Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
/*
 *  acpi_osl.c - OS-dependent functions ($Revision: 83 $)
 *
 *  Copyright (C) 2000       Andrew Henroid
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/pci.h>
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/kmod.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/nmi.h>
#include <acpi/acpi.h>
#include <asm/io.h>
#include <acpi/acpi_bus.h>
#include <acpi/processor.h>
#include <asm/uaccess.h>

#include <linux/efi.h>

#define _COMPONENT		ACPI_OS_SERVICES
ACPI_MODULE_NAME("osl")
#define PREFIX		"ACPI: "
struct acpi_os_dpc {
	acpi_osd_exec_callback function;
	void *context;
	struct work_struct work;
};

#ifdef CONFIG_ACPI_CUSTOM_DSDT
#include CONFIG_ACPI_CUSTOM_DSDT_FILE
#endif

#ifdef ENABLE_DEBUGGER
#include <linux/kdb.h>

/* stuff for debugger support */
int acpi_in_debugger;
EXPORT_SYMBOL(acpi_in_debugger);

extern char line_buf[80];
#endif				/*ENABLE_DEBUGGER */

int acpi_specific_hotkey_enabled = TRUE;
EXPORT_SYMBOL(acpi_specific_hotkey_enabled);

static unsigned int acpi_irq_irq;
static acpi_osd_handler acpi_irq_handler;
static void *acpi_irq_context;
static struct workqueue_struct *kacpid_wq;

acpi_status acpi_os_initialize(void)
{
	return AE_OK;
}

acpi_status acpi_os_initialize1(void)
{
	/*
	 * Initialize PCI configuration space access, as we'll need to access
	 * it while walking the namespace (bus 0 and root bridges w/ _BBNs).
	 */
	if (!raw_pci_ops) {
		printk(KERN_ERR PREFIX
		       "Access to PCI configuration space unavailable\n");
		return AE_NULL_ENTRY;
	}
	kacpid_wq = create_singlethread_workqueue("kacpid");
	BUG_ON(!kacpid_wq);

	return AE_OK;
}

acpi_status acpi_os_terminate(void)
{
	if (acpi_irq_handler) {
		acpi_os_remove_interrupt_handler(acpi_irq_irq,
						 acpi_irq_handler);
	}

	destroy_workqueue(kacpid_wq);

	return AE_OK;
}

void acpi_os_printf(const char *fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	acpi_os_vprintf(fmt, args);
	va_end(args);
}

EXPORT_SYMBOL(acpi_os_printf);

void acpi_os_vprintf(const char *fmt, va_list args)
{
	static char buffer[512];

	vsprintf(buffer, fmt, args);

#ifdef ENABLE_DEBUGGER
	if (acpi_in_debugger) {
		kdb_printf("%s", buffer);
	} else {
		printk("%s", buffer);
	}
#else
	printk("%s", buffer);
#endif
}

acpi_status acpi_os_get_root_pointer(u32 flags, struct acpi_pointer *addr)
{
	if (efi_enabled) {
		addr->pointer_type = ACPI_PHYSICAL_POINTER;
		if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
			addr->pointer.physical = efi.acpi20;
		else if (efi.acpi != EFI_INVALID_TABLE_ADDR)
			addr->pointer.physical = efi.acpi;
		else {
			printk(KERN_ERR PREFIX
			       "System description tables not found\n");
			return AE_NOT_FOUND;
		}
	} else {
		if (ACPI_FAILURE(acpi_find_root_pointer(flags, addr))) {
			printk(KERN_ERR PREFIX
			       "System description tables not found\n");
			return AE_NOT_FOUND;
		}
	}

	return AE_OK;
}

acpi_status
acpi_os_map_memory(acpi_physical_address phys, acpi_size size,
		   void __iomem ** virt)
{
	if (phys > ULONG_MAX) {
		printk(KERN_ERR PREFIX "Cannot map memory that high\n");
		return AE_BAD_PARAMETER;
	}
	/*
	 * ioremap checks to ensure this is in reserved space
	 */
	*virt = ioremap((unsigned long)phys, size);

	if (!*virt)
		return AE_NO_MEMORY;

	return AE_OK;
}
EXPORT_SYMBOL_GPL(acpi_os_map_memory);

void acpi_os_unmap_memory(void __iomem * virt, acpi_size size)
{
	iounmap(virt);
}
EXPORT_SYMBOL_GPL(acpi_os_unmap_memory);

