xref: /linux/drivers/acpi/tables.c (revision 2decec48b0fd28ffdbf4cc684bd04e735f0839dd)
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/memblock.h>
35 #include <linux/earlycpio.h>
36 #include <linux/initrd.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: size of the root table
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  * The table_size is not the size of the complete ACPI table (the length
236  * field in the header struct), but only the size of the root table; i.e.,
237  * the offset from the very first byte of the complete ACPI table, to the
238  * first byte of the very first subtable.
239  *
240  * On success returns sum of all matching entries for all proc handlers.
241  * Otherwise, -ENODEV or -EINVAL is returned.
242  */
243 static int __init acpi_parse_entries_array(char *id, unsigned long table_size,
244 		struct acpi_table_header *table_header,
245 		struct acpi_subtable_proc *proc, int proc_num,
246 		unsigned int max_entries)
247 {
248 	struct acpi_subtable_header *entry;
249 	unsigned long table_end;
250 	int count = 0;
251 	int errs = 0;
252 	int i;
253 
254 	if (acpi_disabled)
255 		return -ENODEV;
256 
257 	if (!id)
258 		return -EINVAL;
259 
260 	if (!table_size)
261 		return -EINVAL;
262 
263 	if (!table_header) {
264 		pr_warn("%4.4s not present\n", id);
265 		return -ENODEV;
266 	}
267 
268 	table_end = (unsigned long)table_header + table_header->length;
269 
270 	/* Parse all entries looking for a match. */
271 
272 	entry = (struct acpi_subtable_header *)
273 	    ((unsigned long)table_header + table_size);
274 
275 	while (((unsigned long)entry) + sizeof(struct acpi_subtable_header) <
276 	       table_end) {
277 		if (max_entries && count >= max_entries)
278 			break;
279 
280 		for (i = 0; i < proc_num; i++) {
281 			if (entry->type != proc[i].id)
282 				continue;
283 			if (!proc[i].handler ||
284 			     (!errs && proc[i].handler(entry, table_end))) {
285 				errs++;
286 				continue;
287 			}
288 
289 			proc[i].count++;
290 			break;
291 		}
292 		if (i != proc_num)
293 			count++;
294 
295 		/*
296 		 * If entry->length is 0, break from this loop to avoid
297 		 * infinite loop.
298 		 */
299 		if (entry->length == 0) {
300 			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
301 			return -EINVAL;
302 		}
303 
304 		entry = (struct acpi_subtable_header *)
305 		    ((unsigned long)entry + entry->length);
306 	}
307 
308 	if (max_entries && count > max_entries) {
309 		pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
310 			id, proc->id, count);
311 	}
312 
313 	return errs ? -EINVAL : count;
314 }
315 
316 int __init acpi_table_parse_entries_array(char *id,
317 			 unsigned long table_size,
318 			 struct acpi_subtable_proc *proc, int proc_num,
319 			 unsigned int max_entries)
320 {
321 	struct acpi_table_header *table_header = NULL;
322 	int count;
323 	u32 instance = 0;
324 
325 	if (acpi_disabled)
326 		return -ENODEV;
327 
328 	if (!id)
329 		return -EINVAL;
330 
331 	if (!strncmp(id, ACPI_SIG_MADT, 4))
332 		instance = acpi_apic_instance;
333 
334 	acpi_get_table(id, instance, &table_header);
335 	if (!table_header) {
336 		pr_warn("%4.4s not present\n", id);
337 		return -ENODEV;
338 	}
339 
340 	count = acpi_parse_entries_array(id, table_size, table_header,
341 			proc, proc_num, max_entries);
342 
343 	acpi_put_table(table_header);
344 	return count;
345 }
346 
347 int __init acpi_table_parse_entries(char *id,
348 			unsigned long table_size,
349 			int entry_id,
350 			acpi_tbl_entry_handler handler,
351 			unsigned int max_entries)
352 {
353 	struct acpi_subtable_proc proc = {
354 		.id		= entry_id,
355 		.handler	= handler,
356 	};
357 
358 	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
359 						max_entries);
360 }
361 
362 int __init 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, ACPI_SIG_IORT,
460 	ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT, NULL };
461 
462 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
463 
464 #define NR_ACPI_INITRD_TABLES 64
465 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
466 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
467 
468 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
469 
470 void __init acpi_table_upgrade(void)
471 {
472 	void *data;
473 	size_t size;
474 	int sig, no, table_nr = 0, total_offset = 0;
475 	long offset = 0;
476 	struct acpi_table_header *table;
477 	char cpio_path[32] = "kernel/firmware/acpi/";
478 	struct cpio_data file;
479 
480 	if (IS_ENABLED(CONFIG_ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD)) {
