xref: /linux/drivers/acpi/tables.c (revision fd639726bf15fca8ee1a00dce8e0096d0ad9bd18)
1 /*
2  *  acpi_tables.c - ACPI Boot-Time Table Parsing
3  *
4  *  Copyright (C) 2001 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
5  *
6  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 of the License, or
11  *  (at your option) any later version.
12  *
13  *  This program is distributed in the hope that it will be useful,
14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  *  GNU General Public License for more details.
17  *
18  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
19  *
20  */
21 
22 /* Uncomment next line to get verbose printout */
23 /* #define DEBUG */
24 #define pr_fmt(fmt) "ACPI: " fmt
25 
26 #include <linux/init.h>
27 #include <linux/kernel.h>
28 #include <linux/smp.h>
29 #include <linux/string.h>
30 #include <linux/types.h>
31 #include <linux/irq.h>
32 #include <linux/errno.h>
33 #include <linux/acpi.h>
34 #include <linux/bootmem.h>
35 #include <linux/earlycpio.h>
36 #include <linux/memblock.h>
37 #include <linux/initrd.h>
38 #include "internal.h"
39 
40 #ifdef CONFIG_ACPI_CUSTOM_DSDT
41 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
42 #endif
43 
44 #define ACPI_MAX_TABLES		128
45 
46 static char *mps_inti_flags_polarity[] = { "dfl", "high", "res", "low" };
47 static char *mps_inti_flags_trigger[] = { "dfl", "edge", "res", "level" };
48 
49 static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
50 
51 static int acpi_apic_instance __initdata;
52 
53 /*
54  * Disable table checksum verification for the early stage due to the size
55  * limitation of the current x86 early mapping implementation.
56  */
57 static bool acpi_verify_table_checksum __initdata = false;
58 
59 void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
60 {
61 	if (!header)
62 		return;
63 
64 	switch (header->type) {
65 
66 	case ACPI_MADT_TYPE_LOCAL_APIC:
67 		{
68 			struct acpi_madt_local_apic *p =
69 			    (struct acpi_madt_local_apic *)header;
70 			pr_debug("LAPIC (acpi_id[0x%02x] lapic_id[0x%02x] %s)\n",
71 				 p->processor_id, p->id,
72 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
73 		}
74 		break;
75 
76 	case ACPI_MADT_TYPE_LOCAL_X2APIC:
77 		{
78 			struct acpi_madt_local_x2apic *p =
79 			    (struct acpi_madt_local_x2apic *)header;
80 			pr_debug("X2APIC (apic_id[0x%02x] uid[0x%02x] %s)\n",
81 				 p->local_apic_id, p->uid,
82 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
83 		}
84 		break;
85 
86 	case ACPI_MADT_TYPE_IO_APIC:
87 		{
88 			struct acpi_madt_io_apic *p =
89 			    (struct acpi_madt_io_apic *)header;
90 			pr_debug("IOAPIC (id[0x%02x] address[0x%08x] gsi_base[%d])\n",
91 				 p->id, p->address, p->global_irq_base);
92 		}
93 		break;
94 
95 	case ACPI_MADT_TYPE_INTERRUPT_OVERRIDE:
96 		{
97 			struct acpi_madt_interrupt_override *p =
98 			    (struct acpi_madt_interrupt_override *)header;
99 			pr_info("INT_SRC_OVR (bus %d bus_irq %d global_irq %d %s %s)\n",
100 				p->bus, p->source_irq, p->global_irq,
101 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
102 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2]);
103 			if (p->inti_flags  &
104 			    ~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK))
105 				pr_info("INT_SRC_OVR unexpected reserved flags: 0x%x\n",
106 					p->inti_flags  &
107 					~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK));
108 		}
109 		break;
110 
111 	case ACPI_MADT_TYPE_NMI_SOURCE:
112 		{
113 			struct acpi_madt_nmi_source *p =
114 			    (struct acpi_madt_nmi_source *)header;
115 			pr_info("NMI_SRC (%s %s global_irq %d)\n",
116 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
117 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
