xref: /openbmc/linux/arch/x86/kernel/acpi/boot.c (revision 78c99ba1)
1 /*
2  *  boot.c - Architecture-Specific Low-Level ACPI Boot Support
3  *
4  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
5  *  Copyright (C) 2001 Jun Nakajima <jun.nakajima@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
12  *  (at your option) any later version.
13  *
14  *  This program is distributed in the hope that it will be useful,
15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  *  GNU General Public License for more details.
18  *
19  *  You should have received a copy of the GNU General Public License
20  *  along with this program; if not, write to the Free Software
21  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
22  *
23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
24  */
25 
26 #include <linux/init.h>
27 #include <linux/acpi.h>
28 #include <linux/acpi_pmtmr.h>
29 #include <linux/efi.h>
30 #include <linux/cpumask.h>
31 #include <linux/module.h>
32 #include <linux/dmi.h>
33 #include <linux/irq.h>
34 #include <linux/bootmem.h>
35 #include <linux/ioport.h>
36 #include <linux/pci.h>
37 
38 #include <asm/pgtable.h>
39 #include <asm/io_apic.h>
40 #include <asm/apic.h>
41 #include <asm/io.h>
42 #include <asm/mpspec.h>
43 #include <asm/smp.h>
44 
45 static int __initdata acpi_force = 0;
46 u32 acpi_rsdt_forced;
47 #ifdef	CONFIG_ACPI
48 int acpi_disabled = 0;
49 #else
50 int acpi_disabled = 1;
51 #endif
52 EXPORT_SYMBOL(acpi_disabled);
53 
54 #ifdef	CONFIG_X86_64
55 # include <asm/proto.h>
56 #endif				/* X86 */
57 
58 #define BAD_MADT_ENTRY(entry, end) (					    \
59 		(!entry) || (unsigned long)entry + sizeof(*entry) > end ||  \
60 		((struct acpi_subtable_header *)entry)->length < sizeof(*entry))
61 
62 #define PREFIX			"ACPI: "
63 
64 int acpi_noirq;				/* skip ACPI IRQ initialization */
65 int acpi_pci_disabled;		/* skip ACPI PCI scan and IRQ initialization */
66 EXPORT_SYMBOL(acpi_pci_disabled);
67 int acpi_ht __initdata = 1;	/* enable HT */
68 
69 int acpi_lapic;
70 int acpi_ioapic;
71 int acpi_strict;
72 
73 u8 acpi_sci_flags __initdata;
74 int acpi_sci_override_gsi __initdata;
75 int acpi_skip_timer_override __initdata;
76 int acpi_use_timer_override __initdata;
77 
78 #ifdef CONFIG_X86_LOCAL_APIC
79 static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;
80 #endif
81 
82 #ifndef __HAVE_ARCH_CMPXCHG
83 #warning ACPI uses CMPXCHG, i486 and later hardware
84 #endif
85 
86 /* --------------------------------------------------------------------------
87                               Boot-time Configuration
88    -------------------------------------------------------------------------- */
89 
90 /*
91  * The default interrupt routing model is PIC (8259).  This gets
92  * overridden if IOAPICs are enumerated (below).
93  */
94 enum acpi_irq_model_id acpi_irq_model = ACPI_IRQ_MODEL_PIC;
95 
96 
97 /*
98  * Temporarily use the virtual area starting from FIX_IO_APIC_BASE_END,
99  * to map the target physical address. The problem is that set_fixmap()
100  * provides a single page, and it is possible that the page is not
101  * sufficient.
102  * By using this area, we can map up to MAX_IO_APICS pages temporarily,
103  * i.e. until the next __va_range() call.
104  *
105  * Important Safety Note:  The fixed I/O APIC page numbers are *subtracted*
106  * from the fixed base.  That's why we start at FIX_IO_APIC_BASE_END and
107  * count idx down while incrementing the phys address.
108  */
109 char *__init __acpi_map_table(unsigned long phys, unsigned long size)
110 {
111 
112 	if (!phys || !size)
113 		return NULL;
114 
115 	return early_ioremap(phys, size);
116 }
117 void __init __acpi_unmap_table(char *map, unsigned long size)
118 {
119 	if (!map || !size)
120 		return;
121 
122 	early_iounmap(map, size);
123 }
124 
125 #ifdef CONFIG_PCI_MMCONFIG
126 
127 static int acpi_mcfg_64bit_base_addr __initdata = FALSE;
128 
129 /* The physical address of the MMCONFIG aperture.  Set from ACPI tables. */
130 struct acpi_mcfg_allocation *pci_mmcfg_config;
131 int pci_mmcfg_config_num;
132 
133 static int __init acpi_mcfg_oem_check(struct acpi_table_mcfg *mcfg)
134 {
135 	if (!strcmp(mcfg->header.oem_id, "SGI"))
136 		acpi_mcfg_64bit_base_addr = TRUE;
137 
138 	return 0;
139 }
140 
141 int __init acpi_parse_mcfg(struct acpi_table_header *header)
142 {
143 	struct acpi_table_mcfg *mcfg;
144 	unsigned long i;
145 	int config_size;
146 
147 	if (!header)
148 		return -EINVAL;
149 
150 	mcfg = (struct acpi_table_mcfg *)header;
151 
152 	/* how many config structures do we have */
153 	pci_mmcfg_config_num = 0;
154 	i = header->length - sizeof(struct acpi_table_mcfg);
155 	while (i >= sizeof(struct acpi_mcfg_allocation)) {
156 		++pci_mmcfg_config_num;
157 		i -= sizeof(struct acpi_mcfg_allocation);
158 	};
159 	if (pci_mmcfg_config_num == 0) {
160 		printk(KERN_ERR PREFIX "MMCONFIG has no entries\n");
161 		return -ENODEV;
162 	}
163 
164 	config_size = pci_mmcfg_config_num * sizeof(*pci_mmcfg_config);
165 	pci_mmcfg_config = kmalloc(config_size, GFP_KERNEL);
166 	if (!pci_mmcfg_config) {
167 		printk(KERN_WARNING PREFIX
168 		       "No memory for MCFG config tables\n");
169 		return -ENOMEM;
170 	}
171 
172 	memcpy(pci_mmcfg_config, &mcfg[1], config_size);
173 
174 	acpi_mcfg_oem_check(mcfg);
175 
176 	for (i = 0; i < pci_mmcfg_config_num; ++i) {
177 		if ((pci_mmcfg_config[i].address > 0xFFFFFFFF) &&
178 		    !acpi_mcfg_64bit_base_addr) {
179 			printk(KERN_ERR PREFIX
180 			       "MMCONFIG not in low 4GB of memory\n");
181 			kfree(pci_mmcfg_config);
182 			pci_mmcfg_config_num = 0;
183 			return -ENODEV;
184 		}
185 	}
186 
187 	return 0;
188 }
189 #endif				/* CONFIG_PCI_MMCONFIG */
190 
191 #ifdef CONFIG_X86_LOCAL_APIC
192 static int __init acpi_parse_madt(struct acpi_table_header *table)
193 {
194 	struct acpi_table_madt *madt = NULL;
195 
196 	if (!cpu_has_apic)
197 		return -EINVAL;
198 
199 	madt = (struct acpi_table_madt *)table;
200 	if (!madt) {
201 		printk(KERN_WARNING PREFIX "Unable to map MADT\n");
202 		return -ENODEV;
203 	}
204 
205 	if (madt->address) {
206 		acpi_lapic_addr = (u64) madt->address;
207 
208 		printk(KERN_DEBUG PREFIX "Local APIC address 0x%08x\n",
209 		       madt->address);
210 	}
211 
212 	default_acpi_madt_oem_check(madt->header.oem_id,
213 				    madt->header.oem_table_id);
214 
215 	return 0;
216 }
217 
218 static void __cpuinit acpi_register_lapic(int id, u8 enabled)
219 {
220 	unsigned int ver = 0;
221 
222 	if (!enabled) {
223 		++disabled_cpus;
224 		return;
225 	}
226 
227 	if (boot_cpu_physical_apicid != -1U)
228 		ver = apic_version[boot_cpu_physical_apicid];
229 
230 	generic_processor_info(id, ver);
231 }
232 
233 static int __init
234 acpi_parse_x2apic(struct acpi_subtable_header *header, const unsigned long end)
235 {
236 	struct acpi_madt_local_x2apic *processor = NULL;
237 
238 	processor = (struct acpi_madt_local_x2apic *)header;
239 
240 	if (BAD_MADT_ENTRY(processor, end))
241 		return -EINVAL;
242 
243 	acpi_table_print_madt_entry(header);
244 
245 #ifdef CONFIG_X86_X2APIC
246 	/*
247 	 * We need to register disabled CPU as well to permit
248 	 * counting disabled CPUs. This allows us to size
249 	 * cpus_possible_map more accurately, to permit
250 	 * to not preallocating memory for all NR_CPUS
251 	 * when we use CPU hotplug.
