xref: /kernel/linux/linux-5.10/drivers/acpi/tables.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  acpi_tables.c - ACPI Boot-Time Table Parsing
4 *
5 *  Copyright (C) 2001 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 */
7
8/* Uncomment next line to get verbose printout */
9/* #define DEBUG */
10#define pr_fmt(fmt) "ACPI: " fmt
11
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/smp.h>
15#include <linux/string.h>
16#include <linux/types.h>
17#include <linux/irq.h>
18#include <linux/errno.h>
19#include <linux/acpi.h>
20#include <linux/memblock.h>
21#include <linux/earlycpio.h>
22#include <linux/initrd.h>
23#include <linux/security.h>
24#include "internal.h"
25
26#ifdef CONFIG_ACPI_CUSTOM_DSDT
27#include CONFIG_ACPI_CUSTOM_DSDT_FILE
28#endif
29
30#define ACPI_MAX_TABLES		128
31
32static char *mps_inti_flags_polarity[] = { "dfl", "high", "res", "low" };
33static char *mps_inti_flags_trigger[] = { "dfl", "edge", "res", "level" };
34
35static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
36
37static int acpi_apic_instance __initdata;
38
39enum acpi_subtable_type {
40	ACPI_SUBTABLE_COMMON,
41	ACPI_SUBTABLE_HMAT,
42};
43
44struct acpi_subtable_entry {
45	union acpi_subtable_headers *hdr;
46	enum acpi_subtable_type type;
47};
48
49/*
50 * Disable table checksum verification for the early stage due to the size
51 * limitation of the current x86 early mapping implementation.
52 */
53static bool acpi_verify_table_checksum __initdata = false;
54
55void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
56{
57	if (!header)
58		return;
59
60	switch (header->type) {
61
62	case ACPI_MADT_TYPE_LOCAL_APIC:
63		{
64			struct acpi_madt_local_apic *p =
65			    (struct acpi_madt_local_apic *)header;
66			pr_debug("LAPIC (acpi_id[0x%02x] lapic_id[0x%02x] %s)\n",
67				 p->processor_id, p->id,
68				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
69		}
70		break;
71
72	case ACPI_MADT_TYPE_LOCAL_X2APIC:
73		{
74			struct acpi_madt_local_x2apic *p =
75			    (struct acpi_madt_local_x2apic *)header;
76			pr_debug("X2APIC (apic_id[0x%02x] uid[0x%02x] %s)\n",
77				 p->local_apic_id, p->uid,
78				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
79		}
80		break;
81
82	case ACPI_MADT_TYPE_IO_APIC:
83		{
84			struct acpi_madt_io_apic *p =
85			    (struct acpi_madt_io_apic *)header;
86			pr_debug("IOAPIC (id[0x%02x] address[0x%08x] gsi_base[%d])\n",
87				 p->id, p->address, p->global_irq_base);
88		}
89		break;
90
91	case ACPI_MADT_TYPE_INTERRUPT_OVERRIDE:
92		{
93			struct acpi_madt_interrupt_override *p =
94			    (struct acpi_madt_interrupt_override *)header;
95			pr_info("INT_SRC_OVR (bus %d bus_irq %d global_irq %d %s %s)\n",
96				p->bus, p->source_irq, p->global_irq,
97				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
98				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2]);
99			if (p->inti_flags  &
100			    ~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK))
101				pr_info("INT_SRC_OVR unexpected reserved flags: 0x%x\n",
102					p->inti_flags  &
103					~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK));
104		}
105		break;
106
107	case ACPI_MADT_TYPE_NMI_SOURCE:
108		{
109			struct acpi_madt_nmi_source *p =
110			    (struct acpi_madt_nmi_source *)header;
111			pr_info("NMI_SRC (%s %s global_irq %d)\n",
112				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
113				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
