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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <[email protected]>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
7 */
8
9#define pr_fmt(fmt) "ACPI: utils: " fmt
10
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/slab.h>
14#include <linux/init.h>
15#include <linux/types.h>
16#include <linux/hardirq.h>
17#include <linux/acpi.h>
18#include <linux/dynamic_debug.h>
19
20#include "internal.h"
21#include "sleep.h"
22
23/* --------------------------------------------------------------------------
24 Object Evaluation Helpers
25 -------------------------------------------------------------------------- */
26static void acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
27{
28 acpi_handle_debug(h, "Evaluate [%s]: %s\n", p, acpi_format_exception(s));
29}
30
31acpi_status
32acpi_extract_package(union acpi_object *package,
33 struct acpi_buffer *format, struct acpi_buffer *buffer)
34{
35 u32 size_required = 0;
36 u32 tail_offset = 0;
37 char *format_string = NULL;
38 u32 format_count = 0;
39 u32 i = 0;
40 u8 *head = NULL;
41 u8 *tail = NULL;
42
43
44 if (!package || (package->type != ACPI_TYPE_PACKAGE)
45 || (package->package.count < 1)) {
46 pr_debug("Invalid package argument\n");
47 return AE_BAD_PARAMETER;
48 }
49
50 if (!format || !format->pointer || (format->length < 1)) {
51 pr_debug("Invalid format argument\n");
52 return AE_BAD_PARAMETER;
53 }
54
55 if (!buffer) {
56 pr_debug("Invalid buffer argument\n");
57 return AE_BAD_PARAMETER;
58 }
59
60 format_count = (format->length / sizeof(char)) - 1;
61 if (format_count > package->package.count) {
62 pr_debug("Format specifies more objects [%d] than present [%d]\n",
63 format_count, package->package.count);
64 return AE_BAD_DATA;
65 }
66
67 format_string = format->pointer;
68
69 /*
70 * Calculate size_required.
71 */
72 for (i = 0; i < format_count; i++) {
73
74 union acpi_object *element = &(package->package.elements[i]);
75
76 switch (element->type) {
77
78 case ACPI_TYPE_INTEGER:
79 switch (format_string[i]) {
80 case 'N':
81 size_required += sizeof(u64);
82 tail_offset += sizeof(u64);
83 break;
84 case 'S':
85 size_required +=
86 sizeof(char *) + sizeof(u64) +
87 sizeof(char);
88 tail_offset += sizeof(char *);
89 break;
90 default:
91 pr_debug("Invalid package element [%d]: got number, expected [%c]\n",
92 i, format_string[i]);
93 return AE_BAD_DATA;
94 }
95 break;
96
97 case ACPI_TYPE_STRING:
98 case ACPI_TYPE_BUFFER:
99 switch (format_string[i]) {
100 case 'S':
101 size_required +=
102 sizeof(char *) +
103 (element->string.length * sizeof(char)) +
104 sizeof(char);
105 tail_offset += sizeof(char *);
106 break;
107 case 'B':
108 size_required +=
109 sizeof(u8 *) + element->buffer.length;
110 tail_offset += sizeof(u8 *);
111 break;
112 default:
113 pr_debug("Invalid package element [%d] got string/buffer, expected [%c]\n",
114 i, format_string[i]);
115 return AE_BAD_DATA;
116 }
117 break;
118 case ACPI_TYPE_LOCAL_REFERENCE:
119 switch (format_string[i]) {
120 case 'R':
121 size_required += sizeof(void *);
122 tail_offset += sizeof(void *);
123 break;
124 default:
125 pr_debug("Invalid package element [%d] got reference, expected [%c]\n",
126 i, format_string[i]);
127 return AE_BAD_DATA;
128 }
129 break;
130
131 case ACPI_TYPE_PACKAGE:
132 default:
133 pr_debug("Unsupported element at index=%d\n", i);
134 /* TBD: handle nested packages... */
135 return AE_SUPPORT;
136 }
137 }
138
139 /*
140 * Validate output buffer.