252 	 */
253 	acpi_register_lapic(processor->local_apic_id,	/* APIC ID */
254 			    processor->lapic_flags & ACPI_MADT_ENABLED);
255 #else
256 	printk(KERN_WARNING PREFIX "x2apic entry ignored\n");
257 #endif
258 
259 	return 0;
260 }
261 
262 static int __init
263 acpi_parse_lapic(struct acpi_subtable_header * header, const unsigned long end)
264 {
265 	struct acpi_madt_local_apic *processor = NULL;
266 
267 	processor = (struct acpi_madt_local_apic *)header;
268 
269 	if (BAD_MADT_ENTRY(processor, end))
270 		return -EINVAL;
271 
272 	acpi_table_print_madt_entry(header);
273 
274 	/*
275 	 * We need to register disabled CPU as well to permit
276 	 * counting disabled CPUs. This allows us to size
277 	 * cpus_possible_map more accurately, to permit
278 	 * to not preallocating memory for all NR_CPUS
279 	 * when we use CPU hotplug.
280 	 */
281 	acpi_register_lapic(processor->id,	/* APIC ID */
282 			    processor->lapic_flags & ACPI_MADT_ENABLED);
283 
284 	return 0;
285 }
286 
287 static int __init
288 acpi_parse_sapic(struct acpi_subtable_header *header, const unsigned long end)
289 {
290 	struct acpi_madt_local_sapic *processor = NULL;
291 
292 	processor = (struct acpi_madt_local_sapic *)header;
293 
294 	if (BAD_MADT_ENTRY(processor, end))
295 		return -EINVAL;
296 
297 	acpi_table_print_madt_entry(header);
298 
299 	acpi_register_lapic((processor->id << 8) | processor->eid,/* APIC ID */
300 			    processor->lapic_flags & ACPI_MADT_ENABLED);
301 
302 	return 0;
303 }
304 
305 static int __init
306 acpi_parse_lapic_addr_ovr(struct acpi_subtable_header * header,
307 			  const unsigned long end)
308 {
309 	struct acpi_madt_local_apic_override *lapic_addr_ovr = NULL;
310 
311 	lapic_addr_ovr = (struct acpi_madt_local_apic_override *)header;
312 
313 	if (BAD_MADT_ENTRY(lapic_addr_ovr, end))
314 		return -EINVAL;
315 
316 	acpi_lapic_addr = lapic_addr_ovr->address;
317 
318 	return 0;
319 }
320 
321 static int __init
322 acpi_parse_x2apic_nmi(struct acpi_subtable_header *header,
323 		      const unsigned long end)
324 {
325 	struct acpi_madt_local_x2apic_nmi *x2apic_nmi = NULL;
326 
327 	x2apic_nmi = (struct acpi_madt_local_x2apic_nmi *)header;
328 
329 	if (BAD_MADT_ENTRY(x2apic_nmi, end))
330 		return -EINVAL;
331 
332 	acpi_table_print_madt_entry(header);
333 
334 	if (x2apic_nmi->lint != 1)
335 		printk(KERN_WARNING PREFIX "NMI not connected to LINT 1!\n");
336 
337 	return 0;
338 }
339 
340 static int __init
341 acpi_parse_lapic_nmi(struct acpi_subtable_header * header, const unsigned long end)
342 {
343 	struct acpi_madt_local_apic_nmi *lapic_nmi = NULL;
344 
345 	lapic_nmi = (struct acpi_madt_local_apic_nmi *)header;
346 
347 	if (BAD_MADT_ENTRY(lapic_nmi, end))
348 		return -EINVAL;
349 
350 	acpi_table_print_madt_entry(header);
351 
352 	if (lapic_nmi->lint != 1)
353 		printk(KERN_WARNING PREFIX "NMI not connected to LINT 1!\n");
354 
355 	return 0;
356 }
357 
358 #endif				/*CONFIG_X86_LOCAL_APIC */
359 
360 #ifdef CONFIG_X86_IO_APIC
361 
362 static int __init
363 acpi_parse_ioapic(struct acpi_subtable_header * header, const unsigned long end)
364 {
365 	struct acpi_madt_io_apic *ioapic = NULL;
366 
367 	ioapic = (struct acpi_madt_io_apic *)header;
368 
369 	if (BAD_MADT_ENTRY(ioapic, end))
370 		return -EINVAL;
371 
372 	acpi_table_print_madt_entry(header);
373 
374 	mp_register_ioapic(ioapic->id,
375 			   ioapic->address, ioapic->global_irq_base);
376 
377 	return 0;
378 }
379 
380 /*
381  * Parse Interrupt Source Override for the ACPI SCI
382  */
383 static void __init acpi_sci_ioapic_setup(u32 gsi, u16 polarity, u16 trigger)
384 {
385 	if (trigger == 0)	/* compatible SCI trigger is level */
386 		trigger = 3;
387 
388 	if (polarity == 0)	/* compatible SCI polarity is low */
389 		polarity = 3;
390 
391 	/* Command-line over-ride via acpi_sci= */
392 	if (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)
393 		trigger = (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
394 
395 	if (acpi_sci_flags & ACPI_MADT_POLARITY_MASK)
396 		polarity = acpi_sci_flags & ACPI_MADT_POLARITY_MASK;
397 
398 	/*
399 	 * mp_config_acpi_legacy_irqs() already setup IRQs < 16
400 	 * If GSI is < 16, this will update its flags,
401 	 * else it will create a new mp_irqs[] entry.
402 	 */
403 	mp_override_legacy_irq(gsi, polarity, trigger, gsi);
404 
405 	/*
406 	 * stash over-ride to indicate we've been here
407 	 * and for later update of acpi_gbl_FADT
408 	 */
409 	acpi_sci_override_gsi = gsi;
410 	return;
411 }
412 
413 static int __init
414 acpi_parse_int_src_ovr(struct acpi_subtable_header * header,
415 		       const unsigned long end)
416 {
417 	struct acpi_madt_interrupt_override *intsrc = NULL;
418 
419 	intsrc = (struct acpi_madt_interrupt_override *)header;
420 
421 	if (BAD_MADT_ENTRY(intsrc, end))
422 		return -EINVAL;
423 
424 	acpi_table_print_madt_entry(header);
425 
426 	if (intsrc->source_irq == acpi_gbl_FADT.sci_interrupt) {
427 		acpi_sci_ioapic_setup(intsrc->global_irq,
428 				      intsrc->inti_flags & ACPI_MADT_POLARITY_MASK,
429 				      (intsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
430 		return 0;
431 	}
432 
433 	if (acpi_skip_timer_override &&
434 	    intsrc->source_irq == 0 && intsrc->global_irq == 2) {
435 		printk(PREFIX "BIOS IRQ0 pin2 override ignored.\n");
436 		return 0;
437 	}
438 
439 	mp_override_legacy_irq(intsrc->source_irq,
440 				intsrc->inti_flags & ACPI_MADT_POLARITY_MASK,
441 				(intsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2,
442 				intsrc->global_irq);
443 
444 	return 0;
445 }
446 
447 static int __init
448 acpi_parse_nmi_src(struct acpi_subtable_header * header, const unsigned long end)
449 {
450 	struct acpi_madt_nmi_source *nmi_src = NULL;
451 
452 	nmi_src = (struct acpi_madt_nmi_source *)header;
453 
454 	if (BAD_MADT_ENTRY(nmi_src, end))
455 		return -EINVAL;
456 
457 	acpi_table_print_madt_entry(header);
458 
459 	/* TBD: Support nimsrc entries? */
460 
461 	return 0;
462 }
463 
464 #endif				/* CONFIG_X86_IO_APIC */
465 
466 /*
467  * acpi_pic_sci_set_trigger()
468  *
469  * use ELCR to set PIC-mode trigger type for SCI
470  *
471  * If a PIC-mode SCI is not recognized or gives spurious IRQ7's
472  * it may require Edge Trigger -- use "acpi_sci=edge"
473  *
474  * Port 0x4d0-4d1 are ECLR1 and ECLR2, the Edge/Level Control Registers
475  * for the 8259 PIC.  bit[n] = 1 means irq[n] is Level, otherwise Edge.
476  * ECLR1 is IRQs 0-7 (IRQ 0, 1, 2 must be 0)
477  * ECLR2 is IRQs 8-15 (IRQ 8, 13 must be 0)
478  */
479 
480 void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger)
481 {
482 	unsigned int mask = 1 << irq;
483 	unsigned int old, new;
484 
485 	/* Real old ELCR mask */
486 	old = inb(0x4d0) | (inb(0x4d1) << 8);
487 
488 	/*
489 	 * If we use ACPI to set PCI IRQs, then we should clear ELCR
490 	 * since we will set it correctly as we enable the PCI irq
491 	 * routing.
