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 <andrew.grover@intel.com>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
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(object: handle, pathname, parameter_objects: arguments, return_object_buffer: &buffer);
261 if (ACPI_FAILURE(status)) {
262 acpi_util_eval_error(h: handle, p: pathname, s: status);
263 return status;
264 }
265
266 if (element.type != ACPI_TYPE_INTEGER) {
267 acpi_util_eval_error(h: handle, p: 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_address(acpi_handle handle, u32 *addr)
281{
282 unsigned long long adr;
283 acpi_status status;
284
285 status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
286 if (ACPI_FAILURE(status))
287 return -ENODATA;
288
289 *addr = (u32)adr;
290 return 0;
291}
292EXPORT_SYMBOL(acpi_get_local_address);
293
294#define ACPI_MAX_SUB_BUF_SIZE 9
295
296const char *acpi_get_subsystem_id(acpi_handle handle)
297{
298 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
299 union acpi_object *obj;
300 acpi_status status;
301 const char *sub;
302 size_t len;
303
304 status = acpi_evaluate_object(object: handle, METHOD_NAME__SUB, NULL, return_object_buffer: &buffer);
305 if (ACPI_FAILURE(status)) {
306 acpi_handle_debug(handle, "Reading ACPI _SUB failed: %#x\n", status);
307 return ERR_PTR(error: -ENODATA);
308 }
309
310 obj = buffer.pointer;
311 if (obj->type == ACPI_TYPE_STRING) {
312 len = strlen(obj->string.pointer);
313 if (len < ACPI_MAX_SUB_BUF_SIZE && len > 0) {
314 sub = kstrdup(s: obj->string.pointer, GFP_KERNEL);
315 if (!sub)
316 sub = ERR_PTR(error: -ENOMEM);
317 } else {
318 acpi_handle_err(handle, "ACPI _SUB Length %zu is Invalid\n", len);
319 sub = ERR_PTR(error: -ENODATA);
320 }
321 } else {
322 acpi_handle_warn(handle, "Warning ACPI _SUB did not return a string\n");
323 sub = ERR_PTR(error: -ENODATA);
324 }
325
326 acpi_os_free(memory: buffer.pointer);
327
328 return sub;
329}
330EXPORT_SYMBOL_GPL(acpi_get_subsystem_id);
331
332acpi_status
333acpi_evaluate_reference(acpi_handle handle,
334 acpi_string pathname,
335 struct acpi_object_list *arguments,
336 struct acpi_handle_list *list)
337{
338 acpi_status status = AE_OK;
339 union acpi_object *package = NULL;
340 union acpi_object *element = NULL;
341 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
342 u32 i = 0;
343
344
345 if (!list)
346 return AE_BAD_PARAMETER;
347
348 /* Evaluate object. */
349
350 status = acpi_evaluate_object(object: handle, pathname, parameter_objects: arguments, return_object_buffer: &buffer);
351 if (ACPI_FAILURE(status))
352 goto end;
353
354 package = buffer.pointer;
355
356 if ((buffer.length == 0) || !package) {
357 status = AE_BAD_DATA;
358 acpi_util_eval_error(h: handle, p: pathname, s: status);
359 goto end;
360 }
361 if (package->type != ACPI_TYPE_PACKAGE) {
362 status = AE_BAD_DATA;
363 acpi_util_eval_error(h: handle, p: pathname, s: status);
364 goto end;
365 }
366 if (!package->package.count) {
367 status = AE_BAD_DATA;
368 acpi_util_eval_error(h: handle, p: pathname, s: status);
369 goto end;
370 }
371
372 list->handles = kcalloc(n: package->package.count, size: sizeof(*list->handles), GFP_KERNEL);
373 if (!list->handles) {
374 kfree(objp: package);
375 return AE_NO_MEMORY;
376 }
377 list->count = package->package.count;
378
379 /* Extract package data. */
380
381 for (i = 0; i < list->count; i++) {
382
383 element = &(package->package.elements[i]);
384
385 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
386 status = AE_BAD_DATA;
387 acpi_util_eval_error(h: handle, p: pathname, s: status);
388 break;
389 }
390
391 if (!element->reference.handle) {
392 status = AE_NULL_ENTRY;
393 acpi_util_eval_error(h: handle, p: pathname, s: status);
394 break;
395 }
396 /* Get the acpi_handle. */
397
398 list->handles[i] = element->reference.handle;
399 acpi_handle_debug(list->handles[i], "Found in reference list\n");
400 }
401
402end:
403 if (ACPI_FAILURE(status)) {
404 list->count = 0;
405 kfree(objp: list->handles);
406 list->handles = NULL;
407 }
408
409 kfree(objp: buffer.pointer);
410
411 return status;
412}
413
414EXPORT_SYMBOL(acpi_evaluate_reference);
415
416/**
417 * acpi_handle_list_equal - Check if two ACPI handle lists are the same
418 * @list1: First list to compare.
