min/max: remove sparse warnings when they're nested
[cascardo/linux.git] / drivers / acpi / acpica / evregion.c
1 /******************************************************************************
2  *
3  * Module Name: evregion - Operation Region 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 <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acevents.h"
47 #include "acnamesp.h"
48 #include "acinterp.h"
49
50 #define _COMPONENT          ACPI_EVENTS
51 ACPI_MODULE_NAME("evregion")
52
53 extern u8 acpi_gbl_default_address_spaces[];
54
55 /* Local prototypes */
56
57 static void
58 acpi_ev_orphan_ec_reg_method(struct acpi_namespace_node *ec_device_node);
59
60 static acpi_status
61 acpi_ev_reg_run(acpi_handle obj_handle,
62                 u32 level, void *context, void **return_value);
63
64 /*******************************************************************************
65  *
66  * FUNCTION:    acpi_ev_initialize_op_regions
67  *
68  * PARAMETERS:  None
69  *
70  * RETURN:      Status
71  *
72  * DESCRIPTION: Execute _REG methods for all Operation Regions that have
73  *              an installed default region handler.
74  *
75  ******************************************************************************/
76
77 acpi_status acpi_ev_initialize_op_regions(void)
78 {
79         acpi_status status;
80         u32 i;
81
82         ACPI_FUNCTION_TRACE(ev_initialize_op_regions);
83
84         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
85         if (ACPI_FAILURE(status)) {
86                 return_ACPI_STATUS(status);
87         }
88
89         /* Run the _REG methods for op_regions in each default address space */
90
91         for (i = 0; i < ACPI_NUM_DEFAULT_SPACES; i++) {
92                 /*
93                  * Make sure the installed handler is the DEFAULT handler. If not the
94                  * default, the _REG methods will have already been run (when the
95                  * handler was installed)
96                  */
97                 if (acpi_ev_has_default_handler(acpi_gbl_root_node,
98                                                 acpi_gbl_default_address_spaces
99                                                 [i])) {
100                         acpi_ev_execute_reg_methods(acpi_gbl_root_node,
101                                                     acpi_gbl_default_address_spaces
102                                                     [i], ACPI_REG_CONNECT);
103                 }
104         }
105
106         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
107         return_ACPI_STATUS(status);
108 }
109
110 /*******************************************************************************
111  *
112  * FUNCTION:    acpi_ev_address_space_dispatch
113  *
114  * PARAMETERS:  region_obj          - Internal region object
115  *              field_obj           - Corresponding field. Can be NULL.
116  *              function            - Read or Write operation
117  *              region_offset       - Where in the region to read or write
118  *              bit_width           - Field width in bits (8, 16, 32, or 64)
119  *              value               - Pointer to in or out value, must be
120  *                                    a full 64-bit integer
121  *
122  * RETURN:      Status
123  *
124  * DESCRIPTION: Dispatch an address space or operation region access to
125  *              a previously installed handler.
126  *
127  * NOTE: During early initialization, we always install the default region
128  * handlers for Memory, I/O and PCI_Config. This ensures that these operation
129  * region address spaces are always available as per the ACPI specification.
130  * This is especially needed in order to support the execution of
131  * module-level AML code during loading of the ACPI tables.
132  *
133  ******************************************************************************/
134
135 acpi_status
136 acpi_ev_address_space_dispatch(union acpi_operand_object *region_obj,
137                                union acpi_operand_object *field_obj,
138                                u32 function,
139                                u32 region_offset, u32 bit_width, u64 *value)
140 {
141         acpi_status status;
142         acpi_adr_space_handler handler;
143         acpi_adr_space_setup region_setup;
144         union acpi_operand_object *handler_desc;
145         union acpi_operand_object *region_obj2;
146         void *region_context = NULL;
147         struct acpi_connection_info *context;
148         acpi_physical_address address;
149
150         ACPI_FUNCTION_TRACE(ev_address_space_dispatch);
151
152         region_obj2 = acpi_ns_get_secondary_object(region_obj);
153         if (!region_obj2) {
154                 return_ACPI_STATUS(AE_NOT_EXIST);
155         }
156
157         /* Ensure that there is a handler associated with this region */
158
159         handler_desc = region_obj->region.handler;
160         if (!handler_desc) {
161                 ACPI_ERROR((AE_INFO,
162                             "No handler for Region [%4.4s] (%p) [%s]",
163                             acpi_ut_get_node_name(region_obj->region.node),
164                             region_obj,
165                             acpi_ut_get_region_name(region_obj->region.