492 	 */
493 	new = acpi_noirq ? old : 0;
494 
495 	/*
496 	 * Update SCI information in the ELCR, it isn't in the PCI
497 	 * routing tables..
498 	 */
499 	switch (trigger) {
500 	case 1:		/* Edge - clear */
501 		new &= ~mask;
502 		break;
503 	case 3:		/* Level - set */
504 		new |= mask;
505 		break;
506 	}
507 
508 	if (old == new)
509 		return;
510 
511 	printk(PREFIX "setting ELCR to %04x (from %04x)\n", new, old);
512 	outb(new, 0x4d0);
513 	outb(new >> 8, 0x4d1);
514 }
515 
516 int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
517 {
518 	*irq = gsi;
519 	return 0;
520 }
521 
522 /*
523  * success: return IRQ number (>=0)
524  * failure: return < 0
525  */
526 int acpi_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
527 {
528 	unsigned int irq;
529 	unsigned int plat_gsi = gsi;
530 
531 #ifdef CONFIG_PCI
532 	/*
533 	 * Make sure all (legacy) PCI IRQs are set as level-triggered.
534 	 */
535 	if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) {
536 		if (trigger == ACPI_LEVEL_SENSITIVE)
537 			eisa_set_level_irq(gsi);
538 	}
539 #endif
540 
541 #ifdef CONFIG_X86_IO_APIC
542 	if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC) {
543 		plat_gsi = mp_register_gsi(dev, gsi, trigger, polarity);
544 	}
545 #endif
546 	acpi_gsi_to_irq(plat_gsi, &irq);
547 	return irq;
548 }
549 
550 /*
551  *  ACPI based hotplug support for CPU
552  */
553 #ifdef CONFIG_ACPI_HOTPLUG_CPU
554 
555 static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int *pcpu)
556 {
557 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
558 	union acpi_object *obj;
559 	struct acpi_madt_local_apic *lapic;
560 	cpumask_var_t tmp_map, new_map;
561 	u8 physid;
562 	int cpu;
563 	int retval = -ENOMEM;
564 
565 	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
566 		return -EINVAL;
567 
568 	if (!buffer.length || !buffer.pointer)
569 		return -EINVAL;
570 
571 	obj = buffer.pointer;
572 	if (obj->type != ACPI_TYPE_BUFFER ||
573 	    obj->buffer.length < sizeof(*lapic)) {
574 		kfree(buffer.pointer);
575 		return -EINVAL;
576 	}
577 
578 	lapic = (struct acpi_madt_local_apic *)obj->buffer.pointer;
579 
580 	if (lapic->header.type != ACPI_MADT_TYPE_LOCAL_APIC ||
581 	    !(lapic->lapic_flags & ACPI_MADT_ENABLED)) {
582 		kfree(buffer.pointer);
583 		return -EINVAL;
584 	}
585 
586 	physid = lapic->id;
587 
588 	kfree(buffer.pointer);
589 	buffer.length = ACPI_ALLOCATE_BUFFER;
590 	buffer.pointer = NULL;
591 
592 	if (!alloc_cpumask_var(&tmp_map, GFP_KERNEL))
593 		goto out;
594 
595 	if (!alloc_cpumask_var(&new_map, GFP_KERNEL))
596 		goto free_tmp_map;
597 
598 	cpumask_copy(tmp_map, cpu_present_mask);
599 	acpi_register_lapic(physid, lapic->lapic_flags & ACPI_MADT_ENABLED);
600 
601 	/*
602 	 * If mp_register_lapic successfully generates a new logical cpu
603 	 * number, then the following will get us exactly what was mapped
604 	 */
605 	cpumask_andnot(new_map, cpu_present_mask, tmp_map);
606 	if (cpumask_empty(new_map)) {
607 		printk ("Unable to map lapic to logical cpu number\n");
608 		retval = -EINVAL;
609 		goto free_new_map;
610 	}
611 
612 	cpu = cpumask_first(new_map);
613 
614 	*pcpu = cpu;
615 	retval = 0;
616 
617 free_new_map:
618 	free_cpumask_var(new_map);
619 free_tmp_map:
620 	free_cpumask_var(tmp_map);
621 out:
622 	return retval;
623 }
624 
625 /* wrapper to silence section mismatch warning */
626 int __ref acpi_map_lsapic(acpi_handle handle, int *pcpu)
627 {
628 	return _acpi_map_lsapic(handle, pcpu);
629 }
630 EXPORT_SYMBOL(acpi_map_lsapic);
631 
632 int acpi_unmap_lsapic(int cpu)
633 {
634 	per_cpu(x86_cpu_to_apicid, cpu) = -1;
635 	set_cpu_present(cpu, false);
636 	num_processors--;
637 
638 	return (0);
639 }
640 
641 EXPORT_SYMBOL(acpi_unmap_lsapic);
642 #endif				/* CONFIG_ACPI_HOTPLUG_CPU */
643 
644 int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base)
645 {
646 	/* TBD */
647 	return -EINVAL;
648 }
649 
650 EXPORT_SYMBOL(acpi_register_ioapic);
651 
652 int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base)
653 {
654 	/* TBD */
655 	return -EINVAL;
656 }
657 
658 EXPORT_SYMBOL(acpi_unregister_ioapic);
659 
660 static int __init acpi_parse_sbf(struct acpi_table_header *table)
661 {
662 	struct acpi_table_boot *sb;
663 
664 	sb = (struct acpi_table_boot *)table;
665 	if (!sb) {
666 		printk(KERN_WARNING PREFIX "Unable to map SBF\n");
667 		return -ENODEV;
668 	}
669 
670 	sbf_port = sb->cmos_index;	/* Save CMOS port */
671 
672 	return 0;
673 }
674 
675 #ifdef CONFIG_HPET_TIMER
676 #include <asm/hpet.h>
677 
678 static struct __initdata resource *hpet_res;
679 
680 static int __init acpi_parse_hpet(struct acpi_table_header *table)
681 {
682 	struct acpi_table_hpet *hpet_tbl;
683 
684 	hpet_tbl = (struct acpi_table_hpet *)table;
685 	if (!hpet_tbl) {
686 		printk(KERN_WARNING PREFIX "Unable to map HPET\n");
687 		return -ENODEV;
688 	}
689 
690 	if (hpet_tbl->address.space_id != ACPI_SPACE_MEM) {
691 		printk(KERN_WARNING PREFIX "HPET timers must be located in "
692 		       "memory.\n");
693 		return -1;
694 	}
695 
696 	hpet_address = hpet_tbl->address.address;
697 
698 	/*
699 	 * Some broken BIOSes advertise HPET at 0x0. We really do not
700 	 * want to allocate a resource there.
701 	 */
702 	if (!hpet_address) {
703 		printk(KERN_WARNING PREFIX
704 		       "HPET id: %#x base: %#lx is invalid\n",
705 		       hpet_tbl->id, hpet_address);
706 		return 0;
707 	}
708 #ifdef CONFIG_X86_64
709 	/*
710 	 * Some even more broken BIOSes advertise HPET at
711 	 * 0xfed0000000000000 instead of 0xfed00000. Fix it up and add
712 	 * some noise:
713 	 */
714 	if (hpet_address == 0xfed0000000000000UL) {
715 		if (!hpet_force_user) {
716 			printk(KERN_WARNING PREFIX "HPET id: %#x "
717 			       "base: 0xfed0000000000000 is bogus\n "
718 			       "try hpet=force on the kernel command line to "
719 			       "fix it up to 0xfed00000.\n", hpet_tbl->id);
720 			hpet_address = 0;
721 			return 0;
722 		}
723 		printk(KERN_WARNING PREFIX
724 		       "HPET id: %#x base: 0xfed0000000000000 fixed up "
725 		       "to 0xfed00000.\n", hpet_tbl->id);
726 		hpet_address >>= 32;
727 	}
728 #endif
729 	printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
730 	       hpet_tbl->id, hpet_address);
731 
732 	/*
733 	 * Allocate and initialize the HPET firmware resource for adding into
734 	 * the resource tree during the lateinit timeframe.
735 	 */
736 #define HPET_RESOURCE_NAME_SIZE 9
737 	hpet_res = alloc_bootmem(sizeof(*hpet_res) + HPET_RESOURCE_NAME_SIZE);
738 
739 	hpet_res->name = (void *)&hpet_res[1];
740 	hpet_res->flags = IORESOURCE_MEM;
741 	snprintf((char *)hpet_res->name, HPET_RESOURCE_NAME_SIZE, "HPET %u",
742 		 hpet_tbl->sequence);
743 
744 	hpet_res->start = hpet_address;
745 	hpet_res->end = hpet_address + (1 * 1024) - 1;
746 
747 	return 0;
748 }
749 
750 /*
751  * hpet_insert_resource inserts the HPET resources used into the resource
752  * tree.
