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 - 2025, 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 <contrib/dev/acpica/include/acpi.h>
153 #include <contrib/dev/acpica/include/accommon.h>
154 #include <contrib/dev/acpica/include/acevents.h>
155 #include <contrib/dev/acpica/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
AcpiEvInitGlobalLockHandler(void)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 if (!AcpiGbl_UseGlobalLock)
199 {
200 return_ACPI_STATUS (AE_OK);
201 }
202
203 /* Attempt installation of the global lock handler */
204
205 Status = AcpiInstallFixedEventHandler (ACPI_EVENT_GLOBAL,
206 AcpiEvGlobalLockHandler, NULL);
207
208 /*
209 * If the global lock does not exist on this platform, the attempt to
210 * enable GBL_STATUS will fail (the GBL_ENABLE bit will not stick).
211 * Map to AE_OK, but mark global lock as not present. Any attempt to
212 * actually use the global lock will be flagged with an error.
213 */
214 AcpiGbl_GlobalLockPresent = FALSE;
215 if (Status == AE_NO_HARDWARE_RESPONSE)
216 {
217 ACPI_ERROR ((AE_INFO,
218 "No response from Global Lock hardware, disabling lock"));
219
220 return_ACPI_STATUS (AE_OK);
221 }
222
223 Status = AcpiOsCreateLock (&AcpiGbl_GlobalLockPendingLock);
224 if (ACPI_FAILURE (Status))
225 {
226 return_ACPI_STATUS (Status);
227 }
228
229 AcpiGbl_GlobalLockPending = FALSE;
230 AcpiGbl_GlobalLockPresent = TRUE;
231 return_ACPI_STATUS (Status);
232 }
233
234
235 /*******************************************************************************
236 *
237 * FUNCTION: AcpiEvRemoveGlobalLockHandler
238 *
239 * PARAMETERS: None
240 *
241 * RETURN: Status
242 *
243 * DESCRIPTION: Remove the handler for the Global Lock
244 *
245 ******************************************************************************/
246
247 ACPI_STATUS
AcpiEvRemoveGlobalLockHandler(void)248 AcpiEvRemoveGlobalLockHandler (
249 void)
250 {
251 ACPI_STATUS Status;
252
253
254 ACPI_FUNCTION_TRACE (EvRemoveGlobalLockHandler);
255
256
257 AcpiGbl_GlobalLockPresent = FALSE;
258 Status = AcpiRemoveFixedEventHandler (ACPI_EVENT_GLOBAL,
259 AcpiEvGlobalLockHandler);
260
261 AcpiOsDeleteLock (AcpiGbl_GlobalLockPendingLock);
262 return_ACPI_STATUS (Status);
263 }
264
265
266 /*******************************************************************************
267 *
268 * FUNCTION: AcpiEvGlobalLockHandler
269 *
270 * PARAMETERS: Context - From thread interface, not used
271 *
272 * RETURN: ACPI_INTERRUPT_HANDLED
273 *
274 * DESCRIPTION: Invoked directly from the SCI handler when a global lock
275 * release interrupt occurs. If there is actually a pending
276 * request for the lock, signal the waiting thread.
277 *
278 ******************************************************************************/
279
280 static UINT32
AcpiEvGlobalLockHandler(void * Context)281 AcpiEvGlobalLockHandler (
282 void *Context)
283 {
284 ACPI_STATUS Status;
285 ACPI_CPU_FLAGS Flags;
286
287
288 Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock);
289
290 /*
291 * If a request for the global lock is not actually pending,
292 * we are done. This handles "spurious" global lock interrupts
293 * which are possible (and have been seen) with bad BIOSs.
294 */
295 if (!AcpiGbl_GlobalLockPending)
296 {
297 goto CleanupAndExit;
298 }
299
300 /*
301 * Send a unit to the global lock semaphore. The actual acquisition
302 * of the global lock will be performed by the waiting thread.
303 */
304 Status = AcpiOsSignalSemaphore (AcpiGbl_GlobalLockSemaphore, 1);
305 if (ACPI_FAILURE (Status))
306 {
307 ACPI_ERROR ((AE_INFO, "Could not signal Global Lock semaphore"));
308 }
309
310 AcpiGbl_GlobalLockPending = FALSE;
311
312
313 CleanupAndExit:
314
315 AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags);
316 return (ACPI_INTERRUPT_HANDLED);
317 }
318
319
320 /******************************************************************************
321 *
322 * FUNCTION: AcpiEvAcquireGlobalLock
323 *
324 * PARAMETERS: Timeout - Max time to wait for the lock, in millisec.
325 *
326 * RETURN: Status
327 *
328 * DESCRIPTION: Attempt to gain ownership of the Global Lock.
329 *
330 * MUTEX: Interpreter must be locked
331 *
332 * Note: The original implementation allowed multiple threads to "acquire" the
333 * Global Lock, and the OS would hold the lock until the last thread had
334 * released it. However, this could potentially starve the BIOS out of the
335 * lock, especially in the case where there is a tight handshake between the
336 * Embedded Controller driver and the BIOS. Therefore, this implementation
337 * allows only one thread to acquire the HW Global Lock at a time, and makes
338 * the global lock appear as a standard mutex on the OS side.
