xref: /linux/drivers/acpi/tables.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
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 <linux/acpi.h>
39 #include "internal.h"
40 
41 #ifdef CONFIG_ACPI_CUSTOM_DSDT
42 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
43 #endif
44 
45 #define ACPI_MAX_TABLES		128
46 
47 static char *mps_inti_flags_polarity[] = { "dfl", "high", "res", "low" };
48 static char *mps_inti_flags_trigger[] = { "dfl", "edge", "res", "level" };
49 
50 static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
51 
52 static int acpi_apic_instance __initdata;
53 
54 /*
55  * Disable table checksum verification for the early stage due to the size
56  * limitation of the current x86 early mapping implementation.
57  */
58 static bool acpi_verify_table_checksum __initdata = false;
59 
60 void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
61 {
62 	if (!header)
63 		return;
64 
65 	switch (header->type) {
66 
67 	case ACPI_MADT_TYPE_LOCAL_APIC:
68 		{
69 			struct acpi_madt_local_apic *p =
70 			    (struct acpi_madt_local_apic *)header;
71 			pr_debug("LAPIC (acpi_id[0x%02x] lapic_id[0x%02x] %s)\n",
72 				 p->processor_id, p->id,
73 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
74 		}
75 		break;
76 
77 	case ACPI_MADT_TYPE_LOCAL_X2APIC:
78 		{
79 			struct acpi_madt_local_x2apic *p =
80 			    (struct acpi_madt_local_x2apic *)header;
81 			pr_debug("X2APIC (apic_id[0x%02x] uid[0x%02x] %s)\n",
82 				 p->local_apic_id, p->uid,
83 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
84 		}
85 		break;
86 
87 	case ACPI_MADT_TYPE_IO_APIC:
88 		{
89 			struct acpi_madt_io_apic *p =
90 			    (struct acpi_madt_io_apic *)header;
91 			pr_debug("IOAPIC (id[0x%02x] address[0x%08x] gsi_base[%d])\n",
92 				 p->id, p->address, p->global_irq_base);
93 		}
94 		break;
95 
96 	case ACPI_MADT_TYPE_INTERRUPT_OVERRIDE:
97 		{
98 			struct acpi_madt_interrupt_override *p =
99 			    (struct acpi_madt_interrupt_override *)header;
100 			pr_info("INT_SRC_OVR (bus %d bus_irq %d global_irq %d %s %s)\n",
101 				p->bus, p->source_irq, p->global_irq,
102 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
103 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2]);
104 			if (p->inti_flags  &
105 			    ~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK))
106 				pr_info("INT_SRC_OVR unexpected reserved flags: 0x%x\n",
107 					p->inti_flags  &
108 					~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK));
109 		}
110 		break;
111 
112 	case ACPI_MADT_TYPE_NMI_SOURCE:
113 		{
114 			struct acpi_madt_nmi_source *p =
115 			    (struct acpi_madt_nmi_source *)header;
116 			pr_info("NMI_SRC (%s %s global_irq %d)\n",
117 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
118 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
119 				p->global_irq);
120 		}
121 		break;
122 
123 	case ACPI_MADT_TYPE_LOCAL_APIC_NMI:
124 		{
125 			struct acpi_madt_local_apic_nmi *p =
126 			    (struct acpi_madt_local_apic_nmi *)header;
127 			pr_info("LAPIC_NMI (acpi_id[0x%02x] %s %s lint[0x%x])\n",
128 				p->processor_id,
129 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK	],
130 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
131 				p->lint);
132 		}
133 		break;
134 
135 	case ACPI_MADT_TYPE_LOCAL_X2APIC_NMI:
136 		{
137 			u16 polarity, trigger;
138 			struct acpi_madt_local_x2apic_nmi *p =
139 			    (struct acpi_madt_local_x2apic_nmi *)header;
140 
141 			polarity = p->inti_flags & ACPI_MADT_POLARITY_MASK;
142 			trigger = (p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
143 
144 			pr_info("X2APIC_NMI (uid[0x%02x] %s %s lint[0x%x])\n",
145 				p->uid,
146 				mps_inti_flags_polarity[polarity],