118 				p->global_irq);
119 		}
120 		break;
121 
122 	case ACPI_MADT_TYPE_LOCAL_APIC_NMI:
123 		{
124 			struct acpi_madt_local_apic_nmi *p =
125 			    (struct acpi_madt_local_apic_nmi *)header;
126 			pr_info("LAPIC_NMI (acpi_id[0x%02x] %s %s lint[0x%x])\n",
127 				p->processor_id,
128 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK	],
129 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
130 				p->lint);
131 		}
132 		break;
133 
134 	case ACPI_MADT_TYPE_LOCAL_X2APIC_NMI:
135 		{
136 			u16 polarity, trigger;
137 			struct acpi_madt_local_x2apic_nmi *p =
138 			    (struct acpi_madt_local_x2apic_nmi *)header;
139 
140 			polarity = p->inti_flags & ACPI_MADT_POLARITY_MASK;
141 			trigger = (p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
142 
143 			pr_info("X2APIC_NMI (uid[0x%02x] %s %s lint[0x%x])\n",
144 				p->uid,
145 				mps_inti_flags_polarity[polarity],
146 				mps_inti_flags_trigger[trigger],
147 				p->lint);
148 		}
149 		break;
150 
151 	case ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE:
152 		{
153 			struct acpi_madt_local_apic_override *p =
154 			    (struct acpi_madt_local_apic_override *)header;
155 			pr_info("LAPIC_ADDR_OVR (address[%p])\n",
156 				(void *)(unsigned long)p->address);
157 		}
158 		break;
159 
160 	case ACPI_MADT_TYPE_IO_SAPIC:
161 		{
162 			struct acpi_madt_io_sapic *p =
163 			    (struct acpi_madt_io_sapic *)header;
164 			pr_debug("IOSAPIC (id[0x%x] address[%p] gsi_base[%d])\n",
165 				 p->id, (void *)(unsigned long)p->address,
166 				 p->global_irq_base);
167 		}
168 		break;
169 
170 	case ACPI_MADT_TYPE_LOCAL_SAPIC:
171 		{
172 			struct acpi_madt_local_sapic *p =
173 			    (struct acpi_madt_local_sapic *)header;
174 			pr_debug("LSAPIC (acpi_id[0x%02x] lsapic_id[0x%02x] lsapic_eid[0x%02x] %s)\n",
175 				 p->processor_id, p->id, p->eid,
176 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
177 		}
178 		break;
179 
180 	case ACPI_MADT_TYPE_INTERRUPT_SOURCE:
181 		{
182 			struct acpi_madt_interrupt_source *p =
183 			    (struct acpi_madt_interrupt_source *)header;
184 			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",
185 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
186 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
187 				p->type, p->id, p->eid, p->io_sapic_vector,
188 				p->global_irq);
189 		}
190 		break;
191 
192 	case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
193 		{
194 			struct acpi_madt_generic_interrupt *p =
195 				(struct acpi_madt_generic_interrupt *)header;
196 			pr_debug("GICC (acpi_id[0x%04x] address[%llx] MPIDR[0x%llx] %s)\n",
197 				 p->uid, p->base_address,
198 				 p->arm_mpidr,
199 				 (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
200 
201 		}
202 		break;
203 
204 	case ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR:
205 		{
206 			struct acpi_madt_generic_distributor *p =
207 				(struct acpi_madt_generic_distributor *)header;
208 			pr_debug("GIC Distributor (gic_id[0x%04x] address[%llx] gsi_base[%d])\n",
209 				 p->gic_id, p->base_address,
210 				 p->global_irq_base);
211 		}
212 		break;
213 
214 	default:
215 		pr_warn("Found unsupported MADT entry (type = 0x%x)\n",
216 			header->type);
217 		break;
218 	}
219 }
220 
221 /**
222  * acpi_parse_entries_array - for each proc_num find a suitable subtable
223  *
224  * @id: table id (for debugging purposes)
225  * @table_size: single entry size
226  * @table_header: where does the table start?
227  * @proc: array of acpi_subtable_proc struct containing entry id
228  *        and associated handler with it
229  * @proc_num: how big proc is?
230  * @max_entries: how many entries can we process?
