xref: /openbmc/linux/drivers/acpi/tables.c (revision 6c33a6f4)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  acpi_tables.c - ACPI Boot-Time Table Parsing
4  *
5  *  Copyright (C) 2001 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  */
7 
8 /* Uncomment next line to get verbose printout */
9 /* #define DEBUG */
10 #define pr_fmt(fmt) "ACPI: " fmt
11 
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/smp.h>
15 #include <linux/string.h>
16 #include <linux/types.h>
17 #include <linux/irq.h>
18 #include <linux/errno.h>
19 #include <linux/acpi.h>
20 #include <linux/memblock.h>
21 #include <linux/earlycpio.h>
22 #include <linux/initrd.h>
23 #include <linux/security.h>
24 #include "internal.h"
25 
26 #ifdef CONFIG_ACPI_CUSTOM_DSDT
27 #include CONFIG_ACPI_CUSTOM_DSDT_FILE
28 #endif
29 
30 #define ACPI_MAX_TABLES		128
31 
32 static char *mps_inti_flags_polarity[] = { "dfl", "high", "res", "low" };
33 static char *mps_inti_flags_trigger[] = { "dfl", "edge", "res", "level" };
34 
35 static struct acpi_table_desc initial_tables[ACPI_MAX_TABLES] __initdata;
36 
37 static int acpi_apic_instance __initdata;
38 
39 enum acpi_subtable_type {
40 	ACPI_SUBTABLE_COMMON,
41 	ACPI_SUBTABLE_HMAT,
42 };
43 
44 struct acpi_subtable_entry {
45 	union acpi_subtable_headers *hdr;
46 	enum acpi_subtable_type type;
47 };
48 
49 /*
50  * Disable table checksum verification for the early stage due to the size
51  * limitation of the current x86 early mapping implementation.
52  */
53 static bool acpi_verify_table_checksum __initdata = false;
54 
55 void acpi_table_print_madt_entry(struct acpi_subtable_header *header)
56 {
57 	if (!header)
58 		return;
59 
60 	switch (header->type) {
61 
62 	case ACPI_MADT_TYPE_LOCAL_APIC:
63 		{
64 			struct acpi_madt_local_apic *p =
65 			    (struct acpi_madt_local_apic *)header;
66 			pr_debug("LAPIC (acpi_id[0x%02x] lapic_id[0x%02x] %s)\n",
67 				 p->processor_id, p->id,
68 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
69 		}
70 		break;
71 
72 	case ACPI_MADT_TYPE_LOCAL_X2APIC:
73 		{
74 			struct acpi_madt_local_x2apic *p =
75 			    (struct acpi_madt_local_x2apic *)header;
76 			pr_debug("X2APIC (apic_id[0x%02x] uid[0x%02x] %s)\n",
77 				 p->local_apic_id, p->uid,
78 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
79 		}
80 		break;
81 
82 	case ACPI_MADT_TYPE_IO_APIC:
83 		{
84 			struct acpi_madt_io_apic *p =
85 			    (struct acpi_madt_io_apic *)header;
86 			pr_debug("IOAPIC (id[0x%02x] address[0x%08x] gsi_base[%d])\n",
87 				 p->id, p->address, p->global_irq_base);
88 		}
89 		break;
90 
91 	case ACPI_MADT_TYPE_INTERRUPT_OVERRIDE:
92 		{
93 			struct acpi_madt_interrupt_override *p =
94 			    (struct acpi_madt_interrupt_override *)header;
95 			pr_info("INT_SRC_OVR (bus %d bus_irq %d global_irq %d %s %s)\n",
96 				p->bus, p->source_irq, p->global_irq,
97 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
98 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2]);
99 			if (p->inti_flags  &