#ifdef ACPI_FUTURE_USAGE
acpi_status
acpi_os_get_physical_address(void *virt, acpi_physical_address * phys)
{
	if (!phys || !virt)
		return AE_BAD_PARAMETER;

	*phys = virt_to_phys(virt);

	return AE_OK;
}
#endif

#define ACPI_MAX_OVERRIDE_LEN 100

static char acpi_os_name[ACPI_MAX_OVERRIDE_LEN];

acpi_status
acpi_os_predefined_override(const struct acpi_predefined_names *init_val,
			    acpi_string * new_val)
{
	if (!init_val || !new_val)
		return AE_BAD_PARAMETER;

	*new_val = NULL;
	if (!memcmp(init_val->name, "_OS_", 4) && strlen(acpi_os_name)) {
		printk(KERN_INFO PREFIX "Overriding _OS definition to '%s'\n",
		       acpi_os_name);
		*new_val = acpi_os_name;
	}

	return AE_OK;
}

acpi_status
acpi_os_table_override(struct acpi_table_header * existing_table,
		       struct acpi_table_header ** new_table)
{
	if (!existing_table || !new_table)
		return AE_BAD_PARAMETER;

#ifdef CONFIG_ACPI_CUSTOM_DSDT
	if (strncmp(existing_table->signature, "DSDT", 4) == 0)
		*new_table = (struct acpi_table_header *)AmlCode;
	else
		*new_table = NULL;
#else
	*new_table = NULL;
#endif
	return AE_OK;
}

static irqreturn_t acpi_irq(int irq, void *dev_id)
{
	return (*acpi_irq_handler) (acpi_irq_context) ? IRQ_HANDLED : IRQ_NONE;
}

acpi_status
acpi_os_install_interrupt_handler(u32 gsi, acpi_osd_handler handler,
				  void *context)
{
	unsigned int irq;

	/*
	 * Ignore the GSI from the core, and use the value in our copy of the
	 * FADT. It may not be the same if an interrupt source override exists
	 * for the SCI.
	 */
	gsi = acpi_fadt.sci_int;
	if (acpi_gsi_to_irq(gsi, &irq) < 0) {
		printk(KERN_ERR PREFIX "SCI (ACPI GSI %d) not registered\n",
		       gsi);
		return AE_OK;
	}

	acpi_irq_handler = handler;
	acpi_irq_context = context;
	if (request_irq(irq, acpi_irq, IRQF_SHARED, "acpi", acpi_irq)) {
		printk(KERN_ERR PREFIX "SCI (IRQ%d) allocation failed\n", irq);
		return AE_NOT_ACQUIRED;
	}
	acpi_irq_irq = irq;

	return AE_OK;
}

acpi_status acpi_os_remove_interrupt_handler(u32 irq, acpi_osd_handler handler)
{
	if (irq) {
		free_irq(irq, acpi_irq);
		acpi_irq_handler = NULL;
		acpi_irq_irq = 0;
	}

	return AE_OK;
}

/*
 * Running in interpreter thread context, safe to sleep
 */

void acpi_os_sleep(acpi_integer ms)
{
	schedule_timeout_interruptible(msecs_to_jiffies(ms));
}

EXPORT_SYMBOL(acpi_os_sleep);

void acpi_os_stall(u32 us)
{
	while (us) {
		u32 delay = 1000;

		if (delay > us)
			delay = us;
		udelay(delay);
		touch_nmi_watchdog();
		us -= delay;
	}
}

EXPORT_SYMBOL(acpi_os_stall);

/*
 * Support ACPI 3.0 AML Timer operand
 * Returns 64-bit free-running, monotonically increasing timer
 * with 100ns granularity
 */
u64 acpi_os_get_timer(void)
{
	static u64 t;

