summaryrefslogtreecommitdiffstats
path: root/arch/i386/kernel/acpi/boot.c
blob: 5fafbacdd4cb11cf84cb62120afcd08c45da5464 (plain)
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
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
/*
 *  boot.c - Architecture-Specific Low-Level ACPI Boot Support
 *
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *  Copyright (C) 2001 Jun Nakajima <jun.nakajima@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/init.h>
#include <linux/acpi.h>
#include <linux/efi.h>
#include <linux/cpumask.h>
#include <linux/module.h>
#include <linux/dmi.h>
#include <linux/irq.h>
#include <linux/bootmem.h>
#include <linux/ioport.h>

#include <asm/pgtable.h>
#include <asm/io_apic.h>
#include <asm/apic.h>
#include <asm/io.h>
#include <asm/mpspec.h>

static int __initdata acpi_force = 0;

#ifdef	CONFIG_ACPI
int acpi_disabled = 0;
#else
int acpi_disabled = 1;
#endif
EXPORT_SYMBOL(acpi_disabled);

#ifdef	CONFIG_X86_64

#include <asm/proto.h>

static inline int acpi_madt_oem_check(char *oem_id, char *oem_table_id) { return 0; }


#else				/* X86 */

#ifdef	CONFIG_X86_LOCAL_APIC
#include <mach_apic.h>
#include <mach_mpparse.h>
#endif				/* CONFIG_X86_LOCAL_APIC */

#endif				/* X86 */

#define BAD_MADT_ENTRY(entry, end) (					    \
		(!entry) || (unsigned long)entry + sizeof(*entry) > end ||  \
		((struct acpi_subtable_header *)entry)->length < sizeof(*entry))

#define PREFIX			"ACPI: "

int acpi_noirq;				/* skip ACPI IRQ initialization */
int acpi_pci_disabled __initdata;	/* skip ACPI PCI scan and IRQ initialization */
int acpi_ht __initdata = 1;	/* enable HT */

int acpi_lapic;
int acpi_ioapic;
int acpi_strict;
EXPORT_SYMBOL(acpi_strict);

u8 acpi_sci_flags __initdata;
int acpi_sci_override_gsi __initdata;
int acpi_skip_timer_override __initdata;
int acpi_use_timer_override __initdata;

#ifdef CONFIG_X86_LOCAL_APIC
static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;
#endif

#ifndef __HAVE_ARCH_CMPXCHG
#warning ACPI uses CMPXCHG, i486 and later hardware
#endif

#define MAX_MADT_ENTRIES	256
u8 x86_acpiid_to_apicid[MAX_MADT_ENTRIES] =
    {[0 ... MAX_MADT_ENTRIES - 1] = 0xff };
EXPORT_SYMBOL(x86_acpiid_to_apicid);

/* --------------------------------------------------------------------------
                              Boot-time Configuration
   -------------------------------------------------------------------------- */

/*
 * The default interrupt routing model is PIC (8259).  This gets
 * overriden if IOAPICs are enumerated (below).
 */
enum acpi_irq_model_id acpi_irq_model = ACPI_IRQ_MODEL_PIC;

#ifdef	CONFIG_X86_64

/* rely on all ACPI tables being in the direct mapping */
char *__acpi_map_table(unsigned long phys_addr, unsigned long size)
{
	if (!phys_addr || !size)
		return NULL;

	if (phys_addr+size <= (end_pfn_map << PAGE_SHIFT) + PAGE_SIZE)
		return __va(phys_addr);

	return NULL;
}

#else

/*
 * Temporarily use the virtual area starting from FIX_IO_APIC_BASE_END,
 * to map the target physical address. The problem is that set_fixmap()
 * provides a single page, and it is possible that the page is not
 * sufficient.
 * By using this area, we can map up to MAX_IO_APICS pages temporarily,
 * i.e. until the next __va_range() call.
 *
 * Important Safety Note:  The fixed I/O APIC page numbers are *subtracted*
 * from the fixed base.  That's why we start at FIX_IO_APIC_BASE_END and
 * count idx down while incrementing the phys address.
 */
char *__acpi_map_table(unsigned long phys, unsigned long size)
{
	unsigned long base, offset, mapped_size;
	int idx;

	if (phys + size < 8 * 1024 * 1024)
		return __va(phys);

	offset = phys & (PAGE_SIZE - 1);
	mapped_size = PAGE_SIZE - offset;
	set_fixmap(FIX_ACPI_END, phys);
	base = fix_to_virt(FIX_ACPI_END);