419 * @list2: Second list to compare.
420 *
421 * Return true if the given ACPI handle lists are of the same size and
422 * contain the same ACPI handles in the same order. Otherwise, return false.
423 */
424bool acpi_handle_list_equal(struct acpi_handle_list *list1,
425 struct acpi_handle_list *list2)
426{
427 return list1->count == list2->count &&
428 !memcmp(p: list1->handles, q: list2->handles,
429 size: list1->count * sizeof(acpi_handle));
430}
431EXPORT_SYMBOL_GPL(acpi_handle_list_equal);
432
433/**
434 * acpi_handle_list_replace - Replace one ACPI handle list with another
435 * @dst: ACPI handle list to replace.
436 * @src: Source ACPI handle list.
437 *
438 * Free the handles table in @dst, move the handles table from @src to @dst,
439 * copy count from @src to @dst and clear @src.
440 */
441void acpi_handle_list_replace(struct acpi_handle_list *dst,
442 struct acpi_handle_list *src)
443{
444 if (dst->count)
445 kfree(objp: dst->handles);
446
447 dst->count = src->count;
448 dst->handles = src->handles;
449
450 src->handles = NULL;
451 src->count = 0;
452}
453EXPORT_SYMBOL_GPL(acpi_handle_list_replace);
454
455/**
456 * acpi_handle_list_free - Free the handles table in an ACPI handle list
457 * @list: ACPI handle list to free.
458 *
459 * Free the handles table in @list and clear its count field.
460 */
461void acpi_handle_list_free(struct acpi_handle_list *list)
462{
463 if (!list->count)
464 return;
465
466 kfree(objp: list->handles);
467 list->count = 0;
468}
469EXPORT_SYMBOL_GPL(acpi_handle_list_free);
470
471acpi_status
472acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
473{
474 acpi_status status;
475 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
476 union acpi_object *output;
477
478 status = acpi_evaluate_object(object: handle, pathname: "_PLD", NULL, return_object_buffer: &buffer);
479
480 if (ACPI_FAILURE(status))
481 return status;
482
483 output = buffer.pointer;
484
485 if (!output || output->type != ACPI_TYPE_PACKAGE
486 || !output->package.count
487 || output->package.elements[0].type != ACPI_TYPE_BUFFER
488 || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
489 status = AE_TYPE;
490 goto out;
491 }
492
493 status = acpi_decode_pld_buffer(
494 in_buffer: output->package.elements[0].buffer.pointer,
495 length: output->package.elements[0].buffer.length,
496 return_buffer: pld);
497
498out:
499 kfree(objp: buffer.pointer);
500 return status;
501}
502EXPORT_SYMBOL(acpi_get_physical_device_location);
503
504/**
505 * acpi_evaluate_ost: Evaluate _OST for hotplug operations
506 * @handle: ACPI device handle
507 * @source_event: source event code
508 * @status_code: status code
509 * @status_buf: optional detailed information (NULL if none)
510 *
511 * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
512 * must call this function when evaluating _OST for hotplug operations.
