xref: /openbmc/linux/arch/x86/kernel/acpi/boot.c (revision b3dff59e)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  boot.c - Architecture-Specific Low-Level ACPI Boot Support
4  *
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2001 Jun Nakajima <jun.nakajima@intel.com>
7  */
8 #define pr_fmt(fmt) "ACPI: " fmt
9 
10 #include <linux/init.h>
11 #include <linux/acpi.h>
12 #include <linux/acpi_pmtmr.h>
13 #include <linux/efi.h>
14 #include <linux/cpumask.h>
15 #include <linux/export.h>
16 #include <linux/dmi.h>
17 #include <linux/irq.h>
18 #include <linux/slab.h>
19 #include <linux/memblock.h>
20 #include <linux/ioport.h>
21 #include <linux/pci.h>
22 #include <linux/efi-bgrt.h>
23 #include <linux/serial_core.h>
24 #include <linux/pgtable.h>
25 
26 #include <asm/e820/api.h>
27 #include <asm/irqdomain.h>
28 #include <asm/pci_x86.h>
29 #include <asm/io_apic.h>
30 #include <asm/apic.h>
31 #include <asm/io.h>
32 #include <asm/mpspec.h>
33 #include <asm/smp.h>
34 #include <asm/i8259.h>
35 #include <asm/setup.h>
36 
37 #include "sleep.h" /* To include x86_acpi_suspend_lowlevel */
38 static int __initdata acpi_force = 0;
39 int acpi_disabled;
40 EXPORT_SYMBOL(acpi_disabled);
41 
42 #ifdef	CONFIG_X86_64
43 # include <asm/proto.h>
44 #endif				/* X86 */
45 
46 int acpi_noirq;				/* skip ACPI IRQ initialization */
47 static int acpi_nobgrt;			/* skip ACPI BGRT */
48 int acpi_pci_disabled;		/* skip ACPI PCI scan and IRQ initialization */
49 EXPORT_SYMBOL(acpi_pci_disabled);
50 
51 int acpi_lapic;
52 int acpi_ioapic;
53 int acpi_strict;
54 int acpi_disable_cmcff;
55 
56 /* ACPI SCI override configuration */
57 u8 acpi_sci_flags __initdata;
58 u32 acpi_sci_override_gsi __initdata = INVALID_ACPI_IRQ;
59 int acpi_skip_timer_override __initdata;
60 int acpi_use_timer_override __initdata;
61 int acpi_fix_pin2_polarity __initdata;
62 
63 #ifdef CONFIG_X86_LOCAL_APIC
64 static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;
65 static bool acpi_support_online_capable;
66 #endif
67 
68 #ifdef CONFIG_X86_64
69 /* Physical address of the Multiprocessor Wakeup Structure mailbox */
70 static u64 acpi_mp_wake_mailbox_paddr;
71 /* Virtual address of the Multiprocessor Wakeup Structure mailbox */
72 static struct acpi_madt_multiproc_wakeup_mailbox *acpi_mp_wake_mailbox;
73 #endif
74 
75 #ifdef CONFIG_X86_IO_APIC
76 /*
77  * Locks related to IOAPIC hotplug
78  * Hotplug side:
79  *	->device_hotplug_lock
80  *		->acpi_ioapic_lock
81  *			->ioapic_lock
82  * Interrupt mapping side:
83  *	->acpi_ioapic_lock
84  *		->ioapic_mutex
85  *			->ioapic_lock
86  */
87 static DEFINE_MUTEX(acpi_ioapic_lock);
88 #endif
89 
90 /* --------------------------------------------------------------------------
91                               Boot-time Configuration
92    -------------------------------------------------------------------------- */
93 
94 /*
95  * The default interrupt routing model is PIC (8259).  This gets
96  * overridden if IOAPICs are enumerated (below).
97  */
98 enum acpi_irq_model_id acpi_irq_model = ACPI_IRQ_MODEL_PIC;
99 
100 
101 /*
102  * ISA irqs by default are the first 16 gsis but can be
103  * any gsi as specified by an interrupt source override.
104  */
105 static u32 isa_irq_to_gsi[NR_IRQS_LEGACY] __read_mostly = {
106 	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
107 };
108 
109 /*
110  * This is just a simple wrapper around early_memremap(),
111  * with sanity checks for phys == 0 and size == 0.
112  */
113 void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
114 {
115 
116 	if (!phys || !size)
117 		return NULL;
118 
119 	return early_memremap(phys, size);
120 }
121 
122 void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
123 {
124 	if (!map || !size)
125 		return;
126 
127 	early_memunmap(map, size);
128 }
129 
130 #ifdef CONFIG_X86_LOCAL_APIC
131 static int __init acpi_parse_madt(struct acpi_table_header *table)
132 {
133 	struct acpi_table_madt *madt = NULL;
134 
135 	if (!boot_cpu_has(X86_FEATURE_APIC))
136 		return -EINVAL;
137 
138 	madt = (struct acpi_table_madt *)table;
139 	if (!madt) {
140 		pr_warn("Unable to map MADT\n");
141 		return -ENODEV;
142 	}
143 
144 	if (madt->address) {
145 		acpi_lapic_addr = (u64) madt->address;
146 
147 		pr_debug("Local APIC address 0x%08x\n", madt->address);
148 	}
149 	if (madt->header.revision >= 5)
150 		acpi_support_online_capable = true;
151 
152 	default_acpi_madt_oem_check(madt->header.oem_id,
153 				    madt->header.oem_table_id);
154 
155 	return 0;
156 }
157 
158 /**
159  * acpi_register_lapic - register a local apic and generates a logic cpu number
160  * @id: local apic id to register
161  * @acpiid: ACPI id to register
162  * @enabled: this cpu is enabled or not
163  *
164  * Returns the logic cpu number which maps to the local apic
165  */
166 static int acpi_register_lapic(int id, u32 acpiid, u8 enabled)
167 {
168 	unsigned int ver = 0;
169 	int cpu;
170 
171 	if (id >= MAX_LOCAL_APIC) {
172 		pr_info("skipped apicid that is too big\n");
173 		return -EINVAL;
174 	}
175 
176 	if (!enabled) {
177 		++disabled_cpus;
178 		return -EINVAL;
179 	}
180 
181 	if (boot_cpu_physical_apicid != -1U)
182 		ver = boot_cpu_apic_version;
183 
184 	cpu = generic_processor_info(id, ver);
185 	if (cpu >= 0)
186 		early_per_cpu(x86_cpu_to_acpiid, cpu) = acpiid;
187 
188 	return cpu;
189 }
190 
191 static bool __init acpi_is_processor_usable(u32 lapic_flags)
192 {
193 	if (lapic_flags & ACPI_MADT_ENABLED)
194 		return true;
195 
196 	if (acpi_support_online_capable && (lapic_flags & ACPI_MADT_ONLINE_CAPABLE))
197 		return true;
198 
199 	return false;
200 }
201 
202 static int __init
203 acpi_parse_x2apic(union acpi_subtable_headers *header, const unsigned long end)
204 {
205 	struct acpi_madt_local_x2apic *processor = NULL;
206 #ifdef CONFIG_X86_X2APIC
207 	u32 apic_id;
208 	u8 enabled;
209 #endif
210 
211 	processor = (struct acpi_madt_local_x2apic *)header;
212 
213 	if (BAD_MADT_ENTRY(processor, end))
214 		return -EINVAL;
215 
216 	acpi_table_print_madt_entry(&header->common);
217 
218 #ifdef CONFIG_X86_X2APIC
219 	apic_id = processor->local_apic_id;
220 	enabled = processor->lapic_flags & ACPI_MADT_ENABLED;
221 
222 	/* Ignore invalid ID */
223 	if (apic_id == 0xffffffff)
224 		return 0;
225 
226 	/* don't register processors that cannot be onlined */
227 	if (!acpi_is_processor_usable(processor->lapic_flags))
228 		return 0;
229 
230 	/*
231 	 * We need to register disabled CPU as well to permit
232 	 * counting disabled CPUs. This allows us to size
233 	 * cpus_possible_map more accurately, to permit
234 	 * to not preallocating memory for all NR_CPUS
235 	 * when we use CPU hotplug.
236 	 */
237 	if (!apic->apic_id_valid(apic_id)) {
238 		if (enabled)
239 			pr_warn("x2apic entry ignored\n");
240 		return 0;
241 	}
242 
243 	acpi_register_lapic(apic_id, processor->uid, enabled);
244 #else
245 	pr_warn("x2apic entry ignored\n");
246 #endif
247 
248 	return 0;
249 }
250 
251 static int __init
252 acpi_parse_lapic(union acpi_subtable_headers * header, const unsigned long end)
253 {
254 	struct acpi_madt_local_apic *processor = NULL;
255 
256 	processor = (struct acpi_madt_local_apic *)header;
257 
258 	if (BAD_MADT_ENTRY(processor, end))
259 		return -EINVAL;
260 
261 	acpi_table_print_madt_entry(&header->common);
262 
263 	/* Ignore invalid ID */
264 	if (processor->id == 0xff)
265 		return 0;
266 
267 	/* don't register processors that can not be onlined */
268 	if (!acpi_is_processor_usable(processor->lapic_flags))
269 		return 0;
270 
271 	/*
272 	 * We need to register disabled CPU as well to permit
273 	 * counting disabled CPUs. This allows us to size
274 	 * cpus_possible_map more accurately, to permit
275 	 * to not preallocating memory for all NR_CPUS
276 	 * when we use CPU hotplug.