#ifdef	CONFIG_HPET
	/* TBD: use HPET if available */
#endif

#ifdef	CONFIG_X86_PM_TIMER
	/* TBD: default to PM timer if HPET was not available */
#endif
	if (!t)
		printk(KERN_ERR PREFIX "acpi_os_get_timer() TBD\n");

	return ++t;
}

acpi_status acpi_os_read_port(acpi_io_address port, u32 * value, u32 width)
{
	u32 dummy;

	if (!value)
		value = &dummy;

	switch (width) {
	case 8:
		*(u8 *) value = inb(port);
		break;
	case 16:
		*(u16 *) value = inw(port);
		break;
	case 32:
		*(u32 *) value = inl(port);
		break;
	default:
		BUG();
	}

	return AE_OK;
}

EXPORT_SYMBOL(acpi_os_read_port);

acpi_status acpi_os_write_port(acpi_io_address port, u32 value, u32 width)
{
	switch (width) {
	case 8:
		outb(value, port);
		break;
	case 16:
		outw(value, port);
		break;
	case 32:
		outl(value, port);
		break;
	default:
		BUG();
	}

	return AE_OK;
}

EXPORT_SYMBOL(acpi_os_write_port);

acpi_status
acpi_os_read_memory(acpi_physical_address phys_addr, u32 * value, u32 width)
{
	u32 dummy;
	void __iomem *virt_addr;

	virt_addr = ioremap(phys_addr, width);
	if (!value)
		value = &dummy;

	switch (width) {
	case 8:
		*(u8 *) value = readb(virt_addr);
		break;
	case 16:
		*(u16 *) value = readw(virt_addr);
		break;
	case 32:
		*(u32 *) value = readl(virt_addr);
		break;
	default:
		BUG();
	}

	iounmap(virt_addr);

	return AE_OK;
}

acpi_status
acpi_os_write_memory(acpi_physical_address phys_addr, u32 value, u32 width)
{
	void __iomem *virt_addr;

	virt_addr = ioremap(phys_addr, width);

	switch (width) {
	case 8:
		writeb(value, virt_addr);
		break;
	case 16:
		writew(value, virt_addr);
		break;
	case 32:
		writel(value, virt_addr);
		break;
	default:
		BUG();
	}

	iounmap(virt_addr);

	return AE_OK;
}

acpi_status
acpi_os_read_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
			       void *value, u32 width)
{
	int result, size;

	if (!value)
		return AE_BAD_PARAMETER;

	switch (width) {
	case 8:
		size = 1;
		break;
	case 16:
		size = 2;
		break;
	case 32:
		size = 4;
		break;
	default:
		return AE_ERROR;
	}

	BUG_ON(!raw_pci_ops);

	result = raw_pci_ops->read(pci_id->segment, pci_id->bus,
				   PCI_DEVFN(pci_id->device, pci_id->function),
				   reg, size, value);

	return (result ? AE_ERROR : AE_OK);
}

EXPORT_SYMBOL(acpi_os_read_pci_configuration);

acpi_status
acpi_os_write_pci_configuration(struct acpi_pci_id * pci_id, u32 reg,
				acpi_integer value, u32 width)
{
	int result, size;

	switch (width) {
	case 8:
		size = 1;
		break;
	case 16:
		size = 2;
		break;
	case 32:
		size = 4;
		break;
	default:
		return AE_ERROR;
	}

	BUG_ON(!raw_pci_ops);

	result = raw_pci_ops->write(pci_id->segment, pci_id->bus,
				    PCI_DEVFN(pci_id->device, pci_id->function),
				    reg, size, value);

	return (result ? AE_ERROR : AE_OK);
}

/* TODO: Change code to take advantage of driver model more */
static void acpi_os_derive_pci_id_2(acpi_handle rhandle,	/* upper bound  */
				    acpi_handle chandle,	/* current node */
				    struct acpi_pci_id **id,
				    int *is_bridge, u8 * bus_number)
{
	acpi_handle handle;
	struct acpi_pci_id *pci_id = *id;
	acpi_status status;
	unsigned long temp;
	acpi_object_type type;
	u8 tu8;

	acpi_get_parent(chandle, &handle);
	if (handle != rhandle) {
		acpi_os_derive_pci_id_2(rhandle, handle, &pci_id, is_bridge,
					bus_number);

		status = acpi_get_type(handle, &type);
		if ((ACPI_FAILURE(status)) || (type != ACPI_TYPE_DEVICE))
			return;

		status =
		    acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL,
					  &temp);
		if (ACPI_SUCCESS(status)) {
			pci_id->device = ACPI_HIWORD(ACPI_LODWORD(temp));
			pci_id->function = ACPI_LOWORD(ACPI_LODWORD(temp));

			if (*is_bridge)
				pci_id->bus = *bus_number;

