ACPI: remove unnecessary sizeof(u8)
[linux-drm-fsl-dcu.git] / drivers / acpi / utils.c
1 /*
2  *  acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *
7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8  *
9  *  This program is free software; you can redistribute it and/or modify
10  *  it under the terms of the GNU General Public License as published by
11  *  the Free Software Foundation; either version 2 of the License, or (at
12  *  your option) any later version.
13  *
14  *  This program is distributed in the hope that it will be useful, but
15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17  *  General Public License for more details.
18  *
19  *  You should have received a copy of the GNU General Public License along
20  *  with this program; if not, write to the Free Software Foundation, Inc.,
21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
22  *
23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24  */
25
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/slab.h>
29 #include <linux/init.h>
30 #include <linux/types.h>
31 #include <linux/hardirq.h>
32 #include <linux/acpi.h>
33 #include <linux/dynamic_debug.h>
34
35 #include "internal.h"
36
37 #define _COMPONENT              ACPI_BUS_COMPONENT
38 ACPI_MODULE_NAME("utils");
39
40 /* --------------------------------------------------------------------------
41                             Object Evaluation Helpers
42    -------------------------------------------------------------------------- */
43 static void
44 acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
45 {
46 #ifdef ACPI_DEBUG_OUTPUT
47         char prefix[80] = {'\0'};
48         struct acpi_buffer buffer = {sizeof(prefix), prefix};
49         acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);
50         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluate [%s.%s]: %s\n",
51                 (char *) prefix, p, acpi_format_exception(s)));
52 #else
53         return;
54 #endif
55 }
56
57 acpi_status
58 acpi_extract_package(union acpi_object *package,
59                      struct acpi_buffer *format, struct acpi_buffer *buffer)
60 {
61         u32 size_required = 0;
62         u32 tail_offset = 0;
63         char *format_string = NULL;
64         u32 format_count = 0;
65         u32 i = 0;
66         u8 *head = NULL;
67         u8 *tail = NULL;
68
69
70         if (!package || (package->type != ACPI_TYPE_PACKAGE)
71             || (package->package.count < 1)) {
72                 printk(KERN_WARNING PREFIX "Invalid package argument\n");
73                 return AE_BAD_PARAMETER;
74         }
75
76         if (!format || !format->pointer || (format->length < 1)) {
77                 printk(KERN_WARNING PREFIX "Invalid format argument\n");
78                 return AE_BAD_PARAMETER;
79         }
80
81         if (!buffer) {
82                 printk(KERN_WARNING PREFIX "Invalid buffer argument\n");
83                 return AE_BAD_PARAMETER;
84         }
85
86         format_count = (format->length / sizeof(char)) - 1;
87         if (format_count > package->package.count) {
88                 printk(KERN_WARNING PREFIX "Format specifies more objects [%d]"
89                               " than exist in package [%d].\n",
90                               format_count, package->package.count);
91                 return AE_BAD_DATA;
92         }
93
94         format_string = format->pointer;
95
96         /*
97          * Calculate size_required.
98          */
99         for (i = 0; i < format_count; i++) {
100
101                 union acpi_object *element = &(package->package.elements[i]);
102
103                 switch (element->type) {
104
105                 case ACPI_TYPE_INTEGER:
106                         switch (format_string[i]) {
107                         case 'N':
108                                 size_required += sizeof(u64);
109                                 tail_offset += sizeof(u64);
110                                 break;
111                         case 'S':
112                                 size_required +=
113                                     sizeof(char *) + sizeof(u64) +
114                                     sizeof(char);
115                                 tail_offset += sizeof(char *);
116                                 break;
117                         default:
118                                 printk(KERN_WARNING PREFIX "Invalid package element"
119                                               " [%d]: got number, expecting"
120                                               " [%c]\n",
121                                               i, format_string[i]);
122                                 return AE_BAD_DATA;
123                                 break;
124                         }
125                         break;
126
127                 case ACPI_TYPE_STRING:
128                 case ACPI_TYPE_BUFFER:
129                         switch (format_string[i]) {
130                         case 'S':
131                                 size_required +=
132                                     sizeof(char *) +
133                                     (element->string.length * sizeof(char)) +
134                                     sizeof(char);
135                                 tail_offset += sizeof(char *);
136                                 break;
137                         case 'B':
138                                 size_required +=
139                                     sizeof(u8 *) + element->buffer.length;
140                                 tail_offset += sizeof(u8 *);
141                                 break;
142                         default:
143                                 printk(KERN_WARNING PREFIX "Invalid package element"
144                                               " [%d] got string/buffer,"
145                                               " expecting [%c]\n",
146                                               i, format_string[i]);
147                                 return AE_BAD_DATA;
148                                 break;
149                         }
150                         break;
151                 case ACPI_TYPE_LOCAL_REFERENCE:
152                         switch (format_string[i]) {
153                         case 'R':
154                                 size_required += sizeof(void *);
155                                 tail_offset += sizeof(void *);
156                                 break;
157                         default:
158                                 printk(KERN_WARNING PREFIX "Invalid package element"
159                                               " [%d] got reference,"
160                                               " expecting [%c]\n",
161                                               i, format_string[i]);
162                                 return AE_BAD_DATA;
163                                 break;
164                         }
165                         break;
166
167                 case ACPI_TYPE_PACKAGE:
168                 default:
169                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
170                                           "Found unsupported element at index=%d\n",
171                                           i));
172                         /* TBD: handle nested packages... */
173                         return AE_SUPPORT;
174                         break;
175                 }
176         }
177
178         /*
179          * Validate output buffer.
