drm/etnaviv: rename etnaviv_gem_vaddr to etnaviv_gem_vmap
[linux-2.6-block.git] / drivers / acpi / utils.c
CommitLineData
1da177e4
LT
1/*
2 * acpi_utils.c - ACPI Utility Functions ($Revision: 10 $)
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 *
7 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or (at
12 * your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
1da177e4
LT
19 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
20 */
21
22#include <linux/kernel.h>
23#include <linux/module.h>
5a0e3ad6 24#include <linux/slab.h>
1da177e4
LT
25#include <linux/init.h>
26#include <linux/types.h>
fbfddae6
TK
27#include <linux/hardirq.h>
28#include <linux/acpi.h>
45fef5b8 29#include <linux/dynamic_debug.h>
1da177e4 30
a192a958 31#include "internal.h"
2d12b6b3 32#include "sleep.h"
a192a958 33
1da177e4 34#define _COMPONENT ACPI_BUS_COMPONENT
f52fd66d 35ACPI_MODULE_NAME("utils");
1da177e4
LT
36
37/* --------------------------------------------------------------------------
38 Object Evaluation Helpers
39 -------------------------------------------------------------------------- */
4fd7f518
HH
40static void
41acpi_util_eval_error(acpi_handle h, acpi_string p, acpi_status s)
42{
1da177e4 43#ifdef ACPI_DEBUG_OUTPUT
4fd7f518
HH
44 char prefix[80] = {'\0'};
45 struct acpi_buffer buffer = {sizeof(prefix), prefix};
46 acpi_get_name(h, ACPI_FULL_PATHNAME, &buffer);
47 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Evaluate [%s.%s]: %s\n",
48 (char *) prefix, p, acpi_format_exception(s)));
1da177e4 49#else
4fd7f518 50 return;
1da177e4 51#endif
4fd7f518
HH
52}
53
1da177e4 54acpi_status
4be44fcd
LB
55acpi_extract_package(union acpi_object *package,
56 struct acpi_buffer *format, struct acpi_buffer *buffer)
1da177e4 57{
4be44fcd
LB
58 u32 size_required = 0;
59 u32 tail_offset = 0;
60 char *format_string = NULL;
61 u32 format_count = 0;
62 u32 i = 0;
63 u8 *head = NULL;
64 u8 *tail = NULL;
1da177e4 65
1da177e4 66
4be44fcd
LB
67 if (!package || (package->type != ACPI_TYPE_PACKAGE)
68 || (package->package.count < 1)) {
cece9296 69 printk(KERN_WARNING PREFIX "Invalid package argument\n");
d550d98d 70 return AE_BAD_PARAMETER;
1da177e4
LT
71 }
72
73 if (!format || !format->pointer || (format->length < 1)) {
cece9296 74 printk(KERN_WARNING PREFIX "Invalid format argument\n");
d550d98d 75 return AE_BAD_PARAMETER;
1da177e4
LT
76 }
77
78 if (!buffer) {
cece9296 79 printk(KERN_WARNING PREFIX "Invalid buffer argument\n");
d550d98d 80 return AE_BAD_PARAMETER;
1da177e4
LT
81 }
82
4be44fcd 83 format_count = (format->length / sizeof(char)) - 1;
1da177e4 84 if (format_count > package->package.count) {
cece9296
LB
85 printk(KERN_WARNING PREFIX "Format specifies more objects [%d]"
86 " than exist in package [%d].\n",
87 format_count, package->package.count);
d550d98d 88 return AE_BAD_DATA;
1da177e4
LT
89 }
90
50dd0969 91 format_string = format->pointer;
1da177e4
LT
92
93 /*
94 * Calculate size_required.