	/*
	 * Most cases can be covered by the below.
	 */
	idx = FIX_ACPI_END;
	while (mapped_size < size) {
		if (--idx < FIX_ACPI_BEGIN)
			return NULL;	/* cannot handle this */
		phys += PAGE_SIZE;
		set_fixmap(idx, phys);
		mapped_size += PAGE_SIZE;
	}

	return ((unsigned char *)base + offset);
}
#endif

#ifdef CONFIG_PCI_MMCONFIG
/* The physical address of the MMCONFIG aperture.  Set from ACPI tables. */
struct acpi_table_mcfg_config *pci_mmcfg_config;
int pci_mmcfg_config_num;

int __init acpi_parse_mcfg(struct acpi_table_header *header)
{
	struct acpi_table_mcfg *mcfg;
	unsigned long i;
	int config_size;

	if (!header)
		return -EINVAL;

	mcfg = (struct acpi_table_mcfg *)header;
	if (!mcfg) {
		printk(KERN_WARNING PREFIX "Unable to map MCFG\n");
		return -ENODEV;
	}

	/* how many config structures do we have */
	pci_mmcfg_config_num = 0;
	i = header->length - sizeof(struct acpi_table_mcfg);
	while (i >= sizeof(struct acpi_table_mcfg_config)) {
		++pci_mmcfg_config_num;
		i -= sizeof(struct acpi_table_mcfg_config);
	};
	if (pci_mmcfg_config_num == 0) {
		printk(KERN_ERR PREFIX "MMCONFIG has no entries\n");
		return -ENODEV;
	}

	config_size = pci_mmcfg_config_num * sizeof(*pci_mmcfg_config);
	pci_mmcfg_config = kmalloc(config_size, GFP_KERNEL);
	if (!pci_mmcfg_config) {
		printk(KERN_WARNING PREFIX
		       "No memory for MCFG config tables\n");
		return -ENOMEM;
	}

	memcpy(pci_mmcfg_config, &mcfg[1], config_size);
	for (i = 0; i < pci_mmcfg_config_num; ++i) {
		if (pci_mmcfg_config[i].base_reserved) {
			printk(KERN_ERR PREFIX
			       "MMCONFIG not in low 4GB of memory\n");
			kfree(pci_mmcfg_config);
			pci_mmcfg_config_num = 0;
			return -ENODEV;
		}
	}

	return 0;
}
#endif				/* CONFIG_PCI_MMCONFIG */

#ifdef CONFIG_X86_LOCAL_APIC
static int __init acpi_parse_madt(struct acpi_table_header *header)
{
	struct acpi_table_madt *madt = NULL;

	if (!header|| !cpu_has_apic)
		return -EINVAL;

	madt = (struct acpi_table_madt *)header;
	if (!madt) {
		printk(KERN_WARNING PREFIX "Unable to map MADT\n");
		return -ENODEV;
	}

	if (madt->address) {
		acpi_lapic_addr = (u64) madt->address;

		printk(KERN_DEBUG PREFIX "Local APIC address 0x%08x\n",
		       madt->address);
	}

	acpi_madt_oem_check(madt->header.oem_id, madt->header.oem_table_id);

	return 0;
}

static int __init
acpi_parse_lapic(struct acpi_subtable_header * header, const unsigned long end)
{
	struct acpi_madt_local_apic *processor = NULL;

	processor = (struct acpi_madt_local_apic *)header;

	if (BAD_MADT_ENTRY(processor, end))
		return -EINVAL;

	acpi_table_print_madt_entry(header);

	/* Record local apic id only when enabled */
	if (processor->lapic_flags & ACPI_MADT_ENABLED)
		x86_acpiid_to_apicid[processor->processor_id] = processor->id;

	/*
	 * We need to register disabled CPU as well to permit
	 * counting disabled CPUs. This allows us to size
	 * cpus_possible_map more accurately, to permit
	 * to not preallocating memory for all NR_CPUS
	 * when we use CPU hotplug.
	 */
	mp_register_lapic(processor->id,	/* APIC ID */
			  processor->lapic_flags & ACPI_MADT_ENABLED);	/* Enabled? */

	return 0;
}

static int __init
acpi_parse_lapic_addr_ovr(struct acpi_subtable_header * header,
			  const unsigned long end)
{
	struct acpi_madt_local_apic_override *lapic_addr_ovr = NULL;

	lapic_addr_ovr = (struct acpi_madt_local_apic_override *)header;

	if (BAD_MADT_ENTRY(lapic_addr_ovr, end))
		return -EINVAL;

	acpi_lapic_addr = lapic_addr_ovr->address;

	return 0;
}

static int __init
acpi_parse_lapic_nmi(struct acpi_subtable_header * header, const unsigned long end)
{
	struct acpi_madt_local_apic_nmi *lapic_nmi = NULL;

	lapic_nmi = (struct acpi_madt_local_apic_nmi *)header;

	if (BAD_MADT_ENTRY(lapic_nmi, end))
		return -EINVAL;

	acpi_table_print_madt_entry(header);

	if (lapic_nmi->lint != 1)
		printk(KERN_WARNING PREFIX "NMI not connected to LINT 1!\n");

	return 0;
}

#endif				/*CONFIG_X86_LOCAL_APIC */

#ifdef CONFIG_X86_IO_APIC

static int __init
acpi_parse_ioapic(struct acpi_subtable_header * header, const unsigned long end)
{
	struct acpi_madt_io_apic *ioapic = NULL;

	ioapic = (struct acpi_madt_io_apic *)header;

	if (BAD_MADT_ENTRY(ioapic, end))
		return -EINVAL;

	acpi_table_print_madt_entry(header);

	mp_register_ioapic(ioapic->id,
			   ioapic->address, ioapic->global_irq_base);

	return 0;
}

/*
 * Parse Interrupt Source Override for the ACPI SCI
 */
static void __init acpi_sci_ioapic_setup(u32 gsi, u16 polarity, u16 trigger)
{
	if (trigger == 0)	/* compatible SCI trigger is level */
		trigger = 3;

	if (polarity == 0)	/* compatible SCI polarity is low */
		polarity = 3;