166                                                     space_id)));
167
168                 return_ACPI_STATUS(AE_NOT_EXIST);
169         }
170
171         context = handler_desc->address_space.context;
172
173         /*
174          * It may be the case that the region has never been initialized.
175          * Some types of regions require special init code
176          */
177         if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
178
179                 /* This region has not been initialized yet, do it */
180
181                 region_setup = handler_desc->address_space.setup;
182                 if (!region_setup) {
183
184                         /* No initialization routine, exit with error */
185
186                         ACPI_ERROR((AE_INFO,
187                                     "No init routine for region(%p) [%s]",
188                                     region_obj,
189                                     acpi_ut_get_region_name(region_obj->region.
190                                                             space_id)));
191                         return_ACPI_STATUS(AE_NOT_EXIST);
192                 }
193
194                 /*
195                  * We must exit the interpreter because the region setup will
196                  * potentially execute control methods (for example, the _REG method
197                  * for this region)
198                  */
199                 acpi_ex_exit_interpreter();
200
201                 status = region_setup(region_obj, ACPI_REGION_ACTIVATE,
202                                       context, &region_context);
203
204                 /* Re-enter the interpreter */
205
206                 acpi_ex_enter_interpreter();
207
208                 /* Check for failure of the Region Setup */
209
210                 if (ACPI_FAILURE(status)) {
211                         ACPI_EXCEPTION((AE_INFO, status,
212                                         "During region initialization: [%s]",
213                                         acpi_ut_get_region_name(region_obj->
214                                                                 region.
215                                                                 space_id)));
216                         return_ACPI_STATUS(status);
217                 }
218
219                 /* Region initialization may have been completed by region_setup */
220
221                 if (!(region_obj->region.flags & AOPOBJ_SETUP_COMPLETE)) {
222                         region_obj->region.flags |= AOPOBJ_SETUP_COMPLETE;
223
224                         /*
225                          * Save the returned context for use in all accesses to
226                          * the handler for this particular region
227                          */
228                         if (!(region_obj2->extra.region_context)) {
229                                 region_obj2->extra.region_context =
230                                     region_context;
231                         }
232                 }
233         }
234
235         /* We have everything we need, we can invoke the address space handler */
236
237         handler = handler_desc->address_space.handler;
238         address = (region_obj->region.address + region_offset);
239
240         /*
241          * Special handling for generic_serial_bus and general_purpose_io:
242          * There are three extra parameters that must be passed to the
243          * handler via the context:
244          *   1) Connection buffer, a resource template from Connection() op
245          *   2) Length of the above buffer
246          *   3) Actual access length from the access_as() op
247          *
248          * In addition, for general_purpose_io, the Address and bit_width fields
249          * are defined as follows:
250          *   1) Address is the pin number index of the field (bit offset from
251          *      the previous Connection)
252          *   2) bit_width is the actual bit length of the field (number of pins)
253          */
254         if ((region_obj->region.space_id == ACPI_ADR_SPACE_GSBUS) &&
255             context && field_obj) {
256
257                 /* Get the Connection (resource_template) buffer */
258
259                 context->connection = field_obj->field.resource_buffer;
260                 context->length = field_obj->field.resource_length;
261                 context->access_length = field_obj->field.access_length;
262         }
263         if ((region_obj->region.space_id == ACPI_ADR_SPACE_GPIO) &&
264             context && field_obj) {
265
266                 /* Get the Connection (resource_template) buffer */
267
268                 context->connection = field_obj->field.resource_buffer;
269                 context->length = field_obj->field.resource_length;
270                 context->access_length = field_obj->field.access_length;
271                 address = field_obj->field.pin_number_index;
272                 bit_width = field_obj->field.bit_length;
273         }
274
275         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
276                           "Handler %p (@%p) Address %8.8X%8.8X [%s]\n",
277                           &region_obj->region.handler->address_space, handler,
278                           ACPI_FORMAT_UINT64(address),
279                           acpi_ut_get_region_name(region_obj->region.