180          */
181         if (buffer->length == ACPI_ALLOCATE_BUFFER) {
182                 buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
183                 if (!buffer->pointer)
184                         return AE_NO_MEMORY;
185                 buffer->length = size_required;
186         } else {
187                 if (buffer->length < size_required) {
188                         buffer->length = size_required;
189                         return AE_BUFFER_OVERFLOW;
190                 } else if (buffer->length != size_required ||
191                            !buffer->pointer) {
192                         return AE_BAD_PARAMETER;
193                 }
194         }
195
196         head = buffer->pointer;
197         tail = buffer->pointer + tail_offset;
198
199         /*
200          * Extract package data.
201          */
202         for (i = 0; i < format_count; i++) {
203
204                 u8 **pointer = NULL;
205                 union acpi_object *element = &(package->package.elements[i]);
206
207                 if (!element) {
208                         return AE_BAD_DATA;
209                 }
210
211                 switch (element->type) {
212
213                 case ACPI_TYPE_INTEGER:
214                         switch (format_string[i]) {
215                         case 'N':
216                                 *((u64 *) head) =
217                                     element->integer.value;
218                                 head += sizeof(u64);
219                                 break;
220                         case 'S':
221                                 pointer = (u8 **) head;
222                                 *pointer = tail;
223                                 *((u64 *) tail) =
224                                     element->integer.value;
225                                 head += sizeof(u64 *);
226                                 tail += sizeof(u64);
227                                 /* NULL terminate string */
228                                 *tail = (char)0;
229                                 tail += sizeof(char);
230                                 break;
231                         default:
232                                 /* Should never get here */
233                                 break;
234                         }
235                         break;
236
237                 case ACPI_TYPE_STRING:
238                 case ACPI_TYPE_BUFFER:
239                         switch (format_string[i]) {
240                         case 'S':
241                                 pointer = (u8 **) head;
242                                 *pointer = tail;
243                                 memcpy(tail, element->string.pointer,
244                                        element->string.length);
245                                 head += sizeof(char *);
246                                 tail += element->string.length * sizeof(char);
247                                 /* NULL terminate string */
248                                 *tail = (char)0;
249                                 tail += sizeof(char);
250                                 break;
251                         case 'B':
252                                 pointer = (u8 **) head;
253                                 *pointer = tail;
254                                 memcpy(tail, element->buffer.pointer,
255                                        element->buffer.length);
256                                 head += sizeof(u8 *);
257                                 tail += element->buffer.length;
258                                 break;
259                         default:
260                                 /* Should never get here */
261                                 break;
262                         }
263                         break;
264                 case ACPI_TYPE_LOCAL_REFERENCE:
265                         switch (format_string[i]) {
266                         case 'R':
267                                 *(void **)head =
268                                     (void *)element->reference.handle;
269                                 head += sizeof(void *);
270                                 break;
271                         default:
272                                 /* Should never get here */
273                                 break;
274                         }
275                         break;
276                 case ACPI_TYPE_PACKAGE:
277                         /* TBD: handle nested packages... */
278                 default:
279                         /* Should never get here */
280                         break;
281                 }
282         }
283
284         return AE_OK;
285 }
286
287 EXPORT_SYMBOL(acpi_extract_package);
288
289 acpi_status
290 acpi_evaluate_integer(acpi_handle handle,
291                       acpi_string pathname,
292                       struct acpi_object_list *arguments, unsigned long long *data)
293 {
294         acpi_status status = AE_OK;
295         union acpi_object element;
296         struct acpi_buffer buffer = { 0, NULL };
297
298         if (!data)
299                 return AE_BAD_PARAMETER;
300
301         buffer.length = sizeof(union acpi_object);
302         buffer.pointer = &element;
303         status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
304         if (ACPI_FAILURE(status)) {
305                 acpi_util_eval_error(handle, pathname, status);
