1 /****************************************************************************** 2 * 3 * Module Name: evglock - Global Lock support 4 * 5 *****************************************************************************/ 6 7 /****************************************************************************** 8 * 9 * 1. Copyright Notice 10 * 11 * Some or all of this work - Copyright (c) 1999 - 2018, Intel Corp. 12 * All rights reserved. 13 * 14 * 2. License 15 * 16 * 2.1. This is your license from Intel Corp. under its intellectual property 17 * rights. You may have additional license terms from the party that provided 18 * you this software, covering your right to use that party's intellectual 19 * property rights. 20 * 21 * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a 22 * copy of the source code appearing in this file ("Covered Code") an 23 * irrevocable, perpetual, worldwide license under Intel's copyrights in the 24 * base code distributed originally by Intel ("Original Intel Code") to copy, 25 * make derivatives, distribute, use and display any portion of the Covered 26 * Code in any form, with the right to sublicense such rights; and 27 * 28 * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent 29 * license (with the right to sublicense), under only those claims of Intel 30 * patents that are infringed by the Original Intel Code, to make, use, sell, 31 * offer to sell, and import the Covered Code and derivative works thereof 32 * solely to the minimum extent necessary to exercise the above copyright 33 * license, and in no event shall the patent license extend to any additions 34 * to or modifications of the Original Intel Code. No other license or right 35 * is granted directly or by implication, estoppel or otherwise; 36 * 37 * The above copyright and patent license is granted only if the following 38 * conditions are met: 39 * 40 * 3. Conditions 41 * 42 * 3.1. Redistribution of Source with Rights to Further Distribute Source. 43 * Redistribution of source code of any substantial portion of the Covered 44 * Code or modification with rights to further distribute source must include 45 * the above Copyright Notice, the above License, this list of Conditions, 46 * and the following Disclaimer and Export Compliance provision. In addition, 47 * Licensee must cause all Covered Code to which Licensee contributes to 48 * contain a file documenting the changes Licensee made to create that Covered 49 * Code and the date of any change. Licensee must include in that file the 50 * documentation of any changes made by any predecessor Licensee. Licensee 51 * must include a prominent statement that the modification is derived, 52 * directly or indirectly, from Original Intel Code. 53 * 54 * 3.2. Redistribution of Source with no Rights to Further Distribute Source. 55 * Redistribution of source code of any substantial portion of the Covered 56 * Code or modification without rights to further distribute source must 57 * include the following Disclaimer and Export Compliance provision in the 58 * documentation and/or other materials provided with distribution. In 59 * addition, Licensee may not authorize further sublicense of source of any 60 * portion of the Covered Code, and must include terms to the effect that the 61 * license from Licensee to its licensee is limited to the intellectual 62 * property embodied in the software Licensee provides to its licensee, and 63 * not to intellectual property embodied in modifications its licensee may 64 * make. 65 * 66 * 3.3. Redistribution of Executable. Redistribution in executable form of any 67 * substantial portion of the Covered Code or modification must reproduce the 68 * above Copyright Notice, and the following Disclaimer and Export Compliance 69 * provision in the documentation and/or other materials provided with the 70 * distribution. 71 * 72 * 3.4. Intel retains all right, title, and interest in and to the Original 73 * Intel Code. 74 * 75 * 3.5. Neither the name Intel nor any other trademark owned or controlled by 76 * Intel shall be used in advertising or otherwise to promote the sale, use or 77 * other dealings in products derived from or relating to the Covered Code 78 * without prior written authorization from Intel. 