95 */
4be44fcd 96 for (i = 0; i < format_count; i++) {
1da177e4
LT
97
98 union acpi_object *element = &(package->package.elements[i]);
99
1da177e4
LT
100 switch (element->type) {
101
102 case ACPI_TYPE_INTEGER:
103 switch (format_string[i]) {
104 case 'N':
439913ff
LM
105 size_required += sizeof(u64);
106 tail_offset += sizeof(u64);
1da177e4
LT
107 break;
108 case 'S':
4be44fcd 109 size_required +=
439913ff 110 sizeof(char *) + sizeof(u64) +
4be44fcd
LB
111 sizeof(char);
112 tail_offset += sizeof(char *);
1da177e4
LT
113 break;
114 default:
cece9296 115 printk(KERN_WARNING PREFIX "Invalid package element"
e7e92ec9 116 " [%d]: got number, expecting"
cece9296
LB
117 " [%c]\n",
118 i, format_string[i]);
d550d98d 119 return AE_BAD_DATA;
1da177e4
LT
120 break;
121 }
122 break;
123
124 case ACPI_TYPE_STRING:
125 case ACPI_TYPE_BUFFER:
126 switch (format_string[i]) {
127 case 'S':
4be44fcd
LB
128 size_required +=
129 sizeof(char *) +
130 (element->string.length * sizeof(char)) +
131 sizeof(char);
132 tail_offset += sizeof(char *);
1da177e4
LT
133 break;
134 case 'B':
4be44fcd 135 size_required +=
d93de345 136 sizeof(u8 *) + element->buffer.length;
4be44fcd 137 tail_offset += sizeof(u8 *);
1da177e4
LT
138 break;
139 default:
cece9296 140 printk(KERN_WARNING PREFIX "Invalid package element"
a6fc6720 141 " [%d] got string/buffer,"
e7e92ec9 142 " expecting [%c]\n",
cece9296 143 i, format_string[i]);
d550d98d 144 return AE_BAD_DATA;
1da177e4
LT
145 break;
146 }
147 break;
e3ec483a
ZR
148 case ACPI_TYPE_LOCAL_REFERENCE:
149 switch (format_string[i]) {
150 case 'R':
151 size_required += sizeof(void *);
152 tail_offset += sizeof(void *);
153 break;
154 default:
155 printk(KERN_WARNING PREFIX "Invalid package element"
156 " [%d] got reference,"
157 " expecting [%c]\n",
158 i, format_string[i]);
159 return AE_BAD_DATA;
160 break;
161 }
162 break;
1da177e4
LT
163
164 case ACPI_TYPE_PACKAGE:
165 default:
4be44fcd
LB
166 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
167 "Found unsupported element at index=%d\n",
168 i));
1da177e4 169 /* TBD: handle nested packages... */
d550d98d 170 return AE_SUPPORT;
1da177e4
LT
171 break;
172 }
173 }
174
175 /*
176 * Validate output buffer.
177 */
e83dda06 178 if (buffer->length == ACPI_ALLOCATE_BUFFER) {
2d0acb4a 179 buffer->pointer = ACPI_ALLOCATE_ZEROED(size_required);
e83dda06
AS
180 if (!buffer->pointer)
181 return AE_NO_MEMORY;
1da177e4 182 buffer->length = size_required;
e83dda06
AS
183 } else {
184 if (buffer->length < size_required) {
185 buffer->length = size_required;
186 return AE_BUFFER_OVERFLOW;
187 } else if (buffer->length != size_required ||
188 !buffer->pointer) {
189 return AE_BAD_PARAMETER;
190 }
1da177e4
LT
191 }
192
193 head = buffer->pointer;
194 tail = buffer->pointer + tail_offset;
195
196 /*
197 * Extract package data.