	/* Command-line over-ride via acpi_sci= */
	if (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)
		trigger = (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2;

	if (acpi_sci_flags & ACPI_MADT_POLARITY_MASK)
		polarity = acpi_sci_flags & ACPI_MADT_POLARITY_MASK;

	/*
	 * mp_config_acpi_legacy_irqs() already setup IRQs < 16
	 * If GSI is < 16, this will update its flags,
	 * else it will create a new mp_irqs[] entry.
	 */
	mp_override_legacy_irq(gsi, polarity, trigger, gsi);

	/*
	 * stash over-ride to indicate we've been here
	 * and for later update of acpi_gbl_FADT
	 */
	acpi_sci_override_gsi = gsi;
	return;
}

static int __init
acpi_parse_int_src_ovr(struct acpi_subtable_header * header,
		       const unsigned long end)
{
	struct acpi_madt_interrupt_override *intsrc = NULL;

	intsrc = (struct acpi_madt_interrupt_override *)header;

	if (BAD_MADT_ENTRY(intsrc, end))
		return -EINVAL;

	acpi_table_print_madt_entry(header);

	if (intsrc->source_irq == acpi_gbl_FADT.sci_interrupt) {
		acpi_sci_ioapic_setup(intsrc->global_irq,
				      intsrc->inti_flags & ACPI_MADT_POLARITY_MASK,
				      (intsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
		return 0;
	}

	if (acpi_skip_timer_override &&
	    intsrc->source_irq == 0 && intsrc->global_irq == 2) {
		printk(PREFIX "BIOS IRQ0 pin2 override ignored.\n");
		return 0;
	}

	mp_override_legacy_irq(intsrc->source_irq,
				intsrc->inti_flags & ACPI_MADT_POLARITY_MASK,
				(intsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2,
				intsrc->global_irq);

	return 0;
}

static int __init
acpi_parse_nmi_src(struct acpi_subtable_header * header, const unsigned long end)
{
	struct acpi_madt_nmi_source *nmi_src = NULL;

	nmi_src = (struct acpi_madt_nmi_source *)header;

	if (BAD_MADT_ENTRY(nmi_src, end))
		return -EINVAL;

	acpi_table_print_madt_entry(header);

	/* TBD: Support nimsrc entries? */

	return 0;
}

#endif				/* CONFIG_X86_IO_APIC */

/*
 * acpi_pic_sci_set_trigger()
 *
 * use ELCR to set PIC-mode trigger type for SCI
 *
 * If a PIC-mode SCI is not recognized or gives spurious IRQ7's
 * it may require Edge Trigger -- use "acpi_sci=edge"
 *
 * Port 0x4d0-4d1 are ECLR1 and ECLR2, the Edge/Level Control Registers
 * for the 8259 PIC.  bit[n] = 1 means irq[n] is Level, otherwise Edge.
 * ECLR1 is IRQ's 0-7 (IRQ 0, 1, 2 must be 0)
 * ECLR2 is IRQ's 8-15 (IRQ 8, 13 must be 0)
 */

void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger)
{
	unsigned int mask = 1 << irq;
	unsigned int old, new;

	/* Real old ELCR mask */
	old = inb(0x4d0) | (inb(0x4d1) << 8);

	/*
	 * If we use ACPI to set PCI irq's, then we should clear ELCR
	 * since we will set it correctly as we enable the PCI irq
	 * routing.
	 */
	new = acpi_noirq ? old : 0;

	/*
	 * Update SCI information in the ELCR, it isn't in the PCI
	 * routing tables..
	 */
	switch (trigger) {
	case 1:		/* Edge - clear */
		new &= ~mask;
		break;
	case 3:		/* Level - set */
		new |= mask;
		break;
	}

	if (old == new)
		return;

	printk(PREFIX "setting ELCR to %04x (from %04x)\n", new, old);
	outb(new, 0x4d0);
	outb(new >> 8, 0x4d1);
}

int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
{
	*irq = gsi;
	return 0;
}

/*
 * success: return IRQ number (>=0)
 * failure: return < 0
 */
int acpi_register_gsi(u32 gsi, int triggering, int polarity)
{
	unsigned int irq;
	unsigned int plat_gsi = gsi;

