1/******************************************************************************
2 *
3 * Module Name: evhandler - Support for Address Space handlers
4 *
5 *****************************************************************************/
6
7/******************************************************************************
8 *
9 * 1. Copyright Notice
10 *
11 * Some or all of this work - Copyright (c) 1999 - 2023, 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 "acnamesp.h"
156#include "acinterp.h"
157
158#define _COMPONENT          ACPI_EVENTS
159        ACPI_MODULE_NAME    ("evhandler")
160
161
162/* Local prototypes */
163
164static ACPI_STATUS
165AcpiEvInstallHandler (
166    ACPI_HANDLE             ObjHandle,
167    UINT32                  Level,
168    void                    *Context,
169    void                    **ReturnValue);
170
171
172/* These are the address spaces that will get default handlers */
173
174UINT8        AcpiGbl_DefaultAddressSpaces[ACPI_NUM_DEFAULT_SPACES] =
175{
176    ACPI_ADR_SPACE_SYSTEM_MEMORY,
177    ACPI_ADR_SPACE_SYSTEM_IO,
178    ACPI_ADR_SPACE_PCI_CONFIG,
179    ACPI_ADR_SPACE_DATA_TABLE
180};
181
182
183/*******************************************************************************
184 *
185 * FUNCTION:    AcpiEvInstallRegionHandlers
186 *
187 * PARAMETERS:  None
188 *
189 * RETURN:      Status
190 *
191 * DESCRIPTION: Installs the core subsystem default address space handlers.
192 *
193 ******************************************************************************/
194
195ACPI_STATUS
196AcpiEvInstallRegionHandlers (
197    void)
198{
199    ACPI_STATUS             Status;
200    UINT32                  i;
201
202
203    ACPI_FUNCTION_TRACE (EvInstallRegionHandlers);
204
205
206    Status = AcpiUtAcquireMutex (ACPI_MTX_NAMESPACE);
207    if (ACPI_FAILURE (Status))
208    {
209        return_ACPI_STATUS (Status);
210    }
211
212    /*
213     * All address spaces (PCI Config, EC, SMBus) are scope dependent and
214     * registration must occur for a specific device.
215     *
216     * In the case of the system memory and IO address spaces there is
217     * currently no device associated with the address space. For these we
218     * use the root.
219     *
220     * We install the default PCI config space handler at the root so that
221     * this space is immediately available even though the we have not
222     * enumerated all the PCI Root Buses yet. This is to conform to the ACPI
223     * specification which states that the PCI config space must be always
224     * available -- even though we are nowhere near ready to find the PCI root
225     * buses at this point.
226     *
227     * NOTE: We ignore AE_ALREADY_EXISTS because this means that a handler
228     * has already been installed (via AcpiInstallAddressSpaceHandler).
229     * Similar for AE_SAME_HANDLER.
230     */
231    for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++)
232    {
233        Status = AcpiEvInstallSpaceHandler (AcpiGbl_RootNode,
234            AcpiGbl_DefaultAddressSpaces[i],
235            ACPI_DEFAULT_HANDLER, NULL, NULL);
236        switch (Status)
237        {
238        case AE_OK:
239        case AE_SAME_HANDLER:
240        case AE_ALREADY_EXISTS:
241
242            /* These exceptions are all OK */
243
244            Status = AE_OK;
245            break;
246
247        default:
248
249            goto UnlockAndExit;
250        }
251    }
252
253UnlockAndExit:
254    (void) AcpiUtReleaseMutex (ACPI_MTX_NAMESPACE);
255    return_ACPI_STATUS (Status);
256}
257
258
259/*******************************************************************************
260 *
261 * FUNCTION:    AcpiEvHasDefaultHandler
262 *
263 * PARAMETERS:  Node                - Namespace node for the device
264 *              SpaceId             - The address space ID
265 *
266 * RETURN:      TRUE if default handler is installed, FALSE otherwise
267 *
268 * DESCRIPTION: Check if the default handler is installed for the requested
269 *              space ID.
