1 /****************************************************************************** 2 * 3 * Module Name: evglock - Global Lock support 4 * 5 *****************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2016, Intel Corp. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions, and the following disclaimer, 16 * without modification. 17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 18 * substantially similar to the "NO WARRANTY" disclaimer below 19 * ("Disclaimer") and any redistribution must be conditioned upon 20 * including a substantially similar Disclaimer requirement for further 21 * binary redistribution. 22 * 3. Neither the names of the above-listed copyright holders nor the names 23 * of any contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * Alternatively, this software may be distributed under the terms of the 27 * GNU General Public License ("GPL") version 2 as published by the Free 28 * Software Foundation. 29 * 30 * NO WARRANTY 31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR 34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 41 * POSSIBILITY OF SUCH DAMAGES. 42 */ 43 44 #include <contrib/dev/acpica/include/acpi.h> 45 #include <contrib/dev/acpica/include/accommon.h> 46 #include <contrib/dev/acpica/include/acevents.h> 47 #include <contrib/dev/acpica/include/acinterp.h> 48 49 #define _COMPONENT ACPI_EVENTS 50 ACPI_MODULE_NAME ("evglock") 51 52 #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ 53 54 /* Local prototypes */ 55 56 static UINT32 57 AcpiEvGlobalLockHandler ( 58 void *Context); 59 60 61 /******************************************************************************* 62 * 63 * FUNCTION: AcpiEvInitGlobalLockHandler 64 * 65 * PARAMETERS: None 66 * 67 * RETURN: Status 68 * 69 * DESCRIPTION: Install a handler for the global lock release event 70 * 71 ******************************************************************************/ 72 73 ACPI_STATUS 74 AcpiEvInitGlobalLockHandler ( 75 void) 76 { 77 ACPI_STATUS Status; 78 79 80 ACPI_FUNCTION_TRACE (EvInitGlobalLockHandler); 81 82 83 /* If Hardware Reduced flag is set, there is no global lock */ 84 85 if (AcpiGbl_ReducedHardware) 86 { 87 return_ACPI_STATUS (AE_OK); 88 } 89 90 /* Attempt installation of the global lock handler */ 91 92 Status = AcpiInstallFixedEventHandler (ACPI_EVENT_GLOBAL, 93 AcpiEvGlobalLockHandler, NULL); 94 95 /* 96 * If the global lock does not exist on this platform, the attempt to 97 * enable GBL_STATUS will fail (the GBL_ENABLE bit will not stick). 98 * Map to AE_OK, but mark global lock as not present. Any attempt to 99 * actually use the global lock will be flagged with an error. 100 */ 101 AcpiGbl_GlobalLockPresent = FALSE; 102 if (Status == AE_NO_HARDWARE_RESPONSE) 103 { 104 ACPI_ERROR ((AE_INFO, 105 "No response from Global Lock hardware, disabling lock")); 106 107 return_ACPI_STATUS (AE_OK); 108 } 109 110 Status = AcpiOsCreateLock (&AcpiGbl_GlobalLockPendingLock); 111 if (ACPI_FAILURE (Status)) 112 { 113 return_ACPI_STATUS (Status); 114 } 115 116 AcpiGbl_GlobalLockPending = FALSE; 117 AcpiGbl_GlobalLockPresent = TRUE; 118 return_ACPI_STATUS (Status); 119 } 120 121 122 /******************************************************************************* 123 * 124 * FUNCTION: AcpiEvRemoveGlobalLockHandler 125 * 126 * PARAMETERS: None 127 * 128 * RETURN: Status 129 * 130 * DESCRIPTION: Remove the handler for the Global Lock 131 * 132 ******************************************************************************/ 133 134 