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 -------------------------------------------------------------------------- */
acpi_util_eval_error(acpi_handle h,acpi_string p,acpi_status s)26 static 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
31 acpi_status
acpi_extract_package(union acpi_object * package,struct acpi_buffer * format,struct acpi_buffer * buffer)32 acpi_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
244 EXPORT_SYMBOL(acpi_extract_package);
245
246 acpi_status
acpi_evaluate_integer(acpi_handle handle,acpi_string pathname,struct acpi_object_list * arguments,unsigned long long * data)247 acpi_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
278 EXPORT_SYMBOL(acpi_evaluate_integer);
279
acpi_get_local_address(acpi_handle handle,u32 * addr)280 int 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 }
292 EXPORT_SYMBOL(acpi_get_local_address);
293
294 acpi_status
acpi_evaluate_reference(acpi_handle handle,acpi_string pathname,struct acpi_object_list * arguments,struct acpi_handle_list * list)295 acpi_evaluate_reference(acpi_handle handle,
296 acpi_string pathname,
297 struct acpi_object_list *arguments,
298 struct acpi_handle_list *list)
299 {
300 acpi_status status = AE_OK;
301 union acpi_object *package = NULL;
302 union acpi_object *element = NULL;
303 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
304 u32 i = 0;
305
306
307 if (!list) {
308 return AE_BAD_PARAMETER;
309 }
310
311 /* Evaluate object. */
312
313 status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
314 if (ACPI_FAILURE(status))
315 goto end;
316
317 package = buffer.pointer;
318
319 if ((buffer.length == 0) || !package) {
320 status = AE_BAD_DATA;
321 acpi_util_eval_error(handle, pathname, status);
322 goto end;
323 }
324 if (package->type != ACPI_TYPE_PACKAGE) {
325 status = AE_BAD_DATA;
326 acpi_util_eval_error(handle, pathname, status);
327 goto end;
328 }
329 if (!package->package.count) {
330 status = AE_BAD_DATA;
331 acpi_util_eval_error(handle, pathname, status);
332 goto end;
333 }
334
335 if (package->package.count > ACPI_MAX_HANDLES) {
336 kfree(package);
337 return AE_NO_MEMORY;
338 }
339 list->count = package->package.count;
340
341 /* Extract package data. */
342
343 for (i = 0; i < list->count; i++) {
344
345 element = &(package->package.elements[i]);
346
347 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
348 status = AE_BAD_DATA;
349 acpi_util_eval_error(handle, pathname, status);
350 break;
351 }
352
353 if (!element->reference.handle) {
354 status = AE_NULL_ENTRY;
355 acpi_util_eval_error(handle, pathname, status);
356 break;
357 }
358 /* Get the acpi_handle. */
359
360 list->handles[i] = element->reference.handle;
361 acpi_handle_debug(list->handles[i], "Found in reference list\n");
362 }
363
364 end:
365 if (ACPI_FAILURE(status)) {
366 list->count = 0;
367 //kfree(list->handles);
368 }
369
370 kfree(buffer.pointer);
371
372 return status;
373 }
374
375 EXPORT_SYMBOL(acpi_evaluate_reference);
376
377 acpi_status
acpi_get_physical_device_location(acpi_handle handle,struct acpi_pld_info ** pld)378 acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
379 {
380 acpi_status status;
381 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
382 union acpi_object *output;
383
384 status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
385
386 if (ACPI_FAILURE(status))
387 return status;
388
389 output = buffer.pointer;
390
391 if (!output || output->type != ACPI_TYPE_PACKAGE
392 || !output->package.count
393 || output->package.elements[0].type != ACPI_TYPE_BUFFER
394 || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
395 status = AE_TYPE;
396 goto out;
397 }
398
399 status = acpi_decode_pld_buffer(
400 output->package.elements[0].buffer.pointer,
401 output->package.elements[0].buffer.length,
402 pld);
403
404 out:
405 kfree(buffer.pointer);
406 return status;
407 }
408 EXPORT_SYMBOL(acpi_get_physical_device_location);
409
410 /**
411 * acpi_evaluate_ost: Evaluate _OST for hotplug operations
412 * @handle: ACPI device handle
413 * @source_event: source event code
414 * @status_code: status code
415 * @status_buf: optional detailed information (NULL if none)
416 *
417 * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
418 * must call this function when evaluating _OST for hotplug operations.
