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