280                                                   space_id)));
281
282         if (!(handler_desc->address_space.handler_flags &
283               ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
284                 /*
285                  * For handlers other than the default (supplied) handlers, we must
286                  * exit the interpreter because the handler *might* block -- we don't
287                  * know what it will do, so we can't hold the lock on the intepreter.
288                  */
289                 acpi_ex_exit_interpreter();
290         }
291
292         /* Call the handler */
293
294         status = handler(function, address, bit_width, value, context,
295                          region_obj2->extra.region_context);
296
297         if (ACPI_FAILURE(status)) {
298                 ACPI_EXCEPTION((AE_INFO, status, "Returned by Handler for [%s]",
299                                 acpi_ut_get_region_name(region_obj->region.
300                                                         space_id)));
301         }
302
303         if (!(handler_desc->address_space.handler_flags &
304               ACPI_ADDR_HANDLER_DEFAULT_INSTALLED)) {
305                 /*
306                  * We just returned from a non-default handler, we must re-enter the
307                  * interpreter
308                  */
309                 acpi_ex_enter_interpreter();
310         }
311
312         return_ACPI_STATUS(status);
313 }
314
315 /*******************************************************************************
316  *
317  * FUNCTION:    acpi_ev_detach_region
318  *
319  * PARAMETERS:  region_obj          - Region Object
320  *              acpi_ns_is_locked   - Namespace Region Already Locked?
321  *
322  * RETURN:      None
323  *
324  * DESCRIPTION: Break the association between the handler and the region
325  *              this is a two way association.
326  *
327  ******************************************************************************/
328
329 void
330 acpi_ev_detach_region(union acpi_operand_object *region_obj,
331                       u8 acpi_ns_is_locked)
332 {
333         union acpi_operand_object *handler_obj;
334         union acpi_operand_object *obj_desc;
335         union acpi_operand_object *start_desc;
336         union acpi_operand_object **last_obj_ptr;
337         acpi_adr_space_setup region_setup;
338         void **region_context;
339         union acpi_operand_object *region_obj2;
340         acpi_status status;
341
342         ACPI_FUNCTION_TRACE(ev_detach_region);
343
344         region_obj2 = acpi_ns_get_secondary_object(region_obj);
345         if (!region_obj2) {
346                 return_VOID;
347         }
348         region_context = &region_obj2->extra.region_context;
349
350         /* Get the address handler from the region object */
351
352         handler_obj = region_obj->region.handler;
353         if (!handler_obj) {
354
355                 /* This region has no handler, all done */
356
357                 return_VOID;
358         }
359
360         /* Find this region in the handler's list */
361
362         obj_desc = handler_obj->address_space.region_list;
363         start_desc = obj_desc;
364         last_obj_ptr = &handler_obj->address_space.region_list;
365
366         while (obj_desc) {
367
368                 /* Is this the correct Region? */
369
370                 if (obj_desc == region_obj) {
371                         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
372                                           "Removing Region %p from address handler %p\n",
373                                           region_obj, handler_obj));
374
375                         /* This is it, remove it from the handler's list */
376
377                         *last_obj_ptr = obj_desc->region.next;
378                         obj_desc->region.next = NULL;   /* Must clear field */
379
380                         if (acpi_ns_is_locked) {
381                                 status =
382                                     acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
383                                 if (ACPI_FAILURE(status)) {
384                                         return_VOID;
385                                 }
386                         }
387
388                         /* Now stop region accesses by executing the _REG method */
389
390                         status =
391                             acpi_ev_execute_reg_method(region_obj,
392                                                        ACPI_REG_DISCONNECT);
393                         if (ACPI_FAILURE(status)) {
394                                 ACPI_EXCEPTION((AE_INFO, status,
395                                                 "from region _REG, [%s]",
396                                                 acpi_ut_get_region_name
397                                                 (region_obj->region.space_id)));
398                         }
399
400                         if (acpi_ns_is_locked) {
401                                 status =
402                                     acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
403                                 if (ACPI_FAILURE(status)) {
404                                         return_VOID;
405                                 }
406                         }
407
408                         /*
409                          * If the region has been activated, call the setup handler with
410                          * the deactivate notification
411                          */
412                         if (region_obj->region.flags & AOPOBJ_SETUP_COMPLETE) {
413                                 region_setup = handler_obj->address_space.setup;
414                                 status =
415                                     region_setup(region_obj,
416                                                  ACPI_REGION_DEACTIVATE,
417                                                  handler_obj->address_space.