419 * When the platform does not support _OST, this function has no effect.
420 */
421 acpi_status
acpi_evaluate_ost(acpi_handle handle,u32 source_event,u32 status_code,struct acpi_buffer * status_buf)422 acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
423 struct acpi_buffer *status_buf)
424 {
425 union acpi_object params[3] = {
426 {.type = ACPI_TYPE_INTEGER,},
427 {.type = ACPI_TYPE_INTEGER,},
428 {.type = ACPI_TYPE_BUFFER,}
429 };
430 struct acpi_object_list arg_list = {3, params};
431
432 params[0].integer.value = source_event;
433 params[1].integer.value = status_code;
434 if (status_buf != NULL) {
435 params[2].buffer.pointer = status_buf->pointer;
436 params[2].buffer.length = status_buf->length;
437 } else {
438 params[2].buffer.pointer = NULL;
439 params[2].buffer.length = 0;
440 }
441
442 return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
443 }
444 EXPORT_SYMBOL(acpi_evaluate_ost);
445
446 /**
447 * acpi_handle_path: Return the object path of handle
448 * @handle: ACPI device handle
449 *
450 * Caller must free the returned buffer
451 */
acpi_handle_path(acpi_handle handle)452 static char *acpi_handle_path(acpi_handle handle)
453 {
454 struct acpi_buffer buffer = {
455 .length = ACPI_ALLOCATE_BUFFER,
456 .pointer = NULL
457 };
458
459 if (in_interrupt() ||
460 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
461 return NULL;
462 return buffer.pointer;
463 }
464
465 /**
466 * acpi_handle_printk: Print message with ACPI prefix and object path
467 * @level: log level
468 * @handle: ACPI device handle
469 * @fmt: format string
470 *
471 * This function is called through acpi_handle_<level> macros and prints
472 * a message with ACPI prefix and object path. This function acquires
473 * the global namespace mutex to obtain an object path. In interrupt
474 * context, it shows the object path as <n/a>.
475 */
476 void
acpi_handle_printk(const char * level,acpi_handle handle,const char * fmt,...)477 acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
478 {
479 struct va_format vaf;
480 va_list args;
481 const char *path;
482
483 va_start(args, fmt);
484 vaf.fmt = fmt;
485 vaf.va = &args;
486
487 path = acpi_handle_path(handle);
488 printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf);
489
490 va_end(args);
491 kfree(path);
492 }
493 EXPORT_SYMBOL(acpi_handle_printk);
494
495 #if defined(CONFIG_DYNAMIC_DEBUG)
496 /**
497 * __acpi_handle_debug: pr_debug with ACPI prefix and object path
498 * @descriptor: Dynamic Debug descriptor
499 * @handle: ACPI device handle
500 * @fmt: format string
501 *
502 * This function is called through acpi_handle_debug macro and debug
503 * prints a message with ACPI prefix and object path. This function
504 * acquires the global namespace mutex to obtain an object path. In
505 * interrupt context, it shows the object path as <n/a>.
506 */
507 void
__acpi_handle_debug(struct _ddebug * descriptor,acpi_handle handle,const char * fmt,...)508 __acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
509 const char *fmt, ...)
510 {
511 struct va_format vaf;
512 va_list args;
513 const char *path;
514
515 va_start(args, fmt);
516 vaf.fmt = fmt;
517 vaf.va = &args;
518
519 path = acpi_handle_path(handle);
520 __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
521
522 va_end(args);
523 kfree(path);
524 }
525 EXPORT_SYMBOL(__acpi_handle_debug);
526 #endif
527
528 /**
529 * acpi_evaluation_failure_warn - Log evaluation failure warning.
530 * @handle: Parent object handle.
531 * @name: Name of the object whose evaluation has failed.
532 * @status: Status value returned by the failing object evaluation.