100 			    ~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK))
101 				pr_info("INT_SRC_OVR unexpected reserved flags: 0x%x\n",
102 					p->inti_flags  &
103 					~(ACPI_MADT_POLARITY_MASK | ACPI_MADT_TRIGGER_MASK));
104 		}
105 		break;
106 
107 	case ACPI_MADT_TYPE_NMI_SOURCE:
108 		{
109 			struct acpi_madt_nmi_source *p =
110 			    (struct acpi_madt_nmi_source *)header;
111 			pr_info("NMI_SRC (%s %s global_irq %d)\n",
112 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
113 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
114 				p->global_irq);
115 		}
116 		break;
117 
118 	case ACPI_MADT_TYPE_LOCAL_APIC_NMI:
119 		{
120 			struct acpi_madt_local_apic_nmi *p =
121 			    (struct acpi_madt_local_apic_nmi *)header;
122 			pr_info("LAPIC_NMI (acpi_id[0x%02x] %s %s lint[0x%x])\n",
123 				p->processor_id,
124 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK	],
125 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
126 				p->lint);
127 		}
128 		break;
129 
130 	case ACPI_MADT_TYPE_LOCAL_X2APIC_NMI:
131 		{
132 			u16 polarity, trigger;
133 			struct acpi_madt_local_x2apic_nmi *p =
134 			    (struct acpi_madt_local_x2apic_nmi *)header;
135 
136 			polarity = p->inti_flags & ACPI_MADT_POLARITY_MASK;
137 			trigger = (p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
138 
139 			pr_info("X2APIC_NMI (uid[0x%02x] %s %s lint[0x%x])\n",
140 				p->uid,
141 				mps_inti_flags_polarity[polarity],
142 				mps_inti_flags_trigger[trigger],
143 				p->lint);
144 		}
145 		break;
146 
147 	case ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE:
148 		{
149 			struct acpi_madt_local_apic_override *p =
150 			    (struct acpi_madt_local_apic_override *)header;
151 			pr_info("LAPIC_ADDR_OVR (address[%p])\n",
152 				(void *)(unsigned long)p->address);
153 		}
154 		break;
155 
156 	case ACPI_MADT_TYPE_IO_SAPIC:
157 		{
158 			struct acpi_madt_io_sapic *p =
159 			    (struct acpi_madt_io_sapic *)header;
160 			pr_debug("IOSAPIC (id[0x%x] address[%p] gsi_base[%d])\n",
161 				 p->id, (void *)(unsigned long)p->address,
162 				 p->global_irq_base);
163 		}
164 		break;
165 
166 	case ACPI_MADT_TYPE_LOCAL_SAPIC:
167 		{
168 			struct acpi_madt_local_sapic *p =
169 			    (struct acpi_madt_local_sapic *)header;
170 			pr_debug("LSAPIC (acpi_id[0x%02x] lsapic_id[0x%02x] lsapic_eid[0x%02x] %s)\n",
171 				 p->processor_id, p->id, p->eid,
172 				 (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
173 		}
174 		break;
175 
176 	case ACPI_MADT_TYPE_INTERRUPT_SOURCE:
177 		{
178 			struct acpi_madt_interrupt_source *p =
179 			    (struct acpi_madt_interrupt_source *)header;
180 			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",
181 				mps_inti_flags_polarity[p->inti_flags & ACPI_MADT_POLARITY_MASK],
182 				mps_inti_flags_trigger[(p->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2],
183 				p->type, p->id, p->eid, p->io_sapic_vector,
184 				p->global_irq);
185 		}
186 		break;
187 
