xref: /linux/drivers/acpi/tables.c (revision c484a6783d2b800ebbb110b28b0d96444f8b81ca)
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 enum acpi_subtable_type {
53 	ACPI_SUBTABLE_COMMON,
54 	ACPI_SUBTABLE_HMAT,
55 };
56 
57 struct acpi_subtable_entry {
58 	union acpi_subtable_headers *hdr;
59 	enum acpi_subtable_type type;
60 };
61 
62 /*
63  * Disable table checksum verification for the early stage due to the size
64  * limitation of the current x86 early mapping implementation.
65  */
66 static bool acpi_verify_table_checksum __initdata = false;
67 
68 void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
69 {
70 	if (!header)
71 		return;
72 
73 	switch (header->type) {
74 
75 	case ACPI_MADT_TYPE_LOCAL_APIC:
76 		{
77 			struct acpi_madt_local_apic *p =
78 			    (struct acpi_madt_local_apic *)header;
79 			pr_debug("LAPIC (acpi_id[0x%02x] lapic_id[0x%02x] %s)\n",
80 				 p->processor_id, p->id,
81 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
82 		}
83 		break;
84 
85 	case ACPI_MADT_TYPE_LOCAL_X2APIC:
86 		{
87 			struct acpi_madt_local_x2apic *p =
88 			    (struct acpi_madt_local_x2apic *)header;
89 			pr_debug("X2APIC (apic_id[0x%02x] uid[0x%02x] %s)\n",
90 				 p->local_apic_id, p->uid,
91 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
92 		}
93 		break;
94 
95 	case ACPI_MADT_TYPE_IO_APIC:
96 		{
97 			struct acpi_madt_io_apic *p =
98 			    (struct acpi_madt_io_apic *)header;
99 			pr_debug("IOAPIC (id[0x%02x] address[0x%08x] gsi_base[%d])\n",
100 				 p->id, p->address, p->global_irq_base);
101 		}
102 		break;
103 
104 	case ACPI_MADT_TYPE_INTERRUPT_OVERRIDE:
105 		{
106 			struct acpi_madt_interrupt_override *p =
107 			    (struct acpi_madt_interrupt_override *)header;
108 			pr_info("INT_SRC_OVR (bus %d bus_irq %d global_irq %d %s %s)\n",
109 				p->bus, p->source_irq, p->global_irq,
110 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
111 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2]);
112 			if (p->inti_flags  &
113 			    ~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK))
114 				pr_info("INT_SRC_OVR unexpected reserved flags: 0x%x\n",
115 					p->inti_flags  &
116 					~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK));
117 		}
118 		break;
119 
120 	case ACPI_MADT_TYPE_NMI_SOURCE:
121 		{
122 			struct acpi_madt_nmi_source *p =
123 			    (struct acpi_madt_nmi_source *)header;
124 			pr_info("NMI_SRC (%s %s global_irq %d)\n",
125 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
126 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
127 				p->global_irq);
128 		}
129 		break;
130 
131 	case ACPI_MADT_TYPE_LOCAL_APIC_NMI:
132 		{
133 			struct acpi_madt_local_apic_nmi *p =
134 			    (struct acpi_madt_local_apic_nmi *)header;
135 			pr_info("LAPIC_NMI (acpi_id[0x%02x] %s %s lint[0x%x])\n",
136 				p->processor_id,
137 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK	],
138 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
139 				p->lint);
140 		}
141 		break;
142 
143 	case ACPI_MADT_TYPE_LOCAL_X2APIC_NMI:
144 		{
145 			u16 polarity, trigger;
146 			struct acpi_madt_local_x2apic_nmi *p =
147 			    (struct acpi_madt_local_x2apic_nmi *)header;
148 
149 			polarity = p->inti_flags & ACPI_MADT_POLARITY_MASK;
150 			trigger = (p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
151 
152 			pr_info("X2APIC_NMI (uid[0x%02x] %s %s lint[0x%x])\n",
153 				p->uid,
154 				mps_inti_flags_polarity[polarity],
155 				mps_inti_flags_trigger[trigger],
156 				p->lint);
157 		}
158 		break;
159 
160 	case ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE:
161 		{
162 			struct acpi_madt_local_apic_override *p =
163 			    (struct acpi_madt_local_apic_override *)header;
164 			pr_info("LAPIC_ADDR_OVR (address[%p])\n",