418                                                  context, region_context);
419
420                                 /*
421                                  * region_context should have been released by the deactivate
422                                  * operation. We don't need access to it anymore here.
423                                  */
424                                 if (region_context) {
425                                         *region_context = NULL;
426                                 }
427
428                                 /* Init routine may fail, Just ignore errors */
429
430                                 if (ACPI_FAILURE(status)) {
431                                         ACPI_EXCEPTION((AE_INFO, status,
432                                                         "from region handler - deactivate, [%s]",
433                                                         acpi_ut_get_region_name
434                                                         (region_obj->region.
435                                                          space_id)));
436                                 }
437
438                                 region_obj->region.flags &=
439                                     ~(AOPOBJ_SETUP_COMPLETE);
440                         }
441
442                         /*
443                          * Remove handler reference in the region
444                          *
445                          * NOTE: this doesn't mean that the region goes away, the region
446                          * is just inaccessible as indicated to the _REG method
447                          *
448                          * If the region is on the handler's list, this must be the
449                          * region's handler
450                          */
451                         region_obj->region.handler = NULL;
452                         acpi_ut_remove_reference(handler_obj);
453
454                         return_VOID;
455                 }
456
457                 /* Walk the linked list of handlers */
458
459                 last_obj_ptr = &obj_desc->region.next;
460                 obj_desc = obj_desc->region.next;
461
462                 /* Prevent infinite loop if list is corrupted */
463
464                 if (obj_desc == start_desc) {
465                         ACPI_ERROR((AE_INFO,
466                                     "Circular handler list in region object %p",
467                                     region_obj));
468                         return_VOID;
469                 }
470         }
471
472         /* If we get here, the region was not in the handler's region list */
473
474         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
475                           "Cannot remove region %p from address handler %p\n",
476                           region_obj, handler_obj));
477
478         return_VOID;
479 }
480
481 /*******************************************************************************
482  *
483  * FUNCTION:    acpi_ev_attach_region
484  *
485  * PARAMETERS:  handler_obj         - Handler Object
486  *              region_obj          - Region Object
487  *              acpi_ns_is_locked   - Namespace Region Already Locked?
488  *
489  * RETURN:      None
490  *
491  * DESCRIPTION: Create the association between the handler and the region
492  *              this is a two way association.
493  *
494  ******************************************************************************/
495
496 acpi_status
497 acpi_ev_attach_region(union acpi_operand_object *handler_obj,
498                       union acpi_operand_object *region_obj,
499                       u8 acpi_ns_is_locked)
500 {
501
502         ACPI_FUNCTION_TRACE(ev_attach_region);
503
504         /* Install the region's handler */
505
506         if (region_obj->region.handler) {
507                 return_ACPI_STATUS(AE_ALREADY_EXISTS);
508         }
509
510         ACPI_DEBUG_PRINT((ACPI_DB_OPREGION,
511                           "Adding Region [%4.4s] %p to address handler %p [%s]\n",
512                           acpi_ut_get_node_name(region_obj->region.node),
513                           region_obj, handler_obj,
514                           acpi_ut_get_region_name(region_obj->region.
