xref: /openbmc/linux/drivers/acpi/tables.c (revision 4f205687)
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 "internal.h"
38 
39 #ifdef CONFIG_ACPI_CUSTOM_DSDT
40 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
41 #endif
42 
43 #define ACPI_MAX_TABLES		128
44 
45 static char *mps_inti_flags_polarity[] = { "dfl", "high", "res", "low" };
46 static char *mps_inti_flags_trigger[] = { "dfl", "edge", "res", "level" };
47 
48 static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
49 
50 static int acpi_apic_instance __initdata;
51 
52 /*
53  * Disable table checksum verification for the early stage due to the size
54  * limitation of the current x86 early mapping implementation.
55  */
56 static bool acpi_verify_table_checksum __initdata = false;
57 
58 void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
59 {
60 	if (!header)
61 		return;
62 
63 	switch (header->type) {
64 
65 	case ACPI_MADT_TYPE_LOCAL_APIC:
66 		{
67 			struct acpi_madt_local_apic *p =
68 			    (struct acpi_madt_local_apic *)header;
69 			pr_debug("LAPIC (acpi_id[0x%02x] lapic_id[0x%02x] %s)\n",
70 				 p->processor_id, p->id,
71 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
72 		}
73 		break;
74 
75 	case ACPI_MADT_TYPE_LOCAL_X2APIC:
76 		{
77 			struct acpi_madt_local_x2apic *p =
78 			    (struct acpi_madt_local_x2apic *)header;
79 			pr_debug("X2APIC (apic_id[0x%02x] uid[0x%02x] %s)\n",
80 				 p->local_apic_id, p->uid,
81 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
82 		}
83 		break;
84 
85 	case ACPI_MADT_TYPE_IO_APIC:
86 		{
87 			struct acpi_madt_io_apic *p =
88 			    (struct acpi_madt_io_apic *)header;
89 			pr_debug("IOAPIC (id[0x%02x] address[0x%08x] gsi_base[%d])\n",
90 				 p->id, p->address, p->global_irq_base);
91 		}
92 		break;
93 
94 	case ACPI_MADT_TYPE_INTERRUPT_OVERRIDE:
95 		{
96 			struct acpi_madt_interrupt_override *p =
97 			    (struct acpi_madt_interrupt_override *)header;
98 			pr_info("INT_SRC_OVR (bus %d bus_irq %d global_irq %d %s %s)\n",
99 				p->bus, p->source_irq, p->global_irq,
100 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
101 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2]);
102 			if (p->inti_flags  &
103 			    ~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK))
104 				pr_info("INT_SRC_OVR unexpected reserved flags: 0x%x\n",
105 					p->inti_flags  &
106 					~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK));
107 		}
108 		break;
109 
110 	case ACPI_MADT_TYPE_NMI_SOURCE:
111 		{
112 			struct acpi_madt_nmi_source *p =
113 			    (struct acpi_madt_nmi_source *)header;
114 			pr_info("NMI_SRC (%s %s global_irq %d)\n",
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->global_irq);
118 		}
119 		break;
120 
121 	case ACPI_MADT_TYPE_LOCAL_APIC_NMI:
122 		{
123 			struct acpi_madt_local_apic_nmi *p =
124 			    (struct acpi_madt_local_apic_nmi *)header;
125 			pr_info("LAPIC_NMI (acpi_id[0x%02x] %s %s lint[0x%x])\n",
126 				p->processor_id,
127 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK	],
128 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
129 				p->lint);
130 		}
131 		break;
132 
133 	case ACPI_MADT_TYPE_LOCAL_X2APIC_NMI:
134 		{
135 			u16 polarity, trigger;
136 			struct acpi_madt_local_x2apic_nmi *p =
137 			    (struct acpi_madt_local_x2apic_nmi *)header;
138 