165 				(void *)(unsigned long)p->address);
166 		}
167 		break;
168 
169 	case ACPI_MADT_TYPE_IO_SAPIC:
170 		{
171 			struct acpi_madt_io_sapic *p =
172 			    (struct acpi_madt_io_sapic *)header;
173 			pr_debug("IOSAPIC (id[0x%x] address[%p] gsi_base[%d])\n",
174 				 p->id, (void *)(unsigned long)p->address,
175 				 p->global_irq_base);
176 		}
177 		break;
178 
179 	case ACPI_MADT_TYPE_LOCAL_SAPIC:
180 		{
181 			struct acpi_madt_local_sapic *p =
182 			    (struct acpi_madt_local_sapic *)header;
183 			pr_debug("LSAPIC (acpi_id[0x%02x] lsapic_id[0x%02x] lsapic_eid[0x%02x] %s)\n",
184 				 p->processor_id, p->id, p->eid,
185 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
186 		}
187 		break;
188 
189 	case ACPI_MADT_TYPE_INTERRUPT_SOURCE:
190 		{
191 			struct acpi_madt_interrupt_source *p =
192 			    (struct acpi_madt_interrupt_source *)header;
193 			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",
194 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
195 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
196 				p->type, p->id, p->eid, p->io_sapic_vector,
197 				p->global_irq);
198 		}
199 		break;
200 
201 	case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
202 		{
203 			struct acpi_madt_generic_interrupt *p =
204 				(struct acpi_madt_generic_interrupt *)header;
205 			pr_debug("GICC (acpi_id[0x%04x] address[%llx] MPIDR[0x%llx] %s)\n",
206 				 p->uid, p->base_address,
207 				 p->arm_mpidr,
208 				 (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
209 
210 		}
211 		break;
212 
213 	case ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR:
214 		{
215 			struct acpi_madt_generic_distributor *p =
216 				(struct acpi_madt_generic_distributor *)header;
217 			pr_debug("GIC Distributor (gic_id[0x%04x] address[%llx] gsi_base[%d])\n",
218 				 p->gic_id, p->base_address,
219 				 p->global_irq_base);
220 		}
221 		break;
222 
223 	default:
224 		pr_warn("Found unsupported MADT entry (type = 0x%x)\n",
225 			header->type);
226 		break;
227 	}
228 }
229 
230 static unsigned long __init
231 acpi_get_entry_type(struct acpi_subtable_entry *entry)
232 {
233 	switch (entry->type) {
234 	case ACPI_SUBTABLE_COMMON:
235 		return entry->hdr->common.type;
236 	case ACPI_SUBTABLE_HMAT:
237 		return entry->hdr->hmat.type;
238 	}
239 	return 0;
240 }
241 
242 static unsigned long __init
243 acpi_get_entry_length(struct acpi_subtable_entry *entry)
244 {
245 	switch (entry->type) {
246 	case ACPI_SUBTABLE_COMMON:
247 		return entry->hdr->common.length;
248 	case ACPI_SUBTABLE_HMAT:
249 		return entry->hdr->hmat.length;
250 	}
251 	return 0;
252 }
253 
254 static unsigned long __init
255 acpi_get_subtable_header_length(struct acpi_subtable_entry *entry)
256 {
257 	switch (entry->type) {
258 	case ACPI_SUBTABLE_COMMON:
259 		return sizeof(entry->hdr->common);
260 	case ACPI_SUBTABLE_HMAT:
261 		return sizeof(entry->hdr->hmat);
262 	}
263 	return 0;
264 }
265 
266 static enum acpi_subtable_type __init
267 acpi_get_subtable_type(char *id)
268 {
269 	if (strncmp(id, ACPI_SIG_HMAT, 4) == 0)
270 		return ACPI_SUBTABLE_HMAT;
271 	return ACPI_SUBTABLE_COMMON;
272 }
273 
274 /**
275  * acpi_parse_entries_array - for each proc_num find a suitable subtable
276  *
277  * @id: table id (for debugging purposes)
278  * @table_size: size of the root table
279  * @table_header: where does the table start?
280  * @proc: array of acpi_subtable_proc struct containing entry id
281  *        and associated handler with it
282  * @proc_num: how big proc is?
283  * @max_entries: how many entries can we process?
284  *
285  * For each proc_num find a subtable with proc->id and run proc->handler
286  * on it. Assumption is that there's only single handler for particular
287  * entry id.