513 * When the platform does not support _OST, this function has no effect.
514 */
515acpi_status
516acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
517 struct acpi_buffer *status_buf)
518{
519 union acpi_object params[3] = {
520 {.type = ACPI_TYPE_INTEGER,},
521 {.type = ACPI_TYPE_INTEGER,},
522 {.type = ACPI_TYPE_BUFFER,}
523 };
524 struct acpi_object_list arg_list = {3, params};
525
526 params[0].integer.value = source_event;
527 params[1].integer.value = status_code;
528 if (status_buf != NULL) {
529 params[2].buffer.pointer = status_buf->pointer;
530 params[2].buffer.length = status_buf->length;
531 } else {
532 params[2].buffer.pointer = NULL;
533 params[2].buffer.length = 0;
534 }
535
536 return acpi_evaluate_object(object: handle, pathname: "_OST", parameter_objects: &arg_list, NULL);
537}
538EXPORT_SYMBOL(acpi_evaluate_ost);
539
540/**
541 * acpi_handle_path: Return the object path of handle
542 * @handle: ACPI device handle
543 *
544 * Caller must free the returned buffer
545 */
546static char *acpi_handle_path(acpi_handle handle)
547{
548 struct acpi_buffer buffer = {
549 .length = ACPI_ALLOCATE_BUFFER,
550 .pointer = NULL
551 };
552
553 if (in_interrupt() ||
554 acpi_get_name(object: handle, ACPI_FULL_PATHNAME, ret_path_ptr: &buffer) != AE_OK)
555 return NULL;
556 return buffer.pointer;
557}
558
559/**
560 * acpi_handle_printk: Print message with ACPI prefix and object path
561 * @level: log level
562 * @handle: ACPI device handle
563 * @fmt: format string
564 *
565 * This function is called through acpi_handle_<level> macros and prints
566 * a message with ACPI prefix and object path. This function acquires
567 * the global namespace mutex to obtain an object path. In interrupt
568 * context, it shows the object path as <n/a>.
569 */
570void
571acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
572{
573 struct va_format vaf;
574 va_list args;
575 const char *path;
576
577 va_start(args, fmt);
578 vaf.fmt = fmt;
579 vaf.va = &args;
580
581 path = acpi_handle_path(handle);
582 printk("%sACPI: %s: %pV", level, path ? path : "<n/a>", &vaf);
583
584 va_end(args);
585 kfree(objp: path);
586}
587EXPORT_SYMBOL(acpi_handle_printk);
588
589#if defined(CONFIG_DYNAMIC_DEBUG)
590/**
591 * __acpi_handle_debug: pr_debug with ACPI prefix and object path
592 * @descriptor: Dynamic Debug descriptor
593 * @handle: ACPI device handle
594 * @fmt: format string
595 *
596 * This function is called through acpi_handle_debug macro and debug
597 * prints a message with ACPI prefix and object path. This function
598 * acquires the global namespace mutex to obtain an object path. In
599 * interrupt context, it shows the object path as <n/a>.
600 */
601void
602__acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
603 const char *fmt, ...)
604{
605 struct va_format vaf;
606 va_list args;
607 const char *path;
608
609 va_start(args, fmt);
610 vaf.fmt = fmt;
611 vaf.va = &args;
612
613 path = acpi_handle_path(handle);
614 __dynamic_pr_debug(descriptor, fmt: "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
615
616 va_end(args);
617 kfree(objp: path);
618}
619EXPORT_SYMBOL(__acpi_handle_debug);
620#endif
621
622/**
623 * acpi_evaluation_failure_warn - Log evaluation failure warning.
624 * @handle: Parent object handle.
625 * @name: Name of the object whose evaluation has failed.
626 * @status: Status value returned by the failing object evaluation.