141 */
142 if (buffer->length == ACPI_ALLOCATE_BUFFER) {
143 buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
144 if (!buffer->pointer)
145 return AE_NO_MEMORY;
146 buffer->length = size_required;
147 } else {
148 if (buffer->length < size_required) {
149 buffer->length = size_required;
150 return AE_BUFFER_OVERFLOW;
151 } else if (buffer->length != size_required ||
152 !buffer->pointer) {
153 return AE_BAD_PARAMETER;
154 }
155 }
156
157 head = buffer->pointer;
158 tail = buffer->pointer + tail_offset;
159
160 /*
161 * Extract package data.
162 */
163 for (i = 0; i < format_count; i++) {
164
165 u8 **pointer = NULL;
166 union acpi_object *element = &(package->package.elements[i]);
167
168 switch (element->type) {
169
170 case ACPI_TYPE_INTEGER:
171 switch (format_string[i]) {
172 case 'N':
173 *((u64 *) head) =
174 element->integer.value;
175 head += sizeof(u64);
176 break;
177 case 'S':
178 pointer = (u8 **) head;
179 *pointer = tail;
180 *((u64 *) tail) =
181 element->integer.value;
182 head += sizeof(u64 *);
183 tail += sizeof(u64);
184 /* NULL terminate string */
185 *tail = (char)0;
186 tail += sizeof(char);
187 break;
188 default:
189 /* Should never get here */
190 break;
191 }
192 break;
193
194 case ACPI_TYPE_STRING:
195 case ACPI_TYPE_BUFFER:
196 switch (format_string[i]) {
197 case 'S':
198 pointer = (u8 **) head;
199 *pointer = tail;
200 memcpy(tail, element->string.pointer,
201 element->string.length);
202 head += sizeof(char *);
203 tail += element->string.length * sizeof(char);
204 /* NULL terminate string */
205 *tail = (char)0;
206 tail += sizeof(char);
207 break;
208 case 'B':
209 pointer = (u8 **) head;
210 *pointer = tail;
211 memcpy(tail, element->buffer.pointer,
212 element->buffer.length);
213 head += sizeof(u8 *);
214 tail += element->buffer.length;
215 break;
216 default:
217 /* Should never get here */
218 break;
219 }
220 break;
221 case ACPI_TYPE_LOCAL_REFERENCE:
222 switch (format_string[i]) {
223 case 'R':
224 *(void **)head =
225 (void *)element->reference.handle;
226 head += sizeof(void *);
227 break;
228 default:
229 /* Should never get here */
230 break;
231 }
232 break;
233 case ACPI_TYPE_PACKAGE:
234 /* TBD: handle nested packages... */
235 default:
236 /* Should never get here */
237 break;
238 }
239 }
240
241 return AE_OK;
242}
243
244EXPORT_SYMBOL(acpi_extract_package);
245
246acpi_status
247acpi_evaluate_integer(acpi_handle handle,
248 acpi_string pathname,
249 struct acpi_object_list *arguments, unsigned long long *data)
250{
251 acpi_status status = AE_OK;
252 union acpi_object element;
253 struct acpi_buffer buffer = { 0, NULL };
254
255 if (!data)
256 return AE_BAD_PARAMETER;
257
258 buffer.length = sizeof(union acpi_object);
259 buffer.pointer = &element;
260 status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
261 if (ACPI_FAILURE(status)) {
262 acpi_util_eval_error(handle, pathname, status);
263 return status;
264 }
265
266 if (element.type != ACPI_TYPE_INTEGER) {
267 acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
268 return AE_BAD_DATA;
269 }
270
271 *data = element.integer.value;
272
273 acpi_handle_debug(handle, "Return value [%llu]\n", *data);
274
275 return AE_OK;
276}
277
278EXPORT_SYMBOL(acpi_evaluate_integer);
279
280int acpi_get_local_u64_address(acpi_handle handle, u64 *addr)
281{
282 acpi_status status;
283
284 status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, addr);
285 if (ACPI_FAILURE(status))
286 return -ENODATA;
287 return 0;
288}
289EXPORT_SYMBOL(acpi_get_local_u64_address);
290
291int acpi_get_local_address(acpi_handle handle, u32 *addr)
292{
293 u64 adr;
294 int ret;
295
