xref: /linux/drivers/acpi/tables.c (revision 0678df8271820bcf8fb4f877129f05d68a237de4)
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 <linux/kmemleak.h>
25 #include "internal.h"
26 
27 #ifdef CONFIG_ACPI_CUSTOM_DSDT
28 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
29 #endif
30 
31 #define ACPI_MAX_TABLES		128
32 
33 static char *mps_inti_flags_polarity[] = { "dfl", "high", "res", "low" };
34 static char *mps_inti_flags_trigger[] = { "dfl", "edge", "res", "level" };
35 
36 static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
37 
38 static int acpi_apic_instance __initdata_or_acpilib;
39 
40 /*
41  * Disable table checksum verification for the early stage due to the size
42  * limitation of the current x86 early mapping implementation.
43  */
44 static bool acpi_verify_table_checksum __initdata_or_acpilib = false;
45 
46 void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
47 {
48 	if (!header)
49 		return;
50 
51 	switch (header->type) {
52 
53 	case ACPI_MADT_TYPE_LOCAL_APIC:
54 		{
55 			struct acpi_madt_local_apic *p =
56 			    (struct acpi_madt_local_apic *)header;
57 			pr_debug("LAPIC (acpi_id[0x%02x] lapic_id[0x%02x] %s)\n",
58 				 p->processor_id, p->id,
59 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
60 		}
61 		break;
62 
63 	case ACPI_MADT_TYPE_LOCAL_X2APIC:
64 		{
65 			struct acpi_madt_local_x2apic *p =
66 			    (struct acpi_madt_local_x2apic *)header;
67 			pr_debug("X2APIC (apic_id[0x%02x] uid[0x%02x] %s)\n",
68 				 p->local_apic_id, p->uid,
69 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
70 		}
71 		break;
72 
73 	case ACPI_MADT_TYPE_IO_APIC:
74 		{
75 			struct acpi_madt_io_apic *p =
76 			    (struct acpi_madt_io_apic *)header;
77 			pr_debug("IOAPIC (id[0x%02x] address[0x%08x] gsi_base[%d])\n",
78 				 p->id, p->address, p->global_irq_base);
79 		}
80 		break;
81 
82 	case ACPI_MADT_TYPE_INTERRUPT_OVERRIDE:
83 		{
84 			struct acpi_madt_interrupt_override *p =
85 			    (struct acpi_madt_interrupt_override *)header;
86 			pr_info("INT_SRC_OVR (bus %d bus_irq %d global_irq %d %s %s)\n",
87 				p->bus, p->source_irq, p->global_irq,
88 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
89 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2]);
90 			if (p->inti_flags  &
91 			    ~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK))
92 				pr_info("INT_SRC_OVR unexpected reserved flags: 0x%x\n",
93 					p->inti_flags  &
94 					~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK));
95 		}
96 		break;
97 
98 	case ACPI_MADT_TYPE_NMI_SOURCE:
99 		{
100 			struct acpi_madt_nmi_source *p =
101 			    (struct acpi_madt_nmi_source *)header;
102 			pr_info("NMI_SRC (%s %s global_irq %d)\n",
103 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
104 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
105 				p->global_irq);
106 		}
107 		break;
108 
109 	case ACPI_MADT_TYPE_LOCAL_APIC_NMI:
110 		{
111 			struct acpi_madt_local_apic_nmi *p =
112 			    (struct acpi_madt_local_apic_nmi *)header;
113 			pr_info("LAPIC_NMI (acpi_id[0x%02x] %s %s lint[0x%x])\n",
114 				p->processor_id,
115 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK	],
116 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
117 				p->lint);
118 		}
119 		break;
120 
121 	case ACPI_MADT_TYPE_LOCAL_X2APIC_NMI:
122 		{
123 			u16 polarity, trigger;
124 			struct acpi_madt_local_x2apic_nmi *p =
125 			    (struct acpi_madt_local_x2apic_nmi *)header;
126 
127 			polarity = p->inti_flags & ACPI_MADT_POLARITY_MASK;
128 			trigger = (p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
129 
130 			pr_info("X2APIC_NMI (uid[0x%02x] %s %s lint[0x%x])\n",
131 				p->uid,
132 				mps_inti_flags_polarity[polarity],
133 				mps_inti_flags_trigger[trigger],
134 				p->lint);
135 		}
136 		break;
137 
138 	case ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE:
139 		{
140 			struct acpi_madt_local_apic_override *p =
141 			    (struct acpi_madt_local_apic_override *)header;
142 			pr_info("LAPIC_ADDR_OVR (address[0x%llx])\n",
143 				p->address);
144 		}
145 		break;
146 
147 	case ACPI_MADT_TYPE_IO_SAPIC:
148 		{
149 			struct acpi_madt_io_sapic *p =
150 			    (struct acpi_madt_io_sapic *)header;
151 			pr_debug("IOSAPIC (id[0x%x] address[%p] gsi_base[%d])\n",
152 				 p->id, (void *)(unsigned long)p->address,
153 				 p->global_irq_base);
154 		}
155 		break;
156 
157 	case ACPI_MADT_TYPE_LOCAL_SAPIC:
158 		{
159 			struct acpi_madt_local_sapic *p =
160 			    (struct acpi_madt_local_sapic *)header;
161 			pr_debug("LSAPIC (acpi_id[0x%02x] lsapic_id[0x%02x] lsapic_eid[0x%02x] %s)\n",
162 				 p->processor_id, p->id, p->eid,
163 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
164 		}
165 		break;
166 
167 	case ACPI_MADT_TYPE_INTERRUPT_SOURCE:
168 		{
169 			struct acpi_madt_interrupt_source *p =
170 			    (struct acpi_madt_interrupt_source *)header;
171 			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",
172 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
173 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
174 				p->type, p->id, p->eid, p->io_sapic_vector,
175 				p->global_irq);
176 		}
177 		break;
178 
179 	case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
180 		{
181 			struct acpi_madt_generic_interrupt *p =
182 				(struct acpi_madt_generic_interrupt *)header;
183 			pr_debug("GICC (acpi_id[0x%04x] address[%llx] MPIDR[0x%llx] %s)\n",
184 				 p->uid, p->base_address,
185 				 p->arm_mpidr,
186 				 (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
187 
188 		}
189 		break;
190 
191 	case ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR:
192 		{
193 			struct acpi_madt_generic_distributor *p =
194 				(struct acpi_madt_generic_distributor *)header;
195 			pr_debug("GIC Distributor (gic_id[0x%04x] address[%llx] gsi_base[%d])\n",
196 				 p->gic_id, p->base_address,
197 				 p->global_irq_base);
198 		}
199 		break;
200 
201 	case ACPI_MADT_TYPE_CORE_PIC:
202 		{
203 			struct acpi_madt_core_pic *p = (struct acpi_madt_core_pic *)header;
204 
205 			pr_debug("CORE PIC (processor_id[0x%02x] core_id[0x%02x] %s)\n",
206 				 p->processor_id, p->core_id,
207 				 (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
208 		}
209 		break;
210 
211 	case ACPI_MADT_TYPE_RINTC:
212 		{
213 			struct acpi_madt_rintc *p = (struct acpi_madt_rintc *)header;
214 
215 			pr_debug("RISC-V INTC (acpi_uid[0x%04x] hart_id[0x%llx] %s)\n",
216 				 p->uid, p->hart_id,
217 				 (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
218 		}
219 		break;
220 
221 	default:
222 		pr_warn("Found unsupported MADT entry (type = 0x%x)\n",