277 	 */
278 	acpi_register_lapic(processor->id,	/* APIC ID */
279 			    processor->processor_id, /* ACPI ID */
280 			    processor->lapic_flags & ACPI_MADT_ENABLED);
281 
282 	return 0;
283 }
284 
285 static int __init
286 acpi_parse_sapic(union acpi_subtable_headers *header, const unsigned long end)
287 {
288 	struct acpi_madt_local_sapic *processor = NULL;
289 
290 	processor = (struct acpi_madt_local_sapic *)header;
291 
292 	if (BAD_MADT_ENTRY(processor, end))
293 		return -EINVAL;
294 
295 	acpi_table_print_madt_entry(&header->common);
296 
297 	acpi_register_lapic((processor->id << 8) | processor->eid,/* APIC ID */
298 			    processor->processor_id, /* ACPI ID */
299 			    processor->lapic_flags & ACPI_MADT_ENABLED);
300 
301 	return 0;
302 }
303 
304 static int __init
305 acpi_parse_lapic_addr_ovr(union acpi_subtable_headers * header,
306 			  const unsigned long end)
307 {
308 	struct acpi_madt_local_apic_override *lapic_addr_ovr = NULL;
309 
310 	lapic_addr_ovr = (struct acpi_madt_local_apic_override *)header;
311 
312 	if (BAD_MADT_ENTRY(lapic_addr_ovr, end))
313 		return -EINVAL;
314 
315 	acpi_table_print_madt_entry(&header->common);
316 
317 	acpi_lapic_addr = lapic_addr_ovr->address;
318 
319 	return 0;
320 }
321 
322 static int __init
323 acpi_parse_x2apic_nmi(union acpi_subtable_headers *header,
324 		      const unsigned long end)
325 {
326 	struct acpi_madt_local_x2apic_nmi *x2apic_nmi = NULL;
327 
328 	x2apic_nmi = (struct acpi_madt_local_x2apic_nmi *)header;
329 
330 	if (BAD_MADT_ENTRY(x2apic_nmi, end))
331 		return -EINVAL;
332 
333 	acpi_table_print_madt_entry(&header->common);
334 
335 	if (x2apic_nmi->lint != 1)
336 		pr_warn("NMI not connected to LINT 1!\n");
337 
338 	return 0;
339 }
340 
341 static int __init
342 acpi_parse_lapic_nmi(union acpi_subtable_headers * header, const unsigned long end)
343 {
344 	struct acpi_madt_local_apic_nmi *lapic_nmi = NULL;
345 
346 	lapic_nmi = (struct acpi_madt_local_apic_nmi *)header;
347 
348 	if (BAD_MADT_ENTRY(lapic_nmi, end))
349 		return -EINVAL;
350 
351 	acpi_table_print_madt_entry(&header->common);
352 
353 	if (lapic_nmi->lint != 1)
354 		pr_warn("NMI not connected to LINT 1!\n");
355 
356 	return 0;
357 }
358 
359 #ifdef CONFIG_X86_64
360 static int acpi_wakeup_cpu(int apicid, unsigned long start_ip)
361 {
362 	/*
363 	 * Remap mailbox memory only for the first call to acpi_wakeup_cpu().
364 	 *
365 	 * Wakeup of secondary CPUs is fully serialized in the core code.
366 	 * No need to protect acpi_mp_wake_mailbox from concurrent accesses.
367 	 */
368 	if (!acpi_mp_wake_mailbox) {
369 		acpi_mp_wake_mailbox = memremap(acpi_mp_wake_mailbox_paddr,
370 						sizeof(*acpi_mp_wake_mailbox),
371 						MEMREMAP_WB);
372 	}
373 
374 	/*
375 	 * Mailbox memory is shared between the firmware and OS. Firmware will
376 	 * listen on mailbox command address, and once it receives the wakeup
377 	 * command, the CPU associated with the given apicid will be booted.
378 	 *
379 	 * The value of 'apic_id' and 'wakeup_vector' must be visible to the
380 	 * firmware before the wakeup command is visible.  smp_store_release()
381 	 * ensures ordering and visibility.
382 	 */
383 	acpi_mp_wake_mailbox->apic_id	    = apicid;
384 	acpi_mp_wake_mailbox->wakeup_vector = start_ip;
385 	smp_store_release(&acpi_mp_wake_mailbox->command,
386 			  ACPI_MP_WAKE_COMMAND_WAKEUP);
387 
388 	/*
389 	 * Wait for the CPU to wake up.
390 	 *
391 	 * The CPU being woken up is essentially in a spin loop waiting to be
392 	 * woken up. It should not take long for it wake up and acknowledge by
393 	 * zeroing out ->command.
394 	 *
395 	 * ACPI specification doesn't provide any guidance on how long kernel
396 	 * has to wait for a wake up acknowledgement. It also doesn't provide
397 	 * a way to cancel a wake up request if it takes too long.
398 	 *
399 	 * In TDX environment, the VMM has control over how long it takes to
400 	 * wake up secondary. It can postpone scheduling secondary vCPU
401 	 * indefinitely. Giving up on wake up request and reporting error opens
402 	 * possible attack vector for VMM: it can wake up a secondary CPU when
403 	 * kernel doesn't expect it. Wait until positive result of the wake up
404 	 * request.
405 	 */
406 	while (READ_ONCE(acpi_mp_wake_mailbox->command))
407 		cpu_relax();
408 
409 	return 0;
410 }
411 #endif /* CONFIG_X86_64 */
412 #endif /* CONFIG_X86_LOCAL_APIC */
413 
414 #ifdef CONFIG_X86_IO_APIC
415 #define MP_ISA_BUS		0
416 
417 static int __init mp_register_ioapic_irq(u8 bus_irq, u8 polarity,
418 						u8 trigger, u32 gsi);
419 
420 static void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger,
421 					  u32 gsi)
422 {
423 	/*
424 	 * Check bus_irq boundary.
425 	 */
426 	if (bus_irq >= NR_IRQS_LEGACY) {
427 		pr_warn("Invalid bus_irq %u for legacy override\n", bus_irq);
428 		return;
429 	}
430 
431 	/*
432 	 * TBD: This check is for faulty timer entries, where the override
433 	 *      erroneously sets the trigger to level, resulting in a HUGE
434 	 *      increase of timer interrupts!
435 	 */
436 	if ((bus_irq == 0) && (trigger == 3))
437 		trigger = 1;
438 
439 	if (mp_register_ioapic_irq(bus_irq, polarity, trigger, gsi) < 0)
440 		return;
441 	/*
442 	 * Reset default identity mapping if gsi is also an legacy IRQ,
443 	 * otherwise there will be more than one entry with the same GSI
444 	 * and acpi_isa_irq_to_gsi() may give wrong result.
