xref: /linux/drivers/acpi/tables.c (revision 4e0385dd7469d933c4adf84a617f872ca547aa07)
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_parse_entries(char *id,
315 			unsigned long table_size,
316 			acpi_tbl_entry_handler handler,
317 			struct acpi_table_header *table_header,
318 			int entry_id, unsigned int max_entries)
319 {
320 	struct acpi_subtable_proc proc = {
321 		.id		= entry_id,
322 		.handler	= handler,
323 	};
324 
325 	return acpi_parse_entries_array(id, table_size, table_header,
326 			&proc, 1, max_entries);
327 }
328 
329 int __init
330 acpi_table_parse_entries_array(char *id,
331 			 unsigned long table_size,
332 			 struct acpi_subtable_proc *proc, int proc_num,
333 			 unsigned int max_entries)
334 {
335 	struct acpi_table_header *table_header = NULL;
336 	int count;
337 	u32 instance = 0;
338 
339 	if (acpi_disabled)
340 		return -ENODEV;
341 
342 	if (!id)
343 		return -EINVAL;
344 
345 	if (!strncmp(id, ACPI_SIG_MADT, 4))
346 		instance = acpi_apic_instance;
347 
348 	acpi_get_table(id, instance, &table_header);
349 	if (!table_header) {
350 		pr_warn("%4.4s not present\n", id);
351 		return -ENODEV;
352 	}
353 
354 	count = acpi_parse_entries_array(id, table_size, table_header,
355 			proc, proc_num, max_entries);
356 
357 	acpi_put_table(table_header);
358 	return count;
359 }
360 
361 int __init
362 acpi_table_parse_entries(char *id,
363 			unsigned long table_size,
364 			int entry_id,
365 			acpi_tbl_entry_handler handler,
366 			unsigned int max_entries)
367 {
368 	struct acpi_subtable_proc proc = {
369 		.id		= entry_id,
370 		.handler	= handler,
371 	};
372 
373 	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
374 						max_entries);
375 }
376 
377 int __init
378 acpi_table_parse_madt(enum acpi_madt_type id,
379 		      acpi_tbl_entry_handler handler, unsigned int max_entries)
380 {
381 	return acpi_table_parse_entries(ACPI_SIG_MADT,
382 					    sizeof(struct acpi_table_madt), id,
383 					    handler, max_entries);
384 }
385 
386 /**
387  * acpi_table_parse - find table with @id, run @handler on it
388  * @id: table id to find
389  * @handler: handler to run
390  *
391  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
392  * run @handler on it.
393  *
394  * Return 0 if table found, -errno if not.
395  */
396 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
397 {
398 	struct acpi_table_header *table = NULL;
399 
400 	if (acpi_disabled)
401 		return -ENODEV;
402 
403 	if (!id || !handler)
404 		return -EINVAL;
405 
406 	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
407 		acpi_get_table(id, acpi_apic_instance, &table);
408 	else
409 		acpi_get_table(id, 0, &table);
410 
411 	if (table) {
412 		handler(table);
413 		acpi_put_table(table);
414 		return 0;
415 	} else
416 		return -ENODEV;
417 }
418 
419 /*
420  * The BIOS is supposed to supply a single APIC/MADT,
421  * but some report two.  Provide a knob to use either.
422  * (don't you wish instance 0 and 1 were not the same?)
423  */
424 static void __init check_multiple_madt(void)
425 {
426 	struct acpi_table_header *table = NULL;
427 
428 	acpi_get_table(ACPI_SIG_MADT, 2, &table);
429 	if (table) {
430 		pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
431 			acpi_apic_instance);
432 		pr_warn("If \"acpi_apic_instance=%d\" works better, "
433 			"notify linux-acpi@vger.kernel.org\n",
434 			acpi_apic_instance ? 0 : 2);
435 		acpi_put_table(table);
436 
437 	} else
438 		acpi_apic_instance = 0;
439 
440 	return;
441 }
442 
443 static void acpi_table_taint(struct acpi_table_header *table)
444 {
445 	pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
446 		table->signature, table->oem_table_id);
447 	add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
448 }
449 
450 #ifdef CONFIG_ACPI_TABLE_UPGRADE
451 static u64 acpi_tables_addr;
452 static int all_tables_size;
453 
454 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
455 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
456 {
457 	u8 sum = 0;
458 	u8 *end = buffer + length;
459 
460 	while (buffer < end)
461 		sum = (u8) (sum + *(buffer++));
462 	return sum;
463 }
464 
465 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
466 static const char * const table_sigs[] = {
467 	ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ,
468 	ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT,
469 	ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF,
470 	ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET,
471 	ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI,
472 	ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA,
473 	ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT,
474 	ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT,
475 	ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, NULL };
476 
477 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
478 
479 #define NR_ACPI_INITRD_TABLES 64