223 			header->type);
224 		break;
225 	}
226 }
227 
228 int __init_or_acpilib acpi_table_parse_entries_array(
229 	char *id, unsigned long table_size, struct acpi_subtable_proc *proc,
230 	int proc_num, unsigned int max_entries)
231 {
232 	struct acpi_table_header *table_header = NULL;
233 	int count;
234 	u32 instance = 0;
235 
236 	if (acpi_disabled)
237 		return -ENODEV;
238 
239 	if (!id)
240 		return -EINVAL;
241 
242 	if (!table_size)
243 		return -EINVAL;
244 
245 	if (!strncmp(id, ACPI_SIG_MADT, 4))
246 		instance = acpi_apic_instance;
247 
248 	acpi_get_table(id, instance, &table_header);
249 	if (!table_header) {
250 		pr_debug("%4.4s not present\n", id);
251 		return -ENODEV;
252 	}
253 
254 	count = acpi_parse_entries_array(id, table_size, table_header,
255 			proc, proc_num, max_entries);
256 
257 	acpi_put_table(table_header);
258 	return count;
259 }
260 
261 static int __init_or_acpilib __acpi_table_parse_entries(
262 	char *id, unsigned long table_size, int entry_id,
263 	acpi_tbl_entry_handler handler, acpi_tbl_entry_handler_arg handler_arg,
264 	void *arg, unsigned int max_entries)
265 {
266 	struct acpi_subtable_proc proc = {
267 		.id		= entry_id,
268 		.handler	= handler,
269 		.handler_arg	= handler_arg,
270 		.arg		= arg,
271 	};
272 
273 	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
274 						max_entries);
275 }
276 
277 int __init_or_acpilib
278 acpi_table_parse_cedt(enum acpi_cedt_type id,
279 		      acpi_tbl_entry_handler_arg handler_arg, void *arg)
280 {
281 	return __acpi_table_parse_entries(ACPI_SIG_CEDT,
282 					  sizeof(struct acpi_table_cedt), id,
283 					  NULL, handler_arg, arg, 0);
284 }
285 EXPORT_SYMBOL_ACPI_LIB(acpi_table_parse_cedt);
286 
287 int __init acpi_table_parse_entries(char *id, unsigned long table_size,
288 				    int entry_id,
289 				    acpi_tbl_entry_handler handler,
290 				    unsigned int max_entries)
291 {
292 	return __acpi_table_parse_entries(id, table_size, entry_id, handler,
293 					  NULL, NULL, max_entries);
294 }
295 
296 int __init acpi_table_parse_madt(enum acpi_madt_type id,
297 		      acpi_tbl_entry_handler handler, unsigned int max_entries)
298 {
299 	return acpi_table_parse_entries(ACPI_SIG_MADT,
300 					    sizeof(struct acpi_table_madt), id,
301 					    handler, max_entries);
302 }
303 
304 /**
305  * acpi_table_parse - find table with @id, run @handler on it
306  * @id: table id to find
307  * @handler: handler to run
308  *
309  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
310  * run @handler on it.
311  *
312  * Return 0 if table found, -errno if not.
313  */
314 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
315 {
316 	struct acpi_table_header *table = NULL;
317 
318 	if (acpi_disabled)
319 		return -ENODEV;
320 
321 	if (!id || !handler)
322 		return -EINVAL;
323 
324 	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
325 		acpi_get_table(id, acpi_apic_instance, &table);
326 	else
327 		acpi_get_table(id, 0, &table);
328 
329 	if (table) {
330 		handler(table);
331 		acpi_put_table(table);
332 		return 0;
333 	} else
334 		return -ENODEV;
335 }
336 
337 /*
338  * The BIOS is supposed to supply a single APIC/MADT,
339  * but some report two.  Provide a knob to use either.
340  * (don't you wish instance 0 and 1 were not the same?)