114				p->global_irq);
115		}
116		break;
117
118	case ACPI_MADT_TYPE_LOCAL_APIC_NMI:
119		{
120			struct acpi_madt_local_apic_nmi *p =
121			    (struct acpi_madt_local_apic_nmi *)header;
122			pr_info("LAPIC_NMI (acpi_id[0x%02x] %s %s lint[0x%x])\n",
123				p->processor_id,
124				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK	],
125				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
126				p->lint);
127		}
128		break;
129
130	case ACPI_MADT_TYPE_LOCAL_X2APIC_NMI:
131		{
132			u16 polarity, trigger;
133			struct acpi_madt_local_x2apic_nmi *p =
134			    (struct acpi_madt_local_x2apic_nmi *)header;
135
136			polarity = p->inti_flags & ACPI_MADT_POLARITY_MASK;
137			trigger = (p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
138
139			pr_info("X2APIC_NMI (uid[0x%02x] %s %s lint[0x%x])\n",
140				p->uid,
141				mps_inti_flags_polarity[polarity],
142				mps_inti_flags_trigger[trigger],
143				p->lint);
144		}
145		break;
146
147	case ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE:
148		{
149			struct acpi_madt_local_apic_override *p =
150			    (struct acpi_madt_local_apic_override *)header;
151			pr_info("LAPIC_ADDR_OVR (address[%p])\n",
152				(void *)(unsigned long)p->address);
153		}
154		break;
155
156	case ACPI_MADT_TYPE_IO_SAPIC:
157		{
158			struct acpi_madt_io_sapic *p =
159			    (struct acpi_madt_io_sapic *)header;
160			pr_debug("IOSAPIC (id[0x%x] address[%p] gsi_base[%d])\n",
161				 p->id, (void *)(unsigned long)p->address,
162				 p->global_irq_base);
163		}
164		break;
165
166	case ACPI_MADT_TYPE_LOCAL_SAPIC:
167		{
168			struct acpi_madt_local_sapic *p =
169			    (struct acpi_madt_local_sapic *)header;
170			pr_debug("LSAPIC (acpi_id[0x%02x] lsapic_id[0x%02x] lsapic_eid[0x%02x] %s)\n",
171				 p->processor_id, p->id, p->eid,
172				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
173		}
174		break;
175
176	case ACPI_MADT_TYPE_INTERRUPT_SOURCE:
177		{
178			struct acpi_madt_interrupt_source *p =
179			    (struct acpi_madt_interrupt_source *)header;
180			pr_info("PLAT_INT_SRC (%s %s type[0x%x] id[0x%04x] eid[0x%x] iosapic_vector[0x%x] global_irq[0x%x]\n",
181				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
182				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
183				p->type, p->id, p->eid, p->io_sapic_vector,
184				p->global_irq);
185		}
186		break;
187
188	case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
189		{
190			struct acpi_madt_generic_interrupt *p =
191				(struct acpi_madt_generic_interrupt *)header;
192			pr_debug("GICC (acpi_id[0x%04x] address[%llx] MPIDR[0x%llx] %s)\n",
193				 p->uid, p->base_address,
194				 p->arm_mpidr,
195				 (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
196
197		}
198		break;
199
200	case ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR:
201		{
202			struct acpi_madt_generic_distributor *p =
203				(struct acpi_madt_generic_distributor *)header;
204			pr_debug("GIC Distributor (gic_id[0x%04x] address[%llx] gsi_base[%d])\n",
205				 p->gic_id, p->base_address,
206				 p->global_irq_base);
207		}
208		break;
209
210	case ACPI_MADT_TYPE_CORE_PIC:
211		{
212			struct acpi_madt_core_pic *p =
213			    (struct acpi_madt_core_pic *)header;
214			pr_debug("CORE PIC (processor_id[0x%02x] core_id[0x%02x] %s)\n",
215				 p->processor_id, p->core_id,
216				 (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
217		}
218		break;
219
220	default:
221		pr_warn("Found unsupported MADT entry (type = 0x%x)\n",
222			header->type);
223		break;
224	}
225}
226
227static unsigned long __init
228acpi_get_entry_type(struct acpi_subtable_entry *entry)
229{
230	switch (entry->type) {
231	case ACPI_SUBTABLE_COMMON:
232		return entry->hdr->common.type;
233	case ACPI_SUBTABLE_HMAT:
234		return entry->hdr->hmat.type;
235	}
236	return 0;
237}
238
239static unsigned long __init
240acpi_get_entry_length(struct acpi_subtable_entry *entry)
241{
242	switch (entry->type) {
243	case ACPI_SUBTABLE_COMMON:
244		return entry->hdr->common.length;
245	case ACPI_SUBTABLE_HMAT:
246		return entry->hdr->hmat.length;
247	}
248	return 0;
249}
250
251static unsigned long __init
252acpi_get_subtable_header_length(struct acpi_subtable_entry *entry)
253{
254	switch (entry->type) {
255	case ACPI_SUBTABLE_COMMON:
256		return sizeof(entry->hdr->common);
257	case ACPI_SUBTABLE_HMAT:
258		return sizeof(entry->hdr->hmat);
259	}
260	return 0;
261}
262
263static enum acpi_subtable_type __init
264acpi_get_subtable_type(char *id)
265{
266	if (strncmp(id, ACPI_SIG_HMAT, 4) == 0)
267		return ACPI_SUBTABLE_HMAT;
268	return ACPI_SUBTABLE_COMMON;
269}
270
271/**
272 * acpi_parse_entries_array - for each proc_num find a suitable subtable
273 *
274 * @id: table id (for debugging purposes)
275 * @table_size: size of the root table
276 * @table_header: where does the table start?
277 * @proc: array of acpi_subtable_proc struct containing entry id
278 *        and associated handler with it
279 * @proc_num: how big proc is?
280 * @max_entries: how many entries can we process?
281 *
282 * For each proc_num find a subtable with proc->id and run proc->handler
283 * on it. Assumption is that there's only single handler for particular
284 * entry id.
285 *
286 * The table_size is not the size of the complete ACPI table (the length
287 * field in the header struct), but only the size of the root table; i.e.,
288 * the offset from the very first byte of the complete ACPI table, to the
289 * first byte of the very first subtable.
290 *
291 * On success returns sum of all matching entries for all proc handlers.
292 * Otherwise, -ENODEV or -EINVAL is returned.
293 */
294static int __init acpi_parse_entries_array(char *id, unsigned long table_size,
295		struct acpi_table_header *table_header,
296		struct acpi_subtable_proc *proc, int proc_num,
297		unsigned int max_entries)
298{
299	struct acpi_subtable_entry entry;
300	unsigned long table_end, subtable_len, entry_len;
301	int count = 0;
302	int errs = 0;
303	int i;
304
305	table_end = (unsigned long)table_header + table_header->length;
306
307	/* Parse all entries looking for a match. */
308
309	entry.type = acpi_get_subtable_type(id);
310	entry.hdr = (union acpi_subtable_headers *)
311	    ((unsigned long)table_header + table_size);
312	subtable_len = acpi_get_subtable_header_length(&entry);
313
314	while (((unsigned long)entry.hdr) + subtable_len  < table_end) {
315		if (max_entries && count >= max_entries)
316			break;
317
318		for (i = 0; i < proc_num; i++) {
319			if (acpi_get_entry_type(&entry) != proc[i].id)
320				continue;
321			if (!proc[i].handler ||
322			     (!errs && proc[i].handler(entry.hdr, table_end))) {
323				errs++;
324				continue;
325			}
326
327			proc[i].count++;
328			break;
329		}
330		if (i != proc_num)
331			count++;
332
333		/*
334		 * If entry->length is 0, break from this loop to avoid
335		 * infinite loop.