231  *
232  * For each proc_num find a subtable with proc->id and run proc->handler
233  * on it. Assumption is that there's only single handler for particular
234  * entry id.
235  *
236  * On success returns sum of all matching entries for all proc handlers.
237  * Otherwise, -ENODEV or -EINVAL is returned.
238  */
239 static int __init
240 acpi_parse_entries_array(char *id, unsigned long table_size,
241 		struct acpi_table_header *table_header,
242 		struct acpi_subtable_proc *proc, int proc_num,
243 		unsigned int max_entries)
244 {
245 	struct acpi_subtable_header *entry;
246 	unsigned long table_end;
247 	int count = 0;
248 	int errs = 0;
249 	int i;
250 
251 	if (acpi_disabled)
252 		return -ENODEV;
253 
254 	if (!id)
255 		return -EINVAL;
256 
257 	if (!table_size)
258 		return -EINVAL;
259 
260 	if (!table_header) {
261 		pr_warn("%4.4s not present\n", id);
262 		return -ENODEV;
263 	}
264 
265 	table_end = (unsigned long)table_header + table_header->length;
266 
267 	/* Parse all entries looking for a match. */
268 
269 	entry = (struct acpi_subtable_header *)
270 	    ((unsigned long)table_header + table_size);
271 
272 	while (((unsigned long)entry) + sizeof(struct acpi_subtable_header) <
273 	       table_end) {
274 		if (max_entries && count >= max_entries)
275 			break;
276 
277 		for (i = 0; i < proc_num; i++) {
278 			if (entry->type != proc[i].id)
279 				continue;
280 			if (!proc[i].handler ||
281 			     (!errs && proc[i].handler(entry, table_end))) {
282 				errs++;
283 				continue;
284 			}
285 
286 			proc[i].count++;
287 			break;
288 		}
289 		if (i != proc_num)
290 			count++;
291 
292 		/*
293 		 * If entry->length is 0, break from this loop to avoid
294 		 * infinite loop.
295 		 */
296 		if (entry->length == 0) {
297 			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
298 			return -EINVAL;
299 		}
300 
301 		entry = (struct acpi_subtable_header *)
302 		    ((unsigned long)entry + entry->length);
303 	}
304 
305 	if (max_entries && count > max_entries) {
306 		pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
307 			id, proc->id, count);
308 	}
309 
310 	return errs ? -EINVAL : count;
311 }
312 
313 int __init
314 acpi_table_parse_entries_array(char *id,
315 			 unsigned long table_size,
316 			 struct acpi_subtable_proc *proc, int proc_num,
317 			 unsigned int max_entries)
318 {
319 	struct acpi_table_header *table_header = NULL;
320 	int count;
321 	u32 instance = 0;
322 
323 	if (acpi_disabled)
324 		return -ENODEV;
325 
326 	if (!id)
327 		return -EINVAL;
328 
329 	if (!strncmp(id, ACPI_SIG_MADT, 4))
330 		instance = acpi_apic_instance;
331 
332 	acpi_get_table(id, instance, &table_header);
333 	if (!table_header) {
334 		pr_warn("%4.4s not present\n", id);
335 		return -ENODEV;
336 	}
337 
338 	count = acpi_parse_entries_array(id, table_size, table_header,
339 			proc, proc_num, max_entries);
340 
341 	acpi_put_table(table_header);
342 	return count;
343 }
344 
345 int __init
346 acpi_table_parse_entries(char *id,
347 			unsigned long table_size,
348 			int entry_id,
349 			acpi_tbl_entry_handler handler,
350 			unsigned int max_entries)
351 {
352 	struct acpi_subtable_proc proc = {
353 		.id		= entry_id,
354 		.handler	= handler,
355 	};
356 
357 	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
358 						max_entries);
359 }
360 
361 int __init
362 acpi_table_parse_madt(enum acpi_madt_type id,
363 		      acpi_tbl_entry_handler handler, unsigned int max_entries)
364 {
365 	return acpi_table_parse_entries(ACPI_SIG_MADT,
366 					    sizeof(struct acpi_table_madt), id,
367 					    handler, max_entries);
368 }
369 
370 /**
371  * acpi_table_parse - find table with @id, run @handler on it
372  * @id: table id to find
373  * @handler: handler to run
374  *
375  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
376  * run @handler on it.