270 *
271 ******************************************************************************/
272
273BOOLEAN
274AcpiEvHasDefaultHandler (
275    ACPI_NAMESPACE_NODE     *Node,
276    ACPI_ADR_SPACE_TYPE     SpaceId)
277{
278    ACPI_OPERAND_OBJECT     *ObjDesc;
279    ACPI_OPERAND_OBJECT     *HandlerObj;
280
281
282    /* Must have an existing internal object */
283
284    ObjDesc = AcpiNsGetAttachedObject (Node);
285    if (ObjDesc)
286    {
287        HandlerObj = ObjDesc->CommonNotify.Handler;
288
289        /* Walk the linked list of handlers for this object */
290
291        while (HandlerObj)
292        {
293            if (HandlerObj->AddressSpace.SpaceId == SpaceId)
294            {
295                if (HandlerObj->AddressSpace.HandlerFlags &
296                    ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)
297                {
298                    return (TRUE);
299                }
300            }
301
302            HandlerObj = HandlerObj->AddressSpace.Next;
303        }
304    }
305
306    return (FALSE);
307}
308
309
310/*******************************************************************************
311 *
312 * FUNCTION:    AcpiEvInstallHandler
313 *
314 * PARAMETERS:  WalkNamespace callback
315 *
316 * DESCRIPTION: This routine installs an address handler into objects that are
317 *              of type Region or Device.
318 *
319 *              If the Object is a Device, and the device has a handler of
320 *              the same type then the search is terminated in that branch.
321 *
322 *              This is because the existing handler is closer in proximity
323 *              to any more regions than the one we are trying to install.
324 *
325 ******************************************************************************/
326
327static ACPI_STATUS
328AcpiEvInstallHandler (
329    ACPI_HANDLE             ObjHandle,
330    UINT32                  Level,
331    void                    *Context,
332    void                    **ReturnValue)
333{
334    ACPI_OPERAND_OBJECT     *HandlerObj;
335    ACPI_OPERAND_OBJECT     *NextHandlerObj;
336    ACPI_OPERAND_OBJECT     *ObjDesc;
337    ACPI_NAMESPACE_NODE     *Node;
338    ACPI_STATUS             Status;
339
340
341    ACPI_FUNCTION_NAME (EvInstallHandler);
342
343
344    HandlerObj = (ACPI_OPERAND_OBJECT  *) Context;
345
346    /* Parameter validation */
347
348    if (!HandlerObj)
349    {
350        return (AE_OK);
351    }
352
353    /* Convert and validate the device handle */
354
355    Node = AcpiNsValidateHandle (ObjHandle);
356    if (!Node)
357    {
358        return (AE_BAD_PARAMETER);
359    }
360
361    /*
362     * We only care about regions and objects that are allowed to have
363     * address space handlers
364     */
365    if ((Node->Type != ACPI_TYPE_DEVICE) &&
366        (Node->Type != ACPI_TYPE_REGION) &&
367        (Node != AcpiGbl_RootNode))
368    {
369        return (AE_OK);
370    }
371
372    /* Check for an existing internal object */
373
374    ObjDesc = AcpiNsGetAttachedObject (Node);
375    if (!ObjDesc)
376    {
377        /* No object, just exit */
378
379        return (AE_OK);
380    }
381
382    /* Devices are handled different than regions */
383
384    if (ObjDesc->Common.Type == ACPI_TYPE_DEVICE)
385    {
386        /* Check if this Device already has a handler for this address space */
387
388        NextHandlerObj = AcpiEvFindRegionHandler (
389            HandlerObj->AddressSpace.SpaceId, ObjDesc->CommonNotify.Handler);
390        if (NextHandlerObj)
391        {
392            /* Found a handler, is it for the same address space? */
393
394            ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
395                "Found handler for region [%s] in device %p(%p) handler %p\n",
396                AcpiUtGetRegionName (HandlerObj->AddressSpace.SpaceId),
397                ObjDesc, NextHandlerObj, HandlerObj));
398
399            /*
400             * Since the object we found it on was a device, then it means
401             * that someone has already installed a handler for the branch
402             * of the namespace from this device on. Just bail out telling
403             * the walk routine to not traverse this branch. This preserves
404             * the scoping rule for handlers.
405             */
406            return (AE_CTRL_DEPTH);
407        }
408
409        /*
410         * As long as the device didn't have a handler for this space we
411         * don't care about it. We just ignore it and proceed.
412         */
413        return (AE_OK);
414    }
415
416    /* Object is a Region */
417
418    if (ObjDesc->Region.SpaceId != HandlerObj->AddressSpace.SpaceId)
419    {
420        /* This region is for a different address space, just ignore it */
421
422        return (AE_OK);
423    }
424
425    /*
426     * Now we have a region and it is for the handler's address space type.
427     *
428     * First disconnect region for any previous handler (if any)
429     */
430    AcpiEvDetachRegion (ObjDesc, FALSE);
431
432    /* Connect the region to the new handler */
433
434    Status = AcpiEvAttachRegion (HandlerObj, ObjDesc, FALSE);
435    return (Status);
436}
437
438
439/*******************************************************************************
440 *
441 * FUNCTION:    AcpiEvFindRegionHandler
442 *
443 * PARAMETERS:  SpaceId         - The address space ID
444 *              HandlerObj      - Head of the handler object list
445 *
446 * RETURN:      Matching handler object. NULL if space ID not matched
447 *
448 * DESCRIPTION: Search a handler object list for a match on the address
449 *              space ID.