288  *
289  * The table_size is not the size of the complete ACPI table (the length
290  * field in the header struct), but only the size of the root table; i.e.,
291  * the offset from the very first byte of the complete ACPI table, to the
292  * first byte of the very first subtable.
293  *
294  * On success returns sum of all matching entries for all proc handlers.
295  * Otherwise, -ENODEV or -EINVAL is returned.
296  */
297 static int __init
298 acpi_parse_entries_array(char *id, unsigned long table_size,
299 		struct acpi_table_header *table_header,
300 		struct acpi_subtable_proc *proc, int proc_num,
301 		unsigned int max_entries)
302 {
303 	struct acpi_subtable_entry entry;
304 	unsigned long table_end, subtable_len, entry_len;
305 	int count = 0;
306 	int errs = 0;
307 	int i;
308 
309 	if (acpi_disabled)
310 		return -ENODEV;
311 
312 	if (!id)
313 		return -EINVAL;
314 
315 	if (!table_size)
316 		return -EINVAL;
317 
318 	if (!table_header) {
319 		pr_warn("%4.4s not present\n", id);
320 		return -ENODEV;
321 	}
322 
323 	table_end = (unsigned long)table_header + table_header->length;
324 
325 	/* Parse all entries looking for a match. */
326 
327 	entry.type = acpi_get_subtable_type(id);
328 	entry.hdr = (union acpi_subtable_headers *)
329 	    ((unsigned long)table_header + table_size);
330 	subtable_len = acpi_get_subtable_header_length(&entry);
331 
332 	while (((unsigned long)entry.hdr) + subtable_len  < table_end) {
333 		if (max_entries && count >= max_entries)
334 			break;
335 
336 		for (i = 0; i < proc_num; i++) {
337 			if (acpi_get_entry_type(&entry) != proc[i].id)
338 				continue;
339 			if (!proc[i].handler ||
340 			     (!errs && proc[i].handler(entry.hdr, table_end))) {
341 				errs++;
342 				continue;
343 			}
344 
345 			proc[i].count++;
346 			break;
347 		}
348 		if (i != proc_num)
349 			count++;
350 
351 		/*
352 		 * If entry->length is 0, break from this loop to avoid
353 		 * infinite loop.
354 		 */
355 		entry_len = acpi_get_entry_length(&entry);
356 		if (entry_len == 0) {
357 			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
358 			return -EINVAL;
359 		}
360 
361 		entry.hdr = (union acpi_subtable_headers *)
362 		    ((unsigned long)entry.hdr + entry_len);
363 	}
364 
365 	if (max_entries && count > max_entries) {
366 		pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
367 			id, proc->id, count);
368 	}
369 
370 	return errs ? -EINVAL : count;
371 }
372 
373 int __init
374 acpi_table_parse_entries_array(char *id,
375 			 unsigned long table_size,
376 			 struct acpi_subtable_proc *proc, int proc_num,
377 			 unsigned int max_entries)
378 {
379 	struct acpi_table_header *table_header = NULL;
380 	int count;
381 	u32 instance = 0;
382 
383 	if (acpi_disabled)
384 		return -ENODEV;
385 
386 	if (!id)
387 		return -EINVAL;
388 
389 	if (!strncmp(id, ACPI_SIG_MADT, 4))
390 		instance = acpi_apic_instance;
391 
392 	acpi_get_table(id, instance, &table_header);
393 	if (!table_header) {
394 		pr_warn("%4.4s not present\n", id);
395 		return -ENODEV;
396 	}
397 
398 	count = acpi_parse_entries_array(id, table_size, table_header,
399 			proc, proc_num, max_entries);
400 
401 	acpi_put_table(table_header);
402 	return count;
403 }
404 
405 int __init
406 acpi_table_parse_entries(char *id,
407 			unsigned long table_size,
408 			int entry_id,
409 			acpi_tbl_entry_handler handler,
410 			unsigned int max_entries)
411 {
412 	struct acpi_subtable_proc proc = {
413 		.id		= entry_id,
414 		.handler	= handler,
415 	};
416 
417 	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
418 						max_entries);
419 }
420 
421 int __init
422 acpi_table_parse_madt(enum acpi_madt_type id,
423 		      acpi_tbl_entry_handler handler, unsigned int max_entries)
424 {
425 	return acpi_table_parse_entries(ACPI_SIG_MADT,
426 					    sizeof(struct acpi_table_madt), id,
427 					    handler, max_entries);
428 }
429 
430 /**
431  * acpi_table_parse - find table with @id, run @handler on it
432  * @id: table id to find
433  * @handler: handler to run
434  *
435  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
436  * run @handler on it.