515                                                   space_id)));
516
517         /* Link this region to the front of the handler's list */
518
519         region_obj->region.next = handler_obj->address_space.region_list;
520         handler_obj->address_space.region_list = region_obj;
521         region_obj->region.handler = handler_obj;
522         acpi_ut_add_reference(handler_obj);
523
524         return_ACPI_STATUS(AE_OK);
525 }
526
527 /*******************************************************************************
528  *
529  * FUNCTION:    acpi_ev_execute_reg_method
530  *
531  * PARAMETERS:  region_obj          - Region object
532  *              function            - Passed to _REG: On (1) or Off (0)
533  *
534  * RETURN:      Status
535  *
536  * DESCRIPTION: Execute _REG method for a region
537  *
538  ******************************************************************************/
539
540 acpi_status
541 acpi_ev_execute_reg_method(union acpi_operand_object *region_obj, u32 function)
542 {
543         struct acpi_evaluate_info *info;
544         union acpi_operand_object *args[3];
545         union acpi_operand_object *region_obj2;
546         const acpi_name *reg_name_ptr =
547             ACPI_CAST_PTR(acpi_name, METHOD_NAME__REG);
548         struct acpi_namespace_node *method_node;
549         struct acpi_namespace_node *node;
550         acpi_status status;
551
552         ACPI_FUNCTION_TRACE(ev_execute_reg_method);
553
554         if (!acpi_gbl_namespace_initialized ||
555             region_obj->region.handler == NULL) {
556                 return_ACPI_STATUS(AE_OK);
557         }
558
559         region_obj2 = acpi_ns_get_secondary_object(region_obj);
560         if (!region_obj2) {
561                 return_ACPI_STATUS(AE_NOT_EXIST);
562         }
563
564         /*
565          * Find any "_REG" method associated with this region definition.
566          * The method should always be updated as this function may be
567          * invoked after a namespace change.
568          */
569         node = region_obj->region.node->parent;
570         status =
571             acpi_ns_search_one_scope(*reg_name_ptr, node, ACPI_TYPE_METHOD,
572                                      &method_node);
573         if (ACPI_SUCCESS(status)) {
574                 /*
575                  * The _REG method is optional and there can be only one per
576                  * region definition. This will be executed when the handler is
577                  * attached or removed.
578                  */
579                 region_obj2->extra.method_REG = method_node;
580         }
581         if (region_obj2->extra.method_REG == NULL) {
582                 return_ACPI_STATUS(AE_OK);
583         }
584
585         /* _REG(DISCONNECT) should be paired with _REG(CONNECT) */
586
587         if ((function == ACPI_REG_CONNECT &&
588              region_obj->common.flags & AOPOBJ_REG_CONNECTED) ||
589             (function == ACPI_REG_DISCONNECT &&
590              !(region_obj->common.flags & AOPOBJ_REG_CONNECTED))) {
591                 return_ACPI_STATUS(AE_OK);
592         }
593
594         /* Allocate and initialize the evaluation information block */
595
596         info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
597         if (!info) {
598                 return_ACPI_STATUS(AE_NO_MEMORY);
599         }
600
601         info->prefix_node = region_obj2->extra.method_REG;
602         info->relative_pathname = NULL;
603         info->parameters = args;
604         info->flags = ACPI_IGNORE_RETURN_VALUE;
605
606         /*
607          * The _REG method has two arguments:
608          *
609          * arg0 - Integer:
610          *  Operation region space ID Same value as region_obj->Region.space_id
611          *
612          * arg1 - Integer:
613          *  connection status 1 for connecting the handler, 0 for disconnecting
614          *  the handler (Passed as a parameter)
615          */
616         args[0] =
617             acpi_ut_create_integer_object((u64)region_obj->region.space_id);
618         if (!args[0]) {
619                 status = AE_NO_MEMORY;
620                 goto cleanup1;
621         }
622
623         args[1] = acpi_ut_create_integer_object((u64)function);
624         if (!args[1]) {
625                 status = AE_NO_MEMORY;
626                 goto cleanup2;
627         }