188 	case ACPI_MADT_TYPE_GENERIC_INTERRUPT:
189 		{
190 			struct acpi_madt_generic_interrupt *p =
191 				(struct acpi_madt_generic_interrupt *)header;
192 			pr_debug("GICC (acpi_id[0x%04x] address[%llx] MPIDR[0x%llx] %s)\n",
193 				 p->uid, p->base_address,
194 				 p->arm_mpidr,
195 				 (p->flags & ACPI_MADT_ENABLED) ? "enabled" : "disabled");
196 
197 		}
198 		break;
199 
200 	case ACPI_MADT_TYPE_GENERIC_DISTRIBUTOR:
201 		{
202 			struct acpi_madt_generic_distributor *p =
203 				(struct acpi_madt_generic_distributor *)header;
204 			pr_debug("GIC Distributor (gic_id[0x%04x] address[%llx] gsi_base[%d])\n",
205 				 p->gic_id, p->base_address,
206 				 p->global_irq_base);
207 		}
208 		break;
209 
210 	default:
211 		pr_warn("Found unsupported MADT entry (type = 0x%x)\n",
212 			header->type);
213 		break;
214 	}
215 }
216 
217 static unsigned long __init
218 acpi_get_entry_type(struct acpi_subtable_entry *entry)
219 {
220 	switch (entry->type) {
221 	case ACPI_SUBTABLE_COMMON:
222 		return entry->hdr->common.type;
223 	case ACPI_SUBTABLE_HMAT:
224 		return entry->hdr->hmat.type;
225 	}
226 	return 0;
227 }
228 
229 static unsigned long __init
230 acpi_get_entry_length(struct acpi_subtable_entry *entry)
231 {
232 	switch (entry->type) {
233 	case ACPI_SUBTABLE_COMMON:
234 		return entry->hdr->common.length;
235 	case ACPI_SUBTABLE_HMAT:
236 		return entry->hdr->hmat.length;
237 	}
238 	return 0;
239 }
240 
241 static unsigned long __init
242 acpi_get_subtable_header_length(struct acpi_subtable_entry *entry)
243 {
244 	switch (entry->type) {
245 	case ACPI_SUBTABLE_COMMON:
246 		return sizeof(entry->hdr->common);
247 	case ACPI_SUBTABLE_HMAT:
248 		return sizeof(entry->hdr->hmat);
249 	}
250 	return 0;
251 }
252 
253 static enum acpi_subtable_type __init
254 acpi_get_subtable_type(char *id)
255 {
256 	if (strncmp(id, ACPI_SIG_HMAT, 4) == 0)
257 		return ACPI_SUBTABLE_HMAT;
258 	return ACPI_SUBTABLE_COMMON;
259 }
260 
261 /**
262  * acpi_parse_entries_array - for each proc_num find a suitable subtable
263  *
264  * @id: table id (for debugging purposes)
265  * @table_size: size of the root table
266  * @table_header: where does the table start?
267  * @proc: array of acpi_subtable_proc struct containing entry id
268  *        and associated handler with it
269  * @proc_num: how big proc is?
270  * @max_entries: how many entries can we process?
271  *
272  * For each proc_num find a subtable with proc->id and run proc->handler
273  * on it. Assumption is that there's only single handler for particular
274  * entry id.
275  *
276  * The table_size is not the size of the complete ACPI table (the length
277  * field in the header struct), but only the size of the root table; i.e.,
278  * the offset from the very first byte of the complete ACPI table, to the
279  * first byte of the very first subtable.
280  *
281  * On success returns sum of all matching entries for all proc handlers.
282  * Otherwise, -ENODEV or -EINVAL is returned.