533 */
acpi_evaluation_failure_warn(acpi_handle handle,const char * name,acpi_status status)534 void acpi_evaluation_failure_warn(acpi_handle handle, const char *name,
535 acpi_status status)
536 {
537 acpi_handle_warn(handle, "%s evaluation failed: %s\n", name,
538 acpi_format_exception(status));
539 }
540 EXPORT_SYMBOL_GPL(acpi_evaluation_failure_warn);
541
542 /**
543 * acpi_has_method: Check whether @handle has a method named @name
544 * @handle: ACPI device handle
545 * @name: name of object or method
546 *
547 * Check whether @handle has a method named @name.
548 */
acpi_has_method(acpi_handle handle,char * name)549 bool acpi_has_method(acpi_handle handle, char *name)
550 {
551 acpi_handle tmp;
552
553 return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
554 }
555 EXPORT_SYMBOL(acpi_has_method);
556
acpi_execute_simple_method(acpi_handle handle,char * method,u64 arg)557 acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
558 u64 arg)
559 {
560 union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
561 struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
562
563 obj.integer.value = arg;
564
565 return acpi_evaluate_object(handle, method, &arg_list, NULL);
566 }
567 EXPORT_SYMBOL(acpi_execute_simple_method);
568
569 /**
570 * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
571 * @handle: ACPI device handle
572 *
573 * Evaluate device's _EJ0 method for hotplug operations.
574 */
acpi_evaluate_ej0(acpi_handle handle)575 acpi_status acpi_evaluate_ej0(acpi_handle handle)
576 {
577 acpi_status status;
578
579 status = acpi_execute_simple_method(handle, "_EJ0", 1);
580 if (status == AE_NOT_FOUND)
581 acpi_handle_warn(handle, "No _EJ0 support for device\n");
582 else if (ACPI_FAILURE(status))
583 acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
584
585 return status;
586 }
587
588 /**
589 * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
590 * @handle: ACPI device handle
591 * @lock: lock device if non-zero, otherwise unlock device
592 *
593 * Evaluate device's _LCK method if present to lock/unlock device
594 */
acpi_evaluate_lck(acpi_handle handle,int lock)595 acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
596 {
597 acpi_status status;
598
599 status = acpi_execute_simple_method(handle, "_LCK", !!lock);
600 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
601 if (lock)
602 acpi_handle_warn(handle,
603 "Locking device failed (0x%x)\n", status);
604 else
605 acpi_handle_warn(handle,
606 "Unlocking device failed (0x%x)\n", status);
607 }
608
609 return status;
610 }
611
612 /**
613 * acpi_evaluate_reg: Evaluate _REG method to register OpRegion presence
614 * @handle: ACPI device handle
615 * @space_id: ACPI address space id to register OpRegion presence for
616 * @function: Parameter to pass to _REG one of ACPI_REG_CONNECT or
617 * ACPI_REG_DISCONNECT
618 *
619 * Evaluate device's _REG method to register OpRegion presence.
620 */
acpi_evaluate_reg(acpi_handle handle,u8 space_id,u32 function)621 acpi_status acpi_evaluate_reg(acpi_handle handle, u8 space_id, u32 function)
622 {
623 struct acpi_object_list arg_list;
624 union acpi_object params[2];
625
626 params[0].type = ACPI_TYPE_INTEGER;
627 params[0].integer.value = space_id;
628 params[1].type = ACPI_TYPE_INTEGER;
629 params[1].integer.value = function;
630 arg_list.count = 2;
631 arg_list.pointer = params;
632
633 return acpi_evaluate_object(handle, "_REG", &arg_list, NULL);
634 }
635 EXPORT_SYMBOL(acpi_evaluate_reg);
636
637 /**
638 * acpi_evaluate_dsm - evaluate device's _DSM method
639 * @handle: ACPI device handle
640 * @guid: GUID of requested functions, should be 16 bytes
641 * @rev: revision number of requested function
642 * @func: requested function number
643 * @argv4: the function specific parameter
644 *
645 * Evaluate device's _DSM method with specified GUID, revision id and
646 * function number. Caller needs to free the returned object.