198 */
4be44fcd 199 for (i = 0; i < format_count; i++) {
1da177e4
LT
200
201 u8 **pointer = NULL;
202 union acpi_object *element = &(package->package.elements[i]);
203
204 if (!element) {
d550d98d 205 return AE_BAD_DATA;
1da177e4
LT
206 }
207
208 switch (element->type) {
209
210 case ACPI_TYPE_INTEGER:
211 switch (format_string[i]) {
212 case 'N':
439913ff 213 *((u64 *) head) =
4be44fcd 214 element->integer.value;
439913ff 215 head += sizeof(u64);
1da177e4
LT
216 break;
217 case 'S':
4be44fcd 218 pointer = (u8 **) head;
1da177e4 219 *pointer = tail;
439913ff 220 *((u64 *) tail) =
4be44fcd 221 element->integer.value;
439913ff
LM
222 head += sizeof(u64 *);
223 tail += sizeof(u64);
1da177e4
LT
224 /* NULL terminate string */
225 *tail = (char)0;
226 tail += sizeof(char);
227 break;
228 default:
229 /* Should never get here */
230 break;
231 }
232 break;
233
234 case ACPI_TYPE_STRING:
235 case ACPI_TYPE_BUFFER:
236 switch (format_string[i]) {
237 case 'S':
4be44fcd 238 pointer = (u8 **) head;
1da177e4 239 *pointer = tail;
4be44fcd
LB
240 memcpy(tail, element->string.pointer,
241 element->string.length);
242 head += sizeof(char *);
1da177e4
LT
243 tail += element->string.length * sizeof(char);
244 /* NULL terminate string */
245 *tail = (char)0;
246 tail += sizeof(char);
247 break;
248 case 'B':
4be44fcd 249 pointer = (u8 **) head;
1da177e4 250 *pointer = tail;
4be44fcd
LB
251 memcpy(tail, element->buffer.pointer,
252 element->buffer.length);
253 head += sizeof(u8 *);
d93de345 254 tail += element->buffer.length;
1da177e4
LT
255 break;
256 default:
257 /* Should never get here */
258 break;
259 }
260 break;
e3ec483a
ZR
261 case ACPI_TYPE_LOCAL_REFERENCE:
262 switch (format_string[i]) {
263 case 'R':
264 *(void **)head =
265 (void *)element->reference.handle;
266 head += sizeof(void *);
267 break;
268 default:
269 /* Should never get here */
270 break;
271 }
272 break;
1da177e4
LT
273 case ACPI_TYPE_PACKAGE:
274 /* TBD: handle nested packages... */
275 default:
276 /* Should never get here */
277 break;
278 }
279 }
280
d550d98d 281 return AE_OK;
1da177e4 282}
1da177e4 283
4be44fcd 284EXPORT_SYMBOL(acpi_extract_package);
1da177e4
LT
285
286acpi_status
4be44fcd
LB
287acpi_evaluate_integer(acpi_handle handle,
288 acpi_string pathname,
27663c58 289 struct acpi_object_list *arguments, unsigned long long *data)
1da177e4 290{
4be44fcd 291 acpi_status status = AE_OK;
40599072 292 union acpi_object element;
4be44fcd 293 struct acpi_buffer buffer = { 0, NULL };
1da177e4 294
1da177e4 295 if (!data)
d550d98d 296 return AE_BAD_PARAMETER;
1da177e4 297
1da177e4 298 buffer.length = sizeof(union acpi_object);
40599072 299 buffer.pointer = &element;
1da177e4
LT
300 status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
301 if (ACPI_FAILURE(status)) {
302 acpi_util_eval_error(handle, pathname, status);
d550d98d 303 return status;
1da177e4
LT
304 }
305
40599072 306 if (element.type != ACPI_TYPE_INTEGER) {
1da177e4 307 acpi_util_eval_error(handle, pathname, AE_BAD_DATA);
d550d98d 308 return AE_BAD_DATA;
1da177e4
LT
309 }
310
40599072 311 *data = element.integer.value;
1da177e4 312
27663c58 313 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Return value [%llu]\n", *data));
1da177e4 314
d550d98d 315 return AE_OK;
1da177e4 316}
1da177e4 317
4be44fcd 318EXPORT_SYMBOL(acpi_evaluate_integer);
1da177e4 319
1da177e4 320acpi_status
4be44fcd
LB
321acpi_evaluate_reference(acpi_handle handle,
322 acpi_string pathname,
323 struct acpi_object_list *arguments,
324 struct acpi_handle_list *list)