79 * 80 * 4. Disclaimer and Export Compliance 81 * 82 * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED 83 * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE 84 * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, 85 * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY 86 * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY 87 * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A 88 * PARTICULAR PURPOSE. 89 * 90 * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES 91 * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR 92 * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, 93 * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY 94 * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL 95 * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS 96 * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY 97 * LIMITED REMEDY. 98 * 99 * 4.3. Licensee shall not export, either directly or indirectly, any of this 100 * software or system incorporating such software without first obtaining any 101 * required license or other approval from the U. S. Department of Commerce or 102 * any other agency or department of the United States Government. In the 103 * event Licensee exports any such software from the United States or 104 * re-exports any such software from a foreign destination, Licensee shall 105 * ensure that the distribution and export/re-export of the software is in 106 * compliance with all laws, regulations, orders, or other restrictions of the 107 * U.S. Export Administration Regulations. Licensee agrees that neither it nor 108 * any of its subsidiaries will export/re-export any technical data, process, 109 * software, or service, directly or indirectly, to any country for which the 110 * United States government or any agency thereof requires an export license, 111 * other governmental approval, or letter of assurance, without first obtaining 112 * such license, approval or letter. 113 * 114 ***************************************************************************** 115 * 116 * Alternatively, you may choose to be licensed under the terms of the 117 * following license: 118 * 119 * Redistribution and use in source and binary forms, with or without 120 * modification, are permitted provided that the following conditions 121 * are met: 122 * 1. Redistributions of source code must retain the above copyright 123 * notice, this list of conditions, and the following disclaimer, 124 * without modification. 125 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 126 * substantially similar to the "NO WARRANTY" disclaimer below 127 * ("Disclaimer") and any redistribution must be conditioned upon 128 * including a substantially similar Disclaimer requirement for further 129 * binary redistribution. 130 * 3. Neither the names of the above-listed copyright holders nor the names 131 * of any contributors may be used to endorse or promote products derived 132 * from this software without specific prior written permission. 133 * 134 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 135 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 136 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 137 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 138 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 139 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 140 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 141 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 142 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 143 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 144 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 145 * 146 * Alternatively, you may choose to be licensed under the terms of the 147 * GNU General Public License ("GPL") version 2 as published by the Free 148 * Software Foundation. 149 * 150 *****************************************************************************/ 151 152 #include "acpi.h" 153 #include "accommon.h" 154 #include "acevents.h" 155 #include "acinterp.h" 156 157 #define _COMPONENT ACPI_EVENTS 158 ACPI_MODULE_NAME ("evglock") 159 160 #if (!ACPI_REDUCED_HARDWARE) /* Entire module */ 161 162 /* Local prototypes */ 163 164 static UINT32 165 AcpiEvGlobalLockHandler ( 166 void *Context); 167 168 169 /******************************************************************************* 170 * 171 * FUNCTION: AcpiEvInitGlobalLockHandler 172 * 173 * PARAMETERS: None 174 * 175 * RETURN: Status 176 * 177 * DESCRIPTION: Install a handler for the