647 *
648 * Though ACPI defines the fourth parameter for _DSM should be a package,
649 * some old BIOSes do expect a buffer or an integer etc.
650 */
651 union acpi_object *
acpi_evaluate_dsm(acpi_handle handle,const guid_t * guid,u64 rev,u64 func,union acpi_object * argv4)652 acpi_evaluate_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 func,
653 union acpi_object *argv4)
654 {
655 acpi_status ret;
656 struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
657 union acpi_object params[4];
658 struct acpi_object_list input = {
659 .count = 4,
660 .pointer = params,
661 };
662
663 params[0].type = ACPI_TYPE_BUFFER;
664 params[0].buffer.length = 16;
665 params[0].buffer.pointer = (u8 *)guid;
666 params[1].type = ACPI_TYPE_INTEGER;
667 params[1].integer.value = rev;
668 params[2].type = ACPI_TYPE_INTEGER;
669 params[2].integer.value = func;
670 if (argv4) {
671 params[3] = *argv4;
672 } else {
673 params[3].type = ACPI_TYPE_PACKAGE;
674 params[3].package.count = 0;
675 params[3].package.elements = NULL;
676 }
677
678 ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
679 if (ACPI_SUCCESS(ret))
680 return (union acpi_object *)buf.pointer;
681
682 if (ret != AE_NOT_FOUND)
683 acpi_handle_warn(handle,
684 "failed to evaluate _DSM (0x%x)\n", ret);
685
686 return NULL;
687 }
688 EXPORT_SYMBOL(acpi_evaluate_dsm);
689
690 /**
691 * acpi_check_dsm - check if _DSM method supports requested functions.
692 * @handle: ACPI device handle
693 * @guid: GUID of requested functions, should be 16 bytes at least
694 * @rev: revision number of requested functions
695 * @funcs: bitmap of requested functions
696 *
697 * Evaluate device's _DSM method to check whether it supports requested
698 * functions. Currently only support 64 functions at maximum, should be
699 * enough for now.
700 */
acpi_check_dsm(acpi_handle handle,const guid_t * guid,u64 rev,u64 funcs)701 bool acpi_check_dsm(acpi_handle handle, const guid_t *guid, u64 rev, u64 funcs)
702 {
703 int i;
704 u64 mask = 0;
705 union acpi_object *obj;
706
707 if (funcs == 0)
708 return false;
709
710 obj = acpi_evaluate_dsm(handle, guid, rev, 0, NULL);
711 if (!obj)
712 return false;
713
714 /* For compatibility, old BIOSes may return an integer */
715 if (obj->type == ACPI_TYPE_INTEGER)
716 mask = obj->integer.value;
717 else if (obj->type == ACPI_TYPE_BUFFER)
718 for (i = 0; i < obj->buffer.length && i < 8; i++)
719 mask |= (((u64)obj->buffer.pointer[i]) << (i * 8));
720 ACPI_FREE(obj);
721
722 /*
723 * Bit 0 indicates whether there's support for any functions other than
724 * function 0 for the specified GUID and revision.
725 */
726 if ((mask & 0x1) && (mask & funcs) == funcs)
727 return true;
728
729 return false;
730 }
731 EXPORT_SYMBOL(acpi_check_dsm);
732
733 /**
734 * acpi_dev_hid_uid_match - Match device by supplied HID and UID
735 * @adev: ACPI device to match.
736 * @hid2: Hardware ID of the device.
737 * @uid2: Unique ID of the device, pass NULL to not check _UID.
738 *
739 * Matches HID and UID in @adev with given @hid2 and @uid2.
740 * Returns true if matches.
741 */
acpi_dev_hid_uid_match(struct acpi_device * adev,const char * hid2,const char * uid2)742 bool acpi_dev_hid_uid_match(struct acpi_device *adev,
743 const char *hid2, const char *uid2)
744 {
745 const char *hid1 = acpi_device_hid(adev);
746 const char *uid1 = acpi_device_uid(adev);
747
748 if (strcmp(hid1, hid2))
749 return false;
750
751 if (!uid2)
752 return true;
753
754 return uid1 && !strcmp(uid1, uid2);
755 }
756 EXPORT_SYMBOL(acpi_dev_hid_uid_match);
757
758 /**
759 * acpi_dev_found - Detect presence of a given ACPI device in the namespace.