306                 return status;
307         }
308
309         if (element.type != ACPI_TYPE_INTEGER) {
310                 acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
311                 return AE_BAD_DATA;
312         }
313
314         *data = element.integer.value;
315
316         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]\n", *data));
317
318         return AE_OK;
319 }
320
321 EXPORT_SYMBOL(acpi_evaluate_integer);
322
323 acpi_status
324 acpi_evaluate_reference(acpi_handle handle,
325                         acpi_string pathname,
326                         struct acpi_object_list *arguments,
327                         struct acpi_handle_list *list)
328 {
329         acpi_status status = AE_OK;
330         union acpi_object *package = NULL;
331         union acpi_object *element = NULL;
332         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
333         u32 i = 0;
334
335
336         if (!list) {
337                 return AE_BAD_PARAMETER;
338         }
339
340         /* Evaluate object. */
341
342         status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
343         if (ACPI_FAILURE(status))
344                 goto end;
345
346         package = buffer.pointer;
347
348         if ((buffer.length == 0) || !package) {
349                 printk(KERN_ERR PREFIX "No return object (len %X ptr %p)\n",
350                             (unsigned)buffer.length, package);
351                 status = AE_BAD_DATA;
352                 acpi_util_eval_error(handle, pathname, status);
353                 goto end;
354         }
355         if (package->type != ACPI_TYPE_PACKAGE) {
356                 printk(KERN_ERR PREFIX "Expecting a [Package], found type %X\n",
357                             package->type);
358                 status = AE_BAD_DATA;
359                 acpi_util_eval_error(handle, pathname, status);
360                 goto end;
361         }
362         if (!package->package.count) {
363                 printk(KERN_ERR PREFIX "[Package] has zero elements (%p)\n",
364                             package);
365                 status = AE_BAD_DATA;
366                 acpi_util_eval_error(handle, pathname, status);
367                 goto end;
368         }
369
370         if (package->package.count > ACPI_MAX_HANDLES) {
371                 return AE_NO_MEMORY;
372         }
373         list->count = package->package.count;
374
375         /* Extract package data. */
376
377         for (i = 0; i < list->count; i++) {
378
379                 element = &(package->package.elements[i]);
380
381                 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
382                         status = AE_BAD_DATA;
383                         printk(KERN_ERR PREFIX
384                                     "Expecting a [Reference] package element, found type %X\n",
385                                     element->type);
386                         acpi_util_eval_error(handle, pathname, status);
387                         break;
388                 }
389
390                 if (!element->reference.handle) {
391                         printk(KERN_WARNING PREFIX "Invalid reference in"
392                                " package %s\n", pathname);
393                         status = AE_NULL_ENTRY;
394                         break;
395                 }
396                 /* Get the  acpi_handle. */
397
398                 list->handles[i] = element->reference.handle;
399                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found reference [%p]\n",
400                                   list->handles[i]));
401         }
402
403       end:
404         if (ACPI_FAILURE(status)) {
405                 list->count = 0;
406                 //kfree(list->handles);
407         }
408
409         kfree(buffer.pointer);
410
411         return status;
412 }
413
414 EXPORT_SYMBOL(acpi_evaluate_reference);
415
416 acpi_status
417 acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
418 {
419         acpi_status status;
420         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
421         union acpi_object *output;
422
423         status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
424
425         if (ACPI_FAILURE(status))
426                 return status;
427
428         output = buffer.pointer;
429
430         if (!output || output->type != ACPI_TYPE_PACKAGE
431             || !output->package.count
432             || output->package.elements[0].type != ACPI_TYPE_BUFFER
433             || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
434                 status = AE_TYPE;
435                 goto out;
436         }
437
438         status = acpi_decode_pld_buffer(
439                         output->package.elements[0].buffer.pointer,
440                         output->package.elements[0].buffer.length,
441                         pld);
442
443 out:
444         kfree(buffer.pointer);
445         return status;
446 }
447 EXPORT_SYMBOL(acpi_get_physical_device_location);
448
449 /**
450  * acpi_evaluate_ost: Evaluate _OST for hotplug operations
451  * @handle: ACPI device handle
452  * @source_event: source event code
453  * @status_code: status code
454  * @status_buf: optional detailed information (NULL if none)
455  *
456  * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
457  * must call this function when evaluating _OST for hotplug operations.