147 				mps_inti_flags_trigger[trigger],
148 				p->lint);
149 		}
150 		break;
151 
152 	case ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE:
153 		{
154 			struct acpi_madt_local_apic_override *p =
155 			    (struct acpi_madt_local_apic_override *)header;
156 			pr_info("LAPIC_ADDR_OVR (address[%p])\n",
157 				(void *)(unsigned long)p->address);
158 		}
159 		break;
160 
161 	case ACPI_MADT_TYPE_IO_SAPIC:
162 		{
163 			struct acpi_madt_io_sapic *p =
164 			    (struct acpi_madt_io_sapic *)header;
165 			pr_debug("IOSAPIC (id[0x%x] address[%p] gsi_base[%d])\n",
166 				 p->id, (void *)(unsigned long)p->address,
167 				 p->global_irq_base);
168 		}
169 		break;
170 
171 	case ACPI_MADT_TYPE_LOCAL_SAPIC:
172 		{
173 			struct acpi_madt_local_sapic *p =
174 			    (struct acpi_madt_local_sapic *)header;
175 			pr_debug("LSAPIC (acpi_id[0x%02x] lsapic_id[0x%02x] lsapic_eid[0x%02x] %s)\n",
176 				 p->processor_id, p->id, p->eid,
177 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
178 		}
179 		break;
180 
181 	case ACPI_MADT_TYPE_INTERRUPT_SOURCE:
182 		{
183 			struct acpi_madt_interrupt_source *p =
184 			    (struct acpi_madt_interrupt_source *)header;
185 			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",
186 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
187 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
188 				p->type, p->id, p->eid, p->io_sapic_vector,
189 				p->global_irq);
190 		}
191 		break;
192 
193 	case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
194 		{
195 			struct acpi_madt_generic_interrupt *p =
196 				(struct acpi_madt_generic_interrupt *)header;
197 			pr_debug("GICC (acpi_id[0x%04x] address[%llx] MPIDR[0x%llx] %s)\n",
198 				 p->uid, p->base_address,
199 				 p->arm_mpidr,
200 				 (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
201 
202 		}
203 		break;
204 
205 	case ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR:
206 		{
207 			struct acpi_madt_generic_distributor *p =
208 				(struct acpi_madt_generic_distributor *)header;
209 			pr_debug("GIC Distributor (gic_id[0x%04x] address[%llx] gsi_base[%d])\n",
210 				 p->gic_id, p->base_address,
211 				 p->global_irq_base);
212 		}
213 		break;
214 
215 	default:
216 		pr_warn("Found unsupported MADT entry (type = 0x%x)\n",
217 			header->type);
218 		break;
219 	}
220 }
221 
222 /**
223  * acpi_parse_entries_array - for each proc_num find a suitable subtable
224  *
225  * @id: table id (for debugging purposes)
226  * @table_size: single entry size
227  * @table_header: where does the table start?
228  * @proc: array of acpi_subtable_proc struct containing entry id
229  *        and associated handler with it
230  * @proc_num: how big proc is?
231  * @max_entries: how many entries can we process?
232  *
233  * For each proc_num find a subtable with proc->id and run proc->handler
234  * on it. Assumption is that there's only single handler for particular
235  * entry id.
236  *
237  * On success returns sum of all matching entries for all proc handlers.
238  * Otherwise, -ENODEV or -EINVAL is returned.
239  */
240 static int __init
241 acpi_parse_entries_array(char *id, unsigned long table_size,
242 		struct acpi_table_header *table_header,
243 		struct acpi_subtable_proc *proc, int proc_num,
244 		unsigned int max_entries)
245 {
246 	struct acpi_subtable_header *entry;
247 	unsigned long table_end;
248 	int count = 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 			     proc[i].handler(entry, table_end))
282 				return -EINVAL;
283 
284 			proc->count++;
285 			break;
286 		}
287 		if (i != proc_num)
288 			count++;
289 
290 		/*
291 		 * If entry->length is 0, break from this loop to avoid
292 		 * infinite loop.