445 	 */
446 	if (gsi < nr_legacy_irqs() && isa_irq_to_gsi[gsi] == gsi)
447 		isa_irq_to_gsi[gsi] = INVALID_ACPI_IRQ;
448 	isa_irq_to_gsi[bus_irq] = gsi;
449 }
450 
451 static void mp_config_acpi_gsi(struct device *dev, u32 gsi, int trigger,
452 			int polarity)
453 {
454 #ifdef CONFIG_X86_MPPARSE
455 	struct mpc_intsrc mp_irq;
456 	struct pci_dev *pdev;
457 	unsigned char number;
458 	unsigned int devfn;
459 	int ioapic;
460 	u8 pin;
461 
462 	if (!acpi_ioapic)
463 		return;
464 	if (!dev || !dev_is_pci(dev))
465 		return;
466 
467 	pdev = to_pci_dev(dev);
468 	number = pdev->bus->number;
469 	devfn = pdev->devfn;
470 	pin = pdev->pin;
471 	/* print the entry should happen on mptable identically */
472 	mp_irq.type = MP_INTSRC;
473 	mp_irq.irqtype = mp_INT;
474 	mp_irq.irqflag = (trigger == ACPI_EDGE_SENSITIVE ? 4 : 0x0c) |
475 				(polarity == ACPI_ACTIVE_HIGH ? 1 : 3);
476 	mp_irq.srcbus = number;
477 	mp_irq.srcbusirq = (((devfn >> 3) & 0x1f) << 2) | ((pin - 1) & 3);
478 	ioapic = mp_find_ioapic(gsi);
479 	mp_irq.dstapic = mpc_ioapic_id(ioapic);
480 	mp_irq.dstirq = mp_find_ioapic_pin(ioapic, gsi);
481 
482 	mp_save_irq(&mp_irq);
483 #endif
484 }
485 
486 static int __init mp_register_ioapic_irq(u8 bus_irq, u8 polarity,
487 						u8 trigger, u32 gsi)
488 {
489 	struct mpc_intsrc mp_irq;
490 	int ioapic, pin;
491 
492 	/* Convert 'gsi' to 'ioapic.pin'(INTIN#) */
493 	ioapic = mp_find_ioapic(gsi);
494 	if (ioapic < 0) {
495 		pr_warn("Failed to find ioapic for gsi : %u\n", gsi);
496 		return ioapic;
497 	}
498 
499 	pin = mp_find_ioapic_pin(ioapic, gsi);
500 
501 	mp_irq.type = MP_INTSRC;
502 	mp_irq.irqtype = mp_INT;
503 	mp_irq.irqflag = (trigger << 2) | polarity;
504 	mp_irq.srcbus = MP_ISA_BUS;
505 	mp_irq.srcbusirq = bus_irq;
506 	mp_irq.dstapic = mpc_ioapic_id(ioapic);
507 	mp_irq.dstirq = pin;
508 
509 	mp_save_irq(&mp_irq);
510 
511 	return 0;
512 }
513 
514 static int __init
515 acpi_parse_ioapic(union acpi_subtable_headers * header, const unsigned long end)
516 {
517 	struct acpi_madt_io_apic *ioapic = NULL;
518 	struct ioapic_domain_cfg cfg = {
519 		.type = IOAPIC_DOMAIN_DYNAMIC,
520 		.ops = &mp_ioapic_irqdomain_ops,
521 	};
522 
523 	ioapic = (struct acpi_madt_io_apic *)header;
524 
525 	if (BAD_MADT_ENTRY(ioapic, end))
526 		return -EINVAL;
527 
528 	acpi_table_print_madt_entry(&header->common);
529 
530 	/* Statically assign IRQ numbers for IOAPICs hosting legacy IRQs */
531 	if (ioapic->global_irq_base < nr_legacy_irqs())
532 		cfg.type = IOAPIC_DOMAIN_LEGACY;
533 
534 	mp_register_ioapic(ioapic->id, ioapic->address, ioapic->global_irq_base,
535 			   &cfg);
536 
537 	return 0;
538 }
539 
540 /*
541  * Parse Interrupt Source Override for the ACPI SCI
542  */
543 static void __init acpi_sci_ioapic_setup(u8 bus_irq, u16 polarity, u16 trigger, u32 gsi)
544 {
545 	if (trigger == 0)	/* compatible SCI trigger is level */
546 		trigger = 3;
547 
548 	if (polarity == 0)	/* compatible SCI polarity is low */
549 		polarity = 3;
550 
551 	/* Command-line over-ride via acpi_sci= */
552 	if (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)
553 		trigger = (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
554 
555 	if (acpi_sci_flags & ACPI_MADT_POLARITY_MASK)
556 		polarity = acpi_sci_flags & ACPI_MADT_POLARITY_MASK;
557 
558 	if (bus_irq < NR_IRQS_LEGACY)
559 		mp_override_legacy_irq(bus_irq, polarity, trigger, gsi);
560 	else
561 		mp_register_ioapic_irq(bus_irq, polarity, trigger, gsi);
562 
563 	acpi_penalize_sci_irq(bus_irq, trigger, polarity);
564 
565 	/*
566 	 * stash over-ride to indicate we've been here
567 	 * and for later update of acpi_gbl_FADT
568 	 */
569 	acpi_sci_override_gsi = gsi;
570 	return;
571 }
572 
573 static int __init
574 acpi_parse_int_src_ovr(union acpi_subtable_headers * header,
575 		       const unsigned long end)
576 {
577 	struct acpi_madt_interrupt_override *intsrc = NULL;
578 
579 	intsrc = (struct acpi_madt_interrupt_override *)header;
580 
581 	if (BAD_MADT_ENTRY(intsrc, end))
582 		return -EINVAL;
583 
584 	acpi_table_print_madt_entry(&header->common);
585 
586 	if (intsrc->source_irq == acpi_gbl_FADT.sci_interrupt) {
587 		acpi_sci_ioapic_setup(intsrc->source_irq,
588 				      intsrc->inti_flags & ACPI_MADT_POLARITY_MASK,
589 				      (intsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2,
590 				      intsrc->global_irq);
591 		return 0;
592 	}
593 
594 	if (intsrc->source_irq == 0) {
595 		if (acpi_skip_timer_override) {
596 			pr_warn("BIOS IRQ0 override ignored.\n");
597 			return 0;
598 		}
599 
600 		if ((intsrc->global_irq == 2) && acpi_fix_pin2_polarity
601 			&& (intsrc->inti_flags & ACPI_MADT_POLARITY_MASK)) {
602 			intsrc->inti_flags &= ~ACPI_MADT_POLARITY_MASK;
603 			pr_warn("BIOS IRQ0 pin2 override: forcing polarity to high active.\n");
604 		}
605 	}
606 
607 	mp_override_legacy_irq(intsrc->source_irq,
608 				intsrc->inti_flags & ACPI_MADT_POLARITY_MASK,
609 				(intsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2,
610 				intsrc->global_irq);
611 
612 	return 0;
613 }
614 
615 static int __init
616 acpi_parse_nmi_src(union acpi_subtable_headers * header, const unsigned long end)
617 {
618 	struct acpi_madt_nmi_source *nmi_src = NULL;
619 
620 	nmi_src = (struct acpi_madt_nmi_source *)header;
621 
622 	if (BAD_MADT_ENTRY(nmi_src, end))
623 		return -EINVAL;
624 
625 	acpi_table_print_madt_entry(&header->common);
626 
627 	/* TBD: Support nimsrc entries? */
628 
629 	return 0;
630 }
631 
632 #endif				/* CONFIG_X86_IO_APIC */
633 
634 /*
635  * acpi_pic_sci_set_trigger()
636  *
637  * use ELCR to set PIC-mode trigger type for SCI
638  *
639  * If a PIC-mode SCI is not recognized or gives spurious IRQ7's
640  * it may require Edge Trigger -- use "acpi_sci=edge"
641  *
642  * Port 0x4d0-4d1 are ELCR1 and ELCR2, the Edge/Level Control Registers
643  * for the 8259 PIC.  bit[n] = 1 means irq[n] is Level, otherwise Edge.
644  * ELCR1 is IRQs 0-7 (IRQ 0, 1, 2 must be 0)
645  * ELCR2 is IRQs 8-15 (IRQ 8, 13 must be 0)
646  */
647 
648 void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger)
649 {
650 	unsigned int mask = 1 << irq;
651 	unsigned int old, new;
652 
653 	/* Real old ELCR mask */
654 	old = inb(PIC_ELCR1) | (inb(PIC_ELCR2) << 8);
655 
656 	/*
657 	 * If we use ACPI to set PCI IRQs, then we should clear ELCR
658 	 * since we will set it correctly as we enable the PCI irq
659 	 * routing.
660 	 */
661 	new = acpi_noirq ? old : 0;
662 
663 	/*
664 	 * Update SCI information in the ELCR, it isn't in the PCI
665 	 * routing tables..
666 	 */
667 	switch (trigger) {
668 	case 1:		/* Edge - clear */
669 		new &= ~mask;
670 		break;
671 	case 3:		/* Level - set */
672 		new |= mask;
673 		break;
674 	}
675 
676 	if (old == new)
677 		return;
678 
679 	pr_warn("setting ELCR to %04x (from %04x)\n", new, old);
680 	outb(new, PIC_ELCR1);
681 	outb(new >> 8, PIC_ELCR2);
682 }
683 
684 int acpi_gsi_to_irq(u32 gsi, unsigned int *irqp)
685 {
686 	int rc, irq, trigger, polarity;
687 
688 	if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) {
689 		*irqp = gsi;
690 		return 0;
691 	}
692 
693 	rc = acpi_get_override_irq(gsi, &trigger, &polarity);
694 	if (rc)
695 		return rc;
696 
697 	trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
698 	polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
699 	irq = acpi_register_gsi(NULL, gsi, trigger, polarity);
700 	if (irq < 0)
701 		return irq;
702 
703 	*irqp = irq;
704 	return 0;
705 }
706 EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
707 
708 int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi)
709 {
710 	if (isa_irq < nr_legacy_irqs() &&
711 	    isa_irq_to_gsi[isa_irq] != INVALID_ACPI_IRQ) {
712 		*gsi = isa_irq_to_gsi[isa_irq];
713 		return 0;
714 	}
715 
716 	return -1;
717 }
718 
719 static int acpi_register_gsi_pic(struct device *dev, u32 gsi,
720 				 int trigger, int polarity)
721 {
722 #ifdef CONFIG_PCI
723 	/*
724 	 * Make sure all (legacy) PCI IRQs are set as level-triggered.