450 *
451 ******************************************************************************/
452
453ACPI_OPERAND_OBJECT *
454AcpiEvFindRegionHandler (
455    ACPI_ADR_SPACE_TYPE     SpaceId,
456    ACPI_OPERAND_OBJECT     *HandlerObj)
457{
458
459    /* Walk the handler list for this device */
460
461    while (HandlerObj)
462    {
463        /* Same SpaceId indicates a handler is installed */
464
465        if (HandlerObj->AddressSpace.SpaceId == SpaceId)
466        {
467            return (HandlerObj);
468        }
469
470        /* Next handler object */
471
472        HandlerObj = HandlerObj->AddressSpace.Next;
473    }
474
475    return (NULL);
476}
477
478
479/*******************************************************************************
480 *
481 * FUNCTION:    AcpiEvInstallSpaceHandler
482 *
483 * PARAMETERS:  Node            - Namespace node for the device
484 *              SpaceId         - The address space ID
485 *              Handler         - Address of the handler
486 *              Setup           - Address of the setup function
487 *              Context         - Value passed to the handler on each access
488 *
489 * RETURN:      Status
490 *
491 * DESCRIPTION: Install a handler for all OpRegions of a given SpaceId.
492 *              Assumes namespace is locked
493 *
494 ******************************************************************************/
495
496ACPI_STATUS
497AcpiEvInstallSpaceHandler (
498    ACPI_NAMESPACE_NODE     *Node,
499    ACPI_ADR_SPACE_TYPE     SpaceId,
500    ACPI_ADR_SPACE_HANDLER  Handler,
501    ACPI_ADR_SPACE_SETUP    Setup,
502    void                    *Context)
503{
504    ACPI_OPERAND_OBJECT     *ObjDesc;
505    ACPI_OPERAND_OBJECT     *HandlerObj;
506    ACPI_STATUS             Status = AE_OK;
507    ACPI_OBJECT_TYPE        Type;
508    UINT8                   Flags = 0;
509
510
511    ACPI_FUNCTION_TRACE (EvInstallSpaceHandler);
512
513
514    /*
515     * This registration is valid for only the types below and the root.
516     * The root node is where the default handlers get installed.
517     */
518    if ((Node->Type != ACPI_TYPE_DEVICE)     &&
519        (Node->Type != ACPI_TYPE_PROCESSOR)  &&
520        (Node->Type != ACPI_TYPE_THERMAL)    &&
521        (Node != AcpiGbl_RootNode))
522    {
523        Status = AE_BAD_PARAMETER;
524        goto UnlockAndExit;
525    }
526
527    if (Handler == ACPI_DEFAULT_HANDLER)
528    {
529        Flags = ACPI_ADDR_HANDLER_DEFAULT_INSTALLED;
530
531        switch (SpaceId)
532        {
533        case ACPI_ADR_SPACE_SYSTEM_MEMORY:
534
535            Handler = AcpiExSystemMemorySpaceHandler;
536            Setup   = AcpiEvSystemMemoryRegionSetup;
537            break;
538
539        case ACPI_ADR_SPACE_SYSTEM_IO:
540
541            Handler = AcpiExSystemIoSpaceHandler;
542            Setup   = AcpiEvIoSpaceRegionSetup;
543            break;
544
545        case ACPI_ADR_SPACE_PCI_CONFIG:
546
547            Handler = AcpiExPciConfigSpaceHandler;
548            Setup   = AcpiEvPciConfigRegionSetup;
549            break;
550
551        case ACPI_ADR_SPACE_CMOS:
552
553            Handler = AcpiExCmosSpaceHandler;
554            Setup   = AcpiEvCmosRegionSetup;
555            break;
556
557        case ACPI_ADR_SPACE_PCI_BAR_TARGET:
558
559            Handler = AcpiExPciBarSpaceHandler;
560            Setup   = AcpiEvPciBarRegionSetup;
561            break;
562
563        case ACPI_ADR_SPACE_DATA_TABLE:
564
565            Handler = AcpiExDataTableSpaceHandler;
566            Setup   = AcpiEvDataTableRegionSetup;
567            break;
568
569        default:
570
571            Status = AE_BAD_PARAMETER;
572            goto UnlockAndExit;
573        }
574    }
575
576    /* If the caller hasn't specified a setup routine, use the default */
577
578    if (!Setup)
579    {
580        Setup = AcpiEvDefaultRegionSetup;
581    }
582
583    /* Check for an existing internal object */
584
585    ObjDesc = AcpiNsGetAttachedObject (Node);
586    if (ObjDesc)
587    {
588        /*
589         * The attached device object already exists. Now make sure
590         * the handler is not already installed.