437  *
438  * Return 0 if table found, -errno if not.
439  */
440 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
441 {
442 	struct acpi_table_header *table = NULL;
443 
444 	if (acpi_disabled)
445 		return -ENODEV;
446 
447 	if (!id || !handler)
448 		return -EINVAL;
449 
450 	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
451 		acpi_get_table(id, acpi_apic_instance, &table);
452 	else
453 		acpi_get_table(id, 0, &table);
454 
455 	if (table) {
456 		handler(table);
457 		acpi_put_table(table);
458 		return 0;
459 	} else
460 		return -ENODEV;
461 }
462 
463 /*
464  * The BIOS is supposed to supply a single APIC/MADT,
465  * but some report two.  Provide a knob to use either.
466  * (don't you wish instance 0 and 1 were not the same?)
467  */
468 static void __init check_multiple_madt(void)
469 {
470 	struct acpi_table_header *table = NULL;
471 
472 	acpi_get_table(ACPI_SIG_MADT, 2, &table);
473 	if (table) {
474 		pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
475 			acpi_apic_instance);
476 		pr_warn("If \"acpi_apic_instance=%d\" works better, "
477 			"notify linux-acpi@vger.kernel.org\n",
478 			acpi_apic_instance ? 0 : 2);
479 		acpi_put_table(table);
480 
481 	} else
482 		acpi_apic_instance = 0;
483 
484 	return;
485 }
486 
487 static void acpi_table_taint(struct acpi_table_header *table)
488 {
489 	pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
490 		table->signature, table->oem_table_id);
491 	add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
492 }
493 
494 #ifdef CONFIG_ACPI_TABLE_UPGRADE
495 static u64 acpi_tables_addr;
496 static int all_tables_size;
497 
498 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
499 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
500 {
501 	u8 sum = 0;
502 	u8 *end = buffer + length;
503 
504 	while (buffer < end)
505 		sum = (u8) (sum + *(buffer++));
506 	return sum;
507 }
508 
509 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
510 static const char * const table_sigs[] = {
511 	ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ,
512 	ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT,
513 	ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF,
514 	ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET,
515 	ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI,
516 	ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA,
517 	ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT,
518 	ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT,
519 	ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, ACPI_SIG_IORT,
520 	ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT, NULL };
521 
522 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
523 
524 #define NR_ACPI_INITRD_TABLES 64
525 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
526 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
527 
528 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
529 
530 void __init acpi_table_upgrade(void)
531 {
532 	void *data;
533 	size_t size;
534 	int sig, no, table_nr = 0, total_offset = 0;
535 	long offset = 0;
536 	struct acpi_table_header *table;
537 	char cpio_path[32] = "kernel/firmware/acpi/";
538 	struct cpio_data file;
539 
540 	if (IS_ENABLED(CONFIG_ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD)) {
541 		data = __initramfs_start;
542 		size = __initramfs_size;
543 	} else {
544 		data = (void *)initrd_start;
545 		size = initrd_end - initrd_start;
546 	}
547 
548 	if (data == NULL || size == 0)
549 		return;
550 
551 	for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
552 		file = find_cpio_data(cpio_path, data, size, &offset);
553 		if (!file.data)
554 			break;
555 
556 		data += offset;
557 		size -= offset;
558 
559 		if (file.size < sizeof(struct acpi_table_header)) {
560 			pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
561 				cpio_path, file.name);
562 			continue;
563 		}
564 
565 		table = file.data;
566 
567 		for (sig = 0; table_sigs[sig]; sig++)
568 			if (!memcmp(table->signature, table_sigs[sig], 4))
569 				break;
570 
571 		if (!table_sigs[sig]) {
572 			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
573 				cpio_path, file.name);
574 			continue;
575 		}
576 		if (file.size != table->length) {
577 			pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
578 				cpio_path, file.name);
579 			continue;
580 		}
581 		if (acpi_table_checksum(file.data, table->length)) {
582 			pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
583 				cpio_path, file.name);
584 			continue;
585 		}
586 
587 		pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
588 			table->signature, cpio_path, file.name, table->length);
589 
590 		all_tables_size += table->length;
591 		acpi_initrd_files[table_nr].data = file.data;
592 		acpi_initrd_files[table_nr].size = file.size;
593 		table_nr++;
594 	}
595 	if (table_nr == 0)
596 		return;
597 
598 	acpi_tables_addr =
599 		memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
600 				       all_tables_size, PAGE_SIZE);
601 	if (!acpi_tables_addr) {
602 		WARN_ON(1);
603 		return;
604 	}
605 	/*
606 	 * Only calling e820_add_reserve does not work and the
607 	 * tables are invalid (memory got used) later.