336		 */
337		entry_len = acpi_get_entry_length(&entry);
338		if (entry_len == 0) {
339			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
340			return -EINVAL;
341		}
342
343		entry.hdr = (union acpi_subtable_headers *)
344		    ((unsigned long)entry.hdr + entry_len);
345	}
346
347	if (max_entries && count > max_entries) {
348		pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
349			id, proc->id, count);
350	}
351
352	return errs ? -EINVAL : count;
353}
354
355int __init acpi_table_parse_entries_array(char *id,
356			 unsigned long table_size,
357			 struct acpi_subtable_proc *proc, int proc_num,
358			 unsigned int max_entries)
359{
360	struct acpi_table_header *table_header = NULL;
361	int count;
362	u32 instance = 0;
363
364	if (acpi_disabled)
365		return -ENODEV;
366
367	if (!id)
368		return -EINVAL;
369
370	if (!table_size)
371		return -EINVAL;
372
373	if (!strncmp(id, ACPI_SIG_MADT, 4))
374		instance = acpi_apic_instance;
375
376	acpi_get_table(id, instance, &table_header);
377	if (!table_header) {
378		pr_warn("%4.4s not present\n", id);
379		return -ENODEV;
380	}
381
382	count = acpi_parse_entries_array(id, table_size, table_header,
383			proc, proc_num, max_entries);
384
385	acpi_put_table(table_header);
386	return count;
387}
388
389int __init acpi_table_parse_entries(char *id,
390			unsigned long table_size,
391			int entry_id,
392			acpi_tbl_entry_handler handler,
393			unsigned int max_entries)
394{
395	struct acpi_subtable_proc proc = {
396		.id		= entry_id,
397		.handler	= handler,
398	};
399
400	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
401						max_entries);
402}
403
404int __init acpi_table_parse_madt(enum acpi_madt_type id,
405		      acpi_tbl_entry_handler handler, unsigned int max_entries)
406{
407	return acpi_table_parse_entries(ACPI_SIG_MADT,
408					    sizeof(struct acpi_table_madt), id,
409					    handler, max_entries);
410}
411
412/**
413 * acpi_table_parse - find table with @id, run @handler on it
414 * @id: table id to find
415 * @handler: handler to run
416 *
417 * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
418 * run @handler on it.
419 *
420 * Return 0 if table found, -errno if not.
421 */
422int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
423{
424	struct acpi_table_header *table = NULL;
425
426	if (acpi_disabled)
427		return -ENODEV;
428
429	if (!id || !handler)
430		return -EINVAL;
431
432	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
433		acpi_get_table(id, acpi_apic_instance, &table);
434	else
435		acpi_get_table(id, 0, &table);
436
437	if (table) {
438		handler(table);
439		acpi_put_table(table);
440		return 0;
441	} else
442		return -ENODEV;
443}
444
445/*
446 * The BIOS is supposed to supply a single APIC/MADT,
447 * but some report two.  Provide a knob to use either.
448 * (don't you wish instance 0 and 1 were not the same?)