753  */
754 static __init int hpet_insert_resource(void)
755 {
756 	if (!hpet_res)
757 		return 1;
758 
759 	return insert_resource(&iomem_resource, hpet_res);
760 }
761 
762 late_initcall(hpet_insert_resource);
763 
764 #else
765 #define	acpi_parse_hpet	NULL
766 #endif
767 
768 static int __init acpi_parse_fadt(struct acpi_table_header *table)
769 {
770 
771 #ifdef CONFIG_X86_PM_TIMER
772 	/* detect the location of the ACPI PM Timer */
773 	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) {
774 		/* FADT rev. 2 */
775 		if (acpi_gbl_FADT.xpm_timer_block.space_id !=
776 		    ACPI_ADR_SPACE_SYSTEM_IO)
777 			return 0;
778 
779 		pmtmr_ioport = acpi_gbl_FADT.xpm_timer_block.address;
780 		/*
781 		 * "X" fields are optional extensions to the original V1.0
782 		 * fields, so we must selectively expand V1.0 fields if the
783 		 * corresponding X field is zero.
784 	 	 */
785 		if (!pmtmr_ioport)
786 			pmtmr_ioport = acpi_gbl_FADT.pm_timer_block;
787 	} else {
788 		/* FADT rev. 1 */
789 		pmtmr_ioport = acpi_gbl_FADT.pm_timer_block;
790 	}
791 	if (pmtmr_ioport)
792 		printk(KERN_INFO PREFIX "PM-Timer IO Port: %#x\n",
793 		       pmtmr_ioport);
794 #endif
795 	return 0;
796 }
797 
798 #ifdef	CONFIG_X86_LOCAL_APIC
799 /*
800  * Parse LAPIC entries in MADT
801  * returns 0 on success, < 0 on error
802  */
803 
804 static void __init acpi_register_lapic_address(unsigned long address)
805 {
806 	mp_lapic_addr = address;
807 
808 	set_fixmap_nocache(FIX_APIC_BASE, address);
809 	if (boot_cpu_physical_apicid == -1U) {
810 		boot_cpu_physical_apicid  = read_apic_id();
811 		apic_version[boot_cpu_physical_apicid] =
812 			 GET_APIC_VERSION(apic_read(APIC_LVR));
813 	}
814 }
815 
816 static int __init early_acpi_parse_madt_lapic_addr_ovr(void)
817 {
818 	int count;
819 
820 	if (!cpu_has_apic)
821 		return -ENODEV;
822 
823 	/*
824 	 * Note that the LAPIC address is obtained from the MADT (32-bit value)
825 	 * and (optionally) overriden by a LAPIC_ADDR_OVR entry (64-bit value).
826 	 */
827 
828 	count =
829 	    acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE,
830 				  acpi_parse_lapic_addr_ovr, 0);
831 	if (count < 0) {
832 		printk(KERN_ERR PREFIX
833 		       "Error parsing LAPIC address override entry\n");
834 		return count;
835 	}
836 
837 	acpi_register_lapic_address(acpi_lapic_addr);
838 
839 	return count;
840 }
841 
842 static int __init acpi_parse_madt_lapic_entries(void)
843 {
844 	int count;
845 	int x2count = 0;
846 
847 	if (!cpu_has_apic)
848 		return -ENODEV;
849 
850 	/*
851 	 * Note that the LAPIC address is obtained from the MADT (32-bit value)
852 	 * and (optionally) overriden by a LAPIC_ADDR_OVR entry (64-bit value).
853 	 */
854 
855 	count =
856 	    acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE,
857 				  acpi_parse_lapic_addr_ovr, 0);
858 	if (count < 0) {
859 		printk(KERN_ERR PREFIX
860 		       "Error parsing LAPIC address override entry\n");
861 		return count;
862 	}
863 
864 	acpi_register_lapic_address(acpi_lapic_addr);
865 
866 	count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_SAPIC,
867 				      acpi_parse_sapic, MAX_APICS);
868 
869 	if (!count) {
870 		x2count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_X2APIC,
871 						acpi_parse_x2apic, MAX_APICS);
872 		count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC,
873 					      acpi_parse_lapic, MAX_APICS);
874 	}
875 	if (!count && !x2count) {
876 		printk(KERN_ERR PREFIX "No LAPIC entries present\n");
877 		/* TBD: Cleanup to allow fallback to MPS */
878 		return -ENODEV;
879 	} else if (count < 0 || x2count < 0) {
880 		printk(KERN_ERR PREFIX "Error parsing LAPIC entry\n");
881 		/* TBD: Cleanup to allow fallback to MPS */
882 		return count;
883 	}
884 
885 	x2count =
886 	    acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_X2APIC_NMI,
887 				  acpi_parse_x2apic_nmi, 0);
888 	count =
889 	    acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_NMI, acpi_parse_lapic_nmi, 0);
890 	if (count < 0 || x2count < 0) {
891 		printk(KERN_ERR PREFIX "Error parsing LAPIC NMI entry\n");
892 		/* TBD: Cleanup to allow fallback to MPS */
893 		return count;
894 	}
895 	return 0;
896 }
897 #endif				/* CONFIG_X86_LOCAL_APIC */
898 
899 #ifdef	CONFIG_X86_IO_APIC
900 #define MP_ISA_BUS		0
901 
902 #ifdef CONFIG_X86_ES7000
903 extern int es7000_plat;
904 #endif
905 
906 static struct {
907 	int gsi_base;
908 	int gsi_end;
909 } mp_ioapic_routing[MAX_IO_APICS];
910 
911 int mp_find_ioapic(int gsi)
912 {
913 	int i = 0;
914 
915 	/* Find the IOAPIC that manages this GSI. */
916 	for (i = 0; i < nr_ioapics; i++) {
917 		if ((gsi >= mp_ioapic_routing[i].gsi_base)
918 		    && (gsi <= mp_ioapic_routing[i].gsi_end))
919 			return i;
920 	}
921 
922 	printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
923 	return -1;
924 }
925 
926 int mp_find_ioapic_pin(int ioapic, int gsi)
927 {
928 	if (WARN_ON(ioapic == -1))
929 		return -1;
930 	if (WARN_ON(gsi > mp_ioapic_routing[ioapic].gsi_end))
931 		return -1;
932 
933 	return gsi - mp_ioapic_routing[ioapic].gsi_base;
934 }
935 
936 static u8 __init uniq_ioapic_id(u8 id)
937 {
938 #ifdef CONFIG_X86_32
939 	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
940 	    !APIC_XAPIC(apic_version[boot_cpu_physical_apicid]))
941 		return io_apic_get_unique_id(nr_ioapics, id);
942 	else
943 		return id;
944 #else
945 	int i;
946 	DECLARE_BITMAP(used, 256);
947 	bitmap_zero(used, 256);
948 	for (i = 0; i < nr_ioapics; i++) {
949 		struct mpc_ioapic *ia = &mp_ioapics[i];
950 		__set_bit(ia->apicid, used);
951 	}
952 	if (!test_bit(id, used))
953 		return id;
954 	return find_first_zero_bit(used, 256);
955 #endif
956 }
957 
958 static int bad_ioapic(unsigned long address)
959 {
960 	if (nr_ioapics >= MAX_IO_APICS) {
961 		printk(KERN_ERR "ERROR: Max # of I/O APICs (%d) exceeded "
962 		       "(found %d)\n", MAX_IO_APICS, nr_ioapics);
963 		panic("Recompile kernel with bigger MAX_IO_APICS!\n");
964 	}
965 	if (!address) {
966 		printk(KERN_ERR "WARNING: Bogus (zero) I/O APIC address"
967 		       " found in table, skipping!\n");
968 		return 1;
969 	}
970 	return 0;
971 }
972 
973 void __init mp_register_ioapic(int id, u32 address, u32 gsi_base)
974 {
975 	int idx = 0;
976 
977 	if (bad_ioapic(address))
978 		return;
979 
980 	idx = nr_ioapics;
981 
982 	mp_ioapics[idx].type = MP_IOAPIC;
983 	mp_ioapics[idx].flags = MPC_APIC_USABLE;
984 	mp_ioapics[idx].apicaddr = address;
985 
986 	set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
987 	mp_ioapics[idx].apicid = uniq_ioapic_id(id);
988 	mp_ioapics[idx].apicver = io_apic_get_version(idx);
989 
990 	/*
991 	 * Build basic GSI lookup table to facilitate gsi->io_apic lookups
992 	 * and to prevent reprogramming of IOAPIC pins (PCI GSIs).