608 	 * memblock_reserve works as expected and the tables won't get modified.
609 	 * But it's not enough on X86 because ioremap will
610 	 * complain later (used by acpi_os_map_memory) that the pages
611 	 * that should get mapped are not marked "reserved".
612 	 * Both memblock_reserve and e820__range_add (via arch_reserve_mem_area)
613 	 * works fine.
614 	 */
615 	memblock_reserve(acpi_tables_addr, all_tables_size);
616 	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
617 
618 	/*
619 	 * early_ioremap only can remap 256k one time. If we map all
620 	 * tables one time, we will hit the limit. Need to map chunks
621 	 * one by one during copying the same as that in relocate_initrd().
622 	 */
623 	for (no = 0; no < table_nr; no++) {
624 		unsigned char *src_p = acpi_initrd_files[no].data;
625 		phys_addr_t size = acpi_initrd_files[no].size;
626 		phys_addr_t dest_addr = acpi_tables_addr + total_offset;
627 		phys_addr_t slop, clen;
628 		char *dest_p;
629 
630 		total_offset += size;
631 
632 		while (size) {
633 			slop = dest_addr & ~PAGE_MASK;
634 			clen = size;
635 			if (clen > MAP_CHUNK_SIZE - slop)
636 				clen = MAP_CHUNK_SIZE - slop;
637 			dest_p = early_memremap(dest_addr & PAGE_MASK,
638 						clen + slop);
639 			memcpy(dest_p + slop, src_p, clen);
640 			early_memunmap(dest_p, clen + slop);
641 			src_p += clen;
642 			dest_addr += clen;
643 			size -= clen;
644 		}
645 	}
646 }
647 
648 static acpi_status
649 acpi_table_initrd_override(struct acpi_table_header *existing_table,
650 			   acpi_physical_address *address, u32 *length)
651 {
652 	int table_offset = 0;
653 	int table_index = 0;
654 	struct acpi_table_header *table;
655 	u32 table_length;
656 
657 	*length = 0;
658 	*address = 0;
659 	if (!acpi_tables_addr)
660 		return AE_OK;
661 
662 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
663 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
664 					   ACPI_HEADER_SIZE);
665 		if (table_offset + table->length > all_tables_size) {
666 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
667 			WARN_ON(1);
668 			return AE_OK;
669 		}
670 
671 		table_length = table->length;
672 
673 		/* Only override tables matched */
674 		if (memcmp(existing_table->signature, table->signature, 4) ||
675 		    memcmp(table->oem_id, existing_table->oem_id,
676 			   ACPI_OEM_ID_SIZE) ||
677 		    memcmp(table->oem_table_id, existing_table->oem_table_id,
678 			   ACPI_OEM_TABLE_ID_SIZE)) {
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_scan() and check the revision.
685 		 */
686 		if (test_and_set_bit(table_index, acpi_initrd_installed) ||
687 		    existing_table->oem_revision >= table->oem_revision) {
688 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
689 			goto next_table;
690 		}
691 
692 		*length = table_length;
693 		*address = acpi_tables_addr + table_offset;
694 		pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
695 			table->signature, table->oem_id,
696 			table->oem_table_id);
697 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
698 		break;
699 
700 next_table:
701 		table_offset += table_length;
702 		table_index++;
703 	}
704 	return AE_OK;
705 }
706 
707 static void __init acpi_table_initrd_scan(void)
708 {
709 	int table_offset = 0;
710 	int table_index = 0;
711 	u32 table_length;
712 	struct acpi_table_header *table;
713 
714 	if (!acpi_tables_addr)
715 		return;
716 
717 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
718 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
719 					   ACPI_HEADER_SIZE);
720 		if (table_offset + table->length > all_tables_size) {
721 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
722 			WARN_ON(1);
723 			return;
724 		}
725 
726 		table_length = table->length;
727 
728 		/* Skip RSDT/XSDT which should only be used for override */
729 		if (ACPI_COMPARE_NAME(table->signature, ACPI_SIG_RSDT) ||
730 		    ACPI_COMPARE_NAME(table->signature, ACPI_SIG_XSDT)) {
731 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
732 			goto next_table;
733 		}
734 		/*
735 		 * Mark the table to avoid being used in
736 		 * acpi_table_initrd_override(). Though this is not possible
737 		 * because override is disabled in acpi_install_table().