			/* any nicer way to get bus number of bridge ? */
			status =
			    acpi_os_read_pci_configuration(pci_id, 0x0e, &tu8,
							   8);
			if (ACPI_SUCCESS(status)
			    && ((tu8 & 0x7f) == 1 || (tu8 & 0x7f) == 2)) {
				status =
				    acpi_os_read_pci_configuration(pci_id, 0x18,
								   &tu8, 8);
				if (!ACPI_SUCCESS(status)) {
					/* Certainly broken...  FIX ME */
					return;
				}
				*is_bridge = 1;
				pci_id->bus = tu8;
				status =
				    acpi_os_read_pci_configuration(pci_id, 0x19,
								   &tu8, 8);
				if (ACPI_SUCCESS(status)) {
					*bus_number = tu8;
				}
			} else
				*is_bridge = 0;
		}
	}
}

void acpi_os_derive_pci_id(acpi_handle rhandle,	/* upper bound  */
			   acpi_handle chandle,	/* current node */
			   struct acpi_pci_id **id)
{
	int is_bridge = 1;
	u8 bus_number = (*id)->bus;

	acpi_os_derive_pci_id_2(rhandle, chandle, id, &is_bridge, &bus_number);
}

static void acpi_os_execute_deferred(struct work_struct *work)
{
	struct acpi_os_dpc *dpc = container_of(work, struct acpi_os_dpc, work);

	if (!dpc) {
		printk(KERN_ERR PREFIX "Invalid (NULL) context\n");
		return;
	}

	dpc->function(dpc->context);

	kfree(dpc);

	return;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_execute
 *
 * PARAMETERS:  Type               - Type of the callback
 *              Function           - Function to be executed
 *              Context            - Function parameters
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Depending on type, either queues function for deferred execution or
 *              immediately executes function on a separate thread.
 *
 ******************************************************************************/

acpi_status acpi_os_execute(acpi_execute_type type,
			    acpi_osd_exec_callback function, void *context)
{
	acpi_status status = AE_OK;
	struct acpi_os_dpc *dpc;

	ACPI_FUNCTION_TRACE("os_queue_for_execution");

	ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
			  "Scheduling function [%p(%p)] for deferred execution.\n",
			  function, context));

	if (!function)
		return_ACPI_STATUS(AE_BAD_PARAMETER);

	/*
	 * Allocate/initialize DPC structure.  Note that this memory will be
	 * freed by the callee.  The kernel handles the work_struct list  in a
	 * way that allows us to also free its memory inside the callee.
	 * Because we may want to schedule several tasks with different
	 * parameters we can't use the approach some kernel code uses of
	 * having a static work_struct.
	 */

	dpc = kmalloc(sizeof(struct acpi_os_dpc), GFP_ATOMIC);
	if (!dpc)
		return_ACPI_STATUS(AE_NO_MEMORY);

	dpc->function = function;
	dpc->context = context;

	INIT_WORK(&dpc->work, acpi_os_execute_deferred);
	if (!queue_work(kacpid_wq, &dpc->work)) {
		ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
				  "Call to queue_work() failed.\n"));
		kfree(dpc);
		status = AE_ERROR;
	}

	return_ACPI_STATUS(status);
}

EXPORT_SYMBOL(acpi_os_execute);

void acpi_os_wait_events_complete(void *context)
{
	flush_workqueue(kacpid_wq);
}

EXPORT_SYMBOL(acpi_os_wait_events_complete);