139 			polarity = p->inti_flags & ACPI_MADT_POLARITY_MASK;
140 			trigger = (p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
141 
142 			pr_info("X2APIC_NMI (uid[0x%02x] %s %s lint[0x%x])\n",
143 				p->uid,
144 				mps_inti_flags_polarity[polarity],
145 				mps_inti_flags_trigger[trigger],
146 				p->lint);
147 		}
148 		break;
149 
150 	case ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE:
151 		{
152 			struct acpi_madt_local_apic_override *p =
153 			    (struct acpi_madt_local_apic_override *)header;
154 			pr_info("LAPIC_ADDR_OVR (address[%p])\n",
155 				(void *)(unsigned long)p->address);
156 		}
157 		break;
158 
159 	case ACPI_MADT_TYPE_IO_SAPIC:
160 		{
161 			struct acpi_madt_io_sapic *p =
162 			    (struct acpi_madt_io_sapic *)header;
163 			pr_debug("IOSAPIC (id[0x%x] address[%p] gsi_base[%d])\n",
164 				 p->id, (void *)(unsigned long)p->address,
165 				 p->global_irq_base);
166 		}
167 		break;
168 
169 	case ACPI_MADT_TYPE_LOCAL_SAPIC:
170 		{
171 			struct acpi_madt_local_sapic *p =
172 			    (struct acpi_madt_local_sapic *)header;
173 			pr_debug("LSAPIC (acpi_id[0x%02x] lsapic_id[0x%02x] lsapic_eid[0x%02x] %s)\n",
174 				 p->processor_id, p->id, p->eid,
175 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
176 		}
177 		break;
178 
179 	case ACPI_MADT_TYPE_INTERRUPT_SOURCE:
180 		{
181 			struct acpi_madt_interrupt_source *p =
182 			    (struct acpi_madt_interrupt_source *)header;
183 			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",
184 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
185 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
186 				p->type, p->id, p->eid, p->io_sapic_vector,
187 				p->global_irq);
188 		}
189 		break;
190 
191 	case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
192 		{
193 			struct acpi_madt_generic_interrupt *p =
194 				(struct acpi_madt_generic_interrupt *)header;
195 			pr_debug("GICC (acpi_id[0x%04x] address[%llx] MPIDR[0x%llx] %s)\n",
196 				 p->uid, p->base_address,
197 				 p->arm_mpidr,
198 				 (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
199 
200 		}
201 		break;
202 
203 	case ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR:
204 		{
205 			struct acpi_madt_generic_distributor *p =
206 				(struct acpi_madt_generic_distributor *)header;
207 			pr_debug("GIC Distributor (gic_id[0x%04x] address[%llx] gsi_base[%d])\n",
208 				 p->gic_id, p->base_address,
209 				 p->global_irq_base);
210 		}
211 		break;
212 
213 	default:
214 		pr_warn("Found unsupported MADT entry (type = 0x%x)\n",
215 			header->type);
216 		break;
217 	}
218 }
219 
220 /**
221  * acpi_parse_entries_array - for each proc_num find a suitable subtable
222  *
223  * @id: table id (for debugging purposes)
224  * @table_size: single entry size
225  * @table_header: where does the table start?
226  * @proc: array of acpi_subtable_proc struct containing entry id
227  *        and associated handler with it
228  * @proc_num: how big proc is?
229  * @max_entries: how many entries can we process?
230  *
231  * For each proc_num find a subtable with proc->id and run proc->handler
232  * on it. Assumption is that there's only single handler for particular
233  * entry id.
234  *
235  * On success returns sum of all matching entries for all proc handlers.
236  * Otherwise, -ENODEV or -EINVAL is returned.