725 	 */
726 	if (trigger == ACPI_LEVEL_SENSITIVE)
727 		elcr_set_level_irq(gsi);
728 #endif
729 
730 	return gsi;
731 }
732 
733 #ifdef CONFIG_X86_LOCAL_APIC
734 static int acpi_register_gsi_ioapic(struct device *dev, u32 gsi,
735 				    int trigger, int polarity)
736 {
737 	int irq = gsi;
738 #ifdef CONFIG_X86_IO_APIC
739 	int node;
740 	struct irq_alloc_info info;
741 
742 	node = dev ? dev_to_node(dev) : NUMA_NO_NODE;
743 	trigger = trigger == ACPI_EDGE_SENSITIVE ? 0 : 1;
744 	polarity = polarity == ACPI_ACTIVE_HIGH ? 0 : 1;
745 	ioapic_set_alloc_attr(&info, node, trigger, polarity);
746 
747 	mutex_lock(&acpi_ioapic_lock);
748 	irq = mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC, &info);
749 	/* Don't set up the ACPI SCI because it's already set up */
750 	if (irq >= 0 && enable_update_mptable && gsi != acpi_gbl_FADT.sci_interrupt)
751 		mp_config_acpi_gsi(dev, gsi, trigger, polarity);
752 	mutex_unlock(&acpi_ioapic_lock);
753 #endif
754 
755 	return irq;
756 }
757 
758 static void acpi_unregister_gsi_ioapic(u32 gsi)
759 {
760 #ifdef CONFIG_X86_IO_APIC
761 	int irq;
762 
763 	mutex_lock(&acpi_ioapic_lock);
764 	irq = mp_map_gsi_to_irq(gsi, 0, NULL);
765 	if (irq > 0)
766 		mp_unmap_irq(irq);
767 	mutex_unlock(&acpi_ioapic_lock);
768 #endif
769 }
770 #endif
771 
772 int (*__acpi_register_gsi)(struct device *dev, u32 gsi,
773 			   int trigger, int polarity) = acpi_register_gsi_pic;
774 void (*__acpi_unregister_gsi)(u32 gsi) = NULL;
775 
776 #ifdef CONFIG_ACPI_SLEEP
777 int (*acpi_suspend_lowlevel)(void) = x86_acpi_suspend_lowlevel;
778 #else
779 int (*acpi_suspend_lowlevel)(void);
780 #endif
781 
782 /*
783  * success: return IRQ number (>=0)
784  * failure: return < 0
785  */
786 int acpi_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
787 {
788 	return __acpi_register_gsi(dev, gsi, trigger, polarity);
789 }
790 EXPORT_SYMBOL_GPL(acpi_register_gsi);
791 
792 void acpi_unregister_gsi(u32 gsi)
793 {
794 	if (__acpi_unregister_gsi)
795 		__acpi_unregister_gsi(gsi);
796 }
797 EXPORT_SYMBOL_GPL(acpi_unregister_gsi);
798 
799 #ifdef CONFIG_X86_LOCAL_APIC
800 static void __init acpi_set_irq_model_ioapic(void)
801 {
802 	acpi_irq_model = ACPI_IRQ_MODEL_IOAPIC;
803 	__acpi_register_gsi = acpi_register_gsi_ioapic;
804 	__acpi_unregister_gsi = acpi_unregister_gsi_ioapic;
805 	acpi_ioapic = 1;
806 }
807 #endif
808 
809 /*
810  *  ACPI based hotplug support for CPU
811  */
812 #ifdef CONFIG_ACPI_HOTPLUG_CPU
813 #include <acpi/processor.h>
814 
815 static int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
816 {
817 #ifdef CONFIG_ACPI_NUMA
818 	int nid;
819 
820 	nid = acpi_get_node(handle);
821 	if (nid != NUMA_NO_NODE) {
822 		set_apicid_to_node(physid, nid);
823 		numa_set_node(cpu, nid);
824 	}
825 #endif
826 	return 0;
827 }
828 
829 int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id,
830 		 int *pcpu)
831 {
832 	int cpu;
833 
834 	cpu = acpi_register_lapic(physid, acpi_id, ACPI_MADT_ENABLED);
835 	if (cpu < 0) {
836 		pr_info("Unable to map lapic to logical cpu number\n");
837 		return cpu;
838 	}
839 
840 	acpi_processor_set_pdc(handle);
841 	acpi_map_cpu2node(handle, cpu, physid);
842 
843 	*pcpu = cpu;
844 	return 0;
845 }
846 EXPORT_SYMBOL(acpi_map_cpu);
847 
848 int acpi_unmap_cpu(int cpu)
849 {
850 #ifdef CONFIG_ACPI_NUMA
851 	set_apicid_to_node(per_cpu(x86_cpu_to_apicid, cpu), NUMA_NO_NODE);
852 #endif
853 
854 	per_cpu(x86_cpu_to_apicid, cpu) = -1;
855 	set_cpu_present(cpu, false);
856 	num_processors--;
857 
858 	return (0);
859 }
860 EXPORT_SYMBOL(acpi_unmap_cpu);
861 #endif				/* CONFIG_ACPI_HOTPLUG_CPU */
862 
863 int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base)
864 {
865 	int ret = -ENOSYS;
866 #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
867 	int ioapic_id;
868 	u64 addr;
869 	struct ioapic_domain_cfg cfg = {
870 		.type = IOAPIC_DOMAIN_DYNAMIC,
871 		.ops = &mp_ioapic_irqdomain_ops,
872 	};
873 
874 	ioapic_id = acpi_get_ioapic_id(handle, gsi_base, &addr);
875 	if (ioapic_id < 0) {
876 		unsigned long long uid;
877 		acpi_status status;
878 
879 		status = acpi_evaluate_integer(handle, METHOD_NAME__UID,
880 					       NULL, &uid);
881 		if (ACPI_FAILURE(status)) {
882 			acpi_handle_warn(handle, "failed to get IOAPIC ID.\n");
883 			return -EINVAL;
884 		}
885 		ioapic_id = (int)uid;
886 	}
887 
888 	mutex_lock(&acpi_ioapic_lock);
889 	ret  = mp_register_ioapic(ioapic_id, phys_addr, gsi_base, &cfg);
890 	mutex_unlock(&acpi_ioapic_lock);
891 #endif
892 
893 	return ret;
894 }
895 EXPORT_SYMBOL(acpi_register_ioapic);
896 
897 int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base)
898 {
899 	int ret = -ENOSYS;
900 
901 #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
902 	mutex_lock(&acpi_ioapic_lock);
903 	ret  = mp_unregister_ioapic(gsi_base);
904 	mutex_unlock(&acpi_ioapic_lock);
905 #endif
906 
907 	return ret;
908 }
909 EXPORT_SYMBOL(acpi_unregister_ioapic);
910 
911 /**
912  * acpi_ioapic_registered - Check whether IOAPIC associated with @gsi_base
913  *			    has been registered
914  * @handle:	ACPI handle of the IOAPIC device
915  * @gsi_base:	GSI base associated with the IOAPIC
916  *
917  * Assume caller holds some type of lock to serialize acpi_ioapic_registered()
918  * with acpi_register_ioapic()/acpi_unregister_ioapic().
919  */
920 int acpi_ioapic_registered(acpi_handle handle, u32 gsi_base)
921 {
922 	int ret = 0;
923 
924 #ifdef CONFIG_ACPI_HOTPLUG_IOAPIC
925 	mutex_lock(&acpi_ioapic_lock);
926 	ret  = mp_ioapic_registered(gsi_base);
927 	mutex_unlock(&acpi_ioapic_lock);
928 #endif
929 
930 	return ret;
931 }
932 
933 static int __init acpi_parse_sbf(struct acpi_table_header *table)
934 {
935 	struct acpi_table_boot *sb = (struct acpi_table_boot *)table;
936 
937 	sbf_port = sb->cmos_index;	/* Save CMOS port */
938 
939 	return 0;
940 }
941 
942 #ifdef CONFIG_HPET_TIMER
943 #include <asm/hpet.h>
944 
945 static struct resource *hpet_res __initdata;
946 
947 static int __init acpi_parse_hpet(struct acpi_table_header *table)
948 {
949 	struct acpi_table_hpet *hpet_tbl = (struct acpi_table_hpet *)table;
950 
951 	if (hpet_tbl->address.space_id != ACPI_SPACE_MEM) {
952 		pr_warn("HPET timers must be located in memory.\n");
953 		return -1;
954 	}
955 
956 	hpet_address = hpet_tbl->address.address;
957 	hpet_blockid = hpet_tbl->sequence;
958 
959 	/*
960 	 * Some broken BIOSes advertise HPET at 0x0. We really do not
961 	 * want to allocate a resource there.