283  */
284 static int __init acpi_parse_entries_array(char *id, unsigned long table_size,
285 		struct acpi_table_header *table_header,
286 		struct acpi_subtable_proc *proc, int proc_num,
287 		unsigned int max_entries)
288 {
289 	struct acpi_subtable_entry entry;
290 	unsigned long table_end, subtable_len, entry_len;
291 	int count = 0;
292 	int errs = 0;
293 	int i;
294 
295 	if (acpi_disabled)
296 		return -ENODEV;
297 
298 	if (!id)
299 		return -EINVAL;
300 
301 	if (!table_size)
302 		return -EINVAL;
303 
304 	if (!table_header) {
305 		pr_warn("%4.4s not present\n", id);
306 		return -ENODEV;
307 	}
308 
309 	table_end = (unsigned long)table_header + table_header->length;
310 
311 	/* Parse all entries looking for a match. */
312 
313 	entry.type = acpi_get_subtable_type(id);
314 	entry.hdr = (union acpi_subtable_headers *)
315 	    ((unsigned long)table_header + table_size);
316 	subtable_len = acpi_get_subtable_header_length(&entry);
317 
318 	while (((unsigned long)entry.hdr) + subtable_len  < table_end) {
319 		if (max_entries && count >= max_entries)
320 			break;
321 
322 		for (i = 0; i < proc_num; i++) {
323 			if (acpi_get_entry_type(&entry) != proc[i].id)
324 				continue;
325 			if (!proc[i].handler ||
326 			     (!errs && proc[i].handler(entry.hdr, table_end))) {
327 				errs++;
328 				continue;
329 			}
330 
331 			proc[i].count++;
332 			break;
333 		}
334 		if (i != proc_num)
335 			count++;
336 
337 		/*
338 		 * If entry->length is 0, break from this loop to avoid
339 		 * infinite loop.
340 		 */
341 		entry_len = acpi_get_entry_length(&entry);
342 		if (entry_len == 0) {
343 			pr_err("[%4.4s:0x%02x] Invalid zero length\n", id, proc->id);
344 			return -EINVAL;
345 		}
346 
347 		entry.hdr = (union acpi_subtable_headers *)
348 		    ((unsigned long)entry.hdr + entry_len);
349 	}
350 
351 	if (max_entries && count > max_entries) {
352 		pr_warn("[%4.4s:0x%02x] found the maximum %i entries\n",
353 			id, proc->id, count);
354 	}
355 
356 	return errs ? -EINVAL : count;
357 }
358 
359 int __init acpi_table_parse_entries_array(char *id,
360 			 unsigned long table_size,
361 			 struct acpi_subtable_proc *proc, int proc_num,
362 			 unsigned int max_entries)
363 {
364 	struct acpi_table_header *table_header = NULL;
365 	int count;
366 	u32 instance = 0;
367 
368 	if (acpi_disabled)
369 		return -ENODEV;
370 
371 	if (!id)
372 		return -EINVAL;
373 
374 	if (!strncmp(id, ACPI_SIG_MADT, 4))
375 		instance = acpi_apic_instance;
376 
377 	acpi_get_table(id, instance, &table_header);
378 	if (!table_header) {
379 		pr_warn("%4.4s not present\n", id);
380 		return -ENODEV;
381 	}
382 
383 	count = acpi_parse_entries_array(id, table_size, table_header,
384 			proc, proc_num, max_entries);
385 
386 	acpi_put_table(table_header);
387 	return count;
388 }
389 
390 int __init acpi_table_parse_entries(char *id,
391 			unsigned long table_size,
392 			int entry_id,
393 			acpi_tbl_entry_handler handler,
394 			unsigned int max_entries)
395 {
396 	struct acpi_subtable_proc proc = {
397 		.id		= entry_id,
398 		.handler	= handler,
399 	};
400 
401 	return acpi_table_parse_entries_array(id, table_size, &proc, 1,
402 						max_entries);
403 }
404 
405 int __init acpi_table_parse_madt(enum acpi_madt_type id,
406 		      acpi_tbl_entry_handler handler, unsigned int max_entries)
407 {
408 	return acpi_table_parse_entries(ACPI_SIG_MADT,
409 					    sizeof(struct acpi_table_madt), id,
410 					    handler, max_entries);
411 }
412 
413 /**
414  * acpi_table_parse - find table with @id, run @handler on it
415  * @id: table id to find
416  * @handler: handler to run
417  *
418  * Scan the ACPI System Descriptor Table (STD) for a table matching @id,
419  * run @handler on it.
420  *
421  * Return 0 if table found, -errno if not.