ACPI_STATUS 135 AcpiEvRemoveGlobalLockHandler ( 136 void) 137 { 138 ACPI_STATUS Status; 139 140 141 ACPI_FUNCTION_TRACE (EvRemoveGlobalLockHandler); 142 143 144 AcpiGbl_GlobalLockPresent = FALSE; 145 Status = AcpiRemoveFixedEventHandler (ACPI_EVENT_GLOBAL, 146 AcpiEvGlobalLockHandler); 147 148 AcpiOsDeleteLock (AcpiGbl_GlobalLockPendingLock); 149 return_ACPI_STATUS (Status); 150 } 151 152 153 /******************************************************************************* 154 * 155 * FUNCTION: AcpiEvGlobalLockHandler 156 * 157 * PARAMETERS: Context - From thread interface, not used 158 * 159 * RETURN: ACPI_INTERRUPT_HANDLED 160 * 161 * DESCRIPTION: Invoked directly from the SCI handler when a global lock 162 * release interrupt occurs. If there is actually a pending 163 * request for the lock, signal the waiting thread. 164 * 165 ******************************************************************************/ 166 167 static UINT32 168 AcpiEvGlobalLockHandler ( 169 void *Context) 170 { 171 ACPI_STATUS Status; 172 ACPI_CPU_FLAGS Flags; 173 174 175 Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock); 176 177 /* 178 * If a request for the global lock is not actually pending, 179 * we are done. This handles "spurious" global lock interrupts 180 * which are possible (and have been seen) with bad BIOSs. 181 */ 182 if (!AcpiGbl_GlobalLockPending) 183 { 184 goto CleanupAndExit; 185 } 186 187 /* 188 * Send a unit to the global lock semaphore. The actual acquisition 189 * of the global lock will be performed by the waiting thread. 190 */ 191 Status = AcpiOsSignalSemaphore (AcpiGbl_GlobalLockSemaphore, 1); 192 if (ACPI_FAILURE (Status)) 193 { 194 ACPI_ERROR ((AE_INFO, "Could not signal Global Lock semaphore")); 195 } 196 197 AcpiGbl_GlobalLockPending = FALSE; 198 199 200 CleanupAndExit: 201 202 AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags); 203 return (ACPI_INTERRUPT_HANDLED); 204 } 205 206 207 /****************************************************************************** 208 * 209 * FUNCTION: AcpiEvAcquireGlobalLock 210 * 211 * PARAMETERS: Timeout - Max time to wait for the lock, in millisec. 212 * 213 * RETURN: Status 214 * 215 * DESCRIPTION: Attempt to gain ownership of the Global Lock. 216 * 217 * MUTEX: Interpreter must be locked 218 * 219 * Note: The original implementation allowed multiple threads to "acquire" the 220 * Global Lock, and the OS would hold the lock until the last thread had 221 * released it. However, this could potentially starve the BIOS out of the 222 * lock, especially in the case where there is a tight handshake between the 223 * Embedded Controller driver and the BIOS. Therefore, this implementation 224 * allows only one thread to acquire the HW Global Lock at a time, and makes 225 * the global lock appear as a standard mutex on the OS side. 226 * 227 *****************************************************************************/ 228 229 ACPI_STATUS 230 AcpiEvAcquireGlobalLock ( 231 UINT16 Timeout) 232 { 233 ACPI_CPU_FLAGS Flags; 234 ACPI_STATUS Status; 235 BOOLEAN Acquired = FALSE; 236 237 238 ACPI_FUNCTION_TRACE (EvAcquireGlobalLock); 239 240 241 /* 242 * Only one thread can acquire the GL at a time, the GlobalLockMutex 243 * enforces this. This interface releases the interpreter if we must wait. 244 */ 245 Status = AcpiExSystemWaitMutex (AcpiGbl_GlobalLockMutex->Mutex.OsMutex, 246 Timeout); 247 if (ACPI_FAILURE (Status)) 248 { 249 return_ACPI_STATUS (Status); 250 } 251 252 /* 253 * Update the global lock handle and check for wraparound. The handle is 254 * only used for the external global lock interfaces, but it is updated 255 * here to properly handle the case where a single thread may acquire the 256 * lock via both the AML and the AcpiAcquireGlobalLock interfaces. The 257 * handle is therefore updated on the first acquire from a given thread 258 * regardless of where the acquisition request originated. 