293 		 */
294 		if (entry->length == 0) {
295 			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
296 			return -EINVAL;
297 		}
298 
299 		entry = (struct acpi_subtable_header *)
300 		    ((unsigned long)entry + entry->length);
301 	}
302 
303 	if (max_entries && count > max_entries) {
304 		pr_warn("[%4.4s:0x%02x] ignored %i entries of %i found\n",
305 			id, proc->id, count - max_entries, count);
306 	}
307 
308 	return count;
309 }
310 
311 int __init
312 acpi_parse_entries(char *id,
313 			unsigned long table_size,
314 			acpi_tbl_entry_handler handler,
315 			struct acpi_table_header *table_header,
316 			int entry_id, unsigned int max_entries)
317 {
318 	struct acpi_subtable_proc proc = {
319 		.id		= entry_id,
320 		.handler	= handler,
321 	};
322 
323 	return acpi_parse_entries_array(id, table_size, table_header,
324 			&proc, 1, max_entries);
325 }
326 
327 int __init
328 acpi_table_parse_entries_array(char *id,
329 			 unsigned long table_size,
330 			 struct acpi_subtable_proc *proc, int proc_num,
331 			 unsigned int max_entries)
332 {
333 	struct acpi_table_header *table_header = NULL;
334 	acpi_size tbl_size;
335 	int count;
336 	u32 instance = 0;
337 
338 	if (acpi_disabled)
339 		return -ENODEV;
340 
341 	if (!id)
342 		return -EINVAL;
343 
344 	if (!strncmp(id, ACPI_SIG_MADT, 4))
345 		instance = acpi_apic_instance;
346 
347 	acpi_get_table_with_size(id, instance, &table_header, &tbl_size);
348 	if (!table_header) {
349 		pr_warn("%4.4s not present\n", id);
350 		return -ENODEV;
351 	}
352 
353 	count = acpi_parse_entries_array(id, table_size, table_header,
354 			proc, proc_num, max_entries);
355 
356 	early_acpi_os_unmap_memory((char *)table_header, tbl_size);
357 	return count;
358 }
359 
360 int __init
361 acpi_table_parse_entries(char *id,
362 			unsigned long table_size,
363 			int entry_id,
364 			acpi_tbl_entry_handler handler,
365 			unsigned int max_entries)
366 {
367 	struct acpi_subtable_proc proc = {
368 		.id		= entry_id,
369 		.handler	= handler,
370 	};
371 
372 	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
373 						max_entries);
374 }
375 
376 int __init
377 acpi_table_parse_madt(enum acpi_madt_type id,
378 		      acpi_tbl_entry_handler handler, unsigned int max_entries)
379 {
380 	return acpi_table_parse_entries(ACPI_SIG_MADT,
381 					    sizeof(struct acpi_table_madt), id,
382 					    handler, max_entries);
383 }
384 
385 /**
386  * acpi_table_parse - find table with @id, run @handler on it
387  * @id: table id to find
388  * @handler: handler to run
389  *
390  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
391  * run @handler on it.
392  *
393  * Return 0 if table found, -errno if not.
394  */
395 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
396 {
397 	struct acpi_table_header *table = NULL;
398 	acpi_size tbl_size;
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_with_size(id, acpi_apic_instance, &table, &tbl_size);
408 	else
409 		acpi_get_table_with_size(id, 0, &table, &tbl_size);
410 
411 	if (table) {
412 		handler(table);
413 		early_acpi_os_unmap_memory(table, tbl_size);
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 	acpi_size tbl_size;
428 
429 	acpi_get_table_with_size(ACPI_SIG_MADT, 2, &table, &tbl_size);
430 	if (table) {
431 		pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
432 			acpi_apic_instance);
433 		pr_warn("If \"acpi_apic_instance=%d\" works better, "
434 			"notify linux-acpi@vger.kernel.org\n",
435 			acpi_apic_instance ? 0 : 2);
436 		early_acpi_os_unmap_memory(table, tbl_size);
437 
438 	} else
439 		acpi_apic_instance = 0;
440 
441 	return;
442 }
443 
444 static void acpi_table_taint(struct acpi_table_header *table)
445 {
446 	pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
447 		table->signature, table->oem_table_id);
448 	add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
449 }
450 
451 #ifdef CONFIG_ACPI_TABLE_UPGRADE
452 static u64 acpi_tables_addr;
453 static int all_tables_size;
454 
455 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
456 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
457 {
458 	u8 sum = 0;
459 	u8 *end = buffer + length;
460 
461 	while (buffer < end)
462 		sum = (u8) (sum + *(buffer++));
463 	return sum;
464 }
465 
466 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
467 static const char * const table_sigs[] = {
468 	ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ,
469 	ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT,
470 	ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF,
471 	ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET,
472 	ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI,
473 	ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA,
474 	ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT,
475 	ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT,
476 	ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, NULL };
477 
478 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