422  */
423 int __init acpi_table_parse(char *id, acpi_tbl_table_handler handler)
424 {
425 	struct acpi_table_header *table = NULL;
426 
427 	if (acpi_disabled)
428 		return -ENODEV;
429 
430 	if (!id || !handler)
431 		return -EINVAL;
432 
433 	if (strncmp(id, ACPI_SIG_MADT, 4) == 0)
434 		acpi_get_table(id, acpi_apic_instance, &table);
435 	else
436 		acpi_get_table(id, 0, &table);
437 
438 	if (table) {
439 		handler(table);
440 		acpi_put_table(table);
441 		return 0;
442 	} else
443 		return -ENODEV;
444 }
445 
446 /*
447  * The BIOS is supposed to supply a single APIC/MADT,
448  * but some report two.  Provide a knob to use either.
449  * (don't you wish instance 0 and 1 were not the same?)
450  */
451 static void __init check_multiple_madt(void)
452 {
453 	struct acpi_table_header *table = NULL;
454 
455 	acpi_get_table(ACPI_SIG_MADT, 2, &table);
456 	if (table) {
457 		pr_warn("BIOS bug: multiple APIC/MADT found, using %d\n",
458 			acpi_apic_instance);
459 		pr_warn("If \"acpi_apic_instance=%d\" works better, "
460 			"notify linux-acpi@vger.kernel.org\n",
461 			acpi_apic_instance ? 0 : 2);
462 		acpi_put_table(table);
463 
464 	} else
465 		acpi_apic_instance = 0;
466 
467 	return;
468 }
469 
470 static void acpi_table_taint(struct acpi_table_header *table)
471 {
472 	pr_warn("Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n",
473 		table->signature, table->oem_table_id);
474 	add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
475 }
476 
477 #ifdef CONFIG_ACPI_TABLE_UPGRADE
478 static u64 acpi_tables_addr;
479 static int all_tables_size;
480 
481 /* Copied from acpica/tbutils.c:acpi_tb_checksum() */
482 static u8 __init acpi_table_checksum(u8 *buffer, u32 length)
483 {
484 	u8 sum = 0;
485 	u8 *end = buffer + length;
486 
487 	while (buffer < end)
488 		sum = (u8) (sum + *(buffer++));
489 	return sum;
490 }
491 
492 /* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */
493 static const char * const table_sigs[] = {
494 	ACPI_SIG_BERT, ACPI_SIG_BGRT, ACPI_SIG_CPEP, ACPI_SIG_ECDT,
495 	ACPI_SIG_EINJ, ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT,
496 	ACPI_SIG_MSCT, ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT,
497 	ACPI_SIG_ASF,  ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR,
498 	ACPI_SIG_HPET, ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG,
499 	ACPI_SIG_MCHI, ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI,
500 	ACPI_SIG_TCPA, ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT,
501 	ACPI_SIG_WDDT, ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT,
502 	ACPI_SIG_PSDT, ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT,
503 	ACPI_SIG_IORT, ACPI_SIG_NFIT, ACPI_SIG_HMAT, ACPI_SIG_PPTT,
504 	NULL };
505 
506 #define ACPI_HEADER_SIZE sizeof(struct acpi_table_header)
507 
508 #define NR_ACPI_INITRD_TABLES 64
509 static struct cpio_data __initdata acpi_initrd_files[NR_ACPI_INITRD_TABLES];
510 static DECLARE_BITMAP(acpi_initrd_installed, NR_ACPI_INITRD_TABLES);
511 
512 #define MAP_CHUNK_SIZE   (NR_FIX_BTMAPS << PAGE_SHIFT)
513 
514 void __init acpi_table_upgrade(void)
