1086 lines · c
1// SPDX-License-Identifier: GPL-2.0-or-later2/*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: " fmt10 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 Helpers25 -------------------------------------------------------------------------- */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_status32acpi_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_status247acpi_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 9305 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 = kcalloc(list->count, sizeof(*list->handles), GFP_KERNEL);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 same410 * @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 and414 * 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 another427 * @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 list449 * @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 dependency465 * @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 for469 * @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 497acpi_status498acpi_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);505 506 if (ACPI_FAILURE(status))507 return status;508 509 output = buffer.pointer;510 511 if (!output || output->type != ACPI_TYPE_PACKAGE512 || !output->package.count513 || output->package.elements[0].type != ACPI_TYPE_BUFFER514 || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {515 status = AE_TYPE;516 goto out;517 }518 519 status = acpi_decode_pld_buffer(520 output->package.elements[0].buffer.pointer,521 output->package.elements[0].buffer.length,522 pld);523 524out:525 kfree(buffer.pointer);526 return status;527}528EXPORT_SYMBOL(acpi_get_physical_device_location);529 530/**531 * acpi_evaluate_ost: Evaluate _OST for hotplug operations532 * @handle: ACPI device handle533 * @source_event: source event code534 * @status_code: status code535 * @status_buf: optional detailed information (NULL if none)536 *537 * Evaluate _OST for hotplug operations. All ACPI hotplug handlers538 * must call this function when evaluating _OST for hotplug operations.539 * When the platform does not support _OST, this function has no effect.540 */541acpi_status542acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,543 struct acpi_buffer *status_buf)544{545 union acpi_object params[3] = {546 {.type = ACPI_TYPE_INTEGER,},547 {.type = ACPI_TYPE_INTEGER,},548 {.type = ACPI_TYPE_BUFFER,}549 };550 struct acpi_object_list arg_list = {3, params};551 552 params[0].integer.value = source_event;553 params[1].integer.value = status_code;554 if (status_buf != NULL) {555 params[2].buffer.pointer = status_buf->pointer;556 params[2].buffer.length = status_buf->length;557 } else {558 params[2].buffer.pointer = NULL;559 params[2].buffer.length = 0;560 }561 562 return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);563}564EXPORT_SYMBOL(acpi_evaluate_ost);565 566/**567 * acpi_handle_path: Return the object path of handle568 * @handle: ACPI device handle569 *570 * Caller must free the returned buffer571 */572char *acpi_handle_path(acpi_handle handle)573{574 struct acpi_buffer buffer = {575 .length = ACPI_ALLOCATE_BUFFER,576 .pointer = NULL577 };578 579 if (in_interrupt() ||580 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)581 return NULL;582 return buffer.pointer;583}584 585/**586 * acpi_handle_printk: Print message with ACPI prefix and object path587 * @level: log level588 * @handle: ACPI device handle589 * @fmt: format string590 *591 * This function is called through acpi_handle_<level> macros and prints592 * a message with ACPI prefix and object path. This function acquires593 * the global namespace mutex to obtain an object path. In interrupt594 * context, it shows the object path as <n/a>.595 */596void597acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)598{599 struct va_format vaf;600 va_list args;601 const char *path;602 603 va_start(args, fmt);604 vaf.fmt = fmt;605 vaf.va = &args;606 607 path = acpi_handle_path(handle);608 printk("%sACPI: %s: %pV", level, path ? path : "<n/a>", &vaf);609 610 va_end(args);611 kfree(path);612}613EXPORT_SYMBOL(acpi_handle_printk);614 615#if defined(CONFIG_DYNAMIC_DEBUG)616/**617 * __acpi_handle_debug: pr_debug with ACPI prefix and object path618 * @descriptor: Dynamic Debug descriptor619 * @handle: ACPI device handle620 * @fmt: format string621 *622 * This function is called through acpi_handle_debug macro and debug623 * prints a message with ACPI prefix and object path. This function624 * acquires the global namespace mutex to obtain an object path. In625 * interrupt context, it shows the object path as <n/a>.626 */627void628__acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,629 