962 	 */
963 	if (!hpet_address) {
964 		pr_warn("HPET id: %#x base: %#lx is invalid\n", hpet_tbl->id, hpet_address);
965 		return 0;
966 	}
967 #ifdef CONFIG_X86_64
968 	/*
969 	 * Some even more broken BIOSes advertise HPET at
970 	 * 0xfed0000000000000 instead of 0xfed00000. Fix it up and add
971 	 * some noise:
972 	 */
973 	if (hpet_address == 0xfed0000000000000UL) {
974 		if (!hpet_force_user) {
975 			pr_warn("HPET id: %#x base: 0xfed0000000000000 is bogus, try hpet=force on the kernel command line to fix it up to 0xfed00000.\n",
976 				hpet_tbl->id);
977 			hpet_address = 0;
978 			return 0;
979 		}
980 		pr_warn("HPET id: %#x base: 0xfed0000000000000 fixed up to 0xfed00000.\n",
981 			hpet_tbl->id);
982 		hpet_address >>= 32;
983 	}
984 #endif
985 	pr_info("HPET id: %#x base: %#lx\n", hpet_tbl->id, hpet_address);
986 
987 	/*
988 	 * Allocate and initialize the HPET firmware resource for adding into
989 	 * the resource tree during the lateinit timeframe.
990 	 */
991 #define HPET_RESOURCE_NAME_SIZE 9
992 	hpet_res = memblock_alloc(sizeof(*hpet_res) + HPET_RESOURCE_NAME_SIZE,
993 				  SMP_CACHE_BYTES);
994 	if (!hpet_res)
995 		panic("%s: Failed to allocate %zu bytes\n", __func__,
996 		      sizeof(*hpet_res) + HPET_RESOURCE_NAME_SIZE);
997 
998 	hpet_res->name = (void *)&hpet_res[1];
999 	hpet_res->flags = IORESOURCE_MEM;
1000 	snprintf((char *)hpet_res->name, HPET_RESOURCE_NAME_SIZE, "HPET %u",
1001 		 hpet_tbl->sequence);
1002 
1003 	hpet_res->start = hpet_address;
1004 	hpet_res->end = hpet_address + (1 * 1024) - 1;
1005 
1006 	return 0;
1007 }
1008 
1009 /*
1010  * hpet_insert_resource inserts the HPET resources used into the resource
1011  * tree.
1012  */
1013 static __init int hpet_insert_resource(void)
1014 {
1015 	if (!hpet_res)
1016 		return 1;
1017 
1018 	return insert_resource(&iomem_resource, hpet_res);
1019 }
1020 
1021 late_initcall(hpet_insert_resource);
1022 
1023 #else
1024 #define	acpi_parse_hpet	NULL
1025 #endif
1026 
1027 static int __init acpi_parse_fadt(struct acpi_table_header *table)
1028 {
1029 	if (!(acpi_gbl_FADT.boot_flags & ACPI_FADT_LEGACY_DEVICES)) {
1030 		pr_debug("no legacy devices present\n");
1031 		x86_platform.legacy.devices.pnpbios = 0;
1032 	}
1033 
1034 	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID &&
1035 	    !(acpi_gbl_FADT.boot_flags & ACPI_FADT_8042) &&
1036 	    x86_platform.legacy.i8042 != X86_LEGACY_I8042_PLATFORM_ABSENT) {
1037 		pr_debug("i8042 controller is absent\n");
1038 		x86_platform.legacy.i8042 = X86_LEGACY_I8042_FIRMWARE_ABSENT;
1039 	}
1040 
1041 	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_CMOS_RTC) {
1042 		pr_debug("not registering RTC platform device\n");
1043 		x86_platform.legacy.rtc = 0;
1044 	}
1045 
1046 	if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_VGA) {
1047 		pr_debug("probing for VGA not safe\n");
1048 		x86_platform.legacy.no_vga = 1;
1049 	}
1050 
1051 #ifdef CONFIG_X86_PM_TIMER
1052 	/* detect the location of the ACPI PM Timer */
1053 	if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) {
1054 		/* FADT rev. 2 */
1055 		if (acpi_gbl_FADT.xpm_timer_block.space_id !=
1056 		    ACPI_ADR_SPACE_SYSTEM_IO)
1057 			return 0;
1058 
1059 		pmtmr_ioport = acpi_gbl_FADT.xpm_timer_block.address;
1060 		/*
1061 		 * "X" fields are optional extensions to the original V1.0
1062 		 * fields, so we must selectively expand V1.0 fields if the
1063 		 * corresponding X field is zero.
1064 	 	 */
1065 		if (!pmtmr_ioport)
1066 			pmtmr_ioport = acpi_gbl_FADT.pm_timer_block;
1067 	} else {
1068 		/* FADT rev. 1 */
1069 		pmtmr_ioport = acpi_gbl_FADT.pm_timer_block;
1070 	}
1071 	if (pmtmr_ioport)
1072 		pr_info("PM-Timer IO Port: %#x\n", pmtmr_ioport);
1073 #endif
1074 	return 0;
1075 }
1076 
1077 #ifdef	CONFIG_X86_LOCAL_APIC
1078 /*
1079  * Parse LAPIC entries in MADT
1080  * returns 0 on success, < 0 on error
1081  */
1082 
1083 static int __init early_acpi_parse_madt_lapic_addr_ovr(void)
1084 {
1085 	int count;
1086 
1087 	if (!boot_cpu_has(X86_FEATURE_APIC))
1088 		return -ENODEV;
1089 
1090 	/*
1091 	 * Note that the LAPIC address is obtained from the MADT (32-bit value)
1092 	 * and (optionally) overridden by a LAPIC_ADDR_OVR entry (64-bit value).
1093 	 */
1094 
1095 	count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE,
1096 				      acpi_parse_lapic_addr_ovr, 0);
1097 	if (count < 0) {
1098 		pr_err("Error parsing LAPIC address override entry\n");
1099 		return count;
1100 	}
1101 
1102 	register_lapic_address(acpi_lapic_addr);
1103 
1104 	return count;
1105 }
1106 
1107 static int __init acpi_parse_madt_lapic_entries(void)
1108 {
1109 	int count;
1110 	int x2count = 0;
1111 	int ret;
1112 	struct acpi_subtable_proc madt_proc[2];
1113 
1114 	if (!boot_cpu_has(X86_FEATURE_APIC))
1115 		return -ENODEV;
1116 
1117 	count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_SAPIC,
1118 				      acpi_parse_sapic, MAX_LOCAL_APIC);
1119 
1120 	if (!count) {
1121 		memset(madt_proc, 0, sizeof(madt_proc));
1122 		madt_proc[0].id = ACPI_MADT_TYPE_LOCAL_APIC;
1123 		madt_proc[0].handler = acpi_parse_lapic;
1124 		madt_proc[1].id = ACPI_MADT_TYPE_LOCAL_X2APIC;
1125 		madt_proc[1].handler = acpi_parse_x2apic;
1126 		ret = acpi_table_parse_entries_array(ACPI_SIG_MADT,
1127 				sizeof(struct acpi_table_madt),
1128 				madt_proc, ARRAY_SIZE(madt_proc), MAX_LOCAL_APIC);
1129 		if (ret < 0) {
1130 			pr_err("Error parsing LAPIC/X2APIC entries\n");
1131 			return ret;
1132 		}
1133 
1134 		count = madt_proc[0].count;
1135 		x2count = madt_proc[1].count;
1136 	}
1137 	if (!count && !x2count) {
1138 		pr_err("No LAPIC entries present\n");
1139 		/* TBD: Cleanup to allow fallback to MPS */
1140 		return -ENODEV;
1141 	} else if (count < 0 || x2count < 0) {
1142 		pr_err("Error parsing LAPIC entry\n");
1143 		/* TBD: Cleanup to allow fallback to MPS */
1144 		return count;
1145 	}
1146 
1147 	x2count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_X2APIC_NMI,
1148 					acpi_parse_x2apic_nmi, 0);
1149 	count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_NMI,
1150 				      acpi_parse_lapic_nmi, 0);
1151 	if (count < 0 || x2count < 0) {
1152 		pr_err("Error parsing LAPIC NMI entry\n");
1153 		/* TBD: Cleanup to allow fallback to MPS */
1154 		return count;
1155 	}
1156 	return 0;
1157 }
1158 
1159 #ifdef CONFIG_X86_64
1160 static int __init acpi_parse_mp_wake(union acpi_subtable_headers *header,
1161 				     const unsigned long end)
1162 {
1163 	struct acpi_madt_multiproc_wakeup *mp_wake;
1164 
1165 	if (!IS_ENABLED(CONFIG_SMP))
1166 		return -ENODEV;
1167 
1168 	mp_wake = (struct acpi_madt_multiproc_wakeup *)header;
1169 	if (BAD_MADT_ENTRY(mp_wake, end))
1170 		return -EINVAL;
1171 
1172 	acpi_table_print_madt_entry(&header->common);
1173 
1174 	acpi_mp_wake_mailbox_paddr = mp_wake->base_address;
1175 
1176 	acpi_wake_cpu_handler_update(acpi_wakeup_cpu);
1177 
1178 	return 0;
1179 }
1180 #endif				/* CONFIG_X86_64 */
1181 #endif				/* CONFIG_X86_LOCAL_APIC */
1182 
1183 #ifdef	CONFIG_X86_IO_APIC
1184 static void __init mp_config_acpi_legacy_irqs(void)
1185 {
1186 	int i;
1187 	struct mpc_intsrc mp_irq;
1188 
1189 #ifdef CONFIG_EISA
1190 	/*
1191 	 * Fabricate the legacy ISA bus (bus #31).