515 {
516 	void *data;
517 	size_t size;
518 	int sig, no, table_nr = 0, total_offset = 0;
519 	long offset = 0;
520 	struct acpi_table_header *table;
521 	char cpio_path[32] = "kernel/firmware/acpi/";
522 	struct cpio_data file;
523 
524 	if (IS_ENABLED(CONFIG_ACPI_TABLE_OVERRIDE_VIA_BUILTIN_INITRD)) {
525 		data = __initramfs_start;
526 		size = __initramfs_size;
527 	} else {
528 		data = (void *)initrd_start;
529 		size = initrd_end - initrd_start;
530 	}
531 
532 	if (data == NULL || size == 0)
533 		return;
534 
535 	for (no = 0; no < NR_ACPI_INITRD_TABLES; no++) {
536 		file = find_cpio_data(cpio_path, data, size, &offset);
537 		if (!file.data)
538 			break;
539 
540 		data += offset;
541 		size -= offset;
542 
543 		if (file.size < sizeof(struct acpi_table_header)) {
544 			pr_err("ACPI OVERRIDE: Table smaller than ACPI header [%s%s]\n",
545 				cpio_path, file.name);
546 			continue;
547 		}
548 
549 		table = file.data;
550 
551 		for (sig = 0; table_sigs[sig]; sig++)
552 			if (!memcmp(table->signature, table_sigs[sig], 4))
553 				break;
554 
555 		if (!table_sigs[sig]) {
556 			pr_err("ACPI OVERRIDE: Unknown signature [%s%s]\n",
557 				cpio_path, file.name);
558 			continue;
559 		}
560 		if (file.size != table->length) {
561 			pr_err("ACPI OVERRIDE: File length does not match table length [%s%s]\n",
562 				cpio_path, file.name);
563 			continue;
564 		}
565 		if (acpi_table_checksum(file.data, table->length)) {
566 			pr_err("ACPI OVERRIDE: Bad table checksum [%s%s]\n",
567 				cpio_path, file.name);
568 			continue;
569 		}
570 
571 		pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n",
572 			table->signature, cpio_path, file.name, table->length);
573 
574 		all_tables_size += table->length;
575 		acpi_initrd_files[table_nr].data = file.data;
576 		acpi_initrd_files[table_nr].size = file.size;
577 		table_nr++;
578 	}
579 	if (table_nr == 0)
580 		return;
581 
582 	if (security_locked_down(LOCKDOWN_ACPI_TABLES)) {
583 		pr_notice("kernel is locked down, ignoring table override\n");
584 		return;
585 	}
586 
587 	acpi_tables_addr =
588 		memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
589 				       all_tables_size, PAGE_SIZE);
590 	if (!acpi_tables_addr) {
591 		WARN_ON(1);
592 		return;
593 	}
594 	/*
595 	 * Only calling e820_add_reserve does not work and the
596 	 * tables are invalid (memory got used) later.
597 	 * memblock_reserve works as expected and the tables won't get modified.
598 	 * But it's not enough on X86 because ioremap will
599 	 * complain later (used by acpi_os_map_memory) that the pages
600 	 * that should get mapped are not marked "reserved".
601 	 * Both memblock_reserve and e820__range_add (via arch_reserve_mem_area)
602 	 * works fine.
603 	 */
604 	memblock_reserve(acpi_tables_addr, all_tables_size);
605 	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
606 
607 	/*
608 	 * early_ioremap only can remap 256k one time. If we map all
609 	 * tables one time, we will hit the limit. Need to map chunks
610 	 * one by one during copying the same as that in relocate_initrd().