1da177e4 325{
4be44fcd
LB
326 acpi_status status = AE_OK;
327 union acpi_object *package = NULL;
328 union acpi_object *element = NULL;
329 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
330 u32 i = 0;
1da177e4 331
1da177e4
LT
332
333 if (!list) {
d550d98d 334 return AE_BAD_PARAMETER;
1da177e4
LT
335 }
336
337 /* Evaluate object. */
338
339 status = acpi_evaluate_object(handle, pathname, arguments, &buffer);
340 if (ACPI_FAILURE(status))
341 goto end;
342
50dd0969 343 package = buffer.pointer;
1da177e4
LT
344
345 if ((buffer.length == 0) || !package) {
1da177e4
LT
346 status = AE_BAD_DATA;
347 acpi_util_eval_error(handle, pathname, status);
348 goto end;
349 }
350 if (package->type != ACPI_TYPE_PACKAGE) {
1da177e4
LT
351 status = AE_BAD_DATA;
352 acpi_util_eval_error(handle, pathname, status);
353 goto end;
354 }
355 if (!package->package.count) {
1da177e4
LT
356 status = AE_BAD_DATA;
357 acpi_util_eval_error(handle, pathname, status);
358 goto end;
359 }
360
361 if (package->package.count > ACPI_MAX_HANDLES) {
d550d98d 362 return AE_NO_MEMORY;
1da177e4
LT
363 }
364 list->count = package->package.count;
365
366 /* Extract package data. */
367
368 for (i = 0; i < list->count; i++) {
369
370 element = &(package->package.elements[i]);
371
cd0b2248 372 if (element->type != ACPI_TYPE_LOCAL_REFERENCE) {
1da177e4 373 status = AE_BAD_DATA;
1da177e4
LT
374 acpi_util_eval_error(handle, pathname, status);
375 break;
376 }
377
b6a16387 378 if (!element->reference.handle) {
b6a16387 379 status = AE_NULL_ENTRY;
c48cf1b9 380 acpi_util_eval_error(handle, pathname, status);
b6a16387
TR
381 break;
382 }
1da177e4
LT
383 /* Get the acpi_handle. */
384
385 list->handles[i] = element->reference.handle;
386 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found reference [%p]\n",
4be44fcd 387 list->handles[i]));
1da177e4
LT
388 }
389
4be44fcd 390 end:
1da177e4
LT
391 if (ACPI_FAILURE(status)) {
392 list->count = 0;
393 //kfree(list->handles);
394 }
395
02438d87 396 kfree(buffer.pointer);
1da177e4 397
d550d98d 398 return status;
1da177e4 399}
1da177e4 400
4be44fcd 401EXPORT_SYMBOL(acpi_evaluate_reference);
38ac0f1b
MG
402
403acpi_status
8ede06ab 404acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld_info **pld)
38ac0f1b
MG
405{
406 acpi_status status;
407 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
408 union acpi_object *output;
409
410 status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
411
412 if (ACPI_FAILURE(status))
413 return status;
414
415 output = buffer.pointer;
416
417 if (!output || output->type != ACPI_TYPE_PACKAGE
418 || !output->package.count
419 || output->package.elements[0].type != ACPI_TYPE_BUFFER
8ede06ab 420 || output->package.elements[0].buffer.length < ACPI_PLD_REV1_BUFFER_SIZE) {
38ac0f1b
MG
421 status = AE_TYPE;
422 goto out;
423 }
424
8ede06ab
FT
425 status = acpi_decode_pld_buffer(
426 output->package.elements[0].buffer.pointer,
427 output->package.elements[0].buffer.length,
428 pld);
429
38ac0f1b
MG
430out:
431 kfree(buffer.pointer);
432 return status;
433}
434EXPORT_SYMBOL(acpi_get_physical_device_location);
275c58d7
TK
435
436/**
700b8422 437 * acpi_evaluate_ost: Evaluate _OST for hotplug operations
275c58d7
TK
438 * @handle: ACPI device handle
439 * @source_event: source event code
440 * @status_code: status code
441 * @status_buf: optional detailed information (NULL if none)
442 *
443 * Evaluate _OST for hotplug operations. All ACPI hotplug handlers
444 * must call this function when evaluating _OST for hotplug operations.