237  */
238 static int __init
239 acpi_parse_entries_array(char *id, unsigned long table_size,
240 		struct acpi_table_header *table_header,
241 		struct acpi_subtable_proc *proc, int proc_num,
242 		unsigned int max_entries)
243 {
244 	struct acpi_subtable_header *entry;
245 	unsigned long table_end;
246 	int count = 0;
247 	int i;
248 
249 	if (acpi_disabled)
250 		return -ENODEV;
251 
252 	if (!id)
253 		return -EINVAL;
254 
255 	if (!table_size)
256 		return -EINVAL;
257 
258 	if (!table_header) {
259 		pr_warn("%4.4s not present\n", id);
260 		return -ENODEV;
261 	}
262 
263 	table_end = (unsigned long)table_header + table_header->length;
264 
265 	/* Parse all entries looking for a match. */
266 
267 	entry = (struct acpi_subtable_header *)
268 	    ((unsigned long)table_header + table_size);
269 
270 	while (((unsigned long)entry) + sizeof(struct acpi_subtable_header) <
271 	       table_end) {
272 		if (max_entries && count >= max_entries)
273 			break;
274 
275 		for (i = 0; i < proc_num; i++) {
276 			if (entry->type != proc[i].id)
277 				continue;
278 			if (!proc[i].handler ||
279 			     proc[i].handler(entry, table_end))
280 				return -EINVAL;
281 
282 			proc->count++;
283 			break;
284 		}
285 		if (i != proc_num)
286 			count++;
287 
288 		/*
289 		 * If entry->length is 0, break from this loop to avoid
290 		 * infinite loop.
291 		 */
292 		if (entry->length == 0) {
293 			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
294 			return -EINVAL;
295 		}
296 
297 		entry = (struct acpi_subtable_header *)
298 		    ((unsigned long)entry + entry->length);
299 	}
300 
301 	if (max_entries && count > max_entries) {
302 		pr_warn("[%4.4s:0x%02x] ignored %i entries of %i found\n",
303 			id, proc->id, count - max_entries, count);
304 	}
305 
306 	return count;
307 }
308 
309 int __init
310 acpi_parse_entries(char *id,
311 			unsigned long table_size,
312 			acpi_tbl_entry_handler handler,
313 			struct acpi_table_header *table_header,
314 			int entry_id, unsigned int max_entries)
315 {
316 	struct acpi_subtable_proc proc = {
317 		.id		= entry_id,
318 		.handler	= handler,
319 	};
320 
321 	return acpi_parse_entries_array(id, table_size, table_header,
322 			&proc, 1, max_entries);
323 }
324 
325 int __init
326 acpi_table_parse_entries_array(char *id,
327 			 unsigned long table_size,
328 			 struct acpi_subtable_proc *proc, int proc_num,
329 			 unsigned int max_entries)
330 {
331 	struct acpi_table_header *table_header = NULL;
332 	acpi_size tbl_size;
333 	int count;
334 	u32 instance = 0;
335 
336 	if (acpi_disabled)
337 		return -ENODEV;
338 
339 	if (!id)
340 		return -EINVAL;
341 
342 	if (!strncmp(id, ACPI_SIG_MADT, 4))
343 		instance = acpi_apic_instance;
344 
345 	acpi_get_table_with_size(id, instance, &table_header, &tbl_size);
346 	if (!table_header) {
347 		pr_warn("%4.4s not present\n", id);
348 		return -ENODEV;
349 	}
350 
351 	count = acpi_parse_entries_array(id, table_size, table_header,
352 			proc, proc_num, max_entries);
353 
354 	early_acpi_os_unmap_memory((char *)table_header, tbl_size);
355 	return count;
356 }
357 
358 int __init
359 acpi_table_parse_entries(char *id,
360 			unsigned long table_size,
361 			int entry_id,
362 			acpi_tbl_entry_handler handler,
363 			unsigned int max_entries)
364 {
365 	struct acpi_subtable_proc proc = {
366 		.id		= entry_id,
367 		.handler	= handler,
368 	};
369 
370 	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
371 						max_entries);
372 }
373 
374 int __init
375 acpi_table_parse_madt(enum acpi_madt_type id,
376 		      acpi_tbl_entry_handler handler, unsigned int max_entries)
377 {
378 	return acpi_table_parse_entries(ACPI_SIG_MADT,
379 					    sizeof(struct acpi_table_madt), id,
380 					    handler, max_entries);
381 }
382 
383 /**
384  * acpi_table_parse - find table with @id, run @handler on it
385  * @id: table id to find
386  * @handler: handler to run
387  *
388  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
389  * run @handler on it.
390  *
391  * Return 0 if table found, -errno if not.