296 ret = acpi_get_local_u64_address(handle, &adr);
297 if (ret < 0)
298 return ret;
299 *addr = (u32)adr;
300 return 0;
301}
302EXPORT_SYMBOL(acpi_get_local_address);
303
304#define ACPI_MAX_SUB_BUF_SIZE 9
305
306const char *acpi_get_subsystem_id(acpi_handle handle)
307{
308 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
309 union acpi_object *obj;
310 acpi_status status;
311 const char *sub;
312 size_t len;
313
314 status = acpi_evaluate_object(handle, METHOD_NAME__SUB, NULL, &buffer);
315 if (ACPI_FAILURE(status)) {
316 acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);
317 return ERR_PTR(-ENODATA);
318 }
319
320 obj = buffer.pointer;
321 if (obj->type == ACPI_TYPE_STRING) {
322 len = strlen(obj->string.pointer);
323 if (len < ACPI_MAX_SUB_BUF_SIZE && len > 0) {
324 sub = kstrdup(obj->string.pointer, GFP_KERNEL);
325 if (!sub)
326 sub = ERR_PTR(-ENOMEM);
327 } else {
328 acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n", len);
329 sub = ERR_PTR(-ENODATA);
330 }
331 } else {
332 acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
333 sub = ERR_PTR(-ENODATA);
334 }
335
336 acpi_os_free(buffer.pointer);
337
338 return sub;
339}
340EXPORT_SYMBOL_GPL(acpi_get_subsystem_id);
341
342bool acpi_evaluate_reference(acpi_handle handle, acpi_string pathname,
343 struct acpi_object_list *arguments,
344 struct acpi_handle_list *list)
345{
346 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
347 union acpi_object *package;
348 acpi_status status;
349 bool ret = false;
350 u32 i;
351
352 if (!list)
353 return false;
354
355 /* Evaluate object. */
356
357 status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
358 if (ACPI_FAILURE(status))
359 goto end;
360
361 package = buffer.pointer;
362
363 if (buffer.length == 0 || !package ||
364 package->type != ACPI_TYPE_PACKAGE || !package->package.count)
365 goto err;
366
367 list->count = package->package.count;
368 list->handles = kzalloc_objs(*list->handles, list->count);
369 if (!list->handles)
370 goto err_clear;
371
372 /* Extract package data. */
373
374 for (i = 0; i < list->count; i++) {
375 union acpi_object *element = &(package->package.elements[i]);
376
377 if (element->type != ACPI_TYPE_LOCAL_REFERENCE ||
378 !element->reference.handle)
379 goto err_free;
380
381 /* Get the acpi_handle. */
382
383 list->handles[i] = element->reference.handle;
384 acpi_handle_debug(list->handles[i], "Found in reference list\n");
385 }
386
387 ret = true;
388
389end:
390 kfree(buffer.pointer);
391
392 return ret;
393
394err_free:
395 kfree(list->handles);
396 list->handles = NULL;
397
398err_clear:
399 list->count = 0;
400
401err:
402 acpi_util_eval_error(handle, pathname, status);
403 goto end;
404}
405
406EXPORT_SYMBOL(acpi_evaluate_reference);
407
408/**
409 * acpi_handle_list_equal - Check if two ACPI handle lists are the same
410 * @list1: First list to compare.
411 * @list2: Second list to compare.
412 *
413 * Return true if the given ACPI handle lists are of the same size and
414 * contain the same ACPI handles in the same order. Otherwise, return false.
415 */
416bool acpi_handle_list_equal(struct acpi_handle_list *list1,
417 struct acpi_handle_list *list2)
418{
419 return list1->count == list2->count &&
420 !memcmp(list1->handles, list2->handles,
421 list1->count * sizeof(*list1->handles));
422}
423EXPORT_SYMBOL_GPL(acpi_handle_list_equal);
424
425/**
426 * acpi_handle_list_replace - Replace one ACPI handle list with another
427 * @dst: ACPI handle list to replace.
428 * @src: Source ACPI handle list.
429 *
430 * Free the handles table in @dst, move the handles table from @src to @dst,
431 * copy count from @src to @dst and clear @src.