/*
 * Allocate the memory for a spinlock and initialize it.
 */
acpi_status acpi_os_create_lock(acpi_spinlock * handle)
{
	spin_lock_init(*handle);

	return AE_OK;
}

/*
 * Deallocate the memory for a spinlock.
 */
void acpi_os_delete_lock(acpi_spinlock handle)
{
	return;
}

acpi_status
acpi_os_create_semaphore(u32 max_units, u32 initial_units, acpi_handle * handle)
{
	struct semaphore *sem = NULL;


	sem = acpi_os_allocate(sizeof(struct semaphore));
	if (!sem)
		return AE_NO_MEMORY;
	memset(sem, 0, sizeof(struct semaphore));

	sema_init(sem, initial_units);

	*handle = (acpi_handle *) sem;

	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Creating semaphore[%p|%d].\n",
			  *handle, initial_units));

	return AE_OK;
}

EXPORT_SYMBOL(acpi_os_create_semaphore);

/*
 * TODO: A better way to delete semaphores?  Linux doesn't have a
 * 'delete_semaphore()' function -- may result in an invalid
 * pointer dereference for non-synchronized consumers.	Should
 * we at least check for blocked threads and signal/cancel them?
 */

acpi_status acpi_os_delete_semaphore(acpi_handle handle)
{
	struct semaphore *sem = (struct semaphore *)handle;


	if (!sem)
		return AE_BAD_PARAMETER;

	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Deleting semaphore[%p].\n", handle));

	kfree(sem);
	sem = NULL;

	return AE_OK;
}

EXPORT_SYMBOL(acpi_os_delete_semaphore);

/*
 * TODO: The kernel doesn't have a 'down_timeout' function -- had to
 * improvise.  The process is to sleep for one scheduler quantum
 * until the semaphore becomes available.  Downside is that this
 * may result in starvation for timeout-based waits when there's
 * lots of semaphore activity.
 *
 * TODO: Support for units > 1?
 */
acpi_status acpi_os_wait_semaphore(acpi_handle handle, u32 units, u16 timeout)
{
	acpi_status status = AE_OK;
	struct semaphore *sem = (struct semaphore *)handle;
	int ret = 0;


	if (!sem || (units < 1))
		return AE_BAD_PARAMETER;

	if (units > 1)
		return AE_SUPPORT;

	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Waiting for semaphore[%p|%d|%d]\n",
			  handle, units, timeout));

	/*
	 * This can be called during resume with interrupts off.
	 * Like boot-time, we should be single threaded and will
	 * always get the lock if we try -- timeout or not.
	 * If this doesn't succeed, then we will oops courtesy of
	 * might_sleep() in down().
	 */
	if (!down_trylock(sem))
		return AE_OK;

	switch (timeout) {
		/*
		 * No Wait:
		 * --------
		 * A zero timeout value indicates that we shouldn't wait - just
		 * acquire the semaphore if available otherwise return AE_TIME
		 * (a.k.a. 'would block').
		 */
	case 0:
		if (down_trylock(sem))
			status = AE_TIME;
		break;

		/*
		 * Wait Indefinitely:
		 * ------------------
		 */
	case ACPI_WAIT_FOREVER:
		down(sem);
		break;

		/*
		 * Wait w/ Timeout:
		 * ----------------
		 */
	default:
		// TODO: A better timeout algorithm?
		{
			int i = 0;
			static const int quantum_ms = 1000 / HZ;

			ret = down_trylock(sem);
			for (i = timeout; (i > 0 && ret != 0); i -= quantum_ms) {
				schedule_timeout_interruptible(1);
				ret = down_trylock(sem);
			}

			if (ret != 0)
				status = AE_TIME;
		}
		break;
	}

	if (ACPI_FAILURE(status)) {
		ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
				  "Failed to acquire semaphore[%p|%d|%d], %s",
				  handle, units, timeout,
				  acpi_format_exception(status)));
	} else {
		ACPI_DEBUG_PRINT((ACPI_DB_MUTEX,
				  "Acquired semaphore[%p|%d|%d]", handle,
				  units, timeout));
	}

	return status;
}

EXPORT_SYMBOL(acpi_os_wait_semaphore);