259 */ 260 AcpiGbl_GlobalLockHandle++; 261 if (AcpiGbl_GlobalLockHandle == 0) 262 { 263 AcpiGbl_GlobalLockHandle = 1; 264 } 265 266 /* 267 * Make sure that a global lock actually exists. If not, just 268 * treat the lock as a standard mutex. 269 */ 270 if (!AcpiGbl_GlobalLockPresent) 271 { 272 AcpiGbl_GlobalLockAcquired = TRUE; 273 return_ACPI_STATUS (AE_OK); 274 } 275 276 Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock); 277 278 do 279 { 280 /* Attempt to acquire the actual hardware lock */ 281 282 ACPI_ACQUIRE_GLOBAL_LOCK (AcpiGbl_FACS, Acquired); 283 if (Acquired) 284 { 285 AcpiGbl_GlobalLockAcquired = TRUE; 286 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, 287 "Acquired hardware Global Lock\n")); 288 break; 289 } 290 291 /* 292 * Did not get the lock. The pending bit was set above, and 293 * we must now wait until we receive the global lock 294 * released interrupt. 295 */ 296 AcpiGbl_GlobalLockPending = TRUE; 297 AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags); 298 299 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, 300 "Waiting for hardware Global Lock\n")); 301 302 /* 303 * Wait for handshake with the global lock interrupt handler. 304 * This interface releases the interpreter if we must wait. 305 */ 306 Status = AcpiExSystemWaitSemaphore ( 307 AcpiGbl_GlobalLockSemaphore, ACPI_WAIT_FOREVER); 308 309 Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock); 310 311 } while (ACPI_SUCCESS (Status)); 312 313 AcpiGbl_GlobalLockPending = FALSE; 314 AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags); 315 316 return_ACPI_STATUS (Status); 317 } 318 319 320 /******************************************************************************* 321 * 322 * FUNCTION: AcpiEvReleaseGlobalLock 323 * 324 * PARAMETERS: None 325 * 326 * RETURN: Status 327 * 328 * DESCRIPTION: Releases ownership of the Global Lock. 329 * 330 ******************************************************************************/ 331 332 ACPI_STATUS 333 AcpiEvReleaseGlobalLock ( 334 void) 335 { 336 BOOLEAN Pending = FALSE; 337 ACPI_STATUS Status = AE_OK; 338 339 340 ACPI_FUNCTION_TRACE (EvReleaseGlobalLock); 341 342 343 /* Lock must be already acquired */ 344 345 if (!AcpiGbl_GlobalLockAcquired) 346 { 347 ACPI_WARNING ((AE_INFO, 348 "Cannot release the ACPI Global Lock, it has not been acquired")); 349 return_ACPI_STATUS (AE_NOT_ACQUIRED); 350 } 351 352 if (AcpiGbl_GlobalLockPresent) 353 { 354 /* Allow any thread to release the lock */ 355 356 ACPI_RELEASE_GLOBAL_LOCK (AcpiGbl_FACS, Pending); 357 358 /* 359 * If the pending bit was set, we must write GBL_RLS to the control 360 * register 361 */ 362 if (Pending) 363 { 364 Status = AcpiWriteBitRegister ( 365 ACPI_BITREG_GLOBAL_LOCK_RELEASE, ACPI_ENABLE_EVENT); 366 } 367 368 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Released hardware Global Lock\n")); 369 } 370 371 AcpiGbl_GlobalLockAcquired = FALSE; 372 373 /* Release the local GL mutex */ 374 375 AcpiOsReleaseMutex (AcpiGbl_GlobalLockMutex->Mutex.OsMutex); 376 return_ACPI_STATUS (Status); 377 } 378 379 #endif /* !ACPI_REDUCED_HARDWARE */ 380