392  */
393 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
394 {
395 	struct acpi_table_header *table = NULL;
396 	acpi_size tbl_size;
397 
398 	if (acpi_disabled)
399 		return -ENODEV;
400 
401 	if (!id || !handler)
402 		return -EINVAL;
403 
404 	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
405 		acpi_get_table_with_size(id, acpi_apic_instance, &table, &tbl_size);
406 	else
407 		acpi_get_table_with_size(id, 0, &table, &tbl_size);
408 
409 	if (table) {
410 		handler(table);
411 		early_acpi_os_unmap_memory(table, tbl_size);
412 		return 0;
413 	} else
414 		return -ENODEV;
415 }
416 
417 /*
418  * The BIOS is supposed to supply a single APIC/MADT,
419  * but some report two.  Provide a knob to use either.
420  * (don't you wish instance 0 and 1 were not the same?)
421  */
422 static void __init check_multiple_madt(void)
423 {
424 	struct acpi_table_header *table = NULL;
425 	acpi_size tbl_size;
426 
427 	acpi_get_table_with_size(ACPI_SIG_MADT, 2, &table, &tbl_size);
428 	if (table) {
429 		pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
430 			acpi_apic_instance);
431 		pr_warn("If \"acpi_apic_instance=%d\" works better, "
432 			"notify linux-acpi@vger.kernel.org\n",
433 			acpi_apic_instance ? 0 : 2);
434 		early_acpi_os_unmap_memory(table, tbl_size);
435 
436 	} else
437 		acpi_apic_instance = 0;
438 
439 	return;
440 }
441 
442 static void acpi_table_taint(struct acpi_table_header *table)
443 {
444 	pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
445 		table->signature, table->oem_table_id);
446 	add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
447 }
448 
449 #ifdef CONFIG_ACPI_TABLE_UPGRADE
450 static u64 acpi_tables_addr;
451 static int all_tables_size;
452 
453 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
454 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
455 {
456 	u8 sum = 0;
457 	u8 *end = buffer + length;
458 
459 	while (buffer < end)
460 		sum = (u8) (sum + *(buffer++));
461 	return sum;
462 }
463 
464 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
465 static const char * const table_sigs[] = {
466 	ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ,
467 	ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT,
468 	ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF,
469 	ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET,
470 	ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI,
471 	ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA,
472 	ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT,
473 	ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT,
474 	ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, NULL };
475 
476 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
477 
478 #define NR_ACPI_INITRD_TABLES 64
479 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
480 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
481 
482 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
483 
484 static void __init acpi_table_initrd_init(void *data, size_t size)
485 {
486 	int sig, no, table_nr = 0, total_offset = 0;
487 	long offset = 0;
488 	struct acpi_table_header *table;
489 	char cpio_path[32] = "kernel/firmware/acpi/";
490 	struct cpio_data file;
491 
492 	if (data == NULL || size == 0)
493 		return;
494 
495 	for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
496 		file = find_cpio_data(cpio_path, data, size, &offset);
497 		if (!file.data)
498 			break;
499 
500 		data += offset;
501 		size -= offset;
502 
503 		if (file.size < sizeof(struct acpi_table_header)) {
504 			pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
505 				cpio_path, file.name);
506 			continue;
507 		}
508 
509 		table = file.data;
510 
511 		for (sig = 0; table_sigs[sig]; sig++)
512 			if (!memcmp(table->signature, table_sigs[sig], 4))
513 				break;
514 
515 		if (!table_sigs[sig]) {
516 			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
517 				cpio_path, file.name);
518 			continue;
519 		}
520 		if (file.size != table->length) {
521 			pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
522 				cpio_path, file.name);
523 			continue;
524 		}
525 		if (acpi_table_checksum(file.data, table->length)) {
526 			pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
527 				cpio_path, file.name);
528 			continue;
529 		}
530 
531 		pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
532 			table->signature, cpio_path, file.name, table->length);
533 
534 		all_tables_size += table->length;
535 		acpi_initrd_files[table_nr].data = file.data;
536 		acpi_initrd_files[table_nr].size = file.size;
537 		table_nr++;
538 	}
539 	if (table_nr == 0)
540 		return;
541 
542 	acpi_tables_addr =
543 		memblock_find_in_range(0, max_low_pfn_mapped << PAGE_SHIFT,
544 				       all_tables_size, PAGE_SIZE);
545 	if (!acpi_tables_addr) {
546 		WARN_ON(1);
547 		return;
548 	}
549 	/*
550 	 * Only calling e820_add_reserve does not work and the
551 	 * tables are invalid (memory got used) later.