/*
 * TODO: Support for units > 1?
 */
acpi_status acpi_os_signal_semaphore(acpi_handle handle, u32 units)
{
	struct semaphore *sem = (struct semaphore *)handle;


	if (!sem || (units < 1))
		return AE_BAD_PARAMETER;

	if (units > 1)
		return AE_SUPPORT;

	ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Signaling semaphore[%p|%d]\n", handle,
			  units));

	up(sem);

	return AE_OK;
}

EXPORT_SYMBOL(acpi_os_signal_semaphore);

#ifdef ACPI_FUTURE_USAGE
u32 acpi_os_get_line(char *buffer)
{

#ifdef ENABLE_DEBUGGER
	if (acpi_in_debugger) {
		u32 chars;

		kdb_read(buffer, sizeof(line_buf));

		/* remove the CR kdb includes */
		chars = strlen(buffer) - 1;
		buffer[chars] = '\0';
	}
#endif

	return 0;
}
#endif				/*  ACPI_FUTURE_USAGE  */

/* Assumes no unreadable holes inbetween */
u8 acpi_os_readable(void *ptr, acpi_size len)
{
#if defined(__i386__) || defined(__x86_64__)
	char tmp;
	return !__get_user(tmp, (char __user *)ptr)
	    && !__get_user(tmp, (char __user *)ptr + len - 1);
#endif
	return 1;
}

#ifdef ACPI_FUTURE_USAGE
u8 acpi_os_writable(void *ptr, acpi_size len)
{
	/* could do dummy write (racy) or a kernel page table lookup.
	   The later may be difficult at early boot when kmap doesn't work yet. */
	return 1;
}
#endif

acpi_status acpi_os_signal(u32 function, void *info)
{
	switch (function) {
	case ACPI_SIGNAL_FATAL:
		printk(KERN_ERR PREFIX "Fatal opcode executed\n");
		break;
	case ACPI_SIGNAL_BREAKPOINT:
		/*
		 * AML Breakpoint
		 * ACPI spec. says to treat it as a NOP unless
		 * you are debugging.  So if/when we integrate
		 * AML debugger into the kernel debugger its
		 * hook will go here.  But until then it is
		 * not useful to print anything on breakpoints.
		 */
		break;
	default:
		break;
	}

	return AE_OK;
}

EXPORT_SYMBOL(acpi_os_signal);

static int __init acpi_os_name_setup(char *str)
{
	char *p = acpi_os_name;
	int count = ACPI_MAX_OVERRIDE_LEN - 1;

	if (!str || !*str)
		return 0;

	for (; count-- && str && *str; str++) {
		if (isalnum(*str) || *str == ' ' || *str == ':')
			*p++ = *str;
		else if (*str == '\'' || *str == '"')
			continue;
		else
			break;
	}
	*p = 0;

	return 1;

}

__setup("acpi_os_name=", acpi_os_name_setup);

/*
 * _OSI control
 * empty string disables _OSI
 * TBD additional string adds to _OSI
 */
static int __init acpi_osi_setup(char *str)
{
	if (str == NULL || *str == '\0') {
		printk(KERN_INFO PREFIX "_OSI method disabled\n");
		acpi_gbl_create_osi_method = FALSE;
	} else {
		/* TBD */
		printk(KERN_ERR PREFIX "_OSI additional string ignored -- %s\n",
		       str);
	}

	return 1;
}

__setup("acpi_osi=", acpi_osi_setup);

/* enable serialization to combat AE_ALREADY_EXISTS errors */
static int __init acpi_serialize_setup(char *str)
{
	printk(KERN_INFO PREFIX "serialize enabled\n");

	acpi_gbl_all_methods_serialized = TRUE;

	return 1;
}

__setup("acpi_serialize", acpi_serialize_setup);

/*
 * Wake and Run-Time GPES are expected to be separate.
 * We disable wake-GPEs at run-time to prevent spurious
 * interrupts.
 *
 * However, if a system exists that shares Wake and
 * Run-time events on the same GPE this flag is available
 * to tell Linux to keep the wake-time GPEs enabled at run-time.
 */
static int __init acpi_wake_gpes_always_on_setup(char *str)
{
	printk(KERN_INFO PREFIX "wake GPEs not disabled\n");

	acpi_gbl_leave_wake_gpes_disabled = FALSE;

	return 1;
}

__setup("acpi_wake_gpes_always_on", acpi_wake_gpes_always_on_setup);

static int __init acpi_hotkey_setup(char *str)
{
	acpi_specific_hotkey_enabled = FALSE;
	return 1;
}