#ifdef CONFIG_PCI
	/*
	 * Make sure all (legacy) PCI IRQs are set as level-triggered.
	 */
	if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) {
		extern void eisa_set_level_irq(unsigned int irq);

		if (triggering == ACPI_LEVEL_SENSITIVE)
			eisa_set_level_irq(gsi);
	}
#endif

#ifdef CONFIG_X86_IO_APIC
	if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC) {
		plat_gsi = mp_register_gsi(gsi, triggering, polarity);
	}
#endif
	acpi_gsi_to_irq(plat_gsi, &irq);
	return irq;
}

EXPORT_SYMBOL(acpi_register_gsi);

/*
 *  ACPI based hotplug support for CPU
 */
#ifdef CONFIG_ACPI_HOTPLUG_CPU
int acpi_map_lsapic(acpi_handle handle, int *pcpu)
{
	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;
	struct acpi_madt_local_apic *lapic;
	cpumask_t tmp_map, new_map;
	u8 physid;
	int cpu;

	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
		return -EINVAL;

	if (!buffer.length || !buffer.pointer)
		return -EINVAL;

	obj = buffer.pointer;
	if (obj->type != ACPI_TYPE_BUFFER ||
	    obj->buffer.length < sizeof(*lapic)) {
		kfree(buffer.pointer);
		return -EINVAL;
	}

	lapic = (struct acpi_madt_local_apic *)obj->buffer.pointer;

	if (lapic->header.type != ACPI_MADT_TYPE_LOCAL_APIC ||
	    !(lapic->lapic_flags & ACPI_MADT_ENABLED)) {
		kfree(buffer.pointer);
		return -EINVAL;
	}

	physid = lapic->id;

	kfree(buffer.pointer);
	buffer.length = ACPI_ALLOCATE_BUFFER;
	buffer.pointer = NULL;

	tmp_map = cpu_present_map;
	mp_register_lapic(physid, lapic->lapic_flags & ACPI_MADT_ENABLED);

	/*
	 * If mp_register_lapic successfully generates a new logical cpu
	 * number, then the following will get us exactly what was mapped
	 */
	cpus_andnot(new_map, cpu_present_map, tmp_map);
	if (cpus_empty(new_map)) {
		printk ("Unable to map lapic to logical cpu number\n");
		return -EINVAL;
	}

	cpu = first_cpu(new_map);

	*pcpu = cpu;
	return 0;
}

EXPORT_SYMBOL(acpi_map_lsapic);

int acpi_unmap_lsapic(int cpu)
{
	int i;

	for_each_possible_cpu(i) {
		if (x86_acpiid_to_apicid[i] == x86_cpu_to_apicid[cpu]) {
			x86_acpiid_to_apicid[i] = -1;
			break;
		}
	}
	x86_cpu_to_apicid[cpu] = -1;
	cpu_clear(cpu, cpu_present_map);
	num_processors--;

	return (0);
}

EXPORT_SYMBOL(acpi_unmap_lsapic);
#endif				/* CONFIG_ACPI_HOTPLUG_CPU */

int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base)
{
	/* TBD */
	return -EINVAL;
}

EXPORT_SYMBOL(acpi_register_ioapic);

int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base)
{
	/* TBD */
	return -EINVAL;
}

EXPORT_SYMBOL(acpi_unregister_ioapic);

static unsigned long __init
acpi_scan_rsdp(unsigned long start, unsigned long length)
{
	unsigned long offset = 0;
	unsigned long sig_len = sizeof("RSD PTR ") - 1;

	/*
	 * Scan all 16-byte boundaries of the physical memory region for the
	 * RSDP signature.
	 */
	for (offset = 0; offset < length; offset += 16) {
		if (strncmp((char *)(phys_to_virt(start) + offset), "RSD PTR ", sig_len))
			continue;
		return (start + offset);
	}

	return 0;
}

static int __init acpi_parse_sbf(struct acpi_table_header *table)
{
	struct acpi_table_boot *sb;

	sb = (struct acpi_table_boot *)table;
	if (!sb) {
		printk(KERN_WARNING PREFIX "Unable to map SBF\n");
		return -ENODEV;
	}

	sbf_port = sb->cmos_index;	/* Save CMOS port */

	return 0;
}

#ifdef CONFIG_HPET_TIMER

static int __init acpi_parse_hpet(struct acpi_table_header *table)
{
	struct acpi_table_hpet *hpet_tbl;
	struct resource *hpet_res;
	resource_size_t res_start;

	hpet_tbl = (struct acpi_table_hpet *)table;
	if (!hpet_tbl) {
		printk(KERN_WARNING PREFIX "Unable to map HPET\n");
		return -ENODEV;
	}

	if (hpet_tbl->address.space_id != ACPI_SPACE_MEM) {
		printk(KERN_WARNING PREFIX "HPET timers must be located in "
		       "memory.\n");
		return -1;
	}