449 */
450static void __init check_multiple_madt(void)
451{
452	struct acpi_table_header *table = NULL;
453
454	acpi_get_table(ACPI_SIG_MADT, 2, &table);
455	if (table) {
456		pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
457			acpi_apic_instance);
458		pr_warn("If \"acpi_apic_instance=%d\" works better, "
459			"notify linux-acpi@vger.kernel.org\n",
460			acpi_apic_instance ? 0 : 2);
461		acpi_put_table(table);
462
463	} else
464		acpi_apic_instance = 0;
465
466	return;
467}
468
469static void acpi_table_taint(struct acpi_table_header *table)
470{
471	pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
472		table->signature, table->oem_table_id);
473	add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
474}
475
476#ifdef CONFIG_ACPI_TABLE_UPGRADE
477static u64 acpi_tables_addr;
478static int all_tables_size;
479
480/* Copied from acpica/tbutils.c:acpi_tb_checksum() */
481static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
482{
483	u8 sum = 0;
484	u8 *end = buffer + length;
485
486	while (buffer < end)
487		sum = (u8) (sum + *(buffer++));
488	return sum;
489}
490
491/* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
492static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst = {
493	ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,
494	ACPI_SIG_EINJ, ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT,
495	ACPI_SIG_MSCT, ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT,
496	ACPI_SIG_ASF,  ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR,
497	ACPI_SIG_HPET, ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG,
498	ACPI_SIG_MCHI, ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI,
499	ACPI_SIG_TCPA, ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT,
500	ACPI_SIG_WDDT, ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT,
501	ACPI_SIG_PSDT, ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT,
502	ACPI_SIG_IORT, ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT,
503	ACPI_SIG_NHLT };
504
505#define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
506
507#define NR_ACPI_INITRD_TABLES 64
508static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
509static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
510
511#define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
512
513void __init acpi_table_upgrade(void)
514{
515	void *data;
516	size_t size;
517	int sig, no, table_nr = 0, total_offset = 0;
518	long offset = 0;
519	struct acpi_table_header *table;
520	char cpio_path[32] = "kernel/firmware/acpi/";
521	struct cpio_data file;
522
523	if (IS_ENABLED(CONFIG_ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD)) {
524		data = __initramfs_start;
525		size = __initramfs_size;
526	} else {
527		data = (void *)initrd_start;
528		size = initrd_end - initrd_start;
529	}
530
531	if (data == NULL || size == 0)
532		return;
533
534	for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
535		file = find_cpio_data(cpio_path, data, size, &offset);
536		if (!file.data)
537			break;
538
539		data += offset;
540		size -= offset;
541
542		if (file.size < sizeof(struct acpi_table_header)) {
543			pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
544				cpio_path, file.name);
545			continue;
546		}
547
548		table = file.data;
549
550		for (sig = 0; sig < ARRAY_SIZE(table_sigs); sig++)
551			if (!memcmp(table->signature, table_sigs[sig], 4))
552				break;
553
554		if (sig >= ARRAY_SIZE(table_sigs)) {
555			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
556				cpio_path, file.name);
557			continue;
558		}
559		if (file.size != table->length) {
560			pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
561				cpio_path, file.name);
562			continue;
563		}
564		if (acpi_table_checksum(file.data, table->length)) {
565			pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
566				cpio_path, file.name);
567			continue;
568		}
569
570		pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
571			table->signature, cpio_path, file.name, table->length);
572
573		all_tables_size += table->length;
574		acpi_initrd_files[table_nr].data = file.data;
575		acpi_initrd_files[table_nr].size = file.size;
576		table_nr++;
577	}
578	if (table_nr == 0)
579		return;
580
581	if (security_locked_down(LOCKDOWN_ACPI_TABLES)) {
582		pr_notice("kernel is locked down, ignoring table override\n");
583		return;
584	}
585
586	acpi_tables_addr =
587		memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
588				       all_tables_size, PAGE_SIZE);
589	if (!acpi_tables_addr) {
590		WARN_ON(1);
591		return;
592	}
593	/*
594	 * Only calling e820_add_reserve does not work and the
595	 * tables are invalid (memory got used) later.
596	 * memblock_reserve works as expected and the tables won't get modified.
597	 * But it's not enough on X86 because ioremap will
598	 * complain later (used by acpi_os_map_memory) that the pages
599	 * that should get mapped are not marked "reserved".
600	 * Both memblock_reserve and e820__range_add (via arch_reserve_mem_area)
601	 * works fine.
602	 */
603	memblock_reserve(acpi_tables_addr, all_tables_size);
604	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
605
606	/*
607	 * early_ioremap only can remap 256k one time. If we map all
608	 * tables one time, we will hit the limit. Need to map chunks
609	 * one by one during copying the same as that in relocate_initrd().