552 	 * memblock_reserve works as expected and the tables won't get modified.
553 	 * But it's not enough on X86 because ioremap will
554 	 * complain later (used by acpi_os_map_memory) that the pages
555 	 * that should get mapped are not marked "reserved".
556 	 * Both memblock_reserve and e820_add_region (via arch_reserve_mem_area)
557 	 * works fine.
558 	 */
559 	memblock_reserve(acpi_tables_addr, all_tables_size);
560 	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
561 
562 	/*
563 	 * early_ioremap only can remap 256k one time. If we map all
564 	 * tables one time, we will hit the limit. Need to map chunks
565 	 * one by one during copying the same as that in relocate_initrd().
566 	 */
567 	for (no = 0; no < table_nr; no++) {
568 		unsigned char *src_p = acpi_initrd_files[no].data;
569 		phys_addr_t size = acpi_initrd_files[no].size;
570 		phys_addr_t dest_addr = acpi_tables_addr + total_offset;
571 		phys_addr_t slop, clen;
572 		char *dest_p;
573 
574 		total_offset += size;
575 
576 		while (size) {
577 			slop = dest_addr & ~PAGE_MASK;
578 			clen = size;
579 			if (clen > MAP_CHUNK_SIZE - slop)
580 				clen = MAP_CHUNK_SIZE - slop;
581 			dest_p = early_ioremap(dest_addr & PAGE_MASK,
582 						 clen + slop);
583 			memcpy(dest_p + slop, src_p, clen);
584 			early_iounmap(dest_p, clen + slop);
585 			src_p += clen;
586 			dest_addr += clen;
587 			size -= clen;
588 		}
589 	}
590 }
591 
592 static acpi_status
593 acpi_table_initrd_override(struct acpi_table_header *existing_table,
594 			   acpi_physical_address *address, u32 *length)
595 {
596 	int table_offset = 0;
597 	int table_index = 0;
598 	struct acpi_table_header *table;
599 	u32 table_length;
600 
601 	*length = 0;
602 	*address = 0;
603 	if (!acpi_tables_addr)
604 		return AE_OK;
605 
606 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
607 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
608 					   ACPI_HEADER_SIZE);
609 		if (table_offset + table->length > all_tables_size) {
610 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
611 			WARN_ON(1);
612 			return AE_OK;
613 		}
614 
615 		table_length = table->length;
616 
617 		/* Only override tables matched */
618 		if (memcmp(existing_table->signature, table->signature, 4) ||
619 		    memcmp(table->oem_id, existing_table->oem_id,
620 			   ACPI_OEM_ID_SIZE) ||
621 		    memcmp(table->oem_table_id, existing_table->oem_table_id,
622 			   ACPI_OEM_TABLE_ID_SIZE)) {
623 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
624 			goto next_table;
625 		}
626 		/*
627 		 * Mark the table to avoid being used in
628 		 * acpi_table_initrd_scan() and check the revision.
629 		 */
630 		if (test_and_set_bit(table_index, acpi_initrd_installed) ||
631 		    existing_table->oem_revision >= table->oem_revision) {
632 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
633 			goto next_table;
634 		}
635 
636 		*length = table_length;
637 		*address = acpi_tables_addr + table_offset;
638 		pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
639 			table->signature, table->oem_id,
640 			table->oem_table_id);
641 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
642 		break;
643 
644 next_table:
645 		table_offset += table_length;
646 		table_index++;
647 	}
648 	return AE_OK;
649 }
650 
651 static void __init acpi_table_initrd_scan(void)
652 {
653 	int table_offset = 0;
654 	int table_index = 0;
655 	u32 table_length;
656 	struct acpi_table_header *table;
657 
658 	if (!acpi_tables_addr)
659 		return;
660 
661 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
662 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
663 					   ACPI_HEADER_SIZE);
664 		if (table_offset + table->length > all_tables_size) {
665 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
666 			WARN_ON(1);
667 			return;
668 		}
669 
670 		table_length = table->length;
671 
672 		/* Skip RSDT/XSDT which should only be used for override */
673 		if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_RSDT) ||
674 		    ACPI_COMPARE_NAME(table->signature, ACPI_SIG_XSDT)) {
675 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
676 			goto next_table;
677 		}
678 		/*
679 		 * Mark the table to avoid being used in
680 		 * acpi_table_initrd_override(). Though this is not possible
681 		 * because override is disabled in acpi_install_table().