445 * When the platform does not support _OST, this function has no effect.
446 */
447acpi_status
05730c19
JL
448acpi_evaluate_ost(acpi_handle handle, u32 source_event, u32 status_code,
449 struct acpi_buffer *status_buf)
275c58d7 450{
275c58d7
TK
451 union acpi_object params[3] = {
452 {.type = ACPI_TYPE_INTEGER,},
453 {.type = ACPI_TYPE_INTEGER,},
454 {.type = ACPI_TYPE_BUFFER,}
455 };
456 struct acpi_object_list arg_list = {3, params};
275c58d7
TK
457
458 params[0].integer.value = source_event;
459 params[1].integer.value = status_code;
460 if (status_buf != NULL) {
461 params[2].buffer.pointer = status_buf->pointer;
462 params[2].buffer.length = status_buf->length;
463 } else {
464 params[2].buffer.pointer = NULL;
465 params[2].buffer.length = 0;
466 }
467
05730c19 468 return acpi_evaluate_object(handle, "_OST", &arg_list, NULL);
275c58d7 469}
05730c19 470EXPORT_SYMBOL(acpi_evaluate_ost);
fbfddae6 471
45fef5b8
BM
472/**
473 * acpi_handle_path: Return the object path of handle
474 *
475 * Caller must free the returned buffer
476 */
477static char *acpi_handle_path(acpi_handle handle)
478{
479 struct acpi_buffer buffer = {
480 .length = ACPI_ALLOCATE_BUFFER,
481 .pointer = NULL
482 };
483
484 if (in_interrupt() ||
485 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer) != AE_OK)
486 return NULL;
487 return buffer.pointer;
488}
489
fbfddae6
TK
490/**
491 * acpi_handle_printk: Print message with ACPI prefix and object path
492 *
493 * This function is called through acpi_handle_<level> macros and prints
494 * a message with ACPI prefix and object path. This function acquires
495 * the global namespace mutex to obtain an object path. In interrupt
496 * context, it shows the object path as <n/a>.
497 */
498void
499acpi_handle_printk(const char *level, acpi_handle handle, const char *fmt, ...)
500{
501 struct va_format vaf;
502 va_list args;
fbfddae6
TK
503 const char *path;
504
505 va_start(args, fmt);
506 vaf.fmt = fmt;
507 vaf.va = &args;
508
45fef5b8
BM
509 path = acpi_handle_path(handle);
510 printk("%sACPI: %s: %pV", level, path ? path : "<n/a>" , &vaf);
fbfddae6
TK
511
512 va_end(args);
45fef5b8 513 kfree(path);
fbfddae6
TK
514}
515EXPORT_SYMBOL(acpi_handle_printk);
952c63e9 516
45fef5b8
BM
517#if defined(CONFIG_DYNAMIC_DEBUG)
518/**
519 * __acpi_handle_debug: pr_debug with ACPI prefix and object path
520 *
521 * This function is called through acpi_handle_debug macro and debug
522 * prints a message with ACPI prefix and object path. This function
523 * acquires the global namespace mutex to obtain an object path. In
524 * interrupt context, it shows the object path as <n/a>.
525 */
526void
527__acpi_handle_debug(struct _ddebug *descriptor, acpi_handle handle,
528 const char *fmt, ...)
