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