global lock release event 178 * 179 ******************************************************************************/ 180 181 ACPI_STATUS 182 AcpiEvInitGlobalLockHandler ( 183 void) 184 { 185 ACPI_STATUS Status; 186 187 188 ACPI_FUNCTION_TRACE (EvInitGlobalLockHandler); 189 190 191 /* If Hardware Reduced flag is set, there is no global lock */ 192 193 if (AcpiGbl_ReducedHardware) 194 { 195 return_ACPI_STATUS (AE_OK); 196 } 197 198 /* Attempt installation of the global lock handler */ 199 200 Status = AcpiInstallFixedEventHandler (ACPI_EVENT_GLOBAL, 201 AcpiEvGlobalLockHandler, NULL); 202 203 /* 204 * If the global lock does not exist on this platform, the attempt to 205 * enable GBL_STATUS will fail (the GBL_ENABLE bit will not stick). 206 * Map to AE_OK, but mark global lock as not present. Any attempt to 207 * actually use the global lock will be flagged with an error. 208 */ 209 AcpiGbl_GlobalLockPresent = FALSE; 210 if (Status == AE_NO_HARDWARE_RESPONSE) 211 { 212 ACPI_ERROR ((AE_INFO, 213 "No response from Global Lock hardware, disabling lock")); 214 215 return_ACPI_STATUS (AE_OK); 216 } 217 218 Status = AcpiOsCreateLock (&AcpiGbl_GlobalLockPendingLock); 219 if (ACPI_FAILURE (Status)) 220 { 221 return_ACPI_STATUS (Status); 222 } 223 224 AcpiGbl_GlobalLockPending = FALSE; 225 AcpiGbl_GlobalLockPresent = TRUE; 226 return_ACPI_STATUS (Status); 227 } 228 229 230 /******************************************************************************* 231 * 232 * FUNCTION: AcpiEvRemoveGlobalLockHandler 233 * 234 * PARAMETERS: None 235 * 236 * RETURN: Status 237 * 238 * DESCRIPTION: Remove the handler for the Global Lock 239 * 240 ******************************************************************************/ 241 242 ACPI_STATUS 243 AcpiEvRemoveGlobalLockHandler ( 244 void) 245 { 246 ACPI_STATUS Status; 247 248 249 ACPI_FUNCTION_TRACE (EvRemoveGlobalLockHandler); 250 251 252 AcpiGbl_GlobalLockPresent = FALSE; 253 Status = AcpiRemoveFixedEventHandler (ACPI_EVENT_GLOBAL, 254 AcpiEvGlobalLockHandler); 255 256 AcpiOsDeleteLock (AcpiGbl_GlobalLockPendingLock); 257 return_ACPI_STATUS (Status); 258 } 259 260 261 /******************************************************************************* 262 * 263 * FUNCTION: AcpiEvGlobalLockHandler 264 * 265 * PARAMETERS: Context - From thread interface, not used 266 * 267 * RETURN: ACPI_INTERRUPT_HANDLED 268 * 269 * DESCRIPTION: Invoked directly from the SCI handler when a global lock 270 * release interrupt occurs. If there is actually a pending 271 * request for the lock, signal the waiting thread. 272 * 273 ******************************************************************************/ 274 275 static UINT32 276 AcpiEvGlobalLockHandler ( 277 void *Context) 278 { 279 ACPI_STATUS Status; 280 ACPI_CPU_FLAGS Flags; 281 282 283 Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock); 284 285 /* 286 * If a request for the global lock is not actually pending, 287 * we are done. This handles "spurious" global lock interrupts 288 * which are possible (and have been seen) with bad BIOSs. 289 */ 290 if (!AcpiGbl_GlobalLockPending) 291 { 292 goto CleanupAndExit; 293 } 294 295 /* 296 * Send a unit to the global lock semaphore. The actual acquisition 297 * of the global lock will be performed by the waiting thread. 298 */ 299 Status = AcpiOsSignalSemaphore (AcpiGbl_GlobalLockSemaphore, 1); 300 if (ACPI_FAILURE (Status)) 301 { 302 ACPI_ERROR ((AE_INFO, "Could not signal Global Lock semaphore")); 303 } 304 305 AcpiGbl_GlobalLockPending = FALSE; 306 307 308 CleanupAndExit: 309 310 AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags); 311 return (ACPI_INTERRUPT_HANDLED); 312 } 313 314 315 /****************************************************************************** 316 * 317 * FUNCTION: AcpiEvAcquireGlobalLock 318 * 319 * PARAMETERS: Timeout - Max time to wait for the lock, in millisec. 