432 */
433void acpi_handle_list_replace(struct acpi_handle_list *dst,
434 struct acpi_handle_list *src)
435{
436 if (dst->count)
437 kfree(dst->handles);
438
439 dst->count = src->count;
440 dst->handles = src->handles;
441
442 src->handles = NULL;
443 src->count = 0;
444}
445EXPORT_SYMBOL_GPL(acpi_handle_list_replace);
446
447/**
448 * acpi_handle_list_free - Free the handles table in an ACPI handle list
449 * @list: ACPI handle list to free.
450 *
451 * Free the handles table in @list and clear its count field.
452 */
453void acpi_handle_list_free(struct acpi_handle_list *list)
454{
455 if (!list->count)
456 return;
457
458 kfree(list->handles);
459 list->count = 0;
460}
461EXPORT_SYMBOL_GPL(acpi_handle_list_free);
462
463/**
464 * acpi_device_dep - Check ACPI device dependency
465 * @target: ACPI handle of the target ACPI device.
466 * @match: ACPI handle to look up in the target's _DEP list.
467 *
468 * Return true if @match is present in the list returned by _DEP for
469 * @target or false otherwise.
470 */
471bool acpi_device_dep(acpi_handle target, acpi_handle match)
472{
473 struct acpi_handle_list dep_devices;
474 bool ret = false;
475 int i;
476
477 if (!acpi_has_method(target, "_DEP"))
478 return false;
479
480 if (!acpi_evaluate_reference(target, "_DEP", NULL, &dep_devices)) {
481 acpi_handle_debug(target, "Failed to evaluate _DEP.\n");
482 return false;
483 }
484
485 for (i = 0; i < dep_devices.count; i++) {
486 if (dep_devices.handles[i] == match) {
487 ret = true;
488 break;
489 }
490 }
491
492 acpi_handle_list_free(&dep_devices);
493 return ret;
494}
495EXPORT_SYMBOL_GPL(acpi_device_dep);
496
497bool
498acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
499{
500 acpi_status status;
501 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
502 union acpi_object *output;
503
504 status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
505 if (ACPI_FAILURE(status))
506 return false;
507
508 output = buffer.pointer;
509
510 if (!output || output->type != ACPI_TYPE_PACKAGE
511 || !output->package.count
512 || output->package.elements[0].type != ACPI_TYPE_BUFFER
513 || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
514 status = AE_TYPE;
515 goto out;
516 }
517
518 status = acpi_decode_pld_buffer(
519 output->package.elements[0].buffer.pointer,
520 output->package.elements[0].buffer.length,
521 pld);
522
523out:
524 kfree(buffer.pointer);
525 return ACPI_SUCCESS(status);
526}
527EXPORT_SYMBOL(acpi_get_physical_device_location);
528
529/**
530 * acpi_evaluate_ost: Evaluate _OST for hotplug operations
531 * @handle: ACPI device handle
532 * @source_event: source event code
533 * @status_code: status code
534 * @status_buf: optional detailed information (NULL if none)
535 *
536 * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
537 * must call this function when evaluating _OST for hotplug operations.
538 * When the platform does not support _OST, this function has no effect.
539 */
540acpi_status
541acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
542 struct acpi_buffer *status_buf)
543{
544 union acpi_object params[3] = {
545 {.type = ACPI_TYPE_INTEGER,},
546 {.type = ACPI_TYPE_INTEGER,},
547 {.type = ACPI_TYPE_BUFFER,}
548 };
549 struct acpi_object_list arg_list = {3, params};
550
551 params[0].integer.value = source_event;
552 params[1].integer.value = status_code;
553 if (status_buf != NULL) {
554 params[2].buffer.pointer = status_buf->pointer;
555 params[2].buffer.length = status_buf->length;
556 } else {
557 params[2].buffer.pointer = NULL;
558 params[2].buffer.length = 0;
559 }
560
561 return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
562}
563EXPORT_SYMBOL(acpi_evaluate_ost);
564
565/**
566 * acpi_handle_path: Return the object path of handle
567 * @handle: ACPI device handle
568 *
569 * Caller must free the returned buffer
570 */
571char *acpi_handle_path(acpi_handle handle)
572{
573 struct acpi_buffer buffer = {
574 .length = ACPI_ALLOCATE_BUFFER,
575 .pointer = NULL
576 };
577
578 if (in_interrupt() ||
579 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
580 return NULL;
581 return buffer.pointer;
582}
583
584/**
585 * acpi_handle_printk: Print message with ACPI prefix and object path
586 * @level: log level
587 * @handle: ACPI device handle
588 * @fmt: format string
589 *
590 * This function is called through acpi_handle_<level> macros and prints
591 * a message with ACPI prefix and object path. This function acquires
592 * the global namespace mutex to obtain an object path. In interrupt
593 * context, it shows the object path as <n/a>.