481 		data = __initramfs_start;
482 		size = __initramfs_size;
483 	} else {
484 		data = (void *)initrd_start;
485 		size = initrd_end - initrd_start;
486 	}
487 
488 	if (data == NULL || size == 0)
489 		return;
490 
491 	for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
492 		file = find_cpio_data(cpio_path, data, size, &offset);
493 		if (!file.data)
494 			break;
495 
496 		data += offset;
497 		size -= offset;
498 
499 		if (file.size < sizeof(struct acpi_table_header)) {
500 			pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
501 				cpio_path, file.name);
502 			continue;
503 		}
504 
505 		table = file.data;
506 
507 		for (sig = 0; table_sigs[sig]; sig++)
508 			if (!memcmp(table->signature, table_sigs[sig], 4))
509 				break;
510 
511 		if (!table_sigs[sig]) {
512 			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
513 				cpio_path, file.name);
514 			continue;
515 		}
516 		if (file.size != table->length) {
517 			pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
518 				cpio_path, file.name);
519 			continue;
520 		}
521 		if (acpi_table_checksum(file.data, table->length)) {
522 			pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
523 				cpio_path, file.name);
524 			continue;
525 		}
526 
527 		pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
528 			table->signature, cpio_path, file.name, table->length);
529 
530 		all_tables_size += table->length;
531 		acpi_initrd_files[table_nr].data = file.data;
532 		acpi_initrd_files[table_nr].size = file.size;
533 		table_nr++;
534 	}
535 	if (table_nr == 0)
536 		return;
537 
538 	acpi_tables_addr =
539 		memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
540 				       all_tables_size, PAGE_SIZE);
541 	if (!acpi_tables_addr) {
542 		WARN_ON(1);
543 		return;
544 	}
545 	/*
546 	 * Only calling e820_add_reserve does not work and the
547 	 * tables are invalid (memory got used) later.
548 	 * memblock_reserve works as expected and the tables won't get modified.
549 	 * But it's not enough on X86 because ioremap will
550 	 * complain later (used by acpi_os_map_memory) that the pages
551 	 * that should get mapped are not marked "reserved".
552 	 * Both memblock_reserve and e820__range_add (via arch_reserve_mem_area)
553 	 * works fine.
554 	 */
555 	memblock_reserve(acpi_tables_addr, all_tables_size);
556 	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
557 
558 	/*
559 	 * early_ioremap only can remap 256k one time. If we map all
560 	 * tables one time, we will hit the limit. Need to map chunks
561 	 * one by one during copying the same as that in relocate_initrd().
562 	 */
563 	for (no = 0; no < table_nr; no++) {
564 		unsigned char *src_p = acpi_initrd_files[no].data;
565 		phys_addr_t size = acpi_initrd_files[no].size;
566 		phys_addr_t dest_addr = acpi_tables_addr + total_offset;
567 		phys_addr_t slop, clen;
568 		char *dest_p;
569 
570 		total_offset += size;
571 
572 		while (size) {
573 			slop = dest_addr & ~PAGE_MASK;
574 			clen = size;
575 			if (clen > MAP_CHUNK_SIZE - slop)
576 				clen = MAP_CHUNK_SIZE - slop;
577 			dest_p = early_memremap(dest_addr & PAGE_MASK,
578 						clen + slop);
579 			memcpy(dest_p + slop, src_p, clen);
580 			early_memunmap(dest_p, clen + slop);
581 			src_p += clen;
582 			dest_addr += clen;
583 			size -= clen;
584 		}
585 	}
586 }
587 
588 static acpi_status
589 acpi_table_initrd_override(struct acpi_table_header *existing_table,
590 			   acpi_physical_address *address, u32 *length)
591 {
592 	int table_offset = 0;
593 	int table_index = 0;
594 	struct acpi_table_header *table;
595 	u32 table_length;
596 
597 	*length = 0;
598 	*address = 0;
599 	if (!acpi_tables_addr)
600 		return AE_OK;
601 
602 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
603 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
604 					   ACPI_HEADER_SIZE);
605 		if (table_offset + table->length > all_tables_size) {
606 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
607 			WARN_ON(1);
608 			return AE_OK;
609 		}
610 
611 		table_length = table->length;
612 
613 		/* Only override tables matched */
614 		if (memcmp(existing_table->signature, table->signature, 4) ||
615 		    memcmp(table->oem_id, existing_table->oem_id,
616 			   ACPI_OEM_ID_SIZE) ||
617 		    memcmp(table->oem_table_id, existing_table->oem_table_id,
618 			   ACPI_OEM_TABLE_ID_SIZE)) {
619 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
620 			goto next_table;
621 		}
622 		/*
623 		 * Mark the table to avoid being used in
624 		 * acpi_table_initrd_scan() and check the revision.