627 */
628void acpi_evaluation_failure_warn(acpi_handle handle, const char *name,
629 acpi_status status)
630{
631 acpi_handle_warn(handle, "%s evaluation failed: %s\n", name,
632 acpi_format_exception(status));
633}
634EXPORT_SYMBOL_GPL(acpi_evaluation_failure_warn);
635
636/**
637 * acpi_has_method: Check whether @handle has a method named @name
638 * @handle: ACPI device handle
639 * @name: name of object or method
640 *
641 * Check whether @handle has a method named @name.
642 */
643bool acpi_has_method(acpi_handle handle, char *name)
644{
645 acpi_handle tmp;
646
647 return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
648}
649EXPORT_SYMBOL(acpi_has_method);
650
651acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
652 u64 arg)
653{
654 union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
655 struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
656
657 obj.integer.value = arg;
658
659 return acpi_evaluate_object(object: handle, pathname: method, parameter_objects: &arg_list, NULL);
660}
661EXPORT_SYMBOL(acpi_execute_simple_method);
662
663/**
664 * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
665 * @handle: ACPI device handle
666 *
667 * Evaluate device's _EJ0 method for hotplug operations.
668 */
669acpi_status acpi_evaluate_ej0(acpi_handle handle)
670{
671 acpi_status status;
672
673 status = acpi_execute_simple_method(handle, "_EJ0", 1);
674 if (status == AE_NOT_FOUND)
675 acpi_handle_warn(handle, "No _EJ0 support for device\n");
676 else if (ACPI_FAILURE(status))
677 acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
678
679 return status;
680}
681
682/**
683 * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
684 * @handle: ACPI device handle
685 * @lock: lock device if non-zero, otherwise unlock device
686 *
687 * Evaluate device's _LCK method if present to lock/unlock device
688 */
689acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
690{
691 acpi_status status;
692
693 status = acpi_execute_simple_method(handle, "_LCK", !!lock);
694 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
695 if (lock)
696 acpi_handle_warn(handle,
697 "Locking device failed (0x%x)\n", status);
698 else
699 acpi_handle_warn(handle,
700 "Unlocking device failed (0x%x)\n", status);
701 }
702
703 return status;
704}
705
706/**
707 * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence
708 * @handle: ACPI device handle
709 * @space_id: ACPI address space id to register OpRegion presence for
710 * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or
711 * ACPI_REG_DISCONNECT
712 *
713 * Evaluate device's _REG method to register OpRegion presence.
714 */
715acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function)
716{
717 struct acpi_object_list arg_list;
718 union acpi_object params[2];
719
720 params[0].type = ACPI_TYPE_INTEGER;
721 params[0].integer.value = space_id;
722 params[1].type = ACPI_TYPE_INTEGER;
723 params[1].integer.value = function;
724 arg_list.count = 2;
725 arg_list.pointer = params;
726
727 return acpi_evaluate_object(object: handle, pathname: "_REG", parameter_objects: &arg_list, NULL);
728}
729EXPORT_SYMBOL(acpi_evaluate_reg);
730
731/**
732 * acpi_evaluate_dsm - evaluate device's _DSM method
733 * @handle: ACPI device handle
734 * @guid: GUID of requested functions, should be 16 bytes
735 * @rev: revision number of requested function
736 * @func: requested function number
737 * @argv4: the function specific parameter
738 *
739 * Evaluate device's _DSM method with specified GUID, revision id and
740 * function number. Caller needs to free the returned object.
741 *
742 * Though ACPI defines the fourth parameter for _DSM should be a package,
743 * some old BIOSes do expect a buffer or an integer etc.