1192 	 */
1193 	mp_bus_id_to_type[MP_ISA_BUS] = MP_BUS_ISA;
1194 #endif
1195 	set_bit(MP_ISA_BUS, mp_bus_not_pci);
1196 	pr_debug("Bus #%d is ISA (nIRQs: %d)\n", MP_ISA_BUS, nr_legacy_irqs());
1197 
1198 	/*
1199 	 * Use the default configuration for the IRQs 0-15.  Unless
1200 	 * overridden by (MADT) interrupt source override entries.
1201 	 */
1202 	for (i = 0; i < nr_legacy_irqs(); i++) {
1203 		int ioapic, pin;
1204 		unsigned int dstapic;
1205 		int idx;
1206 		u32 gsi;
1207 
1208 		/* Locate the gsi that irq i maps to. */
1209 		if (acpi_isa_irq_to_gsi(i, &gsi))
1210 			continue;
1211 
1212 		/*
1213 		 * Locate the IOAPIC that manages the ISA IRQ.
1214 		 */
1215 		ioapic = mp_find_ioapic(gsi);
1216 		if (ioapic < 0)
1217 			continue;
1218 		pin = mp_find_ioapic_pin(ioapic, gsi);
1219 		dstapic = mpc_ioapic_id(ioapic);
1220 
1221 		for (idx = 0; idx < mp_irq_entries; idx++) {
1222 			struct mpc_intsrc *irq = mp_irqs + idx;
1223 
1224 			/* Do we already have a mapping for this ISA IRQ? */
1225 			if (irq->srcbus == MP_ISA_BUS && irq->srcbusirq == i)
1226 				break;
1227 
1228 			/* Do we already have a mapping for this IOAPIC pin */
1229 			if (irq->dstapic == dstapic && irq->dstirq == pin)
1230 				break;
1231 		}
1232 
1233 		if (idx != mp_irq_entries) {
1234 			pr_debug("ACPI: IRQ%d used by override.\n", i);
1235 			continue;	/* IRQ already used */
1236 		}
1237 
1238 		mp_irq.type = MP_INTSRC;
1239 		mp_irq.irqflag = 0;	/* Conforming */
1240 		mp_irq.srcbus = MP_ISA_BUS;
1241 		mp_irq.dstapic = dstapic;
1242 		mp_irq.irqtype = mp_INT;
1243 		mp_irq.srcbusirq = i; /* Identity mapped */
1244 		mp_irq.dstirq = pin;
1245 
1246 		mp_save_irq(&mp_irq);
1247 	}
1248 }
1249 
1250 /*
1251  * Parse IOAPIC related entries in MADT
1252  * returns 0 on success, < 0 on error
1253  */
1254 static int __init acpi_parse_madt_ioapic_entries(void)
1255 {
1256 	int count;
1257 
1258 	/*
1259 	 * ACPI interpreter is required to complete interrupt setup,
1260 	 * so if it is off, don't enumerate the io-apics with ACPI.
1261 	 * If MPS is present, it will handle them,
1262 	 * otherwise the system will stay in PIC mode
1263 	 */
1264 	if (acpi_disabled || acpi_noirq)
1265 		return -ENODEV;
1266 
1267 	if (!boot_cpu_has(X86_FEATURE_APIC))
1268 		return -ENODEV;
1269 
1270 	/*
1271 	 * if "noapic" boot option, don't look for IO-APICs
1272 	 */
1273 	if (skip_ioapic_setup) {
1274 		pr_info("Skipping IOAPIC probe due to 'noapic' option.\n");
1275 		return -ENODEV;
1276 	}
1277 
1278 	count = acpi_table_parse_madt(ACPI_MADT_TYPE_IO_APIC, acpi_parse_ioapic,
1279 				      MAX_IO_APICS);
1280 	if (!count) {
1281 		pr_err("No IOAPIC entries present\n");
1282 		return -ENODEV;
1283 	} else if (count < 0) {
1284 		pr_err("Error parsing IOAPIC entry\n");
1285 		return count;
1286 	}
1287 
1288 	count = acpi_table_parse_madt(ACPI_MADT_TYPE_INTERRUPT_OVERRIDE,
1289 				      acpi_parse_int_src_ovr, nr_irqs);
1290 	if (count < 0) {
1291 		pr_err("Error parsing interrupt source overrides entry\n");
1292 		/* TBD: Cleanup to allow fallback to MPS */
1293 		return count;
1294 	}
1295 
1296 	/*
1297 	 * If BIOS did not supply an INT_SRC_OVR for the SCI
1298 	 * pretend we got one so we can set the SCI flags.
1299 	 * But ignore setting up SCI on hardware reduced platforms.
1300 	 */
1301 	if (acpi_sci_override_gsi == INVALID_ACPI_IRQ && !acpi_gbl_reduced_hardware)
1302 		acpi_sci_ioapic_setup(acpi_gbl_FADT.sci_interrupt, 0, 0,
1303 				      acpi_gbl_FADT.sci_interrupt);
1304 
1305 	/* Fill in identity legacy mappings where no override */
1306 	mp_config_acpi_legacy_irqs();
1307 
1308 	count = acpi_table_parse_madt(ACPI_MADT_TYPE_NMI_SOURCE,
1309 				      acpi_parse_nmi_src, nr_irqs);
1310 	if (count < 0) {
1311 		pr_err("Error parsing NMI SRC entry\n");
1312 		/* TBD: Cleanup to allow fallback to MPS */
1313 		return count;
1314 	}
1315 
1316 	return 0;
1317 }
1318 #else
1319 static inline int acpi_parse_madt_ioapic_entries(void)
1320 {
1321 	return -1;
1322 }
1323 #endif	/* !CONFIG_X86_IO_APIC */
1324 
1325 static void __init early_acpi_process_madt(void)
1326 {
1327 #ifdef CONFIG_X86_LOCAL_APIC
1328 	int error;
1329 
1330 	if (!acpi_table_parse(ACPI_SIG_MADT, acpi_parse_madt)) {
1331 
1332 		/*
1333 		 * Parse MADT LAPIC entries
1334 		 */
1335 		error = early_acpi_parse_madt_lapic_addr_ovr();
1336 		if (!error) {
1337 			acpi_lapic = 1;
1338 			smp_found_config = 1;
1339 		}
1340 		if (error == -EINVAL) {
1341 			/*
1342 			 * Dell Precision Workstation 410, 610 come here.
1343 			 */
1344 			pr_err("Invalid BIOS MADT, disabling ACPI\n");
1345 			disable_acpi();
1346 		}
1347 	}
1348 #endif
1349 }
1350 
1351 static void __init acpi_process_madt(void)
1352 {
1353 #ifdef CONFIG_X86_LOCAL_APIC
1354 	int error;
1355 
1356 	if (!acpi_table_parse(ACPI_SIG_MADT, acpi_parse_madt)) {
1357 
1358 		/*
1359 		 * Parse MADT LAPIC entries
1360 		 */
1361 		error = acpi_parse_madt_lapic_entries();
1362 		if (!error) {
1363 			acpi_lapic = 1;
1364 
1365 			/*
1366 			 * Parse MADT IO-APIC entries
1367 			 */
1368 			mutex_lock(&acpi_ioapic_lock);
1369 			error = acpi_parse_madt_ioapic_entries();
1370 			mutex_unlock(&acpi_ioapic_lock);
1371 			if (!error) {
1372 				acpi_set_irq_model_ioapic();
1373 
1374 				smp_found_config = 1;
1375 			}
1376 
1377 #ifdef CONFIG_X86_64
1378 			/*
1379 			 * Parse MADT MP Wake entry.
1380 			 */
1381 			acpi_table_parse_madt(ACPI_MADT_TYPE_MULTIPROC_WAKEUP,
1382 					      acpi_parse_mp_wake, 1);
1383 #endif
1384 		}
1385 		if (error == -EINVAL) {
1386 			/*
1387 			 * Dell Precision Workstation 410, 610 come here.
1388 			 */
1389 			pr_err("Invalid BIOS MADT, disabling ACPI\n");
1390 			disable_acpi();
1391 		}
1392 	} else {
1393 		/*
1394  		 * ACPI found no MADT, and so ACPI wants UP PIC mode.
1395  		 * In the event an MPS table was found, forget it.
1396  		 * Boot with "acpi=off" to use MPS on such a system.
1397  		 */
1398 		if (smp_found_config) {
1399 			pr_warn("No APIC-table, disabling MPS\n");
1400 			smp_found_config = 0;
1401 		}
1402 	}
1403 
1404 	/*
1405 	 * ACPI supports both logical (e.g. Hyper-Threading) and physical
1406 	 * processors, where MPS only supports physical.