#define HPET_RESOURCE_NAME_SIZE 9
	hpet_res = alloc_bootmem(sizeof(*hpet_res) + HPET_RESOURCE_NAME_SIZE);
	if (hpet_res) {
		memset(hpet_res, 0, sizeof(*hpet_res));
		hpet_res->name = (void *)&hpet_res[1];
		hpet_res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
		snprintf((char *)hpet_res->name, HPET_RESOURCE_NAME_SIZE,
			 "HPET %u", hpet_tbl->sequence);
		hpet_res->end = (1 * 1024) - 1;
	}

#ifdef CONFIG_X86_64
	vxtime.hpet_address = hpet_tbl->address.address;

	printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
		hpet_tbl->id, vxtime.hpet_address);

	res_start = vxtime.hpet_address;
#else                          /* X86 */
	{
		extern unsigned long hpet_address;

		hpet_address = hpet_tbl->address.address;
		printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
			hpet_tbl->id, hpet_address);

		res_start = hpet_address;
	}
#endif                         /* X86 */

	if (hpet_res) {
		hpet_res->start = res_start;
		hpet_res->end += res_start;
		insert_resource(&iomem_resource, hpet_res);
	}

	return 0;
}
#else
#define	acpi_parse_hpet	NULL
#endif

#ifdef CONFIG_X86_PM_TIMER
extern u32 pmtmr_ioport;
#endif

static int __init acpi_parse_fadt(struct acpi_table_header *table)
{

#ifdef CONFIG_X86_PM_TIMER
	/* detect the location of the ACPI PM Timer */
	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) {
		/* FADT rev. 2 */
		if (acpi_gbl_FADT.xpm_timer_block.space_id !=
		    ACPI_ADR_SPACE_SYSTEM_IO)
			return 0;

		pmtmr_ioport = acpi_gbl_FADT.xpm_timer_block.address;
		/*
		 * "X" fields are optional extensions to the original V1.0
		 * fields, so we must selectively expand V1.0 fields if the
		 * corresponding X field is zero.
	 	 */
		if (!pmtmr_ioport)
			pmtmr_ioport = acpi_gbl_FADT.pm_timer_block;
	} else {
		/* FADT rev. 1 */
		pmtmr_ioport = acpi_gbl_FADT.pm_timer_block;
	}
	if (pmtmr_ioport)
		printk(KERN_INFO PREFIX "PM-Timer IO Port: %#x\n",
		       pmtmr_ioport);
#endif
	return 0;
}

unsigned long __init acpi_find_rsdp(void)
{
	unsigned long rsdp_phys = 0;

	if (efi_enabled) {
		if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
			return efi.acpi20;
		else if (efi.acpi != EFI_INVALID_TABLE_ADDR)
			return efi.acpi;
	}
	/*
	 * Scan memory looking for the RSDP signature. First search EBDA (low
	 * memory) paragraphs and then search upper memory (E0000-FFFFF).
	 */
	rsdp_phys = acpi_scan_rsdp(0, 0x400);
	if (!rsdp_phys)
		rsdp_phys = acpi_scan_rsdp(0xE0000, 0x20000);

	return rsdp_phys;
}

#ifdef	CONFIG_X86_LOCAL_APIC
/*
 * Parse LAPIC entries in MADT
 * returns 0 on success, < 0 on error
 */
static int __init acpi_parse_madt_lapic_entries(void)
{
	int count;

	if (!cpu_has_apic)
		return -ENODEV;

	/*
	 * Note that the LAPIC address is obtained from the MADT (32-bit value)
	 * and (optionally) overriden by a LAPIC_ADDR_OVR entry (64-bit value).
	 */

	count =
	    acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE,
				  acpi_parse_lapic_addr_ovr, 0);
	if (count < 0) {
		printk(KERN_ERR PREFIX
		       "Error parsing LAPIC address override entry\n");
		return count;
	}

	mp_register_lapic_address(acpi_lapic_addr);

	count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC, acpi_parse_lapic,
				      MAX_APICS);
	if (!count) {
		printk(KERN_ERR PREFIX "No LAPIC entries present\n");
		/* TBD: Cleanup to allow fallback to MPS */
		return -ENODEV;
	} else if (count < 0) {
		printk(KERN_ERR PREFIX "Error parsing LAPIC entry\n");
		/* TBD: Cleanup to allow fallback to MPS */
		return count;
	}

	count =
	    acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_NMI, acpi_parse_lapic_nmi, 0);
	if (count < 0) {
		printk(KERN_ERR PREFIX "Error parsing LAPIC NMI entry\n");
		/* TBD: Cleanup to allow fallback to MPS */
		return count;
	}
	return 0;
}
#endif				/* CONFIG_X86_LOCAL_APIC */

#ifdef	CONFIG_X86_IO_APIC
/*
 * Parse IOAPIC related entries in MADT
 * returns 0 on success, < 0 on error
 */
static int __init acpi_parse_madt_ioapic_entries(void)
{
	int count;

	/*
	 * ACPI interpreter is required to complete interrupt setup,
	 * so if it is off, don't enumerate the io-apics with ACPI.
	 * If MPS is present, it will handle them,
	 * otherwise the system will stay in PIC mode
	 */
	if (acpi_disabled || acpi_noirq) {
		return -ENODEV;
	}

	if (!cpu_has_apic)
		return -ENODEV;