744 */
745union acpi_object *
746acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
747 union acpi_object *argv4)
748{
749 acpi_status ret;
750 struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
751 union acpi_object params[4];
752 struct acpi_object_list input = {
753 .count = 4,
754 .pointer = params,
755 };
756
757 params[0].type = ACPI_TYPE_BUFFER;
758 params[0].buffer.length = 16;
759 params[0].buffer.pointer = (u8 *)guid;
760 params[1].type = ACPI_TYPE_INTEGER;
761 params[1].integer.value = rev;
762 params[2].type = ACPI_TYPE_INTEGER;
763 params[2].integer.value = func;
764 if (argv4) {
765 params[3] = *argv4;
766 } else {
767 params[3].type = ACPI_TYPE_PACKAGE;
768 params[3].package.count = 0;
769 params[3].package.elements = NULL;
770 }
771
772 ret = acpi_evaluate_object(object: handle, pathname: "_DSM", parameter_objects: &input, return_object_buffer: &buf);
773 if (ACPI_SUCCESS(ret))
774 return (union acpi_object *)buf.pointer;
775
776 if (ret != AE_NOT_FOUND)
777 acpi_handle_warn(handle,
778 "failed to evaluate _DSM %pUb (0x%x)\n", guid, ret);
779
780 return NULL;
781}
782EXPORT_SYMBOL(acpi_evaluate_dsm);
783
784/**
785 * acpi_check_dsm - check if _DSM method supports requested functions.
786 * @handle: ACPI device handle
787 * @guid: GUID of requested functions, should be 16 bytes at least
788 * @rev: revision number of requested functions
789 * @funcs: bitmap of requested functions
790 *
791 * Evaluate device's _DSM method to check whether it supports requested
792 * functions. Currently only support 64 functions at maximum, should be
793 * enough for now.
794 */
795bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
796{
797 int i;
798 u64 mask = 0;
799 union acpi_object *obj;
800
801 if (funcs == 0)
802 return false;
803
804 obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);
805 if (!obj)
806 return false;
807
808 /* For compatibility, old BIOSes may return an integer */
809 if (obj->type == ACPI_TYPE_INTEGER)
810 mask = obj->integer.value;
811 else if (obj->type == ACPI_TYPE_BUFFER)
812 for (i = 0; i < obj->buffer.length && i < 8; i++)
813 mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
814 ACPI_FREE(obj);
815
816 /*
817 * Bit 0 indicates whether there's support for any functions other than
818 * function 0 for the specified GUID and revision.
819 */
820 if ((mask & 0x1) && (mask & funcs) == funcs)
821 return true;
822
823 return false;
824}
825EXPORT_SYMBOL(acpi_check_dsm);
826
827/**
828 * acpi_dev_uid_match - Match device by supplied UID
829 * @adev: ACPI device to match.
830 * @uid2: Unique ID of the device.
831 *
832 * Matches UID in @adev with given @uid2.
833 *
834 * Returns:
835 * - %true if matches.
836 * - %false otherwise.
837 */
838bool acpi_dev_uid_match(struct acpi_device *adev, const char *uid2)
839{
840 const char *uid1 = acpi_device_uid(adev);
841
842 return uid1 && uid2 && !strcmp(uid1, uid2);
843}
844EXPORT_SYMBOL_GPL(acpi_dev_uid_match);
845
846/**
847 * acpi_dev_hid_uid_match - Match device by supplied HID and UID
848 * @adev: ACPI device to match.
849 * @hid2: Hardware ID of the device.
850 * @uid2: Unique ID of the device, pass NULL to not check _UID.
851 *
852 * Matches HID and UID in @adev with given @hid2 and @uid2. Absence of @uid2
853 * will be treated as a match. If user wants to validate @uid2, it should be
854 * done before calling this function.
855 *
856 * Returns:
857 * - %true if matches or @uid2 is NULL.
858 * - %false otherwise.
859 */
860bool acpi_dev_hid_uid_match(struct acpi_device *adev,
861 const char *hid2, const char *uid2)
862{
863 const char *hid1 = acpi_device_hid(device: adev);
864
865 if (strcmp(hid1, hid2))
866 return false;
867
868 if (!uid2)
869 return true;
870
871 return acpi_dev_uid_match(adev, uid2);
872}
873EXPORT_SYMBOL(acpi_dev_hid_uid_match);
874
875/**
876 * acpi_dev_uid_to_integer - treat ACPI device _UID as integer
877 * @adev: ACPI device to get _UID from
878 * @integer: output buffer for integer
879 *
880 * Considers _UID as integer and converts it to @integer.