993 	 */
994 	mp_ioapic_routing[idx].gsi_base = gsi_base;
995 	mp_ioapic_routing[idx].gsi_end = gsi_base +
996 	    io_apic_get_redir_entries(idx);
997 
998 	printk(KERN_INFO "IOAPIC[%d]: apic_id %d, version %d, address 0x%x, "
999 	       "GSI %d-%d\n", idx, mp_ioapics[idx].apicid,
1000 	       mp_ioapics[idx].apicver, mp_ioapics[idx].apicaddr,
1001 	       mp_ioapic_routing[idx].gsi_base, mp_ioapic_routing[idx].gsi_end);
1002 
1003 	nr_ioapics++;
1004 }
1005 
1006 int __init acpi_probe_gsi(void)
1007 {
1008 	int idx;
1009 	int gsi;
1010 	int max_gsi = 0;
1011 
1012 	if (acpi_disabled)
1013 		return 0;
1014 
1015 	if (!acpi_ioapic)
1016 		return 0;
1017 
1018 	max_gsi = 0;
1019 	for (idx = 0; idx < nr_ioapics; idx++) {
1020 		gsi = mp_ioapic_routing[idx].gsi_end;
1021 
1022 		if (gsi > max_gsi)
1023 			max_gsi = gsi;
1024 	}
1025 
1026 	return max_gsi + 1;
1027 }
1028 
1029 static void assign_to_mp_irq(struct mpc_intsrc *m,
1030 				    struct mpc_intsrc *mp_irq)
1031 {
1032 	memcpy(mp_irq, m, sizeof(struct mpc_intsrc));
1033 }
1034 
1035 static int mp_irq_cmp(struct mpc_intsrc *mp_irq,
1036 				struct mpc_intsrc *m)
1037 {
1038 	return memcmp(mp_irq, m, sizeof(struct mpc_intsrc));
1039 }
1040 
1041 static void save_mp_irq(struct mpc_intsrc *m)
1042 {
1043 	int i;
1044 
1045 	for (i = 0; i < mp_irq_entries; i++) {
1046 		if (!mp_irq_cmp(&mp_irqs[i], m))
1047 			return;
1048 	}
1049 
1050 	assign_to_mp_irq(m, &mp_irqs[mp_irq_entries]);
1051 	if (++mp_irq_entries == MAX_IRQ_SOURCES)
1052 		panic("Max # of irq sources exceeded!!\n");
1053 }
1054 
1055 void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger, u32 gsi)
1056 {
1057 	int ioapic;
1058 	int pin;
1059 	struct mpc_intsrc mp_irq;
1060 
1061 	/*
1062 	 * Convert 'gsi' to 'ioapic.pin'.
1063 	 */
1064 	ioapic = mp_find_ioapic(gsi);
1065 	if (ioapic < 0)
1066 		return;
1067 	pin = mp_find_ioapic_pin(ioapic, gsi);
1068 
1069 	/*
1070 	 * TBD: This check is for faulty timer entries, where the override
1071 	 *      erroneously sets the trigger to level, resulting in a HUGE
1072 	 *      increase of timer interrupts!
1073 	 */
1074 	if ((bus_irq == 0) && (trigger == 3))
1075 		trigger = 1;
1076 
1077 	mp_irq.type = MP_INTSRC;
1078 	mp_irq.irqtype = mp_INT;
1079 	mp_irq.irqflag = (trigger << 2) | polarity;
1080 	mp_irq.srcbus = MP_ISA_BUS;
1081 	mp_irq.srcbusirq = bus_irq;	/* IRQ */
1082 	mp_irq.dstapic = mp_ioapics[ioapic].apicid; /* APIC ID */
1083 	mp_irq.dstirq = pin;	/* INTIN# */
1084 
1085 	save_mp_irq(&mp_irq);
1086 }
1087 
1088 void __init mp_config_acpi_legacy_irqs(void)
1089 {
1090 	int i;
1091 	int ioapic;
1092 	unsigned int dstapic;
1093 	struct mpc_intsrc mp_irq;
1094 
1095 #if defined (CONFIG_MCA) || defined (CONFIG_EISA)
1096 	/*
1097 	 * Fabricate the legacy ISA bus (bus #31).
1098 	 */
1099 	mp_bus_id_to_type[MP_ISA_BUS] = MP_BUS_ISA;
1100 #endif
1101 	set_bit(MP_ISA_BUS, mp_bus_not_pci);
1102 	pr_debug("Bus #%d is ISA\n", MP_ISA_BUS);
1103 
1104 #ifdef CONFIG_X86_ES7000
1105 	/*
1106 	 * Older generations of ES7000 have no legacy identity mappings
1107 	 */
1108 	if (es7000_plat == 1)
1109 		return;
1110 #endif
1111 
1112 	/*
1113 	 * Locate the IOAPIC that manages the ISA IRQs (0-15).
1114 	 */
1115 	ioapic = mp_find_ioapic(0);
1116 	if (ioapic < 0)
1117 		return;
1118 	dstapic = mp_ioapics[ioapic].apicid;
1119 
1120 	/*
1121 	 * Use the default configuration for the IRQs 0-15.  Unless
1122 	 * overridden by (MADT) interrupt source override entries.
1123 	 */
1124 	for (i = 0; i < 16; i++) {
1125 		int idx;
1126 
1127 		for (idx = 0; idx < mp_irq_entries; idx++) {
1128 			struct mpc_intsrc *irq = mp_irqs + idx;
1129 
1130 			/* Do we already have a mapping for this ISA IRQ? */
1131 			if (irq->srcbus == MP_ISA_BUS && irq->srcbusirq == i)
1132 				break;
1133 
1134 			/* Do we already have a mapping for this IOAPIC pin */
1135 			if (irq->dstapic == dstapic && irq->dstirq == i)
1136 				break;
1137 		}
1138 
1139 		if (idx != mp_irq_entries) {
1140 			printk(KERN_DEBUG "ACPI: IRQ%d used by override.\n", i);
1141 			continue;	/* IRQ already used */
1142 		}
1143 
1144 		mp_irq.type = MP_INTSRC;
1145 		mp_irq.irqflag = 0;	/* Conforming */
1146 		mp_irq.srcbus = MP_ISA_BUS;
1147 		mp_irq.dstapic = dstapic;
1148 		mp_irq.irqtype = mp_INT;
1149 		mp_irq.srcbusirq = i; /* Identity mapped */
1150 		mp_irq.dstirq = i;
1151 
1152 		save_mp_irq(&mp_irq);
1153 	}
1154 }
1155 
1156 static int mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
1157 			int polarity)
1158 {
1159 #ifdef CONFIG_X86_MPPARSE
1160 	struct mpc_intsrc mp_irq;
1161 	struct pci_dev *pdev;
1162 	unsigned char number;
1163 	unsigned int devfn;
1164 	int ioapic;
1165 	u8 pin;
1166 
1167 	if (!acpi_ioapic)
1168 		return 0;
1169 	if (!dev)
1170 		return 0;
1171 	if (dev->bus != &pci_bus_type)
1172 		return 0;
1173 
1174 	pdev = to_pci_dev(dev);
1175 	number = pdev->bus->number;
1176 	devfn = pdev->devfn;
1177 	pin = pdev->pin;
1178 	/* print the entry should happen on mptable identically */
1179 	mp_irq.type = MP_INTSRC;
1180 	mp_irq.irqtype = mp_INT;
1181 	mp_irq.irqflag = (trigger == ACPI_EDGE_SENSITIVE ? 4 : 0x0c) |
1182 				(polarity == ACPI_ACTIVE_HIGH ? 1 : 3);
1183 	mp_irq.srcbus = number;
1184 	mp_irq.srcbusirq = (((devfn >> 3) & 0x1f) << 2) | ((pin - 1) & 3);
1185 	ioapic = mp_find_ioapic(gsi);
1186 	mp_irq.dstapic = mp_ioapics[ioapic].apicid;
1187 	mp_irq.dstirq = mp_find_ioapic_pin(ioapic, gsi);
1188 
1189 	save_mp_irq(&mp_irq);
1190 #endif
1191 	return 0;
1192 }
1193 
1194 int mp_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
1195 {
1196 	int ioapic;
1197 	int ioapic_pin;
1198 	struct io_apic_irq_attr irq_attr;
1199 
1200 	if (acpi_irq_model != ACPI_IRQ_MODEL_IOAPIC)
1201 		return gsi;
1202 
1203 	/* Don't set up the ACPI SCI because it's already set up */
1204 	if (acpi_gbl_FADT.sci_interrupt == gsi)
1205 		return gsi;
1206 
1207 	ioapic = mp_find_ioapic(gsi);
1208 	if (ioapic < 0) {
1209 		printk(KERN_WARNING "No IOAPIC for GSI %u\n", gsi);
1210 		return gsi;
1211 	}
1212 
1213 	ioapic_pin = mp_find_ioapic_pin(ioapic, gsi);
1214 
1215 #ifdef CONFIG_X86_32
1216 	if (ioapic_renumber_irq)
1217 		gsi = ioapic_renumber_irq(ioapic, gsi);
1218 #endif
1219 
1220 	if (ioapic_pin > MP_MAX_IOAPIC_PIN) {
1221 		printk(KERN_ERR "Invalid reference to IOAPIC pin "
1222 		       "%d-%d\n", mp_ioapics[ioapic].apicid,
1223 		       ioapic_pin);
1224 		return gsi;
1225 	}
1226 
1227 	if (enable_update_mptable)
1228 		mp_config_acpi_gsi(dev, gsi, trigger, polarity);
1229 
1230 	set_io_apic_irq_attr(&irq_attr, ioapic, ioapic_pin,
1231 			     trigger == ACPI_EDGE_SENSITIVE ? 0 : 1,
1232 			     polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
1233 	io_apic_set_pci_routing(dev, gsi, &irq_attr);
1234 
1235 	return gsi;
1236 }
1237 
1238 /*
1239  * Parse IOAPIC related entries in MADT
1240  * returns 0 on success, < 0 on error
1241  */
1242 static int __init acpi_parse_madt_ioapic_entries(void)
1243 {
1244 	int count;
1245 
1246 	/*
1247 	 * ACPI interpreter is required to complete interrupt setup,
1248 	 * so if it is off, don't enumerate the io-apics with ACPI.