594 */
595void
596acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
597{
598 struct va_format vaf;
599 va_list args;
600 const char *path;
601
602 va_start(args, fmt);
603 vaf.fmt = fmt;
604 vaf.va = &args;
605
606 path = acpi_handle_path(handle);
607 printk("%sACPI: %s: %pV", level, path ? path : "<n/a>", &vaf);
608
609 va_end(args);
610 kfree(path);
611}
612EXPORT_SYMBOL(acpi_handle_printk);
613
614#if defined(CONFIG_DYNAMIC_DEBUG)
615/**
616 * __acpi_handle_debug: pr_debug with ACPI prefix and object path
617 * @descriptor: Dynamic Debug descriptor
618 * @handle: ACPI device handle
619 * @fmt: format string
620 *
621 * This function is called through acpi_handle_debug macro and debug
622 * prints a message with ACPI prefix and object path. This function
623 * acquires the global namespace mutex to obtain an object path. In
624 * interrupt context, it shows the object path as <n/a>.
625 */
626void
627__acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
628 const char *fmt, ...)
629{
630 struct va_format vaf;
631 va_list args;
632 const char *path;
633
634 va_start(args, fmt);
635 vaf.fmt = fmt;
636 vaf.va = &args;
637
638 path = acpi_handle_path(handle);
639 __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
640
641 va_end(args);
642 kfree(path);
643}
644EXPORT_SYMBOL(__acpi_handle_debug);
645#endif
646
647/**
648 * acpi_evaluation_failure_warn - Log evaluation failure warning.
649 * @handle: Parent object handle.
650 * @name: Name of the object whose evaluation has failed.
651 * @status: Status value returned by the failing object evaluation.
652 */
653void acpi_evaluation_failure_warn(acpi_handle handle, const char *name,
654 acpi_status status)
655{
656 acpi_handle_warn(handle, "%s evaluation failed: %s\n", name,
657 acpi_format_exception(status));
658}
659EXPORT_SYMBOL_GPL(acpi_evaluation_failure_warn);
660
661/**
662 * acpi_has_method: Check whether @handle has a method named @name
663 * @handle: ACPI device handle
664 * @name: name of object or method
665 *
666 * Check whether @handle has a method named @name.
667 */
668bool acpi_has_method(acpi_handle handle, char *name)
669{
670 acpi_handle tmp;
671
672 return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
673}
674EXPORT_SYMBOL(acpi_has_method);
675
676acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
677 u64 arg)
678{
679 union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
680 struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
681
682 obj.integer.value = arg;
683
684 return acpi_evaluate_object(handle, method, &arg_list, NULL);
685}
686EXPORT_SYMBOL(acpi_execute_simple_method);
687
688/**
689 * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
690 * @handle: ACPI device handle
691 *
692 * Evaluate device's _EJ0 method for hotplug operations.
693 */
694acpi_status acpi_evaluate_ej0(acpi_handle handle)
695{
696 acpi_status status;
697
698 status = acpi_execute_simple_method(handle, "_EJ0", 1);
699 if (status == AE_NOT_FOUND)
700 acpi_handle_warn(handle, "No _EJ0 support for device\n");
701 else if (ACPI_FAILURE(status))
702 acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
703
704 return status;
705}
706
707/**
708 * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
709 * @handle: ACPI device handle
710 * @lock: lock device if non-zero, otherwise unlock device
711 *
712 * Evaluate device's _LCK method if present to lock/unlock device
713 */
714acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
715{
716 acpi_status status;
717
718 status = acpi_execute_simple_method(handle, "_LCK", !!lock);
719 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
720 if (lock)
721 acpi_handle_warn(handle,
722 "Locking device failed (0x%x)\n", status);
723 else
724 acpi_handle_warn(handle,
725 "Unlocking device failed (0x%x)\n", status);
726 }
727
728 return status;
729}
730
731/**
732 * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence
733 * @handle: ACPI device handle
734 * @space_id: ACPI address space id to register OpRegion presence for
735 * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or
736 * ACPI_REG_DISCONNECT
737 *
738 * Evaluate device's _REG method to register OpRegion presence.