738 		 */
739 		if (test_and_set_bit(table_index, acpi_initrd_installed)) {
740 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
741 			goto next_table;
742 		}
743 
744 		pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
745 			table->signature, table->oem_id,
746 			table->oem_table_id);
747 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
748 		acpi_install_table(acpi_tables_addr + table_offset, TRUE);
749 next_table:
750 		table_offset += table_length;
751 		table_index++;
752 	}
753 }
754 #else
755 static acpi_status
756 acpi_table_initrd_override(struct acpi_table_header *existing_table,
757 			   acpi_physical_address *address,
758 			   u32 *table_length)
759 {
760 	*table_length = 0;
761 	*address = 0;
762 	return AE_OK;
763 }
764 
765 static void __init acpi_table_initrd_scan(void)
766 {
767 }
768 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
769 
770 acpi_status
771 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
772 				acpi_physical_address *address,
773 				u32 *table_length)
774 {
775 	return acpi_table_initrd_override(existing_table, address,
776 					  table_length);
777 }
778 
779 #ifdef CONFIG_ACPI_CUSTOM_DSDT
780 static void *amlcode __attribute__ ((weakref("AmlCode")));
781 static void *dsdt_amlcode __attribute__ ((weakref("dsdt_aml_code")));
782 #endif
783 
784 acpi_status
785 acpi_os_table_override(struct acpi_table_header *existing_table,
786 		       struct acpi_table_header **new_table)
787 {
788 	if (!existing_table || !new_table)
789 		return AE_BAD_PARAMETER;
790 
791 	*new_table = NULL;
792 
793 #ifdef CONFIG_ACPI_CUSTOM_DSDT
794 	if (!strncmp(existing_table->signature, "DSDT", 4)) {
795 		*new_table = (struct acpi_table_header *)&amlcode;
796 		if (!(*new_table))
797 			*new_table = (struct acpi_table_header *)&dsdt_amlcode;
798 	}
799 #endif
800 	if (*new_table != NULL)
801 		acpi_table_taint(existing_table);
802 	return AE_OK;
803 }
804 
805 /*
806  * acpi_table_init()
807  *
808  * find RSDP, find and checksum SDT/XSDT.
809  * checksum all tables, print SDT/XSDT
810  *
811  * result: sdt_entry[] is initialized
812  */
813 
814 int __init acpi_table_init(void)
815 {
816 	acpi_status status;
817 
818 	if (acpi_verify_table_checksum) {
819 		pr_info("Early table checksum verification enabled\n");
820 		acpi_gbl_enable_table_validation = TRUE;
821 	} else {
822 		pr_info("Early table checksum verification disabled\n");
823 		acpi_gbl_enable_table_validation = FALSE;
824 	}
825 
826 	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
827 	if (ACPI_FAILURE(status))
828 		return -EINVAL;
829 	acpi_table_initrd_scan();
830 
831 	check_multiple_madt();
832 	return 0;
833 }
834 
835 static int __init acpi_parse_apic_instance(char *str)
836 {
837 	if (!str)
838 		return -EINVAL;
839 
840 	if (kstrtoint(str, 0, &acpi_apic_instance))
841 		return -EINVAL;
842 
843 	pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
844 
845 	return 0;
846 }
847 
848 early_param("acpi_apic_instance", acpi_parse_apic_instance);
849 
850 static int __init acpi_force_table_verification_setup(char *s)
851 {
852 	acpi_verify_table_checksum = true;
853 
854 	return 0;
855 }
856 
857 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
858 
859 static int __init acpi_force_32bit_fadt_addr(char *s)
860 {
861 	pr_info("Forcing 32 Bit FADT addresses\n");
862 	acpi_gbl_use32_bit_fadt_addresses = TRUE;
863 
864 	return 0;
865 }
866 
867 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);
868