591         */
592        HandlerObj = AcpiEvFindRegionHandler (SpaceId,
593            ObjDesc->CommonNotify.Handler);
594
595        if (HandlerObj)
596        {
597            if (HandlerObj->AddressSpace.Handler == Handler)
598            {
599                /*
600                 * It is (relatively) OK to attempt to install the SAME
601                 * handler twice. This can easily happen with the
602                 * PCI_Config space.
603                 */
604                Status = AE_SAME_HANDLER;
605                goto UnlockAndExit;
606            }
607            else
608            {
609                /* A handler is already installed */
610
611                Status = AE_ALREADY_EXISTS;
612            }
613
614            goto UnlockAndExit;
615        }
616    }
617    else
618    {
619        ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
620            "Creating object on Device %p while installing handler\n",
621            Node));
622
623        /* ObjDesc does not exist, create one */
624
625        if (Node->Type == ACPI_TYPE_ANY)
626        {
627            Type = ACPI_TYPE_DEVICE;
628        }
629        else
630        {
631            Type = Node->Type;
632        }
633
634        ObjDesc = AcpiUtCreateInternalObject (Type);
635        if (!ObjDesc)
636        {
637            Status = AE_NO_MEMORY;
638            goto UnlockAndExit;
639        }
640
641        /* Init new descriptor */
642
643        ObjDesc->Common.Type = (UINT8) Type;
644
645        /* Attach the new object to the Node */
646
647        Status = AcpiNsAttachObject (Node, ObjDesc, Type);
648
649        /* Remove local reference to the object */
650
651        AcpiUtRemoveReference (ObjDesc);
652
653        if (ACPI_FAILURE (Status))
654        {
655            goto UnlockAndExit;
656        }
657    }
658
659    ACPI_DEBUG_PRINT ((ACPI_DB_OPREGION,
660        "Installing address handler for region %s(%X) "
661        "on Device %4.4s %p(%p)\n",
662        AcpiUtGetRegionName (SpaceId), SpaceId,
663        AcpiUtGetNodeName (Node), Node, ObjDesc));
664
665    /*
666     * Install the handler
667     *
668     * At this point there is no existing handler. Just allocate the object
669     * for the handler and link it into the list.
670     */
671    HandlerObj = AcpiUtCreateInternalObject (ACPI_TYPE_LOCAL_ADDRESS_HANDLER);
672    if (!HandlerObj)
673    {
674        Status = AE_NO_MEMORY;
675        goto UnlockAndExit;
676    }
677
678    /* Init handler obj */
679
680    Status = AcpiOsCreateMutex (&HandlerObj->AddressSpace.ContextMutex);
681    if (ACPI_FAILURE (Status))
682    {
683        AcpiUtRemoveReference (HandlerObj);
684        goto UnlockAndExit;
685    }
686
687    HandlerObj->AddressSpace.SpaceId = (UINT8) SpaceId;
688    HandlerObj->AddressSpace.HandlerFlags = Flags;
689    HandlerObj->AddressSpace.RegionList = NULL;
690    HandlerObj->AddressSpace.Node = Node;
691    HandlerObj->AddressSpace.Handler = Handler;
692    HandlerObj->AddressSpace.Context = Context;
693    HandlerObj->AddressSpace.Setup = Setup;
694
695    /* Install at head of Device.AddressSpace list */
696
697    HandlerObj->AddressSpace.Next = ObjDesc->CommonNotify.Handler;
698
699    /*
700     * The Device object is the first reference on the HandlerObj.
701     * Each region that uses the handler adds a reference.
702     */
703    ObjDesc->CommonNotify.Handler = HandlerObj;
704
705    /*
706     * Walk the namespace finding all of the regions this handler will
707     * manage.
708     *
709     * Start at the device and search the branch toward the leaf nodes
710     * until either the leaf is encountered or a device is detected that
711     * has an address handler of the same type.
712     *
713     * In either case, back up and search down the remainder of the branch
714     */
715    Status = AcpiNsWalkNamespace (ACPI_TYPE_ANY, Node,
716        ACPI_UINT32_MAX, ACPI_NS_WALK_UNLOCK,
717        AcpiEvInstallHandler, NULL, HandlerObj, NULL);
718
719UnlockAndExit:
720    return_ACPI_STATUS (Status);
721}
722