	/*
	 * if "noapic" boot option, don't look for IO-APICs
	 */
	if (skip_ioapic_setup) {
		printk(KERN_INFO PREFIX "Skipping IOAPIC probe "
		       "due to 'noapic' option.\n");
		return -ENODEV;
	}

	count =
	    acpi_table_parse_madt(ACPI_MADT_TYPE_IO_APIC, acpi_parse_ioapic,
				  MAX_IO_APICS);
	if (!count) {
		printk(KERN_ERR PREFIX "No IOAPIC entries present\n");
		return -ENODEV;
	} else if (count < 0) {
		printk(KERN_ERR PREFIX "Error parsing IOAPIC entry\n");
		return count;
	}

	count =
	    acpi_table_parse_madt(ACPI_MADT_TYPE_INTERRUPT_OVERRIDE, acpi_parse_int_src_ovr,
				  NR_IRQ_VECTORS);
	if (count < 0) {
		printk(KERN_ERR PREFIX
		       "Error parsing interrupt source overrides entry\n");
		/* TBD: Cleanup to allow fallback to MPS */
		return count;
	}

	/*
	 * If BIOS did not supply an INT_SRC_OVR for the SCI
	 * pretend we got one so we can set the SCI flags.
	 */
	if (!acpi_sci_override_gsi)
		acpi_sci_ioapic_setup(acpi_gbl_FADT.sci_interrupt, 0, 0);

	/* Fill in identity legacy mapings where no override */
	mp_config_acpi_legacy_irqs();

	count =
	    acpi_table_parse_madt(ACPI_MADT_TYPE_NMI_SOURCE, acpi_parse_nmi_src,
				  NR_IRQ_VECTORS);
	if (count < 0) {
		printk(KERN_ERR PREFIX "Error parsing NMI SRC entry\n");
		/* TBD: Cleanup to allow fallback to MPS */
		return count;
	}

	return 0;
}
#else
static inline int acpi_parse_madt_ioapic_entries(void)
{
	return -1;
}
#endif	/* !CONFIG_X86_IO_APIC */

static void __init acpi_process_madt(void)
{
#ifdef CONFIG_X86_LOCAL_APIC
	int count, error;

	count = acpi_table_parse(ACPI_SIG_MADT, acpi_parse_madt);
	if (count >= 1) {

		/*
		 * Parse MADT LAPIC entries
		 */
		error = acpi_parse_madt_lapic_entries();
		if (!error) {
			acpi_lapic = 1;

#ifdef CONFIG_X86_GENERICARCH
			generic_bigsmp_probe();
#endif
			/*
			 * Parse MADT IO-APIC entries
			 */
			error = acpi_parse_madt_ioapic_entries();
			if (!error) {
				acpi_irq_model = ACPI_IRQ_MODEL_IOAPIC;
				acpi_irq_balance_set(NULL);
				acpi_ioapic = 1;

				smp_found_config = 1;
				clustered_apic_check();
			}
		}
		if (error == -EINVAL) {
			/*
			 * Dell Precision Workstation 410, 610 come here.
			 */
			printk(KERN_ERR PREFIX
			       "Invalid BIOS MADT, disabling ACPI\n");
			disable_acpi();
		}
	}
#endif
	return;
}

#ifdef __i386__

static int __init disable_acpi_irq(struct dmi_system_id *d)
{
	if (!acpi_force) {
		printk(KERN_NOTICE "%s detected: force use of acpi=noirq\n",
		       d->ident);
		acpi_noirq_set();
	}
	return 0;
}

static int __init disable_acpi_pci(struct dmi_system_id *d)
{
	if (!acpi_force) {
		printk(KERN_NOTICE "%s detected: force use of pci=noacpi\n",
		       d->ident);
		acpi_disable_pci();
	}
	return 0;
}

static int __init dmi_disable_acpi(struct dmi_system_id *d)
{
	if (!acpi_force) {
		printk(KERN_NOTICE "%s detected: acpi off\n", d->ident);
		disable_acpi();
	} else {
		printk(KERN_NOTICE
		       "Warning: DMI blacklist says broken, but acpi forced\n");
	}
	return 0;
}

/*
 * Limit ACPI to CPU enumeration for HT
 */
static int __init force_acpi_ht(struct dmi_system_id *d)
{
	if (!acpi_force) {
		printk(KERN_NOTICE "%s detected: force use of acpi=ht\n",
		       d->ident);
		disable_acpi();
		acpi_ht = 1;
	} else {
		printk(KERN_NOTICE
		       "Warning: acpi=force overrules DMI blacklist: acpi=ht\n");
	}
	return 0;
}

/*
 * If your system is blacklisted here, but you find that acpi=force
 * works for you, please contact acpi-devel@sourceforge.net
 */
static struct dmi_system_id __initdata acpi_dmi_table[] = {
	/*
	 * Boxes that need ACPI disabled
	 */
	{
	 .callback = dmi_disable_acpi,
	 .ident = "IBM Thinkpad",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
		     DMI_MATCH(DMI_BOARD_NAME, "2629H1G"),
		     },
	 },