__setup("acpi_generic_hotkey", acpi_hotkey_setup);

/*
 * max_cstate is defined in the base kernel so modules can
 * change it w/o depending on the state of the processor module.
 */
unsigned int max_cstate = ACPI_PROCESSOR_MAX_POWER;

EXPORT_SYMBOL(max_cstate);

/*
 * Acquire a spinlock.
 *
 * handle is a pointer to the spinlock_t.
 */

acpi_cpu_flags acpi_os_acquire_lock(acpi_spinlock lockp)
{
	acpi_cpu_flags flags;
	spin_lock_irqsave(lockp, flags);
	return flags;
}

/*
 * Release a spinlock. See above.
 */

void acpi_os_release_lock(acpi_spinlock lockp, acpi_cpu_flags flags)
{
	spin_unlock_irqrestore(lockp, flags);
}

#ifndef ACPI_USE_LOCAL_CACHE

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_create_cache
 *
 * PARAMETERS:  name      - Ascii name for the cache
 *              size      - Size of each cached object
 *              depth     - Maximum depth of the cache (in objects) <ignored>
 *              cache     - Where the new cache object is returned
 *
 * RETURN:      status
 *
 * DESCRIPTION: Create a cache object
 *
 ******************************************************************************/

acpi_status
acpi_os_create_cache(char *name, u16 size, u16 depth, acpi_cache_t ** cache)
{
	*cache = kmem_cache_create(name, size, 0, 0, NULL, NULL);
	if (*cache == NULL)
		return AE_ERROR;
	else
		return AE_OK;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_purge_cache
 *
 * PARAMETERS:  Cache           - Handle to cache object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Free all objects within the requested cache.
 *
 ******************************************************************************/

acpi_status acpi_os_purge_cache(acpi_cache_t * cache)
{
	kmem_cache_shrink(cache);
	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_delete_cache
 *
 * PARAMETERS:  Cache           - Handle to cache object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Free all objects within the requested cache and delete the
 *              cache object.
 *
 ******************************************************************************/

acpi_status acpi_os_delete_cache(acpi_cache_t * cache)
{
	kmem_cache_destroy(cache);
	return (AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_os_release_object
 *
 * PARAMETERS:  Cache       - Handle to cache object
 *              Object      - The object to be released
 *
 * RETURN:      None
 *
 * DESCRIPTION: Release an object to the specified cache.  If cache is full,
 *              the object is deleted.
 *
 ******************************************************************************/

acpi_status acpi_os_release_object(acpi_cache_t * cache, void *object)
{
	kmem_cache_free(cache, object);
	return (AE_OK);
}

/******************************************************************************
 *
 * FUNCTION:    acpi_os_validate_interface
 *
 * PARAMETERS:  interface           - Requested interface to be validated
 *
 * RETURN:      AE_OK if interface is supported, AE_SUPPORT otherwise
 *
 * DESCRIPTION: Match an interface string to the interfaces supported by the
 *              host. Strings originate from an AML call to the _OSI method.
 *
 *****************************************************************************/

acpi_status
acpi_os_validate_interface (char *interface)
{

    return AE_SUPPORT;
}


/******************************************************************************
 *
 * FUNCTION:    acpi_os_validate_address
 *
 * PARAMETERS:  space_id             - ACPI space ID
 *              address             - Physical address
 *              length              - Address length
 *
 * RETURN:      AE_OK if address/length is valid for the space_id. Otherwise,
 *              should return AE_AML_ILLEGAL_ADDRESS.
 *
 * DESCRIPTION: Validate a system address via the host OS. Used to validate
 *              the addresses accessed by AML operation regions.
 *
 *****************************************************************************/

acpi_status
acpi_os_validate_address (
    u8                   space_id,
    acpi_physical_address   address,
    acpi_size               length)
{

    return AE_OK;
}


#endif