341  */
342 static void __init check_multiple_madt(void)
343 {
344 	struct acpi_table_header *table = NULL;
345 
346 	acpi_get_table(ACPI_SIG_MADT, 2, &table);
347 	if (table) {
348 		pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
349 			acpi_apic_instance);
350 		pr_warn("If \"acpi_apic_instance=%d\" works better, "
351 			"notify linux-acpi@vger.kernel.org\n",
352 			acpi_apic_instance ? 0 : 2);
353 		acpi_put_table(table);
354 
355 	} else
356 		acpi_apic_instance = 0;
357 
358 	return;
359 }
360 
361 static void acpi_table_taint(struct acpi_table_header *table)
362 {
363 	pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
364 		table->signature, table->oem_table_id);
365 	add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
366 }
367 
368 #ifdef CONFIG_ACPI_TABLE_UPGRADE
369 static u64 acpi_tables_addr;
370 static int all_tables_size;
371 
372 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
373 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
374 {
375 	u8 sum = 0;
376 	u8 *end = buffer + length;
377 
378 	while (buffer < end)
379 		sum = (u8) (sum + *(buffer++));
380 	return sum;
381 }
382 
383 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
384 static const char table_sigs[][ACPI_NAMESEG_SIZE] __initconst = {
385 	ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,
386 	ACPI_SIG_EINJ, ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT,
387 	ACPI_SIG_MSCT, ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT,
388 	ACPI_SIG_ASF,  ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR,
389 	ACPI_SIG_HPET, ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG,
390 	ACPI_SIG_MCHI, ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI,
391 	ACPI_SIG_TCPA, ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT,
392 	ACPI_SIG_WDDT, ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT,
393 	ACPI_SIG_PSDT, ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT,
394 	ACPI_SIG_IORT, ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT,
395 	ACPI_SIG_NHLT, ACPI_SIG_AEST, ACPI_SIG_CEDT, ACPI_SIG_AGDI,
396 	ACPI_SIG_NBFT };
397 
398 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
399 
400 #define NR_ACPI_INITRD_TABLES 64
401 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
402 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
403 
404 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
405 
406 void __init acpi_table_upgrade(void)
407 {
408 	void *data;
409 	size_t size;
410 	int sig, no, table_nr = 0, total_offset = 0;
411 	long offset = 0;
412 	struct acpi_table_header *table;
413 	char cpio_path[32] = "kernel/firmware/acpi/";
414 	struct cpio_data file;
415 
416 	if (IS_ENABLED(CONFIG_ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD)) {
417 		data = __initramfs_start;
418 		size = __initramfs_size;
419 	} else {
420 		data = (void *)initrd_start;
421 		size = initrd_end - initrd_start;
422 	}
423 
424 	if (data == NULL || size == 0)
425 		return;
426 
427 	for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
428 		file = find_cpio_data(cpio_path, data, size, &offset);
429 		if (!file.data)
430 			break;
431 
432 		data += offset;
433 		size -= offset;
434 
435 		if (file.size < sizeof(struct acpi_table_header)) {
436 			pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
437 				cpio_path, file.name);
438 			continue;
439 		}
440 
441 		table = file.data;
442 
443 		for (sig = 0; sig < ARRAY_SIZE(table_sigs); sig++)
444 			if (!memcmp(table->signature, table_sigs[sig], 4))
445 				break;
446 
447 		if (sig >= ARRAY_SIZE(table_sigs)) {
448 			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
449 				cpio_path, file.name);
450 			continue;
451 		}
452 		if (file.size != table->length) {
453 			pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
454 				cpio_path, file.name);
455 			continue;
456 		}
457 		if (acpi_table_checksum(file.data, table->length)) {
458 			pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
459 				cpio_path, file.name);
460 			continue;
461 		}
462 
463 		pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
464 			table->signature, cpio_path, file.name, table->length);
465 
466 		all_tables_size += table->length;
467 		acpi_initrd_files[table_nr].data = file.data;
468 		acpi_initrd_files[table_nr].size = file.size;
469 		table_nr++;
470 	}
471 	if (table_nr == 0)
472 		return;
473 
474 	if (security_locked_down(LOCKDOWN_ACPI_TABLES)) {
475 		pr_notice("kernel is locked down, ignoring table override\n");
476 		return;
477 	}
478 
479 	acpi_tables_addr =
480 		memblock_phys_alloc_range(all_tables_size, PAGE_SIZE,
481 					  0, ACPI_TABLE_UPGRADE_MAX_PHYS);
482 	if (!acpi_tables_addr) {
483 		WARN_ON(1);
484 		return;
485 	}
486 	/*
487 	 * Only calling e820_add_reserve does not work and the
488 	 * tables are invalid (memory got used) later.
489 	 * memblock_reserve works as expected and the tables won't get modified.
490 	 * But it's not enough on X86 because ioremap will
491 	 * complain later (used by acpi_os_map_memory) that the pages
492 	 * that should get mapped are not marked "reserved".
493 	 * Both memblock_reserve and e820__range_add (via arch_reserve_mem_area)
494 	 * works fine.
495 	 */
496 	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
497 
498 	kmemleak_ignore_phys(acpi_tables_addr);
499 
500 	/*
501 	 * early_ioremap only can remap 256k one time. If we map all
502 	 * tables one time, we will hit the limit. Need to map chunks
503 	 * one by one during copying the same as that in relocate_initrd().