1407 	 */
1408 	if (acpi_lapic && acpi_ioapic)
1409 		pr_info("Using ACPI (MADT) for SMP configuration information\n");
1410 	else if (acpi_lapic)
1411 		pr_info("Using ACPI for processor (LAPIC) configuration information\n");
1412 #endif
1413 	return;
1414 }
1415 
1416 static int __init disable_acpi_irq(const struct dmi_system_id *d)
1417 {
1418 	if (!acpi_force) {
1419 		pr_notice("%s detected: force use of acpi=noirq\n", d->ident);
1420 		acpi_noirq_set();
1421 	}
1422 	return 0;
1423 }
1424 
1425 static int __init disable_acpi_pci(const struct dmi_system_id *d)
1426 {
1427 	if (!acpi_force) {
1428 		pr_notice("%s detected: force use of pci=noacpi\n", d->ident);
1429 		acpi_disable_pci();
1430 	}
1431 	return 0;
1432 }
1433 
1434 static int __init disable_acpi_xsdt(const struct dmi_system_id *d)
1435 {
1436 	if (!acpi_force) {
1437 		pr_notice("%s detected: force use of acpi=rsdt\n", d->ident);
1438 		acpi_gbl_do_not_use_xsdt = TRUE;
1439 	} else {
1440 		pr_notice("Warning: DMI blacklist says broken, but acpi XSDT forced\n");
1441 	}
1442 	return 0;
1443 }
1444 
1445 static int __init dmi_disable_acpi(const struct dmi_system_id *d)
1446 {
1447 	if (!acpi_force) {
1448 		pr_notice("%s detected: acpi off\n", d->ident);
1449 		disable_acpi();
1450 	} else {
1451 		pr_notice("Warning: DMI blacklist says broken, but acpi forced\n");
1452 	}
1453 	return 0;
1454 }
1455 
1456 /*
1457  * Force ignoring BIOS IRQ0 override
1458  */
1459 static int __init dmi_ignore_irq0_timer_override(const struct dmi_system_id *d)
1460 {
1461 	if (!acpi_skip_timer_override) {
1462 		pr_notice("%s detected: Ignoring BIOS IRQ0 override\n",
1463 			d->ident);
1464 		acpi_skip_timer_override = 1;
1465 	}
1466 	return 0;
1467 }
1468 
1469 /*
1470  * ACPI offers an alternative platform interface model that removes
1471  * ACPI hardware requirements for platforms that do not implement
1472  * the PC Architecture.
1473  *
1474  * We initialize the Hardware-reduced ACPI model here:
1475  */
1476 void __init acpi_generic_reduced_hw_init(void)
1477 {
1478 	/*
1479 	 * Override x86_init functions and bypass legacy PIC in
1480 	 * hardware reduced ACPI mode.
1481 	 */
1482 	x86_init.timers.timer_init	= x86_init_noop;
1483 	x86_init.irqs.pre_vector_init	= x86_init_noop;
1484 	legacy_pic			= &null_legacy_pic;
1485 }
1486 
1487 static void __init acpi_reduced_hw_init(void)
1488 {
1489 	if (acpi_gbl_reduced_hardware)
1490 		x86_init.acpi.reduced_hw_early_init();
1491 }
1492 
1493 /*
1494  * If your system is blacklisted here, but you find that acpi=force
1495  * works for you, please contact linux-acpi@vger.kernel.org
1496  */
1497 static const struct dmi_system_id acpi_dmi_table[] __initconst = {
1498 	/*
1499 	 * Boxes that need ACPI disabled
1500 	 */
1501 	{
1502 	 .callback = dmi_disable_acpi,
1503 	 .ident = "IBM Thinkpad",
1504 	 .matches = {
1505 		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1506 		     DMI_MATCH(DMI_BOARD_NAME, "2629H1G"),
1507 		     },
1508 	 },
1509 
1510 	/*
1511 	 * Boxes that need ACPI PCI IRQ routing disabled
1512 	 */
1513 	{
1514 	 .callback = disable_acpi_irq,
1515 	 .ident = "ASUS A7V",
1516 	 .matches = {
1517 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC"),
1518 		     DMI_MATCH(DMI_BOARD_NAME, "<A7V>"),
1519 		     /* newer BIOS, Revision 1011, does work */
1520 		     DMI_MATCH(DMI_BIOS_VERSION,
1521 			       "ASUS A7V ACPI BIOS Revision 1007"),
1522 		     },
1523 	 },
1524 	{
1525 		/*
1526 		 * Latest BIOS for IBM 600E (1.16) has bad pcinum
1527 		 * for LPC bridge, which is needed for the PCI
1528 		 * interrupt links to work. DSDT fix is in bug 5966.
1529 		 * 2645, 2646 model numbers are shared with 600/600E/600X
1530 		 */
1531 	 .callback = disable_acpi_irq,
1532 	 .ident = "IBM Thinkpad 600 Series 2645",
1533 	 .matches = {
1534 		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1535 		     DMI_MATCH(DMI_BOARD_NAME, "2645"),
1536 		     },
1537 	 },
1538 	{
1539 	 .callback = disable_acpi_irq,
1540 	 .ident = "IBM Thinkpad 600 Series 2646",
1541 	 .matches = {
1542 		     DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1543 		     DMI_MATCH(DMI_BOARD_NAME, "2646"),
1544 		     },
1545 	 },
1546 	/*
1547 	 * Boxes that need ACPI PCI IRQ routing and PCI scan disabled
1548 	 */
1549 	{			/* _BBN 0 bug */
1550 	 .callback = disable_acpi_pci,
1551 	 .ident = "ASUS PR-DLS",
1552 	 .matches = {
1553 		     DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
1554 		     DMI_MATCH(DMI_BOARD_NAME, "PR-DLS"),
1555 		     DMI_MATCH(DMI_BIOS_VERSION,
1556 			       "ASUS PR-DLS ACPI BIOS Revision 1010"),
1557 		     DMI_MATCH(DMI_BIOS_DATE, "03/21/2003")
1558 		     },
1559 	 },
1560 	{
1561 	 .callback = disable_acpi_pci,
1562 	 .ident = "Acer TravelMate 36x Laptop",
1563 	 .matches = {
1564 		     DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1565 		     DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 360"),
1566 		     },
1567 	 },
1568 	/*
1569 	 * Boxes that need ACPI XSDT use disabled due to corrupted tables
1570 	 */
1571 	{
1572 	 .callback = disable_acpi_xsdt,
1573 	 .ident = "Advantech DAC-BJ01",
1574 	 .matches = {
1575 		     DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
1576 		     DMI_MATCH(DMI_PRODUCT_NAME, "Bearlake CRB Board"),
1577 		     DMI_MATCH(DMI_BIOS_VERSION, "V1.12"),
1578 		     DMI_MATCH(DMI_BIOS_DATE, "02/01/2011"),
1579 		     },
1580 	 },
1581 	{}
1582 };
1583 
1584 /* second table for DMI checks that should run after early-quirks */
1585 static const struct dmi_system_id acpi_dmi_table_late[] __initconst = {
1586 	/*
1587 	 * HP laptops which use a DSDT reporting as HP/SB400/10000,
1588 	 * which includes some code which overrides all temperature
1589 	 * trip points to 16C if the INTIN2 input of the I/O APIC
1590 	 * is enabled.  This input is incorrectly designated the
1591 	 * ISA IRQ 0 via an interrupt source override even though
1592 	 * it is wired to the output of the master 8259A and INTIN0
1593 	 * is not connected at all.  Force ignoring BIOS IRQ0
1594 	 * override in that cases.
1595 	 */
1596 	{
1597 	 .callback = dmi_ignore_irq0_timer_override,
1598 	 .ident = "HP nx6115 laptop",
1599 	 .matches = {
1600 		     DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1601 		     DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq nx6115"),
1602 		     },
1603 	 },
1604 	{
1605 	 .callback = dmi_ignore_irq0_timer_override,
1606 	 .ident = "HP NX6125 laptop",
1607 	 .matches = {
1608 		     DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1609 		     DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq nx6125"),
1610 		     },
1611 	 },
1612 	{
1613 	 .callback = dmi_ignore_irq0_timer_override,
1614 	 .ident = "HP NX6325 laptop",
1615 	 .matches = {
1616 		     DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1617 		     DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq nx6325"),
1618 		     },
1619 	 },
1620 	{
1621 	 .callback = dmi_ignore_irq0_timer_override,
1622 	 .ident = "HP 6715b laptop",
1623 	 .matches = {
1624 		     DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
1625 		     DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq 6715b"),
1626 		     },
1627 	 },
1628 	{
1629 	 .callback = dmi_ignore_irq0_timer_override,
1630 	 .ident = "FUJITSU SIEMENS",
1631 	 .matches = {
1632 		     DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
1633 		     DMI_MATCH(DMI_PRODUCT_NAME, "AMILO PRO V2030"),
1634 		     },
1635 	 },
1636 	{}
1637 };
1638 
1639 /*
1640  * acpi_boot_table_init() and acpi_boot_init()
1641  *  called from setup_arch(), always.
1642  *	1. checksums all tables
1643  *	2. enumerates lapics
1644  *	3. enumerates io-apics
1645  *
1646  * acpi_table_init() is separate to allow reading SRAT without
1647  * other side effects.