339 *
340 *****************************************************************************/
341
342 ACPI_STATUS
AcpiEvAcquireGlobalLock(UINT16 Timeout)343 AcpiEvAcquireGlobalLock (
344 UINT16 Timeout)
345 {
346 ACPI_CPU_FLAGS Flags;
347 ACPI_STATUS Status;
348 BOOLEAN Acquired = FALSE;
349
350
351 ACPI_FUNCTION_TRACE (EvAcquireGlobalLock);
352
353
354 /*
355 * Only one thread can acquire the GL at a time, the GlobalLockMutex
356 * enforces this. This interface releases the interpreter if we must wait.
357 */
358 Status = AcpiExSystemWaitMutex (AcpiGbl_GlobalLockMutex->Mutex.OsMutex,
359 Timeout);
360 if (ACPI_FAILURE (Status))
361 {
362 return_ACPI_STATUS (Status);
363 }
364
365 /*
366 * Update the global lock handle and check for wraparound. The handle is
367 * only used for the external global lock interfaces, but it is updated
368 * here to properly handle the case where a single thread may acquire the
369 * lock via both the AML and the AcpiAcquireGlobalLock interfaces. The
370 * handle is therefore updated on the first acquire from a given thread
371 * regardless of where the acquisition request originated.
372 */
373 AcpiGbl_GlobalLockHandle++;
374 if (AcpiGbl_GlobalLockHandle == 0)
375 {
376 AcpiGbl_GlobalLockHandle = 1;
377 }
378
379 /*
380 * Make sure that a global lock actually exists. If not, just
381 * treat the lock as a standard mutex.
382 */
383 if (!AcpiGbl_GlobalLockPresent)
384 {
385 AcpiGbl_GlobalLockAcquired = TRUE;
386 return_ACPI_STATUS (AE_OK);
387 }
388
389 Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock);
390
391 do
392 {
393 /* Attempt to acquire the actual hardware lock */
394
395 ACPI_ACQUIRE_GLOBAL_LOCK (AcpiGbl_FACS, Acquired);
396 if (Acquired)
397 {
398 AcpiGbl_GlobalLockAcquired = TRUE;
399 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
400 "Acquired hardware Global Lock\n"));
401 break;
402 }
403
404 /*
405 * Did not get the lock. The pending bit was set above, and
406 * we must now wait until we receive the global lock
407 * released interrupt.
408 */
409 AcpiGbl_GlobalLockPending = TRUE;
410 AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags);
411
412 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
413 "Waiting for hardware Global Lock\n"));
414
415 /*
416 * Wait for handshake with the global lock interrupt handler.
417 * This interface releases the interpreter if we must wait.
418 */
419 Status = AcpiExSystemWaitSemaphore (
420 AcpiGbl_GlobalLockSemaphore, ACPI_WAIT_FOREVER);
421
422 Flags = AcpiOsAcquireLock (AcpiGbl_GlobalLockPendingLock);
423
424 } while (ACPI_SUCCESS (Status));
425
426 AcpiGbl_GlobalLockPending = FALSE;
427 AcpiOsReleaseLock (AcpiGbl_GlobalLockPendingLock, Flags);
428
429 return_ACPI_STATUS (Status);
430 }
431
432
433 /*******************************************************************************
434 *
435 * FUNCTION: AcpiEvReleaseGlobalLock
436 *
437 * PARAMETERS: None
438 *
439 * RETURN: Status
440 *
441 * DESCRIPTION: Releases ownership of the Global Lock.
442 *
443 ******************************************************************************/
444
445 ACPI_STATUS
AcpiEvReleaseGlobalLock(void)446 AcpiEvReleaseGlobalLock (
447 void)
448 {
449 BOOLEAN Pending = FALSE;
450 ACPI_STATUS Status = AE_OK;
451
452
453 ACPI_FUNCTION_TRACE (EvReleaseGlobalLock);
454
455
456 /* Lock must be already acquired */
457
458 if (!AcpiGbl_GlobalLockAcquired)
459 {
460 ACPI_WARNING ((AE_INFO,
461 "Cannot release the ACPI Global Lock, it has not been acquired"));
462 return_ACPI_STATUS (AE_NOT_ACQUIRED);
463 }
464
465 if (AcpiGbl_GlobalLockPresent)
466 {
467 /* Allow any thread to release the lock */
468
469 ACPI_RELEASE_GLOBAL_LOCK (AcpiGbl_FACS, Pending);
470
471 /*
472 * If the pending bit was set, we must write GBL_RLS to the control
473 * register
474 */
475 if (Pending)
476 {
477 Status = AcpiWriteBitRegister (
478 ACPI_BITREG_GLOBAL_LOCK_RELEASE, ACPI_ENABLE_EVENT);
479 }
480
481 ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Released hardware Global Lock\n"));
482 }
483
484 AcpiGbl_GlobalLockAcquired = FALSE;
485
486 /* Release the local GL mutex */
487
488 AcpiOsReleaseMutex (AcpiGbl_GlobalLockMutex->Mutex.OsMutex);
489 return_ACPI_STATUS (Status);
490 }
491
492 #endif /* !ACPI_REDUCED_HARDWARE */
493