	/*
	 * Boxes that need acpi=ht
	 */
	{
	 .callback = force_acpi_ht,
	 .ident = "FSC Primergy T850",
	 .matches = {
		     DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
		     DMI_MATCH(DMI_PRODUCT_NAME, "PRIMERGY T850"),
		     },
	 },
	{
	 .callback = force_acpi_ht,
	 .ident = "DELL GX240",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "Dell Computer Corporation"),
		     DMI_MATCH(DMI_BOARD_NAME, "OptiPlex GX240"),
		     },
	 },
	{
	 .callback = force_acpi_ht,
	 .ident = "HP VISUALIZE NT Workstation",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
		     DMI_MATCH(DMI_PRODUCT_NAME, "HP VISUALIZE NT Workstation"),
		     },
	 },
	{
	 .callback = force_acpi_ht,
	 .ident = "Compaq Workstation W8000",
	 .matches = {
		     DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
		     DMI_MATCH(DMI_PRODUCT_NAME, "Workstation W8000"),
		     },
	 },
	{
	 .callback = force_acpi_ht,
	 .ident = "ASUS P4B266",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
		     DMI_MATCH(DMI_BOARD_NAME, "P4B266"),
		     },
	 },
	{
	 .callback = force_acpi_ht,
	 .ident = "ASUS P2B-DS",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
		     DMI_MATCH(DMI_BOARD_NAME, "P2B-DS"),
		     },
	 },
	{
	 .callback = force_acpi_ht,
	 .ident = "ASUS CUR-DLS",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
		     DMI_MATCH(DMI_BOARD_NAME, "CUR-DLS"),
		     },
	 },
	{
	 .callback = force_acpi_ht,
	 .ident = "ABIT i440BX-W83977",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "ABIT <http://www.abit.com>"),
		     DMI_MATCH(DMI_BOARD_NAME, "i440BX-W83977 (BP6)"),
		     },
	 },
	{
	 .callback = force_acpi_ht,
	 .ident = "IBM Bladecenter",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
		     DMI_MATCH(DMI_BOARD_NAME, "IBM eServer BladeCenter HS20"),
		     },
	 },
	{
	 .callback = force_acpi_ht,
	 .ident = "IBM eServer xSeries 360",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
		     DMI_MATCH(DMI_BOARD_NAME, "eServer xSeries 360"),
		     },
	 },
	{
	 .callback = force_acpi_ht,
	 .ident = "IBM eserver xSeries 330",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
		     DMI_MATCH(DMI_BOARD_NAME, "eserver xSeries 330"),
		     },
	 },
	{
	 .callback = force_acpi_ht,
	 .ident = "IBM eserver xSeries 440",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
		     DMI_MATCH(DMI_PRODUCT_NAME, "eserver xSeries 440"),
		     },
	 },

	/*
	 * Boxes that need ACPI PCI IRQ routing disabled
	 */
	{
	 .callback = disable_acpi_irq,
	 .ident = "ASUS A7V",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC"),
		     DMI_MATCH(DMI_BOARD_NAME, "<A7V>"),
		     /* newer BIOS, Revision 1011, does work */
		     DMI_MATCH(DMI_BIOS_VERSION,
			       "ASUS A7V ACPI BIOS Revision 1007"),
		     },
	 },

	/*
	 * Boxes that need ACPI PCI IRQ routing and PCI scan disabled
	 */
	{			/* _BBN 0 bug */
	 .callback = disable_acpi_pci,
	 .ident = "ASUS PR-DLS",
	 .matches = {
		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
		     DMI_MATCH(DMI_BOARD_NAME, "PR-DLS"),
		     DMI_MATCH(DMI_BIOS_VERSION,
			       "ASUS PR-DLS ACPI BIOS Revision 1010"),
		     DMI_MATCH(DMI_BIOS_DATE, "03/21/2003")
		     },
	 },
	{
	 .callback = disable_acpi_pci,
	 .ident = "Acer TravelMate 36x Laptop",
	 .matches = {
		     DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
		     DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 360"),
		     },
	 },
	{}
};

#endif				/* __i386__ */

/*
 * acpi_boot_table_init() and acpi_boot_init()
 *  called from setup_arch(), always.
 *	1. checksums all tables
 *	2. enumerates lapics
 *	3. enumerates io-apics
 *
 * acpi_table_init() is separate to allow reading SRAT without
 * other side effects.
 *
 * side effects of acpi_boot_init:
 *	acpi_lapic = 1 if LAPIC found
 *	acpi_ioapic = 1 if IOAPIC found
 *	if (acpi_lapic && acpi_ioapic) smp_found_config = 1;
 *	if acpi_blacklisted() acpi_disabled = 1;
 *	acpi_irq_model=...
 *	...
 *
 * return value: (currently ignored)
 *	0: success
 *	!0: failure
 */

int __init acpi_boot_table_init(void)
{
	int error;

