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
164static UINT32
165AcpiEvGlobalLockHandler (
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
181ACPI_STATUS
182AcpiEvInitGlobalLockHandler (
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
242ACPI_STATUS
243AcpiEvRemoveGlobalLockHandler (
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
275static UINT32
276AcpiEvGlobalLockHandler (
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
308CleanupAndExit:
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
337ACPI_STATUS
338AcpiEvAcquireGlobalLock (
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
440ACPI_STATUS
441AcpiEvReleaseGlobalLock (
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