739 */
740acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function)
741{
742 struct acpi_object_list arg_list;
743 union acpi_object params[2];
744
745 params[0].type = ACPI_TYPE_INTEGER;
746 params[0].integer.value = space_id;
747 params[1].type = ACPI_TYPE_INTEGER;
748 params[1].integer.value = function;
749 arg_list.count = 2;
750 arg_list.pointer = params;
751
752 return acpi_evaluate_object(handle, "_REG", &arg_list, NULL);
753}
754EXPORT_SYMBOL(acpi_evaluate_reg);
755
756/**
757 * acpi_evaluate_dsm - evaluate device's _DSM method
758 * @handle: ACPI device handle
759 * @guid: GUID of requested functions, should be 16 bytes
760 * @rev: revision number of requested function
761 * @func: requested function number
762 * @argv4: the function specific parameter
763 *
764 * Evaluate device's _DSM method with specified GUID, revision id and
765 * function number. Caller needs to free the returned object.
766 *
767 * Though ACPI defines the fourth parameter for _DSM should be a package,
768 * some old BIOSes do expect a buffer or an integer etc.
769 */
770union acpi_object *
771acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
772 union acpi_object *argv4)
773{
774 acpi_status ret;
775 struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
776 union acpi_object params[4];
777 struct acpi_object_list input = {
778 .count = 4,
779 .pointer = params,
780 };
781
782 params[0].type = ACPI_TYPE_BUFFER;
783 params[0].buffer.length = 16;
784 params[0].buffer.pointer = (u8 *)guid;
785 params[1].type = ACPI_TYPE_INTEGER;
786 params[1].integer.value = rev;
787 params[2].type = ACPI_TYPE_INTEGER;
788 params[2].integer.value = func;
789 if (argv4) {
790 params[3] = *argv4;
791 } else {
792 params[3].type = ACPI_TYPE_PACKAGE;
793 params[3].package.count = 0;
794 params[3].package.elements = NULL;
795 }
796
797 ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
798 if (ACPI_SUCCESS(ret))
799 return (union acpi_object *)buf.pointer;
800
801 if (ret != AE_NOT_FOUND)
802 acpi_handle_warn(handle,
803 "failed to evaluate _DSM %pUb rev:%lld func:%lld (0x%x)\n",
804 guid, rev, func, ret);
805
806 return NULL;
807}
808EXPORT_SYMBOL(acpi_evaluate_dsm);
809
810/**
811 * acpi_check_dsm - check if _DSM method supports requested functions.
812 * @handle: ACPI device handle
813 * @guid: GUID of requested functions, should be 16 bytes at least
814 * @rev: revision number of requested functions
815 * @funcs: bitmap of requested functions
816 *
817 * Evaluate device's _DSM method to check whether it supports requested
818 * functions. Currently only support 64 functions at maximum, should be
819 * enough for now.
820 */
821bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
822{
823 int i;
824 u64 mask = 0;
825 union acpi_object *obj;
826
827 if (funcs == 0)
828 return false;
829
830 obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);
831 if (!obj)
832 return false;
833
834 /* For compatibility, old BIOSes may return an integer */
835 if (obj->type == ACPI_TYPE_INTEGER)
836 mask = obj->integer.value;
837 else if (obj->type == ACPI_TYPE_BUFFER)
838 for (i = 0; i < obj->buffer.length && i < 8; i++)
839 mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
840 ACPI_FREE(obj);
841
842 /*
843 * Bit 0 indicates whether there's support for any functions other than
844 * function 0 for the specified GUID and revision.