const char *fmt, ...)630{631 struct va_format vaf;632 va_list args;633 const char *path;634 635 va_start(args, fmt);636 vaf.fmt = fmt;637 vaf.va = &args;638 639 path = acpi_handle_path(handle);640 __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);641 642 va_end(args);643 kfree(path);644}645EXPORT_SYMBOL(__acpi_handle_debug);646#endif647 648/**649 * acpi_evaluation_failure_warn - Log evaluation failure warning.650 * @handle: Parent object handle.651 * @name: Name of the object whose evaluation has failed.652 * @status: Status value returned by the failing object evaluation.653 */654void acpi_evaluation_failure_warn(acpi_handle handle, const char *name,655 acpi_status status)656{657 acpi_handle_warn(handle, "%s evaluation failed: %s\n", name,658 acpi_format_exception(status));659}660EXPORT_SYMBOL_GPL(acpi_evaluation_failure_warn);661 662/**663 * acpi_has_method: Check whether @handle has a method named @name664 * @handle: ACPI device handle665 * @name: name of object or method666 *667 * Check whether @handle has a method named @name.668 */669bool acpi_has_method(acpi_handle handle, char *name)670{671 acpi_handle tmp;672 673 return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));674}675EXPORT_SYMBOL(acpi_has_method);676 677acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,678 u64 arg)679{680 union acpi_object obj = { .type = ACPI_TYPE_INTEGER };681 struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };682 683 obj.integer.value = arg;684 685 return acpi_evaluate_object(handle, method, &arg_list, NULL);686}687EXPORT_SYMBOL(acpi_execute_simple_method);688 689/**690 * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations691 * @handle: ACPI device handle692 *693 * Evaluate device's _EJ0 method for hotplug operations.694 */695acpi_status acpi_evaluate_ej0(acpi_handle handle)696{697 acpi_status status;698 699 status = acpi_execute_simple_method(handle, "_EJ0", 1);700 if (status == AE_NOT_FOUND)701 acpi_handle_warn(handle, "No _EJ0 support for device\n");702 else if (ACPI_FAILURE(status))703 acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);704 705 return status;706}707 708/**709 * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device710 * @handle: ACPI device handle711 * @lock: lock device if non-zero, otherwise unlock device712 *713 * Evaluate device's _LCK method if present to lock/unlock device714 */715acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)716{717 acpi_status status;718 719 status = acpi_execute_simple_method(handle, "_LCK", !!lock);720 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {721 if (lock)722 acpi_handle_warn(handle,723 "Locking device failed (0x%x)\n", status);724 else725 acpi_handle_warn(handle,726 "Unlocking device failed (0x%x)\n", status);727 }728 729 return status;730}731 732/**733 * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence734 * @handle: ACPI device handle735 * @space_id: ACPI address space id to register OpRegion presence for736 * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or737 * ACPI_REG_DISCONNECT738 *739 * Evaluate device's _REG method to register OpRegion presence.740 */741acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function)742{743 struct acpi_object_list arg_list;744 union acpi_object params[2];745 746 params[0].type = ACPI_TYPE_INTEGER;747 params[0].integer.value = space_id;748 params[1].type = ACPI_TYPE_INTEGER;749 params[1].integer.value = function;750 arg_list.count = 2;751 arg_list.pointer = params;752 753 return acpi_evaluate_object(handle, "_REG", &arg_list, NULL);754}755EXPORT_SYMBOL(acpi_evaluate_reg);756 757/**758 * acpi_evaluate_dsm - evaluate device's _DSM method759 * @handle: ACPI device handle760 * @guid: GUID of requested functions, should be 16 bytes761 * @rev: revision number of requested function762 * @func: requested function number763 * @argv4: the function specific parameter764 *765 * Evaluate device's _DSM method with specified GUID, revision id and766 * function number. Caller needs to free the returned object.767 *768 * Though ACPI defines the fourth parameter for _DSM should be a package,769 * some old BIOSes do expect a buffer or an integer etc.770 */771union acpi_object *772acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,773 union acpi_object *argv4)774{775 acpi_status ret;776 struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};777 union acpi_object params[4];778 struct acpi_object_list input = {779 .count = 4,780 .pointer = params,781 };782 783 params[0].type = ACPI_TYPE_BUFFER;784 params[0].buffer.length = 16;785 params[0].buffer.pointer = (u8 *)guid;786 params[1].type = ACPI_TYPE_INTEGER;787 params[1].integer.value = rev;788 params[2].type = ACPI_TYPE_INTEGER;789 params[2].integer.value = func;790 if (argv4) {791 params[3] = *argv4;792 } else {793 params[3].type = ACPI_TYPE_PACKAGE;794 params[3].package.count = 0;795 params[3].package.elements = NULL;796 }797 798 ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);799 if (ACPI_SUCCESS(ret))800 return (union acpi_object *)buf.pointer;801 802 if (ret != AE_NOT_FOUND)803 acpi_handle_warn(handle,804 "failed to evaluate _DSM %pUb rev:%lld func:%lld (0x%x)\n",805 guid, rev, func, ret);806 807 return NULL;808}809EXPORT_SYMBOL(acpi_evaluate_dsm);810 811/**812 * acpi_check_dsm - check if _DSM method supports requested functions.813 * @handle: ACPI device handle814 * @guid: GUID of requested functions, should be 16 bytes at least815 * @rev: revision number of requested functions816 * @funcs: bitmap of requested functions817 *818 * Evaluate device's _DSM method to check whether it supports requested819 * functions. Currently only support 64 functions at maximum, should be820 * enough for now.821 */822bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)823{824 int i;825 u64 mask = 0;826 union acpi_object *obj;827 828 if (funcs == 0)829 return false;830 831 obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);832 if (!obj)833 return false;834 835 /* For compatibility, old BIOSes may return an integer */836 if (obj->type == ACPI_TYPE_INTEGER)837 mask = obj->integer.value;838 else if (obj->type == ACPI_TYPE_BUFFER)839 for (i = 0; i < obj->buffer.length && i < 8; i++)840 mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));841 ACPI_FREE(obj);842 843 /*844 * Bit 0 indicates whether there's support for any functions other than845 * function 0 for the specified GUID and revision.846 */847 if ((mask & 0x1) && (mask & funcs) == funcs)848 return true;849 850 return false;851}852EXPORT_SYMBOL(acpi_check_dsm);853 854/**855 * acpi_dev_uid_to_integer - treat ACPI device _UID as integer856 * @adev: ACPI device to get _UID from857 * @integer: output buffer for integer858 *859 * Considers _UID as integer and converts it to @integer.860 *861 * Returns 0 on success, or negative error code otherwise.862 */863int acpi_dev_uid_to_integer(struct acpi_device *adev, u64 *integer)864{865 const char *uid;866 867 if (!adev)868 return -ENODEV;869 870 uid = acpi_device_uid(adev);871 if (!uid)872 return -ENODATA;873 874 return kstrtou64(uid, 0, integer);875}876EXPORT_SYMBOL(acpi_dev_uid_to_integer);877 878/**879 * acpi_dev_found - Detect presence of a given ACPI device in the namespace.880 * @hid: Hardware ID of the device.881 *882 * Return %true if the device was present at the moment of invocation.883 * Note that if the device is pluggable, it may since have disappeared.884 *885 * For this function to work, acpi_bus_scan() must have been executed886 * which happens in the subsys_initcall() subsection. Hence, do not887 * call from a subsys_initcall() or earlier (use acpi_get_devices()888 * instead). Calling from module_init() is fine (which is synonymous889 * with device_initcall()).890 */891bool acpi_dev_found(const char *hid)892{893 struct acpi_device_bus_id *acpi_device_bus_id;894 bool found = false;895 896 mutex_lock(&acpi_device_lock);897 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)898 if (!strcmp(acpi_device_bus_id->bus_id, hid)) {899 found = true;900 break;901 }902 mutex_unlock(&acpi_device_lock);903 904 return found;905}906EXPORT_SYMBOL(acpi_dev_found);907 908struct acpi_dev_match_info {909 struct acpi_device_id hid[2];910 const char *uid;911 s64 hrv;912};913 914static int acpi_dev_match_cb(struct device *dev, const void *data)915{916 struct acpi_device *adev = to_acpi_device(dev);917 const struct acpi_dev_match_info *match = data;918 unsigned long long hrv;919 acpi_status status;920 921 if (acpi_match_device_ids(adev, match->hid))922 return 0;923 924 if (match->uid && !acpi_dev_uid_match(adev, match->uid))925 return 0;926 927 if (match->hrv == -1)928 return 1;929 930 status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);931 if (ACPI_FAILURE(status))932 return 0;933 934 return hrv == match->hrv;935}936 937/**938 * acpi_dev_present - Detect that a given ACPI device is present939 * @hid: Hardware ID of the device.940 * @uid: Unique ID of the device, pass NULL to not check _UID941 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV942 *943 * Return %true if a matching device was present at the moment of invocation.944 * Note that if the device is pluggable, it may since have disappeared.945 *946 * Note that unlike acpi_dev_found() this function checks the status947 * of the device. So for devices which are present in the DSDT, but948 * which are