377  *
378  * Return 0 if table found, -errno if not.
379  */
380 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
381 {
382 	struct acpi_table_header *table = NULL;
383 
384 	if (acpi_disabled)
385 		return -ENODEV;
386 
387 	if (!id || !handler)
388 		return -EINVAL;
389 
390 	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
391 		acpi_get_table(id, acpi_apic_instance, &table);
392 	else
393 		acpi_get_table(id, 0, &table);
394 
395 	if (table) {
396 		handler(table);
397 		acpi_put_table(table);
398 		return 0;
399 	} else
400 		return -ENODEV;
401 }
402 
403 /*
404  * The BIOS is supposed to supply a single APIC/MADT,
405  * but some report two.  Provide a knob to use either.
406  * (don't you wish instance 0 and 1 were not the same?)
407  */
408 static void __init check_multiple_madt(void)
409 {
410 	struct acpi_table_header *table = NULL;
411 
412 	acpi_get_table(ACPI_SIG_MADT, 2, &table);
413 	if (table) {
414 		pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
415 			acpi_apic_instance);
416 		pr_warn("If \"acpi_apic_instance=%d\" works better, "
417 			"notify linux-acpi@vger.kernel.org\n",
418 			acpi_apic_instance ? 0 : 2);
419 		acpi_put_table(table);
420 
421 	} else
422 		acpi_apic_instance = 0;
423 
424 	return;
425 }
426 
427 static void acpi_table_taint(struct acpi_table_header *table)
428 {
429 	pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
430 		table->signature, table->oem_table_id);
431 	add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
432 }
433 
434 #ifdef CONFIG_ACPI_TABLE_UPGRADE
435 static u64 acpi_tables_addr;
436 static int all_tables_size;
437 
438 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
439 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
440 {
441 	u8 sum = 0;
442 	u8 *end = buffer + length;
443 
444 	while (buffer < end)
445 		sum = (u8) (sum + *(buffer++));
446 	return sum;
447 }
448 
449 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
450 static const char * const table_sigs[] = {
451 	ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ,
452 	ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT,
453 	ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF,
454 	ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET,
455 	ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI,
456 	ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA,
457 	ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT,
458 	ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT,
459 	ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, NULL };
460 
461 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
462 
463 #define NR_ACPI_INITRD_TABLES 64
464 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
465 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
466 
467 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
468 
469 void __init acpi_table_upgrade(void)
470 {
471 	void *data = (void *)initrd_start;
472 	size_t size = initrd_end - initrd_start;
473 	int sig, no, table_nr = 0, total_offset = 0;
474 	long offset = 0;
475 	struct acpi_table_header *table;
476 	char cpio_path[32] = "kernel/firmware/acpi/";
477 	struct cpio_data file;
478 
479 	if (data == NULL || size == 0)
480 		return;
481 
482 	for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
483 		file = find_cpio_data(cpio_path, data, size, &offset);
484 		if (!file.data)
485 			break;
486 
487 		data += offset;
488 		size -= offset;
489 
490 		if (file.size < sizeof(struct acpi_table_header)) {
491 			pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
492 				cpio_path, file.name);
493 			continue;
494 		}
495 
496 		table = file.data;
497 
498 		for (sig = 0; table_sigs[sig]; sig++)
499 			if (!memcmp(table->signature, table_sigs[sig], 4))
500 				break;
501 
502 		if (!table_sigs[sig]) {
503 			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
504 				cpio_path, file.name);
505 			continue;
506 		}
507 		if (file.size != table->length) {
508 			pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
509 				cpio_path, file.name);
510 			continue;
511 		}
512 		if (acpi_table_checksum(file.data, table->length)) {
513 			pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
514 				cpio_path, file.name);
515 			continue;
516 		}
517 
518 		pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
519 			table->signature, cpio_path, file.name, table->length);
520 
521 		all_tables_size += table->length;
522 		acpi_initrd_files[table_nr].data = file.data;
523 		acpi_initrd_files[table_nr].size = file.size;
524 		table_nr++;
525 	}
526 	if (table_nr == 0)
527 		return;
528 
529 	acpi_tables_addr =
530 		memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
531 				       all_tables_size, PAGE_SIZE);
532 	if (!acpi_tables_addr) {
533 		WARN_ON(1);
534 		return;
535 	}
536 	/*
537 	 * Only calling e820_add_reserve does not work and the
538 	 * tables are invalid (memory got used) later.