479 
480 #define NR_ACPI_INITRD_TABLES 64
481 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
482 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
483 
484 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
485 
486 void __init acpi_table_upgrade(void)
487 {
488 	void *data = (void *)initrd_start;
489 	size_t size = initrd_end - initrd_start;
490 	int sig, no, table_nr = 0, total_offset = 0;
491 	long offset = 0;
492 	struct acpi_table_header *table;
493 	char cpio_path[32] = "kernel/firmware/acpi/";
494 	struct cpio_data file;
495 
496 	if (data == NULL || size == 0)
497 		return;
498 
499 	for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
500 		file = find_cpio_data(cpio_path, data, size, &offset);
501 		if (!file.data)
502 			break;
503 
504 		data += offset;
505 		size -= offset;
506 
507 		if (file.size < sizeof(struct acpi_table_header)) {
508 			pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
509 				cpio_path, file.name);
510 			continue;
511 		}
512 
513 		table = file.data;
514 
515 		for (sig = 0; table_sigs[sig]; sig++)
516 			if (!memcmp(table->signature, table_sigs[sig], 4))
517 				break;
518 
519 		if (!table_sigs[sig]) {
520 			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
521 				cpio_path, file.name);
522 			continue;
523 		}
524 		if (file.size != table->length) {
525 			pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
526 				cpio_path, file.name);
527 			continue;
528 		}
529 		if (acpi_table_checksum(file.data, table->length)) {
530 			pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
531 				cpio_path, file.name);
532 			continue;
533 		}
534 
535 		pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
536 			table->signature, cpio_path, file.name, table->length);
537 
538 		all_tables_size += table->length;
539 		acpi_initrd_files[table_nr].data = file.data;
540 		acpi_initrd_files[table_nr].size = file.size;
541 		table_nr++;
542 	}
543 	if (table_nr == 0)
544 		return;
545 
546 	acpi_tables_addr =
547 		memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
548 				       all_tables_size, PAGE_SIZE);
549 	if (!acpi_tables_addr) {
550 		WARN_ON(1);
551 		return;
552 	}
553 	/*
554 	 * Only calling e820_add_reserve does not work and the
555 	 * tables are invalid (memory got used) later.
556 	 * memblock_reserve works as expected and the tables won't get modified.
557 	 * But it's not enough on X86 because ioremap will
558 	 * complain later (used by acpi_os_map_memory) that the pages
559 	 * that should get mapped are not marked "reserved".
560 	 * Both memblock_reserve and e820_add_region (via arch_reserve_mem_area)
561 	 * works fine.
562 	 */
563 	memblock_reserve(acpi_tables_addr, all_tables_size);
564 	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
565 
566 	/*
567 	 * early_ioremap only can remap 256k one time. If we map all
568 	 * tables one time, we will hit the limit. Need to map chunks
569 	 * one by one during copying the same as that in relocate_initrd().
570 	 */
571 	for (no = 0; no < table_nr; no++) {
572 		unsigned char *src_p = acpi_initrd_files[no].data;
573 		phys_addr_t size = acpi_initrd_files[no].size;
574 		phys_addr_t dest_addr = acpi_tables_addr + total_offset;
575 		phys_addr_t slop, clen;
576 		char *dest_p;
577 
578 		total_offset += size;
579 
580 		while (size) {
581 			slop = dest_addr & ~PAGE_MASK;
582 			clen = size;
583 			if (clen > MAP_CHUNK_SIZE - slop)
584 				clen = MAP_CHUNK_SIZE - slop;
585 			dest_p = early_memremap(dest_addr & PAGE_MASK,
586 						clen + slop);
587 			memcpy(dest_p + slop, src_p, clen);
588 			early_memunmap(dest_p, clen + slop);
589 			src_p += clen;
590 			dest_addr += clen;
591 			size -= clen;
592 		}
593 	}
594 }
595 
596 static acpi_status
597 acpi_table_initrd_override(struct acpi_table_header *existing_table,
598 			   acpi_physical_address *address, u32 *length)
599 {
600 	int table_offset = 0;
601 	int table_index = 0;
602 	struct acpi_table_header *table;
603 	u32 table_length;
604 
605 	*length = 0;
606 	*address = 0;
607 	if (!acpi_tables_addr)
608 		return AE_OK;
609 
610 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
611 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
612 					   ACPI_HEADER_SIZE);
613 		if (table_offset + table->length > all_tables_size) {
614 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
615 			WARN_ON(1);
616 			return AE_OK;
617 		}
618 
619 		table_length = table->length;
620 
621 		/* Only override tables matched */
622 		if (memcmp(existing_table->signature, table->signature, 4) ||
623 		    memcmp(table->oem_id, existing_table->oem_id,
624 			   ACPI_OEM_ID_SIZE) ||
625 		    memcmp(table->oem_table_id, existing_table->oem_table_id,
626 			   ACPI_OEM_TABLE_ID_SIZE)) {
627 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
628 			goto next_table;
629 		}
630 		/*
631 		 * Mark the table to avoid being used in
632 		 * acpi_table_initrd_scan() and check the revision.