504 	 */
505 	for (no = 0; no < table_nr; no++) {
506 		unsigned char *src_p = acpi_initrd_files[no].data;
507 		phys_addr_t size = acpi_initrd_files[no].size;
508 		phys_addr_t dest_addr = acpi_tables_addr + total_offset;
509 		phys_addr_t slop, clen;
510 		char *dest_p;
511 
512 		total_offset += size;
513 
514 		while (size) {
515 			slop = dest_addr & ~PAGE_MASK;
516 			clen = size;
517 			if (clen > MAP_CHUNK_SIZE - slop)
518 				clen = MAP_CHUNK_SIZE - slop;
519 			dest_p = early_memremap(dest_addr & PAGE_MASK,
520 						clen + slop);
521 			memcpy(dest_p + slop, src_p, clen);
522 			early_memunmap(dest_p, clen + slop);
523 			src_p += clen;
524 			dest_addr += clen;
525 			size -= clen;
526 		}
527 	}
528 }
529 
530 static acpi_status
531 acpi_table_initrd_override(struct acpi_table_header *existing_table,
532 			   acpi_physical_address *address, u32 *length)
533 {
534 	int table_offset = 0;
535 	int table_index = 0;
536 	struct acpi_table_header *table;
537 	u32 table_length;
538 
539 	*length = 0;
540 	*address = 0;
541 	if (!acpi_tables_addr)
542 		return AE_OK;
543 
544 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
545 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
546 					   ACPI_HEADER_SIZE);
547 		if (table_offset + table->length > all_tables_size) {
548 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
549 			WARN_ON(1);
550 			return AE_OK;
551 		}
552 
553 		table_length = table->length;
554 
555 		/* Only override tables matched */
556 		if (memcmp(existing_table->signature, table->signature, 4) ||
557 		    memcmp(table->oem_id, existing_table->oem_id,
558 			   ACPI_OEM_ID_SIZE) ||
559 		    memcmp(table->oem_table_id, existing_table->oem_table_id,
560 			   ACPI_OEM_TABLE_ID_SIZE)) {
561 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
562 			goto next_table;
563 		}
564 		/*
565 		 * Mark the table to avoid being used in
566 		 * acpi_table_initrd_scan() and check the revision.
567 		 */
568 		if (test_and_set_bit(table_index, acpi_initrd_installed) ||
569 		    existing_table->oem_revision >= table->oem_revision) {
570 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
571 			goto next_table;
572 		}
573 
574 		*length = table_length;
575 		*address = acpi_tables_addr + table_offset;
576 		pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
577 			table->signature, table->oem_id,
578 			table->oem_table_id);
579 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
580 		break;
581 
582 next_table:
583 		table_offset += table_length;
584 		table_index++;
585 	}
586 	return AE_OK;
587 }
588 
589 static void __init acpi_table_initrd_scan(void)
590 {
591 	int table_offset = 0;
592 	int table_index = 0;
593 	u32 table_length;
594 	struct acpi_table_header *table;
595 
596 	if (!acpi_tables_addr)
597 		return;
598 
599 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
600 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
601 					   ACPI_HEADER_SIZE);
602 		if (table_offset + table->length > all_tables_size) {
603 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
604 			WARN_ON(1);
605 			return;
606 		}
607 
608 		table_length = table->length;
609 
610 		/* Skip RSDT/XSDT which should only be used for override */
611 		if (ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_RSDT) ||
612 		    ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_XSDT)) {
613 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
614 			goto next_table;
615 		}
616 		/*
617 		 * Mark the table to avoid being used in
618 		 * acpi_table_initrd_override(). Though this is not possible
619 		 * because override is disabled in acpi_install_physical_table().