845 */
846 if ((mask & 0x1) && (mask & funcs) == funcs)
847 return true;
848
849 return false;
850}
851EXPORT_SYMBOL(acpi_check_dsm);
852
853/**
854 * acpi_dev_uid_to_integer - treat ACPI device _UID as integer
855 * @adev: ACPI device to get _UID from
856 * @integer: output buffer for integer
857 *
858 * Considers _UID as integer and converts it to @integer.
859 *
860 * Returns 0 on success, or negative error code otherwise.
861 */
862int acpi_dev_uid_to_integer(struct acpi_device *adev, u64 *integer)
863{
864 const char *uid;
865
866 if (!adev)
867 return -ENODEV;
868
869 uid = acpi_device_uid(adev);
870 if (!uid)
871 return -ENODATA;
872
873 return kstrtou64(uid, 0, integer);
874}
875EXPORT_SYMBOL(acpi_dev_uid_to_integer);
876
877/**
878 * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
879 * @hid: Hardware ID of the device.
880 *
881 * Return %true if the device was present at the moment of invocation.
882 * Note that if the device is pluggable, it may since have disappeared.
883 *
884 * For this function to work, acpi_bus_scan() must have been executed
885 * which happens in the subsys_initcall() subsection. Hence, do not
886 * call from a subsys_initcall() or earlier (use acpi_get_devices()
887 * instead). Calling from module_init() is fine (which is synonymous
888 * with device_initcall()).
889 */
890bool acpi_dev_found(const char *hid)
891{
892 struct acpi_device_bus_id *acpi_device_bus_id;
893 bool found = false;
894
895 mutex_lock(&acpi_device_lock);
896 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
897 if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
898 found = true;
899 break;
900 }
901 mutex_unlock(&acpi_device_lock);
902
903 return found;
904}
905EXPORT_SYMBOL(acpi_dev_found);
906
907struct acpi_dev_match_info {
908 struct acpi_device_id hid[2];
909 const char *uid;
910 s64 hrv;
911};
912
913static int acpi_dev_match_cb(struct device *dev, const void *data)
914{
915 struct acpi_device *adev = to_acpi_device(dev);
916 const struct acpi_dev_match_info *match = data;
917 unsigned long long hrv;
918 acpi_status status;
919
920 if (acpi_match_device_ids(adev, match->hid))
921 return 0;
922
923 if (match->uid && !acpi_dev_uid_match(adev, match->uid))
924 return 0;
925
926 if (match->hrv == -1)
927 return 1;
928
929 status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);
930 if (ACPI_FAILURE(status))
931 return 0;
932
933 return hrv == match->hrv;
934}
935
936/**
937 * acpi_dev_present - Detect that a given ACPI device is present
938 * @hid: Hardware ID of the device.
939 * @uid: Unique ID of the device, pass NULL to not check _UID
940 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
941 *
942 * Return %true if a matching device was present at the moment of invocation.
943 * Note that if the device is pluggable, it may since have disappeared.
944 *
945 * Note that unlike acpi_dev_found() this function checks the status
946 * of the device. So for devices which are present in the DSDT, but
947 * which are disabled (their _STA callback returns 0) this function
948 * will return false.
949 *
950 * For this function to work, acpi_bus_scan() must have been executed
951 * which happens in the subsys_initcall() subsection. Hence, do not
952 * call from a subsys_initcall() or earlier (use acpi_get_devices()
953 * instead). Calling from module_init() is fine (which is synonymous
954 * with device_initcall()).
955 */
956bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
957{
958 struct acpi_dev_match_info match = {};
959 struct device *dev;
960
961 strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
962 match.uid = uid;
963 match.hrv = hrv;
964
965 dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
966 put_device(dev);
967 return !!dev;
968}
969EXPORT_SYMBOL(acpi_dev_present);
970
971/**
972 * acpi_dev_get_next_match_dev - Return the next match of ACPI device
973 * @adev: Pointer to the previous ACPI device matching this @hid, @uid and @hrv
974 * @hid: Hardware ID of the device.
975 * @uid: Unique ID of the device, pass NULL to not check _UID
976 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
977 *
978 * Return the next match of ACPI device if another matching device was present
979 * at the moment of invocation, or NULL otherwise.