458  * When the platform does not support _OST, this function has no effect.
459  */
460 acpi_status
461 acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
462                   struct acpi_buffer *status_buf)
463 {
464         union acpi_object params[3] = {
465                 {.type = ACPI_TYPE_INTEGER,},
466                 {.type = ACPI_TYPE_INTEGER,},
467                 {.type = ACPI_TYPE_BUFFER,}
468         };
469         struct acpi_object_list arg_list = {3, params};
470
471         params[0].integer.value = source_event;
472         params[1].integer.value = status_code;
473         if (status_buf != NULL) {
474                 params[2].buffer.pointer = status_buf->pointer;
475                 params[2].buffer.length = status_buf->length;
476         } else {
477                 params[2].buffer.pointer = NULL;
478                 params[2].buffer.length = 0;
479         }
480
481         return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
482 }
483 EXPORT_SYMBOL(acpi_evaluate_ost);
484
485 /**
486  * acpi_handle_path: Return the object path of handle
487  *
488  * Caller must free the returned buffer
489  */
490 static char *acpi_handle_path(acpi_handle handle)
491 {
492         struct acpi_buffer buffer = {
493                 .length = ACPI_ALLOCATE_BUFFER,
494                 .pointer = NULL
495         };
496
497         if (in_interrupt() ||
498             acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
499                 return NULL;
500         return buffer.pointer;
501 }
502
503 /**
504  * acpi_handle_printk: Print message with ACPI prefix and object path
505  *
506  * This function is called through acpi_handle_<level> macros and prints
507  * a message with ACPI prefix and object path.  This function acquires
508  * the global namespace mutex to obtain an object path.  In interrupt
509  * context, it shows the object path as <n/a>.
510  */
511 void
512 acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
513 {
514         struct va_format vaf;
515         va_list args;
516         const char *path;
517
518         va_start(args, fmt);
519         vaf.fmt = fmt;
520         vaf.va = &args;
521
522         path = acpi_handle_path(handle);
523         printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf);
524
525         va_end(args);
526         kfree(path);
527 }
528 EXPORT_SYMBOL(acpi_handle_printk);
529
530 #if defined(CONFIG_DYNAMIC_DEBUG)
531 /**
532  * __acpi_handle_debug: pr_debug with ACPI prefix and object path
533  *
534  * This function is called through acpi_handle_debug macro and debug
535  * prints a message with ACPI prefix and object path. This function
536  * acquires the global namespace mutex to obtain an object path.  In
537  * interrupt context, it shows the object path as <n/a>.
538  */
539 void
540 __acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
541                     const char *fmt, ...)
542 {
543         struct va_format vaf;
544         va_list args;
545         const char *path;
546
547         va_start(args, fmt);
548         vaf.fmt = fmt;
549         vaf.va = &args;
550
551         path = acpi_handle_path(handle);
552         __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
553
554         va_end(args);
555         kfree(path);
556 }
557 EXPORT_SYMBOL(__acpi_handle_debug);
558 #endif
559
560 /**
561  * acpi_has_method: Check whether @handle has a method named @name
562  * @handle: ACPI device handle
563  * @name: name of object or method
564  *
565  * Check whether @handle has a method named @name.
566  */
567 bool acpi_has_method(acpi_handle handle, char *name)
568 {
569         acpi_handle tmp;
570
571         return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
572 }
573 EXPORT_SYMBOL(acpi_has_method);
574
575 acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
576                                        u64 arg)
577 {
578         union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
579         struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
580
581         obj.integer.value = arg;
582
583         return acpi_evaluate_object(handle, method, &arg_list, NULL);
584 }
585 EXPORT_SYMBOL(acpi_execute_simple_method);
586
587 /**
588  * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
589  * @handle: ACPI device handle
590  *
591  * Evaluate device's _EJ0 method for hotplug operations.