320 * 321 * RETURN: Status 322 * 323 * DESCRIPTION: Attempt to gain ownership of the Global Lock. 324 * 325 * MUTEX: Interpreter must be locked 326 * 327 * Note: The original implementation allowed multiple threads to "acquire" the 328 * Global Lock, and the OS would hold the lock until the last thread had 329 * released it. However, this could potentially starve the BIOS out of the 330 * lock, especially in the case where there is a tight handshake between the 331 * Embedded Controller driver and the BIOS. Therefore, this implementation 332 * allows only one thread to acquire the HW Global Lock at a time, and makes 333 * the global lock appear as a standard mutex on the OS side. 334 * 335 *****************************************************************************/ 336 337 ACPI_STATUS 338 AcpiEvAcquireGlobalLock ( 339 UINT16 Timeout) 340 { 341 ACPI_CPU_FLAGS Flags; 342 ACPI_STATUS Status; 343 BOOLEAN Acquired = FALSE; 344 345 346 ACPI_FUNCTION_TRACE (EvAcquireGlobalLock); 347 348 349 /* 350 * Only one thread can acquire the GL at a time, the GlobalLockMutex 351 * enforces this. This interface releases the interpreter if we must wait. 352 */ 353 Status = AcpiExSystemWaitMutex (AcpiGbl_GlobalLockMutex->Mutex.OsMutex, 354 Timeout); 355 if (ACPI_FAILURE (Status)) 356 { 357 return_ACPI_STATUS (Status); 358 } 359 360 /* 361 * Update the global lock handle and check for wraparound. The handle is 362 * only used for the external global lock interfaces, but it is updated 363 * here to properly handle the case where a single thread may acquire the 364 * lock via both the AML and the AcpiAcquireGlobalLock interfaces. The 365 * handle is therefore updated on the first acquire from a given thread 366 * regardless of where the acquisition request originated. 367 */ 368 AcpiGbl_GlobalLockHandle++; 369 if (AcpiGbl_GlobalLockHandle == 0) 370 { 371 AcpiGbl_GlobalLockHandle = 1; 372 } 373 374 /* 375 * Make sure that a global lock actually exists. If not, just 376 * treat the lock as a standard mutex. 377 */ 378 if (!AcpiGbl_GlobalLockPresent) 379 { 380 AcpiGbl_GlobalLockAcquired = TRUE; 381 return_ACPI_STATUS (AE_OK); 382 } 383 384 Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock); 385 386 do 387 { 388 /* Attempt to acquire the actual hardware lock */ 389 390 ACPI_ACQUIRE_GLOBAL_LOCK (AcpiGbl_FACS, Acquired); 391 if (Acquired) 392 { 393 AcpiGbl_GlobalLockAcquired = TRUE; 394 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, 395 "Acquired hardware Global Lock\n")); 396 break; 397 } 398 399 /* 400 * Did not get the lock. The pending bit was set above, and 401 * we must now wait until we receive the global lock 402 * released interrupt. 403 */ 404 AcpiGbl_GlobalLockPending = TRUE; 405 AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags); 406 407 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, 408 "Waiting for hardware Global Lock\n")); 409 410 /* 411 * Wait for handshake with the global lock interrupt handler. 412 * This interface releases the interpreter if we must wait. 413 */ 414 Status = AcpiExSystemWaitSemaphore ( 415 AcpiGbl_GlobalLockSemaphore, ACPI_WAIT_FOREVER); 416 417 Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock); 418 419 } while (ACPI_SUCCESS (Status)); 420 421 AcpiGbl_GlobalLockPending = FALSE; 422 AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags); 423 424 return_ACPI_STATUS (Status); 425 } 426 427 428 /******************************************************************************* 429 * 430 * FUNCTION: AcpiEvReleaseGlobalLock 431 * 432 * PARAMETERS: None 433 * 434 * RETURN: Status 435 * 436 * DESCRIPTION: Releases ownership of the Global Lock. 437 * 438 ******************************************************************************/ 439 440 ACPI_STATUS 441 AcpiEvReleaseGlobalLock ( 442 void) 443 { 444 BOOLEAN Pending = FALSE; 445 ACPI_STATUS Status = AE_OK; 446 447 448 ACPI_FUNCTION_TRACE (EvReleaseGlobalLock); 449 450 451 /* Lock must be already acquired */ 452 453 if (!AcpiGbl_GlobalLockAcquired) 454 { 455 ACPI_WARNING ((AE_INFO, 456 "Cannot release the ACPI Global Lock, it has not been acquired")); 457 return_ACPI_STATUS (AE_NOT_ACQUIRED); 458 } 459 460 if (AcpiGbl_GlobalLockPresent) 461 { 462 /* Allow any thread to release the lock */ 463 464 ACPI_RELEASE_GLOBAL_LOCK (AcpiGbl_FACS, Pending); 465 466 /* 467 * If the pending bit was set, we must write GBL_RLS to the control 468 * register 469 */ 470 if (Pending) 471 { 472 Status = AcpiWriteBitRegister ( 473 ACPI_BITREG_GLOBAL_LOCK_RELEASE, ACPI_ENABLE_EVENT); 474 } 475 476 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Released hardware Global Lock\n")); 477 } 478 479 AcpiGbl_GlobalLockAcquired = FALSE; 480 481 /* Release the local GL mutex */ 482 483 AcpiOsReleaseMutex (AcpiGbl_GlobalLockMutex->Mutex.OsMutex); 484 return_ACPI_STATUS (Status); 485 } 486 487 #endif /* !ACPI_REDUCED_HARDWARE */ 488