611 	 */
612 	for (no = 0; no < table_nr; no++) {
613 		unsigned char *src_p = acpi_initrd_files[no].data;
614 		phys_addr_t size = acpi_initrd_files[no].size;
615 		phys_addr_t dest_addr = acpi_tables_addr + total_offset;
616 		phys_addr_t slop, clen;
617 		char *dest_p;
618 
619 		total_offset += size;
620 
621 		while (size) {
622 			slop = dest_addr & ~PAGE_MASK;
623 			clen = size;
624 			if (clen > MAP_CHUNK_SIZE - slop)
625 				clen = MAP_CHUNK_SIZE - slop;
626 			dest_p = early_memremap(dest_addr & PAGE_MASK,
627 						clen + slop);
628 			memcpy(dest_p + slop, src_p, clen);
629 			early_memunmap(dest_p, clen + slop);
630 			src_p += clen;
631 			dest_addr += clen;
632 			size -= clen;
633 		}
634 	}
635 }
636 
637 static acpi_status
638 acpi_table_initrd_override(struct acpi_table_header *existing_table,
639 			   acpi_physical_address *address, u32 *length)
640 {
641 	int table_offset = 0;
642 	int table_index = 0;
643 	struct acpi_table_header *table;
644 	u32 table_length;
645 
646 	*length = 0;
647 	*address = 0;
648 	if (!acpi_tables_addr)
649 		return AE_OK;
650 
651 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
652 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
653 					   ACPI_HEADER_SIZE);
654 		if (table_offset + table->length > all_tables_size) {
655 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
656 			WARN_ON(1);
657 			return AE_OK;
658 		}
659 
660 		table_length = table->length;
661 
662 		/* Only override tables matched */
663 		if (memcmp(existing_table->signature, table->signature, 4) ||
664 		    memcmp(table->oem_id, existing_table->oem_id,
665 			   ACPI_OEM_ID_SIZE) ||
666 		    memcmp(table->oem_table_id, existing_table->oem_table_id,
667 			   ACPI_OEM_TABLE_ID_SIZE)) {
668 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
669 			goto next_table;
670 		}
671 		/*
672 		 * Mark the table to avoid being used in
673 		 * acpi_table_initrd_scan() and check the revision.
674 		 */
675 		if (test_and_set_bit(table_index, acpi_initrd_installed) ||
676 		    existing_table->oem_revision >= table->oem_revision) {
677 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
678 			goto next_table;
679 		}
680 
681 		*length = table_length;
682 		*address = acpi_tables_addr + table_offset;
683 		pr_info("Table Upgrade: override [%4.4s-%6.6s-%8.8s]\n",
684 			table->signature, table->oem_id,
685 			table->oem_table_id);
686 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
687 		break;
688 
689 next_table:
690 		table_offset += table_length;
691 		table_index++;
692 	}
693 	return AE_OK;
694 }
695 
696 static void __init acpi_table_initrd_scan(void)
697 {
698 	int table_offset = 0;
699 	int table_index = 0;
700 	u32 table_length;
701 	struct acpi_table_header *table;
702 
703 	if (!acpi_tables_addr)
704 		return;
705 
706 	while (table_offset + ACPI_HEADER_SIZE <= all_tables_size) {
707 		table = acpi_os_map_memory(acpi_tables_addr + table_offset,
708 					   ACPI_HEADER_SIZE);
709 		if (table_offset + table->length > all_tables_size) {
710 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
711 			WARN_ON(1);
712 			return;
713 		}
714 
715 		table_length = table->length;
716 
717 		/* Skip RSDT/XSDT which should only be used for override */
718 		if (ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_RSDT) ||
719 		    ACPI_COMPARE_NAMESEG(table->signature, ACPI_SIG_XSDT)) {
720 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
721 			goto next_table;
722 		}
723 		/*
724 		 * Mark the table to avoid being used in
725 		 * acpi_table_initrd_override(). Though this is not possible
726 		 * because override is disabled in acpi_install_table().