592  */
593 acpi_status acpi_evaluate_ej0(acpi_handle handle)
594 {
595         acpi_status status;
596
597         status = acpi_execute_simple_method(handle, "_EJ0", 1);
598         if (status == AE_NOT_FOUND)
599                 acpi_handle_warn(handle, "No _EJ0 support for device\n");
600         else if (ACPI_FAILURE(status))
601                 acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
602
603         return status;
604 }
605
606 /**
607  * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
608  * @handle: ACPI device handle
609  * @lock: lock device if non-zero, otherwise unlock device
610  *
611  * Evaluate device's _LCK method if present to lock/unlock device
612  */
613 acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
614 {
615         acpi_status status;
616
617         status = acpi_execute_simple_method(handle, "_LCK", !!lock);
618         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
619                 if (lock)
620                         acpi_handle_warn(handle,
621                                 "Locking device failed (0x%x)\n", status);
622                 else
623                         acpi_handle_warn(handle,
624                                 "Unlocking device failed (0x%x)\n", status);
625         }
626
627         return status;
628 }
629
630 /**
631  * acpi_evaluate_dsm - evaluate device's _DSM method
632  * @handle: ACPI device handle
633  * @uuid: UUID of requested functions, should be 16 bytes
634  * @rev: revision number of requested function
635  * @func: requested function number
636  * @argv4: the function specific parameter
637  *
638  * Evaluate device's _DSM method with specified UUID, revision id and
639  * function number. Caller needs to free the returned object.
640  *
641  * Though ACPI defines the fourth parameter for _DSM should be a package,
642  * some old BIOSes do expect a buffer or an integer etc.
643  */
644 union acpi_object *
645 acpi_evaluate_dsm(acpi_handle handle, const u8 *uuid, int rev, int func,
646                   union acpi_object *argv4)
647 {
648         acpi_status ret;
649         struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
650         union acpi_object params[4];
651         struct acpi_object_list input = {
652                 .count = 4,
653                 .pointer = params,
654         };
655
656         params[0].type = ACPI_TYPE_BUFFER;
657         params[0].buffer.length = 16;
658         params[0].buffer.pointer = (char *)uuid;
659         params[1].type = ACPI_TYPE_INTEGER;
660         params[1].integer.value = rev;
661         params[2].type = ACPI_TYPE_INTEGER;
662         params[2].integer.value = func;
663         if (argv4) {
664                 params[3] = *argv4;
665         } else {
666                 params[3].type = ACPI_TYPE_PACKAGE;
667                 params[3].package.count = 0;
668                 params[3].package.elements = NULL;
669         }
670
671         ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
672         if (ACPI_SUCCESS(ret))
673                 return (union acpi_object *)buf.pointer;
674
675         if (ret != AE_NOT_FOUND)
676                 acpi_handle_warn(handle,
677                                 "failed to evaluate _DSM (0x%x)\n", ret);
678
679         return NULL;
680 }
681 EXPORT_SYMBOL(acpi_evaluate_dsm);
682
683 /**
684  * acpi_check_dsm - check if _DSM method supports requested functions.
685  * @handle: ACPI device handle
686  * @uuid: UUID of requested functions, should be 16 bytes at least
687  * @rev: revision number of requested functions
688  * @funcs: bitmap of requested functions
689  *
690  * Evaluate device's _DSM method to check whether it supports requested
691  * functions. Currently only support 64 functions at maximum, should be
692  * enough for now.
693  */
694 bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, int rev, u64 funcs)
695 {
696         int i;
697         u64 mask = 0;
698         union acpi_object *obj;
699
700         if (funcs == 0)
701                 return false;
702
703         obj = acpi_evaluate_dsm(handle, uuid, rev, 0, NULL);
704         if (!obj)
705                 return false;
706
707         /* For compatibility, old BIOSes may return an integer */
708         if (obj->type == ACPI_TYPE_INTEGER)
709                 mask = obj->integer.value;
710         else if (obj->type == ACPI_TYPE_BUFFER)
711                 for (i = 0; i < obj->buffer.length && i < 8; i++)
712                         mask |= (((u8)obj->buffer.pointer[i]) << (i * 8));
713         ACPI_FREE(obj);
714
715         /*
716          * Bit 0 indicates whether there's support for any functions other than
717          * function 0 for the specified UUID and revision.
718          */
719         if ((mask & 0x1) && (mask & funcs) == funcs)
720                 return true;
721
722         return false;
723 }
724 EXPORT_SYMBOL(acpi_check_dsm);