529{
530 struct va_format vaf;
531 va_list args;
532 const char *path;
533
534 va_start(args, fmt);
535 vaf.fmt = fmt;
536 vaf.va = &args;
537
538 path = acpi_handle_path(handle);
539 __dynamic_pr_debug(descriptor, "ACPI: %s: %pV", path ? path : "<n/a>", &vaf);
540
541 va_end(args);
542 kfree(path);
543}
544EXPORT_SYMBOL(__acpi_handle_debug);
545#endif
546
952c63e9
JL
547/**
548 * acpi_has_method: Check whether @handle has a method named @name
549 * @handle: ACPI device handle
550 * @name: name of object or method
551 *
552 * Check whether @handle has a method named @name.
553 */
554bool acpi_has_method(acpi_handle handle, char *name)
555{
556 acpi_handle tmp;
557
558 return ACPI_SUCCESS(acpi_get_handle(handle, name, &tmp));
559}
560EXPORT_SYMBOL(acpi_has_method);
0db98202
JL
561
562acpi_status acpi_execute_simple_method(acpi_handle handle, char *method,
563 u64 arg)
564{
565 union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
566 struct acpi_object_list arg_list = { .count = 1, .pointer = &obj, };
567
568 obj.integer.value = arg;
569
570 return acpi_evaluate_object(handle, method, &arg_list, NULL);
571}
572EXPORT_SYMBOL(acpi_execute_simple_method);
7d2421f8
JL
573
574/**
575 * acpi_evaluate_ej0: Evaluate _EJ0 method for hotplug operations
576 * @handle: ACPI device handle
577 *
578 * Evaluate device's _EJ0 method for hotplug operations.
579 */
580acpi_status acpi_evaluate_ej0(acpi_handle handle)
581{
582 acpi_status status;
583
584 status = acpi_execute_simple_method(handle, "_EJ0", 1);
585 if (status == AE_NOT_FOUND)
586 acpi_handle_warn(handle, "No _EJ0 support for device\n");
587 else if (ACPI_FAILURE(status))
588 acpi_handle_warn(handle, "Eject failed (0x%x)\n", status);
589
590 return status;
591}
592
593/**
594 * acpi_evaluate_lck: Evaluate _LCK method to lock/unlock device
595 * @handle: ACPI device handle
596 * @lock: lock device if non-zero, otherwise unlock device
597 *
598 * Evaluate device's _LCK method if present to lock/unlock device
599 */
600acpi_status acpi_evaluate_lck(acpi_handle handle, int lock)
601{
602 acpi_status status;
603
604 status = acpi_execute_simple_method(handle, "_LCK", !!lock);
605 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
606 if (lock)
607 acpi_handle_warn(handle,
608 "Locking device failed (0x%x)\n", status);
609 else
610 acpi_handle_warn(handle,
611 "Unlocking device failed (0x%x)\n", status);
612 }
613
614 return status;
615}
a65ac520
JL
616
617/**
618 * acpi_evaluate_dsm - evaluate device's _DSM method
619 * @handle: ACPI device handle
620 * @uuid: UUID of requested functions, should be 16 bytes
621 * @rev: revision number of requested function
622 * @func: requested function number
623 * @argv4: the function specific parameter
624 *
625 * Evaluate device's _DSM method with specified UUID, revision id and
626 * function number. Caller needs to free the returned object.
627 *
628 * Though ACPI defines the fourth parameter for _DSM should be a package,
629 * some old BIOSes do expect a buffer or an integer etc.