628
629         args[2] = NULL;         /* Terminate list */
630
631         /* Execute the method, no return value */
632
633         ACPI_DEBUG_EXEC(acpi_ut_display_init_pathname
634                         (ACPI_TYPE_METHOD, info->prefix_node, NULL));
635
636         status = acpi_ns_evaluate(info);
637         acpi_ut_remove_reference(args[1]);
638
639         if (ACPI_FAILURE(status)) {
640                 goto cleanup2;
641         }
642
643         if (function == ACPI_REG_CONNECT) {
644                 region_obj->common.flags |= AOPOBJ_REG_CONNECTED;
645         } else {
646                 region_obj->common.flags &= ~AOPOBJ_REG_CONNECTED;
647         }
648
649 cleanup2:
650         acpi_ut_remove_reference(args[0]);
651
652 cleanup1:
653         ACPI_FREE(info);
654         return_ACPI_STATUS(status);
655 }
656
657 /*******************************************************************************
658  *
659  * FUNCTION:    acpi_ev_execute_reg_methods
660  *
661  * PARAMETERS:  node            - Namespace node for the device
662  *              space_id        - The address space ID
663  *              function        - Passed to _REG: On (1) or Off (0)
664  *
665  * RETURN:      None
666  *
667  * DESCRIPTION: Run all _REG methods for the input Space ID;
668  *              Note: assumes namespace is locked, or system init time.
669  *
670  ******************************************************************************/
671
672 void
673 acpi_ev_execute_reg_methods(struct acpi_namespace_node *node,
674                             acpi_adr_space_type space_id, u32 function)
675 {
676         struct acpi_reg_walk_info info;
677
678         ACPI_FUNCTION_TRACE(ev_execute_reg_methods);
679
680         info.space_id = space_id;
681         info.function = function;
682         info.reg_run_count = 0;
683
684         ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES,
685                               "    Running _REG methods for SpaceId %s\n",
686                               acpi_ut_get_region_name(info.space_id)));
687
688         /*
689          * Run all _REG methods for all Operation Regions for this space ID. This
690          * is a separate walk in order to handle any interdependencies between
691          * regions and _REG methods. (i.e. handlers must be installed for all
692          * regions of this Space ID before we can run any _REG methods)
693          */
694         (void)acpi_ns_walk_namespace(ACPI_TYPE_ANY, node, ACPI_UINT32_MAX,
695                                      ACPI_NS_WALK_UNLOCK, acpi_ev_reg_run, NULL,
696                                      &info, NULL);
697
698         /* Special case for EC: handle "orphan" _REG methods with no region */
699
700         if (space_id == ACPI_ADR_SPACE_EC) {
701                 acpi_ev_orphan_ec_reg_method(node);
702         }
703
704         ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES,
705                               "    Executed %u _REG methods for SpaceId %s\n",
706                               info.reg_run_count,
707                               acpi_ut_get_region_name(info.space_id)));
708
709         return_VOID;
710 }
711
712 /*******************************************************************************
713  *
714  * FUNCTION:    acpi_ev_reg_run
715  *
716  * PARAMETERS:  walk_namespace callback
717  *
718  * DESCRIPTION: Run _REG method for region objects of the requested spaceID
719  *
720  ******************************************************************************/
721
722 static acpi_status
723 acpi_ev_reg_run(acpi_handle obj_handle,
724                 u32 level, void *context, void **return_value)
725 {
726         union acpi_operand_object *obj_desc;
727         struct acpi_namespace_node *node;
728         acpi_status status;
729         struct acpi_reg_walk_info *info;
730
731         info = ACPI_CAST_PTR(struct acpi_reg_walk_info, context);
732
733         /* Convert and validate the device handle */
734
735         node = acpi_ns_validate_handle(obj_handle);
736         if (!node) {
737                 return (AE_BAD_PARAMETER);
738         }
739
740         /*
741          * We only care about regions.and objects that are allowed to have address
742          * space handlers
743          */
744         if ((node->type != ACPI_TYPE_REGION) && (node != acpi_gbl_root_node)) {