610	 */
611	for (no = 0; no < table_nr; no++) {
612		unsigned char *src_p = acpi_initrd_files[no].data;
613		phys_addr_t size = acpi_initrd_files[no].size;
614		phys_addr_t dest_addr = acpi_tables_addr + total_offset;
615		phys_addr_t slop, clen;
616		char *dest_p;
617
618		total_offset += size;
619
620		while (size) {
621			slop = dest_addr & ~PAGE_MASK;
622			clen = size;
623			if (clen > MAP_CHUNK_SIZE - slop)
624				clen = MAP_CHUNK_SIZE - slop;
625			dest_p = early_memremap(dest_addr & PAGE_MASK,
626						clen + slop);
627			memcpy(dest_p + slop, src_p, clen);
628			early_memunmap(dest_p, clen + slop);
629			src_p += clen;
630			dest_addr += clen;
631			size -= clen;
632		}
633	}
634}
635
636static acpi_status
637acpi_table_initrd_override(struct acpi_table_header *existing_table,
638			   acpi_physical_address *address, u32 *length)
639{
640	int table_offset = 0;
641	int table_index = 0;
642	struct acpi_table_header *table;
643	u32 table_length;
644
645	*length = 0;
646	*address = 0;
647	if (!acpi_tables_addr)
648		return AE_OK;
649
650	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
651		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
652					   ACPI_HEADER_SIZE);
653		if (table_offset + table->length > all_tables_size) {
654			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
655			WARN_ON(1);
656			return AE_OK;
657		}
658
659		table_length = table->length;
660
661		/* Only override tables matched */
662		if (memcmp(existing_table->signature, table->signature, 4) ||
663		    memcmp(table->oem_id, existing_table->oem_id,
664			   ACPI_OEM_ID_SIZE) ||
665		    memcmp(table->oem_table_id, existing_table->oem_table_id,
666			   ACPI_OEM_TABLE_ID_SIZE)) {
667			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
668			goto next_table;
669		}
670		/*
671		 * Mark the table to avoid being used in
672		 * acpi_table_initrd_scan() and check the revision.
673		 */
674		if (test_and_set_bit(table_index, acpi_initrd_installed) ||
675		    existing_table->oem_revision >= table->oem_revision) {
676			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
677			goto next_table;
678		}
679
680		*length = table_length;
681		*address = acpi_tables_addr + table_offset;
682		pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
683			table->signature, table->oem_id,
684			table->oem_table_id);
685		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
686		break;
687
688next_table:
689		table_offset += table_length;
690		table_index++;
691	}
692	return AE_OK;
693}
694
695static void __init acpi_table_initrd_scan(void)
696{
697	int table_offset = 0;
698	int table_index = 0;
699	u32 table_length;
700	struct acpi_table_header *table;
701
702	if (!acpi_tables_addr)
703		return;
704
705	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
706		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
707					   ACPI_HEADER_SIZE);
708		if (table_offset + table->length > all_tables_size) {
709			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
710			WARN_ON(1);
711			return;
712		}
713
714		table_length = table->length;
715
716		/* Skip RSDT/XSDT which should only be used for override */
717		if (ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_RSDT) ||
718		    ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_XSDT)) {
719			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
720			goto next_table;
721		}
722		/*
723		 * Mark the table to avoid being used in
724		 * acpi_table_initrd_override(). Though this is not possible
725		 * because override is disabled in acpi_install_table().
