR A watchdog timer could not be programmed due to a device 152 error. 153 154 **/ 155 EFI_STATUS 156 EFIAPI 157 WatchdogTimerDriverSetTimerPeriod ( 158 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This, 159 IN UINT64 TimerPeriod 160 ) 161 { 162 mWatchdogTimerPeriod = TimerPeriod; 163 164 return gBS->SetTimer ( 165 mWatchdogTimerEvent, 166 (mWatchdogTimerPeriod == 0) ? TimerCancel : TimerRelative, 167 mWatchdogTimerPeriod 168 ); 169 } 170 171 /** 172 Retrieves the amount of time in 100 ns units that the system will wait before firing the watchdog timer. 173 174 This function retrieves the amount of time the system will wait before firing 175 the watchdog timer. This period is returned in TimerPeriod, and EFI_SUCCESS 176 is returned. If TimerPeriod is NULL, then EFI_INVALID_PARAMETER is returned. 177 178 @param This The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance. 179 @param TimerPeriod A pointer to the amount of time in 100 ns units that the system 180 will wait before the watchdog timer is fired. If TimerPeriod of 181 zero is returned, then the watchdog timer is disabled. 182 183 @retval EFI_SUCCESS The amount of time that the system will wait before 184 firing the watchdog timer was returned in TimerPeriod. 185 @retval EFI_INVALID_PARAMETER TimerPeriod is NULL. 186 187 **/ 188 EFI_STATUS 189 EFIAPI 190 WatchdogTimerDriverGetTimerPeriod ( 191 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This, 192 IN UINT64 *TimerPeriod 193 ) 194 { 195 if (TimerPeriod == NULL) { 196 return EFI_INVALID_PARAMETER; 197 } 198 199 *TimerPeriod = mWatchdogTimerPeriod; 200 201 return EFI_SUCCESS; 202 } 203 204 /** 205 Entry point of the Watchdog Timer Architectural Protocol driver. 206 207 @param ImageHandle The image handle of this driver. 208 @param SystemTable The pointer of EFI_SYSTEM_TABLE. 209 210 @retval EFI_SUCCESS Watchdog Timer Architectural Protocol successfully installed. 211 212 **/ 213 EFI_STATUS 214 EFIAPI 215 WatchdogTimerDriverInitialize ( 216 IN EFI_HANDLE ImageHandle, 217 IN EFI_SYSTEM_TABLE *SystemTable 218 ) 219 { 220 EFI_STATUS Status; 221 222 // 223 // Make sure the Watchdog Timer Architectural Protocol has not been installed in the system yet. 224 // 225 ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiWatchdogTimerArchProtocolGuid); 226 227 // 228 // Create the timer event to implement a simple watchdog timer 229 // 230 Status = gBS->CreateEvent ( 231 EVT_TIMER | EVT_NOTIFY_SIGNAL, 232 TPL_NOTIFY, 233 WatchdogTimerDriverExpires, 234 NULL, 235 &mWatchdogTimerEvent 236 ); 237 ASSERT_EFI_ERROR (Status); 238 239 // 240 // Install the Watchdog Timer Arch Protocol onto a new handle 241 // 242 Status = gBS->InstallMultipleProtocolInterfaces ( 243 &mWatchdogTimerHandle, 244 &gEfiWatchdogTimerArchProtocolGuid, 245 &mWatchdogTimer, 246 NULL 247 ); 248 ASSERT_EFI_ERROR (Status); 249 250 return EFI_SUCCESS; 251 } 252