760 * @hid: Hardware ID of the device.
761 *
762 * Return %true if the device was present at the moment of invocation.
763 * Note that if the device is pluggable, it may since have disappeared.
764 *
765 * For this function to work, acpi_bus_scan() must have been executed
766 * which happens in the subsys_initcall() subsection. Hence, do not
767 * call from a subsys_initcall() or earlier (use acpi_get_devices()
768 * instead). Calling from module_init() is fine (which is synonymous
769 * with device_initcall()).
770 */
acpi_dev_found(const char * hid)771 bool acpi_dev_found(const char *hid)
772 {
773 struct acpi_device_bus_id *acpi_device_bus_id;
774 bool found = false;
775
776 mutex_lock(&acpi_device_lock);
777 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
778 if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
779 found = true;
780 break;
781 }
782 mutex_unlock(&acpi_device_lock);
783
784 return found;
785 }
786 EXPORT_SYMBOL(acpi_dev_found);
787
788 struct acpi_dev_match_info {
789 struct acpi_device_id hid[2];
790 const char *uid;
791 s64 hrv;
792 };
793
acpi_dev_match_cb(struct device * dev,const void * data)794 static int acpi_dev_match_cb(struct device *dev, const void *data)
795 {
796 struct acpi_device *adev = to_acpi_device(dev);
797 const struct acpi_dev_match_info *match = data;
798 unsigned long long hrv;
799 acpi_status status;
800
801 if (acpi_match_device_ids(adev, match->hid))
802 return 0;
803
804 if (match->uid && (!adev->pnp.unique_id ||
805 strcmp(adev->pnp.unique_id, match->uid)))
806 return 0;
807
808 if (match->hrv == -1)
809 return 1;
810
811 status = acpi_evaluate_integer(adev->handle, "_HRV", NULL, &hrv);
812 if (ACPI_FAILURE(status))
813 return 0;
814
815 return hrv == match->hrv;
816 }
817
818 /**
819 * acpi_dev_present - Detect that a given ACPI device is present
820 * @hid: Hardware ID of the device.
821 * @uid: Unique ID of the device, pass NULL to not check _UID
822 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
823 *
824 * Return %true if a matching device was present at the moment of invocation.
825 * Note that if the device is pluggable, it may since have disappeared.
826 *
827 * Note that unlike acpi_dev_found() this function checks the status
828 * of the device. So for devices which are present in the DSDT, but
829 * which are disabled (their _STA callback returns 0) this function
830 * will return false.
831 *
832 * For this function to work, acpi_bus_scan() must have been executed
833 * which happens in the subsys_initcall() subsection. Hence, do not
834 * call from a subsys_initcall() or earlier (use acpi_get_devices()
835 * instead). Calling from module_init() is fine (which is synonymous
836 * with device_initcall()).
837 */
acpi_dev_present(const char * hid,const char * uid,s64 hrv)838 bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
839 {
840 struct acpi_dev_match_info match = {};
841 struct device *dev;
842
843 strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
844 match.uid = uid;
845 match.hrv = hrv;
846
847 dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
848 put_device(dev);
849 return !!dev;
850 }
851 EXPORT_SYMBOL(acpi_dev_present);
852
853 /**
854 * acpi_dev_get_next_match_dev - Return the next match of ACPI device
855 * @adev: Pointer to the previous ACPI device matching this @hid, @uid and @hrv
856 * @hid: Hardware ID of the device.
857 * @uid: Unique ID of the device, pass NULL to not check _UID
858 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
859 *
860 * Return the next match of ACPI device if another matching device was present
861 * at the moment of invocation, or NULL otherwise.
862 *
863 * The caller is responsible for invoking acpi_dev_put() on the returned device.
864 * On the other hand the function invokes acpi_dev_put() on the given @adev
865 * assuming that its reference counter had been increased beforehand.