881 *
882 * Returns 0 on success, or negative error code otherwise.
883 */
884int acpi_dev_uid_to_integer(struct acpi_device *adev, u64 *integer)
885{
886 const char *uid;
887
888 if (!adev)
889 return -ENODEV;
890
891 uid = acpi_device_uid(adev);
892 if (!uid)
893 return -ENODATA;
894
895 return kstrtou64(s: uid, base: 0, res: integer);
896}
897EXPORT_SYMBOL(acpi_dev_uid_to_integer);
898
899/**
900 * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
901 * @hid: Hardware ID of the device.
902 *
903 * Return %true if the device was present at the moment of invocation.
904 * Note that if the device is pluggable, it may since have disappeared.
905 *
906 * For this function to work, acpi_bus_scan() must have been executed
907 * which happens in the subsys_initcall() subsection. Hence, do not
908 * call from a subsys_initcall() or earlier (use acpi_get_devices()
909 * instead). Calling from module_init() is fine (which is synonymous
910 * with device_initcall()).
911 */
912bool acpi_dev_found(const char *hid)
913{
914 struct acpi_device_bus_id *acpi_device_bus_id;
915 bool found = false;
916
917 mutex_lock(&acpi_device_lock);
918 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
919 if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
920 found = true;
921 break;
922 }
923 mutex_unlock(lock: &acpi_device_lock);
924
925 return found;
926}
927EXPORT_SYMBOL(acpi_dev_found);
928
929struct acpi_dev_match_info {
930 struct acpi_device_id hid[2];
931 const char *uid;
932 s64 hrv;
933};
934
935static int acpi_dev_match_cb(struct device *dev, const void *data)
936{
937 struct acpi_device *adev = to_acpi_device(dev);
938 const struct acpi_dev_match_info *match = data;
939 unsigned long long hrv;
940 acpi_status status;
941
942 if (acpi_match_device_ids(device: adev, ids: match->hid))
943 return 0;
944
945 if (match->uid && !acpi_dev_uid_match(adev, match->uid))
946 return 0;
947
948 if (match->hrv == -1)
949 return 1;
950
951 status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);
952 if (ACPI_FAILURE(status))
953 return 0;
954
955 return hrv == match->hrv;
956}
957
958/**
959 * acpi_dev_present - Detect that a given ACPI device is present
960 * @hid: Hardware ID of the device.
961 * @uid: Unique ID of the device, pass NULL to not check _UID
962 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
963 *
964 * Return %true if a matching device was present at the moment of invocation.
965 * Note that if the device is pluggable, it may since have disappeared.
966 *
967 * Note that unlike acpi_dev_found() this function checks the status
968 * of the device. So for devices which are present in the DSDT, but
969 * which are disabled (their _STA callback returns 0) this function
970 * will return false.
971 *
972 * For this function to work, acpi_bus_scan() must have been executed
973 * which happens in the subsys_initcall() subsection. Hence, do not
974 * call from a subsys_initcall() or earlier (use acpi_get_devices()
975 * instead). Calling from module_init() is fine (which is synonymous
976 * with device_initcall()).
977 */
978bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
979{
980 struct acpi_dev_match_info match = {};
981 struct device *dev;
982
983 strscpy(p: match.hid[0].id, q: hid, size: sizeof(match.hid[0].id));
984 match.uid = uid;
985 match.hrv = hrv;
986
987 dev = bus_find_device(bus: &acpi_bus_type, NULL, data: &match, match: acpi_dev_match_cb);
988 put_device(dev);
989 return !!dev;
990}
991EXPORT_SYMBOL(acpi_dev_present);
992
993/**
994 * acpi_dev_get_next_match_dev - Return the next match of ACPI device
995 * @adev: Pointer to the previous ACPI device matching this @hid, @uid and @hrv
996 * @hid: Hardware ID of the device.