633 		 */
634 		if (test_and_set_bit(table_index, acpi_initrd_installed) ||
635 		    existing_table->oem_revision >= table->oem_revision) {
636 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
637 			goto next_table;
638 		}
639 
640 		*length = table_length;
641 		*address = acpi_tables_addr + table_offset;
642 		pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
643 			table->signature, table->oem_id,
644 			table->oem_table_id);
645 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
646 		break;
647 
648 next_table:
649 		table_offset += table_length;
650 		table_index++;
651 	}
652 	return AE_OK;
653 }
654 
655 static void __init acpi_table_initrd_scan(void)
656 {
657 	int table_offset = 0;
658 	int table_index = 0;
659 	u32 table_length;
660 	struct acpi_table_header *table;
661 
662 	if (!acpi_tables_addr)
663 		return;
664 
665 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
666 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
667 					   ACPI_HEADER_SIZE);
668 		if (table_offset + table->length > all_tables_size) {
669 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
670 			WARN_ON(1);
671 			return;
672 		}
673 
674 		table_length = table->length;
675 
676 		/* Skip RSDT/XSDT which should only be used for override */
677 		if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_RSDT) ||
678 		    ACPI_COMPARE_NAME(table->signature, ACPI_SIG_XSDT)) {
679 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
680 			goto next_table;
681 		}
682 		/*
683 		 * Mark the table to avoid being used in
684 		 * acpi_table_initrd_override(). Though this is not possible
685 		 * because override is disabled in acpi_install_table().
686 		 */
687 		if (test_and_set_bit(table_index, acpi_initrd_installed)) {
688 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
689 			goto next_table;
690 		}
691 
692 		pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
693 			table->signature, table->oem_id,
694 			table->oem_table_id);
695 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
696 		acpi_install_table(acpi_tables_addr + table_offset, TRUE);
697 next_table:
698 		table_offset += table_length;
699 		table_index++;
700 	}
701 }
702 #else
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 /*
746  * acpi_table_init()
747  *
748  * find RSDP, find and checksum SDT/XSDT.
749  * checksum all tables, print SDT/XSDT
750  *
751  * result: sdt_entry[] is initialized
752  */
753 
754 int __init acpi_table_init(void)
755 {
756 	acpi_status status;
757 
758 	if (acpi_verify_table_checksum) {
759 		pr_info("Early table checksum verification enabled\n");
760 		acpi_gbl_verify_table_checksum = TRUE;
761 	} else {
762 		pr_info("Early table checksum verification disabled\n");
763 		acpi_gbl_verify_table_checksum = FALSE;
764 	}
765 
766 	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
767 	if (ACPI_FAILURE(status))
768 		return -EINVAL;
769 	acpi_table_initrd_scan();
770 
771 	check_multiple_madt();
772 	return 0;
773 }
774 
775 static int __init acpi_parse_apic_instance(char *str)
776 {
777 	if (!str)
778 		return -EINVAL;
779 
780 	if (kstrtoint(str, 0, &acpi_apic_instance))
781 		return -EINVAL;
782 
783 	pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
784 
785 	return 0;
786 }
787 
788 early_param("acpi_apic_instance", acpi_parse_apic_instance);
789 
790 static int __init acpi_force_table_verification_setup(char *s)
791 {
792 	acpi_verify_table_checksum = true;
793 
794 	return 0;
795 }
796 
797 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
798 
799 static int __init acpi_force_32bit_fadt_addr(char *s)
800 {
801 	pr_info("Forcing 32 Bit FADT addresses\n");
802 	acpi_gbl_use32_bit_fadt_addresses = TRUE;
803 
804 	return 0;
805 }
806 
807 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);
808