1249 	 * If MPS is present, it will handle them,
1250 	 * otherwise the system will stay in PIC mode
1251 	 */
1252 	if (acpi_disabled || acpi_noirq) {
1253 		return -ENODEV;
1254 	}
1255 
1256 	if (!cpu_has_apic)
1257 		return -ENODEV;
1258 
1259 	/*
1260 	 * if "noapic" boot option, don't look for IO-APICs
1261 	 */
1262 	if (skip_ioapic_setup) {
1263 		printk(KERN_INFO PREFIX "Skipping IOAPIC probe "
1264 		       "due to 'noapic' option.\n");
1265 		return -ENODEV;
1266 	}
1267 
1268 	count =
1269 	    acpi_table_parse_madt(ACPI_MADT_TYPE_IO_APIC, acpi_parse_ioapic,
1270 				  MAX_IO_APICS);
1271 	if (!count) {
1272 		printk(KERN_ERR PREFIX "No IOAPIC entries present\n");
1273 		return -ENODEV;
1274 	} else if (count < 0) {
1275 		printk(KERN_ERR PREFIX "Error parsing IOAPIC entry\n");
1276 		return count;
1277 	}
1278 
1279 	count =
1280 	    acpi_table_parse_madt(ACPI_MADT_TYPE_INTERRUPT_OVERRIDE, acpi_parse_int_src_ovr,
1281 				  nr_irqs);
1282 	if (count < 0) {
1283 		printk(KERN_ERR PREFIX
1284 		       "Error parsing interrupt source overrides entry\n");
1285 		/* TBD: Cleanup to allow fallback to MPS */
1286 		return count;
1287 	}
1288 
1289 	/*
1290 	 * If BIOS did not supply an INT_SRC_OVR for the SCI
1291 	 * pretend we got one so we can set the SCI flags.
1292 	 */
1293 	if (!acpi_sci_override_gsi)
1294 		acpi_sci_ioapic_setup(acpi_gbl_FADT.sci_interrupt, 0, 0);
1295 
1296 	/* Fill in identity legacy mapings where no override */
1297 	mp_config_acpi_legacy_irqs();
1298 
1299 	count =
1300 	    acpi_table_parse_madt(ACPI_MADT_TYPE_NMI_SOURCE, acpi_parse_nmi_src,
1301 				  nr_irqs);
1302 	if (count < 0) {
1303 		printk(KERN_ERR PREFIX "Error parsing NMI SRC entry\n");
1304 		/* TBD: Cleanup to allow fallback to MPS */
1305 		return count;
1306 	}
1307 
1308 	return 0;
1309 }
1310 #else
1311 static inline int acpi_parse_madt_ioapic_entries(void)
1312 {
1313 	return -1;
1314 }
1315 #endif	/* !CONFIG_X86_IO_APIC */
1316 
1317 static void __init early_acpi_process_madt(void)
1318 {
1319 #ifdef CONFIG_X86_LOCAL_APIC
1320 	int error;
1321 
1322 	if (!acpi_table_parse(ACPI_SIG_MADT, acpi_parse_madt)) {
1323 
1324 		/*
1325 		 * Parse MADT LAPIC entries
1326 		 */
1327 		error = early_acpi_parse_madt_lapic_addr_ovr();
1328 		if (!error) {
1329 			acpi_lapic = 1;
1330 			smp_found_config = 1;
1331 		}
1332 		if (error == -EINVAL) {
1333 			/*
1334 			 * Dell Precision Workstation 410, 610 come here.
1335 			 */
1336 			printk(KERN_ERR PREFIX
1337 			       "Invalid BIOS MADT, disabling ACPI\n");
1338 			disable_acpi();
1339 		}
1340 	}
1341 #endif
1342 }
1343 
1344 static void __init acpi_process_madt(void)
1345 {
1346 #ifdef CONFIG_X86_LOCAL_APIC
1347 	int error;
1348 
1349 	if (!acpi_table_parse(ACPI_SIG_MADT, acpi_parse_madt)) {
1350 
1351 		/*
1352 		 * Parse MADT LAPIC entries
1353 		 */
1354 		error = acpi_parse_madt_lapic_entries();
1355 		if (!error) {
1356 			acpi_lapic = 1;
1357 
1358 #ifdef CONFIG_X86_BIGSMP
1359 			generic_bigsmp_probe();
1360 #endif
1361 			/*
1362 			 * Parse MADT IO-APIC entries
1363 			 */
1364 			error = acpi_parse_madt_ioapic_entries();
1365 			if (!error) {
1366 				acpi_irq_model = ACPI_IRQ_MODEL_IOAPIC;
1367 				acpi_ioapic = 1;
1368 
1369 				smp_found_config = 1;
1370 				if (apic->setup_apic_routing)
1371 					apic->setup_apic_routing();
1372 			}
1373 		}
1374 		if (error == -EINVAL) {
1375 			/*
1376 			 * Dell Precision Workstation 410, 610 come here.
1377 			 */
1378 			printk(KERN_ERR PREFIX
1379 			       "Invalid BIOS MADT, disabling ACPI\n");
1380 			disable_acpi();
1381 		}
1382 	} else {
1383 		/*
1384  		 * ACPI found no MADT, and so ACPI wants UP PIC mode.
1385  		 * In the event an MPS table was found, forget it.
1386  		 * Boot with "acpi=off" to use MPS on such a system.
1387  		 */
1388 		if (smp_found_config) {
1389 			printk(KERN_WARNING PREFIX
1390 				"No APIC-table, disabling MPS\n");
1391 			smp_found_config = 0;
1392 		}
1393 	}
1394 
1395 	/*
1396 	 * ACPI supports both logical (e.g. Hyper-Threading) and physical
1397 	 * processors, where MPS only supports physical.