625 		 */
626 		if (test_and_set_bit(table_index, acpi_initrd_installed) ||
627 		    existing_table->oem_revision >= table->oem_revision) {
628 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
629 			goto next_table;
630 		}
631 
632 		*length = table_length;
633 		*address = acpi_tables_addr + table_offset;
634 		pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
635 			table->signature, table->oem_id,
636 			table->oem_table_id);
637 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
638 		break;
639 
640 next_table:
641 		table_offset += table_length;
642 		table_index++;
643 	}
644 	return AE_OK;
645 }
646 
647 static void __init acpi_table_initrd_scan(void)
648 {
649 	int table_offset = 0;
650 	int table_index = 0;
651 	u32 table_length;
652 	struct acpi_table_header *table;
653 
654 	if (!acpi_tables_addr)
655 		return;
656 
657 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
658 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
659 					   ACPI_HEADER_SIZE);
660 		if (table_offset + table->length > all_tables_size) {
661 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
662 			WARN_ON(1);
663 			return;
664 		}
665 
666 		table_length = table->length;
667 
668 		/* Skip RSDT/XSDT which should only be used for override */
669 		if (ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_RSDT) ||
670 		    ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_XSDT)) {
671 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
672 			goto next_table;
673 		}
674 		/*
675 		 * Mark the table to avoid being used in
676 		 * acpi_table_initrd_override(). Though this is not possible
677 		 * because override is disabled in acpi_install_table().
678 		 */
679 		if (test_and_set_bit(table_index, acpi_initrd_installed)) {
680 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
681 			goto next_table;
682 		}
683 
684 		pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
685 			table->signature, table->oem_id,
686 			table->oem_table_id);
687 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
688 		acpi_install_table(acpi_tables_addr + table_offset, TRUE);
689 next_table:
690 		table_offset += table_length;
691 		table_index++;
692 	}
693 }
694 #else
695 static acpi_status
696 acpi_table_initrd_override(struct acpi_table_header *existing_table,
697 			   acpi_physical_address *address,
698 			   u32 *table_length)
699 {
700 	*table_length = 0;
701 	*address = 0;
702 	return AE_OK;
703 }
704 
705 static void __init acpi_table_initrd_scan(void)
706 {
707 }
708 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
709 
710 acpi_status
711 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
712 				acpi_physical_address *address,
713 				u32 *table_length)
714 {
715 	return acpi_table_initrd_override(existing_table, address,
716 					  table_length);
717 }
718 
719 #ifdef CONFIG_ACPI_CUSTOM_DSDT
720 static void *amlcode __attribute__ ((weakref("AmlCode")));
721 static void *dsdt_amlcode __attribute__ ((weakref("dsdt_aml_code")));
722 #endif
723 
724 acpi_status acpi_os_table_override(struct acpi_table_header *existing_table,
725 		       struct acpi_table_header **new_table)
726 {
727 	if (!existing_table || !new_table)
728 		return AE_BAD_PARAMETER;
729 
730 	*new_table = NULL;
731 
732 #ifdef CONFIG_ACPI_CUSTOM_DSDT
733 	if (!strncmp(existing_table->signature, "DSDT", 4)) {
734 		*new_table = (struct acpi_table_header *)&amlcode;
735 		if (!(*new_table))
736 			*new_table = (struct acpi_table_header *)&dsdt_amlcode;
737 	}
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_enable_table_validation = TRUE;
760 	} else {
761 		pr_info("Early table checksum verification disabled\n");
762 		acpi_gbl_enable_table_validation = 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 early_param("acpi_apic_instance", acpi_parse_apic_instance);
787 
788 static int __init acpi_force_table_verification_setup(char *s)
789 {
790 	acpi_verify_table_checksum = true;
791 
792 	return 0;
793 }
794 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
795 
796 static int __init acpi_force_32bit_fadt_addr(char *s)
797 {
798 	pr_info("Forcing 32 Bit FADT addresses\n");
799 	acpi_gbl_use32_bit_fadt_addresses = TRUE;
800 
801 	return 0;
802 }
803 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);
804