866 *
867 * See additional information in acpi_dev_present() as well.
868 */
869 struct acpi_device *
acpi_dev_get_next_match_dev(struct acpi_device * adev,const char * hid,const char * uid,s64 hrv)870 acpi_dev_get_next_match_dev(struct acpi_device *adev, const char *hid, const char *uid, s64 hrv)
871 {
872 struct device *start = adev ? &adev->dev : NULL;
873 struct acpi_dev_match_info match = {};
874 struct device *dev;
875
876 strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
877 match.uid = uid;
878 match.hrv = hrv;
879
880 dev = bus_find_device(&acpi_bus_type, start, &match, acpi_dev_match_cb);
881 acpi_dev_put(adev);
882 return dev ? to_acpi_device(dev) : NULL;
883 }
884 EXPORT_SYMBOL(acpi_dev_get_next_match_dev);
885
886 /**
887 * acpi_dev_get_first_match_dev - Return the first match of ACPI device
888 * @hid: Hardware ID of the device.
889 * @uid: Unique ID of the device, pass NULL to not check _UID
890 * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
891 *
892 * Return the first match of ACPI device if a matching device was present
893 * at the moment of invocation, or NULL otherwise.
894 *
895 * The caller is responsible for invoking acpi_dev_put() on the returned device.
896 *
897 * See additional information in acpi_dev_present() as well.
898 */
899 struct acpi_device *
acpi_dev_get_first_match_dev(const char * hid,const char * uid,s64 hrv)900 acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
901 {
902 return acpi_dev_get_next_match_dev(NULL, hid, uid, hrv);
903 }
904 EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
905
906 /**
907 * acpi_reduced_hardware - Return if this is an ACPI-reduced-hw machine
908 *
909 * Return true when running on an ACPI-reduced-hw machine, false otherwise.
910 */
acpi_reduced_hardware(void)911 bool acpi_reduced_hardware(void)
912 {
913 return acpi_gbl_reduced_hardware;
914 }
915 EXPORT_SYMBOL_GPL(acpi_reduced_hardware);
916
917 /*
918 * acpi_backlight= handling, this is done here rather then in video_detect.c
919 * because __setup cannot be used in modules.
920 */
921 char acpi_video_backlight_string[16];
922 EXPORT_SYMBOL(acpi_video_backlight_string);
923
acpi_backlight(char * str)924 static int __init acpi_backlight(char *str)
925 {
926 strlcpy(acpi_video_backlight_string, str,
927 sizeof(acpi_video_backlight_string));
928 return 1;
929 }
930 __setup("acpi_backlight=", acpi_backlight);
931
932 /**
933 * acpi_match_platform_list - Check if the system matches with a given list
934 * @plat: pointer to acpi_platform_list table terminated by a NULL entry
935 *
936 * Return the matched index if the system is found in the platform list.
937 * Otherwise, return a negative error code.
938 */
acpi_match_platform_list(const struct acpi_platform_list * plat)939 int acpi_match_platform_list(const struct acpi_platform_list *plat)
940 {
941 struct acpi_table_header hdr;
942 int idx = 0;
943
944 if (acpi_disabled)
945 return -ENODEV;
946
947 for (; plat->oem_id[0]; plat++, idx++) {
948 if (ACPI_FAILURE(acpi_get_table_header(plat->table, 0, &hdr)))
949 continue;
950
951 if (strncmp(plat->oem_id, hdr.oem_id, ACPI_OEM_ID_SIZE))
952 continue;
953
954 if (strncmp(plat->oem_table_id, hdr.oem_table_id, ACPI_OEM_TABLE_ID_SIZE))
955 continue;
956
957 if ((plat->pred == all_versions) ||
958 (plat->pred == less_than_or_equal && hdr.oem_revision <= plat->oem_revision) ||
959 (plat->pred == greater_than_or_equal && hdr.oem_revision >= plat->oem_revision) ||
960 (plat->pred == equal && hdr.oem_revision == plat->oem_revision))
961 return idx;
962 }
963
964 return -ENODEV;
965 }
966 EXPORT_SYMBOL(acpi_match_platform_list);
967