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