726		 */
727		if (test_and_set_bit(table_index, acpi_initrd_installed)) {
728			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
729			goto next_table;
730		}
731
732		pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
733			table->signature, table->oem_id,
734			table->oem_table_id);
735		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
736		acpi_install_table(acpi_tables_addr + table_offset, TRUE);
737next_table:
738		table_offset += table_length;
739		table_index++;
740	}
741}
742#else
743static acpi_status
744acpi_table_initrd_override(struct acpi_table_header *existing_table,
745			   acpi_physical_address *address,
746			   u32 *table_length)
747{
748	*table_length = 0;
749	*address = 0;
750	return AE_OK;
751}
752
753static void __init acpi_table_initrd_scan(void)
754{
755}
756#endif /* CONFIG_ACPI_TABLE_UPGRADE */
757
758acpi_status
759acpi_os_physical_table_override(struct acpi_table_header *existing_table,
760				acpi_physical_address *address,
761				u32 *table_length)
762{
763	return acpi_table_initrd_override(existing_table, address,
764					  table_length);
765}
766
767#ifdef CONFIG_ACPI_CUSTOM_DSDT
768static void *amlcode __attribute__ ((weakref("AmlCode")));
769static void *dsdt_amlcode __attribute__ ((weakref("dsdt_aml_code")));
770#endif
771
772acpi_status acpi_os_table_override(struct acpi_table_header *existing_table,
773		       struct acpi_table_header **new_table)
774{
775	if (!existing_table || !new_table)
776		return AE_BAD_PARAMETER;
777
778	*new_table = NULL;
779
780#ifdef CONFIG_ACPI_CUSTOM_DSDT
781	if (!strncmp(existing_table->signature, "DSDT", 4)) {
782		*new_table = (struct acpi_table_header *)&amlcode;
783		if (!(*new_table))
784			*new_table = (struct acpi_table_header *)&dsdt_amlcode;
785	}
786#endif
787	if (*new_table != NULL)
788		acpi_table_taint(existing_table);
789	return AE_OK;
790}
791
792/*
793 * acpi_locate_initial_tables()
794 *
795 * find RSDP, find and checksum SDT/XSDT.
796 * checksum all tables, print SDT/XSDT
797 *
798 * result: sdt_entry[] is initialized
799 */
800
801int __init acpi_locate_initial_tables(void)
802{
803	acpi_status status;
804
805	if (acpi_verify_table_checksum) {
806		pr_info("Early table checksum verification enabled\n");
807		acpi_gbl_enable_table_validation = TRUE;
808	} else {
809		pr_info("Early table checksum verification disabled\n");
810		acpi_gbl_enable_table_validation = FALSE;
811	}
812
813	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
814	if (ACPI_FAILURE(status))
815		return -EINVAL;
816
817	return 0;
818}
819
820void __init acpi_reserve_initial_tables(void)
821{
822	int i;
823
824	for (i = 0; i < ACPI_MAX_TABLES; i++) {
825		struct acpi_table_desc *table_desc = &initial_tables[i];
826		u64 start = table_desc->address;
827		u64 size = table_desc->length;
828
829		if (!start || !size)
830			break;
831
832		pr_info("Reserving %4s table memory at [mem 0x%llx-0x%llx]\n",
833			table_desc->signature.ascii, start, start + size - 1);
834
835		memblock_reserve(start, size);
836	}
837}
838
839void __init acpi_table_init_complete(void)
840{
841	acpi_table_initrd_scan();
842	check_multiple_madt();
843}
844
845int __init acpi_table_init(void)
846{
847	int ret;
848
849	ret = acpi_locate_initial_tables();
850	if (ret)
851		return ret;
852
853	acpi_table_init_complete();
854
855	return 0;
856}
857
858static int __init acpi_parse_apic_instance(char *str)
859{
860	if (!str)
861		return -EINVAL;
862
863	if (kstrtoint(str, 0, &acpi_apic_instance))
864		return -EINVAL;
865
866	pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
867
868	return 0;
869}
870early_param("acpi_apic_instance", acpi_parse_apic_instance);
871
872static int __init acpi_force_table_verification_setup(char *s)
873{
874	acpi_verify_table_checksum = true;
875
876	return 0;
877}
878early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
879
880static int __init acpi_force_32bit_fadt_addr(char *s)
881{
882	pr_info("Forcing 32 Bit FADT addresses\n");
883	acpi_gbl_use32_bit_fadt_addresses = TRUE;
884
885	return 0;
886}
887early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);
888