disabled (their _STA callback returns 0) this function949 * will return false.950 *951 * For this function to work, acpi_bus_scan() must have been executed952 * which happens in the subsys_initcall() subsection. Hence, do not953 * call from a subsys_initcall() or earlier (use acpi_get_devices()954 * instead). Calling from module_init() is fine (which is synonymous955 * with device_initcall()).956 */957bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)958{959 struct acpi_dev_match_info match = {};960 struct device *dev;961 962 strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));963 match.uid = uid;964 match.hrv = hrv;965 966 dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);967 put_device(dev);968 return !!dev;969}970EXPORT_SYMBOL(acpi_dev_present);971 972/**973 * acpi_dev_get_next_match_dev - Return the next match of ACPI device974 * @adev: Pointer to the previous ACPI device matching this @hid, @uid and @hrv975 * @hid: Hardware ID of the device.976 * @uid: Unique ID of the device, pass NULL to not check _UID977 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV978 *979 * Return the next match of ACPI device if another matching device was present980 * at the moment of invocation, or NULL otherwise.981 *982 * The caller is responsible for invoking acpi_dev_put() on the returned device.983 * On the other hand the function invokes acpi_dev_put() on the given @adev984 * assuming that its reference counter had been increased beforehand.985 *986 * See additional information in acpi_dev_present() as well.987 */988struct acpi_device *989acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv)990{991 struct device *start = adev ? &adev->dev : NULL;992 struct acpi_dev_match_info match = {};993 struct device *dev;994 995 strscpy(match.hid[0].id, hid, sizeof(match.hid[0].id));996 match.uid = uid;997 match.hrv = hrv;998 999 dev = bus_find_device(&acpi_bus_type, start, &match, acpi_dev_match_cb);1000 acpi_dev_put(adev);1001 return dev ? to_acpi_device(dev) : NULL;1002}1003EXPORT_SYMBOL(acpi_dev_get_next_match_dev);1004 1005/**1006 * acpi_dev_get_first_match_dev - Return the first match of ACPI device1007 * @hid: Hardware ID of the device.1008 * @uid: Unique ID of the device, pass NULL to not check _UID1009 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV1010 *1011 * Return the first match of ACPI device if a matching device was present1012 * at the moment of invocation, or NULL otherwise.1013 *1014 * The caller is responsible for invoking acpi_dev_put() on the returned device.1015 *1016 * See additional information in acpi_dev_present() as well.1017 */1018struct acpi_device *1019acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)1020{1021 return acpi_dev_get_next_match_dev(NULL, hid, uid, hrv);1022}1023EXPORT_SYMBOL(acpi_dev_get_first_match_dev);1024 1025/**1026 * acpi_reduced_hardware - Return if this is an ACPI-reduced-hw machine1027 *1028 * Return true when running on an ACPI-reduced-hw machine, false otherwise.1029 */1030bool acpi_reduced_hardware(void)1031{1032 return acpi_gbl_reduced_hardware;1033}1034EXPORT_SYMBOL_GPL(acpi_reduced_hardware);1035 1036/*1037 * acpi_backlight= handling, this is done here rather then in video_detect.c1038 * because __setup cannot be used in modules.1039 */1040char acpi_video_backlight_string[16];1041EXPORT_SYMBOL(acpi_video_backlight_string);1042 1043static int __init acpi_backlight(char *str)1044{1045 strscpy(acpi_video_backlight_string, str,1046 sizeof(acpi_video_backlight_string));1047 return 1;1048}1049__setup("acpi_backlight=", acpi_backlight);1050 1051/**1052 * acpi_match_platform_list - Check if the system matches with a given list1053 * @plat: pointer to acpi_platform_list table terminated by a NULL entry1054 *1055 * Return the matched index if the system is found in the platform list.1056 * Otherwise, return a negative error code.1057 */1058int acpi_match_platform_list(const struct acpi_platform_list *plat)1059{1060 struct acpi_table_header hdr;1061 int idx = 0;1062 1063 if (acpi_disabled)1064 return -ENODEV;1065 1066 for (; plat->oem_id[0]; plat++, idx++) {1067 if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))1068 continue;1069 1070 if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))1071 continue;1072 1073 if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))1074 continue;1075 1076 if ((plat->pred == all_versions) ||1077 (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||1078 (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||1079 (plat->pred == equal && hdr.oem_revision == plat->oem_revision))1080 return idx;1081 }1082 1083 return -ENODEV;1084}1085EXPORT_SYMBOL(acpi_match_platform_list);1086