630 */
631union acpi_object *
632acpi_evaluate_dsm(acpi_handle handle, const u8 *uuid, int rev, int func,
633 union acpi_object *argv4)
634{
635 acpi_status ret;
636 struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
637 union acpi_object params[4];
638 struct acpi_object_list input = {
639 .count = 4,
640 .pointer = params,
641 };
642
643 params[0].type = ACPI_TYPE_BUFFER;
644 params[0].buffer.length = 16;
645 params[0].buffer.pointer = (char *)uuid;
646 params[1].type = ACPI_TYPE_INTEGER;
647 params[1].integer.value = rev;
648 params[2].type = ACPI_TYPE_INTEGER;
649 params[2].integer.value = func;
650 if (argv4) {
651 params[3] = *argv4;
652 } else {
653 params[3].type = ACPI_TYPE_PACKAGE;
654 params[3].package.count = 0;
655 params[3].package.elements = NULL;
656 }
657
658 ret = acpi_evaluate_object(handle, "_DSM", &input, &buf);
659 if (ACPI_SUCCESS(ret))
660 return (union acpi_object *)buf.pointer;
661
662 if (ret != AE_NOT_FOUND)
663 acpi_handle_warn(handle,
664 "failed to evaluate _DSM (0x%x)\n", ret);
665
666 return NULL;
667}
668EXPORT_SYMBOL(acpi_evaluate_dsm);
669
670/**
671 * acpi_check_dsm - check if _DSM method supports requested functions.
672 * @handle: ACPI device handle
673 * @uuid: UUID of requested functions, should be 16 bytes at least
674 * @rev: revision number of requested functions
675 * @funcs: bitmap of requested functions
a65ac520
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676 *
677 * Evaluate device's _DSM method to check whether it supports requested
678 * functions. Currently only support 64 functions at maximum, should be
679 * enough for now.
680 */
681bool acpi_check_dsm(acpi_handle handle, const u8 *uuid, int rev, u64 funcs)
682{
683 int i;
684 u64 mask = 0;
685 union acpi_object *obj;
686
687 if (funcs == 0)
688 return false;
689
690 obj = acpi_evaluate_dsm(handle, uuid, rev, 0, NULL);
691 if (!obj)
692 return false;
693
694 /* For compatibility, old BIOSes may return an integer */
695 if (obj->type == ACPI_TYPE_INTEGER)
696 mask = obj->integer.value;
697 else if (obj->type == ACPI_TYPE_BUFFER)
698 for (i = 0; i < obj->buffer.length && i < 8; i++)
699 mask |= (((u8)obj->buffer.pointer[i]) << (i * 8));
700 ACPI_FREE(obj);
701
702 /*
703 * Bit 0 indicates whether there's support for any functions other than
704 * function 0 for the specified UUID and revision.
705 */
706 if ((mask & 0x1) && (mask & funcs) == funcs)
707 return true;
708
709 return false;
710}
711EXPORT_SYMBOL(acpi_check_dsm);
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713/**
714 * acpi_dev_present - Detect presence of a given ACPI device in the system.
715 * @hid: Hardware ID of the device.
716 *
717 * Return %true if the device was present at the moment of invocation.
718 * Note that if the device is pluggable, it may since have disappeared.
719 *
720 * For this function to work, acpi_bus_scan() must have been executed
721 * which happens in the subsys_initcall() subsection. Hence, do not
722 * call from a subsys_initcall() or earlier (use acpi_get_devices()
723 * instead). Calling from module_init() is fine (which is synonymous
724 * with device_initcall()).
725 */
726bool acpi_dev_present(const char *hid)
727{
728 struct acpi_device_bus_id *acpi_device_bus_id;
729 bool found = false;
730
731 mutex_lock(&acpi_device_lock);
732 list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node)
733 if (!strcmp(acpi_device_bus_id->bus_id, hid)) {
734 found = true;
735 break;
736 }
737 mutex_unlock(&acpi_device_lock);
738
739 return found;
740}
741EXPORT_SYMBOL(acpi_dev_present);
742
14ca7a47
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743/*
744 * acpi_backlight= handling, this is done here rather then in video_detect.c
745 * because __setup cannot be used in modules.
746 */
747char acpi_video_backlight_string[16];
748EXPORT_SYMBOL(acpi_video_backlight_string);
749
750static int __init acpi_backlight(char *str)
751{
752 strlcpy(acpi_video_backlight_string, str,
753 sizeof(acpi_video_backlight_string));
754 return 1;
755}
756__setup("acpi_backlight=", acpi_backlight);