#ifdef __i386__
	dmi_check_system(acpi_dmi_table);
#endif

	/*
	 * If acpi_disabled, bail out
	 * One exception: acpi=ht continues far enough to enumerate LAPICs
	 */
	if (acpi_disabled && !acpi_ht)
		return 1;

	/*
	 * Initialize the ACPI boot-time table parser.
	 */
	error = acpi_table_init();
	if (error) {
		disable_acpi();
		return error;
	}

	acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);

	/*
	 * blacklist may disable ACPI entirely
	 */
	error = acpi_blacklisted();
	if (error) {
		if (acpi_force) {
			printk(KERN_WARNING PREFIX "acpi=force override\n");
		} else {
			printk(KERN_WARNING PREFIX "Disabling ACPI support\n");
			disable_acpi();
			return error;
		}
	}

	return 0;
}

int __init acpi_boot_init(void)
{
	/*
	 * If acpi_disabled, bail out
	 * One exception: acpi=ht continues far enough to enumerate LAPICs
	 */
	if (acpi_disabled && !acpi_ht)
		return 1;

	acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);

	/*
	 * set sci_int and PM timer address
	 */
	acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt);

	/*
	 * Process the Multiple APIC Description Table (MADT), if present
	 */
	acpi_process_madt();

	acpi_table_parse(ACPI_SIG_HPET, acpi_parse_hpet);

	return 0;
}

static int __init parse_acpi(char *arg)
{
	if (!arg)
		return -EINVAL;

	/* "acpi=off" disables both ACPI table parsing and interpreter */
	if (strcmp(arg, "off") == 0) {
		disable_acpi();
	}
	/* acpi=force to over-ride black-list */
	else if (strcmp(arg, "force") == 0) {
		acpi_force = 1;
		acpi_ht = 1;
		acpi_disabled = 0;
	}
	/* acpi=strict disables out-of-spec workarounds */
	else if (strcmp(arg, "strict") == 0) {
		acpi_strict = 1;
	}
	/* Limit ACPI just to boot-time to enable HT */
	else if (strcmp(arg, "ht") == 0) {
		if (!acpi_force)
			disable_acpi();
		acpi_ht = 1;
	}
	/* "acpi=noirq" disables ACPI interrupt routing */
	else if (strcmp(arg, "noirq") == 0) {
		acpi_noirq_set();
	} else {
		/* Core will printk when we return error. */
		return -EINVAL;
	}
	return 0;
}
early_param("acpi", parse_acpi);

/* FIXME: Using pci= for an ACPI parameter is a travesty. */
static int __init parse_pci(char *arg)
{
	if (arg && strcmp(arg, "noacpi") == 0)
		acpi_disable_pci();
	return 0;
}
early_param("pci", parse_pci);

#ifdef CONFIG_X86_IO_APIC
static int __init parse_acpi_skip_timer_override(char *arg)
{
	acpi_skip_timer_override = 1;
	return 0;
}
early_param("acpi_skip_timer_override", parse_acpi_skip_timer_override);

static int __init parse_acpi_use_timer_override(char *arg)
{
	acpi_use_timer_override = 1;
	return 0;
}
early_param("acpi_use_timer_override", parse_acpi_use_timer_override);
#endif /* CONFIG_X86_IO_APIC */

static int __init setup_acpi_sci(char *s)
{
	if (!s)
		return -EINVAL;
	if (!strcmp(s, "edge"))
		acpi_sci_flags =  ACPI_MADT_TRIGGER_EDGE |
			(acpi_sci_flags & ~ACPI_MADT_TRIGGER_MASK);
	else if (!strcmp(s, "level"))
		acpi_sci_flags = ACPI_MADT_TRIGGER_LEVEL |
			(acpi_sci_flags & ~ACPI_MADT_TRIGGER_MASK);
	else if (!strcmp(s, "high"))
		acpi_sci_flags = ACPI_MADT_POLARITY_ACTIVE_HIGH |
			(acpi_sci_flags & ~ACPI_MADT_POLARITY_MASK);
	else if (!strcmp(s, "low"))
		acpi_sci_flags = ACPI_MADT_POLARITY_ACTIVE_LOW |
			(acpi_sci_flags & ~ACPI_MADT_POLARITY_MASK);
	else
		return -EINVAL;
	return 0;
}
early_param("acpi_sci", setup_acpi_sci);

int __acpi_acquire_global_lock(unsigned int *lock)
{
	unsigned int old, new, val;
	do {
		old = *lock;
		new = (((old & ~0x3) + 2) + ((old >> 1) & 0x1));
		val = cmpxchg(lock, old, new);
	} while (unlikely (val != old));
	return (new < 3) ? -1 : 0;
}

int __acpi_release_global_lock(unsigned int *lock)
{
	unsigned int old, new, val;
	do {
		old = *lock;
		new = old & ~0x3;
		val = cmpxchg(lock, old, new);
	} while (unlikely (val != old));
	return old & 0x1;
}