997 * @uid: Unique ID of the device, pass NULL to not check _UID
998 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
999 *
1000 * Return the next match of ACPI device if another matching device was present
1001 * at the moment of invocation, or NULL otherwise.
1002 *
1003 * The caller is responsible for invoking acpi_dev_put() on the returned device.
1004 * On the other hand the function invokes acpi_dev_put() on the given @adev
1005 * assuming that its reference counter had been increased beforehand.
1006 *
1007 * See additional information in acpi_dev_present() as well.
1008 */
1009struct acpi_device *
1010acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv)
1011{
1012 struct device *start = adev ? &adev->dev : NULL;
1013 struct acpi_dev_match_info match = {};
1014 struct device *dev;
1015
1016 strscpy(p: match.hid[0].id, q: hid, size: sizeof(match.hid[0].id));
1017 match.uid = uid;
1018 match.hrv = hrv;
1019
1020 dev = bus_find_device(bus: &acpi_bus_type, start, data: &match, match: acpi_dev_match_cb);
1021 acpi_dev_put(adev);
1022 return dev ? to_acpi_device(dev) : NULL;
1023}
1024EXPORT_SYMBOL(acpi_dev_get_next_match_dev);
1025
1026/**
1027 * acpi_dev_get_first_match_dev - Return the first match of ACPI device
1028 * @hid: Hardware ID of the device.
1029 * @uid: Unique ID of the device, pass NULL to not check _UID
1030 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
1031 *
1032 * Return the first match of ACPI device if a matching device was present
1033 * at the moment of invocation, or NULL otherwise.
1034 *
1035 * The caller is responsible for invoking acpi_dev_put() on the returned device.
1036 *
1037 * See additional information in acpi_dev_present() as well.
1038 */
1039struct acpi_device *
1040acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
1041{
1042 return acpi_dev_get_next_match_dev(NULL, hid, uid, hrv);
1043}
1044EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
1045
1046/**
1047 * acpi_reduced_hardware - Return if this is an ACPI-reduced-hw machine
1048 *
1049 * Return true when running on an ACPI-reduced-hw machine, false otherwise.
1050 */
1051bool acpi_reduced_hardware(void)
1052{
1053 return acpi_gbl_reduced_hardware;
1054}
1055EXPORT_SYMBOL_GPL(acpi_reduced_hardware);
1056
1057/*
1058 * acpi_backlight= handling, this is done here rather then in video_detect.c
1059 * because __setup cannot be used in modules.
1060 */
1061char acpi_video_backlight_string[16];
1062EXPORT_SYMBOL(acpi_video_backlight_string);
1063
1064static int __init acpi_backlight(char *str)
1065{
1066 strscpy(p: acpi_video_backlight_string, q: str,
1067 size: sizeof(acpi_video_backlight_string));
1068 return 1;
1069}
1070__setup("acpi_backlight=", acpi_backlight);
1071
1072/**
1073 * acpi_match_platform_list - Check if the system matches with a given list
1074 * @plat: pointer to acpi_platform_list table terminated by a NULL entry
1075 *
1076 * Return the matched index if the system is found in the platform list.
1077 * Otherwise, return a negative error code.
1078 */
1079int acpi_match_platform_list(const struct acpi_platform_list *plat)
1080{
1081 struct acpi_table_header hdr;
1082 int idx = 0;
1083
1084 if (acpi_disabled)
1085 return -ENODEV;
1086
1087 for (; plat->oem_id[0]; plat++, idx++) {
1088 if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))
1089 continue;
1090
1091 if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
1092 continue;
1093
1094 if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))
1095 continue;
1096
1097 if ((plat->pred == all_versions) ||
1098 (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||
1099 (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||
1100 (plat->pred == equal && hdr.oem_revision == plat->oem_revision))
1101 return idx;
1102 }
1103
1104 return -ENODEV;
1105}
1106EXPORT_SYMBOL(acpi_match_platform_list);
1107

source code of linux/drivers/acpi/utils.c