980 *
981 * The caller is responsible for invoking acpi_dev_put() on the returned device.
982 * On the other hand the function invokes acpi_dev_put() on the given @adev
983 * assuming that its reference counter had been increased beforehand.
984 *
985 * See additional information in acpi_dev_present() as well.
986 */
987struct acpi_device *
988acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv)
989{
990 struct device *start = adev ? &adev->dev : NULL;
991 struct acpi_dev_match_info match = {};
992 struct device *dev;
993
994 strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
995 match.uid = uid;
996 match.hrv = hrv;
997
998 dev = bus_find_device(&acpi_bus_type, start, &match, acpi_dev_match_cb);
999 acpi_dev_put(adev);
1000 return dev ? to_acpi_device(dev) : NULL;
1001}
1002EXPORT_SYMBOL(acpi_dev_get_next_match_dev);
1003
1004/**
1005 * acpi_dev_get_first_match_dev - Return the first match of ACPI device
1006 * @hid: Hardware ID of the device.
1007 * @uid: Unique ID of the device, pass NULL to not check _UID
1008 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
1009 *
1010 * Return the first match of ACPI device if a matching device was present
1011 * at the moment of invocation, or NULL otherwise.
1012 *
1013 * The caller is responsible for invoking acpi_dev_put() on the returned device.
1014 *
1015 * See additional information in acpi_dev_present() as well.
1016 */
1017struct acpi_device *
1018acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
1019{
1020 return acpi_dev_get_next_match_dev(NULL, hid, uid, hrv);
1021}
1022EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
1023
1024/**
1025 * acpi_reduced_hardware - Return if this is an ACPI-reduced-hw machine
1026 *
1027 * Return true when running on an ACPI-reduced-hw machine, false otherwise.
1028 */
1029bool acpi_reduced_hardware(void)
1030{
1031 return acpi_gbl_reduced_hardware;
1032}
1033EXPORT_SYMBOL_GPL(acpi_reduced_hardware);
1034
1035/*
1036 * acpi_backlight= handling, this is done here rather then in video_detect.c
1037 * because __setup cannot be used in modules.
1038 */
1039char acpi_video_backlight_string[16];
1040EXPORT_SYMBOL(acpi_video_backlight_string);
1041
1042static int __init acpi_backlight(char *str)
1043{
1044 strscpy(acpi_video_backlight_string, str,
1045 sizeof(acpi_video_backlight_string));
1046 return 1;
1047}
1048__setup("acpi_backlight=", acpi_backlight);
1049
1050/**
1051 * acpi_dev_is_video_device - test if device matches against ACPI video device IDs
1052 * @adev: ACPI device to test
1053 *
1054 * Return: true when matches, otherwise false.
1055 */
1056bool acpi_dev_is_video_device(struct acpi_device *adev)
1057{
1058 static const struct acpi_device_id video_device_ids[] = {
1059 { .id = ACPI_VIDEO_HID },
1060 { }
1061 };
1062
1063 return adev && !acpi_match_device_ids(adev, video_device_ids);
1064}
1065EXPORT_SYMBOL(acpi_dev_is_video_device);
1066
1067/**
1068 * acpi_match_platform_list - Check if the system matches with a given list
1069 * @plat: pointer to acpi_platform_list table terminated by a NULL entry
1070 *
1071 * Return the matched index if the system is found in the platform list.
1072 * Otherwise, return a negative error code.
1073 */
1074int acpi_match_platform_list(const struct acpi_platform_list *plat)
1075{
1076 struct acpi_table_header hdr;
1077 int idx = 0;
1078
1079 if (acpi_disabled)
1080 return -ENODEV;
1081
1082 for (; plat->oem_id[0]; plat++, idx++) {
1083 if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))
1084 continue;
1085
1086 if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
1087 continue;
1088
1089 if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))
1090 continue;
1091
1092 if ((plat->pred == all_versions) ||
1093 (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||
1094 (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||
1095 (plat->pred == equal && hdr.oem_revision == plat->oem_revision))
1096 return idx;
1097 }
1098
1099 return -ENODEV;
1100}
1101EXPORT_SYMBOL(acpi_match_platform_list);