727 		 */
728 		if (test_and_set_bit(table_index, acpi_initrd_installed)) {
729 			acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
730 			goto next_table;
731 		}
732 
733 		pr_info("Table Upgrade: install [%4.4s-%6.6s-%8.8s]\n",
734 			table->signature, table->oem_id,
735 			table->oem_table_id);
736 		acpi_os_unmap_memory(table, ACPI_HEADER_SIZE);
737 		acpi_install_table(acpi_tables_addr + table_offset, TRUE);
738 next_table:
739 		table_offset += table_length;
740 		table_index++;
741 	}
742 }
743 #else
744 static acpi_status
745 acpi_table_initrd_override(struct acpi_table_header *existing_table,
746 			   acpi_physical_address *address,
747 			   u32 *table_length)
748 {
749 	*table_length = 0;
750 	*address = 0;
751 	return AE_OK;
752 }
753 
754 static void __init acpi_table_initrd_scan(void)
755 {
756 }
757 #endif /* CONFIG_ACPI_TABLE_UPGRADE */
758 
759 acpi_status
760 acpi_os_physical_table_override(struct acpi_table_header *existing_table,
761 				acpi_physical_address *address,
762 				u32 *table_length)
763 {
764 	return acpi_table_initrd_override(existing_table, address,
765 					  table_length);
766 }
767 
768 #ifdef CONFIG_ACPI_CUSTOM_DSDT
769 static void *amlcode __attribute__ ((weakref("AmlCode")));
770 static void *dsdt_amlcode __attribute__ ((weakref("dsdt_aml_code")));
771 #endif
772 
773 acpi_status acpi_os_table_override(struct acpi_table_header *existing_table,
774 		       struct acpi_table_header **new_table)
775 {
776 	if (!existing_table || !new_table)
777 		return AE_BAD_PARAMETER;
778 
779 	*new_table = NULL;
780 
781 #ifdef CONFIG_ACPI_CUSTOM_DSDT
782 	if (!strncmp(existing_table->signature, "DSDT", 4)) {
783 		*new_table = (struct acpi_table_header *)&amlcode;
784 		if (!(*new_table))
785 			*new_table = (struct acpi_table_header *)&dsdt_amlcode;
786 	}
787 #endif
788 	if (*new_table != NULL)
789 		acpi_table_taint(existing_table);
790 	return AE_OK;
791 }
792 
793 /*
794  * acpi_table_init()
795  *
796  * find RSDP, find and checksum SDT/XSDT.
797  * checksum all tables, print SDT/XSDT
798  *
799  * result: sdt_entry[] is initialized
800  */
801 
802 int __init acpi_table_init(void)
803 {
804 	acpi_status status;
805 
806 	if (acpi_verify_table_checksum) {
807 		pr_info("Early table checksum verification enabled\n");
808 		acpi_gbl_enable_table_validation = TRUE;
809 	} else {
810 		pr_info("Early table checksum verification disabled\n");
811 		acpi_gbl_enable_table_validation = FALSE;
812 	}
813 
814 	status = acpi_initialize_tables(initial_tables, ACPI_MAX_TABLES, 0);
815 	if (ACPI_FAILURE(status))
816 		return -EINVAL;
817 	acpi_table_initrd_scan();
818 
819 	check_multiple_madt();
820 	return 0;
821 }
822 
823 static int __init acpi_parse_apic_instance(char *str)
824 {
825 	if (!str)
826 		return -EINVAL;
827 
828 	if (kstrtoint(str, 0, &acpi_apic_instance))
829 		return -EINVAL;
830 
831 	pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance);
832 
833 	return 0;
834 }
835 early_param("acpi_apic_instance", acpi_parse_apic_instance);
836 
837 static int __init acpi_force_table_verification_setup(char *s)
838 {
839 	acpi_verify_table_checksum = true;
840 
841 	return 0;
842 }
843 early_param("acpi_force_table_verification", acpi_force_table_verification_setup);
844 
845 static int __init acpi_force_32bit_fadt_addr(char *s)
846 {
847 	pr_info("Forcing 32 Bit FADT addresses\n");
848 	acpi_gbl_use32_bit_fadt_addresses = TRUE;
849 
850 	return 0;
851 }
852 early_param("acpi_force_32bit_fadt_addr", acpi_force_32bit_fadt_addr);
853