1648  *
1649  * side effects of acpi_boot_init:
1650  *	acpi_lapic = 1 if LAPIC found
1651  *	acpi_ioapic = 1 if IOAPIC found
1652  *	if (acpi_lapic && acpi_ioapic) smp_found_config = 1;
1653  *	if acpi_blacklisted() acpi_disabled = 1;
1654  *	acpi_irq_model=...
1655  *	...
1656  */
1657 
1658 void __init acpi_boot_table_init(void)
1659 {
1660 	dmi_check_system(acpi_dmi_table);
1661 
1662 	/*
1663 	 * If acpi_disabled, bail out
1664 	 */
1665 	if (acpi_disabled)
1666 		return;
1667 
1668 	/*
1669 	 * Initialize the ACPI boot-time table parser.
1670 	 */
1671 	if (acpi_locate_initial_tables())
1672 		disable_acpi();
1673 	else
1674 		acpi_reserve_initial_tables();
1675 }
1676 
1677 int __init early_acpi_boot_init(void)
1678 {
1679 	if (acpi_disabled)
1680 		return 1;
1681 
1682 	acpi_table_init_complete();
1683 
1684 	acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);
1685 
1686 	/*
1687 	 * blacklist may disable ACPI entirely
1688 	 */
1689 	if (acpi_blacklisted()) {
1690 		if (acpi_force) {
1691 			pr_warn("acpi=force override\n");
1692 		} else {
1693 			pr_warn("Disabling ACPI support\n");
1694 			disable_acpi();
1695 			return 1;
1696 		}
1697 	}
1698 
1699 	/*
1700 	 * Process the Multiple APIC Description Table (MADT), if present
1701 	 */
1702 	early_acpi_process_madt();
1703 
1704 	/*
1705 	 * Hardware-reduced ACPI mode initialization:
1706 	 */
1707 	acpi_reduced_hw_init();
1708 
1709 	return 0;
1710 }
1711 
1712 int __init acpi_boot_init(void)
1713 {
1714 	/* those are executed after early-quirks are executed */
1715 	dmi_check_system(acpi_dmi_table_late);
1716 
1717 	/*
1718 	 * If acpi_disabled, bail out
1719 	 */
1720 	if (acpi_disabled)
1721 		return 1;
1722 
1723 	acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);
1724 
1725 	/*
1726 	 * set sci_int and PM timer address
1727 	 */
1728 	acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt);
1729 
1730 	/*
1731 	 * Process the Multiple APIC Description Table (MADT), if present
1732 	 */
1733 	acpi_process_madt();
1734 
1735 	acpi_table_parse(ACPI_SIG_HPET, acpi_parse_hpet);
1736 	if (IS_ENABLED(CONFIG_ACPI_BGRT) && !acpi_nobgrt)
1737 		acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
1738 
1739 	if (!acpi_noirq)
1740 		x86_init.pci.init = pci_acpi_init;
1741 
1742 	/* Do not enable ACPI SPCR console by default */
1743 	acpi_parse_spcr(earlycon_acpi_spcr_enable, false);
1744 	return 0;
1745 }
1746 
1747 static int __init parse_acpi(char *arg)
1748 {
1749 	if (!arg)
1750 		return -EINVAL;
1751 
1752 	/* "acpi=off" disables both ACPI table parsing and interpreter */
1753 	if (strcmp(arg, "off") == 0) {
1754 		disable_acpi();
1755 	}
1756 	/* acpi=force to over-ride black-list */
1757 	else if (strcmp(arg, "force") == 0) {
1758 		acpi_force = 1;
1759 		acpi_disabled = 0;
1760 	}
1761 	/* acpi=strict disables out-of-spec workarounds */
1762 	else if (strcmp(arg, "strict") == 0) {
1763 		acpi_strict = 1;
1764 	}
1765 	/* acpi=rsdt use RSDT instead of XSDT */
1766 	else if (strcmp(arg, "rsdt") == 0) {
1767 		acpi_gbl_do_not_use_xsdt = TRUE;
1768 	}
1769 	/* "acpi=noirq" disables ACPI interrupt routing */
1770 	else if (strcmp(arg, "noirq") == 0) {
1771 		acpi_noirq_set();
1772 	}
1773 	/* "acpi=copy_dsdt" copies DSDT */
1774 	else if (strcmp(arg, "copy_dsdt") == 0) {
1775 		acpi_gbl_copy_dsdt_locally = 1;
1776 	}
1777 	/* "acpi=nocmcff" disables FF mode for corrected errors */
1778 	else if (strcmp(arg, "nocmcff") == 0) {
1779 		acpi_disable_cmcff = 1;
1780 	} else {
1781 		/* Core will printk when we return error. */
1782 		return -EINVAL;
1783 	}
1784 	return 0;
1785 }
1786 early_param("acpi", parse_acpi);
1787 
1788 static int __init parse_acpi_bgrt(char *arg)
1789 {
1790 	acpi_nobgrt = true;
1791 	return 0;
1792 }
1793 early_param("bgrt_disable", parse_acpi_bgrt);
1794 
1795 /* FIXME: Using pci= for an ACPI parameter is a travesty. */
1796 static int __init parse_pci(char *arg)
1797 {
1798 	if (arg && strcmp(arg, "noacpi") == 0)
1799 		acpi_disable_pci();
1800 	return 0;
1801 }
1802 early_param("pci", parse_pci);
1803 
1804 int __init acpi_mps_check(void)
1805 {
1806 #if defined(CONFIG_X86_LOCAL_APIC) && !defined(CONFIG_X86_MPPARSE)
1807 /* mptable code is not built-in*/
1808 	if (acpi_disabled || acpi_noirq) {
1809 		pr_warn("MPS support code is not built-in, using acpi=off or acpi=noirq or pci=noacpi may have problem\n");
1810 		return 1;
1811 	}
1812 #endif
1813 	return 0;
1814 }
1815 
1816 #ifdef CONFIG_X86_IO_APIC
1817 static int __init parse_acpi_skip_timer_override(char *arg)
1818 {
1819 	acpi_skip_timer_override = 1;
1820 	return 0;
1821 }
1822 early_param("acpi_skip_timer_override", parse_acpi_skip_timer_override);
1823 
1824 static int __init parse_acpi_use_timer_override(char *arg)
1825 {
1826 	acpi_use_timer_override = 1;
1827 	return 0;
1828 }
1829 early_param("acpi_use_timer_override", parse_acpi_use_timer_override);
1830 #endif /* CONFIG_X86_IO_APIC */
1831 
1832 static int __init setup_acpi_sci(char *s)
1833 {
1834 	if (!s)
1835 		return -EINVAL;
1836 	if (!strcmp(s, "edge"))
1837 		acpi_sci_flags =  ACPI_MADT_TRIGGER_EDGE |
1838 			(acpi_sci_flags & ~ACPI_MADT_TRIGGER_MASK);
1839 	else if (!strcmp(s, "level"))
1840 		acpi_sci_flags = ACPI_MADT_TRIGGER_LEVEL |
1841 			(acpi_sci_flags & ~ACPI_MADT_TRIGGER_MASK);
1842 	else if (!strcmp(s, "high"))
1843 		acpi_sci_flags = ACPI_MADT_POLARITY_ACTIVE_HIGH |
1844 			(acpi_sci_flags & ~ACPI_MADT_POLARITY_MASK);
1845 	else if (!strcmp(s, "low"))
1846 		acpi_sci_flags = ACPI_MADT_POLARITY_ACTIVE_LOW |
1847 			(acpi_sci_flags & ~ACPI_MADT_POLARITY_MASK);
1848 	else
1849 		return -EINVAL;
1850 	return 0;
1851 }
1852 early_param("acpi_sci", setup_acpi_sci);
1853 
1854 int __acpi_acquire_global_lock(unsigned int *lock)
1855 {
1856 	unsigned int old, new;
1857 
1858 	old = READ_ONCE(*lock);
1859 	do {
1860 		new = (((old & ~0x3) + 2) + ((old >> 1) & 0x1));
1861 	} while (!try_cmpxchg(lock, &old, new));
1862 	return ((new & 0x3) < 3) ? -1 : 0;
1863 }
1864 
1865 int __acpi_release_global_lock(unsigned int *lock)
1866 {
1867 	unsigned int old, new;
1868 
1869 	old = READ_ONCE(*lock);
1870 	do {
1871 		new = old & ~0x3;
1872 	} while (!try_cmpxchg(lock, &old, new));
1873 	return old & 0x1;
1874 }
1875 
1876 void __init arch_reserve_mem_area(acpi_physical_address addr, size_t size)
1877 {
1878 	e820__range_add(addr, size, E820_TYPE_NVS);
1879 	e820__update_table_print();
1880 }
1881 
1882 void x86_default_set_root_pointer(u64 addr)
1883 {
1884 	boot_params.acpi_rsdp_addr = addr;
1885 }
1886 
1887 u64 x86_default_get_root_pointer(void)
1888 {
1889 	return boot_params.acpi_rsdp_addr;
1890 }
1891