682 		 */
683 		if (test_and_set_bit(table_index, acpi_initrd_installed)) {
684 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
685 			goto next_table;
686 		}
687 
688 		pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
689 			table->signature, table->oem_id,
690 			table->oem_table_id);
691 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
692 		acpi_install_table(acpi_tables_addr + table_offset, TRUE);
693 next_table:
694 		table_offset += table_length;
695 		table_index++;
696 	}
697 }
698 #else
699 static void __init acpi_table_initrd_init(void *data, size_t size)
700 {
701 }
702 
703 static acpi_status
704 acpi_table_initrd_override(struct acpi_table_header *existing_table,
705 			   acpi_physical_address *address,
706 			   u32 *table_length)
707 {
708 	*table_length = 0;
709 	*address = 0;
710 	return AE_OK;
711 }
712 
713 static void __init acpi_table_initrd_scan(void)
714 {
715 }
716 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
717 
718 acpi_status
719 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
720 				acpi_physical_address *address,
721 				u32 *table_length)
722 {
723 	return acpi_table_initrd_override(existing_table, address,
724 					  table_length);
725 }
726 
727 acpi_status
728 acpi_os_table_override(struct acpi_table_header *existing_table,
729 		       struct acpi_table_header **new_table)
730 {
731 	if (!existing_table || !new_table)
732 		return AE_BAD_PARAMETER;
733 
734 	*new_table = NULL;
735 
736 #ifdef CONFIG_ACPI_CUSTOM_DSDT
737 	if (strncmp(existing_table->signature, "DSDT", 4) == 0)
738 		*new_table = (struct acpi_table_header *)AmlCode;
739 #endif
740 	if (*new_table != NULL)
741 		acpi_table_taint(existing_table);
742 	return AE_OK;
743 }
744 
745 void __init early_acpi_table_init(void *data, size_t size)
746 {
747 	acpi_table_initrd_init(data, size);
748 }
749 
750 /*
751  * acpi_table_init()
752  *
753  * find RSDP, find and checksum SDT/XSDT.
754  * checksum all tables, print SDT/XSDT
755  *
756  * result: sdt_entry[] is initialized
757  */
758 
759 int __init acpi_table_init(void)
760 {
761 	acpi_status status;
762 
763 	if (acpi_verify_table_checksum) {
764 		pr_info("Early table checksum verification enabled\n");
765 		acpi_gbl_verify_table_checksum = TRUE;
766 	} else {
767 		pr_info("Early table checksum verification disabled\n");
768 		acpi_gbl_verify_table_checksum = FALSE;
769 	}
770 
771 	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
772 	if (ACPI_FAILURE(status))
773 		return -EINVAL;
774 	acpi_table_initrd_scan();
775 
776 	check_multiple_madt();
777 	return 0;
778 }
779 
780 static int __init acpi_parse_apic_instance(char *str)
781 {
782 	if (!str)
783 		return -EINVAL;
784 
785 	if (kstrtoint(str, 0, &acpi_apic_instance))
786 		return -EINVAL;
787 
788 	pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
789 
790 	return 0;
791 }
792 
793 early_param("acpi_apic_instance", acpi_parse_apic_instance);
794 
795 static int __init acpi_force_table_verification_setup(char *s)
796 {
797 	acpi_verify_table_checksum = true;
798 
799 	return 0;
800 }
801 
802 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
803 
804 static int __init acpi_force_32bit_fadt_addr(char *s)
805 {
806 	pr_info("Forcing 32 Bit FADT addresses\n");
807 	acpi_gbl_use32_bit_fadt_addresses = TRUE;
808 
809 	return 0;
810 }
811 
812 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);
813