480 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
481 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
482 
483 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
484 
485 void __init acpi_table_upgrade(void)
486 {
487 	void *data = (void *)initrd_start;
488 	size_t size = initrd_end - initrd_start;
489 	int sig, no, table_nr = 0, total_offset = 0;
490 	long offset = 0;
491 	struct acpi_table_header *table;
492 	char cpio_path[32] = "kernel/firmware/acpi/";
493 	struct cpio_data file;
494 
495 	if (data == NULL || size == 0)
496 		return;
497 
498 	for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
499 		file = find_cpio_data(cpio_path, data, size, &offset);
500 		if (!file.data)
501 			break;
502 
503 		data += offset;
504 		size -= offset;
505 
506 		if (file.size < sizeof(struct acpi_table_header)) {
507 			pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
508 				cpio_path, file.name);
509 			continue;
510 		}
511 
512 		table = file.data;
513 
514 		for (sig = 0; table_sigs[sig]; sig++)
515 			if (!memcmp(table->signature, table_sigs[sig], 4))
516 				break;
517 
518 		if (!table_sigs[sig]) {
519 			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
520 				cpio_path, file.name);
521 			continue;
522 		}
523 		if (file.size != table->length) {
524 			pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
525 				cpio_path, file.name);
526 			continue;
527 		}
528 		if (acpi_table_checksum(file.data, table->length)) {
529 			pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
530 				cpio_path, file.name);
531 			continue;
532 		}
533 
534 		pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
535 			table->signature, cpio_path, file.name, table->length);
536 
537 		all_tables_size += table->length;
538 		acpi_initrd_files[table_nr].data = file.data;
539 		acpi_initrd_files[table_nr].size = file.size;
540 		table_nr++;
541 	}
542 	if (table_nr == 0)
543 		return;
544 
545 	acpi_tables_addr =
546 		memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
547 				       all_tables_size, PAGE_SIZE);
548 	if (!acpi_tables_addr) {
549 		WARN_ON(1);
550 		return;
551 	}
552 	/*
553 	 * Only calling e820_add_reserve does not work and the
554 	 * tables are invalid (memory got used) later.
555 	 * memblock_reserve works as expected and the tables won't get modified.
556 	 * But it's not enough on X86 because ioremap will
557 	 * complain later (used by acpi_os_map_memory) that the pages
558 	 * that should get mapped are not marked "reserved".
559 	 * Both memblock_reserve and e820_add_region (via arch_reserve_mem_area)
560 	 * works fine.
561 	 */
562 	memblock_reserve(acpi_tables_addr, all_tables_size);
563 	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
564 
565 	/*
566 	 * early_ioremap only can remap 256k one time. If we map all
567 	 * tables one time, we will hit the limit. Need to map chunks
568 	 * one by one during copying the same as that in relocate_initrd().
569 	 */
570 	for (no = 0; no < table_nr; no++) {
571 		unsigned char *src_p = acpi_initrd_files[no].data;
572 		phys_addr_t size = acpi_initrd_files[no].size;
573 		phys_addr_t dest_addr = acpi_tables_addr + total_offset;
574 		phys_addr_t slop, clen;
575 		char *dest_p;
576 
577 		total_offset += size;
578 
579 		while (size) {
580 			slop = dest_addr & ~PAGE_MASK;
581 			clen = size;
582 			if (clen > MAP_CHUNK_SIZE - slop)
583 				clen = MAP_CHUNK_SIZE - slop;
584 			dest_p = early_memremap(dest_addr & PAGE_MASK,
585 						clen + slop);
586 			memcpy(dest_p + slop, src_p, clen);
587 			early_memunmap(dest_p, clen + slop);
588 			src_p += clen;
589 			dest_addr += clen;
590 			size -= clen;
591 		}
592 	}
593 }
594 
595 static acpi_status
596 acpi_table_initrd_override(struct acpi_table_header *existing_table,
597 			   acpi_physical_address *address, u32 *length)
598 {
599 	int table_offset = 0;
600 	int table_index = 0;
601 	struct acpi_table_header *table;
602 	u32 table_length;
603 
604 	*length = 0;
605 	*address = 0;
606 	if (!acpi_tables_addr)
607 		return AE_OK;
608 
609 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
610 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
611 					   ACPI_HEADER_SIZE);
612 		if (table_offset + table->length > all_tables_size) {
613 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
614 			WARN_ON(1);
615 			return AE_OK;
616 		}
617 
618 		table_length = table->length;
619 
620 		/* Only override tables matched */
621 		if (memcmp(existing_table->signature, table->signature, 4) ||
622 		    memcmp(table->oem_id, existing_table->oem_id,
623 			   ACPI_OEM_ID_SIZE) ||
624 		    memcmp(table->oem_table_id, existing_table->oem_table_id,
625 			   ACPI_OEM_TABLE_ID_SIZE)) {
626 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
627 			goto next_table;
628 		}
629 		/*
630 		 * Mark the table to avoid being used in
631 		 * acpi_table_initrd_scan() and check the revision.