539 	 * memblock_reserve works as expected and the tables won't get modified.
540 	 * But it's not enough on X86 because ioremap will
541 	 * complain later (used by acpi_os_map_memory) that the pages
542 	 * that should get mapped are not marked "reserved".
543 	 * Both memblock_reserve and e820__range_add (via arch_reserve_mem_area)
544 	 * works fine.
545 	 */
546 	memblock_reserve(acpi_tables_addr, all_tables_size);
547 	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
548 
549 	/*
550 	 * early_ioremap only can remap 256k one time. If we map all
551 	 * tables one time, we will hit the limit. Need to map chunks
552 	 * one by one during copying the same as that in relocate_initrd().
553 	 */
554 	for (no = 0; no < table_nr; no++) {
555 		unsigned char *src_p = acpi_initrd_files[no].data;
556 		phys_addr_t size = acpi_initrd_files[no].size;
557 		phys_addr_t dest_addr = acpi_tables_addr + total_offset;
558 		phys_addr_t slop, clen;
559 		char *dest_p;
560 
561 		total_offset += size;
562 
563 		while (size) {
564 			slop = dest_addr & ~PAGE_MASK;
565 			clen = size;
566 			if (clen > MAP_CHUNK_SIZE - slop)
567 				clen = MAP_CHUNK_SIZE - slop;
568 			dest_p = early_memremap(dest_addr & PAGE_MASK,
569 						clen + slop);
570 			memcpy(dest_p + slop, src_p, clen);
571 			early_memunmap(dest_p, clen + slop);
572 			src_p += clen;
573 			dest_addr += clen;
574 			size -= clen;
575 		}
576 	}
577 }
578 
579 static acpi_status
580 acpi_table_initrd_override(struct acpi_table_header *existing_table,
581 			   acpi_physical_address *address, u32 *length)
582 {
583 	int table_offset = 0;
584 	int table_index = 0;
585 	struct acpi_table_header *table;
586 	u32 table_length;
587 
588 	*length = 0;
589 	*address = 0;
590 	if (!acpi_tables_addr)
591 		return AE_OK;
592 
593 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
594 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
595 					   ACPI_HEADER_SIZE);
596 		if (table_offset + table->length > all_tables_size) {
597 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
598 			WARN_ON(1);
599 			return AE_OK;
600 		}
601 
602 		table_length = table->length;
603 
604 		/* Only override tables matched */
605 		if (memcmp(existing_table->signature, table->signature, 4) ||
606 		    memcmp(table->oem_id, existing_table->oem_id,
607 			   ACPI_OEM_ID_SIZE) ||
608 		    memcmp(table->oem_table_id, existing_table->oem_table_id,
609 			   ACPI_OEM_TABLE_ID_SIZE)) {
610 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
611 			goto next_table;
612 		}
613 		/*
614 		 * Mark the table to avoid being used in
615 		 * acpi_table_initrd_scan() and check the revision.
616 		 */
617 		if (test_and_set_bit(table_index, acpi_initrd_installed) ||
618 		    existing_table->oem_revision >= table->oem_revision) {
619 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
620 			goto next_table;
621 		}
622 
623 		*length = table_length;
624 		*address = acpi_tables_addr + table_offset;
625 		pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
626 			table->signature, table->oem_id,
627 			table->oem_table_id);
628 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
629 		break;
630 
631 next_table:
632 		table_offset += table_length;
633 		table_index++;
634 	}
635 	return AE_OK;
636 }
637 
638 static void __init acpi_table_initrd_scan(void)
639 {
640 	int table_offset = 0;
641 	int table_index = 0;
642 	u32 table_length;
643 	struct acpi_table_header *table;
644 
645 	if (!acpi_tables_addr)
646 		return;
647 
648 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
649 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
650 					   ACPI_HEADER_SIZE);
651 		if (table_offset + table->length > all_tables_size) {
652 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
653 			WARN_ON(1);
654 			return;
655 		}
656 
657 		table_length = table->length;
658 
659 		/* Skip RSDT/XSDT which should only be used for override */
660 		if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_RSDT) ||
661 		    ACPI_COMPARE_NAME(table->signature, ACPI_SIG_XSDT)) {
662 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
663 			goto next_table;
664 		}
665 		/*
666 		 * Mark the table to avoid being used in
667 		 * acpi_table_initrd_override(). Though this is not possible
668 		 * because override is disabled in acpi_install_table().