1398 	 */
1399 	if (acpi_lapic && acpi_ioapic)
1400 		printk(KERN_INFO "Using ACPI (MADT) for SMP configuration "
1401 		       "information\n");
1402 	else if (acpi_lapic)
1403 		printk(KERN_INFO "Using ACPI for processor (LAPIC) "
1404 		       "configuration information\n");
1405 #endif
1406 	return;
1407 }
1408 
1409 static int __init disable_acpi_irq(const struct dmi_system_id *d)
1410 {
1411 	if (!acpi_force) {
1412 		printk(KERN_NOTICE "%s detected: force use of acpi=noirq\n",
1413 		       d->ident);
1414 		acpi_noirq_set();
1415 	}
1416 	return 0;
1417 }
1418 
1419 static int __init disable_acpi_pci(const struct dmi_system_id *d)
1420 {
1421 	if (!acpi_force) {
1422 		printk(KERN_NOTICE "%s detected: force use of pci=noacpi\n",
1423 		       d->ident);
1424 		acpi_disable_pci();
1425 	}
1426 	return 0;
1427 }
1428 
1429 static int __init dmi_disable_acpi(const struct dmi_system_id *d)
1430 {
1431 	if (!acpi_force) {
1432 		printk(KERN_NOTICE "%s detected: acpi off\n", d->ident);
1433 		disable_acpi();
1434 	} else {
1435 		printk(KERN_NOTICE
1436 		       "Warning: DMI blacklist says broken, but acpi forced\n");
1437 	}
1438 	return 0;
1439 }
1440 
1441 /*
1442  * Limit ACPI to CPU enumeration for HT
1443  */
1444 static int __init force_acpi_ht(const struct dmi_system_id *d)
1445 {
1446 	if (!acpi_force) {
1447 		printk(KERN_NOTICE "%s detected: force use of acpi=ht\n",
1448 		       d->ident);
1449 		disable_acpi();
1450 		acpi_ht = 1;
1451 	} else {
1452 		printk(KERN_NOTICE
1453 		       "Warning: acpi=force overrules DMI blacklist: acpi=ht\n");
1454 	}
1455 	return 0;
1456 }
1457 
1458 /*
1459  * Force ignoring BIOS IRQ0 pin2 override
1460  */
1461 static int __init dmi_ignore_irq0_timer_override(const struct dmi_system_id *d)
1462 {
1463 	/*
1464 	 * The ati_ixp4x0_rev() early PCI quirk should have set
1465 	 * the acpi_skip_timer_override flag already:
1466 	 */
1467 	if (!acpi_skip_timer_override) {
1468 		WARN(1, KERN_ERR "ati_ixp4x0 quirk not complete.\n");
1469 		pr_notice("%s detected: Ignoring BIOS IRQ0 pin2 override\n",
1470 			d->ident);
1471 		acpi_skip_timer_override = 1;
1472 	}
1473 	return 0;
1474 }
1475 
1476 /*
1477  * If your system is blacklisted here, but you find that acpi=force
1478  * works for you, please contact linux-acpi@vger.kernel.org
1479  */
1480 static struct dmi_system_id __initdata acpi_dmi_table[] = {
1481 	/*
1482 	 * Boxes that need ACPI disabled
1483 	 */
1484 	{
1485 	 .callback = dmi_disable_acpi,
1486 	 .ident = "IBM Thinkpad",
1487 	 .matches = {
1488 		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1489 		     DMI_MATCH(DMI_BOARD_NAME, "2629H1G"),
1490 		     },
1491 	 },
1492 
1493 	/*
1494 	 * Boxes that need acpi=ht
1495 	 */
1496 	{
1497 	 .callback = force_acpi_ht,
1498 	 .ident = "FSC Primergy T850",
1499 	 .matches = {
1500 		     DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
1501 		     DMI_MATCH(DMI_PRODUCT_NAME, "PRIMERGY T850"),
1502 		     },
1503 	 },
1504 	{
1505 	 .callback = force_acpi_ht,
1506 	 .ident = "HP VISUALIZE NT Workstation",
1507 	 .matches = {
1508 		     DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
1509 		     DMI_MATCH(DMI_PRODUCT_NAME, "HP VISUALIZE NT Workstation"),
1510 		     },
1511 	 },
1512 	{
1513 	 .callback = force_acpi_ht,
1514 	 .ident = "Compaq Workstation W8000",
1515 	 .matches = {
1516 		     DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
1517 		     DMI_MATCH(DMI_PRODUCT_NAME, "Workstation W8000"),
1518 		     },
1519 	 },
1520 	{
1521 	 .callback = force_acpi_ht,
1522 	 .ident = "ASUS P4B266",
1523 	 .matches = {
1524 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
1525 		     DMI_MATCH(DMI_BOARD_NAME, "P4B266"),
1526 		     },
1527 	 },
1528 	{
1529 	 .callback = force_acpi_ht,
1530 	 .ident = "ASUS P2B-DS",
1531 	 .matches = {
1532 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
1533 		     DMI_MATCH(DMI_BOARD_NAME, "P2B-DS"),
1534 		     },
1535 	 },
1536 	{
1537 	 .callback = force_acpi_ht,
1538 	 .ident = "ASUS CUR-DLS",
1539 	 .matches = {
1540 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
1541 		     DMI_MATCH(DMI_BOARD_NAME, "CUR-DLS"),
1542 		     },
1543 	 },
1544 	{
1545 	 .callback = force_acpi_ht,
1546 	 .ident = "ABIT i440BX-W83977",
1547 	 .matches = {
1548 		     DMI_MATCH(DMI_BOARD_VENDOR, "ABIT <http://www.abit.com>"),
1549 		     DMI_MATCH(DMI_BOARD_NAME, "i440BX-W83977 (BP6)"),
1550 		     },
1551 	 },
1552 	{
1553 	 .callback = force_acpi_ht,
1554 	 .ident = "IBM Bladecenter",
1555 	 .matches = {
1556 		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1557 		     DMI_MATCH(DMI_BOARD_NAME, "IBM eServer BladeCenter HS20"),
1558 		     },
1559 	 },
1560 	{
1561 	 .callback = force_acpi_ht,
1562 	 .ident = "IBM eServer xSeries 360",
1563 	 .matches = {
1564 		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1565 		     DMI_MATCH(DMI_BOARD_NAME, "eServer xSeries 360"),
1566 		     },
1567 	 },
1568 	{
1569 	 .callback = force_acpi_ht,
1570 	 .ident = "IBM eserver xSeries 330",
1571 	 .matches = {
1572 		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1573 		     DMI_MATCH(DMI_BOARD_NAME, "eserver xSeries 330"),
1574 		     },
1575 	 },
1576 	{
1577 	 .callback = force_acpi_ht,
1578 	 .ident = "IBM eserver xSeries 440",
1579 	 .matches = {
1580 		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1581 		     DMI_MATCH(DMI_PRODUCT_NAME, "eserver xSeries 440"),
1582 		     },
1583 	 },
1584 
1585 	/*
1586 	 * Boxes that need ACPI PCI IRQ routing disabled
1587 	 */
1588 	{
1589 	 .callback = disable_acpi_irq,
1590 	 .ident = "ASUS A7V",
1591 	 .matches = {
1592 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC"),
1593 		     DMI_MATCH(DMI_BOARD_NAME, "<A7V>"),
1594 		     /* newer BIOS, Revision 1011, does work */
1595 		     DMI_MATCH(DMI_BIOS_VERSION,
1596 			       "ASUS A7V ACPI BIOS Revision 1007"),
1597 		     },
1598 	 },
1599 	{
1600 		/*
1601 		 * Latest BIOS for IBM 600E (1.16) has bad pcinum
1602 		 * for LPC bridge, which is needed for the PCI
1603 		 * interrupt links to work. DSDT fix is in bug 5966.
1604 		 * 2645, 2646 model numbers are shared with 600/600E/600X
1605 		 */
1606 	 .callback = disable_acpi_irq,
1607 	 .ident = "IBM Thinkpad 600 Series 2645",
1608 	 .matches = {
1609 		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1610 		     DMI_MATCH(DMI_BOARD_NAME, "2645"),
1611 		     },
1612 	 },
1613 	{
1614 	 .callback = disable_acpi_irq,
1615 	 .ident = "IBM Thinkpad 600 Series 2646",
1616 	 .matches = {
1617 		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1618 		     DMI_MATCH(DMI_BOARD_NAME, "2646"),
1619 		     },
1620 	 },
1621 	/*
1622 	 * Boxes that need ACPI PCI IRQ routing and PCI scan disabled
1623 	 */
1624 	{			/* _BBN 0 bug */
1625 	 .callback = disable_acpi_pci,
1626 	 .ident = "ASUS PR-DLS",
1627 	 .matches = {
1628 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
1629 		     DMI_MATCH(DMI_BOARD_NAME, "PR-DLS"),
1630 		     DMI_MATCH(DMI_BIOS_VERSION,
1631 			       "ASUS PR-DLS ACPI BIOS Revision 1010"),
1632 		     DMI_MATCH(DMI_BIOS_DATE, "03/21/2003")
1633 		     },
1634 	 },
1635 	{
1636 	 .callback = disable_acpi_pci,
1637 	 .ident = "Acer TravelMate 36x Laptop",
1638 	 .matches = {
1639 		     DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1640 		     DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 360"),
1641 		     },
1642 	 },
1643 	{}
1644 };
1645 
1646 /* second table for DMI checks that should run after early-quirks */
1647 static struct dmi_system_id __initdata acpi_dmi_table_late[] = {
1648 	/*
1649 	 * HP laptops which use a DSDT reporting as HP/SB400/10000,
1650 	 * which includes some code which overrides all temperature
1651 	 * trip points to 16C if the INTIN2 input of the I/O APIC
1652 	 * is enabled.  This input is incorrectly designated the
1653 	 * ISA IRQ 0 via an interrupt source override even though
1654 	 * it is wired to the output of the master 8259A and INTIN0
1655 	 * is not connected at all.  Force ignoring BIOS IRQ0 pin2
1656 	 * override in that cases.
1657 	 */
1658 	{
1659 	 .callback = dmi_ignore_irq0_timer_override,
1660 	 .ident = "HP nx6115 laptop",
1661 	 .matches = {
1662 		     DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1663 		     DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq nx6115"),
1664 		     },
1665 	 },
1666 	{
1667 	 .callback = dmi_ignore_irq0_timer_override,
1668 	 .ident = "HP NX6125 laptop",
1669 	 .matches = {
1670 		     DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1671 		     DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq nx6125"),
1672 		     },
1673 	 },
1674 	{
1675 	 .callback = dmi_ignore_irq0_timer_override,
1676 	 .ident = "HP NX6325 laptop",
1677 	 .matches = {
1678 		     DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1679 		     DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq nx6325"),
1680 		     },
1681 	 },
1682 	{
1683 	 .callback = dmi_ignore_irq0_timer_override,
1684 	 .ident = "HP 6715b laptop",
1685 	 .matches = {
1686 		     DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1687 		     DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq 6715b"),
1688 		     },
1689 	 },
1690 	{}
1691 };
1692 
1693 /*
1694  * acpi_boot_table_init() and acpi_boot_init()
1695  *  called from setup_arch(), always.