632 		 */
633 		if (test_and_set_bit(table_index, acpi_initrd_installed) ||
634 		    existing_table->oem_revision >= table->oem_revision) {
635 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
636 			goto next_table;
637 		}
638 
639 		*length = table_length;
640 		*address = acpi_tables_addr + table_offset;
641 		pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
642 			table->signature, table->oem_id,
643 			table->oem_table_id);
644 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
645 		break;
646 
647 next_table:
648 		table_offset += table_length;
649 		table_index++;
650 	}
651 	return AE_OK;
652 }
653 
654 static void __init acpi_table_initrd_scan(void)
655 {
656 	int table_offset = 0;
657 	int table_index = 0;
658 	u32 table_length;
659 	struct acpi_table_header *table;
660 
661 	if (!acpi_tables_addr)
662 		return;
663 
664 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
665 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
666 					   ACPI_HEADER_SIZE);
667 		if (table_offset + table->length > all_tables_size) {
668 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
669 			WARN_ON(1);
670 			return;
671 		}
672 
673 		table_length = table->length;
674 
675 		/* Skip RSDT/XSDT which should only be used for override */
676 		if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_RSDT) ||
677 		    ACPI_COMPARE_NAME(table->signature, ACPI_SIG_XSDT)) {
678 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
679 			goto next_table;
680 		}
681 		/*
682 		 * Mark the table to avoid being used in
683 		 * acpi_table_initrd_override(). Though this is not possible
684 		 * because override is disabled in acpi_install_table().
685 		 */
686 		if (test_and_set_bit(table_index, acpi_initrd_installed)) {
687 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
688 			goto next_table;
689 		}
690 
691 		pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
692 			table->signature, table->oem_id,
693 			table->oem_table_id);
694 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
695 		acpi_install_table(acpi_tables_addr + table_offset, TRUE);
696 next_table:
697 		table_offset += table_length;
698 		table_index++;
699 	}
700 }
701 #else
702 static acpi_status
703 acpi_table_initrd_override(struct acpi_table_header *existing_table,
704 			   acpi_physical_address *address,
705 			   u32 *table_length)
706 {
707 	*table_length = 0;
708 	*address = 0;
709 	return AE_OK;
710 }
711 
712 static void __init acpi_table_initrd_scan(void)
713 {
714 }
715 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
716 
717 acpi_status
718 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
719 				acpi_physical_address *address,
720 				u32 *table_length)
721 {
722 	return acpi_table_initrd_override(existing_table, address,
723 					  table_length);
724 }
725 
726 acpi_status
727 acpi_os_table_override(struct acpi_table_header *existing_table,
728 		       struct acpi_table_header **new_table)
729 {
730 	if (!existing_table || !new_table)
731 		return AE_BAD_PARAMETER;
732 
733 	*new_table = NULL;
734 
735 #ifdef CONFIG_ACPI_CUSTOM_DSDT
736 	if (strncmp(existing_table->signature, "DSDT", 4) == 0)
737 		*new_table = (struct acpi_table_header *)AmlCode;
738 #endif
739 	if (*new_table != NULL)
740 		acpi_table_taint(existing_table);
741 	return AE_OK;
742 }
743 
744 /*
745  * acpi_table_init()
746  *
747  * find RSDP, find and checksum SDT/XSDT.
748  * checksum all tables, print SDT/XSDT
749  *
750  * result: sdt_entry[] is initialized
751  */
752 
753 int __init acpi_table_init(void)
754 {
755 	acpi_status status;
756 
757 	if (acpi_verify_table_checksum) {
758 		pr_info("Early table checksum verification enabled\n");
759 		acpi_gbl_verify_table_checksum = TRUE;
760 	} else {
761 		pr_info("Early table checksum verification disabled\n");
762 		acpi_gbl_verify_table_checksum = FALSE;
763 	}
764 
765 	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
766 	if (ACPI_FAILURE(status))
767 		return -EINVAL;
768 	acpi_table_initrd_scan();
769 
770 	check_multiple_madt();
771 	return 0;
772 }
773 
774 static int __init acpi_parse_apic_instance(char *str)
775 {
776 	if (!str)
777 		return -EINVAL;
778 
779 	if (kstrtoint(str, 0, &acpi_apic_instance))
780 		return -EINVAL;
781 
782 	pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
783 
784 	return 0;
785 }
786 
787 early_param("acpi_apic_instance", acpi_parse_apic_instance);
788 
789 static int __init acpi_force_table_verification_setup(char *s)
790 {
791 	acpi_verify_table_checksum = true;
792 
793 	return 0;
794 }
795 
796 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
797 
798 static int __init acpi_force_32bit_fadt_addr(char *s)
799 {
800 	pr_info("Forcing 32 Bit FADT addresses\n");
801 	acpi_gbl_use32_bit_fadt_addresses = TRUE;
802 
803 	return 0;
804 }
805 
806 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);
807