669 		 */
670 		if (test_and_set_bit(table_index, acpi_initrd_installed)) {
671 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
672 			goto next_table;
673 		}
674 
675 		pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
676 			table->signature, table->oem_id,
677 			table->oem_table_id);
678 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
679 		acpi_install_table(acpi_tables_addr + table_offset, TRUE);
680 next_table:
681 		table_offset += table_length;
682 		table_index++;
683 	}
684 }
685 #else
686 static acpi_status
687 acpi_table_initrd_override(struct acpi_table_header *existing_table,
688 			   acpi_physical_address *address,
689 			   u32 *table_length)
690 {
691 	*table_length = 0;
692 	*address = 0;
693 	return AE_OK;
694 }
695 
696 static void __init acpi_table_initrd_scan(void)
697 {
698 }
699 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
700 
701 acpi_status
702 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
703 				acpi_physical_address *address,
704 				u32 *table_length)
705 {
706 	return acpi_table_initrd_override(existing_table, address,
707 					  table_length);
708 }
709 
710 acpi_status
711 acpi_os_table_override(struct acpi_table_header *existing_table,
712 		       struct acpi_table_header **new_table)
713 {
714 	if (!existing_table || !new_table)
715 		return AE_BAD_PARAMETER;
716 
717 	*new_table = NULL;
718 
719 #ifdef CONFIG_ACPI_CUSTOM_DSDT
720 	if (strncmp(existing_table->signature, "DSDT", 4) == 0)
721 		*new_table = (struct acpi_table_header *)AmlCode;
722 #endif
723 	if (*new_table != NULL)
724 		acpi_table_taint(existing_table);
725 	return AE_OK;
726 }
727 
728 /*
729  * acpi_table_init()
730  *
731  * find RSDP, find and checksum SDT/XSDT.
732  * checksum all tables, print SDT/XSDT
733  *
734  * result: sdt_entry[] is initialized
735  */
736 
737 int __init acpi_table_init(void)
738 {
739 	acpi_status status;
740 
741 	if (acpi_verify_table_checksum) {
742 		pr_info("Early table checksum verification enabled\n");
743 		acpi_gbl_enable_table_validation = TRUE;
744 	} else {
745 		pr_info("Early table checksum verification disabled\n");
746 		acpi_gbl_enable_table_validation = FALSE;
747 	}
748 
749 	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
750 	if (ACPI_FAILURE(status))
751 		return -EINVAL;
752 	acpi_table_initrd_scan();
753 
754 	check_multiple_madt();
755 	return 0;
756 }
757 
758 static int __init acpi_parse_apic_instance(char *str)
759 {
760 	if (!str)
761 		return -EINVAL;
762 
763 	if (kstrtoint(str, 0, &acpi_apic_instance))
764 		return -EINVAL;
765 
766 	pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
767 
768 	return 0;
769 }
770 
771 early_param("acpi_apic_instance", acpi_parse_apic_instance);
772 
773 static int __init acpi_force_table_verification_setup(char *s)
774 {
775 	acpi_verify_table_checksum = true;
776 
777 	return 0;
778 }
779 
780 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
781 
782 static int __init acpi_force_32bit_fadt_addr(char *s)
783 {
784 	pr_info("Forcing 32 Bit FADT addresses\n");
785 	acpi_gbl_use32_bit_fadt_addresses = TRUE;
786 
787 	return 0;
788 }
789 
790 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);
791