1696  *	1. checksums all tables
1697  *	2. enumerates lapics
1698  *	3. enumerates io-apics
1699  *
1700  * acpi_table_init() is separate to allow reading SRAT without
1701  * other side effects.
1702  *
1703  * side effects of acpi_boot_init:
1704  *	acpi_lapic = 1 if LAPIC found
1705  *	acpi_ioapic = 1 if IOAPIC found
1706  *	if (acpi_lapic && acpi_ioapic) smp_found_config = 1;
1707  *	if acpi_blacklisted() acpi_disabled = 1;
1708  *	acpi_irq_model=...
1709  *	...
1710  *
1711  * return value: (currently ignored)
1712  *	0: success
1713  *	!0: failure
1714  */
1715 
1716 int __init acpi_boot_table_init(void)
1717 {
1718 	int error;
1719 
1720 	dmi_check_system(acpi_dmi_table);
1721 
1722 	/*
1723 	 * If acpi_disabled, bail out
1724 	 * One exception: acpi=ht continues far enough to enumerate LAPICs
1725 	 */
1726 	if (acpi_disabled && !acpi_ht)
1727 		return 1;
1728 
1729 	/*
1730 	 * Initialize the ACPI boot-time table parser.
1731 	 */
1732 	error = acpi_table_init();
1733 	if (error) {
1734 		disable_acpi();
1735 		return error;
1736 	}
1737 
1738 	acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);
1739 
1740 	/*
1741 	 * blacklist may disable ACPI entirely
1742 	 */
1743 	error = acpi_blacklisted();
1744 	if (error) {
1745 		if (acpi_force) {
1746 			printk(KERN_WARNING PREFIX "acpi=force override\n");
1747 		} else {
1748 			printk(KERN_WARNING PREFIX "Disabling ACPI support\n");
1749 			disable_acpi();
1750 			return error;
1751 		}
1752 	}
1753 
1754 	return 0;
1755 }
1756 
1757 int __init early_acpi_boot_init(void)
1758 {
1759 	/*
1760 	 * If acpi_disabled, bail out
1761 	 * One exception: acpi=ht continues far enough to enumerate LAPICs
1762 	 */
1763 	if (acpi_disabled && !acpi_ht)
1764 		return 1;
1765 
1766 	/*
1767 	 * Process the Multiple APIC Description Table (MADT), if present
1768 	 */
1769 	early_acpi_process_madt();
1770 
1771 	return 0;
1772 }
1773 
1774 int __init acpi_boot_init(void)
1775 {
1776 	/* those are executed after early-quirks are executed */
1777 	dmi_check_system(acpi_dmi_table_late);
1778 
1779 	/*
1780 	 * If acpi_disabled, bail out
1781 	 * One exception: acpi=ht continues far enough to enumerate LAPICs
1782 	 */
1783 	if (acpi_disabled && !acpi_ht)
1784 		return 1;
1785 
1786 	acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);
1787 
1788 	/*
1789 	 * set sci_int and PM timer address
1790 	 */
1791 	acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt);
1792 
1793 	/*
1794 	 * Process the Multiple APIC Description Table (MADT), if present
1795 	 */
1796 	acpi_process_madt();
1797 
1798 	acpi_table_parse(ACPI_SIG_HPET, acpi_parse_hpet);
1799 
1800 	return 0;
1801 }
1802 
1803 static int __init parse_acpi(char *arg)
1804 {
1805 	if (!arg)
1806 		return -EINVAL;
1807 
1808 	/* "acpi=off" disables both ACPI table parsing and interpreter */
1809 	if (strcmp(arg, "off") == 0) {
1810 		disable_acpi();
1811 	}
1812 	/* acpi=force to over-ride black-list */
1813 	else if (strcmp(arg, "force") == 0) {
1814 		acpi_force = 1;
1815 		acpi_ht = 1;
1816 		acpi_disabled = 0;
1817 	}
1818 	/* acpi=strict disables out-of-spec workarounds */
1819 	else if (strcmp(arg, "strict") == 0) {
1820 		acpi_strict = 1;
1821 	}
1822 	/* Limit ACPI just to boot-time to enable HT */
1823 	else if (strcmp(arg, "ht") == 0) {
1824 		if (!acpi_force)
1825 			disable_acpi();
1826 		acpi_ht = 1;
1827 	}
1828 	/* acpi=rsdt use RSDT instead of XSDT */
1829 	else if (strcmp(arg, "rsdt") == 0) {
1830 		acpi_rsdt_forced = 1;
1831 	}
1832 	/* "acpi=noirq" disables ACPI interrupt routing */
1833 	else if (strcmp(arg, "noirq") == 0) {
1834 		acpi_noirq_set();
1835 	} else {
1836 		/* Core will printk when we return error. */
1837 		return -EINVAL;
1838 	}
1839 	return 0;
1840 }
1841 early_param("acpi", parse_acpi);
1842 
1843 /* FIXME: Using pci= for an ACPI parameter is a travesty. */
1844 static int __init parse_pci(char *arg)
1845 {
1846 	if (arg && strcmp(arg, "noacpi") == 0)
1847 		acpi_disable_pci();
1848 	return 0;
1849 }
1850 early_param("pci", parse_pci);
1851 
1852 int __init acpi_mps_check(void)
1853 {
1854 #if defined(CONFIG_X86_LOCAL_APIC) && !defined(CONFIG_X86_MPPARSE)
1855 /* mptable code is not built-in*/
1856 	if (acpi_disabled || acpi_noirq) {
1857 		printk(KERN_WARNING "MPS support code is not built-in.\n"
1858 		       "Using acpi=off or acpi=noirq or pci=noacpi "
1859 		       "may have problem\n");
1860 		return 1;
1861 	}
1862 #endif
1863 	return 0;
1864 }
1865 
1866 #ifdef CONFIG_X86_IO_APIC
1867 static int __init parse_acpi_skip_timer_override(char *arg)
1868 {
1869 	acpi_skip_timer_override = 1;
1870 	return 0;
1871 }
1872 early_param("acpi_skip_timer_override", parse_acpi_skip_timer_override);
1873 
1874 static int __init parse_acpi_use_timer_override(char *arg)
1875 {
1876 	acpi_use_timer_override = 1;
1877 	return 0;
1878 }
1879 early_param("acpi_use_timer_override", parse_acpi_use_timer_override);
1880 #endif /* CONFIG_X86_IO_APIC */
1881 
1882 static int __init setup_acpi_sci(char *s)
1883 {
1884 	if (!s)
1885 		return -EINVAL;
1886 	if (!strcmp(s, "edge"))
1887 		acpi_sci_flags =  ACPI_MADT_TRIGGER_EDGE |
1888 			(acpi_sci_flags & ~ACPI_MADT_TRIGGER_MASK);
1889 	else if (!strcmp(s, "level"))
1890 		acpi_sci_flags = ACPI_MADT_TRIGGER_LEVEL |
1891 			(acpi_sci_flags & ~ACPI_MADT_TRIGGER_MASK);
1892 	else if (!strcmp(s, "high"))
1893 		acpi_sci_flags = ACPI_MADT_POLARITY_ACTIVE_HIGH |
1894 			(acpi_sci_flags & ~ACPI_MADT_POLARITY_MASK);
1895 	else if (!strcmp(s, "low"))
1896 		acpi_sci_flags = ACPI_MADT_POLARITY_ACTIVE_LOW |
1897 			(acpi_sci_flags & ~ACPI_MADT_POLARITY_MASK);
1898 	else
1899 		return -EINVAL;
1900 	return 0;
1901 }
1902 early_param("acpi_sci", setup_acpi_sci);
1903 
1904 int __acpi_acquire_global_lock(unsigned int *lock)
1905 {
1906 	unsigned int old, new, val;
1907 	do {
1908 		old = *lock;
1909 		new = (((old & ~0x3) + 2) + ((old >> 1) & 0x1));
1910 		val = cmpxchg(lock, old, new);
1911 	} while (unlikely (val != old));
1912 	return (new < 3) ? -1 : 0;
1913 }
1914 
1915 int __acpi_release_global_lock(unsigned int *lock)
1916 {
1917 	unsigned int old, new, val;
1918 	do {
1919 		old = *lock;
1920 		new = old & ~0x3;
1921 		val = cmpxchg(lock, old, new);
1922 	} while (unlikely (val != old));
1923 	return old & 0x1;
1924 }
1925