620 		 */
621 		if (test_and_set_bit(table_index, acpi_initrd_installed)) {
622 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
623 			goto next_table;
624 		}
625 
626 		pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
627 			table->signature, table->oem_id,
628 			table->oem_table_id);
629 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
630 		acpi_install_physical_table(acpi_tables_addr + table_offset);
631 next_table:
632 		table_offset += table_length;
633 		table_index++;
634 	}
635 }
636 #else
637 static acpi_status
638 acpi_table_initrd_override(struct acpi_table_header *existing_table,
639 			   acpi_physical_address *address,
640 			   u32 *table_length)
641 {
642 	*table_length = 0;
643 	*address = 0;
644 	return AE_OK;
645 }
646 
647 static void __init acpi_table_initrd_scan(void)
648 {
649 }
650 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
651 
652 acpi_status
653 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
654 				acpi_physical_address *address,
655 				u32 *table_length)
656 {
657 	return acpi_table_initrd_override(existing_table, address,
658 					  table_length);
659 }
660 
661 #ifdef CONFIG_ACPI_CUSTOM_DSDT
662 static void *amlcode __attribute__ ((weakref("AmlCode")));
663 static void *dsdt_amlcode __attribute__ ((weakref("dsdt_aml_code")));
664 #endif
665 
666 acpi_status acpi_os_table_override(struct acpi_table_header *existing_table,
667 		       struct acpi_table_header **new_table)
668 {
669 	if (!existing_table || !new_table)
670 		return AE_BAD_PARAMETER;
671 
672 	*new_table = NULL;
673 
674 #ifdef CONFIG_ACPI_CUSTOM_DSDT
675 	if (!strncmp(existing_table->signature, "DSDT", 4)) {
676 		*new_table = (struct acpi_table_header *)&amlcode;
677 		if (!(*new_table))
678 			*new_table = (struct acpi_table_header *)&dsdt_amlcode;
679 	}
680 #endif
681 	if (*new_table != NULL)
682 		acpi_table_taint(existing_table);
683 	return AE_OK;
684 }
685 
686 /*
687  * acpi_locate_initial_tables()
688  *
689  * Get the RSDP, then find and checksum all the ACPI tables.
690  *
691  * result: initial_tables[] is initialized, and points to
692  * a list of ACPI tables.
693  */
694 int __init acpi_locate_initial_tables(void)
695 {
696 	acpi_status status;
697 
698 	if (acpi_verify_table_checksum) {
699 		pr_info("Early table checksum verification enabled\n");
700 		acpi_gbl_enable_table_validation = TRUE;
701 	} else {
702 		pr_info("Early table checksum verification disabled\n");
703 		acpi_gbl_enable_table_validation = FALSE;
704 	}
705 
706 	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
707 	if (ACPI_FAILURE(status))
708 		return -EINVAL;
709 
710 	return 0;
711 }
712 
713 void __init acpi_reserve_initial_tables(void)
714 {
715 	int i;
716 
717 	for (i = 0; i < ACPI_MAX_TABLES; i++) {
718 		struct acpi_table_desc *table_desc = &initial_tables[i];
719 		u64 start = table_desc->address;
720 		u64 size = table_desc->length;
721 
722 		if (!start || !size)
723 			break;
724 
725 		pr_info("Reserving %4s table memory at [mem 0x%llx-0x%llx]\n",
726 			table_desc->signature.ascii, start, start + size - 1);
727 
728 		memblock_reserve(start, size);
729 	}
730 }
731 
732 void __init acpi_table_init_complete(void)
733 {
734 	acpi_table_initrd_scan();
735 	check_multiple_madt();
736 }
737 
738 int __init acpi_table_init(void)
739 {
740 	int ret;
741 
742 	ret = acpi_locate_initial_tables();
743 	if (ret)
744 		return ret;
745 
746 	acpi_table_init_complete();
747 
748 	return 0;
749 }
750 
751 static int __init acpi_parse_apic_instance(char *str)
752 {
753 	if (!str)
754 		return -EINVAL;
755 
756 	if (kstrtoint(str, 0, &acpi_apic_instance))
757 		return -EINVAL;
758 
759 	pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
760 
761 	return 0;
762 }
763 early_param("acpi_apic_instance", acpi_parse_apic_instance);
764 
765 static int __init acpi_force_table_verification_setup(char *s)
766 {
767 	acpi_verify_table_checksum = true;
768 
769 	return 0;
770 }
771 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
772 
773 static int __init acpi_force_32bit_fadt_addr(char *s)
774 {
775 	pr_info("Forcing 32 Bit FADT addresses\n");
776 	acpi_gbl_use32_bit_fadt_addresses = TRUE;
777 
778 	return 0;
779 }
780 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);
781