745                 return (AE_OK);
746         }
747
748         /* Check for an existing internal object */
749
750         obj_desc = acpi_ns_get_attached_object(node);
751         if (!obj_desc) {
752
753                 /* No object, just exit */
754
755                 return (AE_OK);
756         }
757
758         /* Object is a Region */
759
760         if (obj_desc->region.space_id != info->space_id) {
761
762                 /* This region is for a different address space, just ignore it */
763
764                 return (AE_OK);
765         }
766
767         info->reg_run_count++;
768         status = acpi_ev_execute_reg_method(obj_desc, info->function);
769         return (status);
770 }
771
772 /*******************************************************************************
773  *
774  * FUNCTION:    acpi_ev_orphan_ec_reg_method
775  *
776  * PARAMETERS:  ec_device_node      - Namespace node for an EC device
777  *
778  * RETURN:      None
779  *
780  * DESCRIPTION: Execute an "orphan" _REG method that appears under the EC
781  *              device. This is a _REG method that has no corresponding region
782  *              within the EC device scope. The orphan _REG method appears to
783  *              have been enabled by the description of the ECDT in the ACPI
784  *              specification: "The availability of the region space can be
785  *              detected by providing a _REG method object underneath the
786  *              Embedded Controller device."
787  *
788  *              To quickly access the EC device, we use the ec_device_node used
789  *              during EC handler installation. Otherwise, we would need to
790  *              perform a time consuming namespace walk, executing _HID
791  *              methods to find the EC device.
792  *
793  *  MUTEX:      Assumes the namespace is locked
794  *
795  ******************************************************************************/
796
797 static void
798 acpi_ev_orphan_ec_reg_method(struct acpi_namespace_node *ec_device_node)
799 {
800         acpi_handle reg_method;
801         struct acpi_namespace_node *next_node;
802         acpi_status status;
803         struct acpi_object_list args;
804         union acpi_object objects[2];
805
806         ACPI_FUNCTION_TRACE(ev_orphan_ec_reg_method);
807
808         if (!ec_device_node) {
809                 return_VOID;
810         }
811
812         /* Namespace is currently locked, must release */
813
814         (void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
815
816         /* Get a handle to a _REG method immediately under the EC device */
817
818         status = acpi_get_handle(ec_device_node, METHOD_NAME__REG, &reg_method);
819         if (ACPI_FAILURE(status)) {
820                 goto exit;      /* There is no _REG method present */
821         }
822
823         /*
824          * Execute the _REG method only if there is no Operation Region in
825          * this scope with the Embedded Controller space ID. Otherwise, it
826          * will already have been executed. Note, this allows for Regions
827          * with other space IDs to be present; but the code below will then
828          * execute the _REG method with the embedded_control space_ID argument.
829          */
830         next_node = acpi_ns_get_next_node(ec_device_node, NULL);
831         while (next_node) {
832                 if ((next_node->type == ACPI_TYPE_REGION) &&
833                     (next_node->object) &&
834                     (next_node->object->region.space_id == ACPI_ADR_SPACE_EC)) {
835                         goto exit;      /* Do not execute the _REG */
836                 }
837
838                 next_node = acpi_ns_get_next_node(ec_device_node, next_node);
839         }
840
841         /* Evaluate the _REG(embedded_control,Connect) method */
842
843         args.count = 2;
844         args.pointer = objects;
845         objects[0].type = ACPI_TYPE_INTEGER;
846         objects[0].integer.value = ACPI_ADR_SPACE_EC;
847         objects[1].type = ACPI_TYPE_INTEGER;
848         objects[1].integer.value = ACPI_REG_CONNECT;
849
850         status = acpi_evaluate_object(reg_method, NULL, &args, NULL);
851
852 exit:
853         /* We ignore all errors from above, don't care */
854
855         status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
856         return_VOID;
857 }